A1 Segment Research Articles

Endovascular treatment for the flow-related aneurysm originating from an anterior inferior cerebellar artery supplying the cerebellar arteriovenous malformation.

When a flow-related aneurysm originates from an anterior inferior cerebellar artery (AICA) supplying the cerebellar arteriovenous malformation (AVM), the management becomes very complicated. Endovascular treatment (EVT) was an option, but no consensus has been achieved.Methods and materials: A retrospective investigation was performed for patients with flow-related aneurysm originating from an AICA supplying the cerebellar AVM. Ten patients, harboring 13 aneurysms, were identified. Of the 5 a1 aneurysms, 2 underwent stent assisted coiling, 2 underwent parent artery occlusion (PAO), and 1 was intact. Of the 8 a2 aneurysms, 3 underwent coiling with preservation of the AICA, 3 underwent PAO with Onyx, 1 underwent PAO with coils, and 1 was intact. Seven patients underwent partial embolization of the cerebellar AVM, 3 were intact. One patient died 6 hours postoperatively for cerebellar AVM rebleeding. During a follow-up from 6 months to 6 years, 9 patients had favorable recovery. For the flow-related aneurysm originating from an AICA supplying the cerebellar AVM, the EVT depends on the specific circumstances. When the aneurysm is located at the a1 segment, coiling of the aneurysm with preservation of the parent AICA should be performed. PAO is the last resort. When the a2 aneurysm is proximal to the internal auditory artery, coiling of the aneurysm with preservation of the AICA is preferred. When the aneurysm is distal to the internal auditory artery, PAO can be safely performed.

Morphological risk model assessing anterior communicating artery aneurysm rupture: Development and validation

ObjectivePrediction of the rupture risk in anterior communicating artery (ACoA) aneurysms remains challenging. We aimed to investigate the association of detailed morphologies with ACoA aneurysm rupture. Patient and methods759 consecutive patients with ACoA aneurysms were identified from December 2007 to January 2016. An independent cohort was collected for validation from March 2017 to October 2019. Morphological parameters of the aneurysms were measured using CT angiography. Univariable and multivariable analyses were used to investigate the association of morphological characteristics with aneurysm rupture. Area under receiver operating characteristic curves (AUC) were used to assess the performance of the model. ResultsA total of 650 patients with 650 ACoA aneurysms were included for the derivation, and 41 patients with 41 ACoA aneurysms were included for the validation. Aneurysm size, neck size, aspect ratio, size ratio, vessel angle, anterior projection, dominant A1 segment, irregular shape, the presence of a daughter dome, vessel size, and aneurysm angle were risk factors for rupture. The multivariable analysis showed that a larger aneurysm, anterior projection of aneurysms, dominant A1 segment, and irregular aneurysms were associated with aneurysm rupture, whereas larger vessel size was inversely associated with rupture. The morphological risk score showed good discrimination of ruptured and unruptured aneurysms with an AUC of 0.73 in the derivation and an AUC of 0.80 in the validation, and good calibration in both cohorts, signifying a good fit. ConclusionThe morphological risk model may contribute to evaluating the risk of rupture of ACoA aneurysms.

Computer Modeling of Clot Retrieval-Circle of Willis.

Endovascular clot retrieval, often referred to as mechanical thrombectomy, has transformed the treatment of patients with ischemic stroke based on an underlying large cerebral vessel occlusion, ranging from the extracranial internal carotid artery (ICA) to the M1 (proximal) segment of the middle cerebral artery (MCA). The aim of this study was to evaluate the effect of a progressive occlusion of the extracranial portion of the ICA on the cerebral blood flow either with a conventional guiding catheter or a balloon-guiding catheter, which enables the operator to completely occlude the parent artery by inflating the balloon around the tip of this type of guiding catheter. We evaluated the impact of flow reduction in the ICA in the setting of ipsilateral MCA occlusion given the different configurations of the circle of Willis (CoW). The computer model of cerebral arteries was based on anatomical works by Rhoton (1) and van der Eecken (2). The interactive experimental results are available on the web at https://gntem3.shinyapps.io/ecrsim. In the setting of left MCA occlusion, compensation from the anterior and posterior communicating artery preserved the flow in the left anterior cerebral artery (ACA) but not the left MCA branches. Under selected CoW configurations, such as classic, missing Acom, or missing A1 segment of the ACA and concurrent right ICA occlusion, there was a progressive decrease of flow in the left ACA to a minimum of 78% when the simulated catheter fully occluded the left ICA. Flow collapsed (<10%) in the left ACA and MCA branches under CoW configurations, such as bilateral fetal PCA. In summary, compensatory flow collapsed under certain clot retrieval scenarios and unusual configurations of CoW.

