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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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2
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Toia GV, Mileto A, Borhani AA, Chen GH, Ren L, Uyeda JW, Marin D. Approaches, advantages, and challenges to photon counting detector and multi-energy CT. Abdom Radiol (NY) 2024; 49:3251-3260. [PMID: 38744702 DOI: 10.1007/s00261-024-04357-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: 03/21/2024] [Revised: 04/21/2024] [Accepted: 04/21/2024] [Indexed: 05/16/2024]
Abstract
Photon counting detector CT (PCD-CT) is the newest major development in CT technology and has been commercially available since 2021. It offers major technological advantages over current standard-of-care energy integrating detector CT (EID-CT) including improved spatial resolution, improved iodine contrast to noise ratio, multi-energy imaging, and reduced noise. This article serves as a foundational basis to the technical approaches and concepts of PCD-CT technology with primary emphasis on detector technology in direct comparison to EID-CT. The article also addresses current technological challenges to PCD-CT with particular attention to cross talk and its causes (e.g., Compton scattering, fluorescence, charge sharing, K-escape) as well as pile-up.
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Affiliation(s)
- Giuseppe V Toia
- Departments of Radiology and Medical Physics, University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI, 53792, USA.
| | - Achille Mileto
- Department of Radiology, University of Washington, Seattle, WA, USA
| | - Amir A Borhani
- Department of Radiology, Northwestern University, Chicago, IL, USA
| | - Guang-Hong Chen
- Departments of Radiology and Medical Physics, University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI, 53792, USA
| | - Liqiang Ren
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Jennifer W Uyeda
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Daniele Marin
- Department of Radiology, Duke University Health System, Durham, NC, USA
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3
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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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4
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Madhavan AA, Brinjikji W, Cutsforth-Gregory JK, Amrhein TJ, Kranz PG, Benson JC, Diehn FE, Johnson-Tesch BA, Liebo GB, Lehman VT, Mark IT, Morris PP, Oien MP, Shlapak DP, Verdoorn JT. Myelographic Techniques for the Localization of CSF-Venous Fistulas: Updates in 2024. AJNR Am J Neuroradiol 2024:ajnr.A8299. [PMID: 39089875 DOI: 10.3174/ajnr.a8299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 02/14/2024] [Indexed: 08/04/2024]
Abstract
CSF-venous fistulas (CVFs) are a common cause of spontaneous intracranial hypotension. Despite their relatively frequent occurrence, they can be exceedingly difficult to detect on imaging. Since the initial description of CVFs in 2014, the recognition and diagnosis of this type of CSF leak has continually increased. As a result of multi-institutional efforts, a wide spectrum of imaging modalities and specialized techniques for CVF detection is now available. It is important for radiologists to be familiar with the multitude of available techniques, because each has unique advantages and drawbacks. In this article, we review the spectrum of imaging modalities available for the detection of CVFs, explain the advantages and disadvantages of each, provide typical imaging examples, and discuss provocative maneuvers that may improve the conspicuity of CVFs. Discussed modalities include conventional CT myelography, dynamic myelography, digital subtraction myelography, conebeam CT myelography, decubitus CT myelography by using conventional energy-integrating detector scanners, decubitus photon counting CT myelography, and intrathecal gadolinium MR myelography. Additional topics to be discussed include optimal patient positioning, respiratory techniques, and intrathecal pressure augmentation.
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Affiliation(s)
- Ajay A Madhavan
- From the Division of Neuroradiology, Department of Radiology (A.A.M., W.B., J.C.B., F.E.D., B.A.J.-T., G.L., V.T.L., I.T.M., P.P.M., M.P.O., D.P.S., J.T.V.), Mayo Clinic, Rochester, Minnesota
| | - Waleed Brinjikji
- From the Division of Neuroradiology, Department of Radiology (A.A.M., W.B., J.C.B., F.E.D., B.A.J.-T., G.L., V.T.L., I.T.M., P.P.M., M.P.O., D.P.S., J.T.V.), Mayo Clinic, Rochester, Minnesota
| | | | - Timothy J Amrhein
- Division of Neuroradiology, Department of Radiology (T.J.A., P.G.K.), Duke Health, Durham, North Carolina
| | - Peter G Kranz
- Division of Neuroradiology, Department of Radiology (T.J.A., P.G.K.), Duke Health, Durham, North Carolina
| | - John C Benson
- From the Division of Neuroradiology, Department of Radiology (A.A.M., W.B., J.C.B., F.E.D., B.A.J.-T., G.L., V.T.L., I.T.M., P.P.M., M.P.O., D.P.S., J.T.V.), Mayo Clinic, Rochester, Minnesota
| | - Felix E Diehn
- From the Division of Neuroradiology, Department of Radiology (A.A.M., W.B., J.C.B., F.E.D., B.A.J.-T., G.L., V.T.L., I.T.M., P.P.M., M.P.O., D.P.S., J.T.V.), Mayo Clinic, Rochester, Minnesota
| | - Ben A Johnson-Tesch
- From the Division of Neuroradiology, Department of Radiology (A.A.M., W.B., J.C.B., F.E.D., B.A.J.-T., G.L., V.T.L., I.T.M., P.P.M., M.P.O., D.P.S., J.T.V.), Mayo Clinic, Rochester, Minnesota
| | - Greta B Liebo
- From the Division of Neuroradiology, Department of Radiology (A.A.M., W.B., J.C.B., F.E.D., B.A.J.-T., G.L., V.T.L., I.T.M., P.P.M., M.P.O., D.P.S., J.T.V.), Mayo Clinic, Rochester, Minnesota
| | - Vance T Lehman
- From the Division of Neuroradiology, Department of Radiology (A.A.M., W.B., J.C.B., F.E.D., B.A.J.-T., G.L., V.T.L., I.T.M., P.P.M., M.P.O., D.P.S., J.T.V.), Mayo Clinic, Rochester, Minnesota
| | - Ian T Mark
