Contrast Agents for Liver MRI

Gadolinium Chelates

• Most commonly used contrast agent
• Standard dose 0.1 mmol Gd/kg
• Bolus injection, dynamic study during arterial (20-30s) to detect hypervascular lesions, portovenous phase (60-90s) to detect hypovascular lesions, and equilibrium phase (between 2-10 min) to allow hemangiomas to fill-in and cholangiocarcinoma and inflammation to enhance

Liver-Specific Agents

• Teslascan (Mn-DPDP)
• MultiHance (gadobenate dimeglumine)
• Primovist (gadoxetic acid)
• SPIO (Endorem/Feridex)

Teslascan

• Hepatocyte-specific MR contrast agent
• Uptake into hepatocyte and partially excretes into the bile
• Drip infusion
• Increased T1 signal intensity
• Differentiate tumors of hepatocellular origin from nonhepatocellular origin

MultiHance

• 4% biliary excretion
• Can be bolus injected, images also taken 1-2 hours later for tumor detection (uptake into liver parenchyma to increase conspicuity of metastases)

Primovist

• Strong biliary excretion
• Can be bolus injected (doses 0.025 mmol/kg), images on delayed phase can be taken as early as 20 min

Superparamagnetic Iron Oxide Particles (SPIO)

• Accumulates within phagocytes in the liver (typically, there is absence of phagocytes in malignancy)
• On T2WI, normal tissues or lesions with phagocytes (ie, FNH, hepatocellular adenoma, well-differentiated HCC) appear dark
• Drip infusion
• Imaging done several hours after contrast administration

Above image: gadolinium metal, from www.emovendo.net

Reference:

Reimer P, Parizel PM, Meaney JFM, Stichnoth FA. Clinical MR Imaging, 2010