What is the impact of collimator design on a gamma camera sensitivity?

The impact of collimator design on a gamma camera's sensitivity is significant because the collimator is responsible for allowing only gamma rays that are traveling along specific directions to reach the detector. A well-designed collimator can enhance the sensitivity of the gamma camera by effectively filtering out scattered photons and minimizing the detection of unwanted gamma rays. This leads to a better signal-to-noise ratio, allowing for more accurate imaging of the radiopharmaceutical distribution within the body.

Different designs can optimize certain parameters—such as hole size, geometry, and material—which can directly affect how many gamma photons are detected versus those that are blocked or scattered. For instance, if a collimator has larger holes, it can increase sensitivity by allowing more photons to pass through, but this might come at the cost of reduced spatial resolution. Conversely, a denser collimator might improve resolution but decrease sensitivity. Thus, when collimators are designed properly, they can strike a balance that enhances the overall sensitivity of the system, making it crucial to choose the right design for the specific imaging requirements.