“…found in the literature. Such studies which used deep learning methods to discriminate thigh and leg tissues from MRI scans obtained very high accuracy performances, namely DSC of 0.97, 0.94 and 0.80 [4] and 0.96, 0.92 and 0.93 [3] for muscle, fat and inter-muscular adipose tissue respectively. In our study, however, as in [9] we used a different approach as we started from ground truth segmentation of muscles based on their anatomy, resulting in a network capable of replicating the manual segmentation of muscles ROIs done by hand.…”
Section: Discussionmentioning
confidence: 99%
“…In particular, recent studies applied diverse approaches including variational segmentation methods combined with statistical clustering-based techniques on T1-weighted scans [10,22], machine-learning classification techniques on intensity-based features extracted from multi-contrast Dixon scans [29], Deep Neural Networks (DNN) methods based on convolutional architectures combined with variational contour detector on T1-w scans [30] and DNN methods based on an encoder-decoder U-net architecture [27] combined with a clustering algorithm on T2 and proton density (PD) maps from multi spin echo scans [3]. Finally, Anwar et al applied a semi-supervised deep learning approach based on an encoder-decoder architecture on multi-contrast Dixon scans [4]. This latter work provided a unified framework to automatically segment both the multiple tissues regions and the edges of the fascia lata, which separates the adipose tissue domain into subcutaneous and inter-muscular.…”
Objective
In this study we address the automatic segmentation of selected muscles of the thigh and leg through a supervised deep learning approach.
Material and methods
The application of quantitative imaging in neuromuscular diseases requires the availability of regions of interest (ROI) drawn on muscles to extract quantitative parameters. Up to now, manual drawing of ROIs has been considered the gold standard in clinical studies, with no clear and universally accepted standardized procedure for segmentation. Several automatic methods, based mainly on machine learning and deep learning algorithms, have recently been proposed to discriminate between skeletal muscle, bone, subcutaneous and intermuscular adipose tissue. We develop a supervised deep learning approach based on a unified framework for ROI segmentation.
Results
The proposed network generates segmentation maps with high accuracy, consisting in Dice Scores ranging from 0.89 to 0.95, with respect to “ground truth” manually segmented labelled images, also showing high average performance in both mild and severe cases of disease involvement (i.e. entity of fatty replacement).
Discussion
The presented results are promising and potentially translatable to different skeletal muscle groups and other MRI sequences with different contrast and resolution.
“…found in the literature. Such studies which used deep learning methods to discriminate thigh and leg tissues from MRI scans obtained very high accuracy performances, namely DSC of 0.97, 0.94 and 0.80 [4] and 0.96, 0.92 and 0.93 [3] for muscle, fat and inter-muscular adipose tissue respectively. In our study, however, as in [9] we used a different approach as we started from ground truth segmentation of muscles based on their anatomy, resulting in a network capable of replicating the manual segmentation of muscles ROIs done by hand.…”
Section: Discussionmentioning
confidence: 99%
“…In particular, recent studies applied diverse approaches including variational segmentation methods combined with statistical clustering-based techniques on T1-weighted scans [10,22], machine-learning classification techniques on intensity-based features extracted from multi-contrast Dixon scans [29], Deep Neural Networks (DNN) methods based on convolutional architectures combined with variational contour detector on T1-w scans [30] and DNN methods based on an encoder-decoder U-net architecture [27] combined with a clustering algorithm on T2 and proton density (PD) maps from multi spin echo scans [3]. Finally, Anwar et al applied a semi-supervised deep learning approach based on an encoder-decoder architecture on multi-contrast Dixon scans [4]. This latter work provided a unified framework to automatically segment both the multiple tissues regions and the edges of the fascia lata, which separates the adipose tissue domain into subcutaneous and inter-muscular.…”
Objective
In this study we address the automatic segmentation of selected muscles of the thigh and leg through a supervised deep learning approach.
Material and methods
The application of quantitative imaging in neuromuscular diseases requires the availability of regions of interest (ROI) drawn on muscles to extract quantitative parameters. Up to now, manual drawing of ROIs has been considered the gold standard in clinical studies, with no clear and universally accepted standardized procedure for segmentation. Several automatic methods, based mainly on machine learning and deep learning algorithms, have recently been proposed to discriminate between skeletal muscle, bone, subcutaneous and intermuscular adipose tissue. We develop a supervised deep learning approach based on a unified framework for ROI segmentation.
