[Unilateral absence of pulmonary perfusion by lung scanning with 99mTc-MAA: report of two cases].

Unilateral absence of pulmonary artery perfusion by 99mTc-MAA lung scanning is associated with a variety of congenital, inflammatory, neoplastic, vascular etiologies. We present of two cases of this scan abnormality. One case had isolated agenesis of the right pulmonary artery and the other was the systemic-to-pulmonary artery fistula associated with recurrent pneumonia. Although pulmonary angiography, including IVDSA, is indicated to rule out other possibilities, eg. thromboembolism, radionuclide perfusion scan is a non-invasive method suitable for the screening.