IS Case 295: Right to left shunt with pulmonary hypertension

Mary Fontanella, MD

Imaging Sciences URMC 2009
Publication Date: 2009-08-05


Patient is a 25-year-old female with known right-to-left shunt and pulmonary hypertension presenting for follow-up of abnormal pulmonary ventilation/perfusion scan (VQ) scan.


Perfusion, but not ventilation, images demonstrate radiotracer uptake by the kidneys consistent with known left-to-right shunt.


Right to left shunt with pulmonary hypertension


On VQ scan, the finding of radiotracer uptake in the kidneys on perfusion images is consistent with a right to left shunt. When a shunt exists, there is immediate renal activity, best seen on posterior and lateral views. Additional findings with shunting in a VQ scan would include uptake in the brain, but, since this study was not specifically performed to evaluate for shunt, imaging of the brain was not performed.

When shunt is present the dose of MAA should be reduced as while adverse effects on the coronary and cerebral circulation are rare they are possible.


  1. Mettler FA Jr, Guiberteau MJ. Essentials of Nuclear Medicine Imaging. 5th ed., Philadelphia: Saunders Elsevier, 2006.

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