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Patzer TS, Grunz JP, Huflage H, Hennes JL, Pannenbecker P, Gruschwitz P, Afat S, Herrmann J, Bley TA, Kunz AS. Ultra-high resolution photon-counting CT with tin prefiltration for bone-metal interface visualization. Eur J Radiol 2024; 170:111209. [PMID: 37992609 DOI: 10.1016/j.ejrad.2023.111209] [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: 09/14/2023] [Revised: 11/08/2023] [Accepted: 11/16/2023] [Indexed: 11/24/2023]
Abstract
PURPOSE To investigate the metal artifact suppression potential of combining tin prefiltration and virtual monoenergetic imaging (VMI) for osseous microarchitecture depiction in ultra-high-resolution (UHR) photon-counting CT (PCCT) of the lower extremity. METHOD Derived from tin-filtered UHR scans at 140 kVp, polychromatic datasets (T3D) and VMI reconstructions at 70, 110, 150, and 190 keV were compared in 117 patients with lower extremity metal implants (53 female; 62.1 ± 18.0 years). Three implant groups were investigated (total arthroplasty [n = 48], osteosynthetic material [n = 43], and external fixation [n = 26]). Image quality was assessed with regions of interest placed in the most pronounced artifacts and adjacent soft tissue, measuring the respective attenuation. Additionally, artifact extent, bone-metal interface interpretability and overall image quality were independently evaluated by three radiologists. RESULTS Artifact reduction was superior with increasing keV level of VMI. While T3D was superior to VMI70keV (p ≥ 0.117), artifacts were more severe in T3D than in VMI ≥ 110 keV (all p ≤ 0.036). Image noise was highest for VMI70keV (all p < 0.001) and lowest for VMI110keV with comparable results for VMI110keV - VMI190keV. Subjective image quality regarding artifacts was superior for VMI ≥ 110 keV (all p ≤ 0.042) and comparable for VMI110keV - VMI190keV. Bone-metal interface interpretability was superior for VMI110keV (all p ≤ 0.001), while T3D, VMI150keV and VMI190keV were comparable. Overall image quality was deemed best for VMI110keV and VMI150keV. Interreader reliability was good in all cases (ICC ≥ 0.833). CONCLUSIONS Tin-filtered UHR-PCCT scans of the lower extremity combined with VMI reconstructions allow for efficient artifact reduction in the vicinity of bone-metal interfaces.
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Affiliation(s)
- Theresa Sophie Patzer
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany.
| | - Jan-Peter Grunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Henner Huflage
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Jan-Lucca Hennes
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Pauline Pannenbecker
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Philipp Gruschwitz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Saif Afat
- Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Hoppe-Seyler-Str 3, 72076 Tübingen, Germany
| | - Judith Herrmann
- Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Hoppe-Seyler-Str 3, 72076 Tübingen, Germany
| | - Thorsten Alexander Bley
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Andreas Steven Kunz
- Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Hoppe-Seyler-Str 3, 72076 Tübingen, Germany
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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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Hagen F, Grimmer R, Ditt H, Walder L, Wrazidlo R, Karolin B, Hofmann J, Estler A, Horger M. Effects of different virtual monoenergetic CT image data on chest wall post-processing "unfolded ribs" and proposal of an algorithm improvement. Int J Comput Assist Radiol Surg 2023; 18:339-351. [PMID: 35962904 DOI: 10.1007/s11548-022-02721-0] [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: 03/13/2022] [Accepted: 07/12/2022] [Indexed: 02/03/2023]
Abstract
PURPOSE To find out if the use of different virtual monoenergetic data sets enabled by DECT technology might have a negative impact on post-processing applications, specifically in case of the "unfolded ribs" algorithm. Metal or beam hardening artifacts are suspected to generate image artifacts and thus reduce diagnostic accuracy. This paper tries to find out how the generation of "unfolded rib" CT image reformates is influenced by different virtual monoenergetic CT images and looks for possible improvement of the post-processing tool. MATERIAL AND METHODS Between March 2021 and April 2021, thin-slice dual-energy CT image data of the chest were used creating "unfolded rib" reformates. The same data sets were analyzed in three steps: first the gold standard with the original algorithm on mixed image data sets followed by the original algorithm on different keV levels (40-120 keV) and finally using a modified algorithm which in the first step used segmentation based on mixed image data sets, followed by segmentation based on different keV levels. Image quality (presence of artifacts), lesion and fracture detectability were assessed for all series. RESULTS Both, the original and the modified algorithm resulted in more artifact-free image data sets compared to the gold standard. The modified algorithm resulted in significantly more artifact-free image data sets at the keV-edges (40-120 keV) compared the original algorithm. Especially "black artifacts" and pseudo-lesions, potentially inducing false positive findings, could be reduced in all keV level with the modified algorithm. Detection of focal sclerotic, lytic or mixed (k = 0.990-1.000) lesions was very good for all keV levels. The Fleiss-kappa test for detection of fresh and old rib fractures was ≥ 0.997. CONCLUSION The use of different virtual monoenergetic keVs for the "unfolded rib" algorithm is generating different artifacts. Segmentation-based artifacts could be eliminated by the proposed new algorithm, showing the best results at 70-80 keV.
