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1.
Radiol Clin North Am ; 59(3): 323-334, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33926680

RESUMO

Neuroimaging plays an essential role in the initial diagnosis and continued surveillance of intracranial neoplasms. The advent of perfusion techniques with computed tomography and MR imaging have proven useful in neuro-oncology, offering enhanced approaches for tumor grading, guiding stereotactic biopsies, and monitoring treatment efficacy. Perfusion imaging can help to identify treatment-related processes, such as radiation necrosis, pseudoprogression, and pseudoregression, and can help to inform treatment-related decision making. Perfusion imaging is useful to differentiate between tumor types and between tumor and nonneoplastic conditions. This article reviews the clinical relevance and implications of perfusion imaging in neuro-oncology and highlights promising perfusion biomarkers.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Neuroimagem/métodos , Imagem de Perfusão/métodos , Tomografia Computadorizada por Raios X/métodos , Encéfalo/diagnóstico por imagem , Humanos
2.
Medicine (Baltimore) ; 100(16): e25627, 2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33879737

RESUMO

ABSTRACT: The aim of the current study was to explore the value of tumor attenuation and quantitative analysis of perfusion parameters obtained from traditional tri-phasic CT scans in grading hepatocellular carcinoma (HCC).Totally 39 patients (42 lesion samples) with pathologically confirmed HCC who underwent tri-phasic CT scans were enrolled. HCC lesions were divided into non-poorly differentiated HCC (NP-HCC; n = 31) and poorly differentiated HCC (pHCC; n = 11). All lesions were divided into 5 groups according to the attenuation on different CT enhancement phase. The values of tumor attenuation on different scanning phases were measured. The following parameters were calculated: arterial enhancement fraction (AEF), portal venous supply coefficient (PVC), and hepatic arterial supply coefficient (HAC). The relationship of perfusion parameters with the histological grade of HCC was analyzed. Receiver operating characteristic curves were generated.No significant correlation was observed between the perfusion parameters and tumor grading. Only HAC showed a non-significant trend in different grades of HCC (pHCC < NP-HCC; P = .07). The pHCC cases had significantly decreased values of tumor attenuation on the unenhanced phase (TAu), tumor attenuation on the portal phase portal phase (TAp), and equilibrium phase (TAe) (P < .01). The difference of tumor attenuation between the portal phase and the unenhanced phase (TAp-TAu) of the pHCC cases was decreased than that of the NP-HCC cases (P < .01), whereas the difference of attenuation between the equilibrium phase and portal phase (TAe-TAp) was significantly higher in the pHCC cases than that in the NP-HCC cases (P < .01). TAe-TAp had the highest area under the curve. The number of tumor enhancement pattern in Group 5 of HCCs with a diameter of 3 cm or more was significantly more than that of HCCs with a diameter of less than 3 cm or with other different enhancement patterns (P < .01).Histological HCC grading cannot be predicted by the perfusion parameters derived from traditional tri-phasic CT scans, whereas the tumor attenuation on different phases and the tumor attenuation differences among different phases, especially the mean value of TAe-TAp, might be useful for non-invasive prediction on the degree of HCC differentiation.


Assuntos
Carcinoma Hepatocelular/irrigação sanguínea , Carcinoma Hepatocelular/diagnóstico por imagem , Neoplasias Hepáticas/irrigação sanguínea , Neoplasias Hepáticas/diagnóstico por imagem , Gradação de Tumores/métodos , Imagem de Perfusão/métodos , Tomografia Computadorizada por Raios X/métodos , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/patologia , Feminino , Artéria Hepática/patologia , Humanos , Fígado/irrigação sanguínea , Fígado/patologia , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Perfusão , Veia Porta/patologia , Valor Preditivo dos Testes , Curva ROC , Estatísticas não Paramétricas
3.
Anticancer Res ; 41(3): 1451-1458, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33788737

