Background: The medical literature states that solid radionuclide gastric emptying studies are more sensitive than liquid studies for detection of gastroparesis and thus liquid studies are rarely indicated. At our institution, patients are often referred for both studies. Our initial purpose was to review the results in those patients. The surprising results led us to initiate a prospective investigation to more directly determine the relative value of solid versus liquid emptying studies.
Methods: The retrospective review included 21 patients who had both studies performed on separate days. The subsequent prospective investigation was initiated so that the solid and liquid emptying studies were acquired sequentially on the same day. A total of 40 consecutive patients with symptoms suggestive of gastroparesis (mean age 44.8, 12 males, 28 females) were investigated. All ingested 300 mL water with radiotracer and were imaged each minute 30. They then ingested the radiolabeled solid meal and were imaged each hour 4. A liquid emptying rate (T1/2) and solid percent emptying each hour 4 was determined.
Results: In the retrospective review, 17 of 21 patients had normal solid emptying; of those, 13 had delayed liquid emptying. In the subsequent prospective study, 30/40 (75%) had normal solid emptying; of those, 10 (33%) had delayed liquid emptying. Nine patients (23%) had delayed solid emptying; 13 (32%) had delayed liquid emptying.
Conclusions: Liquid gastric emptying is commonly abnormal in patients who have normal solid studies. Liquid studies should be routinely performed in addition to solid studies to fully evaluate gastric motility in patients with symptoms suggestive of gastroparesis.