TABLE 3

¹⁸F-FDG PET in the Evaluation of Nondemented Subjects (Cognitively Unimpaired or Mildly Impaired)

Gold standard	Subjects	Major findings	Comments	Reference
C	11 NI	Anterior parahippocampal gyrus best distinguished MCI patients from healthy controls. Middle/inferior temporal gyri best distinguished MCI patients from AD patients.	The ability of ¹⁸F-FDG PET and MRI volume measures to differentiate between patients with clinical diagnoses of MCI, AD, and no cognitive impairment was tested.	(77)
	15 MCI
	12 AD
C	24 NI	Group analysis showed that presence of posterior cingulate hypometabolism increased risk of dementia by more than 2-fold for each 1 SD decline in metabolism.	This study evaluated a population-based cohort of Mexican Americans with varying degrees of cognitive impairment.	(78)
	50 AAMI
	10 CIND
	9 D
L	48 NI	Metabolism of entorhinal cortex in progressive group was decreased by 18%, compared with nonprogressive group. Sens. for progressive = 83%; Spec. for nonprogressive = 85%.	Patients had MMSE scores > 28 and scored a 1 or 2 on Global Dementia Scale.	(79)
L	17 MCI	Progressive vs. nonprogressive classification accuracy for right temporoparietal cortex was 100%. Classification accuracy for posterior cingulate cortex was 94%.	Patients had memory complaints but lacked any neurologic, medical, or psychiatric disorders. Memory performances were >1.5 SD below age-matched normal mean in Rey Figure delayed recall or 1 subscore of Grober–Buschke test.	(80)
L	22 MCI	Group analysis revealed significantly lower metabolism of bilateral posterior cingulate cortex and right precuneus in progressive group than in nonprogressive group.	Patients had subjective complaints of memory impairment, a performance of at least 1.5 SDs below the age normal on the CERAD delayed verbal recall, a CDR of 0.5, and preserved basic activities of daily living.	(81)
L	20 MCI	The most effective predictor for progressive cognitive decline was the combination of cerebral metabolic rate assessment and psychometric measures. rCMRGlu accuracy = 75%; neuropsychiatric accuracy = 75%; rCMRGlu + neuropsychiatric accuracy = 95%.	Patients were initially investigated for suspected dementia. All demonstrated symptoms for stage 3 of GDS but lacked symptoms to fulfill DSM-IV criteria.	(82)
L	58 Progressive	¹⁸F-FDG PET data provided more accurate prognosis of cognitive decline. Clinical diagnosis: Sens. for progressive disease = 77%; Spec. for nonprogressive disease = 76%. ¹⁸F-FDG PET: Sens. for progressive diease = 95%; Spec. for nonprogressive disease = 79%.	The mean ± SD for MMSE scores was 24.0 ± 6.4.	(54)
	44 Nonprogressive		The mean ± SD for MMSE scores was 24.0 ± 6.4.

C = clinical evaluation; L = longitudinal follow-up; NI = cognitively normal; MCI = mild cognitive impairment; AAMI = age-associated memory impairment; CIND = cognitively impaired nondemented; D = dementia; rCMRGlu = regional cerebral metabolic rate of glucose; Sens = sensitivity with respect to correctly identifying presence of Alzheimer’s or other progressive disease; Spec = specificity with respect to correctly specifying that progressive disease is absent; CERAD = Consortium to Establish a Registry for Alzheimer’s Disease; CDR = Clinical Dementia Rating; GDS = Global Dementia Scale; DSM-IV = Diagnostic and Statistical Manual of Mental Disorders, 4th Edition.