Added Value in Combined Use of Fusion Imaging and Contrast-enhanced Ultrasonography Compared to Fusion Imaging Alone for Percutaneous Biopsies of Focal Liver Lesions

Despite the rapid development of tumor markers and liver imaging, pathological confirmation is still necessary for atypical liver lesions that do not meet imaging criteria. US guided procedures are widely used as a method to identify focal lesions of the liver pathologically, and these US guided procedures have no burden on the operation, can be easily accessed, and have a lower cost than surgery. However, the frequency of pathological confirmation with this US guided procedure remains at around 90%. In order to increase this probability, a technique for fusion of liver CT/MRI and US has been widely used in recent years, and this allows accurate targeting of small lesions through structures seen in CT and MR. Through the fusion technique, the biopsy success rate for focal lesions can be increased to 94.4%. However, there are many cases where lesions deeply located in patients with cirrhosis are invisible, and biopsy is difficult only with fusion due to poor sonic window in patients with high BMI. To this end, a technique called contrast-enhanced ultrasonography (CEUS), such as the fusion technique, was added, which is a technique that can identify tumor vascularity in real-time using second-generation contrast media. In recent studies, there are studies combining this fusion technique and CEUS technique, and the success rate of these techniques varies from 87.6% to 97.5%. Although CEUS with fusion techniques are theoretically superior to fusion only technique, the use of CEUS adds cost of contrast media and is limited in patients with side effects on contrast media. . Also, there is no study comparing the two so far, and this study intends to compare the technique combining CEUS and fusion and the technique using only fusion.