Jan Valošek

Mr. Jan Valošek

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 August 2021 in Nature Protocols
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Journal Article
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JCJulien Cohen-Adad
Julien Cohen-Adad
EAEva Alonso-Ortiz
Eva Alonso-Ortiz
MAMihael Abramovic
Mihael Abramovic
CACarina Arneitz
Carina Arneitz
NANicole Atcheson
Nicole Atcheson
JXJunqian Xu
Junqian Xu

16 August 2021 in Scientific Data
Verified
Journal Article
Open access
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JCJulien Cohen-Adad
Julien Cohen-Adad
EAEva Alonso-Ortiz
Eva Alonso-Ortiz
MAMihael Abramovic
Mihael Abramovic
CACarina Arneitz
Carina Arneitz
NANicole Atcheson
Nicole Atcheson
JXJunqian Xu
Junqian Xu
In a companion paper by Cohen-Adadet al. we introduce thespine genericquantitative MRI protocol that provides valuable metrics for assessing spinal cord macrostructural and microstructural integrity. This protocol was used to acquire a single subject dataset across 19 centers and a multi-subject dataset across 42 centers (for a total of 260 participants), spanning the three main MRI manufacturers: GE, Philips and Siemens. Both datasets are publicly available via git-annex. Data were analysed using the Spinal Cord Toolbox to produce normative values as well as inter/intra-site and inter/intra-manufacturer statistics. Reproducibility for thespine genericprotocol was high across sites and manufacturers, with an average inter-site coefficient of variation of less than 5% for all the metrics. Full documentation and results can be found athttps://spine-generic.rtfd.io/. The datasets and analysis pipeline will help pave the way towards accessible and reproducible quantitative MRI in the spinal cord.

1 January 2024 in Magnetic Resonance in Medical Sciences
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Journal Article
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JVJan Valošek
Jan Valošek
JCJulien Cohen-Adad
Julien Cohen-Adad
The spinal cord plays a pivotal role in the central nervous system, providing communication between the brain and the body and containing critical motor and sensory networks. Recent advancements in spinal cord MRI data acquisition and image analysis have shown a potential to improve the diagnostics, prognosis, and management of a variety of pathological conditions. In this review, we first discuss the significance of standardized spinal cord MRI acquisition protocol in multi-center and multi-manufacturer studies. Then, we cover open-access spinal cord MRI datasets, which are important for reproducible science and validation of new methods. Finally, we elaborate on the recent advances in spinal cord MRI data analysis techniques implemented in the open-source software package Spinal Cord Toolbox (SCT).

21 July 2021 in European Journal of Neurology
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Journal Article
Open access
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JVJan Valošek
Jan Valošek
RLRené Labounek
René Labounek
THTomáš Horák
Tomáš Horák
MHMagda Horáková
Magda Horáková
PBPetr Bednarik
Petr Bednarik
ASAlena Svátková
Alena Svátková
Background and purpose: Non‐myelopathic degenerative cervical spinal cord compression (NMDC) frequently occurs throughout aging and may progress to potentially irreversible degenerative cervical myelopathy (DCM). Whereas standard clinical magnetic resonance imaging (MRI) and electrophysiological measures assess compression severity and neurological dysfunction, respectively, underlying microstructural deficits still have to be established in NMDC and DCM patients. The study aims to establish tract‐specific diffusion MRI markers of electrophysiological deficits to predict the progression of asymptomatic NMDC to symptomatic DCM.Methods: High‐resolution 3 T diffusion MRI was acquired for 103 NMDC and 21 DCM patients compared to 60 healthy controls to reveal diffusion alterations and relationships between tract‐specific diffusion metrics and corresponding electrophysiological measures and compression severity. Relationship between the degree of DCM disability, assessed by the modified Japanese Orthopaedic Association scale, and tract‐specific microstructural changes in DCM patients was also explored.Results: The study identified diffusion‐derived abnormalities in the gray matter, dorsal and lateral tracts congruent with trans‐synaptic degeneration and demyelination in chronic degenerative spinal cord compression with more profound alterations in DCM than NMDC. Diffusion metrics were affected in the C3‐6 area as well as above the compression level at C3 with more profound rostral deficits in DCM than NMDC. Alterations in lateral motor and dorsal sensory tracts correlated with motor and sensory evoked potentials, respectively, whereas electromyography outcomes corresponded with gray matter microstructure. DCM disability corresponded with microstructure alteration in lateral columns.Conclusions: Outcomes imply the necessity of high‐resolution tract‐specific diffusion MRI for monitoring degenerative spinal pathology in longitudinal studies.

1 January 2025 in Radiology: Artificial Intelligence
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Journal Article
Closed access
EKEnamundram Naga Karthik
Enamundram Naga Karthik
JVJan Valošek
Jan Valošek
ASAndrew C. Smith
Andrew C. Smith
DPDario Pfyffer
Dario Pfyffer
SSSimon Schading-Sassenhausen
Simon Schading-Sassenhausen
JCJulien Cohen-Adad
Julien Cohen-Adad
The proposed deep learning model accurately segmented the spinal cord and spinal cord injury lesions in a diverse, multicenter dataset of T2-weighted MRI scans.

16 October 2020 in Scientific Reports
Verified
Journal Article
Open access
PDF file
RLRené Labounek
René Labounek
JVJan Valošek
Jan Valošek
THTomáš Horák
Tomáš Horák
ASAlena Svátková
Alena Svátková
PBPetr Bednarik
Petr Bednarik
PHPetr Hluštík
Petr Hluštík
Diffusion magnetic resonance imaging (dMRI) proved promising in patients with non-myelopathic degenerative cervical cord compression (NMDCCC), i.e., without clinically manifested myelopathy. Aim of the study is to present a fast multi-shell HARDI-ZOOMit dMRI protocol and validate its usability to detect microstructural myelopathy in NMDCCC patients. In 7 young healthy volunteers, 13 age-comparable healthy controls, 18 patients with mild NMDCCC and 15 patients with severe NMDCCC, the protocol provided higher signal-to-noise ratio, enhanced visualization of white/gray matter structures in microstructural maps, improved dMRI metric reproducibility, preserved sensitivity (SE = 87.88%) and increased specificity (SP = 92.31%) of control-patient group differences when compared to DTI-RESOLVE protocol (SE = 87.88%, SP = 76.92%). Of the 56 tested microstructural parameters, HARDI-ZOOMit yielded significant patient-control differences in 19 parameters, whereas in DTI-RESOLVE data, differences were observed in 10 parameters, with mostly lower robustness. Novel marker the white-gray matter diffusivity gradient demonstrated the highest separation. HARDI-ZOOMit protocol detected larger number of crossing fibers (5–15% of voxels) with physiologically plausible orientations than DTI-RESOLVE protocol (0–8% of voxels). Crossings were detected in areas of dorsal horns and anterior white commissure. HARDI-ZOOMit protocol proved to be a sensitive and practical tool for clinical quantitative spinal cord imaging.