A database of the healthy human spinal cord morphometry in the PAM50 template space

Abstract

Measures of spinal cord morphometry computed from magnetic resonance images serve as relevant prognostic biomarkers for a range of spinal cord pathologies, including traumatic and non-traumatic spinal cord injury and neurodegenerative diseases. However, interpreting these imaging biomarkers is difficult due to considerable intra- and inter-subject variability. Yet, there is no clear consensus on a normalization method that would help reduce this variability and more insights into the distribution of these morphometrics are needed. In this study, we computed a database of normative values for six commonly used measures of spinal cord morphometry: cross-sectional area, anteroposterior diameter, transverse diameter, compression ratio, eccentricity, and solidity. Normative values were computed from a large open-access dataset of healthy adult volunteers (N = 203) and were brought to the common space of the PAM50 spinal cord template using a newly proposed normalization method based on linear interpolation. Compared to traditional image-based registration, the proposed normalization approach does not involve image transformations and, therefore, does not introduce distortions of spinal cord anatomy. This is a crucial consideration in preserving the integrity of the spinal cord anatomy in conditions such as spinal cord injury. This new morphometric database allows researchers to normalize based on sex and age, thereby minimizing inter-subject variability associated with demographic and biological factors. The proposed methodology is open-source and accessible through the Spinal Cord Toolbox (SCT) v6.0 and higher.

Body size interacts with the structure of the central nervous system: A multi-center in vivo neuroimaging study

“…However, the spine-generic database identifies an additional 61 subjects with mild degenerative compression and 2 subjects with severe degenerative compression and radiological myelopathy. 49 Analysis power decreased, but minimal nuances were detected in correlation coefficients when tested separately on subjects without or with degenerative cervical SC compression (see Supplementary Slides ). Thus, we conclude that SC compression had a minimal impact on the current study outcomes.…”

Normalizing Spinal Cord Compression Morphometric Measures: Application in Degenerative Cervical Myelopathy

“…Previous studies have reported that the prevalence of spinal cord compression increases with age 11,38,42 . Further work will include extending the normative database 11 to a wider age range.…”

“…Therefore, we implemented the normalization approach for several morphometric measures provided by SCT's sct_process_segmentation. Those metrics are: 1) AP diameter, 2) RL diameter, 3) CSA, 4) eccentricity, and 5) solidity 11 . Note that the original MSCC normalizes only the AP diameter 13 (see Figure 1B).…”

“…(B) Morphometric measures used to compute morphometric ratios and normalized morphometric ratios. Adapted from 11 .…”

“…Inter-subject variability, on the other hand, is associated with the differences between individuals in terms of age, sex, and body size (weight, height). For instance, a significantly smaller spinal cord area is consistently reported in females relative to males 11,14,15 . Similarly, age-related changes in spinal cord size and shape can also impact spinal cord morphometrics and may require different normalization strategies for different age groups 15 .…”