Sorry about the latest news. Did you actually read the radiologist's report on your imaging? Perhaps there is a spur that slowly developed and is impinging on a nerve?
Also, what's very helpful to know is that a radiologist will usually note changes from previous studies. And you can request a re-read as well as a comparison.
Let us know the exact language of the latest radiology report...
Also see this dermatome chart:
http://tlccrx.com/resources/printable-dermatome-chart/