心脏磁共振扩散加权成像在狼疮性肾炎患者心肌损伤诊断中的应用价值

Cardiac magnetic resonance diffusion weighted imaging in lupus nephritis patients with myocardial injury

目的:探讨心脏磁共振(CMR)扩散加权成像(DWI)在狼疮性肾炎(LN)伴狼疮心肌炎(LM)患者中心肌损伤诊断和评估的应用价值。方法:回顾性分析66例LN患者心脏DWI影像资料,于心脏短轴位分别测量室间隔上部、下部、侧壁及环周总体的表观扩散系数(ADC)值。比较LN伴LM组(42例)、LN不伴LM组(24例)和正常对照组(42例)间ADC值差异,并应用ROC曲线分析ADC值对心肌炎的诊断效能及最佳诊断分界值。结果:49例(74.2%)LN患者符合肾病综合征,38例(57.6%)存在急性肾损伤(AKI),8例(12.1%)为慢性肾功能不全。LM患者心脏损伤以呼吸困难(64.3%)最为常见,其次为心悸(33.3%)和胸痛(9.5%)。LM患者较非LM患者年龄轻,狼疮活动明显,多合并血栓性微血管病,尿蛋白定量、血清肌酐水平更高,肾功能损伤程度更重。LN患者室间隔上部和下部、左心室侧壁和环周总体ADC值显著高于正常对照组(P<0.05);LM患者左心室ADC值高于非LM患者(P>0.05)。左心室环周总体ADC值诊断LN患者的ROC曲线下面积0.876(95%CI 0.799~0.932,P<0.001),阈值为5×10^(-3)mm^(2)/s。左心室环周总体ADC值诊断LN患者合并LM的ROC曲线下面积0.746(95%CI 0.654~0.825,P<0.001),阈值为6.85×10^(-3)mm^(2)/s。结论:DWI可定量评估狼疮心肌损伤,ADC值对LM具有较好的诊断价值。

Objective:To investigate the value of cardiac magnetic resonance(CMR)diffusion weighted imaging(DWI)in lupus nephritis patients with lupus myocarditis.Methodology:CMR examination data of 66 patients with lupus nephritis(LN)and 42 healthy volunteers were retrospectively analyzed.According to the diagnostic criteria for myocarditis,patients were divided into LN with LM group and LN without LM group.Apparent diffusion coefficient(ADC)value were measured in anterior,posterior,lateral wall and global left ventricular on the standard cardiac short axis images.The difference ADC value between three groups were compared.Assess the diagnostic efficacy of ADC value and calculated its diagnostic cut off point using ROC curve for myocarditis.Results:49(74.2%)suffered from nephrotic syndrome,38(57.6%)suffered from AKI,and 8(12.1%)suffered from chronic renal insufficiency.Symptoms of myocarditis consisted of dyspnea(64.2%),palpitation(33.3%)and chest pain(9.5%).Indicators of renal injury were more serious in LM patients,always associated with TMA,with the younger age,higher SLE-DAI,urinary protein quantity and serum creatinine.LN group ADC value were significantly higher than those in control group(P<0.05).LM group ADC value were higher than those in non-LM group(P>0.05).The area under ROC curve of LV circumferential ADC in the diagnosis of LN patients was 0.876(95%CI 0.799-0.932,P<0.001),the cut off point were 5×10^(-3)mm^(2)/s.The area under ROC curve of LV circumferential ADC in the diagnosis of LN patients with LM was 0.746(95%CI 0.654-0.825,P<0.001),the cut off point were 6.85×10^(-3)mm^(2)/s.Conclusion:DWI can quantify myocardial injury.The ADC value has good diagnostic value for LN complicated with myocardial injury.