ABSTRACT: The apparent diffusion coefficient (ADC) from diffusion-weighted imaging (DWI) can quantify alterations in water diffusivity resulting from microscopic structural changes from amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD).
To investigate the ADC value for aMCI and AD using Brain Search (BS) software based on anatomical volumes of interest (AVOI).
In total, 174 aged people were screened, and 25 patients with AD, 26 patients with aMCI, and 18 normal controls (NCs) were recruited. DWI was performed at 1.5 T with a fluid-attenuated inversion recovery (FLAIR), and the independent ADC mapping was generated after imaging acquisition. Ninety regional parcellations were adopted in a Brain Search (BS) based on the automated anatomic labeling atlas. The gray scale intensities (water diffusivity) from the collected ADC mappings were analyzed with BS. The mean value of each anatomical brain region was compared among aMCI, AD, and NC. The statistically significant (P < 0.05) group differences are displayed in color.
During the pathological process of AD, the changes of water diffusivity appeared first in the left hippocampus, then gradually progressed to the bilateral sides and eventually displayed right lateralization. The ADC values from aMCI were obviously elevated compared to the values from the NC group in the left limbic cortex. Between the AD and NC groups, the significantly different brain areas included the bilateral hippocampus, the Cingulum_Mid, the ParaHippocampal_R, and the Temporal and Frontal lobes. There was a negative correlation between the ADC values and the scores from MMSE, MoCA, the Digit test, Raven's IQ, and WAIS IQ. Additionally, the ADC values were positively correlated with the scores from CDR, ADL, and ADAS-Cog.
The water diffusivity for aMCI and AD displays asymmetric anatomical lateralization. The water diffusivity alterations can be analyzed and visualized with our newly designed analytic imaging software, BS, which can be used as a good reference for examining and diagnosing aMCI and AD patients.
Acta Radiologica 12/2011; 52(10):1147-54. · 1.37 Impact Factor
ABSTRACT: To study the change of cerebral metabolism rate of glucose (CMRglc) of cerebral white matter in Alzheimer's Disease.
Positron emission tomography (PET) was performed on 13 AD patients, 6 with behavioral and psychological symptoms of dementia (BPSD) and 7 without BPSD, and 10 healthy controls. The regional cerebral metabolism of glucose (rCMRglc) of some brain regions and nuclei were detected.
(1) The rCMRglc of the cerebral white matter decreased extensively in the AD patients, especially in the right frontal lobe, superior gyrus of the left frontal lobe (P = 0.001). (2) The rCMRglc of subcortical white matter of the left medial prefrontal lobe and the left cuneus of occipital lobe increased in the AD patients. (3) The levels of rCMRglc of the subcortical white matter of both side middle occipital lobe, left cuneus of occipital lobe, right inferior parietal lobule, left fusiform gyrus of temporal lobe and the left medial prefrontal lobe were all significantly higher in the AD patients with BPSD than in those without BPSD (P = 0.001). While the levels of rCMRglc of the subcortical white matter of both side paracentral lobule, right superior and middle frontal lobe, and left superior temporal lobe were all significantly lower in the AD patients with BPSD than in those without BPSD (all P = 0.001).
There is diffuse abnormal rCMRglc in the cerebral white matter in the AD patients: the rCMRglc decreases in the frontal-temporal-occipital association area, and the rCMRglc of the medial prefrontal lobe and cuneus of occipital lobe increases. BPSD is correlated with the abnormal metabolism of related cerebral regions.
Zhonghua yi xue za zhi 11/2007; 87(39):2777-9.
ABSTRACT: To measure the changes of regional cerebral metabolism rate of glucose (rCMRglc) in patients with Alzheimer's disease (AD) and explore their value to diagnosis of AD.
10 patients with AD who met the diagnostic criteria of DSM-IV and 10 normal controls (NC) were assessed with (18)F-2-fluoro-deoxy-D-glucose positron emission tomography (PET).
The two groups were matched in age, gender and education. The mean total scores of the mini-mental status examination (MMSE) were 16.5 +/- 6.1 for AD and 28.7 +/- 1.6 for NC. The mean total memory quotient of Wechsler Memory Scales (MQ) were 32.3 +/- 19.6 for AD and 93.1 +/- 9.0 for NC. Comparing to NC, the AD groups showed statistically significant decline of rCMRglc in frontal lobe, temporal lobe and the hippocampal formation with decreased rates ranged from 3.3% to 28.4% (P < 0.05, P < 0.01). The hypo-metabolism was more salient in the regions of upper and middle frontal gyri, middle temporal gyrus, orbital gyrus and anterior cingulate gyrus, in which areas the metabolism decreased over 20% compared to NC. The hypo-metabolism was correlated to the severity of dementia. Discriminant analysis demonstrated that the variables of right inferior temporal gyrus, left upper temporal gyrus, left hippocampus and right insular lobe were entered into the discriminant functions and the total discriminant accuracy reached 100%.
(18)F-FDG PET is a very sensitive tool in measurement of the changes of rCMRglc in patients with AD. The findings show a frontal-temporal type of metabolism in AD patients and suggest that hypo-metabolism in hippocampal formation and temporal lobe is helpful in early detection of AD.
Zhonghua yi xue za zhi 11/2005; 85(42):2975-9.