Evaluating the Relationship of Body Mass Index and Waist Circumference on the Image Quality of Abdominal Computed Radiography

Abstract

Body sizes of patients undergoing x-ray examination vary in accordance with the range of body mass index (BMI) and waist circumference (WC). The aims of this study were to determine the relationship between BMI and waist circumference on the image quality of computed radiography (CR) abdomen. Anteroposterior (AP) supine abdomen projection was conducted on 69 patients from Hospital Raja Perempuan Bainun, Ipoh using a Siemens Multixtop general x-ray unit and the images were processed with CR Carestream Direct view Max. Samples were categorized into normal BMI (n = 23), overweight (n = 23), and obese (n = 23). Image quality was measured quantitatively in signal to noise ratio (SNR) and qualitatively, visual grading analysis (VGA) based on the European Commission (CEC) image criteria. Data were analyzed by using analysis of variance (ANOVA) and Pearson's correlation for comparison and relationship between BMI, WC and the image quality. Results showed a significant difference (p < 0.01) in image quality of VGA mean (normal 4.40 ± 0.15, overweight 4.35 ± 0.13, obese 4.03 ± 0.34) and SNR mean (normal 60.79 ± 2.19, overweight 59.66 ± 1.68, obese 55.78 ± 4.31). A moderate to high negative correlation exists between SNR (r = -0.73), VGA (r = -0.7) with BMI (p < 0.01), and SNR (r = -0.83), VGA (r = -0.79) with WC (p < 0.01). This study suggests that WC has a higher negative linear relationship compared to BMI and could also be used as a better image quality predictor for CR abdominal examination. DOI : http://dx.doi.org/10.17576/JSKM-2020-1801-02