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2.
AJNR Am J Neuroradiol ; 42(1): 65-72, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33431503

RESUMO

BACKGROUND AND PURPOSE: Detecting intracranial distal arterial occlusions on CTA is challenging but increasingly relevant to clinical decision-making. Our purpose was to determine whether the use of CTP-derived time-to-maximum of the tissue residue function maps improves diagnostic performance for detecting these occlusions. MATERIALS AND METHODS: Seventy consecutive patients with a distal arterial occlusion and 70 randomly selected controls who underwent multimodal CT with CTA and CTP for a suspected acute ischemic stroke were included in this retrospective study. Four readers with different levels of experience independently read the CTAs in 2 separate sessions, with and without time-to-maximum of the tissue residue function maps, recording the presence or absence of an occlusion, diagnostic confidence, and interpretation time. Accuracy for detecting distal occlusions was assessed using receiver operating characteristic analysis, and areas under curves were compared to assess whether accuracy improved with use of time-to-maximum of the tissue residue function. Changes in diagnostic confidence and interpretation time were assessed using the Wilcoxon signed rank test. RESULTS: Mean sensitivity for detecting occlusions on CTA increased from 70.7% to 90.4% with use of time-to-maximum of the tissue residue function maps. Diagnostic accuracy improved significantly for the 4 readers (P < .001), with areas under the receiver operating characteristic curves increasing by 0.186, 0.136, 0.114, and 0.121, respectively. Diagnostic confidence and speed also significantly increased. CONCLUSIONS: All assessed metrics of diagnostic performance for detecting distal arterial occlusions improved with the use of time-to-maximum of the tissue residue function maps, encouraging their use to aid in interpretation of CTA by both experienced and inexperienced readers. These findings show the added diagnostic value of including CTP in the acute stroke imaging protocol.


Assuntos
Arteriopatias Oclusivas/diagnóstico por imagem , Angiografia Cerebral/métodos , Angiografia por Tomografia Computadorizada/métodos , Interpretação de Imagem Assistida por Computador/métodos , /diagnóstico por imagem , Idoso , Arteriopatias Oclusivas/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neuroimagem/métodos , Curva ROC , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos
3.
Neurosurgery ; 88(2): E179-E189, 2021 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-33319900

RESUMO

BACKGROUND: The optimal magnetic resonance angiography (MRA) sequence for assessing the aneurysm occlusion state or in-stent flow after endovascular coiling is not well established. OBJECTIVE: To evaluate the diagnostic performance of pointwise encoding time reduction with radial acquisition (PETRA)-MRA in patients who underwent endovascular coiling relative to that of time-of-flight (TOF)-MRA and contrast-enhanced (CE)-MRA. METHODS: We evaluated the aneurysm occlusion state using digital subtraction angiography (DSA) and MRA. In patients who underwent stent-assisted coiling, we estimated the visibility of in-stent flow. RESULTS: We enrolled 189 patients with assessable TOF, PETRA, and CE-MRAs after coiling. In patients who underwent simple coiling (128 patients), PETRA showed a higher sensitivity in the detection of residual flow than TOF and CE (PETRA, 100%; CE, 83%; TOF, 80%). There were no significant differences in the height of residual flow between DSA (0.68 ± 1.45 mm) and PETRA (0.70 ± 1.50 mm; P = 1.000). In patients who underwent stent-assisted coiling (61 patients), PETRA showed the highest sensitivity (88%) in detecting residual flow (CE, 56%; TOF, 31%). Regarding in-stent flow, PETRA, CE, and TOF showed visual scores of ≥3 with frequencies of 96.7%, 85.2%, and 37.7%, respectively. Relative signal-to-noise ratio of PETRA (0.62 ± 0.18) was significantly higher than that of CE (0.56 ± 0.12) and TOF (0.39 ± 0.12; P < .001 for both). CONCLUSION: PETRA-MRA showed excellent diagnostic performance in terms of residual flow detection and in-stent flow assessment. PETRA could be a versatile alternative sequence for following up patients with coiled aneurysm.


Assuntos
Angiografia Digital/métodos , Angiografia Cerebral/métodos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/terapia , Angiografia por Ressonância Magnética/métodos , Adulto , Idoso , Procedimentos Endovasculares/métodos , Feminino , Seguimentos , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Stents , Resultado do Tratamento
4.
PLoS One ; 15(9): e0239510, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32960912

