doi: 10.3174/ajnr.A1678
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American Journal of Neuroradiology 30:1665-1671, October 2009
© 2009 American Society of Neuroradiology
INTERVENTIONAL
Evaluation of the Occlusion Status of Coiled Intracranial Aneurysms with MR Angiography at 3T: Is Contrast Enhancement Necessary?
aFrom the Department Radiology (M.E.S.S., R.v.d.B, E.M.A., S.P.F., C.B.L.M.), Academic Medical Center, Amsterdam, the Netherlands
bDepartment of Radiology (W.J.v.R.), St. Elisabeth Ziekenhuis, Tilburg, the Netherlands
cDepartment of Neurology (J.D.S., G.J.E.R.), Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, the Netherlands.
Please address correspondence to Marieke E.S. Sprengers, MD, Department of Radiology, Academic Medical Center Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands; e-mail: M.E.Sprengers{at}amc.uva.nl
BACKGROUND AND PURPOSE: MR angiography (MRA) is increasingly used as a noninvasive imaging technique for the follow-up of coiled intracranial aneurysms. However, the need for contrast enhancement has not yet been elucidated. We compared 3D time-of-flight MRA (TOF-MRA) and contrast-enhanced MRA (CE-MRA) at 3T with catheter angiography.
MATERIALS AND METHODS: Sixty-seven patients with 72 aneurysms underwent TOF-MRA, CE-MRA, and catheter-angiography 6 months after coiling. Occlusion status on MRA was classified as adequate (complete and neck remnant) or incomplete by 2 independent observers. For TOF-MRA and CE-MRA, interobserver agreement, intermodality agreement, and correlation with angiography were assessed by
statistics.
RESULTS: Catheter-angiography revealed incomplete occlusion in 12 (17%) of the 69 aneurysms; 3 aneurysms were excluded due to MR imaging artifacts. Interobserver agreement was good for CE-MRA (
= 0.77; 95% confidence interval [CI], 0.55–0.98) and very good for TOF-MRA (
= 0.89; 95% CI, 0.75–1.00). Correlation of TOF-MRA and CE-MRA with angiography was good. The sensitivity of TOF-MRA and CE-MRA was 75% (95% CI, 43%–95%); the specificity of TOF-MRA was 98% (95% CI, 91%–100%) and of CE-MRA, 97% (95% CI, 88%–100%). All 5 incompletely occluded aneurysms, which were additionally treated, were correctly identified with both MRA techniques. Areas under the receiver operating characteristic curve for TOF-MRA and CE-MRA were 0.90 (95% CI, 0.79–1.00) and 0.91 (95% CI, 0.79–1.00). Intermodality agreement between TOF-MRA and CE-MRA was very good (
= 0.83; 95% CI, 0.65–1.00), with full agreement in 66 (96%) of the 69 aneurysms.
CONCLUSIONS: In this study, TOF-MRA and CE-MRA at 3T were equivalent in evaluating the occlusion status of intracranial aneurysms after coiling. Because TOF-MRA does not involve contrast administration, this method is preferred over CE-MRA.