Role of nuclear medicine in GIT

Question 1

What are milk scans used for

Answer 1

It is useful in the detection of gastro-oesophageal reflux of feeds and subsequent aspiration into the respiratory tracts

Performed by introduction of milk labelled with Tc-99m colloid

Question 2

What are the definitions of the following:
- GOR
- Regurgitation
- Vomiting

Answer 2

GOR - Passage of gastric content into the oesophagus

Regurgitation - Passage of gastric content into the mouth

Vomiting - It is the expulsion of gastric content from the mouth

Question 3

What are the factors causing GOR to progress to GORD

Answer 3

Frequency of reflux
Duration of reflux
Gastric acidity
Esophageal barrier mechanism integrity
Esophageal clearing mechanism
Airway hypersensitivity

Question 4

How is a gastro-oesophageal reflux scintigraphy obtained

Answer 4

Before the study
- Older children fast for 4 to 6 hours
- In younger children radioactive feed replaces normal meal

Radiopharmaceutical feed and feeding
- Tc-99m colloid not absorbed by gut mucosa
- Volume of feed as well as activity is dependant on age of patient
- Radiolabeled meal is fed to patient then the tracer free secodhalf to clear any residual activity in mouth and oesophagus

Question 5

What is the indications for gastric emptying study

Answer 5

• Insulin dependant diabetics with persistent post-prandial symptoms
• Diabetics with difficulty in glycaemic control
• Non-ulcer dyspepsia
• Severe reflux esophagitis
• Unexplained nausea and vomiting
• Evaluate response to prokinetic medications
• Assessment of gastric motility prior to fundoplication
• As part of evaluation of patient with generalised dysmotility of the GIT

Question 6

What are the aims of gastrointestinal bleed scintigraphy

Answer 6

Determine whether bleeding is active
Localise bleeding arterial region
Approximate the bleeding volume for prognostication