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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6009_Библиотеки_им_академика_М_И_Перельмана.pdf
(Left) Sagittal T1WI MR shows
caudal descent of the
cerebellar tissue and 4th
ventricle ſt associated with
callosal dysgenesis st.
Abnormal tectum, or beaking
, is an important associated
Differential Diagnosis
finding. (Right) Sagittal T1WI
C+ MR demonstrates a
homogeneously enhancing
meningioma with conspicuous
dural "tails" ſt along the
anterior margin of the
foramen magnum.
(Left) Sagittal T2WI MR
reveals a large amount of
rheumatoid pannus ſt with
effacement of the spinal canal
and posterior displacement of
the lower medulla. The
odontoid process is
abnormally "pointed" and
eroded . (Right) Axial T2WI
MR shows a jugular foramen
schwannoma with a very large
cisternal component
displacing the medulla and
filling the basal cistern. Note
that the left jugular foramen
is filled by a schwannoma ſt.
Foramen Magnum Mass
Chiari 2 Malformation Meningioma, Clivus
Rheumatoid Arthritis, Adult Schwannoma, Jugular Foramen
410
Chordoma, Clivus Chordoma, Clivus
(Left) Sagittal T1WI C+ MR
shows a very large enhancing
chordoma of the clivus with
involvement of the sphenoid
sinus ſt and C2 vertebra
with extension into the
posterior fossa and foramen
magnum st. (Right) Sagittal
T1WI FS MR reveals a
hyperintense midline
chordoma arising from the
inferior clivus, projecting
anteriorly into the
nasopharynx ſt and
posteriorly into the foramen
magnum . Note the
medullary compression st.
Foramen Magnum Mass
Calcium Pyrophosphate Dihydrate
Ependymoma
Fusiform Aneurysm, ASVD Fusiform Aneurysm, Non-ASVD
Deposition Disease (CPPD)
Differential Diagnosis
(Left) Sagittal T1WI C+ MR
shows an enhancing
ependymoma ſt projecting
from the inferior 4th ventricle
into the superior foramen
magnum . (Right) Sagittal
T2WI MR shows CPPD
involvement of the upper
cervical spine with an
associated low-signal mass ſt
compressing the lower
medulla . Pseudopannus is
nonspecific with differential
diagnoses that include
degenerative arthritis, calcium
pyrophosphate dihydrate
deposition disease, and gout.
(Left) Sagittal T1WI MR shows
a mixed signal intensity
extraaxial mass ſt. An
extraaxial lesion with evidence
of flow and thrombosis is
strongly suggestive of
aneurysm. Only small residual
flow voids are seen on this
sagittal image st. (Right)
Sagittal MRA depicts a
fusiform nonatherosclerotic
aneurysm of the basilar artery
in an adolescent male. The
vessel wall is somewhat
irregular ſt but without
stenosis.
Brainstem Glioma, Pediatric Neurenteric Cyst
(Left) Sagittal T1WI MR shows
a markedly expanded upper
cervical cord ſt, medulla ,
and inferior pons st resulting
from an infiltrative mass
isointense to the brainstem.
Brainstem gliomas often
smoothly enlarge the
brainstem. (Right) Sagittal
T1WI C+ MR shows an
extraaxial mass ſt in the
anterior foramen magnum
elevating and displacing the
medulla. This neurenteric cyst
is slightly hyperintense
compared to cerebrospinal
fluid and was conspicuous on
FLAIR (not shown).
