Follow-up of coiled cerebral aneurysms: comparison of three-dimensional time-of-flight magnetic resonance angiography at 3 tesla with three-dimensional time-of-flight magnetic resonance angiography and contrast-enhanced magnetic resonance angiography at 1.5 Tesla.
OBJECTIVE
To compare three-dimensional (3D) time-of-flight (TOF)-magnetic resonance angiography (MRA) at 3 T with 3D TOF-MRA and ultrafast contrast-enhanced (CE)-MRA at 1.5 T and to determine the optimum MRA sequence for follow-up of cerebral aneurysms treated with Guglielmi detachable coils (GDCs).


METHODS
Twenty-eight patients treated with GDCs for 29 cerebral aneurysms underwent MRA at 3 T and 1.5 T within 24 hours (during the same session for outpatients). All imaging was performed using a sensitivity-encoding head coil (SENSE factor = 2). Unenhanced axial 3D TOF-MRA at 3 T was performed with repetition time (TR)/echo time (TE) = 16/2.9. At 1.5 T, axial 3D TOF-MRA (TR/TE = 23/4) was performed first, followed by axial 3D ultrafast gradient echo MRA (TR/TE = 6/2) enhanced with 0.1 mmol/kg gadobenate dimeglumine (MultiHance). Source images and maximum intensity projection and shaded surface display reconstructions for each acquisition sequence were evaluated for quality of visualization of residual aneurysm patency and scored for visualization preference.


RESULTS
Residual aneurysm was detected in 15/29 cases on CE-MRA at 1.5 T and TOF-MRA at 3 T but in only 11/29 cases on TOF-MRA at 1.5 T. CE-MRA at 1.5 T was preferred to TOF-MRA at 1.5 T in 13 cases (P = 0.004) and to TOF-MRA at 3 T in 3 cases. TOF-MRA at 3 T was preferred to TOF-MRA at 1.5 T in 11 cases (P = 0.04) but was not preferred to CE-MRA at 1.5 T in any case. The parent artery was identifiable in all 29 cases after TOF-MRA at 3 T and CE-MRA at 1.5 T but in only 27 cases after 3D TOF-MRA at 1.5 T.


CONCLUSIONS
TOF-MRA follow-up of coiled aneurysms is better at 3 T than at 1.5 T; nevertheless, greater definition of residual patency is achieved with ultrafast CE-MRA at 1.5 T.
Anzalone
Nicoletta
N
Department of Neuroradiology, Ospedale San Raffaele, Milan, Italy; and daggerBracco Imaging SpA, Milan, Italy. anzalone.nicoletta@hsr.it
Scomazzoni
Francesco
F
Cirillo
Mario
M
Cadioli
Marcello
M
Iadanza
Antonella
A
Kirchin
Miles A
MA
Scotti
Giuseppe
G
D000328:Adult; D000368:Aged; D004621:Embolization, Therapeutic / Q000295:instrumentation*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis* / Q000628:therapy; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged