To be honest a scan at this point may not really add to anything.
No, flying blind without instruments is a doddle.
If you've slipped a disk,
Just what does this mean? Discs don't slip.
in the absence of any neurological symptoms associated and with often effective non-operative treatment (Physio initially), I doubt you'd find a surgeon who would advise an operation at this point.
If this sentence was reconstructed, I'd agree with it...I think.
And why would you want one (MRI scan) before trying the non-surgical options first?
Because manipulating a badly herniated inter-vertebral disc can cause irreversible nerve damage.
The thing is, permanent relief/cure of back pain can sometimes be gained from a chiropractor or osteopath in just one session. It's my opinion, that if the first session doesn't bring relief, then either the procedure is not being carried out properly, or the problem is not going to be resolved by manipulation. Deciding on the course of action is the $64,000 question.
Advising on that is what the Triage session is all about. Sadly, this logical step is often never offered. It is a long established routine of questions and procedure, like pricking the legs and feet to test for responses. It can take an hour of very careful positioning of the back and legs while the test are done, and IMHO still very good diagnostic medicine.
MRI technology is a science on the borderline of man's knowledge of quantum physics. It removes the problem of other types of tomography - with its accumulative X-band radiation. CAT scans are incredible, but they use low levels of X-rays for protracted periods. Some very disquieting questions are being asked about the risk / benefit ratios.