Small hepatocellular carcinoma: using MRI to predict histological grade and Ki-67 expression

Area of Science:

• Hepatobiliary imaging
• Oncologic imaging
• Radiology

Background:

• Hepatocellular carcinoma (HCC) is a common malignancy.
• Small, aggressive HCCs require accurate preoperative identification for optimal management.
• Current methods for differentiating aggressive HCCs preoperatively have limitations.

Purpose of the Study:

• To determine if preoperative magnetic resonance imaging (MRI) parameters can predict aggressive small hepatocellular carcinomas (HCCs).
• To investigate the association between MRI findings and Ki-67 expression and histological grade in HCCs.
• To explore MRI's potential as a non-invasive tool for assessing tumor aggressiveness.

Main Methods:

• Retrospective analysis of 60 patients with small HCCs (≤3 cm, ≤2 tumors).
• Evaluation of contrast-enhanced and diffusion-weighted MRI scans.
• Quantitative measurement of tumor-to-muscle signal intensity (SI) ratio and apparent diffusion coefficient (ADC).

Main Results:

• Tumor-to-muscle SI ratio significantly correlated with histological grade across multiple MRI phases (T1-weighted, arterial, portal venous).
• Apparent diffusion coefficient (ADC) also showed a significant correlation with histological grade.
• Arterial inhomogeneous enhancement on MRI was associated with high Ki-67 expression, a marker of cell proliferation.

Conclusions:

• Preoperative MRI parameters, including SI ratio and enhancement patterns, can serve as non-invasive predictors of small, aggressive HCCs.
• These findings may help guide treatment strategies, potentially avoiding conservative management for aggressive tumors.
• MRI offers a valuable tool for characterizing tumor biology and guiding clinical decisions in HCC management.