ABSTRACT
Background: Computed Tomography (CT) is a medical imaging device. The study is aimed at evaluation of the scan parameters, dose metrics, and their reference levels during 64 slices brain computed tomography.
Methodology: It was an empirical study with patients referred for brain CT scan using 64 slice CT scanner. Participation in the study was voluntary, and ethical clearance was obtained before commencement of the study. The head circumference was measured with a measuring tape that was tightly fitted around the widest aspect of head circumference. The tube current and voltage were selected during the study, and the Volumetric Computed Tomography Dose Index (CTDIvol) obtained by measuring the beam width, width of a single acquired slice, and the radiation dose profile.The Dose Length Product (DLP) was obtained by multiplying the total scan length with the CTDI. A descriptive statistical tool was used to analysis the data, and the obtained results were presented in tables and charts.
Results: The age of participants ranges from 49-74years with a mean age of 61.00±9.12 years. The mean kVp and mAs (±standard deviation) were 87.60±10.91 and 108.20±8.28 respectively. While the mAs reference range was 100 to 120. The CTDI reference range was 20.65 mGy to 380.79 mGy with a mean (±standard deviation) CTDI of 59.31±68.48 (mGy). The DLP reference ranges from 256.60mGy-cm to 1144.80mGy-cm with a mean of 704.43±267.07 mGy-cm. There was a strong positive correlation between kvp and mAs with a Pearson’s Correlation coefficient (r) of 0.689. No correlation was seen between Kvp and CTDI.
Conclusion: The study provided the reference ranges of the kVp, mAs and CTDI. Information concerning the use of the KvP to predict mAs was also provided by the study. There is a need for a multicentre study with increased study population to obtain a multicentre perspective of the reference levels.
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