Spontaneous symptomatic intracranial vertebrobasilar dissection: initial and follow-up imaging findings

Behavior of Extracranial-to-Intracranial Extended Arterial Dissections of the Vertebral Artery

BACKGROUND

Vertebral artery dissections (VADs) may extend from the extracranial to the intracranial vasculature (e+iVAD). We evaluated how the characteristics of e+iVAD differed from those of intracranial VAD (iVAD).

METHODS AND RESULTS

From 2002 to 2019, among consecutive patients with cervicocephalic dissection, those with iVAD and e+iVAD were included, and their clinical characteristics were compared. In patients with unruptured dissections, a composite clinical outcome of subsequent ischemic events, subsequent hemorrhagic stroke, or mortality was evaluated. High-resolution magnetic resonance images were analyzed to evaluate intracranial remodeling index. Among 347 patients, 51 (14.7%) had e+iVAD and 296 (85.3%) had iVAD. The hemorrhagic presentation occurred solely in iVAD (0.0% versus 19.3%), whereas e+iVAD exhibited higher ischemic presentation (84.3% versus 27.4%; P<0.001). e+iVAD predominantly presented steno-occlusive morphology (88.2% versus 27.7%) compared with dilatation patterns (11.8% versus 72.3%; P<0.001) of iVAD. The ischemic presentation was significantly associated with e+iVAD (iVAD as a reference; adjusted odds ratio, 3.97 [95% CI, 1.67-9.45]; P=0.002]). Patients with unruptured VAD showed no differences in the rate of composite clinical outcome between the groups (log-rank, P=0.996). e+iVAD had a lower intracranial remodeling index (1.4±0.3 versus 1.6±0.4; P<0.032) and a shorter distance from dural entry to the maximal dissecting segment (6.9±8.4 versus 15.7±7.4; P<0.001).

CONCLUSIONS

e+iVAD is associated with lower rates of hemorrhages and higher rates of ischemia than iVAD at the time of admission. This may be explained by a lower intracranial remodeling index and less deep intrusion of the dissecting segment into the intracranial space.

Initial and follow-up high-resolution vessel wall MRI study of spontaneous cervicocranial artery dissection

OBJECTIVES

To explore the factors associated with ischemic stroke secondary to spontaneous cervicocranial artery dissection (sCCAD) and evaluate the initial imaging markers related to outcomes.

METHODS

Initial and follow-up high-resolution vessel wall MRI (VW-MRI) in consecutive patients with sCCAD were retrospectively analyzed. The associations of clinical and imaging factors and variants of the circle of Willis (COW) with ischemic stroke were evaluated using binary logistic regression analyses. The anatomical outcomes were categorized as complete, partial, and no remodeling based on changes of the vessel wall and lumen. Ordinal logistic regression analysis was used to assess associations between initial features and outcomes.

RESULTS

A total of 115 dissected arteries (79 strokes, 36 non-strokes) were detected in 103 patients. Follow-up VW-MRI was available in 46 patients (44.7%, with 51 vessels), with a median interval of 8.5 months. Pseudoaneurysm (odd ratio [OR], 0.178; 95% confidence interval [CI], 0.039-0.810; p = 0.026) tended to rarely cause ischemic stroke, while intraluminal thrombus (OR, 5.558; 95% CI, 1.739-17.765; p = 0.004), incomplete COW (OR, 9.309; 95% CI, 2.122-40.840; p = 0.003), and partial complete COW (OR, 4.463; 95% CI, 1.211-16.453; p = 0.025) were independently associated with stroke occurrence. Furthermore, the presence of double lumen (OR, 5.749; 95% CI, 1.358-24.361; p = 0.018) and occlusion (OR, 12.975; 95% CI, 3.022-55.645; p = 0.001) were associated with no remodeling of sCCAD.

CONCLUSIONS

Multiple initial factors were found to be related to stroke occurrence and anatomical outcomes of sCCAD. High-resolution VW-MRI may provide valuable insights into the pathophysiology and evolution of sCCAD.

CLINICAL RELEVANCE STATEMENT

Initial and follow-up high-resolution vessel wall MRI may help elucidate the pathophysiology of spontaneous cervicocranial artery dissection and provide important insights into the evolution and further facilitate the optimal management of patients with spontaneous cervicocranial artery dissection.

KEY POINTS

• Clinical and imaging factors, as well as the status of primary collateral circulation, are associated with ischemic stroke secondary to spontaneous cervicocranial artery dissection. • The follow-up high-resolution vessel wall MRI provides valuable insights into the long-term evolution and anatomical outcomes of spontaneous cervicocranial artery dissection. • The high-resolution vessel wall MRI features related to ischemic stroke and anatomical outcomes may further facilitate the optimal management of patients with spontaneous cervicocranial artery dissection.

Emerging Concept of Intracranial Arterial Diseases: The Role of High Resolution Vessel Wall MRI

Intracranial arterial disease (ICAD) is a heterogeneous condition characterized by distinct pathologies, including atherosclerosis. Advances in magnetic resonance technology have enabled the visualization of intracranial arteries using high-resolution vessel wall imaging (HR-VWI). This review summarizes the anatomical, embryological, and histological differences between the intracranial and extracranial arteries. Next, we review the heterogeneous pathophysiology of ICAD, including atherosclerosis, moyamoya or RNF213 spectrum disease, intracranial dissection, and vasculitis. We also discuss how advances in HR-VWI can be used to differentiate ICAD etiologies. We emphasize that one should consider clinical presentation and timing of imaging in the absence of pathology-radiology correlation data. Future research should focus on understanding the temporal profile of HR-VWI findings and developing quantitative interpretative approaches to improve the decision-making and management of ICAD.

Significance of headache in intracranial vertebrobasilar artery dissections: an observational study

Headache may represent acute phase of intracranial vertebrobasilar artery dissection (iVBAD). We aimed to evaluate its clinical significance in iVBAD. Consecutive acute iVBAD patients were grouped into ruptured iVBAD, unruptured iVBAD with no headache, isolated headache, or concurrent headache with neurological symptoms. Composite hemorrhagic/ischemic endpoints, and dynamic arterial changes were graded. Clinical characteristics of the four groups, and association between headache and composite outcomes was evaluated. Headaches were precedent in 79% of the ruptured iVBAD patients (maximal delay, 10D). In unruptured iVBAD, when patients with no headache (N = 69), concurrent headache (N = 111), and isolated headache (N = 126) were compared, concurrent headache was associated with ischemic endpoints (isolated headache as reference, adjusted odds ratio: 6.40, 95% confidence interval [2.03-20.19]). While there were no differences in hemorrhagic endpoints, dynamic arterial changes were higher in the isolated headache group (aOR: 3.98, 95% CI [1.72-9.18]) but not for the concurrent headache group (aOR: 1.59 [0.75-3.38]) compared to no headache group. Headache was more commonly severe (48.4% vs. 17.3%, p < 0.001) and ipsilateral (59.7% vs. 45.5%, p = 0.03) for isolated headache compared to concurrent headache, indicating a higher causal relationship. In iVBAD, isolated headache may be considered an acute-phase biomarker, associated with dynamic arterial changes.

3D phase-sensitive inversion recovery sequence for intracranial vertebrobasilar artery dissection

BACKGROUND

T1-weighted 3D turbo spin echo (T1W-3D-TSE) sequences with variable refocusing flip angle are commonly used to diagnose intracranial vertebrobasilar artery dissection (iVAD). However, magnetic susceptibility artifacts of the cavernous sinus may cause loss of the basilar and vertebral arteries. This study investigated the effectiveness of a 3D phase-sensitive inversion recovery (3D-PSIR) sequence in reducing magnetic susceptibility artifacts in the cavernous sinus, and its imaging findings for iVAD.

METHODS

Twelve volunteers and eleven patients with iVAD were included. Magnetic resonance imaging (MRI) was performed using a 3.0-T MRI system. 3D-PSIR and T1W-3D-TSE sequences were used. Vessel wall defects and contrast-to-noise ratio (CNR) were evaluated. The MRI findings were visually evaluated.

RESULTS

In the 3D-PSIR images, one volunteer (8 %) had vessel wall defects, and five (42 %) had vessel wall defects (p = 0.046) in the T1W-3D-TSE images. CNR was higher in 3D-PSIR images for vessel wall-to-lumen, whereas it was higher in T1W-3D-TSE images for vessel wall-to-CSF (p < 0.001). Visual evaluation revealed similar MRI findings between the two sequences.

CONCLUSIONS

The 3D-PSIR sequence may be able to improve the vessel wall defects and achieve MRI findings comparable to those of the T1W-3D-TSE sequence in iVAD. The 3D-PSIR sequence can be a useful tool for the imaging-based diagnosis of iVAD.

