Background: The purpose of this study was to investigate whether trained radiologists can distinguish minor differences among computed tomography (CT) images of extended helical pitches of 1.0 to 1.5.
Methods: Between September 2000 and February 2001, 72 patients were randomized into 1 of 3 equal groups: helical pitches of 1.0, 1.3, and 1.5. The imaging parameters of all patients were kept constant. Twelve of the 72 patients were excluded because of various pathological conditions. In a total, 60 examinations were enrolled in the evaluation study. Three radiologists blinded to the image parameters were asked to independently evaluate 9 normal structures and overall images of 60 studies using a scale from 1 (worst) to 5 (best).
Results: There were no statistically significant differences in evaluation of image quality among helical pitches 1.0, 1.3, and 1.5 of abdominal CT when assessing 9 normal structures and overall images independently (p > 0.05).
Conclusions: Abdominal CT performed with helical pitches of 1.0, 1.3, and 1.5 were equivalent in this study. With the use of a helical pitch greater than 1, clinicians can benefit from increased scan coverage in less time and with less radiation than can be achieved with standard helical pitch-1.0 protocols.