Jonathan S. Maltz

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OBJECTIVE Abnormal cutaneous vasodilatory responses to the iontophoresis of vasodilators were previously observed in Alzheimer's disease (AD). We sought to replicate these observations and further identify peripheral vascular components of AD pathology. METHODS Methacholine chloride (MCh), acetylcholine chloride (ACh), and sodium nitroprusside (SNP) were(More)
We present an algorithm of reduced computational cost which is able to estimate kinetic model parameters directly from dynamic ECT sinograms made up of temporally inconsistent projections. The algorithm exploits the extreme degree of parameter redundancy inherent in linear combinations of the exponential functions which represent the modes of first-order(More)
The authors present the design and simulation of an imaging system that employs a compact multiple source x-ray tube to produce a tomosynthesis image from a set of projections obtained at a single tube position. The electron sources within the tube are realized using cold cathode carbon nanotube technology. The primary intended application is(More)
  • J F Gomes De Freitas, I M Macleod, J S Maltz
  • 1996
The suitability of artiicial neural networks (ANNs) for detecting fault conditions in pneumatic control valve actuators is investigated. Speciically, the ability of a neural network to act as a predictor of correct valve behaviour is examined. Experimental results indicate that standard network architectures are unsuitable for temporal prediction of(More)
The RKHS-based optimal image interpolation method, presented by Chen and de Figueiredo (1993), is applied to scattered potential field measurements. The RKHS which admits only interpolants consistent with Laplace's equation is defined and its kernel, derived. The algorithm is compared to bicubic spline interpolation, and is found to yield vastly superior(More)
Quantitative reconstruction of cone beam X-ray computed tomography (CT) datasets requires accurate modeling of scatter, beam-hardening, beam profile, and detector response. Typically, commercial imaging systems use fast empirical corrections that are designed to reduce visible artifacts due to incomplete modeling of the image formation process. In contrast,(More)
Impairment of arterial endothelial function is an early event in atherosclerosis and correlates with the major risk factors for cardiovascular disease. The most widely employed non-invasive measure of endothelial function involves brachial artery (BA) diameter measurement using ultrasound imaging before and after several minutes of blood flow occlusion. The(More)
Sums of decaying real exponentials (SDREs) are frequently used in models of time-varying processes. First-order compartmental models are widely employed to describe mass transit in chemical and biological systems. In these models the evolution of compartment concentration versus time is represented as the convolution of an input function with an SDRE. In(More)
The accurate delivery of external beam radiation therapy is often facilitated through the implantation of radio-opaque fiducial markers (gold seeds). Before the delivery of each treatment fraction, seed positions can be determined via low dose volumetric imaging. By registering these seed locations with the corresponding locations in the previously acquired(More)
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