Abstract: An RF coil assembly for an MRI system includes a resonator formed by a cylindrical shield and pairs of opposing conductive legs disposed symmetrically around a central axis and extending the axial length of the shield. Drive circuitry for each pair of opposing conductive legs includes a current balun that maintains substantially equal and opposite currents in the two conductive legs. Terminal susceptance elements are used to maintain maximum currents and minimum voltage at the midpoints of the conductive legs. Multinuclear measurements can be made simultaneously at different Larmor frequencies.

Abstract: A multi-mode medical device system and method of performing an interventional procedure. The multi-mode medical device system can be capable of MR internal imaging and of being tracked using an MRI system. The multi-mode medical device system can include a medical device, and an electrical circuit coupled to the medical device and electrically coupled to the MRI system. The electrical circuit can include a tracking device configured to transmit a signal to the MRI system indicative of the position of the tracking device relative to a roadmap image, and an imaging device electrically coupled to the tracking device and configured to internally image anatomical structures from the point of view of the medical device. The imaging device can be further configured to be visualized using MR imaging. Tracking the tracking device and internally imaging with the imaging device can be performed in a single pass of the multi-mode medical device system.

Abstract: An MRI system includes an array of series resonant transmit elements 6 and 65 including individual control of RF current in all elements 106, 108, 110, 114, 116, 118, 120. The array 6 and 65 adjusts scan homogeneity during a scan or prescan phase by adjusting amplitude and phase. The array 6 and 65 also selectively excites areas of interest, thus avoiding major power dissipation and avoiding heating in the patient.