An expandable intravenous RF coil for arterial wall imaging

An intravenous (iv) radiofrequency (RF) coil is proposed as a means of obtaining high resolution images of artery wall. The anatomic positioning of peripheral artery/vein pairs was investigated and a phantom mimicking the iliac artery/vein pair was constructed. Imaging results, comparing iv coils with external coils, demonstrated a potential 15- to 20-fold increase in signal-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. Prototype 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 animal model. The iv coils were found to be an excellent alternative to intraarterial coils.