In the setting of VBI, high- resolution vessel wall imaging of the posterior circulation using IV contrast may be of use as both a diagnostic and prognostic tool, but it is not used as initial imaging in the evaluation of suspected VBI. In a single-center study of 219 patients, when compared with MRA, atherosclerotic plaque in the basilar artery and associated luminal stenosis of >50% was more often identified on vessel wall imaging; however, the degree of narrowing was felt to be likely overestimated. Although atherosclerotic vessel narrowing can certainly result in VBI, the clinical applicability of these findings on vessel wall imaging has yet to be fully elucidated [70]. Interestingly, the degree of vessel wall enhancement in basilar artery stenosis on vessel wall imaging has been shown to correlate with the risk of subsequent infarct and may serve as a noninvasive prognostic marker in patients with VBI [71]. Additionally, alterations of perfusion parameters using arterial-spin labelling in the brain has been shown to correlate with the presence and severity of vertebrobasilar stenosis and serves as an adjunct to contrast-enhanced imaging of the vessel wall as well as luminal imaging via MRA/CTA [68]. MRI Head Without IV Contrast MRI head without IV contrast is useful in the evaluation of VBI and for the detection of posterior fossa infarcts. A negative MRI does not exclude the possibility of chronic ischemia without completed infarction and therefore does not replace the need for vascular imaging. Dizziness and Ataxia Variant 6: Adult. Chronic disequilibrium with signs of cerebellar ataxia. Initial imaging. Disequilibrium refers to a sensation of imbalance, unsteadiness, or instability. Disequilibrium in addition to loss of muscle coordination is a common finding in cerebellar ataxia, which indicates loss of coordination due to loss of normal motor control by the cerebellum.
Dizziness and Ataxia. In the setting of VBI, high- resolution vessel wall imaging of the posterior circulation using IV contrast may be of use as both a diagnostic and prognostic tool, but it is not used as initial imaging in the evaluation of suspected VBI. In a single-center study of 219 patients, when compared with MRA, atherosclerotic plaque in the basilar artery and associated luminal stenosis of >50% was more often identified on vessel wall imaging; however, the degree of narrowing was felt to be likely overestimated. Although atherosclerotic vessel narrowing can certainly result in VBI, the clinical applicability of these findings on vessel wall imaging has yet to be fully elucidated [70]. Interestingly, the degree of vessel wall enhancement in basilar artery stenosis on vessel wall imaging has been shown to correlate with the risk of subsequent infarct and may serve as a noninvasive prognostic marker in patients with VBI [71]. Additionally, alterations of perfusion parameters using arterial-spin labelling in the brain has been shown to correlate with the presence and severity of vertebrobasilar stenosis and serves as an adjunct to contrast-enhanced imaging of the vessel wall as well as luminal imaging via MRA/CTA [68]. MRI Head Without IV Contrast MRI head without IV contrast is useful in the evaluation of VBI and for the detection of posterior fossa infarcts. A negative MRI does not exclude the possibility of chronic ischemia without completed infarction and therefore does not replace the need for vascular imaging. Dizziness and Ataxia Variant 6: Adult. Chronic disequilibrium with signs of cerebellar ataxia. Initial imaging. Disequilibrium refers to a sensation of imbalance, unsteadiness, or instability. Disequilibrium in addition to loss of muscle coordination is a common finding in cerebellar ataxia, which indicates loss of coordination due to loss of normal motor control by the cerebellum.