AAP PaperThe non-diagnostic ultrasound in appendicitis: is a non-visualized appendix the same as a negative study?
Section snippets
US technique and diagnostic criteria
Following voiding, a linear 12-5 transducer was used (linear 9-3, and/or curvilinear 9-4, 5-2 or 5-1 MHz for obese patients) for evaluation of the right lower quadrant in transverse and sagittal directions using a graded compression technique to search for the appendix. A positive study was reported upon identification of a blind-ending, tubular, non-compressible structure in the right lower quadrant measuring > 6.5 mm in diameter and showing connection to the cecum. Other signs indicating towards
Ultrasound results
A total of 1383 ultrasounds were performed on 1260 patients in order to evaluate for appendicitis. Two hundred one studies were positive (14.53%), 83 studies were suspicious as described in Section 1.3 (6.00%), 17 studies had low-suspicion (1.23%), 152 studies were negative (10.99%) and 54 studies were positive for an alternative diagnosis (3.90%). The remaining 876 studies were non-diagnostic for acute appendicitis (63.34%). This percentage was slightly higher than the 56–61% that was reported
Discussion
Despite appendicitis being the most common abdominal emergency in the world [1], its diagnosis remains problematic. The most immediate diagnostic tool has always been a skillfully executed history and physical exam. Unfortunately, clinical variations in presenting symptoms, difficulties interpreting the history and physical, non-specific signs and symptoms, and competing differential diagnoses all limit the efficacy of clinical reasoning [5]. A number of scoring systems have been developed to
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Approach to Abdominal Imaging in 2022
2021, Emergency Medicine Clinics of North AmericaCitation Excerpt :A negative or inconclusive ultrasonographic evaluation is common in adults, particularly in pregnant patients.53 Intriguingly, retrospective data in pediatric patients suggest that patients with an inconclusive ultrasonography and a white blood cell count less than 7.5 × 109/L have a negative predictive value of 97%.54 A nondiagnostic ultrasonography should prompt additional imaging, typically CT with IV contrast.41
Diagnostic Applications of Point-of-Care Ultrasound in Pediatric Emergency Medicine
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2019, Obstetrics and Gynecology Clinics of North AmericaCitation Excerpt :However, nonvisualization of the appendix does not exclude AA and requires clinical reassessment before obtaining more imaging studies (short-interval repeat US, CT, or MRI). Some studies have reported that nonvisualization of the appendix may have high negative-predictive value to exclude AA in specific patient populations and clinical settings, particularly if secondary signs of inflammation, such as free fluid, phlegmon, and periappendiceal inflammatory changes, are absent.12,13 The presence of extraluminal gas (echogenic foci with “dirty” shadowing), an extruded appendicolith, frank abscesses, and/or extraluminal fluid/fluid or air/fluid levels is suggestive of perforation.10