Individualized Scan Protocol Based on Body Mass Index in Dual-Energy Computed Tomography Pulmonary Angiography to Reduce Radiation and Contrast Doses with Improved Image Quality

Abstract

Background We evaluated an individualized dual-energy computed tomography (DECT) scan protocol by combining optimal monochromatic images with an appropriate ASIR-V reconstruction strength in computed tomography pulmonary angiography (CTPA) to reduce radiation and iodine doses and superior vena cava (SVC) artifacts. Material/Methods A total of 127 patients who underwent CTPA were prospectively enrolled and randomly divided into a standard (n=63) and individualized group (n=64). The standard group used 120 kVp, 150 mAs, and 60 mL contrast media at an injection rate of 5 mL/s; the individualized group used DECT imaging mode with tube current selected according to patients’ BMI (BMI ≤20 kg/m 2 , 200 mA; 20< BMI ≤23 kg/m 2 , 240 mA; 23< BMI ≤25 kg/m 2 , 280 mA; BMI >25 kg/m 2 , 320 mA). Contrast media intake was 130 mgI/kg with an injection time of 7 s. The data in the individualized group was reconstructed to 55–70 keV (5 keV interval) monochromatic images combined with 40–80% ASIR-V (10% interval). Radiation dose, contrast dose, and image quality were compared between the groups. Results There were no significant differences in patient habitus. Compared with the standard group, the individualized group significantly decreased radiation dose by 33.93% (3.31±0.57 mSv vs 5.01±0.34 mSv) and contrast dose by 56.95% (9.04±1.40 gI vs 21.00±0.00 gI). The 60 keV image with 80%ASIR-V in the individualized group provided the best image quality and further reduced SVC beam-hardening artifacts. Conclusions The use of BMI-dependent DECT protocol in CTPA further reduces radiation dose, contrast agent dose, and SVC artifacts, with the 60 keV images reconstructed using 80%ASiR-V having the best image quality.

Assessment of Pulmonary Arterial Vessels With Newer Ct Examination Protocols With the Aim of Achieving a Ct-x-ray Dose and Cm-dosage Reduction

“…The radiation dose is related to various factors including pitch, detector material, tube voltage, tube current, test subject BMI value and the scanning range [20,21]. Reducing the tube voltage combined with advanced iterative reconstruction techniques is the most effective way to reduce radiation dose and improve image quality [22][23][24]. In our study, the subjects had a BMI value less than 30 kg/m², and during the scans, CARE Dose 4D and X-CARE were enabled.…”