Abstract: Improved methods for providing an image of an internal region of a patient. Embodiments of the invention involve the administration to the patient of a contrast agent which comprises, in an aqueous carrier, a lipid, protein, polymer or surfactant, and a gas. The patient is scanned using ultrasound imaging to obtain a visible image of the region. In embodiments of the invention, the scanning step may comprise applying a first quantity of ultrasound energy to the patient to provide a first image, followed by the application substantially immediately thereafter of a second quantity of ultrasound energy to provide a second image. The first and second images are then processed. The methods are particularly useful for obtaining on-line images of the cardiovascular region which may be employed, for example, to diagnose the presence of diseased tissue in the cardiovascular region of a patient.

Abstract: Novel contrast agents which may be used for diagnostic and therapeutic use. The compositions may comprise a lipid, a protein, polymer and/or surfactant, and a gas, in combination with a targeting ligand. In preferred embodiments, the targeting ligand targets coagula, including emboli and/or thrombi, particularly in patients suffering from an arrhythmic disorder. The contrast media can be used in conjunction with diagnostic imaging, such as ultrasound, as well as therapeutic applications, such as therapeutic ultrasound.