Adrenal glands protocol (MRI)

Adrenal glands protocol is an MRI protocol comprising a group of MRI sequences put together to further assess indeterminate adrenal lesions, in particular, lipid-poor adenomas.

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 protocol might look like:

• T2 weighted
  • plane: axial and coronal
  • sequence: heavily T2-weighted (e.g. TRUEFISP or HASTE)
  • purpose: an anatomical overview
• T1 weighted
  • plane: axial 
  • sequence: gradient-echo (GRE) acquired in-phase (IP) and out-of-phase (OOP) 
  • purpose: IP-OOP: differentiate lipid-rich adrenal adenomas from non-lipid containing adrenal lesions

The use of other sequences for the purpose of differentiating adenomas from non-adenomas is still controversial and not well established in the literature . Additional sequences that may be considered in diverse imaging investigation or depending on local protocols include:

• DWI/ADC
  • plane: axial
  • sequence: routine 2D diffusion-weighted imaging 
• T1 C+ (Gd)​
  • plane: axial 
  • sequence: fat-suppressed gradient-echo (GRE)
    • timing not well established in the literature
  • purpose: tumor enhancement characterization