welcome to Health care magic.
1.Basic remedies for
back pain are back exercises, maintaining good position, flat bed will actually gives relief in most of the patients.
2.You have already underwent the tests and your doctor recommended
MRI means, there is some thing he is suspecting in the spine.
3.MRI will help in disc pathologies,
nerve related , spinal chord related things can be evaluated.
4.So please follow your doctor, as MRI is almost compulsory to evaluate the definitive cause in case of back pain.
5.Sorry cost issues can to be answered, as i do not have any idea about it.
Hope it helps you. Wish you a good health.
Anything to ask ? do not hesitate. Thank you.