RESUMO

AIM: To compare the diagnostic value of liver perfusion computed tomography (PCT) and biphasic contrast-enhanced CT (bpCECT) for detection and characterization of hepatocellular carcinoma (HCC), and to identify potential causes for inter-modal discrepancies. PATIENTS AND METHODS: In this retrospective study, 162 cases with a total of 325 HCC-typical lesions were evaluated using both PCT and bpCECT (mean time between examinations=15 days, range=0-13 days). HCC diagnosis was performed by multi-modality imaging including lesion growth at follow-up. For PCT, a total acquisition time of 40 s (26 measurements) each 1.5 s using 80 kV and 100 mAs, as well as 50 ml iodine contrast agent (at 5 ml/s) covering the entire liver was used. Mean arterial liver perfusion (ALP), portal venous perfusion (PVP) and hepatic arterial index (HPI) for both tumor and non-involved liver parenchyma; mean blood flow, blood volume and k-trans for tumor were quantified. Tumor localization, and size were registered. bpCECT consisted of unenhanced, arterial (30-33 s delay), and portal-venous (70-75 s) phases performed using 120 kV, 200-250 mAs, thin-slice reformates (<1 mm), 100 ml contrast agent (at 3 ml/s) followed by 50 ml saline flush. Finally, we divided the results according to detection by PCT only (i.e. missed by pbCECT), and by both PCT and pbCECT. RESULTS: PCT detected 272 lesions compared to 217 with bpCECT only. HCCs in liver segments 4 and 5 were significantly better detected by PCT (p<0.005). Furthermore, PCT detected significantly smaller HCCs than did bpCECT (p<0.001). Lesions detected by both methods had significantly higher mean ALP (p=0.03) and HPI (p=0.02), and lower mean PVP (p=0.01). Tumor blood flow, blood volume and k-trans proved not to be significant for lesion detection. The mean ALP, HPI, and PVP in inconspicuous cirrhotic liver were also not significant for lesion detection. The PVP(tumor)/HPI(liver) ratio of detected lesions was significantly higher for PCT alone (p=0.04). Pretreated, still vital lesions were better detected by bpCECT. CONCLUSION: Detection of smaller HCC lesions, lesions located in liver segments 4 and 5, as well as lesions presenting lower ALP and HPI, and higher PVP(tumor)/HPI(liver) ratio was better using both methods, emphasizing the important role of PCT.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Fígado/diagnóstico por imagem , Imagem de Perfusão/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/diagnóstico , Meios de Contraste , Feminino , Humanos , Fígado/patologia , Neoplasias Hepáticas/diagnóstico , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
5.
PLoS One ; 16(1): e0245764, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33497385

RESUMO

INTRODUCTION: Targeted therapy against tumor angiogenesis is widely used in clinical practice for patients with colorectal liver metastases (CRLM). Possible predictive biomarkers for tumor angiogenesis, such as, microvessel density (MVD), hypoxia and cell proliferation, can be determined using immunohistochemical staining. However, patients ineligible for surgical treatment need to undergo invasive diagnostic interventions in order to determine these biomarkers. CT perfusion (CTP) is an emerging functional imaging technique, which can non-invasively determine vascular properties of solid tumors. The purpose of this study was to evaluate CTP with histological biomarkers in CRLM. MATERIAL AND METHODS: Patients with CRLM underwent CTP one day before liver surgery. CTP analysis was performed on the entire volume of the largest metastases in each patient. Dual-input maximum slope analysis was used and data concerning arterial flow (AF), portal flow (PF) and perfusion index (PI) were recorded. Immunohistochemical staining with CD34, M75/CA-IX and MIB-1 was performed on the rim in the midsection of the tumor to determine respectively MVD, hypoxia and cell proliferation. RESULTS: Twenty CRLM in 20 patients were studied. Mean size of the largest CRLM was 37 mm (95% CI 21-54 mm). Mean AF and PF were respectively 64 ml/min/100ml (95% CI 48-79) and 30 ml/min/100ml (95% CI 22-38). Mean PI was 68% (95% CI 62-73). No significant correlation was found between tumor growth patterns and CTP (p = 0.95). MVD did not significantly correlate to AF (r = 0.05; p = 0.84), PF (r = 0.17; p = 0.47) and PI (r = -0.12; p = 0.63). Cell proliferation also did not significantly correlate to AF (r = 0.07; p = 0.78), PF (r = -0.01; p = 0.95) and PI (r = 0.15; p = 0.52). Hypoxia did not significantly correlate to AF (r = -0.05; p = 0.83), however, significantly to PF (r = 0.51; p = 0.02) and a trend to negative correlation with PF (r = -0.43; p = 0.06). However, after controlling the false discovery rate, no significant correlation between CTP and used immunohistochemical biomarkers was found. CONCLUSION: In conclusion, this feasibility study found a trend to negative correlation between PI and hypoxia, CTP might therefore possibly evaluate this prognostic marker in CRLM non-invasively. However, CTP is not an appropriate technique for the assessment of microvessels or cell proliferation in CRLM.


Assuntos
Neoplasias Colorretais/patologia , Neoplasias Hepáticas/diagnóstico por imagem , Neovascularização Patológica/diagnóstico por imagem , Imagem de Perfusão/normas , Tomografia Computadorizada por Raios X/normas , Idoso , Biomarcadores Tumorais/metabolismo , Feminino , Humanos , Fígado/diagnóstico por imagem , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/secundário , Masculino , Pessoa de Meia-Idade , Neovascularização Patológica/patologia , Imagem de Perfusão/métodos , Tomografia Computadorizada por Raios X/métodos , Hipóxia Tumoral
6.
AJNR Am J Neuroradiol ; 42(3): 422-428, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33509915