Results
The proposed network generates segmentation maps with high accuracy, consisting in Dice Scores ranging from 0.89 to 0.95, with respect to “ground truth” manually segmented labelled images, also showing high average performance in both mild and severe cases of disease involvement (i.e. entity of fatty replacement).
Discussion
The presented results are promising and potentially translatable to different skeletal muscle groups and other MRI sequences with different contrast and resolution.
“…Distinction between adipose and healthy muscle tissue was performed using the same networks and the corresponding DSC values were also high, i.e., 0.91 ( 66 ) and 0.94 ± 0.07 ( 65 ) for muscle detection. Recently, impressive DSC scores of 0.97 were obtained with an improved U-Net structure using residual connections and dense blocks ( 67 ). However, such a classification did not allow to distinguish perimuscular and intramuscular adipose tissue.…”
Section: Deep Learning-based Segmentation Methodsmentioning
confidence: 99%
“…In that case, each image does not have to be annotated before the network training phase and one can increase the database without a human intervention for the labeling process. Anwar et al ( 67 ) proposed to use a CED on unlabeled data to create labels and thus enlarge their dataset. However, unlabeled data are not always available especially for the study of rare diseases.…”
Section: Deep Learning-based Segmentation Methodsmentioning
Neuromuscular disorders are rare diseases for which few therapeutic strategies currently exist. Assessment of therapeutic strategies efficiency is limited by the lack of biomarkers sensitive to the slow progression of neuromuscular diseases (NMD). Magnetic resonance imaging (MRI) has emerged as a tool of choice for the development of qualitative scores for the study of NMD. The recent emergence of quantitative MRI has enabled to provide quantitative biomarkers more sensitive to the evaluation of pathological changes in muscle tissue. However, in order to extract these biomarkers from specific regions of interest, muscle segmentation is mandatory. The time-consuming aspect of manual segmentation has limited the evaluation of these biomarkers on large cohorts. In recent years, several methods have been proposed to make the segmentation step automatic or semi-automatic. The purpose of this study was to review these methods and discuss their reliability, reproducibility, and limitations in the context of NMD. A particular attention has been paid to recent deep learning methods, as they have emerged as an effective method of image segmentation in many other clinical contexts.
“…Several studies have proposed either semi‐automated or fully automated methods in segmenting muscles on MRI images 16–22 . These automations have been mainly applied to whole limb muscles.…”
Background
Axonal loss denervates muscle, leading to an increase of fat accumulation in the muscle. Therefore, fat fraction (FF) in whole limb muscle using MRI has emerged as a monitoring biomarker for axonal loss in patients with peripheral neuropathies. In this study, we are testing whether deep learning‐based model can automate quantification of the FF in individual muscles. While individual muscle is smaller with irregular shape, manually segmented muscle MRI images have been accumulated in this lab; and make the deep learning feasible.
Purpose
To automate segmentation on muscle MRI images through deep learning for quantifying individual muscle FF in patients with peripheral neuropathies.
Study Type
Retrospective.
Subjects
24 patients and 19 healthy controls.
Field Strength/Sequences
3T; Interleaved 3D GRE.
Assessment
A 3D U‐Net model was implemented in segmenting muscle MRI images. This was enabled by leveraging a large set of manually segmented muscle MRI images. B1+ and B1− maps were used to correct image inhomogeneity. Accuracy of the automation was evaluated using Pixel Accuracy (PA), Dice Coefficient (DC) in binary masks; and Bland‐Altman and Pearson correlation by comparing FF values between manual and automated methods.
Statistical Tests
PA and DC were reported with their median value and standard deviation. Two methods were compared using the ± 95% confidence intervals (CI) of Bland‐Altman analysis and the Pearson’s coefficient (r2).
Results
DC values were from 0.83 ± 0.17 to 0.98 ± 0.02 in thigh and from 0.63 ± 0.18 to 0.96 ± 0.02 in calf muscles. For FF values, the overall ± 95% CI and r2 were [0.49, –0.56] and 0.989 in thigh and [0.84, –0.71] and 0.971 in the calf.
Data Conclusion
Automated results well agreed with the manual results in quantifying FF for individual muscles. This method mitigates the formidable time consumption and intense labor in manual segmentations; and enables the use of individual muscle FF as outcome measures in upcoming longitudinal studies.
Level of Evidence
3
Technical Efficacy Stage
1
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.