RT Journal Article SR Electronic T1 Identification of Intraplaque Hemorrhage on MR Angiography Images: A Comparison of Contrast-Enhanced Mask and Time-of-Flight Techniques JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 454 OP 459 DO 10.3174/ajnr.A2320 VO 32 IS 3 A1 Qiao, Y. A1 Etesami, M. A1 Malhotra, S. A1 Astor, B.C. A1 Virmani, R. A1 Kolodgie, F.D. A1 Trout, H.H. A1 Wasserman, B.A. YR 2011 UL http://www.ajnr.org/content/32/3/454.abstract AB BACKGROUND AND PURPOSE: MRA is widely used to measure carotid narrowing. Standard CE- and TOF-MRA techniques use highly T1-weighted gradient-echo sequences that can detect T1 short blood products, so they have the potential to identify IPH, an indicator of plaque rupture. We sought to determine the accuracy and reliability of these MRA sequences to detect IPH. MATERIALS AND METHODS: 3D TOF and CE carotid MRA scans were obtained at 3T on 15 patients (age range, 58–86 years; 13 men) scheduled for CEA. The source images from the precontrast (mask) CE-MRA and the TOF sequences were reviewed by 2 independent readers for IPH presence (identified as hyperintense signal intensity compared with adjacent muscle). CEA specimens were stained with antibody against glycophorin A and Mallory stain to detect IPH and were correlated with MR images. RESULTS: Nine of 15 CEA specimens (61 of 144 MR images) contained IPH confirmed by histology. Compared with TOF, CE-MRA mask demonstrated greater sensitivity, specificity, PPV, and NPV for IPH detection. The accuracy for correctly identifying IPH by using CE-MRA mask images and TOF images was 94% and 84%, respectively. Inter- and intraobserver agreement for IPH detection was excellent by mask images (κ = 0.91 and κ = 0.94, respectively) and TOF images (κ = 0.77 and κ = 0.84, respectively). CONCLUSIONS: CE-MRA mask images are highly accurate and reliable for identifying IPH, more so than the TOF sequence, and can potentially provide valuable information about risk for rupture. CEcontrast-enhancedCEAcarotid endarterectomyCIconfidence intervalCNRcontrast-to-noise ratioECAexternal carotid arteryFFEfast-field echoICAinternal carotid arteryIPHintraplaque hemorrhageMIPmaximum intensity projectionMPRAGEmagnetization-prepared rapid acquisition of gradient echoMRAMR angiographyMRDTIMR direct thrombus imagingNPVnegative predictive valuePPVpositive predictive valueSIsignal intensitySPGRspoiled gradient-recalledT1WIT1-weighted imagingTOFtime-of-flightTSEturbo spin-echo