Nuclear Magnetic Resonance (NMR) II. Imaging in Dementia

Abstract

Proton NMR imaging of the brain is rapidly becoming established as a useful investigative tool in medicine. This paper examines the usefulness of the NMR parameters--spin-lattice relaxation time (T1) and proton density (PD)--in differentiating groups of patients with senile dementia of Alzheimer type (SDAT) and multi-infarct dementia (MID) from each other, and from elderly controls. T1 values increase with severity of dementia. NMR parameters may also be of use in localising regions of brain damage.

Quantitative Magnetization Transfer Imaging in Alzheimer Disease

“…This could have two possible origins: (a) a decrease in f b , the fraction of the restricted proton pool, or (b) an increase in R A , the inverse of longitudinal relaxation time of the free proton (T1 A ), which corresponds to a decrease in T1 A . Although T1, which could then be related to R A (which equals 1/T1 A ) (26), was not directly measured, it is unlikely to decrease because it has been shown to increase with worsening dementia severity (27,28). Thus, an increase in R A is unlikely.…”

White matter magnetic resonance hyperintensities in dementia of the Alzheimer type: morphological and regional cerebral blood flow correlates.

“…Solitary foci of DWMHs were seen in 70% of our control subjects, a high frequency that corresponds with that reported by Fazekas et al" The lack of difference in DWMH scores between patients with Alzheimer's disease and normal subjects was in agreement with the findings of some previous reports,'s628 but contradicted others.' [29][30][31][32][33] It is well known that the presence of cerebrovascular risk factors increases the risk of DWMHs,26 '6 and Scheltens et The literature on histopathological examination of MRI white matter lesions in Alzheimer's disease is sparse: in a preliminary postmortem report on three patients with definite Alzheimer's disease Morris et al36 found increased water content, but no histological lesions, in regions with "periventricular high signals". Whether these high signals represented deep white matter hyperintensities or periventricular hyperintensities was not defined in their report, and the vessels were not described.…”

Cerebral structure on MRI, part II: Specific changes in Alzheimer's and Huntington's diseases

“…Although studies of AD with MR have emphasized the prevalence and appearance of high signal abnormalities in cortical and subcortical ;auc- (Johnson et al 1987;Fazekas et al 1987), the high incidence of these abnormalities i~: nonsymptomatic elderly controls (Fazekas et al 1987;Gerard and Weisberg 1986;Awad et al 1986aAwad et al , 1986bAwad et al , 1987Kertesz et al 1988) complicates the interpretation of such changes in AD. Attempts to differentiate AD patients from controls and other patients using MR signal values within tissue, such as Tt and proton density values, have met wtth mixed success (Besson et al 1983(Besson et al , 1985Christie et al 1988). In spite of the greatly improved tissue contrast available with MR, few studies have measured individual brain structures in demented patients.…”