Radiation doses and size-specific dose estimate from CT brain examinations according to head sizes in a tertiary hospital in Malaysia

Abstract

The aim of the study is to evaluate radiation dose and its relationship with the effective head diameter obtained during CT brain examination performed via a 640 multi-slice CT scanner. Data from a total of 146 patients, who underwent CT brain examinations in our institutions, was collected retrospectively from January 2019 to June 2019. Data, such as volume Computed Tomography Dose Index (CTDIvol) value, scanning range, dose-length product (DLP) value, and diameter of the patient's head based on Antero-posterior (AP) and Lateral (LAT) were recorded in a standardized form for analyzation. Effective dose (E) and Size-Specific Dose Estimate (SSDE) were determined and compared within plain brain CT and contrast-enhanced CT (CECT). The mean Es of the plain brain CT and CECT were 2.02 ± 0.41 mSv and 4.23 ± 0.75 mSv, respectively, and differed significantly with a p-value of less than 0.05. There are no significant differences of E and SSDE in contrast enhancement when compared among genders (p-value > 0.05) and within race for plain brain CT. The radiation doses differed significantly between male (2.08 ± 0.47 mSv) and female (1.94 ± 0.31 mSv) patients. It was found that skin organs received the highest risk overall, followed by thyroid and then esophagus. This study shows that radiation doses from CT brain mostly depend upon the type of examination. Thus, extra safety measures should be considered for type of examination to reduce the potential risk associated with CT scans.