60 kVp Coronary CT Angiography as a Screening Tool on Asymptomatic Patients

Purpose: To investigate the feasibility of using 60 kVp coronary CT angiography (CCTA) combined with deep learning–based CT reconstruction as a screening tool on asymptomatic patients. Materials and Methods: A total of 156 asymptomatic patients (body mass index, 24.4 ± 2.2 kg/m 2 ) with at least one coronary artery disease (CAD) risk factor were prospectively enrolled for taking an experimental ultra-low dose 60 kVp CCTA followed by a routine 120 kVp CCTA. Stenosis detection, plaque analysis, and image quality assessment were performed on both scans, with 120 kVp CCTA serving as the reference. Results: The mean effective dose and mean contrast medium (CM) dosage were 0.4 ± 0.1 mSv and 27.0 ± 3.2 mL, respectively, for 60 kVp CCTA, corresponding to a 91.5% and 50.0% reduction as compared with 120 kVp CCTA. In both analyses for all plaque types and noncalcific plaques, the sensitivity, specificity, and accuracy in stenosis detection were >92% with 60 kVp CCTA on per-segment, per-vessel, and per-patient basis, and in particular, the negative predictive value was ≥ 97%. However, compared to 120 kVp CCTA, 60 kVp CCTA led to a significant overestimation in plaque volume and stenosis severity ( P <0.01), as well as inferior subjective scores regarding vessel and lumen delineation ( P <0.05). Conclusions: Despite overestimation in plaque volume and stenosis severity, 60 kVp CCTA showed excellent stenosis detection capability with ultra-low radiation dose and reduced CM dosage that may potentially be adopted as a screening tool for asymptomatic patients in routine practice.