Three-dimensional visualisation of the large bowel: a potential tool for assessing targeted drug delivery and colonic pathology.

A study has been undertaken to assess the feasibility of three-dimensional imaging of the dispersion of a non-absorbable tracer released into the colon of normal subjects. Six healthy volunteers were selected who were participating in a scintigraphic study designed to assess the spreading of 1 MBq indium-111 Amberlite resin delivered from a delayed capsule system targeted to release in the ascending colon. In each case subjects were imaged using a rotating gamma camera over a data collection period of approximately 20 min. Three-dimensional volume rendered images demonstrated good visualisation of the dispersion of the tracer throughout the ascending, transverse and descending colon and provided good anatomical visualisation of the shape of the colon, not previously apparent from the planar views. The present study demonstrates for the first time, the successful three-dimensional imaging of a radiolabelled tracer dispersed throughout the colon and opens up the prospects for more detailed study of quantification of the volume and distribution of tracers contained within the colon.