CT enterography at 100 kVp with iterative reconstruction compared to 120 kVp filtered back projection: evaluation of image quality and radiation dose in the same patients.
Academic Article
Overview
abstract
PURPOSE: To perform qualitative and quantitative comparison of images in same patients undergoing CT enterography (CTE) with 100 kVp iterative reconstruction and 120 kVp filtered back projection. METHODS: In this retrospective study, 50 consecutive patients who underwent imaging with 100 kVp and iterative reconstruction (100-IR) and had prior imaging with 120 kVp filtered back projection (120-FBP) were included. Subjective image quality parameters were evaluated by two independent and blinded readers, with higher score implying better image quality. We developed a quantitative measure of image sharpness by measuring edge-width of the psoas-fat interface. Image noise was measured as a standard deviation of attenuation measurement in the homogeneous region of the subcutaneous fat. Image sharpness and noise were measured and compared between 100-IR and 120-FBP acquisitions. RESULTS: There was approximately 33% lower radiation dose as estimated by CTDIvol with 100-IR compared to 120-FBP (9.95 vs. 15.0; p < 0.0001). There were no significant differences in overall image quality, bowel wall sharpness, and subjective assessment of noise and artifact between 100-IR and 120-FBP for both readers. Mesenteric vessel clarity score was significantly higher with 100-IR for 1 reader (4.34 vs. 4.04; p = 0.008), but not for the second reader. There was higher image sharpness (1.62 vs. 1.89; p < 0.0001) and higher image noise (14.4 vs. 13.2; p = 0.020) with 100-IR compared to 120-FBP acquisition. CONCLUSIONS: CTE performed at 100 kVp with iterative reconstruction demonstrates dose reduction without significant impact on various measures of image quality when compared to conventional 120 kVp FBP.
