The optimal velocity encoding of phase-contrast magnetic resonance angiography （PC MRA） in measuring cerebral blood flow volume （BFV） ranges from 60 to 80 cm/s. To verify the accuracy of two-dimensional （2D） PC ...The optimal velocity encoding of phase-contrast magnetic resonance angiography （PC MRA） in measuring cerebral blood flow volume （BFV） ranges from 60 to 80 cm/s. To verify the accuracy of two-dimensional （2D） PC MRA, the present study localized the region of interest at blood vessels of the neck using PC MRA based on three-dimensional time-of-flight sequences, and the velocity encoding was set to 80 cm/s. Results of the measurements showed that the error rate was 7.0±6.0% in the estimation of BFV in the internal carotid artery, the external carotid artery and the ipsilateral common carotid artery. There was no significant difference, and a significant correlation in BFV between internal carotid artery ＋ external carotid artery and ipsilateral common carotid artery. In addition, the BFV of the common carotid artery was correlated with that of the ipsilateral internal carotid artery. The main error was attributed to the external carotid artery and its branches. Therefore, after selecting the appropriate scanning parameters and protocols, 2D PC MRA is more accurate in the determination of BFV in the carotid arteries.展开更多
目的通过对比观察不同角度的楔形导声垫在颈动脉超声检查中获得的参数,探讨楔形导声垫在血管超声检查中的应用价值。方法对50例颈动脉超声检查结果阴性的成人患者右侧颈总动脉进行超声检查,在无导声垫及使用18°、25°、32°...目的通过对比观察不同角度的楔形导声垫在颈动脉超声检查中获得的参数,探讨楔形导声垫在血管超声检查中的应用价值。方法对50例颈动脉超声检查结果阴性的成人患者右侧颈总动脉进行超声检查,在无导声垫及使用18°、25°、32°楔形导声垫四种条件下测量颈总动脉收缩期峰值流速(Peak systolic velocity,PSV,cm/s)及多普勒角度。结果无导声垫及使用18°、25°、32°楔形导声垫,测得的颈总动脉PSV分别为(90.10±8.21)cm/s、(84.42±7.91)cm/s、(78.30±7.88)cm/s、(72.25±7.62)cm/s,差异均有统计学意义,P值均<0.01,变异系数(Coefficient of Variation,CV)分别为0.091、0.094、0.100、0.101;多普勒角度校正分别为(59.78±0.51)°、(54.92±1.51)°、(50.78±2.48)°、(46.22±2.82)°,差异均有统计学意义,P值均<0.01,CV分别为0.008、0.027、0.049、0.061。结论增加楔形导声垫角度可明显降低颈动脉血流速PSV及多普勒角度,潜在提高了超声评估颈动脉血流速度的准确性,对PSV的变异系数影响不明显。展开更多
基金the Medical Program of Scientific & Technical Foundation in Xiamen in 2008, No. 3502Z20084028
文摘The optimal velocity encoding of phase-contrast magnetic resonance angiography （PC MRA） in measuring cerebral blood flow volume （BFV） ranges from 60 to 80 cm/s. To verify the accuracy of two-dimensional （2D） PC MRA, the present study localized the region of interest at blood vessels of the neck using PC MRA based on three-dimensional time-of-flight sequences, and the velocity encoding was set to 80 cm/s. Results of the measurements showed that the error rate was 7.0±6.0% in the estimation of BFV in the internal carotid artery, the external carotid artery and the ipsilateral common carotid artery. There was no significant difference, and a significant correlation in BFV between internal carotid artery ＋ external carotid artery and ipsilateral common carotid artery. In addition, the BFV of the common carotid artery was correlated with that of the ipsilateral internal carotid artery. The main error was attributed to the external carotid artery and its branches. Therefore, after selecting the appropriate scanning parameters and protocols, 2D PC MRA is more accurate in the determination of BFV in the carotid arteries.
文摘目的通过对比观察不同角度的楔形导声垫在颈动脉超声检查中获得的参数,探讨楔形导声垫在血管超声检查中的应用价值。方法对50例颈动脉超声检查结果阴性的成人患者右侧颈总动脉进行超声检查,在无导声垫及使用18°、25°、32°楔形导声垫四种条件下测量颈总动脉收缩期峰值流速(Peak systolic velocity,PSV,cm/s)及多普勒角度。结果无导声垫及使用18°、25°、32°楔形导声垫,测得的颈总动脉PSV分别为(90.10±8.21)cm/s、(84.42±7.91)cm/s、(78.30±7.88)cm/s、(72.25±7.62)cm/s,差异均有统计学意义,P值均<0.01,变异系数(Coefficient of Variation,CV)分别为0.091、0.094、0.100、0.101;多普勒角度校正分别为(59.78±0.51)°、(54.92±1.51)°、(50.78±2.48)°、(46.22±2.82)°,差异均有统计学意义,P值均<0.01,CV分别为0.008、0.027、0.049、0.061。结论增加楔形导声垫角度可明显降低颈动脉血流速PSV及多普勒角度,潜在提高了超声评估颈动脉血流速度的准确性,对PSV的变异系数影响不明显。
