Right posterior oblique: the projection of choice in aortography of hypertensive patients.

The right posterior oblique (RPO) is the most helpful aortographic projection for demonstrating the origins of the renal arteries. In 59% of the 692 hypertensive patients studied, the origins of both renal arteries were seen in this projection. The second most helpful aortographic projection was the anteroposterior (AP) view, which showed the origins of the renal arteries in 22.6% of these patients. The remaining 18.4% of the patients required both the AP and RPO projections in order to show the origins of both renal arteries.