Imaging investigation of cervicocranial artery dissection by using high resolution magnetic resonance VWI and MRA: qualitative and quantitative analysis at different stages

BACKGROUND

To explore the value of magnetic resonance angiography (MRA) and high resolution magnetic resonance vessel wall imaging (HRMR-VWI) in cervicocranial artery dissection (CCAD) for the disease diagnosis, course staging and treatment. On the basis of qualitative evaluation, this study also extract the changes of different stages in vessel wall in different vessel segments to identify imaging indicators for the quantitative evaluation of CCAD.

METHODS

We retrospectively enrolled 34 patients with CCAD (38branches) with conventional MRA and HRMR-VWI examinations. Two radiologists independently analyzed imaging features of vessel wall and lumen in the different stages, and the typical sign detection of artery dissection were compared between MRA and HRMR-VWI. Then the parameters of vessel wall was quantitatively evaluated by the post-processing software (Vesselmass, Leiden University Medical Center, Leiden, The Netherlands.

RESULTS

HRMR-VWI revealed typical sign detection of artery dissection in all patients in the acute and subacute stage. Among them, the intimal flap/double lumen sign ditection were more common than the MRA, there was significant difference (P = 0.012). MRA revealed typical sign detection of artery dissection in more than half the patients, and the detection was no significant difference at the chronic stage between MRA and HRMR-VWI (P = 1.000/1.000/0.761). In the acute and subacute stage, the typical sign detection of intramural hematoma and Grade II enhancement revealed by HR-MRI was higher than the observations in the chronic stage (P = 0.000/0.000/0.016), while there was no significant difference by MRA (P = 0.902). The values of wall thickness, relative signal intensity of vessel wall enhancement, relative signal intensity of intramural hematoma (IMH), and percentage of stenosis in CCAD decreased from acute to subacute and then to chronic stages. Each quantitative parameter in patients with CCAD in the early stages (i.e., acute and subacute stages) was significantly different from that in patients with CCAD in the recovered group at chronic stage (P < 0.05). Wall thickness and relative signal intensity of vessel wall enhancement in patients with CCAD in the early stages were not significantly different from those in patients with CCAD in the incompletely recovered group at chronic stage (P > 0.05).

CONCLUSIONS

As the only noninvasive imaging technology, HRMR-VWI displays the structure of the vessel wall in vivo, showing not only excellent performance in the early diagnosis of CCAD, but also describing the changes of different stages in the qualitative and quantitative characteristics of vessel wall. It also helps to guide the diseasediagnosis, course staging and treatment of CCAD. Although the diagnostic efficacy of MRA was not as good as HRMR-VWI, it should be the first choice of method for routine examination in evaluating CCAD, especially at the chronic stage of CCAD.

Quantitative evaluation for intravascular structures of vertebral artery dissection with a novel zoomed high-resolution black-blood MR imaging

BACKGROUND

Although non-stroke vertebral artery dissection (VAD) is diagnosed using MRI, detecting the subtle intravascular structure remains challenging. This study aimed to evaluate the validity of quantitative intravascular scanning based on novel zoomed high-resolution black blood (Z-HB) MRI for distinguishing VAD from other vessel pathologies.

METHODS

Twenty-one patients with non-stroke VAD and 18 with symptomatic atherosclerotic plaques in their vertebral artery underwent Z-HB MRI and subsequent profile curve processing. Axial Z-HB imaging was obtained from dissected and normal segments in patients with VAD and atherosclerotic plaque in patients with ischemia. We investigated the qualitative categorization of the scanning patterns of the intravascular signals. We also evaluated the quantitative ability of each profile curve to discriminate multiple vessel pathologies by analyzing the receiver operating characteristics curves.

RESULTS

Profile curve processing of 140 Z-HB images categorized the intravascular signal patterns into luminal, asymmetrical, and omega types. The asymmetrical type included both dissecting and atherosclerotic vessels, and the omega type included dissecting and normal vessels. In the asymmetrical type, quantitative evaluation successfully distinguished intramural hematomas of VAD from atherosclerotic plaque with an area under the curve of 0.80. The intimal flap of the VAD was distinguished from the blood flow artifact of the normal vessel with an area under the curve of 0.93 in the omega type.

CONCLUSIONS

A combination of novel Z-HB MRI and profile curve processing provided an ultra-high-resolution analysis of the intravascular structure of non-stroke VAD and successfully distinguished VAD from normal vessels or atherosclerotic plaques.

Periprocedural cerebrovascular complications and 30-day outcomes of endovascular treatment for intracranial vertebral artery dissecting aneurysms

OBJECTIVE

The authors undertook an evaluation of periprocedural cerebrovascular complications and 30-day outcomes of endovascular treatment for intracranial vertebral artery dissecting aneurysms (IVADAs) and assessed the relevant risk factors.

METHODS

The authors included a series of 195 patients who had undergone endovascular treatment for 198 IVADAs. Clinical data, morphological characteristics, treatment details, and periprocedural cerebrovascular complications including intraprocedural rupture, intraprocedural thrombosis, intracranial hemorrhage (ICH), transient ischemic attack (TIA), and ischemic stroke (IS) were recorded. After evaluation of the 30-day modified Rankin Scale (mRS) scores, the authors applied univariate and multivariate logistic regression analyses to identify the risk factors for complications and 30-day unfavorable clinical outcomes.

RESULTS

There were no intraprocedural ruptures, but the authors recorded intraprocedural thrombosis (n = 5), ICH (n = 3), TIA (n = 1), and IS (n = 13), comprising an 11.1% (22/198) complication rate. Multivariate logistic regression analysis indicated that hyperlipidemia (odds ratio [OR] 3.17, 95% confidence interval [CI] 1.20-8.41, p = 0.020), IS history (OR 5.55, 95% CI 1.46-21.01, p = 0.012), and subarachnoid hemorrhage (SAH) (OR 4.48, 95% CI 1.52-13.20, p = 0.007) were risk factors for overall complications, whereas aneurysmal height (OR 0.77, 95% CI 0.61-0.98, p = 0.032) was a protective factor. SAH (OR 6.44, 95% CI 1.54-26.89, p = 0.011) and preprocedural mRS score > 2 (OR 5.07, 95% CI 1.01-25.59, p = 0.049) were independent risk factors for perforator occlusion stroke. Periprocedural cerebrovascular complications (OR 32.09, 95% CI 3.00-343.94, p = 0.004) and preprocedural mRS score > 2 (OR 319.92, 95% CI 30.28-3379.98, p < 0.001) were independent risk factors for 30-day unfavorable clinical outcomes.

CONCLUSIONS

Hyperlipidemia, IS history, and SAH were independent predictors for overall periprocedural cerebrovascular complications of endovascular treatment for IVADAs, but aneurysmal height was an independent protective factor. SAH and preprocedural mRS score > 2 were independent risk factors for perforator occlusion stroke. Preprocedural mRS score > 2 and periprocedural complications were independent risk factors for 30-day unfavorable clinical outcomes.

Morphological characteristics associated with ruptured intracranial vertebral artery dissecting aneurysms

OBJECTIVE

Morphological risk factors for the rupture of intracranial vertebral artery dissecting aneurysms (IVADAs) have not been well characterized. In this study, we aim to identify morphological characteristics associated with IVADA rupture.

METHODS

We conducted a retrospective study of 249 consecutive patients with single IVADAs (31 ruptured and 218 unruptured) admitted to Beijing Tiantan Hospital between January 2016 and December 2020. Various morphological parameters were measured using three-dimensional digital subtraction angiography images. Univariate and multivariate logistic regression analyses were performed to identify morphological characteristics associated with IVADA rupture.

RESULTS

Univariate regression analysis revealed that the coexistence of significant proximal and distal stenosis and posterior inferior cerebellar artery (PICA) involvement were associated with IVADA rupture, while the origin from the dominant vertebral artery was inversely associated with the rupture. Multivariate regression analysis demonstrated that the coexistence of significant proximal and distal stenosis (OR 22.00, 95% CI 5.60 to 86.70, p<0.001) and PICA involvement (OR 4.55, 95% CI 1.36 to 15.20, p=0.014) were independently associated with IVADA rupture.

CONCLUSION

The coexistence of significant proximal and distal stenosis and PICA involvement were independently associated with IVADA rupture. These morphological characteristics may facilitate the assessment of rupture risk in patients with IVADAs.

Headache characteristics to screen for cervicocerebral artery dissection in patients with acute onset unusual headache

OBJECTIVES

The aim of this preplanned primary analysis was to investigate the clinical manifestations of headache to screen for CAD patients with acute onset headache only.

BACKGROUND

Spontaneous cervicocerebral artery dissection (CAD) with acute onset headache is not rare in clinical practice; however, it is underdiagnosed. On the other hand, subsequent infarction or subarachnoid hemorrhage mainly occurs within 1 week of headache onset.

