What is the primary function of a collimator in a gamma camera?

The primary function of a collimator in a gamma camera is to allow only gamma rays from specific angles to reach the detector. This is essential because gamma cameras capture emissions from radioactive isotopes in the body, and without a collimator, photons coming from all directions would be detected, leading to a blurred image with poor resolution. The collimator is designed with a series of holes or channels that align with the detector, permitting only those photons traveling in predetermined directions to pass through. This selective filtering significantly enhances image quality and spatial resolution by ensuring that only the relevant gamma rays contribute to the final image.

In essence, the collimator plays a critical role in the imaging process, ensuring that the resulting images accurately reflect the distribution of radiopharmaceuticals within the body, making its function vital for effective diagnostic imaging.