It appears u have a syrinx resulting from an injury from ur fall, it is small in size and is not causing compression at this time....I have to ask tho...was this MRI done in 2007 and the report printed in 2011? If so, have u had a new MRI to compare?
A syrinx can grow slowly or it could go quicker than expected so if this was ur last MRI u r over due for a new one!!