METHODS

Between April 2017 and January 2022, we conducted a single-center, cross-sectional retrospective study on 197 consecutive referred patients from neurosurgical outpatient clinics with acute onset unusual headache (stronger or longer headache than usual). All patients underwent magnetic resonance imaging to screen for secondary headache and were diagnosed based on the diagnostic protocol. We examined patient background data and the following headache characteristics: distribution, condition at the onset of headache, accompanying vomiting or nausea, worsening headache, and analgesic effects against headache. These factors were analyzed to identify independent diagnostic predictors of CAD. In this study, the rate of missing data was 41% for improvement of headache by analgesia and multiple imputation by chained equations was performed.

RESULTS

A total of 93 patients (46 men and 47 women; mean age: 48 years, range: 25-73 years) were diagnosed with CAD. Univariate logistic regression analysis showed CAD was associated with current smoking, systolic blood pressure >140 mmHg, unilateral headache, worsening headache, and no headache improvement by analgesia. Unilateral, worsening headache and no headache improvement by analgesia remained independent diagnostic predictors in multivariable logistic regression after multiple imputation. No headache improvement by analgesia had the highest sensitivity (86%), while worsening headache had the highest specificity (84%).

CONCLUSIONS

CAD needs to be considered in patients with unilateral, worsening headache and no headache improvement by analgesia.

Characteristic image on cerebral angiography in ruptured blood blister-like aneurysms

OBJECTIVE

To evaluate the static and dynamic features of blood blister-like aneurysms (BBAs) using cerebral angiography to identify characteristic features to improve the diagnosis of these uncommon aneurysms.

METHODS

Digital subtraction angiography (DSA) images were compared between patients with BBAs (n = 12, group A) and patients with unruptured paraclinoid aneurysms ≤ 5 mm in size treated by endovascular procedures (n = 12, group B). DSA images were assessed for irregularities in the diameter of the parent artery and delayed inflow and outflow of contrast medium in the aneurysm. Enlargement of the aneurysm and morphological changes from the first assessment were also evaluated in patients with BBAs.

RESULTS

Compared to the group B, group A had a higher proportion of irregular vessel diameter (p = 0.013) and the delayed contrast medium outflow (p = 0.014). As well, stagnation of contrast medium along the aneurysm wall was a characteristic finding of BBAs, even for small aneurysms.

CONCLUSION

Irregular morphological features of the parent artery and delayed contrast medium outflow as characteristic findings of ruptured BBAs may improve the diagnosis of these uncommon aneurysms, which remains challenging in practice.

Sequential detection rates of intramural hematoma for diagnosing spontaneous intracranial artery dissection

BACKGROUND AND PURPOSE

Spontaneous intracranial artery dissection (IAD) can be definitively diagnosed by detecting intramural hematoma (IMH) on arterial wall imaging. However, evidence of a time-dependent natural history for the development of radiological findings is lacking. Therefore, this study aimed to determine when imaging detects IAD.

METHODS

We obtained data from our cohort databases between March 2011 and August 2018 on consecutive patients who had definite, probable, or possible IAD based on the multidisciplinary expert consensus criteria. We assessed IMH on initial and follow-up high-resolution three-dimensional T1-weighted imaging (HR-3D-T1WI). We retrospectively investigated the association between IMH detection and days from symptom onset to initial HR-3D-T1WI and compared the IMH detection rate with other definitive diagnostic arterial dissection findings.

RESULTS

We analyzed 106 patients (mean age = 51 ± 13 years, 31 women) with at least initial HR-3D-T1WI data. The final diagnoses were definite, probable, and possible IAD in 83, 18, and 5 patients, respectively. IMHs were observed in 63 patients (59%, 95% confidence interval [CI] = 49%-69%). Overall IMH detection rate was 55% (95% CI = 45%-64%), 20% (95% CI = 3%-60%), 40% (95% CI = 21%-64%), and 50% (95% CI = 37%-63%) on the initial HR-3D-T1WI and Days 3, 7, and 13, respectively. Among 68 patients evaluated with digital subtraction angiography and HR-3D-T1WI, IMH was confirmed more frequently than other definitive diagnostic arterial dissection findings.

CONCLUSIONS

The overall IMH detection rate on HR-3D-T1WI was >50% and peaked in 1-2 weeks. IMH was a frequently detectable finding for the diagnosis of IAD compared to other radiological findings.

Clinical characteristics, endovascular choices, and surgical outcomes of intracranial vertebral artery dissecting aneurysms: a consecutive series of 196 patients

OBJECTIVE

The authors aimed to evaluate the clinical features, endovascular strategy selection, and outcomes of vertebral artery (VA) dissecting aneurysms (VADAs) near the origin of the posterior inferior cerebellar artery (PICA).

METHODS

Clinical data were obtained from 196 patients with 202 VADAs who had been surgically treated at the authors' hospital between 2005 and 2021. The patients' medical records, imaging data, and follow-up outcomes were retrospectively analyzed.

RESULTS

All 196 patients (148 male, 48 female; mean age 53 years) underwent endovascular therapy for VADA. The most common chief complaints were headache (56.6%), dizziness (40.8%), and other occasional symptoms (18.4%). Twenty-six patients experienced posterior circulation ischemia, and 25 patients experienced subarachnoid hemorrhage (SAH). On DSA images, 37 aneurysms were found in the dominant VA, and 165 aneurysms were found on the nondominant side. Eighty-eight VADAs had stenosis. Regarding the VADA location, there were 59 distal, 51 proximal, 23 ventral, 64 PICA, and 5 obliteration types. Single-stent implantation (10.9%), overlapping stent implantation (23.8%), flow diverter (FD) implantation (11.9%), single stent-assisted coil (SAC) embolization (31.7%), overlapping SAC embolization (12.9%), parent artery occlusion (PAO) (8.4%), and FD-assisted coil embolization (0.5%) were chosen. The follow-up rate was 82.7%. The modified Rankin Scale (mRS) score was 0.5 ± 1.1. Ninety-six patients underwent DSA. The complete occlusion rates were 100%, 81.4%, 56.7%, and 76.5% in the PAO group, SAC reconstruction group, stent implantation group, and FD implantation group, respectively.

CONCLUSIONS

Young patients showed a higher probability of SAH, and elderly patients showed a higher probability of posterior circulation infarction. The surgical plan selection should be based on the SAH history, VA dominant side, and PICA origin location.

Comparison of Parent Artery Occlusion and Stent-Assisted Treatments in Ruptured Vertebral Artery Dissecting Aneurysms

OBJECTIVE

To assess clinical outcomes of ruptured vertebral artery dissecting aneurysms, focusing on comparing parent artery occlusion (PAO) with stent-assisted treatments, and to identify risk factors for unfavorable outcomes and postprocedural complications.

METHODS

This retrospective review included 36 ruptured vertebral artery dissecting aneurysms treated between February 2009 and April 2020. Treatment modalities included PAO without stent and stent-assisted treatments. Stent-assisted treatments included PAO with posterior inferior cerebellar artery (PICA) stenting and stent-assisted coiling. Univariate and multivariate analyses were conducted to evaluate risk factors for unfavorable outcomes and postprocedural complications.

RESULTS

Patients were treated with PAO only (24, 66.7%), PAO with PICA stenting (4, 11.1%), and PAO with stent-assisted coiling (8, 22.2%). There were only fusiform aneurysms with PICA involvement in the PAO with PICA stenting group. In the stent-assisted coiling group, 4 aneurysms incorporated PICA, and 4 aneurysms involved dominant vertebral artery. Old age (odds ratio [OR] = 1.25, 95% confidence interval [CI] = 1.01-1.56, P = 0.044) and poor Hunt-Hess grade (OR = 537.99, 95% CI = 6.73-42994.1, P = 0.005) were significantly associated with unfavorable clinical outcomes after a mean follow-up of 37.5 ± 32.8 months. Fusiform dilatation shape (OR = 15.97, 95% CI = 1.52-167.38, P = 0.021) and PICA involvement (OR = 13.71, 95% CI = 1.29-145.89, P = 0.030) were independent risk factors for ischemic complications.

CONCLUSIONS

Unfavorable clinical outcomes were significantly related to old age and poor Hunt-Hess grade. There were no significant differences between treatment groups in clinical outcomes or ischemic complications. Stent-assisted treatments might be effective and safe methods for ruptured vertebral artery dissecting aneurysms.

Influence of endothelial function and arterial stiffness on the behavior of cervicocephalic arterial dissections: An observational study

Background

The mechanical and physiological properties of the arterial wall might affect the behavior of spontaneous cervicocephalic arterial dissections (CCAD). We aimed to determine the effects of endothelial function and arterial stiffness on the clinical characteristics and outcomes of CCAD using brachial flow-mediated dilation (FMD) and brachial-ankle pulse wave velocity (PWV).

Methods

From a single-center database, we identified patients admitted from April 2011 to December 2021 with a diagnosis of CCAD who underwent both FMD and PWV. FMD was classified as normal and decreased according to institutional thresholds. PWV was categorized into tertiles. Comparative and multivariable analyses were performed to determine the effects of FMD and PWV values on major clinical outcomes.