RESUMO

BACKGROUND AND PURPOSE: Both ASPECTS and core volume on CTP are used to estimate infarct volume in acute ischemic stroke. To evaluate the potential role of ASPECTS for acute endovascular treatment decisions, we studied the correlation between ASPECTS and CTP core, depending on the timing and the presence of large-vessel occlusion. MATERIALS AND METHODS: We retrospectively reviewed all MCA acute ischemic strokes with standardized reconstructions of CTP maps entered in the Acute STroke Registry and Analysis of Lausanne (ASTRAL) registry. Correlation between ASPECTS and CTP core was determined for early (<6 hours) versus late (6-24 hours) times from stroke onset and in the presence versus absence of large-vessel occlusion. We used correlation coefficients and adjusted multiple linear regression models. RESULTS: We included 1046 patients with a median age of 71.4 years (interquartile range, IQR = 59.8-79.4 years), an NIHSS score of 12 (IQR, 6-18), an ASPECTS of 9 (IQR, 7-10), and a CTP core of 13.6 mL (IQR, 0.6-52.8 mL). The overall correlation between ASPECTS and CTP core was moderate (ρ = -0.49, P < .01) but significantly stronger in the late-versus-early window (ρ = -0.56 and ρ = -0.48, respectively; P = .05) and in the presence versus absence of large-vessel occlusion (ρ = -0.40 and ρ = -0.20, respectively; P < .01). In the regression model, the independent association between ASPECTS and CTP core was confirmed and was twice as strong in late-arriving patients with large-vessel occlusion (ß = -0.21 per 10 mL; 95% CI, -0.27 to -0.15; P < .01) than in the overall population (ß = -0.10; 95% CI, -0.14 to -0.07; P < .01). CONCLUSIONS: In a large cohort of patients with acute ischemic stroke, we found a moderate correlation between ASPECTS and CTP core. However, this was stronger in patients with large-vessel occlusion and longer delay from stroke onset. Our results could support the use of ASPECTS as a surrogate marker of CTP core in late-arriving patients with acute ischemic stroke with large-vessel occlusion.


Assuntos
AVC Isquêmico/diagnóstico por imagem , Imagem de Perfusão/métodos , Tomografia Computadorizada por Raios X/métodos , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , AVC Isquêmico/patologia , Masculino , Pessoa de Meia-Idade , Neuroimagem/métodos , Estudos Retrospectivos , Tempo para o Tratamento
7.
Trials ; 22(1): 93, 2021 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-33499916

RESUMO

BACKGROUND: All of the existing medication and surgical therapies currently cannot completely inhibit intracerebral hemorrhage (ICH)-mediated brain damage, resulting in disability in different degrees in the involved patients. Normobaric oxygenation (NBO) was reported attenuating ischemic brain injury. Herein, we aimed to explore the safety and efficacy of NBO on rescuing the damaged brain tissues secondary to acute ICH, especially those in the perihematoma area being threatened by ischemia and hypoxia. METHODS: A total of 150 patients confirmed as acute spontaneous ICH by computed tomography (CT) within 6 h after symptoms onset, will enroll in this study after signing the informed consent, and enter into the NBO group or control group randomly according to a random number. In the NBO group, patients will inhale high-flow oxygen (8 L/min, 1 h each time for 6 cycles daily) and intake low-flow oxygen (2 L/min) in intermittent periods by mask for a total of 7 days. While in the control group, patients will breathe in only low-flow oxygen (2 L/min) by mask for 7 consecutive days. Computed tomography and perfusion (CT/CTP) will be used to evaluate cerebral perfusion status and brain edema. CT and CTP maps in the two groups at baseline and day 7 and 14 after NBO or low-flow oxygen control will be compared. The primary endpoint is mRS at both Day14 post-ICH and the end of the 3rd month follow-up. The secondary endpoints include NIHSS and plasma biomarkers at baseline and Day-1, 7, and 14 after treatment, as well as the NIHSS at the end of the 3rd month post-ICH and the incidence of bleeding recurrence and the mortalities within 3 months post-ICH. DISCUSSION: This study will provide preliminary clinical evidence about the safety and efficacy of NBO on correcting acute ICH and explore some mechanisms accordingly, to offer reference for larger clinical trials in the future. TRIAL REGISTRATION: ClinicalTrials.gov NCT04144868 . Retrospectively registered on October 29, 2019.


Assuntos
Edema Encefálico/terapia , Lesões Encefálicas/terapia , Hemorragia Cerebral/terapia , Oxigenoterapia/efeitos adversos , Oxigênio/efeitos adversos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Edema Encefálico/diagnóstico , Edema Encefálico/etiologia , Lesões Encefálicas/diagnóstico , Lesões Encefálicas/etiologia , Córtex Cerebral/diagnóstico por imagem , Hemorragia Cerebral/complicações , Hemorragia Cerebral/diagnóstico , Feminino , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Masculino , Máscaras , Pessoa de Meia-Idade , Oxigênio/administração & dosagem , Oxigenoterapia/instrumentação , Oxigenoterapia/métodos , Imagem de Perfusão/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Adulto Jovem
8.
Stroke ; 52(1): 232-240, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33349010

