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Beste NC, Jende J, Kronlage M, Kurz F, Heiland S, Bendszus M, Meredig H. Automated peripheral nerve segmentation for MR-neurography. Eur Radiol Exp 2024; 8:97. [PMID: 39186183 PMCID: PMC11347527 DOI: 10.1186/s41747-024-00503-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 08/01/2024] [Indexed: 08/27/2024] Open
Abstract
BACKGROUND Magnetic resonance neurography (MRN) is increasingly used as a diagnostic tool for peripheral neuropathies. Quantitative measures enhance MRN interpretation but require nerve segmentation which is time-consuming and error-prone and has not become clinical routine. In this study, we applied neural networks for the automated segmentation of peripheral nerves. METHODS A neural segmentation network was trained to segment the sciatic nerve and its proximal branches on the MRN scans of the right and left upper leg of 35 healthy individuals, resulting in 70 training examples, via 5-fold cross-validation (CV). The model performance was evaluated on an independent test set of one-sided MRN scans of 60 healthy individuals. RESULTS Mean Dice similarity coefficient (DSC) in CV was 0.892 (95% confidence interval [CI]: 0.888-0.897) with a mean Jaccard index (JI) of 0.806 (95% CI: 0.799-0.814) and mean Hausdorff distance (HD) of 2.146 (95% CI: 2.184-2.208). For the independent test set, DSC and JI were lower while HD was higher, with a mean DSC of 0.789 (95% CI: 0.760-0.815), mean JI of 0.672 (95% CI: 0.642-0.699), and mean HD of 2.118 (95% CI: 2.047-2.190). CONCLUSION The deep learning-based segmentation model showed a good performance for the task of nerve segmentation. Future work will focus on extending training data and including individuals with peripheral neuropathies in training to enable advanced peripheral nerve disease characterization. RELEVANCE STATEMENT The results will serve as a baseline to build upon while developing an automated quantitative MRN feature analysis framework for application in routine reading of MRN examinations. KEY POINTS Quantitative measures enhance MRN interpretation, requiring complex and challenging nerve segmentation. We present a deep learning-based segmentation model with good performance. Our results may serve as a baseline for clinical automated quantitative MRN segmentation.
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Affiliation(s)
- Nedim Christoph Beste
- Institute of Neuroradiology, University Hospital of Heidelberg, Heidelberg, Germany.
| | - Johann Jende
- Institute of Neuroradiology, University Hospital of Heidelberg, Heidelberg, Germany
| | - Moritz Kronlage
- Institute of Neuroradiology, University Hospital of Heidelberg, Heidelberg, Germany
| | - Felix Kurz
- DKFZ German Cancer Research Center, Heidelberg, Germany
| | - Sabine Heiland
- Institute of Neuroradiology, University Hospital of Heidelberg, Heidelberg, Germany
| | - Martin Bendszus
- Institute of Neuroradiology, University Hospital of Heidelberg, Heidelberg, Germany
| | - Hagen Meredig
- Institute of Neuroradiology, University Hospital of Heidelberg, Heidelberg, Germany
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Snoj Ž, Pušnik L, Cvetko E, Burica Matičič U, Jengojan SA, Omejec G. Sciatic nerve fascicle differentiation on high-resolution ultrasound with histological verification: An ex vivo study. Muscle Nerve 2024; 70:265-272. [PMID: 38877775 DOI: 10.1002/mus.28181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 05/28/2024] [Accepted: 06/01/2024] [Indexed: 06/16/2024]
Abstract
INTRODUCTION/AIMS The development of high-resolution ultrasound (HRUS) has enabled the depiction of peripheral nerve microanatomy in vivo. This study compared HRUS fascicle differentiation to the structural depiction in histological cross-sections (HCS). METHODS A human cadaveric sciatic nerve was marked with 10 surgical sutures, and HRUS image acquisition was performed with a 22-MHz probe. The nerve was excised and cut into five segments for HCS preparation. Selected HCS were cross-referenced to HRUS, with sutures to improve orientation. Sciatic nerve and fascicle contouring were performed to assess nerve and fascicular cross-sectional area (CSA), fascicle count, and interfascicular distances. Three groups were defined based on HRUS fascicle differentiation in comparison to HCS, namely single fascicle (SF), fascicular cluster (FC), and no depiction (ND) group. RESULTS On cross-referenced HRUS to HCS images, 58% of fascicles were differentiated. On HRUS, significantly larger fascicle CSA and smaller fascicle count were observed compared with HCS. Group analysis showed that 41% of fascicles were defined as SF, 47% as FC, and 12% as ND. The mean fascicle CSA in the ND group was 0.05 mm2. Compared with the SF, the FC had significantly larger fascicle CSA (1.2 ± 0.7 vs. 0.6 ± 0.4 mm2; p < .001) and shorter interfascicular distances (0.1 ± 0.04 vs. 0.5 ± 0.3 μm; p < .001). DISCUSSION While HRUS can depict fascicular anatomy, only half of the fascicles visualized on HRUS directly correspond to single fascicles observed on HCS. The amount of interfascicular epineurium appears to influence the ability of HRUS to differentiate individual fascicles.
