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Goller SS, Sutter R. Advanced Imaging of Total Knee Arthroplasty. Semin Musculoskelet Radiol 2024; 28:282-292. [PMID: 38768593 DOI: 10.1055/s-0044-1781470] [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: 05/22/2024]
Abstract
The prevalence of total knee arthroplasty (TKA) is increasing with the aging population. Although long-term results are satisfactory, suspected postoperative complications often require imaging with the implant in place. Advancements in computed tomography (CT), such as tin prefiltration, metal artifact reduction algorithms, dual-energy CT with virtual monoenergetic imaging postprocessing, and the application of cone-beam CT and photon-counting detector CT, allow a better depiction of the tissues adjacent to the metal. For magnetic resonance imaging (MRI), high bandwidth (BW) optimization, the combination of view angle tilting and high BW, as well as multispectral imaging techniques with multiacquisition variable-resonance image combination or slice encoding metal artifact correction, have significantly improved imaging around metal implants, turning MRI into a useful clinical tool for patients with suspected TKA complications.
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Affiliation(s)
- Sophia Samira Goller
- Department of Radiology, Balgrist University Hospital, Faculty of Medicine, University of Zurich, Zurich, Switzerland
| | - Reto Sutter
- Department of Radiology, Balgrist University Hospital, Faculty of Medicine, University of Zurich, Zurich, Switzerland
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2
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Cheong SCW, Yan YY, Sheikh A, Ouellette HA, Munk PL, Murray N, Mallinson PI. Dual-energy CT applications in musculoskeletal disorders. Br J Radiol 2024; 97:705-715. [PMID: 38291893 PMCID: PMC11027318 DOI: 10.1093/bjr/tqae023] [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: 07/30/2023] [Revised: 01/06/2024] [Accepted: 01/24/2024] [Indexed: 02/01/2024] Open
Abstract
Dual-energy CT (DECT) is an exciting application in CT technology conferring many advantages over conventional single-energy CT at no additional with comparable radiation dose to the patient. Various emerging and increasingly established clinical DECT applications in musculoskeletal (MSK) imaging such as bone marrow oedema detection, metal artefact reduction, monosodium urate analysis, and collagen analysis for ligamentous, meniscal, and disc injuries are made possible through its advanced DECT post-processing capabilities. These provide superior information on tissue composition, artefact reduction and image optimization. Newer DECT applications to evaluate fat fraction for sarcopenia, Rho/Z application for soft tissue calcification differentiation, 3D rendering, and AI integration are being assessed for future use. In this article, we will discuss the established and developing applications of DECT in the setting of MSK radiology as well as the basic principles of DECT which facilitate them.
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Affiliation(s)
- Sook Chuei W Cheong
- Musculoskeletal section, Department of Radiology, Vancouver General Hospital, University of British Columbia, Vancouver, BC, V5Z 1M9 Canada
- Department of Radiology, Changi General Hospital, Singapore 529889, Singapore
| | - Yet Yen Yan
- Musculoskeletal section, Department of Radiology, Vancouver General Hospital, University of British Columbia, Vancouver, BC, V5Z 1M9 Canada
- Department of Radiology, Changi General Hospital, Singapore 529889, Singapore
| | - Adnan Sheikh
- Musculoskeletal section, Department of Radiology, Vancouver General Hospital, University of British Columbia, Vancouver, BC, V5Z 1M9 Canada
| | - Hugue A Ouellette
- Musculoskeletal section, Department of Radiology, Vancouver General Hospital, University of British Columbia, Vancouver, BC, V5Z 1M9 Canada
| | - Peter L Munk
- Musculoskeletal section, Department of Radiology, Vancouver General Hospital, University of British Columbia, Vancouver, BC, V5Z 1M9 Canada
| | - Nicolas Murray
- Musculoskeletal section, Department of Radiology, Vancouver General Hospital, University of British Columbia, Vancouver, BC, V5Z 1M9 Canada
| | - Paul I Mallinson
- Musculoskeletal section, Department of Radiology, Vancouver General Hospital, University of British Columbia, Vancouver, BC, V5Z 1M9 Canada
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3
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Mizuki M, Yasaka K, Miyo R, Ohtake Y, Hamada A, Hosoi R, Abe O. Deep Learning Reconstruction Plus Single-Energy Metal Artifact Reduction for Supra Hyoid Neck CT in Patients With Dental Metals. Can Assoc Radiol J 2024; 75:74-81. [PMID: 37387607 DOI: 10.1177/08465371231182904] [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: 07/01/2023] Open
Abstract
Purpose: We investigated the effect of deep learning reconstruction (DLR) plus single-energy metal artifact reduction (SEMAR) on neck CT in patients with dental metals, comparing it with DLR and with hybrid iterative reconstruction (Hybrid IR)-SEMAR. Methods: In this retrospective study, 32 patients (25 men, 7 women; mean age: 63 ± 15 years) with dental metals underwent contrast-enhanced CT of the oral and oropharyngeal regions. Axial images were reconstructed using DLR, Hybrid IR-SEMAR, and DLR-SEMAR. In quantitative analyses, degrees of image noise and artifacts were evaluated. In one-by-one qualitative analyses, 2 radiologists evaluated metal artifacts, the depiction of structures, and noise on five-point scales. In side-by-side qualitative analyses, artifacts and overall image quality were evaluated by comparing Hybrid IR-SEMAR with DLR-SEMAR. Results: Artifacts were significantly less with DLR-SEMAR than with DLR in quantitative (P < .001) and one-by-one qualitative (P < .001) analyses, which resulted in significantly better depiction of most structures (P < .004). Artifacts in side-by-side analysis and image noise in quantitative and one-by-one qualitative analyses (P < .001) were significantly less with DLR-SEMAR than with Hybrid IR-SEMAR, resulting in significantly better overall quality of DLR-SEMAR. Conclusions: Compared with DLR and Hybrid IR-SEMAR, DLR-SEMAR provided significantly better supra hyoid neck CT images in patients with dental metals.
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Affiliation(s)
- Masumi Mizuki
- Department of Radiology, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
| | - Koichiro Yasaka
- Department of Radiology, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
| | - Rintaro Miyo
- Department of Radiology, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
| | - Yuta Ohtake
- Department of Radiology, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
| | - Akiyoshi Hamada
- Department of Radiology, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
| | - Reina Hosoi
- Department of Radiology, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
| | - Osamu Abe
- Department of Radiology, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
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4
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Selles M, van Osch JAC, Maas M, Boomsma MF, Wellenberg RHH. Advances in metal artifact reduction in CT images: A review of traditional and novel metal artifact reduction techniques. Eur J Radiol 2024; 170:111276. [PMID: 38142571 DOI: 10.1016/j.ejrad.2023.111276] [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: 11/02/2023] [Revised: 12/14/2023] [Accepted: 12/18/2023] [Indexed: 12/26/2023]
Abstract
Metal artifacts degrade CT image quality, hampering clinical assessment. Numerous metal artifact reduction methods are available to improve the image quality of CT images with metal implants. In this review, an overview of traditional methods is provided including the modification of acquisition and reconstruction parameters, projection-based metal artifact reduction techniques (MAR), dual energy CT (DECT) and the combination of these techniques. Furthermore, the additional value and challenges of novel metal artifact reduction techniques that have been introduced over the past years are discussed such as photon counting CT (PCCT) and deep learning based metal artifact reduction techniques.
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Affiliation(s)
- Mark Selles
- Department of Radiology, Isala, 8025 AB Zwolle, the Netherlands; Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centre, 1105 AZ Amsterdam, the Netherlands; Amsterdam Movement Sciences, 1081 BT Amsterdam, the Netherlands.
| | | | - Mario Maas
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centre, 1105 AZ Amsterdam, the Netherlands; Amsterdam Movement Sciences, 1081 BT Amsterdam, the Netherlands
| | | | - Ruud H H Wellenberg
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centre, 1105 AZ Amsterdam, the Netherlands; Amsterdam Movement Sciences, 1081 BT Amsterdam, the Netherlands
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5
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Zhou J, See CW, Sreenivasamurthy S, Zhu D. Customized Additive Manufacturing in Bone Scaffolds-The Gateway to Precise Bone Defect Treatment. RESEARCH (WASHINGTON, D.C.) 2023; 6:0239. [PMID: 37818034 PMCID: PMC10561823 DOI: 10.34133/research.0239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 09/07/2023] [Indexed: 10/12/2023]
Abstract
In the advancing landscape of technology and novel material development, additive manufacturing (AM) is steadily making strides within the biomedical sector. Moving away from traditional, one-size-fits-all implant solutions, the advent of AM technology allows for patient-specific scaffolds that could improve integration and enhance wound healing. These scaffolds, meticulously designed with a myriad of geometries, mechanical properties, and biological responses, are made possible through the vast selection of materials and fabrication methods at our disposal. Recognizing the importance of precision in the treatment of bone defects, which display variability from macroscopic to microscopic scales in each case, a tailored treatment strategy is required. A patient-specific AM bone scaffold perfectly addresses this necessity. This review elucidates the pivotal role that customized AM bone scaffolds play in bone defect treatment, while offering comprehensive guidelines for their customization. This includes aspects such as bone defect imaging, material selection, topography design, and fabrication methodology. Additionally, we propose a cooperative model involving the patient, clinician, and engineer, thereby underscoring the interdisciplinary approach necessary for the effective design and clinical application of these customized AM bone scaffolds. This collaboration promises to usher in a new era of bioactive medical materials, responsive to individualized needs and capable of pushing boundaries in personalized medicine beyond those set by traditional medical materials.
