Low-tube voltage computed tomography during hepatic arterial phase: The effect of body habitus on image quality

Purpose: This study aimed to evaluate the impact of body habitus factors on image quality of low-tube voltage computed tomography (CT) during the hepatic arterial phase. Materials and Methods: Ninety-seven patients (66 men, 31 women; age range, 26-78 years) who underwent clinically indicated liver dynamic CTexamination were enrolled in the study. Analysis with 80-kVp CT and intermediate tube current (277-337 mA) was performed in the late hepatic arterial phase using a 320-detector row scanner with adaptive iterative dose reduction 3-dimensional reconstruction. Patient body habitus was measured using body weight (BW), body mass index (BMI), lateral width (LW) of the abdomen, and muscle volume (MV) of the abdominalwall. On hepatic arterial phase, the mean image noise and contrast-to-noise ratio (CNR) for the aorta and liver were assessed. The correlations between body habitus factors and image quality parameters were evaluated. Results: In all patients, MV showed the strongest correlation with image noise, followed by BWand LW(r = 0.684, 0.570, and 0.555, respectively). The BMI showed the fourth strongest correlation with image noise among all body habitus factors (r = 0.377). With respect to CNR of the aorta, MV and BWshowed the strongest inverse correlation (r = 0.590 and 0.600, respectively), followed by LWand BMI (r = 0.557 and 0.423, respectively). Regarding the CNR of the liver,MVshowed the strongest inverse correlation (r = 0.279), although the correlation efficiency was weak compared with other correlations. Conclusions: Among various body habitus factors, MV showed the strongest association with image noise and CNR in the hepatic arterial phase using 80-kVp CT.