RESUMO

BACKGROUND AND PURPOSE: Non-contrast computed tomography (NCCT) Alberta Stroke Program Early CT Score (ASPECTS) and assessment of collateral flow with multiphase computed tomography angiography (CTA) have been investigated as predictors of clinical outcome in patients with acute ischemic stroke. This study assessed the value of multiphase CTA ASPECTS in predicting final infarction core and clinical outcome in patients undergoing endovascular treatment of acute ischemic stroke. METHODS: We retrospectively studied consecutive patients who underwent multiphase CTA prior to endovascular treatment of acute stroke due to anterior circulation large artery occlusion. Multiphase CTA and final diffusion-weighted imaging (DWI) scans were evaluated by two independent observers for NCCT ASPECTS, acute phase CTA (CTA-AP) ASPECTS, delayed phase CTA (CTA-DP) ASPECTS, and final DWI ASPECTS. Modified Rankin Scale score ≤2 at 3 months was considered a favorable outcome. RESULTS: A total of 74 patients were analyzed. We found that CTA-DP ASPECTS (r = 0.82; 95% CI, 0.73-0.91; p < 0.001) correlated with final DWI ASPECTS better than NCCT ASPECTS (r = 0.49; 95% CI, 0.39-0.59) and CTA-AP ASPECTS (r = 0.71; 95% CI, 0.64-0.78). Interobserver agreement was higher for CTA-DP ASPECTS (k = 0.84). Good CTA-DP ASPECTS was an independent predictor of favorable outcome (odds ratio, 8.71; 95% CI, 3.71-17.3; p < 0.001). CONCLUSION: CTA-DP ASPECTS is a reliable predictor of final infarction core and neurological outcome.


Assuntos
Isquemia Encefálica/patologia , Angiografia Cerebral/métodos , Angiografia por Tomografia Computadorizada/métodos , Infarto/patologia , Acidente Vascular Cerebral/patologia , Tomografia Computadorizada por Raios X/métodos , Idoso , Meios de Contraste/administração & dosagem , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Humanos , Masculino , Estudos Retrospectivos , Índice de Gravidade de Doença , Resultado do Tratamento
5.
PLoS One ; 15(9): e0238952, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32941466

RESUMO

OBJECTIVE: To meet increasing demands to train neuroendovascular techniques, we developed a dedicated simulator applying individualized three-dimensional intracranial aneurysm models ('HANNES'; Hamburg Anatomic Neurointerventional Endovascular Simulator). We hypothesized that HANNES provides a realistic and reproducible training environment to practice coil embolization and to exemplify disparities between neurointerventionalists, thus objectively benchmarking operators at different levels of experience. METHODS: Six physicians with different degrees of neurointerventional procedural experience were recruited into a standardized training protocol comprising catheterization of two internal carotid artery (ICA) aneurysms and one basilar tip aneurysm, followed by introduction of one framing coil into each aneurysm and finally complete coil embolization of one determined ICA aneurysm. The level of difficulty increased with every aneurysm. Fluoroscopy was recorded and assessed for procedural characteristics and adverse events. RESULTS: Physicians were divided into inexperienced and experienced operators, depending on their experience with microcatheter handling. Mean overall catheterization times increased with difficulty of the aneurysm model. Inexperienced operators showed longer catheterization times (median; IQR: 47; 30-84s) than experienced operators (21; 13-58s, p = 0.011) and became significantly faster during the course of the attempts (rho = -0.493, p = 0.009) than the experienced physicians (rho = -0.318, p = 0.106). Number of dangerous maneuvers throughout all attempts was significantly higher for inexperienced operators (median; IQR: 1.0; 0.0-1.5) as compared to experienced operators (0.0; 0.0-1.0, p = 0.014). CONCLUSION: HANNES represents a modular neurointerventional training environment for practicing aneurysm coil embolization in vitro. Objective procedural metrics correlate with operator experience, suggesting that the system could be useful for assessing operator proficiency.


Assuntos
Educação Médica/métodos , Embolização Terapêutica/métodos , Treinamento por Simulação/métodos , Adulto , Prótese Vascular , Cateterismo/métodos , Angiografia Cerebral/métodos , Simulação por Computador , Estudos de Viabilidade , Feminino , Humanos , Aneurisma Intracraniano/terapia , Masculino , Pessoa de Meia-Idade , Modelos Biológicos
6.
J Comput Assist Tomogr ; 44(5): 708-713, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32936578

RESUMO

OBJECTIVE: Assessing collateral status is important in acute ischemic stroke (AIS). The purpose of this study was to establish an easy and rapid method for evaluating collateral flow. METHODS: A total of 60 patients with AIS were enrolled. The patients were aged 18 to 85 years with endovascular therapy treatment within 10 hours after the appearance of stroke symptoms, prestroke modified Rankin Scale ≤1, Alberta Stroke Program Early CT Score ≥6, and the occlusion of large vessels in anterior circulation. We reformed imaging strategies by conducting a small-dose group-injection test before normal computed tomography angiography (CTA) scanning and selected the visual collateral score and the regional leptomeningeal score scales as the single-phase CTA collateral flow assessment scales with the replacement of the parasagittal anterior cerebral artery territory by anterior cerebral artery regions adjacent to the longitudinal fissure and then verified, respectively, the consistencies between the 2 single-phase CTA-based collateral scales and the digital subtraction angiography (DSA)-based American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology scale and compared the prognosis of endovascular therapy between the AIS patients in the poor-collateral-flow group and the other patients' group assessed by 2 single-phase CTA-based collateral scales. RESULTS: There was a high consistency between the 2 single-phase CTA-based collateral flow scales with DSA-based American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology scale. The assessment by using CTA-based collateral flow assessment methods generated consistent results. CONCLUSION: The single-phase CTA-based visual collateral score scale and regional leptomeningeal score scale can be used as the imaging evidence for the evaluation of collateral flow in AIS patients in the majority of grassroots hospitals where DSA is difficult to carry out.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , Angiografia Cerebral/métodos , Circulação Colateral/fisiologia , Angiografia por Tomografia Computadorizada/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Idoso , Angiografia Digital/métodos , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Isquemia Encefálica/complicações , Isquemia Encefálica/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/fisiopatologia
7.
J Stroke Cerebrovasc Dis ; 29(10): 105064, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32912539

