However, this is typically not an initial imaging test in the setting of stroke due to the poor anatomical delineation of US and potential consequences of delayed treatment in the setting of LVO [39]. Variant 3: Adult. Recent ischemic infarct; less than 24 hours. Initial imaging. This variant is focused on new clinical presentation of stroke in the acute phase, <24 hours from onset of symptoms, but beyond hyperacute clinical presentation. Because stroke due to LVO is a significant source of death and disability, rapid stroke diagnosis and triage remain essential, particularly in the setting of possible LVO [39]. Recent studies have shown the benefit of extending the thrombolytic window up to 9 hours using perfusion imaging [40- 43]. However, a number of positive RCTs have demonstrated the benefit of EVT in the treatment of stroke due to LVO up to 24 hours underscoring the urgency of LVO detection and resulting in a paradigmatic shift in the urgency of obtaining vascular imaging [44-49]. In the context of nonemergent suspected stroke, parenchymal and vascular imaging are still needed, although the determination of eligibility for EVT in cases of delayed or unknown presentation may require additional MRI sequences or perfusion imaging with CT or MRI depending on the time since last known normal and the severity of the neurological deficit [52]. In the absence of LVO, the workup of a new stroke focuses on treatment of complications, rehabilitation, and secondary prevention. Arteriography Cervicocerebral Cerebral angiography has the highest spatial and temporal resolution of any vascular imaging study. Due to the invasive nature of catheter-directed angiography, other modalities are typically preferred in the initial workup for stroke.
Cerebrovascular Diseases Stroke and Stroke Related Conditions PCAs. However, this is typically not an initial imaging test in the setting of stroke due to the poor anatomical delineation of US and potential consequences of delayed treatment in the setting of LVO [39]. Variant 3: Adult. Recent ischemic infarct; less than 24 hours. Initial imaging. This variant is focused on new clinical presentation of stroke in the acute phase, <24 hours from onset of symptoms, but beyond hyperacute clinical presentation. Because stroke due to LVO is a significant source of death and disability, rapid stroke diagnosis and triage remain essential, particularly in the setting of possible LVO [39]. Recent studies have shown the benefit of extending the thrombolytic window up to 9 hours using perfusion imaging [40- 43]. However, a number of positive RCTs have demonstrated the benefit of EVT in the treatment of stroke due to LVO up to 24 hours underscoring the urgency of LVO detection and resulting in a paradigmatic shift in the urgency of obtaining vascular imaging [44-49]. In the context of nonemergent suspected stroke, parenchymal and vascular imaging are still needed, although the determination of eligibility for EVT in cases of delayed or unknown presentation may require additional MRI sequences or perfusion imaging with CT or MRI depending on the time since last known normal and the severity of the neurological deficit [52]. In the absence of LVO, the workup of a new stroke focuses on treatment of complications, rehabilitation, and secondary prevention. Arteriography Cervicocerebral Cerebral angiography has the highest spatial and temporal resolution of any vascular imaging study. Due to the invasive nature of catheter-directed angiography, other modalities are typically preferred in the initial workup for stroke.