Utility of CISS imaging in the management of tethered cord syndrome

Abstract

To compare the utility of constructive interference in steady-state (CISS) sequence over T2-weighted (T2W) sequence in the accurate delineation of the tethering element on magnetic resonance (MR) imaging in patients of tethered cord syndrome (TCS) and correlation with intraoperative findings. MR findings of fifty-six consecutive patients with operative findings of TCS were studied. The intraoperative findings of all patients were studied and compared with the preoperative imaging findings on T2W imaging and CISS images. CISS images provided more information than T2W imaging. The overall sensitivity of CISS in MR evaluation of patients with TCS was higher (99.17%) as compared with the T2W sequence (71.48%) especially in the detection of precise position/extent of tethered cord, assessment of filum terminale thickening, detection of a fibrous spur in cases of split cord malformation, detection of dorsal dermal sinus, and evaluation of its precise extent and ramifications. The area under the ROC curve was higher with CISS (0.99) than with T2W sequence (0.85) which reflects its good predictive value as a screening test. This information was useful to the operating surgeon. CISS sequence for imaging TCS can help enhance the overall surgical outcome of the patients ensuring completeness of the surgery. CISS should be routinely performed in the work-up of patients with tethered cord syndrome.