The presence of increased signal in the ACL during an MRI examination of the knee often represents degeneration and injury to the ligament. The signal of the cruciate ligament in the normal state should be relatively uniform low signal, but occasionally at the upper or lower end of the intersection, there can be a line of high signal, that is a normal signal change. However, if there is a wide range of signal increase, patchy or flaky changes, it suggests that the ligament has been damaged, and the extent of the damage can be determined according to the range of signal increase.