Radial keyhole sequences for low field projection reconstruction interventional MRI.

Interventional magnetic resonance imaging (IMRI) is a rapidly emerging application for MRI in which diagnostic and therapeutic procedures are performed with MR image guidance. Real-time or near-real-time image acquisition and relative insensitivity to motion are essential for most intraoperative, therapeutic, and diagnostic procedures performed under MR guidance. The purpose of this work was to demonstrate the development and utility of two alternative rapid acquisition strategies during IMRI that are analogous to computed tomography fluoroscopy or keyhole MRI in a radial rather than rectilinear coordinate frame. The two strategies discussed here, interleaved projection reconstruction and continuous projection reconstruction, are compared and the feasibility of their application in experimental interventional applications is studied. J. Magn. Reson. Imaging 2001;13:142-151. Copyright 2001 Wiley-Liss, Inc.