Radiology, Vol 209, 775-779, Copyright © 1998 by Radiological Society of North America

ARTICLES

Colonic diverticulitis: evaluation of the arrowhead sign and the inflamed diverticulum for CT diagnosis

PM Rao and JT Rhea
Department of Radiology, Massachusetts General Hospital, Boston 02114, USA.

PURPOSE: To determine the frequency of visualization of the arrowhead sign and an inflamed diverticulum on abdominal computed tomographic (CT) scans in patients with acute colonic diverticulitis and to assess the specificity of these signs. MATERIALS AND METHODS: One hundred fifty consecutive patients suspected of having diverticulitis prospectively underwent helical CT after the administration of contrast material by means of an enema. Sixty-four patients (43%) had a final clinical diagnosis of colonic diverticulitis. Each scan was reviewed for the arrowhead sign, an arrowhead-shaped collection of contrast material within focal colonic wall thickening, and for an inflamed diverticulum, a rounded, paracolic outpouching centered within fat stranding. RESULTS: The arrowhead sign was noted at CT in 17 (27%) of the 64 patients with diverticulitis. An inflamed diverticulum was noted in 21 patients (33%) at CT, with either calcium or similar high- attenuation material in 10 (48%) of the 21 patients, soft-tissue attenuation in six patients (29%), air attenuation in four patients (19%), and barium attenuation in one patient (5%). Neither sign was demonstrated in patients with alternative conditions (100% specificity). CONCLUSION: The arrowhead sign and an inflamed diverticulum are occasional, specific CT signs of colonic diverticulitis. Their identification can add diagnostic specificity to CT of acute colonic processes.

This article has been cited by other articles:

				T. Lawrimore and J. T. Rhea Computed Tomography Evaluation of Diverticulitis J Intensive Care Med, July 1, 2004; 19(4): 194 - 204. [Abstract] [PDF]

				M. F. Kircher, J. T. Rhea, D. Kihiczak, and R. A. Novelline Frequency, Sensitivity, and Specificity of Individual Signs of Diverticulitis on Thin-Section Helical CT with Colonic Contrast Material: Experience with 312 Cases Am. J. Roentgenol., June 1, 2002; 178(6): 1313 - 1318. [Abstract] [Full Text] [PDF]

				A. Hollerweger, T. Rettenbacher, P. Macheiner, W. Brunner, and N. Gritzmann Sigmoid Diverticulitis: Value of Transrectal Sonography in Addition to Transabdominal Sonography Am. J. Roentgenol., October 1, 2000; 175(4): 1155 - 1160. [Abstract] [Full Text] [PDF]

				H.-J. Jang, H. K. Lim, S. J. Lee, W. J. Lee, E. Y. Kim, and S. H. Kim Acute Diverticulitis of the Cecum and Ascending Colon: The Value of Thin-Section Helical CT Findings in Excluding Colonic Carcinoma Am. J. Roentgenol., May 1, 2000; 174(5): 1397 - 1402. [Abstract] [Full Text] [PDF]

				R. M. Gore, F. H. Miller, F. S. Pereles, V. Yaghmai, and J. W. Berlin Helical CT in the Evaluation of the Acute Abdomen Am. J. Roentgenol., April 1, 2000; 174(4): 901 - 913. [Full Text] [PDF]