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Affiliation(s)
- Juncen Zhou
- Department of Biomedical Engineering,
Stony Brook University, Stony Brook, NY, USA
| | - Carmine Wang See
- Department of Biomedical Engineering,
Stony Brook University, Stony Brook, NY, USA
| | - Sai Sreenivasamurthy
- Department of Biomedical Engineering,
Stony Brook University, Stony Brook, NY, USA
| | - Donghui Zhu
- Department of Biomedical Engineering,
Stony Brook University, Stony Brook, NY, USA
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Rau A, Straehle J, Stein T, Diallo T, Rau S, Faby S, Nikolaou K, Schoenberg SO, Overhoff D, Beck J, Urbach H, Klingler JH, Bamberg F, Weiss J. Photon-Counting Computed Tomography (PC-CT) of the spine: impact on diagnostic confidence and radiation dose. Eur Radiol 2023; 33:5578-5586. [PMID: 36890304 PMCID: PMC10326119 DOI: 10.1007/s00330-023-09511-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 01/23/2023] [Accepted: 02/10/2023] [Indexed: 03/10/2023]
Abstract
OBJECTIVES Computed tomography (CT) is employed to evaluate surgical outcome after spinal interventions. Here, we investigate the potential of multispectral photon-counting computed tomography (PC-CT) on image quality, diagnostic confidence, and radiation dose compared to an energy-integrating CT (EID-CT). METHODS In this prospective study, 32 patients underwent PC-CT of the spine. Data was reconstructed in two ways: (1) standard bone kernel with 65-keV (PC-CTstd) and (2) 130-keV monoenergetic images (PC-CT130 keV). Prior EID-CT was available for 17 patients; for the remaining 15, an age-, sex-, and body mass index-matched EID-CT cohort was identified. Image quality (5-point Likert scales on overall, sharpness, artifacts, noise, diagnostic confidence) of PC-CTstd and EID-CT was assessed by four radiologists independently. If metallic implants were present (n = 10), PC-CTstd and PC-CT130 keV images were again assessed by 5-point Likert scales by the same radiologists. Hounsfield units (HU) were measured within metallic artifact and compared between PC-CTstd and PC-CT130 keV. Finally, the radiation dose (CTDIvol) was evaluated. RESULTS Sharpness was rated significantly higher (p = 0.009) and noise significantly lower (p < 0.001) in PC-CTstd vs. EID-CT. In the subset of patients with metallic implants, reading scores for PC-CT130 keV revealed superior ratings vs. PC-CTstd for image quality, artifacts, noise, and diagnostic confidence (all p < 0.001) accompanied by a significant increase of HU values within the artifact (p < 0.001). Radiation dose was significantly lower for PC-CT vs. EID-CT (mean CTDIvol: 8.83 vs. 15.7 mGy; p < 0.001). CONCLUSIONS PC-CT of the spine with high-kiloelectronvolt reconstructions provides sharper images, higher diagnostic confidence, and lower radiation dose in patients with metallic implants. KEY POINTS • Compared to energy-integrating CT, photon-counting CT of the spine had significantly higher sharpness and lower image noise while radiation dose was reduced by 45%. • In patients with metallic implants, virtual monochromatic photon-counting images at 130 keV were superior to standard reconstruction at 65 keV in terms of image quality, artifacts, noise, and diagnostic confidence.
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Affiliation(s)
- Alexander Rau
- Department of Diagnostic and Interventional Radiology, University Hospital, Hugstetter Straße 55, 79106, Freiburg, Germany.
- Department of Neuroradiology, University Hospital, Breisacher Straße 64, 79106, Freiburg, Germany.
| | - Jakob Straehle
- Department of Neurosurgery, University Hospital, Breisacher Straße 64, 79106, Freiburg, Germany
| | - Thomas Stein
- Department of Diagnostic and Interventional Radiology, University Hospital, Hugstetter Straße 55, 79106, Freiburg, Germany
| | - Thierno Diallo
- Department of Diagnostic and Interventional Radiology, University Hospital, Hugstetter Straße 55, 79106, Freiburg, Germany
| | - Stephan Rau
- Department of Diagnostic and Interventional Radiology, University Hospital, Hugstetter Straße 55, 79106, Freiburg, Germany
- Department of Neuroradiology, University Hospital, Breisacher Straße 64, 79106, Freiburg, Germany
| | | | - Konstantin Nikolaou
- Department of Diagnostic and Interventional Radiology, University Tuebingen, Hoppe-Seyler Straße 3, 72076, Tuebingen, Germany
| | - Stefan O Schoenberg
- Department of Radiology and Nuclear Medicine, University Medical Center Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Daniel Overhoff
- Department of Radiology and Nuclear Medicine, University Medical Center Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Jürgen Beck
- Department of Neurosurgery, University Hospital, Breisacher Straße 64, 79106, Freiburg, Germany
| | - Horst Urbach
- Department of Neuroradiology, University Hospital, Breisacher Straße 64, 79106, Freiburg, Germany
| | - Jan-Helge Klingler
- Department of Neurosurgery, University Hospital, Breisacher Straße 64, 79106, Freiburg, Germany
| | - Fabian Bamberg
- Department of Diagnostic and Interventional Radiology, University Hospital, Hugstetter Straße 55, 79106, Freiburg, Germany
| | - Jakob Weiss
- Department of Diagnostic and Interventional Radiology, University Hospital, Hugstetter Straße 55, 79106, Freiburg, Germany
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7
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Advances in Bone Joint Imaging-Metal Artifact Reduction. Diagnostics (Basel) 2022; 12:diagnostics12123079. [PMID: 36553086 PMCID: PMC9776622 DOI: 10.3390/diagnostics12123079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/01/2022] [Accepted: 12/04/2022] [Indexed: 12/12/2022] Open
Abstract
Numerous types of metal implants have been introduced in orthopedic surgery and are used in everyday practice. To precisely evaluate the postoperative condition of arthroplasty or trauma surgery, periprosthetic infection, and the loosening of implants, it is important to reduce artifacts induced by metal implants. In this review, we focused on technical advances in metal artifact reduction using digital tomosynthesis, computed tomography, and magnetic resonance imaging. We discussed new developments in diagnostic imaging methods and the continuous introduction of novel technologies to reduce metal artifacts; however, these innovations have not yet completely removed metal artifacts. Different algorithms need to be selected depending on the size, shape, material and implanted body parts of an implant. Future advances in metal artifact reduction algorithms and techniques and the development of new sequences may enable further reductions in metal artifacts even on original images taken previously. Moreover, the combination of different imaging modalities may contribute to further reductions in metal artifacts. Clinicians must constantly update their knowledge and work closely with radiologists to select the best diagnostic imaging method for each metal implant.
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8
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Dual-source computed tomography protocols for the pediatric chest - scan optimization techniques. Pediatr Radiol 2022:10.1007/s00247-022-05468-7. [PMID: 35948645 PMCID: PMC9365683 DOI: 10.1007/s00247-022-05468-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/28/2022] [Accepted: 07/21/2022] [Indexed: 11/26/2022]
Abstract
The gold standard for pediatric chest imaging remains the CT scan. An ideal pediatric chest CT has the lowest radiation dose with the least motion degradation possible in a diagnostic scan. Because of the known inherent risks and costs of anesthesia, non-sedate options are preferred. Dual-source CTs are currently the fastest, lowest-dose CT scanners available, utilizing an ultra-high-pitch mode resulting in sub-second CTs. The dual-energy technique, available on dual-source CT scanners, gathers additional information such as pulmonary blood volume and includes relative contrast enhancement and metallic artifact reduction, features that are not available in high-pitch flash mode. In this article we discuss the benefits and tradeoffs of dual-source CT scan modes and tips on image optimization.
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9
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Cheraya G, Sharma S, Chhabra A. Dual energy CT in musculoskeletal applications beyond crystal imaging: bone marrow maps and metal artifact reduction. Skeletal Radiol 2022; 51:1521-1534. [PMID: 35112139 DOI: 10.1007/s00256-021-03979-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 02/02/2023]
Abstract
Dual energy CT (DECT) is becoming increasingly popular and valuable in the domain of musculoskeletal imaging. Gout maps and crystal detection have been predominant indications for about a decade. Other important indications of bone marrow maps and metal artifact reduction are also frequent with added advantages of detection and characterization of bone marrow lesions similar to MR imaging and diagnosis of hardware related complications, respectively. This article discusses technical considerations and physics of DECT imaging and its role in musculoskeletal indications apart from crystal imaging with respective case examples and review of the related literature. DECT pitfalls in these domains are also highlighted and the reader can gain knowledge of above concepts for prudent use of DECT in their musculoskeletal and general practices.
