Low Tube Voltage Chest Computed Tomography With Enhancement Using Low-Concentration Iodinated Contrast Media: Comparison of 240 mg/mL Versus 300 mg/mL Iodinated Contrast Media.

Purpose: To evaluate the image quality of low voltage chest computed tomography with enhancement (CECT) using low-concentration-iodine contrast media (LCCM). Method: From 9 December to 19 December 2019, three different protocols were used for 263 patients undergoing chest CECT. Chest CECT was done using routine (300 mgI/ml contrast media with 100 kVp) protocol (group 1), LCCM (240 mgI/ml contrast media)-100 kVp protocol (group 2) and LCCM-80 kVp protocol (group 3) in 91, 97 and 75 patients, respectively. The overall diagnostic acceptability, anatomical depiction, noise and contrast-related artifacts were assessed. Additionally, the mean attenuation, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and figure of merit (FOM) in the aorta and the main pulmonary trunk were measured. Results: The overall diagnostic acceptability scores were not significantly different between groups 1 and 2 ( P = .261); group 3 demonstrated significantly lower overall diagnostic acceptability score compared with group 1 ( P = .011) or group 2 ( P < .001). However, in CECT with iterative reconstruction (IR), the overall diagnostic acceptability scores did not show significant difference among 3 groups. Group 3 showed significantly lower effective radiation dose compared with group 1 (2.33 vs 1.22 mSv, P < .001) or group 2 (2.28 vs .22 mSv, P < .001). Conclusions: In 100 kVp chest CECT, the image quality of using 240 mg/mL iodinated contrast media is comparable to that using 300 mg/mL iodine contrast media, regardless of application of IR; with IR, chest CECT using 80 kVp and 240 mg/mL iodinated contrast media results in acceptable image quality and lower radiation dose.