411
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SECTION 13
Peripheral Nerve and Plexus
Normal Plexus and Nerve Anatomy 414
Superior Sulcus Tumor
Thoracic Outlet Syndrome
Muscle Denervation
Brachial Plexus Traction Injury
Idiopathic Brachial Plexus Neuritis 422
Traumatic Neuroma
Radiation Plexopathy
Peripheral Nerve Sheath Tumor
Peripheral Neurolymphomatosis
Hypertrophic Neuropathy 427
Femoral Neuropathy
Ulnar Neuropathy
Suprascapular Neuropathy
Median Neuropathy
Common Peroneal Neuropathy 432
Tibial Neuropathy
418
419
420
421
423
424
425
426
428
429
430
431
433
Normal Plexus and Nerve Anatomy
Terminology
Nerve rootlets: Individual neural filaments of dorsal and
ventral roots directly exiting from spinal cord
Nerve roots: Composed of multiple individual dorsal or
ventral nerve rootlets
• Dorsal sensory roots exit from dorsolateral cord and
have cell bodies within dorsal root ganglion (DRG)
• Ventral motor roots arise from anterior cord gray matter
and have cell bodies within cord
DRG: Dorsal nerve root sensory ganglion, resides in neural
Peripheral Nerve and Plexus
foramen
Spinal nerve (proper): Union of dorsal and ventral nerve roots
• 31 nerve pairs (8 cervical, 12 thoracic, 5 lumbar, 5 sacral,
and 1 coccygeal)
• Proper spinal nerve is short in length, bifurcates into
ventral and dorsal rami
Ramus: 1st spinal nerve branch
• Larger ventral primary ramus supplies ventral
musculature and facets
• Smaller dorsal primary ramus supplies paraspinal muscles
and part of facet
Peripheral nerve: Combination of 1 or more rami into single
neural conduit
Plexus: Neural network of anastomosing nerves
Imaging Anatomy
Cervical Plexus
The cervical plexus forms from the ventral rami of C1-C4 and,
variably, a C5 minor branch. It has ascending superficial,
descending superficial, and deep branches that supply nuchal
muscles, the diaphragm, and cutaneous head/neck tissues.
Brachial Plexus
The brachial plexus (BP) forms from the ventral rami of C5-T1
and variably from minor branches of C4 or T2. The BP
contributes to several nerves originating above the BP proper,
including the dorsal scapular nerve, long thoracic nerve,
nerves to scalene/longus colli muscles, and a branch to the
phrenic nerve. The remaining minor and all major terminal
nerve branches arise from the BP proper. Depending on the
cranial or caudal variation of the nerves supplying the BP, it
can be defined as prefixed or postfixed. A prefixed BP has a
large contribution from C4 with or without a small
contribution from T1. A postfixed BP has a large contribution
from T2 and little to no communication with C5.
Anatomically, the BP is classically divided sequentially
(proximal to distal) into 5 segments: Roots/rami, trunks,
divisions, cords, and terminal branches. The roots/rami
originate directly from the spinal cord levels C5 to T1. The 3
trunks include the superior or upper (C5-C6), middle (C7), and
inferior or lower (C8, T1) trunks. Important minor nerves
arising directly from the trunks include the suprascapular
nerve and nerve to subclavius muscle. Two divisions are
described: Anterior division innervates anterior (flexor)
muscles and posterior division innervates posterior (extensor)
muscles. No named minor nerves arise directly from the
anterior or posterior divisions. The 3 cords include the lateral
cord (anterior divisions of superior, middle trunks) that
innervates anterior (flexor) muscles, the medial cord (anterior
division of inferior trunk) that innervates anterior (flexor)
muscles, and the posterior cord (posterior divisions of all 3
414
trunks) that innervates posterior (extensor) muscles. The
cords branch to form several important named terminal
peripheral nerve branches.
Clinically, the BP is divided into 3 discrete segments based on
anatomic relationship to the clavicle. These include the
supraclavicular (roots, trunks), retroclavicular (divisions), and
infraclavicular (cords, terminal branches) plexus.
Lumbar Plexus
The lumbar plexus derives from the L1-L4 ventral rami and a
minor branch from T12. Important named minor nerve
branches include the iliohypogastric, ilioinguinal,
genitofemoral, lateral femoral cutaneous (L2-L3), and superior
(L4-S1) and inferior (L5-S2) gluteal nerves. Important major
nerve branches include the femoral (posterior division L2-L4)
and obturator (anterior division L2-L4) nerves (Table 2).
Lumbosacral Trunk
The lumbosacral trunk (LST) is derived from the ventral rami of
L4 (minor branch) and L5, and it is easily followed on axial
imaging as it transits along the ventral surface of the sacral ala
to join the sacral plexus in the pelvis.
Sacral Plexus
The sacral plexus is composed of the LST, S1-S3 ventral rami,
and a minor branch from S4. The sacral rami and LST converge
into the upper sacral neural band (LST and S1-S3) that forms
the sciatic nerve and the lower sacral neural band (S3-S4) that
forms the pudendal nerve.
Coccygeal Plexus
The coccygeal plexus converges from the S5 ventral ramus,
Cx1, and a minor branch of S4. The major named branch is the
anococcygeal nerve.
