The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Avneesh Chhabra - One of the best experts on this subject based on the ideXlab platform.

  • does presurgical Magnetic Resonance Neurography predict surgical gap size in trigeminal class iv and v injuries
    Journal of Oral and Maxillofacial Surgery, 2021
    Co-Authors: John R Zuniga, Omar Abdelbaky, Ali Alian, Uma Thakur, Parham Pezeshk, Avneesh Chhabra
    Abstract:

    Purpose The accuracy of Magnetic Resonance Neurography (MRN) for quantitative assessment of nerve injury gap is unknown. We tested the hypothesis that presurgical MRN predicts the final surgical gap size after neuroma resection at the time of surgery. Materials and Methods This was a retrospective, single-blinded, nonrandomized cohort study on 43 patients with Sunderland Class IV and V injuries of the inferior alveolar (IAN) or the lingual nerve (LN). The MRN maxillofacial protocol was performed on a 3T scanner and was read by 2 musculoskeletal radiologists to determine the maximum size of neuroma and the abnormal nerve segment. Two independent variables were recorded during surgery: 1) the length of neuroma from histologic specimens since only 9 of the 43 neuroma size measurements were accurately measureable at the time of surgery; and 2) the length of nerve gap size after the neuroma was removed and normal fascicles were identified. Results There were 7 IAN and 36 LN cases analyzed. The mean time in months from injury to MRN was 6.97 ± 9.18 and MRN to surgery was 1.21 ± 1.4. The mean length of the neuroma at surgery was 7.22 ± 2.78 mm and mean nerve gap size was 12.02 ± 4.41 mm. Intraclass coefficient (ICC) agreement was fair for abnormal nerve thickness and neuroma length (ICC = 0.28, 0.39) while it was moderate for neuroma thickness and abnormal nerve length (0.50, 0.59). There was no significant correlation between MRN based measurements and surgical gap size for both readers (P > .05). Conclusions Abnormal nerve and neuromas of the peripheral trigeminal nerve as identified on MRN imaging demonstrates no correlation of the assessed MRN findings with the final surgical gap after neuroma removal.

  • quantitative assessment of diabetic amyotrophy using Magnetic Resonance Neurography a case control analysis
    European Radiology, 2019
    Co-Authors: Rocco Hlis, Meredith Bryarly, Yin Xi, Avneesh Chhabra
    Abstract:

    Objectives To quantitatively characterize diabetic amyotrophy (DA), or diabetic lumbosacral radiculoplexopathy, and compare with controls using Magnetic Resonance Neurography (MRN).

  • top 10 tips for getting started with Magnetic Resonance Neurography
    Seminars in Musculoskeletal Radiology, 2019
    Co-Authors: Majid Chalian, Avneesh Chhabra
    Abstract:

    Magnetic Resonance Neurography (MRN), also known as MR Neurography, is a dedicated imaging technique for the peripheral nerves, used both in a clinical setting and research. However, like any other new diagnostic processes, there are technical, cost, and patient selection issues to overcome as well as potential imaging pitfalls to recognize before MRN can be adopted efficiently into routine clinical practice. This review focuses on the 10 most important practical tips to get started with MRN with a view to shortening the time needed for radiologists to implement this clinically useful technique into their imaging practices.

  • quantitative assessment of diabetic amyotrophy using Magnetic Resonance Neurography a case control analysis
    European Radiology, 2019
    Co-Authors: Rocco Hlis, Meredith Bryarly, Feng Poh, Avneesh Chhabra
    Abstract:

    To quantitatively characterize diabetic amyotrophy (DA), or diabetic lumbosacral radiculoplexopathy, and compare with controls using Magnetic Resonance Neurography (MRN). Forty controls and 23 DA cases were analyzed qualitatively and quantitatively. Cross-sectional areas (CSAs) of bilateral L3 through S2 lumbosacral nerve roots, femoral nerves, and sciatic nerves (proximal and distal measurements) were measured. A linear model was used to assess the nerve location and case/control effect on angle-corrected CSAs. Intra- and inter-reader analysis was performed using intraclass correlation (ICC). In DA cases, abnormalities of the lumbosacral nerve roots, sciatic, femoral, and obturator nerves were seen in 21/23, 16/23, 21/23, and 9/23, respectively. Denervation abnormalities of multiple abdominopelvic muscles were seen. Quantitatively, the CSA of all measured LS plexus nerve roots and bilateral femoral nerves were significantly larger in DA cases vs. controls by 45% (95% CI, (30%, 49%); p < 0.001). The ICC was moderate for inter-rater analysis = 0.547 (95% CI, 0.456–0.626) and excellent for intra-rater analysis = 0.90 (95% CI, 0.89–92). Multifocal neuromuscular lesions related to diabetic amyotrophy were qualitatively and quantitatively detected on MRN. Qualitative abnormalities distinguished cases from controls, and nerve CSAs of cases were significantly larger than those of controls. Therefore, MRN may be employed as a non-invasive diagnostic tool for the evaluation of diabetic amyotrophy. • Qualitative abnormalities of lumbosacral nerve roots, their peripheral branches, and muscles are seen in DA. • The lumbosacral nerve roots and their peripheral branches in diabetic amyotrophy cases are significantly larger in cross-sectional area than non-diabetic subjects by 45% (95 CI, 30%, 49%; p < 0.001). • The ICC was moderate for inter-rater analysis = 0.547 (95% CI, 0.456–0.626) and excellent for intra-rater analysis = 0.90 (95% CI, 0.89–92).

