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

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✓ 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.

Article Information

Address reprint requests to: Aaron G. Filler, M.D., Ph.D., Division of Neurosurgery, University of California at Los Angeles Medical Center, CHS 74–140, 10833 Le Conte Avenue, Los Angeles, California 90095–6901.

© AANS, except where prohibited by US copyright law.

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    Magnetic resonance neurogram revealing nerve fascicles of the proximal peroneal nerve brightening and splaying out around a series of intraneural ganglion cysts. This demonstrates the intraneural location of a palpable mass near the fibular head in a 40-year-old man with progressively severe pain and weakness in a peroneal distribution. Fast spin—echo protocol: 6-in phased-array coil; 512 × 512 resolution; number of excitations: 2; field of view: 16 × 16 cm.56

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    Magnetic resonance neurogram revealing a schwannoma in the C-6 spinal nerve that demonstrates upstream hyperintensity in the nerve.13 The lesion had previously been approached surgically as a presumed enlarged cervical lymph node. The image shows the lesion to be in the upper trunk of the brachial plexus and shows increased signal in the proximal C-6 and C-5 spinal nerves extending over several centimeters from the lesion. Hyperintensity and swelling resolved after excision of the mass. Sc = schwannoma. Fast spin—echo protocol: volume neck coil; 512 × 512 resolution; number of excitations: 1; field of view: 18 × 18 cm.

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    Magnetic resonance neurogram (upper) and corresponding drawing (lower) showing the mandible of a patient with acquired immunodeficiency syndrome who presented with unilateral lower-lip numbness and had lymphoma (Lym) involving the mandibular ramus and extending into the inferior alveolar foramen. Upper: Magnetic resonance neurogram showing the inferior alveolar nerve (IAN) in the left mandible as it divides to form the inferior dental plexus. Comparison with images of the contralateral nerve confirmed distal hyperintensity in the IAN. A portion of the mass is seen as well. PrM = premolar; SmG = submandibular gland. Fast spin—echo protocol: 6-in phased-array coil; 512 × 384 resolution; number of excitations: 2; field of view: 16 × 16 cm; maximum intensity projection. Lower: Line drawing indicating the thick slab image resulting from an overlay reconstruction of several image sections.

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    Magnetic resonance neurogram (left) and colorized diagram (right) showing an overlay reconstruction of the right brachial plexus in a 15-year-old patient who exhibited flail arm symptoms 2 months after being injured in a motorcycle accident. The C-8 root sleeve shows a cerebrospinal fluid diverticulum. The C-7 root (SN) appears to be massively swollen but in continuity and there is mild hypertrophy in the C-6 root as well. The C-5 root appears fairly normal in caliber but is markedly hyperintense upstream from the injury. The upper trunk and lateral cord of the plexus are grossly disrupted and demonstrate a series of hyperintense swellings and discontinuities. The lower trunk is grossly in continuity. The patient underwent graft repair of the upper trunk. Co = coracoid process; DG = dorsal root ganglia; Hu = humerus; Pe = pedicles; SN = swollen nerve; TS = thecal sac. Fast spin—echo protocol: 6-in. phased-array coil; 512 × 384 resolution; number of excitations: 2; field of view: 24 × 24 cm; maximum intensity projection.

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    Magnetic resonance (MR) neurograms of the distal sciatic nerve in a 36-year-old bus driver who presented with a focal left lower-extremity painful neuritis of unclear cause. After a 10-hour drive, she developed pain in the buttock that progressed to lower-extremity weakness and gross muscle atrophy. Routine computerized tomography and MR imaging were normal, but electromyography and nerve conduction studies suggested a lesion near the popliteal fossa or fibular head. Upper: Maximum intensity projection reconstruction of the tibial and peroneal nerves created from a selected volume containing the nerve cross-sections. There is diffuse hyperintensity over a distance of some 10 cm. The annotation (PN = peroneal nerve) indicates the location of the cross-section (Fig. 4 lower, ii) demonstrating the most severe injury. The hyperintensity extends both proximal and distal to this point (maximum intensity projection). Lower: Cross-sections of the sciatic nerve as it divides into tibial and peroneal components. The fascicles in more proximal images are small (i), with many becoming grossly swollen in the middle of the lesion (ii). In an image collected with lower spatial resolution, this effect would appear as a further increase in nerve image intensity because bright fascicles consume nearly all of the space within the nerve at the expense of dark interfascicular tissue. The normal fascicular anatomy is seen to be reconstituting in the more distal cross-sections (iii and iv), with the exception of one particularly bright and swollen fascicle (f) in the peroneal component. Fast spin—echo protocol: 6-in phased-array coil; 512 × 256 resolution; number of excitations: 2; field of view: 12 × 12 cm.

