Cerebello-Pontine Angle (CPA) MRI Protocol

Intended to provide a detailed examination of the seventh and eight cranial nerves and the other C-P angle structures, especially for detecting acoustic neuromas. The fifth cranial nerve is included on imaging. General brain images are obtained to make the exam more comprehensive.


Typical Indications

• ? acoustic neuroma
• ? CP angle lesion
• SN deafness
• Vertigo or Tinnitus

Sequences stored under Head/ CP_ANGLE

SCOUT Three plane low resolution scout

PD + T2 AXIAL Full brain coverage TSE axials. 5 mm thick with 50% gap

Position slices parallel to the line joining the Genu and Splenium of the Corpus Callosum.

Cover the brain from below the Foramen Magnum to the Vertex.

Sat band just below inferior slice and parallel to the slice

CISS_Axial High resolution 3D bright fluid sequence to define the cochlea and semi-circular canals and outline the cranial nerves.

Centre on the Acoustic nerves, angle to place scan plane roughly parallel to the roof of the 4^th ventricle.

Use MPR software to correct positional errors and display full length of the nerves. 

Variations & Optional Sequences

• If the CISS images show an acoustic neuroma, or look suspicious do the isotropic MP-RAGE and make axial MPRs.
• For follow up of known acoustics, and lesions treated with radiosurgery just do post contrast isotropic MP-RAGE with axial and coronal reconstructions.

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