Pulmonary hypertension: CT of the chest in pulmonary venoocclusive disease.

OBJECTIVE: Pulmonary venoocclusive disease is a rare cause of pulmonary hypertension that is often difficult to distinguish from severe primary pulmonary hypertension. Unfortunately, medical treatment of primary pulmonary hypertension with prostacyclin can be fatal in patients with venoocclusive disease, and an early pretreatment diagnosis of this uncommon condition is critical. The aim of our study was to evaluate this disease noninvasively using CT of the chest. MATERIALS AND METHODS: We reviewed cross-referenced records from 1996 to 2001 in our departments of radiology and pathology and identified 15 patients with initial pretreatment CT scans who had pathologically confirmed pulmonary venoocclusive disease. Their CT scans were compared with the CT scans of 15 consecutive patients with pathologically confirmed primary pulmonary hypertension. All patients had undergone a postmortem or posttransplantation examination. RESULTS: Ground-glass opacities were significantly more frequent in pulmonary venoocclusive disease (p = 0.003); the opacities were abundant with random zonal predominance and preferentially centrilobular distribution (p = 0.03). Subpleural septal lines and adenopathy were also significantly more frequent (p < 0.0001). CONCLUSION: On the initial pretreatment chest CT scan, the presence of ground-glass opacities (particularly with a centrilobular distribution), septal lines, and adenopathy are indicative of pulmonary venoocclusive disease in patients displaying pulmonary hypertension. Caution should be exercised before vasodilator therapy is initiated in the patients whose scans show such radiologic abnormalities.