RESUMO

BACKGROUND AND PURPOSE: Mechanical thrombectomy (MT) is the recommended treatment for acute ischemic stroke caused by anterior circulation large vessel occlusion. However, despite a high rate of reperfusion, the clinical response to successful MT remains highly variable in the early time window where optimal imaging selection criteria have not been established. We hypothesize that the baseline perfusion imaging profile may help forecast the clinical response to MT in this setting. METHODS: We conducted a prospective multicenter cohort study of patients with large vessel occlusion-related acute ischemic stroke treated by MT within 6 hours. Treatment decisions and the modified Rankin Scale evaluation at 3 months were performed blinded to the results of baseline perfusion imaging. Study groups were defined a posteriori based on predefined imaging profiles: target mismatch (TMM; core volume <70 mL/mismatch ratio >1.2 and mismatch volume >10 mL) versus no TMM or mismatch (MM; mismatch ratio >1.2 and volume >10 mL) versus no MM. Functional recovery (modified Rankin Scale, 0-2) at 3 months was compared based on imaging profile at baseline and whether reperfusion (modified Thrombolysis in Cerebral Infarction 2bc3) was achieved. RESULTS: Two hundred eighteen patients (mean age, 71±15 years; median National Institutes of Health Stroke Scale score, 17 [interquartile range, 12-21]) were enrolled. Perfusion imaging profiles were 71% TMM and 82% MM. The rate of functional recovery was 54% overall. Both TMM and MM profiles were independently associated with a higher rate on functional recovery at 3 months Adjusted odds ratios were 3.3 (95% CI, 1.4-7.9) for TMM and 5.9 (95% CI, 1.8-19.6) for MM. Reperfusion (modified Thrombolysis in Cerebral Infarction 2bc3) was achieved in 86% and was more frequent in TMM and MM patients. Reperfusion was associated with a higher rate of functional recovery in MM and TMM patients but not among those with no MM. CONCLUSIONS: In this cohort study, about 80% of the patients with a large vessel occlusion-related acute ischemic stroke had evidence of penumbra, regardless of infarction volume. Perfusion imaging profiles predict the clinical response to MT.


Assuntos
AVC Isquêmico/cirurgia , Trombectomia/métodos , Idoso , Idoso de 80 Anos ou mais , Arteriopatias Oclusivas/cirurgia , Estudos de Coortes , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Imagem de Perfusão/métodos , Estudos Prospectivos , Recuperação de Função Fisiológica , Resultado do Tratamento
9.
Stroke ; 52(1): 339-343, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33370180

RESUMO

BACKGROUND AND PURPOSE: Lacunar syndromes correlate with a lacunar stroke on imaging in 50% to 60% of cases. Computed tomography perfusion (CTP) is becoming the preferred imaging modality for acute stroke triage. We aimed to estimate the sensitivity, specificity, and predictive values for noncontrast computed tomography and CTP in lacunar syndromes, and for cortical, subcortical, and posterior fossa regions. METHODS: A retrospective analysis of confirmed ischemic stroke patients who underwent acute CTP and follow-up magnetic resonance imaging between 2010 and 2018 was performed. Brain noncontrast computed tomography and CTP were assessed independently by 2 stroke neurologists. Receiver operating characteristic curve analysis was performed to estimate sensitivity, specificity, and area under the curve (AUC) for the detection of strokes in patients with lacunar syndromes using different CTP maps. RESULTS: We found 106 clinical lacunar syndromes, but on diffusion-weighted imaging, these consisted of 59 lacunar, 33 cortical, and 14 posterior fossa strokes. The discrimination of ischemia identification was very poor using noncontrast computed tomography in all 3 regions, but good for cortical (AUC, 0.82) and poor for subcortical and posterior regions (AUCs, 0.55 and 0.66) using automated core-penumbra maps. The addition of delay time and mean transient time maps substantially increased subcortical (AUC, 0.80) and slightly posterior stroke detection (AUC, 0.69). CONCLUSIONS: Analysis of mean transient time and delay time maps in combination with core-penumbra maps improves detection of subcortical and posterior strokes.


Assuntos
Imagem de Perfusão/métodos , Acidente Vascular Cerebral Lacunar/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Idoso , Mapeamento Encefálico , Córtex Cerebral/diagnóstico por imagem , Diagnóstico Diferencial , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Curva ROC , Estudos Retrospectivos , Sensibilidade e Especificidade , Acidente Vascular Cerebral Lacunar/diagnóstico , Síndrome , Triagem/métodos , Triagem/tendências
10.
Crit Care ; 24(1): 619, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-33087155

