A case of Takayasu arteritis complicated with pulmonary infarction.

Takayasu arteritis (TAK) is a vasculitis that causes inflammation in the arterial walls of large blood vessels. The complication rate of pulmonary artery lesion in TAK has been reported to be relatively high. Severe pulmonary artery stenosis can cause pulmonary infarction in rare cases. A 48-year-old woman had experienced cough and fever persistently for 3 months and visited a city hospital. Contrast-enhanced computed tomography (CT) and positron emission tomography (PET)-CT scans revealed TAK complicated with left pulmonary artery lesion. Contrast-enhanced CT couldn't detect wall thickening in the left smaller bifurcated pulmonary artery branch, but PET-CT did reveal this inflammation. Several weeks after we initiated treatment with high-dose prednisolone, the patient's symptoms and inflammatory findings disappeared. PET-CT may be useful for evaluating the inflammation of the pulmonary artery in TAK, and high-dose steroid monotherapy as induction therapy may be effective for TAK complicated with pulmonary artery lesions causing pulmonary infarction.