- From the Division of Neuroradiology, Department of Radiology (A.A.M., W.B., J.C.B., F.E.D., B.A.J.-T., G.L., V.T.L., I.T.M., P.P.M., M.P.O., D.P.S., J.T.V.), Mayo Clinic, Rochester, Minnesota
| | - Pearse P Morris
- From the Division of Neuroradiology, Department of Radiology (A.A.M., W.B., J.C.B., F.E.D., B.A.J.-T., G.L., V.T.L., I.T.M., P.P.M., M.P.O., D.P.S., J.T.V.), Mayo Clinic, Rochester, Minnesota
| | - Michael P Oien
- From the Division of Neuroradiology, Department of Radiology (A.A.M., W.B., J.C.B., F.E.D., B.A.J.-T., G.L., V.T.L., I.T.M., P.P.M., M.P.O., D.P.S., J.T.V.), Mayo Clinic, Rochester, Minnesota
| | - Darya P Shlapak
- From the Division of Neuroradiology, Department of Radiology (A.A.M., W.B., J.C.B., F.E.D., B.A.J.-T., G.L., V.T.L., I.T.M., P.P.M., M.P.O., D.P.S., J.T.V.), Mayo Clinic, Rochester, Minnesota
| | - Jared T Verdoorn
- From the Division of Neuroradiology, Department of Radiology (A.A.M., W.B., J.C.B., F.E.D., B.A.J.-T., G.L., V.T.L., I.T.M., P.P.M., M.P.O., D.P.S., J.T.V.), Mayo Clinic, Rochester, Minnesota
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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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6
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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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7
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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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8
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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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9
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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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10
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Klempka A, Schröder A, Neumayer P, Groden C, Clausen S, Hetjens S. Cranial Computer Tomography with Photon Counting and Energy-Integrated Detectors: Objective Comparison in the Same Patients. Diagnostics (Basel) 2024; 14:1019. [PMID: 38786317 PMCID: PMC11119038 DOI: 10.3390/diagnostics14101019] [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: 04/03/2024] [Revised: 05/10/2024] [Accepted: 05/13/2024] [Indexed: 05/25/2024] Open
Abstract
This study provides an objective comparison of cranial computed tomography (CT) imaging quality and radiation dose between photon counting detectors (PCCTs) and energy-integrated detectors (EIDs). We retrospectively analyzed 158 CT scans from 76 patients, employing both detector types on the same individuals to ensure a consistent comparison. Our analysis focused on the Computed Tomography Dose Index and the Dose-Length Product together with the contrast-to-noise ratio and the signal-to-noise ratio for brain gray and white matter. We utilized standardized imaging protocols and consistent patient positioning to minimize variables. PCCT showed a potential for higher image quality and lower radiation doses, as highlighted by this study, thus achieving diagnostic clarity with reduced radiation exposure, underlining its significance in patient care, particularly for patients requiring multiple scans. The results demonstrated that while both systems were effective, PCCT offered enhanced imaging and patient safety in neuroradiological evaluations.
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Affiliation(s)
- Anna Klempka
- 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
| | - Philipp Neumayer
- Department of Neuroradiology, 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
| | - Sven Clausen
- Department of Radiation Oncology, 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
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11
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Kämmerling N, Tesselaar E, Booij R, Fornander L, Persson A, Farnebo S. A comparative study of image quality and diagnostic confidence in diagnosis and follow-up of scaphoid fractures using photon-counting detector CT and energy-integrating detector CT. Eur J Radiol 2024; 173:111383. [PMID: 38377892 DOI: 10.1016/j.ejrad.2024.111383] [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: 09/28/2023] [Revised: 01/08/2024] [Accepted: 02/16/2024] [Indexed: 02/22/2024]
Abstract
PURPOSE Scaphoid fractures in patients and assessment of healing using PCD-CT have, as far as we know, not yet been studied. Therefore, the aim was to compare photon counting detector CT (PCD-CT) with energy integrating detector CT (EID-CT) in terms of fracture visibility and evaluation of fracture healing. METHOD Eight patients with scaphoid fracture were examined with EID-CT and PCD-CT within the first week post-trauma, and with additional scans at 4, 6 and 8 weeks. Our clinical protocol for wrist examination with EID-CT was used (CTDIvol 3.1 ± 0.1 mGy, UHR kernel Ur77). For PCD-CT matched radiation dose, reconstruction kernel Br89. Quantitative analyses of noise, CNR, trabecular and cortical sharpness, and bone volume fraction were conducted. Five radiologists evaluated the images for fracture visibility, fracture gap consolidation and image quality, and rated their confidence in the diagnosis. RESULTS The trabecular and cortical sharpness were superior in images obtained with PCD-CT compared with EID-CT. A successive reduction in trabecular bone volume fraction during the immobilized periods was found with both systems. Despite higher noise and lower CNR with PCD-CT, radiologists rated the image quality of PCD-CT as superior. The visibility of the fracture line within 1-week post-trauma was rated higher with PCD-CT as was diagnostic confidence, but the subsequent assessments of fracture gap consolidation during healing process and the confidence in diagnosis were found equivalent between both systems. CONCLUSION PCD-CT offers superior visibility of bone microstructure compared with EID-CT. The evaluation of fracture healing and confidence in diagnosis were rated equally with both systems, but the radiologists found primary fracture visibility and overall image quality superior with PCD-CT.
