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Low-artifact intravascular devices: MR imaging evaluation 总被引:2,自引:0,他引:2
Teitelbaum GP; Ortega HV; Vinitski S; Stern H; Tsuruda JS; Mitchell DG; Rifkin MD; Bradley WG Jr 《Radiology》1988,168(3):713-719
Flow-phantom magnetic resonance (MR) imaging, with use of both spin-echo (SE) and gradient-echo (GRE) techniques at 1.5 T, was performed on the percutaneous Greenfield (beta-III titanium alloy [TMA wire]), Amplatz (MP32-N alloy), and Simon nitinol filters and TMA wire facsimiles of the bird's nest, Gunther, new retrievable, and Amplatz vena caval filters. SE imaging allowed detection of thrombi as small as 5 X 5 mm trapped within the percutaneous Greenfield, Simon nitinol, and TMA-wire facsimile filters; with the MP32-N Amplatz filter, a larger volume of thrombus (10 X 20-mm clots) was necessary for clot detection. GRE imaging allowed detection of intraluminal tilting of the percutaneous Greenfield and facsimile Amplatz (TMA-wire) filters. GRE imaging was useful for demonstrating postfilter turbulence due to clots, which was greatest for the Amplatz filter. Imaging of facsimile vascular devices made of tantalum or TMA wire did not cause the severe "black-hole" MR artifacts typical of the stainless-steel devices. SE and GRE imaging were very useful for determining caval patency in two patients with previously placed Mobin-Uddin filters. Noninvasive MR evaluation of blood vessels in the presence of a variety of low-artifact intravascular devices appears feasible. 相似文献
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Variability of skin temperature in the waking monkey 总被引:3,自引:0,他引:3
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There are many arenas within which health promotion may be located.This paper addresses the issues involved in the developmentof health promotion in one such arena: the community healthmovement. This movement is complex and dynamic. When referenceis made to non-statutory health action, or to community involvementin health, this complexity may not be fully appreciated. Thereis a tendency for the range of activity to be reduced to itsmost "visible" form: self-help activity. However, there is moreto the community health movement than this. A typology is offered here in which three levels of community-basedactivity in Britain are identified. These are referred to asself-help groups, community health groups and community developmenthealth projects. The breadth and range of this activity reflectsthe inability of formalized health care to tackle many of theunderlying causes of ill-health. Each type of community healthactivity exists as a declaration of this failure, but some formsof activity may be welcomed by the health professions whilstothers may not. In particular the numerically small communitydevelopment health projects offer a significant challenge toformal health care because they seek to encourage collectivehealth activity by those who are least in control of their ownhealth. It is within the context of developing strategies for healthpromotion that community health action is most relevant. Nationaland local strategy documents suggest that community involvementis essential for the successful promotion of health. Fully comprehensiveparticipation by community groups signifies a major shift inour perceptions of health and health care. An appreciation ofthe existing range of health action in communities is an importantstarting point for medical health professionals engaged in thistask. 相似文献
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Rao VM; Dalinka MK; Mitchell DG; Spritzer CE; Kaplan F; August CS; Axel L; Kressel HY 《Radiology》1986,161(1):217-220
Four patients with proved osteopetrosis (three with the infantile malignant form and one with the benign form) were examined with magnetic resonance imaging at 1.5 T. All patients were studied in the coronal and sagittal planes using both short and long repetition time/echo time sequences. The infantile malignant form was characterized by a complete lack of signal from the marrow alternating with a signal intensity equivalent to that of the intervertebral disks, resulting in a "stepladder" appearance. In the benign form or after successful marrow transplantation in the infantile malignant form, intermediate or high signal intensity in the vertebrae was noted, suggesting the presence of some marrow elements. 相似文献
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