Purpose: Histologic grade is currently the best predictor of clinical course in chondrosarcoma patients. Grading suffers, however, from extensive interobserver variability and new objective markers are needed. Hence, we have investigated DNA copy numbers in chondrosarcomas with the purpose of identifying markers useful for prognosis and subclassification. Experimental Design: The overall pattern of genomic imbalances was assessed in a series of 67 chondrosarcomas using array comparative genomic hybridization. Statistical analyses were applied to evaluate the significance of alterations detected in subgroups based on clinical data, morphology, grade, tumor size, and karyotypic features. Also, the global gene expression profiles were obtained in a subset of the tumors. Results: Genomic imbalances, in most tumors affecting large regions of the genome, were found in 90% of the cases. Several apparently distinctive aberrations affecting conventional central and peripheral tumors, respectively, were identified. Although rare, recurrent amplifications were found at 8q24.21-q24.22 and 11q22.1-q22.3, and homozygous deletions of loci previously implicated in chondrosarcoma development affected the CDKN2A, EXT1, and EXT2 genes. The chromosomal imbalances in two distinct groups of predominantly near-haploid and near-triploid tumors, respectively, support the notion that polyploidization of an initially hyperhaploid/ hypodiploid cell population is a common mechanism of chondrosarcoma progression. Increasing patient age as well as tumor grade were associated with adverse outcome, but no copy number imbalance affected metastasis development or tumor-associated death. Conclusion: Despite similarities in the overall genomic patterns, the present findings suggest that some regions are specifically altered in conventional central and peripheral tumors, respectively.

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The proposed 3D multi-scale QPBO algorithm offers accurate water-fat separation, robustness to noise, and fast reconstruction. The software implementation is freely available to the research community. Magn Reson Med 78:941-949, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Background Clinical MRI protocols are time‐consuming; hence, new faster techniques are needed. One new fast multicontrast MRI technique, called echo planar image mix (EPIMix) (including contrasts T1‐FLAIR, T2‐weighted, diffusion‐weighted images [DWI], apparent diffusion coefficient [ADC], T2*‐weighted, and T2‐FLAIR images) needs to be tested. Purpose To assess if EPIMix has comparable diagnostic performance as routine clinical brain MRI. Study Type Prospective. Population A consecutive series of 103 patients' brain MRI (January 2018 to May 2018). Field Strength/Sequence 1.5 T or 3T. EPIMix and routine clinical protocol (clinical MRI included all or some of the contrasts T1‐FLAIR, T2‐weighted, DWI, T2*‐weighted, T2‐FLAIR, 3D‐FSE). Assessment Two neuroradiologists assessed EPIMix and clinical scans and categorized the images as abnormal or normal and described diagnosis, artifacts, diagnostic confidence image quality, and comparison of imaging time. Statistical Tests Pivot tables with diagnostic performance calculated by receiver operating characteristics (ROC) and the area under curve (AUC). Disease categorization and image quality measures were evaluated. The study protocol is published at http://clinicaltrials.gov NCT03338270. Results After exclusion of 21 patients, 82 patients had a routine clinical MRI with comparable contrasts to EPIMix and were evaluated. The diagnostic performance to categorize a full brain MRI investigation as abnormal or normal was comparable between EPIMix (AUC 0.99 (95% confidence interval [CI] 0.97–1.00) and 0.99 (95% CI 0.97–1.00)) and routine clinical MRI (n = 82). Sensitivity was 95% (95% CI 88–95) and 93% (95% CI 86–98), and specificity 100% (95% CI 97–100) and 100% (95% CI 90–100). Disease categorization was congruent between EPIMix and clinical routine MRI in 90% (reader 2) and 93% (reader 1). Image quality was generally rated lower for EPIMix (P < 0.001). Imaging time was 78 seconds for EPIMix and for the same contrasts 12 minutes 29 seconds for conventional 3T MRI. Data Conclusion EPIMix has comparable diagnostic performance (disease identification and categorization) for most patients investigated in clinical routine. Level of Evidence 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1824–1833.