RESUMO

BACKGROUND: Subtraction CT angiography (sCTA) is a technique used to evaluate pulmonary perfusion based on iodine distribution maps. The aim of this study is to assess lung perfusion changes with sCTA seen in patients with COVID-19 pneumonia and correlate them with clinical outcomes. MATERIAL AND METHODS: A prospective cohort study was carried out with 45 RT-PCR-confirmed COVID-19 patients that required hospitalization at three different hospitals, between April and May 2020. In all cases, a basic clinical and demographic profile was obtained. Lung perfusion was assessed using sCTA. Evaluated imaging features included: Pattern predominance of injured lung parenchyma in both lungs (ground-glass opacities, consolidation and mixed pattern) and anatomical extension; predominant type of perfusion abnormality (increased perfusion or hypoperfusion), perfusion abnormality distribution (focal or diffuse), extension of perfusion abnormalities (mild, moderate and severe involvement); presence of vascular dilatation and vascular tortuosity. All participants were followed-up until hospital discharge searching for the development of any of the study endpoints. These endpoints included intensive-care unit (ICU) admission, initiation of invasive mechanical ventilation (IMV) and death. RESULTS: Forty-one patients (55.2 ± 16.5 years, 22 men) with RT-PCR-confirmed SARS-CoV-2 infection and an interpretable iodine map were included. Patients with perfusion anomalies on sCTA in morphologically normal lung parenchyma showed lower Pa/Fi values (294 ± 111.3 vs. 397 ± 37.7, p = 0.035), and higher D-dimer levels (1156 ± 1018 vs. 378 ± 60.2, p < 0.01). The main common patterns seen in lung CT scans were ground-glass opacities, mixed pattern with predominant ground-glass opacities and mixed pattern with predominant consolidation in 56.1%, 24.4% and 19.5% respectively. Perfusion abnormalities were common (36 patients, 87.8%), mainly hypoperfusion in areas of apparently healthy lung. Patients with severe hypoperfusion in areas of apparently healthy lung parenchyma had an increased probability of being admitted to ICU and to initiate IMV (HR of 11.9 (95% CI 1.55-91.9) and HR 7.8 (95% CI 1.05-61.1), respectively). CONCLUSION: Perfusion abnormalities evidenced in iodine maps obtained by sCTA are associated with increased admission to ICU and initiation of IMV in COVID-19 patients.


Assuntos
Meios de Contraste , Infecções por Coronavirus/diagnóstico por imagem , Iodo , Imagem de Perfusão/métodos , Pneumonia Viral/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Estudos Prospectivos
11.
J Stroke Cerebrovasc Dis ; 29(10): 105116, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32912568

RESUMO

BACKGROUND: A neck size >4.0 mm is a risk factor for recanalization after coil embolization. The high inflow magnitude of pretreatment wide-neck aneurysms may be correlated to recanalization. We aimed to elucidate the effect of the neck size on the inflow magnitude evaluated on four-dimensional (4D) flow magnetic resonance imaging (MRI) in pretreatment unruptured internal carotid artery (ICA) aneurysms. METHODS: Thirty-three untreated ICA aneurysms were subjected to 4D flow MRI to evaluate the inflow magnitude parameters including the maximum spatially-averaged inflow velocity (MSAIV), maximum inflow velocity, maximum inflow rate (MIR), and their ratios to each corresponding flow parameter in the parent artery. RESULTS: The neck size was linearly correlated to all inflow parameters investigated in this study. A strong correlation was observed between the neck size and the following: MSAIV (r = .755, p < .0001), MIR (r = .715, p < .0001), MSAIV ratio (r = .724, p < .0001), and MIR ratio (r = .741, p < .0001). The predicted value of MIR ratio of an aneurysm with the neck size of 4.0 mm was 23.0% and 20.6%, based on the linear regression equation of all aneurysms and on that of aneurysms with the neck size >4.0 mm, respectively. CONCLUSIONS: The neck size was linearly correlated with the inflow magnitude of unruptured ICA aneurysms. Inflow magnitude evaluation using 4D flow MRI may help to hemodynamically identify aneurysms with a high risk of recanalization after endovascular coil embolization.


Assuntos
Artéria Carótida Interna/diagnóstico por imagem , Circulação Cerebrovascular , Aneurisma Intracraniano/diagnóstico por imagem , Imageamento por Ressonância Magnética , Imagem de Perfusão/métodos , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo , Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/fisiopatologia , Artéria Carótida Interna/fisiopatologia , Feminino , Humanos , Aneurisma Intracraniano/fisiopatologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes
12.
J Cardiovasc Magn Reson ; 22(1): 59, 2020 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-32772927