RESUMO

BACKGROUND: It was previously demonstrated that decreased cortical venous drainage is a predictive factor of poor clinical outcome in patients with an acute ischemic stroke. The aim of this investigation is to test the hypothesis that the decline in blood flow in medullary veins (MV) on CT angiogram (CTA) of patients with acute ischemic stroke (AIS) can also be predictive of clinical outcome. METHODS: We retrospectively reviewed a database of patients with AIS who were evaluated by multiphase CTA and enrolled individuals with AIS and evidence of occlusion of the intracranial internal carotid artery, the M1 or M2 segment of the middle cerebral artery, or combination of two occlusions. To characterize asymmetry of MV we used similar principle that was previously established for MV on SWI MR-images; asymmetry was defined was presence of 5 or more contrast opacified MV in one hemisphere as compared to the contralateral side. Clinical outcomes were evaluated by mRS in 90 days. The Fisher Exact test was used to examine the significance of the MV asymmetry. Odds ratio and interrater variability were calculated. RESULTS: 66 patients with AIS were included. The presence of asymmetry in MV was associated with the higher frequency of poor clinical outcomes (84.6% vs 50.9%); the OR was 5.3. Interrater agreement in assessment on MV was moderate in our study (κ=0.55). CONCLUSION: This study shows that (a) medullary veins can be reliably assessed on multiphase CTA, (b) in patients with AIS, asymmetric appearance of MV is associated with poor clinical outcome.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , Angiografia Cerebral/métodos , Veias Cerebrais/diagnóstico por imagem , Angiografia por Tomografia Computadorizada , Bulbo/irrigação sanguínea , Acidente Vascular Cerebral/diagnóstico por imagem , Adulto , Idoso , Isquemia Encefálica/fisiopatologia , Veias Cerebrais/fisiopatologia , Circulação Cerebrovascular , Circulação Colateral , Bases de Dados Factuais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Reprodutibilidade dos Testes , Estudos Retrospectivos , Acidente Vascular Cerebral/fisiopatologia
8.
J Stroke Cerebrovasc Dis ; 29(9): 105058, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32807463

RESUMO

OBJECTIVES: Arterial spin labeling (ASL) is a magnetic resonance imaging (MRI) technique used to assess cerebral perfusion. When tissue perfusion is impaired, such as in Moyamoya disease, a hyperintense band called the arterial transit artifact (ATA) may occur, which interferes with accurate measurements on ASL-MRI. In this study, we evaluated the correlation of ATAs with magnetic resonance angiography (MRA) and single-photon emission computed tomography (SPECT) imaging results in Moyamoya disease. The aim of our study was to elucidate the pathophysiology of ATAs and risk factors for high ATA scores. MATERIALS AND METHODS: This retrospective study included 28 patients (56 hemispheres) with Moyamoya disease treated at our institution. MRI, MRA, ASL perfusion, and N-isopropyl-[123I] b-iodoamphetamine (123I-IMP) SPECT were performed. In order to semi-quantitatively evaluate the degree of ATA, the ATA scores were measured according to the number of hyperintense signal bands in the cerebral cortex. The relationship between the ATA scores and clinical and radiological factors were analyzed. RESULTS: Regional cerebral blood flow (rCBF) determined with ASL weakly correlated with that determined by 123I-IMP SPECT (ρ=0.31, p=0.027). There was no significant association between the ATA scores and rCBF values determined with 123I-IMP SPECT (p=0.872, 0.745, 0.743 at PLD1000 (post-labeling delay), 1500, and 2000, respectively). However, there was a significant correlation between ATA scores and MRA scores (ρ=0.427 p=0.001; ρ=0.612 p=0.001; ρ=0.563 p=0.001 at PLD1000, 1500, and 2000, respectively). An analysis of patient background characteristics revealed a significantly higher incidence of high ATA scores in female patients, patients with high MRA scores, and patients with a distinguishable ivy sign. A multivariate analysis confirmed that female sex, high MRA score, and presence of an ivy sign were risk factors for high ATA scores. CONCLUSION: ATA scores were moderately correlated with MRA scores, and presence of an ivy sign was the most predictive factor for high ATA scores. A high ATA score determined using ASL in a patient with Moyamoya disease might suggest an advanced disease stage and a reduction in cerebrovascular reserve capacity.


