Article Figures & Data
Figures
- FIG 1.
Different acquisitions of T1-weighted MR imaging on the axial planes of the lumbar region at the level of the L4–L5 intervertebral disc in an 18-year-old patient. A, T1 FSE sequence shows the dark-signal thecal sac containing the barely visible hypo- to iso-signal intensity cauda equina nerve roots and a round midline intradural lesion (black arrow) with bright signal intensity located posteriorly in the spinal canal at the expected anatomic site of the filum terminale, consistent with a FIL. Phase wrap-around artifacts are noted on both sides of the image. B, A radiofrequency spoiled 3D gradient-echo sequence known as VIBE of the same patient study at the same level shows a similar bright-signal intradural structure (black arrow), the FIL. Note the smaller AP and RL dimensions of the FIL compared with the T1 FSE sequence (A). The cauda equina nerve roots are well-demarcated as opposed to the T1 FSE sequence (A). VIBE/LAVA can underrate the AP and RL diameters of the FILs.
- FIG 2.
Different acquisitions of T1-weighted MR imaging on the axial plane through the lumbar region at the L4–L5 intervertebral disc in a 10-year-old boy. A, A T1 FSE sequence shows a tiny, round, midline intradural lesion (black arrow) with bright signal intensity located posteriorly in the spinal canal at the expected anatomic site of the filum terminale, consistent with a FIL. B, VIBE of the same patient at the same level shows iso-signal intensity nerve roots of the cauda equina traversing the spinal canal. Although the window level and width are adjusted for better detection of bright lesions, the VIBE sequence failed to reveal the FIL. Note the smaller AP and RL dimensions of the FIL compared with the case in Fig 3. The VIBE sequence is less sensitive in the detection of small FILs and can miss such lesions.
- FIG 3.
ROC curve for FIL AP diameter (area under the curve = 0.810, P value = .017).
- FIG 4.
ROC curve for FIL RL diameter (area under the curve = 0.815, P value = .016).
Tables
Indication for MR Imaging Total FIL +ve FIL –ve Sacral abnormality 16 (24.2%) 9 (40.9%) 7 (16%) Urinary dysfunction 10 (15.1%) 5 (22.7%) 5 (11.3%) Bowel dysfunction 8 (12.1%) 2 (9%) 6 (13.6) Scoliosis 7 (10.6%) 2 (9%) 5 (11.3%) Lower-extremity weakness 6 (9%) 1 (4.5%) 5 (11.3%) Back pain 6 (9%) 1 (4.5%) 5 (11.3%) Othera 13 (19.5%) 2 (9%) 11 (25%) Total 66 22 44 Note:—FIL +ve indicates positive detection of a FIL; FIL –ve, negative detection of a FIL.
↵a Other indications for MR imaging include abnormal gait, Chiari I malformation, abnormal findings on spine sonography, and vertebral defects, anal atresia, cardiac defects, tracheo-esophageal fistula, renal anomalies, and limb abnormalities (VACTERL).
Sequence FIL +ve FIL +ve Mean AP FIL +ve Mean RL FIL +ve Mean CC +T1 FSE and +VIBE/LAVA, measured in T1 FSE 21/22 (95.4) 5.4 5 3.8 +T1 FSE and +VIBE/LAVA, measured in VIBE/LAVA 12/22 (54.5) 4.9 4.6 2.2 +T1 FSE and −VIBE/LAVA, measured in T1 FSE 9/21 (42.9) 1.5 1.6 2.5 Note:—RL indicates right-left dimension; CC, craniocaudal dimension; FIL +ve, positive detection of a FIL; FIL –ve, negative detection of a FIL.
Jump to section
Related Articles
Cited By...
- No citing articles found.