Results

A total of 146 patients (age: 47 ± 11 years; men: 77.4%) were included. The main presentation was ischemic stroke in 76.7% of the patients, while 23.3% presented with headache or other symptoms. Healing of the dissection was observed in 55.8%. In multivariable analysis, Normal FMD levels (vs. decreased; adjusted OR: 4.52, 95% CI [1.95 −10.52]) were associated with spontaneous healing of the dissection. Highest PWV tertile (vs. lowest; adjusted OR: 17.05, 95% CI [3.07–94.82]) was associated with ischemic presentation. There was a higher ischemic stroke recurrence in the 3rd PWV tertile, and more frequent aneurysmal enlargement in the lowest PWV tertile, but their frequency was low, precluding multivariable analysis.

Conclusion

In spontaneous CCAD, preserved endothelial function was associated with spontaneous arterial healing. Arterial stiffness is associated with ischemic presentation.

Diagnostic accuracy of MR vessel wall imaging at 2 weeks to predict morphological healing of vertebral artery dissection

OBJECTIVES

The spontaneous healing of non-hemorrhagic intracranial vertebral artery dissection (VAD) may be associated with the stabilization of intramural hematoma (IMH). We previously suggested that the signal intensity of IMH increases until approximately 2 weeks in VAD with spontaneous healing. We herein investigated the diagnostic accuracy of the signal intensity of IMH at 2 weeks to predict the spontaneous healing of VAD.

METHODS

From April 2017 to April 2021, we prospectively investigated patients with non-hemorrhagic VAD who underwent vessel wall imaging (VWI). Morphological healing of VAD was evaluated by MR angiography three months after its onset. The relative signal intensity (RSI) of IMH against the posterior cervical muscle on VWI was calculated. Univariate and multivariate analyses were performed on factors associated with the spontaneous healing of VAD among patient baseline data, vascular morphology at the diagnosis, and RSI parameters.

RESULTS

Forty-eight patients (23 men and 25 women; mean age: 51 years, range: 34-73 years) with 50 non-hemorrhagic VAD were included in the present study. Spontaneous healing was observed in 28 VAD (56%). RSI two weeks after the onset of VAD (RSI_2w) and morphological feature such as the string sign were associated with spontaneous healing, respectively. The multivariate logistic regression analysis identified RSI_2w as an independent predictive factor of spontaneous healing (OR: 7.3; 95% CI, 1.9-28, p = 0.004). The cut-off value for RSI_2w to predict spontaneous healing was 1.22 (AUC = 0.90, sensitivity: 91%, specificity: 82%).

CONCLUSION

RSI_2w predicted the spontaneous healing of non-hemorrhagic VAD 3 months after its onset.

Endovascular treatment of intracranial vertebral artery unruptured dissecting aneurysms: Comparison of flow diversion and stent-assisted coiling or stenting alone

Purpose

To investigate the effect and safety of flow diverters in the treatment of unruptured dissecting intracranial aneurysms of the vertebral artery in comparison with stent-assisted coiling or stenting alone.

Materials and methods

Patients with unruptured dissecting intracranial aneurysms of the vertebral artery treated with the flow diverter, stent-assisted coiling, or stenting alone were retrospectively enrolled. The clinical data were analyzed and compared.

Results

Twenty-five patients were enrolled in the flow diversion group and 42 patients in the stenting group. Twenty-six flow diverters were deployed in the flow diversion group. Immediate angiography revealed contrast agent retention within the aneurysm cavity in all patients. In the stenting group, 48 stents were deployed, and immediate angiographic outcome showed O'Kelly-Marotta (OKM) grade D in 18 (42.9%) aneurysms, grade C in 16 (38.1%), and grade B in 8 (19.0%). Periprocedural ischemic complications of thrombosis occurred in two (4.8%) patients and were treated with thrombolysis. In the flow diversion group, 19 (76%) patients underwent angiographic follow-up 3–46 (median 24) months after the procedure, with the OKM grade D in 11 (57.9%) patients, C in two (10.5%), and B in six (31.6%). The aneurysm recurrence rate was zero, and all diverters remained patent. Asymptomatic instent stenosis occurred in two (10.5%) patients. In seven of the ten patients with mild or moderate parent artery stenosis before the procedure who experienced angiographic follow-up, the stenosis was improved in five (71.4%) patients. In the stenting group, angiographic follow-up was carried out in 33 (78.6%) patients 6–58 months (median 34) after the procedure, with OKM grade D in 22 (66.7%) patients, grade C in five (15.2%), grade B in three (9.1%), and aneurysm recurrence (grade B, with increased contrast agent into the aneurysm cavity) in three (9.1%). Five (16.7%) patients experienced asymptomatic instent stenosis, and six of the 12 patients (50%) with parent artery stenosis were improved.

Conclusion

Flow diverters with or without selective adjunctive coiling for the treatment of unruptured dissecting intracranial aneurysms of the vertebral artery may be safe and effective with good occlusion effects not inferior to those of stent-assisted coiling and stenting alone even though the long-term effect still warrants confirmation.

Outcomes of reconstructive endovascular treatment of vertebrobasilar dissecting aneurysms with intramural hematoma

Background

Vertebrobasilar dissecting aneurysms (VBDAs) with an intramural hematoma (IMH) usually cause symptoms because of mass effect and grow in size over time. Clinical outcomes are generally poor.

Objective

This study aimed to examine outcomes of reconstructive endovascular treatment (EVT) in patients with VBDAs with IMH. Safety and effectiveness were compared between flow diverters (FDs) and conventional stents.

Methods

We retrospectively analyzed the clinical and radiological data of 36 VBDAs with IMH in 36 patients who underwent EVT with either FDs or conventional stents from January 2012 to December 2020 at our institution.

Results

Among the 36 study patients, 20 were treated with FDs and 16 with conventional stents. Incidence of procedure-related complications did not significantly differ between the two stents. IMH growth occurred after EVT in a significantly higher proportion of conventional stent group aneurysms (zero vs. 31.3% [5/16]; p = 0.012). Among the five aneurysms with IMHs that grew, all recurred. Change in IMH size after EVT was significantly lower in the FD group (−2.7 vs. +8.1%, p = 0.036). However, after the recurrent aneurysms were removed from the conventional stent group, change in IMH size did not significantly differ between the two groups (−2.7 vs. +1.0%, p = 0.332). The proportion of patients who experienced an improvement in mRS score after EVT was significantly higher in the FD group (60 vs. 25%, p = 0.036).

Conclusion

IMHs in VBDAs stop growing after successful reconstructive EVT. Although both FD and conventional stent treatment are effective, FD treatment may be superior based on clinical outcomes and effect on IMH size.

Clinical and radiological risk factors for rupture of vertebral artery dissecting aneurysm: significance of the stagnation sign

OBJECTIVE

The aim of this study was to investigate the clinical and radiological factors associated with the rupture of a vertebral artery dissecting aneurysm (VADA) and to evaluate whether the stagnation sign is a significant risk factor for rupture of VADA.

METHODS

Clinical and radiological variables of 117 VADAs treated in a tertiary hospital from September 2008 to December 2020 were retrospectively reviewed. The stagnation sign is defined as the finding of contrast agent remaining in the lesion until the venous phase of angiography. Univariate and multivariate analyses were executed to reveal the associations between rupture status and VADA characteristics.

RESULTS

The rate of ruptured VADAs was 29.1% (34 of 117) and the stagnation sign was observed in 39.3% (46 of 117). Fusiform shape (OR 5.105, 95% CI 1.591-16.383, p = 0.006), irregular surface (OR 4.200, 95% CI 1.412-12.495, p = 0.010), posterior inferior cerebellar artery (PICA) involvement (OR 3.788, 95% CI 1.288-11.136, p = 0.016), and the stagnation sign (OR = 3.317, 95% CI 1.131-9.732, p = 0.029) were significantly related to rupture of VADA in multivariate logistic regression analysis.

CONCLUSIONS

This study showed that fusiform shape, irregular surface, PICA involvement, and the stagnation sign may be independent risk factors for the rupture of VADA. Therefore, when the potential risk factors are observed in unruptured VADA, more aggressive treatment rather than follow-up or medical therapy may be considered.

Flow diverter for the treatment of large (> 10 mm) vertebral artery dissecting aneurysms

OBJECTIVE

To evaluate the outcomes of flow-diverting device (FDD) treatment for large vertebral artery dissecting aneurysms (VADAs).

METHODS

This retrospective study evaluated 12 patients with 12 VADAs who were treated using FDD between 2013 and 2020. Clinical and radiographic data, including procedure-related complications and clinical outcomes assessed using the modified Rankin Scale (mRS) at the time of the last follow-up, were collected and reviewed.