Anatomy-Based Imaging Issues
Normal Nerve Findings
Surrounding perineural fat provides excellent visualization of
nerves and allows them to be easily distinguished from
adjacent soft tissues. The normal peripheral nerve is a
round/ovoid shape with well-defined internal fascicular
architecture. Normal nerve fascicles are uniform in size and
shape, and this characteristic fascicular pattern helps
distinguish peripheral nerves from other lesions, such as
schwannoma or a ganglion cyst, which also demonstrate high
intrinsic T2 signal intensity.
Intrafascicular signal intensity is determined predominately by
endoneurial fluid and axoplasmic water, whereas the
interfascicular signal is dominated by fibrofatty connective
tissue that is amenable to fat suppression. Therefore, normal
nerve fascicles are isointense to adjacent muscle tissue on
T1WI and mildly hyperintense relative to muscle interspersed
within hypointense fibrofatty connective tissue on fatsaturated T2WI or STIR MR. No abrupt change in nerve caliber
or course should be observed in an anatomically normal nerve.
Abnormal Nerve Findings
The acutely abnormal nerve demonstrates 1 or more of the
following findings: Segmental nerve enlargement, disruption
of nerve anatomic continuity, T2 signal intensity approaching
that of regional blood vessels on fat-saturated T2WI or STIR
sequences, or disruption or distortion of normal fascicular
architecture. Entrapped or scarred nerves may show abrupt
change in caliber or course.
The abnormal nerve, therefore, remains isointense on T1WI
but becomes increasingly hyperintense to muscle on T2WI. In
Normal Plexus and Nerve Anatomy
the setting of injury, it is postulated that increased
endoneurial free water content alters the normal signal
characteristics of peripheral nerves. The cause of abnormal
high signal on T2WI and STIR sequences is not definitively
known, but it has been speculated that edema from increased
endoneurial fluid due to disordered endoneurial fluid flow or
local venous obstruction may explain abnormal T2
hyperintensity. Alterations in axoplasmic flow may also
produce increased signal. Axoplasmic flow is impeded by
nerve compression, and increased axoplasm proximal and
distal to the injury site may produce T2 hyperintensity.
Imaging Pitfalls
It can sometimes be difficult to distinguish peripheral nerve
from adjacent vascular structures, particularly if the abnormal
nerve displays high T2 signal intensity. Vessels demonstrate
internal flow voids, branch at large angles, and show intense
contrast enhancement. On the other hand, nerves do not
show flow voids, branch at relatively acute angles, enhance
minimally, and display a discrete distinctive fascicular
architecture on transverse imaging.
Clinical Implications
High-resolution MR technique readily identifies the large
major nerves and major plexi and permits visualization of their
internal neural anatomy. Conversely, smaller major and
essentially all minor peripheral nerves are too small to directly
visualize.
Successful peripheral nerve imaging requires a strong working
knowledge of normal plexus and nerve anatomy. Additionally,
peripheral nerve imaging is time consuming and necessitates
constraining the imaging volume to clinically relevant regions
rather than general "screening" surveys. It is critical to have all
pertinent clinical and electrodiagnostic data available to
appropriately constrain imaging volume and help detect
subtle abnormalities.
Differential Diagnosis
Normal Nerve/Plexus
The normal nerve/plexus shows normal course, caliber,
contour, and internal fascicular architecture. Consider
myopathic or other nonneural etiology in symptomatic
patients.
Nerve/Plexus Mass
Neural neoplasms are most commonly of neural sheath origin.
Consider solitary or plexiform neurofibroma, schwannoma, or
malignant peripheral nerve sheath tumor. Less common
considerations include neurolymphomatosis and peripheral
nerve metastasis.
Trauma
Etiologies include traction (stretch or avulsion), laceration
(projectile, fracture fragment, sharp object), or direct
compression (hematoma, fracture).
MR is sensitive for the detection, and in some cases,
discrimination of all 3 described peripheral nerve injury levels.
