Use of radionuclide labelled microspheres to show the distribution of the pulmonary perfusion with multifocal pulmonary blood supply.

In pulmonary atresia with a ventricular septal defect and similar congenital heart disorders the pulmonary blood supply is often multifocal. The relative distribution of pulmonary perfusion from individual sources is usually demonstrated by selective angiography. A new technique using a selective injection of radionuclide labelled human albumin microspheres was performed in four patients with a complex pulmonary blood supply. In these cases the physiological distribution of each of the multiple sources of pulmonary perfusion was demonstrated. This is a useful additional technique in the assessment of such patients.