In PV, the red cell count is frequently a better indicator of erythrocytosis than the hematocrit. Changes in the (A) hematocrit and (B) RBC count in a 37-year-old woman with PV-associated HVT treated with phlebotomy, Coumadin, and a transjugular intrahepatic portosystemic shunt (TIPS), demonstrating the correlation of the RBC but not the hematocrit with TIPS thrombosis (arrows) on 2 occasions. M/CU MM, millions per cubic millimeter; PCV, packed cell volume.