Left A2 Fusiform Aneurysm: 2-Dimensional Operative Video.

Anterior cerebral artery aneurysms within the A2 segment that are fusiform or giant A2 aneurysms with a wide neck often are not candidates for endovascular treatment and require surgical intervention. These lesions necessitate a bypass procedure to preserve distal flow along the anterior cerebral artery. This patient demonstrated a left-sided unruptured A2 fusiform aneurysm that necessitated a bypass procedure for management. The patient was positioned with the head rotated laterally to permit orientation of the interhemispheric fissure within the horizontal plane and achieve gravity retraction of the dependent hemisphere. The bilateral pericallosal branches were exposed and liberated from arachnoid adhesions to permit mobilization necessary for the side-to-side anastomosis. While the anastomosis was performed, the continuous suture loops were left loose to permit complete visualization of the inner and outer walls prior to the final tightening and tying of the anastomotic suture. Following the completion of the anastomosis, the temporary clips were removed. A permanent clip was placed on the distal A2 to prevent outflow from the parent artery and thereby allow for aneurysm thrombosis. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Abstract 494: Mitral to Meninges: Aspergillus Endocarditis With Septic Emboli

Introduction: Fungal endocarditis comprises less than 2% of infective endocarditis, with Aspergillus causing less than 28% of fungal endocarditis. Fungal endocarditis should be suspected in immunocompromised patients with persistent fevers, negative blood cultures, and vegetation on echocardiography. Invasive Aspergillus can affect any organ, but typically begins in the respiratory tract. Mortality rates climb to 90% with signs of hematogenous spread, such as cerebral abscesses. Case Presentation: Patient is a 53-year-old female with a past medical history of Sweet syndrome and chronic pancreatitis. Patient was admitted for persistent fevers and confusion. Patient was tachycardic but normotensive with a temperature of 102.5 F. Labs included significantly elevated serum LDH and Beta-D-Glucan. Blood cultures remained negative. Lumbar puncture cultures were negative; CSF cytology revealed pleocytosis with positive Aspergillus galactomannan serum antigen. Head MRI revealed multiple peripherally enhancing supratentorial lesions and intracranial abscesses (largest 8.4 mm) with ventriculitis of lateral ventricles, right greater than left. Transesophageal Echocardiogram (TEE) revealed mitral valve vegetation at A2 segment, no surrounding perivalvular abscess, minimal mitral regurgitation (MR). Management: Antibiotics were discontinued and patient was counseled on avoiding glucocorticoids. Patient was transferred to large tertiary center for Neurosurgery evaluation but was not candidate for biopsy/aspiration of the ring-enhancing lesions per Neurosurgery. Cardiothoracic Surgery was also consulted and patient was not a candidate for mitral valve replacement due to small size of vegetation without abscess and only mild MR. Voriconazole was continued and patient ultimately demonstrated a slow improvement in her strength and mental status over the next 6 months. Discussion: Mitral endocarditis from Aspergillus is rare but has a very high mortality rate. This case illustrates the importance of early recognition of systemic fungal infections in the setting of immunosuppression. Glucocorticoids and broad-spectrum antibiotics placed this patient at elevated risk for invasive Aspergillosis, which led to mitral endocarditis and subsequent cerebral abscesses from septic emboli.

Treatment of cerebral vasospasm secondary to subarachnoid hemorrhage utilizing the Comaneci device

Delayed cerebral ischemia due to vasospasm following subarachnoid hemorrhage continues to have high morbidity and mortality despite current treatments. This report highlights the use of the Comaneci (Rapid Medical, Yokneam, Israel), a device FDA approved for temporary coil embolization assistance, for the treatment of symptomatic vasospasm. Ten days post subarachnoid hemorrhage, a patient developed acute left-sided hemiparesis with angiographic vasospasm. Through a Headway 17 microcatheter, a Comaneci 17 was deployed in the right ICA terminus, M1, M2, A1, and, A2 segments resulting in improvement of angiographic vasospasm and the patient's left-sided hemiparesis. On the following day, a repeat angiogram demonstrated no recurrence of vasospasm. The patient had complete return on neurologic function by post bleed day 18 continuing to her four-week follow-up appointment. This case demonstrates the feasibility of the Comaneci device as an effective tool in the treatment of vasospasm following subarachnoid hemorrhage.