  • Magnetic Resonance Neurography in the diagnosis of a retroperitoneal ganglioneuroma case report and literature review
    Radiology Case Reports, 2018
    Co-Authors: Claudio Regis Sampaio Silveira, Clarissa Gadelha Maia Vieira, Brenda Machado Pereira, Edson Lopes, Gunter Gerson, Daniel Gurgel Fernandes Tavora, Avneesh Chhabra
    Abstract:

    Magnetic Resonance Neurography is a technique for identifying anatomy and pathologic lesions of nerves, and has emerged as a helpful technique for localizing lesions and elucidating the underlying etiology. Ganglioneuromas are highly differentiated benign tumors. This lesion is rare and exhibits undetermined symptoms, the features of using the Magnetic Resonance Neurography are a great ally to determine its diagnosis. The authors illustrate a case of retroperitoneal ganglioneuroma emphasizing its image characteristics using Magnetic Resonance Neurography with the diagnosis confirmed by histopathological examination.

Martin Bendszus - One of the best experts on this subject based on the ideXlab platform.

  • Magnetic Resonance Neurography improved diagnosis of peripheral neuropathies
    Neurotherapeutics, 2021
    Co-Authors: Jennifer Kollmer, Martin Bendszus
    Abstract:

    Peripheral neuropathies account for the most frequent disorders seen by neurologists, and causes are manifold. The traditional diagnostic gold-standard consists of clinical neurologic examinations supplemented by nerve conduction studies. Due to well-known limitations of standard diagnostics and atypical clinical presentations, establishing the correct diagnosis can be challenging but is critical for appropriate therapies. Magnetic Resonance Neurography (MRN) is a relatively novel technique that was developed for the high-resolution imaging of the peripheral nervous system. In focal neuropathies, whether traumatic or due to nerve entrapment, MRN has improved the diagnostic accuracy by directly visualizing underlying nerve lesions and providing information on the exact lesion localization, extension, and spatial distribution, thereby assisting surgical planning. Notably, the differentiation between distally located, complete cross-sectional nerve lesions, and more proximally located lesions involving only certain fascicles within a nerve can hold difficulties that MRN can overcome, when basic technical requirements to achieve sufficient spatial resolution are implemented. Typical MRN-specific pitfalls are essential to understand in order to prevent overdiagnosing neuropathies. Heavily T2-weighted sequences with fat saturation are the most established sequences for MRN. Newer techniques, such as T2-relaxometry, magnetization transfer contrast imaging, and diffusion tensor imaging, allow the quantification of nerve lesions and have become increasingly important, especially when evaluating diffuse, non-focal neuropathies. Innovative studies in hereditary, metabolic or inflammatory polyneuropathies, and motor neuron diseases have contributed to a better understanding of the underlying pathomechanism. New imaging biomarkers might be used for an earlier diagnosis and monitoring of structural nerve injury under causative treatments in the future.

  • troponin t parallels structural nerve damage in type 2 diabetes a cross sectional study using Magnetic Resonance Neurography
    Diabetes, 2020
    Co-Authors: Johann M E Jende, Sabine Heiland, Martin Bendszus, Peter P Nawroth, Jan B Groener, Zoltan Kender, Artur Hahn, Jakob Morgenstern, Stefan Kopf, Felix T Kurz
    Abstract:

