scholarly journals Dual-Layer Spectral CTA for TAVI Planning Using a Split-Phase Protocol and Low-keV Virtual Monoenergetic Images: Improved Image Quality in Comparison with Single-Phase Conventional CTA

2021 ◽  
Author(s):  
David Mangold ◽  
Janek Salatzki ◽  
Johannes Riffel ◽  
Hans-Ulrich Kauczor ◽  
Tim Frederik Weber
Keyword(s):  
Image Quality ◽  
Ct Angiography ◽  
Single Phase ◽  
Access Route ◽  
Ct Scanner ◽  
Arterial Access ◽  
Transcatheter Aortic Valve ◽  
Gated Acquisition ◽  
Virtual Monoenergetic Images ◽  
Monoenergetic Images

Purpose Adaptation of computed tomography protocols for transcatheter aortic valve implantation (TAVI) planning is required when a first-generation dual-layer spectral CT scanner (DLCT) is used. The purpose of this study was to evaluate the objective image quality of aortic CT angiography (CTA) for TAVI planning using a split-phase technique with reconstruction of 40 keV virtual monoenergetic images (40 keV-VMI) obtained with a DLCT scanner. CT angiography obtained with a single-phase protocol of a conventional single-detector CT (SLCT) was used for comparison. Materials and Methods 75 CTA scans from DLCT were retrospectively compared to 75 CTA scans from SLCT. For DLCT, spiral CTA without ECG-synchronization was performed immediately after a retrospectively ECG-gated acquisition covering the heart and aortic arch. For SLCT, spiral CTA with retrospective ECG-gating was performed to capture the heart and the access route simultaneously in one scan. Objective image quality was compared at different levels of the arterial access route. Results 40 keV virtual monoenergetic images of DLCT showed a significantly higher mean vessel attenuation, SNR, and CNR at all levels of the arterial access route. With 40 keV-VMI of DLCT, the overall mean aortic attenuation of all six measured regions was 589.6 ± 243 HU compared to 492.7 ± 209 HU of SLCT (p < 0.01). A similar trend could be observed for SNR (23.6 ± 18 vs. 18.6 ± 9; p < 0.01) and CNR (21.1 ± 18 vs. 16.4 ± 8; p < 0.01). No deterioration was observed for vascular noise (27.8 ± 9 HU vs. 28.1 ± 8 HU; p = 0.599). Conclusion Using a DLCT scanner with a split-phase protocol and 40 keV-VMI for TAVI planning, higher objective image quality can be obtained compared to a single-phase protocol of a conventional CT scanner. Key Points:  Citation Format

Image quality characteristics for virtual monoenergetic images using dual-layer spectral detector CT: Comparison with conventional tube-voltage images

2018 ◽  
Vol 49 ◽  
pp. 5-10 ◽  
Author(s):  
Daisuke Sakabe ◽  
Yoshinori Funama ◽  
Katsuyuki Taguchi ◽  
Takeshi Nakaura ◽  
Daisuke Utsunomiya ◽  
...  
Keyword(s):  
Image Quality ◽  
Quality Characteristics ◽  
Tube Voltage ◽  
Spectral Detector Ct ◽  
Virtual Monoenergetic Images ◽  
Monoenergetic Images

scholarly journals Multiphase CT Angiography versus Single-Phase CT Angiography: Comparison of Image Quality and Radiation Dose

2008 ◽  
Vol 29 (7) ◽  
pp. 1288-1295 ◽  
Author(s):  
C.-Y. Yang ◽  
Y.-F. Chen ◽  
C.-W. Lee ◽  
A. Huang ◽  
Y. Shen ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Ct Angiography ◽  
Single Phase ◽  
Multiphase Ct

Noise characteristics of virtual monoenergetic images from a novel detector-based spectral CT scanner

2018 ◽  
Vol 98 ◽  
pp. 118-125 ◽  
Author(s):  
Kevin Kalisz ◽  
Negin Rassouli ◽  
Amar Dhanantwari ◽  
David Jordan ◽  
Prabhakar Rajiah
Keyword(s):  
Ct Scanner ◽  
Spectral Ct ◽  
Noise Characteristics ◽  
Virtual Monoenergetic Images ◽  
Monoenergetic Images

Image Quality on Dual-energy CTPA Virtual Monoenergetic Images

2018 ◽  
Vol 25 (8) ◽  
pp. 1075-1086 ◽  
Author(s):  
Bari Dane ◽  
Hersh Patel ◽  
Thomas O'Donnell ◽  
Francis Girvin ◽  
Geraldine Brusca-Augello ◽  
...  
Keyword(s):  
Image Quality ◽  
Dual Energy ◽  
Virtual Monoenergetic Images ◽  
Monoenergetic Images

scholarly journals Virtual monoenergetic images from spectral detector computed tomography facilitate washout assessment in arterially hyper-enhancing liver lesions

2020 ◽  
Author(s):  
R. P. Reimer ◽  
N. Große Hokamp ◽  
A. Fehrmann Efferoth ◽  
A. Krauskopf ◽  
D. Zopfs ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Visual Analysis ◽  
Quality Parameters ◽  
Wilcoxon Test ◽  
Liver Lesions ◽  
Diagnostic Confidence ◽  
Virtual Monoenergetic Images ◽  
Noise Ratio ◽  
Monoenergetic Images

