Application of magnetic resonance neurography in the evaluation of patients with peripheral nerve pathology

1996 ◽  
Vol 85 (2) ◽  
pp. 299-309 ◽  
Author(s):  
Aaron G. Filler ◽  
Michel Kliot ◽  
Franklyn A. Howe ◽  
Cecil E. Hayes ◽  
Dawn E. Saunders ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Time Course ◽  
Spin Echo ◽  
Fast Spin Echo ◽  
Mr Neurography ◽  
Magnetic Resonance Neurography ◽  
Cross Sectional ◽  
Content Type ◽  
Direct Nerve ◽  
Fine Print

✓ Currently, diagnosis and management of disorders involving nerves are generally undertaken without images of the nerves themselves. The authors evaluated whether direct nerve images obtained using the new technique of magnetic resonance (MR) neurography could be used to make clinically important diagnostic distinctions that cannot be readily accomplished using existing methods. The authors obtained T2-weighted fast spin—echo fat-suppressed (chemical shift selection or inversion recovery) and T1-weighted images with planes parallel or transverse to the long axis of nerves using standard or phased-array coils in healthy volunteers and referred patients in 242 sessions. Longitudinal and cross-sectional fascicular images readily distinguished perineural from intraneural masses, thus predicting both resectability and requirement for intraoperative electrophysiological monitoring. Fascicle pattern and longitudinal anatomy firmly identified nerves and thus improved the safety of image-guided procedures. In severe trauma, MR neurography identified nerve discontinuity at the fascicular level preoperatively, thus verifying the need for surgical repair. Direct images readily demonstrated increased diameter in injured nerves and showed the linear extent and time course of image hyperintensity associated with nerve injury. These findings confirm and precisely localize focal nerve compressions, thus avoiding some exploratory surgery and allowing for smaller targeted exposures when surgery is indicated. Direct nerve imaging can demonstrate nerve continuity, distinguish intraneural from perineural masses, and localize nerve compressions prior to surgical exploration. Magnetic resonance neurography can add clinically useful diagnostic information in many situations in which physical examinations, electrodiagnostic tests, and existing image techniques are inconclusive.

Magnetic resonance neurography of peripheral nerve following experimental crush injury, and correlation with functional deficit

2002 ◽  
Vol 96 (4) ◽  
pp. 755-759 ◽  
Author(s):  
Simon A. Cudlip ◽  
Franklyn A. Howe ◽  
John R. Griffiths ◽  
B. Anthony Bell
Keyword(s):  
Magnetic Resonance ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Mr Neurography ◽  
Magnetic Resonance Neurography ◽  
Nerve Crush ◽  
Content Type ◽  
Functional Deficit ◽  
Track Analysis ◽  
Fine Print

Object. In a number of clinical studies magnetic resonance (MR) neurography has been used to examine patients with peripheral nerve damage, but little is understood about the sequence of imaging changes following nerve injuries, and how they correlate with functional deficit. The goal of this study was to further understanding of these changes and their implications. Methods. Using the rat sciatic nerve crush model, the sciatic nerve was imaged at intervals over 70 days in 12 rats. Sham-operated contralateral nerves served as controls. A 4.7-tesla MR imager with a custom-made surface coil was used. The T2 maps were calculated from images obtained at four echo times and from regions of interest designated on the nerve at three sites. Walking-track analysis was performed at the same intervals as imaging. Magnetic resonance neurography revealed a mean T2 of normal sciatic nerve of 36 msec (standard deviation [SD] 1.2 msec). Crushed nerves demonstrated a sequence of changes in signal intensity that were maximal at 14 days, with a mean T2 of 64 msec (SD 5.2 msec), then falling to a T2 of 53 msec (SD 3.7 msec). Sham-operated nerves had a short and nonsustained rise in signal at 7 days. Walking-track analysis revealed maximum deficit immediately postinjury, with an improvement in function approaching that of control nerves at 30 days. Conclusions. In this study the authors demonstrate that quantitative assessment of nerve signals with MR neurography allows the sequence of events following nerve crush injury to be followed in vivo, and that a return toward a normal signal correlates with functional improvement. Assessment of peripheral nerve injury in patients by using MR neurography has the potential to confirm acute nerve injury as well as to monitor the recovery process.

