Combined MRI/OCT for image guidance of CTOs

Nigel Munce, PhD candidate

Chronic total occlusions (CTOs) are arteries that appear occluded under X-ray angiography, in which the lesion is older than three months. These occlusions have tiny channels within both the lumen and the wall of the artery. I am studying the vascular morphology of these channels using high-resolution micro-computed tomography. An example of such work is shown in the image below which shows a cork-screw entrance into the occlusion.

I am also interested in the development of forward-viewing intravascular probes for guidance through these lesions. Shown below are images taken of ex vivo arterial occlusions using optical coherence tomography (OCT). In the picture on the left, the OCT volume shows that the micro-channel proceeds safely through the lesion, while on the right, the channel appears to exit, which is a cause for concern.

I am also involved in developing a prototype forward-viewing catheter. We have designed and built a scanning forward-viewing catheter using electrostatic actuation.

Shown below is a picture of the probe in motion and an OCT image of a plastic phantom mimicking the appearance of a CTO taken using the catheter.