Real-time MRI: recent advances using radial FLASH. (August 2012)

• Record Type: Journal Article
• Authors: Uecker, Martin; Zhang, Shuo; Voit, Dirk; Merboldt, Klaus-Dietmar; Frahm, Jens
• Is Part Of: Imaging in medicine. Volume 4:Number 4(2012)
• Page Start: 461
• Page End: 476
• Publication Date: 2012-08
• Subjects: cardiovascular MR -- dynamic imaging -- MRI -- nonlinear inverse reconstruction -- real-time imaging -- speaking -- swallowing; Diagnostic imaging -- Periodicals; 616.075405
• DOI: 10.2217/iim.12.32
• Languages: English
• ISSNs: 1755-5205

Abstract

Recent advances in real-time MRI result in high-quality images with acquisition times of only approximately 30 ms. The technique employs a fast low-angle shot sequence with proton density, T1 or T2 /T1 contrast and radial data encoding for motion robustness. High temporal resolution is achieved by an up to 20-fold undersampling of the radial data. An iterative reconstruction algorithm estimates the image as the solution of a nonlinear inverse problem and ensures image fidelity by temporal regularization, which exploits the temporal continuity of successive frames during dynamic imaging. Preliminary real-time examinations at a field strength of 3T range from joint dynamics, speaking and swallowing to the 3D localization of objects in space. In particular, real-time MRI largely facilitates assessments of cardiovascular function and quantitative blood flow. Taken together, advanced real-time MRI methods allow for hitherto inaccessible studies, lead to more robust and shorter examinations, improve patient comfort and offer new diagnostic opportunities.