Fast spin—echo magnetic resonance imaging for radiological assessment of neonatal brachial plexus injury

1995 ◽  
Vol 83 (3) ◽  
pp. 461-466 ◽  
Author(s):  
Paul C. Francel ◽  
Myles Koby ◽  
T. S. Park ◽  
Benjamin C. P. Lee ◽  
Michael J. Noetzel ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Brachial Plexus ◽  
General Anesthesia ◽  
Spin Echo ◽  
Fast Spin Echo ◽  
Ct Myelography ◽  
Content Type ◽  
Fast Spin ◽  
Fine Print

✓ Neurosurgical management of birth-related brachial plexus palsy involves observing the patient for a period of several months. Operative intervention is usually undertaken at 3 to 6 months of age or more in infants who have shown little or no improvement in affected muscle groups. Ancillary tests such as electromyography and nerve conduction studies are occasionally useful. No radiological study has been consistently helpful in operative planning, except for contrast computerized tomography (CT) myelography, which requires general anesthesia in infants. This is because the infant's small size exceeds the functional resolution of the imaging modalities. This report describes the use of a special sequence of magnetic resonance (MR) imaging entitled “fast spin echo” (FSE-MR). Unlike CT myelography, this technique provides high-speed noninvasive imaging that allows clinicians to evaluate preganglionic nerve root injuries without the use of general anesthesia and lumbar puncture. The utility of this technique is illustrated in three cases, two involving either infraclavicular exploration or a combination of infraclavicular and supraclavicular exposure based on FSE-MR findings. The FSE-MR imaging offers an excellent alternative to contrast CT myelography in evaluation of infants with birth-related brachial plexus injuries.

Sciatica of nondisc origin and piriformis syndrome: diagnosis by magnetic resonance neurography and interventional magnetic resonance imaging with outcome study of resulting treatment

2005 ◽  
Vol 2 (2) ◽  
pp. 99-115 ◽  
Author(s):  
Aaron G. Filler ◽  
Jodean Haynes ◽  
Sheldon E. Jordan ◽  
Joshua Prager ◽  
J. Pablo Villablanca ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Nerve Root ◽  
Piriformis Syndrome ◽  
Piriformis Muscle ◽  
Mr Neurography ◽  
Content Type ◽  
Interventional Mr ◽  
Interventional Mr Imaging ◽  
Fine Print

Object. Because lumbar magnetic resonance (MR) imaging fails to identify a treatable cause of chronic sciatica in nearly 1 million patients annually, the authors conducted MR neurography and interventional MR imaging in 239 consecutive patients with sciatica in whom standard diagnosis and treatment failed to effect improvement. Methods. After performing MR neurography and interventional MR imaging, the final rediagnoses included the following: piriformis syndrome (67.8%), distal foraminal nerve root entrapment (6%), ischial tunnel syndrome (4.7%), discogenic pain with referred leg pain (3.4%), pudendal nerve entrapment with referred pain (3%), distal sciatic entrapment (2.1%), sciatic tumor (1.7%), lumbosacral plexus entrapment (1.3%), unappreciated lateral disc herniation (1.3%), nerve root injury due to spinal surgery (1.3%), inadequate spinal nerve root decompression (0.8%), lumbar stenosis (0.8%), sacroiliac joint inflammation (0.8%), lumbosacral plexus tumor (0.4%), sacral fracture (0.4%), and no diagnosis (4.2%). Open MR—guided Marcaine injection into the piriformis muscle produced the following results: no response (15.7%), relief of greater than 8 months (14.9%), relief lasting 2 to 4 months with continuing relief after second injection (7.5%), relief for 2 to 4 months with subsequent recurrence (36.6%), and relief for 1 to 14 days with full recurrence (25.4%). Piriformis surgery (62 operations; 3-cm incision, transgluteal approach, 55% outpatient; 40% with local or epidural anesthesia) resulted in excellent outcome in 58.5%, good outcome in 22.6%, limited benefit in 13.2%, no benefit in 3.8%, and worsened symptoms in 1.9%. Conclusions. This Class A quality evaluation of MR neurography's diagnostic efficacy revealed that piriformis muscle asymmetry and sciatic nerve hyperintensity at the sciatic notch exhibited a 93% specificity and 64% sensitivity in distinguishing patients with piriformis syndrome from those without who had similar symptoms (p < 0.01). Evaluation of the nerve beyond the proximal foramen provided eight additional diagnostic categories affecting 96% of these patients. More than 80% of the population good or excellent functional outcome was achieved.

