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 T1-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.