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Tarkowski P, Siek E, Staśkiewicz G, Bielecki DK, Czekajska-Chehab E. Angle Dependence of Electrode Lead-Related Artifacts in Single- and Dual-Energy Cardiac ECG-Gated CT Scanning-A Phantom Study. J Clin Med 2024; 13:3746. [PMID: 38999312 PMCID: PMC11242805 DOI: 10.3390/jcm13133746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Revised: 06/19/2024] [Accepted: 06/21/2024] [Indexed: 07/14/2024] Open
Abstract
Background: The electrodes of implantable cardiac devices (ICDs) may cause significant problems in cardiac computed tomography (CT) because they are a source of artifacts that obscure surrounding structures and possible pathology. There are a few million patients currently with ICDs, and some of these patients will require cardiac imaging due to coronary artery disease or problems with ICDs. Modern CT scanners can reduce some of the metal artifacts because of MAR software, but in some vendors, it does not work with ECG gating. Introduced in 2008, dual-energy CT scanners can generate virtual monoenergetic images (VMIs), which are much less susceptible to metal artifacts than standard CT images. Objective: This study aimed to evaluate if dual-energy CT can reduce metal artifacts caused by ICD leads by using VMIs. The second objective was to determine how the angle between the electrode and the plane of imaging affects the severity of the artifacts in three planes of imaging. Methods: A 3D-printed model was constructed to obtain a 0-90-degree field at 5-degree intervals between the electrode and each of the planes: axial, coronal, and sagittal. This electrode was scanned in dual-energy and single-energy protocols. VMIs with an energy of 40-140 keV with 10 keV intervals were reconstructed. The length of the two most extended artifacts originating from the tip of the electrode and 2 cm above it-at the point where the thick metallic defibrillating portion of the electrode begins-was measured. Results: For the sagittal plane, these observations were similar for both points of the ICDs that were used as the reference location. VMIs with an energy over 80 keV produce images with fewer artifacts than similar images obtained in the single-energy scanning mode. Conclusions: Virtual monoenergetic imaging techniques may reduce streak artifacts arising from ICD electrodes and improve the quality of the image. Increasing the angle of the electrode as well as the imaging plane can reduce artifacts. The angle between the electrode and the beam of X-rays can be increased by tilting the gantry of the scanner or lifting the upper body of the patient.
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Affiliation(s)
- Piotr Tarkowski
- Department of Radiology, Medical University of Lublin, 20-090 Lublin, Poland
| | - Elżbieta Siek
- Department of Clinical and Radiological Anatomy, Medical University of Lublin, 20-090 Lublin, Poland
- Department of Radiology and Nuclear Medicine, University Hospital No 4, 20-090 Lublin, Poland
| | - Grzegorz Staśkiewicz
- Department of Clinical and Radiological Anatomy, Medical University of Lublin, 20-090 Lublin, Poland
- Department of Radiology and Nuclear Medicine, University Hospital No 4, 20-090 Lublin, Poland
| | - Dennis K Bielecki
- Department of Diagnostic Imaging, Kings College Hospital, London SE5 9RS, UK
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Park D, Park EA, Jeong B, Lee YS, Lee W. Quantitative analysis of blooming artifact caused by calcification based on X-ray energy difference using computed tomography. Sci Rep 2024; 14:11539. [PMID: 38773167 PMCID: PMC11109228 DOI: 10.1038/s41598-024-61187-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 05/02/2024] [Indexed: 05/23/2024] Open
Abstract
Blooming artifacts caused by calcifications appearing on computed tomography (CT) images lead to an underestimation of the coronary artery lumen size, and higher X-ray energy levels are suggested to reduce the blooming artifacts with subjective visual assessment. This study aimed to evaluate the effect of higher X-ray energy levels on the quantitative measurement of adjacent pixels affected by calcification using CT images. In this two-part study, CT images were acquired from dual-energy CT scanners by changing the X-ray energy levels such as kilovoltage peak (kVp) and kilo-electron volts (keV). Adjacent pixels affected by calcification were measured using the brightened length, excluding the actual calcified length, as determined by the full width at third maximum. In a separate clinical study, the adjacent affected pixels associated with 23 calcifications across 10 patients were measured using the same method as that used in the phantom study. Phantom and clinical studies showed that the change in kVp (field of view [FOV] 300 mm: p = 0.167, 0.494, and 0.861 for vendors 1, 2, and 3, respectively) and keV levels (p = 0.178 for vendor 2) failed to reduce the adjacent pixels affected by calcification, respectively. Moreover, the change in keV levels showed different aspects of adjacent pixels affected by calcification in the phantom study (FOV 300 mm: no significant difference [p = 0.191], increase [p < 0.001], and decrease [p < 0.001] for vendors 1, 2, and 3, respectively). Quantitative measurements revealed no significant relationship between higher X-ray energy levels and the adjacent pixels affected by calcification.
