Display Option: Compare

The Compare display option is available in 3x3, 2x3, and 1x3 layouts. You can compare datasets using all three standard axes (MPR images).

The composition of the fusion image is predefined. You might see a pair of datasets superimposed on the fusion image that are different from the datasets presented in the other windows.

Important: A three-dimensional image is not supported in the Compare Display Option.

Example of Compare 1x3

Axial, PET

Coronal, PET

Sagittal, PET

Example of Compare 2x3

Axial, PET	Coronal, PET	Sagittal, PET
Axial, CT	Coronal, CT	Sagittal, CT

Example of Compare 3x3

Axial, PET	Coronal, PET	Sagittal, PET
Axial, CT	Coronal, CT	Sagittal, CT
Axial, Fusion	Coronal, Fusion	Sagittal, Fusion

Example of Compare with No Attenuation Correction (NAC)

Axial, PET	Coronal, PET	Sagittal, PET
Axial, NAC	Coronal, NAC	Sagittal, NAC
Axial, CT	Coronal, CT	Sagittal, CT

Common Scenarios for Using Compare

Compare PET/CT, PET/Fusion, or CT/Fusion pairs, or compare a CT/PET/Fusion triplet
Compare a current CT/PET/Fusion dataset with a prior dataset
Compare different windowing for the same set; for example, CT with different windowing
Compare any two datasets; for example, CT with MR
Compare original data in the Volume Matching viewbox with secondary or tertiary data

Exceptions and Behaviors

Orientation

Each row of MPR images shows a single dataset. The same row cannot mix different datasets. The first two rows in the 3x3 layout could show the exact same data, which you can view with different windowing. The third row in the 3x3 layout window will always show the PET/CT fusion image.

Each column of MPR images shows a single orientation. The same column cannot mix different orientations.

You can change the MPR orientation/planar view.

You cannot view registered datasets in different orientations simultaneously. Each column of registered MPR images is synchronized when you change the orientation.

You can view unregistered datasets in different orientations simultaneously. Because the MPR windows are not synchronized, you can control the orientation in each window separately.

Parameters

The Zoom, Pan, and Windowing parameters are synchronized between each row of windows. For example, changing the zoom and windowing of the axial PET image also affects the coronal PET and sagittal PET images.

The Zoom, Pan, and Windowing parameters are synchronized between each column of windows. For example, changing the windowing of PET or CT images also affects the Fusion image.

You cannot scroll across an orientation or window across a dataset individually. The parameters are synchronized.

You can change the dataset by using the Replace With annotation or the PMA. Each dataset replacement affects the windows belonging to the row that you selected. The other rows are not affected.

Relate Mode

You can use Relate Mode to relate all datasets. See Correlating Regions of Interest in Registered Studies (Relate Mode).