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Affiliation(s)
| | - Salil Sharma
- Mary Imogene Bassett Hospital, Cooperstown, NY, USA
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10
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Byl A, Klein L, Sawall S, Heinze S, Schlemmer HP, Kachelrieß M. Photon-counting normalized metal artifact reduction (NMAR) in diagnostic CT. Med Phys 2021; 48:3572-3582. [PMID: 33973237 DOI: 10.1002/mp.14931] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 04/02/2021] [Accepted: 04/12/2021] [Indexed: 11/12/2022] Open
Abstract
PURPOSE Metal artifacts can drastically reduce the diagnostic value of computed tomography (CT) images. Even the state-of-the-art algorithms cannot remove them completely. Photon-counting CT inherently provides spectral information, similar to dual-energy CT. Many applications, such as material decomposition, are not possible when metal artifacts are present. Our aim is to develop a prior-based metal artifact reduction specifically for photon-counting CT that can correct each bin image individually or in their combinations. METHODS Photon-counting CT sorts incoming photons into several energy bins, producing bin and threshold images containing spectral information. We use this spectral information to obtain a better prior image for the state-of-the-art metal artifact reduction algorithm FSNMAR. First, we apply a non-linear transformation to the bin images to obtain bone-emphasized images. Subsequently, we forward-project the bin images and bone-emphasized images and multiply the resulting sinograms with each other element-wise to mimic beam hardening effects. These sinograms are reconstructed and linearly combined to produce an artifact-reduced image. The coefficients of this linear combination are automatically determined by minimizing a threshold-based cost function in the image domain. After thresholding, we obtain the prior image for FSNMAR, which is applied to the individual bin images and the lowest threshold image. We test our photon-counting normalized metal artifact reduction (PCNMAR) on forensic CT data and compare it to conventional FSNMAR, where the prior is generated via linear sinogram inpainting. For numerical analysis, we compute both the standard deviation in an ROI with metal artifacts and the CNR of soft tissue and fat. RESULTS PCNMAR can effectively reduce metal artifacts without sacrificing the overall image quality. Compared to FSNMAR, our method produces fewer secondary artifacts and is more consistent with the measurements. Areas that contain metal, air, and soft tissue are more accurate in PCNMAR. In some cases, the standard deviation in the artifact ROI is reduced by more than 50% relative to FSNMAR, while the CNR values are similar. If extreme artifacts are present, PCNMAR is unable to outperform FSNMAR. Using either two, four, or only the highest energy bin to produce the prior image yielded comparable results. CONCLUSIONS PCNMAR is an effective method of reducing metal artifacts in photon-counting CT. The spectral information available in photon-counting CT is highly beneficial for metal artifact reduction, especially the high-energy bin, which inherently contains fewer artifacts. While scanning with four instead of two bins does not provide a better artifact reduction, it allows for more freedom in the selection of energy thresholds.
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Affiliation(s)
- Achim Byl
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany.,Department of Physics and Astronomy, Ruprecht-Karls-University Heidelberg, Heidelberg, 69120, Germany
| | - Laura Klein
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany.,Department of Physics and Astronomy, Ruprecht-Karls-University Heidelberg, Heidelberg, 69120, Germany
| | - Stefan Sawall
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany.,Medical Faculty, Ruprecht-Karls-University Heidelberg, Heidelberg, 69120, Germany
| | - Sarah Heinze
- Institute of Forensic and Traffic Medicine, University Hospital Heidelberg, Heidelberg, 69115, Germany
| | - Heinz-Peter Schlemmer
- Division of Radiology, German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany
| | - Marc Kachelrieß
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany.,Medical Faculty, Ruprecht-Karls-University Heidelberg, Heidelberg, 69120, Germany
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11
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Metal artefact reduction of different alloys with dual energy computed tomography (DECT). Sci Rep 2021; 11:2211. [PMID: 33500471 PMCID: PMC7838173 DOI: 10.1038/s41598-021-81600-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 01/07/2021] [Indexed: 11/10/2022] Open
Abstract
To evaluate the influence of dual-energy CT (DECT) and Virtual monochromatic spectral (VMS) imaging on: (1) the artefact size of geometrically identical orthopaedic implants consisting of three different compositions and (2) the image quality of the surrounding bone, three similar phantoms—each featuring one femoral stem composed of either titanium, chrome-cobalt or stainless steel surrounded by five calcium pellets (200 mg hydroxyapatite/calcium carbonate) to simulate bony tissue and one reference pellet located away from the femoral stem—were built. DECT with two sequential scans (80 kVp and 140 kVp; scan-to-scan technique) was performed, and VMS images were calculated between 40 and 190 keV. The artefact sizes were measured volumetrically by semiautomatic selection of regions of interest (ROIs), considering the VMS energies and the polychromatic spectres. Moreover, density and image noise within the pellets were measured. All three phantoms exhibit artefact size reduction as energy increases from 40 to 190 keV. Titanium exhibited a stronger reduction than chrome-cobalt and stainless steel. The artefacts were dependent on the diameter of the stem. Image quality increases with higher energies on VMS with a better depiction of surrounding structures. Monoenergetic energies 70 keV and 140 keV demonstrate superior image quality to those produced by spectral energies 80 kVp and 140 kVp.
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12
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Ishiwata Y, Hieda Y, Kaki S, Aso S, Horie K, Kobayashi Y, Nakamura M, Yamada K, Yamashiro T, Utsunomiya D. Improved Diagnostic Accuracy of Bone Metastasis Detection by Water-HAP Associated to Non-Contrast CT. Diagnostics (Basel) 2020; 10:diagnostics10100853. [PMID: 33092274 PMCID: PMC7589875 DOI: 10.3390/diagnostics10100853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 10/17/2020] [Accepted: 10/19/2020] [Indexed: 11/30/2022] Open
Abstract
We examined whether water-hydroxyapatite (HAP) images improve the diagnostic accuracy of bone metastasis compared with non-contrast CT alone. We retrospectively evaluated dual-energy computed tomography (DECT) images of 83 cancer patients (bone metastasis, 31; without bone metastasis, 52) from May 2018 to June 2019. Initially, two evaluators examined for bone metastasis on conventional CT images. In the second session, both CT and CT images plus water-HAP images on DECT. The confidence of bone metastasis was scored from 1 (benign) to 5 (malignant). The sensitivity, specificity, positive predictive values, and negative predictive values for both modalities were calculated based on true positive and negative findings. The intra-observer area under curve (AUC) for detecting bone metastasis was compared by receiver operating characteristic analysis. Kappa coefficient calculated the inter-observer agreement. In conventional CT images, sensitivity, specificity, positive predictive value, and negative predictive value of raters 1 and 2 for the identification of bone metastases were 0.742 and 0.710, 0.981 and 0.981, 0.958 and 0.957, and 0.864 and 0.850, respectively. In water-HAP, they were 1.00 and 1.00, 0.981 and 1.00, 0.969 and 1.00, and 1.00 and 1.00, respectively. In CT, AUCs were 0.861 and 0.845 in each observer. On water-HAP images, AUCs were 0.990 and 1.00. Kappa coefficient was 0.964 for CT and 0.976 for water-HAP images. The combination of CT and water-HAP images significantly increased diagnostic accuracy for detecting bone metastasis. Water-HAP images on DECT may enable accurate initial staging, reduced radiation exposure, and cost.
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Affiliation(s)
- Yoshinobu Ishiwata
- Department of Radiology, Yokohama City University Hospital, 3–9 Fukuura, Kanazawa-ward, Yokohama City 2360004, Japan; (S.A.); (K.H.); (T.Y.); (D.U.)
