Dynamic contrast-enhanced MR imaging in osteoid osteoma: relationships with clinical and CT characteristics.

Abstract

To correlate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) features to clinical and computed tomography (CT) morphological features of osteoid osteoma (OO). Our institutional review board approved this retrospective study, waiving the need for informed consent. We included the 102 patients treated with interstitial laser ablation for histologically documented OO at our institution in 2008-2013. DCE-MRI variables were the time-enhancement pattern and rising slope (Slope_rise) and CT variables were the bone and segment involved (OO_bone and OO_segment, respectively), OO location relative to the native cortex (OO_cortex), nidus surface area, vessel sign, and largest neighboring-vessel diameter (Dmax_vessel). Descriptive statistics and correlations linking DCE-MRI findings to clinical and CT characteristics were computed. DCE-MRI showed early arterial peak enhancement in 95 (93%) cases, with a mean Slope_rise of 9.30 ± 8.10. CT visualized a vessel sign in 84 (82%) cases with a mean Dmax_vessel of 1.10 ± 0.60 mm. By univariate analysis, Slope_rise correlated significantly with pain duration and Dmax_vessel (r = 0.30, P = 0.003; and r = 0.22, P = 0.03; respectively). Analysis of variance showed that Slope_rise correlated significantly with OO_bone (P < 0.001), with a steeper slope for OOs located in short or flat bones. This study suggests more abundant vascularization of OOs with long-lasting pain and location on short or flat bones.