The Correct Selection of Pitch for Optimal CT Scanning: Avoiding Common Misconceptions

Abstract

Today’s state-of-the-art CT scanners include many features that aid in the selection of optimal technique parameters. Vendors offer solutions for choosing the optimal beam energy (tube voltage), automatic exposure control (AEC) via tube current modulation control, patient positioning within the gantry, and patient-specific contrast injection protocols. The trend seems to be leading to a “push button” CT scanner in which only the dose, noise level, and image sharpness, determined by the clinical indication, need to be prescribed. This trend will likely decrease the frequency of nondiagnostic CT scans. However, it should not mitigate the need to understand some of the fundamental relationships between acquisition parameters and dose. We illustrate the most common misconceptions concerning the selection of pitch in this article.