title: Correlation of Subchondral Bone Density and Structure from Plain Radiographs with Micro Computed Tomography Ex Vivo.
abstract: Osteoarthritis causes changes in the subchondral bone structure and composition. Plain radiography is a cheap, fast, and widely available imaging method. Bone tissue can be well seen from plain radiograph, which however is only a 2D projection of the actual 3D structure. Therefore, the aim was to investigate the relationship between bone density- and structure-related parameters from 2D plain radiograph and 3D bone parameters assessed from micro computed tomography (µCT) ex vivo. Right tibiae from eleven cadavers without any diagnosed joint disease were imaged using radiography and with µCT. Bone density- and structure-related parameters were calculated from four different locations from the radiographs of proximal tibia and compared with the volumetric bone microarchitecture from the corresponding regions. Bone density from the plain radiograph was significantly related with the bone volume fraction (r = 0.86; n = 44; p < 0.01). Mean homogeneity index for orientation of local binary patterns (HI(angle,mean)) and fractal dimension of vertical structures (FD(Ver)) were related (p < 0.01) with connectivity density (HI(angle,mean): r = -0.73, FD(Ver): r = 0.69) and trabecular separation (HI(angle,mean): r = 0.73, FD(Ver): r = -0.70) when all ROIs were pooled together (n = 44). Bone density and structure in tibia from standard clinically available 2D radiographs are significantly correlated with true 3D microstructure of bone.
authors.affiliation: Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, POB 5000, 90014, Oulu, Finland. jukka.hirvasniemi@oulu.fi.|Infotech Oulu, University of Oulu, Oulu, Finland. jukka.hirvasniemi@oulu.fi.
authors.forename: Jukka
authors.initials: J
authors.lastname: Hirvasniemi
authors.affiliation: Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, POB 5000, 90014, Oulu, Finland.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Thevenot
authors.affiliation: Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Harri T
authors.initials: HT
authors.lastname: Kokkonen
authors.affiliation: Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, POB 5000, 90014, Oulu, Finland.|Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.|Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.
authors.forename: Mikko A
authors.initials: MA
authors.lastname: Finnilä
authors.affiliation: Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.|Cancer Center, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Mikko S
authors.initials: MS
authors.lastname: Venäläinen
authors.affiliation: Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, POB 5000, 90014, Oulu, Finland.|Infotech Oulu, University of Oulu, Oulu, Finland.|Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.|Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.
authors.forename: Timo
authors.initials: T
authors.lastname: Jämsä
authors.affiliation: Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland.|Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
authors.forename: Rami K
authors.initials: RK
authors.lastname: Korhonen
authors.affiliation: Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland.|Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
authors.forename: Juha
authors.initials: J
authors.lastname: Töyräs
authors.affiliation: Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, POB 5000, 90014, Oulu, Finland.|Infotech Oulu, University of Oulu, Oulu, Finland.|Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.|Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.
authors.forename: Simo
authors.initials: S
authors.lastname: Saarakkala
mesh_terms: D000328:Adult; D000368:Aged; D015519:Bone Density; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000000981:diagnostic imaging / Q000378:metabolism; D013977:Tibia / Q000000981:diagnostic imaging / Q000378:metabolism; D055114:X-Ray Microtomography / Q000379:methods*
keywords: Bone; Micro computed tomography; Radiography; Structural analysis; Texture analysis