- Correspondence: ; Tel.: +81-457-872-696; Fax: +81-457-860-369
| | - Yojiro Hieda
- Department of Radiology, Odawara Municipal Hospital, 46 Kuno, Odawara City 2508558, Japan; (Y.H.); (S.K.); (K.Y.)
| | - Soichiro Kaki
- Department of Radiology, Odawara Municipal Hospital, 46 Kuno, Odawara City 2508558, Japan; (Y.H.); (S.K.); (K.Y.)
| | - Shinjiro Aso
- Department of Radiology, Yokohama City University Hospital, 3–9 Fukuura, Kanazawa-ward, Yokohama City 2360004, Japan; (S.A.); (K.H.); (T.Y.); (D.U.)
| | - Keiichi Horie
- Department of Radiology, Yokohama City University Hospital, 3–9 Fukuura, Kanazawa-ward, Yokohama City 2360004, Japan; (S.A.); (K.H.); (T.Y.); (D.U.)
| | - Yusuke Kobayashi
- Department of Radiology, Yokohama City University Medical Center, 4–57 Urafune, Minami-ward, Yokohama City 2320024, Japan; (Y.K.); (M.N.)
| | - Motoki Nakamura
- Department of Radiology, Yokohama City University Medical Center, 4–57 Urafune, Minami-ward, Yokohama City 2320024, Japan; (Y.K.); (M.N.)
| | - Kazuhiko Yamada
- Department of Radiology, Odawara Municipal Hospital, 46 Kuno, Odawara City 2508558, Japan; (Y.H.); (S.K.); (K.Y.)
| | - Tsuneo Yamashiro
- Department of Radiology, Yokohama City University Hospital, 3–9 Fukuura, Kanazawa-ward, Yokohama City 2360004, Japan; (S.A.); (K.H.); (T.Y.); (D.U.)
| | - Daisuke Utsunomiya
- Department of Radiology, Yokohama City University Hospital, 3–9 Fukuura, Kanazawa-ward, Yokohama City 2360004, Japan; (S.A.); (K.H.); (T.Y.); (D.U.)
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Vaishnav JY, Ghammraoui B, Leifer M, Zeng R, Jiang L, Myers KJ. CT metal artifact reduction algorithms: Toward a framework for objective performance assessment. Med Phys 2020; 47:3344-3355. [PMID: 32406534 PMCID: PMC7496341 DOI: 10.1002/mp.14231] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 04/05/2020] [Accepted: 04/29/2020] [Indexed: 12/26/2022] Open
Abstract
Purpose Although several metal artifact reduction (MAR) algorithms for computed tomography (CT) scanning are commercially available, no quantitative, rigorous, and reproducible method exists for assessing their performance. The lack of assessment methods poses a challenge to regulators, consumers, and industry. We explored a phantom‐based framework for assessing an important aspect of MAR performance: how applying MAR in the presence of metal affects model observer performance at a low‐contrast detectability (LCD) task This work is, to our knowledge, the first model observer–based framework for the evaluation of MAR algorithms in the published literature. Methods We designed a numerical head phantom with metal implants. In order to incorporate an element of randomness, the phantom included a rotatable inset with an inhomogeneous background. We generated simulated projection data for the phantom. We applied two variants of a simple MAR algorithm, sinogram inpainting, to the projection data, that we reconstructed using filtered backprojection. To assess how MAR affected observer performance, we examined the detectability of a signal at the center of a region of interest (ROI) by a channelized Hotelling observer (CHO). As a figure of merit, we used the area under the ROC curve (AUC). Results We used simulation to test our framework on two variants of the MAR technique of sinogram inpainting. We found that our method was able to resolve the difference in two different MAR algorithms’ effect on LCD task performance, as well as the difference in task performances when MAR was applied, vs not. Conclusion We laid out a phantom‐based framework for objective assessment of how MAR impacts low‐contrast detectability, that we tested on two MAR algorithms. Our results demonstrate the importance of testing MAR performance over a range of object and imaging parameters, since applying MAR does not always improve the quality of an image for a given diagnostic task. Our framework is an initial step toward developing a more comprehensive objective assessment method for MAR, which would require developing additional phantoms and methods specific to various clinical applications of MAR, and increasing study efficiency.
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Affiliation(s)
- J Y Vaishnav
- Diagnostic X-Ray Systems Branch, Office of In Vitro Diagnostic Devices and Radiological Health, Center for Devices and Radiological Health, United States Food & Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD, 20993, USA.,Canon Medical Systems, USA, Inc., 2441 Michelle Drive, Tustin, CA, 92780, USA
| | - B Ghammraoui
- Division of Imaging, Diagnostics, and Software Reliability, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food & Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD, 20993, USA
| | - M Leifer
- Division of Imaging, Diagnostics, and Software Reliability, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food & Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD, 20993, USA
| | - R Zeng
- Division of Imaging, Diagnostics, and Software Reliability, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food & Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD, 20993, USA
| | - L Jiang
- Diagnostic X-Ray Systems Branch, Office of In Vitro Diagnostic Devices and Radiological Health, Center for Devices and Radiological Health, United States Food & Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD, 20993, USA
| | - K J Myers
- Division of Imaging, Diagnostics, and Software Reliability, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food & Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD, 20993, USA
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Alexander LF, Hanna TN, LeGout JD, Roda MS, Cernigliaro JG, Mittal PK, Harri PA. Multidetector CT Findings in the Abdomen and Pelvis after Damage Control Surgery for Acute Traumatic Injuries. Radiographics 2020; 39:1183-1202. [PMID: 31283454 DOI: 10.1148/rg.2019180153] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
After experiencing blunt or penetrating trauma, patients in unstable condition who are more likely to die of uncorrected shock than of incomplete injury repairs undergo emergency limited exploratory laparotomy, which is also known as damage control surgery (DCS). This surgery is part of a series of resuscitation steps, with the goal of stabilizing the patient's condition, with rapid surgical control of hemorrhage followed by supportive measures in the intensive care unit before definitive repair of injuries. These patients often are imaged with multidetector CT within 24-48 hours of the initial surgery. Knowledge of this treatment plan is critical to CT interpretation, because there are anatomic derangements and foreign bodies that would not be present in patients undergoing surgery for other reasons. Patients may have injuries beyond the surgical field that are only identified at imaging, which can alter the care plan. Abnormalities related to the resuscitation period such as the CT hypoperfusion complex and ongoing hemorrhage can be recognized at CT. Familiarity with these imaging and clinical findings is important, because they can be seen not only in trauma patients after DCS but also in other patients in the critical care setting. The interpretation of imaging studies can be helped by an understanding of the diagnostic challenges of grading organ injuries with surgical materials in place and the awareness of potential artifacts on images in these patients. Online supplemental material is available for this article. ©RSNA, 2019 See discussion on this article by LeBedis .
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Affiliation(s)
- Lauren F Alexander
- From the Department of Radiology, Mayo Clinic, 4500 San Pablo Rd, Jacksonville, FL 32224 (L.F.A., J.D.L., J.G.C.); Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Ga (T.N.H., P.A.H.); Department of Radiology, University of Mississippi Medical Center, Jackson, Miss (M.S.R.); and Department of Radiology and Imaging, Medical College of Georgia, Augusta, Ga (P.K.M.)
| | - Tarek N Hanna
- From the Department of Radiology, Mayo Clinic, 4500 San Pablo Rd, Jacksonville, FL 32224 (L.F.A., J.D.L., J.G.C.); Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Ga (T.N.H., P.A.H.); Department of Radiology, University of Mississippi Medical Center, Jackson, Miss (M.S.R.); and Department of Radiology and Imaging, Medical College of Georgia, Augusta, Ga (P.K.M.)
| | - Jordan D LeGout
- From the Department of Radiology, Mayo Clinic, 4500 San Pablo Rd, Jacksonville, FL 32224 (L.F.A., J.D.L., J.G.C.); Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Ga (T.N.H., P.A.H.); Department of Radiology, University of Mississippi Medical Center, Jackson, Miss (M.S.R.); and Department of Radiology and Imaging, Medical College of Georgia, Augusta, Ga (P.K.M.)
| | - Manohar S Roda
- From the Department of Radiology, Mayo Clinic, 4500 San Pablo Rd, Jacksonville, FL 32224 (L.F.A., J.D.L., J.G.C.); Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Ga (T.N.H., P.A.H.); Department of Radiology, University of Mississippi Medical Center, Jackson, Miss (M.S.R.); and Department of Radiology and Imaging, Medical College of Georgia, Augusta, Ga (P.K.M.)
| | - Joseph G Cernigliaro
- From the Department of Radiology, Mayo Clinic, 4500 San Pablo Rd, Jacksonville, FL 32224 (L.F.A., J.D.L., J.G.C.); Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Ga (T.N.H., P.A.H.); Department of Radiology, University of Mississippi Medical Center, Jackson, Miss (M.S.R.); and Department of Radiology and Imaging, Medical College of Georgia, Augusta, Ga (P.K.M.)
| | - Pardeep K Mittal
- From the Department of Radiology, Mayo Clinic, 4500 San Pablo Rd, Jacksonville, FL 32224 (L.F.A., J.D.L., J.G.C.); Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Ga (T.N.H., P.A.H.); Department of Radiology, University of Mississippi Medical Center, Jackson, Miss (M.S.R.); and Department of Radiology and Imaging, Medical College of Georgia, Augusta, Ga (P.K.M.)
| | - Peter A Harri
- From the Department of Radiology, Mayo Clinic, 4500 San Pablo Rd, Jacksonville, FL 32224 (L.F.A., J.D.L., J.G.C.); Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Ga (T.N.H., P.A.H.); Department of Radiology, University of Mississippi Medical Center, Jackson, Miss (M.S.R.); and Department of Radiology and Imaging, Medical College of Georgia, Augusta, Ga (P.K.M.)
