[Analysis of the drawbacks of single photon emission computed tomography and positron emission tomography imaging]

Brain imaging is a nuclear medicine imaging technique that is unlike the other diagnostic imaging techniques; it provides images of brain circulation, metabolism, and neuroreceptors in vivo. Evidences of its efficacy in obtaining clinical findings of various functional diseases has been obtained through many researches and analyses of clinical cases. However, this technique is a functional imaging technique; therefore, it has some distinct drawbacks due to the lack of morphometric information. For example, images of functional brain activities, even in the absence of an organic lesion, show various distributions under different physiological conditions, and these change with growth or aging. In recent years, statistical analyses of medical images have been conducted, such as statistical image analysis with standard brain coordinates (voxel-wise) and measurement of CBF by compartment model analysis; however, there are characteristic artifacts that should be considered during these analyses. Here, I report the points to be considered during the interpretation of clinical images. SPECT images were mainly used to understand this nuclear medicine brain imaging technique and describe its drawbacks.