Susceptibility-diffusion mismatch in middle cerebral artery territory acute ischemic stroke: clinical and imaging implications

The role of asymmetrical prominent veins sign in early neurological deterioration of acute ischemic stroke patients

Background and purpose

Asymmetrical prominent veins sign (APVS) often appears on susceptibility-weighted angiography (SWAN) images in patients with acute stroke. Early neurological deterioration (END) is highly correlated with survival prognosis in patients with ischemic stroke. This study sought to explore the relationship between APVS and END in patients with acute stroke.

Methods

The subjects retrospectively enrolled in this study were patients with acute ischemic stroke in the middle cerebral artery supply area. All patients underwent head MRI, including the SWAN sequence, within 7 days of stroke symptom onset. END was defined as clinical deterioration or recurrence within 72 h after ischemic stroke. The volume of infarction on diffusion-weighted imaging was measured. Univariate and multivariate analyses were used to analyze the relationship between APVS and END. Spearman correlation between APVS grades and infarct volume, white matter hyperintensity (WMH) volume, and offending vessel were also analyzed.

Results

A total of 157 patients with middle cerebral artery infarct between September 2018 and April 2020 were included in the study. APVS appeared on MRI in 84 of 157 patients, and 34 of 157 patients were diagnosed with END. In patients with END, the proportion of severe APVS was higher than in patients without END (P = 0.001, x² = 14.659). Patients with END were older and had a larger volume of infarct and WMH than patients without END (all P < 0.05). After adjustments were made for related risk factors of END, the severity of APVS was still related to END (OR = 2.56, 95% CI, 1.38–4.75; P for trend = 0.003). Spearman correlation showed that APVS grades were positively related to infarct volume (r = 0.289, P < 0.001) and 3-month modified Rankin Scale score (r = 0.203, P = 0.011) and negatively related to offending vessels (r = −0.170, P = 0.034).

Conclusion

APVS may be an important predictor of END in patients with acute ischemic stroke.

Changes of prominent vessel sign and susceptibility vessel sign in acute ischemic stroke patients with and without successful recanalization: a study based on susceptibility weighted images

OBJECTIVES

To investigate the changes of prominent vessel sign (PVS) and susceptibility vessel sign (SVS) in acute ischemic stroke (AIS) patients with successful and non-successful vascular recanalization treatment, and to study the associations between the susceptibility-weighted imaging (SWI) findings and early clinical and imaging prognosis.

METHODS

Thirty-five patients with the acute MCA territory infarction were retrospectively included and classified into Group_re (n = 25) and Group_non (n = 10) according to the success of vascular recanalization. NIHSS was used for clinical assessment. PVS and DWI were analyzed using ASPECT scores. Baseline, post-treatment, the changes of PVS and SVS, and SVS length were recorded and compared between two groups. Correlation analysis was performed between SWI factors and early post-treatment clinical and imaging factors.

RESULTS

The mean PVS_pre value was 5.20 ± 1.76 and PVS_post was 8.20 ± 1.86. PVS_pre and PVS_post showed statistical significance between Group_re and Group_non (both p < 0.001). A significant difference wasfound in SVS_post(+) (p < 0.001), SVS_post-pre(+) (p = 0.001), SVS_post-pre length (p = 0.036) and SVSpost length (p = 0.001) between the two groups.  A positive correlation was found between PVS_pre and DWI_post (p < 0.001, r = 0.564). There were positive correlations between PVS-DWI mismatch and NIHSS_post in Group_re (p = 0.042, r = 0.410) and in Group_non (p = 0.006, r = 0.789).

CONCLUSIONS

PVS and SVS changes are influenced by the success of vascular recanalization. However, the changes are unrelated to either early clinical or imaging outcomes in AIS patients. PVS-DWI mismatch can be taken as an imaging biomarker for early clinical outcomes, both for patients with or without successful vascular recanalization.

Diffusion- and Susceptibility Weighted Imaging Mismatch Correlates With Collateral Circulation and Prognosis After Middle Cerebral Artery M1-Segment Occlusion

Objective: To explore the relation between diffusion-weighted and susceptibility weighted imaging (DWI-SWI) mismatch and collateral circulation or prognosis in patients with occluded M1 segments of middle cerebral artery (MCA).

