Knutsson Linda, Lindgren Emelie, Ahlgren André, van Osch Matthias J P, Markenroth Bloch Karin, Surova Yulia, Ståhlberg Freddy, van Westen Danielle, Wirestam Ronnie
Department of Medical Radiation Physics, Lund University, Lund, Sweden.
J Magn Reson Imaging. 2015 Apr;41(4):903-8. doi: 10.1002/jmri.24621. Epub 2014 Mar 24.
To evaluate and mutually compare the tail-scaling approach and the prebolus administration concept for reduction of arterial partial volume effects (PVEs), because reproducible absolute quantification of cerebral blood flow (CBF) by dynamic susceptibility contrast magnetic resonance imaging (MRI) is often hampered by PVEs in the arterial input function (AIF) registration.
Twenty healthy volunteers were scanned in a test-retest study with 7-20 days between investigations to examine the quantitative values and the repeatability of CBF estimates obtained from the tail-scaling and the prebolus administration approaches.
Average grey matter CBF was 80 ± 18 mL/100 g/min (mean ± SD) using tail-scaling and 56 ± 18 mL/100 g/min using prebolus administration. The intraclass correlation coefficient was 0.52 for the tail-scaling approach and 0.86 for the prebolus administration concept.
Both correction methods resulted in considerably reduced arterial PVEs, leading to quantitative estimates of perfusion approaching those typically obtained by other perfusion modalities. The CBF estimates obtained using the prebolus administration concept showed superior repeatability. Potential sources of uncertainty in the tail-scaling approach include the use of venous concentration curves influenced by PVEs or by geometric distortions (ie, vessel pixel shifts) in the steady-state period.
评估并相互比较尾端缩放法和预团注给药概念在减少动脉部分容积效应(PVE)方面的效果,因为在动脉输入函数(AIF)配准过程中,PVE常常会干扰通过动态磁敏感对比磁共振成像(MRI)对脑血流量(CBF)进行可重复的绝对定量分析。
对20名健康志愿者进行重测研究,两次检查间隔7至20天,以检验从尾端缩放法和预团注给药法获得的CBF估计值的定量数值及可重复性。
采用尾端缩放法时,平均灰质CBF为80±18 mL/100 g/min(均值±标准差);采用预团注给药法时,平均灰质CBF为56±18 mL/100 g/min。尾端缩放法的组内相关系数为0.52,预团注给药概念的组内相关系数为0.86。
两种校正方法均能显著减少动脉PVE,使灌注的定量估计值接近其他灌注方式通常获得的数值。采用预团注给药概念获得的CBF估计值显示出更好的可重复性。尾端缩放法中潜在的不确定来源包括使用受PVE影响或稳态期几何失真(即血管像素移位)影响的静脉浓度曲线。