Magnetic Resonance Imaging in Basilar Artery Occlusion

Abstract

Context: Acute basilar artery occlusion has particularly high mortality and morbidity.Objective: To determine the potential utility of advanced magnetic resonance imaging (MRI) methods, including diffusion-weighted imaging, for the early management of patients with basilar artery thrombosis.Design: Case series. Setting:Patients: In 4 patients with occlusion of the basilar artery, MRI was performed, including T2-weighted and diffusion-weighted imaging (DWI) sequences and magnetic resonance angiography (MRA) in the short-term phase (Ͻ12 hours). Three patients underwent intraarterial thrombolysis. Clinical outcome was obtained 10 days after symptom onset. Results:The MRA was performed 3.5 to 11.5 hours after symptom onset and showed basilar artery occlusion in all cases. The DWI revealed different patterns of ischemic lesions. In 2 patients, no or only small lesions could be identified; the remaining showed multiple and large lesions within the posterior circulation territory. Initial clinical status was severely impaired in all cases (Rankin scale score, 4-5). Thrombolysis was initiated in 3 patients, leading to successful recanalization in 2. Clinical outcome was favorable in the 2 patients with small DWI lesions and successful reperfusion (Rankin scale score, 2), whereas it was worse in those with large DWI lesions and persisting occlusion (death, persisting coma). Conclusions:In critically ill patients with acute basilar occlusion, the extent of DWI lesion involvement can be highly variable. Small DWI lesions seem to be associated with a favorable outcome if reperfusion is achieved with thrombolysis. This could potentially be the case independent of time from symptom onset.

Extent of Hypoattenuation on CT Angiography Source Images Predicts Functional Outcome in Patients With Basilar Artery Occlusion

“…20 Demonstration of small DWI lesions or a diffusion-perfusion mismatch has been proposed to identify patients with BAO who potentially benefit from thrombolysis. 21,22 This concept has not been validated in a larger series of patients. Feasibility of MRI may be limited in these frequently unstable patients.…”

Extent of Hypoattenuation on CT Angiography Source Images Predicts Functional Outcome in Patients With Basilar Artery Occlusion

“…20 Demonstration of small DWI lesions or a diffusion-perfusion mismatch has been proposed to identify patients with BAO who potentially benefit from thrombolysis. 21,22 This concept has not been validated in a larger series of patients. Feasibility of MRI may be limited in these frequently unstable patients.…”

Diagnostic and Prognostic Impact of pc‐ASPECTS Applied to Perfusion CT in the Basilar Artery International Cooperation Study

“…A recently introduced DWI score was an independent predictor for favorable outcome following IA thrombolysis in patients with vertebrobasilar occlusion . Moreover, two small case series have described an MRI‐based mismatch model in patients with basilar artery occlusion who underwent IA thrombolysis . However, CT is the most commonly applied imaging modality in the local general hospital where most patients with acute ischemic stroke present .…”

“…12 Moreover, two small case series have described an MRI-based mismatch model in patients with basilar artery occlusion who underwent IA thrombolysis. 13,14 However, CT is the most commonly applied imaging modality in the local general hospital where most patients with acute ischemic stroke present. 6,15 In the BASICS registry population, about 60% of patients with acute basilar artery occlusion initially presented to a local general hospital.…”

DWI Reversibility after Intra-Arterial Thrombolysis

“…MRI with diffusion, perfusion and angiographic techniques offers a noninvasive, sensitive, specific and convenient approach to early confirmation and definition of the ischemic pathology in patients with significant clinical deficits 44-46 . rior circulation and there is not such a rigid exclusion of patients with acute vertebrobasilar occlusion from local intra-arterial fibrinolysis because of worse outcome with conventional therapy, lower risk of hemorrhagic transformation of smaller infarct volumes and pathophysiological differences, such as collateral flow patterns, that involve a slower evolution of irreversible ischemia within this region. However, currently there are no established guidelines to select patients who will likely benefit from thrombolysis and in which time window aggressive treatment should be initiated 30,38 . Our so-called diffusion-perfusion mismatch, defined as the difference between the region with an abnormal PWI map and the smaller hyperintense area on DWI, has been proposed as an early pragmatic estimation of tissue at risk for lesion growth 49 .…”

“…Moreover this model assumes that DWI lesions represent irreversibly damaged tissue but new evidence suggests that DWI lesions may be reversible, especially with reperfusion, by now well demonstrated in animal models 36,42,47,[50][51][52][53][54][55][56][57][58] . Therefore acute DWI lesions probably contain not only irreversibly injured tissue but also parts of the penumbra 30,38,51,59 .…”

Extent of Hypoattenuation on CT Angiography Source Images Predicts Functional Outcome in Patients With Basilar Artery Occlusion

“…20 Demonstration of small DWI lesions or a diffusion-perfusion mismatch has been proposed to identify patients with BAO who potentially benefit from thrombolysis. 21,22 This concept has not been validated in a larger series of patients. Feasibility of MRI may be limited in these frequently unstable patients.…”