Multiple Acute Ischemic Strokes in a COVID-19 Patient: a Case Report.

We describe a case of a 47-year-old Italian, immunocompromised, and obese woman infected by COVID-19 presenting with fever (39.6 °C) and respiratory symptoms. Neurological examination was normal. Chest CT findings consist of bilateral interstitial pneumonia (visual score extension: 30%). The patient was treated with antiviral drugs and anti-inflammatory drugs with supportive care. Seven days after admission to Covid-19 Unit, the patient rapidly developed worsening respiratory failure and acute respiratory distress syndrome (ARDS). She suddenly developed partial left hemispheric syndrome. A new HRCT scan of her thorax revealed diffuse ground-glass opacities in both lungs (visual score extension: 90%). Brain CT performed 2 h after sudden-onset left-sided weakness showed subtle low attenuation within the right insular ribbon and frontal lobe (ASPECT Score 8). Multiphasic CT angiography (MCTA) demonstrated occlusion of both the dominant inferior division of the right middle cerebral artery and the A2 segment of the right anterior cerebral artery. After 24 h, her pupils became dilated and unreactive, and brain CT demonstrated large bilateral infarctions of both the cerebellar and cerebral hemispheres. She had a rapid progression of interstitial pneumonia from COVID-19, developed multiple strokes, and died 1 day later. SARS-CoV-2 infection seems to predispose pluripathological subjects to cerebrovascular complications.

Correlation of internal carotid artery diameter and carotid flow with asymmetry of the circle of Willis

BackgroundThe purpose of this study was to clarify the effect of asymmetric COW variants on carotid flow changes, and proposed an easy estimate of the representative carotid flow volume for accurate numerical simulation.MethodsA total of 210 healthy adults receiving magnetic resonance angiography and carotid duplex sonography were included. Three anterior cerebral artery asymmetry (AA) groups were defined based on the diameter ratio difference (DRD) of bilateral A1 segments: AA1 group, one-side A1 aplasia; AA2, A1 DRD ≥ 50%; AA3, A1 DRD between 10 and 50%. Similarly, 3 posterior communicating artery (PcomA) asymmetry (PA) groups were defined: PA1 group, one fetal-origin posterior cerebral artery and absent contralateral PcomA; PA2, PcomA DRD ≥ 50%; PA3, PcomA DRD between 10 and 50%.ResultsWith A1 asymmetry, the ICA diameter of the dominant A1 is significantly greater than the contralateral side. Significant differences of bilateral ICA flow were present in the AA1 and AA2 groups (mean flow difference 42.9 and 30.7%, respectively). Significant bilateral ICA diameter and flow differences were only found in the PA1 group. Linear regression analysis of ICA diameter and flow found a moderately positive correlation between ICA diameter and flow in all AA groups, with a 1 mm increment in vessel diameter corresponding to a 62.6 ml increment of flow volume. The product of bilateral ICA diameter and flow volume difference (ICA-PDF) could be a potential discriminator with a cutoff of 4.31 to predict A1 asymmetry ≥50% with a sensitivity of 0.81 and specificity of 0.76.ConclusionsThe study verifies that A1 asymmetry causes unequal bilateral carotid inflow, and consequently different bilateral ICA diameters. Adjustment of the inflow boundary conditions according to the COW variants would be necessary to improve the accuracy of numerical simulation.

