Kohei Yuda1, Takashige Yoshida1, Yuki Furukawa1, Masami Yoneyama2, Seishi Takoi1, and Nobuo Kawauchi3
1Radiology, Tokyo Metropolitan Police Hospital, Tokyo, Japan, 2MR Clinical Scientist, Philips Electronics Japan,Ltd, Tokyo, Japan, 3Radiology of division, Tokyo Metropolitan Police Hospital, Tokyo, Japan
Synopsis
Black blood imaging (BBI) for atherosclerotic plaque
compartment usually have evaluated by pre-pulse sequence such as dual inversion
recovery(DIR) turbo spin echo (TSE) with cardiac synchronization.
This study aimed to evaluate the scan time
reduction sequence of zoomed imaging quadruple inversion recovery using VISTA (zQIR-VISTA) in black blood MR imaging
of cerebral artery and compare with a conventional VISTA.Background and purpose
Black blood imaging (BBI) for atherosclerotic
plaque compartment usually have evaluated by pre-pulse sequence such as dual
inversion recovery(DIR) turbo spin echo (TSE) with cardiac synchronization. It
is limitation to need to long scan time and the image coverage. In recently 3D
imaging using volume isotropic TSE acquisition (VISTA) is possible to obtain wide
coverage BBI without cardiac synchronization. (1) However VISTA is spend long scan time, it
cause to decrease image quality by motion such as swallowing and respiratory. Therefore,
scan time reduction is necessary to improve image quality for BBI using VISTA.
The zoomed imaging quadruple inversion
recovery (zQIR) method reducible scan time by twice DIRs pre-pulse using
selective excitation. (2)(3)
This study aimed to evaluate the scan time
reduction sequence of zQIR using VISTA (zQIR-VISTA) in black blood MR imaging
of cerebral artery and compare with a conventional VISTA.
Method
Using our institutional review board-approved procedures,
15 volunteers were imaged using a 3.0T Philips MR system and 8channel - head
coil. VISTA and zQIR-VISTA sequences were the following parameters : TR/TE (ms)
= 575/12, matrix scan=256×192, TSE factor = 12 , refocusing angle = 50deg, fold
over direction = RL , RFOV(%)= 25~100 , NSA = 1. The influence to reduce FOV on
a conventional and zQIR-VISTA was assessed by handmade phantoms as a basically
study. It was evaluated quantity of aliasing artifacts using line profile
(Experiment1). The basilar artery (BA) images of 15 volunteers was obtain both a
conventional and zQIR-VISTA. These images measured CSF and BA signal intensity (SI)
by region of interest, and The SI was calculated contrast ratio (CR=(SICSF-SIBA)/
( SICSF+SIBA)) (Experiment2).
Results
In the experiment1, a conventional
VISTA of aliasing artifact was confirmed
in 45% reduced FOV. Meanwhile, the
signal intensity on outer FOV with zQIR-VISTA was suppressed, directly aliasing
artifacts were disappeared. However, the aliasing artifacts of
noise component was confirmed with to set less than 35% FOV. In the
experiment2, zQIR-VISTA showed higher
CR than a conventional VISTA.
Discussion
The aliasing artifact of
small FOV with a conventional VISTA was impossible to removal it. Moreover the aliasing
artifact removal techniques such as fold-over suppression increased scan time.
However zQIR -VISTA was possible to removal aliasing artifact without increase
scan time. The reason was cause to suppress signal intensity on outer FOV by
twice selective DIRs pre-pulse. In addition zQIR-VISTA improved CR than a
conventional VISTA by the magnetization transfer effect of selective DIRs pre-pulse.
Conclusion
It is possible to provide black
blood image decreasing scan time by VISTA using zoom quadruple inversion recovery.
Acknowledgements
No acknowledgement found.References
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Tabuchi , Atsushi
Takemura , Makoto
Obara Optimization of 3D-variable refocusing flip angle RARE imaging for
high-resolution volumetric black-blood angiography.
2. Vasily L. Yarnykh* and Chun Yuan : Simultaneous
Outer Volume and Blood Suppression by Quadruple Inversion-Recovery
3.Zoom Imaging for Rapid Aortic Vessel Wall Imaging and Cardiovascular
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