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Affiliation(s)
- Žiga Snoj
- Radiology Institute, University Medical Centre Ljubljana, Ljubljana, Slovenia
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Luka Pušnik
- Faculty of Medicine, Institute of Anatomy, University of Ljubljana, Ljubljana, Slovenia
| | - Erika Cvetko
- Faculty of Medicine, Institute of Anatomy, University of Ljubljana, Ljubljana, Slovenia
| | - Urša Burica Matičič
- Radiology Institute, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Suren Armeni Jengojan
- Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Gregor Omejec
- Division of Neurology, Institute of Clinical Neurophysiology, University Medical Center Ljubljana, Ljubljana, Slovenia
- The Higher Education Institution Fizioterapevtika, Ljubljana, Slovenia
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Harinesan N, Silsby M, Simon NG. Carpal tunnel syndrome. HANDBOOK OF CLINICAL NEUROLOGY 2024; 201:61-88. [PMID: 38697747 DOI: 10.1016/b978-0-323-90108-6.00005-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Abstract
Median neuropathy at the wrist, commonly referred to as carpal tunnel syndrome (CTS), is the most common entrapment neuropathy. It is caused by chronic compression of the median nerve at the wrist within the space-limited carpal tunnel. Risk factors that contribute to the etiology of compression include female gender, obesity, work-related factors, and underlying medical conditions, such as hypothyroidism, pregnancy, and amyloidosis. The diagnosis is made on clinical grounds, although these can be confounded by anatomical variations. Electrodiagnostic studies, which are specific and sensitive in diagnosing CTS, support the diagnosis; however, a subgroup may present with normal results. The advent of imaging techniques, including ultrasound and MRI, further assists the diagnostic process. The management of CTS is divided into the nonsurgical approaches that include hand therapy, splinting and corticosteroid injection, and surgical decompression of the carpal tunnel. Although several surgical techniques have been developed, no one method is more effective than the other. Each of these management approaches are effective at providing symptom relief and are utilized at different severities of the condition. There is, however, a lack of consensus on standardized diagnostic criteria, as well as when and to whom to refer patients for surgery.
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Affiliation(s)
- Nimalan Harinesan
- Westmead Clinical School, University of Sydney, Sydney, NSW, Australia
| | - Matthew Silsby
- Westmead Clinical School, University of Sydney, Sydney, NSW, Australia
| | - Neil G Simon
- Northern Beaches Clinical School, Macquarie University, Sydney, NSW, Australia.
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Žiga S, Igor S, Urša M, Plut D, Erika C, Gregor O. Median and ulnar nerve fascicle imaging using MR microscopy and high-resolution ultrasound. J Neuroimaging 2022; 32:420-429. [PMID: 35229399 DOI: 10.1111/jon.12982] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/10/2022] [Accepted: 02/14/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND AND PURPOSE Understanding nerve microanatomy is important as different neuropathies and some nerve neoplasms present with fascicle enlargement. The aim of our study was to gain clinically oriented knowledge on nerve fascicular anatomy using imaging modalities. METHODS On a cadaveric upper extremity, high-resolution ultrasound (HRUS) scan with 22 MHz probe was performed. Sections of the median and ulnar nerves were excised at the level of the distal arm and after magnetic resonance microscopy (MRM), histological cross-sections (HCS) were prepared. Cross-referencing of the MRM and HRUS images with HCS was performed. Fascicle and nerve contouring was performed with morphometric software in order to assess nerve and fascicular cross-sectional area (CSA), fascicle count, and interfascicular distances. Based on fascicle differentiation, factual fascicle (FF) group and fascicular cluster (FC) group were defined. RESULTS On the cross-referenced imaging material, fascicles were differentiated in 92.7% on MRM and in 57.3% on HRUS. High to very high positive correlation among imaging material was observed for the fascicle CSA. FF depiction was 30.1% on HRUS. In comparison to the FF group, the FC group had significantly larger fascicle CSA and shorter interfascicular distances. DISCUSSION The findings of our study contribute to understanding of fascicle depiction on imaging modalities. HRUS offers good visualization of fascicles. The capability of differentiating fascicles is modality specific and depends on the fascicle CSA and the amount of interfascicular epineurium.