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Wellenberg RHH, Donders JCE, Guitton TG, Streekstra GJ, Kloen P, Maas M. Interdisciplinary consensus of virtual monochromatic dual-energy CT images: is there discrepancy in preferred photon energy between surgeons and radiologists for the assessment of non-unions? Clin Radiol 2020; 75:448-456. [PMID: 32070481 DOI: 10.1016/j.crad.2020.01.009] [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: 11/04/2019] [Accepted: 01/15/2020] [Indexed: 11/18/2022]
Abstract
AIM To investigate possible differences between surgeons and radiologists in selecting optimal photon energy settings from a set of virtual monochromatic dual-energy computed tomography (CT) images for the assessment of bone union in patients with a suspected non-union of the appendicular skeleton. MATERIALS AND METHODS Fifty patients suspected of having bone non-union after operative fracture treatment with a variety of fixation implants were included. Patients were scanned on a dual-source CT machine using 150/100-kVp. Monochromatic images were extracted at 70, 90, 110, 130, 150, and 190 keV. Images were reviewed by 159 orthopaedic trauma surgeons and 12 musculoskeletal radiologists in order to select the best and worst energy setting to assess bone union. Furthermore, a confidence score (1-4) was given in selecting the best and worst setting to assess bone union. RESULTS Monochromatic 190 keV images were selected most frequently as the optimal energy in titanium (34.8%), stainless steel (40%), and combined implants of stainless steel and titanium (40.5%). Confidence scores and average optimal energies were higher and average worst energies were lower for radiologists compared to surgeons in all hardware (p<0.05). Differences in optimal energy were not statistically significant for different alloys or type of fixation implant in both groups. CONCLUSIONS In both observer groups, 190 keV images were selected most frequently as the optimal energy to assess bone union in patients with a suspected non-union of the appendicular skeleton with hardware in situ. On average, musculoskeletal radiologists selected higher optimal and lower worst energy settings and were more confident in selecting both energy settings than orthopaedic trauma surgeons.
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Affiliation(s)
- R H H Wellenberg
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location AMC, Amsterdam Movement Sciences, Amsterdam, the Netherlands; Department of Radiology, Isala, Zwolle, the Netherlands.
| | - J C E Donders
- Department of Orthopaedic Surgery, Amsterdam UMC, location AMC, Amsterdam Movement Sciences, Amsterdam, the Netherlands
| | - T G Guitton
- Department of Plastic, Reconstructive, Hand and Burn Surgery, Martini Hospital, Dutch Burn Center Groningen, Groningen, the Netherlands
| | - G J Streekstra
- Department of Biomedical Engineering and Physics, Amsterdam UMC, location AMC, Amsterdam, the Netherlands
| | - P Kloen
- Department of Orthopaedic Surgery, Amsterdam UMC, location AMC, Amsterdam Movement Sciences, Amsterdam, the Netherlands
| | - M Maas
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location AMC, Amsterdam Movement Sciences, Amsterdam, the Netherlands
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Metal Artifact Reduction for Orthopedic Prosthesis in Lower Extremity CT Venography: Evaluation of Image Quality and Vessel Conspicuity. Cardiovasc Intervent Radiol 2019; 42:1619-1626. [DOI: 10.1007/s00270-019-02326-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 08/22/2019] [Accepted: 08/24/2019] [Indexed: 11/26/2022]
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17
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Dual-Energy CT in Musculoskeletal Imaging: What Is the Role Beyond Gout? AJR Am J Roentgenol 2019; 213:493-505. [DOI: 10.2214/ajr.19.21095] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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18
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Optimization of Monoenergetic Extrapolations in Dual-Energy CT for Metal Artifact Reduction in Different Body Regions and Orthopedic Implants. Acad Radiol 2019; 26:e67-e74. [PMID: 30072295 DOI: 10.1016/j.acra.2018.06.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/21/2018] [Accepted: 06/21/2018] [Indexed: 11/20/2022]
Abstract
RATIONALE AND OBJECTIVES To define an optimal monoenergetic extrapolation (ME) in dual-energy computed tomography (DECT) for metal artifact reduction (MAR) including different body regions and orthopedic implants. MATERIAL AND METHODS DECT scans were acquired with dual-source CT (SOMATOM Force, Siemens, Germany) at tube voltage A 80-100 kV/B Sn150 kV from 39 patients (mean 54.1 ± 20.7 years, 23 male vs. 16 female) with orthopedic implants ranging from wires to joint implants. Scans were assembled in four groups based on scan regions and volume. Single- and weighted-energy images at a ratio of 0.3 and MEs at 100, 130, 160, and 190 keV were produced using vendor-specific postprocessing software (Syngo.Via, Siemens, Germany). Artifact degree was assessed quantitatively by metal-induced Hounsfield unit changes in relation to reference tissues. Visibility of screw-bone interface, hardware integrity, adjacent bone, and soft tissues were visually rated on a four-point Likert scale (0, none; 3, strong artifacts with nondiagnostic quality). Optimal energy was visually determined by side-by-side comparisons. Artifact degree was statistically compared between regions and energies. RESULTS Metal-induced attenuation changes were most severe in large scan volume groups for all energies. Reference tissue attenuation outside metal artifacts was not affected by ME (p = 0.57). Independent of region, ME at 130-190 keV quantitatively performed significantly better for MAR than the remainder. ME 130 keV showed the highest frequency (54%) in optimal energy ratings based on qualitative image criteria. CONCLUSION DECT significantly reduces image artifacts in patients with orthopedic hardware and prospective choice of ME at 130 keV may suit best for optimal MAR, independent of region or implant.
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Nouh MR. Imaging of the spine: Where do we stand? World J Radiol 2019; 11:55-61. [PMID: 31110605 PMCID: PMC6503457 DOI: 10.4329/wjr.v11.i4.55] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 03/11/2019] [Accepted: 03/16/2019] [Indexed: 02/06/2023] Open
Abstract
The number of patients presenting with spine-related problems has globally increased, with an enormous growing demand for the use of medical imaging to address this problem. The last three decades witnessed great leaps for diagnostic imaging modalities, including those exploited for imaging the spine. These developments improved our diagnostic capabilities in different spinal pathologies, especially with multi-detector computed tomography and magnetic resonance imaging, via both hardware and software improvisations. Nowadays, imaging may depict subtle spinal instability caused by various osseous and ligamentous failures, and could elucidate dynamic instabilities. Consequently, recent diagnostic modalities can discern clinically relevant spinal canal stenosis. Likewise, improvement in diagnostic imaging capabilities revolutionized our understanding of spinal degenerative diseases via quantitative biomarkers rather than mere subjective perspectives. Furthermore, prognostication of spinal cord injury has become feasible, and this is expected to be translated into better effective patient tailoring to management plans with better clinical outcomes. Meanwhile, our confidence in diagnosing spinal infections and assessing the different spinal instrumentation has greatly improved over the past few last decades. Overall, revolutions in diagnostic imaging over the past few decades have upgraded spinal imaging from simple subjective and qualitative indices into a more sophisticated yet precise era of objective metrics via deploying quantitative imaging biomarkers.
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Affiliation(s)
- Mohamed R Nouh
- Faculty of Medicine, Alexandria University, Alexandria 21521, Egypt
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20
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Burke MC, Garg A, Youngner JM, Deshmukh SD, Omar IM. Initial experience with dual-energy computed tomography-guided bone biopsies of bone lesions that are occult on monoenergetic CT. Skeletal Radiol 2019; 48:605-613. [PMID: 30343440 DOI: 10.1007/s00256-018-3087-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 09/24/2018] [Accepted: 10/01/2018] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Our purpose was to determine whether dual-energy CT (DECT), specifically the bone marrow setting of the virtual noncalcium (VNCa) algorithm, could be used to identify and accurately biopsy suspected bone malignancies that were visible on magnetic resonance imaging (MRI), nuclear bone scintigraphy, or positron-emission tomography/computed tomography (PET/CT), but occult on monoenergetic computed tomography (CT) by virtue of being either isodense or nearly isodense to surrounding normal bone. MATERIALS AND METHODS We present 4 cases in which DECT was used to detect various malignant bone lesions and was successfully used to direct percutaneous DECT-guided bone biopsies. RESULTS Two of the lesions were solid tumor metastases (breast and prostate carcinoma), whereas two others were hematological malignancies (leukemia and lymphoma). This technique enabled us to confidently and accurately direct the biopsy needle into the target lesion. CONCLUSION The authors demonstrate that the DECT VNCa bone marrow algorithm may be helpful in identifying isodense bone lesions of various histologies and may be used to guide percutaneous bone biopsies. This technique may help to maximize diagnostic yield, minimize the number of passes into the region of concern, and prevent patients from undergoing repeat biopsy.
