thrombus is either at the entry of the renal vein or within the inferior vena cava (IVC) < 2 cm from the confluence of the renal vein and the IVC. Level II: Thrombus extends within the IVC > 2 cm above the confluence of the renal vein and IVC but still remains below the hepatic veins. Level III: Thrombus involves the intrahepatic IVC. The size of the thrombus ranges from a narrow tail that extends into the IVC to one that fills the lumen and enlarges the IVC.
What are three main types of rockets that power modern spacecrafts? The three kinds of rockets are solid fuel rockets, liquid fuel rockets, and ion powered rockets. Edit
Multistage rocket. A multistage (or multi-stage) rocket is, like any rocket, propelled by the recoil pressure of the burning gases it emits as it burns fuel. What characterizes it as multi-stage is that it successively jettisons one or more stages as they become empty.