Improved vessel delineation in keyhole time‐resolved contrast‐enhanced MR angiography using a gadolinium doped flush

Abstract

Abstract Purpose To prospectively assess the influence of a gadolinium doped saline flush compared with a pure saline flush on the image quality of the supra‐aortic vessels using time‐resolved contrast‐enhanced MR angiography (4D CE‐MRA) in a randomized double blind clinical trial. Materials and Methods Twenty‐two patients scheduled for contrast‐enhanced craniocerebral MRI underwent a supplemental 4D CE‐MRA covering the carotids to the superior sinus consisting of 30 dynamics of a T1‐weighted 3D gradient‐echo sequence (FFE) in sagittal direction. The temporal resolution of 1.1 s per dataset was achieved using the keyhole technique with the reference scan acquired at the end. Immediately after the intravenous (IV) injection of 0.1 mmol Gd/kg body weight of gadoterate, our patients received a 50‐mL flush consisting either of a 0.9% saline solution (n = 11) or doped with 50 mM gadolinium (n = 11; total Gd: 0.11 mmol/kg) at a flow‐rate of 2 mL/s. Vessel delineation, image quality, signal‐to‐noise‐ (SNR) and contrast‐to‐noise (CNR) ratios over time were compared. Results Both vessel delineation (internal carotid artery [ICA]: slope saline = 308.5; slope Gd = 528.9; P = 0.006; superior sagittal sinus [SSS]: slope saline = 505.3; slope Gd = 674.9; P = 0.007) and CNR (ICA: CNR saline = 57.3; CNR Gd = 80.55; P = 0.0417; SSS: CNR saline = 74.15; CNR Gd = 117.4; P = 0.0331) of the ICA and SSS were significantly increased using the gadolinium doped flush. Conclusion A low concentrated gadolinium flush in comparison to a pure saline flush improves significantly vessel contrast and their delineation in time‐resolved CE‐MRA using the keyhole technique. J. Magn. Reson. Imaging 2009;29:1147–1153. © 2009 Wiley‐Liss, Inc.