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Affiliation(s)
- Michael C Burke
- Department of Radiology, Northwestern University Feinberg School of Medicine, 676 North Saint Clair Street, Suite 800, Chicago, IL, 60611, USA.
| | - Ankur Garg
- Department of Radiology, Northwestern University Feinberg School of Medicine, 676 North Saint Clair Street, Suite 800, Chicago, IL, 60611, USA
| | - Jonathan M Youngner
- Department of Radiology, Northwestern University Feinberg School of Medicine, 676 North Saint Clair Street, Suite 800, Chicago, IL, 60611, USA
| | - Swati D Deshmukh
- Department of Radiology, Northwestern University Feinberg School of Medicine, 676 North Saint Clair Street, Suite 800, Chicago, IL, 60611, USA
| | - Imran M Omar
- Department of Radiology, Northwestern University Feinberg School of Medicine, 676 North Saint Clair Street, Suite 800, Chicago, IL, 60611, USA
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Siegel MJ, Ramirez-Giraldo JC. Dual-Energy CT in Children: Imaging Algorithms and Clinical Applications. Radiology 2019; 291:286-297. [PMID: 30912717 DOI: 10.1148/radiol.2019182289] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Dual-energy CT enables the simultaneous acquisition of CT images at two different x-ray energy spectra. By acquiring high- and low-energy spectral data, dual-energy CT can provide unique qualitative and quantitative information about tissue composition, allowing differentiation of multiple materials including iodinated contrast agents. The two dual-energy CT postprocessing techniques that best exploit the advantages of dual-energy CT in children are the material-decomposition images (which include virtual nonenhanced, iodine, perfused lung blood volume, lung vessel, automated bone removal, and renal stone characterization images) and virtual monoenergetic images. Clinical applications include assessment of the arterial system, lung perfusion, neoplasm, bowel diseases, renal calculi, tumor response to treatment, and metal implants. Of importance, the radiation exposure level of dual-energy CT is equivalent to or less than that of conventional single-energy CT. In this review, the authors discuss the basic principles of the dual-energy CT technologies and postprocessing techniques and review current clinical applications in the pediatric chest and abdomen.
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Affiliation(s)
- Marilyn J Siegel
- From the Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S Kingshighway Blvd, St Louis, Mo 63110 (M.J.S.); and Siemens Healthineers, Malvern, Pa (J.C.R.G.)
| | - Juan Carlos Ramirez-Giraldo
- From the Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S Kingshighway Blvd, St Louis, Mo 63110 (M.J.S.); and Siemens Healthineers, Malvern, Pa (J.C.R.G.)
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22
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23
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Metal Artifact Reduction in Routine Chest and Abdominal Examinations Using Virtual Monoenergetic Images From Spectral Detector Computed Tomography. J Comput Assist Tomogr 2019; 43:713-717. [DOI: 10.1097/rct.0000000000000901] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Effect of external fixation rod coupling in computed tomography. Strategies Trauma Limb Reconstr 2018; 13:137-149. [PMID: 30220005 PMCID: PMC6249148 DOI: 10.1007/s11751-018-0318-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 09/11/2018] [Indexed: 10/28/2022] Open
Abstract
External fixation is a common tool in the treatment of complex fractures, correction of limb deformity, and salvage arthrodesis. These devices typically incorporate radio-opaque metal rods/struts connected at varying distances and orientations between rings. Whilst the predominant imaging modality is plain film radiology, computed tomography (CT) may be performed in order for the surgeon to make a more confident clinical decision (e.g. timing of frame removal, assessment of degree of arthrodesis). We used a fractured sheep leg to systematically assess CT imaging performance with a Discovery CT750 HD CT scanner (GE Healthcare) to show how rod coupling in both traditional Ilizarov and hexapod frames distorts images. We also investigated the role of dual-energy CT (DECT) and metal artefact reduction software (MARS) on the visualisation of the fractured leg. Whilst mechanical reasons predominantly dictate the rod/strut configurations when building a circular frame, rod coupling in CT can be minimised. Firstly, ideally, all or all but one rod can be removed during imaging resulting in no rod coupling. If this is not possible, strategies for configuring the rods to minimise the effect of the rod coupling on the region of interest are demonstrated, e.g., in the case of a four-rod construct, switching the two anterior rods to a more central single one will achieve this goal without particularly jeopardising mechanical strength for a short period. It is also shown that the addition of DECT and MARS results in a reduction of artefacts, but also affects tissue and bone differentiation.
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Wellenberg RHH, Hakvoort ET, Slump CH, Boomsma MF, Maas M, Streekstra GJ. Metal artifact reduction techniques in musculoskeletal CT-imaging. Eur J Radiol 2018; 107:60-69. [PMID: 30292274 DOI: 10.1016/j.ejrad.2018.08.010] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 07/02/2018] [Accepted: 08/11/2018] [Indexed: 01/02/2023]
Abstract
It is known that metal artifacts can be reduced by modifying standard acquisition and reconstruction, by modifying projection data and/or image data and by using virtual monochromatic imaging extracted from dual-energy CT. In this review we focus on the origin of metal artifacts, technical background of commercially available metal artifact reduction (MAR) algorithms and the value of dual-energy CT and MAR software for different metal hardware in current clinical practice. Virtual monochromatic imaging reduces beam-hardening artifacts, where metal artifact reduction software effectively reduces artifacts caused by extensive photon-starvation. Both techniques have their advantages and disadvantages, and the combination of both techniques is often but not always the best solution regarding metal artifact reduction. Advances in prosthetic imaging are reinforced by advances in prosthetic design. Providing implant specific information prior to scanning is important in order to adjust the metal artifact reduction approach, minimize artifacts and optimize image quality and diagnostic value of CT.
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Affiliation(s)
- R H H Wellenberg
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Center, location AMC, University of Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands; Department of Radiology, Isala, Zwolle, The Netherlands.
| | - E T Hakvoort
- Department of Biomedical Engineering and Physics, Amsterdam University Medical Center, location AMC, Amsterdam, The Netherlands.
| | - C H Slump
- MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.
| | - M F Boomsma
- Department of Radiology, Isala, Zwolle, The Netherlands.
| | - M Maas
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Center, location AMC, University of Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands.
| | - G J Streekstra
- Department of Biomedical Engineering and Physics, Amsterdam University Medical Center, location AMC, Amsterdam, The Netherlands.
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Wong WD, Shah S, Murray N, Walstra F, Khosa F, Nicolaou S. Advanced Musculoskeletal Applications of Dual-Energy Computed Tomography. Radiol Clin North Am 2018; 56:587-600. [DOI: 10.1016/j.rcl.2018.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Quantitative Comparison of Virtual Monochromatic Images of Dual Energy Computed Tomography Systems. J Comput Assist Tomogr 2018; 42:648-654. [DOI: 10.1097/rct.0000000000000726] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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28
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Sakaida H, Usui S, Matsuda Y, Masuda S, Takeuchi K. Sonographic diagnosis of acute mastoiditis and subsequent retroauricular abscess in a pediatric cochlear implant recipient: A case report. JOURNAL OF CLINICAL ULTRASOUND : JCU 2017; 45:515-519. [PMID: 28369924 DOI: 10.1002/jcu.22442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 11/15/2016] [Accepted: 12/04/2016] [Indexed: 06/07/2023]
Abstract
When acute mastoiditis occurs in cochlear implant recipients, it can progress to subsequent retroauricular abscess due to the absence of the external mastoid cortex resulting from mastoidectomy performed for cochlear implantation. The management goal is to control infection while preserving the implanted device. A 2-year-old boy with cochlear implants developed acute mastoiditis and a subsequent retroauricular abscess. The patient underwent a surgical intervention based on the diagnosis made utilizing gray-scale and power Doppler sonography. This case illustrates the diagnostic usefulness of sonography in this rare situation. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:515-519, 2017.
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Affiliation(s)
- Hiroshi Sakaida
- Department of Otorhinolaryngology-Head & Neck Surgery, Mie University Graduate School of Medicine, Tsu, Mie, Japan
| | - Satoko Usui
- Department of Otorhinolaryngology, National Mie Hospital, Tsu, Mie, Japan
| | - Yasunori Matsuda
- Department of Otorhinolaryngology-Head & Neck Surgery, Mie University Graduate School of Medicine, Tsu, Mie, Japan
| | - Sawako Masuda
- Department of Otorhinolaryngology, National Mie Hospital, Tsu, Mie, Japan
| | - Kazuhiko Takeuchi
- Department of Otorhinolaryngology-Head & Neck Surgery, Mie University Graduate School of Medicine, Tsu, Mie, Japan
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Norman N, Dimmock M, Lee K, Graham J, Bassed R. The applicability of Dual-Energy Computed Tomography (DECT) in forensic odontology – A review. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.jofri.2017.07.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Mallinson PI, Coupal TM, McLaughlin PD, Nicolaou S, Munk PL, Ouellette HA. Dual-Energy CT for the Musculoskeletal System. Radiology 2017; 281:690-707. [PMID: 27870622 DOI: 10.1148/radiol.2016151109] [Citation(s) in RCA: 153] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The principal advantages of dual-energy computed tomography (CT) over conventional CT in the musculoskeletal setting relate to the additional information provided regarding tissue composition, artifact reduction, and image optimization. This article discusses the manifestations of these in clinical practice-urate and bone marrow edema detection, metal artifact reduction, and tendon analysis, with potential in arthrography, bone densitometry, and metastases surveillance. The basic principles of dual-energy CT physics and scanner design will also be discussed. © RSNA, 2016.
