Published online August 7, 2003, 10.1148/rg.e16
Coronary Artery Imaging with Multidetector CT: Visualization Issues1
Peter M. A. van Ooijen, MSc,
Kai Yiu Ho, MD, PhD,
Joost Dorgelo, MD and
Matthijs Oudkerk, MD, PhD
1 From the Department of Radiology, Groningen University Hospital, Hanzeplein 1, 9700 RB, Groningen, The Netherlands. Presented as an educational exhibit at the 2002 RSNA scientific assembly. Received March 7, 2003, revision requested May 5, final revision received and accepted June 20. Address correspondence to P.M.A.v.O. (e-mail: p.m.a.van.ooyen@rad.azg.nl).
View larger version (86K):
[in a new window]
|
Figure 1. Oblique MPR of the right coronary artery performed with only straight planes. Resulting image of the right coronary artery is shown in the upper right image. The upper left and lower right images show the positioning of the MPR planes in two dimensions. The lower left image shows the positioning of the MPR planes in 3D.
|
|
View larger version (88K):
[in a new window]
|
Figure 2. Curved MPR of the right coronary artery (curved green line in the lower right image). The upper right image shows the resulting visualization of the right coronary artery. The upper left and lower right images show the positioning of the MPR planes in two dimensions. The lower left image shows the positioning of the MPR planes in 3D.
|
|
View larger version (124K):
[in a new window]
|
Figure 3. Curved MPR after automated vessel detection combined with display of sections of the vessel perpendicular to the centerline. The centerline of the vessel is represented by the green line in the 3D image. The two rectangles to the far right show two perpedicular cross sections of the right coronary artery along the (green) centerline. The large square shows a cross section of the artery at the level of the pointer in the rectangular images. The smaller squares show the cross sections along the centerline, both before and after the position of the larger square.
|
|
View larger version (8K):
[in a new window]
|
Figure 4. Schematics show two cross sections of a vessel, one normal (left) and one with a stenosis (right). The horizontal lines denote the selected image plane; the small circles denote the user-selected points within the vessel. False-positive stenoses can be introduced by incorrect placement of the point within the vessel; on the left, the top point is incorrectly placed and results in a smaller vessel diameter than the bottom point. False-negative stenoses can be introduced by incorrect orientation of the plane; on the right, a plane perpendicular to the current one should be selected to visualize the stenosis.
|
|
View larger version (102K):
[in a new window]
|
Figure 5. Fully segmented MIP. Images obtained after (left) and before (right) segmentation of contrast-enhanced cavities and vascular structures other than the coronary arteries. Top images are in anteroposterior view, bottom images in left-to-right view.
|
|
View larger version (24K):
[in a new window]
|
Figure 6. Opacity graph shows opacity ranging from 0 to 100 applied to voxel values (also ranging from 0 to 100).
|
|
View larger version (28K):
[in a new window]
|
Figure 7. Computation of the value of a resulting pixel (gray square on the right) with the equation C = A + B (see text).
|
|
View larger version (82K):
[in a new window]
|
Figure 8. Different opacity settings in the same phantom. Upper left: The soft tissues are opaque (large cylinder). Upper right: The soft tissues are made transparent, thus revealing the calcified lesions within the volume of the heart (large cylinder). Lower left: The soft tissue is made fully transparent, clearly showing the full boundary of the spine (small cylinder) and the calcified lesions. Lower right: The spine is made partly transparent.
|
|
View larger version (83K):
[in a new window]
|
Figure 9. Soft plaque and calcified plaque in stenosis. Top image shows the conventional angiogram (no indication of calcified plaque), middle image shows the DVR, and bottom image shows the thin-slab MIP. Ao = aorta, LAD = left anterior descending artery.
|
|
View larger version (102K):
[in a new window]
|
Figure 10. Both a thin-slab MIP (left) and a DVR (right) show the anastomosis (arrow) of an arterial bypass graft to the left anterior descending artery.
|
|
View larger version (93K):
[in a new window]
|
Figure 11. Curved MPR (defined by the green lines in the DVR image [inset]) shows the lumen of a left anterior descending artery stent.
|
|
Copyright © 2003 by the Radiological Society of North America.
