The morbidity of renal cell carcinoma is only lower to prostate cancer and bladder cancer in urinary tumor, and the mortality rate is up to 40%. At present, diagnostic techniques such as ultrasonography, CT examination and MRI examination are widely used in Clinical practice, which greatly improves the detection rate of asymptomatic renal cell carcinoma. Compared with enhanced MRI and enhanced CT, contrast-enhanced ultrasound (CEUS) has outstanding advantages, including spatial, temporal and contrast resolution, continuous real-time visualization,. Sonazoid, the second generation ultrasound contrast agent, is composed of microbubbles containing chemically stable and insoluble perfluorobutane (PFB) gas and phosphatidylserine sodium hard shell (diameter 2-3μm) wrapped by outer layer. These microbubbles can generate stable nonlinear oscillation in low-power sound field, and generate echo at the second harmonic frequency of transmitted pulse. Sonazoid has the advantages of long-time development and good stability, which may improve the accuracy of distinguishing benign and malignant renal space-occupying lesions, especially small lesions. In addition, the characteristics of long-time development are also helpful to extract more imaging information to assist the clinical staging of renal tumors.
The incidence and mortality of renal cell carcinoma are increasing year by year. Contrast-enhanced ultrasound is helpful for early diagnosis and treatment to renal tumor, and is of great importance to distinguish benign from malignant and clinical stages