3.0T磁共振脑转移瘤IVIM与MR灌注加权成像的相关性研究

目的初步探讨利用体素内不一致运动磁共振成像(introvoxelincoherent motion MR imaging,IVIM-MRI)评价脑转移瘤的灌注,并与灌注加权成像(perfusion weighted Imaging,PWI)的指标进行相关性评价。方法收集在本院2012年6月~2012年12月间26例经手术证实的不同类型癌症发生脑转移的患者行MRI增强检查。扫描序列包括IVIM及PWI。选取颅内转移病灶共60个,应用工作站后处理软件分别测定瘤体及对侧Slow ADC(SADC)、Fast ADC(FADC)、Fraction of FastADC(FFADC)和血流量(cerebral blood flow,CBF)、血容量(cerebral blood volume,CBV),并计算出各个参数的相对值(r),即:r值=(实质病灶值/对侧正常值)×100%。将瘤体与正常侧的IVIM指标进行统计学比较,并将IVIM与PWI的各参数进行Pearson相关性分析。对IVIM和PWI的参数进行转移瘤诊断的ROC分析。结果转移瘤的SADC为(0.437±0.023)×10-3 mm2/s),其对侧脑组织的SADC为(0.223±0.010)×10-3 mm2/s),两者间差异有统计学意义(t=4.83,P0.01);转移瘤的FADC为(3.65±0.11)×10-3 mm2/s),其对侧脑组织的FADC为(2.27±0.12)×10-3 mm2/s),两者间差异有统计学意义(t=8.36,P0.05);转移瘤的FFADC为441.67×10-3±21.19×10-3,其对侧脑组织的FFADC为276.5×10-3±8.07×10-3,两者间差异有统计学意义(t=7.28,P0.01)。转移瘤的rFADC为5.57±31.66,rCBV为2.79±1.27,Person相关性分析显示rFADC与rBV呈弱相关(r=0.274,P0.05),而rFFADC、rSADC与rCBF、rCBV无明显相关性。FADC、FFADC、SADC、CBF、CBV的ROC曲线分析显示,AUCFADC=0.924(P=0.025);AUCFFADC=0.860(P=0.034);AUCSADC=0.896(P=0.030);AUCCBF=0.849(P=0.035);AUCCBV=0.865(P=0.034)。FADC的ROC曲线的AUC最大,诊断准确性更高。结论 IVIM的参数测量能反映转移瘤的灌注特性,但是由于与PWI的技术原理不同,灌注的测量指标之间只具有弱相关性。

A study of IVIM and PWI of brain metastases at 3.0T MR

Objective Preliminary study IVIM-MRI to evaluate the perfusion of brain metastases,and indicate the relevance evaluation with PWI.Methods Twenty-seven patients with metastatic encephaloma from different types of cancer confirmed by surgery between 2012-6 and 2012-12 underwent MRI enhanced inspections.Primary tumor of lung adenocarcinoma in 18 cases,squamous cell carcinoma of the lung in 2 cases,breast cancer in 2 cases,non-small cell lung carcinoma in 1 case,renal cell carcinoma in 1 case,colon cancer in 1 case,small cell lung cancer in 1 case.Obtain IVIM and PWI images.60 intracranial and 60 contralateral metastatic lesions were selected,and determined the slow ADC Bi （SADCBi）,Fast ADC Bi （FADCBi）,Fraction of Fast ADC mono （FFADC）,Fast ADC mono （FADC） and blood flow and blood volume in PWI respectively using the multi ADC Analysis Algorithms and BrainStat GVF coming with the MRI machine.Got the r value,and r =（parenchyma lesions value/ the contralateral normal value）× 100％.The IVIM and PWI values were compared by pearson correlation analysis.P ＜0.05 was considered to indicate a statistically significant difference.Results The SADC value of the brain metastasis tumors is （0.437±0.023） × 10-3 mm2/s） and the FFADC value of the contralateral brain tissue is 0.223 × 10-3 ± 0.010 × 10 3.There is statistically significant difference between them （t =4.83,P ＜0.01）.The FADC value of brain metastasis tumors is （2.27±0.12） × 10-3 mm2/s）and the contralateral is （2.27±0.12） × 10-3 mm2/s）.There is statistically significant difference between them （t =8.36,P ＜0.05）.The FFADC value of the brain metastasis tumors is 441.67 × 10-3 ±21.19 × 10-3 and the FFADC value of the contralateral brain tissue is 276.5 × 10-3 ± 8.07 × 10-3.There is statistically significant difference between them （t =7.28,P ＜0.01）.The rFastADCmono（rFADC）value of the brain metastasis tumors is 5.57±31.66 and the bloodvolume value is 2.79±1.27.The rFADC and rCBV values have weak correlation （r =0.274,P ＜0.05,but the rFFADC,rSADC,rCBF and rCBV values have no significant correlation.The FADC,FFADC,SADC,CBF,CBV ROC curve analysis showed that AUCFADC=0.924 （P =0.025）,AUCFFADC=0.860 （P =0.034）,AUCSADC=0.896 （P =0.030）,AUCCBF=0.849（P =0.035）and AUCCBV=0.865（P =0.034）.Conclusion IVIM parameter measurement can reflect the perfusion characteristics of metastatic tumor.But due to the different from PWI technology principle,it only has a weak correlation between perfusion measurement indicators.