MR三维动脉自旋标记灌注成像与体素内非相干性运动扩散加权成像在骨骼和软组织肿瘤鉴别诊断中的价值

Value of MR three dimensional arterial spin labeling perfusion imaging and intravoxel incoherent motion diffusion weighted imaging in differential diagnosis of musculoskeletal tumors

目的 评价三维动脉自旋标记（3D-ASL）灌注成像与体素内非相干性运动（IVIM）DWI对骨骼及软组织肿瘤进行定量分析和良恶性鉴别诊断的价值.方法 选取44例骨骼或软组织肿瘤患者,根据病理检查结果分为良性组（12例）、交界性组（10例）和恶性组（22例）3组,术前行3D-ASL与IVIM DWI检查,获得定量参数肿瘤血流值（TBF）、标准ADC（ADCstandard）、快速ADC（ADCfast）和慢速ADC（ADCslua）.2名医师独立对上述指标进行测量,利用组内相关系数（ICC）法对观察者间一致性进行判断.运用CD34染色计算肿瘤组织的微血管密度（MVD）.3组间MVD、TBF、ADCfast、ADCslow的比较采用单因素方差分析,3组间ADCstandard的比较采用Kruskal-Wallis检验,并利用ROC曲线对所得参数进行分析,判断最佳诊断阈值及诊断效能.结果 2名医师间测量ADCstandard、ADCslow、ADCfast、TBF的一致性较好（ICC值分别为0.970、0.885、0.778、0.891,P值均＜0.05）.良性组、交界性组和恶性组肿瘤的MVD分别为（10±4）、（15±6）、（33±11）条/高倍视野,3组间MVD差异有统计学意义（F=28.33,P＜0.05）.良性组、交界性组和恶性组肿瘤的TBF值分别为（30±10）、（30±12）、（84±29）ml·min-11·100 g-1,3组间差异有统计学意义（F=32.34,P＜0.05）.TBF=45 ml·min-1·100 g-1时,诊断良恶性肿瘤的ROC曲线下面积最大（0.951）,诊断敏感度为90.9％,特异度为95.5％.良性组、交界性组和恶性组肿瘤的ADCtandard在3组间差异无统计学意义.良性组ADCfast、ADCslow值分别为（9.9±5.1）×10-3、（1.9±0.5）×10-3 mm2/s,交界性组肿瘤ADCfast、ADCslow分别为（8.2±3.6）×10-3、（1.5±0.6）×10-3 mm2/s,恶性组肿瘤ADCfast、ADCslow值分别为（16.9±5.8）× 10-3、（1.4±0.6）× 10-3 mm2/s,3组间ADCfast、ADCslow差异有统计学意义（F值分别为12.75、5.60,P值均＜0.05）.ADCfast=9.4× 10-mm2/s时,诊断良恶性肿瘤的ROC曲线下面积最大（0.861）,诊断敏感度为95.5％,特异度为68.2％.结论 3D-ASL和IVIM DWI对鉴别骨骼及软组织肿瘤的良恶性有重要价值.

Objective To evaluate the value of MR threedimensional arterial spin labeling （3D-ASL） perfusion imaging and intravoxel incoherent motion（IVIM） DWI in differential diagnosis and quantitative analysis of musculoskeletal tumors.Methods Forty-four patients with musculoskeletal tumors were included.According to pathologic results,there were 12 cases of benign tumors,10cases of intermediate tumors and 22 cases of malignant tumors.3D-ASL and IVIM DWI were both performed on forty-four patients to gain tumor blood flow （TBF）,standard ADC （ADCstandard）,slow ADC （ADCslow）and fast ADC （ADCfast）.Immunohistochemical staining of specimens was performed by using CD34 monoclonal antibody to calculate microvessel density （MVD） counts.MVD,TBF,ADCfast and ADCslow of different groups were compared by one-way ANOVA analysis.ADCstandard was compared by Kruskal-Wallis test.ROC curve was used to analyze ASL and IVIM DWI,in order to determine the threshold and diagnostic reliability.Results The MVD of benign tumors was 10±4,the MVD of intermediate tumors was 15±6,and malignant tumors was 33 ± 1 1.There was significant difference among three groups of MVD（F=28.33,P＜0.05）.There was better intra-observer agreement for ADCstandard,ADCfast,ADCslow and TBF（ICC=0.970,0.885,0.778,0.891,respectively,P＜0.05）.The TBF of benign tumors was（30±10）ml· min-1· 100 g-1,intermediate tumors was（30± 12） ml·min 1· 100 g-1,and malignant tumors was（84±29）ml·min 1· 100 g-1.There was significant difference among three groups of TBF（F=32.34,P＜0.05）.According to the ROC analysis,when the cut-offvalue of TBF was 45.5 ml·min-1· 100 g-1,the area under ROC curve was 0.95 1,and the sensitivity and specificity of TBF in diagnosing malignant tumors were 90.9％ and 95.5％ respectively.There was no significant difference among three groups of ADCstandard,ADCfastand ADCslow of benign tumors were（9.9±5.1）× 10-3,（1.9±0.5） × 10-3mm2/s respectively.ADCfast and ADCalow of intermediate tumors were（8.2 ± 3.6） × 10-3,（1.5 ± 0.6） × 10-3mm2/s respectively.ADCfast and ADCalow of malignant tumors were （16.9 ± 5.8） × 10 3,（1.4 ± 0.6） × 10-3mm2/s respectively.There were significant difference of ADCfast and ADCslow among three groups （F=12.75,5.60,P＜ 0.05）.According to the ROC analysis,when the cut-off value of ADCfast was 9.4× 10-3mm2/s,the area under ROC curve was 0.861,the sensitivity and specificity of them in diagnosing malignant tumors were 95.5％ and 68.2％ respectively.Conclusion 3D-ASL and IVIM DWI are valuable in the differential diagnosis of musculoskeletal tumors.