What is the proper procedure to order a liver magnetic resonance imaging (MRI)?

How to Order a Liver MRI

Order a liver MRI with and without IV contrast using an extracellular gadolinium-based contrast agent, specifying multiphase dynamic imaging with at least arterial and portal venous phases, and include T1-weighted in-phase/out-of-phase, T2-weighted, and diffusion-weighted sequences. 1

Essential Protocol Components

Contrast Requirements

• Request multiphase contrast-enhanced imaging with at least two dynamic phases: late arterial phase and portal venous phase, as these are required for characterization of most liver lesions 1
• Specify extracellular gadolinium-based contrast agents for general liver imaging 1
• Consider hepatobiliary contrast agents (gadoxetate disodium or gadobenate dimeglumine) when enhanced lesion detection is needed, particularly for small lesions or when hepatobiliary phase imaging at 20 minutes post-injection would add diagnostic value 1

Required Imaging Sequences

The minimum required sequences per LI-RADS technical guidelines include 2:

• T1-weighted out-of-phase and in-phase imaging (detects fat and iron)
• T2-weighted imaging with fat suppression
• Multiphase T1-weighted dynamic contrast-enhanced imaging (arterial, portal venous, and delayed phases)
• Diffusion-weighted imaging (DWI) - while optional per guidelines, it is mandatory for detecting subcentimeter metastases and improves diagnostic confidence 2, 3

Clinical Context-Specific Ordering

For indeterminate liver lesions >1 cm in patients with normal liver:

• Order MRI abdomen with and without IV contrast as the preferred modality, which establishes definitive diagnosis in 95% of liver lesions 4, 5
• This differentiates between common benign lesions in 70% of cases 4

For patients with chronic liver disease or cirrhosis:

• Specify triple-phase contrast CT or MRI using LI-RADS protocol with arterial, portal venous, and delayed phases 4, 6
• The triphasic protocol evaluates arterial hypervascularity followed by contrast washout—the classic imaging profile of HCC 6

For patients with known extrahepatic malignancy:

• Order MRI with and without IV contrast as the preferred modality for distinguishing metastases from benign lesions 4

For abnormal liver function tests with cholestatic pattern:

• Order MRI abdomen without and with IV contrast with MRCP (magnetic resonance cholangiopancreatography) 1
• MRCP is superior for detecting intrahepatic and extrahepatic biliary tree abnormalities, choledocholithiasis, and biliary strictures 5

Critical Ordering Pitfalls to Avoid

• Never order MRI without contrast alone - this provides inadequate characterization of liver lesions 1, 4
• Never order single-phase contrast imaging - at least dual-phase (arterial and portal venous) is required for proper lesion characterization 1, 6
• Do not order CT when MRI is available - MRI has significantly higher diagnostic accuracy (95% vs 74-95% for CT) for establishing definitive diagnosis of liver lesions 4, 5
• Avoid ordering "MRI abdomen with and without contrast" without specifying multiphase dynamic imaging - the ordering physician must explicitly request arterial and portal venous phase imaging 1

Practical Ordering Language

State on the requisition:

• "MRI liver with and without IV gadolinium contrast"
• "Multiphase dynamic imaging including arterial and portal venous phases"
• "Include T1 in/out of phase, T2 with fat suppression, and DWI sequences"
• Add clinical context: "Rule out [specific lesion/condition]" or "Characterize [specific finding on prior imaging]"
• For cirrhotic patients, add: "LI-RADS protocol" 6
• For biliary evaluation, add: "Include MRCP" 1, 5