King's College London

Siemens Healthineers Ag

Shaihan Jalal Malik

Joseph Vilmos Hajnal

Raphael Tomi-Tricot

Francesco Padormo

Felipe Godinez

Rui Pedro Azeredo Gomes Teixeira

Daniel John West

David Leitão

A method of operating a magnetic resonance scanner includes determining a radio frequency (RF) pulse to be transmitted to jointly homogenize a flip angle and a semisolid saturation that would result from magnetization of a sample to be scanned by the MR scanner using the determined RF pulse. The method also includes controlling an RF transmit coil of the MR scanner to transmit the determined pulse. Homogenizing both semisolid saturation and excitation properties of the RF pulse allows for improved magnetic transfer ratio imaging.

Method of operating a magnetic resonance scanner

The present invention relate to a system and associate method of MRI and MR spectroscopy which provide stable measurements of the relaxation times, T1 and T2, by using tailored multi-band RF pulses that direct control of the saturation conditions in the background pool of macro-molecular protons, and hence provide a flexible means to induce constant Magnetisation Transfer (MT) effects. In doing this, equal saturation of the background pool is obtained for all measurements independent of the parameters that may be changed, for example, the rotation rate used to obtain a desired flip angle, that is, the degree of change in the magnetisation of the free pool of protons.

Controlled excitation and saturation of magnetisation transfer systems

Parallel transmit Magnetic Resonance MR scanner used to image a conductive object such as an interventional device like a guidewire within a subject. This is achieved by determining which Radio Frequency RF transmission modes produced by the parallel RF transmission elements couple with the conductive object and then transmitting at significantly reduced power so as to prevent excessive heating of the conductive object to an extent that would damage the surrounding tissue of the subject, for example, the coupling RF transmission modes may be generated at less than 30%, preferably around 10% of the normal power levels that would conventionally be used for MR imaging. However, even at these low power levels sufficient electric currents are induced in the conductive device to cause detectable MR signals; the location of the conductive object within the subject can thus be visualised. By fast alternate, or simultaneous, iterative application of low-power coupling mode and normal-power non-coupling modes, both the subject and the conductive object can be imaged. During the calibration step of determining which RF transmission modes couples with the conductive object, instead of physically measuring the current induced in the conductive object using sensors, imaging the conductive object using additional very short series of flip angle RF pulses (vLFA) gives a good approximation of the coupling matrix.

Method and system for magnetic resonance imaging

Growing community of inventors

London, United Kingdom

Shaihan Jalal Malik