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While histologic response to neoadjuvant chemotherapy (NChT) is the major prognostic factor for osteosarcoma treatment, evaluating that response is difficult.To evaluate the feasibility of the blood oxygen level-dependent (BOLD) technique to assess the response to NChT.Prospective.Twelve patients with osteosarcoma undergoing NChT.3 T; T2*-weighted BOLD, dynamic contrast-enhanced (DCE) and diffusion-weighted (DW) (b values of 0, 400, and 1400 seconds/mmExamination was performed before treatment (first), after each cycle of treatment (second and third). At each time point, spin dephasing rates (R2*) from BOLD magnetic resonance imaging (MRI), parameters from DCE-MRI (volume transfer constant [KWilcoxon's signed rank test, Spearman's correlation coefficient (ρ) were used. A P-value of0.05 was considered statistically significant.The difference and relative difference of the R2* values between the first/third MRIs in the extraosseous portion were statistically significant. Only the differences in the kThe R2* from the BOLD MRI technique could be a useful biomarker for evaluating treatment response in osteosarcoma treated with NchT.5 TECHNICAL EFFICACY: Stage 2.

Purpose To determine a new cutoff value that can further distinguish between the incomplete and complete discoid lateral meniscus (DLM). Materials and Methods Twenty-one cases of incomplete DLM and 42 cases of complete DLM without tear were included. In all, 105 patients with normal lateral menisci were included as a control group. We measured the ratio of the shortest width of the lateral meniscus to the longest width of the tibia (ratio 1) and the ratio of the shortest width of the medial meniscus to the shortest width of the lateral meniscus (ratio 2). Results By applying a cutoff value of ratio 1 as 0.32 between two incomplete and complete DLM groups, the proportion of the complete and incomplete DLM diagnosed cases among the true cases were 84% and 94%, respectively. By applying a cutoff value of ratio 2 as 0.40 between two incomplete and complete DLM groups, the proportion of the complete and incomplete DLM diagnosed cases among the true cases were 84% and 75%, respectively. Conclusion A cutoff value of 0.32 using the ratio of the shortest width of the lateral meniscus and the longest width of the tibia are probably useful to help distinguish between complete DLM and incomplete DLM. Additionally, the new ratio using the width of the medial meniscus is also useful to improve distinguishing between the types of DLM. J. Magn. Reson. Imaging 2013;38:417–421. © 2013 Wiley Periodicals, Inc.