Methods, apparatuses, and computer-readable media are provided for image based CT Number and volume corrections for thin objects in computed tomography systems. For example, in one embodiment a method is provide which computes an average computed tomography (“CT”) value and volume of voxels that are part of an object. Thereafter, a surface area and a surface CT Number, a boundary area and a boundary CT Number, and a corrected CT Number and a corrected volume for the object are computed. Embodiments of the invention also include other methods, computer-readable mediums, apparatuses, and systems that contain features similar to the features in the above described method.