Assuntos
Artefatos , Angiografia Cerebral/métodos , Artérias Cerebrais/diagnóstico por imagem , Circulação Cerebrovascular , Angiografia por Ressonância Magnética , Doença de Moyamoya/diagnóstico por imagem , Imagem de Perfusão do Miocárdio/métodos , Marcadores de Spin , Tomografia Computadorizada de Emissão de Fóton Único , Adulto , Velocidade do Fluxo Sanguíneo , Artérias Cerebrais/fisiopatologia , Feminino , Humanos , Iofetamina/administração & dosagem , Masculino , Pessoa de Meia-Idade , Doença de Moyamoya/fisiopatologia , Valor Preditivo dos Testes , Compostos Radiofarmacêuticos/administração & dosagem , Reprodutibilidade dos Testes , Estudos Retrospectivos
9.
J Stroke Cerebrovasc Dis ; 29(9): 105062, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32807467

RESUMO

BACKGROUND AND PURPOSE: To study the feasibility and clinical utility of head-neck joint high-resolution vessel wall imaging (HNJ-VWI) in the assessment of ischemic stroke. METHODS: We reviewed our institutional HNJ-VWI database. Patients with transient ischemic attack (TIA) or ischemic stroke were included. Abnormal findings of intracranial and/or extracranial artery were assessed on three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA) and HNJ-VWI modified from high-resolution 3D T1 sequence and classified into three groups including intracranial, extracranial and coexisting based on the locations. Etiologies of stroke were recorded according to Trial of Org 10172 in Acute Stroke Treatment criteria. RESULTS: One hundred and ten consecutive patients were studied. 3D TOF MRA displayed 71.8% (79/110, based on patients) abnormal arteries (stenosis or occlusion) , while HNJ-VWI displayed 96.3% (106/110) abnormal arteries (plaque,wall thickness and occlusion) including four isolated extracranial lesions and ten coexisting lesions. The etiologies of TIA/ischemic stroke included large artery atherosclerosis (80 cases), cerebral small vessel disease (6 cases), cardiogenic (2 cases), dissection (6 cases), vasculitis (4 cases), moyamoya disease (6 cases), others (2 cases) and undetermined (4 cases). For patients with atherosclerosis stroke, re-infarctions were more common in coexisting group than intracranial group (extracranial vs. intracranial vs coexisting: 0% vs. 9.1% vs. 43.7%, p = 0.001). CONCLUSIONS: HNJ-VWI is a feasible and valuable technique in assessment of ischemic stroke by detecting extracranial and intracranial artery abnormalities with one-step scan.


Assuntos
Infarto Encefálico/diagnóstico por imagem , Angiografia Cerebral/métodos , Artérias Cerebrais/diagnóstico por imagem , Ataque Isquêmico Transitório/diagnóstico por imagem , Articulações/irrigação sanguínea , Angiografia por Ressonância Magnética , Adulto , Infarto Encefálico/etiologia , Estudos de Viabilidade , Feminino , Humanos , Ataque Isquêmico Transitório/etiologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos , Fatores de Risco
10.
J Stroke Cerebrovasc Dis ; 29(9): 105081, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32807478

RESUMO

BACKGROUND: Cerebrovascular reactivity (CVR) to acetazolamide (ACZ) on single-photon emission computed tomography (SPECT) can be used to assess the severity of chronic cerebral ischemia; however, this is an invasive method. We examined whether whole-brain magnetic resonance angiography (MRA) at 7T could non-invasively detect impaired CVR in patients with chronic cerebral ischemia by demonstrating the leptomeningeal collaterals (LMCs). METHODS: Fifty-seven patients with symptomatic unilateral cervical stenosis underwent whole-brain time-of-flight MRA at 7T and cerebral perfusion SPECT before/after the ACZ challenge. MRA images were visually assessed based on 6-point grading systems to evaluate the development of LMCs toward the middle cerebral artery (MCA) and antegrade flow of MCA. CVR of the affected side was calculated from the SPECT data. Subsequently, we compared the LMC grades on MRA with CVR on SPECT. RESULTS: CVR was significantly lower in grades ≥ 2 of LMCs than in grades 0-1 (P < 0.05) when applying LMCs from the anterior cerebral artery (ACA) and/or posterior cerebral artery (PCA). These differences were more evident than those in the grading of the antegrade MCA flow. The LMC grades from ACA/PCA readily detected reduced CVR (< 18.4%) with a sensitivity/specificity of 0.79/0.82. CONCLUSION: The development of LMCs on whole-brain MRA at 7T can non-invasively detect reduced CVR with a high sensitivity/specificity in patients with unilateral cervical stenosis.


Assuntos
Angiografia Cerebral/métodos , Circulação Cerebrovascular , Circulação Colateral , Angiografia por Ressonância Magnética , Meninges/irrigação sanguínea , Artéria Cerebral Média/diagnóstico por imagem , Insuficiência Vertebrobasilar/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/fisiopatologia , Imagem de Perfusão , Valor Preditivo dos Testes , Estudos Prospectivos , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Tomografia Computadorizada de Emissão de Fóton Único , Insuficiência Vertebrobasilar/fisiopatologia
11.
PLoS One ; 15(8): e0236196, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760077

