Currently, the set of available reference data and downloadable image sets consists of thoracic 4DCT images and CT image pairs from COPDgene study archive. We will update the library as more cases are added, and will inform all of our registered users as they become available.
Download information
Included with each case are 2 text files containing coordinate information for the reference landmarks on the extreme phase images (T00 and T50):
- "caseID_300_T00_xyz.txt", and
- "caseID_300_T50_xyz.txt"
Additionally, coordinate information is provided for intermediate component phase images. For each case, additional text files are provided:
- "caseID_4D-75_T00_xyz.txt",
- "caseID_4D-75_T10_xyz.txt",
- "caseID_4D-75_T20_xyz.txt", etc.
These files contain a sample of 75 of the total quantity of landmarks for each case, propagated onto multiple phase images (T00 through T50).
To access the download of image sets below from the reference data provided, investigators are encouraged to complete our request form. Once completed, a password to access the available file(s) in Dropbox will be provided.
Reference publications
All of the datasets have previously been reported as part of original peer-reviewed publications describing the data acquisition and analysis process. These include:
- Case numbers 4DCT1-4DCT5
Castillo R, Castillo E, Guerra R, Johnson VE, McPhail T, Garg AK, Guerrero T. 2009. A framework for evaluation of deformable image registration spatial accuracy using large landmark point sets. Phys Med Biol 54 1849-1870. - Case numbers 4DCT6-4DCT10
Castillo E, Castillo R, Martinez J, Shenoy M, Guerrero T. 2009. Four-dimensional deformable image registration using trajectory modeling. Phys Med Biol 55 305-327.
Visit Publications for comprehensive list.
Image Sets and Reference Data
For the 4DCT images, the full point set is identified between the maximum inhalation and exhalation component phase images. Additionally, a subset of 75 features has been propagated onto each of the expiratory phase images (i.e., T00, T10, T20, T30, T40, and T50).
Each case is identified according to the given label.
- The image dimensions are given in voxel units, and the voxel dimensions are given in millimeters.
- The "# Features" designates the total quantity of unique landmark features identified for each case.
- The "Displacement" shows the mean (and standard deviation) displacement of the complete primary feature set.
- The entries under "# Repeats" are formatted as (Nm< / Nobs), where Nm is the number of repeat registration measurements performed by each of Nobs independent observers.
- The "Observers" column shows the combined mean (and standard deviation) repeat registration error for the set of Nobs data sets.
Surface renderings and summary characteristics of the currently available cases are viewable below. Surface renderings of the inhale lung volume are shown, overlain with displacement vectors (T00 --> T50) for each of the validation landmarks. All surface renderings were generated in the MATLAB (Mathworks, Sunnyvale, CA) environment.