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Affiliation(s)
- Daebeom Park
- Department of Clinical Medical Sciences, Seoul National University College of Medicine, Seoul, Korea
| | - Eun-Ah Park
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Korea
- Department of Radiology, Seoul National University College of Medicine, Seoul, Korea
| | - Baren Jeong
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Korea
| | - Yoon Seong Lee
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Korea
| | - Whal Lee
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Korea.
- Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea.
- Department of Clinical Medical Sciences, Seoul National University College of Medicine, Seoul, Korea.
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Nishihara T, Miyoshi T, Nakashima M, Akagi N, Morimitsu Y, Inoue T, Miki T, Yoshida M, Toda H, Nakamura K, Yuasa S. Diagnostic improvements of calcium-removal image reconstruction algorithm using photon-counting detector CT for calcified coronary lesions. Eur J Radiol 2024; 172:111354. [PMID: 38309215 DOI: 10.1016/j.ejrad.2024.111354] [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: 11/01/2023] [Revised: 01/19/2024] [Accepted: 01/29/2024] [Indexed: 02/05/2024]
Abstract
OBJECTIVE To investigate the diagnostic performance of a calcium-removal image reconstruction algorithm with photon-counting detector-computed tomography (PCD-CT), a technology that hides only the calcified plaque from the spectral data in coronary calcified lesions. METHODS This retrospective study included 17 patients who underwent PCD-coronary CT angiography (CCTA) with at least one significant coronary stenosis (≥50 %) with calcified plaque by CCTA and invasive coronary angiography (ICA) performed within 60 days of CCTA. A total of 162 segments with calcified plaque were evaluated for subjective image quality using a 4-point scale. Their calcium-removal images were reconstructed from conventional images, and both images were compared with ICA images as the reference standard. The contrast-to noise ratios for both images were calculated. RESULTS Conventional and calcium-removal images had a subjective image quality of 2.7 ± 0.5 and 3.2 ± 0.9, respectively (p < 0.001). The percentage of segments with a non-diagnostic image quality was 32.7 % for conventional images and 28.3 % for calcium-removal images (p < 0.001). The segment-based diagnostic accuracy revealed an area under the receiver operating characteristic curve of 0.87 for calcium-removal images and 0.79 for conventional images (p = 0.006). Regarding accuracy, the specificity and positive predictive value of calcium-removal images were significantly improved compared with those of conventional images (80.5 % vs. 69.5 %, p = 0.002 and 64.1 % vs. 52.0 %, p < 0.001, respectively). The objective image quality of the mean contrast-to-noise ratio did not differ between the images (13.9 ± 3.6 vs 13.3 ± 3.4, p = 0.356) CONCLUSIONS: Calcium-removal images with PCD-CT can potentially be used to evaluate diagnostic performance for calcified coronary artery lesions.
