Hydrocolonic sonography for evaluating inflammatory bowel disease

Objective. The purpose of our study was to compare the usefulness of hydroc olonic sonography and Tc-99m-hexamethylpropyleneamine oxime (HMPAO)-labeled leukocyte scintigraphy in the examination of patients with inflammatory bo wel disease, using precise sonographic criteria of bowel involvement. Subjects and methods. Sixty-eight consecutive patients with active inflamma tory bowel disease (34 ulcerative colitis and 34 Crohn's disease), 12 with inactive inflammatory bowel disease, and 10 control subjects were prospecti vely studied. Patients with active disease underwent clinical assessment, h ydrocolonic sonography, scintigraphy, and colonoscopy within 72 hr, whereas patients with inactive disease and control subjects underwent clinical exa mination and hydrocolonic sonography. Results. Involvement of a colonic segment by active inflammatory bowel dise ase was best defined by mucosal thickness greater than 1.5 mm, bowel wall t hickness greater than 4 mm, mucosal irregularity, or the absence of haustra ; and involvement of the terminal ileum by bowel wall thickness greater tha n 4 mm. Using these criteria, hydrocolonic sonography had 100% sensitivity for identifying patients with active inflammatory bowel disease and a great er overall accuracy (87%) than scintigraphy (77%) in the assessment of dise ase extension. In addition, strong correlation was shown between a hydrocol onic sonography activity index and clinical and endoscopic activity indexes . Conclusion. This prospective study provides precise sonographic criteria fo r the definition of bowel involvement by active inflammatory bowel disease. Hydrocolonic sonography has a greater accuracy than scintigraphy for asses sing disease extension and activity. Therefore, hydrocolonic sonography sho uld be considered a first-choice technique to complete the study of inflamm atory bowel disease after confirmation of the diagnosis by histology.