Radionuclide esophageal transit (RET) study. The effect of body posture

Radionuclide esophageal transit (RET) was studied in the sitting and supine position in 24 patients with dysphagia. The RET time was invariably longer in the supine position. Seven patients manifested abnormal RET times only in the supine position, which is more sensitive for routine use. There is, however, a place for sitting studies in patients whose RET times are too prolonged to quantify in supine position 3 patients. RET time-activity curves are useful not only quantitatively but also qualitatively, e.g., to differentiate diffuse non-propulsive esophageal contraction from aperistalsis.