Magnetization Transfer Ratio in the Typically Developing Pediatric Spinal Cord: Normative Data and Age Correlation

Background and Purpose

This study presents automated atlas-based magnetization transfer (MT) measurements of the typically developing pediatric cervical spinal cord (SC). We report normative MT ratio (MTR) values from the whole cervical cord white matter (WM) and WM tracts, examining variations with age, sex, height, and weight.

Methods

MT scans of 33 healthy females (mean age = 12.8) and 22 males (mean age = 13.09) were acquired from the cervical SC (C2–C7) using a 3.0 T MRI. Data were processed using the SC Toolbox, segmented, and registered to the PAM50 template. Affine and non-rigid transformations co-registered the PAM50 WM atlas to subject-specific space. MTRs were measured for the specific WM tracts (left and right dorsal fasciculus gracilis, dorsal fasciculus cuneatus, and lateral corticospinal tracts [LCST]) and the whole WM. Descriptive statistics, correlation analysis, and unpaired t-tests (p < 0.05) assessed relationships with age, height, weight, and sex.

Results

Normative MTR measurements were obtained from all regions. The coefficients of variation were low to moderate. No significant differences (p > 0.05) were found across all the cervical levels. However, significant sex differences were observed in whole WM (p = 0.04) and LCST (p = 0.03). MTR values correlated positively with age, with significant correlations at C5 (r = 0.3, p false discovery rate = 0.04). A decreasing trend in MTR values across levels was found for whole WM (r = −0.2, p < 0.001).

Conclusions

This study provides an understanding of MTR values in pediatric cervical SC and their variations by sex, age, height, and weight, providing a baseline for comparisons in pediatric SC diseases.