Fast simultaneous noncontrast angiography and intraplaque hemorrhage (fSNAP) sequence for carotid artery imaging

PurposeTo propose a fast simultaneous noncontrast angiography and intraplaque hemorrhage (fSNAP) sequence for carotid artery imaging. MethodsThe proposed fSNAP sequence uses a low-resolution reference acquisition for phase-sensitive reconstruction to speed up the scan, and an inversion recovery acquisition with arbitrary k-space filling order to generate similar contrast to conventional SNAP. Four healthy volunteers and eight patients were recruited to test the performance of fSNAP in vivo. The lumen area quantification, muscle-blood CNR, IPH-blood CNR, lumen SNR, and standard deviation and intraplaque hemorrhage (IPH) detection accuracy were compared between fSNAP and SNAP. ResultsBy using a low-resolution reference acquisition with 1/4 matrix size of the full-resolution reference scan, the scan time of fSNAP was 37.5% less than that of SNAP. A high agreement of lumen area measurement (ICC=0.97, 95% CI: 0.96-0.99) and IPH detection (Kappa=1) were found between fSNAP and SNAP. Also, no significant difference was found for muscle-blood CNR (P=0.25), IPH-blood CNR (P=0.35), lumen SNR (P=0.60), and standard deviation (P=0.46) between the two techniques. ConclusionThe feasibility of fSNAP was validated. fSNAP can improve the imaging efficiency with similar performance to SNAP on carotid artery imaging. Magn Reson Med 77:753-758, 2017. (c) 2016 International Society for Magnetic Resonance in Medicine.