Reading an MRI Report After a Car Accident
Key Takeaways
- Herniation, protrusion, extrusion, and sequestration are shape words from the NASS nomenclature, not treatment orders.
- Degenerative findings are common in people without pain; Brinjikji’s review is why a bulge on a report does not date the crash by itself.
- Loss of bladder or bowel control, saddle anesthesia, or progressive weakness after a crash needs emergency care now.
MRI Study Language After a Crash
RadiologyInfo.org describes magnetic resonance imaging as a study that uses a powerful magnetic field, radio waves, and a computer to produce detailed pictures of joints, soft tissues, and bones. The report that follows is a radiologist’s language for those pictures, not a ruling on the crash.
Open units exist for patients who cannot tolerate a closed bore. RadiologyInfo notes that open MRI machines are designed to alleviate patient claustrophobia; they are an option, not a substitute for every protocol.
NASS Displacement Terms
The North American Spine Society nomenclature is the dictionary. The NASS/ASSR/ASNR paper defines herniation as a localized displacement of disc material beyond the limits of the intervertebral disc space.
Protrusion is present if the greatest distance between the edges of the disc material beyond the disc space is less than the distance between the edges of the base, in the same plane. Extrusion is present when, in at least one plane, any one distance between the edges of the disc material beyond the disc space is greater than the distance between the edges of the base, or when no continuity exists. Sequestration and migration are further specifications of extrusion.
Those words describe shape. The same paper states that definitions of diagnoses should not define or imply need for specific treatment. Morphology is not cause, and it is not a treatment order.
Wear on Imaging Without Pain
Age changes the background. Brinjikji and colleagues reviewed imaging features of spinal degeneration in asymptomatic populations and found those features are common, with prevalence rising with age. A report that lists disc desiccation or a bulge does not, by itself, date the crash.
Modic changes and high-intensity zones need the same caution. A 2020 narrative review treats Modic changes as findings that still require correlation with symptoms and timing. The crash record supplies the timing; the report supplies the morphology.
Emergency Spine Warning Signs
Emergency Warning Signs
- Loss of bladder or bowel control after new back or neck pain
- Saddle anesthesia, or numbness in the groin and inner thighs
- Progressive weakness in an arm or a leg after the crash
- Fever with a new spine complaint, or a history of cancer with new night pain
- A report that describes cord compression with matching new deficits
MedlinePlus lists loss of bladder or bowel control among the symptoms that require care after a herniated disk, and notes that pain, numbness, or weakness often improves over weeks to months. Improvement is a range, and it does not apply to the emergency list above.
Why Clients Choose Sam Aguiar
Protrusion, Extrusion, and Sequestration
The three labels sit on one spectrum of displacement. They are not three diseases.
| Term | Shape on the report | Named source |
|---|---|---|
| Protrusion | Base wider than the displaced material in the same plane | NASS nomenclature |
| Extrusion | Displaced material wider than the base in at least one plane, or continuity lost | NASS nomenclature; Radiopaedia disc extrusion |
| Sequestration | Displaced disc material that has lost completely any continuity with the parent disc | NASS nomenclature |
Radiopaedia describes extrusion as disc material beyond the margins with a neck narrower than the herniated portion. That is the same shape rule in different words.
Open Magnets and Image Quality
Field strength is a tradeoff. A review of low-field MRI describes clinical uses with signal and image-quality tradeoffs that vary by scanner, protocol, and body part. An open study can be the right study for the patient and still be a weaker study for a small extraforaminal fragment.
The report should name the magnet and the sequences. Without that, later readers cannot tell whether a missed fragment was absent or unseeable on that unit.
Radiologist Hedging Phrases
Radiologists hedge because morphology is not cause. “Consistent with” means the pictures match a described pattern; it does not date the event and it does not assign the crash. The NASS paper’s warning that definitions should not imply treatment is the same caution in different clothes.
The crash record, the examination, and the prior films (if they exist) supply what the hedge leaves open. Related pages on herniated discs and spine injuries cover the clinical side of those findings.
Crash Record Beside the Study
A report without the crash mechanism is a vocabulary list. Seat position, intrusion, and the onset of symptoms account for timing; the sequences account for shape. The pre-existing condition page covers how degenerative language is read against a new event, and the injuries hub collects the related clinical pages.
Ask for the images, not only the letter. The letter is the radiologist’s reading; the images are what a later reader can still see.
The medical record and the crash record describe the same event from two directions, and they are rarely gathered at the same time. Keeping the imaging, the follow-up visits, and the mechanism of injury in one place is what makes them line up later. Call (502) 888-8888 or request a free case review.