Abstract:
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Purpose: Long term follow-up is mandatory in patients with EC-IC by-pass and even though DSA is still considered the referring standard, follow-up should be performed with non-invasive procedures such as MRA and CTA. The aim of this study was to assess the potential role of multidetector-row CT angiography (MDCTA), contrast-enhanced MRA(CE-MRA) and 3D Time of Flight (TOF) MRA in the follow-up of patients with high-flow EC-IC by pass.
Methods and Materials: Twenty patients who had undergone therapeutic occlusion of the Internal Carotid Artery (ICA) followed by EC-IC saphenous vein bypass grafts, over a five year period (18 for unclippable /uncoilable aneurysms and 2 for meningiomas involving the ICA), were studied with MDCTA and CE-MRA. All examinations were performed using a 0.5 s gantry rotation time multidetector-row spiral CT. A test bolus was performed to determine the delay time. Eighty mL of iodinated contrast agent were injected at a flow rate of 3.5 mL/s. Reconstructions were performed on a dedicated workstation using all available algorithms. MRA examination was performed on a 1.5 T magnet using CE-MRA and TOF sequences. In case either MDCTA or CE-MRA showed a stenosis of the graft, DSA was performed. Image analysis was performed by two experienced radiologists who evaluated: the proximal anastomosis, the controlateral ICA, the extracranial tract of the graft, the distal anastomosis, the Circle of Willis and the cerebral parenchyma. All data were graded to compare image quality on a 3 point scale (1: CTA>MRA; 2: CTA=MRA; 3: CTA>MRA). Moreover readers were asked to assess CTA and MRA images as adequate (useful for rendering an opinion on the presence or absence of pathologic alteration) or inadequate.
Results: MDCTA with VR reconstructions and 3D interactive evaluation provided superior image quality with respect to either CE-MRA or TOF sequences in the evaluation of the graft and the vascular structures, with a mean score of 1.3. CE technique was superior to 3D TOF especially for the visualization of the intracranial vessels. In 1 patient both CTA and MRA showed a stenosis of the distal anastomosis of the graft which was confirmed by DSA.
Conclusion: MDCTA provides high quality images, supplies all required information in the follow-up of patients with EC-IC high flow by-pass graft and has shown to be superior to CE-MRA. We suggest that MDCTA should be utilized in the follow-up evaluation of EC-IC by-pass grafts and DSA should be performed only in patients with suspected stenosis.
Questions about this event email: vaninafinocchi@libero.it
Finocchi MD, V,
Multidetector-Row Angiography (MDCTA) for the Follow-up of Patients with High Flow Saphenous Vein Extracranial (EC)-Intracranial (IC) Bypass Graft. Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL.
http://archive.rsna.org/2003/3105033.html
