title: Imaging discrepancies between magnetic resonance imaging and brain perfusion single-photon emission computed tomography in the diagnosis of Alzheimer's disease, and verification with amyloid positron emission tomography.
abstract: BACKGROUND
  In the diagnosis of Alzheimer's disease (AD), discrepancies are often observed between magnetic resonance imaging (MRI) and brain perfusion single-photon emission computed tomography (SPECT) findings. MRI, brain perfusion SPECT, and amyloid positron emission tomography (PET) findings were compared in patients with mild cognitive impairment or early AD to clarify the discrepancies between imaging modalities.
  
  
  METHODS
  Several imaging markers were investigated, including the cortical average standardized uptake value ratio on amyloid PET, the Z-score of a voxel-based specific regional analysis system for AD on MRI, periventricular hyperintensity grade, deep white matter hyperintense signal grade, number of microbleeds, and three indicators of the easy Z-score imaging system for a specific SPECT volume-of-interest analysis. Based on the results of the regional analysis and the three indicators, we classified patients into four groups and then compared the results of amyloid PET, periventricular hyperintensity grade, deep white matter hyperintense signal grade, and the numbers of microbleeds among the groups.
  
  
  RESULTS
  The amyloid deposition was the highest in the group that presented typical AD findings on both the regional analysis and the three indicators. The two groups that showed an imaging discrepancy between the regional analysis and the three indicators demonstrated intermediate amyloid deposition findings compared with the typical and atypical groups. The patients who showed hippocampal atrophy on the regional analysis and atypical AD findings using the three indicators were approximately 60% amyloid-negative. The mean periventricular hyperintensity grade was highest in the typical group.
  
  
  CONCLUSIONS
  Patients showing discrepancies between MRI and SPECT demonstrated intermediate amyloid deposition findings compared with patients who showed typical or atypical findings. Strong white matter signal abnormalities on MRI in patients who presented typical AD findings provided further evidence for the involvement of vascular factors in AD.
authors: Division of Neurosurgery, Nanpuh Hospital, Kagoshima, Japan.
authors: Shunichi
authors: S
authors: Yokoyama
authors: Yoriko
authors: Y
authors: Kajiya
authors: Takuma
authors: T
authors: Yoshinaga
authors: Atsushi
authors: A
authors: Tani
authors: Hirofumi
authors: H
authors: Hirano
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging; D000554:Ambulatory Care Facilities; D000682:Amyloid / Q000378:metabolism*; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging; D060825:Cognitive Dysfunction / Q000175:diagnosis*; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D059906:Neuroimaging; D012039:Regional Blood Flow; D013844:Thiazoles; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D000682:Amyloid; D013844:Thiazoles
keywords: Alzheimer's disease; amyloid; dementia; magnetic resonance imaging; positron-emission tomography.