Respiratory-Gated MRgHIFU in Upper Abdomen Using an MR-Compatible In-Bore Digital Camera
Figure 1
(a) Active MR-compatible USB-driven digital optical camera and the MR-compatible high power 3 LED lighting device. (b) Optical motion tracking experiment inside the MR bore on sheep abdomen, during forced breathing under general anaesthesia. Note the MR coil connector (1). The green dots are the automatically determined registration points. An exemplary breathing signal curve and a time-scrolled narrow vertical band from the image are shown. (c) A similar experiment, where a patch (2) was applied on the animal skin and high contrast markers were drawn (3). (d) Two overlapped frames from exhalation and inhalation phases, respectively, using a 50% transparency layer, same optical data as (c). The motion vectors of the representative optical registration points are drawn with red arrows.
