Kerri Novak MD, Abstract Co-Author: Research grant, Abbott Laboratories Consultant, Abbott Laboratories Speakers Bureau, Merck KgaA

Gilaad Kaplan, Abstract Co-Author: Advisory Board, Abbott Laboratories Advisory Board, UCB SA Advisory Board, Schering-Plough Corporation

Remo Panaccione MD, Abstract Co-Author: Research Consultant, Abbott Laboratories

Subrata Ghosh MD, FRCPC, Abstract Co-Author: Research Consultant, Abbott Laboratories

Stephanie R. Wilson MD, Presenter: Research grant, Lantheus Medical Imaging, Inc Research grant, Abbott Laboratories Consultant, Lantheus Medical Imaging, Inc Advisory Board, Koninklijke Philips Electronics NV Advisory Board, Siemens AG

To evaluate the effectiveness of transabdominal ultrasound (TAUS) in the diagnosis and detection of inflammatory activity in patients with Crohn Disease (CD).

 TAUS images from controls and patients with CD from a tertiary CD center were reviewed retrospectively . A subgroup with CD (n=235) had ileocolonoscopy (within 3 mo). Fewer (n=103) had CT (3 mo of US).  One expert radiologist evaluated all TAUS for inflammatory parameters: small bowel wall thickness, presence of mesenteric inflammatory fat, presence of mesenteric/perienteric lymphadenopathy, and hyperemia /excess color Doppler signal within the bowel wall.   Parameters were graded from absent to severe.  Similar parameters were evaluated on CT. The Fisher exact test was used to compare parameters amongst three groups: controls, and CD patients with and without active disease. For those with endoscopy and CT, sensitivity and specificity were determined.

A total of 532 patients were identified, 432 with CD and 98 controls. Highly significant differences between the control group and those with CD for all parameters were detected, with ileal wall thickness (p=0.0001) and hyperemia (p=0.0001) showing the greatest difference. Amongst the 432 patients with CD, 50 were in TAUS remission. When inactive patients were compared to those with active disease on TAUS, all parameters were again significantly different (p=0.0001). In the subpopulation with ileocolonoscopy, the most sensitive (88%) and specific (70%) indicator of inflammation was ileal thickness, and agreement between CT and US was greatest for ileal thickness also.

TAUS is highly effective in prediction of inflammatory disease activity, with increased bowel wall thickness and bowel wall hyperemia being the strongest indicators of disease activity, confirmed by ileocolonoscopy. Future endeavors will emphasize the efficacy, cost effectiveness, and lack of ionizing radiation of TAUS, providing an attractive alternative to  CT scan.   

The high demand for imaging and the frequent young age at diagnosis of patients with CD, suggests TAUS could supplant CT for diagnosis and effective determination of disease activity.

Novak, K, Kaplan, G, Panaccione, R, Ghosh, S, Wilson, S, Transabdominal Ultrasound in Crohns Disease: A Safe and Effective Modality for Diagnosis and Determination of Disease Activity.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11012928.html