Spinal cord cross-sectional area during flexion and extension in the patients with cervical ossification of posterior longitudinal ligament

Finding an accurate and affordable method to quantify muscle size following spinal cord injury (SCI) could provide benefits clinically and in research settings. The purpose of this study was to validate the use of anthropometric measurements vs. magnetic resonance imaging (MRI) to evaluate muscle cross-sectional area (CSA) and develop a field equation to predict muscle CSA specific to the SCI population. Twenty-two men with chronic (>1 yr) motor complete SCI participated in the current study. Anthropometric measurements, including midthigh circumference and anterior skinfold thickness (SFT), were taken on the right thigh. The anthropometric muscle cross-sectional area (muscle CSAanthro) was predicted using the following equation: muscle CSAanthro = π[ r − (SFT/2)]2, where r = thigh circumference/2π. MRI analysis yielded whole thigh CSA (thigh CSAMRI), midthigh muscle CSA (muscle CSAMRI), midthigh absolute muscle CSA after subtracting intramuscular fat and bone (muscle CSA-IMFMRI), subcutaneous adipose tissue (SATT) measured at one site as well as at four sites, and bone CSA. Anthropometric measurements were correlated to the thigh CSAMRI [ r2 = 0.90, standard error of the estimate (SEE) = 17.6 cm2, P < 0.001]. Muscle CSAanthro was correlated to muscle CSAMRI ( r2 = 0.78, SEE = 16.6 cm2, P < 0.001) and muscle CSA-IMFMRI ( r2 = 0.75, SEE = 17.6 cm2, P < 0.001). A single SFT was correlated to the polar four-site SATT ( r2 = 0.78, SEE = 0.37 cm, P < 0.001). The average femur CSA and average IMF CSA derived from MRI led to the following field equation: muscle CSApredicted = π[(Thighcircum/2π) − (SFT/2)]2 − 23.2. Anthropometric measurements of muscle CSA exhibited a good agreement with the gold standard MRI method and led to the development of a field equation for clinical use after accounting for bone and IMF. NEW & NOTEWORTHY This study used anthropometric measurements and magnetic resonance imaging (MRI) to evaluate muscle cross-sectional area (CSA) and developed a field equation to predict thigh muscle CSA specific to the spinal cord-injured (SCI) population. Anthropometric measurements were correlated to the whole thigh CSA and muscle CSA as measured by MRI. The correlations led to the development of a SCI-specific field equation that accounted for intramuscular fat and bone areas.

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Quantification of Cervical Cord Cross-Sectional Area: Which Acquisition, Vertebra Level, and Analysis Software? A Multicenter Repeatability Study on a Traveling Healthy Volunteer

Frontiers in Neurology ◽

10.3389/fneur.2021.693333 ◽

2021 ◽

Vol 12 ◽

Author(s):

Carsten Lukas ◽

Barbara Bellenberg ◽

Ferran Prados ◽

Paola Valsasina ◽

Katrin Parmar ◽

...

Keyword(s):

Spinal Cord ◽

Healthy Volunteer ◽

Brain Mri ◽

Cross Sectional Area ◽

Image Resolution ◽

Cervical Cord ◽

Surface Model ◽

Sectional Area ◽

Cross Sectional ◽

Brain Images

Background: Considerable spinal cord (SC) atrophy occurs in multiple sclerosis (MS). While MRI-based techniques for SC cross-sectional area (CSA) quantification have improved over time, there is no common agreement on whether to measure at single vertebral levels or across larger regions and whether upper SC CSA can be reliably measured from brain images.Aim: To compare in a multicenter setting three CSA measurement methods in terms of repeatability at different anatomical levels. To analyze the agreement between measurements performed on the cervical cord and on brain MRI.Method: One healthy volunteer was scanned three times on the same day in six sites (three scanner vendors) using a 3T MRI protocol including sagittal 3D T1-weighted imaging of the brain (covering the upper cervical cord) and of the SC. Images were analyzed using two semiautomated methods [NeuroQLab (NQL) and the Active Surface Model (ASM)] and the fully automated Spinal Cord Toolbox (SCT) on different vertebral levels (C1–C2; C2/3) on SC and brain images and the entire cervical cord (C1–C7) on SC images only.Results: CSA estimates were significantly smaller using SCT compared to NQL and ASM (p < 0.001), regardless of the cord level. Inter-scanner repeatability was best in C1–C7: coefficients of variation for NQL, ASM, and SCT: 0.4, 0.6, and 1.0%, respectively. CSAs estimated in brain MRI were slightly lower than in SC MRI (all p ≤ 0.006 at the C1–C2 level). Despite protocol harmonization between the centers with regard to image resolution and use of high-contrast 3D T1-weighted sequences, the variability of CSA was partly scanner dependent probably due to differences in scanner geometry, coil design, and details of the MRI parameter settings.Conclusion: For CSA quantification, dedicated isotropic SC MRI should be acquired, which yielded best repeatability in the entire cervical cord. In the upper part of the cervical cord, use of brain MRI scans entailed only a minor loss of CSA repeatability compared to SC MRI. Due to systematic differences between scanners and the CSA quantification software, both should be kept constant within a study. The MRI dataset of this study is available publicly to test new analysis approaches.

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