^99mTc-d,l-HMPAO and SPECT of the Brain in Normal Aging

Abstract

Summary: Single photon emission computed tomography (SPECT) with 99mTc-d,l-hexamethylpropyleneamine ox ime (99mTc-d,I-HMPAO) was used to determine global and regional CBF in 53 healthy subjects aged 21-83 years. For the whole group, global CBF normalized to the cer ebellum was 86.4% ± 8.4 (SD). The contribution of age, sex, and atrophy to variations in global CBF was studied using stepwise mUltiple regression analysis. There was a significant negative correlation of global CBF with sub jective ratings of cortical atrophy, but not with ratings of ventricular size, Evans ratio, sex, or age. In a subgroup of 33 subjects, in whom volumetric measurements of atro phy were performed, cortical atrophy was the only sig nificant determinant for global CBF, accounting for 27% of its variance. Mean global CBF as measured with the Tomographic measurement of regional CBF (rCBF) in humans was made possible several years ago with the development of a brain-dedicated dy namic single photon emission computed tomogra phy (SPECT) system designed for inhalation or in jection of the diffusible tracer \33Xe (Stokely et ai., 1980). This technique offers easy, repetitive, and quantitative measurements with a spatial and tem poral resolution sufficient for studying cerebrovas cular disease.The recent development of tracers that are re tained in the brain for several hours and, if ideal, "trapped" in proportion to regional blood flow has

A study of performance on tests from the CANTAB battery sensitive to frontal lobe dysfunction in a large sample of normal volunteers: Implications for theories of executive functioning and cognitive aging

“…Overall, our findings are compatible with the results of studies using a variety of neuroimaging modalities that aging is especially associated with structural, metabolic, and neurochemical changes in regions of the prefrontal cortex (Pantano et al, 1984;Riege et al, 1985;Waldemar et al, 1991), the striatum (Murphy et al, 1992;Riege et al, 1985;Rinne et al, 1993;Sawle et al, 1990;van Dyck et al, 1995), and also the temporal lobes (Arrigada et al, 1992;Loessner et al, 1995;Pantano et al, 1984;Price et al, 1991). This position is not very different from that reached by West (1996), after a comprehensive review of the available neurobiological evidence.…”

Heterogeneity of neocortical cerebral blood flow deficits in dementia of the Alzheimer type: a [99mTc]-d,l-HMPAO SPECT study.

“…The cerebellar hemisphere with the highest count rate was used as the reference region, and its count rate was determined by a lower 60% fractile threshold. 22 The procedure for regional analysis of [99mTc]-d,l-HMPAO data was described in detail in a previous publication.22 Briefly, regions of interest were drawn on each slice with reference to predefined standardised templates with bilateral and symmetrical regions of interest. The design of these templates was performed with reference to an anatomical atlas of the brain27 and based on anatomical structures that are easily recognisable on a typical SPECT image.22 Figure 1 shows the presentation of canthomeatal planes and regions of interest in relation to the lateral brain surface.…”

Differential age effects on cerebral blood flow and BOLD response to encoding: Associations with cognition and stroke risk

“…Some studies have yielded no significant association between advancing age and global (Waldemar et al, 1991) or regional CBF (Yamaguchi et al, 1986). In contrast, other have shown the coupling of age-related atrophy with decreases in perfusion (Kaszniak et al, 1979;Kety et al, 1956;Meyer et al, 1994), suggesting that atrophy results in reduced cerebral metabolism.…”