<prompt> Calcification of Posterior Longitudnal Ligament is best diagnosed byX-RayCTMRIPET  <response>: Calcifications are best seen on CT Scan images. Calcification of Posterior Longitudnal Ligament is OPLL Ossified Posterior Longitudnal Ligament and was traditionally considered more frequent in Japan and common in cervical spine Figure: Illustration of OPLL Figure: OPLL On plain film Figure: OPLL on sagittal CT scan Calcification of Posterior Longitudnal Ligament is also known as Japans Disease. 