David Tso MD, Presenter: Nothing to Disclose

Jennifer Wang BS, Abstract Co-Author: Nothing to Disclose

Patrick McLaughlin FFR(RCSI), Abstract Co-Author: Nothing to Disclose

Douglas S. Katz MD, Abstract Co-Author: Nothing to Disclose

Silvia D. Chang MD, Abstract Co-Author: Nothing to Disclose

Savvas Nicolaou MD, Abstract Co-Author: Nothing to Disclose

This study evaluated the role of ultrasound as a first-line imaging modality for the work-up of acute appendicitis in young adults at an academic teaching hospital with 24/7 staff radiologist on site. This study attempted to determine the specificity and sensitivity of ultrasound in diagnosing appendicitis and the need for further imaging.

A retrospective study design was undertaken examining patients seen in the emergency department of an urban tertiary care teaching hospital between October 1 to December 31, 2013 with the chief complaint of right lower quadrant pain. Patients investigated with ultrasound as first-line imaging were identified. Scan time, findings on ultrasound, and the need for further imaging was documented. Findings were correlated with CT findings and surgical diagnosis when available.

106 patients were identified (80.2% female, mean age 29.1). 39.6% of ultrasound exams were performed between the hours of 5PM and 8AM. Average time for a scan was 28.6 minutes. The appendix was visualized in 28.3% on ultrasound and was equivocal on 11.3%. Of the 30 cases where the appendix was visualized, 76.7% were sonographically diagnostic for acute appendicitis and had an average appendiceal diameter of 10mm. An alternative diagnosis was found in 16% of all cases, with ovarian pathologies being most common. Of the 23 confirmed cases of appendicitis on ultrasound, only 2 patients required further imaging. 18 patients went to the operating room where appendicitis was confirmed on all but one case. Perforation rate was 35.3%. Of the 83 patients with negative or equivocal ultrasound scans, 47.0% required further imaging (64.1% CT, 35.9% MRI). The appendix was seen on all CT scans, but on only 78.7% of all MRI scans. 12 patients went to the operating room where all cases were diagnosed with appendicitis with a perforation rate of 41.7%. The sensitivity and specificity of ultrasound was 70.8% and 92.9% respectively.

First-line ultrasound is utilized in young patients to avoid exposure to radiation. The appendix is not visualized a majority of the time on ultrasound, necessitating further imaging. When the appendix is visualized, ultrasound demonstrates high specificity for the diagnosis of acute appendicitis.

Ultrasound is a useful first-line imaging modality for the diagnosis of appendicitis when the appendix can be visualized.

Tso, D, Wang, J, McLaughlin, P, Katz, D, Chang, S, Nicolaou, S, First-line Ultrasound in the Work-up of Acute Appendicitis at an Academic Teaching Hospital with 24/7 Radiology.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045550.html