# How to calculate left ventricle ejection fraction?

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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 (128x128) (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.

##### 9 Comments

darova
on 20 Sep 2019

### Accepted Answer

darova
on 21 Sep 2019

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)

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