RESULTS

All 12 patients had unruptured aneurysms. There were 3 (25%) female and 9 (75%) male patients, and the mean patient age was 54.6 years. The mean size of the aneurysm was 15.9 ± 4.8 mm. The mean follow-up duration was 15.8 months. Single FDD without additional coils was used in all patients. One patient underwent second-line treatment with FDD for recurrence of large VADA after stent-assisted coiling. Immediate follow-up angiography after placement of the FDD demonstrated intra-aneurysmal contrast stasis. There were 2 (17%) patients who had peri-procedural stroke. Angiography at the 6-month follow-up in 10 patients showed favorable occlusion (OKM grade C3 + D). A total of 11 (92%) patients had good clinical outcome (modified Rankin Scale ≤ 2) at the last follow-up. No re-treatment or delayed aneurysm rupture occurred during the follow-up period.

CONCLUSIONS

Reconstructive technique with FDD is a feasible and effective modality for the treatment of large VADAs, showing favorable occlusion rate and clinical outcome.

Evaluating intracranial artery dissection by using three-dimensional simultaneous non-contrast angiography and intra-plaque hemorrhage high-resolution magnetic resonance imaging: a retrospective study

BACKGROUND

There was no previous report on the three-dimensional simultaneous non-contrast angiography and intra-plaque hemorrhage (3D-SNAP) magnetic resonance imaging (MRI) sequence to diagnose intracranial artery dissection (IAD).

PURPOSE

To improve the diagnostic accuracy and guide the clinical treatment for IAD by elucidating its pathological features using 3D-SNAP MRI.

MATERIAL AND METHODS

From January 2015 to September 2018, 113 patients with suspected IAD were analyzed. They were divided into IAD and non-IAD groups according to the spontaneous coronary artery dissection (SCAD) criteria. All patients underwent 3D-SNAP, 3D-TOF, T2W imaging, 3D-PD, 3D-T1W-VISTA, and 3D-T1WCE) using 3.0-T MRI; clinical data were collected. The IAD imaging findings (intramural hematoma, double lumen, intimal flap, aneurysmal dilatation, stenosis, or occlusion) in every sequence were analyzed. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic efficiency of each sequence.

RESULTS

There was a significant difference in the probability of intramural hematoma, relative signal intensity of intramural hematoma, double lumen, stenosis, or occlusion signs on 3D-TOF, T2W, 3D-PD, 3D-T1W-VISTA, 3D-SNAP, and 3D-T1WCE sequences (P<0.05). The 3D-SNAP and 3D-T1WCE sequences were most sensitive for diagnosing intramural hematoma and displaying double-lumen signs, respectively. The diagnostic efficiency of the 3D-SNAP sequence combined with 3D-T1WCE was the highest (area under the curve [AUC] 0.966). The AUC value of the 3D-SNAP sequence (AUC 0.897) was slightly inferior to that of 3D-T1W enhancement (AUC 0.903).

CONCLUSION

3D-SNAP MRI is a non-invasive and effective method and had the greatest potential among those methods tested for improving the diagnostic accuracy for IAD.

Diagnostic Performance of High-Resolution Vessel Wall Magnetic Resonance Imaging and Digital Subtraction Angiography in Intracranial Vertebral Artery Dissection

Purpose: Intracranial vertebral artery dissection (VAD) is being increasingly recognized as a leading cause of Wallenberg syndrome and subarachnoid hemorrhage. Conventional angiography is considered the standard diagnostic modality, but the diagnosis of VAD remains challenging. This study aimed to compare the diagnostic performance of high-resolution vessel wall imaging (HR-VWI) with digital subtraction angiography (DSA) for intracranial VAD. Materials and methods: Twenty-four patients with 27 VADs, who underwent both HR-VWI and DSA within 2 weeks, were consecutively enrolled in the study from March 2016 to September 2020. HR-VWI and DSA were performed to diagnose VAD and to categorize its angiographic features as either definite dissection or suspicious dissection. Features of HR-VWI were used to evaluate direct arterial wall imaging. The reference standard was set from the clinicoradiologic diagnosis. Two independent raters evaluated the angiographic features, dissection signs, and interrater agreement. Each subject was also dichotomized into two groups (suspicious or definite VAD) in each modality, and diagnosis from HR-VWI and DSA was compared with the final diagnosis by consensus. Results: HR-VWI had higher agreement (90.6% vs. 53.1%) with the final diagnosis and better interrater reliability (kappa value (κ) = 0.91; 95% confidence interval (CI) = 0.64–1.00) compared with DSA (κ = 0.58; 95% CI = 0.35–1.00). HR-VWI provided a more detailed identification of dissection signs (77.7% vs. 22.2%) and better reliability (κ = 0.88; 95% CI = 0.58–1.00 vs. κ = 0.75; 95% CI = 0.36–1.00), compared to DSA. HR-VWI was comparable to DSA for the depiction of angiographic features for VAD. Conclusions: HR-VWI may be useful to evaluate VAD, with better diagnostic confidence compared to DSA.

[Spontaneous craniocervical dissection]

Spontaneous craniocervical dissection is one of the main causes of stroke in juvenile and middle-aged patients. It is caused by intramural hematoma which may result in stenosis or even occlusion of the artery. Clinical manifestation varies from local pain to ischemic complications. The imaging modality of choice is magnetic resonance imaging (MRI) which is able to detect all characteristic signs of dissection. Intramural hematoma is detected with thin slice fat-saturated 3D black-blood images. However, with the use of special imaging techniques, questionable findings can be clarified and especially the more difficult to detect intradural dissection can be accurately diagnosed. Acute treatment depends on the severity of neurological symptoms and their duration. Factors like the location of the dissection, cerebral infarction or hemorrhage influence the choice of medication for primary and secondary prophylaxis. Resorption of the intramural hematoma often leads to spontaneous recanalization within a few months.

Identification of high risk clinical and imaging features for intracranial artery dissection using high-resolution cardiovascular magnetic resonance

BACKGROUND

Intracranial artery dissection (IAD) often causes headache and cerebral vascular ischemic events. The imaging characteristics of IAD remain unclear. This study aims to characterize the appearance of culprit and non-culprit IAD using high-resolution cardiovascular magnetic resonance imaging (hrCMR) and quantify the incremental value of hrCMR in identifying higher risk lesions.

METHODS

Imaging data from patients who underwent intervention examination or treatment using digital subtraction angiography (DSA) and hrCMR using a 3 T CMR system within 30 days after the onset of neurological symptoms were collected. The CMR protocol included diffusion-weighted imaging (DWI), black blood T1-, T2- and contrast-enhanced T1-weighted sequences. Lesions were classified as culprit and non-culprit according to imaging findings and patient clinical presentations. Univariate and multivariate analyses were performed to assess the difference between culprit and non-culprit lesions and complementary value of hrCMR in identifying higher risk lesions.

RESULTS

In total, 75 patients were included in this study. According to the morphology, lesions could be classified into five types: Type I, classical dissection (n = 50); Type II, fusiform aneurysm (n = 1); Type III, long dissected aneurysm (n = 3); Type IV, dolichoectatic dissecting aneurysm (n = 9) and Type V, saccular aneurysm (n = 12). Regression analyses showed that age and hypertension were both associated with culprit lesions (age: OR, 0.83; 95% CI 0.75-0.92; p < 0.001 and hypertension: OR, 66.62; 95% CI 5.91-751.11; p = 0.001). Hematoma identified by hrCMR was significantly associated with culprit lesions (OR, 16.80; 95% CI 1.01-280.81; p = 0.037). Moreover, 17 cases (16 lesions were judged to be culprit) were diagnosed as IAD but not visible in DSA and 15 were Type I lesion.

CONCLUSION

hrCMR is helpful in visualizing and characterizing IAD. It provides a significant complementary value over DSA for the diagnosis of IAD.

Factors Predictive of Enlargement of Dissecting Aneurysms in the Vertebral Artery

OBJECTIVE

To elucidate the incidence rate of enlargement of vertebral artery dissecting aneurysms (VADAs) during the acute phase and factors associated with enlargement.

METHODS

Of 115 patients with unilateral intracranial vertebral artery dissection who did not experience subarachnoid hemorrhage, 64 with the pearl sign of vertebral artery dissection (VADA without stenosis) participated in the study. We performed initial magnetic resonance imaging to diagnose VADA and subsequent magnetic resonance imaging to evaluate VADA enlargement. The presence of a hyperintense intramural signal was confirmed using T1-weighted three-dimensional turbo spin-echo imaging. Enlargement of VADAs between the initial and subsequent examinations was evaluated via magnetic resonance angiography and defined as the end point. We studied the rate of VADA enlargement using Kaplan-Meier curve analysis. After independent variables were determined, the Cox proportional hazards model was applied in multivariable analysis to identify the factors significantly associated with VADA enlargement.

RESULTS

Of 64 patients (mean age, 55.7 ± 13.0 years; 44 men and 20 women), 15 exhibited VADA enlargement. Kaplan-Meier curve analysis indicated that 24.8% of VADA enlargements were detected 30 days after initial magnetic resonance imaging. The Cox proportional hazards model revealed that young age (hazard ratio 0.953, P = 0.043) and the presence of hyperintense intramural signal (hazard ratio 2.841, P = 0.033) were significantly associated with VADA enlargement.

