A 50 year old woman has post-prandial epigastric discomfort, intermittent dysphagia, and episodes of regurgitation. She presents for gastric-emptying study.
The image above shows anterior and posterior images of the upper abdomen at the time of meal ingestion and 1 hr, 2 hr, 3 hr, and 4 hr later. A region of interest is drawn around the stomach, and the amount of radiotracer activity in the stomach at each timepoint is calculated (using the geometric mean to correct for anterior/posterior positional variation). Percent residual activity and percent emptying are shown in the graph and table on the right, respectively.
When using a standardized meal (a low-fat meal including Tc99m sulfur colloid in egg whites), delayed gastric emptying is defined as <10% emptying at 1 hr, <40% emptying at 2 hr, or <90% emptying at 4 hr. Tougas G, et al. Assessment of gastric emptying using a low fat meal: establishment of international control values. Am J Gastroenterol 2000;95:1456-1492. Ziessman HA, et al. Experience with a simplified, standardized 4-hour gastric-emptying protocol. J Nucl Med 2007;48:568-572.
This patient has near-normal emptying of the stomach over 4 hours, with slightly abnormal emptying at the 4 hr timepoint. However note the linear radiotracer activity superior to the stomach, with minimal change on all images.
Sequential images from an upper GI series demonstrate a dilated esophagus and “beak”-like narrowing at the lower esophageal sphincter, with slow passage of liquid barium into the stomach.
Later images show slow passage of barium tablets and an air-water level as the patient is imaged upright.
Upper GI findings are virtually diagnostic of achalasia, or failure of relaxation of the lower esophageal sphincter (LES). The diagnosis is usually confirmed with esophageal manometry (elevated resting LES pressure >45 mmHg, incomplete LES relaxation to <8 mm Hg above gastric pressure, aperistalsis). Endoscopy is recommended to exclude secondary causes such as esophageal/gastric malignancy. Vaezi MF, et al. Diagnosis and management of achalasia. Am J Gastroenterol 2013;108:1238-1249.
Achalasia classically presents with dysphagia as the predominant symptom, however as in this case symptoms may overlap with those of delayed gastric emptying (post-prandial fullness, nausea, vomiting).