The Incremental Value of Magnetic Resonance Neurography for the Neurosurgeon: Review of the Literature (original) (raw)
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MR neurography: diagnostic utility in the surgical treatment of peripheral nerve disorders
Neuroimaging clinics of North America, 2004
Advances in MR imaging have improved the visualization of normal and pathologic peripheral nerve structures in various clinical settings. Peripheral nerve imaging has the potential to dramatically change the diagnosis and treatment of peripheral nerve pathology and lead to an improved understanding of peripheral nerve pathophysiology. Currently, MR imaging serves as a problem-solving tool when additional anatomic information is needed to clarify ambiguous electrodiagnostic and clinical examinations. The next major advance in MR imaging of peripheral nerves will likely be the transition from anatomic to physiologic imaging with higher resolution as better phased-array surface coils and higher-field-strength magnets become available. Finally, MR neurography should remain complementary to the clinical examination and electrodiagnostic studies in the evaluation of peripheral nerve disorders.
Peripheral Nerve Surgery: The Role of High-Resolution MR Neurography
American Journal of Neuroradiology, 2011
High-resolution MRN is becoming increasingly available due to recent technical advancements, including higher magnetic field strengths (eg, 3T), 3D image acquisition, evolution of novel fat-suppression methods, and improved coil design. This review describes the MRN techniques for obtaining high-quality images of the peripheral nerves and their small branches and imaging findings in normal as well as injured nerves with relevant intraoperative correlations. Various microsurgical techniques in peripheral nerves, such as neurolysis, nerve repairs by using nerve grafts, and conduits are discussed, and MRN findings of surgically treated nerves are demonstrated.
Technical Update on MR Neurography
Seminars in Musculoskeletal Radiology
Imaging evaluation of peripheral nerves (PNs) is challenging. Magnetic resonance imaging (MRI) and ultrasonography are the modalities of choice in the imaging assessment of PNs. Both conventional MRI pulse sequences and advanced techniques have important roles. Routine MR sequences are the workhorse, with the main goal to provide superb anatomical definition and identify focal or diffuse nerve T2 signal abnormalities. Selective techniques, such as three-dimensional (3D) cranial nerve imaging (CRANI) or 3D NerveVIEW, allow for a more detailed evaluation of normal and pathologic states. These conventional pulse sequences have a limited role in the comprehensive assessment of pathophysiologic and ultrastructural abnormalities of PNs. Advanced functional MR neurography sequences, such as diffusion tensor imaging tractography or T2 mapping, provide useful and robust quantitative parameters that can be useful in the assessment of PNs on a microscopic level. This article offers an overview...
European radiology, 2015
To evaluate the impact of magnetic resonance neurography (MRN) on diagnostic thinking and therapeutic choices in patients with suspected peripheral neuropathy. IRB approval was obtained for this HIPAA-compliant study. Questionnaires were administered to six surgeons regarding the diagnosis and treatment in 85 patients suspected of having peripheral neuropathy, before (pretest) and after (posttest) MRN. Multiple outcome measures related to diagnostic confidence and surgical decision-making were assessed. The final cohort included 81 patients (30 men and 51 women, age 47 ± 17 years). The following changes were observed from pretest to posttest questionnaires: 23 % in nerve involvement (P < 0.05), 48 % in degree of confidence of nerve involvement (P < 0.01), 27 % in grade of injury (P < 0.05), 33 % in differential diagnosis (P < 0.05), 63 % in degree of confidence in need for surgery (P < 0.001), 41 % in timing of surgery (P < 0.01), 30 % in approach to surgery (P <...
Journal of …, 1996
ISSUE-selective images of bone and blood vessels play prominent roles in clinical diagnosis. Direct images of nerves, however, have not been available in the past. The advent of magnetic resonance (MR) neurography 14,26 now makes it possible to learn how such images can alter and improve the process of neurological diagnosis. Radiological images of structures adjacent to nerves are used extensively in diagnosis; 3,56 however, data concerning the nerves themselves arise primarily from the patient's clinical history, neurological examination, and electrodiagnostic tests. 30,36 The x-ray-absorptive properties of nerves provide little distinction from surrounding tissues; 19,46 conventional MR imaging of nerves has been restricted to a limited number of sites in the body, 8,29 and their ultrasound imaging 21 is even more limited. Recently, there have been reports of MR imaging protocols that achieve dramatic increases in the conspicuity of nerve. 26,27 The result is a novel type of medical image termed an "MR neurogram." The "diffusion-based" methods of this technique first reported have very high nerve selectivity, but require strong magnetic field gradients 12 not generally available for clinical MR imaging.
Radiology Research and Practice, 2013
High resolution and high field magnetic resonance neurography (MR neurography, MRN) is shown to have excellent anatomic capability. There have been considerable advances in the technology in the last few years leading to various feasibility studies using different structural and functional imaging approaches in both clinical and research settings. This paper is intended to be a useful seminar for readers who want to gain knowledge of the advancements in the MRN pulse sequences currently used in clinical practice as well as learn about the other techniques on the horizon aimed at better depiction of nerve anatomy, pathology, and potential noninvasive evaluation of nerve degeneration or regeneration.
Functional MR Neurography in Evaluation of Peripheral Nerve Trauma and Postsurgical Assessment
RadioGraphics, 2019
Evaluation of traumatic peripheral nerve injuries has classically been based on clinical and electrophysiologic criteria. US and MRI have been widely used for morphologic assessment of nerve injury sites and concomitant lesions. In the past few years, morphologic MR neurography has significantly increased its clinical applications on the basis of three-dimensional or two-dimensional images with and without fat-suppression techniques. However, these sequences have a major drawback: absence of pathophysiologic information about functional integrity or axonal flow of peripheral nerves. In this scenario, functional MRI techniques such as diffusion-weighted imaging (DWI) or diffusion tensor imaging (DTI) can be used as a complementary tool in initial evaluation of peripheral nerve trauma or in assessment of trauma undergoing surgical repair. These approaches provide not only morphologic but also functional information about extent and degree of nerve impairment. Functional MR neurography can also be applied to selection, planning, and monitoring of surgical procedures that can be performed after traumatic peripheral nerve injuries, such as neurorrhaphy, nerve graft, or neurolysis, as it provides surgeons with valuable information about the functional status of the nerves involved and axonal flow integrity. The physical basis of DWI and DTI and the technical adjustments required for their appropriate performance for peripheral nerve evaluation are reviewed. Also, the clinical value of DWI and DTI in assessment of peripheral nerve trauma is discussed, enhancing their potential impact on selection, planning, and monitoring of surgical procedures employed for peripheral nerve repair.
Indian Journal of Radiology and Imaging
Background High-resolution ultrasound (HRUS) and magnetic resonance neurography (MRN) are considered complementary to clinical and neurophysiological assessment for neuropathies. Aims The aim of our study was to compare the accuracy of HRUS and MRN for detecting various peripheral nerve pathologies, to choose the correct investigation to facilitate prompt patient management. Materials and Methods This prospective study was done using HRUS with 14 MHz linear-transducer and 3 or 1.5T MR in cases referred for the assessment of peripheral nerve pathologies. Image interpretation was done using a scoring system (score 0–3 confidence level) to assess for nerve continuity/discontinuity, increased nerve signal/edema, fascicular change, caliber change, and neuroma/mass lesion. We determined the accuracy, sensitivity, and specificity of these modalities compared with the diagnostic standard determined by surgical and/or histopathological, if not performed then clinical and/or electrodiagnostic...