IN-VIVO VALIDATION OF MAGNETIC-RESONANCE BLOOD-VOLUME FLOW MEASUREMENTS WITH LIMITED SPATIAL-RESOLUTION IN SMALL VESSELS
IN-VIVO VALIDATION OF MAGNETIC-RESONANCE BLOOD-VOLUME FLOW MEASUREMENTS WITH LIMITED SPATIAL-RESOLUTION IN SMALL VESSELS
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DOI：
10.1002/mrm.1910330606
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发表时间：
1995-06-01
影响因子：
3.3
通讯作者：
WESTERHOF, N
中科院分区：
文献类型：
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作者：
HOFMAN, MBM;VISSER, FC;WESTERHOF, N
由于血管边界处的部分容积效应，预计小血管中磁共振相位对比容积流量测量的准确度小于大血管中的准确度。使用超声渡越时间流量计（TT）在犬股动脉（直径3.5 +/- 0.7 mm）中验证了准确度。每个血管直径的像素数（N-D）范围为1.6至4.8。使用幅度图像中的阈值确定血管横截面。两种方法之间的相关系数为0.95（范围10-200 ml/min），比例差（PD）（Q（TT）- Q（MR））/1/2（Q（TT）+ Q（MR））为0.8%，表明两种方法之间无系统差异。PD标准偏差为27%，流速高于30 ml/min时为19%，仅在最高N-D值处发现PD方差的显著减小，这表明除了部分容积效应之外还有其他误差来源。得出的结论是，在N-D值约为3的情况下，可以确定准确的血液容积流速。
The accuracy of magnetic resonance phase contrast volume flow measurements in small blood vessels is expected to be smaller than in large vessels, because of partial volume effects at the vessel boundary, Accuracy was validated in the dog femoral artery, diameter 3.5 +/- 0.7 mm, using an ultrasonic transit-time flowmeter (TT). The number of pixels per vessel diameter (N-D) ranged from 1,6 to 4.8, The vessel cross-section was determined using a threshold in the magnitude image. Between the two methods the correlation coefficient was 0.95 (range 10-200 ml/min), The proportional difference (PD), (Q(TT) - Q(MR))/1/2(Q(TT) + Q(MR)), was 0.8%, showing no systematic difference between the methods, The PDs standard deviation was 27%, and 19% for flow rates above 30 ml/min, Only a significant decrease of the PDs variance was found at the highest N-D values, suggesting other sources of error than partial volume effects, It is concluded that with an N-D value of about 3, accurate blood Volume flow rates can be determined.