Defining a Structure to be Traced

• Renaming an existing structure
• Defining a new structure
• Setting the currently selected structure

Before you start to trace an anatomic structure, you should name the structure. The name that you choose will also determine the name under which MultiTracer will save the structure if you later choose to export the trace as a UCF file (spaces will be converted to underscores and .ucf will be appended, e.g., "left caudate" becomes "left_caudate.ucf"). Consequently, the name that you choose is effectively a file name. MultiTracer will promt for permission to overwrite if a file with that name already exists.

MultiTracer provides a default temporary structure name for convenience. This temporary file name includes the characters 'unexportable'. Any structure name with these characters cannot be exported as a UCF file unless it is renamed. Consequently, you may want to enter your first structure name by simply renaming this structure.

To rename a structure:

1. Select "Edit Structure Name" from the main "Contour" menu
2. Enter a new structure name
3. Press the "OK" button
4. If the structure name was successfully changed, the revised name will persist in the control panel. If not, it will revert to the old name.

To define a new structure name by adding a structure:

1. Set the orientation of the main window to the orientation in which you will draw the structure
2. Choose a name for the structure (e.g., "left upper hippocampus")
3. From the "Contours" menu, select "Add Structure"
4. Enter the name of the stucture. This name can be preceded by a Unix style directory path if you like (e.g., "/data/patients/patient01/left upper hippocampus"). However it is best to avoid absolute paths if you want to be able to move the data to some other machine where /data/patients/patient01/ might not exist before exporting the data as a UCF. You can use the "Set Working Directory" item under the "File" menu to change the directory used to resolve relative paths.
5. Press the "OK" button
6. If the structure has been successfully defined, the name that you entered will appear in the control panel in the main window, and the text of the "Trace" button on the control panel will turn red indicating that MultiTracer is now in tracing mode.
7. You can repeat the above steps to define additional structures if you like.

Structures are only defined for one orientation. For example, if you defined a structure with the images displayed transversely, that structure will not be accessible if you switch to a coronal or sagittal display. If you want to trace the same structure in more than one orientation, you will need to define unique names for the structure in each orientation (e.g., "coronal left hippocampus" and "sagittal left hippocampus".

If you have more than one structure defined for a given orientation, you can switch from one structure to another in one of two ways:

• By selecting the structure you want in the control panel at the bottom of the main window
• By choosing "Next Structure" in the main window's "Contour" menu until the structure that you want is displayed in the control panel at the bottom of the main window

Modified: August 26, 2012