Magnetic resonance neurography studies of the median nerve before and after carpal tunnel decompression

2002 ◽  
Vol 96 (6) ◽  
pp. 1046-1051 ◽  
Author(s):  
Simon A. Cudlip ◽  
Franklyn A. Howe ◽  
Andrew Clifton ◽  
Martin S. Schwartz ◽  
B. Anthony Bell
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Median Nerve ◽  
Carpal Tunnel ◽  
Surgical Decompression ◽  
Mr Neurography ◽  
Magnetic Resonance Neurography ◽  
Content Type ◽  
Before And After ◽  
Tunnel Syndrome ◽  
Fine Print

Object. Recently developed novel MR protocols called MR neurography, which feature conspicuity for nerve, have been shown to demonstrate signal change and altered median nerve configuration in patients with median nerve compression. The postoperative course following median nerve decompression can be problematic, with persistent symptoms and abnormal results on electrophysiological studies for some months, despite successful surgical decompression. The authors undertook a prospective study in patients with carpal tunnel syndrome, correlating the clinical, electrophysiological, and MR neurography findings before and 3 months after surgery. Methods. Thirty patients and eight control volunteers were recruited to the study. The MR neurography consisted of axial and sagittal images (TR = 2000 msec, TE = 60 msec) obtained using a temporomandibular surface coil, fat saturation, and flow suppression. Maximum intensity projection images were used to follow the median nerve through the carpal tunnel in the sagittal plane. Magnetic resonance neurography in patients with carpal tunnel syndrome demonstrated proximal swelling (p < 0.001) and high signal change in the nerve, together with increased flattening ratios (p < 0.001) and loss of nerve signal in the distal carpal tunnel (p < 0.05). Sagittal images were very effective in precisely demonstrating the site and severity of nerve compression. After surgery, division of the flexor retinaculum could be demonstrated in all cases. Changes in nerve configuration, including increased cross-sectional area, and reduced flattening ratios (p < 0.001) were seen in all patients. In many cases restoration of the T2 signal intensity toward that of controls was seen in the median nerve in the distal carpal tunnel. Sagittal images were excellent in demonstrating expansion of the nerve at the site of surgical decompression. Conclusions. In this study the authors suggest that MR neurography is an effective means of both confirming compression of the median nerve and its successful surgical decompression in patients with carpal tunnel syndrome. This modality may prove useful in the assessment of unconfirmed or complex cases of carpal tunnel syndrome both before and after surgery.

Does new magnetic resonance imaging technology provide better geometrical accuracy during stereotactic imaging?

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 8-13 ◽  
Author(s):  
Josef Novotny ◽  
Josef Vymazal ◽  
Josef Novotny ◽  
Daniela Tlachacova ◽  
Michal Schmitt ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Spin Echo ◽  
Planning System ◽  
Treatment Planning System ◽  
Mr Images ◽  
Content Type ◽  
Stereotactic Frame ◽  
Glass Rods ◽  
Image Orientation ◽  
Fine Print