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Affiliation(s)
- Nina Kämmerling
- Department of Radiology, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.
| | - Erik Tesselaar
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Department of Medical Radiation Physics, Linköping University, Linköping, Sweden
| | - Ronald Booij
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Department of Radiology & Nuclear Medicine, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Lotta Fornander
- Department of Orthopedic Surgery, Norrköping, and Department of Biomedical and Clinical Sciences, Linköping University, Norrköping, Sweden
| | - Anders Persson
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Simon Farnebo
- Department of Hand and Plastic Surgery, Linköping University, Linköping, Sweden
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12
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Schwartz FR, Kranz PG, Malinzak MD, Cox DN, Ria F, McCabe C, Harrawood B, Leithe LG, Samei E, Amrhein TJ. Myelography Using Energy-Integrating Detector CT Versus Photon-Counting Detector CT for Detection of CSF-Venous Fistulas in Patients With Spontaneous Intracranial Hypotension. AJR Am J Roentgenol 2024; 222:e2330673. [PMID: 38294163 DOI: 10.2214/ajr.23.30673] [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: 02/01/2024]
Abstract
BACKGROUND. CSF-venous fistulas (CVFs), which are an increasingly recognized cause of spontaneous intracranial hypotension (SIH), are often diminutive in size and exceedingly difficult to detect by conventional imaging. OBJECTIVE. This purpose of this study was to compare energy-integrating detector (EID) CT myelography and photon-counting detector (PCD) CT myelography in terms of image quality and diagnostic performance for detecting CVFs in patients with SIH. METHODS. This retrospective study included 38 patients (15 men and 23 women; mean age, 55 ± 10 [SD] years) with SIH who underwent both clinically indicated EID CT myelography (slice thickness, 0.625 mm) and PCD CT myelography (slice thickness, 0.2 mm; performed in ultrahigh-resolution mode) to assess for CSF leak. Three blinded radiologists reviewed examinations in random order, assessing image noise, discernibility of spinal nerve root sleeves, and overall image quality (each assessed using a scale of 0-100, with 100 denoting highest quality) and recording locations of the CVFs. Definite CVFs were defined as CVFs described in CT myelography reports using unequivocal language and having an attenuation value greater than 70 HU. RESULTS. For all readers, PCD CT myelography, in comparison with EID CT myelography, showed higher mean image noise (reader 1: 69.9 ± 18.5 [SD] vs 37.6 ± 15.2; reader 2: 59.5 ± 8.7 vs 49.3 ± 12.7; and reader 3: 57.6 ± 13.2 vs 42.1 ± 16.6), higher mean nerve root sleeve discernibility (reader 1: 81.6 ± 21.7 [SD] vs 30.4 ± 13.6; reader 2: 83.6 ± 10 vs 70.1 ± 18.9; and reader 3: 59.6 ± 13.5 vs 50.5 ± 14.4), and higher mean overall image quality (reader 1: 83.2 ± 20.0 [SD] vs 38.1 ± 13.5; reader 2: 80.1 ± 10.1 vs 72.4 ± 19.8; and reader 3: 57.8 ± 11.2 vs 51.9 ± 13.6) (all p < .05). Eleven patients had a definite CVF. Sensitivity and specificity of EID CT myelography and PCD CT myelography for the detection of definite CVF were 45% and 96% versus 64% and 85%, respectively, for reader 1; 36% and 100% versus 55% and 96%, respectively, for reader 2; and 57% and 100% versus 55% and 93%, respectively, for reader 3. The sensitivity was significantly higher for PCD CT myelography than for EID CT myelography for reader 1 and reader 2 (both p < .05) and was not significantly different between the two techniques for reader 3 (p = .45); for all three readers, specificity was not significantly different between the two modalities (all p > .05). CONCLUSION. In comparison with EID CT myelography, PCD CT myelography yielded significantly improved image quality with significantly higher sensitivity for CVFs (for two of three readers), without significant loss of specificity. CLINICAL IMPACT. The findings support a potential role for PCD CT myelography in facilitating earlier diagnosis and targeted treatment of SIH, avoiding high morbidity during potentially prolonged diagnostic workups.
