Clinical trials

Determine the ability of 129Xe MRI/MRS biomarker signatures to non-invasively monitor pulmonary vascular reverse remodeling induced by sotatercept in pulmonary arterial hypertension (PAH).

The overall study objectives outlined in this study are to derive 129Xe MRI pulmonary vascular biomarker signatures that differentiate common subtypes of PAH and to determine the ability of 129Xe MRI to longitudinally monitor disease progression and response to therapy in PAH, with the aid of additional assessments, such as labs, echocardiography, and six-minute walk distance (6MWD).

The main goal of this study is to develop a noninvasive signature for pulmonary vascular remodeling in Group 3 PH patients, using hyperpolarized 129Xe magnetic resonance imaging (129Xe MRI). Such a signature may identify Group 3 PH responders to PAH-specific therapies. PAH's unique 129Xe MRI signature has been shown in previous studies. Past studies have lacked a pathologic "ground truth" correlate of these signatures, which could be provided by comparing them with the pathology of lung explant tissue from patients who have undergone a lung transplant. This signature could be validated in a cohort of patients with Group 3 PH in future studies.

The goal of this NIH-sponsored study is to characterize three biomarkers derived from 129Xe gas exchange MRI and to understand how they change in response to interventions.

The purpose of this study is to develop and evaluate the usefulness of MRI using 129Xe gas for regional assessment of pulmonary function. Specifically, three forms of 129Xe MRI contrast will be the investigators focus - 1) imaging of the 129Xe ventilation distribution, 2) imaging the alveolar microstructure via the 129Xe apparent diffusion coefficient (ADC), and 3) imaging 129Xe that dissolves in the pulmonary blood and tissues upon inhalation. Such imaging of 129Xe gas transfer is expected to be uniquely sensitive to pathologies affecting gas exchange (fibrosis, emphysema, pulmonary hypertension) and provide new insights regarding the normal resting heterogeneity of pulmonary gas exchange.

In this study, xenon MRI will be used to evaluate regional functional consequences of mucus plugs in the lungs of patients with severe asthma. Mucus plugs will be identified using CT imaging, and xenon MRI will be used to evaluate ventilation and gas exchange impairments in regions of the lungs corresponding to the airways downstream of mucus plugs.

The goal of this clinical trial is to evaluate whether inhaled Treprostinil (Tyvaso) can improve oxygen delivery and blood flow in the lungs in adults (age ≥40) with chronic obstructive pulmonary disease (COPD) and hypoxemia who have less severe reduction in lung blood volume (diffusing capacity of the lungs for carbon monoxide \[DLCO\] ≥45%). The main questions it aims to answer are: 1. Does inhaled Treprostinil increase pulmonary capillary blood volume in ventilated lung regions, as measured by hyperpolarized xenon-129 magnetic resonance imaging (HP129Xe MRI)? 2. Does inhaled Treprostinil improve oxygen delivery (measured as red blood cell \[RBC\] chemical shift) and maintain or only slightly change pulmonary vascular resistance (measured by RBC oscillation amplitude)? 3. Can pre-treatment MRI parameters (RBC transfer and RBC oscillation amplitude) predict who will respond to inhaled Treprostinil? Participants will: * Use the Tyvaso nebulizer (inhaled Treprostinil) 4 times daily for 4 weeks, starting at 3 breaths per session and increasing to a maximum of 6 breaths per session as tolerated. * Undergo HP129Xe MRI before and after treatment to assess regional lung function and oxygen exchange. * Complete pulmonary function tests (PFTs), 6-minute walk tests (6MWT), and echocardiograms at the beginning and end of the study. * Be monitored for adverse events, with a phone check-in midway through and after the treatment period.