3D Visualisationof normal and diseased nerves – first ... fileNUS could offer further advantages...
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3D Visualisation of normal and diseased nerves – first experience Doris LIEBA-SAMAL 1* , Christian KOLLMANN 2* 1 Department of Neurology, Medical University of Vienna, Austria 2 Center for Medical Physics & Biomedical Engineering, Medical University of Vienna, Austria *[email protected] Objective 2D Nerve ultrasound (NUS) is established as diagnostic tool in peripheral nerve disorders (PND) like compression syndromes, nerve trauma and nerve tumors. In disorders like inflammatory neuropathy its value concerning diagnosis and monitoring of disease is currently evaluated. However, there was the idea that NUS could offer further advantages like understanding of pathophysiology or progression in hereditary and chronic PND. 1,2 It allows real-time in-vivo imaging, is non-invasive, pain free and works without radiation. Therefore it is ideal for use in longitudinal studies. Currently, the cross sectional area is the most widespread parameter that is used for distinguishing healthy from diseased nerves. For going further, like monitoring of circumscribed lesions and their evolvement over time, use of the third dimension and therefore monitoring volumes might be useful. We therefore aimed at gathering first experience in rendering 3D models of nerves. Methods Clinically affected nerves of one patient with carpal tunnel syndrome (CTS), one with ulnar neuropathy at the elbow (UNE), one with inflammatory neuropathy and three healthy volunteers were scanned for abnormalities with a Logiq E9 platform and a ML6-15 MHz probe, that was connected to a 3D tracker of Piur Imaging (Vienna). Volume data were stored as clips containing between 180-300 separate slices and manual segmentation performed offline afterwards according to available recommendations with measuring just inside the hyperechogenic epineural or perineural rim. Within a final step the segmented rim was rendered to get 3D-views of the nerve. Results Segmentation and further rendering was well possible along the recorded segments for the whole nerve, but not for the single fascicles with a maximum of 15 MHz frequency. Especially in the upper arm, but also in the lower, fascicular exchange prevented reliable rendering. Only in the patient with chronic inflammatory neuropathy single fascicles could be followed through thickening back to normal diameter again. Conclusion 3D ultrasound allows visualisation of whole nerve segments including single diseased fascicles when enlarged with a 15 MHz probe. Using probes with higher frequency might offer additional benefit of fascicle identification. Therefore, it seems plausible that 3D ultrasound can be used for gaining new insights in monitoring progression and knowledge about longitudinal pathophysiologic changes in chronic PND. Figure 1: Manual segmentation of the median nerve as a whole (left column) and subsequent rendered 3D-model (right upper image) Figure 2: Manual segmentation of a single fascicle of and the median nerve as a whole (upper row) and subsequent rendered 3D-model (lower row) 1. Zaidman C et al. Ultrasound of inherited vs. acquired demyelinating polyneuropathies. J Neurol 2013; 260 (12): 3115-21 2. Zaidman C and Pestronk A. Nerve size in CIDP varies with disease activity and therapy response over time: a retrospective ultrasound study. Muscle and Nerve 2014; 50 (5): 733-8 References
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Transcript of 3D Visualisationof normal and diseased nerves – first ... fileNUS could offer further advantages...
3D Visualisation of normal and diseased nerves –first experience
Doris LIEBA-SAMAL1*, Christian KOLLMANN2*
1 Department of Neurology, Medical University of Vienna, Austria 2 Center for Medical Physics & Biomedical Engineering, Medical University of Vienna, Austria *[email protected]
Objective2D Nerve ultrasound (NUS) is established as diagnostic tool inperipheral nerve disorders (PND) like compression syndromes,nerve trauma and nerve tumors. In disorders like inflammatoryneuropathy its value concerning diagnosis and monitoring ofdisease is currently evaluated. However, there was the idea thatNUS could offer further advantages like understanding ofpathophysiology or progression in hereditary and chronicPND.1,2 It allows real-time in-vivo imaging, is non-invasive, painfree and works without radiation. Therefore it is ideal for use inlongitudinal studies. Currently, the cross sectional area is themost widespread parameter that is used for distinguishinghealthy from diseased nerves. For going further, likemonitoring of circumscribed lesions and their evolvement overtime, use of the third dimension and therefore monitoringvolumes might be useful. We therefore aimed at gathering firstexperience in rendering 3D models of nerves.
MethodsClinically affected nerves of one patient with carpal tunnelsyndrome (CTS), one with ulnar neuropathy at the elbow (UNE),one with inflammatory neuropathy and three healthyvolunteers were scanned for abnormalities with a Logiq E9platform and a ML6-15 MHz probe, that was connected to a 3Dtracker of Piur Imaging (Vienna). Volume data were stored asclips containing between 180-300 separate slices and manualsegmentation performed offline afterwards according toavailable recommendations with measuring just inside thehyperechogenic epineural or perineural rim. Within a final stepthe segmented rim was rendered to get 3D-views of the nerve.
ResultsSegmentation and further rendering was well possible alongthe recorded segments for the whole nerve, but not for thesingle fascicles with a maximum of 15 MHz frequency.Especially in the upper arm, but also in the lower, fascicularexchange prevented reliable rendering. Only in the patient withchronic inflammatory neuropathy single fascicles could befollowed through thickening back to normal diameter again.
Conclusion
3D ultrasound allows visualisation of whole nerve segmentsincluding single diseased fascicles when enlarged with a 15MHz probe. Using probes with higher frequency might offeradditional benefit of fascicle identification. Therefore, it seemsplausible that 3D ultrasound can be used for gaining newinsights in monitoring progression and knowledge aboutlongitudinal pathophysiologic changes in chronic PND.
Figure 1: Manual segmentation of the median nerve as a whole (left column) and subsequent rendered 3D-model(right upper image)
Figure 2: Manual segmentation of a single fascicle of and the median nerve as a whole (upper row) andsubsequent rendered 3D-model (lower row)
1. Zaidman C et al. Ultrasound of inherited vs. acquired demyelinating polyneuropathies. J Neurol 2013; 260(12): 3115-21
2. Zaidman C and Pestronk A. Nerve size in CIDP varies with disease activity and therapy response over time: aretrospective ultrasound study. Muscle and Nerve 2014; 50 (5): 733-8
References
