Low-Dose Abdominal CT for Evaluating Suspected Appendicitis: Recommendations for CT Imaging Techniques and Practical Issues

Abstract

A vast disparity exists between science and practice for CT radiation dose. Despite high-level evidence supporting the use of low-dose CT (LDCT) in diagnosing appendicitis, a recent survey showed that many care providers were still concerned that the low image quality of LDCT may lead to incorrect diagnoses. For successful implementation of LDCT practice, it is important to inform and educate the care providers not only of the scientific discoveries but also of concrete guidelines on how to overcome more practical matters. Here, we discuss CT imaging techniques and other practical issues for implementing LDCT practice.

Keywords: abdomen; acute; appendicitis; ionizing; multidetector computed tomography; patient care team; quality control; radiation.

Figure 1

A 34-year-old man with appendicitis. Contrast-enhanced coronal CT images reconstructed by filtered back-projection (FBP) (A) and iterative reconstruction (IR) (B). While both images clearly depict an inflamed appendix (arrows), the image reconstructed using IR generates less noise, which can alleviate the practitioners’ reluctance to low-dose CT.

Figure 2

Radiation dose calibration procedures for each CT machine. * In regular abdomen CT examinations for various purposes in patients not enrolled in the trial. ^† Difference (%) = (measured median DLP—target DLP)/target DLP × 100. ^‡ At the discretion of the lead radiologist. ^§ For each of conventional-dose and low-dose groups. DLP = dose-length product, LD = low dose, SCD = site conventional dose.