CAJ | 학술논문

准连续性动脉自旋标记技术(pCASL)是一种新兴的动脉自旋标记脑灌注成像技术(ASL)：一方面，它克服了连续性动脉自旋标记技术(CASL)需要独立发射线圈的硬件限制；另一方面，也避免了脉冲式动脉自旋标记技术(PASL)带来的标记效率低的影响．为了在1.5 T磁共振系统上开发一款可稳定应用于临床扫描的pCASL序列；并使用该序列准确获得反应灌注功能的局部脑血流量值(Regional Cerebral Blood Flow，rCBF)．该文利用水模测试pCASL序列，验证了标记部分的标记性能并通过人体实验，优化了协议中标记位置中心到成像层面中心的距离和标记部分结束点到成像脉冲开始前的等待时间这两项参数．基于优化了参数的pCASL协议，扫描12组正常志愿者，观测灌注信号分布情况，并对特定灰质区域定量计算，对比不同个体该区域的rCBF值．通过人体实验，经验性地确定了延迟时间为1200 ms、标记距离为70 mm时灌注图像的信噪比达到最优．将两项优化后的参数存入协议中，并使用协议扫描，共获取12组结果，其中的10组都表明灌注信号稳定均匀，并且灰质区域的CBF值同经验结果一致．该工作在1.5 T的磁共振系统上成功实现了pCASL序列，经优化参数后的协议扫描，可以获得准确稳定的脑部灌注信号．
준련속성동맥자선표기기술(pCASL)시일충신흥적동맥자선표기뇌관주성상기술(ASL)：일방면，타극복료련속성동맥자선표기기술(CASL)수요독립발사선권적경건한제；령일방면，야피면료맥충식동맥자선표기기술(PASL)대래적표기효솔저적영향．위료재1.5 T자공진계통상개발일관가은정응용우림상소묘적pCASL서렬；병사용해서렬준학획득반응관주공능적국부뇌혈류량치(Regional Cerebral Blood Flow，rCBF)．해문이용수모측시pCASL서렬，험증료표기부분적표기성능병통과인체실험，우화료협의중표기위치중심도성상층면중심적거리화표기부분결속점도성상맥충개시전적등대시간저량항삼수．기우우화료삼수적pCASL협의，소묘12조정상지원자，관측관주신호분포정황，병대특정회질구역정량계산，대비불동개체해구역적rCBF치．통과인체실험，경험성지학정료연지시간위1200 ms、표기거리위70 mm시관주도상적신조비체도최우．장량항우화후적삼수존입협의중，병사용협의소묘，공획취12조결과，기중적10조도표명관주신호은정균균，병차회질구역적CBF치동경험결과일치．해공작재1.5 T적자공진계통상성공실현료pCASL서렬，경우화삼수후적협의소묘，가이획득준학은정적뇌부관주신호．
Pseudo-continuous arterial spin labeling (pCASL) is perfusion imaging technique that combines the advantages of continuous arterial spin labeling (CASL) and pulsed arterial spin labeling (PASL). In this study, we implemented a pCASL sequence on uMR560 1.5 T MRI systems developed by United Imaging Healthcare Cooperation. Experiments were performed to demonstrate the stability of the pCASL sequence implemented and the accuracy of perfusion quantification. The tagging efficiency was first measured through phantom experiments. In order to achieve the highest signal-to-noise ratio, post-labeling delay time and labeling distance were optimized empirically to be approximately 70 mm blow the imaging slab and 1 200 ms, respectively. Lastly, perfusion-weighted signal intensity and absolute cerebral blood flow (CBF) were measured from 12 normal volunteers using the pCASL sequence implemented, with satisfactory results obtained from 10 subjects. In summary, the pCASL sequence implemented on the uMR560 1.5 T MRI systems can be used for perfusion imaging on human brain, with reasonable stability and accuracy.