Seong Jong Yun, Presenter: Nothing to Disclose

Hyun Cheol Kim, Abstract Co-Author: Nothing to Disclose

Sang Won Kim MD, Abstract Co-Author: Nothing to Disclose

Dal Mo Yang, Abstract Co-Author: Nothing to Disclose

Woo Jin Yang, Abstract Co-Author: Nothing to Disclose

Kyung Jin Lee MD, Abstract Co-Author: Nothing to Disclose

Ji Su Kim, Abstract Co-Author: Nothing to Disclose

To evaluate usefulness of low-dose (LD) non-enhanced CT (NECT) with coronal reformation to diagnose acute appendicitis in comparison with standard-dose (SD) NECT and SD contrast-enhanced CT (CECT).

The institutional review board approved this retrospective study and waived the informed consent. This study population included 452 adult patients (age range, 18–89 years) who underwent CT performed by using a SD (SD NECT and SD CECT1, n = 182) or a LD protocols (LD NECT and SD CECT2, n = 270) for suspected acute appendicitis. Two reviewers independently interpreted the axial and the coronal reformatted images of NECT and CECT scans during separate sessions. They assessed appendix visualization and proposed a diagnosis of appendicitis using a 4-point scale. Diagnostic performance and interobserver agreement for diagnosing acute appendicitis were compared between SD NECT and SD CECT1, LD NECT and SD CECT2, and LD NECT and SD NECT, respectively.

The frequencies of appendix visualization of reviewers 1 and 2 were 95.6% (174/182) and 94.5% (172/182), 98.4% (179/182) and 98.9% (180/182), 90.7% (245/270) and 90% (243/270), and 98.9% (267/270) and 98.1% (265/270) for SD NECT, SD CECT1, LD NECT, and SD CECT2, respectively. Areas under the curves (AUCs) of reviewers 1 and 2 for SD NECT (0.97 and 0.96, respectively) were not significantly lower than those of SD CECT1 (0.99 and 0.97) (P = 0.19 and 0.64, respectively). AUCs of reviewers 1 and 2 for LD NECT (0.95 and 0.95) were significantly lower than those of SD CECT2 (0.99 and 0.98) (P = 0.002 and 0.02, respectively). However, AUCs of reviewers 1 and 2 for LD NECT (0.95 and 0.95) were not significantly lower than those of SD NECT (0.97 and 0.96) (P = 0.18 and 0.92, respectively). All of the values for interobserver agreement of SD NECT, SD CECT1, LD NECT, and SD CECT2 were excellent (k = 0.84, 0.84, 0.85, and 0.86, respectively).

LD NECT with coronal reformation was not inferior to SD NECT for the initial evaluation of acute appendicitis.

LD NECT can be used as the first-line imaging tool in the workup of patients with suspected acute appendicitis.

Yun, S, Kim, H, Kim, S, Yang, D, Yang, W, Lee, K, Kim, J, Usefulness of Low-Dose Non-enhanced CT with Coronal Reformations in Patients with Suspected Acute Appendicitis: Comparison with Standard-Dose Non-enhanced CT.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14010646.html