The absence of obvious blood flow signals within the liver nodule can be interpreted as the absence of blood supply for nutrition within the nodule, which usually suggests a high likelihood of benign diseases, which may be due to hepatic cysts, hepatic angiomyolipoma and other diseases. 1. Liver cysts: they are common benign diseases of the liver, most of them grow inside the liver in multiple, round shapes of different sizes, which are filled with bright yellowish fluid secreted by cyst cells and epithelial cells, and because there is no blood supply in them, ultrasonographic examination does not show any obvious blood flow signals. 2. Hepatic vascular smooth muscle lipoma: the lesion is mostly composed of a mixture of multiple cells, including smooth muscle cells, fat cells and blood vessels. When the tumor has more adipose tissue and less vascular components, ultrasonography may show that no obvious blood flow signal is seen in the liver nodule. If the patient’s examination shows that no obvious blood flow signal is seen in the liver nodule, it is recommended to consult a doctor in time, and under the doctor’s guidance, improve the relevant examination, clarify the cause of the disease and standardize the treatment.