RESUMO

BACKGROUND: Dynamic CT angiography (dCTA) contrast extravasation, known as the "dynamic spot sign", can predict hematoma expansion (HE) in intracerebral hemorrhage (ICH). Recent reports suggest the phase of spot sign appearance is related to the magnitude of HE. We used dCTA to explore the association between the phase of spot sign appearance and HE, clinical outcome, and contrast extravasation rates. METHODS: We assessed consecutive patients who presented with primary ICH within 4.5 hours from symptom onset who underwent a standardized dCTA protocol and were spot sign positive. The independent variable was the phase of spot sign appearance. The primary outcome was significant HE (either 6 mL or 33% growth). Secondary outcomes included total absolute HE, mortality, and discharge mRS. Mann-Whitney U, Fisher's exact test, and logistic regression were used, as appropriate. RESULTS: Of the 35 patients with spot signs, 27/35 (77%) appeared in the arterial phase and 8/35 (23%) appeared in the venous phase. Thirty patients had follow-up CT scans. Significant HE was seen in 14/23 (60.87%) and 3/7 (42.86%) of arterial and venous cohorts, respectively (p = 0.67). The sensitivity and specificity in predicting significant HE were 82% and 31% for the arterial phase and 18% and 69% for the venous phase, respectively. There was a non-significant trend towards greater total HE, in-hospital mortality, and discharge mRS of 4-6 in the arterial spot sign cohort. Arterial spot signs demonstrated a higher median contrast extravasation rate (0.137 mL/min) compared to venous spot signs (0.109 mL/min). CONCLUSION: Our exploratory analyses suggest that spot sign appearance in the arterial phase may be more likely associated with HE and poorer prognosis in ICH. This may be related to higher extravasation rates of arterial phase spot signs. However, further studies with larger sample sizes are warranted to confirm the findings.


Assuntos
Angiografia Cerebral/métodos , Hemorragia Cerebral/mortalidade , Angiografia por Tomografia Computadorizada/métodos , Extravasamento de Materiais Terapêuticos e Diagnósticos/diagnóstico , Hematoma/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Artérias/diagnóstico por imagem , Hemorragia Cerebral/complicações , Hemorragia Cerebral/diagnóstico , Cérebro/irrigação sanguínea , Cérebro/diagnóstico por imagem , Extravasamento de Materiais Terapêuticos e Diagnósticos/etiologia , Feminino , Seguimentos , Hematoma/etiologia , Mortalidade Hospitalar , Humanos , Masculino , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Sensibilidade e Especificidade
12.
PLoS One ; 15(7): e0237092, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32735633

RESUMO

Cerebral computed tomography angiography is a widely available imaging technique that helps in the diagnosis of vascular pathologies. Contrast administration is needed to accurately assess the arteries. On non-contrast computed tomography, arteries are hardly distinguishable from the brain tissue, therefore, radiologists do not consider this imaging modality appropriate for the evaluation of vascular pathologies. There are known contraindications to administering iodinated contrast media, and in these cases, the patient has to undergo another examination to visualize cerebral arteries, such as magnetic resonance angiography. Deep learning for image segmentation has proven to perform well on medical data for a variety of tasks. The aim of this research was to apply deep learning methods to segment cerebral arteries on non-contrast computed tomography scans and consequently, generate angiographies without the need for contrast administration. The dataset for this research included 131 patients who underwent brain non-contrast computed tomography directly followed by computed tomography with contrast administration. Then, the segmentations of arteries were generated and aligned with non-contrast computed tomography scans. A deep learning model based on the U-net architecture was trained to perform the segmentation of blood vessels on non-contrast computed tomography. An evaluation was performed on separate test data, as well as using cross-validation, reaching Dice coefficients of 0.638 and 0.673, respectively. This study proves that deep learning methods can be leveraged to quickly solve problems that are difficult and time-consuming for a human observer, therefore providing physicians with additional information on the patient. To encourage the further development of similar tools, all code used for this research is publicly available.


Assuntos
Encéfalo/diagnóstico por imagem , Angiografia Cerebral/métodos , Meios de Contraste , Aprendizado Profundo/tendências , Angiografia por Tomografia Computadorizada/métodos , Meios de Contraste/efeitos adversos , Meios de Contraste/farmacologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Estudos Retrospectivos
13.
Cerebrovasc Dis ; 49(4): 396-403, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32829323

RESUMO

INTRODUCTION: Superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis is an effective surgical procedure for adult patients with moyamoya disease (MMD) and is known to have the potential to prevent cerebral ischemia and/or hemorrhagic stroke. Cerebral hyperperfusion (CHP) syndrome is one of the serious complications of this procedure that can result in deleterious outcomes, such as delayed intracerebral hemorrhage, but the prediction of CHP before revascularization surgery remains challenging. The present study evaluated the diagnostic value of preoperative three-dimensional (3D)-time-of-flight (TOF) magnetic resonance angiography (MRA) for predicting CHP after STA-MCA anastomosis for MMD. MATERIALS AND METHODS: The signal intensity of the peripheral portion of the intracranial major arteries, such as the anterior cerebral artery (ACA), MCA, and posterior cerebral artery (PCA) ipsilateral to STA-MCA anastomosis, on preoperative MRA was graded (0-2 in each vessel) according to the ability to visualize each vessel on 97 affected hemispheres in 83 adult MMD patients. Local cerebral blood flow (CBF) at the site of anastomosis was quantitatively measured by N-isopropyl-p-[123I]-iodoamphetamine single-photon emission computed tomography 1 and 7 days after surgery, in addition to the preoperative CBF value at the corresponding area. Then, we investigated the correlation between the preoperative MRA score and the development of CHP. RESULTS: The CHP phenomenon 1 day after STA-MCA anastomosis (local CBF increase over 150% compared with the preoperative value) was evident in 27 patients (27/97 hemispheres; 28%). Among them, 8 (8 hemispheres) developed CHP syndrome. Multivariate analysis revealed that the hemispheric MRA score (0-6), the summed ACA, MCA, and PCA scores for the affected hemisphere, was significantly associated with the development of CHP syndrome (p = 0.011). The hemispheric MRA score was also significantly correlated with the CHP phenomenon, either symptomatic or asymptomatic (p < 0.001). CONCLUSION: The signal intensity of the intracranial major arteries, including the ACA, MCA, and PCA, on preoperative 3D-TOF MRA may identify adult MMD patients at higher risk for CHP after direct revascularization surgery.


