MRI for Back Problems

Tomorrow my husband is going to have an MRI because his sciatic nerve has really been bothering him. It hurts to sit on almost any chair but his recliner. It hurts to ride in the car farther than 5 miles. He has tried a number of various leg exercises and for awhile it seems to help but then it is right back again. He has already had x-rays of his back and had surgery 5 years ago on a ruptured disc. He is anxious to see what this MRI will show.