Using Radon transform of standard radiographs of the hip to differentiate between post-menopausal women with and without fracture of the proximal femur
- 76 Downloads
Texture features based on the Radon transform were extracted from clinical radiographs of the hip in post-menopausal women. The novel algorithm allowed us to identify patients with fracture of the proximal femur and may provide an alternative to measuring bone mineral density in predicting the fracture-risk in osteoporosis, especially where densitometry is regionally unavailable.
The aim of this study is to introduce an algorithm for differentiation between patients with and without fracture of the hip using parameters based on the Radon transform (RT) and applied to standard radiographs of the proximal femur and to compare the results with bone mineral density (BMD).
The study comprised 50 post-menopausal women (78.6 ± 11.5 years of age), including 25 patients with hip fracture and 25 age-matched controls. We obtained lumbar and femoral BMD and standard femoral radiographs. In the radiographs we analysed trabecular patterns of the hip in a region-of-interest of 57 x 29 mm using the RT. From the histogram-representation of the RT, we extracted several characteristic parameters. By ROC and discriminant-analysis, we assessed the statistical power of both methods.
For correct differentiation between fracture and non-fracture cases by femoral BMD, area-under-the-curve (AUC) was 0.78; AUC for the RT-based parameters ranged from 0.73 to 0.8. By combination of densitometric and textural information in a multivariate model the fracture status of 84% of subjects was predicted correctly, identification of fracture cases rose to 88%.
Identification of fracture patients by RT applied to femoral radiographs was feasible and seemed to have a discriminative potential comparable to that of standard densitometry. In the future, the new method may provide an alternative to DXA or in conjunction with conventional densitometry may enhance the detection of patients with elevated risk of hip fracture.
KeywordsFracture risk In vivo Osteoporosis Proximal femur Radiographic texture analysis Radon transform
- 4.WHO (1994) Assessment of fracture risk and its application to screening for postmenopausal osteoporosis: report of a WHO study group. WHO Technical Report Series 843Google Scholar
- 19.Pulkkinen P, Jämsä T, Lochmüller EM et al. (2007) Experimental hip fracture load can be predicted from plain radiography by combined analysis of trabecular bone structure and bone geometry. Osteo Int 2007 Sep 22 [Epub ahead of print]Google Scholar
- 27.Huberty C (1994) Applied discriminant-analysis. Wiley, New YorkGoogle Scholar
- 29.Stone M (1977) An asymptotic equivalence of choice of model by cross-validation and akaike’s criterion. J R Stat Soc 38:44–47Google Scholar
- 36.Odgaard A, Kabel J, van Rietbergen B et al (1997) Fabric and elastic principal directions of cancellous bone are closely related. J Biomech 30(11–12):1191–1193Google Scholar
- 40.Wigderowitz CA, Abel EW, Rowley DI (1997) Evaluation of cancellous structure in the distal radius using spectral analysis. Clin Orthop 152–161Google Scholar