Assuntos
Angiografia Cerebral/métodos , Revascularização Cerebral/efeitos adversos , Circulação Cerebrovascular , Transtornos Cerebrovasculares/etiologia , Angiografia por Ressonância Magnética , Artéria Cerebral Média/cirurgia , Doença de Moyamoya/cirurgia , Artérias Temporais/cirurgia , Adolescente , Adulto , Idoso , Anastomose Cirúrgica , Transtornos Cerebrovasculares/diagnóstico por imagem , Transtornos Cerebrovasculares/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/diagnóstico por imagem , Artéria Cerebral Média/fisiopatologia , Doença de Moyamoya/diagnóstico por imagem , Doença de Moyamoya/fisiopatologia , Valor Preditivo dos Testes , Medição de Risco , Fatores de Risco , Síndrome , Artérias Temporais/diagnóstico por imagem , Artérias Temporais/fisiopatologia , Resultado do Tratamento , Adulto Jovem
14.
Cerebrovasc Dis ; 49(4): 437-441, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32721960

RESUMO

INTRODUCTION: Cranial nonenhanced CT (NECT) imaging in hyperacute ischemic stroke is rarely used for assessing arterial obstruction of middle cerebral artery by identifying hyperdense artery sign (HAS). Considering, however, its growing importance due to its impact on the decision-making process of thrombolysis with or without mechanical thrombectomy improved sensitivity to HAS is necessary, particularly in the group of less experienced clinicians being frequently the first one assessing the presence of HAS on NECT. OBJECTIVE: The present study aimed to investigate the effect of different NECT image reconstructions on the correct detection of hyperdense middle cerebral artery sign in a cohort of observers with lower experience level on NECT. Particularly, MIP image reconstructions were expected to be useful for less experienced observers due to both strengthening of the hyperdensity of HAS and streamlining to less image slices. METHODS: Twenty-five of 100 patients' NECT image data presented with HAS. Sixteen observers with lower practice level on NECT (10 radiologists and 6 neurologists) evaluated independently the 3 image reconstructions of each data set with thin slice 1.5 mm, thick slab 5 mm, and 6-mm maximum intensity projection (MIP) and rated the presence of HAS in middle cerebral artery. A GEE model with random observer effect was used to examine the influence of the 3 image reconstructions on sensitivity to HAS. A linear mixed effects regression model was used to investigate the ranking of detectability of HAS. Interrater reliability was determined by Fleiss' kappa coefficient (κ). RESULTS: Recognition of HAS and sensitivity to HAS significantly differed between the 3 image reconstructions (p = 0.0106). MIP and thin slice reconstructions yielded each on average the highest sensitivities with 73% compared to thick slab reconstruction with 45% sensitivity. The interobserver reliability was fair (κ, 0.3-0.4). Detectability of HAS was significantly easier and better visible ranked on MIP and thin slice reconstructions compared to thick slab (p < 0.05). CONCLUSION: MIP and thin slice reconstructions increased the sensitivity to HAS (73%), whereas thick slab reconstructions seemed to be less appropriate (45%).


Assuntos
Angiografia Cerebral/métodos , Angiografia por Tomografia Computadorizada , Interpretação de Imagem Assistida por Computador , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Artéria Cerebral Média/diagnóstico por imagem , Tomografia Computadorizada Multidetectores , Humanos , Infarto da Artéria Cerebral Média/terapia , Variações Dependentes do Observador , Valor Preditivo dos Testes , Prognóstico , Reprodutibilidade dos Testes
15.
AJNR Am J Neuroradiol ; 41(7): 1217-1224, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32554419

