The added diagnostic value of liquid gastric emptying compared with solid emptying alone.

UNLABELLED The medical literature states that solid gastric-emptying studies are more sensitive for the detection of gastroparesis than are liquid studies; thus, liquid studies are rarely required. However, we have seen patients with normal solid but delayed liquid emptying. The purpose of this investigation was to determine whether a study of clear liquid gastric emptying has added value for the diagnosis of gastroparesis over a study of solid emptying alone. METHODS A total of 101 patients underwent both solid and liquid gastric-emptying studies, acquired sequentially on the same day. A 30-min (1-min frames) liquid study (300 mL of water with 7.4 MBq [0.2 mCi] of (111)In-diethylenetriaminepentaacetic acid) was followed by a standardized 4-h solid-meal study (a (99m)Tc-sulfur colloid-labeled egg-substitute sandwich meal). Emptying was quantified as a best-fit exponential emptying rate (T1/2) for liquids and percentage emptying at 4 h for solid emptying. Thirty healthy volunteers underwent a study of clear liquid emptying to establish normal values. The results of the liquid and solid studies were compared. (111)In liquid downscatter into the subsequent (99m)Tc solid meal results was analyzed. RESULTS The upper range of normal for clear liquid emptying (T1/2) for healthy volunteers was 22 min (mean +/- 3 SDs) and 19 min (mean +/- 2 SDs). Of 101 patients, delayed emptying was found in 36% of liquid and 16% of solid studies. Of all patients with normal solid emptying, 32% had delayed liquid emptying. (111)In downscatter into the (99m)Tc window was not generally significant. CONCLUSION For the detection of gastroparesis, a 30-min study of clear liquid gastric-emptying has considerable added diagnostic value over a study of solid emptying alone.