Method of assessing vascular reactivity using magnetic resonance imaging, applications program and media embodying same

A computer system for processing magnetic resonance image data to assess vascular reactivity during an arterial occlusion, said system comprising:

• a computer including a microprocessor;
• a non-transitory applications program for execution on the microprocessor;
• and
• wherein said non-transitory application program comprises instructions, criteria and code segments for:
• (a) finding a center of the arterial cross-section being imaged using one of an MRI magnitude image or an MRI phase image;
• (b) fitting a parabolic curve using selected data of the MRI phase image;
• (c) using an equation of the fitted parabolic curve to measure shear rate;
• and
• (d) calculating a radius of the arterial cross-section using one of the MRI magnitude image or the MRI phase image.

A method for assessing vascular reactivity during an arterial occlusion, comprising:

• constricting an artery for a period of time, such that the artery is fully occluded;
• using a magnetic resonance image scanner to obtain images of an artery from which a pixel array can be acquired, said images being obtained prior to occlusion (at baseline), as well as one or more times during and after occlusion;
• using a first pixel array to determine a center of the arterial cross-section;
• fitting a parabolic curve to velocity data taken from a second pixel array of the phase image;
• using an equation of the parabolic curve to measure shear rate;
• and
• calculating a radius of the arterial cross section using the equation of the parabolic curve.

A method for assessing vascular reactivity during an arterial occlusion, comprising:

• constricting an artery for a period of time, such that the artery is fully occluded;
• using a magnetic resonance image (MRI) scanner to obtain images of an artery from which a pixel array can be acquired, said images being obtained prior to occlusion (at baseline), as well as one or more times during and after occlusion;
• using a first pixel array to determine a center of the arterial cross-section;
• dividing image data from the images obtained from the (MRI) scanner into N sectors surrounding the center of the arterial cross section;
• determining an outer radius of the velocity profile for each of the sectors and determining corresponding datapoints;
• fitting a parabolic curve to the datapoints;
• calculating the slope of the parabolic curve at a lumen-wall interface to determine shear rate;
• and
• calculating a radius of the artery by determining a distance from a center of the parabolic curve to a point where the parabolic curve crosses zero velocity.