BACKGROUND New algorithms were evaluated for their efficacy in detecting and quantifying serial changes in myocardial perfusion from single photon emission computed tomography (SPECT). METHODS AND RESULTS We generated 72 simulations with various left ventricular positions, sizes, count rates, and perfusion defect severities using the nonuniform rational B-splines (NURBs)-based CArdiac Torso (...

Coronary artery imaging with multi-slice helical computed tomography is a promising noninvasive imaging technique. The current major issues include the insufficient temporal resolution and large patient dose. We propose an image reconstruction method which provides a solution to both of the problems. The method uses an iterative approach repeating the following four steps until the difference b...

Simultaneous Tl-201/Tc-99m dual isotope myocardial perfusion SPECT is seriously hampered by down-scatter from Tc-99m into the Tl-201 energy window. This paper presents and optimises the ordered-subsets-expectation-maximisation-(OS-EM-) based reconstruction algorithm, which corrects the down-scatter using an efficient Monte Carlo (MC) simulator. The algorithm starts by first reconstructing the T...

In addition to lower emissions warm mix asphalt has several advantages over hot mix asphalt such as fuel energy savings, decreased binder aging and an extended paving season (Photo courtesy: Matthew Corrigan, FHWA) The National Center for Asphalt Technology (NCAT) is evaluating warm mix asphalt (WMA) technologies. WMA technology allows the mixing, lay down, and compaction of asphalt mixes at si...

introduction: it is a common protocol to use 201tl for the rest and 99mtc for the stress cardiac spect imaging. theoretically, both types of imaging may be performed simultaneously using different energy windows for each radionuclide. however, a potential limitation is the cross-contamination of scattered photons from 99mtc and collimator x-rays into the 201tl energy window. we used a middle en...

introduction: in diagnostic and therapeutic procedures, dosimetric studies are performed on the dosimetric systems in order to comply the radiation safety standards. monte carlo methods are used due to the high complexity and cost of patient-specific phantom construction. the high complexity of the digitized phantoms greatly increases the time and computational task of the monte carlo calculati...

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ATTRA is the national sustainable agriculture information service operated by the National Center for Appropriate Technology, through a grant from the Rural Business-Cooperative Service, U.S. Department of Agriculture. These organizations do not recommend or endorse products, companies, or individuals. NCAT has offices in Fayetteville, Arkansas, Butte, Montana, and Davis, California. ���� ATTRA

ATTRA is the national sustainable agriculture information service operated by the National Center for Appropriate Technology, through a grant from the Rural Business-Cooperative Service, U.S. Department of Agriculture. These organizations do not recommend or endorse products, companies, or individuals. NCAT has offices in Fayetteville, Arkansas, Butte, Montana, and Davis, California. ���� ATTRA