CT Pulmonary Angiography Features of a Hepatopulmonary Syndrome

A 59-year-old man presented a six-month history of worsening dyspnea and dry cough, and not responding to medication. There was no history of fever, hematemesis, loss of appetite, or chest pain. Physical examination revealed peripheral cyanosis and clubbing. Bibasilar crepitations were present but no murmur was auscultated. Platypnea (worsening of dyspnea in a standing position) was present. Arterial gas analysis showed a PaO2 of 52 mm when breathing ambient room air. Laboratory findings were significant for a mildly abnormal liver function test. The chest radiograph revealed reticulo-nodular opacities in the bilateral upper and lower lungs. A high resolution CT of lung showed mild diffuse subpleural septal thickening with abnormally dilated vessels in the periphery of both lower lungs. Because the extent of interstitial lung disease did not explain the persistent hypoxemia, a decision to perform a CT pulmonary angiogram (CTPA) was taken to evaluate for pulmonary thromboembolism. A CTPA ruled out