Optimizing Repeatability of RBC Signal Oscillation Measures from Hyperpolarized 129Xe MRI

Motivation: Hyperpolarized 129Xe MRI (Xe-MRI) RBC signal oscillation imaging is a technique in development for assessing microvascular function. Optimal methods for generating oscillation images have not been established. Goal(s): Using repeatability as a primary outcome, we aim to optimize Xe-MRI oscillation imaging in pulmonary arterial hypertension and scleroderma patients. Approach: Patients were imaged twice within 10 minutes using Xe-MRI gas exchange imaging. Different oscillation imaging strategies were employed, and the repeatability of each was assessed. Results: Global measures of oscillation amplitude showed repeatability similar to standard gas exchange measures. Image-based measures showed weaker repeatability demonstrating a need for additional development of the technique. Impact: Hyperpolarized 129Xe oscillation imaging is a noninvasive technique to assess pulmonary microvascular function. By optimizing the technique for repeatability, it has potential to provide a new means to interrogate pulmonary vascular diseases.