Abstract Objectives To investigate whether the increased soft tissue contrast of virtual monoenergetic images (VMIs) obtained from a spectral detector computed tomography (SDCT) system improves washout assessment of arterially hyper-enhancing liver lesions. Methods Fifty-nine arterially hyper-enhancing lesions in 31 patients (age 65 ± 9 years, M/W 20/11) were included in this IRB-approved study. All patients underwent multi-phase SDCT for HCC screening. MRI, CEUS or biopsy within 3 months served as standard of reference to classify lesions as LiRADS 3 or 4/5. VMIs and conventional images (CIs) were reconstructed. Visual analysis was performed on 40, 60, and 80 kiloelectronvolt (keV) and CIs by 3 radiologists. Presence and visibility of washout were assessed; image quality and confidence of washout evaluation were evaluated on 5-point Likert scales. Signal-to-noise ratio (SNR), lesion-to-liver contrast-to-noise ratio (CNR) (|HUlesion–HUliver|/SDliver) and washout (|HUlesion–HUliver|) were calculated. Statistical assessment was performed using ANOVA and Wilcoxon test. Results On subjective lesion analysis, the highest level of diagnostic confidence and highest sensitivity for the detection of lesion washout were found for 40-keV VMIs (40 keV vs. CI, 81.3 vs. 71.3%). Image quality parameters were significantly better in low-kiloelectronvolt VMIs than in CIs (p < 0.05; e.g. SNRliver: 40 keV vs. CIs, 12.5 ± 4.1 vs. 5.6 ± 1.6). In LiRADS 4/5 lesions, CNR and quantitative washout values were significantly higher in 40-keV VMIs compared to CIs (p < 0.05; e.g. CNR and washout in 40 keV vs. CIs, 2.3 ± 1.6 vs. 0.8 ± 0.5 and 29.0 ± 19.1 vs. 12.9 ± 6.9 HU, respectively). Conclusion By increasing lesion contrast, low-kiloelectronvolt VMIs obtained from SDCT improve washout assessment of hyper-enhancing liver lesions with respect to washout visibility and diagnostic confidence. Key Points • Low-kiloelectronvolt virtual monoenergetic images from spectral detector CT facilitate washout assessment in arterially hyper-enhancing liver lesions. • Image quality and quantitative washout parameters as well as subjective washout visibility and diagnostic confidence benefit from low-kiloelectronvolt virtual monoenergetic images.

scholarly journals Image quality of automatic coronary CT angiography reconstruction for patients with HR ≥ 75 bpm using an AI-assisted 16-cm z-coverage CT scanner

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Cheng Yan ◽  
Guofeng Zhou ◽  
Xue Yang ◽  
Xiuliang Lu ◽  
Mengsu Zeng ◽  
...  
Keyword(s):  
Image Quality ◽  
Ct Angiography ◽  
Motion Correction ◽  
Coronary Ct Angiography ◽  
Average Score ◽  
Ct Scanner ◽  
Phase Selection ◽  
Coronary Ct ◽  
Coronary Artery Segment

Abstract Background Coronary CT angiography (CCTA) is a complicated CT exam in comparison to other CT protocols. Exam success highly depends on image assessment of experienced radiologist and the procedure is often time-consuming. This study aims to evaluate feasibility of automatic CCTA reconstruction in 0.25 s rotation time, 16 cm coverage CT scanner with best phase selection and AI-assisted motion correction. Methods CCTA exams of 90 patients with heart rates higher than 75 bpm were included in this study. Two image series were reconstructed—one at automatically selected phase and another with additional motion correction. All reconstructions were performed without manual interaction of radiologist. A four-point Likert scale rating system was used to evaluate the image quality of coronary artery segment by two experienced radiologists, according to the 18-segment model. Analysis was done on per-segment basis. Results Total 1194 out of the 1620 segments were identified for quality evaluation in 90 patients. After automatic best phase selection, 1172 segments (98.3%) were rated as having diagnostic image quality (scores 2–4) and the average score is 3.64 ± 0.55. When motion corrections were applied, diagnostic segment number increases to 1192 (99.8%) and the average score is 3.85 ± 0.37. Conclusions With the help of 0.25 s rotation speed, 16-cm z-coverage and AI-assisted motion correction algorithm, CCTA exam reconstruction could be performed with minimum radiologist involvement and still meet image quality requirement.

scholarly journals Visualization of small visceral arteries on abdominal CT angiography using ultra-high-resolution CT scanner

2021 ◽  
Author(s):  
Kazuya Ogawa ◽  
Hiromitsu Onishi ◽  
Masatoshi Hori ◽  
Atsushi Nakamoto ◽  
Takashi Ota ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Image Quality ◽  
Ct Angiography ◽  
Ct Scanner ◽  
High Resolution Computed Tomography ◽  
Abdominal Ct ◽  
Small Arteries ◽  
Ct Value ◽  
Visceral Arteries

Abstract Purpose To evaluate the image quality and ability to delineate the small visceral arteries of high-resolution (HR) abdominal CT angiography (CTA) using an ultra-high-resolution computed tomography (UHR CT) scanner. Materials and methods Thirty-seven patients were enrolled who underwent abdominal CTA using a UHR CT scanner. The images were reconstructed with a matrix of 1024 × 1024 and 0.25 mm thickness for HR CTA and with a matrix of 512 × 512 and 0.5 mm thickness for normal resolution (NR) CTA. Maximum CT value, image quality, and delineation of the small arteries were compared between HR CTA and NR CTA. Results HR CTA showed significantly higher maximum CT value, higher image quality, and better delineation of the small arteries than did NR CTA (P < .005). Conclusion HR CTA using a UHR CT scanner showed higher image quality than NR CTA and enhanced the delineation of visceral arteries.

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