A comparison between magnetic resonance angiography at 3 teslas (time-of-flight and contrast-enhanced) and flat-panel digital subtraction angiography in the assessment of embolized brain aneurysms

Abstract

PURPOSE:To compare the time-of-flight and contrast-enhanced- magnetic resonance angiography techniques in a 3 Tesla magnetic resonance unit with digital subtraction angiography with the latest flat-panel technology and 3D reconstruction in the evaluation of embolized cerebral aneurysms.INTRODUCTION:Many embolized aneurysms are subject to a recurrence of intra-aneurismal filling. Traditionally, imaging surveillance of coiled aneurysms has consisted of repeated digital subtraction angiography. However, this method has a small but significant risk of neurological complications, and many authors have advocated the use of noninvasive imaging methods for the surveillance of embolized aneurysms.METHODS:Forty-three aneurysms in 30 patients were studied consecutively between November 2009 and May 2010. Two interventional neuroradiologists rated the time-of-flight-magnetic resonance angiography, the contrast-enhanced-magnetic resonance angiography, and finally the digital subtraction angiography, first independently and then in consensus. The status of aneurysm occlusion was assessed according to the Raymond scale, which indicates the level of recanalization according to degrees: Class 1: excluded aneurysm; Class 2: persistence of a residual neck; Class 3: persistence of a residual aneurysm. The agreement among the analyses was assessed by applying the Kappa statistic.RESULTS:Inter-observer agreement was excellent for both methods (K = 0.93; 95 % CI: 0.84-1). Inter-technical agreement was almost perfect between time-of-flight-magnetic resonance angiography and digital subtraction angiography (K = 0.98; 95 % CI: 0.93-1) and between time-of-flight-magnetic resonance angiography and contrast-enhanced-magnetic resonance angiography (K = 0.98; 95% CI: 0.93-1). Disagreement occurred in only one case (2.3%), which was classified as Class I by time-of-flight-magnetic resonance angiography and Class II by digital subtraction angiography. The agreement between contrast-enhanced-magnetic resonance angiography and digital subtraction angiography was perfect (K = 1; 95% CI: 1-1). In three patients, in-stent stenosis was identified by magnetic resonance angiography but not confirmed by digital subtraction angiography.CONCLUSION:Digital subtraction angiography and both 3T magnetic resonance angiography techniques have excellent reproducibility for the assessment of aneurysms embolized exclusively with coils. In those cases also treated with stent remodeling, digital subtraction angiography may still be necessary to confirm eventual parent artery stenosis, as identified by magnetic resonance angiography.

Effect of stenting on progressive occlusion of small unruptured saccular intracranial aneurysms with residual sac immediately after coil embolization: a propensity score analysis

“…However retrospective in nature, measured variables related to the probability of stent deployment assumed less proportional influence due to propensity score matching. Some studies25 26 have shown the feasibility of TOF-MRA to evaluate aneurysm occlusion using DSA as the reference. In our previous report,27 TOF-MRA (MIP and source image) has been shown to be helpful in estimating the degree of recanalization.…”

Non-enhanced magnetic resonance imaging of unruptured intracranial aneurysms at 7 Tesla: Comparison with digital subtraction angiography

“…Sensitivity rates between 79 % and 97 % have been reported for 1.5-T (T) MRA for detection of small UIAs [9][10][11][12]. Even better performance has been shown for 3-and 7-T (ultra-) highfield non-enhanced MRA, with recent studies reporting sensitivity rates comparable with the gold standard DSA [13][14][15][16]. Increased signal-to-noise (SNR) and contrastto-noise (CNR) ratios at higher magnetic field strength lead to improved spatial resolution and vessel contrast.…”

Stent-Assisted Coil Embolization of Vertebrobasilar Dissecting Aneurysms: Procedural Outcomes and Factors for Recanalization

“…2 in the online-only Data Supplement). Although some studies ( 30 31 ) have shown the feasibility of TOF-MRA to evaluate aneurysm occlusion using digital subtraction angiography (DSA) as the reference, the possibility of the stents causing more artifacts could affect the recurrence rate ( 32 ). In our cohort, most of the recurrence was diagnosed by DSA (n = 9, 90%).…”