System and method for simultaneously registering multiple lung CT scans for quantitative lung analysis

A system for simultaneously registering a plurality of computed tomography (CT) scans of a region of interest of a subject including a subject's lungs for quantitative lung analysis, the system comprising:

• a processor device;
• and
• a non-transitory computer-readable memory storing instructions executable by the processor device, wherein the instructions, when executed by the processor device, cause the system to:
• receive a plurality of CT scans of the region of interest acquired with a CT imaging system;
• receive a breathing surrogate data for the subject, the breathing surrogate data comprising an amplitude for each of the plurality of CT scans;
• and
• determine a deformation based on the plurality of CT scans and the breathing surrogate data using an iterative optimization process of an objective function having a first term based on an approximation of local changes in Hounsfield Units (HU) adjusted for breathing of the subject and a second term based on error in the conservation of mass.