KEYNOTE - Understanding the role of MRI in traumatic and ... · Radiation plexopathy Infectious...
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16.10.2019 1 Carlos Torres, MD, FRCPC Associate Professor of Radiology Department of Radiology, University of Ottawa Ottawa, ON, Canada [email protected] None 1. Simplify the complex imaging anatomy of the BP using clear anatomical landmarks. 2. Outline different MR protocols. 3. Review BP pathologies using a case-based approach. Anatomy Brachial Plexus Formed by ventral rami of the nerves C5 -T1 Responsible for motor and cutaneous innervation of upper extremity, except for: ◦ Motor: Trapezius and levator scapulae ◦ Cutaneous: Axila, suprascapular & scapular regions Roots Trunks Divisions Cords Branches Brachial Plexus Segments
Transcript of KEYNOTE - Understanding the role of MRI in traumatic and ... · Radiation plexopathy Infectious...
16.10.2019
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Carlos Torres, MD, FRCPC
Associate Professor of RadiologyDepartment of Radiology, University of Ottawa Ottawa, ON, [email protected]
None
1. Simplify the complex imaging anatomy of the BP using clear anatomical landmarks.
2. Outline different MR protocols.
3. Review BP pathologies using a case-based approach.
Anatomy
Brachial Plexus
Formed by ventral rami of the nerves C5 -T1
Responsible for motor and cutaneousinnervation of upper extremity, except for:
◦ Motor: Trapezius and levator scapulae◦ Cutaneous: Axila, suprascapular & scapular regions
Roots
TrunksDivisions
Cords
Branches
Brachial Plexus Segments
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Radiologists
Technologists
Drink
Cold
Beer
Brachial Plexus Segments
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R
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The ventral rami of the spinal nerves C5 to T1 are the roots of the plexus.
Roots
A
A
M
P
T
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Trunks C5 - C6: Upper T
C7 : Middle TC8 – T1: Lower T
D
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Each trunk splits in 2 to give an anterior and posterior division
Divisions
Divisions
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B
Lat: Ant divisions of sup & middle trunksMedial: Ant division of lower trunkPost: 3 post divisions
Cords
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B
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Musculocutaneous N.
Axillary N.
Median N.
Radial N.
Ulnar N.
Branches Branches
Method of choice
Multi planar
Exquisite soft-tissue contrast
Castillo. AJR 2005, 185: S196-204Todd et al. Top Magn Reson Imaging 2004, 15: 113-125Saifuddin. Skeletal Radiol 2003, 32: 375-387Wittenberg et al. Radiographics 2000, 20:1023-1032
Surface coil Thin sections with no/small gap (3D) T1, T2 and STIR Contrast may be given Two imaging protocols at TOH
Sequence Time ST TR TE
Cor T2 Space 5:02 1 3800 191
Cor T1 2D 4:10 3.5 643 13
Cor T2 STIR 3:27 1.4 3800 195
Sag T1 2D 4:54 4 730 12
Neck coil and body array Localizer in 3 planes
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Sagittal T1W 3/4 mm (thickness/gap), T2W 3/4 mm Coronal T1W 3/4mm and FAST STIR 3/4 mm Axial T1W 4/5 mm, T2W 3/4 mm, +/- Gadolinium enhanced: Coronal 3/4 mm ,Axial and
sag T1W 4/5 mm with fat saturation
McGill University – University of Ottawa
MODIFIED TECHNIQUE FOR THE STUDY OF THE BRACHIAL PLEXUS
MODIFIED TECHNIQUE:
• 3 plane LOCALIZER
• Increase number of slices for planning coronal localizer
• Parameters FSE T1
• Parameters FSE T2 Matrix: 448x224 cm
CONVENTIONAL TECHNIQUE MODIFIED TECHNIQUE
LOCALIZER
MODIFIED TECHNIQUE FOR THE STUDY OF THE BRACHIAL PLEXUS
CONVENTIONAL TECHNIQUE MODIFIED TECHNIQUE
MODIFIED TECHNIQUE FOR THE STUDY OF THE BRACHIAL PLEXUS WITH MR
MODIFIED TECHNIQUE:
The axial oblique sequences are planned off the coronal localizer parallel to the plane of the roots, trunks and divisions of the brachial plexus.
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MODIFIED TECHNIQUE FOR THE STUDY OF THE BRACHIAL PLEXUS WITH MR
MODIFIED TECHNIQUE:
The coronal sequences are planned off the axial oblique dataset following the plane ofthe brachial plexus.
MODIFIED TECHNIQUE FOR THE STUDY OF THE BRACHIAL PLEXUS WITH MR
MODIFIED TECHNIQUE:
The sagital sequences are planned off the axial oblique images, perpendicular to the segments of the brachial plexus.
