美国放射学会肝脏成像报告和数据系统 (LI-RADS) 标准化了肝细胞癌 (HCC) 患者或有患肝细胞癌 (HCC) 风险的患者的成像技术、报告词汇、疾病分类和管理。 LI-RADS 涵盖美国的 HCC 监测；通过 CT、MRI 或超声造影 (CEUS) 诊断 HCC；使用 CT 或 MRI 进行治疗反应评估 (TRA)。 LI-RADS 最近扩展到包括非放射局部治疗或手术切除后的 CEUS TRA。本报告概述了 LI-RADS CEUS 非辐射 TRA v2024，包括影像学结果词典、技术和治疗后肿瘤活力评估的影像学标准。 LI-RADS CEUS 非辐射 TRA v2024 考虑了活肿瘤的 CEUS 外观差异以及治疗病灶内及其附近的治疗后变化。由于CEUS对血管血流高度敏感，治疗后反应性变化通常表现为病灶周围异常增强但没有消退的区域，特别是在治疗后的前3个月。为了提高非放射 TRA 超声造影的准确性，使用不同的诊断标准来评估治疗病灶边缘内外的肿瘤活力。病灶内增强的更广泛标准提高了肿瘤活力检测的灵敏度。更严格的病灶周围增强标准限制了将治疗后反应性变化误分类为存活肿瘤。最后，TRA 算法协调病灶内和病灶周围肿瘤活力评估，并分配单一 LI-RADS 治疗反应 (LR-TR) 类别：LR-TR 不存活、LR-TR 模棱两可或 LR-TR 存活。© RSNA，2024 另请参阅Milot 在本期的社论。

The American College of Radiology Liver Imaging Reporting and Data System (LI-RADS) standardizes the imaging technique, reporting lexicon, disease categorization, and management for patients with or at risk for hepatocellular carcinoma (HCC). LI-RADS encompasses HCC surveillance with US; HCC diagnosis with CT, MRI, or contrast-enhanced US (CEUS); and treatment response assessment (TRA) with CT or MRI. LI-RADS was recently expanded to include CEUS TRA after nonradiation locoregional therapy or surgical resection. This report provides an overview of LI-RADS CEUS Nonradiation TRA v2024, including a lexicon of imaging findings, techniques, and imaging criteria for posttreatment tumor viability assessment. LI-RADS CEUS Nonradiation TRA v2024 takes into consideration differences in the CEUS appearance of viable tumor and posttreatment changes within and in close proximity to a treated lesion. Due to the high sensitivity of CEUS to vascular flow, posttreatment reactive changes commonly manifest as areas of abnormal perilesional enhancement without washout, especially in the first 3 months after treatment. To improve the accuracy of CEUS for nonradiation TRA, different diagnostic criteria are used to evaluate tumor viability within and outside of the treated lesion margin. Broader criteria for intralesional enhancement increase sensitivity for tumor viability detection. Stricter criteria for perilesional enhancement limit miscategorization of posttreatment reactive changes as viable tumor. Finally, the TRA algorithm reconciles intralesional and perilesional tumor viability assessment and assigns a single LI-RADS treatment response (LR-TR) category: LR-TR nonviable, LR-TR equivocal, or LR-TR viable.© RSNA, 2024 See also the editorial by Milot in this issue.