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Leibold D, van der Sar SJ, Goorden MC, Schaart DR. Framework for evaluating photon-counting detectors under pile-up conditions. J Med Imaging (Bellingham) 2024; 11:S12802. [PMID: 38799269 PMCID: PMC11124237 DOI: 10.1117/1.jmi.11.s1.s12802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 04/11/2024] [Accepted: 05/01/2024] [Indexed: 05/29/2024] Open
Abstract
Purpose While X-ray photon-counting detectors (PCDs) promise to revolutionize medical imaging, theoretical frameworks to evaluate them are commonly limited to incident fluence rates sufficiently low that the detector response can be considered linear. However, typical clinical operating conditions lead to a significant level of pile-up, invalidating this assumption of a linear response. Here, we present a framework that aims to evaluate PCDs, taking into account their non-linear behavior. Approach We employ small-signal analysis to study the behavior of PCDs under pile-up conditions. The response is approximated as linear around a given operating point, determined by the incident spectrum and fluence rate. The detector response is subsequently described by the proposed perturbation point spread function (pPSF). We demonstrate this approach using Monte-Carlo simulations of idealized direct- and indirect-conversion PCDs. Results The pPSFs of two PCDs are calculated. It is then shown how the pPSF allows to determine the sensitivity of the detector signal to an arbitrary lesion. This example illustrates the detrimental influence of pile-up, which may cause non-intuitive effects such as contrast/contrast-to-noise ratio inversion or cancellation between/within energy bins. Conclusions The proposed framework permits quantifying the spectral and spatial performance of PCDs under clinically realistic conditions at a given operating point. The presented example illustrates why PCDs should not be analyzed assuming that they are linear systems. The framework can, for example, be used to guide the development of PCDs and PCD-based systems. Furthermore, it can be applied to adapt commonly used measures, such as the modulation transfer function, to non-linear PCDs.
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Affiliation(s)
- David Leibold
- Delft University of Technology, Department of Radiation Science and Technology, Delft, The Netherlands
| | - Stefan J. van der Sar
- Delft University of Technology, Department of Radiation Science and Technology, Delft, The Netherlands
| | - Marlies C. Goorden
- Delft University of Technology, Department of Radiation Science and Technology, Delft, The Netherlands
| | - Dennis R. Schaart
- Delft University of Technology, Department of Radiation Science and Technology, Delft, The Netherlands
- HollandPTC, Delft, The Netherlands
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2
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Mourad C, Gallego Manzano L, Viry A, Booij R, Oei EHG, Becce F, Omoumi P. Chances and challenges of photon-counting CT in musculoskeletal imaging. Skeletal Radiol 2024; 53:1889-1902. [PMID: 38441616 PMCID: PMC11303444 DOI: 10.1007/s00256-024-04622-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/12/2024] [Accepted: 02/12/2024] [Indexed: 08/09/2024]
Abstract
In musculoskeletal imaging, CT is used in a wide range of indications, either alone or in a synergistic approach with MRI. While MRI is the preferred modality for the assessment of soft tissues and bone marrow, CT excels in the imaging of high-contrast structures, such as mineralized tissue. Additionally, the introduction of dual-energy CT in clinical practice two decades ago opened the door for spectral imaging applications. Recently, the advent of photon-counting detectors (PCDs) has further advanced the potential of CT, at least in theory. Compared to conventional energy-integrating detectors (EIDs), PCDs provide superior spatial resolution, reduced noise, and intrinsic spectral imaging capabilities. This review briefly describes the technical advantages of PCDs. For each technical feature, the corresponding applications in musculoskeletal imaging will be discussed, including high-spatial resolution imaging for the assessment of bone and crystal deposits, low-dose applications such as whole-body CT, as well as spectral imaging applications including the characterization of crystal deposits and imaging of metal hardware. Finally, we will highlight the potential of PCD-CT in emerging applications, underscoring the need for further preclinical and clinical validation to unleash its full clinical potential.
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Affiliation(s)
- Charbel Mourad
- Department of Radiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Department of Diagnostic Imaging and Interventional Therapeutics, Hôpital Libanais Geitaoui-CHU, Beyrouth, Lebanon
| | - Lucia Gallego Manzano
- Institute of Radiation Physics (IRA), Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Anaïs Viry
- Institute of Radiation Physics (IRA), Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Ronald Booij
- Department of Radiology & Nuclear Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Edwin H G Oei
- Department of Radiology & Nuclear Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Fabio Becce
- Department of Radiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Patrick Omoumi
- Department of Radiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
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Carrino JA, Ibad H, Lin Y, Ghotbi E, Klein J, Demehri S, Del Grande F, Bogner E, Boesen MP, Siewerdsen JH. CT in musculoskeletal imaging: still helpful and for what? Skeletal Radiol 2024; 53:1711-1725. [PMID: 38969781 DOI: 10.1007/s00256-024-04737-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 06/17/2024] [Accepted: 06/17/2024] [Indexed: 07/07/2024]
Abstract
Computed tomography (CT) is a common modality employed for musculoskeletal imaging. Conventional CT techniques are useful for the assessment of trauma in detection, characterization and surgical planning of complex fractures. CT arthrography can depict internal derangement lesions and impact medical decision making of orthopedic providers. In oncology, CT can have a role in the characterization of bone tumors and may elucidate soft tissue mineralization patterns. Several advances in CT technology have led to a variety of acquisition techniques with distinct clinical applications. These include four-dimensional CT, which allows examination of joints during motion; cone-beam CT, which allows examination during physiological weight-bearing conditions; dual-energy CT, which allows material decomposition useful in musculoskeletal deposition disorders (e.g., gout) and bone marrow edema detection; and photon-counting CT, which provides increased spatial resolution, decreased radiation, and material decomposition compared to standard multi-detector CT systems due to its ability to directly translate X-ray photon energies into electrical signals. Advanced acquisition techniques provide higher spatial resolution scans capable of enhanced bony microarchitecture and bone mineral density assessment. Together, these CT acquisition techniques will continue to play a substantial role in the practices of orthopedics, rheumatology, metabolic bone, oncology, and interventional radiology.
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Affiliation(s)
- John A Carrino
- Weill Cornell Medicine, New York, NY, USA.
- Department of Radiology and Imaging, Hospital for Special Surgery, 535 East 70th Street, New York, NY, 10021, USA.
| | - Hamza Ibad
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Yenpo Lin
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Elena Ghotbi
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Joshua Klein
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Shadpour Demehri
- Musculoskeletal Radiology, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 601 N. Caroline Street, JHOC 5165, Baltimore, MD, 21287, USA
| | - Filippo Del Grande
- Clinic of Radiology, Imaging Institute of Southern Switzerland (IIMSI), Ente Ospedaliero Cantonale (EOC), Via Tesserete 46, 6900, Lugano, Switzerland
- Faculty of Biomedical Sciences, Università Della Svizzera Italiana (USI), Via G. Buffi 13, 6904, Lugano, Switzerland
| | - Eric Bogner
- Department of Radiology and Imaging, Hospital for Special Surgery, 535 East 70th Street, New York, NY, 10021, USA
| | - Mikael P Boesen
- Department of Radiology, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Nielsine Nielsens Vej 5, Entrance 7A, 3Rd Floor, 2400, Copenhagen, NV, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jeffrey H Siewerdsen
- Department of Imaging Physics, Institute for Data Science in Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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Noro T, Ojio Y, Urano M, Ohta K, Suzuki K, Sato T, Nakayama K, Ohba S, Kawai T, Itoh T, Hiwatashi A. Photon-counting detector CT with an ultra-low-dose contrast media to diagnose a renal pseudoaneurysm: A case report. Radiol Case Rep 2024; 19:3618-3621. [PMID: 38983292 PMCID: PMC11228645 DOI: 10.1016/j.radcr.2024.05.077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 05/22/2024] [Accepted: 05/26/2024] [Indexed: 07/11/2024] Open
Abstract
A 75-year-old male, weighing 71 kg, was admitted to our institution with anemia related to a subcapsular hematoma after accidental extraction of a nephrostomy catheter. While the patient exhibited the progression of chronic kidney disease, he was not yet on dialysis. His serum creatinine level increased to 6.8 mg/dL, with an estimated glomerular filtration rate of 7.4 mL/min/1.73 m2. Radiologists planned contrast-enhanced photon-counting detector CT (PCD-CT) with an ultra-low-dose contrast media to mitigate the impact on renal function. The contrast media dosage was set at 7.4 gI, which was 82.6% lower that used in the standard protocol for a male weighing 71 kg. Non-contrast-enhanced PCD-CT identified a low-density nodular area within the renal subcapsular hematoma. Contrast-enhanced PCD-CT revealed contrast enhancement in both the early and late phases corresponding to the nodular area. On virtual monoenergetic images, the renal pseudoaneurysm was most clearly delineated at 40 keV. Following the diagnosis of a pseudoaneurysm, transcatheter arterial coil embolization was performed. No subsequent progression of anemia or the deterioration of renal function was observed, showcasing the potential of ultra-low-dose contrast-enhanced PCD-CT for the detection of small vascular abnormalities while minimizing adverse effects on renal function.
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Affiliation(s)
- Takayuki Noro
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan
| | - Yoshinao Ojio
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan
| | - Misugi Urano
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan
| | - Kengo Ohta
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan
| | - Kazushi Suzuki
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan
| | - Takafumi Sato
- Department of Radiology, Kariya Toyota General Hospital, Kariya, Japan
| | - Keita Nakayama
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan
| | - Shota Ohba
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan
| | - Tatsuya Kawai
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan
| | - Toshihide Itoh
- CT-Research and Collaboration, Siemens Healthineers, Tokyo, Japan
| | - Akio Hiwatashi
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan
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Park EH, O'Donnell T, Fritz J. Dual-Energy Computed Tomography Applications in Rheumatology. Radiol Clin North Am 2024; 62:849-863. [PMID: 39059976 DOI: 10.1016/j.rcl.2024.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2024]
Abstract
Dual-energy computed tomography (DECT) has emerged as a transformative tool in the past decade. Initially employed in gout within the field of rheumatology to distinguish and quantify monosodium urate crystals through its dual-material discrimination capability, DECT has since broadened its clinical applications. It now encompasses various rheumatic diseases, employing advanced techniques such as bone marrow edema assessment, iodine mapping, and collagen-specific imaging. This review article aims to examine the unique characteristics of DECT, discuss its strengths and limitations, illustrate its applications for accurately evaluating various rheumatic diseases in clinical practice, and propose future directions for DECT in rheumatology.
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Affiliation(s)
- Eun Hae Park
- Division of Musculoskeletal Radiology, Department of Radiology, NYU Grossman School of Medicine, New York, USA; Department of Radiology, Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Geonjiro 20, Deokjin-gu, Jeonju, Jeollabukdo 54907, Republic of Korea
| | - Thomas O'Donnell
- CT Research Collaborations Siemens Healthineers, Malvern PA, USA
| | - Jan Fritz
- Division of Musculoskeletal Radiology, Department of Radiology, NYU Grossman School of Medicine, New York, USA.
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Benson JC, Campeau NG, Diehn FE, Lane JI, Leng S, Moonis G. Photon-Counting CT in the Head and Neck: Current Applications and Future Prospects. AJNR Am J Neuroradiol 2024; 45:1000-1005. [PMID: 38964861 DOI: 10.3174/ajnr.a8265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 02/12/2024] [Indexed: 07/06/2024]
Abstract
Photon-counting detectors (PCDs) represent a major milestone in the evolution of CT imaging. CT scanners using PCD systems have already been shown to generate images with substantially greater spatial resolution, superior iodine contrast-to-noise ratio, and reduced artifact compared with conventional energy-integrating detector-based systems. These benefits can be achieved with considerably decreased radiation dose. Recent studies have focused on the advantages of PCD-CT scanners in numerous anatomic regions, particularly the coronary and cerebral vasculature, pulmonary structures, and musculoskeletal imaging. However, PCD-CT imaging is also anticipated to be a major advantage for head and neck imaging. In this paper, we review current clinical applications of PCD-CT in head and neck imaging, with a focus on the temporal bone, facial bones, and paranasal sinuses; minor arterial vasculature; and the spectral capabilities of PCD systems.
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Affiliation(s)
- John C Benson
- From the Department of Neuroradiology (J.C.B., N.G.C., F.E.D., J.I.L.), Mayo Clinic, Rochester, MN USA
| | - Norbert G Campeau
- From the Department of Neuroradiology (J.C.B., N.G.C., F.E.D., J.I.L.), Mayo Clinic, Rochester, MN USA
| | - Felix E Diehn
- From the Department of Neuroradiology (J.C.B., N.G.C., F.E.D., J.I.L.), Mayo Clinic, Rochester, MN USA
| | - John I Lane
- From the Department of Neuroradiology (J.C.B., N.G.C., F.E.D., J.I.L.), Mayo Clinic, Rochester, MN USA
| | - Shuai Leng
- Department of Radiology (S.L.), Mayo Clinic, Rochester, MN USA
| | - Gul Moonis
- Department of Radiology (G.M.), Columbia University Irving Medical Center, New York, New York
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7
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Greffier J, Faby S, Pastor M, Frandon J, Erath J, Beregi JP, Dabli D. Comparison of the spectral performance between two dual-source CT systems on low-energy virtual monoenergetic images: A phantom study. Phys Med 2024; 124:103429. [PMID: 39024963 DOI: 10.1016/j.ejmp.2024.103429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 07/01/2024] [Accepted: 07/08/2024] [Indexed: 07/20/2024] Open
Abstract
PURPOSE To compare the spectral performance of two different DSCT (DSCT-Pulse and DSCT-Force) on virtual monoenergetic images (VMIs) at low energy levels. METHODS An image quality phantom was scanned on the two DSCTs at three dose levels: 11/6/1.8 mGy. Level 3 of an advanced modeled iterative reconstruction algorithm was used. Noise power spectrum and task-based transfer function were computed on VMIs from 40 to 70 keV to assess noise magnitude and noise texture (fav) and spatial resolution (f50). A detectability index (d') was computed to assess the detection of one contrast-enhanced abdominal lesion as a function of the keV level used. RESULTS For all dose levels and all energy levels, noise magnitude was significantly higher (p < 0.05) with DSCT-Pulse than with DSCT-Force (12.6 ± 2.7 % at 1.8 mGy, 9.1 ± 2.9 % at 6 mGy and 4.0 ± 2.7 % at 11 mGy). For all energy levels, fav values were significantly higher (p < 0.05) with DSCT-Pulse than with DSCT-Force at 1.8 mGy (4.8 ± 3.9 %) and at 6 mGy (5.5 ± 2.5 %) but similar at 11 mGy (0.2 ± 3.6 %; p = 0.518). For all energy levels, f50 values were significantly higher with DSCT-Pulse than with DSCT-Force (12.7 ± 5.6 % at 1.8 mGy, 17.9 ± 4.5 % at 6 mGy and 13.1 ± 2.6 % at 11 mGy). For all keV, similar d' values were found with both DSCT-Force and DSCT-Pulse at 11 mGy (-1.0 ± 3.1 %; p = 0.084). For other dose levels, d' values were significantly lower with DSCT-Pulse than with DSCT-Force (9.1 ± 3.2 % at 1.8 mGy and -6.3 ± 3.9 % at 6 mGy). CONCLUSION Compared with the DSCT-Force, the DSCT-Pulse improved noise texture and spatial resolution, but noise magnitude was slightly higher and detectability slightly lower, particularly when the dose level was reduced.
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Affiliation(s)
- Joël Greffier
- IMAGINE UR UM 103, Montpellier University, Department of Medical Imaging, Nîmes University Hospital, 30900 Nîmes, France.
| | - Sebastian Faby
- Department of Computed Tomography, Siemens Healthineers AG, Siemensstr. 3, 91301 Forchheim, Germany
| | - Maxime Pastor
- IMAGINE UR UM 103, Montpellier University, Department of Medical Imaging, Nîmes University Hospital, 30900 Nîmes, France
| | - Julien Frandon
- IMAGINE UR UM 103, Montpellier University, Department of Medical Imaging, Nîmes University Hospital, 30900 Nîmes, France
| | - Julien Erath
- Department of Computed Tomography, Siemens Healthineers AG, Siemensstr. 3, 91301 Forchheim, Germany
| | - Jean-Paul Beregi
- IMAGINE UR UM 103, Montpellier University, Department of Medical Imaging, Nîmes University Hospital, 30900 Nîmes, France
| | - Djamel Dabli
- IMAGINE UR UM 103, Montpellier University, Department of Medical Imaging, Nîmes University Hospital, 30900 Nîmes, France
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Tóth A, Chetta JA, Yazdani M, Matheus MG, O'Doherty J, Tipnis SV, Spampinato MV. Neurovascular Imaging with Ultra-High-Resolution Photon-Counting CT: Preliminary Findings on Image-Quality Evaluation. AJNR Am J Neuroradiol 2024:ajnr.A8350. [PMID: 38760079 DOI: 10.3174/ajnr.a8350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 05/07/2024] [Indexed: 05/19/2024]
Abstract
BACKGROUND AND PURPOSE The first-generation photon-counting detector CT was recently introduced into clinical practice and represents a promising innovation in high-resolution CT imaging. The purpose of this study was to assess the image quality of ultra-high-resolution photon-counting detector CT compared with energy-integrating detector CT and to explore different reconstruction kernel sharpness levels for the evaluation of intracranial aneurysms. MATERIALS AND METHODS Ten patients with intracranial saccular aneurysms who had previously undergone conventional energy-integrating detector CT were prospectively enrolled. CT angiograms were acquired on a clinical dual-source photon-counting detector CT in ultra-high-resolution mode and reconstructed with 4 vascular kernels (Bv36, Bv40, Bv44, Bv48). Quantitative and qualitative image-quality parameters of the intracranial arteries were evaluated. For the quantitative analysis (image noise, SNR, contrast-to-noise ratio), ROIs were manually placed at standard anatomic intracranial and extracranial locations by 1 author. In addition, vessel border sharpness was evaluated quantitatively. For the qualitative analysis, 3 blinded neuroradiologists rated photon-counting detector CT and energy-integrating detector CT image quality for the evaluation of the intracranial vessels (ie, the aneurysms and 9 standard vascular branching locations) on a 5-point Likert-type scale. Additionally, readers independently selected their preferred kernel among the 4 kernels evaluated on photon-counting detector CT. RESULTS In terms of quantitative image quality, Bv48, the sharpest kernel, yielded increased image noise and decreased SNR and contrast-to-noise ratio parameters compared with Bv36, the smoothest kernel. Compared with energy-integrating detector CT, the Bv48 kernel offered better quantitative image quality for the evaluation of small intracranial vessels (P < .001). Image-quality ratings of the Bv48 were superior to those of the energy-integrating detector CT and not significantly different from ratings of the B44 reconstruction kernel. When comparing side by side all 4 photon-counting detector reconstruction kernels, readers selected the B48 kernel as the best to visualize the aneurysms in 80% of cases. CONCLUSIONS Ultra-high-resolution photon-counting detector CT provides improved image quality for neurovascular imaging. Although the less sharp kernels provided superior SNR and contrast-to-noise ratio, the sharpest kernels delivered the best subjective image quality on photon-counting detector CT for the evaluation of intracranial aneurysms.
