Single-Station Whole-body Real-time Magnetic Resonance Imaging

Abstract

Recently, we have proposed an interactive large field-of-view magnetic resonance imaging using a continuously moving table method. In this technique, the large image is constructed while moving the patient table through the scanner magnet during MR excitation and data acquisition. In this work, a novel implementation strategy for fast and accurate whole-body MR imaging based on the proposed method is presented. The imaging strategy implemented here is based on the realization that the MR 3D Fourier reconstruction is a decomposable process. Because MR data are acquired in the spatial frequency domain, i.e. (kx-ky-kz)-space, rather than image space, this allows one to define a smoothly growing hybrid (x-ky-kz)-space with the same length as the table displacement while acquiring the MR data. Providing accurate measurements of the table position, each sampled readout echo (kx) is immediately Fourier transformed and precisely placed in proper location of the hybrid-space. Image reconstruction (Fourier transforms on ky-kz) is performed continuously, independent of the arbitrary table translation.

We have developed a unique real-time imaging system for whole-body MR imaging that provides seamless images from the head to the toe during a single continuous station. We implemented this technique on a clinical MR scanner, and successfully scanned phantoms and humans, and have begun to evaluate its clinical utility. The results show the feasibility of rapidly acquiring isotropic, continuous images of the whole body and interactively moving the table in response to the real-time visualized data. Technical implementation challenges, engineering issues and their discovered solutions are presented here.