    Clinical studies have suggested that changes in peripheral nerve microcirculation may contribute to nerve damage in diabetic polyneuropathy (DN). High-sensitivity troponin T (hsTNT) assays have been recently shown to provide predictive values for both cardiac and peripheral microangiopathy in type 2 diabetes (T2D). This study investigated the association of sciatic nerve structural damage in 3 Tesla (3T) Magnetic Resonance Neurography (MRN) with hsTNT and N-terminal pro-brain natriuretic peptide serum levels in patients with T2D. MRN at 3T was performed in 51 patients with T2D (23 without DN, 28 with DN) and 10 control subjects without diabetes. The sciatic nerve's fractional anisotropy (FA), a marker of structural nerve integrity, was correlated with clinical, electrophysiological, and serological data. In patients with T2D, hsTNT showed a negative correlation with the sciatic nerve's FA (r = -0.52, P < 0.001), with a closer correlation in DN patients (r = -0.66, P < 0.001). hsTNT further correlated positively with the neuropathy disability score (r = 0.39, P = 0.005). Negative correlations were found with sural nerve conduction velocities (NCVs) (r = -0.65, P < 0.001) and tibial NCVs (r = -0.44, P = 0.002) and amplitudes (r = -0.53, P < 0.001). This study is the first to show that hsTNT is a potential indicator for structural nerve damage in T2D. Our results indirectly support the hypothesis that microangiopathy contributes to structural nerve damage in T2D.

  • Magnetic Resonance Neurography normal values and demographic determinants of nerve caliber and t2 relaxometry in 60 healthy individuals
    Clinical Neuroradiology-klinische Neuroradiologie, 2019
    Co-Authors: Moritz Kronlage, Sabine Heiland, Daniel Schwarz, Martin Bendszus, Philipp Baumer, Tim Godel, Veronique Schwehr
    Abstract:

    To establish normal values and to identify demographic determinants of quantitative biomarkers in Magnetic Resonance Neurography (MRN). In this study 60 healthy individuals (5 men and 5 women of every decade between 20 and 80 years) were examined according to a standardized MRN protocol at 3 T, including multiecho T2 relaxometry. Nerve cross-sectional area (CSA), transverse relaxation time (T2), and proton spin density (PSD) were assessed for the sciatic, tibial, median, ulnar, and radial nerves. Correlation with demographic variables, such as height, weight, body mass index (BMI), and age was expressed by Pearson coefficients and t‑tests were used to compare MRN biomarkers between men and women with and without normalization to body weight and BMI by linear regression. The average nerve CSA correlated moderately with height (r = 0.28, p = 0.04), weight (r = 0.40, p = 0.002), and BMI (r = 0.35, p = 0.008), but not with age (r = 0.23, p = 0.09). While T2 did not correlate with demographic parameters, PSD was strongly inversely associated with BMI (r = −0.64, p < 0.001) and weight (r = −0.557, p < 0.001). Sex-dependent differences in imaging marker values were found for CSA but became negligible after normalization to body weight. Quantitative biomarkers of MRN co-vary with demographic variables. As particularly important determinants, we identified body weight for nerve CSA and BMI for PSD. The presented normal values and demographic determinants may assist investigations into the potential of MRN biomarkers in further disease-specific studies.

  • High-resolution nerve ultrasound and Magnetic Resonance Neurography as complementary neuroimaging tools for chronic inflammatory demyelinating polyneuropathy:
    Therapeutic advances in neurological disorders, 2018
    Co-Authors: Kalliopi Pitarokoili, Daniel Schwarz, Martin Bendszus, Moritz Kronlage, Philip Bäumer, Ralf Gold, Min-suk Yoon
    Abstract:

    Background:We present a clinical, electrophysiological, sonographical and Magnetic Resonance Neurography (MRN) study examining the complementary role of two neuroimaging methods of the peripheral n...

  • supplementary_tables – Supplemental material for High-resolution nerve ultrasound and Magnetic Resonance Neurography as complementary neuroimaging tools for chronic inflammatory demyelinating polyneuropathy
    2018
    Co-Authors: Kalliopi Pitarokoili, Daniel Schwarz, Martin Bendszus, Moritz Kronlage, Philip Bäumer, Ralf Gold, Min-suk Yoon
    Abstract:

    Supplemental material, supplementary_tables for High-resolution nerve ultrasound and Magnetic Resonance Neurography as complementary neuroimaging tools for chronic inflammatory demyelinating polyneuropathy by Kalliopi Pitarokoili, Moritz Kronlage, Philip Bäumer, Daniel Schwarz, Ralf Gold, Martin Bendszus and Min-Suk Yoon in Therapeutic Advances in Neurological Disorders

Sabine Heiland - One of the best experts on this subject based on the ideXlab platform.

