Objective to study the feasibility of MR arthrography of knee joint by using intravenous injection of MR contrast agent which disperses into the knee joint, to optimize the scanning parameters.

Targeted micro-bubble contrast agent can reach a specific target via intravenous injection, and improve the resolution of local tissues under the action of low power ultrasound imaging.

Objective to study the enhancement of color Doppler signals on hepatic neoplasms with intravenous ultrasound contrast agent and to evaluate the significance in diagnosis of hepatic neoplasms.