I believe that would resize all dimensions by that, including the 90, which obvisouly you don't want. I think you need to do it one slice at a time.
imageSize = size(spect130);
spect128 = zeros(128, 128, 1, imageSize(4), class(spect130))
for slice = 1 : imageSize(4)
thisSlice = spect130(:, :, 1, slice);
spect128(:, :, 1, slice) = imresize(thisSlice, [128, 128]);
end
As far as writing the new metadata to the output file, I don't know. You'd have to look into the dicomwrite() documentation.
