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Difficulty: HardInterpreting Imaging Results

Evaluate the following multiphasic cross-sectional imaging descriptions of incidentally discovered solid liver lesions. Match each specific contrast-enhancement kinetic pattern observed on computed tomography (CT) or magnetic resonance imaging (MRI) with its most likely corresponding hepatic diagnosis.

  • Arterial phase hyperenhancement with rapid contrast washout in the portal venous and delayed phases, often accompanied by an enhancing pseudocapsuleHepatocellular carcinoma
  • Early discontinuous, peripheral nodular enhancement during the arterial phase, followed by progressive centripetal fill-in on delayed phasesHepatic hemangioma
  • Intense, homogeneous enhancement during the arterial phase with a central hypointense region that demonstrates contrast retention and hyperintensity on delayed phasesFocal nodular hyperplasia
  • Peripheral rim enhancement during the arterial phase with progressive, persistent delayed central enhancement, frequently associated with overlying hepatic capsular retractionIntrahepatic cholangiocarcinoma

Answer

The correct matching pairs Hepatocellular carcinoma with arterial hyperenhancement and venous washout; Hepatic hemangioma with peripheral nodular centripetal fill-in; Focal nodular hyperplasia with arterial enhancement and a delayed-enhancing central scar; and Intrahepatic cholangiocarcinoma with progressive delayed enhancement and capsular retraction.
The non-invasive diagnosis of focal liver lesions relies heavily on understanding their distinct hemodynamic properties as captured by multiphasic contrast-enhanced imaging. The timing of contrast arrival, retention, and clearance (washout) relative to the normal liver parenchyma—which receives a unique dual blood supply from the portal vein and hepatic artery—provides pathognomonic signatures that often preclude the need for biopsy.

Step-by-Step Solution

1
Analyze the 'washout' pattern on multiphasic imaging.
Arterial enhancement with subsequent portal venous and delayed washout defines hepatocellular carcinoma.
This kinetic pattern differentiates malignant neovascularization from benign, dual-supplied liver parenchyma.
2
Evaluate the 'centripetal fill-in' pattern.
Discontinuous peripheral enhancement that progressively fills in toward the center over time is characteristic of a hepatic hemangioma.
This reflects the extremely slow flow dynamics within the cavernous vascular spaces of this benign tumor.
3
Assess the 'central scar' enhancement kinetics.
A lesion with uniform arterial enhancement but a central scar that only enhances on delayed phases points to focal nodular hyperplasia.
The fibrous central scar is relatively hypovascular during the arterial phase but slowly retains contrast, becoming bright late in the study.
4
Identify the 'capsular retraction' and delayed enhancement.
A lesion showing delayed central enhancement with surrounding capsular retraction indicates a highly fibrotic tumor, characteristic of intrahepatic cholangiocarcinoma.
The severe desmoplastic stroma characteristic of this malignancy causes tissue contraction and extremely slow contrast pooling.

Key Concept

Multiphasic CT/MRI contrast enhancement kinetics of focal liver lesions
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Interpreting Imaging Results

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