MRI ANATOMY OF THE CRANIAL NERVES. Alexandra Borges Radiology Dpt. Instituto Português de Oncologia de Lisboa

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1 MRI ANATOMY OF THE CRANIAL NERVES Alexandra Borges Radiology Dpt. Instituto Português de Oncologia de Lisboa SENR 2014

2 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)

3 CRANIAL NERVES: Anatomy Segments: Brainstem/ fascicular Cisternal (cavernous sinus CNs III, IV, VI) Skull base Exocranial 3DFT CISS Borges A, Casselman J. "Imaging the cranial nerves Part I. Eur Radiol 17(8): , 2007

4 CNs MR IMAGING TECHNIQUE MR FSE T2W 3DFT-CISS SE T1W pre- and post gad 3DFT- MPRAGE TR TE FA 180º 70º 90º 12º Acq. time Thick Matrix 242x x x x256 FOV Pixel size 0.62x x x x0.94

5 FACIAL NERVE (CN VII) Brainstem segment (lower pons) Cisternal segment (CPA cistern) Temporal bone segment: Intracanalicular Labyrinthine Tympanic Mastoid Parotid segment

6 BRAINSTEM SEGMENT Axial TSE T2W 3T Mn Gn CN VIn Ln Axial CISS T2* 7T Courtesy from Prof. Francis Veillon Courtesy from Dr. Teresa Ferreira

7 TEMPORAL BONE AND PAROTID SEGMENTS From Ric Harnsberger Imaging anatomy

8 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

9 VESTIBULO-COCLEAR NERVE

10 VESTIBULO-COCLEAR NERVE Bill s bar ANT. POST. Crista falciformis VII VIIIvs VIIIc VIIIvi Courtesy from Prof. Francis Veillon

11 VESTIBULO-COCLEAR NERVE Organ of Corti MIP CISS Scarpa ganglion Courtesy from Dr. Jan Casselman Spiral ganglion

12 LOWER CRANIAL NERVES (IX, X, XI) Spinal V Solitary Inf. salivatory Ambiguous

13 LOWER CRANIAL NERVES

14 JUGULAR FORAMEN EAC Petrous bone Carotid artery Jugular vein Inf. petrous sinus Jacobson nerve Meningeal branches Pars vascularis JF

15 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)

16 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

17 CN X (VAGUS NERVE) Superior laryngeal branch Recurrent laryngeal branch

18 CN X (VAGUS 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)

19 CN XI (SPINAL ACCESSORY NERVE

20 CN XII (HYPOGLOSSAL NERVE)

21 CN XII

22 CONCLUSIONS 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

23 Thank you very much for your attention!