Adding a 3D Sphere

Introduction

Use the 3D Sphere option to create a 3D sphere on 2D, 3D, or fused images to measure density or the maximum standardized uptake value (SUV) inside the sphere. When you add a 3D sphere to 2D, 3D, or fused images, all series with the same frame of reference (FOR) display the 3D sphere.

The 3D Sphere option is also used to calculate the Peak SUV on Positron Emission Tomography (PET) images, by identifying the regions with the largest average radiotracer uptake of all 1 cm3 spherical volumes of interest (VOI) within the annotation.

Note:

Manual calibration does not apply to volume annotations in a 3D sphere .

Steps

  1. Right-click the image to display a context menu.
  2. Do one of the following:
    • Select Annotations > 3D Sphere.
    • Press 0 on the keyboard.
  3. Click the image and hold the left-mouse button down.
  4. Drag the mouse to the outside edge of your circle and release the mouse button.
  5. Optional: To change the size of the sphere, click, hold, and drag the edge of the sphere.

Results

For images that do not support SUV measurements, Synapse displays the following measurements:

  • Diameter (D)
  • Volume (V)
  • Maximum density (Max)

For images that support SUV measurements, Synapse displays the following measurements:

  • Diameter (D)
  • Volume (V)
  • Maximum SUV (Max SUV)
  • Peak SUV

Note:

Peak SUV requires a minimum of 1 cm3 sphere to calculate.

For fused images, Synapse displays the maximum density for both the overlay and the base images.

Additional Options

Click ROI Sphere on the icon menu.

Related Topics

Density Value

Configuring Custom Shortcut Keys