Patent attributes
Apparatus and methods are described for use with an endoluminal data-acquisition device configured to be moved through a lumen, the device having a radiopaque marker coupled thereto. While the device is being moved through the lumen (a) endoluminal data points of the lumen are acquired using the device, (b) contrast agent is continuously injected into the lumen, and (c) angiographic images of the device are acquired. It is determined that endoluminal data points correspond to respective locations within the lumen, by determining locations of the radiopaque marker within the angiographic images of the lumen, by performing image processing on the angiographic images, the locations of the radiopaque marker within the angiographic images of the lumen corresponding to respective endoluminal data points. Other applications are also described.