RESUMO

BACKGROUND AND PURPOSE: Previous studies have reported that MCA bifurcation aneurysms usually emerge on inclined bifurcations; however, the reason is unclear. We designed this study to explore hemodynamic mechanisms that correlate with the initiation of MCA bifurcation aneurysms. MATERIALS AND METHODS: Fifty-four patients with unilateral MCA bifurcation aneurysms and 54 control patients were enrolled in this study after propensity score matching, and their clinical and CTA data were collected. We extracted the morphologic features of aneurysmal MCA bifurcations to build a simplified MCA bifurcation model and performed a computational fluid dynamics analysis. RESULTS: The presence of MCA aneurysms correlated with smaller parent-daughter angles of MCA bifurcations (P < .001). Aneurysmal MCA bifurcations usually presented with inclined shapes. The computational fluid dynamics analysis demonstrated that when arterial bifurcations became inclined, the high-pressure regions and low wall shear stress regions shifted from the apexes of the arterial bifurcations to the inclined daughter arteries, while the initial sites of MCA bifurcation aneurysms often overlapped with the shifted high-pressure regions and low wall shear stress regions. CONCLUSIONS: Our results suggest that the initiation of MCA bifurcation aneurysms may correlate with shifts of high-pressure regions and low wall shear stress regions that occur on inclined MCA bifurcations.


Assuntos
Hemodinâmica/fisiologia , Aneurisma Intracraniano/fisiopatologia , Adulto , Angiografia Cerebral/métodos , Angiografia por Tomografia Computadorizada/métodos , Feminino , Humanos , Hidrodinâmica , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média , Estresse Mecânico
16.
Niger J Clin Pract ; 23(6): 879-882, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32525126

RESUMO

Dural arteriovenous fistulas (DAVFs) of the sphenoparietal sinus are extremely rare. In the present report, we describe a 46-year-old male patient who presented with headache, pulsatile tinnitus on the right side, and a single course of focal seizure starting 2 months after a closed head injury causing right temporal and occipital bone fractures. Cranial magnetic resonance imaging which was obtained 11 months after the injury showed white matter necrosis in the right frontal lobe while digital subtraction angiography (DSA) revealed a right-sided DAVF in the region of sphenoparietal sinus. The patient underwent successful intra-arterial Onyx-18 embolization using Scepter C balloon microcatheter. Complete occlusion of the fistula was confirmed by control cerebral DSA at 6-month follow-up. Thus, we conclude that double lumen Scepter C balloon microcatheter is a feasible, safe and effective treatment for intra-arterial Onyx-18 embolization of the DAVFs of the sphenoparietal sinus, particularly in cases with high tortuosity.


Assuntos
Cateterismo Venoso Central , Malformações Vasculares do Sistema Nervoso Central/terapia , Veias Cerebrais/diagnóstico por imagem , Embolização Terapêutica/métodos , Polivinil , Tantálio , Oclusão com Balão , Malformações Vasculares do Sistema Nervoso Central/diagnóstico por imagem , Angiografia Cerebral/métodos , Meios de Contraste , Combinação de Medicamentos , Embolização Terapêutica/instrumentação , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
18.
Stroke ; 51(7): 2051-2057, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32568647

RESUMO

BACKGROUND AND PURPOSE: To evaluate outcome and safety of endovascular treatment beyond 6 hours of onset of ischemic stroke due to large vessel occlusion in the anterior circulation, in routine clinical practice. METHODS: From the Italian Registry of Endovascular Thrombectomy, we extracted clinical and outcome data of patients treated for stroke of known onset beyond 6 hours. Additional inclusion criteria were prestroke modified Rankin Scale score ≤2 and ASPECTS score ≥6. Patients were selected on individual basis by a combination of CT perfusion mismatch (difference between total hypoperfusion and infarct core sizes) and CT collateral score. The primary outcome measure was the score on modified Rankin Scale at 90 days. Safety outcomes were 90-day mortality and the occurrence of symptomatic intracranial hemorrhage. Data were compared with those from patients treated within 6 hours. RESULTS: Out of 3057 patients, 327 were treated beyond 6 hours. Their mean age was 66.8±14.9 years, the median baseline National Institutes of Health Stroke Scale 16, and the median onset to groin puncture time 430 minutes. The most frequent site of occlusion was middle cerebral artery (45.1%). Functional independence (90-day modified Rankin Scale score, 0-2) was achieved by 41.3% of cases. Symptomatic intracranial hemorrhage occurred in 6.7% of patients, and 3-month case fatality rate was 17.1%. The probability of surviving with modified Rankin Scale score, 0-2 (odds ratio, 0.58 [95% CI, 0.43-0.77]) was significantly lower in patients treated beyond 6 hours as compared with patients treated earlier No differences were found regarding recanalization rates and safety outcomes between patients treated within and beyond 6 hours. There were no differences in outcome between people treated 6-12 hours from onset (278 patients) and those treated 12 to 24 hours from onset (49 patients). CONCLUSIONS: This real-world study suggests that in patients with large vessel occlusion selected on the basis of CT perfusion and collateral circulation assessment, endovascular treatment beyond 6 hours is feasible and safe with no increase in symptomatic intracranial hemorrhage.


