Abstract
Background In clinical practice, we noted that the end section of the thecal sac is apparently
different in patients with Tarlov cyst compared with that of the normal population.
We conducted this clinical study based on magnetic resonance imaging (MRI).
Methods Our study included 30 patients with Tarlov cyst and 30 healthy volunteers as the
control. The L4, L5 cross-section areas, the L4, L5 anteroposterior diameters, and
the terminal length of the thecal sac were measured from the lumbosacral spine MRI.
Results The L4, L5 cross-section areas and the L4, L5 anteroposterior diameters are larger
for the Tarlov cyst patients than the controls, but the terminal length of the thecal
sac is shorter.
Conclusion The Tarlov cyst is correlated with a short broad end of the thecal sac. Possibly,
this anatomical variant is a causative factor of Tarlov cyst.
Keywords
Tarlov cyst - etiology - thecal sac