1. An instance of an atypical intraspinal cyst presenting as S1 radiculopathy: a case report and brief review of pathophysiology1 
Michael J DePalma, MD, Jeffrey A Strakowski, MD, Eiran M Mandelker, MD, William R Zerick, MD 
Archives of Physical Medicine and Rehabilitation 
Volume 85, Issue 6, Pages (June 2004)
DOI: /j.apmr

2. Fig 1
Axial T2 image through the L5-S1 level shows the pseudocyst (black arrow) just anterior to the right S1 nerve root (dark-gray arrow). The ipsilateral pars fracture is indicated the white arrow, and the contralateral stress reaction is indicated by the light gray arrow.
Archives of Physical Medicine and Rehabilitation  , DOI: ( /j.apmr )

3. Fig 2
Sagittal T2 image through the lumbosacral spine depicts the exiting right L5 (black arrow) and S1 (gray arrow) nerve roots, superior and inferior, respectively, to the pseudocyst (white arrow).
Archives of Physical Medicine and Rehabilitation  , DOI: ( /j.apmr )

4. Fig 3
Axial CT through the L5-S1 level depicts a chronic spondylolytic defect in the right pars interarticularis (white arrow) and the contralateral pars stress reaction (black arrow).
Archives of Physical Medicine and Rehabilitation  , DOI: ( /j.apmr )

5. Fig 4
Axial CT through the L5-S1 level demonstrates normal fat (white arrow) between the thecal sac and the normal left S1 nerve root. On the right, the fat is effaced (black arrow) by the pseudocyst.
Archives of Physical Medicine and Rehabilitation  , DOI: ( /j.apmr )