Contrast reagent leakage correction in dynamic susceptibility contrast magnetic resonance imaging
AssigneeOregon Health & Science University
InventorsWilliam Rooney, Xin Li
Life of this patent
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Abstract
Disclosed are methods and systems for calculating a contrast reagent (CR) extravasation rate constant and generating a contrast reagent leakage corrected relative cerebral blood volume (rCBV) image map of a brain region from dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) time-course image data based on pharmacokinetic first principles. In one example approach, a computerized method may include performing a linearization transform of a DSC MRI time-course equation which accounts for an intravascular contribution and an extravasating component, and calculating CR leakage from a slope of a linear portion of the transformed data.
Claims19
A computerized method for contrast reagent leakage correction of dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) time-course image data of a brain region, the method comprising:
- from the DSC MRI time-course image data, computing a pixel time-course of an effective transverse relaxation rate constant change (ΔR2*(t)) and an estimate of a time-course of an effective transverse relaxation rate constant for relative blood ( ΔR2*(t));
- and
- computing a contrast reagent extravasating rate constant from a slope of a linear portion of a mapping of ΔR2*(t)/ ΔR2*(t) versus ∫0t ΔR2*(t′)dt′/ ΔR2*(t).
A method for producing an image of a patient's brain with a magnetic resonance imaging (MRI) system, comprising:
- acquiring dynamic susceptibility contrast (DSC) MRI time-course image data for a region of interest of the brain prior to an injection of a contrast reagent to obtain a baseline signal intensity;
- acquiring DSC MRI time-course image data for the region of interest following an injection of a contrast reagent into a blood vessel which induces a differential between the susceptibilities of the blood vessel and tissue in the region of interest;
- from the DSC MRI time-course image data, calculating a pixel time-course of an effective transverse relaxation rate constant change (ΔR2*(t)) based on the baseline signal intensity and an imaging echo time of a pulse sequence used to acquire the DSC MRI data;
- calculating an estimate of a time-course of an effective transverse relaxation rate constant for relative blood ( ΔR2*(t)) based on a combination of signal changes from non-leaking pixels within the DSC MRI time-course image data;
- calculating a contrast reagent extravasating rate constant from a slope of a linear portion of a mapping of ΔR2*(t)/ ΔR2*(t) versus ∫0t ΔR2*(t′)dt′/ ΔR2*(t), where the linear portion of the mapping corresponds to DSC MRI time-course image data acquire following a transient period of contrast reagent first pass;
- generating an image map of relative cerebral blood volume (rCBV) in the region of interest based on an integration of ΔR2*(t) over the DSC MRI time-course image data for each pixel in the region of interest;
- generating a corrected rCBV image map to correct the rCBV image map for leakage of the contrast reagent out of the patient's vasculature based on the contrast reagent extravasating rate constant;
- and
- outputting the corrected rCBV image map to a display device.
Dependencies are inferred from the claim text.