title: Differentiation of Low- and High-Grade Gliomas Using High b-Value Diffusion Imaging with a Non-Gaussian Diffusion Model.
abstract: Imaging-based tumor grading is highly desirable but faces challenges in sensitivity, specificity, and diagnostic accuracy. A recently proposed diffusion imaging method by using a fractional order calculus model offers a set of new parameters to probe not only the diffusion process itself but also intravoxel tissue structures, providing new opportunities for noninvasive tumor grading. This study aimed to demonstrate the feasibility of using the fractional order calculus model to differentiate low- from high-grade gliomas in adult patients and illustrate its improved performance over a conventional diffusion imaging method using ADC (or D).
  
  
  
  Fifty-four adult patients (18-70 years of age) with histology-proved gliomas were enrolled and divided into low-grade (n = 24) and high-grade (n = 30) groups. Multi-b-value diffusion MR imaging was performed with 17 b-values (0-4000 s/mm(2)) and was analyzed by using a fractional order calculus model. Mean values and SDs of 3 fractional order calculus parameters (D, β, and μ) were calculated from the normal contralateral thalamus (as a control) and the tumors, respectively. On the basis of these values, the low- and high-grade glioma groups were compared by using a Mann-Whitney U test. Receiver operating characteristic analysis was performed to assess the performance of individual parameters and the combination of multiple parameters for low- versus high-grade differentiation.
  
  
  
  Each of the 3 fractional order calculus parameters exhibited a statistically higher value (P ≤ .011) in the low-grade than in the high-grade gliomas, whereas there was no difference in the normal contralateral thalamus (P ≥ .706). The receiver operating characteristic analysis showed that β (area under the curve = 0.853) produced a higher area under the curve than D (0.781) or μ (0.703) and offered a sensitivity of 87.5%, specificity of 76.7%, and diagnostic accuracy of 82.1%.
  
  
  
  The study demonstrated the feasibility of using a non-Gaussian fractional order calculus diffusion model to differentiate low- and high-grade gliomas. While all 3 fractional order calculus parameters showed statistically significant differences between the 2 groups, β exhibited a better performance than the other 2 parameters, including ADC (or D).
authors.affiliation: From the Center for MR Research (Y.S., Y.X., M.M.K., X.J.Z.) Departments of Bioengineering (Y.S., X.J.Z.).
authors.forename: Y
authors.identifier: 0000-0002-8177-1661
authors.initials: Y
authors.lastname: Sui
authors.affiliation: From the Center for MR Research (Y.S., Y.X., M.M.K., X.J.Z.) Department of Radiology (Y.X., J.J., W.Z.), Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
authors.forename: Y
authors.identifier: 0000-0002-6270-5220
authors.initials: Y
authors.lastname: Xiong
authors.affiliation: Department of Radiology (Y.X., J.J., W.Z.), Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
authors.forename: J
authors.identifier: 0000-0002-0852-930X
authors.initials: J
authors.lastname: Jiang
authors.affiliation: From the Center for MR Research (Y.S., Y.X., M.M.K., X.J.Z.).
authors.forename: M M
authors.identifier: 0000-0002-7080-7307
authors.initials: MM
authors.lastname: Karaman
authors.affiliation: Radiology (K.L.X., X.J.Z.).
authors.forename: K L
authors.identifier: 0000-0003-1373-2975
authors.initials: KL
authors.lastname: Xie
authors.affiliation: Department of Radiology (Y.X., J.J., W.Z.), Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. xjzhou@uic.edu zhuwenzhen@hotmail.com.
authors.forename: W
authors.identifier: 0000-0002-0254-6563
authors.initials: W
authors.lastname: Zhu
authors.affiliation: From the Center for MR Research (Y.S., Y.X., M.M.K., X.J.Z.) Departments of Bioengineering (Y.S., X.J.Z.) Radiology (K.L.X., X.J.Z.) Neurosurgery (X.J.Z.), University of Illinois at Chicago, Chicago, Illinois xjzhou@uic.edu zhuwenzhen@hotmail.com.
authors.forename: X J
authors.identifier: 0000-0003-0793-4925
authors.initials: XJ
authors.lastname: Zhou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading / Q000379:methods*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D055815:Young Adult