**Core Concept**
A Gamma camera is a type of nuclear medicine imaging device that uses a scintillator to detect and convert gamma rays emitted by radioactive isotopes into visible light. This visible light is then converted into an electrical signal that is used to create images of the body's internal structures.

**Why the Correct Answer is Right**
Gamma cameras are used to visualize the distribution and function of radioactive tracers within the body. These tracers are often used to evaluate the structure and function of organs and tissues, such as the heart, lungs, and brain. The gamma camera detects the gamma rays emitted by these tracers, allowing for the creation of detailed images of the body's internal structures. This technology is commonly used in nuclear medicine to diagnose and monitor various diseases, including cancer, cardiovascular disease, and neurological disorders.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as Gamma cameras are not typically used for X-ray imaging, which is a different modality that uses X-rays to create images of the body.
**Option B:** This option is incorrect as Positron Emission Tomography (PET) scanners are a different type of nuclear medicine imaging device that use positron emission to create detailed images of the body's internal structures.
**Option C:** This option is incorrect as Computed Tomography (CT) scanners are a different type of imaging device that use X-rays to create detailed cross-sectional images of the body.

**Clinical Pearl / High-Yield Fact**
Gamma cameras are particularly useful for imaging organs and tissues that have a high metabolic rate, such as the thyroid gland and the bone marrow. This is because these organs and tissues tend to take up radioactive tracers more readily, allowing for better image quality and more accurate diagnosis.

**Correct Answer:** C