Phenotype Identification Based on Multimodal MRI Analysis of Patients With Bronchial Obstructive Diseases

Overview

The hypothesis is that pulmonary and cardiac proton MRI allows phenotyping of patients with bronchial obstruction by cluster analysis based on quantitative multimodal imaging of bronchi, pulmonary vessels, pulmonary parenchyma, right and left ventricular function, myocardial fibrosis and pulmonary arterial pressure. Such imaging will also offer the advantage of being non-irradiating and without contrast products, which will ultimately allow CT to be replaced by MRI in the follow-up of bronchial obstructive patients, thus avoiding the risks associated with repeated exposure to ionizing radiation.

Bronchial obstructive diseases such as asthma and chronic obstructive pulmonary disease (COPD) are very common and represent a major public health problem. The distinction between these two diseases is sometimes difficult. In each of these diseases, several clinical phenotypes or biological endotypes have been defined. For example, frequent exacerbating patients and / or hypereosinophilic patients are present in both diseases. In the severe states, cardiovascular comorbidities are the most frequent comorbidities and alter the prognosis. In these chronic obstructive patients, computed tomography (CT) allows a multimodal analysis of the bronchial wall, the lung parenchyma and pulmonary vessels. CT also allows a score analysis of coronary plaques. However, irradiation is significant and increases with repeated examinations. CT does not allow a comprehensive analysis of cardiac function, or an estimate of pulmonary artery pressure. Magnetic Resonance Imaging (MRI) is a proton non-ionizing alternative to CT, in particular when using 3D ultra-short echo-time (UTE) sequences. These 3D-UTE sequences decrease the effects of magnetic susceptibility and provide morphological and morphometric information on bronchi and lung comparable to those obtained by CT. Moreover, dedicated sequences add functional information on bronchi. Heart MRI allows more analyses, such as right and left ventricular systolic functions, an indirect estimate of pulmonary arterial pressure and the amount of diffuse myocardial fibrosis. Our project aims to identify morphological phenotypes through the pulmonary and heart MRI in patients with obstructive lung disease .