Wu Ed X, Hui Edward S, Cheung Jerry S
Laboratory of Biomedical Imaging and Signal Processing, University of Hong Kong, Hong Kong.
J Magn Reson Imaging. 2007 Aug;26(2):432-6. doi: 10.1002/jmri.20954.
To alleviate the intrinsic limitation of current time-of-flight magnetic resonance angiography (TOF-MRA) techniques, which are insensitive to in-plane blood flow due to the flow saturation effect.
A multi-oblique-stack acquisition (MOSA) technique was proposed in this study to tackle this TOF problem by acquiring two or more TOF image stacks bearing different orientations. The MOSA approach was evaluated in human brain MR angiograms by integrating it with the widely used multiple overlapping thin-slab acquisition (MOTSA) technique. Two TOF image sets in different orientations were acquired using MOTSA. They were combined pixel-by-pixel by taking the maximum intensity value. Maximum intensity projection (MIP) was then performed, and the resulting MRA quality was assessed.
The results demonstrated that MR angiograms obtained by MOSA-MOTSA were clearly improved compared to those acquired by conventional MOTSA in the same scan time.
MOSA clearly demonstrates its advantage over conventional TOF acquisition in visualizing in-plane blood flows.
缓解当前飞行时间磁共振血管造影（TOF-MRA）技术的固有局限性，该技术由于血流饱和效应而对平面内血流不敏感。
本研究提出了一种多斜堆栈采集（MOSA）技术，通过采集两个或更多具有不同方向的TOF图像堆栈来解决这一TOF问题。通过将MOSA方法与广泛使用的多重重叠薄层采集（MOTSA）技术相结合，在人脑MR血管造影中对其进行了评估。使用MOTSA采集两个不同方向的TOF图像集。通过取最大强度值逐像素地将它们组合起来。然后进行最大强度投影（MIP），并评估所得的MRA质量。
结果表明，在相同扫描时间内，与传统MOTSA采集的图像相比，MOSA-MOTSA获得的MR血管造影明显改善。
在可视化平面内血流方面，MOSA明显显示出优于传统TOF采集的优势。