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Affiliation(s)
- Fides R Schwartz
- Department of Radiology, Duke University Health System, Durham, NC
| | - Peter G Kranz
- Department of Radiology, Duke University Health System, Durham, NC
| | | | - David N Cox
- Department of Radiology, Ravin Advanced Imaging Laboratories, Duke University Health System, Durham, NC
| | - Francesco Ria
- Department of Radiology, Ravin Advanced Imaging Laboratories, Duke University Health System, Durham, NC
| | - Cindy McCabe
- Department of Radiology, Ravin Advanced Imaging Laboratories, Duke University Health System, Durham, NC
| | - Brian Harrawood
- Department of Radiology, Ravin Advanced Imaging Laboratories, Duke University Health System, Durham, NC
| | - Linda G Leithe
- Department of Radiology, Duke University Health System, Durham, NC
| | - Ehsan Samei
- Department of Radiology, Duke University Health System, Durham, NC
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13
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Fletcher JG, Inoue A, Bratt A, Horst KK, Koo CW, Rajiah PS, Baffour FI, Ko JP, Remy-Jardin M, McCollough CH, Yu L. Photon-counting CT in Thoracic Imaging: Early Clinical Evidence and Incorporation Into Clinical Practice. Radiology 2024; 310:e231986. [PMID: 38501953 DOI: 10.1148/radiol.231986] [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: 03/20/2024]
Abstract
Photon-counting CT (PCCT) is an emerging advanced CT technology that differs from conventional CT in its ability to directly convert incident x-ray photon energies into electrical signals. The detector design also permits substantial improvements in spatial resolution and radiation dose efficiency and allows for concurrent high-pitch and high-temporal-resolution multienergy imaging. This review summarizes (a) key differences in PCCT image acquisition and image reconstruction compared with conventional CT; (b) early evidence for the clinical benefit of PCCT for high-spatial-resolution diagnostic tasks in thoracic imaging, such as assessment of airway and parenchymal diseases, as well as benefits of high-pitch and multienergy scanning; (c) anticipated radiation dose reduction, depending on the diagnostic task, and increased utility for routine low-dose thoracic CT imaging; (d) adaptations for thoracic imaging in children; (e) potential for further quantitation of thoracic diseases; and (f) limitations and trade-offs. Moreover, important points for conducting and interpreting clinical studies examining the benefit of PCCT relative to conventional CT and integration of PCCT systems into multivendor, multispecialty radiology practices are discussed.
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Affiliation(s)
- Joel G Fletcher
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Akitoshi Inoue
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Alex Bratt
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Kelly K Horst
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Chi Wan Koo
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Prabhakar Shantha Rajiah
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Francis I Baffour
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Jane P Ko
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Martine Remy-Jardin
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Cynthia H McCollough
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Lifeng Yu
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
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14
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Czerny M, Grabenwöger M, Berger T, Aboyans V, Della Corte A, Chen EP, Desai ND, Dumfarth J, Elefteriades JA, Etz CD, Kim KM, Kreibich M, Lescan M, Di Marco L, Martens A, Mestres CA, Milojevic M, Nienaber CA, Piffaretti G, Preventza O, Quintana E, Rylski B, Schlett CL, Schoenhoff F, Trimarchi S, Tsagakis K. EACTS/STS Guidelines for diagnosing and treating acute and chronic syndromes of the aortic organ. Eur J Cardiothorac Surg 2024; 65:ezad426. [PMID: 38408364 DOI: 10.1093/ejcts/ezad426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 09/15/2023] [Accepted: 12/19/2023] [Indexed: 02/28/2024] Open
Affiliation(s)
- Martin Czerny
- Clinic for Cardiovascular Surgery, Department University Heart Center Freiburg Bad Krozingen, University Clinic Freiburg, Freiburg, Germany
- Faculty of Medicine, Albert Ludwigs University Freiburg, Freiburg, Germany
| | - Martin Grabenwöger
- Department of Cardiovascular Surgery, Clinic Floridsdorf, Vienna, Austria
- Medical Faculty, Sigmund Freud Private University, Vienna, Austria
| | - Tim Berger
- Clinic for Cardiovascular Surgery, Department University Heart Center Freiburg Bad Krozingen, University Clinic Freiburg, Freiburg, Germany
- Faculty of Medicine, Albert Ludwigs University Freiburg, Freiburg, Germany
| | - Victor Aboyans
- Department of Cardiology, Dupuytren-2 University Hospital, Limoges, France
- EpiMaCT, Inserm 1094 & IRD 270, Limoges University, Limoges, France
| | - Alessandro Della Corte
- Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
- Cardiac Surgery Unit, Monaldi Hospital, Naples, Italy
| | - Edward P Chen
- Division of Cardiovascular and Thoracic Surgery, Duke University Medical Center, Durham, NC, USA
| | - Nimesh D Desai
- Division of Cardiovascular Surgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Julia Dumfarth
- University Clinic for Cardiac Surgery, Medical University Innsbruck, Innsbruck, Austria
| | - John A Elefteriades
- Aortic Institute at Yale New Haven Hospital, Yale University School of Medicine, New Haven, CT, USA
| | - Christian D Etz
- Department of Cardiac Surgery, University Medicine Rostock, University of Rostock, Rostock, Germany
| | - Karen M Kim
- Division of Cardiovascular and Thoracic Surgery, The University of Texas at Austin/Dell Medical School, Austin, TX, USA
| | - Maximilian Kreibich
- Clinic for Cardiovascular Surgery, Department University Heart Center Freiburg Bad Krozingen, University Clinic Freiburg, Freiburg, Germany
- Faculty of Medicine, Albert Ludwigs University Freiburg, Freiburg, Germany
| | - Mario Lescan
- Department of Thoracic and Cardiovascular Surgery, University Medical Centre Tübingen, Tübingen, Germany
| | - Luca Di Marco
- Cardiac Surgery Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Andreas Martens
- Department of Cardiac Surgery, Klinikum Oldenburg, Oldenburg, Germany
- The Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Carlos A Mestres
- Department of Cardiothoracic Surgery and the Robert WM Frater Cardiovascular Research Centre, The University of the Free State, Bloemfontein, South Africa
