Evaluating the acute response to oxygen using hyperpolarized 129-xenon dissolved-phase MRSI interleaved with global MRS in a porcine model

Motivation: Hyperpolarized xenon (129Xe) gas reveals key characteristics of pulmonary physiology such as ventilation and alveolar-capillary gas transfer. Dissolved-phase red blood cell (RBC) oscillations have been shown to improve detection of pulmonary arterial hypertension. Goal(s): Implement and validate dissolved-phase MRSI with interleaved MRS to image gas transfer and RBC oscillations. Approach: MRSI and interleaved MRS were acquired in 15 s breath-hold with an image resolution of 2x2x3 cm. RBC oscillations were evaluated in 14 healthy pigs under vasoactive interventions of 15% (capillary constriction), 21% (atmosphere) and 40% (capillary dilation) oxygen concentration. Results: RBC oscillations increased in amplitude with oxygen concentration. Impact: The study implements and validates a dissolved-phase MRSI with interleaved MRS to image gas transfer and RBC oscillations during vasoactive interventions. Alveolar-capillary modulation effects on blood oscillations are crucial for the methods application in detection of pulmonary arterial hypertension detection.