Inobitec DICOM Viewer

5.4. Curvilinear Reconstruction

5.4.1 Build Surface

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Functionality is available in the Pro edition
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Curvilinear reconstruction is a section of tissues by a curvilinear surface whose configuration is set by the trajectory passing through the middle of this surface. This trajectory is called a curve.

To activate the Curvilinear reconstruction mode, click the Curve mode .

To build a surface:

Select the plane in which it would be convenient to start building a curve.

Roll the mouse wheel to select the slice where the first point will be located.

Fix the first point on the image by clicking the left mouse button.

If necessary, move to another slice by rolling the mouse wheel.

Move the mouse to select the location of the next point. Fix the point by clicking the left mouse button. The point will appear in the current slice.

Repeat Steps 4 and 5 until the last but one point is fixed.

Fix the last point by left-clicking the mouse twice. While building the curve, the current section will be displayed in the bottom right-hand window. The other windows will display the projections of the curve on the corresponding planes (Fig. 5.5).
If necessary, correct the projections of the curve on the two other planes. For details on how to correct, see the next section.

Figure 5.5: Reconstruction by a curve

5.4.2 Curve settings

To adjust the curve, move the cursor to the curve, right-click the mouse and select the Set curve properties... item. You can set up the following parameters:

color;
line width;
show the curve in the curvlinear reconstruction window (bottom right-hand window).

If you check the Set as default box, then the current settings will be used by default.

5.4.3 Actions with a Curve

Actions with a curve can be performed only if the curvilinear reconstruction mode is active.

The following actions are available:

Drag a point. Locate the cursor on the point so that it enlarges, and drag the point holding down the left mouse button or the button to which this tool is assigned. Then release the mouse button.
Add a point. Locate the cursor on the curve where the point should be added. Right-click the mouse and select the Add point item.
Delete a point. Locate the cursor on the point. Right-click the mouse and select the Remove point item.
Continue a curve. Locate the cursor on one of the border points of the curve. Right-click the mouse and select the Resume curve item. Then, perform Steps 3 and 4 of the curve building algorithm.
Delete a curve. Locate the cursor on any position on the curve where there is no point. Right-click the mouse and select the Remove curve item.

5.4.4 Position of a Curve, Its Nodes and Surface in Space

By the color of the curve, you can determine which part of the curve is located in front of the current image in space. This part of the curve is brighter than the part behind the image.

In Fig. 5.6, the central part and the third point are a brighter color. This means they are located in front of the current section.

Figure 5.6: Reconstruction by a curve

To make it easier to find a node on the curve on all the projections, locate the cursor on this node. The node will be magnified on all the projections.

To rotate the surface relative to the curve, move the cursor to the bottom right-hand window (Surface by curve) and roll the mouse wheel.

To move the cutting planes to the selected point of the curve, move the mouse cursor to the selected point on the curve in the selected window. Left-click while holding down the Ctrl key on the keyboard. The point of intersection of the cutting planes is moved to the specified point on the curve in all the windows.

5.4.5 Curved Reconstructions Cross Sections Mode

The curved reconstruction cross section mode is aimed for viewing the planes that are perpendicular to the curve and evenly spaced.

You can switch to this mode if a curve has been built. To switch, press the arrow on the right-hand side of the Curve mode button and choose Curve slices mode (Fig. 5.7).

Figure 5.7: Switching to the Curve slices mode

The MPR reconstruction tab has two windows: a curved surface window and a slices window. The curved surface window is at the top of the tab, and the slices window is at the bottom (Fig. 5.8).

Figure 5.8: The Curve slices mode

In the curved surface window, a straightened curve and perpendicular cutting planes projections are shown. When you mouse over a cutting plane in the curved surface window, the respective plane and projection will be highlighted. The point in which the cutting plane crosses the curve will be marked with a crosshair in the slices window.

To rotate the surface round the curve, mouse over the curved surface window and scroll the mouse wheel or move the slider in the slices window.

To move the cutting planes along the curve, mouse over the slices window window and scroll the mouse wheel or move the slider in the slices window.

To move the cutting planes automatically, activate the Play tool (see Section 5.5).

To set the curve slices parameters, press the arrow on the right-hand side of the Curve mode button and choose Set curve slices properties... (Fig. 5.9).

Figure 5.9: Activating the dialog box for curve slices properties

A dialog box will pop up (Fig. 5.10), in which you can set the following parameters:

the size of the slices window grid. Choose the suitable number of rows and columns (5x2 or 3x3);
the distance between slices (in millimeters);
the scrolling increment. Choose one of the two variants: Auto (the increment is equal to one voxel) or specify the increment in millimeters;
the color of the cutting plane lines;
the thickness on the cutting plane line and the crosshair in pixels;
the color of the selected cutting plane line and the frame of the slices window;
the crosshair space in pixels. Set the distance from the lines forming the crosshair to its virtual center;
the size of the crosshair in pixels.

If you have checked the Set as default box, these settings will be used by default when you switch to the Curve slices mode.

Figure 5.10: Curve slices properties

There are two ways to activate the Curve slices properties dialog box from the right-click menu:

Mouse over one of the cutting planes in the curved surface window. Right-click and choose Set curve slices properties...
Mouse over the crosshair of one of the slices in the slices window. Right-click and choose Set curve slices properties...

Rotate, Zoom, Pan and Adjust W/L tools are simultaneously activated for all the slices.

DICOM Viewer records videos, exports and prints images from the curved surface window or the slices window, whichever is active.

In the slices window, only the image from the top left-hand cell will be printed. To print or export the slice you need, move the cutting planes along the curve, so that the slice you need appears in the top left-hand cell. You can move the cutting planes by scrolling your wheel or moving the slider in the slices window.

In the slices window, video is recorded for the top left-hand cell. To record a video for the slice you need, move the cutting planes along the curve, so that the slice you need appears in the top left-hand cell.

To record a video, activate the Start video record tool (see Section 5.6).

To escape from the curve slices mode, press the arrow on the right-hand side of the Curve mode button and uncheck the Curve slices mode box.