Gamma rays are widely used in medical imaging and diagnostics because they can penetrate the body and provide information about internal structures and physiological processes. Their main applications include:
- Nuclear Medicine Imaging:
- Radioactive isotopes (like Technetium-99m) emit gamma rays after being introduced into the body.
- Gamma cameras detect this radiation to create images of organs, bones, or tissues.
- Example: SPECT (Single Photon Emission Computed Tomography) produces 3D images showing how organs function.
- Positron Emission Tomography (PET):
- PET uses isotopes that emit positrons, which annihilate with electrons to produce gamma rays.
- Detectors capture these gamma rays to create detailed functional images, often used for cancer detection, brain studies, and heart function analysis.
- Bone Scanning:
- Gamma-emitting tracers accumulate in bones, revealing fractures, infections, or tumors.
- Thyroid and Kidney Function Tests:
- Radioactive iodine emits gamma rays; its uptake by the thyroid is measured to assess thyroid function.
- Similar tracers evaluate renal function by tracking gamma radiation through the kidneys.
- Advantages in Diagnostics:
- Non-invasive and highly sensitive to functional changes, not just structural abnormalities.
- Can detect disease early, before anatomical changes are visible on X-rays or MRI.