6.1. Nuclear medicine - Scintigraphy

What is nuclear medicine?

A medical specialty that uses radioactive tracers (radiopharmaceuticals) to assess bodily functions and to diagnose and treat disease, using specially designed cameras to track the tracers

What is scintigraphy?

A diagnostic test in nuclear medicine (also called a gamma scan) that uses radiopharmaceuticals to produce 2D images using gamma cameras

How does scintigraphy work?

Radiopharmaceuticals travel to a specific organ or tissue, emit gamma radiation, which is detected by gamma cameras to form 2D images

What type of radiation does scintigraphy use?

Ionising radiation

What are the advantages of scintigraphy?

Shows functionality not just structure, shows a sequence of functions over time, painless, non-invasive, minimal side effects, highly sensitive, can reduce need for exploratory surgery

What are the disadvantages of scintigraphy?

Uses radioactivity, complex safety procedures and regulations, issues around pregnancy and lactation, non-specific hot spots, rare allergic reactions, potentially long scan times, relatively costly, produces 2D not 3D images, complex patient preparation may be required

Why may patients need to avoid close contact with children or pregnant people after scintigraphy?

Because they may be slightly radioactive after the scan — iodine isotopes are particularly risky

What complex patient preparation may be required for scintigraphy?

Fasting, hormone administration, pre-medication, or urinary catheter — depending on the function being visualised

What is hepatobiliary scintigraphy used for?

To investigate conditions of the liver, gallbladder, and bile ducts

What symptoms indicate hepatobiliary scintigraphy?

Severe right-sided abdominal pain, pain or fever after gallbladder surgery or liver transplant, severe jaundice in newborns

What is acute cholecystitis and its most common cause?

Gallbladder inflammation, most commonly caused by a blockage from a gallbladder stone

What is chronic cholecystitis?

Intermittent blockage of the gallbladder by stones

What is sphincter of Oddi dysfunction?

A condition where the sphincter of Oddi fails to open when it should

What is biliary atresia?

A rare newborn disorder where bile is blocked from moving from the liver to the duodenum

What is a biliary leak?

Leakage of bile, typically occurring after surgery or trauma

What does bone scintigraphy show increased uptake in for thyroid cancer metastasis?

Proximal humerus, thyroid, and apex of skull

What can bone scintigraphy diagnose?

Metastasis associated with thyroid cancer

What is scintigraphy also known as?

Gamma scan

The following scintigraphy image is indicative of:

Bilary atresia

This is the CORRECT equation to represent electron-positron annihilation:

2e− + e+ → γ + γ

False, e⁻ + e⁺ → γ + γ

The following image shows normal functionality/metabolic activity of the heart

False