Gastric emptying scintigraphy (abbreviation: MESz) is a diagnostic nuclear medicine procedure that can be used to diagnose delayed or accelerated gastric emptying in the presence of various diseases. Primarily, gastric emptying scintigraphy is used when a gastric emptying disorder is suspected in the context of diabetes mellitus, because autonomic neuropathy (functional impairment of the autonomic nervous system) may develop due to diabetes mellitus.
Indications (areas of application)
Gastric dysfunction with delayed emptying:
- Suspected gastroparesis (gastric paralysis)-autonomic neuropathy resulting from diabetes is particularly problematic because adequate drug management of diabetes can only occur if the gastrointestinal tract (GI tract) is functioning physiologically. Gastric emptying scintigraphy allows reproducible measurement of gastric emptying. The relevance of the scintigraphic examination is great, because in conducted studies it could be shown that more than one third of the examined patients show a significantly delayed emptying and even after 90 minutes after application of the radiopharmaceutical, more than 50% residual activity of the radiopharmaceutical is still present.
- Pyloric stenosis (gastric portal stenosis) – this is a narrowing of the pylorus (gastric portal) at the junction with the duodenum (part of the small intestine). The influence of the stenosis on gastric emptying can be checked by gastric emptying scintigraphy.
- Duodenal stenosis (narrowing of the duodenum) – in this usually congenital narrowing of the lumen (opening), gastric emptying scintigraphy is a valuable diagnostic tool in checking gastric emptying.
Gastric dysfunction with dumping syndrome (accelerated emptying):
- Partial gastrectomy (= partial gastric resection or gastric resection, in which only part of the stomach is removed for the treatment of benign diseases of the stomach and duodenum / duodenum) – in the context of a surgical reduction of the stomach, gastric emptying is accelerated.
- Vagotomy – vagotomy represents a therapeutic procedure for the treatment of ventriculi ulcer (gastric ulcer) in which branches of the vagus nerves are cut. Since the vagus nerve is one of the crucial factors in the regulation of gastric emptying, gastric emptying scintigraphy can be used to determine how it affects gastric function.
- Pyloroplasty- due to chronic ulcers (ulcers), there is a possibility that the gastric outlet is reduced in size. Pyloroplasty, a surgical therapy, opens the gastric outlet longitudinally and closes it transversely, which can lead to accelerated gastric emptying.
- Fundoplication – this surgical procedure is used in the presence of erosive (damage to the mucosa) reflux esophagitis (inflammation of the lower esophagus due to reflux (backflow) of gastric juice into the esophagus) with failure of drug therapy and may be associated with dumping syndrome as a complication.
- Gastric pull-up (Engl. gastric pull-up) – this surgical therapy procedure is a method of reconstructing the passageway after performing esophagectomy (surgical removal of the esophagus).
- Microgastria – microgastria represents a congenital defect of the stomach, defined by a significant reduction in the size of the stomach.
Contraindications
Relative contraindications
- Lactation phase (breastfeeding phase) – breastfeeding must be interrupted for 48 hours to prevent risk to the child.
- Repeat examination – no repeat scintigraphy should be performed within three months due to radiation exposure.
Absolute contraindications
- Gravidity (pregnancy)
Before the examination
- Abstention from food and fluid – to ensure a meaningful gastric emptying scintigraphy, no food or fluid should be consumed by the patient for at least 6 hours before the examination. In addition, bladder and bowel emptying should still take place before the examination.
- Application of the radiopharmaceutical – To perform gastric emptying scintigraphy, an oral application of the radioactive 99mTechnetium Albu-Res is performed in adults in the form of a test meal. Usually, an amount of 3-5 MBq (millibecquerel) is administered. The radioactive radiopharmaceutical is administered to the patient, for example, together with two fried scrambled eggs on toast.
The procedure
Gastric emptying scintigraphy represents a highly sensitive procedure for the detection of gastric emptying disorder. However, because of the radiation exposure present, it should not be used in routine diagnostics or without consideration of diagnostic alternatives. To obtain comparable results with gastric emptying scintigraphy, standardized test meals should be used. During the examination, the patient’s upper body is elevated. Immediately after ingestion of the radiolabeled meal, sequence images are taken. The time required for sequence imaging using a gamma camera is 2 hours. In addition, further images of the esophagus can be taken after 4 and/or 24 hours to detect possible reflux. The examination is followed by a computerized evaluation of the scintigraphy. Physiologic (healthy) would be a gastric emptying half-life of less than 50 minutes.
Potential complications
Radiation exposure from the radionuclide used is considered rather low. Nevertheless, the theoretical risk of radiation-induced late malignancy (leukemia or carcinoma) is increased, so a risk-benefit assessment should be performed. Due to reduced bladder emptying, radiation exposure can be significantly higher than in normal cases. Because of this, abnormalities of bladder emptying should be addressed, particularly in the medical history.
