The meniscus is not visible on CT because it is a cartilaginous tissue and does not show up clearly on CT, and the characteristics and severity of meniscal damage can only be determined by MRI. CT examination is particularly sensitive to the visualization of bone lesions, and subtle fractures or collapsed fractures of the joint surface can be clarified by CT examination. Both tests have a focus and are not substitutes for each other, and there is no such thing as which is better or worse. The former is to determine whether there is a fracture in the knee joint and the latter is to determine whether there is a meniscal lesion in the case of a traumatic injury, and there is no suspicion of over-examination, only a clearer diagnosis of the disease.