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
Spacecraft propulsion is any method used to accelerate spacecraft and artificial satellites. There are many different methods. Each method has drawbacks and advantages, and spacecraft propulsion is an active area of research. However, most spacecraft today are propelled by forcing a gas from the back/rear of the vehicle at very high speed through a supersonic de Laval nozzle. This sort of engine is called a rocket engine. All current spacecraft use chemical rockets (bipropellant or solid-fuel) for launch, though some (such as the Pegasus rocket and SpaceShipOne) have used air-breathing engines on their first stage.