  • characterization and quantification of alcohol related polyneuropathy by Magnetic Resonance Neurography
    European Journal of Neurology, 2021
    Co-Authors: Christian Rother, Johann M E Jende, Jan Malte Bumb, Markus Weiler, Anna Brault, Georges Sam, John M Hayes, Adriana Pietsch, Kianush Karimianjazi, Sabine Heiland
    Abstract:

    BACKGROUND We characterized and quantified peripheral nerve damage in alcohol-dependent patients (ADP) by Magnetic Resonance Neurography (MRN) in correlation with clinical and electrophysiologic findings. METHODS Thirty-one adult patients with a history of excessive alcohol consumption and age-/sex-matched healthy controls were prospectively examined. After detailed neurologic and electrophysiologic testing, the patient group was subdivided into ADP with alcohol-related polyneuropathy (ALN) and without ALN (Non-ALN). 3T MRN with anatomical coverage from the proximal thigh down to the tibiotalar joint was performed using dual-echo 2-dimensional relaxometry sequences with spectral fat saturation. Detailed quantification of nerve injury by morphometric (cross-sectional area [CSA]) and microstructural MRN markers (proton spin density [ρ], apparent T2-relaxation-time [T2app ]) was conducted in all study participants. RESULTS MRN detected nerve damage in ADP with and without ALN. A proximal-to-distal gradient was identified for nerve T2-weighted (T2w)-signal and T2app in ADP, indicating a proximal predominance of nerve lesions. While all MRN markers differentiated significantly between ADP and controls, microstructural markers were able to additionally differentiate between subgroups: tibial nerve ρ at thigh level was increased in ALN (p < 0.0001) and in Non-ALN (p = 0.0052) versus controls, and T2app was higher in ALN versus controls (p < 0.0001) and also in ALN versus Non-ALN (p = 0.0214). T2w-signal and CSA were only higher in ALN versus controls. CONCLUSIONS MRN detects and quantifies peripheral nerve damage in ADP in vivo even in the absence of clinically overt ALN. Microstructural markers (T2app , ρ) are most suitable for differentiating between ADP with and without manifest ALN, and may help to elucidate the underlying pathomechanism in ALN.

  • troponin t parallels structural nerve damage in type 2 diabetes a cross sectional study using Magnetic Resonance Neurography
    Diabetes, 2020
    Co-Authors: Johann M E Jende, Sabine Heiland, Martin Bendszus, Peter P Nawroth, Jan B Groener, Zoltan Kender, Artur Hahn, Jakob Morgenstern, Stefan Kopf, Felix T Kurz
    Abstract:

    Clinical studies have suggested that changes in peripheral nerve microcirculation may contribute to nerve damage in diabetic polyneuropathy (DN). High-sensitivity troponin T (hsTNT) assays have been recently shown to provide predictive values for both cardiac and peripheral microangiopathy in type 2 diabetes (T2D). This study investigated the association of sciatic nerve structural damage in 3 Tesla (3T) Magnetic Resonance Neurography (MRN) with hsTNT and N-terminal pro-brain natriuretic peptide serum levels in patients with T2D. MRN at 3T was performed in 51 patients with T2D (23 without DN, 28 with DN) and 10 control subjects without diabetes. The sciatic nerve's fractional anisotropy (FA), a marker of structural nerve integrity, was correlated with clinical, electrophysiological, and serological data. In patients with T2D, hsTNT showed a negative correlation with the sciatic nerve's FA (r = -0.52, P < 0.001), with a closer correlation in DN patients (r = -0.66, P < 0.001). hsTNT further correlated positively with the neuropathy disability score (r = 0.39, P = 0.005). Negative correlations were found with sural nerve conduction velocities (NCVs) (r = -0.65, P < 0.001) and tibial NCVs (r = -0.44, P = 0.002) and amplitudes (r = -0.53, P < 0.001). This study is the first to show that hsTNT is a potential indicator for structural nerve damage in T2D. Our results indirectly support the hypothesis that microangiopathy contributes to structural nerve damage in T2D.

  • Magnetic Resonance Neurography normal values and demographic determinants of nerve caliber and t2 relaxometry in 60 healthy individuals
    Clinical Neuroradiology-klinische Neuroradiologie, 2019
    Co-Authors: Moritz Kronlage, Sabine Heiland, Daniel Schwarz, Martin Bendszus, Philipp Baumer, Tim Godel, Veronique Schwehr
    Abstract:

