MRI Measurement of Upper Cervical Spinal Cord Cross‐Sectional Area in Children

Abstract

BACKGROUND AND PURPOSE: Neurological and neurodegenerative diseases can affect the spinal cord (SC) of pediatric patients. Magnetic resonance imaging (MRI) allows for in vivo quantification of SC atrophy via cross-sectional area (CSA). The study of CSA values in the general population is important to disentangle disease-related changes from intersubject variability. This study aimed at providing normative values for cervical CSA in children, extending our previous work performed with adults. METHODS: Seventy-eight children (age 7-17 years) were selected from a Developmental Dyslexia study. All subjects underwent a 3T brain MRI session and any incidental findings were reported on the scans. A sagittal 1 mm 3 3-dimensional T 1-weighted brain acquisition extended to the upper cervical cord was used to measure CSA at C2-C3, as well as spinal canal area and skull volume (V-scale). These three metrics were linearly fitted as a function of age to extract trends and percentage annual changes. Sex differences of CSA were assessed using least squares regression analyses, adjusting for age. We tested normalization strategies proven to be effective in reducing the intersubject variability of adults' CSA. RESULTS: CSA changed as a function of age at a faster rate when compared with skull volume (CSA: 1.82% increase, V-scale: .60% reduction). Sex had a statistically significant effect on CSA. Normalization methods based on canal area and skull volume reduced the CSA intersubject variability up to 16.84%. CONCLUSIONS: We present CSA normative values in a large cohort of children, reporting on sources of intersubject variability and how to reduce them applying normalization methods previously developed.

Normalization of Spinal Cord Total Cross-Sectional and Gray Matter Areas as Quantified With Radially Sampled Averaged Magnetization Inversion Recovery Acquisitions

“…Analogous normalization of GM areas reduced the % RSD by 18% at the level C4/C5, and also consistently at all other cervical and thoracic levels by 19-34%. The % RSD reduction observed in TCAs by this normalization method are slightly larger than what has been described in a very recently published study in minors aged 7-17 years by normalization with the product of the anterior posterior and lateral diameter of the spinal canal at the level C2/3 and skull volume (30). This difference could be partly explained by difference in in-plane resolution of the images used for SC segmentation (0.5 vs. 1 mm 2 ) (30) and by the chosen predictors.…”

“…This difference could be partly explained by difference in in-plane resolution of the images used for SC segmentation (0.5 vs. 1 mm 2 ) ( 30 ) and by the chosen predictors. Effects on SC GM area were not investigated in that study ( 30 ).…”

“…Nevertheless, the lower levels of the cervical and thoracic SC that contain the motor neurons to the arm and leg muscles are of special relevance to the study of lower motor neuron disorders (e.g., SMA) and have been less wellstudied. There are only a few MRI studies assessing the SC of children and adolescents (28)(29)(30), none focusing on the SC GM. Children and adolescents are the leading target group for the recently approved SMA treatments; therefore, data on SC GM variations are needed to develop treatment monitoring methods.…”

Simultaneous assessment of regional distributions of atrophy across the neuraxis in MS patients

“…For the MPRAGEs, CSA was measured semi-automatically by the same operator (NP), analogously to previous work ( Papinutto et al, 2020b , Papinutto et al, 2018 ). Briefly, the sagittal lesion filled MPRAGE was resampled on the axial plane creating a packet of five contiguous slices 1-mm thick centered at the C2-C3 intevertebral disc.…”

“…The development of a probabilistic brain and spinal cord (BSC) template ( Blaiotta et al, 2018 ) – that is embedded in the SPM framework – now enables the simultaneous assessment of structural changes in the brain and cervical cord by using standard brain T1-weigthed acquisitions extended to the upper cervical spinal cord ( Azzarito et al, 2020 ). In this study we assess this user friendly and fully automated approach (i) to address its clinical validity in MS patients, and (ii) to compare atrophic changes in the cervical cord and their goodness to fit to clinical scores against standard approaches of measuring total cross-sectional area (CSA) at the cervical level C2-C3 from phase sensitive inversion recovery (PSIR) images ( Olney et al, 2018 , Papinutto et al, 2015 , Papinutto and Henry, 2019 , Schlaeger et al, 2014 ) and from the same T1-weigthed scans used for the voxel-based approach ( Liu et al, 2015 , Papinutto et al, 2020b , Papinutto et al, 2018 ).…”