Fig. 6

A magnetic resonance imaging (MRI) scan showed single great cyst in sacral canal. The single cyst combined with tethered cord was showed on T1-weighted images (a, an arrow showed thickening inner terminal filament), and T2-weighted images (b, an arrow showed the high signal cyst). The inner terminal filament showed slight low signal intensity on T1 -weighted fat-suppression phase view (c). The thickening inner terminal filament showed high signal intensity on T2-weighted axial view (d, yellow arrow). Extending cyst without sacral nerve roots fibers was showed on T2-weighted axial view (e). Terminal thecal sac and cyst were shown under microscope intraoperative (f, yellow arrow showed terminal thecal sac and green arrow showed cyst). After the dura opening, the thickened inner terminal filament (g, arrow) was shown. The cyst was opened to confirm without nerve root inside (h). During dissection the distal cyst wall, inner (I, yellow arrow) and outer (green arrow) terminal filament were shown together. The neck of cyst was transfixed, ligated (j, green arrow) and untethering (yellow arrow) was also performed during the same procedure. No residual cyst was seen in the sacral canal two weeks after surgical intervention, as shown on T2-weighted images (k). No cyst recurrence was observed at one year follow up on MRI T2-weighted images (l)