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Affiliation(s)
- Takahiro Nishihara
- Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Toru Miyoshi
- Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
| | - Mitsutaka Nakashima
- Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Noriaki Akagi
- Division of Radiological Technology, Okayama University Hospital, Okayama, Japan
| | - Yusuke Morimitsu
- Division of Radiological Technology, Okayama University Hospital, Okayama, Japan
| | - Tomohiro Inoue
- Division of Radiological Technology, Okayama University Hospital, Okayama, Japan
| | - Takashi Miki
- Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Masatoki Yoshida
- Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Hironobu Toda
- Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Kazufumi Nakamura
- Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Shinsuke Yuasa
- Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
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Böttcher B, Zsarnoczay E, Varga-Szemes A, Schoepf UJ, Meinel FG, van Assen M, De Cecco CN. Dual-Energy Computed Tomography in Cardiac Imaging. Radiol Clin North Am 2023; 61:995-1009. [PMID: 37758366 DOI: 10.1016/j.rcl.2023.05.004] [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: 10/03/2023]
Abstract
Dual-energy computed tomography (DECT) acquires images using two energy spectra and offers a variation of reconstruction techniques for improved cardiac imaging. Virtual monoenergetic images decrease artifacts improving coronary plaque and stent visualization. Further, contrast attenuation is increased allowing significant reduction of contrast dose. Virtual non-contrast reconstructions enable coronary artery calcium scoring from contrast-enhanced scans. DECT provides advanced plaque imaging with detailed analysis of plaque components, indicating plaque stability. Extracellular volume assessment using DECT offers noninvasive detection of myocardial fibrosis. This review aims to outline the current cardiac applications of DECT, summarize recent literature, and discuss their findings.
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Affiliation(s)
- Benjamin Böttcher
- Division of Cardiothoracic Imaging, Department of Radiology and Imaging Sciences, Emory University Hospital, 1364 Clifton Road NE, Suite D112, Atlanta, GA 30322, USA; Institute of Diagnostic and Interventional Radiology, Pediatric Radiology and Neuroradiology, University Medical Centre Rostock, Ernst-Heydemann-Strasse 6, 18057 Rostock, Germany
| | - Emese Zsarnoczay
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Clinical Science Building, 96 Jonathan Lucas Street, Suite 210, MSC 323 Charleston, SC 29425, USA; MTA-SE Cardiovascular Imaging Research Group, Medical Imaging Center, Semmelweis University, Üllői út 26, 1085 Budapest, Hungary
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Clinical Science Building, 96 Jonathan Lucas Street, Suite 210, MSC 323 Charleston, SC 29425, USA
| | - Uwe Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Clinical Science Building, 96 Jonathan Lucas Street, Suite 210, MSC 323 Charleston, SC 29425, USA
| | - Felix G Meinel
- Institute of Diagnostic and Interventional Radiology, Pediatric Radiology and Neuroradiology, University Medical Centre Rostock, Ernst-Heydemann-Strasse 6, 18057 Rostock, Germany
| | - Marly van Assen
- Division of Cardiothoracic Imaging, Department of Radiology and Imaging Sciences, Emory University Hospital, 1364 Clifton Road NE, Suite D112, Atlanta, GA 30322, USA
| | - Carlo N De Cecco
- Division of Cardiothoracic Imaging and Imaging Informatics, Department of Radiology and Imaging Sciences, Emory University Hospital, Emory Healthcare, Inc. 1365 Clifton Road NE, Suite - AT503, Atlanta, GA 30322, USA.
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Xin L, Zhuo W, Liu Q, Xie T, Zaidi H. Triple-source saddle-curve cone-beam photon counting CT image reconstruction: A simulation study. Z Med Phys 2022:S0939-3889(22)00097-6. [PMID: 36336554 DOI: 10.1016/j.zemedi.2022.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 09/18/2022] [Accepted: 10/05/2022] [Indexed: 11/06/2022]
Abstract
PURPOSE The most common detector material in the PC CT system, cannot achieve the best performance at a relatively higher photon flux rate. In the reconstruction view, the most commonly used filtered back projection, is not able to provide sufficient reconstructed image quality in spectral computed tomography (CT). Developing a triple-source saddle-curve cone-beam photon counting CT image reconstruction method can improve the temporal resolution. METHODS Triple-source saddle-curve cone-beam trajectory was rearranged into four trajectory sets for simulation and reconstruction. Projection images in different energy bins were simulated by forward projection and photon counting CT respond model simulation. After simulation, the object was reconstructed using Katsevich's theory after photon counts correction using the pseudo inverse of photon counting CT response matrix. The material decomposition can be performed based on images in different energy bins. RESULTS Root mean square error (RMSE) and structural similarity index (SSIM) are calculated to quantify the image quality of reconstruction images. Compared with FDK images, the RMSE for the triple-source image was improved by 27%, 21%, 14%, 8%, and 6% for the reconstrued image of 20-33, 33-47, 47-58, 58-69, 69-80 keV energy bin. The SSIM was improved by 1.031%, 0.665%, 0.396%, 0.235%, 0.174% for corresponding energy bin. The decomposition image based on corrected images shows improved RMSE and SSIM, each by 33.861% and 0.345%. SSIM of corrected decomposition image of iodine reaches 99.415% of the original image. CONCLUSIONS A new Triple-source saddle-curve cone-beam PC CT image reconstruction method was developed in this work. The exact reconstruction of the triple-source saddle-curve improved both the image quality and temporal resolution.