RESUMO

BACKGROUND: Anatomically pre-shaped sinus prostheses (SP) were developed to mimic the aortic sinus with the goal to preserve near physiological hemodynamic conditions after valve-sparing aortic root replacement. Although SP have shown more physiological flow patterns, a comparison to straight tube prosthesis and the analysis of derived quantitative parameters is lacking. Hence, this study sought to analyze differences in aortic wall shear stress (WSS) between anatomically pre-shaped SP, conventional straight tube prostheses (TP), and age-matched healthy subjects) using time-resolved 3-dimensional flow cardiovascular magnetic resonance (4D Flow CMR). Moreover, the WSS gradient was introduced and analyzed regarding its sensitivity to detect changes in hemodynamics and its dependency on the expression of secondary flow patterns. METHODS: Twelve patients with SP (12 male, 62 ± 9yr), eight patients with TP (6 male, 59 ± 9yr), and twelve healthy subjects (2 male, 55 ± 6yr) were examined at 3 T with a 4D Flow CMR sequence in this case control study. Six analysis planes were placed in the thoracic aorta at reproducible landmarks. The following WSS parameters were recorded: WSSavg (spatially averaged over the contour at peak systole), max. WSSseg (maximum segmental WSS), min. WSSseg (minimum segmental WSS) and the WSS Gradient, calculated as max. WSSseg - min. WSSseg. Kruskal-Wallis- and Mann-Whitney-U-Test were used for statistical comparison of groups. Occurrence and expression of secondary flow patterns were evaluated and correlated to WSS values using Spearman's correlation coefficient. RESULTS: In the planes bordering the prosthesis all WSS values were significantly lower in the SP compared to the TP, approaching the physiological optimum of the healthy subjects. The WSS gradient showed significantly different values in the four proximally localized contours when comparing both prostheses with healthy subjects. Strong correlations between an elevated WSS gradient and secondary flow patterns were found in the ascending aorta and the aortic arch. CONCLUSION: Overall, the SP has a positive impact on WSS, most pronounced at the site and adjacent to the prosthesis. The WSS gradient differed most obviously and the correlation of the WSS gradient with the occurrence of secondary flow patterns provides further evidence for linking disturbed flow, which was markedly increased in patients compared to healthy sub jects, to degenerative remodeling of the vascular wall.


Assuntos
Aorta Torácica/diagnóstico por imagem , Aorta Torácica/cirurgia , Valva Aórtica/diagnóstico por imagem , Implante de Prótese Vascular/instrumentação , Prótese Vascular , Hemodinâmica , Imageamento por Ressonância Magnética , Imagem de Perfusão/métodos , Desenho de Prótese , Adulto , Idoso , Aorta Torácica/fisiopatologia , Valva Aórtica/fisiopatologia , Técnicas de Imagem de Sincronização Cardíaca , Estudos de Casos e Controles , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fluxo Sanguíneo Regional , Estresse Mecânico , Resultado do Tratamento
13.
J Stroke Cerebrovasc Dis ; 29(9): 104978, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32807415

RESUMO

PURPOSE: The aim of the study was to compare the assessment of ischemic changes by expert reading and available automated software for non-contrast CT (NCCT) and CT perfusion on baseline multimodal imaging and demonstrate the accuracy for the final infarct prediction. METHODS: Early ischemic changes were measured by ASPECTS on the baseline neuroimaging of consecutive patients with anterior circulation ischemic stroke. The presence of early ischemic changes was assessed a) on NCCT by two experienced raters, b) on NCCT by e-ASPECTS, and c) visually on derived CT perfusion maps (CBF<30%, Tmax>10s). Accuracy was calculated by comparing presence of final ischemic changes on 24-hour follow-up for each ASPECTS region and expressed as sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The subanalysis for patients with successful recanalization was conducted. RESULTS: Of 263 patients, 81 fulfilled inclusion criteria. Median baseline ASPECTS was 9 for all tested modalities. Accuracy was 0.76 for e-ASPECTS, 0.79 for consensus, 0.82 for CBF<30%, 0.80 for Tmax>10s. e-ASPECTS, consensus, CBF<30%, and Tmax>10s had sensitivity 0.41, 0.46, 0.49, 0.57, respectively; specificity 0.91, 0.93, 0.95, 0.91, respectively; PPV 0.66, 0.75, 0.82, 0.73, respectively; NPV 0.78, 0.80, 0.82, 0.83, respectively. Results did not differ in patients with and without successful recanalization. CONCLUSION: This study demonstrated high accuracy for the assessment of ischemic changes by different CT modalities with the best accuracy for CBF<30% and Tmax>10s. The use of automated software has a potential to improve the detection of ischemic changes.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , Circulação Cerebrovascular , Imagem de Perfusão/métodos , Interpretação de Imagem Radiográfica Assistida por Computador , Software , Acidente Vascular Cerebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/fisiopatologia , Isquemia Encefálica/terapia , Diagnóstico Precoce , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Reprodutibilidade dos Testes , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/terapia , Fatores de Tempo
15.
Lancet ; 396(10244): 129-142, 2020 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-32653056

RESUMO

Stroke is a major cause of death and disability globally. Diagnosis depends on clinical features and brain imaging to differentiate between ischaemic stroke and intracerebral haemorrhage. Non-contrast CT can exclude haemorrhage, but the addition of CT perfusion imaging and angiography allows a positive diagnosis of ischaemic stroke versus mimics and can identify a large vessel occlusion target for endovascular thrombectomy. Management of ischaemic stroke has greatly advanced, with rapid reperfusion by use of intravenous thrombolysis and endovascular thrombectomy shown to reduce disability. These therapies can now be applied in selected patients who present late to medical care if there is imaging evidence of salvageable brain tissue. Both haemostatic agents and surgical interventions are investigational for intracerebral haemorrhage. Prevention of recurrent stroke requires an understanding of the mechanism of stroke to target interventions, such as carotid endarterectomy, anticoagulation for atrial fibrillation, and patent foramen ovale closure. However, interventions such as lowering blood pressure, smoking cessation, and lifestyle optimisation are common to all stroke subtypes.