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Affiliation(s)
- Paul I Mallinson
- From the Department of Radiology, Vancouver General Hospital/University of British Columbia, Jim Pattison Pavilion, 899 W 12th Ave, Vancouver, BC, Canada V5Z 1M9
| | - Tyler M Coupal
- From the Department of Radiology, Vancouver General Hospital/University of British Columbia, Jim Pattison Pavilion, 899 W 12th Ave, Vancouver, BC, Canada V5Z 1M9
| | - Patrick D McLaughlin
- From the Department of Radiology, Vancouver General Hospital/University of British Columbia, Jim Pattison Pavilion, 899 W 12th Ave, Vancouver, BC, Canada V5Z 1M9
| | - Savvas Nicolaou
- From the Department of Radiology, Vancouver General Hospital/University of British Columbia, Jim Pattison Pavilion, 899 W 12th Ave, Vancouver, BC, Canada V5Z 1M9
| | - Peter L Munk
- From the Department of Radiology, Vancouver General Hospital/University of British Columbia, Jim Pattison Pavilion, 899 W 12th Ave, Vancouver, BC, Canada V5Z 1M9
| | - Hugue A Ouellette
- From the Department of Radiology, Vancouver General Hospital/University of British Columbia, Jim Pattison Pavilion, 899 W 12th Ave, Vancouver, BC, Canada V5Z 1M9
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Wellenberg R, Boomsma M, van Osch J, Vlassenbroek A, Milles J, Edens M, Streekstra G, Slump C, Maas M. Quantifying metal artefact reduction using virtual monochromatic dual-layer detector spectral CT imaging in unilateral and bilateral total hip prostheses. Eur J Radiol 2017; 88:61-70. [DOI: 10.1016/j.ejrad.2017.01.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 11/24/2016] [Accepted: 01/03/2017] [Indexed: 10/20/2022]
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Bazzocchi A, Bartoloni A, Rimondi E, Albisinni U, Guglielmi G. Imaging After Hip Joint Replacement Surgery in the Elderly Population. CURRENT RADIOLOGY REPORTS 2017. [DOI: 10.1007/s40134-017-0193-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Zhu X, McCullough WP, Mecca P, Servaes S, Darge K. Dual-energy compared to single-energy CT in pediatric imaging: a phantom study for DECT clinical guidance. Pediatr Radiol 2016; 46:1671-1679. [PMID: 27518078 DOI: 10.1007/s00247-016-3668-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 06/20/2016] [Accepted: 07/20/2016] [Indexed: 12/26/2022]
Abstract
BACKGROUND Dual-energy CT technology is available on scanners from several vendors and offers significant advantages over classic single-energy CT technology in multiple clinical applications. Many studies have detailed dual-energy CT applications in adults and several have evaluated the relative radiation dose performance of dual-energy CT in adult imaging. However, little has been published on dual-energy CT imaging in the pediatric population, and the relative dose performance of dual-energy CT imaging in the pediatric population is not well described. OBJECTIVE When evaluating dual-energy CT technology for implementation into a routine clinical pediatric imaging practice, the radiation dose implications must be considered, and when comparing relative CT dose performance, image quality must also be evaluated. Therefore the purpose of this study is to develop dual-energy CT scan protocols based on our optimized single-energy scan protocols and compare the dose. MATERIALS AND METHODS We scanned the head, chest and abdomen regions of pediatric-size anthropomorphic phantoms with contrast inserts, using our optimized single-energy clinical imaging protocols on a Siemens Flash® CT scanner. We then scanned the phantoms in dual-energy mode using matching image-quality reference settings. The effective CT dose index volume (CTDIvol) of the scans was used as a surrogate for relative dose in comparing the single- and dual-energy scans. Additionally, we evaluated image quality using visual assessment and contrast-to-noise ratio. RESULTS Dual-energy CT scans of the head and abdomen were dose-neutral for all three phantoms. Dual-energy CT scans of the chest showed a relative dose increase over the single-energy scan for 1- and 5-year-old child-based age-equivalent phantoms, ranging 11-20%. Quantitative analysis of image quality showed no statistically significant difference in image quality between the single-energy and dual-energy scans. There was no clinically significant difference in image quality by visual assessment. CONCLUSION Dual-energy CT is dose-neutral in imaging the head and abdomen in children. It is not dose-neutral in chest imaging of very small children. With a better understanding of the dose consequences of converting single-energy protocols to dual-energy protocols we can begin to implement clinical dual-energy CT and utilize its unique capabilities in pediatric imaging.
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Affiliation(s)
- Xiaowei Zhu
- Department of Radiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- The Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - William P McCullough
- Department of Radiology and Medical Imaging, University of Virginia Health System, P.O. Box 800170, Charlottesville, VA, 22908-0170, USA.
| | - Patricia Mecca
- Department of Radiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Sabah Servaes
- Department of Radiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- The Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kassa Darge
- Department of Radiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- The Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Yasaka K, Maeda E, Hanaoka S, Katsura M, Sato J, Ohtomo K. Single-energy metal artifact reduction for helical computed tomography of the pelvis in patients with metal hip prostheses. Jpn J Radiol 2016; 34:625-32. [PMID: 27400700 DOI: 10.1007/s11604-016-0566-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 06/30/2016] [Indexed: 10/21/2022]
Abstract
PURPOSE To compare the quality of helical computed tomography (CT) images of the pelvis in patients with metal hip prostheses reconstructed using adaptive iterative dose reduction (AIDR) and AIDR with single-energy metal artifact reduction (SEMAR-A). MATERIALS AND METHODS This retrospective study included 28 patients (mean age, 64.6 ± 11.4 years; 6 men and 22 women). CT images were reconstructed using AIDR and SEMAR-A. Two radiologists evaluated the extent of metal artifacts and the depiction of structures in the pelvic region and looked for mass lesions. A radiologist placed a region of interest within the bladder and recorded CT attenuation. RESULTS The metal artifacts were significantly reduced in SEMAR-A as compared to AIDR (p < 0.0001). The depictions of the bladder, ureter, prostate/uterus, rectum, and pelvic sidewall were significantly better with SEMAR-A than with AIDR (p < 0.02). All lesions were diagnosed with SEMAR-A, while some were not diagnosed with AIDR. The median and interquartile range (in parentheses) of CT attenuation within the bladder for AIDR were -34.0 (-46.6 to -15.0) Hounsfield units (HU) and were more variable than those seen for SEMAR-A [5.4 (-1.3 to 11.1)] HU (p = 0.033). CONCLUSION In comparison with AIDR, SEMAR-A provided pelvic CT images of significantly better quality for patients with metal hip prostheses.
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Affiliation(s)
- Koichiro Yasaka
- Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan. .,Department of Radiology, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, Japan.
| | - Eriko Maeda
- Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Shouhei Hanaoka
- Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Masaki Katsura
- Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Jiro Sato
- Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Kuni Ohtomo
- Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
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Filograna L, Magarelli N, Leone A, de Waure C, Calabrò GE, Finkenstaedt T, Thali MJ, Bonomo L. Performances of low-dose dual-energy CT in reducing artifacts from implanted metallic orthopedic devices. Skeletal Radiol 2016; 45:937-47. [PMID: 27033858 DOI: 10.1007/s00256-016-2377-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 03/07/2016] [Accepted: 03/14/2016] [Indexed: 02/02/2023]
Abstract
OBJECTIVES The objective was to evaluate the performances of dose-reduced dual-energy computed tomography (DECT) in decreasing metallic artifacts from orthopedic devices compared with dose-neutral DECT, dose-neutral single-energy computed tomography (SECT), and dose-reduced SECT. MATERIALS AND METHODS Thirty implants in 20 consecutive cadavers underwent both SECT and DECT at three fixed CT dose indexes (CTDI): 20.0, 10.0, and 5.0 mGy. Extrapolated monoenergetic DECT images at 64, 69, 88, 105, 120, and 130 keV, and individually adjusted monoenergy for optimized image quality (OPTkeV) were generated. In each group, the image quality of the seven monoenergetic images and of the SECT image was assessed qualitatively and quantitatively by visually rating and by measuring the maximum streak artifact respectively. RESULTS The comparison between SECT and OPTkeV evaluated overall within all groups showed a significant difference (p <0.001), with OPTkeV images providing better images. Comparing OPTkeV with the other DECT images, a significant difference was shown (p <0.001), with OPTkeV and 130-keV images providing the qualitatively best results. The OPTkeV images of 5.0-mGy acquisitions provided percentages of images with scores 1 and 2 of 36 % and 30 % respectively, compared with 0 % and 33.3 % of the corresponding SECT images of 10- and 20-mGy acquisitions. Moreover, DECT reconstructions at the OPTkeV of the low-dose group showed higher CT numbers than the SECT images of dose groups 1 and 2. CONCLUSIONS This study demonstrates that low-dose DECT permits a reduction of artifacts due to metallic implants to be obtained in a similar manner to neutral-dose DECT and better than reduced or neutral-dose SECT.