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Affiliation(s)
- Snoj Žiga
- Radiology Institute, University Medical Centre Ljubljana, Ljubljana, Slovenia.,Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Serša Igor
- Department of Condensed Matter Physics, Jožef Stefan Institute, 1000 Ljubljana, Slovenia
| | - Matičič Urša
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Domen Plut
- Radiology Institute, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Cvetko Erika
- Institute of Anatomy, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Omejec Gregor
- Institute of Clinical Neurophysiology, Division of Neurology, University Medical Center Ljubljana, Ljubljana, Slovenia
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Himeno T, Kamiya H, Nakamura J. Lumos for the long trail: Strategies for clinical diagnosis and severity staging for diabetic polyneuropathy and future directions. J Diabetes Investig 2020; 11:5-16. [PMID: 31677343 PMCID: PMC6944828 DOI: 10.1111/jdi.13173] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/29/2019] [Accepted: 10/31/2019] [Indexed: 02/06/2023] Open
Abstract
Diabetic polyneuropathy, which is a chronic symmetrical length-dependent sensorimotor polyneuropathy, is the most common form of diabetic neuropathy. Although diabetic polyneuropathy is the most important risk factor in cases of diabetic foot, given its poor prognosis, the criteria for diagnosis and staging of diabetic polyneuropathy has not been established; consequently, no disease-modifying treatment is available. Most criteria and scoring systems that were previously proposed consist of clinical signs, symptoms and quantitative examinations, including sensory function tests and nerve conduction study. However, in diabetic polyneuropathy, clinical symptoms, including numbness, pain and allodynia, show no significant correlation with the development of pathophysiological changes in the peripheral nervous system. Therefore, these proposed criteria and scoring systems have failed to become a universal clinical end-point for large-scale clinical trials evaluating the prognosis in diabetes patients. We should use quantitative examinations of which validity has been proven. Nerve conduction study, for example, has been proven effective to evaluate dysfunctions of large nerve fibers. Baba's classification, which uses a nerve conduction study, is one of the most promising diagnostic methods. Loss of small nerve fibers can be determined using corneal confocal microscopy and intra-epidermal nerve fiber density. However, no staging criteria have been proposed using these quantitative evaluations for small fiber neuropathy. To establish a novel diagnostic and staging criteria of diabetic polyneuropathy, we propose three principles to be considered: (i) include only generalizable objective quantitative tests; (ii) exclude clinical symptoms and signs; and (iii) do not restrictively exclude other causes of polyneuropathy.
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Affiliation(s)
- Tatsuhito Himeno
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Hideki Kamiya
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Jiro Nakamura
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
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Radiomics of peripheral nerves MRI in mild carpal and cubital tunnel syndrome. Radiol Med 2019; 125:197-203. [PMID: 31773457 DOI: 10.1007/s11547-019-01110-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 11/13/2019] [Indexed: 12/12/2022]
Abstract
OBJECTIVE To assess the discriminative power of radiomics of peripheral nerves at 1.5T MRI, using common entrapment neuropathies of the upper limb as a model system of focal nerve injury. MATERIALS AND METHODS Radiomics was retrospectively done on peripheral nerve fascicles on T1-weighted 1.5T MRI of 40 patients with diagnosis of mild carpal (n = 25) and cubital tunnel (n = 15) syndrome and of 200 controls. Z-score normalization and Mann-Whitney U test were used to compare features of normal and pathological peripheral nerves. Receiver operating characteristic analysis was performed. RESULTS A total of n = 104 radiomics features were computed for each patient and control. Significant differences between normal and pathological median and ulnar nerves were found in n = 23/104 features (p < 0.001). According to features classification, n = 5/23 features were shape-based, n = 7/23 were first-order features, n = 11/23 features were classified as gray level run length matrix. Nine of the selected features showed an AUC higher that 0.7: minimum AUC of 0.74 (95% CI 0.61-0.89) for sum variance and maximum AUC of 0.90 (95% CI 0.82-0.99) for zone entropy. CONCLUSION Features analysis demonstrated statistically significant differences between normal and pathological nerve. The results suggested that radiomics analysis could assess the median and ulnar nerve inner structure changes due to the loss of the fascicular pattern, intraneural edema, fibrosis or fascicular alterations in mild carpal tunnel and mild cubital tunnel syndromes even when the nerve cross-sectional area does not change.
