Loss of pulmonary capillaries in idiopathic pulmonary arterial hypertension with low diffusion capacity is accompanied by early diffuse emphysema detected by (129)Xe MRI

OBJECTIVES: Recent studies suggest the existence of an idiopathic pulmonary arterial hypertension (IPAH) phenotype affecting mostly patients with a smoking history, characterised by low diffusion capacity for carbon monoxide (D(LCO)) without clinically significant emphysema. This study's objective was to test the hypothesis of a loss of pulmonary capillaries as an underlying mechanism by comparison to other patient groups with and without pulmonary hypertension (PH). MATERIALS AND METHODS: Between March 2019 and June 2023, patients of four groups were recruited for this observational study: IPAH with preserved (1) and low D(LCO) (2), combined pulmonary fibrosis and emphysema with PH (3), and emphysema without PH (4). Patients underwent clinical CT and (129)Xe MRI including dissolved-phase imaging yielding the ratio of (129)Xe in red blood cells and membrane tissues (RBC-M), chemical shift saturation recovery for determining RBC fraction

• Kern, A. L.
• Park, D. H.
• Fuge, J.
• Hohlfeld, J. M.
• Wacker, F.
• Hoeper, M. M.
• Olsson, K. M.
• Vogel-Claussen, J.