Her Majesty the Queen in Right of Canada, As Represented by the Minister of National Defence of Her Majesty's Canadian Government

Canamet Canadian National Medical Technologies Inc

Waheed Younis

Stergios Stergiopoulos

Amar C Dhanantwari

Miroslaw Wrobel

Andreas Freibert

Storgios Stergiopoulos

The present invention relates to a method for tracking motion phase of an object. A plurality of projection data indicative of a cross-sectional image of the object is received. The projection data are processed for determining motion projection data of the object indicative of motion of the object based on the attenuation along at least a same line through the object at different time instances. A motion phase of the object with the object having the least motion is selected. Finally, projection data acquired at time instances within the selected motion phase of the object are selected for tomographical image reconstruction. Reconstructed images clearly show a substantial improvement in image quality by successfully removing motion artifacts using the method for tracking motion phase of an object according to the invention. The method is highly beneficial in cardiac imaging using X-ray CT scan.

Method for tracking motion phase of an object for correcting organ motion artifacts in X-ray CT systems

The present invention relates to a signal processing method and system for correcting organ motion artifacts for cardiac and brain imaging. A plurality of sets of MRI measurement data indicative of at least an image of an object is received. Each set corresponds to one row kof a k-space matrix of at least a k-space matrix. For each set a k-space matrix of the at least a k-space matrix is determined for allocation thereto based on motion information of the object occurring during acquisition of the plurality of sets of the MRI measurement data. In a following step a location within the allocated k-space matrix corresponding to a row of the k-space matrix allocated thereto is determined for each set. At least a k-space matrix is then generated by re-arranging the plurality of sets. Each of the at least a k-space matrix comprises the sets of the plurality of sets of the MRI measurement data allocated thereto. Inverse Fourier transforming of the plurality of k-space matrices provides at least a reconstructed image. Through careful selection of the phases of the cardiac and respiratory cycles and corresponding ranges MRI data acquisition periods are of the order of seconds or a few minutes. Furthermore, integration of motion artifact free MRI images of different phases of organ motion using the coherent k-space synthesis according to the invention allows provision of an animation showing different phases of a cardiac or lung cycle. In an embodiment for correcting motion artifacts for brain imaging a motion vector describing translational and rotational motion of a patient's head is tracked during the MRI data acquisition process. The motion artifacts are then corrected based on coherent k-space synthesis using the motion vector data.

Method and device for correcting organ motion artifacts in MRI systems

Growing community of inventors

Toronto, Canada

Waheed Younis