Diagnostic and Prognostic Impact of pc‐ASPECTS Applied to Perfusion CT in the Basilar Artery International Cooperation Study

“…A recently introduced DWI score was an independent predictor for favorable outcome following IA thrombolysis in patients with vertebrobasilar occlusion . Moreover, two small case series have described an MRI‐based mismatch model in patients with basilar artery occlusion who underwent IA thrombolysis . However, CT is the most commonly applied imaging modality in the local general hospital where most patients with acute ischemic stroke present .…”

“…12 Moreover, two small case series have described an MRI-based mismatch model in patients with basilar artery occlusion who underwent IA thrombolysis. 13,14 However, CT is the most commonly applied imaging modality in the local general hospital where most patients with acute ischemic stroke present. 6,15 In the BASICS registry population, about 60% of patients with acute basilar artery occlusion initially presented to a local general hospital.…”

DWI Reversibility after Intra-Arterial Thrombolysis

“…MRI with diffusion, perfusion and angiographic techniques offers a noninvasive, sensitive, specific and convenient approach to early confirmation and definition of the ischemic pathology in patients with significant clinical deficits 44-46 . rior circulation and there is not such a rigid exclusion of patients with acute vertebrobasilar occlusion from local intra-arterial fibrinolysis because of worse outcome with conventional therapy, lower risk of hemorrhagic transformation of smaller infarct volumes and pathophysiological differences, such as collateral flow patterns, that involve a slower evolution of irreversible ischemia within this region. However, currently there are no established guidelines to select patients who will likely benefit from thrombolysis and in which time window aggressive treatment should be initiated 30,38 . Our so-called diffusion-perfusion mismatch, defined as the difference between the region with an abnormal PWI map and the smaller hyperintense area on DWI, has been proposed as an early pragmatic estimation of tissue at risk for lesion growth 49 .…”

“…Moreover this model assumes that DWI lesions represent irreversibly damaged tissue but new evidence suggests that DWI lesions may be reversible, especially with reperfusion, by now well demonstrated in animal models 36,42,47,[50][51][52][53][54][55][56][57][58] . Therefore acute DWI lesions probably contain not only irreversibly injured tissue but also parts of the penumbra 30,38,51,59 .…”

Extent of Hypoattenuation on CT Angiography Source Images Predicts Functional Outcome in Patients With Basilar Artery Occlusion

“…20 Demonstration of small DWI lesions or a diffusion-perfusion mismatch has been proposed to identify patients with BAO who potentially benefit from thrombolysis. 21,22 This concept has not been validated in a larger series of patients. Feasibility of MRI may be limited in these frequently unstable patients.…”

Diagnostic and Prognostic Impact of pc‐ASPECTS Applied to Perfusion CT in the Basilar Artery International Cooperation Study

“…A recently introduced DWI score was an independent predictor for favorable outcome following IA thrombolysis in patients with vertebrobasilar occlusion . Moreover, two small case series have described an MRI‐based mismatch model in patients with basilar artery occlusion who underwent IA thrombolysis . However, CT is the most commonly applied imaging modality in the local general hospital where most patients with acute ischemic stroke present .…”

“…12 Moreover, two small case series have described an MRI-based mismatch model in patients with basilar artery occlusion who underwent IA thrombolysis. 13,14 However, CT is the most commonly applied imaging modality in the local general hospital where most patients with acute ischemic stroke present. 6,15 In the BASICS registry population, about 60% of patients with acute basilar artery occlusion initially presented to a local general hospital.…”

DWI Reversibility after Intra-Arterial Thrombolysis

“…MRI with diffusion, perfusion and angiographic techniques offers a noninvasive, sensitive, specific and convenient approach to early confirmation and definition of the ischemic pathology in patients with significant clinical deficits 44-46 . rior circulation and there is not such a rigid exclusion of patients with acute vertebrobasilar occlusion from local intra-arterial fibrinolysis because of worse outcome with conventional therapy, lower risk of hemorrhagic transformation of smaller infarct volumes and pathophysiological differences, such as collateral flow patterns, that involve a slower evolution of irreversible ischemia within this region. However, currently there are no established guidelines to select patients who will likely benefit from thrombolysis and in which time window aggressive treatment should be initiated 30,38 . Our so-called diffusion-perfusion mismatch, defined as the difference between the region with an abnormal PWI map and the smaller hyperintense area on DWI, has been proposed as an early pragmatic estimation of tissue at risk for lesion growth 49 .…”

“…Moreover this model assumes that DWI lesions represent irreversibly damaged tissue but new evidence suggests that DWI lesions may be reversible, especially with reperfusion, by now well demonstrated in animal models 36,42,47,[50][51][52][53][54][55][56][57][58] . Therefore acute DWI lesions probably contain not only irreversibly injured tissue but also parts of the penumbra 30,38,51,59 .…”