| | - Milan Milojevic
- Department of Cardiac Surgery and Cardiovascular Research, Dedinje Cardiovascular Institute, Belgrade, Serbia
| | - Christoph A Nienaber
- Division of Cardiology at the Royal Brompton & Harefield Hospitals, Guy's and St. Thomas' NHS Foundation Trust, London, UK
- National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, UK
| | - Gabriele Piffaretti
- Vascular Surgery Department of Medicine and Surgery, University of Insubria School of Medicine, Varese, Italy
| | - Ourania Preventza
- Division of Cardiothoracic Surgery, Department of Surgery, University of Virginia, Charlottesville, VA, USA
| | - Eduard Quintana
- Department of Cardiovascular Surgery, Hospital Clinic de Barcelona, University of Barcelona, Barcelona, Spain
| | - Bartosz Rylski
- Clinic for Cardiovascular Surgery, Department University Heart Center Freiburg Bad Krozingen, University Clinic Freiburg, Freiburg, Germany
- Faculty of Medicine, Albert Ludwigs University Freiburg, Freiburg, Germany
| | - Christopher L Schlett
- Faculty of Medicine, Albert Ludwigs University Freiburg, Freiburg, Germany
- Department of Diagnostic and Interventional Radiology, University Hospital Freiburg, Freiburg, Germany
| | - Florian Schoenhoff
- Department of Cardiac Surgery, University Hospital Bern, Inselspital, University of Bern, Bern, Switzerland
| | - Santi Trimarchi
- Department of Cardiac Thoracic and Vascular Diseases, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Konstantinos Tsagakis
- Department of Thoracic and Cardiovascular Surgery, West German Heart and Vascular Center, University Medicine Essen, Essen, Germany
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15
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Jalal S, Nicolaou S. Advanced Imaging Technology: Photon Counting CT. Can Assoc Radiol J 2024; 75:20-21. [PMID: 37119123 DOI: 10.1177/08465371231172738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023] Open
Affiliation(s)
- Sabeena Jalal
- Department of Radiology, Vancouver General Hospital, Vancouver, Canada
| | - Savvas Nicolaou
- Department of Radiology, Vancouver General Hospital, Vancouver, Canada
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16
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Funama Y, Oda S, Teramoto F, Aoki Y, Takahashi I, Kojima S, Goto T, Tanaka K, Kidoh M, Nagayama Y, Nakaura T, Hirai T. Improving Visualization of In-stent Lumen Using Prototype Photon-counting Detector Computed Tomography with High-resolution Plaque Kernel. J Med Phys 2024; 49:127-132. [PMID: 38828063 PMCID: PMC11141743 DOI: 10.4103/jmp.jmp_163_23] [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: 11/28/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 06/05/2024] Open
Abstract
The study aimed to compare the performance of photon-counting detector computed tomography (PCD CT) with high-resolution (HR)-plaque kernel with that of the energy-integrating detector CT (EID CT) in terms of the visualization of the lumen size and the in-stent stenotic portion at different coronary vessel angles. The lumen sizes in PCD CT and EID CT images were 2.13 and 1.80 mm at 0°, 2.20 and 1.77 mm at 45°, and 2.27 mm and 1.67 mm at 90°, respectively. The lumen sizes in PCD CT with HR-plaque kernel were wider than those in EID CT. The mean degree of the in-stent stenotic portion at 50% was 69.7% for PCD CT and 90.4% for EID CT. PCD CT images with HR-plaque kernel enable improved visualization of lumen size and accurate measurements of the in-stent stenotic portion compared to conventional EID CT images regardless of the stent direction.
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Affiliation(s)
- Yoshinori Funama
- Department of Medical Radiation Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Seitaro Oda
- Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Fuyuhiko Teramoto
- Medical System Research and Development Center, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Yuko Aoki
- Medical System Research and Development Center, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Isao Takahashi
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Shinichi Kojima
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Taiga Goto
- Medical System Research and Development Center, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Kana Tanaka
- Medical System Research and Development Center, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Masafumi Kidoh
- Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Yasunori Nagayama
- Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Takeshi Nakaura
- Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Toshinori Hirai
- Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
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Horst KK, Yu L, McCollough CH, Esquivel A, Thorne JE, Rajiah PS, Baffour F, Hull NC, Weber NM, Thacker PG, Thomas KB, Binkovitz LA, Guerin JB, Fletcher JG. Potential benefits of photon counting detector computed tomography in pediatric imaging. Br J Radiol 2023; 96:20230189. [PMID: 37750939 PMCID: PMC10646626 DOI: 10.1259/bjr.20230189] [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: 02/21/2023] [Revised: 08/29/2023] [Accepted: 08/30/2023] [Indexed: 09/27/2023] Open
Abstract
Photon counting detector (PCD) CT represents the newest advance in CT technology, with improved radiation dose efficiency, increased spatial resolution, inherent spectral imaging capabilities, and the ability to eliminate electronic noise. Its design fundamentally differs from conventional energy integrating detector CT because photons are directly converted to electrical signal in a single step. Rather than converting X-rays to visible light and having an output signal that is a summation of energies, PCD directly counts each photon and records its individual energy information. The current commercially available PCD-CT utilizes a dual-source CT geometry, which allows 66 ms cardiac temporal resolution and high-pitch (up to 3.2) scanning. This can greatly benefit pediatric patients by facilitating high quality fast scanning to allow sedation-free imaging. The energy-resolving nature of the utilized PCDs allows "always-on" dual-energy imaging capabilities, such as the creation of virtual monoenergetic, virtual non-contrast, virtual non-calcium, and other material-specific images. These features may be combined with high-resolution imaging, made possible by the decreased size of individual detector elements and the absence of interelement septa. This work reviews the foundational concepts associated with PCD-CT and presents examples to highlight the benefits of PCD-CT in the pediatric population.
