The 4DCT dataset is a set of data that provides the medical imaging community with reference standard data that objectively and rigorously evaluates the spatial accuracy of Deformable Image Registration (DIR). The chest 4DCT images were obtained from the MD Anderson Cancer Center at the University of Texas at Houston as part of the standard planning process for treating thoracic malignancies, and from the research archives of the National Heart, Lung, and Blood Institute.

Each image dataset along with the associated anatomical coordinates was manually labeled by an expert, and repeated registration was performed by a chrome observer to estimate spatial variations in feature identification, and the point set was used as a reference for assessing the spatial accuracy of DIR within the lung in each case.

The 4DCT dataset was released by Texas MD Anderson Cancer Center et al. in 2009. The related paper is "A framework for evaluation of deformable image registration spatial accuracy using large landmark point sets".