Methods: We enrolled 59 patients with MCA M1-segment occlusion for a retrospective review of baseline clinical and imaging data. As markers of circulatory collaterals, prominent laterality of posterior (PLPCA) and anterior (PLACA) cerebral arteries on magnetic resonance angiography (MRA) studies and a hyperintense vessel sign (HVS) on T2 fluid-attenuated inversion recovery (FLAIR) images were collectively scored. The extent of acute cerebral infarction was then quantified on DWI, using the Alberta Stroke Program Early CT Score (DWI-ASPECTS). Hypointensity vessel sign prominence (PVS) was also evaluated by SWI and similarly scored (SWI-ASPECT) to calculate DWI-SWI mismatch [(DWI-ASPECTS) – (SWI-ASPECTS)], ranging from −10 to 10 points.

Results: DWI-SWI mismatch showed significant associations with PLPCA, PLACA, HVS prominence, and collective collateral scores (all, p < 0.05). National Institutes of Health Stroke Scale (NIHSS), DWI-SWI mismatch, and DWI-ASPECTS also differed significantly according to patient prognosis (good vs. poor) after MCA M1-segment occlusion (p < 0.05). In binary logistic regression analyses, NIHSS and DWI-SWI mismatch emerged as independent prognostic factors (p < 0.05).

Conclusions: Collateral circulation may be an important aspect of DWI-SWI mismatch, which in this study correlated with prognostic outcomes of MCA M1-segment occlusion.

Susceptibility-weighted Imaging in Neuroradiology: Practical Imaging Principles, Pearls and Pitfalls

Susceptibility-weighted imaging (SWI) was one of the recent and helpful advancement in magnetic resonance imaging. Its utilization -provided valuable information for the radiologists in multiple fields, including neuroradiology. SWI was able to demonstrate cerebral paramagnetic and diamagnetic substances. Therefore, the applications of this imaging technique were diverse in research and clinical neuroradiology. This article reviewed the basic technical steps, various clinical applications of SWI, and potential limitations. The practicing radiologist needs to be oriented about using SWI and phase images in the right- and left-handed MRI systems to demonstrate different brain pathologies, including neurovascular diseases, traumatic brain injuries, brain tumors, infectious and inflammatory, and neurodegenerative diseases.

Susceptibility-diffusion mismatch correlated with leptomeningeal collateralization in large vessel occlusion stroke

Objective

To investigate the relationship between asymmetric prominent hypointense vessels (prominent vessel sign, PVS) on susceptibility-weighted imaging (SWI) and leptomeningeal collateralization in patients with acute ischemic stroke due to large vessel occlusion.

Methods

We retrospectively enrolled patients with M1 segment occlusion of the middle cerebral artery who underwent emergency magnetic resonance imaging and digital subtraction angiography within 24 hours from stroke onset. The extent of PVS on SWI was assessed using the Alberta Stroke Program Early CT Score (ASPECTS). Leptomeningeal collateralization on digital subtraction angiography images was assessed using the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) scale. Spearman’s rank correlation test was performed to explore the correlation of ASITN/SIR scores with SWI-ASPECTS and SWI-diffusion-weighted imaging (DWI) mismatch scores.

Results

Thirty-five patients were enrolled. There was no significant correlation between SWI-ASPECTS and ASITN/SIR scores. However, SWI-DWI mismatch scores were positively correlated with ASITN/SIR scores.

Conclusion

The range of PVS on SWI did not closely reflect the collateral status, while the range of SWI-DWI mismatch was significantly correlated with the leptomeningeal collateralization. In patients with acute anterior circulation stroke due to large vessel occlusion, larger SWI-DWI mismatch was associated with better leptomeningeal collaterals.

Are prominent medullary veins better than prominent cortical veins as predictors of early clinical outcome in patients with acute ischemic stroke?

PURPOSE

The prominent vessel sign (PVS) on susceptibility-weighted imaging (SWI) can be dichotomized into prominent cortical veins (PCV) and prominent medullary veins (PMV). This study was designed to compare the predictive value of PCV and PMV in the evaluation of the severity of acute ischemic stroke (AIS) in patients within the reperfusion window.

METHODS

Forty-seven consecutive patients with AIS within the middle cerebral artery territory were recruited. Magnetic resonance imaging was performed within 8 hours of symptom onset and at 7 days after stroke onset. Infarct volume was measured, and the early clinical outcome at 7 days was assessed using the modified Rankin Scale. PVS was dichotomized into cases with both PCV and PMV and cases with only PCV according to location.

RESULTS

Patients with both PCV and PMV (n=32) had higher admission National Institutes of Health Stroke Scale scores (p = 0.020), larger infarct volumes at baseline (p = 0.026) and 7 days (p = 0.007), and larger infarct growth at 7 days (p = 0.050) than those with PCV only. Multivariate regression analysis showed that both the time of onset at baseline (p = 0.013) and infarct growth at 7 days (p = 0.014) could independently predict poor early clinical outcome.

