Bone hypointense shadow is an imaging descriptive language of X-ray film examination or CT examination, because normal human bone shows high-density signal, that is, white color, during X-ray examination or CT examination. If black, or low-density shadow, appears in the middle of normal bone, it suggests that there may be lesions in the middle of the bone, which are more common in the clinic, such as bone cysts and bone tumors. If it is a bone cyst, it is usually some benign lesion. If it is a bone tumor, many of them are malignant lesions, that is, bone cancer, which is more difficult to treat. There is also a condition that hypointense shadow of bone may be internal fatty, and if soft tissue appears in the middle of the bone, it will also show hypointense shadow.