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7b - Answer: A patient with low back pain, left lower extremity numbness, and urinary difficulty

David Yousem MBA, MD
David M Yousem, MBA, MD
Professor of Radiology, Vice Chairman and Associate Dean
Includes DICOM files

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Case Report

HISTORY: Low back pain w/LLE numbness and urinary difficulty.  Please evaluate for nerve impingement or cauda equina. 

TECHNIQUE:  Multiplanar multisequence MRI examination the lumbar spine was performed before and after the administration of intravenous gadolinium based contrast.



At L5-S1, there is a left subarticular disc extrusion, likely a sequestration, with inferior migration measuring 1.3 x 1.3 x 1.3 cm, which compresses the traversing left sacral nerve roots and causes moderate narrowing of the thecal sac. The disc material compresses the left S1 nerve root after it has left the thecal sac and the left S2 nerve root as it leaves the thecal sac seen best on series 5 image 15 and 17. There is reactive enhancement within the adjacent extradural soft tissues. There is mild bilateral neural foraminal stenosis at L5-S1 on the basis of a superimposed circumferential disc bulge with degenerative endplate spurring. There is intervertebral disc space narrowing at L5-S1 with Modic 1 degenerative endplate changes.

The remaining levels of the lumbar spine demonstrate no significant spinal canal or neural foraminal stenosis. Normal vertebral alignment. No acute vertebral fracture or suspicious marrow signal abnormality.

The conus medullaris terminates normally at L1-2 intervertebral space. The lower cord and the cauda equina nerve roots demonstrate no morphologic or signal abnormality.

There is no paralumbar soft tissue swelling.

There is a 3.2 cm left adnexal cyst, likely ovarian (series 9 image 36).


  1. Left subarticular disc extrusion at L5-S1, likely no longer communicating with the parent disc as a sequestrated fragment, with compression of the traversing left S1 and S2 sacral nerve roots and moderate narrowing of the thecal sac.
  2. Degenerative endplate changes at L5-S1 with mild bilateral neural foraminal narrowing.
  3. Left adnexal cyst measuring 3.2 cm. Further evaluation could be obtained with a pelvic ultrasound on a routine basis, if clinically indicated.

Case Challenge: Spine MRI Cases - I-MED Study

Content reviewed: May 12, 2022