Acute appendicitis: diagnostic value of nonenhanced CT with selective use of contrast in routine clinical settings

Abstract

The purposes of this study were to determine the (1) frequency with which nonenhanced computed tomography (CT) (NECT) permits conclusive diagnosis of acute appendicitis, (2) accuracy of NECT when findings are conclusive, and (3) overall accuracy of a CT protocol consisting of NECT with selective use of contrast. Five hundred and thirty-six patients underwent a NECT protocol with selective use of contrast. Diagnostic accuracy was then determined separately for (1) patients with conclusive initial NECT, (2) patients with inconclusive initial NECT, and (3) all patients. NECT was conclusive on initial interpretation in 404/536 patients and inconclusive in 132/536. Of 132 inconclusive studies, 126 were repeated with contrast (intravenous, oral or rectal). Sensitivity, specificity, and positive and negative predictive value for diagnosis of acute appendicitis were (1) 90%, 96.0%, 84.8%, and 97.4% in patients with conclusive NECT (n = 404); (2) 95.6%, 92.3%, 73%, and 99% in patients with inconclusive NECT followed by repeat CT with contrast; and (3) 91.3%, 95%, 82%, and 98% in all patients. The initial diagnosis of appendicitis may be made by NECT in 75% of patients, with contrast administration reserved for inconclusive NECT studies.

The Lack of Efficacy for Oral Contrast in the Diagnosis of Appendicitis by Computed Tomography

“…Since most children tend to have limited amount of intra-abdominal fat, some believe that this limits the usefulness of nonenhanced CT scans [18], while others believe that the accuracy remains unchanged with varying body mass indexes [19]. One study that directly addressed this issue did not find a significant difference in CT accuracy with varying body mass index [20]. Six of the seven studies in this systematic review included radiologists as investigators and all support the use of noncontrast CT scans for the diagnosis of appendicitis [18][19][20][21][22][23].…”

Evaluation of a low-dose CT protocol with oral contrast for assessment of acute appendicitis

“…enhancement for the diagnosis of acute appendicitis in patients with BMI >18.5, and similar sensitivity and specificity as unenhanced standard-dose CT for detection of alternative diagnoses [33,35], it could constitute a useful tool for the triage of patients with suspicion of appendicitis towards standard i.v. enhanced CT.…”

Acute Appendicitis Presenting As Acute Gastritis in an Adult Patient with Undiagnosed Congenital Gut Malrotation: A Case Report

“…The use of CT scanning reduced the rate of negative appendectomies, which, before routine use of CT, was near 20% (12). In a study involving 536 patients with suspected appendicitis, Tamburrini et al found that the sensitivity, specificity, and positive and negative predictive values of non-contrast CT with selective use of contrast were 91.3%, 95%, 82%, and 98%, respectively (13). A recent meta-analysis evaluating the diagnostic accuracy of non-contrast CT for appendicitis found similar results as studies using contrast, with pooled estimate sensitivity and specificity of 92.7% (95% confidence interval 89.5-95%) and 96.1% (95% confidence interval 94.2-97.5%), respectively (14).…”