Non-inferior low-dose coronary computed tomography angiography image quality with knowledge-based iterative model reconstruction for overweight patients

Abstract

We investigated the feasibility of low-dose coronary computed tomography angiography (CCTA), using a prospective electrocardiogram (ECG)-triggered axial scan protocol, knowledge-based iterative model reconstruction (IMR), and fixed tube current, in overweight subjects. Forty non-overweight (group A; body-mass index [BMI] < 25 kg/m2) and 40 overweight individuals (group B; BMI = 25–30 kg/m2), who underwent CCTA for coronary artery disease screening, were retrospectively and consecutively enrolled. A 64-slice CT scanner was used at 100-kVp tube voltage and 150-mA tube current, and images were reconstructed using IMR techniques. Image noise, attenuation at the aorta, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) at the proximal right and left main coronary arteries (pRCA and LMCA) were calculated. CCTA images were qualitatively evaluated using a four-point scale (1, poor; 4, excellent) and analyzed using a non-inferiority test with a pre-defined non-inferiority margin of -0.2. The mean CCTA radiation dose (Group A: 1.33 ± 0.02 mSv; Group B: 1.35 ± 0.10 mSv; p = 0.151) and mean aortic root CT attenuation values (Group A: 447.9 ± 81.6 HU; Group B: 439.5 ± 63.6 HU; p = 0.571) did not differ significantly between the two groups. The mean noise in groups A and B was 26.0 ± 4.8 HU and 29.2 ± 4.4 HU, respectively (p = 0.005). The noise reduction ratio in the groups, compared to filtered back projection, was 65.0% and 68.1%, respectively. The mean grade of image quality did not differ significantly (3.75 ± 0.04 vs. 3.71 ± 0.04, p = 0.478). Group B CCTA image quality was non-inferior (mean difference = -0.043, 95% CI = -0.162–0.077) to that of Group A. We concluded that low-dose CCTA with prospective ECG-triggering and IMR might be applied to overweight subjects, as well as to normal-weight subjects, by using a fixed tube current without an increase in tube current based on the patient’s body size.

Influence of Contrast Agent Injection Scheme Customized by Dual-Source CT Based on Automatic Tube Voltage Technology on Image Quality and Radiation Dose of Coronary Artery Imaging

“…In the past, CCTA examination was limited by actual situation, and tube voltage was selected empirically according to the body mass of patients. However, for patients with the same body mass range, some patients needed higher tube voltage levels to obtain better scanning images because of differences in body shape and muscle and adipose tissue content distribution, and some patients with larger body mass only needed conventional or even lower tube voltage to meet the examination requirements and obtain better image quality ( 15 , 16 ). For patients with normal and same body mass range, using the 3rd generation Shuang Yuan CT automatic tube voltage selection technology, the tube voltage of CCTA examination can be intelligently selected, and effects of other patient parameters on the examination besides body mass should be considered, so as to help technicians to more accurately and reasonably select the optimal voltage value suitable for patients.…”

Image quality of coronary CT angiography at ultra low tube voltage reconstructed with a deep-learning image reconstruction algorithm in patients of different weight

“…For each patient, the volume CT dose index (CTDI vol ) and dose-length product (DLP) automatically displayed by the scanner were recorded to calculate the effective dose (ED), which was calculated as follows: ED = DLP × K, where K is the chest conversion factor of 0.014 mSv/mGy·cm ( 18 ).…”

Clinical utility of single-shot echo-planar diffusion-weighted imaging using L1-regularized iterative sensitivity encoding in prostate MRI

“…The non-inferiority margin was determined at 20%, by referring to the cutoff used in a previous study. [19] Statistics were calculated by using JMP Software (version 16.1.0; SAS Institute Inc., Cary, NC).…”