Combined Assessment of Elevated Plasma Lipoprotein-Associated Phospholipase A2 and Plaque Enhancement Improved Accuracy in the Risk of Acute Ischemic Stroke in Patients with Intracranial Artery Stenosis.

PURPOSE: We evaluated the relationship between plasma lipoprotein-associated phospholipase A2 (Lp-PLA2) concentration and plaque characteristics in patients with intracranial artery stenosis and their clinical relevance in acute ischemic stroke. METHODS: Eighty-seven patients with intracranial atherosclerotic stenosis (66 males, 21 females) were retrospectively enrolled. Plasma Lp-PLA2 concentration was measured, and vessel wall magnetic resonance imaging (VW-MRI) was used to determine intracranial vascular stenosis and plaque characteristics, including plaque enhancement, surface morphology, and T1 hyperintensity. Binary logistic regression was used to evaluate the relationship between Lp-PLA2 concentration and plaque characteristics of intracranial artery after adjusting for demographic and confounding factors and to assess their diagnostic efficacy for the risk of acute ischemic stroke. RESULTS: After adjustment for demographic, medication and related lipid factors, Lp-PLA2 elevation was associated with plaque enhancement (odds ratio [OR]=12.7, 95% confidence interval [CI] 2.51-64.82, P=0.002) and surface irregularity (OR=2.9, 95% CI 1.06-7.98, P=0.038). Both Lp-PLA2 elevation (OR=8.8, 95% CI 1.64-47.72, P=0.011) and plaque enhancement (OR=34.3, 95% CI 5.88-200.4, P=0.001) were associated with acute ischemic stroke. Receiver operating characteristic curve analysis showed that the area under the curve for Lp-PLA2 concentration and plaque enhancement combined in the diagnosis of acute ischemic stroke was 0.884, significantly higher than that for Lp-PLA2 concentration (0.724) and plaque enhancement (0.794) alone. CONCLUSION: Elevated Lp-PLA2 is associated with plaque enhancement and plaque surface irregularity. Combined assessment of Lp-PLA2 concentration and plaque enhancement is of greater diagnostic value for the risk of acute ischemic stroke in patients with intracranial artery stenosis.

Intracranial Arterial Calcification in Black Africans with Acute Ischaemic Stroke.

BACKGROUND: Intracranial arterial calcification (IAC), a recognized marker of atherosclerosis on cranial computed tomography (CT), is an independent risk factor for ischaemic stroke. This study aimed to determine the prevalence, distribution, severity, and associations of IAC in adults with acute ischaemic stroke (AIS) at the University College Hospital, Ibadan, Nigeria. METHODS: Cranial CT images of 130 consecutive adults who presented with AIS were acquired on a 64-slice multi-detector Toshiba Aquilion scanner and evaluated for IAC in bone window on Vitrea® software using a semi-quantitative scoring method for extent, thickness, and length of calcifications in the large intracranial arteries. Associations of IAC with clinical and laboratory data were determined by statistical analysis at p < 0.05. RESULTS: There were 71 males (54.6%), and the mean age of all patients was 63.0 ± 13.2 years. Hypertension was the most common risk factor (83.1%). IAC was found in 121 patients (93.1%), predominantly in the carotid siphon (86.1%) followed by the intracranial vertebral arteries (9.3%), middle cerebral arteries (2.4%), basilar artery (1.2%), and the anterior cerebral arteries (1%). The burden of IAC ranged from mild (17.4%) to moderate (52.1%) to severe (30.6%). Age (p < 0.001), diastolic blood pressure (p = 0.037), and alcohol use (0.046) were significantly different among the patients with mild, moderate, and severe degrees of IAC. IAC was associated with age (p < 0.001), hypertension (p = 0.03), diabetes mellitus (p = 0.02), hyperlipidaemia (p = 0.04), and alcohol use (p < 0.001) but not with sex (p = 0.35). CONCLUSIONS: The burden of IAC is very high among native African patients with AIS and preferentially involves proximal inflow arteries. Therefore, the role of large vessel atherosclerosis in ischaemic stroke in native Africans should be explored in future multinational, multimodality studies.

