PubMed · 10146203
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I Isherwood. 1991. Neuroimaging.. https://pubmed.ncbi.nlm.nih.gov/10146203/
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The diagnosis of deep vein thrombosis (DVT) and pulmonary embolism (PE) has been improved and simplified over the past decade thanks to advances in noninvasive and readily accessible technology. With high degrees of sensitivity and specificity, venous ultrasonography is favored as the initial investigation for DVT. To diagnose PE, most clinicians rely on diagnostic algorithms that combine clinical assessment, noninvasive lung studies, and, if necessary, venous ultrasonography of the legs and D-dimer testing. Substantial progress has also occurred in the treatment of acute venous thromboembolism with the introduction of low-molecular-weight heparins. This class of antithrombotic agents has changed initial therapy from an inpatient, intravenous regimen that required laborious monitoring to an outpatient practice using weight-adjusted doses of once-daily subcutaneous injections. In addition, several new anticoagulants with theoretical advantages over existing agents have entered phase III studies. Aspects of thrombosis treatment that remain controversial include vena caval interruption and the indications for thrombolysis and surgical thromboembolectomy.
The American College of Radiology (ACR) convened a "think tank" of experts on aspects of molecular imaging. The purposes of the colloquium were to develop scenarios about how molecular imaging would develop in the future and to make recommendations to the ACR about how to prepare radiologists for this important set of technologies. The ACR provided participants with background materials, as well as a set of possible questions to keep in mind while reading the materials, prior to the meeting. Subjects covered included the science and technology, regulation and diffusion, training and certification, turf and competition, and a survey of current activities in the realm of molecular imaging in which radiologists are involved. This article presents the observations devolving from the colloquium and recommendations to the ACR.
Time-domain analytical solutions of the diffusion equation for photon migration through highly scattering two- and three-layered slabs have been obtained. The effect of the refractive-index mismatch with the external medium is taken into account, and approximate boundary conditions at the interface between the diffusive layers have been considered. A Monte Carlo code for photon migration through a layered slab has also been developed. Comparisons with the results of Monte Carlo simulations showed that the analytical solutions correctly describe the mean path length followed by photons inside each diffusive layer and the shape of the temporal profile of received photons, while discrepancies are observed for the continuous-wave reflectance or transmittance.