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Affiliation(s)
- Adrienn Tóth
- From the Department of Radiology and Radiological Science (A.T., J.A.C., M.Y., M.G.M., J.O., S.V.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
| | - Justin A Chetta
- From the Department of Radiology and Radiological Science (A.T., J.A.C., M.Y., M.G.M., J.O., S.V.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
| | - Milad Yazdani
- From the Department of Radiology and Radiological Science (A.T., J.A.C., M.Y., M.G.M., J.O., S.V.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
| | - M Gisele Matheus
- From the Department of Radiology and Radiological Science (A.T., J.A.C., M.Y., M.G.M., J.O., S.V.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
| | - Jim O'Doherty
- From the Department of Radiology and Radiological Science (A.T., J.A.C., M.Y., M.G.M., J.O., S.V.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
- Siemens Medical Solutions (J.O.), Malvern, Pennsylvania
| | - Sameer V Tipnis
- From the Department of Radiology and Radiological Science (A.T., J.A.C., M.Y., M.G.M., J.O., S.V.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
| | - M Vittoria Spampinato
- From the Department of Radiology and Radiological Science (A.T., J.A.C., M.Y., M.G.M., J.O., S.V.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
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Graafen D, Bart W, Halfmann MC, Müller L, Hobohm L, Yang Y, Neufang A, Espinola-Klein C, Pitton MB, Kloeckner R, Varga-Szemes A, Emrich T. In vitro and in vivo optimized reconstruction for low-keV virtual monoenergetic photon-counting detector CT angiography of lower legs. Eur Radiol Exp 2024; 8:89. [PMID: 39090380 PMCID: PMC11294310 DOI: 10.1186/s41747-024-00481-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 02/06/2024] [Indexed: 08/04/2024] Open
Abstract
BACKGROUND Lower extremity peripheral artery disease frequently presents with calcifications which reduces the accuracy of computed tomography (CT) angiography, especially below-the-knee. Photon-counting detector (PCD)-CT offers improved spatial resolution and less calcium blooming. We aimed to identify the optimal reconstruction parameters for PCD-CT angiography of the lower legs. METHODS Tubes with different diameters (1-5 mm) were filled with different iodine concentrations and scanned in a water container. Images were reconstructed with 0.4 mm isotropic resolution using a quantitative kernel at all available sharpness levels (Qr36 to Qr76) and using different levels of quantum iterative reconstruction (QIR-2-4). Noise and image sharpness were determined for all reconstructions. Additionally, CT angiograms of 20 patients, reconstructed with a medium (Qr44), sharp (Qr60), and ultrasharp (Qr72) kernel at QIR-2-4, were evaluated by three readers assessing noise, delineation of plaques and vessel walls, and overall quality. RESULTS In the phantom study, increased kernel sharpness led to higher image noise (e.g., 16, 38, 77 HU for Qr44, Qr60, Qr72, and QIR-3). Image sharpness increased with increasing kernel sharpness, reaching a plateau at the medium-high level 60. Higher QIR levels decreased image noise (e.g., 51, 38, 25 HU at QIR-2-4 and Qr60) without reducing vessel sharpness. The qualitative in vivo results confirmed these findings: the sharp kernel (Qr60) with the highest QIR yielded the best overall quality. CONCLUSION The combination of a sharpness level optimized reconstruction kernel (Qr60) and the highest QIR level yield the best image quality for PCD-CT angiography of the lower legs when reconstructed at 0.4-mm resolution. RELEVANCE STATEMENT Using high-resolution PCD-CT angiography with optimized reconstruction parameters might improve diagnostic accuracy and confidence in peripheral artery disease of the lower legs. KEY POINTS Effective exploitation of the potential of PCD-CT angiography requires optimized reconstruction parameters. Too soft or too sharp reconstruction kernels reduce image quality. The highest level of quantum iterative reconstruction provides the best image quality.
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Affiliation(s)
- Dirk Graafen
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.
| | - Willi Bart
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Moritz C Halfmann
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- German Center for Cardiovascular Research (DZHK), Partner-Site Rhine-Main, Mainz, Germany
| | - Lukas Müller
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Lukas Hobohm
- Department of Cardiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Yang Yang
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Achim Neufang
- Department of Cardiac and Vascular Surgery, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Christine Espinola-Klein
- Department of Cardiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Michael B Pitton
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Roman Kloeckner
- Institute of Interventional Radiology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Tilman Emrich
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- German Center for Cardiovascular Research (DZHK), Partner-Site Rhine-Main, Mainz, Germany
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
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10
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Lennartz S, Zopfs D, Große Hokamp N. Dual-energy CT revisited: a focused review of clinical use cases. ROFO-FORTSCHR RONTG 2024; 196:794-806. [PMID: 38176436 DOI: 10.1055/a-2203-2945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Affiliation(s)
- Simon Lennartz
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - David Zopfs
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Nils Große Hokamp
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
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11
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Zhang X, Bao S, Wang M, Xu Z, Yan F, Yang W. Stability and accuracy of fat quantification on photon-counting detector CT with various scan settings: A phantom study. Eur J Radiol 2024; 177:111545. [PMID: 38878499 DOI: 10.1016/j.ejrad.2024.111545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Revised: 05/30/2024] [Accepted: 06/02/2024] [Indexed: 07/24/2024]
Abstract
OBJECTIVE Fat deposition is an important marker of many metabolic diseases. As a noninvasive and convenient examination method, CT has been widely used for fat quantification. With the clinical application of photon-counting detector (PCD)-CT, we aimed to investigate the accuracy, stability, and dose level of PCD-CT using various scan settings for fat quantification. MATERIALS AND METHODS Eleven agar-based lipid-containing phantoms (vials with different fat fractions [FFs]; range: 0 %-100 %) were scanned using PCD-CT. Three scanning types (sequence scan, regular spiral scan with a pitch of 0.8, and high-pitch spiral scan with a pitch of 3.2), four tube voltages (90, 120, 140, and 100 kV with a tin filter), and three image quality (IQ) levels (IQ levels of 20, 40, and 80) were alternated, and each scan setting was used twice. For each scan, a 70-keV image was generated using the same reconstruction parameters. A regular spiral scan at 120 kV with IQ80 was used to transfer the CT numbers of all scans to the FF. Intraclass correlation coefficient (ICC) and Bland-Altman analysis were implemented for accuracy and agreement evaluation, and group differences were compared using analysis of variance. RESULTS Excellent agreement and accuracy of FF derived by PCD-CT with all scan settings was demonstrated by high ICCs (>0.9; range: 0.929-0.998, p < 0.017) and low bias (<5% range: -2.9 %-5%). The root mean square error (RMSE) between the PCD-CT-acquired FF and the reference standard ranged from 1.0 % to 5.0 %, among which the high-pitch scan at 120 kV with IQ20 accounted for the lowest RMSE (1.0 %). The spiral scan at 120 kV with IQ20 and IQ80 yielded the lowest bias (mean value: 1.19 % and 1.23 %, respectively). CONCLUSION Fat quantification using PCD-CT reconstructed at 70 keV was accurate and stable under various scan settings. PCD-CT has great potential for fat quantification using ultralow radiation doses.
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Affiliation(s)
- Xu Zhang
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shouyu Bao
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mengzhen Wang
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhihan Xu
- Siemens Healthineers CT Collaboration, Shanghai, China
| | - Fuhua Yan
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wenjie Yang
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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12
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Scienti OLPP, Darambara DG. To Reconstruct or Discard: A Comparison of Additive and Subtractive Charge Sharing Correction Algorithms at High and Low X-ray Fluxes. SENSORS (BASEL, SWITZERLAND) 2024; 24:4946. [PMID: 39123992 PMCID: PMC11314781 DOI: 10.3390/s24154946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Revised: 07/26/2024] [Accepted: 07/27/2024] [Indexed: 08/12/2024]
Abstract
Effective X-ray photon-counting spectral imaging (x-CSI) detector design involves the optimisation of a wide range of parameters both regarding the sensor (e.g., material, thickness and pixel pitch) and electronics (e.g., signal-processing chain and count-triggering scheme). Our previous publications have looked at the role of pixel pitch, sensor thickness and a range of additive charge sharing correction algorithms (CSCAs), and in this work, we compare additive and subtractive CSCAs to identify the advantages and disadvantages. These CSCAs differ in their approach to dealing with charge sharing: additive approaches attempt to reconstruct the original event, whilst subtractive approaches discard the shared events. Each approach was simulated on data from a wide range of x-CSI detector designs (pixel pitches 100-600 µm, sensor thickness 1.5 mm) and X-ray fluxes (106-109 photons mm-2 s-1), and their performance was characterised in terms of absolute detection efficiency (ADE), absolute photopeak efficiency (APE), relative coincidence counts (RCC) and binned spectral efficiency (BSE). Differences between the two approaches were explained mechanistically in terms of the CSCA's effect on both charge sharing and pule pileup. At low X-ray fluxes, the two approaches perform similarly, but at higher fluxes, they differ in complex ways. Generally, additive CSCAs perform better on absolute metrics (ADE and APE), and subtractive CSCAs perform better on relative metrics (RCC and BSE). Which approach to use will, thus, depend on the expected operating flux and whether dose efficiency or spectral efficiency is more important for the application in mind.
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Affiliation(s)
- Oliver L. P. Pickford Scienti
- Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, London SM2 5NG, UK;
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13
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Rehwald R. Improving the prediction of intracranial aneurysm rupture risk-calcification in the spotlight. Eur Radiol 2024:10.1007/s00330-024-10990-3. [PMID: 39075301 DOI: 10.1007/s00330-024-10990-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 05/28/2024] [Accepted: 06/20/2024] [Indexed: 07/31/2024]
Affiliation(s)
- Rafael Rehwald
- Academic Neuroradiological Unit, Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, London, UK.
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14
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Han K, Ryu CH, Lee CL, Han TH. Deep learning-based material decomposition of iodine and calcium in mobile photon counting detector CT. PLoS One 2024; 19:e0306627. [PMID: 39058758 PMCID: PMC11280148 DOI: 10.1371/journal.pone.0306627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 06/20/2024] [Indexed: 07/28/2024] Open
Abstract
Photon-counting detector (PCD)-based computed tomography (CT) offers several advantages over conventional energy-integrating detector-based CT. Among them, the ability to discriminate energy exhibits significant potential for clinical applications because it provides material-specific information. That is, material decomposition (MD) can be achieved through energy discrimination. In this study, deep learning-based material decomposition was performed using live animal data. We propose MD-Unet, which is a deep learning strategy for material decomposition based on an Unet architecture trained with data from three energy bins. To mitigate the data insufficiency, we developed a pretrained model incorporating various simulation data forms and augmentation strategies. Incorporating these approaches into model training results in enhanced precision in material decomposition, thereby enabling the identification of distinct materials at individual pixel locations. The trained network was applied to the acquired animal data to evaluate material decomposition results. Compared with conventional methods, the newly generated MD-Unet demonstrated more accurate material decomposition imaging. Moreover, the network demonstrated an improved material decomposition ability and significantly reduced noise. In addition, they can potentially offer an enhancement level similar to that of a typical contrast agent. This implies that it can acquire images of the same quality with fewer contrast agents administered to patients, thereby demonstrating its significant clinical value.
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Affiliation(s)
- Kwanhee Han
- Health & Medical Equipment Business Unit, Samsung Electronics, Suwon-si, Gyeonggi-do, Korea
- Department of Digital Media and Communications Engineering, Sungkyunkwan University, Suwon-si, Gyeonggi-do, Korea
| | - Chang Ho Ryu
- Department of Artificial Intelligence, Sungkyunkwan University, Suwon-si, Gyeonggi-do, Korea
| | - Chang-Lae Lee
- Health & Medical Equipment Business Unit, Samsung Electronics, Suwon-si, Gyeonggi-do, Korea
| | - Tae Hee Han
- Department of Semiconductor Systems Engineering, Sungkyunkwan University, Suwon-si, Gyeonggi-do, Korea
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15
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Dane B, Froemming A, Schwartz FR, Toshav A, Ramirez-Giraldo JC, Ananthakrishnan L. Photon counting CT clinical adoption, integration, and workflow. Abdom Radiol (NY) 2024:10.1007/s00261-024-04503-5. [PMID: 39052057 DOI: 10.1007/s00261-024-04503-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 07/15/2024] [Accepted: 07/16/2024] [Indexed: 07/27/2024]
Abstract
Photon counting CT was recently introduced into clinical practice [Rajendran K, Petersilka M, Henning A, Shanblatt ER, Schmidt B, Flohr TG, Ferrero A, Baffour F, Diehn FE, Yu L, Rajiah P, Fletcher JG, Leng S, McCollough CH. First Clinical Photon-counting Detector CT System: Technical Evaluation. Radiology 2022;303(1):130-138. doi: https://doi.org/10.1148/radiol.212579 ]. Photon counting detectors (PCD) afford better spatial resolution, radiation dose efficiency, and iodine contrast-to-noise than EID-CT [Leng S, Bruesewitz M, Tao S, Rajendran K, Halaweish AF, Campeau NG, Fletcher JG, McCollough CH. Photon-counting Detector CT: System Design and Clinical Applications of an Emerging Technology. Radiographics 2019;39(3):729-743. doi: https://doi.org/10.1148/rg.2019180115 ); (Leng S, Rajendran K, Gong H, Zhou W, Halaweish AF, Henning A, Kappler S, Baer M, Fletcher JG, McCollough CH. 150-mum Spatial Resolution Using Photon-Counting Detector Computed Tomography Technology: Technical Performance and First Patient Images. Invest Radiol 2018;53(11):655-662. doi: https://doi.org/10.1097/RLI.0000000000000488 )(Booij R, van der Werf NR, Dijkshoorn ML, van der Lugt A, van Straten M. Assessment of Iodine Contrast-To-Noise Ratio in Virtual Monoenergetic Images Reconstructed from Dual-Source Energy-Integrating CT and Photon-Counting CT Data. Diagnostics (Basel) 2022;12(6). doi: https://doi.org/10.3390/diagnostics12061467 ); (Sawall S, Klein L, Amato C, Wehrse E, Dorn S, Maier J, Heinze S, Schlemmer HP, Ziener CH, Uhrig M, Kachelriess M. Iodine contrast-to-noise ratio improvement at unit dose and contrast media volume reduction in whole-body photon-counting CT. Eur J Radiol 2020;126:108909. doi: https://doi.org/10.1016/j.ejrad.2020.108909 ] while also maintaining multienergy CT (MECT) capabilities[Flohr T, Petersilka M, Henning A, Ulzheimer S, Ferda J, Schmidt B. Photon-counting CT review. Phys Med 2020;79:126-136. doi: https://doi.org/10.1016/j.ejmp.2020.10.030 ]. This article will review the clinical adoption of PCD-CT including protocol development, clinical applications, clinical integration and workflow considerations. Protocol development is institution specific and involves collaborative decision-making among radiologists, physicists, and technologists. Key PCD clinical applications include radiation exposure reduction, intravenous contrast volume reduction, and improved lesion conspicuity. Patients who would most benefit from these improvements may preferentially be scanned with PCD CT. With numerous available reconstructions, radiologists should be strategic in the series sent to PACS for interpretation and routinely sending spectral series to PACS can facilitate integration with clinical workflow. The Society of Abdominal Radiology PCD Emerging Technology Commission endorsed this article.
