Sofie Van Cauter MD, Presenter: Nothing to Disclose

Jelle Veraart, Abstract Co-Author: Nothing to Disclose

Jan Sijbers, Abstract Co-Author: Nothing to Disclose

Uwe Himmelreich PhD, Abstract Co-Author: Nothing to Disclose

Ronald Peeters, Abstract Co-Author: Nothing to Disclose

Stefaan W. Van Gool, Abstract Co-Author: Nothing to Disclose

Wim Van Hecke, Abstract Co-Author: Co-founder, icoMetrix NV

Stefan Sunaert MD, Abstract Co-Author: Speaker, Koninklijke Philips Electronics NV

Steven De Vleeschouwer, Abstract Co-Author: Nothing to Disclose

Frank Van Calenbergh, Abstract Co-Author: Nothing to Disclose

Frederik De Keyzer MSc, Abstract Co-Author: Nothing to Disclose

Current routinely used magnetic resonance (MR) techniques are often insufficient in accurate grading of gliomas. In this study, we assessed the diagnostic accuracy of diffusion kurtosis imaging parameters in grading gliomas. Diffusion kurtosis imaging is an extension of diffusion tensor imaging, in which the degree of non-Gaussian diffusion is quantified.

27 patients with cerebral gliomas prior to any treatment (8F/19M; age range: 20-76, median age: 54) underwent DKI imaging at a 3T MR scanner using a spin-echo diffusion- weighted imaging sequence with b-values of 0, 700, 1000 and 2800 s/mm², applied in 10, 25, 40 and 75 uniformly distributed directions respectively. Diffusion parameters - mean diffusivity (MD), fractional anisotropy (FA), mean kurtosis (MK), radial and axial kurtosis (RK, AK) - were compared in the solid part of 17 high grade gliomas (HGG) and 11 low grade gliomas (LGG) (Mann-Whitney, p<0.05 significance, Bonferroni corrected). MD, FA, MK, RK and AK in solid tumor were furthermore normalized to the corresponding parameter value in contralateral normal appearing white matter (normWM) and the contralateral posterior limb of the internal capsule(PLIC) after age correction and compared among tumor grades.

MK, RK and AK were significantly higher in HGG compared to LGG (p=0.02, p=0.015, p=0.01). FA and MD did not significantly differ between glioma grades. All parameter values, except for AK, normalized to the contralateral white matter were significantly different between HGG and LGG (MK_normWM, p=0.02; RK_normWM, p=0.03; FA_normWM, p=0.025; and MD_normWM, p=0.03). When normalizing to PLIC, none of the considered parameters showed significant differences between HGG and LGG. Highest sensitivity and specificity to discriminate between HGG and LGG was found for MK and MK_normWM in solid tumor (71%; 82% and 100%; 73% respectively). Optimal thresholds for MK and MK_normWM to differentiate HGG from LGG were 0.52 and 0.51 respectively.

We demonstrated significant differences in kurtosis parameters between HGG and LGG, thereby showing better separation compared to parameters from conventional diffusion imaging.

Directional kurtosis metrics derived of the tensor can be regarded as potential new biomarkers in the grading of gliomas.

Van Cauter, S, Veraart, J, Sijbers, J, Himmelreich, U, Peeters, R, Van Gool, S, Van Hecke, W, Sunaert, S, De Vleeschouwer, S, Van Calenbergh, F, De Keyzer, F, DKI in the Grading of Gliomas.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11002748.html