Skip to Main content Skip to Navigation
Theses

Quantification simultanée de la diffusion et de la perfusion cérébrale en imagerie par résonance magnétique : application au diagnostic de l’accident vasculaire cérébral ischémique.

Abstract : Ischemic stroke is a serious neurological disease of public health concern that constitutes a major cause of death and high costs of medical care. A quick and accurate diagnosis based on both clinical signs and medical images is necessary for the therapeutic decision (thrombolysis or mechanical thrombectomy). In accordance with the current recommendations, MRI is the primary intention modality to perform in order to confirm the ischemic stroke suspicion. The choice of a thrombolysis treatment is guided by the presence of a diffusion-perfusion mismatch, determined with two different sequences, and is associated with a better life outcome for the patient. The IVIM (« Intravoxel Incoherent Motion ») MRI sequence allows for the simultaneous diffusion and microperfusion quantification with the biexponential analysis of the diffusion signal obtained by a diffusion sequence sensitized to perfusion. This sequence could be of great interest for the ischemic stroke diagnosis. The methodological aspects implemented during this thesis consisted of the optimization of the acquisitions and data processing of IVIM imaging for quantitative assesments of cerebral diffusion and perfusion. First of all, the conventional biophysical model and IVIM sequence acquisitions were implemented and validated with a study on healthy subjects, in comparison with perfusion assesments obtained using ASL (Arterial Spin Labeling). Secondly, the conventional model was modified to consider the non-gaussian diffusion behavior in tissues with an additional quantitative parameter estimation, the kurtosis (DKI-IVIM model). This new model was also validated with a study on healthy subjects in comparison with the standard biexponential IVIM model. Finally, this method was applied in a clinical setting on five stroke patients. The preliminary results demonstrated the DKI-IVIM method efficiency for the acute ischemic stroke diagnosis when compared with the conventional diffusion-ASL perfusion with the additional estimation of the kurtosis for a better lesion characterization.
Complete list of metadata

https://tel.archives-ouvertes.fr/tel-01743681
Contributor : ABES STAR :  Contact
Submitted on : Monday, March 26, 2018 - 4:11:07 PM
Last modification on : Wednesday, September 14, 2022 - 10:20:04 AM
Long-term archiving on: : Thursday, September 13, 2018 - 10:27:43 AM

File

AudePavilla.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01743681, version 1

Citation

Aude Pavilla. Quantification simultanée de la diffusion et de la perfusion cérébrale en imagerie par résonance magnétique : application au diagnostic de l’accident vasculaire cérébral ischémique.. Traitement du signal et de l'image [eess.SP]. Université Rennes 1, 2017. Français. ⟨NNT : 2017REN1B025⟩. ⟨tel-01743681⟩

Share

Metrics

Record views

627

Files downloads

1127