Selenium (75Se) tauroselcholic acid is an artificial radiotracer used in medical imaging to diagnose and monitor diseases such as cancer, liver disease, and cardiovascular disease. It is a type of radiopharmaceutical, meaning it is a radioactive form of a natural molecule, tauroselcholic acid, that is used to diagnose and treat certain medical conditions. When injected into the body, the selenium-75 isotope emits gamma rays that can be detected and measured using a gamma camera. This information is then used to create images of the body and to diagnose and monitor diseases. Selenium (75Se) tauroselcholic acid has been used to diagnose liver, gallbladder, and pancreatic diseases, as well as to detect and monitor metastatic cancer.
Selenium (75Se) tauroselcholic acid, also known by the brand name SeHCAT, is a radiopharmaceutical used in a medical test [1, 2]. Here's a breakdown of its key aspects:
Medical Use:
- SeHCAT is used for a specific diagnostic test to assess bile acid malabsorption (BAM) [1, 2].
- BAM is a condition where the intestines have difficulty absorbing bile acids produced by the liver. Bile acids are crucial for digestion and fat absorption.
How it Works:
- SeHCAT is a synthetic molecule that mimics the structure of a natural bile acid called taurocholic acid [1]. However, it incorporates a radioactive isotope of selenium (75Se).
- When SeHCAT is swallowed in a capsule, it travels through the digestive system. Normally, the intestines efficiently absorb bile acids.
- In the case of BAM, the damaged intestines fail to absorb SeHCAT properly, and a higher amount is excreted in feces.
Test Procedure:
- A healthcare professional will administer a single capsule of SeHCAT orally.
- Stool samples are then collected over several days to measure the radioactivity levels.
- The amount of radioactivity in the stool indicates the extent of SeHCAT absorption.
- High radioactivity in stool suggests bile acid malabsorption.
Benefits:
- SeHCAT offers a non-invasive and relatively simple way to diagnose bile acid malabsorption [1].
- It helps identify the cause of chronic diarrhea in some patients where other tests might be inconclusive.
Important Considerations:
- SeHCAT is a radioactive medication, so it should only be used under the supervision of a qualified nuclear medicine physician [1].
- It's not suitable for everyone, particularly pregnant or breastfeeding women [2].
- Although the radiation dose is low, there are still safety precautions to consider during the test [2].