If there is a hemangioma on the liver, it can generally be diagnosed through an ultrasound of the liver and biliary system. This is because hemangiomas have some characteristic appearances on ultrasound imaging. First, it's essential to understand the structure of the liver hemangioma which can be roughly considered as sponge-like, with a structure similar to a sponge containing many fine structures. When ultrasound is applied, this sponge-like structure will demonstrate strong echogenicity, appearing as a large mass with medium to strong echogenic responses. Thus, it is quite evident on ultrasound and has relatively high specificity, so it can generally be diagnosed through ultrasound. If the appearance is not typical, further examination with an enhanced CT scan can be carried out for diagnosis.