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    Magnetic resonance neurograms (left and right) and schematic drawing (center) showing the shoulder in a 17-year-old tennis instructor with shoulder pain and difficulty positioning his arm for his serve. The patient had prominent weakness of external rotation at the shoulder; electromyography (EMG) demonstrated denervation of the infraspinatus. After imaging, he had surgical release of his transverse scapular ligament, resulting in improved strength and resolution of his EMG-demonstrated abnormalities. Left: The suprascapular nerve is hyperintense proximal and distal to a point of compression at the superior transverse scapular ligament (arrowhead). Co = coracoid; Gl = glenoid; Hu = humerus; IM = infraspinatus muscle; IN = infraspinatus nerve; SN = suprascapular nerve; SS = spine of scapula. Fast spin—echo protocol: 6-in phased-array coil; 256 × 256 resolution; number of excitations: 2; field of view: 20 × 20 cm; maximum intensity projection. Center: Diagrammatic representation of the angle of view, body position, and field of view (box within dashed lines) shown on the left. The asterisk indicates the superior transverse scapular ligament. Right: The axillary nerve is seen arching out across the neck of the humerus after branching off the posterior cord of the brachial plexus. The nerve intensity appears to undulate, reflecting the interslice spacing in this projection overlay. There is no evidence of focal compression. Ac = acromion; Ax = axillary nerve; Cl = clavicle; PC = posterior cord of plexus; Ra = radial nerve. Fast spin—echo protocol: 6-in phased-array coil; 256 × 256 resolution; number of excitations: 2; field of view: 20 × 20 cm; maximum intensity projection.

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    Magnetic resonance neurogram showing the neck in a 32-year-old man with a 4-month history of neck pain and right arm pain radiating to his thumb. Routine imaging demonstrated a disc bulge and osteophyte. This projection image demonstrates the complete set of cervical spinal nerves bilaterally with swelling and marked hyperintensity affecting the right C-6 nerve root. The patient's symptoms have improved with conservative management. Fast spin—echo protocol: brachial plexus phased-array coil; 512 × 256 resolution; number of excitations: 2; field of view 22 × 22 cm; maximum intensity projection.

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    Magnetic resonance neurograms focusing on normal wrist. Upper: Longitudinal image of normal median nerve in the wrist from maximum intensity projection overlay of three nerve-parallel slices. Image plane orientation protocol (with palm up, hand over head in center of magnet): 1) sagittal scout to locate bright nerve in carpal tunnel; 2) coronal scout to find direction of nerve in x–y plane; and 3) nerve image in the oblique plane between axial and sagittal planes, running parallel to the long axis of the nerve. Fast spin—echo protocol: temporomandibular joint phased-array coil; 256 × 256 resolution; number of excitations: 4; field of view: 12 × 12 cm. Lower: Wrist cross section showing the carpal tunnel in a normal volunteer. The imaging window level shown here is optimized for demonstration of the internal fascicular pattern and for suppression of signal from neighboring structures. Fast spin—echo protocol: wrist phased-array coil; 512 × 512 resolution; number of excitations: 1; field of view: 15 × 15 cm. FR = flexor retinaculum, MN = median nerve, RC = radiocarpal joint.

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    Magnetic resonance neurograms. Left: Overlay projection of coronal image planes in the lower lumbar spine. The two large bulbous structures are dorsal root ganglia (DRG). Fast spin—echo protocol: 6-in phased-array coil; 256 × 256 resolution; number of excitations: 2; field of view: 16 × 16 cm; maximum intensity projection. Right: Series of sacral roots, ganglia, and spinal nerves proceeding through the sacrum. Fast spin—echo protocol: pelvic phased-array coil; 512 × 384; number of excitations: 2; field of view: 26 × 26 cm; maximum intensity projection.

