EFFECTS OF TEST-BOLUS AND LOW-DOSE SCAN ON CT PULMONARY ANGIOGRAPHY IMAGE QUALITY IN PATIENTS WITH DIFFERENT BODY MASS INDEXES.

Abstract

This study aimed to investigate different methods of obtaining high-quality Computed Tomography pulmonary angiography (CTPA) images using low-dose scanning in patients with different body mass index (BMI) values. Sixty patients with suspected pulmonary embolism were grouped based on their BMI values (BMI < 25, designated N, and BMI ≥ 25, designated O) and were assigned to receive either test bolus (TB) or bolus tracking (BT) at conventional (C) or low (L) dose. The effective dose (ED) in the N-TB-L group was lower than in the group N-TB-C (0.56±0.05 vs. 3.78±1.16, p<0.001), with similar image quality (4.90±0.31 vs. 4.70±0.47, p=0.120). The ED in the O-TB-L group was lower than in the O-TB-C group (0.54±0.03 vs. 5.14±1.34, p<0.001), but the group O-TB-C's image quality was higher (4.65±0.59 vs. 3.95±0.89, p=0.006). Groups N-TB-L versus O-TB-L, groups N-TB-L versus N-BT-L and groups O-TB-C versus O-BT-C had similar EDs (all ps>0.05), but the image quality was different (all ps<0.05). In conclusion, the results showed that the image quality of low-dose CTPA scanning using TB was similar to that of the conventional-dose CTPA in patients with BMI < 25 but was lower in patients with BMI ≥ 25. TB was better than BT for all patients, regardless of BMI, when receiving the same ED.