Krassi Ivancev, University College London Hospitals, London, UK, explained how rotational CT angiography is an effective tool for fenestrated and branched stent-graft treatment at the CX Imaging Course 2011.
Rotational CT angiography is a new imaging modality that has the ability to display angiography in 3D CT formats. According to Ivancev, “Using the Innova rotational CTA (GE Healthcare) has proved to be very helpful in orientation of fenestrated/branched stent-grafts.
One way to facilitate such orientation in 3D is to catheterise one or two of the target vessels and then, by using the capabilities of the Innova rotational CTA without contrast medium, it is fully possible to orient the fenestrated/branched stent-grafts accurately using the catheters in the target vessels as reference points. The same technique can be employed for catheterisation of target vessels whereupon a limited amount of contrast medium is used selectively only through the catheters in the target vessels, thus reducing the large amount of contrast medium otherwise necessary for routine 2D angiography/aortogram from differently angled views. This is further facilitated by identifying which particular angulation of the angiographic C-arm is best suited for catheterisation of target vessels, and then programming this specific angulation to be acquired automatically. In addition a 3D mask can be applied as a roadmap, superimposed on the live screen image for that particular view-angle.”
Ivancev commented on the possibility to fuse images from a previous preoperative multidetector computed tomography angiography (MCTA) with images from the Innova rotational CTA with the patient on the table and the fenestrated/branched stent graft fully deployed. “If the anatomy is not excessively distorted by the stent-graft, target vessels can be catheterised on the basis of information derived from preoperative MCTA alone, thus further minimising the use of nephrotoxic contrast medium for catheterisation of target vessels,” noted Ivancev.
Ivancev acknowledged that by using the Innova rotational CTA it is possible to get valuable information on endoleaks. He said, “Instead of using completion 2D angiography, the Innova rotational CTA provides excellent information on possible endoleaks and their underlying causes, such as their origin, either from the fenestrations/branches or from the implantation sites. In this way it is anticipated that rotational CT angiography may replace the need for follow up on MCTAs.”
With rotational CT angiography “complex endografting can be simplified with improved results,” Ivancev concluded.