Radiological classification of azygos anterior cerebral artery and evaluation of the accompanying vascular anomalies

There is not a classification of azygos anterior cerebral artery (ACA) based on anatomical branching levels in the literature. In the present study, a classification of azygos ACA was made based on radiological imaging for a common terminology, and frequency, accompanying vascular anomalies and malformations were investigated. A total of 4913 cases who had brain CTA, MRA, contrast-enhanced MRI and DSA in January 2010-January 2020 period were screened for the study. Based on anatomical branching level, azygos ACAs were classified into four groups. Aneurysms, anomalies and malformations accompanying azygos ACA were identified. The associations of azygos ACA types with the presence of aneurysm or ACA A1 segment anomalies were investigated. Azygos ACA was observed in 57 cases (29 male and 28 female) and frequency of azygos ACA was 1.16%. Average age of the cases with ACA was 56.19 ± 19.65years. Forty-eight of the cases had type C azygos ACA, four cases type B, four cases type D and one case type A azygos ACA. A total of nine intracranial aneurysms were identified in seven of the cases (12.28%). Five of the aneurysms were located in MCA and four in distal ACA. Most common vascular anomalies accompanying azygos ACA were unilateral vertebral artery hypoplasia and ACA A1 segment hypoplasia. Azygos types did not have significant correlations with the presence of aneurysms or ACA A1 segmental anomalies (p = 0.683 and p = 0.949, respectively). Azygos ACA is a rare variation, but it could be accompanied by aneurysms or other vascular anomalies.

Flow modification on the internal carotid artery bifurcation region and A1 segment after M1-internal carotid artery flow diverter deployment

BackgroundClinical and hemodynamic consequences of flow diverters extending from the M1 to the internal carotid artery (ICA), covering the A1 segment, have rarely been investigated. We aimed to provide angiographic...

Application of flow diverters in the treatment of aneurysms in the internal carotid artery bifurcation region.

The treatment of aneurysms in the internal carotid bifurcation region (ICABR), including aneurysms of the true internal carotid artery (ICA) terminus, those inclined on the proximal A1 or M1 segments or at the most distal pre-bifurcation (ICA) segment, is often challenging in microsurgical clipping and endovascular surgery. Few reports had discussed flow diversion as a therapeutic option for this group. This was a retrospective study analysing flow diversion in treating ICABR aneurysms. Seven patients harbouring eight aneurysms in the ICABR were treated with flow diversion. Five aneurysms were inclined on the proximal A1 segment, and three were located at the most distal pre-bifurcation segment. Patients' demographics, presentation, procedure technical description, angiographic and clinical follow-up were recorded. PubMed and Ovid MEDLINE were also reviewed for articles published in English, including case series or case reports, for ICABR aneurysms treated with flow diverters. All patients except one underwent angiographic follow-up. The Karman-Byrne occlusion scale was used to determine the occlusion rate. All six patients with documented angiographic follow-up had a class IV occlusion score. No permanent or transient neurological or non-neurological complications were encountered in this study. Treating ICABR aneurysms using flow diversion is feasible, with a promising angiographic occlusion rate. Further studies are needed to analyse long-term clinical and angiographic results.

Association of Anterior Communicating Artery Aneurysms with Triplicate A2 Segment of the Anterior Cerebral Artery

Triplicate A2 segment of the anterior cerebral artery is a rare anatomical variant (1%-3% prevalence) that which is thought to result mainly from persistence of the embryonic median artery of the corpus callosum. We sought to determine whether the triple-A2 variant is specifically associated with anterior communicating artery (ACoA) aneurysm. We reviewed 2-dimensional digital-subtraction angiography (2D-DSA) as well as 3-dimensional rotational angiography (3D-RA) images of 55 patients with ACoA aneurysms who presented for evaluation and treatment between 2009 and 2014 at our institution. The criteria for definitively obtaining an accurate accounting of all A2 segments was presence of adequate cross-filling across the ACoA on 2D-DSA or 3D-RA imaging, or ability to fuse left and right 3D-RA images. Patients whose imaging did not meet these criteria were excluded from further analysis. We obtained a definitive count of all A2 segments in 36 patients. Among these, 19 patients (5 with the triple-A2 variant) were treated surgically, and 17 patients (2with the triple-A2 variant) were treated endovascularly. The triple-A2 variant was seen in 7 patients. The prevalence of triple-A2 variant among patients with ACoA aneurysm was 19.4%. Patients with ACoA aneurysms had a significantly higher prevalence of the triple-A2 variant compared with the general population (P < 0.00001). Compared with the normal population, patients with ACoA aneurysms deemed to require treatment have a significantly higher likelihood of having triplicate A2 segment. Knowledge of this anatomical variation is of critical importance in planning and executing endovascular and microsurgical treatment of ACoA aneurysms.

