Inter-observer reproducibility of quantitative radionuclide colonic transit imaging

The colonic transit of an indium-111 enteric coated capsule was imaged with a gamma camera over a period of 3 days. The geometric centre of activity i n the colon was calculated from regions drawn over four segments of the col on, plus a fifth segment as the estimated passed stool activity. Fifteen he althy subjects were scanned and the results analysed. The images were analy sed by two observers to assess reproducibility of the geometric centre quan titative index (correlation, r = 0.985). In conclusion, although it can be difficult to identify the anatomical segments of the colon from the gamma c amera images, by following a protocol with clear guidelines for ROI placeme nt, good inter-observer reproducibility can be obtained. ((C) 1999 Lippinco tt Williams & Wilkins).