Stephen N. Wiener

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The magnetic resonance characteristics of 16 intracranial arachnoid cysts were evaluated and several features identified that allowed the differentiation from other cystic lesions. Uncomplicated arachnoid cyst contents respond like CSF to both T1 and T2 weighted sequences. Signal from the contiguous brain is of normal intensity. The absence of signal from(More)
The following report summarizes the authors' initial experience with detecting and aging vertebral fractures in elderly patients with osteoporosis, emphasizing the use of an inversion recovery sequence with a short time to inversion (STIR) and comparing these results to that achieved using RBI.
This paper is an introduction to lesion detection problems of MR. A mathematical model previously developed for normal anatomy has been extended to predict the appearance of any hypothetical lesion in magnetic resonance (MR) images of the head. The model is applied to selected clinical images to demonstrate the loss of lesion visibility attributable to(More)
Magnetic resonance imaging may be the procedure of choice for evaluating patients with diplopia; the absence of signals from cortical bone enables the brain stem and individual cranial nerves to be visualized and the imaging planes selected easily, and there is excellent contrast resolution of pathologic lesions. A clinical assessment of diplopia including(More)
The effect of simple image processing on the interpretation of 201Tl-Cl myocardial perfusion images were evaluated by ROC analysis. Polaroid images of the cathode ray tube of an Anger camera and computer-processed transparent images recorded in color and shades of gray were examined by multiple observers. A total of 198 observer responses was accumulated(More)
The gray scale of nuclear magnetic resonance (NMR) head images is explained in terms of tissue and machine parameters. Tissue parameters considered here include the spin-lattice relaxation time, the spin-spin relaxation time, and the proton density. Machine parameters include the pulse sequence (saturation recovery, inversion recovery, or spin echo), the(More)
A semi-empirical model was used to identify specific pulse sequences that cause most lesions to appear distinctly brighter than normal tissues in magnetic resonance (MR) images of the head. Clinical trials confirm the utility of these sequences for patient screening. As a result, a strategy for effective and efficient MR imaging of the head is proposed. The(More)