Assuntos
Isquemia Encefálica/cirurgia , Hemorragias Intracranianas/cirurgia , Acidente Vascular Cerebral/cirurgia , Trombectomia , Idoso , Angiografia Cerebral/métodos , Procedimentos Endovasculares/métodos , Feminino , Humanos , Isquemia/cirurgia , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/fisiopatologia , Artéria Cerebral Média/cirurgia , Trombectomia/métodos , Fatores de Tempo
19.
Stroke ; 51(7): 2045-2050, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32568658

RESUMO

BACKGROUND AND PURPOSE: Basilar artery occlusion (BAO) is associated with a high risk of disability and mortality. The objective of this study was to investigate prognostic factors in patients with acute basilar artery occlusion treated with mechanical thrombectomy, focusing on collateral status and recanalization time from symptom onset. METHODS: Eligible patients from January 2012 to October 2019 who underwent endovascular treatment due to acute BAO were reviewed. The baseline posterior circulation collateral status was assessed with the basilar artery on computed tomography angiography score and posterior circulation collateral score. Good outcomes were defined as a modified Rankin Scale score of ≤2 at 3 months and successful recanalization as Thrombolysis in Cerebral Infarction grades 2b, 3. The associations between baseline and clinical parameters and favorable outcomes were evaluated with logistic regression. RESULTS: Our sample included a total of 81 eligible patients (49 males, mean age 70.3 years) with a median baseline and discharge National Institutes of Health Stroke Scale score of 12. Patients with good outcomes showed a lower baseline National Institutes of Health Stroke Scale score, a greater proportion of distal BAO, and a higher basilar artery on computed tomography angiography and posterior circulation collateral score (P<0.001). According to subgroup analysis of patients within and over 6 or 12 hours, the time from symptom onset to recanalization was not correlated with good outcomes. Multivariable logistic analysis showed baseline National Institutes of Health Stroke Scale <15 (odds ratio, 8.49 [95% CI, 2.01-35.82]; P=0.004), posterior circulation collateral score ≥6 (odds ratio, 3.79 [95% CI, 1.05-13.66]; P=0.042), and distal BAO (odds ratio, 3.67 [95% CI, 1.10-12.26]; P=0.035) were independent predictors of good outcomes. CONCLUSIONS: This study suggested that good collateral circulation and distal BAO are independent predictors of clinical outcome after endovascular treatment in patients with acute BAO. In particular, patients with good initial collateral status and distal BAO may consider endovascular treatment even if the treatment is started beyond the standard time limits.


Assuntos
Artéria Basilar/cirurgia , Acidente Vascular Cerebral/terapia , Trombectomia , Insuficiência Vertebrobasilar/terapia , Idoso , Idoso de 80 Anos ou mais , Arteriopatias Oclusivas/terapia , Angiografia Cerebral/métodos , Angiografia por Tomografia Computadorizada/métodos , Procedimentos Endovasculares/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Trombectomia/métodos
20.
Medicine (Baltimore) ; 99(21): e20229, 2020 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-32481296

RESUMO

RATIONALE: The incidence of pure arterial malformations is relatively low, and few cases have been reported. Only 2 cases with pure arterial malformation have been reported to receive surgery or endovascular treatment. PATIENT CONCERNS: We report 3 cases and review the relevant literatures. The head examinations of the patients suggested the presence of high-density shadows in front of the pons and midbrain, the dilation of the supraclinoid segment of the right internal carotid artery, and moyamoya in the left brain with an aneurysm-like expansion located on the left posterior communicating artery respectively. After admission, head digital subtraction angiography (DSA) was performed. DIAGNOSES: Digital subtraction angiography (DSA) for these 3 patients showed that the left posterior communicating artery, the supraclinoid segment of the right internal carotid artery, and the left posterior communicating artery appeared dilated, tortuous, and spirally elongated. In addition, the lesions in the latter 2 patients were accompanied with local aneurysmal changes. INTERVENTIONS: Two patients were given conservative treatment, and another patient was given endovascular treatment. A head DSA was reviewed 6 months after therapy. OUTCOMES: The prognosis status of the 3 patients was good. Two patients in the conservative treatment group showed no changes in the lesions on head DSA examination. The DSA examination of the third patient indicated that the vascular remodeling of the diseased vessels was good, the blood vessels were unobstructed, and the aneurysms had disappeared. LESSONS: Pure arterial malformations mostly occur in young women and may involve any blood vessels in the brain. It can be accompanied with local aneurysms and calcification. The patients are often given conservative treatment but need to be reviewed regularly. However, it is beneficial to give endovascular treatment to the patients with local aneurysms.


Assuntos
Aneurisma/diagnóstico por imagem , Angiografia Digital/métodos , Mesencéfalo/diagnóstico por imagem , Doença de Moyamoya/diagnóstico por imagem , Ponte/diagnóstico por imagem , Adolescente , Adulto , Aneurisma/patologia , Aneurisma/terapia , Vasos Sanguíneos/anormalidades , Artéria Carótida Interna/anormalidades , Artéria Carótida Interna/diagnóstico por imagem , Angiografia Cerebral/métodos , Criança , Pré-Escolar , Tratamento Conservador/métodos , Embolização Terapêutica/métodos , Procedimentos Endovasculares/métodos , Feminino , Humanos , Lactente , Doenças Arteriais Intracranianas/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Masculino , Mesencéfalo/irrigação sanguínea , Mesencéfalo/patologia , Pessoa de Meia-Idade , Doença de Moyamoya/terapia , Ponte/irrigação sanguínea , Ponte/patologia , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento , Adulto Jovem
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