Instance-level quantitative saliency in multiple sclerosis lesion segmentation

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Spagnolo, Federico, Molchanova, Nataliia, Cuadra, Meritxell Bach, Pineda, Mario Ocampo, Melie-Garcia, Lester, Granziera, Cristina, Andrearczyk, Vincent, Depeursinge, Adrien
Natura: Preprint
Pubblicazione: 2024
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866917205256437760
author Spagnolo, Federico
Molchanova, Nataliia
Cuadra, Meritxell Bach
Pineda, Mario Ocampo
Melie-Garcia, Lester
Granziera, Cristina
Andrearczyk, Vincent
Depeursinge, Adrien
author_facet Spagnolo, Federico
Molchanova, Nataliia
Cuadra, Meritxell Bach
Pineda, Mario Ocampo
Melie-Garcia, Lester
Granziera, Cristina
Andrearczyk, Vincent
Depeursinge, Adrien
contents Explainable artificial intelligence (XAI) methods have been proposed to interpret model decisions in classification and, more recently, in semantic segmentation. However, instance-level XAI for semantic segmentation, namely explanations focused on a single object among multiple instances of the same class, remains largely unexplored. Such explanations are particularly important in multi-lesional diseases to understand what drives the detection and contouring of a specific lesion. We propose instance-level explanation maps for semantic segmentation by extending SmoothGrad and Grad-CAM++ to obtain quantitative instance saliency. These methods were applied to the segmentation of white matter lesions (WMLs), a magnetic resonance imaging biomarker in multiple sclerosis. We used 4023 FLAIR and MPRAGE MRI scans from 687 patients collected at the University Hospital of Basel, Switzerland, with WML masks annotated by four expert clinicians. Three deep learning architectures, a 3D U-Net, nnU-Net, and Swin UNETR, were trained and evaluated, achieving normalized Dice scores of 0.71, 0.78, and 0.80, respectively. Instance saliency maps showed that the models relied primarily on FLAIR rather than MPRAGE for WML segmentation, with positive saliency inside lesions and negative saliency in their immediate neighborhood, consistent with clinical practice. Peak saliency values differed significantly across correct and incorrect predictions, suggesting that quantitative instance saliency may help identify segmentation errors. In conclusion, we introduce two architecture-agnostic XAI methods that provide quantitative instance-level explanations for semantic segmentation and support clinically meaningful interpretation of model decisions.
format Preprint
id arxiv_https___arxiv_org_abs_2406_09335
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Instance-level quantitative saliency in multiple sclerosis lesion segmentation
Spagnolo, Federico
Molchanova, Nataliia
Cuadra, Meritxell Bach
Pineda, Mario Ocampo
Melie-Garcia, Lester
Granziera, Cristina
Andrearczyk, Vincent
Depeursinge, Adrien
Image and Video Processing
Computer Vision and Pattern Recognition
Machine Learning
Explainable artificial intelligence (XAI) methods have been proposed to interpret model decisions in classification and, more recently, in semantic segmentation. However, instance-level XAI for semantic segmentation, namely explanations focused on a single object among multiple instances of the same class, remains largely unexplored. Such explanations are particularly important in multi-lesional diseases to understand what drives the detection and contouring of a specific lesion. We propose instance-level explanation maps for semantic segmentation by extending SmoothGrad and Grad-CAM++ to obtain quantitative instance saliency. These methods were applied to the segmentation of white matter lesions (WMLs), a magnetic resonance imaging biomarker in multiple sclerosis. We used 4023 FLAIR and MPRAGE MRI scans from 687 patients collected at the University Hospital of Basel, Switzerland, with WML masks annotated by four expert clinicians. Three deep learning architectures, a 3D U-Net, nnU-Net, and Swin UNETR, were trained and evaluated, achieving normalized Dice scores of 0.71, 0.78, and 0.80, respectively. Instance saliency maps showed that the models relied primarily on FLAIR rather than MPRAGE for WML segmentation, with positive saliency inside lesions and negative saliency in their immediate neighborhood, consistent with clinical practice. Peak saliency values differed significantly across correct and incorrect predictions, suggesting that quantitative instance saliency may help identify segmentation errors. In conclusion, we introduce two architecture-agnostic XAI methods that provide quantitative instance-level explanations for semantic segmentation and support clinically meaningful interpretation of model decisions.
title Instance-level quantitative saliency in multiple sclerosis lesion segmentation
topic Image and Video Processing
Computer Vision and Pattern Recognition
Machine Learning
url https://arxiv.org/abs/2406.09335