[Diagnosis and differential diagnosis of small hepatocellular carcinoma in the context of cirrhosis].

In China, most patients with hepatocellular carcinoma (HCC) have progressed to the middle and advanced stages when they are diagnosed, so early-stage diagnosis is a significant key to improving the prognosis. Tumor diameter significantly correlates with the prognosis of patients with small hepatocellular carcinoma (sHCC), which is further classified as early-stage HCC (eHCC) and advanced HCC (pHCC). The "fast in and fast out" enhancement pattern is a typical feature of liver cancer imaging (CECT/CEMRI/CEUS); yet, eHCC with a diameter of <2 cm frequently exhibits hypovascularity. Hepatocyte-specific enhanced MRI (EOB-MRI) displays a unique hepatobiliary-specific phase (HBP) hypointensity, along with atypical manifestations such as lipid-containing nodules, T2 hyperintensity, and restricted diffusion. HBP is a functional radiographic imaging feature for cancerous nodules in cirrhosis. EOB-MRI can significantly increase the hypovascularity detection rate of eHCC in conjunction with serologic markers like alpha-fetoprotein. With a focus on the dynamic changes in hypovascular hypointense nodules in HBP (including diameter size, APHE, DWI, and other parameters), it is recommended that high-risk cirrhotic cohorts undergo routine monitoring (EOB-MRI follow-up every three months) to diagnose early-stage eHCC, based on the existing evidence-based medicine. This recommendation in clinical practice guidelines provides a crucial strategy that can markedly enhance patients' five-year survival rates.