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Affiliation(s)
- Lin Xin
- Institute of Radiation Medicine, Fudan University, Shanghai, China
| | - Weihai Zhuo
- Institute of Radiation Medicine, Fudan University, Shanghai, China
| | - Qian Liu
- School of Biomedical Engineering, Hainan University, Haikou, China.
| | - Tianwu Xie
- Institute of Radiation Medicine, Fudan University, Shanghai, China; Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva, Switzerland.
| | - Habib Zaidi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva, Switzerland; Geneva Neuroscience Center, Geneva University, Geneva, Switzerland; Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands; Department of Nuclear Medicine, University of Southern Denmark, Odense, Denmark
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Artificial Intelligence (Enhanced Super-Resolution Generative Adversarial Network) for Calcium Deblooming in Coronary Computed Tomography Angiography: A Feasibility Study. Diagnostics (Basel) 2022; 12:diagnostics12040991. [PMID: 35454039 PMCID: PMC9027004 DOI: 10.3390/diagnostics12040991] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/08/2022] [Accepted: 04/13/2022] [Indexed: 12/22/2022] Open
Abstract
Background: The presence of heavy calcification in the coronary artery always presents a challenge for coronary computed tomography angiography (CCTA) in assessing the degree of coronary stenosis due to blooming artifacts associated with calcified plaques. Our study purpose was to use an advanced artificial intelligence (enhanced super-resolution generative adversarial network [ESRGAN]) model to suppress the blooming artifact in CCTA and determine its effect on improving the diagnostic performance of CCTA in calcified plaques. Methods: A total of 184 calcified plaques from 50 patients who underwent both CCTA and invasive coronary angiography (ICA) were analysed with measurements of coronary lumen on the original CCTA, and three sets of ESRGAN-processed images including ESRGAN-high-resolution (ESRGAN-HR), ESRGAN-average and ESRGAN-median with ICA as the reference method for determining sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Results: ESRGAN-processed images improved the specificity and PPV at all three coronary arteries (LAD-left anterior descending, LCx-left circumflex and RCA-right coronary artery) compared to original CCTA with ESRGAN-median resulting in the highest values being 41.0% (95% confidence interval [CI]: 30%, 52.7%) and 26.9% (95% CI: 22.9%, 31.4%) at LAD; 41.7% (95% CI: 22.1%, 63.4%) and 36.4% (95% CI: 28.9%, 44.5%) at LCx; 55% (95% CI: 38.5%, 70.7%) and 47.1% (95% CI: 38.7%, 55.6%) at RCA; while corresponding values for original CCTA were 21.8% (95% CI: 13.2%, 32.6%) and 22.8% (95% CI: 20.8%, 24.9%); 12.5% (95% CI: 2.6%, 32.4%) and 27.6% (95% CI: 24.7%, 30.7%); 17.5% (95% CI: 7.3%, 32.8%) and 32.7% (95% CI: 29.6%, 35.9%) at LAD, LCx and RCA, respectively. There was no significant effect on sensitivity and NPV between the original CCTA and ESRGAN-processed images at all three coronary arteries. The area under the receiver operating characteristic curve was the highest with ESRGAN-median images at the RCA level with values being 0.76 (95% CI: 0.64, 0.89), 0.81 (95% CI: 0.69, 0.93), 0.82 (95% CI: 0.71, 0.94) and 0.86 (95% CI: 0.76, 0.96) corresponding to original CCTA and ESRGAN-HR, average and median images, respectively. Conclusions: This feasibility study shows the potential value of ESRGAN-processed images in improving the diagnostic value of CCTA for patients with calcified plaques.
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Yamada M, Yamada Y, Nakahara T, Okuda S, Abe T, Kuribayashi S, Jinzaki M. Accuracy of ultra-high-resolution computed tomography with a 0.3-mm detector for quantitative assessment of coronary artery stenosis grading in comparison with conventional computed tomography: A phantom study. J Cardiovasc Comput Tomogr 2021; 16:239-244. [PMID: 34906436 DOI: 10.1016/j.jcct.2021.11.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 10/15/2021] [Accepted: 11/22/2021] [Indexed: 10/19/2022]
Abstract
BACKGROUND The development of ultra-high-resolution CT (U-HRCT) is expected to improve the accuracy of coronary stenosis evaluation. This study aimed to evaluate the accuracy of the stenosis severities of coronary artery phantoms estimated using U-HRCT by comparing them to those estimated with conventional CT. METHODS Coronary artery phantoms with non-calcified and calcified lesions were scanned with conventional CT (64-row × 0.625 mm) and U-HRCT (32-row × 0.3125 mm). The coronary artery phantoms had lumen diameters of 2.0, 3.0, and 4.0 mm with non-calcified lesions representing 0%, 25%, 50%, and 75% stenosis and 3.0 and 4.0 mm with calcified lesions representing 0%, 25%, 50%, and 75% stenosis. The lumen diameters at the stenotic and non-stenotic regions were measured, and the stenosis severities were compared with the true values. RESULTS For non-calcified lesions, conventional CT significantly underestimated the stenosis severity in the phantom showing 75% stenosis with lumen diameters of 2.0 and 3.0 mm (p < 0.05), while the estimated stenosis severities were not significantly different from the true values at all settings with U-HRCT. For the calcified lesions, conventional CT overestimated the stenosis severities at all settings (p < 0.05), while U-HRCT yielded estimations closer to the true values, although still with some overestimation (p < 0.05). CONCLUSION By using U-HRCT, the estimated stenosis severities of the coronary artery with non-calcified lesion become almost equal to the true value, while those with calcified lesion are still overestimated although they become closer to the true value.
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Affiliation(s)
- Minoru Yamada
- Department of Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Yoshitake Yamada
- Department of Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Takehiro Nakahara
- Department of Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Shigeo Okuda
- Department of Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Takayuki Abe
- Keio University School of Medicine, Clinical and Translational Research Center, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan; Yokohama City University School of Data Science, 22-2, Seto, Kanazawa, Yokohama, Kanagawa, 236-0027, Japan
| | - Sachio Kuribayashi
- Department of Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan; HIMEDIC Imaging Center at Lake Yamanaka, XIV Yamanakako B2F, 562-12 Hirano, Yamanashi, 401-0502, Japan
| | - Masahiro Jinzaki
- Department of Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
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Tarkowski P, Czekajska-Chehab E. Dual-Energy Heart CT: Beyond Better Angiography-Review. J Clin Med 2021; 10:jcm10215193. [PMID: 34768713 PMCID: PMC8584316 DOI: 10.3390/jcm10215193] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/02/2021] [Accepted: 11/04/2021] [Indexed: 12/30/2022] Open
Abstract
Heart CT has undergone substantial development from the use of calcium scores performed on electron beam CT to modern 256+-row CT scanners. The latest big step in its evolution was the invention of dual-energy scanners with much greater capabilities than just performing better ECG-gated angio-CT. In this review, we present the unique features of dual-energy CT in heart diagnostics.
