Degree of colonic distension: intrapatient comparison between CT colonography and CT with water enema.

PURPOSE: Compare colonic distension using CT colonography (CTC) and CT with water enema (CTWE) in the same patients. METHODS AND MATERIALS: Twenty-seven patients who underwent both CTC and CTWE, considering separately supine (CTC-S) and prone (CTC-P) acquisition of CTC were included. The colon was divided into six segments, performing both a qualitative and quantitative analysis. RESULTS: Adequate distension of sigmoid colon was more frequently achieved with CTC-P and CTWE compared to CTC-S (P<.05). CTC-P and CTWE showed better distension of the left colon compared to CTC-S (P<.01 and P=.03 regarding sigmoid colon, respectively; P=.01 and P=.03 regarding descending colon, respectively). CONCLUSIONS: Computed tomography (CT) studies of the colon should be customized to fulfill the clinical query.

Computed tomography of the bowel: a prospective comparison study between four techniques.

OBJECTIVES: The major objective was to prospectively compare the grade of bowel distension obtained with four different computed tomography (CT) techniques dedicated for the examination of the small intestine (CT enteroclysis [CTE] and enterography [CTe]), of the colon (CT with water enema [CT-WE]), or both (CTe with water enema [CTe-WE]). The secondary objective was to assess patients' tolerance toward each CT protocol. MATERIALS AND METHODS: Recruitment was designed to obtain four groups of the same number of patients (30). Each group corresponded to a specific CT technique, for a total of 120 consecutive outpatients (65 male and 55 female, mean age 51.09 ± 13.36 years). CTE was performed after injection of methylcellulose through a nasojejunal tube, while in the CTe protocol a polyethylene glycol electrolyte solution was orally administered to patients prior to the CT acquisition. In the CT-WE protocol intraluminal contrast (water) was administered only by a rectal enema, while CTe-WE technique included both a rectal water enema and oral ingestion of neutral contrast material to obtain a simultaneous distension of small and large bowel. CT studies were reviewed in consensus by two gastrointestinal radiologists who performed a quantitative and qualitative analysis of bowel distension on a per segment basis. The presence and type of adverse effects were recorded. RESULTS: CTE provided the best distension of jejunal loops (median diameter 27 mm, range 17-32 mm) when compared to all the other techniques (p<0.0001). The frequency of patients with an adequate distension of the terminal ileum was not significantly different among the four groups (p=0.0608). At both quantitative and qualitative analysis CT-WE and CTe-WE determined a greater and more consistent luminal filling of the large intestine than that provided by both CTE and CTe (p<0.0001 for all colonic segments). Adverse effects were more frequent in patients belonging to the CTE group (p<0.0028). CONCLUSIONS: CTE allows an optimal distension of jejunal loops, but it is the most uncomfortable CT protocol. When performing CT-WE, an adequate retrograde distension of the terminal ileum was provided in a particularly high percentage of patients. CTe-WE provides a simultaneous optimal distension of both small and large bowel.