Noninvasive diagnosis of pulmonary hypertension with hyperpolarised129Xe magnetic resonance imaging and spectroscopy

Background: Xe MRI/MRS to diagnose PH status compared to right heart catheterisation (RHC). Methods: Xe MRI/MRS to classify subjects as pre-capillary PH, post-capillary PH, no PH and no interstitial lung disease (ILD), or ILD. Results: Xe MRI/MRS diagnostic accuracy was 75% (95% CI 66-84) with a sensitivity of 67% (95% CI 54-79) and a specificity of 86% (95% CI 75-96); for post-capillary PH accuracy was 69% (95% CI 59-78) with sensitivity of 54% (95% CI 34-74) and specificity of 74% (95% CI 63-84). The model performed well in straightforward cases of pre-capillary PH but was less accurate in its diagnosis in the presence of mixed disease, particularly in the presence of ILD or combined post- and pre-capillary PH. Conclusion: Xe dynamic MRS and gas-exchange MRI uniquely provide concurrent, noninvasive assessment of both haemodynamics and gas-exchange impairment that may aid in the detection of PH.