Postoperative Spinal Instability at L3-4 Revealed by Upright Weight-Bearing MRI
The patient was scanned in the FONAR Upright MRI in early 2002, one year after her spinal fusion. Both Upright and recumbent scans were performed on her in the multi-position FONAR Upright MRI. The recumbent MRI (left image) exhibited only a normal lumbar lordotic curve and a modest bulge of the L3-4 intervertebral disc, consistent with her prior recumbent MRI scan on a conventional MRI. The FONAR Upright scan (right image) revealed, however, a marked subluxation (anterolisthesis) at L3-4 and an accompanying spinal stenosis that were not visible on the recumbent MRI.
Surgical Plans Altered by an Upright Flexion-Extension MRI Examination
A 62-year-old woman seeking the cause of her chronic radiating neck pain of 30 years duration underwent a weight-bearing flexion-extension MRI in the FONAR UPRIGHT Multi-Position MRI. Her neutral-sitting examination showed a C5-6 herniation, but her UPRIGHT® cervical extension examination visualized an additional herniation at C4-5 that altered plans for a simple discectomy and fusion at C5-6.
Chiari Malformation Visualization When Upright
The recumbent scan is from a patient with neck pain (being treated conservatively) who developed transient parasthesia and drop attacks. The upright scan revealed
a slight disc protrusion at C5-6 but a much more significant position-related downward herniation of the cerebellar tonsils and brainstem compression against the
odontoid process that was not visible when the patient was in the recumbent position. The correct surgical approach to this patient , a posterior fossa decompression,
could be decided only after the UPRIGHT MRI successfully visualized the Chiari malformation that accounted for the patient's “drop-attacks.
Case courtesy of J.P. Elsig, M.D., fmri Zentrum, Zurich, Switzerland
Fluctuating Spinal Stenosis and Position-Dependent Disc Herniation
The standing-extension sagittal image demonstrates marked stenosis of the central spinal canal that is the result of posterior disc protrusions extending into the
anterior spinal canal and focal ligamentous infolding posteriorly. Compression of the cord is not evident on the recumbent scan. The standing-extension axial image
reveals a position-dependent focal posterior disc herniation at C4/5 that is endangering the cord but is not visible in the recumbent position.
MRI Visualization of Position–Dependent Changes in the Pelvis: Pelvic Floor Dysfunction (PFD)
Inferior prolapse of the bladder and uterus (PFD)(5 cm) is visualized in the Upright Weight-Bearing Position that is not visualized in the recumbent position.
Visualization Of The Effects Of Gravity On The Intervertebral Discs In A True Physiological Upright Weight-Bearing MRI Scan
The recumbent image shows degenerative disc disease at L4/5 and L5/S1 manifest as a loss in hydration but fails to show the loss in disc height
at L4/5 and L5/S1 and the segmental instability (anterolisthesis) that accompanies it. The upright image shows degenerative intersegmental
hypermobile instability (anterolisthesis: arrows) at L4/5 and L5/S1. L4/5 and L5/S1 exhibits narrowing of the disc spaces in the upright