Purpose: To develop a magnetization preparation method to achieve robust, flow-independent blood suppression for cardiac and vascular magnetic resonance imaging (MRI).
Materials and methods: T(2)Prep-IR sequence consists of a T(2) preparation followed by a nonselective adiabatic inversion pulse. T(2)Prep separates the initial longitudinal magnetization of arterial wall from lumen blood. After the inversion recovery pulse the imaging acquisition is then delayed for a period that allows the blood signal to approach the zero-crossing point. Compared to the conventional double inversion recovery (DIR) preparation, T(2)Prep-IR prepares all the spins regardless of their velocity and direction. T(2)Prep-IR was incorporated into the fast spin echo and fast gradient echo acquisition sequences and images in various planes were acquired in the carotid arteries, thoracic aorta, and heart of normal volunteers. Blood suppression and image quality were compared qualitatively between two different preparations.
Results: For in-plane flow carotid images, persistent flow-related artifacts on the DIR images were removed with T(2)Prep-IR. For cardiac applications, T(2)Prep-IR provided robust blood suppression regardless of the flow direction and velocity, including the cardiac long-axis views and the aorta that are often problematic with DIR.
Conclusion: T(2)Prep-IR may overcome the flow dependence of DIR by providing robust flow-independent black-blood images.
(c) 2009 Wiley-Liss, Inc.