Cerebral Aneurysms Treated by Guglielmi Detachable Coils: Evaluation with Diffusion-weighted MR Imaging
Alessandra Biondi
,a,
Catherine Oppenheima,
Elio Vivasa,
Alfredo Casascoa,
Toufik Lalama,
Nader Souroura,
Lise Le Jeana,
Didier Dormonta and
Claude Marsaulta
a From the Departments of Diagnostic and Therapeutic Neuroradiology (A.B., C.O., E.V., A.C., T.L., N.S., D.D., C.M.) and Anesthesiology (L.L.J.), Pitié-Salpêtrière Hospital, Paris, France.
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FIG 1. 48-year-old woman with an aneurysm of the right middle cerebral artery trifurcation treated by GDCs.
A, Before treatment, diffusion-weighted images (2825/92.6/1) appear normal.
B–D, Two hours after embolization, FLAIR images (10002/148/2200/1) (B) show a slight right frontobasal hyperintense signal (arrows). Diffusion-weighted images (2825/92.6/1) (C) show a small right basal hyperintense lesion, caused by a recent ischemic event (arrows). On ADC maps (D), ADC values are decreased relative to contralateral hemisphere and displayed as an area of dark signal (arrowhead).
E–G, Twenty-four hours after embolization, the contrast of the lesion (arrows) has increased on FLAIR (10002/148/2200/1) (E) and diffusion-weighted (F) (2825/92.6/1) images, confirming the ischemic lesion. Values on ADC maps (G) are further decreased in the right frontobasal ischemic lesion (arrowheads).
H, Follow-up FLAIR images at 3 months (10002/148/2200/1) show a very small residual frontobasal hyperintense lesion (arrows).
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FIG 2. 37-year-old woman with an aneurysm of the left posterior communicating artery who presented with subarachnoid hemorrhage (WFNS, grade II).
A, Before embolization, diffusion-weighted images (2825/92.6/1) show foci of slight hyperintense signal due to the presence of subarachnoid hemorrhage.
B and C, Two hours after embolization, four silent small lesions were observed on diffusion-weighted images (2825/92.6/1) (only two of the four lesions are shown [arrows, B]). An area of hypointense signal is seen on ADC maps (arrow, C), with decreased ADC values.
D and E, Twenty-four hours after embolization, lesions are more visible on diffusion-weighted images (D), with a fifth lesion (arrow) apparent in the posterior fossa. On ADC maps (E), decreased ADC values are seen as dark areas for all lesions (arrows), except for the small left frontal lesion. These silent lesions are not all related to the aneurysm's parent artery, and their origin remains uncertain.
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