Intracranial aneurysm stenting: follow-up with MR angiography

Abstract

Intracranial stenting is increasingly being used to treat intracranial aneurysms and stenoses. We wanted to assess the utility of magnetic resonance angiography (MRA) in the follow-up of patients treated with various types of intracranial stents and to assess the utility of performing gadolinium-enhanced MRA. A total of 19 patients having undergone intracranial stenting for aneurysms were imaged by MRI at 1.5T. A total of 20 stents were placed in 19 patients. In addition to conventional T2- and diffusion-weighted MRI, 3D time-of-flight MRA was performed before and after contrast administration. In the case of metallic INX stents (N = 7), there was a signal drop at the level of the vessel. which did not allow to evaluating the parent vessel, whereas this was visible in Nitinol stents (N = 8). Additionally a stent with a wire had a small artifact (N = 3). Contrast administration also improved vessel lumen visualization. In the case of Nitinol stents, MRA can be used to reliably demonstrate the vessel lumen after intracranial stenting. The use of postcontrast 3D time-of-flight imaging helps improve the intraluminal definition.