【摘要】 目的探讨大范围主动脉夹层(AD)3.0 T两段式双期3D CEMRA的扫描技术特点与诊断意义。材料与方法 14例大范围AD患者行循环时间(TT)测试和3D FLASH-turbo MRA序列3D CEMRA连续2期扫描。比较真、假腔在TT、峰值信号(SPE)和3D CEMRA信号方面的差异;观测AD双腔的双期显影、内膜破口及腹主动脉分支与双腔的关系,结果与主动脉DSA对照。结果 AD真、假腔TT分别为(13.4±4.8)s、(17.5±4.7)s(P<0.01);峰值信号分别为108.7±28.4、83.5±39.3(P<0.05)。真、假腔双期3D CEMRA信号分别为第一期:391.4±83.7、142.9±77.2(P<0.01);第二期:225.0±66.1、231.6±80.0(P>0.50)。双期3D CEMRA上AD双腔呈特征性动态显现:第一期,真腔全程显影,假腔节段性显影;第二期,真腔信号减退,假腔全程显影。检出内膜破口23个,数量、位置与DSA一致;8个呈血流喷射征。5条左肾动脉、3条右肾动脉和1条腹腔动脉干开口于假腔。结论基于AD双腔血流动力学差异的TT测试和双期扫描,是大范围AD 3.0 T两段式双期3D CEMRA的技术要点,该方法可满足大范围AD的诊断要求。更多还原

【Abstract】 Objective: To evaluate the operating feature and diagnostic usefulness of two-stop double-phase 3D CEMRA of long-range aortic dissection(AD) on 3.0 T. Materials and Methods: The transit time(TT) test and 3D FLASH-turbo MRA-sequence 3D CEMRA of 2 consecutive phases were prospectively performed in 14 patients with long-range AD. The differences between true and false lumens were compared in the aspects of TT, signal intensity of peak enhancement(SPE), and intensities on 3D CEMRA. MIP and MPR images of double-phase 3D CEMRA were employed to observe the dynamic visualization of true and false lumens, and to assess intimal entrance tear and relationship between abdominal aortic branch and lumens of AD. The findings in double-phase 3D CEMRA were correlated with those found in DSA. Results: The TT of true and false lumens was(13.4±4.8) s,(17.5±4.7) s, respectively, differing significantly(P<0.01). The SPE of true and false lumens was 108.7±28.4, 83.5±39.3, respectively, which differed significantly(P<0.05). The intensity of true and false lumens on double-phase 3D CEMRA was 391.4±83.7, 142.9±77.2, respectively, and different significantly(P<0.01) in 1st phase; 225.0±66.1, 231.6±80.0, respectively, with no difference(P>0.50) in 2nd phase. Dynamic visualization of true and false lumens of AD was displayed on double-phase 3D CEMRA: the whole-length visualization was noted in true lumen while segmented visualization in false lumen in 1st phase, signal subsidence was revealed on true lumen and whole-length visualization on false lumen in 2nd phase. Twenty-three intimal entrance tears were detected in double-phase 3D CEMRA 14 of which located closely distal to orifice of left subclavian artery, 5 at supra-phrenic descending aorta, and 4 at abdominal aorta. Jet sign was demonstrated in 8 tears. The number and location of tears detected on double-phase 3D CEMRA coincided completely with those on aortic DSA. Five left renal arteries, 3 right renal arteries and 1 celiac trunk were noted originating from false lumen. Conclusions: Two-stop double-phase 3D CEMRA could be used in diagnosing long-range AD on 3T, and the technical essentials of which comprise TT test and double-phase scan based on hemodynamic difference between both lumens of AD.更多还原