What does the sensitivity test measure in a gamma camera?

The sensitivity test measures the detection ability of the gamma camera to respond to radiation. This is crucial because it directly relates to how well the camera can detect gamma radiation emitted from radiopharmaceuticals within a patient's body. A highly sensitive gamma camera can detect even small amounts of radiation, which is essential for accurate imaging and diagnosis in nuclear medicine.

Sensitivity is often quantified through a test that measures the camera's response to a known radiation source, typically looking at parameters such as how many counts are detected versus the expected counts from the source. This assessment helps determine the efficiency of the camera in capturing diagnostic images, which can ultimately impact patient care by ensuring that any abnormalities are detected early and accurately.

While other options might relate to important aspects of camera performance, such as uniformity of the gamma source, spatial resolution, and collimator efficiency, they do not pertain directly to the fundamental aspect of sensitivity, which is the camera's overall ability to detect and respond to the radiation emitted from the radiopharmaceuticals used in imaging.