An ultrasound cardiac stimulation system includes: a system for measuring the heart electrical activity; a system for generating a beam of focussed ultrasound signals focussed on a targeted zone, the signals being calibrated to generate electrical stimulation in a zone of the heart, the beam generation being synchronised with a first selected time of the electrocardiogram, the generation of the beam corresponding to a pulse with a duration of less than 80 ms; a system for locating the targeted zone coupled with a system for positioning the system for generating the focussed beam to control the beam of focussed ultrasound signals in the targeted zone, the location system being synchronised with the system for generating the beam of focussed signals; a single monitoring system following in real time a temperature and tissue deformation in the targeted zone, the monitoring system taking measurements in synchronisation with the rhythm of the electrocardiogram.

Electroanatomic mapping is carried out by inserting a multi-electrode probe into a heart of a living subject, recording electrograms from the electrodes concurrently at respective locations in the heart, delimiting respective activation time intervals in the electrograms, generating a map of electrical propagation waves from the activation time intervals, maximizing coherence of the waves by adjusting local activation times within the activation time intervals of the electrograms, and reporting the adjusted local activation times.

In a method and magnetic resonance (MR) apparatus for heart diffusion imaging, when an ECG trigger signal by a computer that operates an MR scanner, the MR scanner is operated to acquire a navigator echo before a stimulated echo sequence, in order to detect diaphragm position information. When the first diaphragm position information is not located in an acquisition window, the stimulated echo sequence is not executed, and the computer waits to receive the next ECG trigger signal. The detection time of the navigator echo after the stimulated echo sequence as well as the acquisition time of the stimulated echo sequence, are thus eliminated when the first diaphragm position information does not meet requirements, so can significantly reduce scanning time, and increase the image SNR.

Methods and systems for performing T1 mapping. T1 samples are obtained from an acquisition including one or more inversion groupings. The acquisition may be designed to result in incomplete tissue magnetization recovery between inversion groupings. The acquisition may be designed for the use of non-uniform, non-180° preparatory pulses. The method may also include the combined use of data from different inversion groupings. A model is used in which fit parameters are variable dependent on the inversion grouping.

Described herein is a method to detect perfusion and brain functional activity using Hyperpolarized xenon-129 (.sup.129Xe) Time-of-Flight (TOF) Magnetic Resonance Imaging (MRI). Specifically, this method uses hyperpolarized .sup.129Xe MRI to detect blood flow and perfusion changes in the region of interest. In addition, this method can be used to detect blood flow changes in brain tissue that corresponds to the brain functional activities by detecting the amount of .sup.129Xe dissolved in blood and brain tissue per unit of time.

In part, the invention relates to an image data collection system. The system can include an interferometer having a reference arm that includes a first optical fiber of length of L1 and a sample arm that includes a second optical fiber of length of L2 and a first rotary coupler configured to interface with an optical tomography imaging probe, wherein the rotary coupler is in optical communication with the sample arm. In one embodiment, L2 is greater than about 5 meters. The first optical fiber and the second optical fiber can both be disposed in a common protective sheath. In one embodiment, the system further includes an optical element configured to adjust the optical path length of the reference arm, wherein the optical element is in optical communication with the reference arm and wherein the optical element is transmissive or reflective.

Functional imaging for localization in biological tissue entails measuring a response in the tissue (240) to electromagnetic radiation. A catheter (200) for real-time monitoring of cardiac ablation is employed to distinguish a hemorrhage zone (232) from the sandwiching necrotic and healthy tissue, or to distinguish exogenous photoacoustic contrast agent from bordering native tissue. A pair of wavelengths is selected for differential absorption (244) of the radiation in, correspondingly, the hemorrhage zone or where the contrast agent exists, and relatively similar absorption elsewhere. Near infrared laser or LED light may be used photoacoustically to serially acquire (S310, S320) the two datasets to be compared, each representative of a time waveform. Alternatively, acquisition is for a pair of wavelength bands of microwave-induced thermoacoustic data. In either case, the members of the dataset pair are combined (110, 122) by subtraction or division to effect the piece-wise cancellation/enhancement for display (218) of the resulting signal in real time.

Methods and systems are disclosed for radiating a moving object. The method may comprise acquiring a plurality of indicators of the phase of a physiological cycle of a patient and a plurality of images of the patient that include a target. Each image may be taken at a different phase of the physiological cycle and may be registered to the phase at which the image was taken. The method may also include identifying the target in each of the plurality of images, calculating a dose of radiation required to treat the target, calculating the number, orientation, and dwell time of one or more radiation beams required to deliver the calculated required dose of radiation to the target, and calculating a position of each of the one or more radiation beams required to achieve the calculated orientation. Each position may be a function of the phase of the physiological cycle to which each of the plurality of images is registered.

Various aspects of a system and a method to provide assistance in a surgery in presence of tissue deformation are disclosed herein. In accordance with an embodiment, the system includes an electronic device that receives one or more tissue material properties of a plurality of surface structures of an anatomical portion. One or more boundary conditions associated with the anatomical portion may also be received. Surface displacement of the anatomical portion may be determined by matching a first surface of the anatomical portion before deformation with a corresponding second surface of the anatomical portion after the deformation. The volume displacement field of the anatomical portion may be computed based on the determined surface displacement, the received one or more tissue material properties, and the received one or more boundary conditions.

An embodiment in accordance with the present invention provides a method for non-invasively determining the functional severity of coronary artery stenosis. The method includes gathering patient-specific data related to concentration of a contrast agent within a coronary artery of a patient using a coronary computed tomography angiography scan (CCTA). The patient-specific data is used to calculate a patient-specific transluminal attenuation gradient for the coronary artery of the patient. The patient specific transluminal attenuation gradient is used to determine an estimate of a coronary flow velocity, pressure gradient, loss coefficient, coronary flow reserve, and/or fractional flow reserve for the patient. Coronary flow velocity, pressure gradient, loss coefficient, coronary flow reserve, and fractional flow reserve can then be used to estimate the functional severity of coronary artery stenosis.