Esophageal transit scintigraphy (ETS) is a noninvasive, quantitative method of assessing esophageal motility. As many as 50% of patients with dysphagia who have normal manometry and barium examinations are found to have esophageal dysmotility on scintigraphy. Early studies reported a high sensitivity for detecting esophageal dysmotility, but later studies reported a lower sensitivity, especially for disorders with intact peristalsis but high-amplitude contractions or isolated elevation of lower esophageal sphincter (LES) pressures.1,2 More recent studies confirm a high sensitivity for detecting a wide range of esophageal motility disorders.

source: Textbook of Gastrointestinal Radiology