Imaging used to be hard to get and expensive. Now most insurance plans cover MRI for back pain after one phone call, and patients often walk in asking for one before we have even examined them. That changes the calculus on whether imaging actually helps.
Here is the honest answer most chiropractors and orthopedists will give you in private: for the vast majority of acute mechanical low back pain, you do not need an MRI. Imaging too early often shows incidental findings that are not the cause of your pain, leads to over-treatment, and increases the chance of unnecessary surgery.
What MRIs actually show in healthy people
One of the most-cited studies in spine medicine looked at lumbar MRIs in people with no back pain at all. The findings:
- By age 30, about 40 percent of pain-free adults have at least one disc bulge on MRI.
- By age 40, about 50 percent.
- By age 60, about 70 percent.
- By age 70, about 80 percent.
If 70 percent of pain-free 60-year-olds have a disc bulge, then a disc bulge on your MRI does not necessarily explain your pain. It might be the cause. It might also be background noise from aging.
When imaging actually helps
There is a clear list of red flag situations where MRI changes the plan and should be ordered fast. If any of these apply to you, do not wait, do not start chiropractic, do not call us first. See a physician or go to the ER.
- Loss of bowel or bladder control
- Saddle numbness in the inner thighs or perineum
- Progressive weakness in a leg, foot drop, or both legs becoming weak
- Severe pain after major trauma (high-speed crash, fall from height)
- Fever with severe back pain
- Unexplained weight loss with the back pain
- Pain that wakes you from sleep and is not relieved by changing position
- Active cancer history with new back pain
Outside of those situations, imaging is usually not the right first move.
When we order MRI in our practice
For acute mechanical back pain without red flags, we usually start with conservative care and re-evaluate at six visits. We order or refer for MRI when:
- There is clear nerve root involvement (sciatica with a recognizable nerve pattern, numbness or weakness)
- Conservative care has not produced enough improvement after 4 to 6 weeks
- We are considering non-surgical spinal decompression as the next step (we require an MRI before starting decompression)
- A red flag develops during care
The bottom line
Imaging is a tool. Like any tool, it is helpful when used at the right time and harmful when used at the wrong time. For most acute back pain, the right time is not visit one. The right time is when conservative care has been given a real shot or when something specific changes the picture.
If you walk in asking for an MRI, we will ask you what you are hoping to learn. If the answer is "I want to know what is wrong," we will examine you and tell you what we think it is. If the exam suggests something that imaging would actually change, we will say so. If not, we will start treatment and hold imaging in reserve.
Related: Low back pain detail · Herniated disc · Spinal decompression