Pilot study on efficacy of reduced cathartic bowel preparation with polyethylene glycol and bisacodyl.

AIM: To evaluate the efficacy of reduced cathartic bowel preparation with 2 L polyethylene glycol (PEG)-4000 electrolyte solution and 10 mg bisacodyl enteric-coated tablets for computed tomographic colonography (CTC). METHODS: Sixty subjects who gave informed consent were randomly assigned to study group A, study group B or the control group. On the day prior to CTC, subjects in study group A were given 20 mL 40% wt/vol barium sulfate suspension before 3 mealtimes, 60 mL 60% diatrizoate meglumine diluted in 250 mL water after supper, and 10 mg bisacodyl enteric-coated tablets 1 h before oral administration of 2 L PEG-4000 electrolyte solution. Subjects in study group B were treated identically to those in study group A, with the exception of bisacodyl which was given 1 h after oral PEG-4000. Subjects in the control group were managed using the same strategy as the subjects in study group A, but without administration of bisacodyl. Residual stool and fluid scores, the attenuation value of residual fluid, and discomfort during bowel preparation in the three groups were analyzed statistically. RESULTS: The mean scores for residual stool and fluid in study group A were lower than those in study group B, but the differences were not statistically significant. Subjects in study group A showed greater stool and fluid cleansing ability than the subjects in study group B. The mean scores for residual stool and fluid in study groups A and B were lower than those in the control group, and were significantly different. There was no significant difference in the mean attenuation value of residual fluid between study group A, study group B and the control group. The total discomfort index during bowel preparation was 46, 45 and 45 in the three groups, respectively, with no significant difference. CONCLUSION: Administration of 10 mg bisacodyl enteric-coated tablets prior to or after oral administration of 2 L PEG-4000 electrolyte solution enhances stool and fluid cleansing ability, and has no impact on the attenuation value of residual fluid or the discomfort index. The former is an excellent alternative for CTC colorectum cleansing.

A knowledge-based fuzzy clustering method with adaptation penalty for bone segmentation of CT images.

Accurate segmentation is critical in many advanced imaging applications such as volume determination, radiation therapy, 3D rendering, and surgery planning. However, due to the complex anatomical structure of tissue and organs, as well as artifacts caused by patient motion, beam hardening, and partial volume effect in CT image, the boundaries between different regions are smeared. In addition, the intensities of bone voxels vary widely that some of them are so close to that of the muscle. They all make the extraction of bone out of surrounding tissue quite difficult in CT images. In this study, a knowledge-based fuzzy clustering method was proposed, which was formulated by modifying the objective function of the standard fuzzy c-means (FCM) algorithm with additive adaptation penalty. Since the membership of voxels in boundary regions is intrinsically fuzzy, unsupervised fuzzy clustering methods turns out to be particularly suitable for handling the bone segmentation problem. The knowledge-based fuzzy clustering method was tested by patient CT images. Experimental results demonstrated that while the conventional FCM methods might loss a significant amount of bone volume during segmentation, the proposed method could improve the performance of bone extraction significantly.