Measurement Tools
Measurement tools are available from the toolbar and allow users to create, label, and analyze measurements directly on medical images.
When a measurement tool is selected, it becomes the active tool. Additional tools can be accessed using the dropdown menu.
When a tool is selected from the toolbar, it becomes enabled and is visually highlighted to indicate its active state. Clicking the same active tool again will disable it, removing the highlighted state from the toolbar.
Key behaviors:
- A selected tool becomes enabled and visually highlighted in the toolbar.
- Clicking an active tool a second time disables it and removes the active/highlighted state.
- When a tool is deactivated, the Window Level tool automatically becomes the active tool, as one tool must be active at all times.
- To re-enable a tool, click its toolbar button again.
- Tools selected from a dropdown or menu automatically become enabled and visually highlighted upon selection.
- This behavior applies only to the toolbar currently in context for the active viewport.
Accessing Measurement Tools
- Select a measurement tool from the toolbar
- Use the dropdown menu to view additional tools
Linear Measurements
Length Tool
The Length Tool measures distance in a straight line between two points.
- Click to place the starting point
- Drag to define the endpoint
Bidirectional Tool
The Bidirectional Tool measures two perpendicular linear distances from a central point.
- Used for assessing lesion size in two dimensions
Annotation
Annotation Tool
The Annotation Tool allows users to create labeled annotations.
- Enter a label when prompted
- Adjust the position after placement
Spine Labeling
The Spine Labeling feature allows users to label vertebral levels directly within the viewport using annotation tools.
This feature is commonly used to identify and document vertebral anatomy during diagnostic review.
Usage
- Select the Spine Labelling Tool from the toolbar
- Click on the desired vertebral location within the viewport
- Enter the appropriate vertebral label (e.g., C1, T12, L5)
- Adjust the label position as needed for clarity
Behavior
- Labels are displayed within the viewport and associated with the active study
- Labels can be edited or repositioned after placement
- Labeled annotations are tracked in the Measurement Panel located on the right side of the application.
Spine labeling is dependent on user input and does not perform automatic vertebral identification.
Use consistent vertebral labeling conventions when reviewing and comparing studies to ensure clarity and accuracy.
Grease Pencil Tool
The Grease Pencil Tool allows users to draw freehand annotations directly on the image for visual reference.
This tool is intended for non-measurement markings such as highlighting structures, outlining areas of interest, or adding visual notes during image review.
Usage
- Select the Grease Pencil Tool from the toolbar
- Click and drag within the viewport to draw freehand
- Release the mouse to complete the drawing
Behavior
- Drawings are displayed as overlay annotations within the viewport
- Grease pencil markings can be edited or removed after placement
- Drawings are associated with the active study
Grease pencil annotations are intended for visual reference only, do not represent quantitative measurements, and are temporary and not persisted.
Use the Grease Pencil Tool to quickly highlight regions of interest or communicate findings during collaborative review.
Area Measurements (ROI Tools)
Ellipse Tool
Measures an elliptical region of interest.
- Area (mm²)
- Mean intensity (HU)
- SUV (when PET data is available)
Circle Tool
Measures a circular region of interest.
- Radius (mm)
- Area (mm²)
- Mean intensity (HU)
Rectangle Tool
Measures a rectangular region of interest.
- Area (mm²)
- Mean intensity (HU)
Advanced ROI Tools
Freehand ROI Tool
Allows users to draw a custom-shaped region of interest.
- Area (mm²)
- Mean intensity (HU)
Spline ROI Tool
Creates a smooth boundary using interpolated control points.
- Area (mm²)
Livewire Tool
Provides edge-detection assistance for tracing anatomical structures.
- Follows image gradients to improve accuracy
Cardiothoracic Ratio (CTR) Tool
Overview
The Cardiothoracic Ratio (CTR) Tool enables clinicians to perform a standardized measurement of cardiac enlargement directly within AdvaView. The tool calculates the ratio of the cardiac shadow width to the thoracic inner diameter on a posteroanterior (PA) chest radiograph and displays the result as a percentage overlaid on the image.
A CTR greater than 50% is generally considered the threshold for cardiomegaly in an adult PA chest radiograph. The CTR Tool supports this assessment by providing a fast, reproducible measurement without leaving the viewer.
Indications for use
The CTR Tool is intended for use on posteroanterior (PA) chest radiographs in adult patients. It is not validated for AP projections, pediatric imaging, or non-chest modalities. Results should always be interpreted in clinical context by a qualified radiologist or clinician.
Activating the tool
- Open a PA chest radiograph in the AdvaView viewport.
- Locate the CTR Tool button in the viewer toolbar.
- Click the button to activate the tool. The cursor will change to indicate the tool is ready for annotation.
Drawing the measurements
The CTR Tool requires two separate line annotations to be drawn on the image. Both lines should be drawn on a true PA projection with the patient upright and at full inspiration for accurate results.
Step 1 — Cardiac shadow width
Draw a horizontal line spanning the widest transverse diameter of the cardiac silhouette. This line should extend from the rightmost border of the right cardiac margin to the leftmost border of the left cardiac margin, parallel to the midline.
The measured value is displayed on the image as Cardiac Shadow in millimeters.
Step 2 — Thoracic inner diameter
Draw a second horizontal line spanning the widest inner diameter of the thoracic cage. This line should run between the inner aspects of the right and left rib margins at their widest point, also parallel to the midline.
The measured value is displayed on the image as Thoracic transverse inner diameter in millimeters.
Output
Once both lines are drawn, AdvaView calculates and overlays three values directly on the image:
| Field | Description |
|---|---|
| Cardiac Shadow | Transverse diameter of the cardiac silhouette, in mm |
| Thoracic transverse inner diameter | Widest inner thoracic diameter, in mm |
| Cardiothoracic Ratio | Cardiac shadow ÷ thoracic diameter, expressed as a percentage |
The overlay is rendered in the viewport and is included in any screenshots or exports taken from the active study.
Note: If measurement values are displayed with an ERMF indicator, the image has not yet been calibrated. Millimeter values will not be accurate until calibration is performed. Calibrate the image before relying on CTR measurements for clinical assessment.
Editing and clearing measurements
- To reposition a line, click and drag either endpoint or the line body.
- To redraw a measurement, activate the CTR Tool again and place a new line; the previous annotation for that step will be replaced.
- To clear all CTR annotations, use the Clear Annotations action in the toolbar or right-click context menu.
Limitations
- CTR measurements are only reliable on true PA projections. AP projections magnify the cardiac silhouette and will produce falsely elevated CTR values.
- The tool does not account for patient rotation, suboptimal inspiration, or overlying pathology (e.g., pleural effusion, consolidation) that may obscure cardiac or thoracic borders.
- This tool is intended to assist clinical assessment and does not replace radiologist judgment.
Angular Measurements
Angle Tool
Measures the angle between two intersecting lines.
Cobb Angle Tool
Measures spinal curvature, commonly used for scoliosis assessment.
General Notes
The availability of measurement tools may depend on the image modality and system configuration.
Use consistent measurement techniques when comparing current and prior studies to ensure accuracy.
Measurement accuracy depends on correct image calibration and the presence of appropriate DICOM metadata.