Background: The diagnosis of small bowel Crohn’s disease (CD) is performed by ileocolonoscopy, whereas the assessment of its extension can be achieved by radiologic studies or, noninvasively, by magnetic resonance (MR) enterography and bowel sonography (BS). However, few comparative studies exist directly comparing the diagnostic accuracy of BS and MRI. The aim of this study was to evaluate the diagnostic accuracy of BS and MRI for the diagnosis of small bowel CD.
Methods: We prospectively performed a noninferiority diagnostic study including 234 consecutive subjects with suspected small bowel CD. All patients underwent IC (used as gold standard for diagnosis), BS, and MR enterography performed in random order by physicians who were blinded about the results.
Results: The diagnosis of small bowel CD was made in 120 of 249 subjects (48%). Sensitivity, specificity, positive predictive value, and negative predictive value for CD diagnosis were 94%, 97%, 97%, and 94% for BS and 96%, 94%, 94%, and 96% for MR enterography, respectively. BS was less accurate than MR enterography in defining CD extension (r = 0.69), whereas the concordance in terms of CD location between the 2 procedures was high (k = 0.81). Also, MRI showed a fair concordance with BS about strictures (k = 0.82) and abscesses (k = 0.88), with better detection of enteroenteric fistulas (k = 0.67).
Conclusions: BS and MR enterography are 2 accurate procedures for the diagnosis of small bowel CD, although MR seems to be more sensitive in defining its extension. BS could be used to select the patients for subsequent MRI examination.
Article first published online 20 February 2013
*Gastroenterology Unit, Department of Clinical and Experimental Medicine;
‡Department of Surgery and Advanced Technologies;
§Department of Colorectal Surgery;
‖Department of Emergency Surgery;
¶Department of Radiology, “Federico II” University of Naples, Naples, Italy.
Reprints: Fabiana Castiglione, MD, Gastroenterologia, Università degli Studi di Napoli “Federico II”, Facoltà di Medicina e Chirurgia, Via S. Pansini 5, 80131, Naples, Italy (e-mail: firstname.lastname@example.org).
The authors have no conflicts of interest to disclose.
Received July 12, 2012
Accepted July 24, 2012