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    Magnetic resonance neurography projection images of cervical spinal nerves radiating away from the vertebral column demonstrating individual differences in angle of progression and in spacing between nerves which are difficult to appreciate in singleimage slices. Patients were positioned with moderate neck flexion so that the cervical spine appeared straight in a T1-weighted sagittal scout image. An oblique coronal image plane was then oriented to be parallel to the posterior longitudinal ligament with additional slices proceeding anteriorly. Slices were acquired with a standard “volume neck” radiofrequency coil, then reassembled via an overlay projection technique. Both images show some image intensity artifacts in the area of the T-1 roots. Edge effects of this type are due to imaging outside the area for which the coil was designed. They are avoided by the use of a specially designed brachial plexus phased-array coil (see Fig. 7) or by use of the commercial pelvic phased-array coil over the upper chest. Upper: The dorsal root ganglia are generally well seen, and these are indicated by the white labeling lines at each segmental level. Lower: The volume neck coil can provide spatial resolution and signal-to-noise ratio comparable to what is provided by a phased-array coil (see Fig. 7) although this requires longer imaging times. Fast spin—echo protocol: 512 × 256 resolution; number of excitations: 4; field of view 22 × 22 cm; maximum intensity projection.

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    Diagram of the anatomy of a polyfascicular nerve demonstrating the relationship of voxel orientation and spatial resolution to the conspicuity of cross-sectional nerve images. Voxels appear elongated because slice thickness (for example, × mm) is much larger than pixel size (for example, 0.5 mm) in the image plane. A poorly aligned voxel (1) mixes the dark signal from the lipid-laden interfascicular epineurium with the bright signal from the endoneurial space (endoneurial fluid and axoplasm) resulting in an image output of featureless gray. A voxel (2) that is well aligned but with spatial resolution significantly larger than the fascicles also returns a featureless gray image. Voxels (3 and 4) that are similar in size to the fascicles and aligned with them return either a dark black or bright white signal and thus reveal the fascicular pattern in the image, while yielding improved contrast relative to surrounding tissues.

References

1.

Beltran JRosenberg ZS: Diagnosis of compressive and entrapment neuropathies of the upper extremity: value of MR imaging. AJR 163:5255311994AJR 163:

2.

Blair DNRapoport SSostman HDet al: Normal brachial plexus: MR imaging. Radiology 165:7637671987Radiology 165:

3.

Boden SDDavis DODina TSet al: Abnormal magnetic-resonance scans of the lumbar spine in asymptomatic subjects. A prospective investigation. J Bone Joint Surg (Am) 72:4034081990J Bone Joint Surg (Am) 72:

4.

Britz GWHaynor DRKuntz Cet al: Ulnar nerve entrapment at the elbow: correlation of magnetic resonance imaging, clinical, electrodiagnostic, and intraoperative findings. Neurosurgery 38:4584651996Neurosurgery 38:

5.

Cline HCSchenck JFHynynen Ket al: MR-guided focused ultrasound surgery. J Comput Assist Tomogr 16:9569651992J Comput Assist Tomogr 16:

6.

Dailey ATTsuruda JSGoodkin Ret al: Magnetic resonance neurography for cervical radiculopathy: a preliminary report. Neurosurgery 38:4884921996Neurosurgery 38:

7.

Does MDSnyder RE: Multiexponential T2 relaxation in degenerating peripheral nerve. Magn Reson Med 35:20721319962 relaxation in degenerating peripheral nerve. Magn Reson Med 35:

8.

Enochs WSWeissleder RW: MR imaging of the peripheral nervous system. J Magn Reson Imaging 4:2512571994J Magn Reson Imaging 4:

9.

Fahr LMSauser DD: Imaging of peripheral nerve lesions. Orthop Clin North Am 19:27411988Orthop Clin North Am 19:

10.

Filler AG: Axonal transport and MR imaging: prospects for contrast agent development. J Magn Reson Imaging 4:2592671994Filler AG: Axonal transport and MR imaging: prospects for contrast agent development. J Magn Reson Imaging 4:

11.

Filler AGBell BABritton JAet al: MR neurography at 0.5 Tesla and 1.5 Tesla for imaging of cervical roots and brachial plexus. Eur Radiol 5 (Suppl):2271995 (Abstract)Eur Radiol 5 (Suppl):

12.

Filler AGGolden RNHowe FAet al: High resolution diffusion gradient imaging for neurography in human subjects Berkeley, CA: Society of Magnetic Resonance in Medicine19931602 (Abstract)

13.

Filler AGHayes CEHowe FAet al: MR neurography for improved characterization of peripheral nerve pathology Berkeley, CA: Society of Magnetic Resonance in Medicine19931101 (Abstract)

14.