Severity assessment of intracranial large artery stenosis by pressure gradient measurements: A feasibility study.

BACKGROUND: Fractional flow reserve (FFR)-guided revascularization strategy is popular in coronary intervention. However, the feasibility of assessing stenotic severity in intracranial large arteries using pressure gradient measurements still remains unclear. METHODS: Between March 2013 and May 2014, 12 consecutive patients with intracranial large artery stenosis (including intracranial internal carotid artery, middle cerebral M1 segment, intracranial vertebral artery, and basilar artery) were enrolled in this study. The trans-stenotic pressure gradient was measured before and/or after percutaneous transluminal angioplasty and stenting (PTAS), and was then compared with percent diameter stenosis. A Pd /Pa cut-off of ≤0.70 was used to guide stenting of hemodynamically significant stenoses. The device-related and procedure-related serious adverse events and recurrent cerebral ischemic events were recorded. RESULTS: The target vessel could be reached in all cases. No technical complications occurred due to the specific study protocol. Excellent pressure signals were obtained in all patients. For seven patients who performed PTAS, the mean pre-procedural pressure gradient decreased from 59.0 ± 17.2 to 13.3 ± 13.6 mm Hg after the procedure (P < 0.01). Only one patient who refused stenting experienced a TIA event in the ipsilateral MCA territory. No recurrent ischemic event was observed in other patients. CONCLUSION: Mean trans-stenotic pressure gradients can be safely and easily measured with a 0.014-inch fluid-filled guide wire in intracranial large arteries. © 2016 Wiley Periodicals, Inc.

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.

Assessment of intracranial arterial stenosis with multidetector row CT angiography: a postprocessing techniques comparison.

BACKGROUND AND PURPOSE: It was demonstrated the some patients with stroke have intracranial stenosis of 50% or greater and the identification of intracranial arterial stenosis is extremely important in order to plan a correct therapeutical approach. The aim of this study was to assess the image quality and intertechnique agreement of various postprocessing methods in the detection of intracranial arterial stenosis. MATERIAL AND METHODS: Eighty-five patients who were studied by using a multidetector row CT scanner were retrospectively analyzed. A total of 2040 segments were examined in the 85 subjects. Intracranial vasculature was assessed by using MPR, CPR, MIP, and VR techniques. Two radiologists reviewed the CT images independently. Cohen weighted kappa statistic was applied to calculate interobserver agreement and for image accuracy for each reconstruction method. Sensitivity, specificity, PPV, and NPV were also calculated by using the consensus read as the reference. RESULTS: Two hundred fifteen (10.5%) stenosed artery segments were identified by the observers in consensus. The best intermethod kappa values between observers 1 and 2 were obtained by VR and MIP (kappa values of 0.878 and 0.861, respectively), whereas MPR provided the lowest value (kappa value of 0.282). VR showed a sensitivity for detecting stenosed segments of 88.8% and 91.6% for observers 1 and 2, respectively. The highest positive predictive value was also obtained by VR at 95% and 99% for observers 1 and 2, respectively. Image accuracy obtained by using VR was the highest among all reconstruction methods in both observers (185/255 and 177/255 for observers 1 and 2, respectively). CONCLUSIONS: The results of our study suggest that VR and MIP techniques provide the best interobserver and intertechnique concordance in the analysis of intravascular cranial stenosis.

Investigation of cerebrovascular disease with MR angiography: comparison of volume rendering and maximum intensity projection algorithms--initial assessment.

We assessed the clinical utility of the volume-rendering (VR) algorithm as a postprocessing technique of intracranial magnetic resonance angiography (MRA) for the evaluation of cerebrovascular disease in comparison with the maximum intensity projection (MIP) algorithm. VR and MIP images were compared with digital subtraction angiography (DSA). Volume-rendered views improved the perceptibility of intracranial vasculature and consequently augmented diagnostic confidence, improved the characterization of underlying vascular pathologies, and facilitated image interpretation. Volume rendering has the potential to expand the role of cerebral MRA in the diagnostic investigation and treatment planning of cerebrovascular disease.