兔实验性急性肺栓塞双源双能量CT与3.0T MR肺动脉成像联合肺灌注成像的对照研究

Experimental Acute Pulmonary Embolism in Rabbits:Correlation of Dual energy CT and MR Angiography at 3T

目的评价双源双能量CT与3.0 T MR诊断家兔急性肺栓塞的准确性。材料与方法经股静脉注入明胶海绵栓子制作家兔急性肺动脉栓塞模型,栓塞后2 h行双能量CT及MRI,得到CT肺动脉图像(CTPA)、双能量肺灌注图像(DEPI)及MR肺动脉图像(MRPA)和MR肺灌注图像(MRPP)。以肺叶为单位,记录栓塞的数目和部位。以病理学为金标准,计算上述方法诊断肺栓塞的敏感性、特异性和一致性。结果 CTPA、DEPI检测肺动脉栓塞的敏感性分别为95.8%、95.8%;特异性分别为94.1%、90.2%;MRPA和MRPP的敏感性和特异性分别为83.3%、90.2%;37.5%、98%。CTPA与DEPI对急性肺动脉栓塞检测的吻合度非常好(Kappa值=0.971,P<0.001),DECT(CTPA和DEPI联合)与MRPA对急性肺动脉栓塞检测的吻合度较好(Kappa值=0.796,P<0.001)。对于诊断急性肺动脉栓塞DECT与MRPA的差别无统计学意义(P>0.05);但DEPI诊断肺栓塞的准确性(92%)高于MRPP(78.7%),差别有统计学意义(P<0.001)。结论双源CT诊断家兔实验性急性肺动脉栓塞的敏感性略高于MRPA,但差别无统计学意义;DEPI显示肺栓塞所致的灌注缺损优于MRPP。

Objective To compare the ability of dual energy CT pulmonary angiography imaging（CTPA）,dual energy CT perfusion imaging（DEPI） and MRI（combined MRPA and MR pulmonary perfusion）to detect pulmonary embolism（PE） in rabbit models.Materials and Methods Experimental rabbit models of acute PE were established by injecting four gelatin sponge emboli into femoral vein.Dual energy CT（DECT） and 3T MRI were performed at 2 hours after embolisation.Images of dual energy CTPA,DEPI,and MRPA and MRPP were obtained.The location and number of the emboli in per lobe were recorded.The pathology results were regarded as the reference standards.Sensitivity,specificity and agreement of the above-mentioned methods were calculated.Results The sensitivity and specificity of CTPA and DEPI were 95.8%,95.8% and 94.1%,90.2%,respectively.The sensitivity and specificity of MRI was 83.3% and 90.2%.Excellent inter modality agreement was obtained between CTPA and DEPI（Kappa value=0.971,P0.001）.Good inter modality agreement was obtained between DECT and MRI（Kappa value=0.796,P0.001）.There was no significant difference between DECT and MRI（P0.05）.DEPI had a higher accuracy（92%） than MRPP（78.7%）（P0.001）.Conclu-sion DECT had a slightly high sensitivity than MRPA with no statistically significance.DEPI had a higher accuracy than MRPP to visualize perfusion defect derived from pulmonary emboli in rabbit model.