Spine Labeling

	Spine Labeling Add spine-related labels to images. In Spine Labeling mode, the Spine Labeling tab is activated to provide access to other spine labeling tools.
	Toggle Spine Labeling Markup Hide or show spine labels. Note that Toggle Markup also hides / shows spine labels.
	Delete All Spine Labels Delete all spine labels in the study.

About spine labels

Annotations on vertebral bodies can help you to more easily understand the approximate position of an image within a patient's body. Typically, spine labeling should be used on studies with multiple views such as CT and MR so that eUnity can use the 3D information contained within the DICOM header of an image to automatically apply spine label annotations to other spatially related images. That is, if you apply labels to a sagittal series, eUnity automatically adds those labels to the corresponding vertebrae in the associated axial and coronal series.

Studies such as CR do not have DICOM information within the DICOM header that spatially relates multiple series. For these types of studies, the Spine Labeling tool can still be used to manually annotate a single image at a time. Images from such modalities are treated as sagittal views with the assumption that the top of the spine is at the top of the image. There is no automatic labeling of images in these non-spatially related modalities.

When you start labeling, eUnity will use the information in the DICOM header and the cursor position relative to the other spine labels to determine whether you are labeling ascending or descending order. The tool icon on the toolbar changes to display the vertebra that will be added on the next click. For example, the Spine Labeling icon () will change to and continue to increase or decrease as the mouse position changes. Sagittal and coronal views display the spine labels to the side of the image with a dashed indicator line and axial views display a text label centered at the top of the image. Text labels and indicator lines can be repositioned in any of the views.

For more information on spine labeling in different series and study types, see Spine labeling workflows below.

Add spine labels

To add spine labels, do the following: 

1. Click the series that you want to label. For CT and MR studies, this will typically be a sagittal view.
2. On the Markup tab, click to turn on Spine Labeling mode and display the Vertebral Bodies menu. Once Spine Labeling mode is turned on, the Spine Labeling tab is activated and it is available until the end of the session.
3. In the Vertebral Bodies menu, click the vertebra that you want to start with.
4. In the image, left-click on a vertebra center to add a spine label. If necessary, click and drag the text label to reposition it. Alternately, to add and reposition the label in one step, click and hold the vertebra center and then drag the cursor to position the text label (note that this behavior does not apply to axial series).
5. Move your cursor to the next vertebra. The Spine Labeling icon on the toolbar indicates which label will be added on next. In case the toolbar displays no vertebra label or a vertebra label different from what you want to add, click the Spine Labeling icon again and select the desired vertebra from the Vertebral Bodies menu. See below for how to Add C8, T13, or L6 labels.

To turn off spine labeling, and return to Navigation mode, click

Add C8, T13, or L6 labels

To apply C8, T13, and L6, simply skip those vertebrae and apply the labels immediately before and after them. When you return your cursor to the skipped vertebra, eUnity will automatically switch to the missing label so you can apply it.

For example, to add the C8 vertebra, do the following:

1. Add the C7 label, skip C8, and apply T1.
2. Move your cursor between the C7 and T1 labels. The Spine Labeling tool icon on the toolbar changes to C8.
3. Left-click the image to apply the C8 label.
4. Move the mouse to the vertebra below T1. The Spine Labeling tool icon will change to T2.

Edit or delete spine labels

To edit a spine label, do any of the following: 

• On sagittal or coronal views, drag the text label or indicator line to a new location. Ensure that you keep the end point of the indicator line as close as possible to vertebra center.
• For non-spatially related studies, drag the text label or indicator line to a new location.
• On axial views, drag the label anywhere in the image.