CONCLUSION

PMV may predict poor early clinical outcome in AIS patients, and reperfusion therapy may, therefore, be required more urgently in patients with PMV.

The Prognostic Impact of Susceptibility-Weighted Imaging Prominent Veins in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

PURPOSE

We aimed to determine the prognostic impact of prominent veins (PVS) after an acute ischemic stroke identified on susceptibility-weighted imaging (PVS-SWI).

METHODS

We searched for studies published in PubMed, Embase, Cochrane Library and Chinese Biomedical Literature Database. Poor functional prognosis, early neurological deterioration, and hemorrhagic transformation were evaluated. Risk ratios (RR) were pooled implementing a random effect model. We performed a subgroup analysis by treatment, location (cortical/medullary) and a sensitivity analysis by follow-up time.

RESULTS

Sixteen studies were included (a total of 1605 patients) in the quantitative meta-analysis. PVS-SWI were related with a poor functional outcome (RR 1.62, 95% CI 1.25 to 2.10), especially in the patients receiving thrombolysis (RR 2.19, 95% CI 1.53 to 3.15) and an augmented risk of early neurological damage (RR 2.85, 95% CI 2.31 to 3.51). Both cortical and medullary prominent veins were accompanied by a poor functional outcome (RR 1.82, 95% CI 1.30 to 2.56/RR 2.59, 95% CI 1.98 to 3.38). PVS-SWI were not associated with poor functional outcomes when patients were treated conservatively (RR 1.35, 95% CI 0.82 to 2.22), or with an increased risk of hemorrhagic transformation (RR 0.97, 95% CI 0.64 to 1.47).

CONCLUSION

PVS-SWI were related to a poor functional prognosis and an increased risk of early neurological damage. In patients treated conservatively, PVS-SWI were not accompanied by a poor prognosis. PVS-SWI were not associated with an augmented risk of hemorrhagic transformation.

Interactive effect of susceptibility-diffusion mismatch and recanalization status on clinical outcome in large vessel occlusion stroke

OBJECTIVE

To investigate the interactive effect of susceptibility-diffusion mismatch and recanalization status on clinical outcome in patients with acute ischemic stroke due to large vessel occlusion.

METHODS

In this prospective study, consecutive ischemic stroke patients admitted within 24 h from symptom onset underwent emergency multimodal MRI at admission, including diffusion-weighted imaging (DWI), susceptibility-weighted imaging (SWI), and time-of-flight magnetic resonance angiography (TOF-MRA). Patients with large vessel occlusion within the anterior circulation were recruited. Follow-up MRI was performed within 24 h after recanalization therapy (intravenous thrombolysis, endovascular therapy, or both). Multivariable logistic regression analysis was performed to estimate the interaction between SWI-DWI mismatch score and recanalization status on clinical outcome.

RESULTS

A total of 90 patients were enrolled. A multiplicative interaction between SWI-DWI mismatch score and recanalization status on clinical outcome was observed (P=0.037). The interaction term "SWI-DWI mismatch score × successful recanalization" was significantly associated with favorable outcome (modified Rankin Scale score of 0-2 at 90 days; adjusted odds ratio [aOR], 2.162; 95% confidence interval [CI], 1.046-4.468). Stratified analysis showed that the likelihood of favorable outcome increased with the increase of SWI-DWI mismatch score in the successful recanalization group (OR, 2.140; 95% CI, 1.376-3.326), while there was no significant relationship between SWI-DWI mismatch score and clinical outcome in the unsuccessful recanalization group (OR, 1.212; 95% CI, 0.933-1.574).

CONCLUSIONS

The effects of SWI-DWI mismatch and recanalization status on clinical outcome were realized through their interaction. In anterior circulation stroke due to large vessel occlusion, patients with both high SWI-DWI mismatch scores and successful recanalization were more likely to achieve a favorable outcome, while patients with unsuccessful recanalization, or with successful recanalization but low SWI-DWI mismatch scores, were less likely to have a good prognosis.

Asymmetric Deep Medullary Veins in Patients With Occlusion of a Large Cerebral Artery: Association With Cortical Veins, Leptomeningeal Collaterals, and Prognosis

