A rapid 2D time‐resolved variable‐rate k ‐space sampling MR technique for passive catheter tracking during endovascular procedures

A new, fast, 2D MR imaging technique allowing passive catheter visualization adequate for use as a tool for guiding the movement of a catheter during endovascular procedures is described. This imaging technique samples low spatial frequencies more often than high spatial frequencies; it also uses both k ‐space view sharing and temporal interpolation. Unlike other techniques for passive visualization that exploit magnetic‐susceptibility–induced artifacts, we have adopted a strategy that takes advantage of the T 1 ‐shortening effect of paramagnetic contrast agents, such as Gd‐DTPA and a projection dephaser. This not only permits visualization of the entire catheter length but also minimizes the risk of intravascular heating. Using this method, a temporal frame rate of up to eight images per second and a tip localization accuracy of ± 1mm (root mean square difference) can be achieved.