Partial Gyrus Rectus Resection as a Technique to Improve the Exposure to the Anterior Communicating Artery Complex through the Junctional Triangle: A Quantitative Study.

Objective The junctional triangle, formed by the distal A1 anterior cerebral artery (ACA) segment, the proximal A2 ACA segment, and the medial surface of gyrus rectus (GR), is a corridor of access to superiorly and posteriorly projecting anterior communicating artery (AComA) aneurysms that is widened by GR retraction or resection. Exposure of the AComA complex through the junctional triangle after GR resection has not been previously quantitatively evaluated. Design GR resection extent and increase in artery exposure through the junctional triangle were assessed in this study. Setting This study was conducted in the laboratory with a pterional approach, exposing the AComA complex. Participants Ten sides of five cadaveric heads were considered. Main Outcome Measures Exposure extent of ipsilateral and contralateral A1, A2, and AComA and accessibility of branches coming off the AComA complex were measured before and after GR resection. The GR was resected until sufficient bilateral A2 and contralateral A1 exposures were achieved. GR resection span was measured. Results The mean (standard deviation) resected span of GR was 7 ± 3.9 mm. After GR resection, the exposed span of the ipsilateral A2 increased from 2 ± 0.7 mm to 4 ± 1.1 mm ( p = 0.001); contralateral A2 exposure increased from 3 ± 1.5 mm to 4 ± 1.1 mm ( p = 0.03). Contralateral recurrent artery of Heubner (RAH) and orbitofrontal artery were accessible in five and eight specimens, respectively, before GR resection and in all 10 after resection. Conclusion GR resection improves exposure of bilateral A2 segments through the junctional triangle. Exposure improvement is greater for the ipsilateral A2 than contralateral A2. The junctional triangle concept is enhanced by partial GR resection during surgery for superior and posterior AComA aneurysms.

Recurrent Giant Anterior Cerebral Artery (ACA) Aneurysm With Previous Coiling, Attempted Clipping Then Direct ACA-to-ACA Bypass: 2-Dimensional Operative Video.

Giant aneurysms are defined as lesions with a widest diameter of 2.5 cm or greater and account for 2% to 5% of all intracranial aneurysms. These lesions are challenging entities for microsurgical management with techniques such as direct aneurysmal neck clipping, aneurysm neck reconstructions, aneurysmotomy, and aneurysmectomy. This patient had a previously coiled, unruptured, superiorly projecting giant anterior communicating artery (ACom) aneurysm, eccentric toward the left, for which surgical intervention was undertaken. A left orbitozygomatic craniotomy was performed, and a temporary clip was applied to the bilateral proximal A1 segments. Aneurysmotomy was then performed with internal debulking of the aneurysmal thrombus. Aneurysmectomy and removal of the coil mass were performed. Next, the aneurysm neck was reconstructed using multiple surgical clips. After anticipated aneurysm neck reconstruction, indocyanine green (ICG) angiography demonstrated a lack of flow in the ipsilateral A2. The ACom was then transected along the aneurysm neck, and an end-to-end anastomosis of the distal A1 and proximal A2 was performed. Repeat ICG angiography demonstrated patency of the A1-A2 anastomosis. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Sizing of mitral annuloplasty rings using real-time three-dimensional transesophageal echocardiography and the difference between patients with and without recurrent mitral regurgitation: retrospective cohort study.

Previous studies showed that the mitral inter-commissural (IC) distance differed by a few millimeters between the systolic and diastolic cardiac cycles. However, sizing of the mitral annuloplasty ring with a ring sizer, which should be performed in the systole, is performed in diastole during hyperkalemic cardioplegic arrest. The aim of this study was to investigate whether three-dimensional transesophageal echocardiography (3D-TEE) measurements of the mitral valve in end-systole are effective to determine the size of the annuloplasty ring. This study retrospectively reviewed 92 patients who underwent mitral annuloplasty for degenerative. The IC distance and anterior leaflet height of the A2 segment of the mitral valve were measured by 3D-TEE at the end-systole. The annuloplasty ring size was measured by the surgeons using specific ring sizers. We compared the IC distance measured by 3D-TEE with the implanted annuloplasty size. We also investigated differences in IC distance, A2 height, and ratio of A2 height to IC distance in patients with and without recurrent mild to moderate MR for 36months. There was a significant correlation between the IC distance by 3D-TEE and the implanted ring size (R2 = 0.7023, p < 0.001). Eight cases had mild or greater recurrent MR. There was a significant difference in the ratio of A2 height to IC distance between patients with and without recurrent MR (p = 0.006). A2 height was greater in patients with recurrent MR, but this difference was not significant (p = 0.059). Our results demonstrated a larger ratio of A2 height to IC distance in patients with recurrent MR. 3D-TEE could be useful for the ring sizing.

