A simple method to increase the diagnostic efficiency of gastroesophageal scintigraphy using the knee-chest position

Purpose: The influence of patient posture on the incidence and severity of gastroesophageal reflux is well known. Scintigraphic imaging, however, is routinely performed with the patient lying in the supine position, because current gamma camera designs do not allow for changes to the angle of the patient table. Methods: To overcome this difficulty and to increase the diagnostic sensitivity of scintigraphy, we used an alternative patient position. Twenty-seven adult patients (eight men, 19 women; mean age, 47.5+/-11.5 years) with gastroesophageal reflux disease were prospectively studied consecutively using two body positions, the supine and the knee-chest positions. Each consisted of dynamic acquisition of 450 seconds. An entire study for each patient required only 15 minutes. Images were interpreted qualitatively by three observers. Results: Although gastroesophageal reflux was positively identified in only 9 of 27 (33%) patients using the supine position, 20 of 27 (74%) patients were shown to have gastroesophageal reflux in the knee-chest position (P < 0.05). No reflux was detected in seven patients using both positions. In five patients, whose study results were positive using both positions, the number of reflux episodes was greater in the knee-chest position compared with the supine position. Conclusion: The knee-chest position increases the diagnostic efficiency of gastroesophageal reflux scintigraphy.