Eovist

Gadoxetate disodium (also known by the tradenames Primovist and Eovist) is a hepatospecific paramagnetic gadolinium-based contrast agent, used exclusively in MRI liver imaging. Its chief use is in hepatic lesion characterization, i.e. assessing focal liver lesions identified on other imaging studies.

Gadoxetic acid distributes into the vascular and extravascular spaces during the arterial, portal venous, and late dynamic phases, and then progressively into the hepatocytes and bile ducts during the hepatobiliary phase . This last phase allows an opportunity to acquire a contrast MRI cholangiogram.

  • linear, ionic molecule 
  • 50% hepatic excretion, 50% renal excretion
  • T1 relaxivity @ 1.5 T: 6.5-7.3 (slightly higher than extracellular contrast agents)
  • concentration: 0.25 mmol/ml
  • recommended dosage: 0.025 mmol/kg

Approximately 50% of an injected dose of gadoxetate disodium is taken up by the liver. The next strongest hepatobiliary agent is gadobenate dimeglumine (MultiHance), with only 5% of the injected dose taken up by the liver .

Protocol
  • a shorter, tighter bolus profile is preferred
  • MRCP should be obtained within 5 minutes of injection
  • hepatobiliary phase is obtained 20 minutes after contrast injection
  • STIR sequence is obtained postcontrast
Indications
  • evaluating focal nodular hyperplasia (FNH) vs adenoma
    • hepatobiliary phase (20 minutes after contrast injection)
      • FNH appears iso- to hyperintense
      • adenoma appears hypointense
  • evaluation of hepatic metastases
    • does not take up the contrast 
    • gadoxetate disodium uptake in a lesion indicates that it contains hepatocytes (or is a vascular malformation), and effectively excludes a metastasis from outside the liver
  • post-liver transplant (except if hepatic artery suspected or if suspecting abscess)
  • HCC surveillance
  • contrast enhanced cholangiogram
    • bile leak
    • suspected gallbladder obstruction
    • hepatojejunostomy evaluation
Disadvantages
  • can cause severe respiratory motion artifact in the arterial phase (also referred to as transient arterial phase respiratory motion-related artifact
    • this may limit the evaluation of a lesion's potential hypervascularity and potentially limits evaluation of HCC
  • should not be used in the short-term after hepatic ablation
  • not best study for hemangioma evaluation or evaluation of inflammatory disease

As with all gadolinium-based contrast agents, it should be used with caution in those with renal impairment, due to the risk of nephrogenic systemic fibrosis.

See also

Siehe auch:
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