    To establish normal values and to identify demographic determinants of quantitative biomarkers in Magnetic Resonance Neurography (MRN). In this study 60 healthy individuals (5 men and 5 women of every decade between 20 and 80 years) were examined according to a standardized MRN protocol at 3 T, including multiecho T2 relaxometry. Nerve cross-sectional area (CSA), transverse relaxation time (T2), and proton spin density (PSD) were assessed for the sciatic, tibial, median, ulnar, and radial nerves. Correlation with demographic variables, such as height, weight, body mass index (BMI), and age was expressed by Pearson coefficients and t‑tests were used to compare MRN biomarkers between men and women with and without normalization to body weight and BMI by linear regression. The average nerve CSA correlated moderately with height (r = 0.28, p = 0.04), weight (r = 0.40, p = 0.002), and BMI (r = 0.35, p = 0.008), but not with age (r = 0.23, p = 0.09). While T2 did not correlate with demographic parameters, PSD was strongly inversely associated with BMI (r = −0.64, p < 0.001) and weight (r = −0.557, p < 0.001). Sex-dependent differences in imaging marker values were found for CSA but became negligible after normalization to body weight. Quantitative biomarkers of MRN co-vary with demographic variables. As particularly important determinants, we identified body weight for nerve CSA and BMI for PSD. The presented normal values and demographic determinants may assist investigations into the potential of MRN biomarkers in further disease-specific studies.

  • somatotopic fascicular lesions of the brachial plexus demonstrated by high resolution Magnetic Resonance Neurography
    Investigative Radiology, 2017
    Co-Authors: Tim Hilgenfeld, Jennifer Kollmer, Sabine Heiland, Daniel Schwarz, Martin Bendszus, Philipp Baumer, Johann M E Jende, Mirko Pham
    Abstract:

    ObjectivesThe aim of this study was to evaluate whether high-resolution brachial plexus (BP) Magnetic Resonance Neurography (MRN) is capable of (1) distinguishing patients with compressive neuropathy or noncompressive plexopathy from age- and sex-matched controls, (2) discriminating between patients

  • peripheral nerve involvement in multiple sclerosis demonstration by Magnetic Resonance Neurography
    Annals of Neurology, 2017
    Co-Authors: Johann M E Jende, Sabine Heiland, Markus Weiler, Gesa H Hauck, Ricarda Diem, Brigitte Wildemann, Mirjam Korporalkuhnke, Wolfgang Wick, John M Hayes
    Abstract:

    OBJECTIVE To detect and quantify peripheral nerve lesions in multiple sclerosis (MS) by Magnetic Resonance Neurography (MRN). METHODS Thirty-six patients diagnosed with MS based on the 2010 McDonald criteria (34 with the relapsing-remitting form, 2 with clinically isolated syndrome) with and without disease-modifying treatment were compared to 35 healthy age-/sex-matched volunteers. All patients underwent detailed neurological and electrophysiological examinations. Three Tesla MRN with large anatomical coverage of both legs and the lumbosacral plexus was performed by using 2-dimensional (2D) fat-saturated, T2-weighted (T2w) and dual echo turbo spin echo sequences as well as a 3D T2-weighted, fat-saturated SPACE sequence. Besides qualitative visual nerve assessment, a T2w signal quantification was performed by calculation of proton spin density and T2 relaxation time. Nerve diameter was measured as a morphometric criterion. RESULTS T2w hyperintense nerve lesions were detectable in all MS patients, with a mean lesion number at thigh level of 151.5 ± 5.7 versus 19.1 ± 2.4 in controls (p < 0.0001). Nerve proton spin density was higher in MS (tibial/peroneal: 371.8 ± 7.7/368.9 ± 8.2) versus controls (tibial/peroneal: 266.0 ± 11.0/276.8 ± 9.7, p < 0.0001). In contrast, T2 relaxation time was significantly higher in controls (tibial/peroneal: 82.0 ± 2.1/78.3 ± 1.7) versus MS (tibial/peroneal: 64.3 ± 1.0/61.2 ± 0.9, p < 0.0001). Proximal tibial and peroneal nerve caliber was higher in MS (tibial: 52.4 ± 2.1mm2 , peroneal: 25.4 ± 1.3mm2 ) versus controls (tibial: 45.2 ± 1.4mm2 , p < 0.0015; peroneal: 21.3 ± 0.7mm2 , p = 0.0049). INTERPRETATION Peripheral nerve lesions could be visualized and quantified in MS in vivo by high-resolution MRN. Lesions are defined by an increase of proton spin density and a decrease of T2 relaxation time, indicating changes in the microstructural organization of the extracellular matrix in peripheral nerve tissue in MS. By showing involvement of the peripheral nervous system in MS, this proof-of-concept study may offer new insights into the pathophysiology and treatment of MS. Ann Neurol 2017;82:676-685.

Daniel Schwarz - One of the best experts on this subject based on the ideXlab platform.