Neurapraxia, the least severe type of injury, is characterized
by focal damage to the myelin sheath without axonal
disruption and manifests as identifiable but swollen and
hyperintense nerve fascicles. Axonotmesis is an intermediate
level of crush or traction injury that produces axonal
disruption and subsequent wallerian degeneration but leaves
the Schwann cells and endoneurium intact. Axonotmesis will
display a homogeneously increased signal intensity nerve with
Peripheral Nerve and Plexus
loss of fascicular architecture at the injury site. Neurotmesis,
the most severe form of nerve injury, cannot always be
distinguished from axonotmesis in the cases of functional
rather than anatomical transaction but may display axonal
disruption with discontinuity of some or all of the surrounding
connective tissues and subsequent wallerian degeneration in
definitive cases.
Entrapment Syndrome
Neural compression occurs at characteristic locations. These
injuries are often, but not always, related to poor ergonomics
or overuse injuries.
Hereditary Motor and Sensory Neuropathy
Inherited peripheral nerve disorders are characterized by
abnormally enlarged peripheral nerves (usually palpable if not
deep) and variable clinical neuropathy presentations. Some
demonstrate the characteristic onion bulb appearance on
micropathology following nerve biopsy, reflecting recurrent
episodes of demyelination and remyelination. The most
common hereditary motor and sensory neuropathy disorder is
Charcot-Marie-Tooth, which has characteristic clinical
manifestations and may involve the cauda equina, peripheral
nerves, or both.
Infection/Inflammation
Myriad pathological etiologies and clinical manifestations
characterize this diverse group of disorders. Important causes
include syphilis (tabes dorsalis), leprosy, infectious neuritis
(usually viral), and sarcoidosis. Immune-mediated
noninfectious disorders include postviral or vaccination
(Guillain-Barré syndrome), chronic immune demyelinating
polyneuropathy, and idiopathic brachial plexitis (ParsonageTurner syndrome).
Drug/Toxic Injury
Neural injuries have been linked to vinca alkaloids, therapeutic
gold, amiodarone, dapsone, thalidomide, and lead or mercury
intoxication.
Vascular Insult
Injury may result from either nerve ischemia related to
peripheral vascular disease or vascular trauma or sequelae of
vasculitis. The most common vasculitis etiologies are diabetes,
Churg-Strauss, polyarteritis nodosa, and Wegener
granulomatosis.
Selected References
1. Chhabra A et al: Peripheral nerve injury grading simplified on MR
neurography: as referenced to Seddon and Sunderland classifications. Indian
J Radiol Imaging. 24(3):217-24, 2014
2. Crush AB et al: Malignant involvement of the peripheral nervous system in
patients with cancer: multimodality imaging and pathologic correlation.
Radiographics. 34(7):1987-2007, 2014
3. Demehri S et al: Conventional and functional MR imaging of peripheral
nerve sheath tumors: initial experience. AJNR Am J Neuroradiol. 35(8):161520, 2014
4. Pham M et al: Peripheral nerves and plexus: imaging by MR-neurography
and high-resolution ultrasound. Curr Opin Neurol. 27(4):370-9, 2014
5. Sureka J et al: MRI of brachial plexopathies. Clin Radiol. 64(2):208-18, 2009
6. Bowen BC et al: Plexopathy. AJNR Am J Neuroradiol. 29(2):400-2, 2008
7. Hof JJ et al: What's new in MRI of peripheral nerve entrapment? Neurosurg
Clin N Am. 19(4):583-95, vi, 2008
8. Kim S et al: Role of magnetic resonance imaging in entrapment and
compressive neuropathy--what, where, and how to see the peripheral
nerves on the musculoskeletal magnetic resonance image: part 2. Upper
extremity. Eur Radiol. 17(2):509-22, 2007
9. Castillo M: Imaging the anatomy of the brachial plexus: review and selfassessment module. AJR Am J Roentgenol. 185(6 Suppl):S196-204, 2005
415
Normal Plexus and Nerve Anatomy
Brachial Plexus Major Nerves
Nerve Definition Motor/Sensory Innervation Important Branches
Radial nerve Terminal branch of posterior
brachial plexus cord
Median nerve Terminal branch arises from both