Infraoptic Course of Anterior Cerebral Artery Coexistence with Double Fenestration of Proximal A2 Segment of Anterior Cerebral Artery with Associated Dysplastic Anterior Communicating Artery Aneurysm Treated with Stent-Assisted Coiling.

Infraoptic Course of Anterior Cerebral Artery Coexistence with Double Fenestration of Proximal A2 Segment of Anterior Cerebral Artery with Associated Dysplastic Anterior Communicating Artery Aneurysm Treated with Stent-Assisted Coiling.

Surgical Management of a Ruptured Dissecting Anterior Cerebral Artery (A2) Aneurysm Utilizing Contralateral Frontopolar for Reconstruction: 2-Dimensional Operative Video.

Dissecting aneurysms can pose an immense surgical challenge, and intervention often involves high risk for rerupture because of the volatile nature of the fibrin thrombus overlying the rupture site. This patient presented following rupture of a dissecting aneurysm along the A2 segment of the anterior cerebral artery (ACA). The patient underwent a right orbitozygomatic craniotomy, and the aneurysm was approached within the interhemispheric fissure. Manipulation of the aneurysm dome resulted in intraoperative rerupture of the aneurysm, which was controlled by the application of a temporary clip on the parent A2 proximally and distally. Aneurysmectomy of the thin diseased vessel wall was performed. The defect was filled by transecting the frontopolar branch of the ACA and sewing the frontopolar branch onto the aneurysmectomy defect. This provided a suitable patch for the ACA defect. Postprocedural indocyanine green angiography demonstrated patency of the A2 and the anastomosed frontopolar branch. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Anterior Communicating Artery Complex Aneurysms Are Caused by the Asymmetric Anterior Cerebral Arteries

Background: Rupture of anterior communicating artery complex (AcomAC) aneurysms is a common cause of haemorrhagic brain strokes. Ability to predict development of aneurysms in advance would allow stroke prevention. Asymmetry of the components of cerebral basal arterial network (CBAN) could alter hemodynamics and may contribute to formation of aneurysms. The asymmetric diameter ratio of first segments of anterior cerebral arteries (A1s), correlates with the occurrence of the AcomAC aneurysms. Materials and Methods: Cerebral Computed Tomography Angiography (CTA) scans of 166 adult patients of both sexes were studied. The internal diameters of the right and left A1 segments of anterior cerebral arteries, perpendicular to the long axis of the vessels were measured. Positions and presence or absence of aneurysms in AcomAC were recorded in each individual case. The ratio of the larger to the smaller A1 diameters was determined as a measure of the asymmetry of A1 segments of anterior cerebral arteries (ACAs). Findings: The risk of development of aneurysms in AcomAC was much greater (risk 80%, odds ratio = 47·3) when one A1 segment's radius was at least 50% larger (i.e. 2·25 times greater cross-sectional area) than the other. The risk of development of aneurysms was just 7·8%, if the A1 asymmetric ratio was less than 1·5 (odds ratio = 0·02). Conclusion: The asymmetry ratio of the A1 segments of anterior cerebral arteries is a good predictor for the development of aneurysms in the AcomAC region. Funding Statement: The authors stated: None. Declaration of Interests: The authors declare that there is no conflict of interests. Ethics Approval Statement: The use of images and accompanying information was approved for research purposes by the University of Adelaide Human Research Ethics Board (approval number: H2014-176). Patients’ personal details, have not been copied, documented, or included in this research.

