![]() Is correctly scaling the image intensity use=ing the formula This demonstrates that the recent version ![]() I will prepare an anonymous sample-DICOM with two converted nifti Used DICOM from two Philips scanners (releases 3.3 and 5.3), and 'intensity scaling factor' is different between releases. These are relative values, and the data and unique number of Up to three million, where we used to have them around 1000/2000.įor anatomies values rise to the hundreds of thousands. Revealed also when using spm_vol to get v_b.pinfo, where the first value is the 'scaling' factor.įor some scans (like EPI series) the values are interpreted to go SPM expressed as Y = 1X), whereas a conversion using the oct2016 version yields inflated values (for instance intensity Y = 35 X, The same DICOM file converted using the june2015 version shows identical values as the raw DICOM (with intensity in These also appear when viewing the images with SPM. I used Mango to give a quick impression of the inflated values but ![]() So the scaling seems to be indeed off by a factor of (2316/5.5) % to be contiguous and each plane has the same scalefactor % If the size of pinfo is 3x1, then the volume is assumed % V.pinfo(3,:) - offset into image (in bytes). % The true voxel intensities of the jth image are given V.pinfo - plane info for each plane of the volume. Nifti converted from the same DICOM source: However, for the 2016 version the following is displayed for a Version the v_b.pinfo information is as follows: Version, so I'm now stuck with greatly inflated values what isĬausing this? Or are previous versions available to downloadĮDIT: I've discovered a change in the information displayed using Unfortunately I cannot find a download for the compiled 2015 linux Happens for both anatomical scans and EPI's. This does not happen when using the June 2015 version. After converting Philips DICOM with the october 2016 version ofĭcm2niix, voxel values in scans have increased by approximately 500
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