CONCLUSIONS

VADAs enlarged by approximately 25% until day 30 after the initial examination. Younger age and the presence of hyperintense intramural signal were significantly associated with VADA enlargement.

Endovascular Treatment of Intracranial Vertebral Artery Dissection

Intracranial vertebral artery dissection (VAD) is the most common arterial dissection in intracranial arteries. Some types of VAD can heal spontaneously after reconstitution of the vessel lumen with excellent prognosis, whereas others can progress to stroke that needs treatment. Recently, endovascular treatment (EVT) has emerged and is suggested as a treatment option for VADs due to perceived low rates of procedure-related morbidity with good efficacy. In the last decade, we have accumulated our strategies to treat those VADs. Here, we try to share our experiences about VADs, including indications and methods of treatment of VADs using EVT. We perform EVT for ruptured VADs presenting with SAH and some of unruptured VADs such as VAD with recurrent or progressive ischemia, dissecting aneurysm larger than 7 mm or with mass effect, early ugly change of VADs in shape and size during follow-up period, involving the basilar artery (BA) and bilateral VADs. We present how we have done in our real practice for the last decade for treating VADs by EVT rather than reviewing and organizing so-far-published literature. We tended to occlude the rupture point by vertebral artery (VA) occlusion in non-dominant VA or stent-assisted coiling in dominant VA for ruptured VADs. We tended to reconstruct original hemodynamics using various stents for unruptured VADs. To decide what to treat and how to treat are very complicated for VADs. However, we believe that EVT is the current mainstay for treating VADs. Each technique of EVT should be determined on a case-by-case basis at the discretion of endovascular neurosurgeons and/or interventional neuroradiologists according to presenting symptoms, hemodynamic status, including sufficiency of the collateral supply and anatomic features of the vertebrobasilar artery as well as the posterior inferior cerebellar artery, anterior spinal artery, and medullary perforators.

Endovascular Approach in Patients with Acute Complete Occlusion Due to Middle Cerebral Artery Dissection

Objective

Dissection of the middle cerebral artery (MCA) is less common than dissection of vessels in the vertebrobasilar system or carotid artery. Acute complete occlusion related to MCA dissection is extremely rare. We report an endovascular approach in patients with acute complete occlusion due to MCA dissection.

Methods

We reviewed retrospectively the endovascular procedure and clinical results for acute-stroke patients who underwent recanalization from October 2014 through December 2018. Initial imaging findings and the endovascular procedure were analyzed for patients with acute complete occlusion due to MCA dissection.

Results

We undertook first-line aspiration thrombectomy using a Penumbra catheter in 294 patients with acute occlusion of the M1 segment. Of these patients, seven were confirmed to have acute complete occlusion due to MCA dissection. All patients had angiographic findings of an intimal flap at the proximal occlusion site of the MCA. One patient complained of severe headache during microcatheter passage through the occluded lesion and died due to massive bleeding caused by rupture of the false lumen. The remaining patients underwent initial contact aspiration thrombectomy without microcatheter passage. After aspiration thrombectomy, six patients had delayed flow through the MCA. One patient underwent stenting of the MCA because of progressive symptoms.

Conclusion

An intimal flap at the proximal portion of an occluded MCA can suggest the possibility of MCA dissection. Contrast aspiration thrombectomy without microcatheter passage can reduce the risk of false lumen rupture in cases of MCA dissection.

Intracranial vessel wall MR imaging of an intradural vertebral artery dissection

Diagnosis of intracranial arterial dissections can be challenging due to the wide spectrum of imaging presentations. High-resolution vessel wall MR imaging can be a useful adjunct to conventional lumen-based imaging techniques for diagnosing arterial dissections. We present a case of a 37-year-old male with a history of a Wolff-Parkinson-White syndrome presenting with acute onset of nausea, vertigo, and left body hemisensory loss of pain and temperature. A conventional brain MRI identified an acute infarct in the right lateral medulla, concordant with clinical symptoms of Wallenberg syndrome. CT angiogram of the head and neck showed lack of opacification of the right intradural vertebral artery. Intracranial vessel wall MR imaging showed findings suggestive of an intimal dissection flap with both intramural and intraluminal thrombus. Intracranial vessel wall MR imaging can provide complementary information to conventional lumen-based imaging to diagnose a vertebral dissection.

Basi-parallel anatomic scanning (BPAS-MRI) compared with high-resolution MRI for the diagnosis of vertebrobasilar artery abnormalities

PURPOSE

To investigate the utility of basi-parallel anatomic scanning magnetic resonance imaging (BPAS-MRI) for the diagnosis of vertebrobasilar artery lesions.

METHOD

From October 2017-November 2018, 105 consecutive patients with abnormal configuration of the vertebrobasilar artery on time-of-flight magnetic resonance angiography (TOF-MRA) were enrolled. Conventional high-resolution MRI combined with TOF-MRA were performed to diagnose lesions and were used as the standard for sensitivity and specificity determination. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of BPAS-MRI combined with TOF-MRA were calculated. The consistencies between the two methods were evaluated by kappa test.

RESULTS

Of the 105 patients, 45 were diagnosed with arteriosclerosis, 46 with vertebral artery dysplasia, 11 with artery dissection or dissecting aneurysm, and 3 as simple dilatation. Results Compared with conventional high-resolution MRI combined with TOF-MRA, for vertebrobasilar arteriosclerosis, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of BPAS-MRI combined with TOF-MRA were 95.6 %, 95.0 %, 93.5 %, 96.6 % and 95.2 %, respectively and kappa value was 0.903. For vertebral artery dysplasia, they were 100 %, 96.6 %, 95.8 %, 100 %, and 98.1 %, respectively and kappa value was 0.961. For vertebrobasilar artery dissection or dissection aneurysm, they were 81.8 %, 96.8 %, 97.8 %, 75.0 % and 95.2 %, respectively and kappa value was 0.756.

CONCLUSIONS

BPAS-MRI can show the outer contour of the vertebrobasilar artery system. Combined with TOF-MRA, it may be used to differentiate among vertebrobasilar artery abnormalities, and be used in hospitals where conventional high-resolution MRI is not feasible.

Association between morphologic subtypes of vertebral artery dissection and vertebral artery hypoplastic appearance

OBJECTIVES

The purpose of this study was to evaluate the associations between vertebral artery hypoplasia (VAH) and the morphologic types of spontaneous vertebral artery dissection (sVAD) and to assess the chronological changes of VAH after sVAD.

METHODS AND MATERIALS

In this retrospective study, we included 208 patients with 216 sVADs which were diagnosed between January 2003 and June 2017 at two tertiary hospitals. Morphologic types of sVAD were classified into aneurysmal dilatation without stenosis, pearl-and-string appearance, and steno-occlusion without aneurysmal dilatation. Baseline clinical characteristics and sVAD types were compared according to the presence of VAH on initial imaging. For 143 sVAD patients with follow-up imaging available, chronological changes of VAH and their associations with sVAD types were also evaluated.

RESULT

VAH was detected in 29 (13.9%) subjects: 18 (8.7%) with ipsilateral VAH and 11 (5.3%) with contralateral VAH to the sVAD site. Primary lesion shape was statistically associated with the presence of VAH (P = 0.001); steno-occlusion without dilatation was more frequently observed in the ipsilateral VAH group (44.4%) than the no-VAH group (20.9%) or contralateral VAH group (0%). Of a total 143 sVAD patients with follow-up imaging available, VAH-like diffuse VA narrowing was newly observed in seven patients and four patients who were initially classified into the VAH group showed their VAH-like appearances resolved.

CONCLUSIONS

The presence of VAH may be associated with the morphologic subtype of sVAD and the VA diameter can dynamically change, making it possible for the VAH-like appearance to be induced after a sVAD event.

Intramural duodenal hematoma: clinical course and imaging findings

Background

Intramural duodenal hematoma is a rare condition. Different imaging modalities are at hand for diagnosis.

Purpose

To identify patients with intramural duodenal hematoma and report imaging findings and clinical courses.

Material and Methods

Typical imaging patterns using ultrasound, computed tomography, and magnetic resonance imaging were carried out on 10 patients.

Results

The mean patient age was 7.5 years. The average disease duration was 13 months. Clinical signs of improvement were observed within 16 days. Residues were still detectable at long-term follow-up.

Conclusion

For patients with intramural duodenal wall hematoma, diagnosis should be considered early. Typical imaging findings should be known to ensure optimal treatment.

Clinical and Radiological Characteristics of Intracranial Artery Dissection Using Recently Proposed Diagnostic Criteria

BACKGROUND

Data on the clinical and radiological characteristics of intracranial artery dissection (IAD) have remained limited. Our purpose was to reveal the clinical and radiological characteristics of IAD according to diagnostic criteria for IAD as recently reported by a group of international experts.

