目的:评价MRI对肾细胞癌下腔静脉瘤栓侵犯下腔静脉壁的诊断价值。方法:回顾性分析2010—2018年在北京大学第一医院行肾根治性切除术及下腔静脉取栓术的肾细胞癌患者,术前行1.5 T或3.0 T MRI检查的56例患者被纳入本研究。由两位影像科医生测量术前MRI图像瘤栓所在水平肾静脉及下腔静脉最大径、下腔静脉瘤栓的长度,并评判瘤栓是否充满下腔静脉腔达两侧缘、瘤栓边缘是否光滑、瘤栓与下腔静脉壁分界是否清晰、下腔静脉壁正常信号是否改变等征象。基于病理证实下腔静脉壁受累与否将患者分为两组,对临床资料及MRI征象进行单因素分析及多因素回归分析。结果:56例患者中男性43例、女性13例,平均年龄(55.64±0.43)岁,有17例(30.4%)病理证实下腔静脉壁受累, 大部分为透明细胞癌。下腔静脉壁受累组与非受累组比较,下腔静脉瘤栓的长度更长[(7.91±3.59) cm vs. (5.94±3.57) cm,P=0.049]、瘤栓充满下腔静脉腔(P=0.002)、瘤栓边缘不光滑(P=0.005)、瘤栓与下腔静脉壁分界不清晰(P=0.001)、下腔静脉壁正常信号改变(P<0.001)出现的概率更大,结合这五个指标诊断下腔静脉壁受累的敏感性及特异性为94.12%和79.49%。结论:MRI可作为评估下腔静脉瘤栓侵犯静脉壁的方法,结合下腔静脉瘤栓的长度及MRI征象可以获得较高的诊断敏感性及特异性。

Objective: To evaluate the diagnostic performance of MRI for the assessment of inferior vena cava (IVC) wall invasion by IVC thrombus in patients with renal cell carcinoma (RCC).Methods: We retrospectively collected patients who underwent radical nephrectomy and thrombectomy for RCC between 2010 and 2018 at Peking University First Hospital. All the patients underwent imaging on a 1.5 Tesla or 3.0 Tesla MRI scanner. Fifty-six patients met the inclusion criteria. Preoperative imaging was reviewed by two radiologists blinded to details of the patient’s surgical procedure and histopathology. Two radiologists measured the maximum anterior-posterior diameter and coronal diameters of the IVC and renal vein, and the craniocaudal extent of tumor thrombus, and evaluated the MRI features of IVC thrombus, including occlusion of the IVC lumen,the margin of the tumor thrombus (smooth vs. irregular), contact of the IVC thrombus and IVC wall, and altered signal of the IVC wall. Univariable and multivariable associations of clinical and radiographic features with IVC wall invasion were evaluated by Logistic regression.Results: Of the 56 patients [male: 43, female: 13, mean age: (55.64±0.43) years], 17 (30.36%) were detected with IVC wall invasion, and most were clear cell carcinoma. Tumor thrombus with IVC wall invasion showed an increase in length of IVC thrombus [(7.91±3.59) cm vs. (5.94±3.57) cm, P=0.049], and more features of complete occlusion of the IVC lumen (P=0.002),irregular margin of the IVC thrombs (P=0.005), contact of the IVC thrombus and IVC wall (P=0.001), and altered signal of the low-intensity vessel wall (P<0.001), with a sensitivity of 94.12% and a specificity of 79.49%.Conclusion: The present study indicates that MRI could be a means of evaluating RCC with IVC wall invasion, and the combination of tumor thrombus length and subjective impression of IVC wall invasion achieved a high sensitivity and specificity for diagnosis.