Contour extraction in multi-phase, multi-slice cardiac mri studies by propagation of seed contours between images

Claim 1

A method of extracting final contours fit to a contour feature in a collection of images obtained by scanning an object undergoing a repetitive motion cycle with magnetic resonance imaging apparatus, each of said images representing a different combination of a slice position, selected from a plurality of successively spatially displaced slice positions in the object, and a phase position, selected from a plurality of successive phase positions in the motion cycle, said method comprising: displaying on a display device an initial image from said collection of images, corresponding to a combination of a predetermined first phase position and a predetermined first slice position; receiving and displaying in said initial image a seed contour input by a user, via an input device, proximate a contour feature in said initial image, to be extracted; automatically propagating said seed contour with a seed-to-final propagation function to produce a final contour which is fit to said contour feature in said initial image; said final contour being a provisional contour for a first pair of in-slice images at the first slice position and at phase positions which respectively immediately precede and immediately succeed said first phase position and for a first pair of in-phase images at the first phase position and at slice positions which respectively immediately precede and immediately succeed said first slice position; automatically, without further action by the user, propagating said provisional contour for said first pair of in-slice images with an in-slice provisional-to-seed propagation function to respective seed contours for said first pair of in-slice images; automatically, without further action by the user, propagating said provisional contour for said first pair of in-phase images with an in-phase provisional-to-seed propagation function to respective seed contours for said first pair of in-phase images; and automatically propagating said seed contours for said first pairs of in-phase and in-slice images with said seed-to-final propagation function to respective final contours fit to said contour feature in said first pairs of in-phase and in-slice images; wherein said seed-to-final propagation function comprises applying a plurality of iterations of an energy minimizing active contour function having an energy which is a function of energy derived from the image at the active contour, active contour stretching energy, and active contour bending energy.

Claim 2

A method of extracting final contours fit to a contour feature in a collection of images obtained by scanning an object undergoing a repetitive motion cycle with magnetic resonance imaging apparatus, each of said images representing a different combination of a slice position, selected from a plurality of successively spatially displaced slice positions in the object, and a phase position, selected from a plurality of successive phase positions in the motion cycle, said method comprising: displaying on a display device an initial image from said collection of images, corresponding to a combination of a predetermined first phase position and a predetermined first slice position; receiving and displaying in said initial image a seed contour input by a user, via an input device, proximate a contour feature in said initial image, to be extracted; automatically propagating said seed contour with a seed-to-final propagation function to produce a final contour which is fit to said contour feature in said initial image; said final contour being a provisional contour for a first pair of in-slice images at the first slice position and at phase positions which respectively immediately precede and immediately succeed said first phase position and for a first pair of in-phase images at the first phase position and at slice positions which respectively immediately precede and immediately succeed said first slice position; automatically, without further action by the user, propagating said provisional contour for said first pair of in-slice images with an in-slice provisional-to-seed propagation function to respective seed contours for said first pair of in-slice images; automatically, without further action by the user, propagating said provisional contour for said first pair of in-phase images with an in-phase provisional-to-seed propagation function to respective seed contours for said first pair of in-phase images; and automatically propagating said seed contours for said first pairs of in-phase and in-slice images with said seed-to-final propagation function to respective final contours fit to said contour feature in said first pairs of in-phase and in-slice images; wherein said seed-to-final propagation function comprises applying a plurality of iterations of an energy minimizing active contour function having an energy which is a function of energy derived from the image at the active contour, active contour stretching energy, and active contour bending energy.

Claim 16

A method of determining a relative volume of a blood pool in a heart chamber of a patient at a pair of generally opposed phase positions in a beating cycle, comprising: scanning a chest region of the patient with magnetic resonance imaging apparatus to obtain a collection of images of slices through the patient's heart chamber, each of said images representing a different combination of a slice position, selected from a plurality of successively spatially displaced slice positions in the heart chamber, and a phase position, selected from a plurality of successive phase positions in the beating cycle; displaying on a display device an initial image from said collection of images, corresponding to a combination of a predetermined one of said phase positions and a slice position at a middle one of said slice positions; receiving and displaying in said initial image a seed contour input by a user, via an input device, proximate an inner wall of said chamber defining said blood pool in said initial image; using said seed contour as the only user input contour proximate the inner wall of said chamber, successively extracting final contours defining said blood pool in said respective images by automatically, without further action by the user, propagating successive extracted final contours from respective images to seed contours for images which adjoin the respective images in slice or phase position, and automatically, without further action by the user, propagating said seed contours to final contours using a seed-to-final propagation function; and using said extracted final contours for images in the first and second phase positions, computing said relative volume; wherein said seed-to-final propagation function comprises applying a plurality of iterations of an energy minimizing active contour function having an energy which is a function of energy derived from the image at the active contour, active contour stretching energy, and active contour bending energy.

