Objective: To investigate the MRI features of hepatic nodular regenerative hyperplasia (NRH) induced by chemotherapy. Methods: The clinical data and MRI of 20 cases with hepatic NRH induced by chemotherapy and confirmed by pathology in Zhongshan Hospital Fudan University from August 2014 to May 2019 were retrospectively analyzed. There were 13 males and 7 females, with an average age of 49.8 ± 9.7 years. Contrast-enhanced MR scan with Gd-DTPA was performed eighteen patients, and two patients underwent contrast-enhanced MR scan with hepatobiliary specific contrast (Gd-EOB-DTPA). The image analysis includes the number, location, size, shape, signal intensity in plain scan and enhancement pattern of lesions. The apparent diffusion coefficient (ADC) values of the lesions and adjacent hepatic parenchyma were measured on the ADC map, and the difference was compared with paired sample t test. Results: A total of 36 lesions in 20 patients were rounded or oval, including 23 (63.9%) lesions in the right lobe, 12 (33.3%) in the left lobe and 1 (2.8%) in the caudate lobe. The average diameter of all lesions was 15.4 ± 6.4 (7.0-37.0) mm. The boundary was clear in 9 (25.0%) lesions and blurred in 27 (75%) lesions. In T1WI, 35 (97.2%) lesions showed slightly hypointensity, and in 1 (2.8%) lesion was iosintensity. All 36 lesions showed slightly hyperintensity in T2WI. 33 (91.7%) lesions showed slightly hyperintensity in DWI, and 3 (8.3%) lesions showed iosintensity. 31 lesions with Gd-DTPA enhanced MR scan were significantly enhanced in the arterial phase and showed slightly high signal intensity in early portal vein phase, late portal vein phase and equilibrium phase. 5 lesions with Gd-EOB-DTPA enhanced MR scan were also significantly enhanced in the arterial phase and showed slightly high signal intensity in early portal vein phase, late portal vein phase and equilibrium phase, then all lesions showed circular high signal intensity in hepatobiliary specific phase. The average ADC value of 29 lesions was (1.471 ± 0.253) × 10(-3) mm(2)/s, and that of adjacent liver parenchyma was (1.460 ± 0.235) ×10(-3) mm(2)/s. There was no significant difference between the two groups (P > 0.05). Conclusion: MR findings of NRH induced by chemotherapy have certain characteristics, and the morphological manifestations, diffusion-weighted imaging, enhanced imaging and hepatobiliary specific phase features of the lesions can help to diagnose the disease.
目的： 探讨化疗引起的肝脏结节性再生性增生（NRH）的MRI特征。 方法： 回顾性分析2014年8月至2019年5月复旦大学附属中山医院经病理证实的20例化疗引起的肝脏NRH患者的临床资料及MR图像。其中男性13例，女性7例，年龄（49.8±9.7）岁。18例患者行常规Gd-DTPA增强MR检查，2例患者行肝胆特异性对比剂(Gd-EOB-DTPA)增强MR检查。图像分析包括病灶的数目、部位、大小、形态、平扫信号强度、增强特征等。在表观扩散系数（ADC）图上测量病灶ADC值及周围肝实质ADC值，采用配对样本t检验比较两者差异有无统计学意义。 结果： 20例患者共36枚病灶，均为类圆形或椭圆形，分别为肝右叶23枚(63.9%)、左叶12枚(33.3%)、尾叶1枚(2.8%)；病灶平均大小为（15.4±6.4）mm，9枚(25.0%)病灶边界清晰，27枚(75%)病灶边界模糊，在T1WI 35枚（97.2%）病灶呈稍低信号，1枚（2.8%）病灶等信号；在T2WI全部病灶均为稍高信号，在DWI 33枚（91.7%）病灶呈稍高信号，3枚（8.3%）病灶呈等信号。行Gd-DTPA增强扫描的31枚病灶动脉期明显强化，门静脉早期、门静脉晚期及平衡期均持续强化，呈稍高信号；行Gd-EOB-DTPA增强扫描的5枚病灶，动脉期明显强化，门静脉早期、门静脉晚期及平衡期均持续强化，呈稍高信号，肝胆特异期均为环形高信号。29枚病灶的ADC值为（1.471±0.253）×10(-3) mm(2)/s，邻近肝实质ADC值为（1.460±0.235）×10(-3) mm(2)/s，两者差异无统计学意义（P > 0.05）。 结论： 化疗引起的NRH的MR表现有一定的特征，病灶的形态学表现、扩散加权成像、增强成像和肝胆特异期特征，可以帮助疾病诊断。.
Keywords: Diffusion weighted imaging; Liver; Magnetic resonance imaging; Nodular regenerative hyperplasia; hepatobiliary specific contrast agent.