Yoshiyuki Watanabe1, Hiroto Takahashi1, Hisashi Tanaka1, Atsuko Arisawa1, Chisato Matsuo1, Eri Yoshioka1, Hajime Nakamura2, and Noriyuki Tomiyama1
1Radiology, Osaka University, Suita, Japan, 2Neurosurgery, Osaka University, Suita, Japan
Synopsis
The
purpose of this study was to elucidate in vivo analysis of the flow dynamics of
ACOM aneurysms from both A1 arteries using 4D-Flow and digital subtraction
angiography (DSA).
2
out of 8 ACOM aneurysms
showed intra-aneurysm flow from both A1 arteries and 6 other patients showed the unilateral A1 inflow.
Inflow findings of all
patients are consistent with 4D-Flow and DSA. 4D-FLOW MRI is able to visualize
cross flow in ACOM aneurysms.Background or Purpose
A
dominant A1 has been identified as a potential risk factor for both ACOM
aneurysm formation and rupture [1]. If there are bilateral A1
arteries, evaluation of ACOM aneurysm flow is difficult by MRA or CTA. 4D-FLOW MRI (ECG-gated 3D-Phase contrast MRA)
is able to show the flow directions in cerebral arteries [2]. The
purpose of this study was to elucidate in vivo analysis of the flow dynamics of
ACOM aneurysms from both A1 arteries using 4D-Flow and digital subtraction
angiography (DSA).
Methods
11 patients with unruptured ACOM aneurysms (M:F=6:5,Mean age 60.1y：43-72y) were included in this study. 3T-MRI（Philips Achieva TX）was performed by 4D-Fflow, TR/TE=8.1/3.8msec FA=15°, FOV=180mm, Matrix=192X2 → 256X2, slice thickness 1.0mm/0.5mm, 55 slice, R-R:15phase, Acquisition time=15-20 minutes, VENC=100cm/sec, Voxel size= 0.70×0.70×0.50 mm reconstruction. 4D-Flow data were analyzed using GT Flow (Gyro Tools). The pathline was drawn from the ROI in both A1 vessels. DSA and bilateral ICA angiography were performed by Philips Allura Xper FD20/20. Two neuroradiologists independently reviewed the DSA and 4D-flow images. Aneurysm flow was evaluated to determine the side of A1 inflow, unilateral or bilateral. Differences in assessments were resolved by consensus.
Result
Patients’ information and ACOM aneurysm flow are summarized in Table. We excluded the A1 aplasia patients and evaluated ACOM flow for 8 patients. 2 out of 8 ACOM aneurysms showed intra-aneurysm flow from both A1 arteries and 6 other patients showed the unilateral A1 inflow. All cross flow findings to ACOM aneurysms were consistent with 4D-flow and DSA.
Conclusions
Inflow findings of all patients are consistent with 4D-Flow and DSA. 4D-FLOW MRI is able to visualize cross flow in ACOM aneurysms.
Acknowledgements
No Acknowledgement.References
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anterior communicating artery and detection of A1 vessel asymmetry by flow
dilution. AJNR Am J Neuroradiol, 2010. 31(7):
p. 1186-91.
2. Hope, T.A., et al., Evaluation of intracranial stenoses and aneurysms with accelerated 4D
flow. Magn Reson Imaging, 2010. 28(1):
p. 41-6.