闭塞性与非闭塞性肺栓塞双源CT双能量肺灌注成像的初步研究

目的:探讨急性肺栓塞(PE)患者双源CT肺动脉成像(CTPA)显示的闭塞性与非闭塞性栓子在双源CT双能量肺灌注成像(DEPI)的视觉分析法及半定量分析的初步研究.方法:搜集本院2015年6月-2017年1月经CTPA及DEPI扫描确诊的31例急性PE患者的病例资料.分析CTPA,记录PE栓子的数量、分布部位及栓塞类型.分析DEPI,分别计算每个栓子栓塞区与对照区肺组织灌注CT值的差值(△CT值).结果:将CTPA所示栓子按其分布部位及栓塞程度分为四型:中央型闭塞型、中央型非闭塞型、周围型闭塞型、周围型非闭塞型.DEPI视觉分析法:闭塞型组中,表现为灌注减低、灌注轻度减低、灌注不变的比例为78.57％(99/126)、21.43％(27/126)、0.00％(0/126).非闭塞组中,其比例分别为19.70％(26/132)、34.09％(45/132)、46.21％(61/132).中央型闭塞型、中央型非闭塞型、周围型闭塞型、周围型非闭塞型视觉阳性率分别为100.00％(85/85)、66.11％(66/108)、100.00％(41/41)、20.83％(5/24).DEPI半定量分析:闭塞型与非闭塞型间差异具有统计学意义[(64.59±12.10)HUvs (33.12±9.72)HU,t=22.968,P＜0.01];中央型闭塞型与中央型非闭塞型、周围型闭塞型与周围型非闭塞型间差异均具有统计学意义[分别为(70.12±13.55)HU vs(36.23±7.87)HU,t=20.506,P＜0.01;(53.12±14.64)HUvs(19.12±5.77)HU,t=13.220,P＜0.01].结论:闭塞型栓子往往引起灌注异常,而非闭塞型栓予,受多种因素影响,DEPI呈现多样化.双源CTPA联合DEPI视觉分析及半定量分析能够对PE治疗前评估提供更加全面、客观的依据.

Preliminary study on lung perfusion imaging in acute occlusive and non-occlusive pulmonary embolisms

Objective:The purpose of this study was to investigate the visual analysis and semi-quantitative analysis of dual energy CT lung perfusion imaging (DEPI) in acute occlusive and non-occlusive pulmonary embolisms (PE).Methods:Consecutive 31 patients with acute PE diagnosed by CT pulmonary angiography (CTPA) and DEPI were recruited between June 2015 and January 2017.Radiologists visually evaluated the PE numbers,distribution locations (central or peripheral) and its nature (occlusive and non-occlusive) on CTPA.DEPI visual analysis and semi-quantitative analysis in different types of PE evaluated by CTPA were analyzed statistically.Results:Four types of PE (central occlusive PE,central non-occlusive PE,peripheral occlusive PE and peripheral non-occlusive PE) were classified.The visual analysis of DEPI representing perfusion defects,slightly perfusion reduction and perfusion preservation were 78.57％ (99/126),21.43％ (27/126),and 0.00％ (0/126) in the occlusive group,19.70％ (26/132),34.09％ (45/132),and 46.21％ (61/132) in the non-occlusive group,respectively.Comparing with CTPA as a standard reference,the positive rates of DEPI visual analysis were 100.00 ％ (85/85),66.11％ (66/108),100.00％ (41/41),and 20.83％ (5/24) in four groups respectively.In the occlusive group and non-occlusive group,mean difference of CT values,with significant differences [(64.59 ± 12.10)HU vs (33.12 ± 9.72) HU,t=22.968,P＜0.01].In the groups of central occlusive PE and central non-occlusive PE,peripheral occlusive PE and peripheral non-occlusive PE,the mean difference of CT values,also with significant differences [(70.12 ± 13.55)HU vs (36.23±7.87)HU,t=20.506,P＜0.01;(53.12±14.64)HU vs (19.12±5.77)HU,t=13.220,P＜0.01].Conclusion:Occlusive PE often manifest as perfusion defect,while non-occlusive PE varies,influenced by many factors.The combination of CTPA and DEPI can offer more comprehensive information in the PE therapeutic evaluation.