Johns Hopkins University

Qin Qin

Peter C Van Zijl

Dan Zhu

Ruoxun Zi

Magnetic resonance imaging according to the present invention includes T1, T2, or diffusion mapping with improved image resolution. The improved image resolution is achieved by leveraging the delay in the image acquisition to remove the partial volume effect of fluid in and around the tissue being imaged.

Quantitative mapping of MRI relaxation parameters

The present invention is directed to a system and method for determining blood volume in a subject. Blood volume is an important hemodynamic parameter for monitoring many disorders, such as stoke and cancer. Current MRI techniques for quantification of absolute blood volume for such clinical applications all require injecting exogenous contrast agents. To reduce associated safety risks and cost, the present invention is directed to a non-contrast-enhanced MRI method for blood volume mapping on MRI. The technique of the present invention employs velocity-selective (VS) pulse trains in paired control and label modules for separating vascular signal by subtraction. The Fourier-transform based VS saturation pulse train (FT-VSS) of the present invention has improved performance over conventional VS pulse trains for the blood volume measurement.

Measurement of blood volume using Fourier-transform based velocity-selective pulse trains on MRI

The present invention is directed to a system and method for magnetic resonance imaging including an extended Fourier transform-based velocity-selective pulse train design with a pair of refocusing pulses within each velocity encoding step and accompanying phase cycling between different velocity encoding steps. The present invention is robust to B0/B1 field inhomogeneity and eddy current effects. The utility of this technique, through a velocity-selective inversion pulse, is demonstrated in a 2D velocity-selective arterials spin labeling study, which shows a reasonable agreement in CBF quantification with the standard PCASL method.

System and method for velocity selective pulses with arbitrary shape using MRI

The present invention is directed to a system and method for measuring blood volume using non-contrast-enhanced magnetic resonance imaging. The method of the present invention includes a subtraction-based method using a pair of acquisitions immediately following velocity-sensitized pulse trains for the label module and its corresponding control module, respectively. The signal of static tissue is canceled out and the difference signal comes from the flowing blood compartment above a cutoff velocity. After normalizing to a proton density-weighted image acquired separately and scaled with the blood T1 and T2 relaxation factors, quantitative measurement of blood volume is then obtained.

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Ellicott City, MD, United States of America

Qin Qin