Intracranial aneurysms: detection with gadolinium-enhanced dynamic three-dimensional MR angiography-initial results.
OBJECTIVE
To assess the clinical utility and accuracy of contrast material-enhanced dynamic three-dimensional (3D) T1-weighted magnetic resonance (MR) angiography in the detection of unruptured intracranial aneurysms.


METHODS
A prospective blinded comparison of 3D contrast-enhanced T1-weighted MR angiography with 3D inflow magnetization transfer and tilted optimized nonsaturating excitation (MT TONE) imaging, phase-contrast MR angiography, and conventional digital subtraction angiography (DSA) was performed in 32 consecutive patients. The first dynamic 3D contrast-enhanced T1-weighted acquisition was individually timed after injection of a bolus of gadolinium-based contrast agent to obtain an arterial phase image followed by two sequential venous phase images (three 18-second acquisitions). Two readers independently interpreted and graded the MR images for diagnostic confidence and depiction of aneurysms and subsequently compared them with DSA images.


RESULTS
Three-dimensional contrast-enhanced T1-weighted MR angiograms depicted all 23 aneurysms detected in 17 patients at DSA (mean size, 6 mm; range, 2-21 mm) with one false-positive result by one reader (sensitivity, 100%; specificity, 94%). MT TONE and phase-contrast images failed to depict one and seven aneurysms, respectively (MT TONE sensitivity of 96% and specificity of 100%, phase-contrast sensitivity of 70% and specificity of 100%). Aneurysm depiction at 3D contrast-enhanced T1-weighted MR angiography was significantly better than that at MT TONE imaging (P <.012), and that with both was significantly superior to that of phase-contrast imaging (P <. 001). Differences in diagnostic confidence in the presence of an aneurysm were not significant between 3D contrast-enhanced T1-weighted and MT TONE imaging (P =.076).


CONCLUSIONS
Dynamic 3D contrast-enhanced T1-weighted MR angiography is a fast, efficient, and minimally invasive imaging method with which to diagnose intracranial aneurysms.
Metens
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Department of Radiology, Unité de RMN, Hôpital Erasme, Université Libre de Bruxelles, 808 route de Lennik, B-1070, Brussels, Belgium. tmetens@ulb.ac.be
Rio
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Balériaux
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Roger
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David
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Rodesch
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D000328:Adult; D000368:Aged; D015901:Angiography, Digital Subtraction; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007091:Image Processing, Computer-Assisted; D002532:Intracranial Aneurysm / Q000175:diagnosis* / Q000000981:diagnostic imaging; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity
D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA