According to the practice parameter for amyloid brain PET that was developed collaboratively by the ACR and the American Society for Neuroradiology (ASNR) [26], indications for amyloid PET mirror those of the amyloid imaging taskforce as above. FDG-PET/CT Brain PET imaging in dementia can be divided into metabolic PET, which uses FDG as a marker for metabolism, and amyloid PET, which uses agents that bind to amyloid deposits within the brain. FDG-PET imaging has been shown to provide greater diagnostic accuracy when compared with clinical evaluations without functional neuroimaging [27]. Hypometabolism on FDG-PET is thought to be related to decreased synaptic activity and is a biomarker of neurodegeneration or neuronal injury [12]. FDG-PET shows characteristic reductions of regional glucose metabolic rates in patients with probable and definite AD in the parietal, temporal, and posterior cingulate regions [28]. FDG- PET accurately discriminates AD patients from normal subjects with a sensitivity of 96% and specificity of 100% [28]. CMS has made FDG-PET available to Medicare recipients to assist with the diagnosis of dementia in the appropriate clinical setting (eg, to distinguish AD from FTD) in recognition of this usefulness [27]. A practice parameter for FDG-PET/CT for patients with cognitive decline has been developed collaboratively by the ACR-ASNR [26]. The qualifications and responsibilities of the personnel conducting the study and the standardized patient preparation, positioning, and protocol are also outlined in this document. An important detail to be emphasized is that the study should be performed at the request of physicians knowledgeable in clinical diagnosis and management of dementia and under circumstances in which the results of the examination are likely to impact patient care [26].
Dementia. According to the practice parameter for amyloid brain PET that was developed collaboratively by the ACR and the American Society for Neuroradiology (ASNR) [26], indications for amyloid PET mirror those of the amyloid imaging taskforce as above. FDG-PET/CT Brain PET imaging in dementia can be divided into metabolic PET, which uses FDG as a marker for metabolism, and amyloid PET, which uses agents that bind to amyloid deposits within the brain. FDG-PET imaging has been shown to provide greater diagnostic accuracy when compared with clinical evaluations without functional neuroimaging [27]. Hypometabolism on FDG-PET is thought to be related to decreased synaptic activity and is a biomarker of neurodegeneration or neuronal injury [12]. FDG-PET shows characteristic reductions of regional glucose metabolic rates in patients with probable and definite AD in the parietal, temporal, and posterior cingulate regions [28]. FDG- PET accurately discriminates AD patients from normal subjects with a sensitivity of 96% and specificity of 100% [28]. CMS has made FDG-PET available to Medicare recipients to assist with the diagnosis of dementia in the appropriate clinical setting (eg, to distinguish AD from FTD) in recognition of this usefulness [27]. A practice parameter for FDG-PET/CT for patients with cognitive decline has been developed collaboratively by the ACR-ASNR [26]. The qualifications and responsibilities of the personnel conducting the study and the standardized patient preparation, positioning, and protocol are also outlined in this document. An important detail to be emphasized is that the study should be performed at the request of physicians knowledgeable in clinical diagnosis and management of dementia and under circumstances in which the results of the examination are likely to impact patient care [26].