Objectives: To evaluate the potential of MR elastography (MRE)–based shear strain mapping to noninvasively predict the presence of microvascular invasion (MVI) in hepatocellular carcinoma (HCC). Methods: Fifty-nine histopathology-proven HCC patients with conventional 60-Hz MRE examinations (+/−MVI, n = 34/25) were enrolled retrospectively between December 2016 and October 2019, with one subgroup comprising 29/59 patients (+/−MVI, n = 16/13) who also underwent 40- and 30-Hz MRE examinations. Octahedral shear strain (OSS) maps were calculated, and the percentage of peritumoral interface length with low shear strain (i.e., a low-shear-strain length, pLSL, %) was recorded. For OSS-pLSL, differences between the MVI (+) and MVI (−) groups and diagnostic performance at different MRE frequencies were analyzed using the Mann-Whitney test and area under the receiver operating characteristic curve (AUC), respectively. Results: The peritumor OSS-pLSL was significantly higher in the MVI (+) group than in the MVI (−) group at the three frequencies (all p < 0.01). The AUC of peritumor OSS-pLSL for predicting MVI was good/excellent in all frequency groups (60-Hz: 0.73 (n = 59)/0.80 (n = 29); 40-Hz: 0.84; 30-Hz: 0.90). On further analysis of the 29 cases with all frequencies, the AUCs were not significantly different. As the frequency decreased from 60-Hz, the specificity of OSS increased at 40-Hz (53.8–61.5%) and further increased at 30-Hz (53.8–76.9%), and the sensitivity remained high at lower frequencies (100.0–93.8%) (all p > 0.05). Conclusions: MRE-based shear strain mapping is a promising technique for noninvasively predicting the presence of MVI in patients with HCC, and the most recommended frequency for OSS is 30-Hz. Key Points: • MR elastography (MRE)–based shear strain mapping has the potential to predict the presence of microvascular invasion (MVI) in hepatocellular carcinoma preoperatively. • The low interface shear strain identified at tumor–liver boundaries was highly correlated with the presence of MVI.
- Elasticity imaging techniques
- Hepatocellular carcinoma
- Magnetic resonance
- Tissue adhesions
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging