**7.5 Radio-nuclear imaging**

Radio nuclear scan has been widely used for the detection of ectopic gastric mucosa especially in cases suspected to have Meckel's diverticulum (Kiratli et al., 2009). Technetium-99m pertechnetate scintigraphy can accurately localize the location of HGMP. The role and use of nuclear imaging in detecting HGMP/CIP remains unknown. One study reported its use in five patients with patches of gastric fundal type columnar epithelium in the proximal esophagus at the level of the upper esophageal sphincter diagnosed by upper endoscopy (Chen et al., 1989). In all instances, the patches contained both chief cells and mucus-secreting cells. Two cases of HGMP/CIP were demonstrated by TcO4-. Unfortunately, TcO4 accumulation in the thyroid glands of three patients caused overlapping activity between the thyroid gland and HGMP/CIP. It was concluded that TcO4- scintigraphy is only suitable for patients who have had a total thyroidectomy or are on suppressive thyroid therapy.

Fig. 8. Narrow band imaging showing an ectopic gastric mucosal patch as salmon coloured patch with greenish background

### **7.6 Contrast fluoroscopy/Barium swallows**

One study showed that careful fluoroscopy study can detect subtle abnormalities that may be due to HGMP/CIP (Takeji et al., 1995). This study detected 27 cases of HGMP/CIP confirmed on endoscopy and biopsy in 1,142 patients undergoing annual health check. The most common radiographic finding was a pair of small indentations on the wall of the esophagus (n=18). Other findings included a rim-like shadow (three patches), a pair of large indentations with a shallowly depression (two patches), one indentation (five patches), a small flat elevation (one patch), a serrated irregular outline (five radiologic lesions consisted of 11 patches), other various irregular outlines (two patches), and a polypoid area (one patch). One study using barium contrast swallow showed features similar to those described for esophageal webs and suggested that in fact, esophageal webs maybe due to HGMP/CIP (Ainley, 2011). This study clearly showed that HGMP/CIP produced the same imaging features of esophageal web on barium swallow. Chronic acid injuries lead to inflammations and subsequent healing results in a web or stricture formation. This has been referred to as type AA ring in contrast to the A (muscular ring) and B (Schatzki ring) rings in the distal esophagus.
