What type of MRI is needed for a patient with splenomegaly, steatosis, and a 1.2cm liver mass?

MRI Protocol for 1.2cm Liver Mass with Steatosis and Splenomegaly

Order a multiphasic dynamic contrast-enhanced MRI with hepatobiliary contrast agent (gadoxetate disodium/Eovist) to evaluate this 1.2cm liver mass, as this protocol provides both dynamic vascular imaging and hepatocyte-phase imaging essential for characterizing small liver lesions in the setting of underlying liver disease. 1, 2

Recommended MRI Protocol

Multiphasic liver protocol MRI should include:

• Pre-contrast sequences including T1-weighted in-phase and out-of-phase imaging (critical for detecting steatosis and differentiating fat-containing lesions) 1, 3
• T2-weighted imaging for lesion characterization 1
• Dynamic contrast-enhanced phases after gadoxetate disodium administration:
  • Arterial phase (15-25 seconds post-injection)
  • Portal venous phase (~60 seconds post-injection)
  • Equilibrium phase (~120 seconds post-injection) 1, 2
• Hepatocyte phase imaging at 10-20 minutes post-injection (can extend to 120 minutes if needed) 1, 2

Rationale for This Specific Protocol

For lesions measuring 1-2 cm (like your 1.2cm mass), NCCN guidelines recommend evaluation using two different imaging modalities showing classic arterial enhancement to diagnose hepatocellular carcinoma (HCC) without biopsy. 1 However, a single high-quality multiphasic MRI with hepatobiliary contrast provides superior diagnostic information compared to other modalities for this size lesion.

The hepatocyte phase is particularly valuable because:

• Lesions lacking hepatocyte function (metastases, cysts, most HCCs) will not accumulate contrast in this phase 2
• Well-differentiated HCC may show some enhancement, requiring additional clinical correlation 2
• This phase improves both detection and characterization of liver lesions compared to pre-contrast imaging alone 2

Key Diagnostic Considerations

The combination of steatosis and splenomegaly raises specific concerns:

• Splenomegaly may indicate underlying portal hypertension or early fibrosis, even in the setting of steatosis, as spleen enlargement can be a feature of NASH rather than simple steatosis 4
• The T1-weighted in-phase and out-of-phase sequences are essential to distinguish hepatic steatosis (which can occasionally present as a mass with mass effect) from fat-rich tumors 3
• Look for signal dropout on out-of-phase images compared to in-phase images, which indicates fat content 3
• Dynamic enhancement pattern should be compared to adjacent normal liver parenchyma 3

Important Caveats

If the patient has elevated bilirubin (>3 mg/dL) or ferritin levels, perform hepatocyte phase imaging no later than 60 minutes post-injection, as these conditions reduce hepatic contrast effect 2

Classic HCC imaging features to assess:

• Arterial hypervascularity (intense arterial enhancement)
• Washout or hypointensity in delayed/portal venous phases 1

For this 1.2cm lesion specifically: If classic arterial enhancement is not observed on MRI, or if imaging findings are atypical, tissue biopsy should be considered for definitive diagnosis 1

Follow-up Algorithm

If the lesion cannot be definitively characterized:

• Repeat imaging with triphasic CT or MRI every 3-4 months 1
• If stable over 18 months, transition to surveillance imaging every 6-12 months 1
• If enlarging, re-evaluate according to size-based diagnostic criteria 1