The Arithmetics operator can be used to add, subtract, multiply, divide, average or merge multiple images. Additionally, a scalar multiplier or addend can be applied to all voxels of an image with the Arithmetic operator.

Getting There

The Arithmetics operator can be accessed via the tool pull-down menu on VivoQuant’s front panel.

Arithmetics Tool
Arithmetics Tool

Using the Tool

Upon selecting the operator, the Arithmetics window is displayed.

Arithmetics Tool Window
Arithmetics Tool Window

The main drop-down menu in the operator window contains a selection of the available operators. In some cases, multiple images can be selected for the operation via the Data Selector Widget.

  • Add, Subtract, Multiply, Divide, and Average: each of these operates on two images. These operations are performed voxel-wise.
  • Scalar Multiply and Scalar Add: can be applied to any of the loaded images. Set the factor or addend by increasing or decreasing the scalar value.
  • Weighted Average: applies a time weighted average across the selected dynamic images. Weights can be set manually per-frame or derived from DICOM header entries.
  • Merge whole integer value phantoms to load into the 3D ROI tool. It can be applied to any of the loaded images. This is very useful for fixed-volume ROI analysis.
Merge
Merge

Click OK to perform the chosen operation. A dialog will appear to indicate successful application of the chosen function.

Operation Applied
Operation Applied

For all arithmetic operations, the user has the option to append the resulting volume(s) or perform the function in-place, thus replacing the existing data with the amended data.

Data List
Data List

Units are considered by the Arithmetics operator. A warning will be displayed if an attempt is made to add, subtract, multiply, divide or average two images of differing units and will allow the user to halt the operation.

Arithmetic Units
Arithmetic Units