3047915 MPAD main pulmonary artery diameter 35 3047916 MPAD main PA diameter 2 3047913 MPAD main pulmonary artery distensibility 2 3047918 MPAD Multilevel peripheral arterial disease 2 3047912 MPAD maximum permissible annual dose 1 3047914 MPAD microvascular pericyte area density 1 3047911 MPAD moderate physical activity duration 1 3047919 MPAD MPA diameter 1 3047917 MPAD MPA distensibility 1