Pineal and tectal plate protocol (MRI)

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MRI protocol for the pineal and tectal plate assessment is a group of MRI sequences put together to best approach tumors involving this region.

The pineal region is best imaged with MRI although CT, angiography, and ultrasound (in infants) also play a role. Please refer to the article pineal region (an approach), for the discussion on a systematic approach to the pineal region.

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 good protocol for this purpose would include:

  • T1 weighted
    • plane: sagittal or volumetric 3D (thin section high-resolution imaging)
    • sequence: fast-spin echo (T1 FSE) or gradient (T1 MPRAGE)
    • purpose: anatomical overview
  • T2 weighted
    • plane: sagittal (thin section high-resolution imaging)
    • sequence: T2 FSE
    • purpose: assessment of pineal cysts, evaluation of basal cisterns, ventricular system, and subdural spaces. Also, it provided good visualization of flow-voids in the surrounding vessels
  • FLAIR
    • plane: axial
    • sequence: FLAIR
    • purpose: asses the presence of edema
  • diffusion-weighted imaging (DWI)
    • plane: axial
    • sequence: DWI: B=0, B=1000 and ADC 
    • purpose: evaluation of the tumor cellularity 
  • susceptibility weighted imaging (SWI)
  • postcontrast sequences
    • plane: at least two different planes or volumetric 3D
    • sequence: post-contrast fast-spin echo (T1 FSE) or gradient (T1 MPRAGE). A fat-saturated sequence is considered in at least one plane
    • purpose: determine how well circumscribed is the mass and assess for local CSF seeding in aggressive lesions