Single- versus multi-detector row CT of the brain: quality assessment.

Abstract

To assess the quality of brain computed tomographic (CT) studies obtained with a four-channel multi-detector row CT scanner compared with those obtained with a single-detector row CT scanner. Forty-seven patients referred for brain CT were imaged with both single- and multi-detector row scanners. Single-detector row CT images were acquired by using a 5-mm-collimated beam in the transverse mode. Multi-detector row CT images were acquired in four simultaneous 2.5-mm-thick sections, which were combined in projection space to create two contiguous 5-mm-thick sections. Two neuroradiologists blinded to the acquisition technique independently evaluated the CT image pairs, which were presented in a stacked mode on two adjacent monitors. Each study was graded by using a five-point scale for posterior fossa artifact, overall image quality, and overall preference. Multi-detector row CT studies were acquired 1.8 times faster than single-detector row CT studies (0.92 vs 0.52 section per second). Multi-detector row CT posterior fossa artifact was less than single-detector row CT posterior fossa artifact in 87 (93%) of 94 studies. Overall preference was expressed for multi-detector row CT in 84 (89%) of 94 studies. The differences in mean posterior fossa artifact scores (P <.001) and mean overall image quality scores (P =.001) were significant. Brain CT images obtained with multi-detector row CT resulted in significantly less posterior fossa artifact and were preferred to single-detector row CT images.