lateral and medial brachial plexus
cords
Ulnar nerve Terminal branch of medial
Peripheral Nerve and Plexus
Musculocutaneous nerve Terminal branch of lateral brachial
Axillary nerve Terminal branch of posterior
brachial plexus cord
plexus cord
brachial plexus cord
Lumbosacral Plexus Major Nerves
Nerve Definition Motor/Sensory Innervation
Obturator nerve Terminal branch of lumbar plexus (anterior
division)
Femoral nerve Terminal branch of lumbar plexus (posterior
division)
Sciatic nerve Largest peripheral nerve branch of sacral plexus Innervates posterior thigh (biceps femoris, semitendinosus,
Common peroneal nerve Major anterior terminal branch of sciatic nerve Innervates anterior leg muscles; superficial peroneal nerve
Tibial nerve Major posterior branch of sciatic nerve Innervates posterior leg muscles (gastrocnemius, soleus, tibialis
Innervates extensor muscles of arm and forearm
(triceps, brachioradialis, extensor forearm muscles)
Innervates flexor muscles of forearm and thumb as
well as 1st and 2nd lumbricals
Innervates flexor carpi ulnaris, 3rd and 4th lumbricals,
and majority of intrinsic hand muscles
Innervates flexor muscles of arm (coracobrachialis,
biceps, and brachialis)
Innervates deltoid and teres minor muscles
Innervates thigh adductor muscles
Innervates iliacus, psoas, and quadriceps muscles
semimembranosus, adductor magnus) and all leg muscles (via tibial
and common peroneal nerve)
innervates peroneus muscles, extensor digitorum brevis; deep
peroneal nerve innervates tibialis anterior, extensor digitorum
longus, extensor hallucis longus muscles
posterior, flexor digitorum longus, flexor hallicus longus)
Most important branch is
posterior interosseous
nerve
Most important branch is
anterior
interosseous nerve
High-Resolution MR Protocols
MR Pulse Sequence Technical Parameters Technical Comments
Coronal T1WI MR 3- to 4-mm slice thickness, 20- to 24-cm FOV, no
interslice gap
Coronal fat-saturated T2WI or STIR MR 3- to 4-mm slice thickness, 20- to 24-cm FOV, no
interslice gap
Direct axial or sagittal oblique T1WI MR 5- to 7-mm slice thickness, 16- to 20-cm FOV, no
interslice gap
Direct axial or sagittal oblique fat-saturated
T2WI or STIR MR
Coronal and axial fat-saturated T1WI C+ MR
(optional)
5- to 7-mm slice thickness, 16- to 20-cm FOV, no
interslice gap
Same planes as unenhanced imaging sequences Use if suspected or confirmed mass or
Direct coronal plane, not oblique
Direct coronal plane, not oblique
Sagittal oblique plane oriented perpendicular
to plexus
Sagittal oblique plane oriented perpendicular
to plexus
infection
416
Normal Plexus and Nerve Anatomy
Peripheral Nerve and Plexus
(Left) Axial graphic of the
thoracic spine shows
formation of a typical spinal
nerve from dorsal and ventral
rootlets to form the spinal
nerve proper ſt. The short
spinal nerve bifurcates into
large ventral and small
dorsal primary rami st. (Right)
Coronal graphic shows the
classic anatomic classification
of the 5 brachial plexus
sections from proximal to
distal: Roots ſt (technically
ventral primary rami) of C5-T1,
trunks , divisions st, cords
, and terminal major
branches are shown.
(Left) Coronal STIR MR of the
upper right brachial plexus
depicts normal mildly
hyperintense brachial plexus
roots/rami of C5 to T1. C5 and
C6 form the superior (upper)
trunk ſt, C7 the middle trunk
, and C8 and T1 the inferior
(lower) trunk st. (Right)
Coronal STIR MR of the lower
right brachial plexus
demonstrates normal C7, C8,
and T1 roots/rami ſt
sequentially forming trunks,
divisions, and cords. The
normal brachial plexus courses
retroclavicular into the axilla.
(Left) Sagittal oblique STIR MR
demonstrates the ventral
primary rami ſt of C5 through
T1 proximal to the trunks. C8
exits above the 1st rib ,
whereas T1 exits below. The
brachial plexus is
"sandwiched" between the
anterior and middle scalene
muscles st. (Right) Sagittal
oblique STIR MR distal to the
root level shows formation of
the upper, middle, and lower
trunks ſt arranged in a
vertical line between the
scalene muscles.
