Water enema CT examination of rectum cancer by reduced amount of water.

OBJECTIVE

To define whether volume of water, administered during water enema CT (WE-CT) for local staging of rectal cancer, may be reduced without compromising the diagnostic value of the examination.

MATERIALS AND

METHODS

29 patients with rectum cancer underwent preoperative WE-CT. Contrast-enhanced CT (equilibrium phase) measurements were performed after i.v. injection of smooth muscle relaxant and rectal administration of 400-500 ml lukewarm tap water. Quality of the obtained scans was evaluated and the images were analyzed for depth of tumor invasion. Results of the CT examinations were compared to findings at surgery.

RESULTS

Despite reduced dose of water enema, 19/29 examinations were of excellent quality, 6/29 good, and 4/29 poor, but still diagnostic. We achieved sensitivity (90.1), specificity (70.1) and accuracy (86.2) in differentiating tumors confined to the bowel wall from those extending beyond it.

CONCLUSION

Large volume of water enema administered during CT examination of the rectum may cause complaints and increases the risk of complications. Our results prove that using lower amount of water does not impair the quality of examination and accuracy of local staging of rectum carcinomas.