Noninvasive myocardial motion analysis using phase contrast MRI maps of myocardial velocity

Claim 2

The method as defined by claim 2 and further including g) forming cine images of said motion of said region of interest.

Claim 3

The method as defined by claim 2 wherein steps c) -g) are repeated for other regions of interest.

Claim 4

The method as defined by claim 1 and wherein steps c) - f) are repeated for other regions of interest.

Claim 5

The method as defined by claim 1 wherein said magnetic field includes time varying magnetic gradients along a plurality of axes and said motion of said region of interest is along said plurality of axes.

Claim 8

The method as defined by claim 6 wherein step d) includes modelling velocity, v x , and velocity, v y , as v x = a + b(x - x ¯ ) + c(y - y ¯ ) v y = d) + e(x - x ¯ ) + f(y - y ¯ ) where a, b, c, d, e, and f) are constants calculated by a least squares fit over said region of interest in each frame.

Claim 9

The method as defined by claim 8 wherein step d) further includes calculating in each frame changes in longitudinal strain as Δε x,xi = bΔt Δε y,yi = fΔt changes in displacement as Δx i = a Δ t Δy i = d Δ t changes in rotation as Δα i = 1/2 [(eΔt)] - (cΔt)] and changes in shear as Δϑ i = [(eΔt) + (cΔt)].

Claim 10

The method as defined by claim 9 and further including the step of (i) combining the motion and deformations estimated in a plurality of time frames.

Claim 11

The method as defined by claim 10 wherein step i) further includes rotation of the coordinate system for said region of interest between frames in estimating combined new position and a new shape of said region of interest.

Claim 12

The method as defined by claim 11 and further including j) forming cine images of said motion and deformation of said region of interest.

Claim 13

The method as defined by claim 12 wherein steps c) - j) are repeated for other regions of interests.

Claim 15

The method as defined by claim 14 wherein step (d) includes forming an image related to the rate of development of strain within said region.

Claim 16

Apparatus for assessing the motion of a region of interest within an object comprising first means for establishing a magnetic field within said object, second means for (b) obtaining magnetic resonance image signals representative of at least one velocity component of said region at a plurality of time frames, third means for (c) identifying the position said region of interest in the image signal at one time frame, fourth means for (d) estimating a new position of said region of interest in a time frame other than said one time frame, fifth means for (e) translating said region of interest to said new position, and sixth means for (f) repeating steps d) and e) for succeeding time frames to determine the motion for said region of interest.

Claim 17

Apparatus for assessing motion and deformation of a region of interest within an object comprising first means for (a) establishing a magnetic field within said object second means for (b) obtaining magnetic resonance image signals representative of at least one velocity component of said region at a plurality of time frames, third means for (c) identifying the position and shape of said region of interest in said image signal at one time frame, fourth means for (d) calculating parameters derived from velocity components within said region of interest at said one time frame, fifth means for (e) estimating a new position and a new shape of said region of interest in a time frame other than said one time frame based on said velocity parameters, sixth means for (f) translating said region of interest to said new position, seventh means for (g) deforming said region of interest at said new position, and eighth means for (h) repeating steps c) - g) for succeeding time frames to determine motion and deformation of said region interest.

Claim 18

Apparatus as defined by claim 17 wherein said fourth means models velocity, v x , and velocity, v y , as v x = a + b(x - x ¯ ) + c(y - y ¯ ) v y = d) + e(x - x ¯ ) + f(y - y ¯ ) where a, b, c, d, e, and f) are constants calculated by a least squares fit over said region of interest in each frame.

Claim 19

Apparatus as defined by claim 18 wherein said fourth means calculates in each frame changes in longitudinal strain as Δε x,xi = bΔt Δε y,yi = fΔt changes in displacement as Δx i = a Δ t Δy i = d Δ t changes in shear as Δϑ i = [(eΔt)] + (cΔt)] and changes in rotation as Δα = 1/2[(eΔt) - (cΔt)].

Claim 20

Apparatus as defined by claim 19 wherein said fifth means rotates the coordinate system for said region of interest between frames in estimating combined new position and a new shape of said region of interest.

Claim 21

Apparatus as defined by claim 20 and further including ninth means for forming cine images of said motion and deformation of said region of interest.

Claim 22

Apparatus for assessing deformation of a region of interest within an object comprising first means for establishing a magnetic field through said object, second means for (b) obtaining magnetic resonance image signals representative of a plurality of velocity components of said region at a plurality of frames, third means for (c) calculating parameters related to said velocity components at a plurality of points within said region, and fourth means for (d) assessing deformation of said region of interest at said plurality of time frames based on spatial derivatives of velocity.

Claim 23

Apparatus as defined by claim 22 wherein said fourth means includes means for forming an image related to the rate of development of strain within said region.