Improved time-of-flight magnetic resonance angiography with IDEAL water-fat separation

• Published in: Journal of magnetic resonance imaging 2009-06, Vol.29 (6), p.1367-1374
• Main Authors: Grayev, Allison, Shimakawa, Ann, Cousins, Joseph, Turski, Patrick, Brittain, Jean, Reeder, Scott
• Format: Article
• Language: English
• Subjects: Adipose Tissue - anatomy & histology; Adult; Aged; Aged, 80 and over; Cerebral Angiography - methods; Cerebral Arteries - anatomy & histology; Cerebrovascular Disorders - diagnosis; Female; Humans; IDEAL; Image Enhancement - methods; Image Processing, Computer-Assisted; Imaging, Three-Dimensional - methods; intracranial MRA; Magnetic Resonance Angiography - methods; Male; Middle Aged; time-of-flight MRA; water-fat separation techniques
• ISSN: 1053-1807; 1522-2586
• DOI: 10.1002/jmri.21780

Purpose To implement IDEAL (iterative decomposition of water and fat using echo asymmetry and least squares estimation) water‐fat separation with 3D time‐of‐flight (TOF) magnetic resonance angiography (MRA) of intracranial vessels for improved background suppression by providing uniform and robust separation of fat signal that appears bright on conventional TOF‐MRA. Materials and Methods IDEAL TOF‐MRA and conventional TOF‐MRA were performed in volunteers and patients undergoing routine brain MRI/MRA on a 3T magnet. Images were reviewed by two radiologists and graded based on vessel visibility and image quality. Results IDEAL TOF‐MRA demonstrated statistically significant improvement in vessel visibility when compared to conventional TOF‐MRA in both volunteer and clinical patients using an image quality grading system. Overall image quality was 3.87 (out of 4) for IDEAL versus 3.55 for conventional TOF imaging (P = 0.02). Visualization of the ophthalmic artery was 3.53 for IDEAL versus 1.97 for conventional TOF imaging (P < 0.00005) and visualization of the superficial temporal artery was 3.92 for IDEAL imaging versus 1.97 for conventional TOF imaging (P < 0.00005). Conclusion By providing uniform suppression of fat, IDEAL TOF‐MRA provides improved background suppression with improved image quality when compared to conventional TOF‐MRA methods. J. Magn. Reson. Imaging 2009;29:1367–1374. © 2009 Wiley‐Liss, Inc.