Filler AGHowe FAHayes CEet al: Magnetic resonance neurography. Lancet 341:6596611993Lancet 341:

15.

Filler AGHowe FAHayes CEet al: MR neurography of cervical roots and brachial plexus. J Neurol Neurosurg Psychiatry 58:1231995 (Abstract)J Neurol Neurosurg Psychiatry 58:

16.

Filler AGHowe FAWinn HRet al: Image neurography on standard-gradient MR imagers. Radiology 185 (Suppl):1521992 (Abstract)Radiology 185 (Suppl):

17.

Filler AGTsuruda JSHayes CEet al: Magnetic resonance neurography reveals spin-spin relaxation rate (T2) changes correlated with onset and recovery from symptoms in traumatic & compressive neuropathy. Soc Neurosci Abstr 19:14861993 (Abstract)2) changes correlated with onset and recovery from symptoms in traumatic & compressive neuropathy. Soc Neurosci Abstr 19:

18.

Foo TKFShellock FGHayes CEet al: High-resolution MR imaging of the wrist and eye with short TR, short TE, and partial-echo acquisition. Radiology 183:2772811992Radiology 183:

19.

Gebarski KSGebarski SSGlazer GMet al: The lumbosacral plexus: anatomic-radiologic-pathologic correlation using CT. Radiographics 6:4014251986Radiographics 6:

20.

Gebarski SSTelian SANiparko JK: Enhancement along the normal facial nerve in the facial canal: MR imaging and anatomic correlation. Radiology 183:3913941992Radiology 183:

21.

Graif MSeton ANerubai Jet al: Sciatic nerve: sonographic evaluation and anatomic-pathologic considerations. Radiology 181:4054081991Radiology 181:

22.

Hamanishi CTanaka S: Dorsal root ganglia in the lumbosacral region observed from the axial views of MRI. Spine 18:175317561993Spine 18:

23.

Hayes CEHattes NRoemer PB: Volume imaging with MR phased arrays. Magn Reson Med 18:3093191991Magn Reson Med 18:

24.

Hayes CETsuruda JSMathis CM: Temporal lobes: surface MR coil phased-array imaging. Radiology 189:9189201993Radiology 189:

25.

Hennig JFriedburg HStröbel B: Rapid nontomographic approach to MR myelography without contrast agents. J Comput Assist Tomogr 10:3753781986J Comput Assist Tomogr 10:

26.

Howe FAFiller AGBell BAet al: Magnetic resonance neurography. Magn Reson Med 28:3283381992Magn Reson Med 28:

27.

Howe FAFiller AGBell BAet al: Magnetic resonance neurography: optimizing imaging techniques for peripheral nerve identification Berkeley, CA: Society of Magnetic Resonance in Medicine199211701 (Abstract)

28.

Howe FASaunders DEFiller AGet al: Magnetic resonance neurography of the median nerve. Br J Radiol 67:116911721994Br J Radiol 67:

29.

Kline DG: Perspectives concerning brachial plexus injury and repair. Neurosurg Clin North Am 2:1511641991Kline DG: Perspectives concerning brachial plexus injury and repair. Neurosurg Clin North Am 2:

30.

Kline DGHudson ARZager E: Selection and preoperative work-up for peripheral nerve surgery. Clin Neurosurg 39:8351992Clin Neurosurg 39:

31.

Kostelic JHaughton VMSether L: Proximal lumbar spinal nerves in axial MR imaging, CT and anatomic sections. Radiology 183:2392411992Radiology 183:

32.

Kostelic JKHaughton VMSether LA: Lumbar spinal nerves in the neural foramen: MR appearance. Radiology 178:8378391991Radiology 178:

33.

Krudy AG: MR myelography using heavily T2-weighted fast spin—echo pulse sequences with fat presaturation. AJR 159:131513201992Krudy AG: MR myelography using heavily T2-weighted fast spin—echo pulse sequences with fat presaturation. AJR 159:

34.

Lufkin RBRobinson JDCastro DJet al: Interventional magnetic resonance imaging in the head and neck. Top Magn Reson Imaging 2:76801990Top Magn Reson Imaging 2:

35.

Lundborg G: Intraneural microcirculation. Orthop Clin North Am 19:1121988Lundborg G: Intraneural microcirculation. Orthop Clin North Am 19:

36.

