How to plot ROI onto a DICOM Image?

Hi,

I have am using an Interactive DICOM 3D Viewer that allows me to view the axial, coronal and sagittal planes of a DICOM image. I am using roipoly to select a region of interest and I want to be able to save those co-ordinates on the specific slice of the CT. However as I scroll through the different slices in say the axial view the region of interest disappears. Any ideas on how to apply this?

Thanks

[Walter Roberson]

Which interactive DICOM 3D viewer are you using?

Answer 1

[Vyoma Shukla]

Hi,

This might help you. I am loading each sagittal slice of my 3D DICOM dataset in a for loop. This code is for drawing an ellipse on the 67th slice and calculating mean and standard deviation of the ellipse. I checked against ImageJ and my calculated values are accurate. You can adapt this code to your data:

I1 = dicomread('I67');

info = dicominfo('I67');

cx = double(getfield(info,'Rows')); % find centre of image

cy = double(getfield(info,'Columns'));

diam = 0.05*cx; % ROI size

h_im = imshow(imadjust(I1));

e = imellipse(gca,[cx/2-(diam/2) cy/2-(diam/2) diam diam]); % this is interactive, may want to pause here

BW = createMask(e);

BW = int16(BW);

I1(BW==0)=[]; % remove background

BW(BW==0)=[];

I1 = imresize(I1, [size(BW,1) size(BW,2)]);

I2 = I1.*BW;

average = mean(I2);

stdev = std2(I2);