Gastric Emptying: in Vivo Studies in Healthy Volunteers
Gastric Emptying: in Vivo Studies in Healthy Volunteers
The Investigators institution has used a meal consisting of mashed potato, peas and Beanfeast
 (soya mince) for gastric emptying studies for a number of decades. Validation of the study
 method was purportedly performed when the study was first implemented at the hospital,
 however no historical data has been found. The current normal ranges are also
 unsubstantiated. There is scientific justification for this research because in vivo studies
 are instrumental to the validation of a new procedure. There is a need for a meal preparation
 that is palatable and meets dietary requirements (vegetarian, gluten free e.t.c.) of patients
 as the diagnosis depends on ingestion of the radiolabelled meal. In addition, reliable normal
 ranges will ensure that the clinical diagnosis is accurate. Scientific justification extends
 beyond the local department as publishing the data acquired will allow other hospitals to
 adopt the same test meals and normal ranges, leading to standardisation of the clinical
 protocol employed across the UK. Since the investigators institution are recognised as the
 leading Nuclear Medicine GI centre in the UK and have previously carried out audits and in
 vitro testing in the area of gastric emptying, it seems fit that they should lead the
 national change in protocol.

 The proposed study will involve recruitment of healthy volunteers who will eat a meal
 containing 10MBq of a radioactive tracer. They will be subsequently scanned using a gamma
 camera with imaging lasting no more than 3 hours in total. Approximately 40 healthy
 volunteers (18-70 years old, no history of gastrointestinal problems or other serious health
 issues e.g. diabetes and pregnant women are excluded) will be recruited and the studies will
 be conducted on site i.e. within the Nuclear Medicine department at City hospital.
After the ingestion and subsequent passage of solid or liquid material into the stomach, the
 gastric contents will undergo gastric emptying from the stomach into the intestine. The rate
 of gastric emptying can be very variable and will depend on the presence of gastric pathology
 or defect, composition and volume of the gastric contents and may even be influenced by
 factors such as gender and reproductive status. Gastric motility disorders such as
 gastroparesis and dumping syndrome can affect the rate of gastric emptying and thus warrant
 the quantitative assessment of emptying. Gastroparesis is a disorder of the stomach
 characterised by delayed gastric emptying in the absence of any mechanical obstruction and
 can be further categorised based on severity; mild gastroparesis (where symptoms can be
 easily controlled), compensated gastroparesis (partial control with use of medication and
 dietary adjustments) and gastric failure (symptoms are not controllable). Dumping syndrome
 occurs as a result of rapid gastric emptying which is usually associated with hypermotility
 of the stomach. It manifests as either early or late dumping syndrome, both of which have
 distinct physiological bases and clinical presentations.

 Typical symptoms of delayed emptying include nausea, vomiting, abdominal pain and abdominal
 fullness after eating whilst diarrhoea, weakness and light headedness after meal times are
 common symptoms of rapid emptying. In the Nuclear Medicine department at City Hospital
 (Birmingham), patients referred for imaging are usually diabetics suffering from feelings of
 bloatedness after eating and occasional vomiting. Most patients studied are clinically
 diagnosed with gastroparesis associated with diabetes (where the vagus nerve responsible for
 controlling movement of food through the digestive tract stops functioning). Dumping is
 rarely reported as there is an effective tablet treatment for the disorder that usually eases
 the symptoms. (This includes octreotide therapies which can exert an effect through various
 mechanisms such as delaying transit, inhibiting the release of gut peptides and impaired
 fluid secretion). If left untreated gastroparesis can make diabetes worse by making it more
 difficult to manage blood glucose. Assessment of gastric emptying rate is therefore an
 important part of diagnosis.

 Gastric emptying scintigraphy is a non-invasive diagnostic tool that is used in Nuclear
 Medicine to study the emptying of contents into the stomach. This form of scintigraphic
 examination is reproducible, simple to perform, accurate, quantitative and exposes the
 patient to only a very small radiation dose. It has been significantly optimised and refined
 over the years and is now well established as the standard method for evaluating gastric
 emptying. As the 'gold standard' gastric emptying scintigraphy is usually the first stage of
 the diagnostic journey for a patient, although some may have had a prior endoscopy (usually
 in cases of severe vomiting).

 The procedure is known to vary between institutions, however will usually involve binding of
 a radiotracer to a solid or liquid meal which is then administered orally. This is followed
 by positioning of the patient in front of a camera and continuous or intermittent imaging is
 performed. Data is acquired over a length of time (usually 1-2 hours) and the data
 subsequently analysed to determine the half emptying time (i.e. the time required for the
 stomach to empty 50% of the ingested meal) which is then compared to established normal
 ranges (i.e. normal emptying rate expected for healthy individual). The current radioactive
 meal used for the study consisting of mashed potato, peas and Beanfeast (soya mince) is not
 particularly palatable, does not meet the dietary requirements of some patients (e.g.
 gluten/wheat free) and is difficult to prepare. In addition, in-house in vitro studies have
 found the current meal to be inferior to other meal preparations. Subjecting the radioactive
 meal to simulated conditions of the stomach has found that the radiolabel retention was
 significantly better in other meals such as scrambled egg and porridge.
Inclusion Criteria:

 -  Male and Female participants

 -  Age range of 18-70 years old

 -  All ethnicities/socio economic grouping

 -  Participants living outside local area (but within UK) included (but excessive travel
 may not be reimbursed)

 Exclusion Criteria:

 -  Outside stated age range

 -  Outside the UK

 -  Have Diabetes or severe gastrointestinal symptoms such as vomiting or diarrhoea.

 -  Have a gastric motility disorder

 -  Pregnant women (If a participant becomes pregnant before their first test, they will
 be withdrawn from the study, If a participant becomes pregnant between the two tests,
 they will not be eligible for the second test but data collected from the first test
 may still be used for analysis).