Appropriateness and Diagnostic Yield of Abdominal and Kidney Ultrasound in the Emergency Department.

Abstract

Background: Diagnostic imaging use in emergency departments (ED) is increasing, namely abdominal and kidney ultrasound (US), urging the continuous evaluation of its appropriateness and diagnostic yield.

Objective: To assess referral reasons, appropriateness, and diagnostic yield of abdominal and kidney US in a tertiary care ED.

Methods: We retrospectively reviewed adult ED patients undergoing urgent abdominal or kidney US between November 2024 and February 2025, excluding point-of-care studies. Appropriateness was determined using American College of Radiology (ACR) Appropriateness Criteria®. Diagnostic yield was defined as at least one finding potentially explaining the clinical presentation.

Results: Among 562 US exams, 295 (52.5%) were abdominal and 267 (47.5%) were kidney US. Most referrals were appropriate (abdominal: 88%; kidney: 43%). Abdominal US yielded positive findings in 29.5% of cases, highest for cholestasis (57%) and lowest for appendicitis (18%). Kidney US yielded positive findings in 13.1% of cases, highest for renal colic (37%).

Discussion and conclusion: While most US referrals met ACR criteria, diagnostic yield was modest, particularly for kidney US in acute kidney injury and pyelonephritis. Abdominal US remains valuable for biliary pathology but shows limited utility for appendicitis in adults. More selective use of US, coupled with improved clinical documentation and decision-support tools, may enhance efficiency and diagnostic impact in the ED.