Which neuroimaging modality evaluates Ca2+ density in tissues?

The evaluation of Ca2+ density in tissues is best conducted using computed tomography (CT). This imaging modality utilizes X-rays to create detailed cross-sectional images of the body and is particularly effective in detecting calcium deposits within tissues, particularly in bone and soft tissues. Calcium has a higher atomic number than many other elements in the body, which results in a greater contrast on CT images, making it easier to visualize areas with increased calcium density.

MRI, while highly useful for soft tissue imaging due to its ability to differentiate between different tissue types based on their magnetic properties, does not provide the same level of detail for calcium deposits since it is less sensitive to density differences. Ultrasound primarily evaluates soft tissues and fluids but is not designed for the detection of mineral density such as that of calcium. Positron emission tomography (PET) is used mainly for metabolic imaging and while it can sometimes be indirectly related to calcium activity through metabolic processes, it does not directly measure calcium density in tissues.

Thus, CT is the modality that specifically provides accurate evaluation of Ca2+ density due to its imaging principles and capabilities.