BRACHIAL PLEXUS IMAGING

1. IMAGING OF
BRACHIAL PLEXUS
DR. SUMIT KAMBLE
DM RESIDENT
GMC, KOTA

2. ANATOMY

3. Magnetic resonance imaging (MRI) of
brachial plexus
• Diagnostic accuracy of MRI is relatively high- 87.8%.
• Accuracy being 93.3% for mass lesions, 87.2% for traumatic
brachial plexus injuries, 83.3% for entrapment syndrome, and
83.7% for post-treatment evaluation.

4. Supraclavicular Lesions
• Involve nerve roots and trunks in scalene triangle
• More common and more severe than lesions at other sites.
Common pathologies in the supraclavicular-
• Brachial plexitis (Parsonage-Turner syndrome),
• Traumatic injury,
• Neoplasms (metastasis, nerve sheath tumor, neurocutaneous
syndrome, pancoast tumor),
• TOS.

5. Normal Oblique sagittalT1-weighted anatomy Roots
(supraclavicularplexus)

6. Retroclavicular Lesions
• Involve brachial plexus divisions.
• Isolated lesions in the divisions are rare.

7. Retroclavicular plexus

8. Infraclavicular Lesions
• Affect cords and terminal branch nerves
• 3 times less commonly seen than supraclavicular lesions
• Have better prognosis and earlier recovery than supraclavicular
lesions.
Common causes –
• Radiation neuropathy,
• Humeral fracture-dislocation,
• Gunshot injury, and iatrogenic injuries.

9. Infraclavicular plexus

10. Normal sagittal anatomy Roots lateral to
intervertebral foramina

11. Axial T1-weighted image
• Trunks of the brachial
plexus (arrowheads)
posterior
• Subclavian artery
(solid black arrow)
• Vein (open arrow).

12. Coronal T1-weighted image

13. T2 STIR coronal image

14. NON TRAUMATIC BRACHIALPLEXOPATHY
• Radiation fibrosis
• Inflammatory plexitis
• Breast cancer
• Lung cancer
• Benign tumors
• Lymphangioma
• Desmoid
• Neurofibroma
• Lipoma
• Other malignant tumors
• Neurofibrosarcoma
• Ewing sarcoma
• Eccrine sarcoma
• Osteosarcoma
• Mesothelioma
• Malignant fibrous histiocytoma
• Metastatic melanoma

15. Inflammatory Plexitis
• May be idiopathic ,or could be associated with viral or bacterial
infection or vaccination
• Affect the lower brachial plexus.
• Presents with acute onset of unilateral shoulder pain followed
by flaccid paralysis of the shoulder and para-scapular muscles.
• Often runs a self-limiting course.

16. • MRI shows diffuse swelling and increased T2W signal in
affected nerves .
• There can be mild oedema of the affected muscles particularly
supra and infraspinatus

17. STIR Coronal shows swollen and hyperintense right sided cords

18. Nerve sheath tumour involving brachial
plexus
• Include schwannoma, neurofibroma ,plexiform neurofibroma
and malignant peripheral nerve sheath tumour.
• Have an ovoid form and the nerve can often be seen entering
and leaving the tumour.
• Similar in signal intensity to muscle on T1W and show
markedly increased signal intensity on T2W .
• Enhance with IV Gadolinium and may demonstrate cystic areas

19. Nerve sheath tumourT1W fat sat post
Gadolinium Coronal image

20. Pancoast Tumour involving brachial plexus
• Non small cell lung carcinomas arise in lung apex and invade
lower brachial plexus, subclavian vessels, upper ribs and
vertebral bodies
• Present with pain in shoulder and arm, weakness and atrophy of
the muscles of the hand and Horner's syndrome (involvement of
stellate ganglion).
• MRI is used to examine local extension of the tumour towards
brachial plexus, subclavian vessels, vertebral bodies and
intervertebral foramina.

21. T1W Coronal shows a lobulated hypointense mass

22. T1WAxial shows a lobulated hypointense mass

23. Metastatic infiltration of brachial plexus
• Breast carcinoma is most common .
• Other sources include lung carcinoma and head and neck
cancer.
• Low signal on T1 weighted images and high signal on T2
weighted images and also shows enhancement post gadolinium.

