Minimal preparation CT: A literature review of a minimally invasive imaging technique for colorectal cancer in a frail, aged population

Computed Tomography Colonography (CTC): Is It Really the Non-Invasive Option We Think It Is? A Patient Experience Study

Aims: Computed tomography colonography (CTC) is seen as a more tolerable alternative to colonoscopy, but patients struggle with the steps required for optimal diagnostic imaging. This prospective study aims to understand the experience of patients undergoing CTC. Methods: A survey was completed by a convenience sample of patients before and after CTC over 7 months. The 13-item questionnaire covered pre-test information, overall and specific experience of the test. The responses were tabulated and analyzed using descriptive statistics. Qualitative free-text responses were coded for content and thematic analysis. Results: At a response rate of 51%, surveys were received from 41 patients. Overall, most patients (54%) found the investigation better than expected. However, 18% stated they were not informed of potential side effects. Side effects were experienced by 49% of patients, including diarrhea (34%) and abdominal pain (24%). About 59% experienced discomfort with gas insufflation, and 86% found turning during the investigation difficult. Conclusion: A significant proportion of patients undergoing CTC experience side effects and difficulties completing the investigation. Patient information is important to improve patient experience of CTC.

Evaluation of Low-Dose Multidetector Computed Tomography Whole Gastroenterography With Oral Administration of Contrast Agents

PURPOSE

To evaluate the degree of gastric, enteric, colonic, and rectal filling in multidetector computed tomography (MDCT) whole gastroenterography.

METHODS

In this prospective study involving 124 patients, 78 and 46 patients underwent MDCT whole gastroenterography using positive and neutral oral contrast agents, respectively. The degree of filling of the stomach, small and large bowel, was qualitatively analyzed by experienced radiologists using a 3-point scoring system.

RESULTS

The majority of patients received a score of ≥2 for small intestine filling using both positive and neutral contrast agents (90.5% and 78.2%, respectively), and <9% of the patients had a score of 0. The highest score for the degree of filling in the small intestine was observed in the ileum, followed by the duodenum and jejunum. There was a significant difference in the degree of filling achieved with positive and neutral contrast agents in the duodenum (P = .013) and jejunum (P = .047). More than 74% of cases had an optimal filling of the stomach, whereas >80% of the cases had an optimal filling of the colorectal segments. Only ≤5.1% had a score of 0 for the analyzed segments of the colorectum. Positive and neutral contrast agents were associated with similar degree of filling in the stomach and colon segments without a significant difference in the extent of contrast agent filling (P > .05).

CONCLUSIONS

Multidetector computed tomography whole gastroenterography was found to be a simple, safe, noninvasive, painless, and effective modality for the diagnosis of stomach and bowel complications in clinical settings.

Utility of minimal preparation computed tomography colonography in detecting colorectal cancer in elderly and frail patients

BACKGROUND

Colorectal cancers result in substantial morbidity and mortality to the Australian society each year. The usual investigation for bowel malignancy is optical colonoscopy (OC), with computed tomography colonography (CTC) used as an alternative investigation. The catharsis and colon insufflation associated with these investigations pose a higher risk in the elderly and frail. Risks include perforation, serum electrolyte disturbance and anaesthesia/sedation risks. Minimal preparation computed tomography colonography (MPCTC) eliminates these risks.

AIMS

To audit the accuracy of a MPCTC programme for the investigation of colonic masses in symptomatic elderly and frail patients.

METHODS

This paper audits a 6-year period of MPCTC in an Australian tertiary referral hospital. A total of 145 patients underwent MPCTC during the study period.

RESULTS

There were seven true positives, two false positives and two false negatives. Analysis of this population indicates a sensitivity of 0.78 (95% CI 0.51-1.05), specificity of 0.99 (95% CI 0.97-1.01), positive predictive value (PPV) of 0.78 (95% CI 0.51-1.05) and negative predictive value (NPV) of 0.99 (95% CI 0.97-1.01). These findings are concordant with other published studies.

CONCLUSIONS

This audit confirms that minimal preparation CT colonography is a reasonable alternative to OC and CTC in detecting colorectal cancer in symptomatic elderly and frail patients, without the procedural risks inherent in more invasive investigations. For most patients, MPCTC ruled out significant colorectal carcinoma with a high NPV.