Gastrointestinal (GI)
In this newsletter, we focus on gastrointestinal imaging. Patients with chronic abdominal pain can often be difficult to evaluate. Ultrasound is usually the first imaging of choice. However Nuclear Medicine is simple, easy and has incremental diagnostic value. It is underutilised and we have illustrated its value in the diagnosis of Gastroparesis, Colonic Inertia and Cholecystitis in the following three case studies.
Colon Transit Study
24 yr old female with chronic abdominal pain and suspected constipation presents for a colonic transit study. The scan demonstrated a large amount of tracer retention along the ascending colon up to 96 hours following tracer ingestion suggestive of severe slow transit constipation. In normal cases, there should only be a small residual amount of tracer in the colorectum by 72hrs.
Gastric Emptying Scan
50 yr old male diabetic with poor control presents with postprandial nausea and vomiting and epigastric pain for 9 months. The scan demonstrated a large amount of tracer retention in the stomach with only a small amount of tracer transit into small bowel in keeping with gastroparesis. For suspected oesophageal dysmotility, a nuclear oesophageal transit study can also be useful.
Hepatobiliary Scan
41 yr old female presented with recurrent right upper quadrant pain for 18 months which was worse after eating fatty meals. Ultrasound and CT were normal. A hepatobiliary scan ordered by the GP demonstrated abnormal gallbladder response to a fatty meal challenge (Ensure Plus) with reduced contraction and an ejection fraction of 10% (normal>32%) consistent with chronic cholecystitis. Nuclear Medicine can also be used to evaluate Focal Nodular Hyperplasia (FNH) and Hyposplenism using a Liver/Spleen scan and for Hepatic Haemangioma, the test of choice is a Labeled Red Blood Cell scan.