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Affiliation(s)
- Bari Dane
- NYU Langone Health, Department of Radiology, 660 1st Avenue, New York, NY, 10016, USA.
| | - Adam Froemming
- Department of Radiology, Mayo Clinic, 200 First Street SW, 55905, Rochester, MN, USA
| | - Fides R Schwartz
- Brigham and Women's Hospital, Department of Radiology, 75 Francis Street, Boston, MA, 02115, USA
| | - Aran Toshav
- Department of Radiology, LSUHSC School of Medicine, 2021 Perdido Street, 7th Floor, New Orleans, LA, 70112, USA
| | | | - Lakshmi Ananthakrishnan
- Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA
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Ota T, Onishi H, Itoh T, Fukui H, Tsuboyama T, Nakamoto A, Enchi Y, Tatsumi M, Tomiyama N. Investigation of abdominal artery delineation by photon-counting detector CT. LA RADIOLOGIA MEDICA 2024:10.1007/s11547-024-01858-z. [PMID: 39043979 DOI: 10.1007/s11547-024-01858-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Accepted: 07/17/2024] [Indexed: 07/25/2024]
Abstract
OBJECTIVES To evaluate the ability of 50-keV virtual monoenergetic images (VMI) to depict abdominal arteries in abdominal CT angiography (CTA) compared with 70-keV VMI with photon-counting detector CT (PCD-CT). METHODS Fifty consecutive patients who underwent multiphase abdominal scans between March and April 2023 were included. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were quantitatively assessed for the abdominal aorta (AA), celiac artery (CeA), superior mesenteric artery (SMA), renal artery (RA), and right hepatic artery (RHA) at both 50- and 70-keV VMI. In addition, 3D images from CTA were analyzed to measure arterial lengths and evaluate the visualization of distal branches. RESULTS Significantly higher SNR and CNR were observed at 50-keV compared to 70-keV VMI for all arteries: AA (36.54 and 48.28 vs. 25.70 and 28.46), CeA (22.39 and 48.38 vs. 19.09 and 29.15), SMA (23.34 and 49.34 vs. 19.67 and 29.71), RA (22.88 and 48.84 vs. 20.15 and 29.41), and RHA (14.38 and 44.41 vs. 13.45 and 27.18), all p < 0.05. Arterial lengths were also significantly longer at 50-keV: RHA (192.6 vs. 180.3 mm), SMA (230.9 vs. 216.5 mm), and RA (95.9 vs. 92.0 mm), all p < 0.001. CONCLUSION In abdominal CTA with PCD-CT, 50-keV VMI demonstrated superior quantitative image quality compared to 70-keV VMI. In addition, 50-keV VMI 3D CTA allowed better visualization of abdominal artery branches, highlighting its potential clinical advantage for improved imaging and detailed assessment of abdominal arteries.
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Affiliation(s)
- Takashi Ota
- Department of Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, D1, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Hiromitsu Onishi
- Department of Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, D1, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Toshihide Itoh
- Department of CT Research and Collaboration, Siemens Healthineers, Tokyo, Japan
| | - Hideyuki Fukui
- Department of Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, D1, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Takahiro Tsuboyama
- Department of Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, D1, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Atsushi Nakamoto
- Department of Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, D1, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yukihiro Enchi
- Department of Medical Technology, Osaka University Hospital, Suita, Japan
| | - Mitsuaki Tatsumi
- Department of Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, D1, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Noriyuki Tomiyama
- Department of Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, D1, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan
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17
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Maisuria D, Chamberlin JH, Baruah D, Hinen S, O'Doherty J, McGuire A, Knight H, Schoepf UJ, Munden RF, Kabakus IM. Polyenergetic reconstruction mitigates streak artifacts by dual source imaging in chest photon counting detector computed tomography. Clin Imaging 2024; 113:110235. [PMID: 39059085 DOI: 10.1016/j.clinimag.2024.110235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 07/01/2024] [Accepted: 07/18/2024] [Indexed: 07/28/2024]
Abstract
OBJECTIVE This study aims to assess the efficacy of polyenergetic reconstruction methods in reducing streak artifacts caused by dual source imaging in Photon Counting Detector Computed Tomography (PCD-CT) imaging, thereby improving image quality and diagnostic accuracy. METHODS A retrospective cohort study was conducted, involving 50 patients who underwent chest Computed Tomography Angiography with PCD-CT, focusing on those with streak artifacts. Quantitative and qualitative analyses were performed on images reconstructed using monoenergetic and polyenergetic techniques. Quantitative evaluations measured the attenuation of tracheal air density in regions affected by streak artifacts, while qualitative assessments employed a modified Likert scale to rate image quality. Statistical analyses included Wilcoxon's signed-rank tests and Spearman's correlation, alongside assessments of inter-rater reliability. RESULTS There was significantly lower attenuation of tracheal air density on the polyenergetic reconstructions (Median - 1010 ± 62 HU vs -930 ± 110 HU; P < 0.001), and significantly decreased variation on the polyenergetic reconstructions (Median 65.2 ± 79.5 HU vs 38.8 ± 33.9 HU; P < 0.001). The median modified-Likert scale were significantly better for the polyenergetic reconstructions (median modified-Likert 4 ± 0.5 vs 2.5 ± 1; P < 0.001). The inter-rater agreement was substantial and not significantly different between reconstructions (Gwet's ACPolyenergetic = 0.78 vs Gwet's ACVMI = 0.775). CONCLUSION Polyenergetic reconstruction significantly mitigates streak artifacts in PCD-CT imaging, enhancing quantitative and qualitative image quality. This advancement addresses a known limitation of current PCD-CT reconstruction techniques, offering a promising approach to improving diagnostic reliability and accuracy in clinical practice. We demonstrate that future software implementations can resolve this artifact.
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Affiliation(s)
- Dhruw Maisuria
- Division of Cardiovascular Imaging, Department of Radiology, Medical University of South Carolina, Charleston, SC, USA
| | - Jordan H Chamberlin
- Division of Cardiovascular Imaging, Department of Radiology, Medical University of South Carolina, Charleston, SC, USA
| | - Dhiraj Baruah
- Division of Cardiovascular Imaging, Department of Radiology, Medical University of South Carolina, Charleston, SC, USA
| | - Shaun Hinen
- Division of Cardiovascular Imaging, Department of Radiology, Medical University of South Carolina, Charleston, SC, USA
| | - Jim O'Doherty
- Division of Cardiovascular Imaging, Department of Radiology, Medical University of South Carolina, Charleston, SC, USA; Siemens Medical Solutions, Malvern, PA, USA
| | - Aaron McGuire
- Division of Cardiovascular Imaging, Department of Radiology, Medical University of South Carolina, Charleston, SC, USA
| | - Heather Knight
- Division of Cardiovascular Imaging, Department of Radiology, Medical University of South Carolina, Charleston, SC, USA
| | - U Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology, Medical University of South Carolina, Charleston, SC, USA
| | - Reginald F Munden
- Division of Cardiovascular Imaging, Department of Radiology, Medical University of South Carolina, Charleston, SC, USA
| | - Ismail M Kabakus
- Division of Cardiovascular Imaging, Department of Radiology, Medical University of South Carolina, Charleston, SC, USA.
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Klempka A, Neumayer P, Schröder A, Ackermann E, Hetjens S, Clausen S, Groden C. Establishing a Foundation for the In Vivo Visualization of Intravascular Blood with Photon-Counting Technology in Spectral Imaging in Cranial CT. Diagnostics (Basel) 2024; 14:1561. [PMID: 39061698 PMCID: PMC11276049 DOI: 10.3390/diagnostics14141561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Revised: 07/12/2024] [Accepted: 07/16/2024] [Indexed: 07/28/2024] Open
Abstract
BACKGROUND Advances in computed tomography (CT) technology, particularly photon-counting CT (PCCT), are reshaping the possibilities for medical imaging. PCCT in spectral imaging enables the high-resolution visualization of tissues with material-specific accuracy. This study aims to establish a foundational approach for the in vivo visualization of intracranial blood using PCCT, focusing on non-enhanced imaging techniques and spectral imaging capabilities. METHODS We employed photon-counting detector within a spectral CT framework to differentiate between venous and arterial intracranial blood. Our analysis included not only monoenergetic +67 keV reconstructions, but also images from virtual non-contrast and iodine phases, enabling detailed assessments of blood's characteristics without the use of contrast agents. RESULTS Our findings demonstrate the ability of PCCT to provide clear and distinct visualizations of intracranial vascular structures. We quantified the signal-to-noise ratio across different imaging phases and found consistent enhancements in image clarity, particularly in the detection and differentiation of arterial and venous blood. CONCLUSION PCCT offers a robust platform for the non-invasive and detailed visualization of intravascular intracranial blood. With its superior resolution and specific imaging capabilities, PCCT lays the groundwork for advancing clinical applications and research, notably in the diagnosis and management of intracranial disorders. This technology promises to improve diagnostic accuracy by enabling more precise imaging assessments.
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Affiliation(s)
- Anna Klempka
- Department of Neuroradiology, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, 68167 Mannheim, Germany
| | - Philipp Neumayer
- Department of Neuroradiology, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, 68167 Mannheim, Germany
| | - Alexander Schröder
- Department of Neuroradiology, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, 68167 Mannheim, Germany
| | - Eduardo Ackermann
- Department of Neuroradiology, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, 68167 Mannheim, Germany
| | - Svetlana Hetjens
- Department of Medical Statistics and Biomathematics, Medical Faculty Mannheim, University of Heidelberg, 68167 Mannheim, Germany
| | - Sven Clausen
- Department of Radiation Oncology, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, 68167 Mannheim, Germany
| | - Christoph Groden
- Department of Neuroradiology, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, 68167 Mannheim, Germany
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Lee JS, Kim J, Bapuraj JR, Srinivasan A. Comparison of Image Quality and Radiation Dose in Pediatric Temporal Bone CT Using Photon-Counting Detector CT and Energy-Integrating Detector CT. AJNR Am J Neuroradiol 2024:ajnr.A8276. [PMID: 38589057 DOI: 10.3174/ajnr.a8276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 03/26/2024] [Indexed: 04/10/2024]
Abstract
BACKGROUND AND PURPOSE Currently, there is a lack of research directly comparing photon-counting detector CT (PCD-CT) and energy-integrating detector CT (EID-CT) in pediatric temporal bone CT imaging. The purpose of this study was to compare the image quality and radiation dose of temporal bone CT scans in pediatric patients acquired with PCD-CT and EID-CT. MATERIALS AND METHODS The retrospective study included a total of 110 pediatric temporal bone CT scans (PCD-CT, n = 52; EID-CT, n = 58). Two independent readers evaluated the spatial resolution of 4 anatomic structures (tympanic membrane, incudostapedial joint, stapedial crura, and cochlear modiolus) and overall image quality by using a 4-point scale. Interreader agreement was assessed. Dose-length product for each CT was compared, and subgroup analyses were performed based on age (younger than 3 years, 3-5 years, 6-11 years, and 12 years and above). RESULTS PCD-CT demonstrated statistically significantly higher scores than EID-CT for all items (tympanic membrane, 2.9 versus 2.4; incudostapedial joint, 3.6 versus 2.6; stapedial crura, 3.2 versus 2.4; cochlear modiolus, 3.4 versus 2.8; overall image quality, 3.6 versus 2.8; P < .05). Interreader agreement ranged from good to excellent (interclass correlation coefficients, 0.6-0.81). PCD-CT exhibited a 43% dose reduction compared with EID-CT, with a particularly substantial reduction of over 70% in the subgroups of children younger than 6 years. CONCLUSIONS PCD temporal bone CT achieves significantly superior imaging quality at a lower radiation dose compared with EID-CT.
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Affiliation(s)
- Jeong Sub Lee
- From the Department of Radiology (J.S.L.), Jeju National University Hospital, Jeju National University College of Medicine, Jeju-si, Jeju-do, Republic of Korea
| | - John Kim
- Department of Radiology (J.K., J.R.B., A.S.), University of Michigan, Ann Arbor, Michigan.
| | - Jayapalli R Bapuraj
- Department of Radiology (J.K., J.R.B., A.S.), University of Michigan, Ann Arbor, Michigan
| | - Ashok Srinivasan
- Department of Radiology (J.K., J.R.B., A.S.), University of Michigan, Ann Arbor, Michigan
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Grözinger M, Wennmann M, Sawall S, Wehrse E, Sedaghat S, Neelsen C, Bauer F, Goldschmidt H, Weru V, Ziener CH, Kopp-Schneider A, Schlemmer HP, Rotkopf LT. Detection of myeloma-associated osteolytic bone lesions with energy-integrating and photon-counting detector CT. RADIOLOGIE (HEIDELBERG, GERMANY) 2024:10.1007/s00117-024-01344-7. [PMID: 39020050 DOI: 10.1007/s00117-024-01344-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/23/2024] [Indexed: 07/19/2024]
Abstract
BACKGROUND A recent innovation in computed tomography (CT) imaging has been the introduction of photon-counting detector CT (PCD-CT) systems, which are able to register the number and the energy level of incoming x‑ray photons and have smaller detector elements compared with conventional CT scanners that operate with energy-integrating detectors (EID-CT). OBJECTIVES The study aimed to evaluate the potential benefits of a novel, non-CE certified PCD-CT in detecting myeloma-associated osteolytic bone lesions (OL) compared with a state-of-the-art EID-CT. MATERIALS AND METHODS Nine patients with multiple myeloma stage III (according to Durie and Salmon) underwent magnetic resonance imaging (MRI), EID-CT, and PCD-CT of the lower lumbar spine and pelvis. The PCD-CT and EID-CT images of all myeloma lesions that were visible in clinical MRI scans were reviewed by three radiologists for corresponding OL. Additionally, the visualization of destructions to cancellous or cortical bone, and trabecular structures, was compared between PCD-CT and EID-CT. RESULTS Readers detected 21% more OL in PCD-CT than in EID-CT images (138 vs. 109; p < 0.0001). The sensitivity advantage of PCD-CT in lesion detection increased with decreasing lesion size. The visualization quality of cancellous and cortical destructions as well as of trabecular structures was rated higher by all three readers in PCD-CT images (mean image quality improvements for PCD-CT over EID-CT were +0.45 for cancellous and +0.13 for cortical destructions). CONCLUSIONS For myeloma-associated OL, PCD-CT demonstrated significantly higher sensitivity, especially with small size. Visualization of bone tissue and lesions was considered significantly better in PCD-CT than in EID-CT. This implies that PCD-CT scanners could potentially be used in the early detection of myeloma-associated bone lesions.
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Affiliation(s)
- Martin Grözinger
- Division of Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Baden-Württemberg, Germany
| | - Markus Wennmann
- Division of Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Baden-Württemberg, Germany
| | - Stefan Sawall
- Division of X-Ray Imaging and CT, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Baden-Württemberg, Germany
| | - Eckhard Wehrse
- Division of Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Baden-Württemberg, Germany
- Medical Faculty, Ruprecht-Karls-University Heidelberg, Im Neuenheimer Feld 672, 69120, Heidelberg, Baden-Württemberg, Germany
| | - Sam Sedaghat
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Christian Neelsen
- Division of Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Baden-Württemberg, Germany
| | - Fabian Bauer
- Division of Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Baden-Württemberg, Germany
- Medical Faculty, Ruprecht-Karls-University Heidelberg, Im Neuenheimer Feld 672, 69120, Heidelberg, Baden-Württemberg, Germany
| | - Hartmut Goldschmidt
- Department of Medicine V, Multiple Myeloma Section, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Vivienn Weru
- Division of Biostatistics, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Baden-Württemberg, Germany
| | - Christian H Ziener
- Division of Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Baden-Württemberg, Germany
| | - Annette Kopp-Schneider
- Division of Biostatistics, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Baden-Württemberg, Germany
| | - Heinz-Peter Schlemmer
- Division of Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Baden-Württemberg, Germany
| | - Lukas T Rotkopf
- Division of Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Baden-Württemberg, Germany.
- Medical Faculty, Ruprecht-Karls-University Heidelberg, Im Neuenheimer Feld 672, 69120, Heidelberg, Baden-Württemberg, Germany.
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21
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Kahmann J, Nörenberg D, Papavassiliu T, Dar SUH, Engelhardt S, Schoenberg SO, Froelich MF, Ayx I. Combined conventional factors and the radiomics signature of coronary plaque texture could improve cardiac risk prediction. Insights Imaging 2024; 15:170. [PMID: 38971903 PMCID: PMC11227490 DOI: 10.1186/s13244-024-01759-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 06/22/2024] [Indexed: 07/08/2024] Open
Abstract
OBJECTIVES This study aims to investigate how radiomics analysis can help understand the association between plaque texture, epicardial adipose tissue (EAT), and cardiovascular risk. Working with a Photon-counting CT, which exhibits enhanced feature stability, offers the potential to advance radiomics analysis and enable its integration into clinical routines. METHODS Coronary plaques were manually segmented in this retrospective, single-centre study and radiomic features were extracted using pyradiomics. The study population was divided into groups according to the presence of high-risk plaques (HRP), plaques with at least 50% stenosis, plaques with at least 70% stenosis, or triple-vessel disease. A combined group with patients exhibiting at least one of these risk factors was formed. Random forest feature selection identified differentiating features for the groups. EAT thickness and density were measured and compared with feature selection results. RESULTS A total number of 306 plaques from 61 patients (mean age 61 years +/- 8.85 [standard deviation], 13 female) were analysed. Plaques of patients with HRP features or relevant stenosis demonstrated a higher presence of texture heterogeneity through various radiomics features compared to patients with only an intermediate stenosis degree. While EAT thickness did not significantly differ, affected patients showed significantly higher mean densities in the 50%, HRP, and combined groups, and insignificantly higher densities in the 70% and triple-vessel groups. CONCLUSION The combination of a higher EAT density and a more heterogeneous plaque texture might offer an additional tool in identifying patients with an elevated risk of cardiovascular events. CLINICAL RELEVANCE STATEMENT Cardiovascular disease is the leading cause of mortality globally. Plaque composition and changes in the EAT are connected to cardiac risk. A better understanding of the interrelation of these risk indicators can lead to improved cardiac risk prediction. KEY POINTS Cardiac plaque composition and changes in the EAT are connected to cardiac risk. Higher EAT density and more heterogeneous plaque texture are related to traditional risk indicators. Radiomics texture analysis conducted on PCCT scans can help identify patients with elevated cardiac risk.
