Possible herniated cervical disc. how to diagnose it? is mri the only sure diagnosis?

MRI is best: Mri is the most accurate way to diagnosis disc herniation in the spine. Next accurate would be a ct scan myelogram which is a ct after a spinal puncture with injection of ct dye into the spinal sac. After that, a ct scan without myelogram. Regular xrays are useless as the discs are invisible on xray. Mri can be performed without dye injection and doesn't involve radiation, hence its popularity.

Weakness and pain.: Usually a herniated disk causes pressure to be put on nerves of that area, causing pain. Cervical disk problems can be localized by a patterrn of motor weakness, and areflexia. This can be seen at the shoulder(c5), biceps(c6), triceps/finger and wrist extensors(c7), finger flexors(c8). Mri is great to comfirm the diagnosis, but it is expensive. See a good neuro. Doctor first.

Myelogram: Of the c spine can also make diagnosis if you can't have mri.