Imaging agents containing hyaluronan (HA) and contrast agents. These imaging agents may include HA complexed with gadolinium, optionally with liposomes, and HA complexed with superparamagnetic iron oxides. A method of producing HA-based imaging agents includes mixing a solution of HA with a solution of contrast agent. A method of imaging using HA-based imaging agents includes using HA-based imaging agents to view cancer cells with magnetic resonance.
