Peter Bannas MD, Presenter: Nothing to Disclose

Joshua Bakke, Abstract Co-Author: Nothing to Disclose

Alejandro Munoz Del Rio PhD, Abstract Co-Author: Research Consultant, Cellectar Biosciences, Inc Reviewer, Wolters Kluwer nv

Perry J. Pickhardt MD, Abstract Co-Author: Co-founder, VirtuoCTC, LLC Stockholder, Cellectar Biosciences, Inc

To perform an objective, intra-individual comparison of residual colonic fluid volume and attenuation associated with magnesium citrate versus sodium phosphate catharsis at CT colonography (CTC).

This retrospective HIPAA-compliant study had institutional review board approval; informed consent was waived. The study cohort included 250 asymptomatic adults (mean age at index, 56.1 years; 124M/126F) who underwent CTC screening twice over a 5–year interval. Colon catharsis at initial and follow-up screening employed single-dose sodium phosphate (NaP) and double-dose magnesium citrate (MgC), respectively, allowing for intra-patient comparison. Automated volumetric analysis of residual colonic fluid volume and attenuation was performed on all 500 CTC studies. Colonic fluid volume < 200 ml and mean attenuation between 300-900 HU were considered optimal. Paired t test and McNemar’s test were used to compare differences.

Residual fluid volumes < 200 ml were recorded in 192 examinations (76.8%) following MgC and in 204 examinations (81.6%) following NaP (p=0.23). The mean total residual fluid volume was 155±114 ml for MgC and 143±100 ml for NaP (p=0.01). The attenuation range of 300-900 HU was significantly more frequent for MgC (n=220, 88.0%) than for NaP (n=127, 50.8%) (p < 0.001). Mean fluid attenuation was significantly lower for MgC (700±165 HU) than for NaP (878±155 HU) (p < 0.001). Concomitant presence of both optimal fluid volume and attenuation was significantly more frequent for MgC 65.2% than for NaP (38.0%) (p < 0.001).

Objective intra-individual automated comparison of residual fluid volume and attenuation shows that magnesium citrate catharsis improves overall CTC examination quality over sodium phosphate.

The current front-line laxative magnesium citrate renders similar volumes but more optimal attenuation of residual colonic fluid and thereby enhances the examination quality of CTC as compared to the previously established sodium phosphate.

Bannas, P, Bakke, J, Munoz Del Rio, A, Pickhardt, P, Intra-individual Comparison of Magnesium Citrate and Sodium Phosphate for Bowel Preparation at CT Colonography: Automated Volumetric Analysis of Residual Fluid for Quality Assessment.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14005733.html