MODIFIED TECHNIQUE FOR THE STUDY OF THE BRACHIAL PLEXUS WITH MR
CONVENTIONAL TECHNIQUE MODIFIED TECHNIQUE CONVENTIONAL TECHNIQUE MODIFIED TECHNIQUE
CONVENTIONAL TECHNIQUE MODIFIED TECHNIQUE
MODIFIED TECHNIQUE FOR THE STUDY OF THE BRACHIAL PLEXUS WITH MR
CONVENTIONAL TECHNIQUE MODIFIED TECHNIQUE
Axial T1 : 7 min 25 sec 3 min 59 sec
Axial T2: 8 min 03 sec 3 min 54 sec
Coronal T1: 4 min 22 sec 4 min 36 sec
Coronal T2: 4 min 44 sec 3 min 54 sec
Sagital T1: 9 min 16 sec 6 min 17 sec
Sagital T2: 7 min 32 sec 6 min 08 sec
Total scan time: 41 min 22 sec 28 min 48 sec
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Neuroradiol J. 2013 Dec 20; 26(6): 699-719.
2005
Case: 27 y/o pt with left ulnar neuropathy
2005
Case: 27 y/o pt with left ulnar neuropathy
2011
SCHWANNOMA
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Pathology Vague and nonspecific symptoms.
Trauma: most common cause of plexopathy
Tumors: 2nd most common
Post radiation
Others : Inflammatory, infectious, hereditary
Trauma & vascular
Patterns of nerve injury
Neurapraxia
Axonotmesis
Neurotmesis
Mildly signal, sizeNo muscle denervation
size, fascicles effacedMuscle denervation
Nerve transectionNeuroma in continuity
Traumatic Nerve Injury
Partial tear“Severe Axonotmesis”
Stretch injury“Neurapraxia”
C/0 Vinil Shah MD, UCSF
Pre-ganglionic Injury
Absent rootlets
Pseudomeningocele
PS muscle edema
C/0 Vinil Shah MD, UCSF
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MVA
Stretch injury Pseudo meningoceles
A B
C
Stretch injuryPseudo meningocele + n root avulsion
“Imaging studies play an essential role in differentiating preganglionic injuries from postganglionic lesions, a differentiation that is crucial for determining the management of BPI”
Nerve Repair Surgery
Preganglionic rupture Nerve transfer
Postganglionic injury Stretch injury:
conservative
Avulsion: nerve grafting/repair
Better prognosis
23 y/o with penetrating trauma 30 y/o with hx of clavicular Fx
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Concentric rings of varying signal intensity due to clot that forms walls of this pseudo aneurysm
Post traumatic pseudo aneurysm
c/o Mauricio Castillo, UNC
Primary:
SchwannomaNeurofibroma
Secondary:
Direct extension/compression: tumors in the vicinityof the BP: lung, bones or soft tissues of the neck.
Metastasis: Breast, lung.
NEUROFIBROMA
NF1
MIP Coronal reconstruction of the 3D STIR SPACE sequence showing a distal schwannoma of the brachial plexus. The displaced fibers of the posterior cord (white arrows) passing around the schwannoma (asterisk) suggesting an easier surgical enucleation. The findings were confirmed at surgery
Vargas M et al. Neuroradiology (2010) 52:237–245
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Step-by-step reconstruction of the tractography of the brachial plexus in a 42 year-old male patient …fibers within and around the benign neurogenic tumor
Vargas M et al. Neuroradiology (2010) 52:237–245
PANCOAST TUMOR
Sixty-five-year-old patient with adenocarcinoma of the lung, disorganization and interruption of nerve fibers on the tractography reconstruction image
Vargas M et al. Neuroradiology (2010) 52:237–245
Post Radiation fibrosis:
Progressive neuropathy resulting from fibrosis and obliteration of the vasa-nervorum.
Patients receiving > 60 Gy. Months – years after therapy Thickenning of n. roots Low signal on both T1 and T2
Inflammatory poly neuropathy : MMN, CMT, CIDP Brachial Neuritis: viral, idiopathic, drugs, hereditary.
60 y/o pt with Hx of Breast Ca + Radiation
Radiation plexopathy
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Radiation plexopathyInfectious Brachial Plexitis
Intrinsic Infection: Enterovirus Plexitis
Extrinsic Infection: Invasive Fungal InfectionC/0 Vinil Shah MD, UCSF
Don’t forget to look at the Spine!
C6-7C6-7
C6
Rads & Techs Drink Cold Beer
MR is the imaging method of choice
Needs to be interpreted in context of clinical history, exam, EMG studies
Take Home Messages
Carlos Torres, MD, FRCPC
Associate Professor of RadiologyDepartment of Radiology, University of Ottawa Ottawa, ON, [email protected]