24. Metastasis from carcinoma breast CoronalT1Wimages shows
spiculated focal mass lesion involving the left cords

25. Lymphoma involving brachial plexus
• Brachial plexus can be compressed or infiltrated by enlarged
lymph nodes or a nodal mass .
• Lymphoma of the paravertebral lymph nodes can extend
through intervertebral foramina and extend to extradural space.

26. T2Wsagittal- lobulatedhyperintenseparavertebrallesion involvingthe roots
lateral to the intervertebralforamina

27. Radiation induced brachial plexopathy
• Upper brachial plexus involvement with lymphoedema and lack
of pain and a latency period of less than 1 year - radiation
induced brachial plexopathy.
• Horner's syndrome, lower brachial plexus involvement, severe
pain, hand weakness and a latency period of more than 1 year is
more suggestive of tumour involvement

28. • Low signal on T1 weighted images and of high signal on T2
weighted images
• Does not enhance post gadolinium.
• Often causes architectural distortion and diffuse thickening of
brachial plexus without the presence of a focal mass.

29. CoronalT1Wimage showsarchitecturaldistortionof right
sidedcords with diffusethickening

30. Surgical ligation involving brachial plexus

31. TRAUMATIC BRACHIALPLEXOAPTHY
Most common causes-
• Motor vehicle crashes
• Obstetric injuries.
• Sports injury, gunshot wound, rucksack injury,
• Iatrogenic traction injuries during anesthesia.

32. Classification
• Preganglionic,
• Postganglionic,
• Combination of both.
• Post ganglionic injuries- better prognosis
• Pre-ganglionic - surgical repair is difficult, Poor prognosis

33. Pre-ganglionic injuries
• Often cause nerve root avulsions with or without an associated
pseudomeningocele (cerebrospinal fluid collection due to a
dural tear).
• Presence of a psuedomeningocele is highly suggestive, but not
pathognomonic of a preganglionic lesion.
• Signal intensity changes are observed in spinal cord in
approximately 20% of patients.

34. • Hyperintense areas on T2-weighted images suggest edema in
acute phase and myelomalacia in the chronic phase.
• Enhancement of intradural nerve roots and root stumps suggests
functional impairment of nerve roots despite morphologic
continuity.
• Abnormal enhancement of paraspinal muscles is an accurate
indirect sign of root avulsion injury (show enhancement as early
as 24 hours)

36. Axialcontrast-enhancedT1-weightedMRimagedemonstratesmarked
enhancementofthespinalcordsurfaceattherightrootexitzone

37. • Axial T2-weighted MR Axial contrast-enhanced T1-weighted MR

38. Postganglionic brachial plexus
• 2D sequences and with the 3D STIR SPACE sequence can
reliably detect masses that compress or stretch the plexus such
as post-traumatic hematomas, clavicular fractures, focal or
diffuse fibrosis and post-traumatic neuromas.
• Allows the visualization of postganglionic ruptures of nerve
roots, cords and trunks of the brachial plexus.
• Edema and fibrosis of the brachial plexus can manifest as
thickening of the plexus.

42. TOS (Entrapment Syndrome)
• Results from dynamic compression of the BPL, the subclavian
artery, or the subclavian vein in the cervicothoracobrachial
region.
• Neurogenic TOS is most common, comprising 95% of all TOS
cases.

43. Causative agents for TOS -
• Cervical rib,
• Elongated C7 transverse process,
• Exostosis of the first rib or clavicle,
• Excessive callus of the clavicle or first rib,
• Congenital fibromuscular anomalies,
• Muscle hypertrophy (scalenus, subclavius, or pectoralis minor muscles),
• Posttraumatic fibrosis of the scalene muscles.

44. Three possible sites of compression
• Interscalene triangle
• Costoclavicular space between first thoracic rib and the clavicle
• Retropectoralis minor space.
• Functional 3D STIR MR with postural maneuvers (upper limb
raised), are helpful in analyzing dynamically induced
compression patterns.

