Author: Liu, Pui-sang Diana
Title: Clinical decision support model in rectal contrast CT for preventing bowel perforation and optimizing the image quality for diagnosing colorectal carcinoma
Degree: M.Sc.
Year: 2010
Subject: Hong Kong Polytechnic University -- Dissertations
Rectum -- Cancer -- Diagnosis.
Colon (Anatomy) -- Cancer -- Diagnosis.
Rectum -- Tomography.
Colon (Anatomy) -- Tomography.
Department: Department of Health Technology and Informatics
Pages: ix, 102 leaves : col. ill. ; 30 cm.
Language: English
Abstract: Aim: The aim of this study is to devise a clinical decision support model for optimizing computed tomography (CT) diagnostic information and ensuring patient safety in administering water enema. Method: A total of 160 patients referred for water enema CT (WECT) were retrospectively evaluated. In part one, the colonic wall thickness of initial administration and additional administration of water enema were measured. In part two, the images were graded for bowel distension and diagnostic value by six radiographers. Result: Age, sex and weight did not contribute any effect on the total amount of water administered. Significant correlation between the percentage change of colonic wall thickness and total volume of water enema were found in ascending colon (r=-0.248, p<0.001). Bowel distension scores in pre intravenous (IV) contrast scans were found significantly correlated with the percentage change of colonic wall thickness in ascending colon, transverse colon, descending colon and sigmoid colon (p<0.01). Diagnostic value was significantly correlated with the percentage change of colonic wall thickness of the same four segments (p<0.01). Through linear extrapolation of the plot of percentage change of colonic wall thickness of the ascending colon against the total amount of water enema to the upper limit of wall thickness, the maximum amount of water at which bowel perforation happened at 1594mL. The minimum amount of water enema for optimum diagnostic value was 1365mL, which was obtained from correlating the percentage change in descending colon wall thickness at the diagnostic value score of 4, and the percentage was then correlated with the total amount of water needed for the region. While the minimum amount of water enema for acceptable CT diagnostic value was 858mL by linear extrapolation of the same plot of the descending colon at the diagnostic value score of 3. Conclusion: This retrospective analysis provides a clinical decision support model for future WECT on adult, where age, weight and sex were not contributed to the amount of rectal enema for adult; but age affected the outcome of bowel distension, and diagnostic value; and the amount of water added solely depended on the ascending colon wall thickness. With no greater than 1594mL addition amount of water enema, the colon met the optimal distension preventing from bowel perforation; 1365mL would be the minimum amount for optimum diagnostic value that was governed by the diagnostic value of descending colon; and with no less than 858mL total amount of water, the colon could be distended enough for acceptable clinical diagnosis.
Rights: All rights reserved
Access: restricted access

Files in This Item:
File Description SizeFormat 
b23526907.pdfFor All Users (off-campus access for PolyU Staff & Students only)3.62 MBAdobe PDFView/Open


Copyright Undertaking

As a bona fide Library user, I declare that:

  1. I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
  2. I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
  3. I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.

By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.

Show full item record

Please use this identifier to cite or link to this item: https://theses.lib.polyu.edu.hk/handle/200/5610