Ultra-low dose one-step CT angiography for coronary, carotid and cerebral arteries using 128-slice dual-source CT: A feasibility study

Application of deep learning image reconstruction-high algorithm in one-stop coronary and carotid-cerebrovascular CT angiography with low radiation and contrast doses

Background

For patients with suspected simultaneous coronary and cerebrovascular atherosclerosis, conventional single-site computed tomography angiography (CTA) for both sites can result in nonnegligible radiation and contrast agent dose. The purpose of this study was to validate the feasibility of one-stop coronary and carotid-cerebrovascular CTA (C&CC-CTA) with a "double-low" (low radiation and contrast) dose protocol reconstructed with deep learning image reconstruction with high setting (DLIR-H) algorithm.

Methods

From February 2018 to January 2019, 60 patients referred to C&CC-CTA simultaneously in West China Hospital were recruited in this prospective cohort study. By random assignment, patients were divided into two groups: double-low dose group (n=30) used 80 kVp and 24 mgI/kg/s contrast dose with images reconstructed using DLIR-H; and routine-dose group (n=30) used 100 kVp and 32 mgI/kg/s contrast dose with images reconstructed using 50% adaptive statistical iterative reconstruction-V (ASIR-V50%). Radiation and contrast doses, subjective image quality score, CT attenuation values, noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured and compared between the groups.

Results

The DLIR-H group used 30% less contrast dose (35.80±4.85 vs. 51.13±6.91 mL) and 48% less overall radiation dose (1.00±0.09 vs. 1.91±0.42 mSv) than the ASIR-V50% group (both P<0.001). There was no statistically significant difference on subjective quality score between the two groups (C-CTA: 4.38±0.67 vs. 4.17±0.81, P=0.337 and CC-CTA: 4.18±0.87 vs. 4.08±0.79, P=0.604). For coronary CTA, lower background noise (18.93±1.43 vs. 22.86±3.75 HU) was reached in DLIR-H group, and SNR and CNR at all assessed branches were significantly increased compared to ASIR-V50% group (all P<0.05), except SNR of left anterior descending (P>0.05). For carotid-cerebrovascular CTA, DLIR-H group was comparable in background noise (19.25±1.42 vs. 20.23±2.40 HU), SNR and CNR at all assessed branches with ASIR-V50% group (all P>0.05).

Conclusions

The "double-low" dose one-stop C&CC-CTA with DLIR-H obtained higher image quality compared with the routine-dose protocol with ASIR-V50% while achieving 48% and 30% reduction in radiation and contrast dose, respectively.

A Heart Rate-Dependent Protocol of "One-Stop" Computed Tomography Angiography of Coronary Combined with Pulmonary Arteries Reduces the Dosages of Contrast Agent

Background:

The personalized, heart rate-dependent computed tomography angiography (CTA) protocol can reduce the use of contrast medium (CM) and the radiation dose. This is especially beneficial for patients with CTA of coronary combined with pulmonary arteries.

Purpose:

To evaluate the feasibility of low CM in one-stop coronary and pulmonary arterial CTA tailored by patients’ heart rate.

Material and Methods:

94 patients set to undergo CTA of coronary combined with pulmonary arteries with one-stop scans. Patients were prospectively randomized into two groups: For group A (n = 47), the timing of the scans was determined according to the patient’s HR using 30 mL CM; For group B (n = 47), in which the routine bolus tracking was applied by setting the ascending aortic threshold of 80 HU with 70 mL CM, scans were performed simultaneously.

Results:

Compared with group B, group A had slightly higher computed tomography (CT) value and image quality of pulmonary artery (CT value: group A 484.7HU; group B 457.9HU; t = 2.446, P = .016; image quality: χ2 = 8.292, P = .016), but in coronary artery wasn’t statistically different between two groups(image quality: χ2 = 2.516, P = .642).

Conclusion:

The heart rate-dependent CM injection protocol can greatly reduce the use of CM, simplify the work-flow, and may obtain comparable or even better image quality compared with the routine bolus tracking.