An expandable intravenous RF coil for arterial wall imaging

An intravenous (iv) radiofrequency (RF) coil is proposed as a means of obta ining high resolution images of artery wall. The anatomic positioning of pe ripheral artery/vein pairs was investigated and a phantom mimicking the ili ac artery/vein pair was constructed. Imaging results, comparing iv coils wi th external coils, demonstrated a potential 15- to 20-fold increase in sign al-to-noise ratio (SNR) with iv coils. The SNR benefit was measured over a cylindrical volume, adjacent to the coil, and typical of artery position. P rototype expandable iv coils were constructed of Cu-Be loops and introduced via an 8-Fr catheter, The effects of local and remote iv coil tuning were investigated and local tuning was found to provide significant SNR benefits . The in vivo performance of iv RF coils was demonstrated in a porcine anim al model. The iv coils were found to be an excellent alternative to intraar terial coils.