Image Annotations

Annotation Toolbar

1. Measure Distance

2. Measure Angle

3. Houndsfield Value

4. Region of Interest

5. Free Region

6. Pointer

7. Text

8. Spine Labeling

The annotation tools are used to add graphics and measurements to images. To display the Annotations toolbar, select Annotation Tools from the Tools dropdown.  They can also be accessed in the second row of the toolbars or by utilizing the mouse controls. Once and annotation has been placed on the image, click on the Default Mode Cursor 

There are eight Annotation Tools available:

• Measure Distance
• Measure Angle
• Houndsfield Value
• Region of Interest
• Free Region
• Pointer
• Text
• Spine Labeling

Measure Distance, Measure Angle, Region of Interest and Free Region are all measurement annotations.

See: Annotating Measurements

Modifying or Removing Annotations

To delete or modify an annotation:

1. Hover over annotation until icon appears and annotation is highlighted.

2. Right click on the image annotation

In the box that opens there are two options: Delete or Delete All. The other options allow modifications, including color and font changes, depending on the annotation.

Text Annotations

Use the Add Text   button, , to create or add text to an annotation to an image.  A window appears with a field for entering the text string. This field is also pull-down list containing the previously entered annotation strings.

Hounsfield Value

The Hounsfield annotation tool creates a region of interest and calculates its average pixel value and the standard deviation on the distribution.

     To obtain the Hounsfield Value of an area of an image:

1. Select the Hounsfield Value icon 

2. Click on the region of interest

3. Drag on the mouse to encircle the area

4. Release the mouse button

  The default region of interest drawn on the image is a true circle. When resizing the ROI, maintain a true circle by using the corner grab points.

Pointer Annotation

The pointer graphic tool draws an arrow on the image.

To insert a pointer arrow:

1. Select the Pointer icon  
2. Drag the mouse to adjust size of pointer

You can rotate the arrow by clicking on the end of it and dragging around.

Spine Labeling

The spine labeling cursor will label disc vertebrae and disk interspaces. These predefined labels are displayed in their corresponding location on images in all orthogonal planes.

To insert a spine label:

1. Select the Spine Labeling icon 
2. Left click the icon next to each vertebrae or interspace to place a level annotation
3. Select the next vertebrae or interspace to place the next level

Right clicking on the screen will reveal a spine label control panel.  This box allows the user to reset the labeling for the vertebrae and the interspace and choose new levels.

The settings tab contain these following options which are reset when the control panel is restarted:

In order to place specified labels in the orthogonal images, the graphic must intersect the image within the defined distance from the focus point which will then appear in the intersecting plane. The spine labels appear in all orthogonal images automatically. If the frame of reference is not predefined, the images would have to be labeled individually. If the focus point falls outside the distance specified, no label appears.

To remove a single label:

1. Select annotation cursor mode

2. Right-click on the label

3. Select Delete

Select Delete All from the same menu to remove the spine labels and all other annotations. To remove all spine labels, including all the labels in intersecting planes, and leave other annotations, click Reset Spine Label on the spine label popup window.

See also:  Annotation Toolbar