Abstract: A method for generating an enhanced ultrasound image comprises intravenously administering to a subject a plurality of microbubbles of sufficient diameter to lodge in the microvasculature of a subject. An ultrasound image of a portion of the subject is generated wherein the image is enhanced by one or more of the administered microbubbles that has lodged in the microvasculature of the imaged portion. An ultrasound contrast media composition comprises a plurality of gas filled microbubbles. At least about 5% of the microbubbles have a diameter of at least about 4 microns (?m), and wherein the composition is suitable for intravenous administration. The administered microbubbles are of sufficient diameter to lodge in the microvasculature of a subject and can be used enhance ultrasound images small animal subjects including mice, rats and rabbits. The described methods and compositions can be used to enhance ultrasound images produced using high frequency ultrasound.

Abstract: A method of measuring changes in microvascular capillary flow in a predetermined region in a subject comprising: (a) administering an ultrasound contrast medium to said subject such that said contrast medium reaches the microvascular capillaries in said predetermined region; (b) measuring microvascular capillary blood flow volume and/or microvascular flow index of said capillaries; (c) applying a defined signal to said subject; and, (d) measuring changes in said microvascular capillary flow.