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US 5,509,412 AGranted
Magnetic resonance imaging of blood volume
AssigneeWisconsin Alumni Research Foundation
InventorMark M. Bahn
Life of this patent
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Abstract
An MRI system acquires a series of images over a course of time using an echo planar imaging pulse sequence. A susceptibility contrast agent is injected into the subject during the scan to momentarily reduce NMR signal strength from voxels with blood flow. A nonlinear regression parameter estimation process is employed to calculate blood volume at each voxel directly from the acquired NMR data.
Claims5
A method for producing an NMR image which indicates blood volume within a slice in a stationary patient, the steps comprising:
- a) acquiring NMR data from the slice for a set of T.sub.2 weighted images depicting the patient over a course of time;
- b) injecting a susceptibility contrast agent into the patient during the course of time such that the patient's blood transports the susceptibility agent through the slice as the NMR data is being acquired;
- c) reconstructing the set of T.sub.2 weighted images using the acquired NMR data, each T.sub.2 weighted image including an array of NMR signal intensity values S.sub.xy ;
- d) calculating a blood volume value BV at a voxel location within the slice by forming a time course NMR signal S.sub.xy (t) using the corresponding NMR signal intensity values S.sub.xy from successive T.sub.2 weighted images and fitting a model curve defined by a set of parameters which include the blood volume BV to the time course NMR signal S.sub.xy (t) using a nonlinear regression parameter estimation process;
- e) repeating step d) for each voxel location in the NMR image;
- and
- f) producing the NMR image using the blood volume values BV calculated in step d).
4 more elements
Dependencies are inferred from the claim text.