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Abstract
Magnetic resonance imaging (MRI) has been used extensively in revealing pathological changes in the central nervous system. However, to date, MRI is very much underutilized in evaluating the peripheral nervous system (PNS). This underutilization is generally due to two perceived weaknesses in MRI: first, the need for very high resolution to image the small structures within the peripheral nerves to visualize morphological changes; second, the lack of normative data in MRI of the PNS and this makes reliable interpretation of the data difficult. This article reviews current state-of-the-art capabilities in
in vivo MRI of human peripheral nerves. It aims to identify areas where progress has been made and those that still require further improvement. In particular, with many new therapies on the horizon, this review addresses how MRI can be used to provide non-invasive and objective biomarkers in the evaluation of peripheral neuropathies. Although a number of techniques are available in diagnosing and tracking pathologies in the PNS, those techniques typically target the distal peripheral nerves, and distal nerves may be completely degenerated during the patient’s first clinic visit. These techniques may also not be able to access the proximal nerves deeply embedded in the tissue. Peripheral nerve MRI would be an alternative to circumvent these problems. In order to address the pressing clinical needs, this review closes with a clinical protocol at 3T that will allow high-resolution, high-contrast, quantitative MRI of the proximal peripheral nerves.
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Affiliation(s)
- Yongsheng Chen
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - E Mark Haacke
- Department of Radiology, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Jun Li
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI, 48201, USA.,Center for Molecular Medicine & Genetics, Wayne State University School of Medicine, Detroit, MI, 48201, USA.,Department of Biochemistry, Microbiology and Immunology, Wayne State University School of Medicine, Detroit, MI, 48201, USA.,John D. Dingell VA Medical Center, Detroit, MI, 48201, USA
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Felisaz PF, Poli A, Vitale R, Vitale G, Asteggiano C, Bergsland N, Callegari I, Vegezzi E, Piccolo L, Cortese A, Pichiecchio A, Bastianello S. MR microneurography and quantitative T2 and DP measurements of the distal tibial nerve in CIDP. J Neurol Sci 2019; 400:15-20. [PMID: 30878635 DOI: 10.1016/j.jns.2019.03.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 02/10/2019] [Accepted: 03/04/2019] [Indexed: 12/14/2022]
Abstract
OBJECTIVE In this study we investigated the potential of magnetic resonance (MR) micro-neurography to detect morphological and relaxometric changes in distal tibial nerves in patients affected with chronic inflammatory demyelinating polyneuropathy (CIDP), and their associations with clinical and electrophysiological features. MATERIALS AND METHODS 10 subjects affected with CIDP and 10 healthy subjects were examined. Multiple MR parameters, including the number of fascicles (N), fascicles diameter (FD), total fascicles area (FA), epineurium area (EA), total nerve area (NA), fascicles to nerve ratio (FNR) and quantitative T2 and proton density (PD) were investigated on high resolution MR images of the distal tibial nerve. Those parameters were correlated with clinical scores, age of onset, disease duration and electrophysiologic data. RESULTS Median NA and FA were significantly increased in the CIDP population (median values for NA in cm2 in CIDP: 0.185; controls: 0.135; p: 0.028; for FA in CIDP 0.136; controls 0.094; p: 0.021). There was no correlation between the parameters investigated and clinical or electrophysiologic features. CONCLUSION MR microneurography can detect increased total nerve and fascicle area in distal tibial nerves in CIDP and may be useful for diagnosing CIDP.
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Affiliation(s)
- Paolo Florent Felisaz
- Department of Neuroradiology, C. Mondino National Neurological Institute, Pavia, Italy.
