Article

Cross-sectional non-experimental study. OBJECTIVES: To examine
diagnostic accuracy of diffusion tensor imaging (DTI) for pediatric spinal cord
injury (SCI). SETTING: Pediatric Orthopedic Hospital. METHODS: Thirty-five
subjects, 10 SCI and 25 controls, mean age 13.38 years underwent two scans with
3.0 T MR scanner. Fractional anisotropy (FA), axial diffusivity (AD) and radial
diffusivity (RD) values were calculated. Subjects with SCI underwent examination
of muscle strength, sensation and sacral sparing. Mean and s.d. values for FA, AD
and RD were compared by group (controls, SCI with sacral sparing, SCI without
sacral sparing) using analysis of variance for repeated measures. Comparisons
were also made of DTI values at the injury site to values from cervical regions
outside of the injury site. Specificity, sensitivity, receiver operating
characteristics area under the curve (ROC AUC) and corresponding 95% confidence
intervals were calculated. Resampling methods were used to validate the estimates
from the final models. RESULTS: FA values differed among SCI subjects with intact
sacral sparing, absent sacral sparing and controls, P<0.003 (adjusted). DTI
values in combination showed the strongest diagnostic accuracy for predicting the
presence of anal contraction (AD, RD; ROC AUC=0.90), deep anal pressure (FA; ROC
AUC=0.88), S4-5 sensation (FA, RD; ROC AUC=0.93), motor level (FA, AD, RD; ROC
AUC=0.92) and MRI level (FA, AD, RD; ROC AUC=0.92). Bootstrap and Jackknife
median values indicated consistency of the parameter estimates. CONCLUSION: The
predictive accuracy of DTI for sacral sparing end points and motor and MRI level
of injury was good to strong.

Langue : ANGLAIS