3.0T MRI快速电影相位对比序列测量非搏动稳态流体模型流速  

Measurement of the velocity of steady fluid flow phantom by using 3.0 T MRI fast cine PC sequence

作　　者：李晖[1] 王志强[1] 张惠英[1] 张伟[1] 尚华[2] 闫乐卡[2] 刘怀军[2] 

机构地区：[1]河北联合大学附属医院MR室,河北唐山063000 [2]河北医科大学第二医院医学影像科,河北石家庄050000

出　　处：《生物医学工程与临床》2014年第3期225-229,共5页Biomedical Engineering and Clinical Medicine

摘　　要：目的通过建立稳态流体模型,验证3.0 T MRI快速电影相位对比(fast cine PC)序列进行血流动力学测量的准确性。方法将直径为3.0mm的医用塑料管固定在水模中,塑料管的一端连接高压注射器,高压注射器以不同流速(0.5、1.0、1.5、2.0、2.5、3.0、3.5、4.0 mL/s)向管腔内注射0.9%氯化钠溶液,管的另一端连入量筒。将流体模型中心置于头部8通道线圈中心,平行放置的医用塑料管与磁体长轴一致。应用3.0TMRI扫描仪进行fastcine PC序列扫描,扫描层面垂直于所测管腔长轴。在不同流速、不同观测者(2名)、不同流动方向(相向和相反)、不同倾斜角度(0°、20°、30°、45°)对流速进行测量。对图像进行后处理。测定感兴趣区流速,进行统计学分析。结果实际流动方向与流速编码方向相同时测得的流速值分别为6.75、13.90、21.14、28.69、36.52、42.48、50.49、57.10 cm/s;实际流动方向与流速编码方向相反时测得的流速值分别为8.09、14.76、22.53、29.79、36.61、44.75、51.08、54.94 cm/s。管腔内实际流速为42.46 cm/s时,不同倾斜角度测得的流速值分别为42.48、42.77、42.38、42.94、42.47、42.62、42.59 cm/s。测量速度与实际速度间差异无统计学意义,且呈正相关(r=0.99,P<0.000 1)。2名观察者的测量值之间差异无统计学意义(t=-0.87,P=0.41>0.05)。液体流动方向与流速编码方向相同、相反测得的流速与实际流速两两之间差异无统计学意义(F=3.51,P=0.06>0.05)。不管管腔在各个方向有无角度,测得的流速与实际流速之间差异均无统计学意义(t=2.01,P=0.09>0.05)。结论 3.0 T fast cine PC序列可以准确测量稳态流体模型流速,为人体血流动力学检测的临床应用提供了可靠的实验依据。Objective To verify the accuracy of the hemodynamics measurement by 3.0 T MRI fast cine phase contrast（fast cine PC） sequence by establishing a steady fluid flow phantom. Methods A plastic tube with diameter of 3.0 mm was fixed in a water phantom. One terminal of the tube was connected to the high pressure injector for injecting physiological saline with different velocity, another terminal was inserted into a volumetrical cylinder for recovering saline water. The phantom was placed in the center of an 8-channel array head coil, and the tube was parallelly placed with the major axis of magnet. Fast cine PC sequence was scanned by 3.0 T high field MRI scanner, with scanning plane perpendicular to the major axis of tube. The flow rate was measured by two investigators at different velocity （0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0 mL/s）, different direction of flow （opposite and contrary）, and different angle （0°, 20°, 30°, 45°） in the lumens. After image postprocessing, the velocity of 30 phases during a cardiac cycle was measured and analyzed by statistical test. Results The actual flow directions were identical with the velocity encoding direction, the measured velocity values were 6.75, 13.90, 21.14, 28.69, 36.52, 42.48, 50.49, 57.10 cm/s; The actual flow direction was opposite with the velocity encoding direction, the measured velocity values were 8.09, 14.76, 22.53, 29.79, 36.61, 44.75, 51.08, 54.94 cm/s. There was no difference between the measured velocity （42.48, 42.77, 42.38, 42.94, 42.47, 42.62, 42.59 cm/s） and actual velocity （42.46 cm/s）, and the measured velocity was positively correlated with the actual velocity（correlation coefficient = 0.99, P〈 0.000 1）. There was no difference between the measured velocity and the actual velocity no matter whether the flow direction of liquid was identical or opposite （F = 3.51, P = 0.06 〉 0.05 ）. There was no difference between the measured velocity and the actual velocity no matter at what angle the tube was different （t =

关 键 词：磁共振成像(MRI) 相位对比序列 电影 非搏动稳态流体模型 

分 类 号：R445.2[医药卫生—影像医学与核医学] R55[医药卫生—诊断学]