Kim Y W, Kim H J, Cho B M, Moon T Y, Eun C K
Department of Radiology, Pusan Paik Hospital, College of Medicine, Inje University, Pusan, Korea.
AJNR Am J Neuroradiol. 2006 Feb;27(2):398-401.
The purpose of this study was to evaluate the cerebral hemodynamic change in the hyperacute stage of cerebral fat embolism induced by triolein emulsion, by using MR perfusion imaging in cat brains.
By using the femoral arterial approach, the internal carotid arteries of 14 cats were infused with an emulsion of triolein 0.05 mL. T2-weighted (T2WI), diffusion-weighted (DWI), apparent diffusion coefficient (ADC) map, perfusion-weighted (PWI), and gadolinium-enhanced T1-weighted (Gd-T1WI) images were obtained serially at 30 minutes and 2, 4, and 6 hours after infusion. The MR images were evaluated qualitatively and quantitatively. Qualitative evaluation was performed by assessing the signal intensity of the serial MR images. Quantitative assessment was performed by comparing the signal-intensity ratio (SIR) of the lesions to the contralateral normal side calculated on T2WIs, Gd-T1WIs, DWIs, and ADC maps at each acquisition time and by comparing the relative cerebral blood volume (rCBV), cerebral blood flow (CBF), and mean transit times (MTT) of the lesions to the contralateral normal side calculated on PWI.
In the qualitative evaluation of the MR images, the lesions showed hyperintensity on T2WIs, enhancement on the Gd-T1WIs, and isointensity on DWIs and the ADC maps. In the quantitative studies, SIRs on the Gd-T1WIs, DWIs, and ADC maps peaked at 2 hours after infusion. The SIRs on the T2WIs peaked at 4 hours after infusion and decreased thereafter. On PWIs, the rCBV, rCBF, and MTT of the lesion showed no significant difference from the contralateral normal side (P = .09, .30, and .13, respectively) and showed no significant change of time course (P = .17, .31, and .66, respectively).
The embolized lesions induced by triolein emulsion showed no significant difference in cerebral hemodynamic parameters from those on the contralateral normal side. The result may suggest that consideration of the hemodynamic factor of embolized lesions is not necessary in further studies of the blood-brain barrier with triolein emulsion.
本研究的目的是通过对猫脑进行磁共振灌注成像，评估三油酸甘油酯乳剂诱导的脑脂肪栓塞超急性期的脑血流动力学变化。
采用股动脉途径，向14只猫的颈内动脉注入0.05 mL三油酸甘油酯乳剂。在注入后30分钟以及2、4和6小时连续获取T2加权（T2WI）、扩散加权（DWI）、表观扩散系数（ADC）图、灌注加权（PWI）和钆增强T1加权（Gd-T1WI）图像。对磁共振图像进行定性和定量评估。定性评估通过评估系列磁共振图像的信号强度进行。定量评估通过比较在每个采集时间点T2WI、Gd-T1WI、DWI和ADC图上病变与对侧正常侧的信号强度比（SIR），以及通过比较在PWI上病变与对侧正常侧的相对脑血容量（rCBV）、脑血流量（CBF）和平均通过时间（MTT）来进行。
在磁共振图像的定性评估中，病变在T2WI上呈高信号，在Gd-T1WI上有强化，在DWI和ADC图上呈等信号。在定量研究中，Gd-T1WI、DWI和ADC图上的SIR在注入后2小时达到峰值。T2WI上的SIR在注入后4小时达到峰值，此后下降。在PWI上，病变的rCBV、rCBF和MTT与对侧正常侧无显著差异（分别为P = 0.09、0.30和0.13），且时间进程无显著变化（分别为P = 0.17、0.31和0.66）。
三油酸甘油酯乳剂诱导的栓塞病变在脑血流动力学参数方面与对侧正常侧无显著差异。该结果可能表明，在使用三油酸甘油酯乳剂进一步研究血脑屏障时，无需考虑栓塞病变的血流动力学因素。
