Flexible interaction with CT scan data for radiotherapy treatment planning and other purposes
W. P. Sharpe, Diana Jenkins · British Journal of Radiology · 1980
The effective use of CT scan data in radiotherapy planning requires the provision of flexible methods of interaction for doctors and technicians with that data. In the Bristol Radiotherapy Centre an EMI IVC Mark II has been enhanced to support a planning system in addition to its use for diagnostic viewing of scans. The system supports two users: the first terminal is the EMI independent viewing console (IVC), extended by the addition of a second screen so that pictures may be displayed while dialogues with the user continue; the second terminal has graphics facilities and a GRAF/PEN digitizing tablet, but no capability for picture display. The prime interaction of a doctor with a scan to be used for planning is in the definition of the volume to be treated; other information can be entered by planning technicians. This interaction is achieved in one of two ways. The first is off-line and is provided by the production of life-size grey-scale copies of scans on an electrostatic printer/plotter. These are marked by the doctor at his convenience and the marks later input to the planning system using the GRAF/PEN. The second mode of interaction is via the IVC, where on-line definition of areas is achieved with the aid of an overlay controlled by the EMI trackerball. This method is useful when the doctor requires full IVC display facilities for defining these areas. No attempt has been made in this note to describe the filing structure of the planning system. It is this which allows easy access at each terminal to data input at the other and which holds the information necessary for the registration of GRAF/PEN data with scan data.