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Nuclear magnetic resonance (NMR) imaging was employed to study 10 patients with Alzheimer's disease (AD) and seven healthy elderly control subjects. Coronal sections were used to make volumetric measurements of the hippocampus, ventricles, subarachnoid space, and brain parenchyma. The hippocampal volume (normalized relative to the size of the lenticular(More)
Hominid brain size increased dramatically in the face of apparently severe associated evolutionary costs. This suggests that increasing brain size must have provided some sort of counterbalancing adaptive benefit. Several recent studies using magnetic resonance imaging (MRI) have indicated that a substantial correlation (mean r = approximately 0.4) exists(More)
To evaluate the physiological thresholds of neuromuscular stimulation relevant to very fast NMR imaging studies that use gradient switching at frequencies of 1-2 kHz and a maximum magnetic field of up to 10 mT, a series of studies were done with human volunteers using an experimental echo planar gradient coil set. The threshold for induction of localized(More)
Simultaneous measurements were made of the electrocardiogram (ECG) and the intraarterial blood pressure of adult male Macaca monkeys during acute exposures to homogeneous stationary magnetic fields ranging in strength up to 1.5 tesla. An instantaneous, field strength-dependent increase in the ECG signal amplitude at the locus of the T wave was observed in(More)
Using an approach that combines gene therapy with aromatic l-amino acid decarboxylase (AADC) gene and a pro-drug (l-dopa), dopamine, the neurotransmitter involved in Parkinson's disease, can be synthesized and regulated. Striatal neurons infected with the AADC gene by an adeno-associated viral vector can convert peripheral l-dopa to dopamine and may(More)
A practical contemporary viewpoint of the advantages and disadvantages of time-of-flight posi tron emission tomography (TOFPET) compared with conventional positron emission tomography (non-TOF) is given in Fig. 1. The advantages of non-TOFPET using a conventional detector such as bismuth germanate (BGO) are high efficiency, high spatial resolution and high(More)
Positron emission tomography (PET) with the hypoxic-cell tracer [18F]fluoromisonidazole presents a possible means of noninvasively demonstrating tumor hypoxia. PET studies using this tracer were performed in three patients with malignant glioma, and in all patients the tumor was clearly seen at 5 min postinjection and initial tumor activity exceeded(More)
Dynamic positron emission tomography with [18F]fluorodeoxyglucose was used in six patients with Alzheimer's disease (AD) and seven healthy age-matched control subjects to estimate the kinetic parameters K1*, k2*, and k3* that describe glucose transport and phosphorylation. A high-resolution tomograph was used to acquire brain uptake data in one tomographic(More)
Computed transverse section emission tomography using 99mTc with the Anger camera is compared to positron annihilation coincident detection using a ring of crystals and 68Ga. The single-photon system has a line spread function (LSF) of 9 mm full width at half maximum (FWHM) at the collimator and gives a transverse section reconstruction LSF of 11 mm FWHM(More)