Diffusional kurtosis imaging (DKI) incorporation into an intravoxel incoherent motion (IVIM) MR model to measure cerebral hypoperfusion induced by hyperventilation challenge in healthy subjects

Aude Pavilla (1, 2) , Giulio Gambarota (1) , Alessandro Arrigo (2) , Mehdi Mejdoubi (2) , Regis Duvauferrier (2) , Hervé Saint-Jalmes (1, 3)

1 LTSI - Laboratoire Traitement du Signal et de l'Image
2 CHU de la Martinique [Fort de France]
3 CRLCC - CRLCC Eugène Marquis

Objectives - The objectives were to investigate the diffusional kurtosis imaging (DKI) incorporation into the intravoxel incoherent motion (IVIM) model for measurements of cerebral hypoperfusion in healthy subjects. Materials and methods - Eight healthy subjects underwent a hyperventilation challenge with a 4-min diffusion weighted imaging protocol, using 8 b values chosen with the Cramer-Rao Lower Bound optimization approach. Four regions of interest in gray matter (GM) were analyzed with the DKI-IVIM model and the bi-exponential IVIM model, for normoventilation and hyperventilation conditions. Results - A significant reduction in the perfusion fraction (f) and in the product fD* of the perfusion fraction with the pseudodiffusion coefficient (D*) was found with the DKI-IVIM model, during the hyperventilation challenge. In the cerebellum GM, the percentage changes were f: -43.7 ± 40.1, p = 0.011 and fD*: -50.6 ± 32.1, p = 0.011; in thalamus GM, f: -47.7 ± 34.7, p = 0.012 and fD*: -47.2 ± 48.7, p = 0.040. In comparison, using the bi-exponential IVIM model, only a significant decrease in the parameter fD* was observed for the same regions of interest. In frontal-GM and posterior-GM, the reduction in f and fD* did not reach statistical significance, either with DKI-IVIM or the bi-exponential IVIM model. Conclusion - When compared to the bi-exponential IVIM model, the DKI-IVIM model displays a higher sensitivity to detect changes in perfusion induced by the hyperventilation condition.

Mots clés: Diffusion magnetic resonance imaging; Kurtosis; Hyperventilation; Perfusion; Intravoxel incoherent motion

Domaines: Traitement du signal et de l'image [eess.SP]; Ingénierie biomédicale

Aude Pavilla, Giulio Gambarota, Alessandro Arrigo, Mehdi Mejdoubi, Regis Duvauferrier, et al.. Diffusional kurtosis imaging (DKI) incorporation into an intravoxel incoherent motion (IVIM) MR model to measure cerebral hypoperfusion induced by hyperventilation challenge in healthy subjects. Magnetic Resonance Materials in Physics, Biology and Medicine, 2017, 30 (6), pp.545-554. ⟨10.1007/s10334-017-0629-9⟩. ⟨hal-01671399⟩