Mackinnon SEDellon AL: Surgery of the Peripheral Nerve. New York: Thieme19886587Surgery of the Peripheral Nerve.

37.

Mesgarzadeh MSchneck CDBonakdarpour A: Carpal tunnel: MR imaging. Part I. Normal anatomy. Radiology 171:7437481989Radiology 171:

38.

Mesgarzadeh MSchneck CDBonakdarpour Aet al: Carpal tunnel: MR imaging. Part II. Carpal tunnel syndrome. Radiology 171:7497541989Radiology 171:

39.

Mizisin APKalichman MWMyers RRet al: Role of the blood-nerve barrier in experimental nerve edema. Toxicol Pathol 18:1701851990Toxicol Pathol 18:

40.

Myers RRRydevik BLHeckman HMet al: Proximodistal gradient in endoneurial fluid pressure. Exp Neurol 102:3683701988Exp Neurol 102:

41.

Poduslo JFLow PANickander KKet al: Mammalian endoneurial fluid: collection and protein analysis from normal and crushed nerves. Brain Res 332:911021985Brain Res 332:

42.

Porter JRWright SMFamili N: Four-channel time domain multiplexer: a cost-effective alternative to multiple receivers. Magn Reson Med 32:4995041994Magn Reson Med 32:

43.

Roemer PBEdelstein WAHayes CEet al: The NMR phased array. Magn Reson Med 16:1922251990Magn Reson Med 16:

44.

Roger BTravers VLaval-Jeantet M: Imaging of posttraumatic brachial plexus injury. Clin Orthop 237:57611988Clin Orthop 237:

45.

Skie MZeiss JEbraheim NAet al: Carpal tunnel changes and median nerve compression during wrist flexion and extension seen by magnetic resonance imaging. J Hand Surg (Am) 15:9349391990J Hand Surg (Am) 15:

46.

Stewart JDSchmidt BWee R: Computed tomography in the evaluation of plexopathies and proximal neuropathies. Can J Neurol Sci 10:2442471983Can J Neurol Sci 10:

47.

Stull MAMoser RP JrKransdorf MJet al: Magnetic resonance appearance of peripheral nerve sheath tumors. Skeletal Radiol 20:9141991Skeletal Radiol 20:

48.

Sugimoto HMiyaji NOhsawa T: Carpal tunnel syndrome: evaluation of median nerve circulation with dynamic contrastenhanced MR imaging. Radiology 190:4594661994Radiology 190:

49.

Suh JSAbenoza PGalloway HRet al: Peripheral (extracranial) nerve tumors: correlation of MR imaging and histologic findings. Radiology 183:3413461992Radiology 183:

50.

Tash RRSze GLeslie DR: Trigeminal neuralgia: MR imaging features. Radiology 172:7677701989Radiology 172:

51.

Teresi LHovda DSeeley ABet al: MR imaging of experimental demyelination. AJR 152:129112981988AJR 152:

52.

Teresi LLufkin RWortham Det al: MR imaging of the intratemporal facial nerve by using surface coils. AJR 148:5895941987AJR 148:

53.

Titelbaum DSFrazier JLGrossman RIet al: Wallerian degeneration and inflammation in rat peripheral nerve detected by in vivo MR imaging. AJNR 10:7417461989in vivo MR imaging. AJNR 10:

54.

Tsuruda JSaloner DNorman D: Artifacts associated with MR neuroangiography. AJNR 13:41114221992AJNR 13:

55.

Tsuruda JSFiller AGHayes CEet al: Phased-array neurography of peripheral nerve pathology. Radiology 189 (Suppl):3281993 (Abstract)Radiology 189 (Suppl):

56.

West GAHaynor DRGoodkin Ret al: Magnetic resonance imaging signal changes in denervated muscles after peripheral nerve injury. Neurosurgery 35:107710861994Neurosurgery 35:

57.

Yug DPHaughton VMSether LAet al: Proximal cervical spinal nerve: MR appearance. Radiology 184:4054081992Radiology 184:

58.

Zeiss JSkie MEbraheim Net al: Anatomic relations between the median nerve and flexor tendons in the carpal tunnel: MR evaluation in normal volunteers. AJR 153:5335361989AJR 153:

59.

Zlatkin MBGreenan T: Magnetic resonance imaging of the wrist. Magn Reson Q 8:65961992Magn Reson Q 8:

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