Levin J M, Kaufman M J, Ross M H, Mendelson J H, Maas L C, Cohen B M, Renshaw P F
Brain Imaging Center, McLean Hospital, Belmont, MA 02178, USA.
Magn Reson Med. 1995 Nov;34(5):655-63. doi: 10.1002/mrm.1910340503.
The stability and reproducibility of the dynamic susceptibility contrast (DSC) MRI method for sequential relative cerebral blood volume (relCBV) measurements was evaluated to validate the method for use in quantitative studies of cerebral hemodynamics in humans. A spin echo echo planar imaging protocol was used in conjunction with multiple bolus injections of the susceptibility contrast agent gadoteridol (GD). The effects of variation in interbolus interval (10 min to 4 h), the number of injections (two to four), and the effect of the cerebral vasodilating agent acetazolamide (ACZ) were evaluated in 44 experiments performed with 22 normal subjects. Two fundamental observations were made. First, with multiple injections of GD, the change in MR signal over time was not consistent from first to subsequent boluses. A second bolus administered 10 min to 2 h after an initial bolus resulted in signal change of greater amplitude and duration, resulting in artifactually elevated estimates of relCBV, consistent with a residual effect of GD. Second, a relative steady state could be reached with serial injections of GD, such that the profile of subsequent boluses closely paralleled those of previous ones. This facilitates the reliable measurement of relCBV during activation, as demonstrated by use of ACZ.
为验证动态磁敏感对比（DSC）MRI方法在人体脑血流动力学定量研究中的应用，对该方法进行连续相对脑血容量（relCBV）测量时的稳定性和可重复性进行了评估。采用自旋回波平面回波成像协议，并结合多次团注磁敏感对比剂钆特醇（GD）。在对22名正常受试者进行的44项实验中，评估了团注间隔（10分钟至4小时）变化、注射次数（2至4次）以及脑血管扩张剂乙酰唑胺（ACZ）的影响。得出了两个基本观察结果。首先，多次注射GD时，从第一次到后续团注，随时间的MR信号变化不一致。在初始团注后10分钟至2小时给予第二次团注，会导致信号变化的幅度和持续时间更大，从而导致relCBV估计值出现人为升高，这与GD的残留效应一致。其次，连续注射GD可达到相对稳定状态，使得后续团注的曲线与先前团注的曲线密切平行。如使用ACZ所示，这有助于在激活过程中可靠地测量relCBV。