Object. The authors sought to compare the accuracy of stereotactic target imaging using the Siemens 1T EXPERT and 1.5T SYMPHONY magnetic resonance (MR) units. Methods. A water-filled cylindrical Perspex phantom with axial and coronal inserts containing grids of glass rods was fixed in the Leksell stereotactic frame and subjected to MR imaging in Siemens 1T EXPERT and Siemens 1.5T SYMPHONY units. Identical sequences were used for each unit. The images were transferred to the GammaPlan treatment planning system. Deviations between stereotactic coordinates based on MR images and estimated real geometrical positions given by the construction of the phantom insert were evaluated for each study. The deviations were further investigated as a function of the MR unit used, MR sequence, the image orientation, and the spatial position of measured points in the investigated volume. Conclusions. Larger distortions were observed when using the SYMPHONY 1.5T unit than those with the EXPERT 1T unit. Typical average distortion in EXPERT 1T was not more than 0.6 mm and 0.9 mm for axial and coronal images, respectively. Typical mean distortion for SYMPHONY 1.5T was not more than 1 mm and 1.3 mm for axial and coronal images, respectively. The image sequence affected the distortions in both units. Coronal T2-weighted spin-echo images performed in subthalamic imaging produced the largest distortions of 2.6 mm and 3 mm in the EXPERT 1T and SYMPHONY 1.5T, respectively. Larger distortions were observed in coronal slices than in axial slices in both units, and this effect was more pronounced in SYMPHONY 1.5T. Noncentrally located slice positions in the investigated volume of the phantom were associated with larger distortions.

Characterization of genetically defined types of Charcot-Marie-Tooth neuropathies by using magnetic resonance neurography

2005 ◽  
Vol 102 (2) ◽  
pp. 242-245 ◽  
Author(s):  
Dilantha B. Ellegala ◽  
Stephen J. Monteith ◽  
David Haynor ◽  
Thomas D. Bird ◽  
Robert Goodkin ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Disease Progression ◽  
Nerve Conduction ◽  
Imaging Techniques ◽  
Case Series ◽  
Mr Neurography ◽  
Content Type ◽  
Charcot Marie Tooth ◽  
Conduction Velocities ◽  
Fine Print

Object. Charcot-Marie-Tooth (CMT) disease is a collection of related genetic disorders affecting peripheral nerves with an incidence of one in every 2500 individuals. A diagnosis of CMT disease has classically relied on a medical history, examination, and measurement of nerve conduction velocities. Advancements in genetic testing and magnetic resonance (MR) imaging techniques may provide clinicians with a more precise diagnostic armamentarium. The authors investigated MR neurography as a possible method to characterize CMT subtypes. Methods. The authors performed MR neurography to evaluate sciatic nerves in the mid-thigh area of seven patients with genetically defined subtypes of CMT, one patient with chronic inflammatory demylinating polyneuropathy, and one patient without neuropathy. The authors correlate their findings with normal nerve conduction velocities (NCVs) and present their results as a descriptive case series. Although MR neurography could not be used to distinguish subtypes of CMT disease on nerve area or fascicle number, it appears to characterize phenotypic features and disease progression noninvasively in patients with some subtypes. Conclusions. In conjunction with NCV measurements, MR neurography may be useful in the diagnosis of CMT neuropathies and in monitoring disease progression.

Use of sagittal images for localization of the subthalamic nucleus

2005 ◽  
Vol 102 (3) ◽  
pp. 571-575 ◽  
Author(s):  
Cole A. Giller ◽  
Evelyn E. Babcock ◽  
Dianne B. Mendelsohn
Keyword(s):  
Subthalamic Nucleus ◽  
Indirect Method ◽  
Spin Echo ◽  
Red Nucleus ◽  
Internal Capsule ◽  
Fast Spin Echo ◽  
Mr Images ◽  
Content Type ◽  
Recovery Technique ◽  
Fine Print

✓ Direct observation of the subthalamic nucleus (STN) is not always possible, and physicians at many centers rely on indirect methods that relate the position of the STN to more easily recognized structures such as the red nucleus (RN). In this paper the authors describe an indirect method of viewing the STN based on the anatomy depicted on sagittal magnetic resonance (MR) images. A review of sagittal slices appearing in standard stereotactic atlases showed that the STN lies within the angle formed by the descending internal capsule (IC) and the substantia nigra (SN). The authors' technique consists of marking the location of the STN in this nigrocapsular angle on each sagittal MR image between the RN and the lateral border of the brainstem, and transferring these points to axial MR images to build a locus of points used to describe the STN. A point is chosen in the center of this locus as the stereotactic target. Two hundred eighty-two sagittal images obtained from 71 MR imaging studies performed in 29 patients by using a fast—spin echo inversion-recovery technique were examined for the presence of the STN, the SN, and the IC. The descending IC could be detected in 97% of the slices, the SN in 95% of the slices, and the STN in 73% of the slices. This indirect method involving sagittal anatomy can be used to refine localization of the STN.

