MRI Head Perfusion With IV Contrast Contrast-enhanced MRI head perfusion imaging (or, if available, noncontrast ASL perfusion) may detect additional at-risk regions not demonstrated by DWI in some patients presenting with stroke beyond the 24-hour period. In patients with complete extracranial internal carotid artery occlusion in whom MR perfusion can be used to determine its hemodynamic effect [31-33]. However, selection of patients with carotid occlusion for revascularization based on hemodynamic compromise does not improve outcome [18]. However, this procedure is more useful as a problem-solving tool and is not considered standard as surveillance imaging in the setting of prior infarct. MRI Head Without and With IV Contrast Rarely, brain tumors or other conditions can mimic ischemic stroke. MRI without and with IV contrast may be helpful in the secondary workup of patients presenting with stroke-like symptoms [62]. MRI Head Without IV Contrast MRI of the head may be a useful initial test in evaluation of the extent of completed ischemic infarct in the setting of late presenting strokes owing to the relatively rapid noninvasive nature of the examination, the lack of need for IV contrast, and the high sensitivity of DWI for concurrent acute ischemic change. Although often performed as part of the initial evaluation of late presenting strokes to delineate the extent of completed ischemic infarct, evaluate potential underlying etiology, and identify any complications, the value of the information provided by MRI over initial CT for improving patient outcome is unclear, as are the circumstances in which it is useful [74-79]. Current AHA guidelines only specify MRI in 2 circumstances: evaluation for wake-up strokes and evaluation for patent foramen ovale closure [12,13].
Cerebrovascular Diseases Stroke and Stroke Related Conditions PCAs. MRI Head Perfusion With IV Contrast Contrast-enhanced MRI head perfusion imaging (or, if available, noncontrast ASL perfusion) may detect additional at-risk regions not demonstrated by DWI in some patients presenting with stroke beyond the 24-hour period. In patients with complete extracranial internal carotid artery occlusion in whom MR perfusion can be used to determine its hemodynamic effect [31-33]. However, selection of patients with carotid occlusion for revascularization based on hemodynamic compromise does not improve outcome [18]. However, this procedure is more useful as a problem-solving tool and is not considered standard as surveillance imaging in the setting of prior infarct. MRI Head Without and With IV Contrast Rarely, brain tumors or other conditions can mimic ischemic stroke. MRI without and with IV contrast may be helpful in the secondary workup of patients presenting with stroke-like symptoms [62]. MRI Head Without IV Contrast MRI of the head may be a useful initial test in evaluation of the extent of completed ischemic infarct in the setting of late presenting strokes owing to the relatively rapid noninvasive nature of the examination, the lack of need for IV contrast, and the high sensitivity of DWI for concurrent acute ischemic change. Although often performed as part of the initial evaluation of late presenting strokes to delineate the extent of completed ischemic infarct, evaluate potential underlying etiology, and identify any complications, the value of the information provided by MRI over initial CT for improving patient outcome is unclear, as are the circumstances in which it is useful [74-79]. Current AHA guidelines only specify MRI in 2 circumstances: evaluation for wake-up strokes and evaluation for patent foramen ovale closure [12,13].