System and method to analyze blood parameters using magnetic resonance imaging

摘要

A system and method for accurately producing MR images of selected vascular compartments includes employing a control scan and a tag scan, each including velocity selective modules that suppress signal from blood flowing faster than a given cutoff velocity, to acquire control and tag sets of NMR data that may be subtracted to produce a compartment-specific MR image that is substantially free of information from stationary tissues and blood outside the selective vascular compartments. Accordingly, physiological parameters, such as oxygen saturation (SaO2), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO2), can be generated from the compartment-specific images. Further still, kinetic curves of oxygen exchange can be created, thus providing detailed insight into oxygen exchange dynamics.

主权项

1. A method of producing an image of a subject using an MRI system, the method comprising the steps of:
a) directing the MRI system to perform a first pulse sequence that includes the following sequential steps:
a1) applying a first velocity-selective pulse to suppress NMR signal from blood flowing faster than a first cutoff velocity through a plurality of vascular compartments of the subject;a2) providing an inflow time delay to allow blood to flow into selected vascular compartments of the plurality of vascular compartments;a3) applying a second velocity-selective pulse to suppress NMR signal from blood flowing faster than a second cutoff velocity through the plurality of vascular compartments; b) acquiring a tag set of NMR data from the subject after step a) and at a tag acquisition time after step a1); c) directing the MRI system to perform a second pulse sequence that includes the following sequential steps:
c1) applying a third velocity-selective pulse to suppress NMR signal from blood flowing faster than a third cutoff velocity through the plurality of vascular compartments of the subject;c2) providing the inflow time delay to allow blood to flow into selected vascular compartments of the subject;c3) optionally applying a fourth velocity selective pulse to suppress NMR signal from blood flowing faster than a fourth cutoff velocity through the plurality of vascular compartments; d) acquiring a control set of NMR data from the subject after step c) and at a control acquisition time after step c1) that is equal to the tag acquisition time; e) reconstructing a tag image from the tag set of NMR data and a control image from the control set of NMR data; and f) subtracting the tag image from the control image to produce the image of the subject, wherein the third cutoff velocity and the fourth cutoff velocity are different velocities, and wherein the image of the subject indicates a characteristic of the blood flowing within the selected vascular compartments and is substantially free of information from both stationary tissue and blood outside the selected vascular compartments.