Turbo 梯度回波 QUICXOTIC（Turbo QUIXOTIC）的功能性氧摄取分数（OEF）成像。

Functional oxygen extraction fraction (OEF) imaging with turbo gradient spin echo QUIXOTIC (Turbo QUIXOTIC).

机构信息

Harvard-MIT Health Sciences and Technology, Institute of Medical Engineering & Science, MIT, Cambridge, Massachusetts, USA.

Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.

出版信息

Magn Reson Med. 2018 May;79(5):2713-2723. doi: 10.1002/mrm.26947. Epub 2017 Oct 5.

PURPOSE

QUantitative Imaging of eXtraction of Oxygen and TIssue Consumption (QUIXOTIC) is a recent technique that measures voxel-wise oxygen extraction fraction (OEF) but suffers from long scan times, limiting its application. We implemented multiecho QUIXOTIC dubbed turbo QUIXOTIC (tQUIXOTIC) that reduces scan time eightfold and then applied it in functional MRI.

METHODS

tQUIXOTIC utilizes a novel turbo gradient spin echo readout enabling measurement of venular blood transverse relaxation rate in a single tag-control acquisition. Using tQUIXOTIC, we estimated cortical gray matter (GM) OEF, created voxel-by-voxel GM OEF maps, and quantified changes in visual cortex OEF during a blocked design flashing checkerboard visual stimulus. Contamination from cerebrospinal fluid partial volume averaging was estimated and corrected.

RESULTS

The average cortical GM OEF was estimated as 0.38 ± 0.06 (n = 8) using a 3.4-min acquisition. The average OEF in the visual cortex was estimated as 0.43 ± 0.04 at baseline and 0.35 ± 0.05 during activation, with an average %ΔOEF of -20%. These values are consistent with those of past studies.

CONCLUSION

tQUIXOTIC successfully estimated cortical GM OEF in clinical scan times and detected changes in OEF during blocked design visual stimulation. tQUIXOTIC will be useful to monitor regional OEF clinically and in blocked design or event-related functional MRI experiments. Magn Reson Med 79:2713-2723, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

目的

QUantitative Imaging of eXtraction of Oxygen and TIssue Consumption（QUIXOTIC）是一种最近的技术，可测量体素水平的氧提取分数（OEF），但扫描时间较长，限制了其应用。我们实现了多回波 QUICXOTIC，称为涡轮 QUICXOTIC（tQUIXOTIC），可将扫描时间缩短八倍，然后将其应用于功能磁共振成像。

方法

tQUIXOTIC 利用一种新颖的涡轮梯度回波读出技术，能够在单个标记-对照采集中测量静脉血横向弛豫率。使用 tQUIXOTIC，我们估计了皮质灰质（GM）的 OEF，创建了体素级 GM 的 OEF 图，并量化了在块设计闪烁棋盘视觉刺激期间视觉皮层 OEF 的变化。估计并校正了脑脊液部分容积平均的污染。