Four multidetector-row helical CT: image quality and volume coverage speed.

Abstract

To evaluate the imaging performance characteristics of four multidetector-row helical computed tomography (CT) and assess improvement in volume coverage speed over that with single multidetector-row helical CT. The section-sensitivity profile and image noise of a four multidetector-row scanner were measured with phantom scans and compared with predictions from theoretic models. Nominal section thickness ranged from 1.25 to 10.00 mm, beam collimation from 1.25 to 5.00 mm, and table speed from 3.75 to 30.00 mm per rotation. Image artifacts with four and single multidetector-row helical CT were compared in both a phantom study and a subjective rating analysis of clinical images. Compared with single multidetector-row helical CT, the volume coverage speed of four multidetector-row helical CT (range, 3.75-30.00 mm per rotation) is at least twice as fast as that with single multidetector-row helical CT (1.0-10.0 mm per rotation) with fully comparable image quality or, in many cases, three times as fast with diagnostically comparable image quality. Compared with single multidetector-row helical CT, four multidetector-row helical CT provides a two- to threefold improvement in volume coverage speed with comparable diagnostic image quality.