MRI ANATOMY OF THE CRANIAL NERVES - GEYSECO · 2018-01-31 · MRI ANATOMY OF THE CRANIAL NERVES...
Transcript of MRI ANATOMY OF THE CRANIAL NERVES - GEYSECO · 2018-01-31 · MRI ANATOMY OF THE CRANIAL NERVES...
MRI ANATOMY OF THE CRANIAL NERVES
Alexandra Borges
Radiology Dpt.
Instituto Português de Oncologia de Lisboa
SENR 2014
CRANIAL NERVES
• Olfactory: I
• Optic: II
• Oculomotor nerves: III, IV, VI
• Trigeminal nerve: (V1, V2, V3)
• Facial nerve (VII)
• Vestibulochoclear (VIII)
• Glossopharyngeal (IX)
• Vagus (X)
• Spinal accessory (XI)
• Hypoglossal nerve (XII)
CRANIAL NERVES: Anatomy
• Segments:
– Brainstem/ fascicular
– Cisternal
(cavernous sinus CNs III, IV, VI)
– Skull base
– Exocranial
Borges A, Casselman J. "Imaging the cranial nerves Part I”. Eur Radiol 17(8):2112-2125, 2007
3DFT CISS
MR FSE T2W 3DFT-CISS SE T1W pre- and post gad
3DFT-MPRAGE
TR 4000 12.25 684 11.6
TE 99 5.9 20 4.9
FA 180º 70º 90º 12º
Acq. time 3 7.14 5.31 10.51
Thick 4 0.7 2 1
Matrix 242x512 192x256 160x256 192x256
FOV 300 95 230 240
Pixel size 0.62x0.59 0.49x0.37 0.90x0.90 0.94x0.94
CNs MR IMAGING TECHNIQUE
FACIAL NERVE (CN VII)
Brainstem segment (lower pons)
Cisternal segment (CPA cistern)
Temporal bone segment:
Intracanalicular
Labyrinthine
Tympanic
Mastoid
Parotid segment
BRAINSTEM SEGMENT
Mn
CN VIn
Gn
Ln
Axial TSE T2W 3T
T2* 7T Axial CISS
Courtesy from Dr. Teresa Ferreira Courtesy from Prof. Francis Veillon
CN VII
• Facial nerve supplies:
– Motor fibers to: stapedius muscle, stylohyoid, occipitalis, posterior digastric, muscles of facial expression, buccinator and platysma
– PS fibers to lacrimal and salivary glands via the GPSN
– Taste fibers to 2 anterior thirds of the tongue via chorda tympani
VII
VIIIc VIIIvi
VIIIvs
Bill’s bar
Crista falciformis
VESTIBULO-COCLEAR NERVE
Courtesy from Prof. Francis Veillon
ANT. POST.
MIP CISS
VESTIBULO-COCLEAR NERVE
Courtesy from Dr. Jan Casselman
Scarpa ganglion
Spiral ganglion
Organ of Corti
Inf. petrous sinus
Jacobson nerve
Jugular vein
Meningeal branches
Carotid artery
EAC
Petrous bone
JUGULAR FORAMEN
JF
Pars vascularis
CN IX (GLOSSOPHARYNGEAL NERVE)
• Provides:
– Motor fibers to the palatoparyngeus
– Sensory fibers to the pharyngeal plexus (CNX)
– Sensory fibers to middle ear and PS fibers to parotid gland (via tympanic branch or Jacobson’s nerve)
– Taste fibers to the posterior third of the tongue (via lingual branch)
CN X (VAGUS NERVE)
• Longest course along the carotid space
• Contributes to pharyngeal plexus
• Gives off two major branches
– Superior laryngeal nerve
– Inferior or recurrent laryngeal nerve
• It also provides:
– Motor innervation to the pharyngeal muscles
– Visceral sensation from the larynx, trachea, esophagus, thoracic and abdominal viscera
– Sensory fibers to the external ear and tympanic membrane (via the auricular nerve or Arnold’s nerve)
CN X (VAGUS NERVE)
• Major technical advances on MR hardware and software led to a dramatic increase on MR imaging resolution
• The intracranial course of CNs can now be nicely imaged: – Detailed knowledge of CN anatomy – Mastering MR technique – Adequate tailoring of imaging to the diffent segments
of the nerves
• Increase the diagnostic yield in patients presenting with CN deficits
CONCLUSIONS