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Affiliation(s)
- Laura Filograna
- Department of Radiological Sciences, Institute of Radiology, Catholic University of Rome, School of Medicine, University Hospital "A. Gemelli", Largo A. Gemelli 8, 00168, Rome, Italy. .,Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, University of Zurich, Winterthurerstrasse 190/52, 8057, Zurich, Switzerland.
| | - Nicola Magarelli
- Department of Radiological Sciences, Institute of Radiology, Catholic University of Rome, School of Medicine, University Hospital "A. Gemelli", Largo A. Gemelli 8, 00168, Rome, Italy
| | - Antonio Leone
- Department of Radiological Sciences, Institute of Radiology, Catholic University of Rome, School of Medicine, University Hospital "A. Gemelli", Largo A. Gemelli 8, 00168, Rome, Italy
| | - Chiara de Waure
- Research Centre for Health Technology Assessment, Department of Public Health, Section of Hygiene, Catholic University of Rome, School of Medicine, University Hospital "A. Gemelli", Largo F. Vito 1, 00168, Rome, Italy
| | - Giovanna Elisa Calabrò
- Research Centre for Health Technology Assessment, Department of Public Health, Section of Hygiene, Catholic University of Rome, School of Medicine, University Hospital "A. Gemelli", Largo F. Vito 1, 00168, Rome, Italy
| | - Tim Finkenstaedt
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
| | - Michael John Thali
- Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, University of Zurich, Winterthurerstrasse 190/52, 8057, Zurich, Switzerland
| | - Lorenzo Bonomo
- Department of Radiological Sciences, Institute of Radiology, Catholic University of Rome, School of Medicine, University Hospital "A. Gemelli", Largo A. Gemelli 8, 00168, Rome, Italy
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Yasaka K, Kamiya K, Irie R, Maeda E, Sato J, Ohtomo K. Metal artefact reduction for patients with metallic dental fillings in helical neck computed tomography: comparison of adaptive iterative dose reduction 3D (AIDR 3D), forward-projected model-based iterative reconstruction solution (FIRST) and AIDR 3D with single-energy metal artefact reduction (SEMAR). Dentomaxillofac Radiol 2016; 45:20160114. [PMID: 27268082 DOI: 10.1259/dmfr.20160114] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To compare the differences in metal artefact degree and the depiction of structures in helical neck CT, in patients with metallic dental fillings, among adaptive iterative dose reduction three dimensional (AIDR 3D), forward-projected model-based iterative reconstruction solution (FIRST) and AIDR 3D with single-energy metal artefact reduction (SEMAR-A). METHODS In this retrospective clinical study, 22 patients (males, 13; females, 9; mean age, 64.6 ± 12.6 years) with metallic dental fillings who underwent contrast-enhanced helical CT involving the oropharyngeal region were included. Neck axial images were reconstructed with AIDR 3D, FIRST and SEMAR-A. Metal artefact degree and depiction of structures (the apex and root of the tongue, parapharyngeal space, superior portion of the internal jugular chain and parotid gland) were evaluated on a four-point scale by two radiologists. Placing regions of interest, standard deviations of the oral cavity and nuchal muscle (at the slice where no metal exists) were measured and metal artefact indices were calculated (the square root of the difference of the squares of them). RESULTS In SEMAR-A, metal artefact was significantly reduced and depictions of all structures were significantly improved compared with those in FIRST and AIDR 3D (p ≤ 0.001, sign test). Metal artefact index for the oral cavity in AIDR 3D/FIRST/SEMAR-A was 572.0/477.7/88.4, and significant differences were seen between each reconstruction algorithm (p < 0.0001, Wilcoxon signed-rank test). CONCLUSIONS SEMAR-A could provide images with lesser metal artefact and better depiction of structures than AIDR 3D and FIRST.
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Affiliation(s)
- Koichiro Yasaka
- Department of Radiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kouhei Kamiya
- Department of Radiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Ryusuke Irie
- Department of Radiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Eriko Maeda
- Department of Radiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Jiro Sato
- Department of Radiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kuni Ohtomo
- Department of Radiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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Hargunani R, Madani H, Khoo M, Fotiadou A, Pressney I, Calleja M, O'Donnell P. Imaging of the Painful Hip Arthroplasty. Can Assoc Radiol J 2016; 67:345-355. [PMID: 27221697 DOI: 10.1016/j.carj.2015.11.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 11/16/2015] [Accepted: 11/18/2015] [Indexed: 12/31/2022] Open
Abstract
The incidence of complications following total hip arthroplasty is low, but due to the frequency of the procedure, they are quite commonly encountered and require appropriate investigation. Complications include aseptic loosening, infection, foreign body granulomatosis (osteolysis), adverse reactions to metal debris, periprosthetic fracture, heterotopic ossification, hardware failure, and a range of soft tissue complications, all of which may result in pain. Relevant imaging findings are illustrated and the role of various imaging modalities is reviewed. A suggested approach for the radiological investigation of each potential complication is outlined, based on our experience at a specialist referral unit.
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Affiliation(s)
- Rikin Hargunani
- Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, United Kingdom.
| | - Hardi Madani
- Royal Free Hospital NHS Trust, London, United Kingdom
| | - Michael Khoo
- Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, United Kingdom
| | - Anastasia Fotiadou
- Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, United Kingdom
| | - Ian Pressney
- Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, United Kingdom
| | - Michele Calleja
- Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, United Kingdom
| | - Paul O'Donnell
- Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, United Kingdom
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Getting the Most From Your Dual-Energy Scanner: Recognizing, Reducing, and Eliminating Artifacts. AJR Am J Roentgenol 2016; 206:119-28. [PMID: 26700343 DOI: 10.2214/ajr.14.13901] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Dual-energy CT (DECT) is an innovative imaging modality that allows superior detection of pulmonary embolism, enhanced detection of urate in gout, and improved assessment of metal prostheses when compared with conventional CT. CONCLUSION The primary aim of this review is to describe these DECT protocols and compare each to its respective diagnostic reference standards. Moreover, this review will describe how to recognize, reduce, and eliminate DECT artifacts, thereby maximizing its diagnostic capabilities.
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Filograna L, Magarelli N, Leone A, Guggenberger R, Winklhofer S, Thali MJ, Bonomo L. Value of monoenergetic dual-energy CT (DECT) for artefact reduction from metallic orthopedic implants in post-mortem studies. Skeletal Radiol 2015; 44:1287-94. [PMID: 25962510 DOI: 10.1007/s00256-015-2155-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 04/10/2015] [Accepted: 04/16/2015] [Indexed: 02/02/2023]
Abstract
OBJECTIVES The aim of this ex vivo study was to assess the performance of monoenergetic dual-energy CT (DECT) reconstructions to reduce metal artefacts in bodies with orthopedic devices in comparison with standard single-energy CT (SECT) examinations in forensic imaging. Forensic and clinical impacts of this study are also discussed. MATERIALS AND METHODS Thirty metallic implants in 20 consecutive cadavers with metallic implants underwent both SECT and DECT with a clinically suitable scanning protocol. Extrapolated monoenergetic DECT images at 64, 69, 88, 105, 120, and 130 keV and individually adjusted monoenergy for optimized image quality (OPTkeV) were generated. Image quality of the seven monoenergetic images and of the corresponding SECT image was assessed qualitatively and quantitatively by visual rating and measurements of attenuation changes induced by streak artefact. RESULTS Qualitative and quantitative analyses showed statistically significant differences between monoenergetic DECT extrapolated images and SECT, with improvements in diagnostic assessment in monoenergetic DECT at higher monoenergies. The mean value of OPTkeV was 137.6 ± 4.9 with a range of 130 to 148 keV. CONCLUSIONS This study demonstrates that monoenergetic DECT images extrapolated at high energy levels significantly reduce metallic artefacts from orthopedic implants and improve image quality compared to SECT examination in forensic imaging.
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Affiliation(s)
- Laura Filograna
- Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, University of Zurich, Winterthurerstrasse 190/52, 8057, Zurich, Switzerland,
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Sun X, Shao X, Chen H. The value of energy spectral CT in the differential diagnosis between benign and malignant soft tissue masses of the musculoskeletal system. Eur J Radiol 2015; 84:1105-8. [DOI: 10.1016/j.ejrad.2015.02.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 01/20/2015] [Accepted: 02/28/2015] [Indexed: 11/24/2022]
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Parmar HA, Ibrahim M, Mukherji SK. Optimizing Craniofacial CT Technique. Neuroimaging Clin N Am 2014; 24:395-405, vii. [DOI: 10.1016/j.nic.2014.03.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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