Evolution of tuberculosis and lung perfusion

Ten patients with pulmonary tuberculosis of strikingly long duration despite intensive antituberculous therapy were examined by combined lung scintigraphy (133Xe in physiologic saline i.v. and 99mTc-MAA/microspheres). As a rule the scintigraphic perfusion defects far exceeded the lesions seen radiologically. These results appear to justify the presumption that the decrease - or even absence - of perfusion in the affected areas is responsible for protracted healing in these patients.