MRI requires the use of radiofrequency coils, and knee joints often have specialized knee coils that can only be used unilaterally. Therefore, when it is really necessary to use a knee coil for an MRI, it can only be performed on one side, and bilateral examinations need to be performed twice separately. If both sides must be examined at the same time, non-knee-specific coils, such as abdominal coils, are also available, but their resolution and clarity are not as high as knee-specific coils. It is not as good at visualizing fine structures, such as menisci, collateral ligaments or cruciate ligaments. Therefore, in general, it is recommended to examine one side of the knee and both sides at the same time is relatively ineffective.