The Radiological Assessment of Gastric Acid Output

Abstract

The augmented histamine test (1) and the maximum histalog (betazole) stimulation (2, 3) (MHS) are accepted as the standard procedures for measurement of gastric acid output. Their main clinical value lies in the finding of achlorhydria (or minimal acid secretion) and exceedingly high acid. Gastric mucosal atrophy is commonly associated with achlorhydria, and increased rugosity of the stomach with coarse duodenal folds is frequently seen in patients harboring non-beta cell tumors of the pancreas (4) or those with high gastric secretion with or without a demonstrable ulcer (5). Recently, attention has been drawn to the fair correlation existing between the gastroduodenal mucosal pattern and the gastric acid output (5, 6). This study was undertaken to see if it is possible to assess gastric acid secretion in different disorders on the basis of a radiological examination of the stomach and duodenum and to test the reliability and reproducibility of such estimation. Material and Methods 1. Measurement of Gastric Acid Output Four hundred consecutive patients were referred for a maximum histalog stimulation test (MHS) (1.5 mg/kg body weight, 7). While in some of the patients no demonstrable organic disease was proved, peptic ulcer, gastric neoplasm, and megaloblastic anemia were represented. A No. 14 F radiopaque tube was placed in the stomach under fluoroscopic control, and a Gomco pump was utilized for continuous suctioning. The basal secretion was collected at fifteen-minute intervals for one hour. Histalog was then given in an appropriate dose, and gastric secretion was collected separately fifteen, thirty, forty-five, and sixty minutes afterward. The free hydrochloric acid concentration was determined by titration with 0.1 N NaOH, using phenol red as the indicator (pH 7). One hour after the administration of histalog, the sum was expressed as milli-equivalents per hour. Note was made of the presence and amount of bile, mucus, blood, and retained food particles. On the basis of our experience in 1,000 cases (7), we arbitrarily defined “low,” “normal,” and “high” acid output as a maximum histalog yield of less than 9, 9–19, and over 20 mEq, respectively, of free hydrochloric acid per hour. 2. Radiologic Studies and Scoring System Different radiologists who were unaware of the present investigation carried out barium meal studies in the 400 patients not more than one month before or after the MHS test. For review and scoring, an incompletely filled stomach and minimally distended duodenum (supine film without compression) were preferable, but not essential. The mucosal pattern of the stomach in the greater curvature and fundus and that of the first and second portions of the duodenum were separately scored by the following scale: The sum of the stomach and duodenum scores represented each individual case.