Retained gastric antrum syndrome diagnosed by [99mTc] pertechnetate scintiphotography in man: hormonal and radioisotopic study of two cases.

Retained-antrum syndrome is a rare condition, occurring in Billroth II gastrectomised patients, in which an ulcer recurs associated with high levels of circulating gastrin. Some gastrin tests are useful to differentiate a retained antrum from a gastrinoma, but a firm diagnosis is sometimes very difficult. We have studied two cases of retained-antrum syndrome both by gastrin tests and by [99mTc] pertechnetate scintiphotography. By this method a prominent area of activity was observed on the anatomic site of the duodenal stump bottom. It appeared after 20 or 30 min and lasted for the 2 hr of observation. After surgical resection, no area of activity was observed at the scintiphotographic followup. No false positive was observed out of the more than 30 subjects studied. Scintiphotography by pertechnetate seems able to demonstrate the presence and the size of retained gastric antrum in B II gastrectomised patients with recurrent ulcer.

Lactulose hydrogen breath test in orocecal transit assessment. Critical evaluation by means of scintigraphic method.

Orocecal transit time can be studied easily using the hydrogen breath test with lactulose, but the method has some important limitations. The orocecal transit time of 10 patients suffering from irritable bowel syndrome was measured twice, at a one-week interval, by breath test and scintigraphy simultaneously using an aqueous solution of 20 g lactulose containing 74 MBq of [99mTc]DTPA. Abdominal radioactivity and alveolar hydrogen values obtained every 5 min were noted and used to obtain the following: orocecal transit time by the two methods; ileocecal lactulose flow; total and per gram of lactulose hydrogen production; mean hydrogen concentration during the right colon filling; and measurement error of the breath test with respect to the scintigraphy. In the case of the breath test, the orocecal transit time intrapatient reproducibility was better (coefficient of variation = 13.5%) when a hydrogen threshold increment of 5 ppm was used; the best correlation with the scintigraphic measurement was observed at this threshold (r = 0.90, P < 0.001). The breath test overestimated orocecal transit time with the error correlating negatively and significantly with the total hydrogen production and, particularly, the mean hydrogen concentration (r = 0.79, P < 0.01): for a mean hydrogen concentration of more than 15 ppm, the error was negligible, while within this value there was a noticeable overestimation. To conclude, the lactulose hydrogen breath test is capable of giving an accurate measurement of orocecal transit time if a hydrogen threshold increment of 5 ppm is chosen and if the mean hydrogen concentration in the first 30 min of the right colon filling is taken into account.