Safety of colon contrast material in (helical) CT examination of patients with suspected diverticulitis

Abstract

Purpose: Today patients with suspected diverticulitis are commonly imaged with a CT scan utilizing a variety of methods of contrast medium administration. Although CT with rectally administered colon contrast has demonstrated a high diagnostic accuracy, concerns have been raised over its safety in patients with diverticulitis. The following retrospective investigation was undertaken to answer this concern. Materials and methods: Between January, 1997, and July, 1999, 308 patients with suspected diverticulitis were examined in the Emergency Radiology Division of the Massachusetts General Hospital by means of a helical CT scan performed with rectally administered colon contrast material. The patients' CT findings were correlated with their clinical courses and/or surgical findings. Results: Of the 308 CT scans, 115 (37.3 %) were positive for diverticulitis. Of 193 patients without diverticulitis, 91 (47.1 % of patients without diverticulitis) had alternative diagnoses made by CT, such as small bowel obstruction, epiploic appendagitis, and urinary tract calculi. No complications due to colon contrast material were noted. Even in cases where there was free extraluminal air, no extravasated contrast material was seen. Rectally administered colon contrast was well tolerated by patients and provided excellent large bowel opacification. This method saved imaging time in an emergency setting, as there was no need to wait for oral contrast to reach the colon. Conclusion: Out of 308 CT scans, there were no complications from the use of rectally administered colon contrast material. No case of traumatic bowel perforation secondary to colon contrast material was observed. Rectally administered colon contrast material is safe in the CT examination of patients with suspected diverticulitis.

Frequency, Sensitivity, and Specificity of Individual Signs of Diverticulitis on Thin-Section Helical CT with Colonic Contrast Material: Experience with 312 Cases

“…Colonic contrast material has also been shown to be safe [23]. In our patient population, the most sensitive signs of diverticulitis with colonic contrast-enhanced CT having a specificity of more than 90% were bowel wall thickening and fat stranding.…”

Length of Stay by Route of Contrast Administration for Diagnosis of Appendicitis by Computed‐tomography Scan

“…[13][14][15][18][19][20] The rationale for rectal contrast is that it more convincingly displays the normal and abnormal appendix; can be performed almost immediately; is safe and well tolerated; and minimizes the discomforts and radiation exposure associated with oral-contrast material. 9,14,15,17 A recent review of 23 prospective and retrospective studies examining various combinations of contrast material in adult patients undergoing CT scanning for suspected appendicitis revealed the rectal-contrast group to have the highest sensitivity, positive predictive value, and accuracy of all modalities (rectal, oral, rectal and oral, oral and IV, and no contrast). 21 The equivalent, if not superior, diagnostic performance of rectal-contrast material and its shorter administration time make this intervention appealing and practical for use in the ED.…”

“…Several studies have shown CT with rectal-contrast material to be as accurate (98%) and safe as CT with oral-contrast material. 6,[15][16][17] Rectal-contrast administration is performed quickly and requires only minutes to ensure visualization of the appendix. Therefore, CT scanning using rectal contrast instead of oral contrast may decrease time to diagnosis and disposition and may shorten patients' overall length of stay in the ED by reducing the time to obtain a CT.…”

CT findings of misleading features of colonic diverticulitis

“…CT performed three weeks later, does not show any suggestion of diverticulitis Non-contrast-enhanced CT : This is the first step in CT examination. Performed before any opacification, it may demonstrate free-air perforation and/or severe intestinal occlusion, which are relative contra-indications of digestive opacification [ 6 ]. Sometimes it gives additional arguments in favour of the diagnosis, such as an intradiverticular stercolith that may be less visible on a contrast-enhanced phase (Fig.…”