Hepatopulmonary Syndrome

Clinical History

Patient with liver cirrhosis and intermittent dyspnea

Imaging Findings

A patient with liver cirrhosis was admitted because of intermittent dyspnea. There is known smoking-related emphysematous diffuse lung disease. Arterial blood-gas analysis showed a decreased pO2 (59mmHg) and pCO2 (26mmHg) on room air. A conventional chest roentgenogram (Figure 1) demonstrates reticulonodular opacities predominantely in the lower lobes. A thin-section CT demonstrates dilated vessels (Figure 2a) with an increased number of terminal branches extending to the pleura (Figure 2b).

Discussion

Hepatopulmonary syndrome is a process associated with end-stage liver disease. The diagnosis is established with three criteria: chronic liver disease, increased alveolar-arterial gradient and evidence of intrapulmonary vascular dilatation [1, 3]. Especially the peripheral vasculature is significantly larger whereas the central pulmonary arteries are spared [2]. In cirrhotic patients the clearence of many circulating mediators is reduced which is believed to be the etiopathogenesis for hepatopulmonary syndrome. However the principal vasoactive substance that causes hepatopulmonary syndrome has not been identified. Hypoxemia is seen in one-third of decompensated cirrhotic patients and is believed to result from an inability of oxygen to diffuse to the center of the massively dilated peripheral vessels. CT is useful in the differential diagnosis as it rules out other causes of hypoxemia such as pulmonary fibrosis. Typical CT features are dilated peripheral vasculature and bibasilar reticulonodular opacities [3].

Differential Diagnosis List

Final Diagnosis

Hepatopulmonary Syndrome

URL:	https://eurorad.org/case/3256
DOI:	10.1594/EURORAD/CASE.3256
ISSN:	1563-4086