Differentiating low‐ and high‐grade pediatric brain tumors using a continuous‐time random‐walk diffusion model at high b‐values. Issue 4 (31st October 2015)

• Record Type: Journal Article
• Authors: Karaman, M. Muge; Sui, Yi; Wang, He; Magin, Richard L.; Li, Yuhua; Zhou, Xiaohong Joe
• Is Part Of: Magnetic resonance in medicine. Volume 76:Issue 4(2016)
• Page Start: 1149
• Page End: 1157
• Publication Date: 2015-10-31
• Subjects: pediatric brain tumor -- non‐Gaussian diffusion -- continuous‐time‐random‐walk -- tumor grading -- high b‐value diffusion imaging; Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.26012
• Languages: English
• ISSNs: 0740-3194

Abstract

Abstract : Purpose: To demonstrate that a continuous‐time random‐walk (CTRW) diffusion model can improve diagnostic accuracy of differentiating low‐ and high‐grade pediatric brain tumors. Methods: Fifty‐four children with histopathologically confirmed brain tumors underwent diffusion MRI scans at 3Twith 12 b ‐values (0‐4000 s/mm 2 ). The diffusion imageswere fit to a simplified CTRW model to extract anomalous diffusion coefficient, Dm, and temporal and spatial heterogeneity parameters, α and β, respectively. Using histopathology results as reference, a k ‐means clustering algorithm and a receiver operating characteristic (ROC) analysis were employed to determine the sensitivity, specificity, and diagnostic accuracy of the CTRW parameters in differentiating tumor grades. Results: Significant differences between the low‐ and high‐grade tumors were observed in the CTRW parameters ( p ‐values<0.001). The k ‐means analysis showed that the combination of three CTRW parameters produced higher diagnostic accuracy (85% vs. 75%) and specificity (83% vs. 54%) than the apparent diffusion coefficient (ADC) from a mono‐exponential model. The ROC analysis revealed that any combination of the CTRW parameters gave a larger area under the curve (0.90‐0.96) than using ADC (0.80). Conclusion: With its sensitivity to intravoxel heterogeneity, the simplified CTRW model is useful for non‐invasive grading of pediatric brain tumors, particularly when surgical biopsy is not feasible. Magn Reson Med 76:1149–1157, 2016. © 2015 Wiley Periodicals, Inc.