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Affiliation(s)
- Jannik Kahmann
- Department of Radiology and Nuclear Medicine, University Medical Centre Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Dominik Nörenberg
- Department of Radiology and Nuclear Medicine, University Medical Centre Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Theano Papavassiliu
- First Department of Internal Medicine, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, 68167, Mannheim, Germany
| | - Salman Ul Hassan Dar
- Department of Internal Medicine III, Heidelberg University Hospital, Heidelberg, Germany
- AI Health Innovation Cluster, Heidelberg, Germany
| | - Sandy Engelhardt
- Department of Internal Medicine III, Heidelberg University Hospital, Heidelberg, Germany
- AI Health Innovation Cluster, Heidelberg, Germany
| | - Stefan O Schoenberg
- Department of Radiology and Nuclear Medicine, University Medical Centre Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Matthias F Froelich
- Department of Radiology and Nuclear Medicine, University Medical Centre Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Isabelle Ayx
- Department of Radiology and Nuclear Medicine, University Medical Centre Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.
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22
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Zander C, Wolf K, El Rahal A, Volz F, Beck J, Urbach H, Lützen N. Spontaneous intracranial hypotension - a spinal disease. ROFO-FORTSCHR RONTG 2024. [PMID: 38968964 DOI: 10.1055/a-2318-8994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/07/2024]
Abstract
Spontaneous intracranial hypotension (SIH) remains an underdiagnosed condition despite increasing awareness due to recent scientific advances. Diagnosis can be delayed by the broad clinical presentation and imaging pitfalls. This results in a high degree of physical impairment for patients, including social and psychological sequelae as well as long-term damage in the case of delayed diagnosis and treatment.The study is based on a selective literature search on PubMed including articles from 1990 to 2023 and the authors' clinical experience from working in a CSF center.SIH mostly affects middle-aged women, with the primary symptom being position-dependent orthostatic headache. In addition, there is a broad spectrum of possible symptoms that can overlap with other clinical conditions and therefore complicate the diagnosis. The causative spinal CSF loss can be divided into three main types: ventral (type 1) or lateral (type 2) dural leak and CSF-venous fistula (type 3). The diagnosis can be made using a two-stage workup. As a first step, noninvasive MRI of the head and spine provides indicators of the presence of SIH. The second step using focused myelography can identify the exact location of the cerebrospinal fluid leak and enable targeted therapy (surgical or interventional). Intrathecal pressure measurement or intrathecal injection of gadolinium is no longer necessary for primary diagnosis. Serious complications in the course of the disease can include space-occupying subdural hematomas, superficial siderosis, and symptoms of brain sagging, which can lead to misinterpretations. Treatment consists of closing the dural leak or the cerebrospinal fluid fistula. Despite successful treatment, a relapse can occur, which highlights the importance of follow-up MRI examinations and emphasizes the chronic nature of the disease. This paper provides an overview of the diagnostic workup of patients with suspected SIH and new developments in imaging and therapy. · SIH is an underdiagnosed condition with a wide range of possible symptoms.. · The first diagnostic step using MRI provides indications of the presence of SIH.. · The second diagnostic step using (dynamic) myelography can identify the CSF leak.. · Collaboration with a CSF center is advisable for further diagnosis and treatment.. · Prompt detection and treatment of SIH improves the outcome.. · Zander C, Wolf K, El Rahal A et al. Spontaneous intracranial hypotension - a spinal disease. Fortschr Röntgenstr 2024; DOI 10.1055/a-2318-8994.
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Affiliation(s)
- Charlotte Zander
- Dept. of Neuroradiology, University Medical Center Freiburg, Freiburg, Germany
| | - Katharina Wolf
- Dept. of Neurosurgery, University Medical Center Freiburg, Freiburg, Germany
| | - Amir El Rahal
- Dept. of Neurosurgery, University Medical Center Freiburg, Freiburg, Germany
| | - Florian Volz
- Dept. of Neurosurgery, University Medical Center Freiburg, Freiburg, Germany
| | - Jürgen Beck
- Dept. of Neurosurgery, University Medical Center Freiburg, Freiburg, Germany
| | - Horst Urbach
- Dept. of Neuroradiology, University Medical Center Freiburg, Freiburg, Germany
| | - Niklas Lützen
- Dept. of Neuroradiology, University Medical Center Freiburg, Freiburg, Germany
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23
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Nezami N, Malayeri AA. Sharper, Smarter, Safer: Unpacking the Potential of Photon-Counting CT in Urolithiasis Imaging. Radiology 2024; 312:e240497. [PMID: 39078304 PMCID: PMC11294758 DOI: 10.1148/radiol.240497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 03/14/2024] [Accepted: 03/15/2024] [Indexed: 07/31/2024]
Affiliation(s)
- Nariman Nezami
- From the Department of Radiology, MedStar Georgetown University
Hospital, 3800 Reservoir Rd NW, CCC Bldg, Rm CG225, Washington, DC 20007 (N.N.);
Georgetown University School of Medicine, Washington, DC (N.N.); Lombardi
Comprehensive Cancer Center, Washington, DC (N.N.); Fischell Department of
Bioengineering, University of Maryland College Park, College Park, Md (N.N.);
and Department of Radiology and Imaging Sciences, National Institutes of Health,
Bethesda, Md (A.A.M.)
| | - Ashkan A. Malayeri
- From the Department of Radiology, MedStar Georgetown University
Hospital, 3800 Reservoir Rd NW, CCC Bldg, Rm CG225, Washington, DC 20007 (N.N.);
Georgetown University School of Medicine, Washington, DC (N.N.); Lombardi
Comprehensive Cancer Center, Washington, DC (N.N.); Fischell Department of
Bioengineering, University of Maryland College Park, College Park, Md (N.N.);
and Department of Radiology and Imaging Sciences, National Institutes of Health,
Bethesda, Md (A.A.M.)
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24
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Augustin AM, Hartung V, Grunz JP, Hennes JL, Huflage H, Bley TA, Petritsch B, Gruschwitz P. Photon-Counting Detector CT Angiography Versus Digital Subtraction Angiography in Patients with Peripheral Arterial Disease. Acad Radiol 2024; 31:2973-2986. [PMID: 38403477 DOI: 10.1016/j.acra.2024.02.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 01/23/2024] [Accepted: 02/05/2024] [Indexed: 02/27/2024]
Abstract
RATIONALE AND OBJECTIVES This study aims to compare the diagnostic confidence of photon-counting detector CT angiography (PCD-CTA) depending on the used vascular reformatting kernels with digital subtraction angiography (DSA) as diagnostic reference standard in peripheral arterial occlusive disease (PAOD). MATERIAL AND METHODS In 39 patients, 45 lower extremity PCD-CTA with subsequent DSA were analyzed. Advanced PAOD (Fontaine stage 4) was ascertained in 77.8% of patients. CTA post-processing comprised three vascular kernels (Bv36/48/56). Objective image quality assessment included vessel attenuation, image noise, contrast-to-noise (CNR) and signal-to-noise ratios (SNR). Subjective evaluation of calcium blooming, vessel sharpness, luminal attenuation and image noise was performed by three radiologists. Diagnostic performance and concordance to DSA were assessed. RESULTS The luminal attenuation remained kernel-independent constant. With sharper kernels, image noise increased substantially, while SNR and CNR decreased. Subjective reduction of calcium blooming and increased vessel sharpness were noted for the sharp Bv56 kernel. While sensitivity in stenosis quantification was comparable between kernels (81.6% vs. 81.5% vs. 81.0%, p = 0.797), specificity increased slightly higher sharpness (71.1% vs. 76.9% vs. 79.6%, p = 0.067). Diagnostic concordance of stenosis ratings compared to DSA increased likewise (Bv36 vs. Bv56, p = 0.002). Severe crural vessel calcifications had no influence on sensitivity, regardless of kernel selection. Contrarily, specificity was substantially worse in severely calcified tibial vessels but could be improved by using the sharp Bv56 kernel (Bv36 vs. Bv56 p = 0.024). Diagnostic confidence was highest for Bv56. CONCLUSION In lower leg PCD-CTA, sharp convolution kernels increase diagnostic confidence compared to DSA by improved vessel delineation and reduced calcium blooming with acceptable image noise.
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Affiliation(s)
- Anne Marie Augustin
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany.
| | - Viktor Hartung
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Jan-Peter Grunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Jan-Lucca Hennes
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Henner Huflage
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Thorsten Alexander Bley
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Bernhard Petritsch
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Philipp Gruschwitz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
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25
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Neubauer J, Wilpert C, Gebler O, Taran FA, Pichotka M, Stein T, Molina-Fuentes MF, Weiss J, Juhasz-Böss I, Bamberg F, Windfuhr-Blum M, Neubauer C. Diagnostic Accuracy of Contrast-Enhanced Thoracic Photon-Counting Computed Tomography for Opportunistic Locoregional Staging of Breast Cancer Compared With Digital Mammography: A Prospective Trial. Invest Radiol 2024; 59:489-494. [PMID: 38038693 DOI: 10.1097/rli.0000000000001051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
OBJECTIVE Accurate locoregional staging is crucial for effective breast cancer treatment. Photon-counting computed tomography (PC-CT) is an emerging technology with high spatial resolution and the ability to depict uptake of contrast agents in tissues, making it a promising tool for breast cancer imaging. The aim of this study was to establish the feasibility of locoregional staging of breast cancer through contrast-enhanced thoracic PC-CT, assess its diagnostic performance, and compare it with that of digital mammography (DM). MATERIALS AND METHODS Patients with newly diagnosed breast cancer, DM, and indication of thoracic CT staging were prospectively enrolled in this clinical cohort study over a period of 6 months. Participants underwent contrast-enhanced thoracic PC-CT and breast magnetic resonance imaging in prone position. After blinding to patient data, 2 radiologists independently rated PC-CT and DM regarding the following 6 characteristics: (1) diameter of the largest mass lesion, (2) infiltration of cutis/pectoral muscle/thoracic wall, (3) number of mass lesions, (4) presence/absence of adjacent ductal carcinoma in situ (DCIS), (5) tumor conspicuity, and (6) diagnostic confidence. Reference standard was generated from consensus reading of magnetic resonance imaging combined with all histopathological/clinical data by an independent adjudication committee applying TNM eighth edition. RESULTS Among 32 enrolled female subjects (mean ± SD age, 59 ± 13.0 years), diagnostic accuracy for T-classification was higher for PC-CT compared with DM (0.94 vs 0.50, P < 0.01). Moreover, the correlation of the number of detected tumor masses with the reference standard was stronger for PC-CT than for DM (0.72 vs 0.50, P < 0.01). We observed that PC-CT significantly ( P < 0.04) outperformed DM regarding not only sensitivity (0.83 and 0.25, respectively) but also specificity (0.99 and 0.80, respectively) for adjacent DCIS. The κ values for interreader reliability were higher for PC-CT compared with DM (mean 0.88 vs 0.54, respectively; P = 0.01). CONCLUSIONS Photon-counting computed tomography outperformed DM in T-classification and provided higher diagnostic accuracy for the detection of adjacent DCIS. Therefore, opportunistic locoregional staging of breast cancer in contrast-enhanced thoracic PC-CT is feasible and could overcome limitations of DM with the potential to improve patient management.
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Affiliation(s)
- Jakob Neubauer
- From the Department of Diagnostic and Interventional Radiology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany (J.N., C.W., O.G., M.F.M.-F., J.W., F.B., M.W.-B., C.N.); Department of Gynecology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany (F.-A.T., I.J.-B.); and Department of Medical Physics, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany (M.P., T.S.)
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Black D, Singh T, Molloi S. Coronary artery calcium quantification technique using dual energy material decomposition: a simulation study. Int J Cardiovasc Imaging 2024; 40:1465-1474. [PMID: 38904849 PMCID: PMC11258084 DOI: 10.1007/s10554-024-03124-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 04/28/2024] [Indexed: 06/22/2024]
Abstract
Coronary artery calcification is a significant predictor of cardiovascular disease, with current detection methods like Agatston scoring having limitations in sensitivity. This study aimed to evaluate the effectiveness of a novel CAC quantification method using dual-energy material decomposition, particularly its ability to detect low-density calcium and microcalcifications. A simulation study was conducted comparing the dual-energy material decomposition technique against the established Agatston scoring method and the newer volume fraction calcium mass technique. Detection accuracy and calcium mass measurement were the primary evaluation metrics. The dual-energy material decomposition technique demonstrated fewer false negatives than both Agatston scoring and volume fraction calcium mass, indicating higher sensitivity. In low-density phantom measurements, material decomposition resulted in only 7.41% false-negative (CAC = 0) measurements compared to 83.95% for Agatston scoring. For high-density phantoms, false negatives were removed (0.0%) compared to 20.99% in Agatston scoring. The dual-energy material decomposition technique presents a more sensitive and reliable method for CAC quantification.
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Affiliation(s)
- Dale Black
- Department of Radiological Sciences, University of California, Medical Sciences I, B-140, Irvine, CA, 92697, USA
| | - Tejus Singh
- Department of Radiological Sciences, University of California, Medical Sciences I, B-140, Irvine, CA, 92697, USA
| | - Sabee Molloi
- Department of Radiological Sciences, University of California, Medical Sciences I, B-140, Irvine, CA, 92697, USA.
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27
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Fix Martinez M, Klein L, Maier J, Rotkopf LT, Schlemmer HP, Schönberg SO, Kachelrieß M, Sawall S. Potential radiation dose reduction in clinical photon-counting CT by the small pixel effect: ultra-high resolution (UHR) acquisitions reconstructed to standard resolution. Eur Radiol 2024; 34:4484-4491. [PMID: 38133673 PMCID: PMC11213748 DOI: 10.1007/s00330-023-10499-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/13/2023] [Accepted: 11/08/2023] [Indexed: 12/23/2023]
Abstract
OBJECTIVE To assess the potential dose reduction achievable with clinical photon-counting CT (PCCT) in ultra-high resolution (UHR) mode compared to acquisitions using the standard resolution detector mode (Std). MATERIALS AND METHODS With smaller detector pixels, PCCT achieves far higher spatial resolution than energy-integrating (EI) CT systems. The reconstruction of UHR acquisitions to the lower spatial resolution of conventional systems results in an image noise and radiation dose reduction. We quantify this small pixel effect in measurements of semi-anthropomorphic abdominal phantoms of different sizes as well as in a porcine knuckle in the first clinical PCCT system by using the UHR mode (0.2 mm pixel size at isocenter) in comparison to the standard resolution mode (0.4 mm). At different slice thicknesses (0.4 up to 4 mm) and dose levels between 4 and 12 mGy, reconstructions using filtered backprojection were performed to the same target spatial resolution, i.e., same modulation transfer function, using both detector modes. Image noise and the resulting potential dose reduction was quantified as a figure of merit. RESULTS Images acquired using the UHR mode yield lower noise in comparison to acquisitions using standard pixels at the same resolution and noise level. This holds for sharper convolution kernels at the spatial resolution limit of the standard mode, e.g., up to a factor 3.2 in noise reduction and a resulting potential dose reduction of up to almost 90%. CONCLUSION Using sharper convolution kernels, UHR acquisitions allow for a significant dose reduction compared to acquisitions using the standard detector mode. CLINICAL RELEVANCE Acquisitions should always be performed using the ultra-high resolution detector mode, if possible, to benefit from the intrinsic noise and dose reduction. KEY POINTS • Ionizing radiation used in computed tomography examinations is a concern to public health. • The ultra-high resolution of novel photon-counting systems can be invested towards a noise and dose reduction if only a spatial resolution below the resolution limit of the detector is desired. • Acquisitions should always be performed in ultra-high resolution mode, if possible, to benefit from an intrinsic dose reduction.
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Affiliation(s)
- Markel Fix Martinez
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Laura Klein
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Joscha Maier
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Lukas Thomas Rotkopf
- Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Heinz-Peter Schlemmer
- Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Stefan Oswald Schönberg
- Department of Clinical Radiology and Nuclear Medicine, University Hospital Mannheim, Theodor-Kurz-Ufer 1-3, 68167, Mannheim, Germany
| | - Marc Kachelrieß
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
- Medical Faculty, Heidelberg University, Im Neuenheimer Feld 672, 69120, Heidelberg, Germany
| | - Stefan Sawall
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.
- Medical Faculty, Heidelberg University, Im Neuenheimer Feld 672, 69120, Heidelberg, Germany.
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28
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Grunz JP, Huflage H. Photon-Counting Computed Tomography: Experience in Musculoskeletal Imaging. Korean J Radiol 2024; 25:662-672. [PMID: 38942460 PMCID: PMC11214923 DOI: 10.3348/kjr.2024.0096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 03/28/2024] [Accepted: 04/19/2024] [Indexed: 06/30/2024] Open
Abstract
Since the emergence of the first photon-counting computed tomography (PCCT) system in late 2021, its advantages and a wide range of applications in all fields of radiology have been demonstrated. Compared to standard energy-integrating detector-CT, PCCT allows for superior geometric dose efficiency in every examination. While this aspect by itself is groundbreaking, the advantages do not stop there. PCCT facilitates an unprecedented combination of ultra-high-resolution imaging without dose penalty or field-of-view restrictions, detector-based elimination of electronic noise, and ubiquitous multi-energy spectral information. Considering the high demands of orthopedic imaging for the visualization of minuscule details while simultaneously covering large portions of skeletal and soft tissue anatomy, no subspecialty may benefit more from this novel detector technology than musculoskeletal radiology. Deeply rooted in experimental and clinical research, this review article aims to provide an introduction to the cosmos of PCCT, explain its technical basics, and highlight the most promising applications for patient care, while also mentioning current limitations that need to be overcome.
