title: Dynamic coil selection for real-time imaging in interventional MRI.
abstract: MR-guided intravascular interventions require image update rates of up to 10 images per second, which can be achieved using parallel imaging. However, parallel imaging requires many coil elements, which increases reconstruction times and thus compromises real-time image reconstruction. In this study a dynamic coil selection (DCS) algorithm is presented that selects a subset of receive coils to reduce image reconstruction times. The center-of-sensitivity coordinates and the relative signal intensities are determined for each coil in a prescan. During the intervention m coils are selected for reconstruction using a coil ranking based on the distance to the current slice or catheter position. In a phantom experiment for m = 6, an optimal signal-to-background ratio (SBR) was achieved and foldover artifacts were avoided. In three animal experiments involving catheter manipulation in the aorta and the right heart chamber, the anatomy was successfully visualized at frame rates of about 5 Hz using active catheter tracking.
authors.affiliation: Deutsches Krebsforschungszentrum, Heidelberg, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Müller
authors.forename: Reiner
authors.initials: R
authors.lastname: Umathum
authors.forename: Peter
authors.initials: P
authors.lastname: Speier
authors.forename: Sven
authors.initials: S
authors.lastname: Zühlsdorff
authors.forename: Sebastian
authors.initials: S
authors.lastname: Ley
authors.forename: Wolfhard
authors.initials: W
authors.lastname: Semmler
authors.forename: Michael
authors.initials: M
authors.lastname: Bock
mesh_terms: D000465:Algorithms; D003199:Computer Systems; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D053783:Magnetic Resonance Imaging, Interventional / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity