US Duplex Doppler Transcranial There is no relevant literature to support the use of TCD in the surveillance of a known, untreated cerebral aneurysm. Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring. Treatment of cerebral aneurysms is common to reduce the risk of aneurysm rupture or rebleeding. Endovascular treatment is now the first-line therapy in most cases, whereas aneurysms not amenable to endovascular repair require surgical clipping or observation. Follow-up imaging after treatment is often performed to assess for potential refilling of aneurysms and detect formation of new aneurysms. Aneurysm remnants after surgical clipping are identified in up to 11% of patients [46] and more frequently after endovascular repair [47,48]. Recurrence of treated aneurysm is most common within 6 months of treatment but can occur in a more delayed manner [49]. Development of de novo aneurysm occurs in 1% to 8% of patients with treated aneurysms [50-52]. Imaging evaluation is focused on not only the treated aneurysm but also the integrity of the parent vessel and formation of new aneurysms. Intracranial aneurysms are treated with several different devices, including surgical clips, detachable coils, stents, and flow diverters, and each device will result in unique appearances as well as challenges, depending on the imaging modality used. Specific knowledge of the technique utilized in prior treatment is helpful in choosing a particular follow-up modality for each patient. Arteriography Cervicocerebral Cervicocerebral arteriography remains the reference standard imaging examination for the evaluation of treated cerebral aneurysms with high spatial resolution, high signal-to-noise ratio, and dynamic image acquisition. Aneurysm and parent vessel appearance is better visualized, as indwelling occlusion device artifacts are less apparent on cervicocerebral arteriography than on MRI or CT.
Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. US Duplex Doppler Transcranial There is no relevant literature to support the use of TCD in the surveillance of a known, untreated cerebral aneurysm. Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring. Treatment of cerebral aneurysms is common to reduce the risk of aneurysm rupture or rebleeding. Endovascular treatment is now the first-line therapy in most cases, whereas aneurysms not amenable to endovascular repair require surgical clipping or observation. Follow-up imaging after treatment is often performed to assess for potential refilling of aneurysms and detect formation of new aneurysms. Aneurysm remnants after surgical clipping are identified in up to 11% of patients [46] and more frequently after endovascular repair [47,48]. Recurrence of treated aneurysm is most common within 6 months of treatment but can occur in a more delayed manner [49]. Development of de novo aneurysm occurs in 1% to 8% of patients with treated aneurysms [50-52]. Imaging evaluation is focused on not only the treated aneurysm but also the integrity of the parent vessel and formation of new aneurysms. Intracranial aneurysms are treated with several different devices, including surgical clips, detachable coils, stents, and flow diverters, and each device will result in unique appearances as well as challenges, depending on the imaging modality used. Specific knowledge of the technique utilized in prior treatment is helpful in choosing a particular follow-up modality for each patient. Arteriography Cervicocerebral Cervicocerebral arteriography remains the reference standard imaging examination for the evaluation of treated cerebral aneurysms with high spatial resolution, high signal-to-noise ratio, and dynamic image acquisition. Aneurysm and parent vessel appearance is better visualized, as indwelling occlusion device artifacts are less apparent on cervicocerebral arteriography than on MRI or CT.