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Affiliation(s)
- Jan-Peter Grunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany.
| | - Henner Huflage
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany
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29
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Zhou S, Liu P, Dong H, Li J, Xu Z, Schmidt B, Lin S, Yang W, Yan F, Qin L. Performance of calcium quantifications on low-dose photon-counting detector CT with high-pitch: A phantom study. Heliyon 2024; 10:e32819. [PMID: 38975110 PMCID: PMC11226852 DOI: 10.1016/j.heliyon.2024.e32819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 06/09/2024] [Accepted: 06/10/2024] [Indexed: 07/09/2024] Open
Abstract
Purpose To evaluate the performance of calcium quantification on photon-counting detector CT (PCD-CT) with high-pitch at low radiation doses compared to third-generation dual-source energy-integrating detector CT (EID-CT). Materials and methods The phantom with three calcium inserts (50, 100, and 300 mg of calcium per milliliter), with and without the elliptical outer layer, was evaluated using high-pitch (3.2) and standard pitch (0.8) on PCD-CT, and standard pitch on EID-CT. Scans were performed with different tube voltages (PCD-CT: 120 and 140 kilo-voltage peak [kVp]; EID-CT: 70/Sn150 and 100/Sn150 kVp) and four radiation doses (1, 3, 5, and, 10 milli-Gray [mGy]). Utilizing the true calcium concentrations (CCtrue) of the phantom as the gold standard references, regression equations for each kVp setting were formulated to convert CT attenuations (CaCT) into measured calcium concentrations (CCm). The correlation analysis between CaCT and CCtrue was performed. The percentage absolute bias (PAB) was calculated from the differences between CCm and CCtrue and used to analyze the effects of scanning parameters on calcium quantification accuracy. Results A strong correlation was found between CaCT and CCtrue on PCD-CT (r > 0.99) and EID-CT (r > 0.98). For high- and standard-pitch scans on PCD-CT, the accuracy of calcium quantification is comparable (p = 0.615): the median (interquartile range [IQR]) of PAB was 5.59% (2.79%-8.31%) and 4.87 % (2.62%-8.01%), respectively. The PAB median (IQR) was 7.43% (3.77%-11.75%) for EID-CT. The calcium quantification accuracy of PCD-CT is superior to EID-CT at the large phantom (5.46% [2.68%-9.55%] versus 9.01% [6.22%-12.74%]), and at the radiation dose of 1 mGy (4.43% [2.08%-8.59%] versus 13.89% [8.93%-23.09%]) and 3 mGy (4.61% [2.75%-6.51%] versus 9.97% [5.17%-14.41%]), all p < 0.001. Conclusions Calcium quantification using low-dose PCD-CT with high-pitch scanning is feasible and accurate, and superior to EID-CT.
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Affiliation(s)
- Shanshui Zhou
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai, 200025, China
- Faculty of Medical Imaging Technology, College of Health Science and Technology, Shanghai Jiao Tong University School of Medicine, No. 150 Ruijin Er Road, Shanghai, 200025, China
| | - Peng Liu
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai, 200025, China
| | - Haipeng Dong
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai, 200025, China
| | - Jiqiang Li
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai, 200025, China
| | - Zhihan Xu
- Siemens Healthineers, 399 West Haiyang Road, Shanghai, 200126, China
| | - Bernhard Schmidt
- Siemens Healthineers, Siemensstrasse 3, 91301 Forchheim, Erlangen, Germany
| | - Shushen Lin
- Siemens Healthineers, 399 West Haiyang Road, Shanghai, 200126, China
| | - Wenjie Yang
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai, 200025, China
| | - Fuhua Yan
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai, 200025, China
- Faculty of Medical Imaging Technology, College of Health Science and Technology, Shanghai Jiao Tong University School of Medicine, No. 150 Ruijin Er Road, Shanghai, 200025, China
| | - Le Qin
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai, 200025, China
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Dirrichs T, Schröder J, Frick M, Huppertz M, Iwa R, Allmendinger T, Mecking I, Kuhl CK. Photon-Counting Versus Dual-Source CT for Transcatheter Aortic Valve Implantation Planning. Acad Radiol 2024:S1076-6332(24)00372-6. [PMID: 38906782 DOI: 10.1016/j.acra.2024.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 06/07/2024] [Accepted: 06/07/2024] [Indexed: 06/23/2024]
Abstract
BACKGROUND Cardiovascular CT is required for planning transcatheter aortic valve implantation (TAVI). PURPOSE To compare image quality, suitability for TAVI planning, and radiation dose of photon-counting CT (PCCT) with that of dual-source CT (DSCT). MATERIAL AND METHODS Retrospective study on consecutive TAVI candidates with aortic valve stenosis who underwent contrast-enhanced aorto-ilio-femoral PCCT and/or DSCT between 01/2022 and 07/2023. Signal-to-noise (SNR) and contrast-to-noise ratio (CNR) were calculated by standardized ROI analysis. Image quality and suitability for TAVI planning were assessed by four independent expert readers (two cardiac radiologists, two cardiologists) on a 5-point-scale. CT dose index (CTDI) and dose-length-product (DLP) were used to calculate effective radiation dose (eRD). RESULTS 300 patients (136 female, median age: 81 years, IQR: 76-84) underwent 302 CT examinations, with PCCT in 202, DSCT in 100; two patients underwent both. Although SNR and CNR were significantly lower in PCCT vs. DSCT images (33.0 ± 10.5 vs. 47.3 ± 16.4 and 47.3 ± 14.8 vs. 59.3 ± 21.9, P < .001, respectively), visual image quality was higher in PCCT vs. DSCT (4.8 vs. 3.3, P < .001), with moderate overall interreader agreement among radiologists and among cardiologists (κ = 0.60, respectively). Image quality was rated as "excellent" in 160/202 (79.2%) of PCCT vs. 5/100 (5%) of DSCT cases. Readers found images suitable to depict the aortic valve hinge points and to map the femoral access path in 99% of PCCT vs. 85% of DSCT (P < 0.01), with suitability ranked significantly higher in PCCT vs. DSCT (4.8 vs. 3.3, P < .001). Mean CTDI and DLP, and thus eRD, were significantly lower for PCCT vs. DSCT (22.4 vs. 62.9; 519.4 vs. 895.5, and 8.8 ± 4.5 mSv vs. 15.3 ± 5.8 mSv; all P < .001). CONCLUSION PCCT improves image quality, effectively avoids non-diagnostic CT imaging for TAVI planning, and is associated with a lower radiation dose compared to state-of-the-art DSCT. Radiologists and cardiologists found PCCT images more suitable for TAVI planning.
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Affiliation(s)
- Timm Dirrichs
- Department of Diagnostic and Interventional Radiology, University Hospital RWTH Aachen, Pauwelsstraße 30, Aachen 52074, Germany.
| | - Jörg Schröder
- Department of Cardiology, Angiology and Internal Intensive Care, University Hospital RWTH Aachen, Pauwelsstraße 30, Aachen 52074, Germany
| | - Michael Frick
- Department of Cardiology, Angiology and Internal Intensive Care, University Hospital RWTH Aachen, Pauwelsstraße 30, Aachen 52074, Germany
| | - Marc Huppertz
- Department of Diagnostic and Interventional Radiology, University Hospital RWTH Aachen, Pauwelsstraße 30, Aachen 52074, Germany
| | - Roman Iwa
- Department of Diagnostic and Interventional Radiology, University Hospital RWTH Aachen, Pauwelsstraße 30, Aachen 52074, Germany
| | | | - Ines Mecking
- Department of Diagnostic and Interventional Radiology, University Hospital RWTH Aachen, Pauwelsstraße 30, Aachen 52074, Germany
| | - Christiane K Kuhl
- Department of Diagnostic and Interventional Radiology, University Hospital RWTH Aachen, Pauwelsstraße 30, Aachen 52074, Germany
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Onishi H, Tsuboyama T, Nakamoto A, Ota T, Fukui H, Tatsumi M, Honda T, Kiso K, Matsumoto S, Kaketaka K, Enchi Y, Kawabata S, Nakasone S, Tomiyama N. Photon-counting CT: technical features and clinical impact on abdominal imaging. Abdom Radiol (NY) 2024:10.1007/s00261-024-04414-5. [PMID: 38888738 DOI: 10.1007/s00261-024-04414-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 05/25/2024] [Accepted: 05/27/2024] [Indexed: 06/20/2024]
Abstract
Photon-counting CT has a completely different detector mechanism than conventional energy-integrating CT. In the photon-counting detector, X-rays are directly converted into electrons and received as electrical signals. Photon-counting CT provides virtual monochromatic images with a high contrast-to-noise ratio for abdominal CT imaging and may improve the ability to visualize small or low-contrast lesions. In addition, photon-counting CT may offer the possibility of reducing radiation dose. This review provides an overview of the actual clinical operation of photon-counting CT and its diagnostic utility in abdominal imaging. We also describe the clinical implications of photon-counting CT including imaging of hepatocellular carcinoma, liver metastases, hepatic steatosis, pancreatic cancer, intraductal mucinous neoplasm of the pancreas, and thrombus.
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Affiliation(s)
- Hiromitsu Onishi
- Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan.
- Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, Suita, Japan.
| | - Takahiro Tsuboyama
- Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Atsushi Nakamoto
- Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Takashi Ota
- Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Hideyuki Fukui
- Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Mitsuaki Tatsumi
- Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Toru Honda
- Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Kengo Kiso
- Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Shohei Matsumoto
- Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Koki Kaketaka
- Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Yukihiro Enchi
- Division of Radiology, Department of Medical Technology, Osaka University Hospital, Suita, Japan
| | - Shuichi Kawabata
- Division of Radiology, Department of Medical Technology, Osaka University Hospital, Suita, Japan
| | - Shinya Nakasone
- Division of Radiology, Department of Medical Technology, Osaka University Hospital, Suita, Japan
| | - Noriyuki Tomiyama
- Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan
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Tore D, Faletti R, Palmisano A, Salto S, Rocco K, Santonocito A, Gaetani C, Biondo A, Bozzo E, Giorgino F, Landolfi I, Menchini F, Esposito A, Fonio P, Gatti M. Cardiac computed tomography with late contrast enhancement: A review. Heliyon 2024; 10:e32436. [PMID: 38933964 PMCID: PMC11200357 DOI: 10.1016/j.heliyon.2024.e32436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 05/19/2024] [Accepted: 06/04/2024] [Indexed: 06/28/2024] Open
Abstract
Cardiac computed tomography (CCT) has assumed an increasingly significant role in the evaluation of coronary artery disease (CAD) during the past few decades, whereas cardiovascular magnetic resonance (CMR) remains the gold standard for myocardial tissue characterization. The discovery of late myocardial enhancement following intravenous contrast administration dates back to the 1970s with ex-vivo CT animal investigations; nevertheless, the clinical application of this phenomenon for cardiac tissue characterization became prevalent for CMR imaging far earlier than for CCT imaging. Recently the technical advances in CT scanners have made it possible to take advantage of late contrast enhancement (LCE) for tissue characterization in CCT exams. Moreover, the introduction of extracellular volume calculation (ECV) on cardiac CT images combined with the possibility of evaluating cardiac function in the same exam is making CCT imaging a multiparametric technique more and more similar to CMR. The aim of our review is to provide a comprehensive overview on the role of CCT with LCE in the evaluation of a wide range of cardiac conditions.
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Affiliation(s)
- Davide Tore
- Radiology Unit, Department of Surgical Sciences, AOU Città Della Salute e Della Scienza di Torino, University of Turin, Turin, Italy
| | - Riccardo Faletti
- Radiology Unit, Department of Surgical Sciences, AOU Città Della Salute e Della Scienza di Torino, University of Turin, Turin, Italy
| | - Anna Palmisano
- Clinical and Experimental Radiology Unit, Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Sara Salto
- Radiology Unit, Department of Surgical Sciences, AOU Città Della Salute e Della Scienza di Torino, University of Turin, Turin, Italy
| | - Katia Rocco
- Radiology Unit, Department of Surgical Sciences, AOU Città Della Salute e Della Scienza di Torino, University of Turin, Turin, Italy
| | - Ambra Santonocito
- Radiology Unit, Department of Surgical Sciences, AOU Città Della Salute e Della Scienza di Torino, University of Turin, Turin, Italy
| | - Clara Gaetani
- Radiology Unit, Department of Surgical Sciences, AOU Città Della Salute e Della Scienza di Torino, University of Turin, Turin, Italy
| | - Andrea Biondo
- Radiology Unit, Department of Surgical Sciences, AOU Città Della Salute e Della Scienza di Torino, University of Turin, Turin, Italy
| | - Elena Bozzo
- Radiology Unit, Department of Surgical Sciences, AOU Città Della Salute e Della Scienza di Torino, University of Turin, Turin, Italy
| | - Fabio Giorgino
- Radiology Unit, Department of Surgical Sciences, AOU Città Della Salute e Della Scienza di Torino, University of Turin, Turin, Italy
| | - Ilenia Landolfi
- Radiology Unit, Department of Surgical Sciences, AOU Città Della Salute e Della Scienza di Torino, University of Turin, Turin, Italy
| | - Francesca Menchini
- Radiology Unit, Department of Surgical Sciences, AOU Città Della Salute e Della Scienza di Torino, University of Turin, Turin, Italy
| | - Antonio Esposito
- Clinical and Experimental Radiology Unit, Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Paolo Fonio
- Radiology Unit, Department of Surgical Sciences, AOU Città Della Salute e Della Scienza di Torino, University of Turin, Turin, Italy
| | - Marco Gatti
- Radiology Unit, Department of Surgical Sciences, AOU Città Della Salute e Della Scienza di Torino, University of Turin, Turin, Italy
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Stański M, Michałowska I, Lemanowicz A, Karmelita-Katulska K, Ratajczak P, Sławińska A, Serafin Z. Dual-Energy and Photon-Counting Computed Tomography in Vascular Applications-Technical Background and Post-Processing Techniques. Diagnostics (Basel) 2024; 14:1223. [PMID: 38928639 PMCID: PMC11202784 DOI: 10.3390/diagnostics14121223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 05/30/2024] [Accepted: 06/06/2024] [Indexed: 06/28/2024] Open
Abstract
The field of computed tomography (CT), which is a basic diagnostic tool in clinical practice, has recently undergone rapid technological advances. These include the evolution of dual-energy CT (DECT) and development of photon-counting computed tomography (PCCT). DECT enables the acquisition of CT images at two different energy spectra, which allows for the differentiation of certain materials, mainly calcium and iodine. PCCT is a recent technology that enables a scanner to quantify the energy of each photon gathered by the detector. This method gives the possibility to decrease the radiation dose and increase the spatial and temporal resolutions of scans. Both of these techniques have found a wide range of applications in radiology, including vascular studies. In this narrative review, the authors present the principles of DECT and PCCT, outline their advantages and drawbacks, and briefly discuss the application of these methods in vascular radiology.
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Affiliation(s)
- Marcin Stański
- Department of General Radiology and Neuroradiology, Poznan University of Medical Sciences, 61-701 Poznań, Poland;
| | - Ilona Michałowska
- Department of Radiology, National Institute of Cardiology, 04-628 Warsaw, Poland;
| | - Adam Lemanowicz
- Department of Radiology and Diagnostic Imaging, Nicolaus Copernicus University, Collegium Medicum, 85-067 Bydgoszcz, Poland; (A.L.); (P.R.); (A.S.); (Z.S.)
| | - Katarzyna Karmelita-Katulska
- Department of General Radiology and Neuroradiology, Poznan University of Medical Sciences, 61-701 Poznań, Poland;
| | - Przemysław Ratajczak
- Department of Radiology and Diagnostic Imaging, Nicolaus Copernicus University, Collegium Medicum, 85-067 Bydgoszcz, Poland; (A.L.); (P.R.); (A.S.); (Z.S.)
| | - Agata Sławińska
- Department of Radiology and Diagnostic Imaging, Nicolaus Copernicus University, Collegium Medicum, 85-067 Bydgoszcz, Poland; (A.L.); (P.R.); (A.S.); (Z.S.)
| | - Zbigniew Serafin
- Department of Radiology and Diagnostic Imaging, Nicolaus Copernicus University, Collegium Medicum, 85-067 Bydgoszcz, Poland; (A.L.); (P.R.); (A.S.); (Z.S.)
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Vellala A, Mogler C, Haag F, Tollens F, Rudolf H, Pietsch F, Wängler C, Wängler B, Schoenberg SO, Froelich MF, Hertel A. Comparing quantitative image parameters between animal and clinical CT-scanners: a translational phantom study analysis. Front Med (Lausanne) 2024; 11:1407235. [PMID: 38903806 PMCID: PMC11188677 DOI: 10.3389/fmed.2024.1407235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 05/27/2024] [Indexed: 06/22/2024] Open
Abstract
Purpose This study compares phantom-based variability of extracted radiomics features from scans on a photon counting CT (PCCT) and an experimental animal PET/CT-scanner (Albira II) to investigate the potential of radiomics for translation from animal models to human scans. While oncological basic research in animal PET/CT has allowed an intrinsic comparison between PET and CT, but no 1:1 translation to a human CT scanner due to resolution and noise limitations, Radiomics as a statistical and thus scale-independent method can potentially close the critical gap. Methods Two phantoms were scanned on a PCCT and animal PET/CT-scanner with different scan parameters and then the radiomics parameters were extracted. A Principal Component Analysis (PCA) was conducted. To overcome the limitation of a small dataset, a data augmentation technique was applied. A Ridge Classifier was trained and a Feature Importance- and Cluster analysis was performed. Results PCA and Cluster Analysis shows a clear differentiation between phantom types while emphasizing the comparability of both scanners. The Ridge Classifier exhibited a strong training performance with 93% accuracy, but faced challenges in generalization with a test accuracy of 62%. Conclusion These results show that radiomics has great potential as a translational tool between animal models and human routine diagnostics, especially using the novel photon counting technique. This is another crucial step towards integration of radiomics analysis into clinical practice.
