Methods of obtaining a suspect nodules' sizes and/or growth rate are provided. In one embodiment, the method begins with at a first time: (i) obtaining a first three dimensional (3D) data set cube of voxels of a patient's anatomy including nodules; (ii) creating a second 3D data set cube of the same size as the first where all voxel values are set to zero; (iii) creating multiple Maximum-Intensity-Projection (MIP) images from the first 3D data set cube taken at different angles; (iv) replacing those voxels in the second 3D data set cube with corresponding voxels from the first 3D data set cube that provide non-zero values in the multiple MIP images; and (v) converting data in the second 3D data set cube into closed surface volumes, cross sectional areas or linear dimensions using image segmentation. Data from a second time can be used to determine growth rate.