Improving image quality with deep learning image reconstruction in double-low-dose head CT angiography compared with standard dose and adaptive statistical iterative reconstruction

Abstract

Objective: To demonstrate similar image quality with deep learning image reconstruction (DLIR) in reduced contrast medium (CM) and radiation dose (double-low-dose) head computed tomography (CT) angiography (CTA), in comparison with standard-dose and adaptive statistical iterative reconstruction-Veo (ASIR-V). Methods: A prospective study was performed in 63 patients who under head CTA using 256-slice CT. Patients were randomized into either the standard-dose group (n = 38) with 40 ml of Iopromide (370 mgI ml−1 at 4.5 ml s−1); or a double-low-dose group (n = 25) with CM of 25 ml at 3.0 ml s−1. For image reconstruction, the double-low-dose group used DLIR-M and DLIR-H strength, and the standard-dose group used ASIR-V with 50% strength. The CT value and standard deviation (SD), SNR and CNR of posterior fossa, neck muscles, carotid, vertebral and middle cerebral arteries were measured. The image noise, vessel edge and structure blurring and overall image quality were assessed by using a 5-grade method. The double-low-dose group reduced CM dose by 37.5% and CT dose index (CTDIvol) by 41% compared with the standard-dose group. DLIR further reduced the SD value of the middle cerebral artery and posterior fossa and provided better overall subjective image quality (p < 0.05). Conclusions: DLIR significantly reduces image noise and provides higher overall image quality in the double-low-dose CTA. Advance in knowledge: It is feasible to reduce CM dose by 37.5% and volume CTDI by 41% with the combination of 80kVp and DLIR in head CTA. Compared with ASIR-V, DLIR further reduces image noise and achieves better image quality with reduced contrast and radiation dose.

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

“…Till now, only a few studies have been done to explore the application CTA images of DLIR in carotid and cerebrovascular vessel under lower radiation and contrast dose settings. Also, these studies could not reach a further decrease in image noise compared with the standard-dose protocol with ASIR-V algorithm ( 20 , 38 ). Even if a mean subjective score of 4.18 in our study proved that our carotid and cerebrovascular images were able to meet the diagnostic criteria, further studies to validate its impact on diagnostic accuracy are warranted to confirm its efficacy.…”