title: Comparative diagnostic utility of different MR modalities in mild cognitive impairment and Alzheimer's disease.
abstract: This study compares the diagnostic accuracy of magnetic resonance (MR)-based hippocampal volumetry, single voxel (1)H MR spectroscopy ((1)H MRS) and MR diffusion-weighted imaging (DWI) measurements in discriminating patients with amnestic mild cognitive impairment (MCI), Alzheimer's disease (AD) and normally aging elderly. Sixty-one normally aging elderly, 24 MCI and 22 AD patients underwent MR-based hippocampal volumetry, (1)H MRS and DWI. (1)H MRS voxels were placed over both of the posterior cingulate gyri, and N-acetyl aspartate (NAA)/creatine (Cr), myoinositol (MI)/Cr and NAA/MI ratios were obtained. Apparent diffusion coefficient (ADC) maps were derived from DWI, and hippocampal borders were traced to measure hippocampal ADC. At 80% specificity, the most sensitive single measurement to discriminate MCI (79%) and AD (86%) from controls was hippocampal volumes. The most sensitive single measurement to discriminate AD from MCI was posterior cingulate gyrus NAA/Cr (67%). At high specificity (>85-90%), combinations of MR measures had superior diagnostic sensitivity compared with any single MR measurement for the AD vs. control and control vs. MCI comparisons. The MR measures that best discriminate more from less affected individuals along the cognitive continuum from normal to AD vary with disease severity. Selection of imaging measures used for clinical assessment or monitoring efficiency of therapeutic intervention should be tailored to the clinical stage of the disease.
authors.affiliation: Department of Diagnostic Radiology, Mayo Clinic, Rochester, Minn., USA.
authors.forename: Kejal
authors.initials: K
authors.lastname: Kantarci
authors.forename: YueCheng
authors.initials: Y
authors.lastname: Xu
authors.forename: Maria M
authors.initials: MM
authors.lastname: Shiung
authors.forename: Peter C
authors.initials: PC
authors.lastname: O'Brien
authors.forename: Ruth H
authors.initials: RH
authors.lastname: Cha
authors.forename: Glenn E
authors.initials: GE
authors.lastname: Smith
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Ivnik
authors.forename: Bradley F
authors.initials: BF
authors.lastname: Boeve
authors.forename: Steven D
authors.initials: SD
authors.lastname: Edland
authors.forename: Emre
authors.initials: E
authors.lastname: Kokmen
authors.forename: Eric G
authors.initials: EG
authors.lastname: Tangalos
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Petersen
authors.forename: Clifford R
authors.initials: CR
authors.lastname: Jack
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000473:pathology; D003072:Cognition Disorders / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D011237:Predictive Value of Tests; D011569:Psychiatric Status Rating Scales; D012720:Severity of Illness Index