  • characterization of experimental diabetic neuropathy using multicontrast Magnetic Resonance Neurography at ultra high field strength
    Scientific Reports, 2020
    Co-Authors: Daniel Schwarz, Manuel Fischer, David Milford, Michael O Breckwoldt, Asa Hidmark, Felix Sahm, Ingrid Hausser, Volker Sturm, Nitin Agarwal
    Abstract:

    In light of the limited treatment options of diabetic polyneuropathy (DPN) available, suitable animal models are essential to investigate pathophysiological mechanisms and to identify potential therapeutic targets. In vivo evaluation with current techniques, however, often provides only restricted information about disease evolution. In the study of patients with DPN, Magnetic Resonance Neurography (MRN) has been introduced as an innovative diagnostic tool detecting characteristic lesions within peripheral nerves. We developed a novel multicontrast ultra high field MRN strategy to examine major peripheral nerve segments in diabetic mice non-invasively. It was first validated in a cross-platform approach on human nerve tissue and then applied to the popular streptozotocin(STZ)-induced mouse model of DPN. In the absence of gross morphologic alterations, a distinct MR-signature within the sciatic nerve was observed mirroring subtle changes of the nerves’ fibre composition and ultrastructure, potentially indicating early re-arrangements of DPN. Interestingly, these signal alterations differed from previously reported typical nerve lesions of patients with DPN. The capacity of our approach to non-invasively assess sciatic nerve tissue structure and function within a given mouse model provides a powerful tool for direct translational comparison to human disease hallmarks not only in diabetes but also in other peripheral neuropathic conditions.

  • Magnetic Resonance Neurography normal values and demographic determinants of nerve caliber and t2 relaxometry in 60 healthy individuals
    Clinical Neuroradiology-klinische Neuroradiologie, 2019
    Co-Authors: Moritz Kronlage, Sabine Heiland, Daniel Schwarz, Martin Bendszus, Philipp Baumer, Tim Godel, Veronique Schwehr
    Abstract:

    To establish normal values and to identify demographic determinants of quantitative biomarkers in Magnetic Resonance Neurography (MRN). In this study 60 healthy individuals (5 men and 5 women of every decade between 20 and 80 years) were examined according to a standardized MRN protocol at 3 T, including multiecho T2 relaxometry. Nerve cross-sectional area (CSA), transverse relaxation time (T2), and proton spin density (PSD) were assessed for the sciatic, tibial, median, ulnar, and radial nerves. Correlation with demographic variables, such as height, weight, body mass index (BMI), and age was expressed by Pearson coefficients and t‑tests were used to compare MRN biomarkers between men and women with and without normalization to body weight and BMI by linear regression. The average nerve CSA correlated moderately with height (r = 0.28, p = 0.04), weight (r = 0.40, p = 0.002), and BMI (r = 0.35, p = 0.008), but not with age (r = 0.23, p = 0.09). While T2 did not correlate with demographic parameters, PSD was strongly inversely associated with BMI (r = −0.64, p < 0.001) and weight (r = −0.557, p < 0.001). Sex-dependent differences in imaging marker values were found for CSA but became negligible after normalization to body weight. Quantitative biomarkers of MRN co-vary with demographic variables. As particularly important determinants, we identified body weight for nerve CSA and BMI for PSD. The presented normal values and demographic determinants may assist investigations into the potential of MRN biomarkers in further disease-specific studies.

  • High-resolution nerve ultrasound and Magnetic Resonance Neurography as complementary neuroimaging tools for chronic inflammatory demyelinating polyneuropathy:
    Therapeutic advances in neurological disorders, 2018
    Co-Authors: Kalliopi Pitarokoili, Daniel Schwarz, Martin Bendszus, Moritz Kronlage, Philip Bäumer, Ralf Gold, Min-suk Yoon
    Abstract:

    Background:We present a clinical, electrophysiological, sonographical and Magnetic Resonance Neurography (MRN) study examining the complementary role of two neuroimaging methods of the peripheral n...

  • supplementary_tables – Supplemental material for High-resolution nerve ultrasound and Magnetic Resonance Neurography as complementary neuroimaging tools for chronic inflammatory demyelinating polyneuropathy
    2018
    Co-Authors: Kalliopi Pitarokoili, Daniel Schwarz, Martin Bendszus, Moritz Kronlage, Philip Bäumer, Ralf Gold, Min-suk Yoon
    Abstract:

    Supplemental material, supplementary_tables for High-resolution nerve ultrasound and Magnetic Resonance Neurography as complementary neuroimaging tools for chronic inflammatory demyelinating polyneuropathy by Kalliopi Pitarokoili, Moritz Kronlage, Philip Bäumer, Daniel Schwarz, Ralf Gold, Martin Bendszus and Min-Suk Yoon in Therapeutic Advances in Neurological Disorders

  • High-resolution nerve ultrasound and Magnetic Resonance Neurography as complementary neuroimaging tools for chronic inflammatory demyelinating polyneuropathy
    SAGE Publishing, 2018
    Co-Authors: Kalliopi Pitarokoili, Daniel Schwarz, Martin Bendszus, Moritz Kronlage, Philip Bäumer, Ralf Gold, Min-suk Yoon
    Abstract:

    Background: We present a clinical, electrophysiological, sonographical and Magnetic Resonance Neurography (MRN) study examining the complementary role of two neuroimaging methods of the peripheral nervous system for patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Furthermore, we explore the significance of cross-sectional area (CSA) increase through correlations with MRN markers of nerve integrity. Methods: A total of 108 nerve segments on the median, ulnar, radial, tibial and fibular nerve, as well as the lumbar and cervical plexus of 18 CIDP patients were examined with high-Resonance nerve ultrasound (HRUS) and MRN additionally to the nerve conduction studies. Results: We observed a fair degree of correlation of the CSA values for all nerves/nerve segments between the two methods, with a low random error in Bland–Altman analysis (bias = HRUS-CSA − MRN-CSA, −0.61 to −3.26 mm). CSA in HRUS correlated with the nerve T2-weighted (nT2) signal increase as well as with diffusion tensor imaging parameters such as fractional anisotropy, a marker of microstructural integrity. HRUS-CSA of the interscalene brachial plexus correlated significantly with the MRN-CSA and nT2 signal of the L5 and S1 roots of the lumbar plexus. Conclusions: HRUS allows for reliable CSA imaging of all peripheral nerves and the cervical plexus, and CSA correlates with markers of nerve integrity. Imaging of proximal segments as well as the estimation of nerve integrity require MRN as a complementary method

Philipp Baumer - One of the best experts on this subject based on the ideXlab platform.

  • Magnetic Resonance Neurography normal values and demographic determinants of nerve caliber and t2 relaxometry in 60 healthy individuals
    Clinical Neuroradiology-klinische Neuroradiologie, 2019
    Co-Authors: Moritz Kronlage, Sabine Heiland, Daniel Schwarz, Martin Bendszus, Philipp Baumer, Tim Godel, Veronique Schwehr
    Abstract:

    To establish normal values and to identify demographic determinants of quantitative biomarkers in Magnetic Resonance Neurography (MRN). In this study 60 healthy individuals (5 men and 5 women of every decade between 20 and 80 years) were examined according to a standardized MRN protocol at 3 T, including multiecho T2 relaxometry. Nerve cross-sectional area (CSA), transverse relaxation time (T2), and proton spin density (PSD) were assessed for the sciatic, tibial, median, ulnar, and radial nerves. Correlation with demographic variables, such as height, weight, body mass index (BMI), and age was expressed by Pearson coefficients and t‑tests were used to compare MRN biomarkers between men and women with and without normalization to body weight and BMI by linear regression. The average nerve CSA correlated moderately with height (r = 0.28, p = 0.04), weight (r = 0.40, p = 0.002), and BMI (r = 0.35, p = 0.008), but not with age (r = 0.23, p = 0.09). While T2 did not correlate with demographic parameters, PSD was strongly inversely associated with BMI (r = −0.64, p < 0.001) and weight (r = −0.557, p < 0.001). Sex-dependent differences in imaging marker values were found for CSA but became negligible after normalization to body weight. Quantitative biomarkers of MRN co-vary with demographic variables. As particularly important determinants, we identified body weight for nerve CSA and BMI for PSD. The presented normal values and demographic determinants may assist investigations into the potential of MRN biomarkers in further disease-specific studies.

  • somatotopic fascicular lesions of the brachial plexus demonstrated by high resolution Magnetic Resonance Neurography
    Investigative Radiology, 2017
    Co-Authors: Tim Hilgenfeld, Jennifer Kollmer, Sabine Heiland, Daniel Schwarz, Martin Bendszus, Philipp Baumer, Johann M E Jende, Mirko Pham
    Abstract:

    ObjectivesThe aim of this study was to evaluate whether high-resolution brachial plexus (BP) Magnetic Resonance Neurography (MRN) is capable of (1) distinguishing patients with compressive neuropathy or noncompressive plexopathy from age- and sex-matched controls, (2) discriminating between patients

  • diagnostic value of Magnetic Resonance Neurography in cervical radiculopathy plexus patterns and peripheral nerve lesions
    Investigative Radiology, 2017
    Co-Authors: Daniel Schwarz, Martin Bendszus, Tim Hilgenfeld, Moritz Kronlage, Henrich Kele, Tim Godel, Philipp Baumer
    Abstract:

    ObjectiveThe aim of this study was to assess the imaging appearance and diagnostic value of plexus and peripheral nerve Magnetic Resonance Neurography (MRN) in cervical radiculopathy.Materials and MethodsThis prospective study was approved by our institutional ethics committee and written informed c

