Spine Task

Vertebral measurements are made by positioning three landmarks for each vertebra: one at the back of the spinous process, and one each on the left and right lamina. These landmarks can be placed by first clicking the appropriate button for that landmark and vertebra, and then clicking in the correct location either on the review window or on the reslice window.

There are also three landmarks used as a reference to define the lateral, axial and dorsal axes. The 'left lower' and 'right lower' landmarks define the lateral axis, and the mid-point defines the start of the axial axis. The other 'central upper' landmark defines the other end of the axial axis. If these landmarks are not defined, the lowest vertebra is used for the lateral axis reference, and the direction from the lowest to the highest as the axial axis reference. If the 'Use reslice as reference' button is pressed, the landmarks will be defined based on the orientation of the current reslice (bottom image window), which is itself defined by the overall geometry of the acquired data set, and the display tools in the spine visualisation window.

Once defined, the corresponding button will change to , and subsequently clicking on this button will find this landmark in both the review and the reslice windows. There is also a 'delete' button which will remove all landmarks associated with one vertebra.

Spine landmarks can be moved and deleted in exactly the same way as other landmarks. They also appear in the landmark task page and are stored in the stradwin file. However, they have specific names in order to be recognisable as spine landmarks. These names can be changed in the normal landmark task page, for instance if the wrong vertebra was marked, but only to other appropriate spine landmark names.