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Sartoretti T, Eberhard M, Nowak T, Gutjahr R, Jost G, Pietsch H, Schmidt B, Flohr T, Alkadhi H, Euler A. Photon-Counting Multienergy Computed Tomography With Spectrally Optimized Contrast Media for Plaque Removal and Stenosis Assessment. Invest Radiol 2021; 56:563-570. [PMID: 33660630 DOI: 10.1097/rli.0000000000000773] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The aim of this study was to systematically evaluate the potential to combine investigational contrast media with spectrally optimized energy-thresholding of photon-counting detector computed tomography (PCCT) for subtraction of calcified plaques in a coronary artery stenosis phantom. METHODS A small vessel phantom containing 3 fillable tubes (diameter, 3 mm each) with calcified plaques was placed into an anthropomorphic chest phantom. The plaques had incremental thicknesses ranging from 0.3 to 2.7 mm, simulating vessel stenoses ranging from 10% to 90% of the lumen diameter. The phantom was filled with 5 different investigational contrast media (iodine, bismuth, hafnium, holmium, and tungsten) at equal mass concentrations (15 mg/mL) and was imaged on a prototype PCCT at 140 kVp using optimized, contrast media-dependent energy thresholds. Contrast maps (CMs) were reconstructed for each contrast medium by applying a linear 2-material decomposition algorithm. Image noise magnitude and noise texture of CM were compared among the contrast media using the noise power spectrum. Two blinded readers independently rated the vessel lumen visualization on short-axis and the overall subjective image quality on long-axis CM relative to iodine as the reference standard. Four readers determined the highest degree of stenosis that could be assessed with high diagnostic confidence on long-axis CM. RESULTS Average image noise on CM was lower for tungsten (49 HU) and hafnium (62 HU) and higher for bismuth (81 HU) and holmium (165 HU) compared with iodine (78 HU). Noise texture of CM was similar among the contrast media. Interreader agreement for vessel lumen visualization on short-axis CM ranged from moderate to excellent (k = 0.567-0.814). Compared with iodine, lumen visualization of each reader was improved using tungsten (P < 0.001 for both readers), similar to improved using hafnium (P = 0.008, P = 0.29), similar using bismuth (P = 0.38, P = 0.69), and decreased using holmium (both, P < 0.001). Overall subjective image quality was similar for holmium and superior for tungsten, hafnium, and bismuth as compared with iodine. Higher-degree stenoses were evaluable with high confidence using tungsten (mean, 70%; interquartile range, 70%-70%), bismuth (70%; 60%-70%), and hafnium (75%; 70%-80%) compared with iodine (50%; 50%-60%) and holmium (50%; 50%-60%). CONCLUSIONS Spectral optimization in PCCT combined with investigational contrast media can improve calcium subtraction and stenosis assessment in small vessels. Contrast maps of tungsten and, to a lesser extent, hafnium as contrast media yielded superior image noise properties and improved vessel lumen visualization, along with a higher subjective image quality compared with the reference standard iodine.
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Affiliation(s)
- Thomas Sartoretti
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Matthias Eberhard
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | | | | | | | | | | | | | - Hatem Alkadhi
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - André Euler
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
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Kwan AC, Pourmorteza A, Stutman D, Bluemke DA, Lima JAC. Next-Generation Hardware Advances in CT: Cardiac Applications. Radiology 2020; 298:3-17. [PMID: 33201793 DOI: 10.1148/radiol.2020192791] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Impending major hardware advances in cardiac CT include three areas: ultra-high-resolution (UHR) CT, photon-counting CT, and phase-contrast CT. Cardiac CT is a particularly demanding CT application that requires a high degree of temporal resolution, spatial resolution, and soft-tissue contrast in a moving structure. In this review, cardiac CT is used to highlight the strengths of these technical advances. UHR CT improves visualization of calcified and stented vessels but may result in increased noise and radiation exposure. Photon-counting CT uses multiple photon energies to reduce artifacts, improve contrast resolution, and perform material decomposition. Finally, phase-contrast CT uses x-ray refraction properties to improve spatial and soft-tissue contrast. This review describes these hardware advances in CT and their relevance to cardiovascular imaging.
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Affiliation(s)
- Alan C Kwan
- From the Smidt Heart Institute, Cedars-Sinai Medical Center, 127 S San Vicente Blvd, AHSP, Suite A3600, Los Angeles, CA 90048-0750 (A.C.K.); Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Winship Cancer Institute, Emory University, Atlanta, Ga (A.P.); Department of Biomedical Engineering, Georgia Institute of Technology-Emory University, Atlanta, Ga (A.P.); Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Md (D.S.); Extreme Light Infrastructure-Nuclear Physics, Bucharest-Magurele, Romania (D.S.); Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wis (D.A.B.); and Department of Cardiology, The Johns Hopkins Hospital, Baltimore, Md (J.A.C.L.)