Assuntos
Encéfalo/diagnóstico por imagem , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/mortalidade , Acidente Vascular Cerebral/prevenção & controle , Administração Intravenosa , Idoso , Idoso de 80 Anos ou mais , Amilose/uso terapêutico , Anticoagulantes/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/prevenção & controle , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/fisiopatologia , Isquemia Encefálica/cirurgia , Hemorragia Cerebral/complicações , Hemorragia Cerebral/tratamento farmacológico , Hemorragia Cerebral/fisiopatologia , Hemorragia Cerebral/cirurgia , Angiografia por Tomografia Computadorizada/métodos , Intervenção Médica Precoce/métodos , Endarterectomia das Carótidas/métodos , Procedimentos Endovasculares/métodos , Forame Oval Patente/cirurgia , Humanos , Pessoa de Meia-Idade , Seleção de Pacientes , Imagem de Perfusão/métodos , Polímeros/uso terapêutico , Recidiva , Acidente Vascular Cerebral/epidemiologia , Succinatos/uso terapêutico , Trombectomia/métodos , Terapia Trombolítica/métodos , Tomografia Computadorizada por Raios X/métodos
16.
Cerebrovasc Dis ; 49(3): 328-333, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32615572

RESUMO

INTRODUCTION: The benefit of intravenous thrombolysis (IVT) in wake-up stroke (WUS), stroke of unknown time of onset (SUKO), or when time exceeds 4.5 h from last-seen-normal (LSN) guided by CT perfusion (CTP) or MRI has been recently suggested. However, there is limited information of IVT in those patients in real-world studies. OBJECTIVE: Our aim was to evaluate safety and efficacy of IVT selected by CTP in patients with WUS, SUKO, or stroke of time onset beyond 4.5 h. MATERIAL AND METHODS: We studied a prospective cohort of patients who underwent IVT from January 2010 to December 2017. Two groups were defined: standard of care group (SC) included patients with time onset <4.5 h and CTP group included patients with WUS, SUKO, or onset beyond >4.5 h from LSN with penumbra area in CTP. We evaluated baseline characteristics, functional outcomes according to modified Rankin Scale (mRS) at discharge and at 90 days, and intracranial hemorrhages rates. RESULTS: 657 patients were studied: 604 (92%) were treated in the SC group and 53 (8%) in the CTP group. The mean NIHSS score was 9.8 in the CTP group versus 13 in the SC group (p = 0.001). Seventeen patients in the CTP group (32.1%) received bridging therapy with mechanical thrombectomy (MT). Last time seen well-to-needle time was 538 versus 155 min (p < 0.001). The incidence of symptomatic intracranial hemorrhage was equal in both groups (3.8 vs. 3.8%, p = 1). Good functional outcome (mRS < 2) was achieved in both groups (72 vs. 60.4%, p = 0.107). CONCLUSIONS: IVT in patients with WUS, SUKO, or stroke beyond >4.5 h from LSN, with salvageable brain tissue on CTP, seems to be safe and has similar functional outcomes at 90 days to the standard therapeutic window, even when combined with MT.


Assuntos
Fibrinolíticos/administração & dosagem , Imagem de Perfusão/métodos , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica , Tempo para o Tratamento , Ativador de Plasminogênio Tecidual/administração & dosagem , Tomografia Computadorizada por Raios X , Administração Intravenosa , Idoso , Idoso de 80 Anos ou mais , Bases de Dados Factuais , Avaliação da Deficiência , Feminino , Fibrinolíticos/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Recuperação de Função Fisiológica , Estudos Retrospectivos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/fisiopatologia , Terapia Trombolítica/efeitos adversos , Fatores de Tempo , Ativador de Plasminogênio Tecidual/efeitos adversos , Resultado do Tratamento
17.
Stroke ; 51(8): 2480-2487, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32684143

