Medical physics

The Medical Physics group is carrying out research activities to improve diagnostic techniques applied to the orthopaedics, and to introduce Information and Communication Technology (ICT) to the clinical practice. The group has developed specific knowledge on microtomographic techniques to characterize bone tissue and biomaterials. Moreover, the group participates to national and international projects for the technology transfer of emerging technologies to the orthopaedic practice:

  • European project VIRTUS: large scale diffusion of telemedicine services (2001-2003);
  • Regional project co-financed by regione Emilia- Romagna HandHealth: for the validation of new handheld devices in the orthopaedic practice (2004-2006);
  • National project co-financed by the Health Ministry: validation of computer aided medicine in orthopaedics, co-financed by the Health Ministry (2005-2007);
  • European project LHDL: Living Human Digital Library: Interactive digital library services to access collections of complex biomedical data on the musculo-skeletal apparatus, (2006-2009);
  • European project VPHOP: The Osteoporotic Virtual Physiological Human, future technologies for the prediction of risk of fractures in the osteoporotic patient (2008-2012);
  • National project co-financed by the Health Ministry: Early diagnosis of pending failures of total hip arthroplasty with hard-to-hard bearings (2010-2014);
  • National project co-financed by the Health Ministry: Manufacturing information of orthopedic articular prosthesis. Analysis of specific safety issues for radiotherapy, magnetic resonance, orthopedic surgery and identification of a traceability model (2012-2015).

2D section of surgical cement with crack propagation


X-ray microtomography (microCT) applied to bone investigation and biomaterials analysis

X-ray microcomputed tomography (microCT) is an emerging technique for the non-destructive characterization of small specimens, in the field of orthopaedics, dentistry and biomaterials research. It is based on the same basic principles as common computed tomography. The system installed at the LTM-IOR,  (Skyscan 1072, Skyscan, Belgium, http://www.skyscan.be), offers high resolution imaging (5-20 microm/pixel) for specimens having sizes of about 4-20 mm. The system has built-in 2D and 3D image reconstruction capability.

MicroCT system Skyscan 1072 installed at LTM-IOR: Left, microCT system. Right, the external PC

 

 

MicroCT 3D image of a human cancellous bone specimen (specimen size 4 x 4 x 4 mm3)

MicroCT 3D image of the transition between trabecular and cortical human bone (specimen size about 4 x 4 x 6 mm3)

 

Fields of investigation in the laboratory:

  • bone histomorphometry (e.g. bone volume fraction, trabecular thickness)
  • biomaterials characterization (e.g. porosity)

Characterization of the structural parameters together with the mechanical properties of the cancellous bone:
An advantage of microCT over conventional histology is that it is a non-destructive method of investigation, leaving the structure of the examined specimen intact and thus allowing further analysis, such as mechanical testing. This permits to combine the structural information of the bone specimen obtained by microCT  (e.g. bone volume fraction, trabecular thickness) with the mechanical properties determined experimentally (e.g. elastic modulus, ultimate stress).

MicroCT examination of a human cancellous bone specimen before and after a mechanical compression test (specimen size: 10mm diameter, 20mm height):

 

MicroCT 3D image before the mechanical test

MicroCT 3D image after the mechanical test, with visible damaged region

Related Publications:

  • Perilli E, Baruffaldi F, Bisi MC, Cristofolini L, Cappello A. A physical phantom for the calibration of three-dimensional X-ray microtomography examination. J Microsc. 2006 May;222(Pt 2):124-34.
  • Perilli E, Baruffaldi F, Visentin M, Bordini B, Traina F, Cappello A, Viceconti M. MicroCT examination of human bone specimens: effects of polymethylmethacrylate embedding on structural parameters. J Microsc. 2007 Feb;225(Pt 2):192-200.
  • Zauli G, Rimondi E, Stea S, Baruffaldi F, Stebel M, Zerbinati C, Corallini F, Secchiero P. TRAIL inhibits osteoclastic differentiation by counteracting RANKL-dependent p27Kip1 accumulation in pre-osteoclast precursors. J Cell Physiol. 2008 Jan;214(1):117-25.
  • Panaroni C, Gioia R, Lupi A, Besio R, Goldstein SA, Kreider J, Leikin S, Vera JC, Mertz EL, Perilli E, Baruffaldi F, Villa I, Farina A, Casasco M, Cetta G, Rossi A, Frattini A, Marini JC, Vezzoni P, Forlino A. In utero transplantation of adult bone marrow decreases perinatal lethality and rescues the bone phenotype in the knockin murine model for classical, dominant osteogenesis imperfecta. Blood. 2009 Jul 9;114(2):459-68.
  • Tassani S, Ohman C, Baleani M, Baruffaldi F, Viceconti M. Anisotropy and inhomogeneity of the trabecular structure can describe the mechanical strength of osteoarthritic cancellous bone. J Biomech. 2010 Apr 19;43(6):1160-6.
  • Tassani S, Ohman C, Baruffaldi F, Baleani M, Viceconti M. Volume to density relation in adult human bone tissue. J Biomech. 2011 Jan 4;44(1):103-8
  • Giannini C, Siliqi D, Bunk O, Beraudi A, Ladisa M, Altamura D, Stea S, Baruffaldi F. Correlative light and scanning X-ray scattering microscopy of healthy and pathologic human bone sections. Sci Rep. 2012;2:435.
  • Tassani S, Matsopoulos GK, Baruffaldi F. 3D identification of trabecular bone fracture zone using an automatic image registration scheme: A validation study. J Biomech. 2012 Jul 26;45(11):2035-40.
  • Benasciutti E, Mariani E, Oliva L, Scolari M, Perilli E, Barras E, Milan E, Orfanelli U, Fazzalari NL, Campana L, Capobianco A, Otten L, Particelli F, Acha-Orbea H, Baruffaldi F, Faccio R, Sitia R, Reith W, Cenci S. MHC class II transactivator is an in vivo regulator of osteoclast differentiation and bone homeostasis co-opted from adaptive immunity. J Bone Miner Res. 2014 Feb;29(2):290-303.

Downloads:

A full MicroCT dataset of a human cancellous bone biopsy is freely available on the net. Click here.

Content updated 25/06/2014 - 10:01
Content edited by: Dott. Fabio Baruffaldi (baruffaldi@tecno.ior.it)
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