Which of the following is not true regarding ossified posterior longitudinal ligament ?

Ossification of posterior longitudinal ligament (OPLL) : Variable thickness ossification along the posterior margin of veebral bodies resulting in spinal canal stenosis. More common is mid and lower cervical spine MRI is investigation of choice for spinal canal stenosis Ossification is represented as low signal on all MR sequences. In gradient echo due to blooming effect the osteophytes size may be exaggerated resulting in overestimation of spinal canal stenosis.