- Poster presentation
- Open Access
Visualization of dynamic active devices via adaptive undersampled projection imaging
© George et al; licensee BioMed Central Ltd. 2010
Published: 21 January 2010
Accurate knowledge of the location of an interventional device is crucial to the success of MR-guided interventions. This paper extends previous work [1, 2] in visualizing an active device at a single time-instant, to the case of moving devices, by updating the dynamic device trajectory from vastly reduced projection data.
To seamlessly visualize dynamic active devices in a multi-slice real-time display by reducing data requirements.
Knowledge of the device trajectory at a particular time-instant is used to adapt the orientation of the two projection images from which the device trajectory at the next time-instant will be estimated. They are chosen to have independent and unobstructed views of the device, a small FOV in the phase-encoding direction, and allow for some device motion between the current time-instant and the next.
To compute the trajectory at a time-instant we evaluate local 2D slices, which are perpendicular to the device trajectory at the previous time-instant, in the volume image formed from the product of the two projection images. We update the previous device trajectory by the location of the centroids of these local 2D slices  and further refine the estimate by extending or cropping the ends of the device based on the re-projection of the 3D point onto each 2D projection image .
Adapting the orientation and size of the projection images to the current estimate of the device trajectory allows for greater reductions in data requirements than previously achieved .