Technique for bone volume measurement from human femur head samples by classification of micro-CT image histograms

• Published in: Annali dell'Istituto superiore di sanita Vol. 49; no. 3; pp. 300 - 305
• Main Authors: MARINOZZI, Franco, BINI, Fabiano, MARINOZZI, Andrea, ZUPPANTE, Francesca, DE PAOLIS, Annalisa, PECCI, Raffaella, BEDINI, Rossella
• Format: Journal Article
• Language: English
• Published: Roma Istituto superiore di sanita 01.01.2013; Istituto Superiore di Sanità
• Subjects: Absorptiometry, Photon; Algorithms; Biological and medical sciences; Bone and Bones - anatomy & histology; bone morphometry; Diseases of the osteoarticular system; Femur Head - diagnostic imaging; General aspects; Genital system. Mammary gland; Health Care Sciences & Services; Humans; image processing; Image Processing, Computer-Assisted; Investigative techniques, diagnostic techniques (general aspects); Magnetic Resonance Imaging; Medical sciences; microtomography; Osteoarthritis; osteoporosis; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Tomography, X-Ray Computed; Trabecular Meshwork - anatomy & histology; X-Ray Microtomography; Human; Femur; Head; bone morphometry; Radiodiagnosis; Image processing; osteoarthritis, osteoporosis; Diseases of the osteoarticular system; Image; Medicine; Osteoporosis; Volume; Classification; Arthropathy; Medical imagery; Degenerative disease; Computerized axial tomography; Bone; Technique; Morphometry; Osteoarthritis; microtomography; image processing; osteoporosis; osteoarthritis
• ISSN: 0021-2571; 2384-8553
• DOI: 10.4415/ANN_13_03_11

Micro-CT analysis is a powerful technique for a non-invasive evaluation of the morphometric parameters of trabecular bone samples. This elaboration requires a previous binarization of the images. A problem which arises from the binarization process is the partial volume artifact. Voxels at the external surface of the sample can contain both bone and air so thresholding operates an incorrect estimation of volume occupied by the two materials. The aim of this study is the extraction of bone volumetric information directly from the image histograms, by fitting them with a suitable set of functions. Nineteen trabecular bone samples were extracted from femoral heads of eight patients subject to a hip arthroplasty surgery. Trabecular bone samples were acquired using micro-CT Scanner. Hystograms of the acquired images were computed and fitted by Gaussian-like functions accounting for: a) gray levels produced by the bone x-ray absorption, b) the portions of the image occupied by air and c) voxels that contain a mixture of bone and air. This latter contribution can be considered such as an estimation of the partial volume effect. The comparison of the proposed technique to the bone volumes measured by a reference instrument such as by a helium pycnometer show the method as a good way for an accurate bone volume calculation of trabecular bone samples.