| | - Amir Pourmorteza
- From the Smidt Heart Institute, Cedars-Sinai Medical Center, 127 S San Vicente Blvd, AHSP, Suite A3600, Los Angeles, CA 90048-0750 (A.C.K.); Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Winship Cancer Institute, Emory University, Atlanta, Ga (A.P.); Department of Biomedical Engineering, Georgia Institute of Technology-Emory University, Atlanta, Ga (A.P.); Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Md (D.S.); Extreme Light Infrastructure-Nuclear Physics, Bucharest-Magurele, Romania (D.S.); Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wis (D.A.B.); and Department of Cardiology, The Johns Hopkins Hospital, Baltimore, Md (J.A.C.L.)
| | - Dan Stutman
- From the Smidt Heart Institute, Cedars-Sinai Medical Center, 127 S San Vicente Blvd, AHSP, Suite A3600, Los Angeles, CA 90048-0750 (A.C.K.); Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Winship Cancer Institute, Emory University, Atlanta, Ga (A.P.); Department of Biomedical Engineering, Georgia Institute of Technology-Emory University, Atlanta, Ga (A.P.); Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Md (D.S.); Extreme Light Infrastructure-Nuclear Physics, Bucharest-Magurele, Romania (D.S.); Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wis (D.A.B.); and Department of Cardiology, The Johns Hopkins Hospital, Baltimore, Md (J.A.C.L.)
| | - David A Bluemke
- From the Smidt Heart Institute, Cedars-Sinai Medical Center, 127 S San Vicente Blvd, AHSP, Suite A3600, Los Angeles, CA 90048-0750 (A.C.K.); Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Winship Cancer Institute, Emory University, Atlanta, Ga (A.P.); Department of Biomedical Engineering, Georgia Institute of Technology-Emory University, Atlanta, Ga (A.P.); Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Md (D.S.); Extreme Light Infrastructure-Nuclear Physics, Bucharest-Magurele, Romania (D.S.); Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wis (D.A.B.); and Department of Cardiology, The Johns Hopkins Hospital, Baltimore, Md (J.A.C.L.)
| | - João A C Lima
- From the Smidt Heart Institute, Cedars-Sinai Medical Center, 127 S San Vicente Blvd, AHSP, Suite A3600, Los Angeles, CA 90048-0750 (A.C.K.); Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Winship Cancer Institute, Emory University, Atlanta, Ga (A.P.); Department of Biomedical Engineering, Georgia Institute of Technology-Emory University, Atlanta, Ga (A.P.); Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Md (D.S.); Extreme Light Infrastructure-Nuclear Physics, Bucharest-Magurele, Romania (D.S.); Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wis (D.A.B.); and Department of Cardiology, The Johns Hopkins Hospital, Baltimore, Md (J.A.C.L.)
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Effect of energy difference in the evaluation of calcification size and luminal diameter in calcified coronary artery plaque using spectral CT. Jpn J Radiol 2020; 38:1142-1149. [PMID: 32767199 DOI: 10.1007/s11604-020-01027-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 07/30/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE This study evaluated the calcium blooming-reducing effect and the differences of luminal diameter among various-energy virtual monochromatic images (VMIs) using rapid kilovolt-switching dual-energy computed tomography (DECT). MATERIALS AND METHODS Forty-five calcified segments in 31 patients were analyzed. For the analysis, 40- to 140-keV VMIs on both non-contrast CT and coronary CT angiography were generated at 10-keV steps, and calcification size and luminal diameter were measured using CT number profile curve and full-width at half-maximum method. We compared calcification size and luminal diameter on each keV VMIs with those on 70-keV VMI. RESULTS There was no significant differences among the 40- to 140-keV VMIs regarding calcification size or luminal diameter. CONCLUSION The 40- to 140-keV VMIs produced by single-source DECT had no effect on the calcification size or luminal diameter in the coronary artery.