Claim 17

A method of determining a relative volume of a blood pool in a heart chamber of a patient at a pair of generally opposed phase positions in a beating cycle, comprising: scanning a chest region of the patient with magnetic resonance imaging apparatus to obtain a collection of images of slices through the patient's heart chamber, each of said images representing a different combination of a slice position, selected from a plurality of successively spatially displaced slice positions in the heart chamber, and a phase position, selected from a plurality of successive phase positions in the beating cycle; displaying on a display device an initial image from said collection of images, corresponding to a combination of a predetermined one of said phase positions and a slice position at a middle one of said slice positions; receiving and displaying in said initial image a seed contour input by a user, via an input device, proximate an inner wall of said chamber defining said blood pool in said initial image; using said seed contour as the only user input contour proximate the inner wall of said chamber, successively extracting final contours defining said blood pool in said respective images by automatically, without further action by the user, propagating successive extracted final contours from respective images to seed contours for images which adjoin the respective images in slice or phase position, and automatically, without further action by the user, propagating said seed contours to final contours using a seed-to-final propagation function; and using said extracted final contours for images in the first and second phase positions, computing said relative volume; wherein said seed-to-final propagation function comprises applying a plurality of iterations of an energy minimizing active contour function having an energy which is a function of energy derived from the image at the active contour, active contour stretching energy, and active contour bending energy.

Claim 18

A method of obtaining final contours fit to a contour feature of an object undergoing a repetitive motion cycle, said method comprising: scanning the object with magnetic resonance imaging apparatus to obtain a collection of images of the object, each of said images representing a different combination of a slice position, selected from a plurality of successively spatially displaced slice positions in the object, and a phase position, selected from a plurality of successive phase positions in the motion cycle; displaying on a display device an initial image from said collection of images, corresponding to a combination of a predetermined first phase position and a predetermined first slice position; receiving and displaying in said initial image a seed contour input by a user, via an input device, proximate a contour feature in said initial image, to be extracted; automatically propagating said seed contour with a seed-to-final propagation function to produce a final contour which is fit to said contour feature in said initial image; said final contour being a provisional contour for a first pair of in-slice images at the first slice position and at phase positions which respectively immediately precede and immediately succeed said first phase position and for a first pair of in-phase images at the first phase position and at slice positions which respectively immediately precede and immediately succeed said first slice position; automatically, without further action by the user, propagating said provisional contour for said first pair of in-slice images with an in-slice provisional-to-seed propagation function to respective seed contours for said first pair of in-slice images; automatically, without further action by the user, propagating said provisional contour for said first pair of in-phase images with an in-phase provisions-to-seed propagation function to respective seed contours for said first pair of in-phase images; and automatically propagating said seed contours for said first pairs of in-phase and in-slice images with said seed-to-final propagation function to respective final contours fit to said contour feature in said first pairs of in-phase and in-slice images; wherein said seed-to-final propagation function comprises applying a plurality of iterations of an energy minimizing active contour function having an energy which is a function of energy derived from the image at the active contour, active contour stretching energy, and active contour bending energy.

Claim 19

A method of obtaining final contours fit to a contour feature of an object undergoing a repetitive motion cycle, said method comprising: scanning the object with magnetic resonance imaging apparatus to obtain a collection of images of the object, each of said images representing a different combination of a slice position, selected from a plurality of successively spatially displaced slice positions in the object, and a phase position, selected from a plurality of successive phase positions in the motion cycle; displaying on a display device an initial image from said collection of images, corresponding to a combination of a predetermined first phase position and a predetermined first slice position; receiving and displaying in said initial image a seed contour input by a user, via an input device, proximate a contour feature in said initial image, to be extracted; automatically propagating said seed contour with a seed-to-final propagation function to produce a final contour which is fit to said contour feature in said initial image; said final contour being a provisional contour for a first pair of in-slice images at the first slice position and at phase positions which respectively immediately precede and immediately succeed said first phase position and for a first pair of in-phase images at the first phase position and at slice positions which respectively immediately precede and immediately succeed said first slice position; automatically, without further action by the user, propagating said provisional contour for said first pair of in-slice images with an in-slice provisional-to-seed propagation function to respective seed contours for said first pair of in-slice images; automatically, without further action by the user, propagating said provisional contour for said first pair of in-phase images with an in-phase provisions-to-seed propagation function to respective seed contours for said first pair of in-phase images; and automatically propagating said seed contours for said first pairs of in-phase and in-slice images with said seed-to-final propagation function to respective final contours fit to said contour feature in said first pairs of in-phase and in-slice images; wherein said seed-to-final propagation function comprises applying a plurality of iterations of an energy minimizing active contour function having an energy which is a function of energy derived from the image at the active contour, active contour stretching energy, and active contour bending energy.