Ultrasound Frame Geometry

The Ultrasound Frame Geometry defines the spatial interpretation of the ultrasound data shown in the images of an Ultrasound Sweep or stream. The Frame Geometry is essential for the correct interpretation of the ultrasound image data, such as only considering the pixels with the fan beam in image registration or calibration algorithms. It is also helpful for the user to understand the spatial orientation of the image data and allows to crop and mask the image data to the fan beam area.

The Ultrasound Frame Geometry can define

  • the imaging depth

  • the location of the image orientation indicator that relates to the fiducial on the ultrasound probe

  • whether the direction of imaging is upward or downward in the image, e.g. for endocavity imaging

  • the shape of the fan beam, e.g. a rectangle or parallelogram for linear probes, or a fan for convex probes.

For Ultrasound Sweeps (pre-recorded data), the Frame Geometry can be edited in the Ultrasound Sweep Properties dialog, in the Fan tab. For live ultrasound data, is the Frame Geometry can either be set by the vendor specific plugin, or in the case of frame grabbing in the GUI of the Process Ultrasound Algorithm (requires the Live Ultrasound module).

There are four different geometries available:

  • Linear

  • Convex (round at top and bottom)

  • Sector (flat at top, flat or round at bottom)

  • Circular

../_images/FrameGeometryConvex.png

Convex Frame Geometry
../_images/FrameGeometryLinear.png

Linear Frame Geometry
../_images/FrameGeometrySector.png

Sector Frame Geometry
../_images/FrameGeometryCircular.png

Circular Frame Geometry

The Frame Geometry dialog allows to adjust the parameters of the selected geometry. All frame geometries have an origin, which is the position of the transducer tip in the image. Alternatively, the geometry can be adjusted by dragging the geometry outline in the image view, or the control points therein.