How do you calculate the volume of tumor from a series of MRI slices contaning tumor

Hie, i am a PG student working on a project detection of tumor from a sequence of MRI slices. After detecting the tumor from the slices, i calculate the volume of tumor. can any one help me out with the code for calculating the volume. i have this code for calculating the volume could u help me understand this code. i didnt understand what does "level" mean.

function [tumorvolume,flag] = volumetumor(handles)

% % % handles % % % pause

delxx = handles.delxx;

delyy = handles.delyy;

delzz = handles.delzz;

imagedata = handles.onlytumor;

[nx,ny,nz] = size(imagedata);

level = 3;

tumorvolume = 0.0;

%%imagedata(:,:,1)

for k=1:nz

BW =(imagedata(:,:,k)>level);

   total = bwarea(BW);
  tumorvolume =tumorvolume+total*delxx*delyy*delzz;
  end

tumorvolume; flag =1;

Answer 1

[David Sanchez]

You have to know the scale of the images.

Once you know the scale (equivalence between pixel-size and mm, for example), you just measure the length and width of the tumor within each slice.

Add up the product of length*width from each slice.

Finally, the volume of the tumor will be the previous summation times the distance between each slice.

Volume = slice_distance*(sum(length*width));

[Sayali Lopez]

Thanks a lot. This will surely help me. i have this code for calculating the volume could u help me understand this code. i didnt understand what does "level" mean.

function [tumorvolume,flag] = volumetumor(handles)

% % % handles % % % pause

delxx = handles.delxx;

delyy = handles.delyy;

delzz = handles.delzz;

imagedata = handles.onlytumor;

[nx,ny,nz] = size(imagedata);

level = 3;

tumorvolume = 0.0;

%%imagedata(:,:,1)

for k=1:nz

BW =(imagedata(:,:,k)>level);

 total = bwarea(BW);

tumorvolume =tumorvolume+total*delxx*delyy*delzz;

end

tumorvolume; flag =1;