COMPARISON OF RADIATION DOSE AND IMAGE QUALITY IN HEAD CT SCANS AMONG MULTIDETECTOR CT SCANNERS

Abstract

The present study compares three different multidetector CT (MDCT) scanners for routine brain imaging in terms of image quality and radiation doses. The volume CT dose index (CTDIvol), dose-length product (DLP), and effective dose (E) were calculated. Subjective image assessment was obtained based on a scale ranging from 1 (unacceptable) to 5 (optimum). All images scored 3.5 or over, with the 160-slice MDCT images being favoured. For the 4-, 16- and 160-slice MDCT scanners, the respective median values for CTDIvol were 57 mGy, 41 mGy, and 28 mGy; DLP values were 901 mGy.cm, 680 mGy.cm, and 551 mGy.cm; and effective doses were 2 mSv, 1.5 mSv, and 1 mSv, respectively. Compared to the 160-slice MDCT, the dose values for the 4- and 16-slice units were significantly greater. In practice, the CT modality used must be carefully selected to avoid elevated radiation doses and maintain image quality.