Transforming Images into Standard Short Axis Orientation

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Transforming Images into Standard Short Axis Orientation

The next step is to rotate the images into the standard short axis orientation, see Standard Reorientation of the Heart. An automatic procedure is available, but when it fails a manual interaction is required.

Automatic Reslicing

The PCARDP tool offers an automatic procedure for the short axis reorientation. As soon as the button indicated below is activated the procedure is started.

PCARD Automatic Reorientation

The images are reoriented, and the resulting parameters shown in the reslicing tab. The box next to the reorientation button is for enabling the automatic mode. If it is checked, the reorientation process is started as soon as anatomical images are generated or loaded.

The arrow below the box can be used to copy the short axis transformation from rest to stress, and vice versa. If the transformation is copied, the target images are immediately resliced. Note that due to patient motion between the studies the copied transformation may not be fully adequate. In this case please fine-tune manually using the handles as described in Manual Reslicing below.

If the automatic reorientation returns an inadequate result, it can be supported by manually indicating the center of the left ventricle using a marker. Please proceed as follows:

Reset the orientation using the Button Clear button indicated above.

Click into the images until the orthogonal planes intersect in the LV center.

Select the PCARD LV Markers button, and click into the LV. A marker appears as illustrated below.

Activate the automatic reorientation button Button Caridiac Reorientation again.

PCARD Reslicing with Marker

Correct Short Axis Orientation after Reslicing

Please verify, that after the automatic and/or manual reorientation the images are oriented as illustrated below:

PCARD Standard Orientation

For the automatic contouring and the subsequent segmentation it is very important that the septum appears to the left in the SA slice. This can be verified by checking the right ventricle in the BLOOD images, which are shown with the same transformation parameters. For the automatic contouring it is helpful if the heart is centered in the center of the image volume.

PCARD SA View Blood

Manual Reslicing

After the averaging process has been completed, the display shows the MYOCARDIUM images in reslicing mode. With the View model size VOI box enabled for the e.g STRESS study as illustrated below:


a green VOI in short axis orientation appears overlaid on the images:

PCARD Reorientation Handles

The model VOI may be used as guidance for the interactive manual short axis orientation.  

The button Button Standard SA Angles  provides a quick way to bring the images into an approximate short-axis orientation:


The fine-adjustment can then be done using the handles which are shown in each of the orthogonal slices:

The large open rectangle in the image center serves for shifting the images along the axes: click+hold the left mouse button into the rectangle and drag the image into the desired direction.

The small closed rectangle connected to the image center allows rotating the images: click+hold the left mouse button onto the rectangle and drag around the center.

The results of translation and/or rotation should look similar to the ones below:


As an alternative to the mouse-operated reslicing numerical values can be entered on the Move and Rotate tabs. If anything goes wrong the transformation can be reset with the Button Reset button.

Once the right orientation has been found it is recommended to quit the reslicing mode in order to avoid inadvertent orientation changes. To this end, select any other tab such as the image presentation tab Color Tab Icon.

Standard Cardiological Report Page

After the images are properly SA reoriented, a myocardium Stress-Rest comparison report can be generated using the report button located left to the Modelling TACs button.


There are various options for the report generation as illustrated in the capture below:


When the box close to the report button is enabled the color table will be scaled to global Stress and Rest maximum.

The report layout is organized in three main sections: the upper section shows 14 slices in SA orientation of the Stress study and the corresponding slices of the Rest study; the middle section displays 7 Stress and Rest slices in vertical long axis orientation; the bottom section shows 7 Stress and the corresponding Rest slices in the horizontal long axes orientation.

Illustrated below is shown the content of the report in which the images are centered according to the display, the color thresholds are set according with the display while scaling to global Stress and Rest maximum is enabled:

PCARD RST STR Comparison report

As usual, the report can be annotated, printed or captured in different formats and sizes.