  • diffusion tensor imaging adds diagnostic accuracy in Magnetic Resonance Neurography
    Investigative Radiology, 2015
    Co-Authors: Michael O Breckwoldt, Sabine Heiland, Mirko Pham, Martin Bendszus, Christian Stock, Annie Xia, Andreas Heckel, Philipp Baumer
    Abstract:

    OBJECTIVE The aim of this study was to determine whether quantitative diffusion tensor imaging (DTI) adds diagnostic accuracy in Magnetic Resonance Neurography. MATERIALS AND METHODS This prospective study was approved by the institutional review board. We enrolled 16 patients with peripheral polyneuropathy of various etiologies involving the upper arm and 30 healthy controls. Magnetic Resonance Neurography was performed at 3 T using transverse T2-weighted (T2-w) turbo spin echo and spin echo planar imaging diffusion-weighted sequences. T2-weighted normalized signal (nT2), fractional anisotropy (FA), apparent diffusion coefficient (ADC), radial diffusivity (RD), and axial diffusivity (AD) of the median, ulnar, and radial nerves were quantified after manual segmentation. Diagnostic performance of each separate parameter and combinations of parameters was assessed using the area under the receiver operating characteristic curve (AUC). Bootstrap validation was used to adjust for potential overfitting. RESULTS Average nT2, ADC, RD, and AD values of the median, ulnar, and radial nerve were significantly increased in neuropathy patients compared with that in healthy controls (nT2, 1.49 ± 0.05 vs 1.05 ± 0.05; ADC, 1.4 × 10(-3) ± 2.8 × 10(-5) mm(2)/s vs 1.1 × 10(-3) ± 1.3 × 10(-5) mm(2)/s; RD, 9.5 × 10(-4) ± 2.9 × 10(-5) mm(2)/s vs 7.2 × 10(-4) ± 1.3 × 10(-5) mm(2)/s; AD, 2.3 × 10(-3) ± 3.7 × 10(-5) mm(2)/s vs 2.0 × 10(-3) ± 2.2 × 10(-5) mm(2)/s; P < 0.001 for all comparisons). Fractional anisotropy values were significantly decreased in patients (0.51 ± 0.01 vs 0.59 ± 0.01; P < 0.001). T2-weighted normalized signal and DTI parameters had comparable diagnostic accuracy (adjusted AUC: T2-w, 0.92; FA, 0.88; ADC, 0.89; AD, 0.84; RD, 0.86). Combining DTI parameters significantly improved the diagnostic accuracy over single-parameter analysis. In addition, the combination of nT2 with DTI parameters yielded excellent adjusted AUCs up to 0.97 (nT2 + FA). CONCLUSIONS Diffusion tensor imaging has high diagnostic accuracy in peripheral neuropathy. Combining DTI with T2 can outperform T2-w imaging alone and provides added value in Magnetic Resonance Neurography.

  • proximal neuropathic lesions in distal symmetric diabetic polyneuropathy findings of high resolution Magnetic Resonance Neurography
    Diabetes Care, 2011
    Co-Authors: Mirko Pham, Sabine Heiland, Philipp Baumer, Dimitrios Oikonomou, Angelika Bierhaus, Per M Humpert, Peter P Nawroth, Martin Bendszus
    Abstract:

    OBJECTIVE This study investigated high-resolution Magnetic Resonance Neurography (MRN) in distal symmetric diabetic polyneuropathy (dPNP). RESEARCH DESIGN AND METHODS MRN comprised high-resolution transaxial imaging of peripheral nerves of the lower limbs in 20 patients with type 2 diabetes (10 with dPNP, type 2/dPNP[+], and 10 without dPNP, type 2/dPNP[−]), seven patients with type 1 diabetes (two with dPNP, type 1/dPNP[+], five without dPNP, type 1/dPNP[−]), and 10 nondiabetic control subjects. Intraneural T2 lesions, as the main diagnostic criterion of MRN, were detected visually by two independent observers and quantitatively by analysis of T2 contrast ratios. RESULTS Multifocal fascicular, symmetric intraneural T2 lesions occurred in the proximal trunks of sciatic nerves in four patients (three with type 2/dPNP[+] and one with type 1/dPNP[+]) but not in control subjects (type 2/dPNP[−], type 1/dPNP[−], nondiabetic control subjects), which was confirmed by quantitative analysis. Clinical severity was higher in patients with T2 lesions (neuropathy deficit score: 10 vs. 7.8; P = 0.05). CONCLUSIONS For the first time, proximal neuropathic lesions of dPNP are reported in vivo. This supports that accumulation of proximal, multifocal fascicular injury may be important in disease progression.