Clinical value of brain CT perfusion imaging combined with head and neck CTA in the diagnosis of acute ischemic stroke

Objective To investigate the clinical value of whole brain CT perfusion imaging combined with head and neck CTA in the diagnosis of acute ischemic stroke. Methods From November 2016 to November 2018, the clinical data and medical imaging data of 220 patients diagnosed as acute ischemic stroke in the Department of Neurology, Dajiangdong Hospital were selected.All patients underwent CT scan followed by a CT perfusion scan and a routine cranial CTA.The radiation dose was recorded.The ischemic lesions and their stenosis were analyzed by CTA.CT perfusion imaging was used to analyze regional cerebral blood flow imaging (rCBF), tissue perfusion (rCBV) and mean passage time (MTT) in all patients..And the test performance of the two inspection methods was compared. Results CTA was used to analyze vascular stenosis.The stenotic vessels were mainly distributed in the M1~M3 segment (3 cases of them were completely obstructed, 11 cases were obstructed ≥50%, 19 cases were 30% ≤ stenosis<50%), and A1~A3 segments (4 cases of them were obstructed, 7 cases were 30% ≤ stenosis<50%), and basilar artery (2 cases of them occlusion, 6 cases of ≥ 50%, 11 cases of 30% ≤ stenosis<50%). CT perfusion examination was performed in the whole brain.The rCBF of the control area was higher than that of the ischemic penumbra and higher than the infarct area.The rCBF values were (50.31±11.21)100 g/min, (34.45±22.17)100 g/min and (6.87±3.52)100 g/min, respectively, the difference was statistically significant (t=17.81, 19.14, all P<0.05). The region rCBV of the control area was higher than that of the ischemic penumbra and the infarct region, and the rCBV values were (3.35±1.01)mL/100g, (2.87±0.55)mL/100g and (6.87±0.51)mL/100g, respectively, the differences are statistically significant (t=6.47, 9.19, all P<0.05). The MTT in the control area was lower than that in the ischemic penumbra and the infarct area, and the MTT values were (4.52±1.21)s, (7.88±1.01)s and (11.81±1.18)s, respectively, the differences are statistically significant(t=10.50, 13.54, all P<0.05). The two methods were compared for consistency, and the kappa value was greater than 0.75, showed a high degree of consistency. Conclusion CT perfusion imaging and CTA have little difference in the diagnostic efficacy for patients with acute ischemic cerebral infarction, and can accurately diagnose the disease.CT perfusion imaging can determine the location of the ischemic penumbra, and CTA can be analyzed based on the stage of the diseased vessel.Both two methods can play different guiding role for individualized treatment. Key words: Tomography, spiral computed; Perfusion imaging; Angiography; Cerebrovascular disorders; Retrospective study

Cerebral collaterals and stroke in patients with isolated carotid artery dissections

To investigate potential association between collateral arterial supply and stroke in patients with isolated internal carotid artery dissection (iCeAD). We hypothesized a lower risk of stroke in patients with more robust collateral supply. This is a single-center, retrospective review of iCeAD patients between 1994 and 2018. iCeAD patients with sufficient neuroimaging data were included. Patients were categorized based on cerebral infarction (stroke) on neuroimaging. The collaterals score, ranging from 0 to 8 with higher scores indicating more robust collaterals, was assessed based on contributions from leptomeningeal arteries (0–2 points), anterior communicating artery (0–2 points) and anterior cerebral artery A1 segment (0–2 points), and posterior communicating artery (0–2 points). The study included 62 iCeAD patients, comprising 33 and 29 patients in the stroke and no stroke groups, respectively. Neurological motor deficit (p < 0.001) and internal carotid artery occlusion (p = 0.033) were independent predictors of stroke. More robust collaterals was associated with lower stroke risk (p = 0.032) in univariable analysis, but not after adjustment for baseline differences. The collaterals score performed poorly in receiver-operating characteristics (ROC) curve analysis, with area under the ROC (AUROC) curve of 0.640. A collaterals score of >4 had a sensitivity and specificity of 89.7% and 36.4% for no stroke, respectively. The covariate-adjusted AUROC curve was 0.514. Collateral circulation appeared to be a poor predictor of cerebral infarction in patients with isolated iCeAD. Future studies in larger, independent cohorts are needed to better understand the interaction of collaterals with stroke in cervical artery dissection.