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Affiliation(s)
- Kelly K. Horst
- Pediatric Radiology Division, Department of Radiology, Mayo Clinic, Rochester, United States
| | - Lifeng Yu
- Department of Radiology, Mayo Clinic, Rochester, United States
| | | | - Andrea Esquivel
- Department of Radiology, Mayo Clinic, Rochester, United States
| | | | | | - Francis Baffour
- Department of Radiology, Mayo Clinic, Rochester, United States
| | - Nathan C. Hull
- Pediatric Radiology Division, Department of Radiology, Mayo Clinic, Rochester, United States
| | | | - Paul G. Thacker
- Pediatric Radiology Division, Department of Radiology, Mayo Clinic, Rochester, United States
| | - Kristen B. Thomas
- Pediatric Radiology Division, Department of Radiology, Mayo Clinic, Rochester, United States
| | - Larry A. Binkovitz
- Pediatric Radiology Division, Department of Radiology, Mayo Clinic, Rochester, United States
| | - Julie B. Guerin
- Department of Radiology, Mayo Clinic, Rochester, United States
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18
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Flohr T, Schmidt B, Ulzheimer S, Alkadhi H. Cardiac imaging with photon counting CT. Br J Radiol 2023; 96:20230407. [PMID: 37750856 PMCID: PMC10646663 DOI: 10.1259/bjr.20230407] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/17/2023] [Accepted: 08/24/2023] [Indexed: 09/27/2023] Open
Abstract
CT of the heart, in particular ECG-controlled coronary CT angiography (cCTA), has become clinical routine due to rapid technical progress with ever new generations of CT equipment. Recently, CT scanners with photon-counting detectors (PCD) have been introduced which have the potential to address some of the remaining challenges for cardiac CT, such as limited spatial resolution and lack of high-quality spectral data. In this review article, we briefly discuss the technical principles of photon-counting detector CT, and we give an overview on how the improved spatial resolution of photon-counting detector CT and the routine availability of spectral data can benefit cardiac applications. We focus on coronary artery calcium scoring, cCTA, and on the evaluation of the myocardium.
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Affiliation(s)
- Thomas Flohr
- Siemens Healthcare GmbH, Computed Tomography, Forchheim, Germany
| | - Bernhard Schmidt
- Siemens Healthcare GmbH, Computed Tomography, Forchheim, Germany
| | - Stefan Ulzheimer
- Siemens Healthcare GmbH, Computed Tomography, Forchheim, Germany
| | - Hatem Alkadhi
- Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
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19
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Mergen V, Sartoretti T, Cundari G, Serifovic M, Higashigaito K, Allmendinger T, Schmidt B, Flohr T, Manka R, Eberhard M, Alkadhi H. The Importance of Temporal Resolution for Ultra-High-Resolution Coronary Angiography: Evidence From Photon-Counting Detector CT. Invest Radiol 2023; 58:767-774. [PMID: 37222522 DOI: 10.1097/rli.0000000000000987] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
PURPOSE The aim of this study was to assess the effect of temporal resolution on subjective and objective image quality of coronary computed tomography angiography (CCTA) in the ultra-high-resolution (UHR) mode with dual-source photon-counting detector (PCD) CT. MATERIALS AND METHODS This retrospective, institutional review board-approved study evaluated 30 patients (9 women; mean age, 80 ± 10 years) undergoing UHR CCTA with a clinical dual-source PCD-CT scanner. Images were acquired with a tube voltage of 120 kV and using a collimation of 120 × 0.2 mm. Gantry rotation time was 0.25 seconds. Each scan was reconstructed using both single-source and dual-source data resulting in an image temporal resolution of 125 milliseconds and 66 milliseconds, respectively. The average heart rate and the heart rate variability were recorded. Images were reconstructed with a slice thickness of 0.2 mm, quantum iterative reconstruction strength level 4, and using the Bv64 and Bv72 kernel for patients without and with coronary stents, respectively. For subjective image quality, 2 experienced readers rated motion artifacts and vessel delineation, or in-stent lumen visualization using 5-point discrete visual scales. For objective image quality, signal-to-noise ratio, contrast-to-noise ratio, stent blooming artifacts, and vessel and stent sharpness were quantified. RESULTS Fifteen patients had coronary stents, and 15 patients had no coronary stents. The mean heart rate and heart rate variability during data acquisition were 72 ± 10 beats per minute and 5 ± 6 beats per minute, respectively. Subjective image quality in the right coronary artery, left anterior descending, and circumflex artery was significantly superior in 66 milliseconds reconstructions compared with 125 milliseconds reconstructions for both readers (all P 's < 0.01; interreader agreement, Krippendorff α = 0.84-1.00). Subjective image quality deteriorated significantly at higher heart rates for 125 milliseconds (ρ = 0.21, P < 0.05) but not for 66 milliseconds reconstructions (ρ = 0.11, P = 0.22). No association was found between heart rate variability and image quality for both 125 milliseconds (ρ = 0.09, P = 0.33) and 66 milliseconds reconstructions (ρ = 0.13, P = 0.17), respectively. Signal-to-noise ratio and contrast-to-noise ratio were similar between 66 milliseconds and 125 milliseconds reconstructions (both P 's > 0.05), respectively. Stent blooming artifacts were significantly lower on 66 milliseconds than on 125 milliseconds reconstructions (46.7% ± 10% vs 52.9% ± 8.9%, P < 0.001). Higher sharpness was found in 66 milliseconds than in 125 milliseconds reconstructions both in native coronary arteries (left anterior descending artery: 1031 ± 265 ∆HU/mm vs 819 ± 253 ∆HU/mm, P < 0.01; right coronary artery: 884 ± 352 ∆HU/mm vs 654 ± 377 ∆HU/mm, P < 0.001) and stents (5318 ± 3874 ∆HU/mm vs 4267 ± 3521 ∆HU/mm, P < 0.001). CONCLUSIONS Coronary angiography with PCD-CT in the UHR mode profits considerably from a high temporal resolution, resulting in less motion artifacts, superior vessel delineation and in-stent lumen visualization, less stent blooming artifacts, and superior vessel and stent sharpness.