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Affiliation(s)
- Florian Hagen
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str.3, 72076, Tübingen, Germany.
| | | | | | - Lukas Walder
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str.3, 72076, Tübingen, Germany
| | - Robin Wrazidlo
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str.3, 72076, Tübingen, Germany
| | - Baumgartner Karolin
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str.3, 72076, Tübingen, Germany
| | - Johannes Hofmann
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str.3, 72076, Tübingen, Germany
| | - Arne Estler
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str.3, 72076, Tübingen, Germany
| | - Marius Horger
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str.3, 72076, Tübingen, Germany
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Bae K, Jeon KN, Kim JE, Park SE, Baek HJ, Moon JI, Ryu KH, Cho E. Abdominal CT in patients with arms down positioning: Effect of virtual monoenergetic reconstruction on diagnostic image quality. Abdom Radiol (NY) 2021; 46:5037-5046. [PMID: 34215901 DOI: 10.1007/s00261-021-03195-5] [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: 04/13/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate effect of virtual monoenergetic reconstruction on contrast-enhanced abdominal CT obtained using a dual-layer detector CT (DLCT) in patients with arms-down positioning, in comparison with conventional 120-kVp image. METHODS A total of 162 consecutive patients who underwent abdominal CT scans using a DLCT with arms-down positioning were retrospectively enrolled. 120-kVp image and virtual monoenergetic images (VMIs) at 40-100 keV were compared for arm-induced artifact reduction capability and image quality through objective and subjective assessments. Diagnostic performance was compared between VMI with the best quality and 120-kVp image. RESULTS VMIs at 60-100 keV showed significantly lower (p < 0.001) artifact index than 120-kVp image. Subjective severity of arm-induced streak artifacts was significantly (p < 0.001) lower in VMIs at 70-100 keV than in 120-kVp image. CNRs measured in artifact and reference areas were superior (p < 0.05) in 40-70 keV to those in 120 kVp. Overall image quality was superior (p < 0.05) in 60-90 keV to 120 kVp. 70-keV VMI was chosen as the best image by two independent readers. In ROC analysis of lesion detection in the liver, spleen, and kidneys, the AUC was significantly higher for 70-keV VMI (reader 1, 0.962; p = 0.011; reader 2, 0.981; p = 0.012) than that for 120-kVp image (reader 1, 0.891; reader 2, 0.922). CONCLUSION The70-keV VMI from DLCT could improve abdominal CT images by reducing streak artifacts and increasing image contrast in patients who could not elevated their arms. The 70-keV VMI showed better diagnostic performance than the conventional 120 kVp image.
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Affiliation(s)
- Kyungsoo Bae
- Department of Radiology, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Korea
- Department of Radiology, Gyeongsang National University Changwon Hospital, 555 Samjeongja-dong, Seongsan-gu, Changwon, Korea
| | - Kyung Nyeo Jeon
- Department of Radiology, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Korea.
