Figure 1a. Drawings show birdcage coils viewed from the inferior aspect. (a) Standard birdcage coil. Internal view demonstrates circular conducting end elements joined by conducting rungs. Arrowheads point to three of the many trim capacitors. (b) Reduced-volume birdcage coil with reflecting end cap (arrows). The metallic end cap on the superior aspect of the coil replaces the superior circular conducting element found on standard birdcage coils. This end cap increases SNR throughout the imaging volume and improves field homogeneity within the superior aspect of the coil.