I have a CT volume displayed axially in a slice view. On this volume I perform different kind of algorithms (this is not the point now) to produce ultrasound-like images.
My question is, how can I apply a mask to convert (or to shape) the slices into a fan-shaped slice, like the (convex) ultrasound images look like?
The easiest is probably to create a mask image and use it to mask the processed CT:
Create a mask image: it can be a single-slice volume that is non-zero inside the fan and zero outside
In slice view controller: select mask image as background, and the CT as foreground imagecontroller
In Volumes module: apply thresholding to the mask volume to hide voxels that has zero value - this not only hides mask volume contents but also the foreground
To move around this slice: apply a transform to the mask image, and use mask image as Driver in Volume Reslice Driver module (available in SlicerIGT extension)
It is possible to create the mask by inputting a uniform image to the SlicerITKUltrasound extension module for a curvilinear array or a 3D phased array.