- Hilar enlargement reflects one of 4 types of processes.
Lymphadenopathy and tumors
- Rounded, nonbranching structures in which the radiopacity abruptly diminishes at the margin of the tumor or lymph node
Pulmonary venous hypertension
- Enlargement of the superior pulmonary veins causes increased vascular density in the upper half of the hilum
- due to left ventricular failure, mitral stenosis or mitral regurgitation
Pulmonary arterial hypertension
- Central pulmonary arteries are dilated and taper abruptly
- due to primary pulmonary hypertension and lung diseases such as COPD
Increased pulmonary blood flow
- Increased central and peripheral pulmonary vascular markings (peripheral lung markings become visible in the peripheral 1–2 cm of the lung)
- due to left-to-right intracardiac shunts and hyperdynamic circulation
References and Links
- Schwartz DT, Reisdorff EJ. Emergency Radiology, McGraw-Hill 2000.