METHODS

Patients were retrospectively enrolled using a prospective single-center stroke registry between 2011 and 2016. Baseline characteristics and radiological findings including conventional magnetic resonance imaging (MRI) sequences, magnetic resonance angiography (MRA), high-resolution 3-dimensional T1-weighted imaging (HR-3D-T1WI), and digital subtraction angiography were reviewed. We performed statistical comparisons to determine which findings from which modalities are useful.

RESULTS

We identified 118 patients with suspected artery dissection, with 64 patients (median age, 51 [interquartile range, 45-56) years; 16 women) finally meeting the criteria for definite (n = 47), probable (n = 15), or possible (n = 2) idiopathic IAD. Ischemic stroke alone was found in 31 patients (48%) on admission. There were 36 patients (56%) suffering from hypertension and 39 (61%) with smoking history. The vertebral artery alone was the most affected in 42 patients (66%). Intramural hematoma (IMH) was more frequently detected on HR-3D-T1WI than on conventional MRI/MRA (odds ratio, 4.72; 95% confidence interval, 1.71-13.00). In 54 patients (84%), the modified Rankin Scale score after 3 months was 0-1.

CONCLUSIONS

Male dominance and age at IAD onset were similar to previous studies, and more than half had hypertension and smoking history. We confirmed that HR-3D-T1WI is useful for detecting IMH in the diagnostic criteria.

Vertebrobasilar artery dissection manifesting as Millard-Gubler syndrome in a young ischemic stroke patient: A case report

BACKGROUND

Millard-Gubler syndrome (MGS) is caused by a lesion in the brainstem at the level of the facial nerve nucleus, and it is also a rare ventral pontine syndrome. Vertebrobasilar artery dissection (VAD) is an uncommon cause of ischemic stroke. To the best of our knowledge, this is the first case report on the coexistence of MGS and VAD in a young acute ischemic stroke patient.

CASE SUMMARY

We herein describe an unusual case of young acute ischemic stroke patient, presenting with acute right peripheral facial palsy, right abducens palsy, and contralateral hemihypesthesia, manifesting as MGS. After receiving dual antiplatelet therapy with aspirin and clopidogrel, as well as rosuvastatin, the patient recovered significantly. The high-resolution magnetic resonance imaging (MRI) indicated a diagnosis of VAD.

CONCLUSION

Our finding further demonstrated that high-resolution MRI is a useful technique to early detect underlying dissection in posterior circulation ischemic stroke.

Comparison of Clinical and Radiologic Outcomes of Diverse Endovascular Treatments in Vertebral Artery Dissecting Aneurysm Involving the Origin of PICA

OBJECTIVE

To determine clinical and radiologic outcomes of vertebral artery dissecting aneurysms involving posterior inferior cerebellar artery according to different types of endovascular treatment.

METHODS

This study included 18 vertebral artery dissecting aneurysms (6 ruptured and 12 unruptured) involving posterior inferior cerebellar artery treated from January 2009 to December 2016. Treatments were multiple stenting, stent-assisted coil embolization, vertebral artery trapping with vertebral artery-posterior inferior cerebellar artery stenting, and Pipeline embolization. Clinical and radiologic information were obtained from retrospective chart review and radiologic review.

RESULTS

Subarachnoid hemorrhage was diagnosed initially in 6 of 18 patients, and infarction was diagnosed initially in 2 patients. Multiple stenting was performed in 4 patients, including 1 (25%) who had cerebellar infarction and 1 (25%) who had recurrence. Stent-assisted coil embolization was performed in 8 patients, including 1 (12.5%) who had postoperative cerebellar infarction and 2 (25%) who had recurrence. Vertebral artery trapping with vertebral artery-posterior inferior cerebellar artery stenting was performed in 4 patients, including 1 (25%) who had postoperative cerebellar infarction. There was no recurrence (0%). Pipeline embolization was performed in 2 patients, including 1 (50%) who had recurrence. There was no postoperative infarction (0%). No subarachnoid hemorrhage occurred during follow-up. Deterioration in modified Rankin Scale score was found only in the stent-assisted coil embolization group (1/8; 12.5%).

CONCLUSIONS

Vertebral artery trapping with vertebral artery-posterior inferior cerebellar artery stenting showed the lowest rate of aneurysm recurrence with high rate of minor infarction and favorable neurologic outcome. Stent-assisted coil embolization showed high recurrence rates with possible fatal disabling infarction.

Why does my patient's basilar artery continue to grow? A four-year case study of a patient with symptoms of vertebrobasilar dolichoectasia

BACKGROUND

Vertebrobasilar dolichoectasia (VBD) is a clinical entity associated with ischemic stroke, compression of cranial nerves or brainstem, and hydrocephalus. There have been relatively few studies following the progression of VBD in patients presenting with a variety of diverse clinical features.

CASE PRESENTATION

Here, we report a case study of a male with progressive VBD who was followed from November 2012 to December 2016. The patient had diagnosed hypertension for several years and suffered from left peripheral facial paralysis, recurrent ischemic attacks in the brainstem and cerebellum, obstructive hydrocephalus and frequent pneumonia. A series of cranial CT and multi-modal MRI scans were performed to explore the brain imaging features of the patient during follow-up.

CONCLUSIONS

The presented case study suggests that aging, uncontrolled hypertension, arterial dissection and infection may contribute to the exacerbation of VBD and recurrent ischemic stroke.

Intracranial Vessel Wall Imaging with Magnetic Resonance Imaging: Current Techniques and Applications

Vessel wall magnetic resonance imaging (VW-MRI) is a modern imaging technique with expanding applications in the characterization of intracranial vessel wall pathology. VW-MRI provides added diagnostic capacity compared with conventional luminal imaging methods. This review explores the principles of VW-MRI and typical imaging features of various vessel wall pathologies, such as atherosclerosis, dissection, and vasculitis. Radiologists should be familiar with this important imaging technique, given its increasing use and future relevance to everyday practice.

Improvement and Aggravation of Spontaneous Unruptured Vertebral Artery Dissection

BACKGROUND

Intracranial vertebral artery dissection (VAD) is a well-recognized cause of stroke in young and middle-aged individuals, especially in Asian populations. However, a long-term natural course remains unclear. We investigated the long-term time course of VAD using imaging findings to examine the rate and predisposing factors for improvement.

METHODS

We registered 56 consecutive patients (40 males; mean age, 51.8 ± 10.7 years) with acute spontaneous VAD and retrospectively investigated neuroimaging and clinical course within 1 month and at 3 months ± 2 weeks, 6 months ± 2 weeks, and 12 months ± 2 weeks after onset to ascertain predisposing factors and time course for improvement.

RESULTS

The most common presenting symptoms were headache and/or posterior neck pain, seen in 41 patients (73%). Magnetic resonance imaging showed brainstem and/or cerebellum infarction in only 32 patients (57%). Of the 56 VADs, 16 (28%) presented with pearl and string sign, 5 (9%) with pearl sign, 15 (27%) with string sign, and 20 (36%) with occlusion sign. VAD occurred on the dominant side in 20 patients and on the nondominant side in the other 36 patients. The pearl and string sign was more frequently noted on the dominant side than on the nondominant side (50 vs. 17%, p = 0.008). On the other hand, occlusion occurred more often on the nondominant side than on the dominant side (47 vs. 15%, p = 0.016). Furthermore, the pearl and string sign was more frequently seen in the improvement group (41 vs. 15%, p = 0.028), whereas the occlusion sign was evident more frequently in the nonimprovement group (21 vs. 52%, p = 0.015). Follow-up neuroimaging evaluation was performed at 1 and 3 months in 91% each, and at 6 and 12 months in 82% each. VAD aggravation was identified within 1 month after onset in 14%, while VAD improvement was seen in 14, 38, 50, and 52% at each period, mainly within 6 months after onset. Older patients and current smoking were negatively associated with VAD improvement.

CONCLUSIONS

VAD improvement primarily occurs within 6 months after onset, and VAD aggravation within 1 month. It seems that older patients and current smoking are negative predictors of VAD improvement as risk factors, and as image findings, the pearl and string sign is a positive predictor and occlusion a negative predictor.

Risk Factors of Recurrence after Stent(s)-Assisted Coiling of Intracranial Vertebrobasilar Dissecting Aneurysms: A Multicenter Study

Background

We aimed to evaluate the risk factors of recurrence after stent(s)-assisted coiling (SAC) of intracranial vertebrobasilar dissecting aneurysms (VBDAs) based on 168 consecutive patients.

Methods

Between January 2011 and December 2015, 168 consecutive patients with 170 intracranial VBDAs, which were treated by SAC, were recruited from four high-volume centers. We used multivariate logistic regression to examine factors that affected recurrence of VBDAs.

