Show simple item record

dc.contributor.authorPodsiadlo, P
dc.contributor.authorWolski, M
dc.contributor.authorStachowiak, Gwidon
dc.date.accessioned2017-01-30T14:57:07Z
dc.date.available2017-01-30T14:57:07Z
dc.date.created2014-03-09T20:00:41Z
dc.date.issued2008
dc.identifier.citationPodsiadlo, P and Wolski, M and Stachowiak, Gwidon. 2008. Automated Selection of Trabecular Bone Regions in Knee Radiographs. Medical Physics. 35 (5): pp. 1870-1883.
dc.identifier.urihttp://hdl.handle.net/20.500.11937/42050
dc.identifier.doi10.1118/1.2905025
dc.description.abstract

Osteoarthritic (OA) changes in knee joints can be assessed by analyzing the structure of trabecular bone (TB) in the tibia. This analysis is performed on TB regions selected manually by a human operator on x-ray images. Manual selection is time-consuming, tedious, and expensive. Even if a radiologist expert or highly trained person is available to select regions, high inter- and intraobserver variabilities are still possible. A fully automated image segmentation method was, therefore, developed to select the bone regions for numerical analyses of changes in bone structures. The newly developed method consists of image preprocessing, delineation of cortical bone plates (active shape model), and location of regions of interest (ROI). The method was trained on an independent set of 40 x-ray images. Automatically selected regions were compared to the "gold standard" that contains ROIs selected manually by a radiologist expert on 132 x-ray images. All images were acquired from subjects locked in a standardized standing position using a radiography rig. The size of each ROI is 12.8×12.8 mm. The automated method results showed a good agreement with the gold standard [similarity index (SI) =0.83 (medial) and 0.81 (lateral) and the offset= [-1.78, 1.27] × [-0.65,0.26] mm (medial) and [-2.15, 1.59] × [-0.58, 0.52] mm (lateral)]. Bland and Altman plots were constructed for fractal signatures, and changes of fractal dimensions (FD) to region offsets calculated between the gold standard and automatically selected regions were calculated. The plots showed a random scatter and the 95% confidence intervals were (-0.006, 0.008) and (-0.001, 0.011). The changes of FDs to region offsets were less than 0.035. Previous studies showed that differences in FDs between non-OA and OA bone regions were greater than 0.05. ROIs were also selected by a second radiologist and then evaluated. Results indicated that the newly developed method could replace a human operator and produces bone regions with an accuracy that is sufficient for fractal analyses of bone texture.

dc.publisherAmerican Association of Physicists in Medicine
dc.subjectTrabecular bone
dc.subjectOsteoarthritis
dc.subjectKnee radiography
dc.subjectComputer-aided diagnosis
dc.titleAutomated Selection of Trabecular Bone Regions in Knee Radiographs
dc.typeJournal Article
dcterms.source.volume35
dcterms.source.number5
dcterms.source.startPage1870
dcterms.source.endPage1883
dcterms.source.issn0094-2405
dcterms.source.titleMedical Physics
curtin.department
curtin.accessStatusFulltext not available


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record