create 3D image from coordinates

11 vues (au cours des 30 derniers jours)
France
France le 24 Déc 2019
Commenté : Image Analyst le 28 Déc 2019
I have got a 3D nifti image (img) that is a breast MRI. For the same image, there are NX3 coordinates (x,y,z) in the file coordsV2f. I need to substitute these coordinates to new values that are in the file pred.txt, in order to highlight some pxels and show them marked in the original 3D image. It works and now I have my zeros image with some highlighted pixel. How can I visualize the marked pixels on the original one (img) and scroll down the slices?
many thanks !!!
img = niftiread([fCompletePath '_image']);
load (['19012302a_coordsV2f']);
x = RCS(:,1);
y = RCS(:,2);
z = RCS(:,3);
new_img = zeros(size(img));
k = 1;
for slice = 1 : length(z)
f = z(slice); %3rd dimension of RCS
newX= (x(k)); % get x
newY= (y(k)); % get y
new_img(newX,newY,f) = pred(k); %assign new value on a zeros image
k = k+1;
end
imshow(new_img(:,:,5),'DisplayRange',[])
save new_img %save in workspace
niftiwrite(new_img, [fName '_prediction.nii.gz']); %save as .nii

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Image Analyst
Image Analyst le 24 Déc 2019
You can extract each slice of the image in a for loop and call imshow(), then call hold on, and plot() to plot a red spot (or whatever) over the changed pixels. Then at the bottom of the loop call questdlg() to let the user see the image and spots before proceeding with the next image.
  2 commentaires
France
France le 28 Déc 2019
Thank you Image Analyst.
This is the code I wrote:
p = 1;
for n = 1: numel(img(:,:,p))
imshow(img(:,:,p), 'DisplayRange',[]);
hold on
plot(img(:,:,p), new_img(:,:,p), 'r');
p = p+1;
end
questdlg(img)
I am not sure you mean this. However, it does not work properly, since it put a red line as contour on the original img...
Thanks in advance for your help!
Image Analyst
Image Analyst le 28 Déc 2019
You certainly would not want to do that. Let's say img is a 3-D RGB image with 3 color channels. Let's say each channel was a megapixel. So you'd be calling imshow() a million times since n would go from 1 to a million. To plot a red dot over the changed pixels stored in x and y, you'd do
imshow(img);
hold on;
plot(x, y, 'r.', 'MarkerSize', 2);
hold off;
questdlg() asks the user a question. It takes a string as a user prompt, and some strings for response options the user can pick. Like
promptMessage = sprintf('Do you want to Continue processing,\nor Quit processing?');
titleBarCaption = 'Continue?';
buttonText = questdlg(promptMessage, titleBarCaption, 'Continue', 'Quit', 'Continue');
if contains(buttonText, 'Quit')
return;
end

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