Pulmonary lesions due to Dirofilaria immitis (dog heartworm). Report of four cases with radiologic findings.

Chest radiographs of 4 patients with Dirofilaria immitis (dog heartworm) revealed solitary, small, peripheral, noncalcified nodular lesions. The pulmonary lesions were apparently produced secondary to lodging of the parasite in peripheral pulmonary vessels. None of the patients had symptoms referable to the heartworm lesions. Needle aspiration in 2 patients revealed a nonspecific inflammatory lesion.