In nuclear medicine imaging, which is the primary purpose of using a collimator?

The primary purpose of using a collimator in nuclear medicine imaging is to enhance image resolution. A collimator is a device that allows only gamma rays emitted from specific angles to reach the detector while blocking those from other directions. This selective filtering improves the spatial resolution of the images by reducing the blurring that can occur when gamma rays from unintended angles are detected.

In practice, this means that the resulting images are clearer and provide more detailed information about the distribution of the radiopharmaceutical within the body. Higher resolution is crucial for accurately diagnosing conditions and assessing the function of organs and tissues.

The other options, while they touch on aspects related to the use of a collimator, do not capture its primary role. For instance, increasing the radiation dose is contrary to the goal of minimizing exposure while maintaining image quality. Reducing image noise may be a beneficial effect of improved image quality but is not the main function of the collimator. Limiting exposure to the patient is more so a consideration of the overall imaging protocol rather than a direct purpose of the collimator itself.