Brain screen protocol (MRI)

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Brain screen protocol is a simple non-contrast MRI protocol comprising a group of basic MRI sequences as a useful approach when imaging the brain when no particular condition is being sought (e.g. headache). The protocol is designed to obtain a good general overview of the brain. Additionally, this sort of protocol forms the foundation of many other more specific protocols by merely adding a sequence or two.

Note: This article is intended to outline some general principles of protocol design. The specifics will vary depending on MRI hardware and software, radiologist's and referrer's preference, institutional protocols, patient factors (e.g. allergy) and time constraints.

Sequences

A standard screening protocol might look like:

  • T1 weighted
    • plane: sagittal (or volumetric 3D)
    • sequence: fast-spin echo (T1 FSE) or gradient (T1 MPRAGE)
    • purpose: anatomical overview, which includes the soft tissues below the base of skull
  • T2 weighted
    • plane: axial
    • sequence: T2 FSE
    • purpose: evaluation of basal cisterns, ventricular system and subdural spaces, and good visualization of flow voids in vessels
  • FLAIR
    • plane: axial
    • sequence: FLAIR
    • purpose: assessment of white-matter disorders (e.g. chronic small vessel disease and demyelination diseases)
  • diffusion weighted imaging (DWI)
    • plane: axial
    • sequence: DWI: B=0, B=1000 and ADC 
    • purpose: multiple possible purposes (from the identification of ischemic stroke to the assessment of active demyelination)
  • susceptibility weighted imaging (SWI)
MRI protocols