- Department of Radiology, Gyeongsang National University Changwon Hospital, 555 Samjeongja-dong, Seongsan-gu, Changwon, Korea.
| | - Ji Eun Kim
- Department of Radiology, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Korea
- Department of Radiology, Gyeongsang National University Hospital, Jinju, Korea
| | - Sung Eun Park
- Department of Radiology, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Korea
- Department of Radiology, Gyeongsang National University Changwon Hospital, 555 Samjeongja-dong, Seongsan-gu, Changwon, Korea
| | - Hye Jin Baek
- Department of Radiology, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Korea
- Department of Radiology, Gyeongsang National University Changwon Hospital, 555 Samjeongja-dong, Seongsan-gu, Changwon, Korea
| | - Jin Il Moon
- Department of Radiology, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Korea
- Department of Radiology, Gyeongsang National University Changwon Hospital, 555 Samjeongja-dong, Seongsan-gu, Changwon, Korea
| | - Kung Hwa Ryu
- Department of Radiology, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Korea
- Department of Radiology, Gyeongsang National University Changwon Hospital, 555 Samjeongja-dong, Seongsan-gu, Changwon, Korea
| | - Eun Cho
- Department of Radiology, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Korea
- Department of Radiology, Gyeongsang National University Changwon Hospital, 555 Samjeongja-dong, Seongsan-gu, Changwon, Korea
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Gupta A, Obmann VC, Jordan M, Lennartz S, Obmann MM, Große Hokamp N, Zopfs D, Pennig L, Fürtjes G, Ramaiya N, Gilkeson R, Laukamp KR. CT artifacts after contrast media injection in chest imaging: evaluation of post-processing algorithms, virtual monoenergetic images and their combination for artifact reduction. Quant Imaging Med Surg 2021; 11:226-239. [PMID: 33392024 DOI: 10.21037/qims-20-435] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Background After injection into a brachial vein, high contrast media concentration in axillary and subclavian veins can cause artifacts that impair diagnostic utility. This study assessed artifact reduction by artifact-reduction-algorithms (ARA) and virtual-monoenergetic-images (VMI), as well as their combination (VMIARA) compared to conventional CT-images (CI). Methods Forty-six spectral-detector-CT (SDCT) examinations of patients that received ARA-reconstructions due to perivenous-artifacts were included in this retrospective study. CI, ARA, VMI, and VMIARA (range: 70-200 keV) were reconstructed. Objective analysis was performed with ROI-based assessment of mean and standard deviation of attenuation (HU) in hypo- and hyperdense artifacts and impaired muscle and arteries as well as artifact-free reference-tissue. Extent of artifact reduction, assessment of surrounding soft tissue and vessels, and appearance of new artifacts were rated visually by two radiologists. Results Hypo- and hyperdense artifacts showed significant improvement as evidenced by decreasing attenuation differences between artifact impaired and artifact-free reference tissue in ARA, VMI ≥80 keV, and VMIARA between 70-200 keV (e.g., CI/ARA/VMI100keV/VMIARA100keV: hypodense artifacts, (-)264.8±150.9/(-)87.1±78.9/(-)48.6±64.6/9.9±63.9 HU; P<0.001); hyperdense artifacts, 164.2±51.1/82.1±73.2/7.9±34.7/(-)17.3±50.7 HU; P<0.001). Artifacts impairing surrounding muscle and arteries were also reduced by all three approaches. In visual assessment, ARA, VMI ≥100 keV, and VMIARA between 70-200 keV also showed significant artifact reduction and improved assessment; however, for assessment of arteries improvement was not significant using ARA alone. New artifacts were reported, particularly at higher keV-values. Conclusions In presence of perivenous-artifacts, ARA, VMI and their combination allow for significant artifact reduction; however, their combination and VMI as a standalone approach yielded best results and should therefore be used, if available.
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Affiliation(s)
- Amit Gupta
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Verena Carola Obmann
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA.,Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Michelle Jordan
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Simon Lennartz
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Markus Michael Obmann
- Clinic of Radiology and Nuclear Medicine, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Nils Große Hokamp
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA.,Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - David Zopfs
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Lenhard Pennig
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Gina Fürtjes
- Center for Neurosurgery, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Nikhil Ramaiya
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Robert Gilkeson
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Kai Roman Laukamp
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA.,Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
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