According to the invention, a concrete dosage formula is implemented and developed in clinical researches. The dosage formula employs perfluorocarbon gas which can provide a substantially enhanced image and a long duration, and combines the gas into polymer particles, such that an ultrasonic contrast medium is prepared. The dosage formula comprises particles formed by biocompatible polymers and perfluorocarbon. Preferably, lipid is mixed in the polymer, and perfluorocarbon is in a form of gas under a body temperature. A patient is administrated with the particles with a dosage effective to enhanced ultrasonography. The duration in the ventricle is longer than 5min and/or the duration in the cardiac muscle is longer than 1min, and the dosage range is 0.025-8.0mg/kg (particles/body weight), and preferably 0.05-4.0mg/kg (particles/body weight). The dosage formula is generally provided in small bottles. In a typical formula, a dosage formula is formed by dry powder which needs to be re-prepared by using sterile water before use. Specifically, water is added to a small bottle or a syringe the bottle or the syringe is shaken, such that isotonic or isoosmotic particle suspension fluid is formed.
