MATLAB: How to calculate left ventricle ejection fraction

Question

Hi all

I would like to calculated left ventricle ejection fraction LVEF of the heart from an image set. I have a series of planner images (128×128) (n =16) for one patient (derived from SPECT modality). LVEF is calculated according to the following equation:

LVEF = (Left ventricle end diastolic counts – left ventricle end systolic counts)/ Left ventricle end diastolic counts

Note:

Left ventricle end diastolic counts: is the image of the highest count in the series.

Left ventricle end systolic counts: is the image of the lowest count in the series.

In order to show count from left ventricle only, i drawn ROI around left ventricle and masked all other parts, so that the left ventricle only is visible. I called this serires LVimages.

can you help me on how to do this calculation? note that my image series is called LVimages.

Answer 1

There is an example with using impoly

I = imread('img1.png');
imshow(I)
h = impoly;                 % draw polygon
msk = h.createMask;         % get pixels inside polygon (binary mask)
number = sum(msk(:));       % number of pixels inside polygon
    % create (M x N x 3) mask and get values
msk3 = uint8( repmat(msk,[1 1 3]) );
I1 = msk3 .* I;
figure
imshow(I1)