Analysis of brain and cerebrospinal fluid volumes with MR imaging: impact on PET data correction for atrophy. Part II. Aging and Alzheimer dementia.

Abstract

A new, computerized segmentation technique, in which magnetic resonance (MR) imaging produces accurate volumetric measurements of brain and cerebrospinal fluid (CSF) without the limitations of computed tomography, was used in a retrospective analysis of digitized T2-weighted MR images of 16 healthy elderly control subjects and 16 patients with Alzheimer dementia. Ventricular and extraventricular CSF was quantified, and the effects of aging were studied; in both groups, the atrophy measurement was used to correct metabolic values obtained with positron emission tomography. Patients with Alzheimer dementia had higher total CSF; extraventricular, total ventricular, and third ventricular CSF volumes (49%, 37%, 99%, and 74%, respectively); and 7% lower brain volumes than the control group. The patients also showed a more marked decline in brain volumes and a greater increase in CSF volumes with advancing age than the control group. They had a 25.0% increase in corrected whole-brain metabolic rates; the control group had only a 15.8% increase. The use of this technique may provide a basis for further studies of aging and dementia, including regional volume analysis.

An MRI study of age-related white and gray matter volume changes in the rhesus monkey

“…The overall decrease from young to old age in the standardized volumes of total forebrain (5.01%), forebrain parenchyma (5.24%), forebrain white matter (11.53%) forebrain gray matter (2.08%), caudate nucleus (11.79%) and globus pallidus (18.26%) that we found have been similarly reported by many human aging studies [ Forebrain white matter and forebrain gray matter volume changes in the monkey closely matches the results of Guttmann and colleagues [14] and Ge and colleagues [9] in humans. We were surprised, however, to find that ventricular CSF volume did not increase significantly with age since the phenomenon has been established as a marker for normal aging in humans [43,56]. CSF volume increase has also been characterized in the rhesus monkey by Andersen and colleagues, [1], but their measure included both cortical surface CSF and ventricular CSF.…”

PET Network Abnormalities and Cognitive Decline in Patients with Mild Cognitive Impairment

“…In several cases, MRI was not conducted in temporal proximity to the PET scan, and hence partial volume correction for atrophy could not be done. The latter has a small but sometimes material effect in the interpretation of PET data in distinguishing AD patients from controls (Tanna et al, 1991;Meltzer et al, 1996). Our sample size was small, thereby reducing statistical power.…”

Quantitative Techniques in PET-CT Imaging

“…Though extensively addressed in brain PET studies [43][44][45][46][47][48][49], this is a major source of concern in optimal assessment of malignant lesions [50]. Typically, the best resolution (as measured by laboratory experiments) achieved by the modern generation of clinical whole-body PET scanners is at best 4 mm [51].…”