Regional cerebral blood flow deficits in mild Alzheimer's disease using high resolution single photon emission computerized tomography

Abstract

In spite of its wide availability, single photon emission computerized tomography (SPECT) scanning is uncommonly used in the assessment of Alzheimer's disease (AD) and related dementias. In light of recent advances in scanning protocols and image analysis, SPECT needs to be re-examined as a tool in the diagnosis of dementia. A total of 18 subjects with early AD and 10 healthy elderly control subjects were examined with high resolution SPECT during the performance of a simple word discrimination task. SPECT images were coregistered with individual magnetic resonance imaging scans, allowing delineation of predetermined neuroanatomical Regions of Interest (ROI).There was a gradation of regional cerebral blood flow (rCBF) values in both groups, with the lowest values being in the hippocampus and the highest in the striatum, thalamus and cerebellum. Compared to healthy controls, AD subjects demonstrated lower relative rCBF in parietal and prefrontal cortices. Analysis of individual ROI demonstrated bilateral reduction of rCBF in prefrontal poles, posterior temporal and anterior parietal cortex, and unilateral reduction of rCBF in left dorsolateral prefrontal cortex, right posterior parietal cortex and the left cingulate body. There were no significant differences for hippocampal, occipital or basal ganglia rCBF. Discriminant function analysis indicated that rCBF in the prefrontal polar regions achieved the best classification of cases. SPECT has utility in the diagnostic assessment of AD if standardized and semiquantitative techniques are used.

Kinetic Modeling of the Tau PET Tracer 18F-AV-1451 in Human Healthy Volunteers and Alzheimer Disease Subjects

“…1T gave poor fits for all subjects and regions, including the cerebellar cortex (data not shown) and is Detailed results of the 2T analysis are given in Table 2 and Figure 5. K 1 was regionally different, highest in the putamen, but appeared similar in YHVs and AHVs in all regions (within ;3%) and across the 3 groups in the cerebellar cortex and putamen, whereas it was lower by approximately 10%-15% in the cortical regions of AD subjects, similar to previous findings (23). K 1 /k 2 was clearly lower by about 30% in YHVs including in the cerebellar cortex (2.7 mL/cm 3 ) compared with AHVs (3.9 mL/cm 3 ) and AD subjects (3.7 mL/cm 3 ).…”

Multivariate and univariate neuroimaging biomarkers of Alzheimer's disease

“…One theme of this research has been to identify diagnostic biomarkers through neuroimaging that enable early detection of the disease, even before the full clinical symptoms of AD have become manifest. Neuroimaging has identified a wide array of biomarkers that can differentiate AD patients from healthy control subjects such as volume loss measured with morphometry (e.g., (Bozzali et al, 2006;Chetelat et al, 2005;Teipel et al, 2005;Thomann et al, 2006) cerebral blood flow (e.g., (Kasama et al, 2005;Nakano et al, 2006;Trollor et al, 2005)), glucose metabolism ( (Burdette et al, 1996;Chetelat et al, 2003b;Foster et al, 2007;Herholz et al, 2002;Higdon et al, 2004)) and betaamyloid deposition (e.g., (Engler et al, 2006;Nichols et al, 2006)). Often these analyses target specific locations (entorhinal cortex, hippocampus, prefrontal cortex, amygdala etc.…”

Total Cerebral Blood Flow and Hippocampal Volume in Patients with Arterial Disease. the SMART-MR Study

“…Therefore, we cannot exclude the possibility that regional differences in the flow are related to volume loss in the hippocampus. For several studies, in which positron emission tomography or single photon emission computed tomography was used to determine regional blood flow, lower regional blood flow in the hippocampus was found in patients with Alzheimer's, a disease in which hippocampal atrophy is a key feature, compared with controls (Donnemiller et al, 1997;Bonte et al, 2001;Trollor et al, 2005). Moreover, we did not measure PaCO 2 during investigation in this study.…”