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Novel developments in non-invasive imaging of peripheral arterial disease with CT: experience with state-of-the-art, ultra-high-resolution CT and subtraction imaging. Clin Radiol 2018; 74:51-58. [PMID: 29627067 DOI: 10.1016/j.crad.2018.03.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 03/01/2018] [Indexed: 11/21/2022]
Abstract
Despite advances, challenges remain for less invasive imaging of peripheral arterial occlusive disease (PAOD) using computed tomography (CT) angiography. The application of dual-energy imaging to PAOD has been reported to improve the diagnostic accuracy of this application; however, severe arteriosclerosis with heavy arterial wall calcification still hampers definitive lesion characterisation, especially in distal and smaller arteries. Recently an ultra-high resolution scanner has been introduced. In combination with advances in post-processing, such as subtraction techniques, these developments may overcome some of the current challenges and allow far more detailed characterisation of PAOD non-invasively. The aim of this review is to describe our current experience with ultra-high resolution CT in combination with subtraction and discuss the potential advantages of their application for peripheral angiography.
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Sharifabadi AD, Korevaar DA, McGrath TA, van Es N, Frank RA, Cherpak L, Dang W, Salameh JP, Nguyen F, Stanley C, McInnes MDF. Reporting bias in imaging: higher accuracy is linked to faster publication. Eur Radiol 2018; 28:3632-3639. [PMID: 29564596 DOI: 10.1007/s00330-018-5354-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 12/28/2017] [Accepted: 01/24/2018] [Indexed: 12/12/2022]
Abstract
OBJECTIVES The objective of this study was to evaluate whether higher reported accuracy estimates are associated with shorter time to publication among imaging diagnostic accuracy studies. METHODS We included primary imaging diagnostic accuracy studies, included in meta-analyses from systematic reviews published in 2015. For each primary study, we extracted accuracy estimates, participant recruitment periods and publication dates. Our primary outcome was the association between Youden's index (sensitivity + specificity - 1, a single measure of diagnostic accuracy) and time to publication. RESULTS We included 55 systematic reviews and 781 primary studies. Study completion dates were missing for 238 (30%) studies. The median time from completion to publication in the remaining 543 studies was 20 months (IQR 14-29). Youden's index was negatively correlated with time from completion to publication (rho = -0.11, p = 0.009). This association remained significant in multivariable Cox regression analyses after adjusting for seven study characteristics: hazard ratio of publication was 1.09 (95% CI 1.03-1.16, p = 0.004) per unit increase for logit-transformed estimates of Youden's index. When dichotomizing Youden's index by a median split, time from completion to publication was 20 months (IQR 13-33) for studies with a Youden's index below the median, and 19 months (14-27) for studies with a Youden's index above the median (p = 0.104). CONCLUSION Imaging diagnostic accuracy studies with higher accuracy estimates were weakly associated with a shorter time to publication. KEY POINTS • Higher accuracy estimates are weakly associated with shorter time to publication. • Lag in time to publication remained significant in multivariate Cox regression analyses. • No correlation between accuracy and time from submission to publication was identified.
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Affiliation(s)
| | - D A Korevaar
- Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Center, Amsterdam, The Netherlands
| | - T A McGrath
- Department of Radiology-Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - N van Es
- Department of Vascular Medicine, Academic Medical Center, Room F4-139, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands
| | - R A Frank
- Department of Radiology-Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - L Cherpak
- Department of Radiology-Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - W Dang
- Department of Radiology-Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - J P Salameh
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
| | - F Nguyen
- Department of Radiology-Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - C Stanley
- Dalhousie University, Halifax, NS, Canada
| | - M D F McInnes
- Department of Radiology, Clinical Epidemiology Program, Ottawa Hospital Research Institute, University of Ottawa, Room c159 Ottawa Hospital Civic Campus, 1053 Carling Ave., Ottawa, ON, K1Y 4E9, Canada.
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Andreini D, Pontone G, Mushtaq S, Mancini ME, Conte E, Guglielmo M, Volpato V, Annoni A, Baggiano A, Formenti A, Ditali V, Perchinunno M, Fiorentini C, Bartorelli AL, Pepi M. Image quality and radiation dose of coronary CT angiography performed with whole-heart coverage CT scanner with intra-cycle motion correction algorithm in patients with atrial fibrillation. Eur Radiol 2017; 28:1383-1392. [DOI: 10.1007/s00330-017-5131-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 10/05/2017] [Accepted: 10/11/2017] [Indexed: 10/18/2022]
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