In addition, there is no current high-quality literature relating detection of vasospasm on TCD to improved patient outcomes [40]. Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring. Cerebral aneurysms are often incidentally discovered on intracranial vascular imaging. Definitive algorithmic guidelines for management and follow-up of incidentally found cerebral aneurysms are lacking [42]. Between 4% and 18% of aneurysms demonstrate growth on imaging follow-up [43,44], with a 12-fold higher risk of rupture in growing aneurysms [44]. Although aneurysm growth is associated with size >7 mm, smaller aneurysms can grow and rupture [44]. Given the evidence of potential for growth and rupture of untreated and unruptured aneurysms, vascular imaging surveillance is recommended. Arteriography Cervicocerebral Cervicocerebral arteriography remains the reference standard imaging examination for the evaluation of cerebral aneurysms with high spatial resolution, high signal-to-noise ratio, and dynamic image acquisition. However, given the invasive nature and potential complications of cervicocerebral arteriography, it is not ideal for routine patient surveillance. CT Head Perfusion There is no relevant literature to support the use of CT head perfusion in the surveillance of a known, untreated cerebral aneurysm. CT Head There is no relevant literature to support the use of CT head in the surveillance of a known, untreated cerebral aneurysm. CTA Head CTA head is a fast and noninvasive study to evaluate the intracranial vasculature. CTA head has been shown to be >90% sensitive and specific in the evaluation for aneurysms [4,10,13-18]. However, CTA head sensitivity for detecting an aneurysm decreases for aneurysms <3 mm in size [4,10,13,15,17,19] and for aneurysms occurring adjacent to an osseous structure [19].
Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. In addition, there is no current high-quality literature relating detection of vasospasm on TCD to improved patient outcomes [40]. Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring. Cerebral aneurysms are often incidentally discovered on intracranial vascular imaging. Definitive algorithmic guidelines for management and follow-up of incidentally found cerebral aneurysms are lacking [42]. Between 4% and 18% of aneurysms demonstrate growth on imaging follow-up [43,44], with a 12-fold higher risk of rupture in growing aneurysms [44]. Although aneurysm growth is associated with size >7 mm, smaller aneurysms can grow and rupture [44]. Given the evidence of potential for growth and rupture of untreated and unruptured aneurysms, vascular imaging surveillance is recommended. Arteriography Cervicocerebral Cervicocerebral arteriography remains the reference standard imaging examination for the evaluation of cerebral aneurysms with high spatial resolution, high signal-to-noise ratio, and dynamic image acquisition. However, given the invasive nature and potential complications of cervicocerebral arteriography, it is not ideal for routine patient surveillance. CT Head Perfusion There is no relevant literature to support the use of CT head perfusion in the surveillance of a known, untreated cerebral aneurysm. CT Head There is no relevant literature to support the use of CT head in the surveillance of a known, untreated cerebral aneurysm. CTA Head CTA head is a fast and noninvasive study to evaluate the intracranial vasculature. CTA head has been shown to be >90% sensitive and specific in the evaluation for aneurysms [4,10,13-18]. However, CTA head sensitivity for detecting an aneurysm decreases for aneurysms <3 mm in size [4,10,13,15,17,19] and for aneurysms occurring adjacent to an osseous structure [19].