1. A computerized method for estimating a DEXA score from three dimensional (3D) computed tomography (CT) imaging data, comprising: receiving 3D imaging data of a CT scan of a body of a patient containing at least a 3D bone portion; segmenting the 3D bone portion from the 3D imaging data of the CT scan; computing at least one grade for the 3D bone portion based on pixel associated values from the 3D bone portion; correlating the at least one grade of the 3D bone portion with at least one score representing a relation to bone density values in a population obtained based on a dual-energy X-ray absorptiometry (DEXA) scan, wherein the at least one grade for the 3D bone portion is computed from a calculation of sub-grades performed for each one or a set of pixels having at least one of a common medial-lateral axial coordinate and a common cranial-caudal axial coordinate along a dorsal-ventral axis of a volume representation of the 3D imaging data of the CT scan; and presenting the at least one score correlated to the least one grade on a presentation unit for diagnosis of at least one of bone mineral density (BMD), osteoporosis, and osteopenia.