Medical Imaging Question- Mean inside a masked image

Hi,

I Am trying to compute the mean values within the brain. I created a binary Mask of the brain. And I am computing my mean as follows. m = the signal. Masked_M = Signals within the brain(Masked to exclude values outside the brain). I suspect the mean ignores the 0 values within the brain. How can I compute a mean of a defined area within a mask and not exclude any 0 intensities within the mask.

masked_m=m.*Mask;
temp=masked_m(masked_m~=0);
mean_dm=mean(temp);

Thanks!

[Gulfam Saju]

Can you share the code of creating binary mask?

Answer 1

[Walter Roberson]

mean() does not exclude 0's. Your design removes the 0s before the calculations.

mean_dm = mean(m(logical(Mask)));

If your Mask variable is already of class logical (true, false) then you can use

mean_dm = mean(m(Mask));