Results

The mean duration of clinical follow-up of the 168 patients was 7.81 months (range, 3–24 months). Of the 168 patients, 4 (2.38%) suffered from intraoperative complications and 16 (9.52%) had postoperative complications. Two (1.19%) had severe disability. Imaging follow-up was available for 168 patients (170 VBDAs), with a mean duration 7.81 months, and 24 (14.12%) cases of recurrence of aneurysms were noted. Aneurysm size and metal coverage of stent(s) at the neck were independent predictors of recurrence after SAC by logistic regression analysis.

Conclusion

This multicenter cohort study shows that aneurysm size and the metal coverage of stent(s) at aneurysmal neck are independent factors associated with recurrence of VBDAs after SAC.

Good recovery of subarachnoid hemorrhage concomitant with ischemia due to anterior cerebral artery dissection by conservative treatment: A case report

The present report describes the case of a 57-year-old woman presenting with subarachnoid hemorrhage (SAH) and acute ischemic stroke (AIS) due to anterior cerebral artery (ACA) dissection, which exhibited severe stenosis at the origin with distal dilatation of the A2 segment and occlusion of the A3 segment. In this case, computed tomography (CT) revealed SAH in right superior frontal sulcus and the interhemispheric fissure. Magnetic resonance imaging demonstrated acute infarct in the territory of the right ACA. Brain digital subtraction angiography showed severe stenosis at the origin of the A2 segment with distal dilatation and occlusion at the origin of the A3 segment of the right ACA, suggesting a diagnosis of dissection. Only treatment with atorvastatin, her clinical condition subsequently improved. The stenosis and dilatation of A2 segment were ameliorated as demonstrated by a follow-up CT angiography 5 months after onset. SAH concomitant with ischemia caused by ACA dissection is rare. Conservative treatment may be a safe and effective choice for patients with SAH concomitant with AIS due to ACA dissection.

Carotid and Vertebral Dissection Imaging

Carotid or vertebral artery dissection is the result of a tear in the vessel lining wherein the intima separates the media. This creates a false or pseudo lumen, often accompanied by hemorrhage into the arterial wall. Dissection of these craniocervical vessels often manifests with pain alone but, if untreated, may result in severe neurologic compromise. The causes of dissection are multifactorial, including spontaneous, iatrogenic, and traumatic insults. Regardless of etiology, treatment consists primarily of anticoagulation, whereas endovascular therapy is reserved for cases with persistent thrombus or flow limitation. Given the high risk of neurological compromise or death and the propensity of these injuries to occur in younger individuals, early diagnosis of carotid and vertebral artery dissections is critical. Although angiography remains the criterion standard for diagnosis, advances in noninvasive imaging have placed magnetic resonance and computed tomography at the forefront of diagnosis. This article examines the current imaging modalities used to diagnose this under-recognized entity.

Treatment for Spontaneous Intracranial Dissecting Aneurysms in Childhood: A Retrospective Study of 26 Cases

OBJECTIVE

This study aimed to assess the clinicoradiological features and treatment outcomes of intracranial dissecting aneurysms (IDAs) in childhood.

METHODS

We conducted a retrospective study of pediatric patients who were treated for spontaneous IDAs in our institute between January 2010 and December 2015. The clinical presentation, aneurysm characteristics, treatment modality, and outcome were studied.

RESULTS

We studied 26 pediatric patients (mean age, 13.4 years; range, 4-18 years) with 31 IDAs who comprised 6.9% of all IDA patients treated during the same period. Seventeen (65.4%) patients were males, and nine (34.6%) were females. The incidence of large (≥10 mm in size) or giant aneurysms (≥25 mm in size) was 65.5%. Twenty-one (80.8%) patients underwent endovascular or surgical treatment and five (19.2%) received conservative treatment. Perioperative complications occurred in three patients, in whom two eventually recovered completely with a Glasgow Outcome Scale (GOS) score of 5 and one partially recovered with a GOS score 4. Overall, 25 (96.2%) patients had a favorable outcome and one (3.8%) had an unfavorable outcome at a mean follow-up of 22.8 months (range, 6-60 months).

CONCLUSION

Pediatric IDAs are rare. In this series, endovascular management was a relatively safe and effective method of treatment for pediatric IDAs. However, continued follow-up is required because of the possibility of aneurysm recurrence and de novo aneurysm formation after treatment.

Spontaneous and Unruptured Chronic Intracranial Artery Dissection : High-resolution Magnetic Resonance Imaging Findings

PURPOSE

The aim of this article is to present high-resolution magnetic resonance imaging (HR-MRI) findings of chronic stage spontaneous and unruptured intracranial artery dissection (ICAD).

MATERIAL AND METHODS

From March 2012 to April 2016 a total of 29 patients (15 male and14 female, age range 37-68 years) with chronic stage spontaneous and unruptured ICAD (vertebral artery 27, posterior inferior cerebellar artery 1 and middle cerebral artery 1) were retrospectively enrolled. Patients underwent HR-MRI more than 2 months (median interval 564 days, range 69-391 days) after symptom onset and were diagnosed at symptom onset or at the first imaging acquisition, which included luminal angiography and/or HR-MRI with clinical information. The HR-MRI findings were evaluated against those of luminal angiography on the basis of the lumen wall morphology, including thickening, contrast enhancement and residual dissection.

RESULTS

The HR-MRI findings were classified into complete normalization (normal lumen and wall with or without mild enhancement, n = 6), complete normalization with minimal wall changes (focal wall thickening with enhancement but normal luminal angiography, n = 8), incomplete normalization (focal wall thickening with enhancement with dilatation and stenosis on luminal angiography, n = 4), dissecting aneurysm (fusiform aneurysm with residual dissection findings, n = 8) and occlusion (small outer arterial diameter with diffuse contrast enhancement, n = 3).

CONCLUSION

The use of HR-MRI can demonstrate the distinguishing morphological features of chronic stage of spontaneous and unruptured ICAD as complete normalization, complete normalization with minimal wall changes, incomplete normalization, dissecting aneurysm and occlusion.

Intracranial Vessel Wall MRI: Principles and Expert Consensus Recommendations of the American Society of Neuroradiology

Intracranial vessel wall MR imaging is an adjunct to conventional angiographic imaging with CTA, MRA, or DSA. The technique has multiple potential uses in the context of ischemic stroke and intracranial hemorrhage. There remain gaps in our understanding of intracranial vessel wall MR imaging findings and research is ongoing, but the technique is already used on a clinical basis at many centers. This article, on behalf of the Vessel Wall Imaging Study Group of the American Society of Neuroradiology, provides expert consensus recommendations for current clinical practice.

Basilar artery dissection: A rare complication of posterior fossa epidermoid cyst resection, and evaluation of the possible effects of cerebrospinal fluid drainage on disease progression

We report a rare case of a 45-year-old female with an unruptured basilar artery dissecting aneurysm presenting with locked-in syndrome due to brainstem ischemia eleven months following resection of a giant cerebellopontine angle epidermoid cyst and three months after insertion of ventriculo peritoneal shunt due to hydrocephalus. The etiology of basilar artery dissection and the effect of hydrocephalus and ventricular cerebrospinal fluid drainage on disease progression in this patient are unclear. Our report suggests a possible effect of hydrocephalus and ventricular cerebrospinal fluid drainage on intracranial arterial dissection progression.

Vessel wall MRI for suspected isolated basilar artery dissection

Isolated basilar artery dissection is an uncommon intracranial vasculopathy with a poor prognosis. Digital subtraction angiography is considered the definitive modality for diagnosis. Vessel wall MRI (VW-MRI) is an emerging non-invasive technique for assessing the structural integrity of intracranial vessel walls and lumina. Recently, a small number of studies have described the vessel wall patterns of intracranial artery dissection. However, studies on vessel wall imaging of isolated basilar artery dissection remain limited. We describe a patient with suspected isolated spontaneous basilar artery dissection diagnosed using VW-MRI.

Epidemiology, pathophysiology, diagnosis, and management of intracranial artery dissection

Spontaneous intracranial artery dissection is an uncommon and probably underdiagnosed cause of stroke that is defined by the occurrence of a haematoma in the wall of an intracranial artery. Patients can present with headache, ischaemic stroke, subarachnoid haemorrhage, or symptoms associated with mass effect, mostly on the brainstem. Although intracranial artery dissection is less common than cervical artery dissection in adults of European ethnic origin, intracranial artery dissection is reportedly more common in children and in Asian populations. Risk factors and mechanisms are poorly understood, and diagnosis is challenging because characteristic imaging features can be difficult to detect in view of the small size of intracranial arteries. Therefore, multimodal follow-up imaging is often needed to confirm the diagnosis. Treatment of intracranial artery dissections is empirical in the absence of data from randomised controlled trials. Most patients with subarachnoid haemorrhage undergo surgical or endovascular treatment to prevent rebleeding, whereas patients with intracranial artery dissection and cerebral ischaemia are treated with antithrombotics. Prognosis seems worse in patients with subarachnoid haemorrhage than in those without.