Measure tool/distance measurement

With the measure tool you can measure distances within the image. The measure tool will display distance in millimeters if pixelsize is specified in the DICOM header. If not, or multiple pixelsizes are found in the DICOM header, you have to use the calibrate tool to convert image pixels to millimeters.

Zoom the image and maximize the window to be able to measure more accurately. Start a measurement by positioning the mouse pointer at the beginning of the object to measure, then single click. Now drag the mouse pointer to the end of the object and single-click again. Press 'Escape' to cancel your current measurement.

Measurements can be modified by moving the mouse pointer over either end of the measurement. It will change the line of the measurement from solid to dotted and a square will be displayed at the selected end of the measurement. Click and drag this square to modify the measurement.

Delete a measurement by moving the mouse pointer over either end, then double click the displayed square. This only works when the distance measurement tool is active, i.e. assigned to a mouse button!
All measurements can be deleted at once by pressing the 'Delete all measurements' button in the toolbar. This will delete all angle and area measurements as well. Go to 'Tools' and 'Delete measurements' in the menu, to delete the distance measurements only.

To start a new measurement from either end of an already existing one, move the mouse pointer over the end of the existing measurement. This measurement will change to dotted and the square will appear, enabling you to drag/modify but disabling you to start a new measurement. Now simply press 'Escape' to remove the focus from the existing measurement to enable the start of a new distance measurement from this position.

When you displaying a run and the measure tool setting is set to 'Display measurement on the displayed image only', the distance measurement will be displayed only on the image on which it is created. You can change this, i.e. display the measurement on all images, by highlighting it and then press 'c' on your keyboard. This measurement will now be displayed on all images. Do the same to undo.

See the Measure tool settings to change the creation- and display characteristics of the tool.