Method for automated analysis of apical four-chamber images of the heart

A method for determining the optical density of a digital image of an apical view of a heart, said method comprising the steps of:

• (a) obtaining a control frame from a baseline period prior to injecting a contrast agent;
• (b) determining a first registration point in said image;
• (c) locating one or more regions of a myocardium in relation to the registration point on said control frame;
• (d) calculating the mean pixel intensity of said one or more regions of the myocardium;
• (e) injecting the contrast agent and obtaining a sequence of framnes;
• (f) determining a second registration point in one or more of said frames of said sequence;
• (g) locating one or more regions of the myocardium on one or more of said frames correspondingto the regions of a control frame;
• (h) calculating the mean pixel intensity of said one or more regions of the myocardium in one or more of said frames of said sequence;
• and
• (i) obtaining a time-mean pixel intensity curve by comparing the mean pixel intensity for said frames following injection of the contrast agent to the control frame,
• wherein said time-mean pixel intensity curve determines the optical density of the digital image in a selected region of the apical long axis view of the heart.

A method for automatically locating an approximate position of the interventricular septum of a heart in a long-axis image, said method comprising the steps of:

• (a) generating an image frame of said heart, said image frame comprising a plurality of rows and a plurality of columns of pixels in a digital format;
• and
• (b) passing a filter through the image to determine a maximum mean pixel intensity,
• wherein said maximum is an approximate position of the interventricular septum in said image.

A method of automatically locating an approximate position of a medial border of a mitral valve annulus in a long-axis diagnostic image of a heart, said method comprising the steps of:

• (a) generating an image frame of the interventricular septum and mitral valve annulus of said heart, said image frame comprising a plurality of rows and a plurality of pixels in a digital format;
• (b) determining an approximate position of said septum from said diagnostic image comprising:
• (i) passing a filter through the image to determine a maximum mean pixel intensity, wherein said maximum is a first approximate position of said interventricular septum;
• (ii) defining a second approximate position of said interventricular septum with a series of straight line filters;
• (iii) obtaining a best fit line through the second approximate positions from the upper portion of said series of straight line filters;
• and
• (c) determining an approximate position of a medial border of said mitral valve annulus by passing a right-angle filter down the best fit line determined from step (b)(iii) until a maximum mean pixel intensity is determined, wherein said maximum is indicative of the approximate position of said mitral valve annulus.

A method of screening a compound for use as a contrast agent in echocardiography, said method comprising the steps of:

• (a) obtaining, from a baseline period prior to injecting said compound, a control frame of a digital image of an apical long-axis view of a heart;
• (b) determining a first registration point in said image;
• (c) locating one or more regions of a myocardium in relation to the registration point on said control frame;
• (d) calculating the mean pixel intensity of said one or more regions of the myocardium;
• (e) injecting said compound and obtaining a sequence of frames;
• (f) determining a second registration point in said frames;
• (g) locating one or more regions of the myocardium on said frame corresponding to the regions of the control frame;
• (h) calculating the mean pixel intensity of said one or more regions of the myocardium in said frame;
• and
• (i) obtaining a time-mean pixel intensity curve by comparing the mean pixel intensity for said frame following injection of the contrast agent to the control frame,
• wherein an increase in the mean pixel intensity in the regions of the myocardium in said frame following injection of the contrast agent over the control frame is indicative of injection of a contrast agent.