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Affiliation(s)
- Abhinay Vellala
- Department of Radiology and Nuclear medicine, University Medical Centre Mannheim, University of Heidelberg, Mannheim, Germany
| | - Carolin Mogler
- Department of Pathology, Technical University of Munich, Munich, Germany
| | - Florian Haag
- Department of Radiology and Nuclear medicine, University Medical Centre Mannheim, University of Heidelberg, Mannheim, Germany
| | - Fabian Tollens
- Department of Radiology and Nuclear medicine, University Medical Centre Mannheim, University of Heidelberg, Mannheim, Germany
| | - Henning Rudolf
- Department of Radiology and Nuclear medicine, University Medical Centre Mannheim, University of Heidelberg, Mannheim, Germany
| | - Friedrich Pietsch
- Department of Radiology and Nuclear medicine, University Medical Centre Mannheim, University of Heidelberg, Mannheim, Germany
| | - Carmen Wängler
- Department of Radiology and Nuclear medicine, University Medical Centre Mannheim, University of Heidelberg, Mannheim, Germany
| | - Björn Wängler
- Department of Radiology and Nuclear medicine, University Medical Centre Mannheim, University of Heidelberg, Mannheim, Germany
| | - Stefan O. Schoenberg
- Department of Radiology and Nuclear medicine, University Medical Centre Mannheim, University of Heidelberg, Mannheim, Germany
| | - Matthias F. Froelich
- Department of Radiology and Nuclear medicine, University Medical Centre Mannheim, University of Heidelberg, Mannheim, Germany
| | - Alexander Hertel
- Department of Radiology and Nuclear medicine, University Medical Centre Mannheim, University of Heidelberg, Mannheim, Germany
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Liu LP, Pasyar P, Liu F, Cao Q, Sandvold OF, Sahbaee P, Shinohara RT, Litt HI, Noël PB. Assessing the Stability of Photon-Counting CT: Insights from a Two-Year Longitudinal Study. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.06.05.24308046. [PMID: 38883741 PMCID: PMC11177916 DOI: 10.1101/2024.06.05.24308046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
Background Among the advancements in computed tomography (CT) technology, photon-counting computed tomography (PCCT) stands out as a significant innovation, providing superior spectral imaging capabilities while simultaneously reducing radiation exposure. Its long-term stability is important for clinical care, especially longitudinal studies, but is currently unknown. Purpose This study sets out to comprehensively analyze the long-term stability of a first-generation clinical PCCT scanner. Materials and Methods Over a two-year period, from November 2021 to November 2023, we conducted weekly identical experiments utilizing the same multi-energy CT protocol. These experiments included various tissue-mimicking inserts to rigorously assess the stability of Hounsfield Units (HU) and image noise in Virtual Monochromatic Images (VMIs) and iodine density maps. Throughout this period, notable software and hardware modifications were meticulously recorded. Each week, VMIs and iodine density maps were reconstructed and analyzed to evaluate quantitative stability over time. Results Spectral results consistently demonstrated the quantitative stability of PCCT. VMIs exhibited stable HU values, such as variation in relative error for VMI 70 keV measuring 0.11% and 0.30% for single-source and dual-source modes, respectively. Similarly, noise levels remained stable with slight fluctuations linked to software changes for VMI 40 and 70 keV that corresponded to changes of 8 and 1 HU, respectively. Furthermore, iodine density quantification maintained stability and showed significant improvement with software and hardware changes, especially in dual-source mode with nominal errors decreasing from 1.44 to 0.03 mg/mL. Conclusion This study provides the first long-term reproducibility assessment of quantitative PCCT imaging, highlighting its potential for the clinical arena. This study indicates its long-term utility in diagnostic radiology, especially for longitudinal studies.
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Nieman K, García-García HM, Hideo-Kajita A, Collet C, Dey D, Pugliese F, Weissman G, Tijssen JGP, Leipsic J, Opolski MP, Ferencik M, Lu MT, Williams MC, Bruining N, Blanco PJ, Maurovich-Horvat P, Achenbach S. Standards for quantitative assessments by coronary computed tomography angiography (CCTA): An expert consensus document of the society of cardiovascular computed tomography (SCCT). J Cardiovasc Comput Tomogr 2024:S1934-5925(24)00341-1. [PMID: 38849237 DOI: 10.1016/j.jcct.2024.05.232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/18/2024] [Accepted: 05/23/2024] [Indexed: 06/09/2024]
Abstract
In current clinical practice, qualitative or semi-quantitative measures are primarily used to report coronary artery disease on cardiac CT. With advancements in cardiac CT technology and automated post-processing tools, quantitative measures of coronary disease severity have become more broadly available. Quantitative coronary CT angiography has great potential value for clinical management of patients, but also for research. This document aims to provide definitions and standards for the performance and reporting of quantitative measures of coronary artery disease by cardiac CT.
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Affiliation(s)
- Koen Nieman
- Stanford University School of Medicine and Cardiovascular Institute, Stanford, CA, United States.
| | - Hector M García-García
- Section of Interventional Cardiology, MedStar Washington Hospital Center, Washington, DC, United States.
| | | | - Carlos Collet
- Onze Lieve Vrouwziekenhuis, Cardiovascular Center Aalst, Aalst, Belgium
| | - Damini Dey
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Francesca Pugliese
- NIHR Cardiovascular Biomedical Research Unit at Barts, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London & Department of Cardiology, Barts Health NHS Trust, London, UK
| | - Gaby Weissman
- Section of Interventional Cardiology, MedStar Washington Hospital Center, Washington, DC, United States
| | - Jan G P Tijssen
- Department of Cardiology, Academic Medical Center, Room G4-230, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands
| | - Jonathon Leipsic
- Department of Radiology and Medicine (Cardiology), University of British Columbia, Vancouver, BC, Canada
| | - Maksymilian P Opolski
- Department of Interventional Cardiology and Angiology, National Institute of Cardiology, Warsaw, Poland
| | - Maros Ferencik
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, United States
| | - Michael T Lu
- Cardiovascular Imaging Research Center, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States
| | - Michelle C Williams
- BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Nico Bruining
- Department of Cardiology, Erasmus University Medical Center, Rotterdam, the Netherlands
| | | | - Pal Maurovich-Horvat
- MTA-SE Cardiovascular Imaging Research Group, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
| | - Stephan Achenbach
- Department of Cardiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
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Quintiens J, van Lenthe GH. Photon-Counting Computed Tomography for Microstructural Imaging of Bone and Joints. Curr Osteoporos Rep 2024:10.1007/s11914-024-00876-0. [PMID: 38833188 DOI: 10.1007/s11914-024-00876-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/29/2024] [Indexed: 06/06/2024]
Abstract
PURPOSE OF REVIEW Recently, photon-counting computed tomography (PCCT) has been introduced in clinical research and diagnostics. This review describes the technological advances and provides an overview of recent applications with a focus on imaging of bone. RECENT FINDINGS PCCT is a full-body scanner with short scanning times that provides better spatial and spectral resolution than conventional energy-integrating-detector CT (EID-CT), along with an up to 50% reduced radiation dose. It can be used to quantify bone mineral density, to perform bone microstructural analyses and to assess cartilage quality with adequate precision and accuracy. Using a virtual monoenergetic image reconstruction, metal artefacts can be greatly reduced when imaging bone-implant interfaces. Current PCCT systems do not allow spectral imaging in ultra-high-resolution (UHR) mode. Given its improved resolution, reduced noise and spectral imaging capabilities PCCT has diagnostic capacities in both qualitative and quantitative imaging that outperform those of conventional CT. Clinical use in monitoring bone health has already been demonstrated. The full potential of PCCT systems will be unlocked when UHR spectral imaging becomes available.
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Affiliation(s)
- Jilmen Quintiens
- Department of Mechanical Engineering, KU Leuven, Leuven, Belgium
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Rajagopal JR, Farhadi F, Solomon J, Saboury B, Sahbaee P, Negussie AH, Pritchard WF, Jones EC, Samei E. Development of a separability index for task specific characterization of spectral computed tomography. Phys Med 2024; 122:103382. [PMID: 38820805 PMCID: PMC11185224 DOI: 10.1016/j.ejmp.2024.103382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 01/26/2024] [Accepted: 05/21/2024] [Indexed: 06/02/2024] Open
Abstract
PURPOSE In this work, we define a signal detection based metrology to characterize the separability of two different multi-dimensional signals in spectral CT acquisitions. METHOD Signal response was modelled as a random process with a deterministic signal and stochastic noise component. A linear Hotelling observer was used to estimate a scalar test statistic distribution that predicts the likelihood of an intensity value belonging to a signal. Two distributions were estimated for two materials of interest and used to derive two metrics separability: a separability index (s') and the area under the curve of the test statistic distributions. Experimental and simulated data of photon-counting CT scanners were used to evaluate each metric. Experimentally, vials of iodine and gadolinium (2, 4, 8 mg/mL) were scanned at multiple tube voltages, tube currents and energy thresholds. Additionally, a simulated dataset with low tube current (10-150 mAs) and material concentrations (0.25-4 mg/mL) was generated. RESULTS Experimental data showed that conditions favorable for low noise and expression of k-edge signal produced the highest separability. Material concentration had the greatest impact on separability. The simulated data showed that under more difficult separation conditions, difference in material concentration still had the greatest impact on separability. CONCLUSION The results demonstrate the utility of a task specific metrology to measure the overlap in signal between different materials in spectral CT. Using experimental and simulated data, the separability index was shown to describe the relationship between image formation factors and the signal responses of material.
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Affiliation(s)
- Jayasai R Rajagopal
- Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC 27705, United States; Medical Physics Graduate Program, Duke University Medical Center, Durham, NC 27705, United States; Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD 20892, United States.
| | - Faraz Farhadi
- Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD 20892, United States; Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, United States
| | - Justin Solomon
- Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC 27705, United States; Medical Physics Graduate Program, Duke University Medical Center, Durham, NC 27705, United States; Clinical Imaging Physics Group, Duke University Medical Center, Durham, NC 27705, United States
| | - Babak Saboury
- Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD 20892, United States
| | - Pooyan Sahbaee
- Siemens Medical Solutions USA, Malvern, PA 19335, United States
| | - Ayele H Negussie
- Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD 20892, United States
| | - William F Pritchard
- Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD 20892, United States
| | - Elizabeth C Jones
- Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD 20892, United States
| | - Ehsan Samei
- Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC 27705, United States; Medical Physics Graduate Program, Duke University Medical Center, Durham, NC 27705, United States; Clinical Imaging Physics Group, Duke University Medical Center, Durham, NC 27705, United States.
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Skornitzke S, Mergen V, Biederer J, Alkadhi H, Do TD, Stiller W, Frauenfelder T, Kauczor HU, Euler A. Metal Artifact Reduction in Photon-Counting Detector CT: Quantitative Evaluation of Artifact Reduction Techniques. Invest Radiol 2024; 59:442-449. [PMID: 37812482 DOI: 10.1097/rli.0000000000001036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
OBJECTIVES With the introduction of clinical photon-counting detector computed tomography (PCD-CT) and its novel reconstruction techniques, a quantitative investigation of different acquisition and reconstruction settings is necessary to optimize clinical acquisition protocols for metal artifact reduction. MATERIALS AND METHODS A multienergy phantom was scanned on a clinical dual-source PCD-CT (NAEOTOM Alpha; Siemens Healthcare GmbH) with 4 different central inserts: water-equivalent plastic, aluminum, steel, and titanium. Acquisitions were performed at 120 kVp and 140 kVp (CTDI vol 10 mGy) and reconstructed as virtual monoenergetic images (VMIs; 110-150 keV), as T3D, and with the standard reconstruction "none" (70 keV VMI) using different reconstruction kernels (Br36, Br56) and with as well as without iterative metal artifact reduction (iMAR). Metal artifacts were quantified, calculating relative percentages of metal artifacts. Mean CT numbers of an adjacent water-equivalent insert and different tissue-equivalent inserts were evaluated, and eccentricity of metal rods was measured. Repeated-measures analysis of variance was performed for statistical analysis. RESULTS Metal artifacts were most prevalent for the steel insert (12.6% average artifacts), followed by titanium (4.2%) and aluminum (1.0%). The strongest metal artifact reduction was noted for iMAR (with iMAR: 1.4%, without iMAR: 10.5%; P < 0.001) or VMI (VMI: 110 keV 2.6% to 150 keV 3.3%, T3D: 11.0%, and none: 16.0%; P < 0.001) individually, with best results when combining iMAR and VMI at 110 keV (1.2%). Changing acquisition tube potential (120 kV: 6.6%, 140 kV: 5.2%; P = 0.33) or reconstruction kernel (Br36: 5.5%, Br56: 6.4%; P = 0.17) was less effective. Mean CT numbers and standard deviations were significantly affected by iMAR (with iMAR: -3.0 ± 21.5 HU, without iMAR: -8.5 ± 24.3 HU; P < 0.001), VMI (VMI: 110 keV -3.6 ± 21.6 HU to 150 keV -1.4 ± 21.2 HU, T3D: -11.7 ± 23.8 HU, and none: -16.9 ± 29.8 HU; P < 0.001), tube potential (120 kV: -4.7 ± 22.8 HU, 140 kV: -6.8 ± 23.0 HU; P = 0.03), and reconstruction kernel (Br36: -5.5 ± 14.2 HU, Br56: -6.8 ± 23.0 HU; P < 0.001). Both iMAR and VMI improved quantitative CT number accuracy and metal rod eccentricity for the steel rod, but iMAR was of limited effectiveness for the aluminum rod. CONCLUSIONS For metal artifact reduction in PCD-CT, a combination of iMAR and VMI at 110 keV demonstrated the strongest artifact reduction of the evaluated options, whereas the impact of reconstruction kernel and tube potential was limited.
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Affiliation(s)
- Stephan Skornitzke
- From the Heidelberg University Hospital, Clinic for Diagnostic and Interventional Radiology, Heidelberg, Germany (S.S., J.B., T.D.D., W.S., and H.-U.K.); Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland (V.M., H.A., T.F., and A.E.); Translational Lung Research Center Heidelberg, Member of the German Lung Research Center, Heidelberg, Germany (J.B., W.S., H.-U.K.); University of Latvia, Faculty of Medicine, Riga, Latvia (J.B.); Christian-Albrechts-Universität zu Kiel, Faculty of Medicine, Kiel, Germany (J.B.); and Kantonsspital Baden, Radiologie Baden, Baden, Switzerland (A.E.)
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de Jong CMM, Kroft LJM, van Mens TE, Huisman MV, Stöger JL, Klok FA. Modern imaging of acute pulmonary embolism. Thromb Res 2024; 238:105-116. [PMID: 38703584 DOI: 10.1016/j.thromres.2024.04.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 03/16/2024] [Accepted: 04/15/2024] [Indexed: 05/06/2024]
Abstract
The first-choice imaging test for visualization of thromboemboli in the pulmonary vasculature in patients with suspected acute pulmonary embolism (PE) is multidetector computed tomography pulmonary angiography (CTPA) - a readily available and widely used imaging technique. Through technological advancements over the past years, alternative imaging techniques for the diagnosis of PE have become available, whilst others are still under investigation. In particular, the evolution of artificial intelligence (AI) is expected to enable further innovation in diagnostic management of PE. In this narrative review, current CTPA techniques and the emerging technology photon-counting CT (PCCT), as well as other modern imaging techniques of acute PE are discussed, including CTPA with iodine maps based on subtraction or dual-energy acquisition, single-photon emission CT (SPECT), magnetic resonance angiography (MRA), and magnetic resonance direct thrombus imaging (MRDTI). Furthermore, potential applications of AI are discussed.
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Affiliation(s)
- C M M de Jong
- Department of Medicine - Thrombosis and Hemostasis, Leiden University Medical Center, Leiden, the Netherlands
| | - L J M Kroft
- Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - T E van Mens
- Department of Medicine - Thrombosis and Hemostasis, Leiden University Medical Center, Leiden, the Netherlands
| | - M V Huisman
- Department of Medicine - Thrombosis and Hemostasis, Leiden University Medical Center, Leiden, the Netherlands
| | - J L Stöger
- Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - F A Klok
- Department of Medicine - Thrombosis and Hemostasis, Leiden University Medical Center, Leiden, the Netherlands.
