Figure 6.

Spatial EPR 3D image data showing the cross-sectional structure of the GI tract at different levels. (Left) The complete 3D surface rendering of the image of the charcoal probe in the GI tract. Planar sections through this image are shown at four levels. Slice a shows a section at the level of the mid stomach where the fundus and pylorus of the stomach can be seen with the taper to the pyloric valve. Slice b shows a section at the level of the mid duodenum. The lumen of the duodenum is seen on the left along with less defined cuts on the right through the lower edge of the lumen of the stomach, anteriorly, and what appear to be the transverse colon and small intestine just below the stomach, posteriorly. Slice c shows a section at the level of the mid colon and mid small intestine where distinct cuts through the ascending colon, small intestine, and descending colon occur. Slice d shows a section at the level of the distal sigmoid colon–rectal junction where the lumen is seen clearly. The parameters for 3D spatial imaging are described in Fig. 4.