Multiphasic Computed Tomography Enhancement Characteristics and Utility of Delayed Phase in Infiltrative...

Area of Science:

• Radiology
• Hepatobiliary Imaging
• Oncology

Background:

• Hepatocellular carcinoma (HCC) presents in various forms, including nodular and infiltrative patterns.
• Differentiating these subtypes is crucial for accurate diagnosis and treatment planning.
• Multiphasic contrast-enhanced computed tomography (CECT) is a primary imaging modality for HCC evaluation.

Purpose of the Study:

• To compare the CECT characteristics of infiltrative HCC versus nodular HCC.
• To evaluate the conspicuity of infiltrative HCC across different CECT phases.
• To identify imaging features that aid in the diagnosis of infiltrative HCC.

Main Methods:

• Retrospective analysis of multiphasic CECT scans (arterial, portal venous, delayed phases) in treatment-naive cirrhotic patients.
• Inclusion of patients diagnosed with infiltrative or nodular HCC based on Liver Imaging Reporting and Data System (LI-RADS) v2018 criteria.
• Independent review of CT images by two radiologists, assessing lesion characteristics and conspicuity.

Main Results:

• Infiltrative HCCs less frequently exhibited arterial phase hyperenhancement, washout, and enhancing capsule compared to nodular HCCs.
• Portal vein thrombosis, hepatic vein thrombosis, biliary dilatation, and ascites were significantly associated with infiltrative HCC.
• The delayed phase of CECT demonstrated the highest interobserver agreement for infiltrative HCC conspicuity.

Conclusions:

• Infiltrative HCC frequently lacks classic LI-RADS features seen in nodular HCC.
• Venous thrombosis is a significant imaging clue for diagnosing infiltrative HCC.
• The delayed phase of multiphasic CECT is essential for detecting infiltrative HCC.