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Holmes TW, Yin Z, Bujila R, Madhav P, Kim C, Maltz JS, Pourmorteza A. Ultrahigh-Resolution K-Edge Imaging of Coronary Arteries With Prototype Deep-Silicon Photon-Counting CT: Initial Results in Phantoms. Radiology 2024; 311:e231598. [PMID: 38916502 DOI: 10.1148/radiol.231598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Background Photon-counting CT (PCCT) represents a recent advancement in CT, offering improved spatial resolution and spectral separability. By using multiple adjustable energy bins, PCCT enables K-edge imaging, allowing mixed contrast agent distinction. Deep-silicon is a new type of photon-counting detector with different characteristics compared with cadmium photon-counting detectors. Purpose To evaluate the performance of a prototype deep-Si PCCT scanner and compare it with that of a state-of-the-art dual-energy energy-integrating detector (EID) scanner in imaging coronary artery plaques enhanced with iodine and K-edge contrast agents. Materials and Methods A series of 10 three-dimensional-printed inserts (diameter, 3.5 mm) was prepared, and materials mimicking soft and calcified plaques were added to simulate stenosed coronary arteries. Inserts filled with an iodine- or gadolinium-based contrast agent (GBCA) were scanned. Virtual monoenergetic images (VMIs) and iodine maps were generated using two- and eight-energy bin data from EID CT and PCCT, respectively. Gadolinium maps were calculated for PCCT. The CT numbers of VMIs and iodine maps were compared. Spatial resolution and blooming artifacts were compared on the 70-keV VMIs in plaque-free and calcified coronary arteries. Results No evidence of a significant difference in the CT number of 70-keV images was found except in inserts containing GBCAs. In the absence of a GBCA, excellent (r > 0.99) agreement for iodine was found. PCCT could quantify the GBCA within 0.2 mg Gd/mL ± 0.8 accuracy of the ground truth, whereas EID CT failed to detect the GBCA. Lumen measurements were more accurate for PCCT than for EID CT, with mean errors of 167 versus 442 µm (P < .001) compared with the 3.5-mm ground truth. Conclusion Deep-Si PCCT demonstrated good accuracy in iodine quantification and could accurately decompose mixtures of two contrast agents. Its improved spatial resolution resulted in sharper images with blooming artifacts reduced by 50% compared with a state-of-the-art dual-energy EID CT scanner. © RSNA, 2024.
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Affiliation(s)
- Thomas Wesley Holmes
- From the Department of Radiology and Imaging Sciences (T.W.H., A.P.) and Winship Cancer Institute (A.P.), Emory University, 1701 Uppergate Dr, Ste 5018A, Atlanta, GA 30322; GE HealthCare, Waukesha, Wis (Z.Y., R.B., P.M., C.K., J.S.M.); and Department of Biomedical Engineering, Emory University-Georgia Institute of Technology, Atlanta, Ga (A.P.)
| | - Zhye Yin
- From the Department of Radiology and Imaging Sciences (T.W.H., A.P.) and Winship Cancer Institute (A.P.), Emory University, 1701 Uppergate Dr, Ste 5018A, Atlanta, GA 30322; GE HealthCare, Waukesha, Wis (Z.Y., R.B., P.M., C.K., J.S.M.); and Department of Biomedical Engineering, Emory University-Georgia Institute of Technology, Atlanta, Ga (A.P.)
| | - Robert Bujila
- From the Department of Radiology and Imaging Sciences (T.W.H., A.P.) and Winship Cancer Institute (A.P.), Emory University, 1701 Uppergate Dr, Ste 5018A, Atlanta, GA 30322; GE HealthCare, Waukesha, Wis (Z.Y., R.B., P.M., C.K., J.S.M.); and Department of Biomedical Engineering, Emory University-Georgia Institute of Technology, Atlanta, Ga (A.P.)
| | - Priti Madhav
- From the Department of Radiology and Imaging Sciences (T.W.H., A.P.) and Winship Cancer Institute (A.P.), Emory University, 1701 Uppergate Dr, Ste 5018A, Atlanta, GA 30322; GE HealthCare, Waukesha, Wis (Z.Y., R.B., P.M., C.K., J.S.M.); and Department of Biomedical Engineering, Emory University-Georgia Institute of Technology, Atlanta, Ga (A.P.)
| | - Changlyong Kim
- From the Department of Radiology and Imaging Sciences (T.W.H., A.P.) and Winship Cancer Institute (A.P.), Emory University, 1701 Uppergate Dr, Ste 5018A, Atlanta, GA 30322; GE HealthCare, Waukesha, Wis (Z.Y., R.B., P.M., C.K., J.S.M.); and Department of Biomedical Engineering, Emory University-Georgia Institute of Technology, Atlanta, Ga (A.P.)
| | - Jonathan S Maltz
- From the Department of Radiology and Imaging Sciences (T.W.H., A.P.) and Winship Cancer Institute (A.P.), Emory University, 1701 Uppergate Dr, Ste 5018A, Atlanta, GA 30322; GE HealthCare, Waukesha, Wis (Z.Y., R.B., P.M., C.K., J.S.M.); and Department of Biomedical Engineering, Emory University-Georgia Institute of Technology, Atlanta, Ga (A.P.)
| | - Amir Pourmorteza
- From the Department of Radiology and Imaging Sciences (T.W.H., A.P.) and Winship Cancer Institute (A.P.), Emory University, 1701 Uppergate Dr, Ste 5018A, Atlanta, GA 30322; GE HealthCare, Waukesha, Wis (Z.Y., R.B., P.M., C.K., J.S.M.); and Department of Biomedical Engineering, Emory University-Georgia Institute of Technology, Atlanta, Ga (A.P.)
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Pallasch FB, Rau A, Reisert M, Rau S, Diallo T, Stein T, Faby S, Bamberg F, Weiss J. Photon-counting detector computed tomography for metal artifact reduction: a comparative study of different artifact reduction techniques in patients with orthopedic implants. LA RADIOLOGIA MEDICA 2024; 129:890-900. [PMID: 38689182 PMCID: PMC11168992 DOI: 10.1007/s11547-024-01822-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 04/16/2024] [Indexed: 05/02/2024]
Abstract
PURPOSE Artifacts caused by metallic implants remain a challenge in computed tomography (CT). We investigated the impact of photon-counting detector computed tomography (PCD-CT) for artifact reduction in patients with orthopedic implants with respect to image quality and diagnostic confidence using different artifact reduction approaches. MATERIAL AND METHODS In this prospective study, consecutive patients with orthopedic implants underwent PCD-CT imaging of the implant area. Four series were reconstructed for each patient (clinical standard reconstruction [PCD-CTStd], monoenergetic images at 140 keV [PCD-CT140keV], iterative metal artifact reduction (iMAR) corrected [PCD-CTiMAR], combination of iMAR and 140 keV monoenergetic [PCD-CT140keV+iMAR]). Subsequently, three radiologists evaluated the reconstructions in a random and blinded manner for image quality, artifact severity, anatomy delineation (adjacent and distant), and diagnostic confidence using a 5-point Likert scale (5 = excellent). In addition, the coefficient of variation [CV] and the relative quantitative artifact reduction potential were obtained as objective measures. RESULTS We enrolled 39 patients with a mean age of 67.3 ± 13.2 years (51%; n = 20 male) and a mean BMI of 26.1 ± 4 kg/m2. All image quality measures and diagnostic confidence were significantly higher for the iMAR vs. non-iMAR reconstructions (all p < 0.001). No significant effect of the different artifact reduction approaches on CV was observed (p = 0.26). The quantitative analysis indicated the most effective artifact reduction for the iMAR reconstructions, which was higher than PCD-CT140keV (p < 0.001). CONCLUSION PCD-CT allows for effective metal artifact reduction in patients with orthopedic implants, resulting in superior image quality and diagnostic confidence with the potential to improve patient management and clinical decision making.
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Affiliation(s)
- Fabian Bernhard Pallasch
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany.
| | - Alexander Rau
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Marco Reisert
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Stephan Rau
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Thierno Diallo
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Thomas Stein
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Sebastian Faby
- Siemens Healthcare GmbH, Siemensstr. 3, 91301, Forchheim, Germany
| | - Fabian Bamberg
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Jakob Weiss
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
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Ganizada BH, J A Veltrop R, Akbulut AC, Koenen RR, Accord R, Lorusso R, Maessen JG, Reesink K, Bidar E, Schurgers LJ. Unveiling cellular and molecular aspects of ascending thoracic aortic aneurysms and dissections. Basic Res Cardiol 2024; 119:371-395. [PMID: 38700707 PMCID: PMC11143007 DOI: 10.1007/s00395-024-01053-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 04/03/2024] [Accepted: 04/26/2024] [Indexed: 06/01/2024]
Abstract
Ascending thoracic aortic aneurysm (ATAA) remains a significant medical concern, with its asymptomatic nature posing diagnostic and monitoring challenges, thereby increasing the risk of aortic wall dissection and rupture. Current management of aortic repair relies on an aortic diameter threshold. However, this approach underestimates the complexity of aortic wall disease due to important knowledge gaps in understanding its underlying pathologic mechanisms.Since traditional risk factors cannot explain the initiation and progression of ATAA leading to dissection, local vascular factors such as extracellular matrix (ECM) and vascular smooth muscle cells (VSMCs) might harbor targets for early diagnosis and intervention. Derived from diverse embryonic lineages, VSMCs exhibit varied responses to genetic abnormalities that regulate their contractility. The transition of VSMCs into different phenotypes is an adaptive response to stress stimuli such as hemodynamic changes resulting from cardiovascular disease, aging, lifestyle, and genetic predisposition. Upon longer exposure to stress stimuli, VSMC phenotypic switching can instigate pathologic remodeling that contributes to the pathogenesis of ATAA.This review aims to illuminate the current understanding of cellular and molecular characteristics associated with ATAA and dissection, emphasizing the need for a more nuanced comprehension of the impaired ECM-VSMC network.
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MESH Headings
- Humans
- Aortic Aneurysm, Thoracic/pathology
- Aortic Aneurysm, Thoracic/genetics
- Aortic Aneurysm, Thoracic/metabolism
- Aortic Aneurysm, Thoracic/physiopathology
- Aortic Dissection/pathology
- Aortic Dissection/genetics
- Aortic Dissection/metabolism
- Animals
- Muscle, Smooth, Vascular/pathology
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/pathology
- Myocytes, Smooth Muscle/metabolism
- Aorta, Thoracic/pathology
- Aorta, Thoracic/physiopathology
- Vascular Remodeling
- Extracellular Matrix/pathology
- Extracellular Matrix/metabolism
- Phenotype
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Affiliation(s)
- Berta H Ganizada
- Department of Cardiothoracic Surgery, Heart and Vascular Centre, Maastricht University Medical Centre, Maastricht, The Netherlands
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Universiteitssingel 50, 6229 ER, Maastricht, The Netherlands
- CARIM, Cardiovascular Research Institute Maastricht, 6200 MD, Maastricht, The Netherlands
| | - Rogier J A Veltrop
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Universiteitssingel 50, 6229 ER, Maastricht, The Netherlands
- CARIM, Cardiovascular Research Institute Maastricht, 6200 MD, Maastricht, The Netherlands
| | - Asim C Akbulut
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Universiteitssingel 50, 6229 ER, Maastricht, The Netherlands
- CARIM, Cardiovascular Research Institute Maastricht, 6200 MD, Maastricht, The Netherlands
| | - Rory R Koenen
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Universiteitssingel 50, 6229 ER, Maastricht, The Netherlands
- CARIM, Cardiovascular Research Institute Maastricht, 6200 MD, Maastricht, The Netherlands
| | - Ryan Accord
- Department of Cardiothoracic Surgery, Center for Congenital Heart Disease, University Medical Center Groningen, Groningen, The Netherlands
| | - Roberto Lorusso
- Department of Cardiothoracic Surgery, Heart and Vascular Centre, Maastricht University Medical Centre, Maastricht, The Netherlands
- CARIM, Cardiovascular Research Institute Maastricht, 6200 MD, Maastricht, The Netherlands
| | - Jos G Maessen
- Department of Cardiothoracic Surgery, Heart and Vascular Centre, Maastricht University Medical Centre, Maastricht, The Netherlands
- CARIM, Cardiovascular Research Institute Maastricht, 6200 MD, Maastricht, The Netherlands
| | - Koen Reesink
- Department of Biomedical Engineering, Heart and Vascular Centre, Maastricht University Medical Centre, Maastricht, The Netherlands
- CARIM, Cardiovascular Research Institute Maastricht, 6200 MD, Maastricht, The Netherlands
| | - Elham Bidar
- Department of Cardiothoracic Surgery, Heart and Vascular Centre, Maastricht University Medical Centre, Maastricht, The Netherlands
- CARIM, Cardiovascular Research Institute Maastricht, 6200 MD, Maastricht, The Netherlands
| | - Leon J Schurgers
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Universiteitssingel 50, 6229 ER, Maastricht, The Netherlands.
- CARIM, Cardiovascular Research Institute Maastricht, 6200 MD, Maastricht, The Netherlands.
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Sharma SP, van der Bie J, van Straten M, Hirsch A, Bos D, Dijkshoorn ML, Booij R, Budde RPJ. Coronary calcium scoring on virtual non-contrast and virtual non-iodine reconstructions compared to true non-contrast images using photon-counting computed tomography. Eur Radiol 2024; 34:3699-3707. [PMID: 37940711 PMCID: PMC11166815 DOI: 10.1007/s00330-023-10402-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 08/17/2023] [Accepted: 09/17/2023] [Indexed: 11/10/2023]
Abstract
OBJECTIVES To compare coronary artery calcification (CAC) scores measured on virtual non-contrast (VNC) and virtual non-iodine (VNI) reconstructions computed from coronary computed tomography angiography (CCTA) using photon-counting computed tomography (PCCT) to true non-contrast (TNC) images. METHODS We included 88 patients (mean age = 59 years ± 13.5, 69% male) who underwent a TNC coronary calcium scan followed by CCTA on PCCT. VNC images were reconstructed in 87 patients and VNI in 88 patients by virtually removing iodine from the CCTA images. For all reconstructions, CAC scores were determined, and patients were classified into risk categories. The overall agreement of the reconstructions was analyzed by Bland-Altman plots and the level of matching classifications. RESULTS The median CAC score on TNC was 27.8 [0-360.4] compared to 8.5 [0.2-101.6] (p < 0.001) on VNC and 72.2 [1.3-398.8] (p < 0.001) on VNI. Bland-Altman plots depicted a bias of 148.8 (ICC = 0.82, p < 0.001) and - 57.7 (ICC = 0.95, p < 0.001) for VNC and VNI, respectively. Of all patients with CACTNC = 0, VNC reconstructions scored 63% of the patients correctly, while VNI scored 54% correctly. Of the patients with CACTNC > 0, VNC and VNI reconstructions detected the presence of coronary calcium in 90% and 92% of the patients. CACVNC tended to underestimate CAC score, whereas CACVNI overestimated, especially in the lower risk categories. According to the risk categories, VNC misclassified 55% of the patients, while VNI misclassified only 32%. CONCLUSION Compared to TNC images, VNC underestimated and VNI overestimated the actual CAC scores. VNI reconstructions quantify and classify coronary calcification scores more accurately than VNC reconstructions. CLINICAL RELEVANCE STATEMENT Photon-counting CT enables spectral imaging, which might obviate the need for non-contrast enhanced coronary calcium scoring, but optimization is necessary for the clinical implementation of the algorithms. KEY POINTS • Photon-counting computed tomography uses spectral information to virtually remove the signal of contrast agents from contrast-enhanced scans. • Virtual non-contrast reconstructions tend to underestimate coronary artery calcium scores compared to true non-contrast images, while virtual non-iodine reconstructions tend to overestimate the calcium scores. • Virtual non-iodine reconstructions might obviate the need for non-contrast enhanced calcium scoring, but optimization is necessary for the clinical implementation of the algorithms.
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Affiliation(s)
- Simran P Sharma
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Cardiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Judith van der Bie
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Marcel van Straten
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Alexander Hirsch
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Cardiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Daniel Bos
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Marcel L Dijkshoorn
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Ronald Booij
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Ricardo P J Budde
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
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Gaffney B, Murphy DJ. Approach to Pulmonary Nodules in Connective Tissue Disease. Semin Respir Crit Care Med 2024; 45:316-328. [PMID: 38547916 DOI: 10.1055/s-0044-1782656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2024]
Abstract
The assessment of pulmonary nodules is a common and often challenging clinical scenario. This evaluation becomes even more complex in patients with connective tissue diseases (CTDs), as a range of disease-related factors must also be taken into account. These diseases are characterized by immune-mediated chronic inflammation, leading to tissue damage, collagen deposition, and subsequent organ dysfunction. A thorough examination of nodule features in these patients is required, incorporating anatomic and functional information, along with patient demographics, clinical factors, and disease-specific knowledge. This integrated approach is vital for effective risk stratification and precise diagnosis. This review article addresses specific CTD-related factors that should be taken into account when evaluating pulmonary nodules in this patient group.