| | - Andrea Poli
- Department of Neuroradiology, C. Mondino National Neurological Institute, Pavia, Italy
| | - Raimondo Vitale
- Department of Neuroradiology, C. Mondino National Neurological Institute, Pavia, Italy; Institute of Radiology, University of Pavia, Italy
| | - Giovanni Vitale
- Department of Neuroradiology, C. Mondino National Neurological Institute, Pavia, Italy; Institute of Radiology, University of Pavia, Italy
| | - Carlo Asteggiano
- Department of Neuroradiology, C. Mondino National Neurological Institute, Pavia, Italy; Institute of Radiology, University of Pavia, Italy
| | - Niels Bergsland
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Ilaria Callegari
- Department of Neurology, C. Mondino National Neurological Institute, Pavia, Italy; Neuroscience Consortium, University of Pavia, Monza Policlinico and Pavia Mondino, Italy
| | - Elisa Vegezzi
- Department of Neurology, C. Mondino National Neurological Institute, Pavia, Italy; Neuroscience Consortium, University of Pavia, Monza Policlinico and Pavia Mondino, Italy
| | - Laura Piccolo
- Department of Neurology, C. Mondino National Neurological Institute, Pavia, Italy
| | - Andrea Cortese
- Department of Neurology, C. Mondino National Neurological Institute, Pavia, Italy
| | - Anna Pichiecchio
- Department of Neuroradiology, C. Mondino National Neurological Institute, Pavia, Italy; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, PV, Italy
| | - Stefano Bastianello
- Department of Neuroradiology, C. Mondino National Neurological Institute, Pavia, Italy; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, PV, Italy
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Balsiger F, Steindel C, Arn M, Wagner B, Grunder L, El-Koussy M, Valenzuela W, Reyes M, Scheidegger O. Segmentation of Peripheral Nerves From Magnetic Resonance Neurography: A Fully-Automatic, Deep Learning-Based Approach. Front Neurol 2018; 9:777. [PMID: 30283397 PMCID: PMC6156270 DOI: 10.3389/fneur.2018.00777] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 08/27/2018] [Indexed: 01/05/2023] Open
Abstract
Diagnosis of peripheral neuropathies relies on neurological examinations, electrodiagnostic studies, and since recently magnetic resonance neurography (MRN). The aim of this study was to develop and evaluate a fully-automatic segmentation method of peripheral nerves of the thigh. T2-weighted sequences without fat suppression acquired on a 3 T MR scanner were retrospectively analyzed in 10 healthy volunteers and 42 patients suffering from clinically and electrophysiologically diagnosed sciatic neuropathy. A fully-convolutional neural network was developed to segment the MRN images into peripheral nerve and background tissues. The performance of the method was compared to manual inter-rater segmentation variability. The proposed method yielded Dice coefficients of 0.859 ± 0.061 and 0.719 ± 0.128, Hausdorff distances of 13.9 ± 26.6 and 12.4 ± 12.1 mm, and volumetric similarities of 0.930 ± 0.054 and 0.897 ± 0.109, for the healthy volunteer and patient cohorts, respectively. The complete segmentation process requires less than one second, which is a significant decrease to manual segmentation with an average duration of 19 ± 8 min. Considering cross-sectional area or signal intensity of the segmented nerves, focal and extended lesions might be detected. Such analyses could be used as biomarker for lesion burden, or serve as volume of interest for further quantitative MRN techniques. We demonstrated that fully-automatic segmentation of healthy and neuropathic sciatic nerves can be performed from standard MRN images with good accuracy and in a clinically feasible time.
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Affiliation(s)
- Fabian Balsiger
- Institute for Surgical Technology and Biomechanics, University of Bern, Bern, Switzerland
| | - Carolin Steindel
- Support Center for Advanced Neuroimaging, Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Mirjam Arn
- Support Center for Advanced Neuroimaging, Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Benedikt Wagner
- Support Center for Advanced Neuroimaging, Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Lorenz Grunder
- Support Center for Advanced Neuroimaging, Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Marwan El-Koussy
- Support Center for Advanced Neuroimaging, Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Waldo Valenzuela
- Institute for Surgical Technology and Biomechanics, University of Bern, Bern, Switzerland.,Support Center for Advanced Neuroimaging, Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Mauricio Reyes
- Institute for Surgical Technology and Biomechanics, University of Bern, Bern, Switzerland
| | - Olivier Scheidegger
- Support Center for Advanced Neuroimaging, Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.,Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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MR Micro-Neurography and a Segmentation Protocol Applied to Diabetic Neuropathy. Radiol Res Pract 2017; 2017:2761818. [PMID: 28567306 PMCID: PMC5439248 DOI: 10.1155/2017/2761818] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 11/29/2016] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to assess with MRI morphometric ultrastructural changes in nerves affected by diabetic peripheral neuropathy (DPN). We used an MR micro-neurography imaging protocol and a semiautomated technique of tissue segmentation to visualize and measure the volume of internal nerve components, such as the epineurium and nerve fascicles. The tibial nerves of 16 patients affected by DPN and of 15 healthy volunteers were imaged. Nerves volume (NV), fascicles volume (FV), fascicles to nerve ratio (FNR), and nerves cross-sectional areas (CSA) were obtained. In patients with DPN the NV was increased and the FNR was decreased, as a result of an increase of the epineurium (FNR in diabetic neuropathy 0,665; in controls 0,699, p = 0,040). CSA was increased in subjects with DPN (12,84 mm2 versus 10,22 mm2, p = 0,003). The FV was increased in patients with moderate to severe DPN. We have demonstrated structural changes occurring in nerves affected by DPN, which otherwise are assessable only with an invasive biopsy. MR micro-neurography appears to be suitable for the study of microscopic changes in tibial nerves of diabetic patients.
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