Objective: To explore the relationships of asymmetric deep medullary veins (ADMV) to asymmetric cortical veins (ACV), leptomeningeal collaterals and prognosis in patients with occlusion of a large cerebral artery. Methods: Clinical and imaging data of 56 patients with occlusion of a large cerebral artery were collected and reviewed. We assessed the time delayed between stroke onset and MR imaging (within 24 h of stroke onset), extension of cerebral infarction using the Alberta stroke program early CT score based on diffusion-weighted imaging (ASPECTs). ADMV and ACV were assessed using susceptibility-weighted imaging. The presence of ADMV (ACV) was defined as deep medullary veins (cortical veins) of the affected hemisphere that were greater in number and diameter than in the contralateral hemisphere. To evaluate leptomeningeal collaterals, the hyperintense vessel sign (HVS) was detected using T2 weighted fluid attenuated inversion recovery images. At 90 days, a modified Rankin scale score (mRS) was assessed to evaluate the clinical outcome. Results: Of 56 patients, 27 presented with ADMV. Those patients who presented with and without ADMV differed significantly in HVS and ACV (P < 0.05) but not in time delayed between stroke onset and MR imaging, age, gender, stroke risk factors, baseline NIHSS score, or modified Rankin scale score at 3 months (P > 0.05). Logistic regression analysis found that the presence of ADMV was independently related to HVS and ACV (ACV: OR 95% C.I., 1.287-4.368; HVS: OR 95% C.I., 1.132-4.887). Conclusions: The presence of ADMV on SWI was associated with prominent ACV and good leptomeningeal collateral flow but was not related to prognosis in patients with occlusion of a large cerebral artery.

Susceptibility-weighted Imaging in Thrombolytic Therapy of Acute Ischemic Stroke

Objective:

To provide a comprehensive and latest overview of susceptibility-weighted imaging (SWI) in the application of thrombolysis in acute ischemic stroke, and to update the decision-making effect and clinical value of SWI on identifying stroke patients suitable for thrombolytic therapy and possible benefits and risks followed.

Data Sources:

Literatures referred to this review were collected from PubMed, Medline, and EMBASE published till May 2017, using the search terms including susceptibility-weighted imaging, gradient-echo, T2*, thrombolysis, recombinant tissue plasminogen activator (rt-PA), thrombolytic therapy, and stroke.

Study Selection:

Papers in English or with available English abstracts were considered, with no limitation of study design. References were also identified from the bibliographies of identified articles and the authors’ files.

Results:

SWI is of guiding significance for thrombolytic therapy in stroke patients, it can predict the location and length of thrombus and ischemic penumbra. It is worthy of noting that susceptibility vessel sign (SVS) on SWI can be used to predict recanalization after thrombolytic therapy and whether it is better to implement endovascular thrombolectomy in combination or alone. SWI is sensitive in detecting cerebral microbleed (CMB), and CMB might not be a contraindication for thrombolytic therapy, yet CMBs in multiple foci could possibly be related to intracranial hemorrhage (ICH) after thrombolysis. SVS and CMB on SWI sequence are of instructive value in performing antiplatelet therapy after thrombolytic therapy. Cerebral venous change on SWI is related to lower recanalization rate and poor outcome after thrombolysis.

Conclusions:

It seems that SWI can be applied to guide individualized thrombolytic therapies and assist clinicians in making better decisions by weighing benefits and risks. However, there still exist controversies about the relationship between signs on SWI and thrombolytic therapy.

Prominent Hypointense Vessel Sign on Susceptibility-Weighted Imaging Is Associated with Clinical Outcome in Acute Ischaemic Stroke

BACKGROUND

Prominent hypointense vessel sign (PHVS) is visualized on susceptibility weighted-imaging (SWI) in acute ischaemic stroke (AIS). We aim to test if PHVS is associated with stroke outcome.

METHODS

Forty patients with acute middle cerebral artery occlusion were recruited. The presence of PHVS, cortical vessel sign (CVS), brush sign (BS) and susceptibility-diffuse weighted imaging mismatch (S-D mismatch) and Alberta Stroke Program Early CT Score (ASPECTS) on SWI were compared between the good outcome group (90-day modified Rankin scale [mRS] of 0-2) and the poor outcome group (mRS of 3-6). The receiver operating characteristic curves (ROC) were used to evaluate the predictive ability to poor outcome of above imaging characteristics.

RESULTS

The presence of PHVS, CVS, BS and S-D mismatch was significantly higher in the poor outcome group (p < 0.001, p = 0.001, p = 0.013, p = 0.014, respectively). SWI-ASPECTS was significantly lower in the poor outcome group (p = 0.002). Regression analysis revealed SWI-ASPECTS; the presence of PHVS and CVS were independently associated with poor outcome (OR 0.347, p = 0.012; OR 55.77, p = 0.004; OR 58.05, p = 0.005). ROC analysis showed that PHVS had the highest predictive value for poor outcome (AUC 0.783).

CONCLUSIONS

The presence of PHVS, CVS and SWI-ASPECTS were associated with poor outcome in AIS. The presence of PHVS was the most effective radiographic marker for predicting outcome.