Lung.

Scintigraphic lung studies are designed to demonstrate patterns of ventilation and perfusion.In the healthy individual there is a balance between regional perfusion and ventilation to achieve optimal gas exchange.When a pulmonary disease causes a deficiency in both ventilation and perfusion, they are "matched." Mismatch implies an imbalance between perfusion and ventilation. The single most important application of lung scintigraphy is the evaluation of patients with suspected pulmonary embolism (PE). The value of scintigraphy in the detection of PE was first demonstrated byWagner in 1964, using 131I-human serum albumin (HSA) for perfusion scintigraphy and a rectilinear scanner for imaging (Wagner 1976). [ABSTRACT FROM AUTHOR]