45. Sagittal T1-weighted image (arm in neutral position)
• Normal costoclavicular space Normal retropectoralis minor space

46. SagittalT1-weighted images with arm in hyperabduction

47. • Sagittal T1-weighted images with arm in neutral and hyperabducted positions reveals
compression of subclavian artery and brachial plexus in costoclavicular space due to a cervical rib

48. Coronal T2

49. MR Neurography
Indications
• 1) Patients with nonspecific shoulder and arm pain or weakness, in
which EMG and traditional MR imaging of the spine are inconclusive
• 2) To confirm nerve abnormalities in patients under consideration for
surgery for TOS;
• 3) To exclude recurrent malignancy/confirm radiation plexopathy;
• 4) To characterize and evaluate the extent of space-occupying lesions

50. • 5) To evaluate and differentiate a simple stretch injury from
higher grade nerve injury;
• 7) To exclude nerve re-entrapment/persistent impingement in
failed surgery cases,
• 8) Guidance in perineural and scalene medication injections.

51. • 3D STIR SPACE sequence, in which nerves appear bright
against a dark fat-suppressed background, is mainly considered
as MRN
• Entire plexus, from its origin at the spinal cord till its terminal
branches can be traced.
• MRN in cases of trauma is done 6 weeks or later after the injury
so that plexus is not obscured by edema and/or haemorrhage

52. • 3D STIR SPACE sequence allows excellent background fat
suppression and isotropic multiplanar and curved planar
reconstructions.
• 3D T2 SPACE images focuses on cervical spine
• Pre-ganglionic intradural nerve segments are best identified on
this sequence.

53. Coronalthree-dimensionalShortTauInversionRecovery(STIR)SamplingPerfectionwith
ApplicationoptimisedContrastsusingavaryingflipangleEvolutions(SPACE)imageshowing
normalbrachialplexusonbothsides

54. Coronal three-dimensional STIR SPACE image

55. Magnetic resonance myelography (MRM)
• Use - diagnosis of traumatic meningoceles and nerve root
avulsion.
• Diagnostic accuracy of traditional MRI in detecting root
avulsions is 52% while MRM is superior with a diagnostic
accuracy of 92%

56. Features of pre-ganglionic lesions detected by MRM
• (1) signal changes in spinal cord,
• (2) hemorrhage near nerve root exit,
• (3) no visualization of nerve roots,
• (4) discontinuity of nerve roots,
• (5) cerebrospinal fluid(CSF) leakage,
• (6) psuedomeningoceles,
• (7) enhancement of paraspinal muscles

57. 3D T2 MR Myelography image

58. Magneticresonancemyelographyimagesinsagittalandcoronalplanesshowing
pseudomeningocoelesatC8 andT1levelsontherightside3DT2SPACE

59. Diffusion-weighted MR Neurography
• Provide improved contrast between nerves of brachial plexus
and surrounding tissues.
• Enable more straightforward three-dimensional evaluation of
brachial plexus.

60. DW MR neurographic image

61. Sonography of brachial plexus
USES
• Entrapment neuropathies due to a cervical rib, elongated C7
transverse process, and other causes of the thoracic outlet
syndrome.
• Nerve tumors from brachial plexus.
• Guiding interventions (i.e., biopsy of a tumor and brachial
plexus anesthesia)
• Can detect root avulsion, nerve injury in the form of a neuroma,
and scar tissue formation

62. Ultrasound-guided interscalene block.

63. THANKYOU

64. REFERENCES
• New approaches in imaging of the brachial plexus European journal of
radiology · March 2014
• Brachial Plexus Injury: Clinical Manifestations, Conventional Imaging
Findings, and the Latest Imaging Techniques RadioGraphics 2013
• MR Imaging of Nontraumatic Brachial Plexopathies: Frequency and
Spectrum of Findings RadioGraphics 2010
• Pictorial essay: Role of magnetic resonance imaging in evaluation of brachial
plexus pathologies Indian Journal of Radiology and Imaging Nov 2012
• MRI of the Brachial Plexus : A pictorial review European Society of
Musculoskeletal system 2013
• High-Resolution 3T MR Neurography of the Brachial Plexus and Its
Branches, with Emphasis on 3D Imaging Mar 2013 www.ajnr.org