In general, the most common method to detect kidney tumors is ultrasound. Currently, more than 90% of patients in outpatient clinics are found to have possible tumors in the kidney through ultrasound examination during physical examinations, and after ultrasound finds the problem, further more in-depth examinations are needed. Usually, the most commonly used test is enhanced CT, which can help doctors determine whether the tumor is benign or malignant by identifying whether the tumor is cystic or solid. However, if the tumor is small, such as less than 1cm or only 0.5cm, the diagnosis may not be confirmed by ultrasound and enhanced CT, and enhanced MRI may be needed. For early stage tumors that cannot be diagnosed, patients will be advised to follow up and observe. Overall, more than 95% of kidney tumors can be diagnosed by enhanced CT, and the benignity and malignancy can be clarified.