To delete spine labels, do any of the following: 

• Click to show the Vertebral Bodies menu. Clear the vertebra that you want to remove.
• Click the spine label that you want to remove and press the Delete key on your keyboard.
• On the Spine Labeling tab, click to turn on the Eraser tool. Click the spine label to remove. Note that the Eraser tool cannot be used to remove to spine labels on axial series.
• To remove all spine labels in the study, on the Spine Labeling tab, click

Navigate using spine labels

1. Double-click the spine label on a sagittal or coronal series to display that vertebra in all series.

Spine labeling workflows

The typical scenarios where spine labeling is used are:

• Labeling a sagittal or coronal series (e.g. a CT or MR)
• Labeling an axial series (e.g. a CT or MR)
• Labeling an image (e.g. a CR or DX)

Labeling workflow for sagittal series

The most common use of spine labeling is to label images within a sagittal series of a DICOM study. This workflow is similar for labeling coronal series.

In this scenario, the common steps are:

Left-click a vertebra on a sagittal image to apply a spine label. For example, C2. The Spine Labeling tool will do the following:

• Apply a spine label of C2 to every image in the selected image’s series.
• Copy a matching spine label of C2 to every image in any spatially related sagittal images within the same study.
• Apply a spine label of C2 to any spatially related axial image within the same study that are near the point selected in the sagittal image.
• Apply a spine label of C2 to any spatially related coronal image within the same study that are near the point selected in the sagittal image.
• Apply a spine label of - / C2 to any spatially related axial image within the same study that are anatomically above the image labeled C2.
• Apply a spine label of C2 / - to any spatially related axial image within the same study that are anatomically below the image labeled C2.

Note: If you move your mouse above and below the C2 spine label annotation, you can see that the spine label tool icon will update its spine label vertebra to C1 and C3, respectively.

Select a second vertebra on a sagittal image to apply another spine label of below the first spine label of C2. The Spine Labeling tool will do the following:

• Apply a spine label of C3 to every image in the selected image’s series.
• Copy a matching spine label of C3 to every image in any spatially related sagittal images within the same study.
• Apply a spine label of C3 to any spatially related coronal image within the same study that are near the point selected in the sagittal image.
• Update the spine label(s) of C2 / - to C3 to the images within the selected series and any spatially related axial image within the same study that are near the point selected in the sagittal image.
• Update the spine label(s) of C2 / - to C2 / C3 to the images within the selected series and any spatially related axial image within the same study that are between the images identified as C2 and C3.
• Update the spine label(s) of C2 / - to C3 / - to the images within the selected series and any spatially related axial image within the same study that are below the images identified as C3.
• This process continues for each spine label the user selects to apply.

Labeling workflow for axial series

This workflow is similar to labeling a sagittal series. It is used when the study does not contain spatially related sagittal or coronal images. Reference lines are useful for adding spine labels on studies that do not have sagittal images.

In this scenario, the user selects the axial image they would like to apply a spine label on (for example, C2) and click to apply the spine label. The Spine Labeling tool does the following: 

• Apply a spine label of C2 to the selected image and any spatially related axial image within the same study that are near the point selected in the axial image.
• Apply a spine label of - / C2 to any spatially related axial image within the same study that are anatomically above the image labeled C2.
• Apply a spine label of C2 / - to any spatially related axial image within the same study that are anatomically below the image labeled C2.

The user navigates to the image that has the vertebra C3 and clicks to apply a spine label. The Spine Labeling tool does the following: 

• Update the spine label(s) of C2 / - to C3 to the selected image and any spatially related axial image within the same study that are near the point selected in the axial image.
• Update the spine label(s) of C2 / - to C2 / C3 to the images within the selected series and any spatially related axial image within the same study that are between the images identified as C2 and C3.
• Update the spine label(s) of C2 / - to C3 / - to the images within the selected Series and any spatially related axial image within the same study that are below the images identified as C3.

Labeling workflow for non-spatially related studies

Spine labels can be applied to modalities that have no image orientation and position information, (that is, studies other than CT and MR). Images from such modalities are treated as sagittal views with assumption that the top of the spine is at the top of the image. There is no automatic labeling of images in these non-spatially related modalities.