A computer-implemented method for quantifying an object in a larger structure using a reconstructed image obtained from an imaging apparatus includes identifying an object boundary in a region of interest of the image and a region of exclusion, and determining a mean value of intensity in a neighborhood of the object to estimate a background value, excluding the region of exclusion. The method further includes determining an interior region, a transition region, and a background region of the object using the object boundary and a transfer function of the imaging apparatus, and determining and displaying a measure of object quantification utilizing intensities of at least one of the determined interior region or the transition region a method for quantifying an object in a larger structure using a reconstructed image obtained from an imaging apparatus.