Reading an MRI Report After a Car Accident

MRI Study Language After a Crash

Magnetic resonance imaging 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 description of those pictures and says nothing about who caused the accident.

Open units exist for patients who cannot tolerate a closed bore, and open MRI machines are designed to alleviate patient claustrophobia. Open units do not fit every protocol.

Disc Displacement Terms

Herniation is 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. Morphology is not cause, and definitions of diagnoses should not define or imply need for specific treatment.

Wear on Imaging Without Pain

Age changes the background. Imaging features of spinal degeneration are common in asymptomatic populations, with prevalence rising with age. A report that lists disc desiccation or a bulge does not, by itself, date the accident.

Modic changes and high-intensity zones need the same caution, because Modic changes are findings that still require correlation with symptoms and timing. The accident record supplies the timing; the report supplies the morphology.

Emergency Spine Warning Signs

Loss of bladder or bowel control is among the symptoms that require care after a herniated disk, while pain, numbness, or weakness often improves over weeks to months. Improvement is a range, and it does not apply to the emergency list above.

Protrusion, Extrusion, and Sequestration

The three labels sit on one spectrum of displacement. They are not three diseases.

Extrusion is disc material beyond the margins with a neck narrower than the herniated portion. That is the same shape rule in different words.

Open MRI Image Quality

Field strength is a tradeoff. Low-field MRI has 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 accident. The same caution appears in the nomenclature: definitions of diagnoses should not define or imply need for specific treatment.

The accident record, the examination, and the prior films (if they exist) supply what the hedge leaves open, whether the finding is a herniated disc or another spine injury from a car accident.

Crash Record Beside the Study

A report cannot place its findings in time without the accident mechanism. Seat position, intrusion, and the onset of symptoms account for timing; the sequences account for shape. Degenerative findings are read against that timing, as in any car accident injury case.

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.