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Affiliation(s)
- Victor Mergen
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland (V.M., T.S., G.C., M.S., K.H., R.M., M.E., H.A.); Department of Radiological, Oncological, and Anatomopathological Sciences, Sapienza University of Rome, Rome, Italy (G.C.); Siemens Healthcare GmbH, Computed Tomography, Forchheim, Germany (T.A., B.S., T.F.); and Institute of Radiology, Spitäler fmi AG, Spital Interlaken, Unterseen, Switzerland (M.E.)
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20
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Popp D, Sinzinger AX, Decker JA, Braun F, Bette S, Risch F, Haerting M, Garthe T, Scheurig-Muenkler C, Kroencke TJ, Schwarz F. Spectral metal artifact reduction after posterior spinal fixation in photon-counting detector CT datasets. Eur J Radiol 2023; 165:110946. [PMID: 37399668 DOI: 10.1016/j.ejrad.2023.110946] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/12/2023] [Accepted: 06/19/2023] [Indexed: 07/05/2023]
Abstract
PURPOSE To investigate the usefulness of virtual monoenergetic image (VMI) reconstructions derived from scans on a novel photon-counting detector CT (PCD-CT) for artifact reduction in patients after posterior spinal fixation. METHODS This retrospective cohort study included 23 patients status post posterior spinal fixation. Subjects were scanned on a novel PCD-CT (NAEOTOM Alpha, Siemens Healthineers, Erlangen, Germany) as part of routine clinical care. 14 sets of VMI reconstructions were derived in 10 keV increments for the interval 60-190 keV. The mean and the standard deviation (SD) of CT-values in 12 defined locations around a pair of pedicle screws on one vertebral level and the SD of homogenous fat were measured and used to calculate an artifact index (AIx). RESULTS Averaged over all regions, the lowest AIx was observed at VMI levels of 110 keV (32.5 (27.8-37.9)) which was significantly different from those of VMIs ≤ 90 keV (p < 0.001) or ≥160 keV (p < 0.015), respectively. Overall AIx values increased in both lower- and higher-keV levels. Regarding individual locations, either a monotonous AIx-decrease for increasing keV values or an AIx-minimum in intermediate-keV levels (100-140 keV) was found. In locations adjacent to larger metal parts, the increase of AIx values at the high-end of the keV spectrum was mainly explained by a reappearance of streak artifacts. CONCLUSION Our findings suggest that 110 keV is the optimal VMI setting for overall artifact suppression. In specific anatomical regions, however, slight adjustments towards higher-keV levels may provide better results.
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Affiliation(s)
- Daniel Popp
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Andrea X Sinzinger
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Josua A Decker
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Franziska Braun
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Stefanie Bette
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Franka Risch
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Mark Haerting
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Tarik Garthe
- Department of Trauma, Orthopedics, Plastic and Hand Surgery, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Christian Scheurig-Muenkler
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Thomas J Kroencke
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Florian Schwarz
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany; Institute for Radiology, DONAUISAR Hospital Deggendorf-Dingolfing-Landau, Perlasberger Str. 41, 94469 Deggendorf, Germany; Medical Faculty, Ludwig Maximilian University Munich, Bavariaring 19, 80336 Munich, Germany.
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21
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Jost G, McDermott M, Gutjahr R, Nowak T, Schmidt B, Pietsch H. New Contrast Media for K-Edge Imaging With Photon-Counting Detector CT. Invest Radiol 2023; 58:515-522. [PMID: 37068840 PMCID: PMC10259215 DOI: 10.1097/rli.0000000000000978] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 03/01/2023] [Indexed: 04/19/2023]
Abstract
ABSTRACT The recent technological developments in photon-counting detector computed tomography (PCD-CT) and the introduction of the first commercially available clinical PCD-CT unit open up new exciting opportunities for contrast media research. With PCD-CT, the efficacy of available iodine-based contrast media improves, allowing for a reduction of iodine dosage or, on the other hand, an improvement of image quality in low contrast indications. Virtual monoenergetic image reconstructions are routinely available and enable the virtual monoenergetic image energy to be adapted to the diagnostic task.A key property of PCD-CT is the ability of spectral separation in combination with improved material decomposition. Thus, the discrimination of contrast media from intrinsic or pathological tissues and the discrimination of 2 or more contrasting elements that characterize different tissues are attractive fields for contrast media research. For these approaches, K-edge imaging in combination with high atomic number elements such as the lanthanides, tungsten, tantalum, or bismuth plays a central role.The purpose of this article is to present an overview of innovative contrast media concepts that use high atomic number elements. The emphasis is on improving contrast enhancement for cardiovascular plaque imaging, stent visualization, and exploring new approaches using 2 contrasting elements. Along with the published research, new experimental findings with a contrast medium that incorporates tungsten are included.Both the literature review and the new experimental data demonstrate the great potential and feasibility for new contrast media to significantly increase diagnostic performance and to enable new clinical fields and indications in combination with PCD-CT.
