Real-time MRI

The real-time magnetic resonance imaging ( real-time MRI) (including MR fluoroscopy), a method on the basis of magnetic resonance imaging for the continuous monitoring of a moving object in real time, that is for representing a motion as an image series or MRI - movie.

Applications

The clinical and research applications of real-time MRI extending from the cardiac imaging to functional studies of the brain ( fMRI) and joints (eg the temporomandibular joint, knee joint ) or the complex sequence of movements of the muscles in the mouth, throat and neck when speaking or swallowing. In addition, missions are in abdominal imaging and interventional MRI (see also interventional radiology), which allows a non-invasive checks of minimally invasive surgery. Even in the non - medical field, real-time MRI can be used for example for the study of turbulent flows.

Physical principle

Basis of real-time MRI are very fast measurement sequences that allow for image acquisition with high temporal resolution. Typical examples are fast gradient echo sequences (e.g., FLASH ) sequence TrueFISP technique or rapid non- segmented Fast-/Turbo-Spin-Echo-Verfahren. The fastest technique combines a fast flash sequence with radial trajectories, and an iterative reconstruction method, to achieve a time resolution of up to 20 ms. An important application of this technique is the cardiac imaging.