If your doctor thinks it's possible you have a herniated disc or spinal stenosis that's causing your sciatica, your doctor may order a magnetic resonance imaging (MRI) test. You may have an x-ray or a computed tomography (CT or CAT) scan. MRI/CT scan can show disc bulges or herniations but may not always correspond to your pain pattern. To diagnose sciatica correctly and develop a list of possible causes, an EMG/NCV (Electromyography/Nerve Conduction Velocity Study) is required. How Your Doctor Properly Diagnoses Sciatic Nerve Pain
