Abstract: A system and method for MR imaging includes a magnetic resonance imaging (MRI) system having a plurality of gradient coils positioned about a bore of a magnet, and an RF transceiver system and an RF switch controlled by a pulse module to transmit RF signals to an RF coil assembly to acquire MR images. The apparatus further includes a controller programmed to determine a variable flip angle (VFA) sequence to excite a hyperpolarized material in a subject and to determine a delay period during which application of the VFA sequence is delayed after injection of a hyperpolarized contrast agent. The delay period is based on dynamic data of the hyperpolarized material acquired from the subject. The controller is also programmed to cause application of the VFA sequence to excite the hyperpolarized material in the subject and to acquire MR data from the hyperpolarized material using an isotropic centric phase encoding (iCPE) technique.

Abstract: A signal representing a physiological condition of a patient is used to modulate an electromagnetic signal received by a transponder so that a modulated electromagnetic signal representative of the signal is re-radiated by the transponder. The transponder includes an antenna and a diode coupled between the antenna and ground. Changing states of a digital signal from an analog-to digital converter that receives an input from a physiological transducer cause the diode to selectively conduct, which causes the impedance of the antenna to change accordingly. The re-radiated electromagnetic signal is demodulated to recover the digital signal, and the output signal of the transducer is recovered and may be displayed to a user and otherwise processed and/or stored.