CISS sequence
Pronunciation: SISS
Also written as: CISS — Constructive Interference in Steady State
A heavily T2-weighted MRI sequence providing high-resolution imaging of CSF spaces and cranial nerves.
Full Definition
Constructive Interference in Steady State (CISS) is a specialized MRI sequence that combines two steady-state free precession acquisitions to create high-resolution, heavily T2-weighted images with excellent contrast between CSF and adjacent structures. This sequence is particularly valuable for evaluating the cerebellopontine angle, internal auditory canals, cranial nerves, and small posterior fossa pathology. The technique provides superior detail for detecting small acoustic neuromas, vascular loops, and other pathology affecting cranial nerves VII and VIII.
Usage
Usage note: Specify when recommending this sequence for cranial nerve or CPA imaging.
In Context
- "CISS imaging revealed a small enhancing nodule within the left internal auditory canal." — MRI protocol description
- "The CISS sequence provided excellent delineation of the trigeminal nerve root entry zone." — Cranial nerve imaging report