Preliminary study of dose reduction and image quality of adult pelvic low-dose CT scan with adaptive statistical iterative reconstruction.

Abstract

Because pelvic computed tomography (CT) is widely used in clinical practice, there are increasing concerns regarding the associated risks of radiation-induced cancer. Therefore, the capability to reduce the CT radiation dose without compromising image quality is desirable. To assess the radiation dose and image quality of adult pelvic CT using both a routine dose and low radiation dose with filtered back projection (FBP) and adaptive statistical iterative reconstruction (ASIR). Forty-five patients underwent both routine-dose CT with FBP reconstruction and low-dose CT with FBP and 50% ASIR blending ratio (ASIR50) reconstruction, respectively. Three different groups of image data were compared for subjective and objective image quality. CT dose index volume (CTDIvol), dose-length product (DLP), and effective dose (ED) were recorded. The resulting CTDIvol, DLP, and ED following low-dose pelvic CT were 10.80 ± 6.0 mGy, 265.0 ± 55.0 mGy.Cm, and 3.97 ± 0.82 mSv, respectively. When compared with the values obtained following routine-dose pelvic CT, the low-dose pelvic CT values decreased by 62%, 55%, and 56%, respectively (P < 0.001). The results following evaluation of subjective and objective image quality revealed that there was no significant difference (P > 0.05) between routine-dose CT with FBP, and low-dose CT with ASIR50. However, significant differences were detected between low-dose CT with FBP, routine-dose CT with FBP, and low-dose CT with ASIR50 (P < 0.01). The application of low-dose pelvic CT with ASIR50 could dramatically reduce the radiation dose and substantially improve image quality.