Pulmonary artery agenesis Diagnosis with ventilation and perfusion scintiphotography.

Abstract

Pulmonary artery agenesis is one of several diagnostic possibilities which may present with similar chest roentgenographic features, including unilateral pulmonary hypoperfusion and nonvisualization of a pulmonary artery. We have applied ventilation and perfusion scintiphotography as an aid in differentiating agenesis from the other conditions with which it may be confused. Four patients presenting with the chest roentgenographic features suggestive of pulmonary artery agenesis were evaluated, when possible, with complete pulmonary function studies, bronchography, cardiac catheterization, and pulmonary and aortic angiography. In all patients, the distribution of ventilation and perfusion were evaluated with the Anger scintillation camera, 133 xenon being used for the ventilation study and 131 I-MAA for the perfusion study. In each patient, perfusion scintiphotography showed no blood flow to the affected lung, while ventilation scintiphotography disclosed preservation of homogeneous ventilation to that lung. Absence of pulmonary artery flow to one lung with maintenance of relatively normal ventilation limits the broad range of diagnostic possibilities to three entities: pulmonary artery agenesis, thrombotic occlusion, and branch stenosis. The history and physical findings should give clues to the latter two diagnoses.