MUSCULOSKELETAL Dynamic contrast-enhanced MR imaging for differentiation between enchondroma and chondrosarcoma T. De Coninck & L. Jans & G. Sys & W. Huysse & T. Verstraeten & R. Forsyth & B. Poffyn & K. Verstraete Received: 13 January 2013 / Revised: 26 April 2013 / Accepted: 26 April 2013 # European Society of Radiology 2013 Abstract Objectives To determine whether dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) can differentiate benign from malignant cartilage tumours compared to standard MRI. To investigate whether a cutoff value could be determined to differentiate enchondroma from low-grade chondrosarcoma (CS) more accurately. Methods One hundred six patients were included in this ret- rospective study: 75 with enchondromas (mean age=41 years) and 31 with CS (mean age=47 years). Within this population, a subgroup of patients was selected with the tumour arising in a long bone. At the time of diagnosis, the tumours were evaluated on MRI, including standard MRI, DCE-MRI, and region-of-interest (ROI) analysis to obtain information on tumour vascularisation and perfusion. Results The main cutoff value to differentiate enchondroma from CS contained a two-fold more relative enhancement compared with muscle, combined with a 4.5 (= 76°) slope value, with 100 % sensitivity and 63.3 % specificity. The prediction of CS diagnosis with DCE-MRI had 93.4 % accuracy. The accuracy of the standard MRI parameters was equal to the DCE-MRI parameters. Conclusions Standard MRI and DCE-MRI both play an im- portant and complementary role in differentiating enchondroma from low-grade CS. A combination of both imaging techniques leads to the highest diagnostic accuracy for differentiating cartilaginous tumours. Key Points • DCE-MRI plays an important role in differentiating be- nign from malignant cartilage tumours. • Retrospective study defined a threshold for 100 % detec- tion of chondrosarcoma with DCE-MRI. • The threshold values were relative enhancement=2 and slope=4.5. • One hundred per cent chondrosarcoma detection corre- sponds with 36.7 % false-positive diagnosis of enchondroma. • Standard MRI is complementary to DCE-MRI in differen- tiating cartilaginous tumours. Keywords DCE-MRI . Dynamic . Differentiation . Chondrosarcoma . Enchondroma Abbreviations and acronyms DCE- MRI dynamic contrast-enhanced magnetic resonance imaging CS chondrosarcoma ROI region of interest SE spin echo GR gradient echo SI signal intensity TIC time-intensity curve AUC area under the curve ROC receiver-operating characteristic Electronic supplementary material The online version of this article (doi:10.1007/s00330-013-2913-z) contains supplementary material, which is available to authorized users. T. De Coninck (*) : L. Jans : W. Huysse : T. Verstraeten : K. Verstraete Department of Radiology, Ghent University Hospital, De Pintelaan 185, 9000, Ghent, Belgium e-mail: tineke.deconinck@ugent.be G. Sys : B. Poffyn Department of Orthopaedic Surgery and Traumatology, Ghent University Hospital, De Pintelaan 185, 9000, Ghent, Belgium R. Forsyth Department of Pathology, Pathlicon Histopathology and Molecular Laboratories, Reibroekstraat 13, 9940, Evergem (Ghent), Belgium Eur Radiol DOI 10.1007/s00330-013-2913-z