Intraneural perineurioma of the common peroneal nerve

2001 ◽  
Vol 94 (5) ◽  
pp. 811-815 ◽  
Author(s):  
Marta E. Heilbrun ◽  
Jay S. Tsuruda ◽  
Jeannette J. Townsend ◽  
M. Peter Heilbrun
Keyword(s):  
Magnetic Resonance ◽  
Surgical Management ◽  
Peroneal Nerve ◽  
Common Peroneal Nerve ◽  
Nerve Graft ◽  
Focal Lesion ◽  
Mr Neurography ◽  
Content Type ◽  
Intraneural Perineurioma ◽  
Fine Print

✓ Intraneural perineurioma, or localized hypertrophic mononeuropathy (LHM), is a focal lesion that produces a slowly progressive mononeuropathy in a peripheral nerve. The authors describe the clinical presentation, magnetic resonance (MR) neurography characteristics, and pathological characteristics of a perineurioma involving the peroneal nerve. Although there has been much debate surrounding the cause of this lesion, a literature review supports the argument that this is a neoplastic lesion, best referred to as intraneural perineurioma. Surgical management includes excision to prevent progression of palsy and placement of a nerve graft if clinically indicated. A 28-year-old woman presented with a 2-year history of progressive painless right peroneal nerve palsy. Magnetic resonance neurography revealed a right common peroneal nerve mass. At surgery, the mass was easily excised, leaving significant nerve fascicles intact. Intraoperative biopsy was not performed nor was a nerve graft placed. Pathological investigation demonstrated onion bulb—shaped whorls consistent with the appearance of intraneural perineurioma; immunochemical analysis confirmed the diagnosis. A review of the literature supports the argument that perineurioma, or LHM, is a neoplastic process, making “intraneural perineurioma” the most appropriate name. The authors also demonstrate the utility of MR neurography in the identification isolated nerve tumors and review the surgical management of this lesion.

Does new magnetic resonance imaging technology provide better geometrical accuracy during stereotactic imaging?

2005 ◽  
Vol 102 ◽  
pp. 8-13 ◽  
Author(s):  
Josef Novotny ◽  
Josef Vymazal ◽  
Josef Novotny ◽  
Daniela Tlachacova ◽  
Michal Schmitt ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Spin Echo ◽  
Planning System ◽  
Treatment Planning System ◽  
Mr Images ◽  
Content Type ◽  
Stereotactic Frame ◽  
Glass Rods ◽  
Image Orientation ◽  
Fine Print

Object.The authors sought to compare the accuracy of stereotactic target imaging using the Siemens 1T EXPERT and 1.5T SYMPHONY magnetic resonance (MR) units.Methods.A water-filled cylindrical Perspex phantom with axial and coronal inserts containing grids of glass rods was fixed in the Leksell stereotactic frame and subjected to MR imaging in Siemens 1T EXPERT and Siemens 1.5T SYMPHONY units. Identical sequences were used for each unit. The images were transferred to the GammaPlan treatment planning system. Deviations between stereotactic coordinates based on MR images and estimated real geometrical positions given by the construction of the phantom insert were evaluated for each study. The deviations were further investigated as a function of the MR unit used, MR sequence, the image orientation, and the spatial position of measured points in the investigated volume.Conclusions.Larger distortions were observed when using the SYMPHONY 1.5T unit than those with the EXPERT 1T unit. Typical average distortion in EXPERT 1T was not more than 0.6 mm and 0.9 mm for axial and coronal images, respectively. Typical mean distortion for SYMPHONY 1.5T was not more than 1 mm and 1.3 mm for axial and coronal images, respectively. The image sequence affected the distortions in both units. Coronal T2-weighted spin-echo images performed in subthalamic imaging produced the largest distortions of 2.6 mm and 3 mm in the EXPERT 1T and SYMPHONY 1.5T, respectively. Larger distortions were observed in coronal slices than in axial slices in both units, and this effect was more pronounced in SYMPHONY 1.5T. Noncentrally located slice positions in the investigated volume of the phantom were associated with larger distortions.

Sign in / Sign up

Export Citation Format

Share Document