dicom image : area calculation

Question

I am developing a program in matlab to to view diacom files and measure the area of a particular target region in the image. Target area will be given as a manual input (number of points).

I know little about the dicom analyzing. But I feel that simply inputting the points (coordinates) to the matlab function polyarea(X,Y) will not give the actual area. I need to know actual area in mm^2. I know pixel spacing and slice thickness too.

Please help me to do this?

Answer 1

If the coordinates you supply to polyarea are measured in pixels, then the result will be measured in square pixels.

If you know the width of a pixel (in mm), then your area (in mm²) is pixelarea * pixelwidth², i.e.:

area = polyarea(X,Y) * power(pixelwidth,2)