Vonken E J, van Osch M J, Bakker C J, Viergever M A
Department of Radiology, Image Sciences Institute, University Hospital Utrecht, 3584 CX Utrecht, The Netherlands.
J Magn Reson Imaging. 1999 Aug;10(2):109-17. doi: 10.1002/(sici)1522-2586(199908)10:2<109::aid-jmri1>3.0.co;2-#.
Quantitative cerebral perfusion was measured in vivo using dynamic susceptibility contrast magnetic resonance imaging. A dual-echo acquisition was used to eliminate T(1)-enhancement. The arterial input curve was measured in a separate slice in the neck to minimize partial volume effects. Data analysis was performed using a maximum likelihood expectation maximization method to be less sensitive to noise or contrast arrival time differences. From the contrast response curves obtained, the cerebral blood volume (CBV) and flow (CBF) and the timing parameters mean transit time (MTT), time of appearance (TA), and time-to-bolus peak (TBP) were obtained. Adjacent slices were measured to permit discrimination between intra- and inter-subject variance. The group investigated consisted of 41 subjects without cerebral pathology on anatomical MRI. Perfusion parameters for gray (GM) and white matter (WM) were obtained: CBV (GM) = 6.78 +/- 0.99 ml/100 ml, CBV (WM) = 3.78 +/- 0. 96 ml/100 ml, CBF (GM) = 68.7 +/- 21.2 ml/100 ml/min, CBF (WM) = 35. 8 +/- 12.7 ml/100 ml/min, and average GM/WM ratio for CBV (GM/WM) = 1.87 +/- 0.42 and CBF (GM/WM) = 1.99 +/- 0.48. Measured temporal aspects of perfusion were: mean transit time (MTT) (GM) = 6.4 +/- 1. 8 seconds, MTT (WM) = 6.9 +/- 2.3 seconds, time of appearance (TA) (GM) = 1.4 +/- 0.9 seconds, TA (WM) = 2.0 +/- 1.0 seconds, and time-to-bolus peak (TBP) (GM) = 2.4 +/- 1.4 seconds, TBP (WM) = 3.0 +/- 1.5 seconds. The average values were in agreement with those from the literature. Inter- and intra-person variances were estimated using an ANOVA test, and the sources of variance in the parameters, such as image noise, biological variability, and measurement errors of the arterial input curve were found to be of the same order of magnitude. J. Magn. Reson. Imaging 1999;10:109-117.
采用动态磁敏感对比磁共振成像技术在体测量脑血流量。使用双回波采集以消除T(1)增强效应。在颈部单独的层面测量动脉输入曲线，以尽量减少部分容积效应。采用最大似然期望最大化方法进行数据分析，以降低对噪声或对比剂到达时间差异的敏感性。根据获得的对比剂响应曲线，得出脑血容量（CBV）、脑血流量（CBF）以及时间参数平均通过时间（MTT）、出现时间（TA）和团注峰值时间（TBP）。测量相邻层面以区分受试者内和受试者间的差异。研究组由41名在解剖学磁共振成像上无脑部病变的受试者组成。获得了灰质（GM）和白质（WM）的灌注参数：CBV（GM）=6.78±0.99 ml/100 ml，CBV（WM）=3.78±0.96 ml/100 ml，CBF（GM）=68.7±21.2 ml/100 ml/min，CBF（WM）=35.8±12.7 ml/100 ml/min，以及CBV的平均GM/WM比值（GM/WM）=1.87±0.42和CBF的平均GM/WM比值（GM/WM）=1.99±0.48。测量的灌注时间参数为：平均通过时间（MTT）（GM）=6.4±1.8秒，MTT（WM）=6.9±2.3秒，出现时间（TA）（GM）=1.4±0.9秒，TA（WM）=2.0±1.0秒，以及团注峰值时间（TBP）（GM）=2.4±1.4秒，TBP（WM）=3.0±1.5秒。这些平均值与文献报道的值一致。使用方差分析测试估计受试者间和受试者内的差异，发现参数中的差异来源，如图像噪声、生物变异性和动脉输入曲线的测量误差，具有相同的数量级。《磁共振成像杂志》1999年；10:109 - 117。
