These are common changes of the marrow adjacent to a degenerated disc.
Some find it useful to compare these changes to levels of physical fitness.
Please note that the most common enhancing pathology in the spine is degenerative.
Executive summary:
The most common enhancing pathology in the spine is degenerative.
Some procedures are reimbusrable if there are Modic type 1 or 2 changes (therefore you may be asked to comment on them)
Reference:
Modic MT, Steinberg PM, Ross JS, et al. : "Degenerative disk disease: assessment of changes in vertebral body marrow with MR imaging". I Radiology 1988;166(1 Pt 1):193-9.
Also
http://radiology.rsna.org/content/168/1/177.full.pdf+html?sid=5032be50-640e-4496-8935-0de891a57dee