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Affiliation(s)
- Gregor Jost
- From the MR and CT Contrast Media Research, Bayer AG, Berlin, Germany
| | - Michael McDermott
- From the MR and CT Contrast Media Research, Bayer AG, Berlin, Germany
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Ralf Gutjahr
- Computed Tomography, Siemens Healthineers, Forchheim, Germany
| | - Tristan Nowak
- Computed Tomography, Siemens Healthineers, Forchheim, Germany
| | | | - Hubertus Pietsch
- From the MR and CT Contrast Media Research, Bayer AG, Berlin, Germany
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22
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Abstract
ABSTRACT In the past decades, we have witnessed tremendous technical innovations in computed tomography (CT) imaging. These included improvements in temporal and spatial resolution, lowering of the radiation dose, the introduction of dual-energy and multi-energy imaging, automated image preprocessing and machine learning algorithms, and, most recently, the development and clinical introduction of photon-counting detector CT. This special issue of Investigative Radiology comprises a collection of expert summaries and reviews on this most impactful recent innovation and cutting-edge technology of photon-counting detector CT. It includes articles on technical details about this new CT scanner type and summaries of the first clinical experience in cardiac and vascular imaging, neuroimaging, as well as chest and abdominal imaging, and concludes with an outlook to new contrast agents with potential for k-edge imaging, which are on the horizon.
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Affiliation(s)
- Hatem Alkadhi
- From the Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich
| | - Val Runge
- Department of Diagnostic, Interventional, and Pediatric Radiology, University Hospital of Bern, Inselspital, University of Bern, Bern, Switzerland
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23
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Flohr T, Schmidt B. Technical Basics and Clinical Benefits of Photon-Counting CT. Invest Radiol 2023; 58:441-450. [PMID: 37185302 PMCID: PMC10259209 DOI: 10.1097/rli.0000000000000980] [Citation(s) in RCA: 36] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 03/05/2023] [Indexed: 05/17/2023]
Abstract
ABSTRACT Novel photon-counting detector CT (PCD-CT) has the potential to address the limitations of previous CT systems, such as insufficient spatial resolution, limited accuracy in detecting small low-contrast structures, or missing routine availability of spectral information. In this review article, we explain the basic principles and potential clinical benefits of PCD-CT, with a focus on recent literature that has grown rapidly since the commercial introduction of a clinically approved PCD-CT.
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24
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Yang Y, Fink N, Emrich T, Graafen D, Richter R, Bockius S, Wolf EV, Laux G, Kavermann L, Müller L, Hell M, Halfmann MC. Optimization of Kernel Type and Sharpness Level Improves Objective and Subjective Image Quality for High-Pitch Photon Counting Coronary CT Angiography. Diagnostics (Basel) 2023; 13:diagnostics13111937. [PMID: 37296789 DOI: 10.3390/diagnostics13111937] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 05/25/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023] Open
Abstract
(1) Background: Photon-counting detector (PCD) CT offers a wide variety of kernels and sharpness levels for image reconstruction. The aim of this retrospective study was to determine optimal settings for coronary CT angiography (CCTA). (2) Methods: Thirty patients (eight female, mean age 63 ± 13 years) underwent PCD-CCTA in a high-pitch mode. Images were reconstructed using three different kernels and four sharpness levels (Br36/40/44/48, Bv36/40/44/48, and Qr36/40/44/48). To analyze objective image quality, the attenuation, image noise, contrast-to-noise ratio (CNR), and vessel sharpness were quantified in proximal and distal coronaries. For subjective image quality, two blinded readers assessed image noise, visually sharp reproduction of coronaries, and the overall image quality using a five-point Likert scale. (3) Results: Attenuation, image noise, CNR, and vessel sharpness significantly differed across kernels (all p < 0.001), with the Br-kernel reaching the highest attenuation. With increasing kernel sharpness, image noise and vessel sharpness increased, whereas CNR continuously decreased. Reconstruction with Br-kernel generally had the highest CNR (Br > Bv > Qr), except Bv-kernel had a superior CNR at sharpness level 40. Bv-kernel had significantly higher vessel sharpness than Br- and Qr-kernel (p < 0.001). Subjective image quality was rated best for kernels Bv40 and Bv36, followed by Br36 and Qr36. (4) Conclusion: Reconstructions with kernel Bv40 are beneficial to achieve optimal image quality in spectral high-pitch CCTA using PCD-CT.
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Affiliation(s)
- Yang Yang
- Department of Diagnostic and Interventional Radiology, University Medical Center Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany
| | - Nicola Fink
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
- Department of Radiology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Tilman Emrich
- Department of Diagnostic and Interventional Radiology, University Medical Center Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
| | - Dirk Graafen
- Department of Diagnostic and Interventional Radiology, University Medical Center Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany
| | - Rosa Richter
- Department of Diagnostic and Interventional Radiology, University Medical Center Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany
| | - Stefanie Bockius
- Department of Diagnostic and Interventional Radiology, University Medical Center Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany
| | - Elias V Wolf
- Department of Diagnostic and Interventional Radiology, University Medical Center Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany
| | - Gerald Laux
- Department of Cardiology, University Medical Center Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany
| | - Larissa Kavermann
- Department of Cardiology, University Medical Center Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany
| | - Lukas Müller
- Department of Diagnostic and Interventional Radiology, University Medical Center Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany
| | - Michaela Hell
- Department of Cardiology, University Medical Center Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany
| | - Moritz C Halfmann
- Department of Diagnostic and Interventional Radiology, University Medical Center Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany
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