Evaluation of Abdominal CT Image Quality After Radiation Dose Reduction in Patients at Pranangklao Hospital

Abstract

To evaluate the effect of radiation dose reduction on image quality in abdominal computed tomography (CT) scans, a prospective study was conducted at Pranangklao Hospital from June to August 2025. Seventy-seven patients undergoing abdominal CT scans were divided into a standard dose group (DoseRight 22) and a reduced dose group (DoseRight 20). The study evaluated radiation dose metrics (CTDIvol and DLP), compared image noise, and assessed radiologist satisfaction. Scanning was performed using a 128-multidetector CT scanner (Ingenuity Core 128, Philips) with the following parameters: 120 kVp, beam collimation of 64 x 0.625 mm, beam pitch of 1.281, and a gantry rotation time of 0.5 seconds. Descriptive statistics were used to summarize the demographic data, reporting frequencies and percentages for categorical data, and means and standard deviations for continuous data. An Independent samples t-test was employed to compare the radiation doses between the two groups. For satisfaction scores, descriptive statistics were utilized to provide a qualitative assessment.

The results showed that the reduced-dose group had significantly lower CTDIvol and DLP values compared to the standard group.  After adjusting for body weight, the radiation dose was reduced by an average of 1.86 mGy and 114.4 mGy·cm respectively (p = 0.003) iDose level 5 yielded the lowest image noise. Meanwhile, radiologist satisfaction remained high across all groups (greater than 3.70 out of 4) and iDose level 4 was found to provide the most balanced results. This study demonstrates that radiation dose reduction combined with iDose level 4 can significantly lower the radiation dose while maintaining image quality sufficient for diagnosis, making it suitable for practical clinical application.