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arXiv · 2505.01364

Monitoring morphometric drift in lifelong learning segmentation of the spinal cord

Enamundram Naga Karthik·Sandrine Bédard·Jan Valošek·Christoph S. Aigner·Elise Bannier·Josef Bednařík·Virginie Callot·Anna Combes·Armin Curt·Gergely David·Falk Eippert·Lynn Farner·Michael G Fehlings·Patrick Freund·Tobias Granberg·Cristina Granziera·RHSCIR Network Imaging Group·Ulrike Horn·Tomáš Horák·Suzanne Humphreys·Markus Hupp·Anne Kerbrat·Nawal Kinany·Shannon Kolind·Petr Kudlička·Anna Lebret·Lisa Eunyoung Lee·Caterina Mainero·Allan R. Martin·Megan McGrath·Govind Nair·Kristin P. O'Grady·Jiwon Oh·Russell Ouellette·Nikolai Pfender·Dario Pfyffer·Pierre-François Pradat·Alexandre Prat·Emanuele Pravatà·Daniel S. Reich·Ilaria Ricchi·Naama Rotem-Kohavi·Simon Schading-Sassenhausen·Maryam Seif·Andrew Smith·Seth A Smith·Grace Sweeney·Roger Tam·Anthony Traboulsee·Constantina Andrada Treaba·Charidimos Tsagkas·Zachary Vavasour·Dimitri Van De Ville·Kenneth Arnold Weber II·Sarath Chandar·Julien Cohen-Adad
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Abstract

Morphometric measures derived from spinal cord segmentations can serve as diagnostic and prognostic biomarkers in neurological diseases and injuries affecting the spinal cord. While robust, automatic segmentation methods to a wide variety of contrasts and pathologies have been developed over the past few years, whether their predictions are stable as the model is updated using new datasets has not been assessed. This is particularly important for deriving normative values from healthy participants. In this study, we present a spinal cord segmentation model trained on a multisite $(n=75)$ dataset, including 9 different MRI contrasts and several spinal cord pathologies. We also introduce a lifelong learning framework to automatically monitor the morphometric drift as the model is updated using additional datasets. The framework is triggered by an automatic GitHub Actions workflow every time a new model is created, recording the morphometric values derived from the model's predictions over time. As a real-world application of the proposed framework, we employed the spinal cord segmentation model to update a recently-introduced normative database of healthy participants containing commonly used measures of spinal cord morphometry. Results showed that: (i) our model outperforms previous versions and pathology-specific models on challenging lumbar spinal cord cases, achieving an average Dice score of $0.95 \pm 0.03$; (ii) the automatic workflow for monitoring morphometric drift provides a quick feedback loop for developing future segmentation models; and (iii) the scaling factor required to update the database of morphometric measures is nearly constant among slices across the given vertebral levels, showing minimum drift between the current and previous versions of the model monitored by the framework. The code and model are open-source and accessible via Spinal Cord Toolbox v7.0.

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Enamundram Naga Karthik, Sandrine Bédard, Jan Valošek, Christoph S. Aigner, Elise Bannier, Josef Bednařík, Virginie Callot, Anna Combes, Armin Curt, Gergely David, Falk Eippert, Lynn Farner, Michael G Fehlings, Patrick Freund, Tobias Granberg, Cristina Granziera, RHSCIR Network Imaging Group, Ulrike Horn, Tomáš Horák, Suzanne Humphreys, Markus Hupp, Anne Kerbrat, Nawal Kinany, Shannon Kolind, Petr Kudlička, Anna Lebret, Lisa Eunyoung Lee, Caterina Mainero, Allan R. Martin, Megan McGrath, Govind Nair, Kristin P. O'Grady, Jiwon Oh, Russell Ouellette, Nikolai Pfender, Dario Pfyffer, Pierre-François Pradat, Alexandre Prat, Emanuele Pravatà, Daniel S. Reich, Ilaria Ricchi, Naama Rotem-Kohavi, Simon Schading-Sassenhausen, Maryam Seif, Andrew Smith, Seth A Smith, Grace Sweeney, Roger Tam, Anthony Traboulsee, Constantina Andrada Treaba, Charidimos Tsagkas, Zachary Vavasour, Dimitri Van De Ville, Kenneth Arnold Weber II, Sarath Chandar, Julien Cohen-Adad. 2025-10-20. Monitoring morphometric drift in lifelong learning segmentation of the spinal cord. https://arxiv.org/abs/2505.01364

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