FIGURE 1.

a) Illustration of the normal pulmonary artery and vein structure stained with Movat Pentachrome (4× magnification). The pulmonary arteries are well rounded in structure, while veins are elongated and irregular. b) Movat Pentachrome-stained normal control and idiopathic pulmonary fibrosis (IPF) of pulmonary arteries’ external and luminal length measurement (20× magnification). External length is measured from one end to the other end of the adventitia layer margin crossing the middle of the lumen, while the luminal length was measured from one end to another end of the intima layer margin. In the inset are layers of various thickness (T1 – intima, T2 – media and T3 – adventitia).