学龄前儿童三维动脉自旋标记脑血流灌注中的最佳标记后延迟时间

Optimal post label delay time in 3D-arterial spin labeling cerebral perfusion in preschool children

目的探讨标记后延迟时间(PLD)对于学龄前儿童3D-动脉自旋标记(ASL)脑血流灌注图像的影响。方法收集常规MRI表现正常的250例学龄前儿童患者,根据年龄分为<1个月、1~6个月、>6~12个月、>1~3岁、>3~6岁组,每组50例,行3D-ASL脑灌注MR扫描,PLD分别设置为1 025ms、1 525ms和2 025ms,分析比较3D-ASL灌注图像的主观质量评价、SNR和脑血流量(CBF),其中甲级图像为SNR高、无伪影、脑沟无信号。结果 <1个月组和1~6个月组中,PLD值为1 025 ms时,图像以甲级为主,分别有43例和46例,脑CBF和SNR均高于PLD值为1 525 ms和2 025ms的图像。>6～12个月组、>1～3岁组和>3～6岁组中,PLD值为1 525ms时,图像以甲级为主,分别有43、45和43例,脑CBF值和SNR均高于PLD值为1 025ms和2 025ms图像。结论不同年龄段学龄前儿童3D-ASL脑血流灌注的最佳PLD值不同,≤6个月婴幼儿的最佳PLD值为1 025ms,对>6个月～6岁儿童PLD值宜选用1 525ms。

Objective To explore the impact of post label delay（PLD）time on 3 D-arterial spin labeling（ASL）cerebral perfusion imaging in preschool children.Methods Totally 250 preschool children with normal MRI demonstration were enrolled and evenly divided into〈1 month,1—6 months,〉6—12 months,〉1—3 years,〉3—6 years groups according to the age.All children underwent 3 D-ASL imaging with PLD time of 1 025 ms,1 525 ms and 2 025 ms.The image quality,SNR and cerebral blood flow（CBF）were compared and analyzed.Images with high SNR,no artifacts and no signal of brain fissure were regarded as class A.Results In 〈1 month and 1—6 months groups,when PLD time was1 025 ms,most images（43 and 46 patients,respectively）were class A,and CBF and SNR were higher than those in images with PLD of 1 525 ms and 2 025 ms.In〉6—12 months,〉1—3 years and〉3—6 years groups,when PLD value was 1 525 ms,most images（43,45,43 patients,respectively）were class A,and CBF and SNR were higher than those in images with PLD of 1 025 ms and 2 025 ms.Conclusion Different PLD time of 3 D-ASL cerebral perfusion imaging is necessary for different aged preschool children.For≤6 months children,the best PLD time may be 1 025 ms,while for〉6 months—6 years old children,the best PLD time may be 1 525 ms.