RESUMO

BACKGROUND AND PURPOSE: Acute onset aphasia may be due to stroke but also to other causes, which are commonly referred to as stroke mimics. We hypothesized that, in patients with acute isolated aphasia, distinct brain perfusion patterns are related to the cause and the clinical outcome. Herein, we analyzed the prognostic yield and the diagnostic usefulness of computed tomography perfusion (CTP) in patients with acute isolated aphasia. METHODS: From a single-center registry, we selected a cohort of 154 patients presenting with acute isolated aphasia who had a whole-brain CTP study available. We collected the main clinical and radiological data. We categorized brain perfusion studies on CTP into vascular and nonvascular perfusion patterns and the cause of aphasia as ischemic stroke, transient ischemic attack, stroke mimic, and undetermined cause. The primary clinical outcome was the persistence of aphasia at discharge. We analyzed the sensitivity, specificity, positive and negative predictive values of perfusion patterns to predict complete clinical recovery and ischemic stroke on follow-up imaging. RESULTS: The cause of aphasia was an ischemic stroke in 58 patients (38%), transient ischemic attack in 3 (2%), stroke mimic in 68 (44%), and undetermined in 25 (16%). CTP showed vascular and nonvascular perfusion pattern in 62 (40%) and 92 (60%) patients, respectively. Overall, complete recovery occurred in 116 patients (75%). A nonvascular perfusion pattern predicted complete recovery (sensitivity 75.9%, specificity 89.5%, positive predictive value 95.7%, and negative predictive value 54.8%), and a vascular perfusion pattern was highly predictive of ischemic stroke (sensitivity 94.8%, specificity 92.7%, positive predictive value 88.7%, and negative predictive value 96.7%). The 3 patients with ischemic stroke without a vascular perfusion pattern fully recovered at discharge. CONCLUSIONS: CTP has prognostic value in the workup of patients with acute isolated aphasia. A nonvascular pattern is associated with higher odds of full recovery and may prompt the search for alternative causes of the symptoms.


Assuntos
Afasia/diagnóstico por imagem , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Imagem de Perfusão/métodos , Tomografia Computadorizada por Raios X/métodos , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Afasia/epidemiologia , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/epidemiologia , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/epidemiologia
18.
Neurology ; 95(12): e1694-e1705, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32675079

RESUMO

OBJECTIVE: Since the strongest risk factor for sudden unexpected death in epilepsy (SUDEP) is frequent bilateral tonic-clonic seizures (BTCS), our aim was to determine whether postictal hypoperfusion in brainstem respiratory centers (BRCs) is more common following tonic-clonic seizures. METHODS: We studied 21 patients with focal epilepsies who underwent perfusion imaging with arterial spin labeling MRI. Subtraction maps of cerebral blood flow were obtained from the postictal and baseline scans. We identified 6 regions of interest in the brainstem that contain key BRCs. Patients were considered to have postictal BRC hypoperfusion if any of the 6 regions of interest were significantly hypoperfused. RESULTS: All 6 patients who experienced BTCS during the study had significant clusters of postictal hypoperfusion in BRCs compared to 7 who had focal impaired awareness seizures (7/15). The association between seizure type studied and the presence of BRC hypoperfusion was significant. Duration of epilepsy and frequency of BTCS were not associated with postictal brainstem hypoperfusion despite also being associated with risk for SUDEP. CONCLUSION: Postictal hypoperfusion in brainstem respiratory centers occurs more often following BTCS than other seizure types, providing a possible explanation for the increased risk of SUDEP in patients who regularly experience BTCS.


Assuntos
Tronco Encefálico/irrigação sanguínea , Convulsões/complicações , Morte Súbita Inesperada na Epilepsia/etiologia , Adulto , Tronco Encefálico/diagnóstico por imagem , Circulação Cerebrovascular/fisiologia , Epilepsias Parciais/complicações , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Neuroimagem/métodos , Imagem de Perfusão/métodos , Fatores de Risco , Adulto Jovem
19.
J Stroke Cerebrovasc Dis ; 29(8): 104974, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32689589
20.
J Stroke Cerebrovasc Dis ; 29(8): 104869, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32417244

RESUMO

Delayed intraparenchymal hemorrhage (DIPH) is one of the complications of flow diverter (FD) treatment, however, the mechanism is unclear. We present the case of a 54-year-old woman with a partially thrombosed large internal carotid artery aneurysm. She presented intraparenchymal hemorrhage in the right parietal lobe three days after the successful FD treatment. We performed endoscopic hematoma removal, and then her consciousness disturbance was fully recovered. IMP single-photon emission computed tomography showed significant increase of cerebral blood flow in the right hemisphere. We diagnosed DIPH associated with hyperperfusion after FD treatment. It is necessary to consider that DIPH due to hyperperfusion may occur after FD treatment.


Assuntos
Artéria Carótida Interna , Hemorragia Cerebral/diagnóstico por imagem , Circulação Cerebrovascular , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/instrumentação , Hematoma/diagnóstico por imagem , Aneurisma Intracraniano/terapia , Artéria Carótida Interna/diagnóstico por imagem , Artéria Carótida Interna/fisiopatologia , Hemorragia Cerebral/etiologia , Hemorragia Cerebral/fisiopatologia , Endoscopia , Feminino , Hematoma/etiologia , Hematoma/fisiopatologia , Hematoma/terapia , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/fisiopatologia , Pessoa de Meia-Idade , Imagem de Perfusão/métodos , Fatores de Tempo , Tomografia Computadorizada de Emissão de Fóton Único , Resultado do Tratamento
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