Local diagnostic reference level based on size-specific dose estimates: case of chest-abdomen-pelvis CT examination in a Moroccan hospital

Abstract

This study aims to establish the local diagnostic reference levels for adult Chest-Abdomen-Pelvis (CAP)CT examination in a Moroccan hospital. DRLs were retrieved for the first time for CAP examination and were size-dependent. Data from 234 patients were collected retrospectively from one scanner for three months. CTDIvol, DLP and calculated SSDE were analyzed with IBM SPSS Statistics version 21. The proposed LDRLs in terms of CTDIvol, DLP and SSDE, the registered medians were 12.9 mGy, 849.3 mGy.cm and 18.16 mGy, respectively. Third quartile values were 15.65 mGy, 1014 mGy.cm and 20.75 mGy, respectively. The derived values were close to regional and international studies, with the exception of higher DLP quantity A comparison of CTDIvol and SSDE LDRLs has underlined the superiority of the SSDE. This result reflects from one side the morphologic nature of our small studied samplel. On the other side, the SSDE is correct for the misconception of the received dose, especially for lsimilar types of patients. The practice of the CAP CT examination has been studied and LDRLs related to DLP quantity revealed the necessity of application of radiation protection measures toward the length of scanned regions. On the other hand, LDRLs related to SSDE show an update of the received dose, higher than usually pretended using only CT outputs. Both results will lead practitioners to review the acquisition parameters and length of scanned regions and consider the patient's morphology to reduce the dose received while keeping an interpretable exam.