CARAT Tutorials: CT Angiography

Suitability of CARAT for CT Reporting

Of the many unique imaging capabilities of CT angiography, defining spatial relationships is clearly a highlight. Translation of these 3-D insights to paper is a challenge that CARAT meets. The “tree” image in Figure 1 illustrates a coronary artery spatial array with clear configuration insight.

(Although tree images are infrequently used in day-to-day CT analysis, this example illustrates the 3-D clarity of this imaging technique.)

CARAT is able to give a credible portrayal of this anatomy (Figure 2).


Figure 1. - CT Tree Image


Figure 2. - CARAT Rendering of Figure 1

Selection of CT Module Within CARAT

Selecting File > Report Heading on the Menu Bar reveals the types of reports available.

For this tutorial, selecting CT Report from this menu will activate the CARAT features unique to CT reporting.


Figure 3. - Accessing CT Report Features

Visualization Quality

Although the coronary tree is adequately seen in most CT angiograms, it is occasionally desirable to specify those distal, septal, or other unique situations in which visualization may be absent or suboptimal.

The CARAT Edit Menu, Figure 4, is accessed by right-clicking the tree diagram background. One of the options available is the Visualization feature.

(When opening the Edit Menu, be careful to select the diagram background; right-clicking the arterial segments offers other options outlined below).


Figure 4. - The CARAT Edit Menu and the “Visualization” Option

While in the Visualization mode, right-clicking on a coronary transition point where visualization quality changes reveals the Visualization submenu (shown in Figure 5).

In the CT example in Figure 1, above, the distal LAD is not visualized - This fact is graphically portrayed on the CARAT diagram.


Figure 5. - Visualization submenu. The ‘Not Seen’ option is selected for the distal LAD

Lesion Reporting

When the Lesion editing mode is selected from the CARAT Menu, lesions can be "drawn" onto the arterial segments by left-clicking, holding, and tracing the length of the lesion, from proximal to distal.

At this point, the lesion should be right-clicked to reveal the CT Lesion submenu (as shown in Figure 6). Lesion severity ranges are presented in keeping with the most current reporting guidelines.

After the severity is selected, selecting CT Feature provides additional lesion character detail on the lesion submenu as shown. Specifically, lesions can be classified as soft, calcified, or mixed; a letter appearing after the numerical severity range shows this designation.

As a reminder, the editing mode currently operative is shown in the lower left corner of the working area. To the right of this designation is a short description of the functionality of the left and right mouse keys while in that particular editing mode.


Figure 6. - CT Lesion Submenu also showing CT Features selection option

One additional coronary artery insight afforded by intravascular ultrasound and CT imaging is the important finding of positive remodeling.

This finding can be portrayed on the CARAT diagram (as shown in Figure 7), and is accomplished by the combined use of the Ectasia option superimposed on a lesion rendering.


Figure 7. - CARAT CT Depiction of Positive Remodeling

 

CARAT