Dynamic Contrast-enhanced MR Imaging Of Musculoskeletal Tumor Or Tumor-like Lesions

Purpose: To study the diagnostic value of dynamic contrast-enhanced MR imaging in differentiating benign from malignant musculoskeletal tumor or tumor-like lesions. Materialc and Metho? Thirty-six patiems were perftuned with rim-contrast conventional MR imaging, STIR,dynamic and static contrast-enhanced scam. The differences of signal intensity homogeneity; border, margin, adjacent n陁rovascular butxlie encasement and patterns of static contrast-enhanced we analysed ami compared between benign lesions and malignant ones. Some enhanced parameters of dynamic MR inuginginckiiing types of SI-rime curve, the early slope value of enhancement and the ratio of rim-to-center differential enhancement rates, were put more analysis. Using ROC curve plotting obtained the best decisive threshold. relation analysis was used to determine the relation between slope and microvessel density of tumor tissues. Results: The diffrences of signal intensity homogeneity, border, adjacent neurovascular bundle encasement, and patterns of static enhancement were not statistical signifinance in conventional MR imaging. but there was a statistical significance for marginal morphology features in STIR and for types of SI-Time curve of dynamic contrast-enhanced MR imaging between benign and malignant tuiriors(p<0.005). The average early slope value of enhancement was 4.33± 2.70% per second (range 0.97-10.500/o per second)for malignant lesions, and was 1 .46±0.97% per second (range 0.37-3.86% per second) for benign ones. There was an apparent statistical significance between benign and malignant tumors(P<0.00l). the slope values can give information about the malignant potential of a tumor by using 2.00/c per second as threshold(sensitivity 83.3%,speciflcity 77.8%,accuracy 80.6%). The average ratio of rim-to-center 2 differential enhancement rates was O.58±0.21(range0.27-0.92) for malignant tumors and 0.15±0.27(range -0.10-0.59) for benign ones. This difference was statistically significance (P<0.001). The ratio of tim-to-center also can give information about the malignant potential of a tumor using 0.25 as threslDld(sei~itivity 100.0%,speciflcity 7.22%,accuracy 86.1%). There are a certain degree of overlap for these dynamic enhanced parameters. There was a linear positive correlation between the slope and the microvessel density(r30.90,P<0.05). Conelusiotu: STiR provides a valuable qualitative indicator to distinguish benign from malignant tumors. The dynamic conizast-enhanced parameters, the slope value and the ratio of rim-to-center differential enhancement rates, provide a diagnostically useful quantitative indicators to differentiate benign from malignant tumors The Ibrmer depicts tissue vasculation and perfusion, and the latter demonstrate different characteristics of vascular distribution and interstitium pressure between benign and malignant tumors.