Published ahead of print on June 12, 2008
doi: 10.3174/ajnr.A1166
Follow-Up of Coiled Cerebral Aneurysms at 3T: Comparison of 3D Time-of-Flight MR Angiography and Contrast-Enhanced MR Angiography
N. Anzalonea,
F. Scomazzonia,
M. Cirilloa,
C. Righia,
F. Simionatoa,
M. Cadiolia,
A. Iadanzaa,
M.A. Kirchinb and
G. Scottia
a Department of Neuroradiology, Ospedale San Raffaele, Milan, Italy
b Worldwide Medical and Regulatory Affairs, Bracco Imaging SpA, Milan, Italy

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Fig 1. A, A large extra-axial lesion and hemorrhagic component indicative of a giant thrombosed aneurysm is apparent in the basal ganglia on the coronal T1-weighted MR image. B, Selective DSA of the right internal carotid artery before treatment reveals a patent portion of the giant thrombosed aneurysm. C, Selective DSA after embolization reveals complete occlusion of the aneurysm and a patent internal carotid artery–external carotid artery bypass. D, Follow-up 3D TOF MRA with MIP reconstruction performed at 1 year after treatment is inconclusive because of artifact related to the methemoglobin component of the thrombosed aneurysm. Additionally, flow-related signal intensity loss in the A1 segment of the anterior cerebral artery is apparent. E, Conversely, follow-up CE-MRA with MIP reconstruction demonstrates both the patent internal carotid artery–external carotid artery bypass and the presence of a small (type I) remnant at the neck of the treated aneurysm.
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Fig 2. A, Selective DSA of the right internal carotid artery before treatment reveals a giant carotid-ophthalmic aneurysm. B, Selective DSA after embolization demonstrates complete occlusion of the aneurysm but with slightly reduced coil compaction near the neck. C and D, Follow-up 3D TOF MRA source image (C) and MIP reconstruction (D) obtained at 8 months after treatment reveal residual patency, but clear definition of the (type 2) remnant is compromised by saturation and methemoglobin artifact. E and F, Clearer depiction of the residual aneurysm is achieved on CE-MRA source images (E) and MIP reconstruction (F).
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Fig 3. A, Selective DSA of the left internal carotid artery before treatment reveals a small aneurysm (arrow) of the anterior communicating artery. B, This aneurysm (arrow) appears completely occluded at follow-up DSA performed after embolization. C and D, Follow-up 3D TOF MRA source image (C) and MIP reconstruction (D) obtained at 3 months after treatment reveal high-signal-intensity inhomogeneities (arrow) in the region of the aneurysm neck but do not clearly demonstrate an aneurysm remnant. E and F, CE-MRA source image (E) and MIP reconstruction (F) clearly reveal the presence of a small (type 2) remnant.
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Fig 4. A, Follow-up DSA at 8 months after embolization of a large basilar artery aneurysm reveals only partial occlusion. B, 3D TOF MRA with MIP reconstruction (B) fails to show the (type 2) remnant entirely, due to flow effects that also compromise visualization of the left posterior cerebral artery. C and D, CE-MRA with MIP (C) and VR (D) reconstruction show both the artery and the residual aneurysm sac.
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