偶发性局灶性肝脏病变 (IFLL) 被定义为因不相关原因而在患者影像中发现的肝脏病变。它们在日常实践中经常遇到，有时会导致不必要的、侵入性的和潜在有害的后续调查。临床表现和影像学方面在决定是否需要进一步评估以及需要进行哪些进一步评估方面发挥着重要作用。在低风险患者（即没有恶性或慢性肝病病史或相关症状）中，尤其是年龄小于 40 岁的患者，95% 以上的 IFLL 可能是良性的。应考虑对周围肝实质进行剪切波肝脏弹性成像（SWE）以排除肝硬化并进行进一步的危险分层。如果低风险患者的 IFLL 在 B 型超声检查中具有典型的良性病变表现（例如，单纯囊肿、钙化、局灶性脂肪变、典型血管瘤），则无需进一步影像学检查。对比增强超声 (CEUS) 应被视为区分良性和恶性 IFLL 的一线对比成像方式，因为它与对比增强 (CE)-MRI 具有相似的准确性。在超声造影中，血管晚期病变的低强化是恶性肿瘤的特征。应避免使用 CE-CT 来表征可能的良性 FLL，并在病变被证明为恶性时保留用于分期。在高危患者（即患有慢性肝病或肿瘤病史）中，每个 IFLL 最初都应被视为潜在恶性，并应尽一切努力确认或排除恶性肿瘤。对于那些无法切除的恶性病变，应考虑超声引导活检，特别是在诊断仍不清楚或需要特定组织诊断时。

An incidental focal liver lesion (IFLL) is defined as a hepatic lesion identified in a patient imaged for an unrelated reason. They are frequently encountered in daily practice, sometimes leading to unnecessary, invasive and potentially harmful follow-up investigations. The clinical presentation and the imaging aspects play an important role in deciding if, and what further evaluation, is needed. In low-risk patients (i.e., without a history of malignant or chronic liver disease or related symptoms), especially in those younger than 40 years old, more than 95% of IFLLs are likely benign. Shear Wave liver Elastography (SWE) of the surrounding liver parenchyma should be considered to exclude liver cirrhosis and for further risk stratification. If an IFLL in a low-risk patient has a typical appearance on B-mode ultrasound of a benign lesion (e.g., simple cyst, calcification, focal fatty change, typical hemangioma), no further imaging is needed. Contrast-Enhanced Ultrasound (CEUS) should be considered as the first-line contrast imaging modality to differentiate benign from malignant IFLLs, since it has a similar accuracy to contrast-enhanced (CE)-MRI. On CEUS, hypoenhancement of a lesion in the late vascular phase is characteristic for malignancy. CE-CT should be avoided for characterizing probable benign FLL and reserved for staging once a lesion is proven malignant. In high-risk patients (i.e., with chronic liver disease or an oncological history), each IFLL should initially be considered as potentially malignant, and every effort should be made to confirm or exclude malignancy. US-guided biopsy should be considered in those with unresectable malignant lesions, particularly if the diagnosis remains unclear, or when a specific tissue diagnosis is needed.