417
Superior Sulcus Tumor
KEY FACTS
TERMINOLOGY
• Synonym: Pancoast tumor
• Benign or malignant neoplasm extending to superior
thoracic inlet with (1) severe shoulder/arm pain along C8,
T1, T2 nerve trunks, (2) Horner syndrome, and (3) weakness
+ atrophy of intrinsic hand muscles (Pancoast syndrome)
IMAGING
• Soft tissue apical lung mass with variable extension into
Peripheral Nerve and Plexus
chest wall, adjacent bone destruction, brachial plexus
invasion
TOP DIFFERENTIAL DIAGNOSES
• Metastatic disease
• Other thoracic tumors (besides non-small cell lung
carcinoma)
• Brachial plexus neural tumors
• Hematologic neoplasms
• Radiation fibrosis
(Left) Coronal STIR MR of a
patient with non-small cell
lung carcinoma, arm pain, and
weakness shows extensive
architectural distortion of the
lung apex by a peripheral lung
mass ſt with extension along
the brachial plexus elements
. (Right) Coronal T1 C+ FS
MR of the same patient
demonstrates a
heterogeneously enhancing
apical lung neoplasm ſt with
tumor extension along the
lower brachial plexus
elements.
• Vascular (venolymphatic) malformation
• Infection
PATHOLOGY
• Bronchogenic carcinomas may arise from either upper lobe
• Invades parietal pleura, endothoracic fascia, subclavian
vessels, brachial plexus, vertebral bodies, and upper ribs
• Non-small cell lung carcinoma most frequent etiology
CLINICAL ISSUES
• Clinical findings determined by tumor location relative to
scalene muscles
• Severe shoulder and arm pain
• Pulmonary symptoms uncommon early in disease course
DIAGNOSTIC CHECKLIST
• Apical lung mass with bone destruction = bronchogenic
carcinoma until proven otherwise
• Rare benign tumors or infection may mimic lung carcinoma
418
(Left) Axial CECT
demonstrates a soft tissue
mass ſt involving the right
upper lobe with extension
beyond the chest wall,
producing destruction of the
right T1, T2 ribs st. (Right)
Axial PET (FDG) CT fusion
image reveals marked
hypermetabolic radiotracer
uptake within the right upper
lobe bronchogenic carcinoma
ſt.
Thoracic Outlet Syndrome
KEY FACTS
Peripheral Nerve and Plexus
TERMINOLOGY
• Neural, venous, &/or arterial compressive syndrome at
thoracic outlet
• Diagnosis made by 1 of 3 methods (by event, affected
structure, or compression cause)
IMAGING
• ± cervical rib, elongated C7 transverse process
• ± brachial plexus compression/distortion, scalene muscle
inflammation, abnormal vascular flow voids at thoracic
outlet
• Positional occlusion or narrowing of subclavian artery with
arm hyperabduction, external rotation
TOP DIFFERENTIAL DIAGNOSES
• Primary and secondary plexus tumors
• Radiation plexopathy
• Trauma
PATHOLOGY
• Cervical ribs, abnormal transverse processes, fibrous bands,
scalene compression of thoracic outlet contents
CLINICAL ISSUES
• "True" neurological thoracic outlet syndrome: Intermittent
arm pain, numbness, and weakness with hyperabduction,
external rotation
○ Pain in shoulder, proximal upper extremity → neck
○ Paresthesias, numbness in forearm/hand
• Vascular thoracic outlet syndrome: Paresthesias 2° to
arterial or venous ischemia
○ Obliteration of brachial, radial pulses with arm
hyperabduction and elevation
DIAGNOSTIC CHECKLIST
• Subclavian artery aneurysm, subclavian vein thrombosis, or
brachial plexus compression at thoracic outlet strongly
suggest thoracic outlet syndrome
(Left) Coronal graphic of the
thoracic outlet demonstrates
brachial plexus compression +
a subclavian artery aneurysm
st arising secondary to the C7
cervical rib and anterior
scalene muscle ſt
compression. (Right)
Anteroposterior radiograph
demonstrates bilateral
rudimentary C7 cervical ribs
. The right cervical rib
articulates with the 1st
thoracic rib.
(Left) Sagittal oblique STIR MR
shows normal anatomy of the
interscalene triangle: Brachial
plexus trunks , anterior ſt
and middle scalene muscles,
subclavian artery st,
subclavian vein , and 1st
thoracic rib . (The anterior
is to the left per radiologic
convention.) (Right) Sagittal
oblique STIR MR (in a
professional drummer)
through the thoracic outlet
shows mild T2 hyperintensity
of some fascicles within the
lower trunk , correlating
with the clinical presentation
with lower brachial
plexopathy.
419