MR angiographic follow-up of intracranial aneurysms treated with detachable coils: evaluation of a blood-pool contrast medium.
OBJECTIVE
Blood-pool agents are promising in the imaging of small vessels with slow or complex flow. Our aim was to compare blood-pool contrast-enhanced MR angiography (BPCE-MRA) using gadofosveset trisodium (Vasovist) with 3D time-of-flight MRA (TOF-MRA) in the follow-up of intracranial aneurysms after endovascular therapy.


METHODS
We included 32 patients with a total of 37 coiled aneurysms. MRAs in the early steady-state phase were performed on a 1.5T scanner within 8 days of digital subtraction angiography (DSA). Two radiologists independently analyzed TOF-MRA and BPCE-MRA images. Consensus was reached by review involving a third neuroradiologist. DSA images were interpreted separately by an interventional radiologist. Findings were assigned to 1 of 3 categories: 1) complete occlusion, 2) residual neck, and 3) residual aneurysm.


RESULTS
Follow-up DSA demonstrated 13 complete obliterations (class 1), 13 residual necks (class 2), and 11 residual aneurysms (class 3). Weighted kappa statistics showed substantial concordance of TOF-MRA and DSA (0.664) as well as BPCE-MRA and DSA (0.724) ratings. Comparison between TOF-MRA and BPCE-MRA found excellent agreement (0.818) with only 6 (16.2%) discrepancies. For detecting residual flow, the difference in accuracy of both MRA techniques (83.8% versus 91.9%) was not significant (McNemar, P = 1.000). BPCE-MRA showed a tendency towards higher sensitivity and specificity (91.7% and 92.3%, respectively) compared with TOF-MRA (87.5% and 76.9%).


CONCLUSIONS
In classifying the completeness of endovascular cerebral aneurysm therapy, we found that BPCE-MRA and 3D TOF-MRA showed very good agreement. The use of Vasovist did not lead to a significantly increased accuracy of MRA follow-up.
Institute of Diagnostic and Interventional Radiology, St. Veiter Strasse 47, Klagenfurt, Austria. t.kau@gmx.at
T
T
Kau
J
J
Gasser
S
S
Celedin
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E
Rabitsch
W
W
Eicher
E
E
Uhl
K A
KA
Hausegger
D003287:Contrast Media; D020878:Device Removal; D004621:Embolization, Therapeutic / Q000295:instrumentation*; D005260:Female; D005500:Follow-Up Studies; D005682:Gadolinium; D015637:Gated Blood-Pool Imaging / Q000379:methods; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D002532:Intracranial Aneurysm / Q000175:diagnosis* / Q000601:surgery*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D003287:Contrast Media; D009942:Organometallic Compounds; D005682:Gadolinium; C109932:gadofosveset trisodium