Evaluate the Microvascular Invasion of Hepatocellular Carcinoma (≤5 cm) and Recurrence Free Survival with Gadoxetate Disodium‐Enhanced MRI‐Based Habitat Imaging

Background Tumors are heterogenous and consist of subregions, also known as tumoral habitats, each exhibiting varied biological characteristics. Each habitat corresponds to a cluster of tissue sharing similar structural, metabolic, or functional characteristics. The habitat imaging technique facilitates both the visualization and quantification of these tumoral habitats. Purpose To evaluate the microvascular invasion (MVI) in hepatocellular carcinoma (HCC) (≤5 cm) and assess the recurrence‐free survival (RFS) using gadoxetate disodium‐enhanced MRI‐based habitat imaging. Study Type Retrospective. Subjects 180 patients (52.9 years ± 11.7, 156 men) with HCC. Field Strength/Sequence 1.5T/contrast‐enhanced T1‐weighted gradient‐echo sequence. Assessment The enhancement ratio of signal intensity at the arterial phase (AER) and hepatobiliary phase (HBPER) were calculated. The HCC lesions and their peritumoral tissues of 3, 5, and 7 mm were encoded into four habitats. The volume fraction of each habitat was then quantified. The diagnostic performance was assessed using the receiver operating characteristic analysis with 5‐fold cross‐validation. The RFS was evaluated with Kaplan–Meier curves. Results Habitat 2 (with median to high AER and low HBPER) within the peritumoral tissue of 3 mm (f 2 ‐P 3 ) and tumor diameter could serve as independent risk factors for MVI and showed the statistical significance (odds ratio (OR) of f 2 ‐P 3 = 1.170, 95% CI = 1.099–1.246; OR of tumor diameter: 6.112, 95% CI = 2.162–17.280). A nomogram was developed by incorporating f 2 ‐P 3 and tumor diameter, demonstrating high diagnostic accuracy. The area under the curve from 5‐fold cross‐validation ranged from 0.880 to 1.000. Additionally, the nomogram model demonstrated high efficacy in risk stratification for RFS. Conclusion Habitat imaging of HCC and its peritumoral microenvironment has the potential for noninvasive and preoperative identification of MVI and prognostic assessment. Level of Evidence 3 Technical Efficacy Stage 2