For the past three years, in response to an RFA, we have been studying the use of magnetic resonance imaging to diagnose deep venous thrombosis completely noninvasively and without toxicity or ionizing radiation. Deep venous thrombosis remains a major clinical problem involving a wide class of patients. Many of these patients have gone through surgical procedures or have been immobile for periods of time. During the course of the research we came up with a superb candidate for venous imaging. Our technique is completely insensitive to flow in that it images blood based solely on its material properties. This behavior is essential for the imaging of veins, which may be totally occluded by thrombus. Although other methods, such as gradient echo imaging, are successful with relatively slow flows, they cannot deal with complete or almost complete occlusions. This method provides a reliable and robust approach toward the imaging of the entire venous system, independent of pathology. In addition, a variety of methods of separating veins and arteries have been studied and implemented. In the course of this research we have become involved with a number of significant related studies. These include clot characterization in which the magnetic resonance parameters are used to determine significant clot characteristics such as age. Also, we have studied a complementary venous imaging approach we call """"""""slab scan,"""""""" which exploits wash-in effects in a sequence of image sections. By making each slab relatively narrow the system becomes responsive to extremely slow flows, although not to a complete occlusion. The desirable properties of this approach include robust vein-artery separation and relative immunity to flow artifacts.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
2R01HL039478-04A1
Application #
3356320
Study Section
Diagnostic Radiology Study Section (RNM)
Project Start
1987-06-01
Project End
1995-03-31
Budget Start
1992-04-01
Budget End
1993-03-31
Support Year
4
Fiscal Year
1992
Total Cost
Indirect Cost
Name
Stanford University
Department
Type
Schools of Engineering
DUNS #
800771545
City
Stanford
State
CA
Country
United States
Zip Code
94305
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