Impact of Body Mass Index and Sex on Image Quality and Radiation Dose of Routine CT Scan

Abstract

The purpose of this study is to investigate the relationship between radiation dose, signal-to-noise ratio (SNR), and image quality in routine CT scan. Emphasis is placed on the influence of anatomical regions and patient BMI on the metrics of image quality. A retrospective analysis was carried out on 136 patients (66 males and 70 females) who underwent routine CT examinations of the brain, thorax, and abdomen using a 16-slice CT scanner manufactured by GE Healthcare, USA. The Patients were categorized according to body mass index (BMI) as underweight (UW), normal weight (NW), overweight (OW), and obese classifications (OB). The image quality was assessed by measuring the signal intensity, noise (i.e. standard deviation S.D), and computing the signal-to-noise ratio (SNR) across the CT brain, CT thorax and CT abdomen. Statistical analysis, such as student’s t-tests, were conducted to evaluate differences in image quality metrics between both genders and BMI groups, with a significant p- value of < 0.05. The study recorded no significant differences in signal intensity, noise levels, and SNR between patients from both genders across the three anatomical regions (p > 0.05), suggesting that the imaging protocols ensured uniform image quality irrespective of gender. Nonetheless, as BMI increased, signal intensity and noise levels exhibited a significant increase (p < 0.05). Significantly, the SNR increased with increased BMI, indicating that larger patients had adequate radiation doses to improve image quality. Notwithstanding the increase in noise associated with increased BMI, the protocol effectively optimized the SNR to guarantee diagnostic image quality. Radiation dose tailoring according to anatomical region and BMI is important for image quality enhancement in CT scans, while reducing radiation exposure. These findings support the adoption of patient-specific dose optimization procedures in clinical practice to enhance diagnostic results.