Tagging-based, electronically cleansed CT colonography: Evaluation of patient comfort and image readability

Purpose: To prospectively compare the homogeneity, adequancy, and patient acceptance of nonionic iodine-based regimens with those of a barium-based regimen for computed tomographic (CT) colonography with electronic subtraction cleansing. Materials and Methods: After institutional review board approval and informed consent wee obtained, 68 subjects (41 men (60%) men, 27 (40%) women : mean age, 60 years +/- 6 [standard deviation]) with average or moderate risk factors for development of colorectal carcinoma were recruited and placed into three groups. Group 1 (n = 25) ingested 150-mL aliquots of 2% barium sulfate suspension with meals and snacks for 48 hours prior to imaging. without other diet modification or a cathartic. Group 2 (n = 21) ingested 10-mL aliguots of nonionic iodinated contrast material (iopromide) with a concentration of 300 mg per millimeter with meals and snacks fro 2 days before imaging without diet modification or a cathartic. Group 3 (n = 22) ingested nonionic iodinated contrastmaterial (iohexol) with a concentration of 300 mg per milliliter with meals and snacks for 2 days before imaging and ingested 64g of colonography was also performed on 10 control subjects who ingested polyethylene glycol electrolyte solution prior to imaging . Subjective and numerical measures of bowel preparation quality, homogeneity, and patient comfort among the noncathartic and cathartic cohorts were compared with nonparametric analysis of variance, the Fisher exact test, and the F test, as appropriate. The study was HPIAA compliant. Results: Study subjects who recieved tagging preperations reported significantly improved discomfort scores when compared with those of the control subjects (P < .05 each comparison). There was no significant difference in discomfort scores among groups 1,2 and 3. For each reader, scores of subtracted image readability were highest for group 3. Dichotomized rates of preperation "success" were also greatest for group 3. Conclusion: In this series, the patient discomfort scores were significantly improvedwith tagging preparations for CT colonography. Nonionic iodinated contrast material in conjunction with hypoerosmotic laxative (magnesium citrate) was associated with the best subjective and numerical indices of readability. (c) RSNA, 2006