Effects of variability in manually contoured spinal cord masks on fMRI co-registration and interpretation.

Autor: Hoggarth MA; Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States., Wang MC; Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, United States., Hemmerling KJ; Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States.; Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, United States., Vigotsky AD; Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, United States.; Department of Statistics, Weinberg College of Arts and Sciences, Northwestern University, Evanston, IL, United States., Smith ZA; Department of Neurological Surgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States., Parrish TB; Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, United States.; Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States., Weber KA 2nd; Systems Neuroscience and Pain Lab, Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Palo Alto, CA, United States., Bright MG; Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States.; Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, United States.
Jazyk: angličtina
Zdroj: Frontiers in neurology [Front Neurol] 2022 Oct 20; Vol. 13, pp. 907581. Date of Electronic Publication: 2022 Oct 20 (Print Publication: 2022).
DOI: 10.3389/fneur.2022.907581
Abstrakt: Functional magnetic resonance imaging (fMRI) of the human spinal cord (SC) is a unique non-invasive method for characterizing neurovascular responses to stimuli. Group-analysis of SC fMRI data involves co-registration of subject-level data to standard space, which requires manual masking of the cord and may result in bias of group-level SC fMRI results. To test this, we examined variability in SC masks drawn in fMRI data from 21 healthy participants from a completed study mapping responses to sensory stimuli of the C7 dermatome. Masks were drawn on temporal mean functional image by eight raters with varying levels of neuroimaging experience, and the rater from the original study acted as a reference. Spatial agreement between rater and reference masks was measured using the Dice Similarity Coefficient, and the influence of rater and dataset was examined using ANOVA. Each rater's masks were used to register functional data to the PAM50 template. Gray matter-white matter signal contrast of registered functional data was used to evaluate the spatial normalization accuracy across raters. Subject- and group-level analyses of activation during left- and right-sided sensory stimuli were performed for each rater's co-registered data. Agreement with the reference SC mask was associated with both rater (F (7, 140) = 32.12, P < 2 × 10 -16 , η 2 = 0.29) and dataset (F (20, 140) = 20.58, P < 2 × 10 -16 , η 2 = 0.53). Dataset variations may reflect image quality metrics: the ratio between the signal intensity of spinal cord voxels and surrounding cerebrospinal fluid was correlated with DSC results ( p < 0.001). As predicted, variability in the manually-drawn masks influenced spatial normalization, and GM:WM contrast in the registered data showed significant effects of rater and dataset (rater: F (8, 160) = 23.57, P < 2 × 10 -16 , η 2 = 0.24; dataset: F (20, 160) = 22.00, P < 2 × 10 -16 , η 2 = 0.56). Registration differences propagated into subject-level activation maps which showed rater-dependent agreement with the reference. Although group-level activation maps differed between raters, no systematic bias was identified. Increasing consistency in manual contouring of spinal cord fMRI data improved co-registration and inter-rater agreement in activation mapping, however our results suggest that improvements in image acquisition and post-processing are also critical to address.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer JC-A declared a past co-authorship with several of the authors ZS, TP, and KW to the handling Editor.
(Copyright © 2022 Hoggarth, Wang, Hemmerling, Vigotsky, Smith, Parrish, Weber and Bright.)
Databáze: MEDLINE
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