Correlation of Anteroposterior Diameter of Abdomen with CT Dose Index and Dose Length Product in Abdomen CT Scan- A Retrospective Study

Abstract

Introduction: Computed Tomography (CT) remains an important tool in diagnostic imaging. Establishment of Diagnostic Reference Levels (DRL) is highly recommended in order to have a check on the radiation exposure. Aim: To study the correlation between the Anteroposterior (AP) diameter of abdomen with the CT Dose Index (CTDI) and Dose Length Product (DLP) in those who underwent abdomen CT scan. Materials and Methods: A retrospective study was conducted at Chettinad Academy of Research and Education, in the Department of Radiology during January 2019 to April 2019. The data of 66 patients (44 males and 22 females, aged 18-80 years), who have undergone CT scan during study period of three months were retrieved from CT console. Axial, coronal, sagittal reconstructions and diameter was measured on axial plane. CTDI and DLP of plane abdomen scan were noted from the dose information from the procedure. CTDI (mGr) and DLP (mGr) were considered as primary outcome variables. Association was assessed by calculating pearson correlation coefficient(r). The p-value <0.05 was considered statistically significant. Co-guide software was used for data analysis. Results: There was a moderate positive correlation between AP diameter and CTDI (mGr) (r-value: 0.684, p-value: <0.001). There was a moderate positive correlation between AP diameter and DLP (mGr) (r-value=0.713, p-value <0.001). Conclusion: The AP diameter of abdomen and CTDI, DLP has positive correlation. Hence, dosage optimisation should be done considering the diameters as indicator.