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Affiliation(s)
- Brian Gaffney
- Department of Radiology, St Vincent's University Hospital, Dublin, Ireland
| | - David J Murphy
- Department of Radiology, St Vincent's University Hospital, Dublin, Ireland
- School of Medicine, University College, Dublin, Ireland
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46
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Stålhammar F, Aurumskjöld ML, Meyer S, Wiklund M, Wingren P, Liuba P, Hedström E. Photon-counting computed tomography for paediatric congenital heart defects yields images of high diagnostic quality with low radiation doses at both 70 kV and 90 kV. Pediatr Radiol 2024; 54:1187-1196. [PMID: 38700554 PMCID: PMC11182870 DOI: 10.1007/s00247-024-05939-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 04/23/2024] [Accepted: 04/24/2024] [Indexed: 06/19/2024]
Abstract
BACKGROUND Photon-counting computed tomography (PCCT) is a new clinical method that may show better diagnostic quality at lower radiation doses than conventional CT. OBJECTIVE To investigate the diagnostic quality and radiation dose of paediatric cardiovascular PCCT for diagnosis of congenital heart defects at 70 kV and 90 kV. MATERIALS AND METHODS This retrospective assessment included clinical non-gated paediatric PCCT examinations for assessment of congenital heart defects. Radiation doses were recorded, and overall and specific diagnostic quality (1-4) were scored by four paediatric radiologists. Agreement, differences, and trends were assessed by percent rater agreement, intraclass correlation, Mann-Whitney tests, and Jonckheere-Terpstra tests. RESULTS Seventy children with congenital heart defects were examined at 70 kV (n = 35; age 2 days-16 years; 63% boys) or 90 kV (n = 35; age 2 days-17 years; 51% boys). All observers gave a median score of 4 (high diagnostic quality) for both 70 kV and 90 kV, with no difference in median values between tube voltages (all P > 0.06). Agreement for overall scores was 66-94% for 70 kV and 60-77% for 90 kV. Agreement for specific scores was 80-97% for 70 kV and 83-89% for 90 kV. Size-dependent dose estimate was 0.68 mGy (0.25-2.02 mGy) for 70 kV and 1.10 mGy (0.58-2.71 mGy; P < 0.001) for 90 kV. Effective dose was 0.30 mSv (0.15-0.82 mSv) for 70 kV and 0.39 mSv (0.22-1.51 mSv; P = 0.01) for 90 kV. CONCLUSION Paediatric cardiovascular PCCT yields images for congenital heart defects of high diagnostic quality with low radiation dose at both 70 kV and 90 kV.
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Affiliation(s)
- Fredrik Stålhammar
- Diagnostic Radiology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
- Department of Radiology, Skåne University Hospital, S-22185, Lund, Sweden
| | - Marie-Louise Aurumskjöld
- Medical Radiation Physics, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden
- Radiation Physics, Department of Haematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Sofie Meyer
- Diagnostic Radiology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
- Department of Radiology, Skåne University Hospital, S-22185, Lund, Sweden
| | - Marie Wiklund
- Diagnostic Radiology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
- Department of Radiology, Skåne University Hospital, S-22185, Lund, Sweden
| | - Pär Wingren
- Diagnostic Radiology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
- Department of Radiology, Skåne University Hospital, S-22185, Lund, Sweden
| | - Petru Liuba
- Paediatric Cardiology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
- Department of Paediatric Cardiology, Skåne University Hospital, Lund, Sweden
| | - Erik Hedström
- Diagnostic Radiology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden.
- Department of Radiology, Skåne University Hospital, S-22185, Lund, Sweden.
- Clinical Physiology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden.
- Department of Clinical Physiology, Skåne University Hospital, Lund, Sweden.
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Pallasch FB, Rau A, Reisert M, Rau S, Diallo T, Stein T, Faby S, Bamberg F, Weiss J. Impact of different metal artifact reduction techniques in photon-counting computed tomography head and neck scans in patients with dental hardware. Eur Radiol 2024; 34:3742-3749. [PMID: 37968474 PMCID: PMC11166854 DOI: 10.1007/s00330-023-10430-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 09/18/2023] [Accepted: 10/02/2023] [Indexed: 11/17/2023]
Abstract
OBJECTIVES Metal artifacts remain a challenge in computed tomography. We investigated the potential of photon-counting computed tomography (PCD-CT) for metal artifact reduction using an iterative metal artifact reduction (iMAR) algorithm alone and in combination with high keV monoenergetic images (140 keV) in patients with dental hardware. MATERIAL AND METHODS Consecutive patients with dental implants were prospectively included in this study and received PCD-CT imaging of the craniofacial area. Four series were reconstructed (standard [PCD-CTstd], monoenergetic at 140 keV [PCD-CT140keV], iMAR corrected [PCD-CTiMAR], combination of iMAR and 140 keV monoenergetic [PCD-CTiMAR+140keV]). All reconstructions were assessed qualitatively by four radiologists (independent and blinded reading on a 5-point Likert scale [5 = excellent; no artifact]) regarding overall image quality, artifact severity, and delineation of adjacent and distant anatomy. To assess signal homogeneity and evaluate the magnitude of artifact reduction, we performed quantitative measures of coefficient of variation (CV) and a region of interest (ROI)-based relative change in artifact reduction [PCD-CT/PCD-CTstd]. RESULTS We enrolled 48 patients (mean age 66.5 ± 11.2 years, 50% (n = 24) males; mean BMI 25.2 ± 4.7 kg/m2; mean CTDIvol 6.2 ± 6 mGy). We found improved overall image quality, reduced artifacts and superior delineation of both adjacent and distant anatomy for the iMAR vs. non-iMAR reconstructions (all p < 0.001). No significant effect of the different artifact reduction approaches on CV was observed (p = 0.42). The ROI-based analysis indicated the most effective artifact reduction for the iMAR reconstructions, which was significantly higher compared to PCD-CT140keV (p < 0.001). CONCLUSION PCD-CT offers highly effective approaches for metal artifact reduction with the potential to overcome current diagnostic challenges in patients with dental implants. CLINICAL RELEVANCE STATEMENT Metallic artifacts pose a significant challenge in CT imaging, potentially leading to missed findings. Our study shows that PCD-CT with iMAR post-processing reduces artifacts, improves image quality, and can possibly reveal pathologies previously obscured by artifacts, without additional dose application. KEY POINTS • Photon-counting detector CT (PCD-CT) offers highly effective approaches for metal artifact reduction in patients with dental fillings/implants. • Iterative metal artifact reduction (iMAR) is superior to high keV monoenergetic reconstructions at 140 keV for artifact reduction and provides higher image quality. • Signal homogeneity of the reconstructed images is not affected by the different artifact reduction techniques.
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Affiliation(s)
- Fabian Bernhard Pallasch
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany.
| | - Alexander Rau
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Marco Reisert
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Stephan Rau
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Thierno Diallo
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Thomas Stein
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Sebastian Faby
- Siemens Healthcare GmbH, Siemensstr. 3, 91301, Forchheim, Germany
| | - Fabian Bamberg
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Jakob Weiss
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
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Nurmohamed NS, van Rosendael AR, Danad I, Ngo-Metzger Q, Taub PR, Ray KK, Figtree G, Bonaca MP, Hsia J, Rodriguez F, Sandhu AT, Nieman K, Earls JP, Hoffmann U, Bax JJ, Min JK, Maron DJ, Bhatt DL. Atherosclerosis evaluation and cardiovascular risk estimation using coronary computed tomography angiography. Eur Heart J 2024; 45:1783-1800. [PMID: 38606889 PMCID: PMC11129796 DOI: 10.1093/eurheartj/ehae190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 02/13/2024] [Accepted: 03/13/2024] [Indexed: 04/13/2024] Open
Abstract
Clinical risk scores based on traditional risk factors of atherosclerosis correlate imprecisely to an individual's complex pathophysiological predisposition to atherosclerosis and provide limited accuracy for predicting major adverse cardiovascular events (MACE). Over the past two decades, computed tomography scanners and techniques for coronary computed tomography angiography (CCTA) analysis have substantially improved, enabling more precise atherosclerotic plaque quantification and characterization. The accuracy of CCTA for quantifying stenosis and atherosclerosis has been validated in numerous multicentre studies and has shown consistent incremental prognostic value for MACE over the clinical risk spectrum in different populations. Serial CCTA studies have advanced our understanding of vascular biology and atherosclerotic disease progression. The direct disease visualization of CCTA has the potential to be used synergistically with indirect markers of risk to significantly improve prevention of MACE, pending large-scale randomized evaluation.
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Affiliation(s)
- Nick S Nurmohamed
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit
Amsterdam, Amsterdam, The
Netherlands
- Department of Vascular Medicine, Amsterdam UMC, University of
Amsterdam, Amsterdam, The
Netherlands
- Division of Cardiology, The George Washington University School of
Medicine, Washington, DC, United States
| | | | - Ibrahim Danad
- Department of Cardiology, University Medical Center Utrecht,
Utrecht, The Netherlands
- Department of Cardiology, Radboud University Medical Center,
Nijmegen, The Netherlands
| | - Quyen Ngo-Metzger
- Department of Health Systems Science, Kaiser Permanente Bernard J. Tyson
School of Medicine, Pasadena, CA, United States
| | - Pam R Taub
- Section of Cardiology, Department of Medicine, University of
California, San Diego, CA, United States
| | - Kausik K Ray
- Department of Primary Care and Public Health, Imperial College
London, London, United
Kingdom
| | - Gemma Figtree
- Faculty of Medicine and Health, University of Sydney,
Australia, St Leonards, Australia
| | - Marc P Bonaca
- Department of Medicine, University of Colorado School of
Medicine, Aurora, CO, United States
| | - Judith Hsia
- Department of Medicine, University of Colorado School of
Medicine, Aurora, CO, United States
| | - Fatima Rodriguez
- Department of Medicine, Stanford University School of
Medicine, Stanford, CA, United States
| | - Alexander T Sandhu
- Department of Medicine, Stanford University School of
Medicine, Stanford, CA, United States
| | - Koen Nieman
- Department of Medicine, Stanford University School of
Medicine, Stanford, CA, United States
| | - James P Earls
- Cleerly, Inc., Denver, CO, United States
- Department of Radiology, The George Washington University School of
Medicine, Washington, DC, United States
| | | | - Jeroen J Bax
- Department of Cardiology, Leiden University Medical Center,
Leiden, The Netherlands
| | | | - David J Maron
- Department of Medicine, Stanford University School of
Medicine, Stanford, CA, United States
| | - Deepak L Bhatt
- Mount Sinai Fuster Heart Hospital, Icahn School of Medicine at Mount
Sinai, 1 Gustave Levy Place, Box 1030, New York, NY
10029, United States
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Dobrolinska MM, Koetzier LR, Greuter MJW, Vliegenthart R, van der Bie J, Prakken NHJ, Slart RHJA, Leiner T, Budde RPJ, Mastrodicasa D, Booij R, Fleischmann D, Willemink MJ, van Straten M, van der Werf NR. Feasibility of virtual non-iodine coronary calcium scoring on dual source photon-counting coronary CT angiography: a dynamic phantom study. Eur Radiol 2024:10.1007/s00330-024-10806-4. [PMID: 38789792 DOI: 10.1007/s00330-024-10806-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/23/2024] [Accepted: 04/05/2024] [Indexed: 05/26/2024]
Abstract
BACKGROUND The aim of our current systematic dynamic phantom study was first, to optimize reconstruction parameters of coronary CTA (CCTA) acquired on photon counting CT (PCCT) for coronary artery calcium (CAC) scoring, and second, to assess the feasibility of calculating CAC scores from CCTA, in comparison to reference calcium scoring CT (CSCT) scans. METHODS In this phantom study, an artificial coronary artery was translated at velocities corresponding to 0, < 60, and 60-75 beats per minute (bpm) within an anthropomorphic phantom. The density of calcifications was 100 (very low), 200 (low), 400 (medium), and 800 (high) mgHA/cm3, respectively. CCTA was reconstructed with the following parameters: virtual non-iodine (VNI), with and without iterative reconstruction (QIR level 2, QIR off, respectively); kernels Qr36 and Qr44f; slice thickness/increment 3.0/1.5 mm and 0.4/0.2 mm. The agreement in risk group classification between CACCCTA and CACCSCT scoring was measured using Cohen weighted linear κ with 95% CI. RESULTS For CCTA reconstructed with 0.4 mm slice thickness, calcium detectability was perfect (100%). At < 60 bpm, CACCCTA of low, and medium density calcification was underestimated by 53%, and 15%, respectively. However, CACCCTA was not significantly different from CACCSCT of very low, and high-density calcifications. The best risk agreement was achieved when CCTA was reconstructed with QIR off, Qr44f, and 0.4 mm slice thickness (κ = 0.762, 95% CI 0.671-0.853). CONCLUSION In this dynamic phantom study, the detection of calcifications with different densities was excellent with CCTA on PCCT using thin-slice VNI reconstruction. Agatston scores were underestimated compared to CSCT but agreement in risk classification was substantial. CLINICAL RELEVANCE STATEMENT Photon counting CT may enable the implementation of coronary artery calcium scoring from coronary CTA in daily clinical practice. KEY POINTS Photon-counting CTA allows for excellent detectability of low-density calcifications at all heart rates. Coronary artery calcium scoring from coronary CTA acquired on photon counting CT is feasible, although improvement is needed. Adoption of the standard acquisition and reconstruction protocol for calcium scoring is needed for improved quantification of coronary artery calcium to fully employ the potential of photon counting CT.
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Affiliation(s)
- Magdalena M Dobrolinska
- Department of Radiology and Nuclear Medicine Rotterdam, Erasmus MC University Medical Center, Rotterdam, The Netherlands.
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Medical Imaging Center, Groningen, The Netherlands.
| | - Lennart R Koetzier
- Department of Radiology and Nuclear Medicine Rotterdam, Erasmus MC University Medical Center, Rotterdam, The Netherlands
- Department of Radiology Stanford, Stanford University School of Medicine, Stanford, CA, USA
| | - Marcel J W Greuter
- Department of Radiology, University of Groningen, University Medical Center Groningen, Medical Imaging Center, Groningen, The Netherlands
| | - Rozemarijn Vliegenthart
- Department of Radiology, University of Groningen, University Medical Center Groningen, Medical Imaging Center, Groningen, The Netherlands
| | - Judith van der Bie
- Department of Radiology and Nuclear Medicine Rotterdam, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Niek H J Prakken
- Department of Radiology, University of Groningen, University Medical Center Groningen, Medical Imaging Center, Groningen, The Netherlands
| | - Riemer H J A Slart
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Medical Imaging Center, Groningen, The Netherlands
| | - Tim Leiner
- Department of Radiology Rochester, Mayo Clinic, Rochester, MN, USA
| | - Ricardo P J Budde
- Department of Radiology and Nuclear Medicine Rotterdam, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Domenico Mastrodicasa
- Department of Radiology Stanford, Stanford University School of Medicine, Stanford, CA, USA
| | - Ronald Booij
- Department of Radiology and Nuclear Medicine Rotterdam, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Dominik Fleischmann
- Department of Radiology Stanford, Stanford University School of Medicine, Stanford, CA, USA
| | - Martin J Willemink
- Department of Radiology Stanford, Stanford University School of Medicine, Stanford, CA, USA
| | - Marcel van Straten
- Department of Radiology and Nuclear Medicine Rotterdam, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Niels R van der Werf
- Department of Radiology and Nuclear Medicine Rotterdam, Erasmus MC University Medical Center, Rotterdam, The Netherlands
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50
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Bette S, Risch F, Becker J, Popp D, Decker JA, Kaufmann D, Friedrich L, Scheurig-Münkler C, Schwarz F, Kröncke TJ. Photon-counting detector CT - first experiences in the field of musculoskeletal radiology. ROFO-FORTSCHR RONTG 2024. [PMID: 38788741 DOI: 10.1055/a-2312-6914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2024]
Abstract
The introduction of photon-counting detector CT (PCD-CT) marks a remarkable leap in innovation in CT imaging. The new detector technology allows X-rays to be converted directly into an electrical signal without an intermediate step via a scintillation layer and allows the energy of individual photons to be measured. Initial data show high spatial resolution, complete elimination of electronic noise, and steady availability of spectral image data sets. In particular, the new technology shows promise with respect to the imaging of osseous structures. Recently, PCD-CT was implemented in the clinical routine. The aim of this review was to summarize recent studies and to show our first experiences with photon-counting detector technology in the field of musculoskeletal radiology.We performed a literature search using Medline and included a total of 90 articles and reviews that covered recent experimental and clinical experiences with the new technology.In this review, we focus on (1) spatial resolution and delineation of fine anatomic structures, (2) reduction of radiation dose, (3) electronic noise, (4) techniques for metal artifact reduction, and (5) possibilities of spectral imaging. This article provides insight into our first experiences with photon-counting detector technology and shows results and images from experimental and clinical studies. · This review summarizes recent experimental and clinical studies in the field of photon-counting detector CT and musculoskeletal radiology.. · The potential of photon-counting detector technology in the field of musculoskeletal radiology includes improved spatial resolution, reduction in radiation dose, metal artifact reduction, and spectral imaging.. · PCD-CT enables imaging at lower radiation doses while maintaining or even enhancing spatial resolution, crucial for reducing patient exposure, especially in repeated or prolonged imaging scenarios.. · It offers promising results in reducing metal artifacts commonly encountered in orthopedic or dental implants, enhancing the interpretability of adjacent structures in postoperative and follow-up imaging.. · With its ability to routinely acquire spectral data, PCD-CT scans allow for material classification, such as detecting urate crystals in suspected gout or visualizing bone marrow edema, potentially reducing reliance on MRI in certain cases.. Bette S, Risch F, Becker J et al. Photon-counting detector CT - first experiences in the field of musculoskeletal radiology. Fortschr Röntgenstr 2024; DOI 10.1055/a-2312-6914.
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Affiliation(s)
- Stefanie Bette
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Augsburg, Germany
| | - Franka Risch
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Augsburg, Germany
| | - Judith Becker
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Augsburg, Germany
| | - Daniel Popp
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Augsburg, Germany
| | - Josua A Decker
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Augsburg, Germany
| | - David Kaufmann
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Augsburg, Germany
| | - Lena Friedrich
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Augsburg, Germany
| | - Christian Scheurig-Münkler
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Augsburg, Germany
| | - Florian Schwarz
- Institute of Conventional and Interventional Radiology, Donauisar Hospital Deggendorf, Deggendorf, Germany
| | - Thomas J Kröncke
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Augsburg, Germany
- Centre for Advanced Analytics and Predictive Sciences (CAAPS), University of Augsburg, Augsburg, Germany
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