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1.
Sci Rep ; 14(1): 4837, 2024 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-38418657

RESUMO

The EOS™2D/3D system is a low-dose, 3D imaging system that utilizes two perpendicular X-ray beams to create simultaneous frontal and lateral images of the body. This is a useful modality to assess spinal pathologies. However, due to the slow imaging acquisition time up to 25 s, motion artifacts (MA) frequently occur. These artifacts may not be distinguishable from pathological findings, such as scoliosis, and may impair the diagnostic process. The aim of this study was to design a method to detect MA in EOS X-ray. We retrospectively analyzed EOS imaging from 40 patients wearing a radiopaque reference device during imaging. We drew a straight vertical line along the reference device. We measured deviations from it to quantify MA, presenting these findings through descriptive statistics. For a subset of patients with high MA, acquisitions were repeated after giving specific instructions to stand still. For these patients, we compared MA between the two acquisitions. In our study, a substantial proportion of patients exhibited MA ≥ 1 mm, with 80% in frontal projections and 87.9% in lateral projections. In the subjects who received a second acquisition, MA was significantly lower in the second images. Our method allows for a precise detection of MA on EOS images through a simple, yet reliable solution. Our method may improve the reliability of spine measurements, and reduce the risk of wrong diagnosis due to low imaging quality.


Assuntos
Artefatos , Imageamento Tridimensional , Humanos , Raios X , Estudos Retrospectivos , Reprodutibilidade dos Testes , Radiografia , Imageamento Tridimensional/métodos
2.
Neurourol Urodyn ; 43(1): 236-245, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37767637

RESUMO

OBJECTIVES: A feasibility proof-of-concept study was conducted to assess the effects of acute tibial nerve stimulation (TNS) on the central nervous system in healthy volunteers using functional magnetic resonance imaging (fMRI). MATERIALS AND METHODS: Fourteen healthy volunteers were included in a prospective, single-site study conducted on a clinical 3T MRI scanner. Four scans of functional MRI, each lasting 6 min, were acquired: two resting-state fMRI scans (prior and following the TNS intervention) and in-between two fMRI scans, both consisting of alternating rest periods and noninvasive acute transcutaneous TNS (TTNS). Whole brain seed-based functional connectivity (FC) correlation analysis was performed comparing TTNS stimulation with rest periods. Cluster-level familywise error (FWE) corrected p and a minimal cluster size of 200 voxels were used to explore FC patterns. RESULTS: Increased FC is reported between inferior frontal gyrus, posterior cingulate gyrus, and middle temporal gyrus with the precuneus as central receiving node. In addition, decreased FC in the cerebellum, hippocampus, and parahippocampal areas was observed. CONCLUSIONS: Altered FC is reported in areas which have been described to be also involved in lower urinary tract control. Although conducted with healthy controls, the assumption that the underlying therapeutic effect of TNS involves the central nervous system is supported and has to be further examined in patients with incomplete spinal cord injury.


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Humanos , Imageamento por Ressonância Magnética/métodos , Estudos Prospectivos , Mapeamento Encefálico/métodos , Nervo Tibial/diagnóstico por imagem
3.
Sci Rep ; 13(1): 7245, 2023 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-37142669

RESUMO

The aim of this exploratory study was the assessment of the metabolic profiles of persons with complete spinal cord injury (SCI) in three region-of-interests (pons, cerebellar vermis, and cerebellar hemisphere), with magnetic resonance spectroscopy, and their correlations to clinical scores. Group differences and association between metabolic and clinical scores were examined. Fifteen people with chronic SCI (cSCI), five people with subacute SCI (sSCI) and fourteen healthy controls were included. Group comparison between cSCI and HC showed lower total N-acetyl-aspartate (tNAA) in the pons (p = 0.04) and higher glutathione (GSH) in the cerebellar vermis (p = 0.02). Choline levels in the cerebellar hemisphere were different between cSCI and HC (p = 0.02) and sSCI and HC (p = 0.02). A correlation was reported for choline containing compounds (tCho) to clinical scores in the pons (rho = - 0.55, p = 0.01). tNAA to total creatine (tNAA/tCr ratio) correlated to clinical scores in the cerebellar vermis (rho = 0.61, p = 0.004) and GSH correlated to the independence score in the cerebellar hemisphere (rho = 0.56, p = 0.01). The correlation of tNAA, tCr, tCho and GSH to clinical scores might be indicators on how well the CNS copes with the post-traumatic remodeling and might be further examined as outcome markers.


Assuntos
Cerebelo , Traumatismos da Medula Espinal , Humanos , Espectroscopia de Prótons por Ressonância Magnética , Cerebelo/metabolismo , Traumatismos da Medula Espinal/metabolismo , Ponte/diagnóstico por imagem , Ponte/metabolismo , Creatina/metabolismo , Metaboloma , Colina/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Ácido Aspártico/metabolismo
4.
NMR Biomed ; 36(3): e4856, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36285630

RESUMO

Diffusion kurtosis imaging (DKI) is applied to gain insights into the microstructural organization of brain tissues. However, the reproducibility of DKI outside brain white matter, particularly in combination with advanced estimation to remedy its noise sensitivity, remains poorly characterized. Therefore, in this study, we investigated the variability and reliability of DKI metrics while correcting implausible values with a fit method called mean kurtosis (MK)-Curve. A total of 10 volunteers (four women; age: 41.4 ± 9.6 years) were included and underwent two MRI examinations of the brain. The images were acquired on a clinical 3-T scanner and included a T1-weighted image and a diffusion sequence with multiple diffusion weightings suitable for DKI. Region of interest analysis of common kurtosis and tensor metrics derived with the MK-Curve DKI fit was performed, including intraclass correlation (ICC) and Bland-Altman (BA) plot statistics. A p value of less than 0.05 was considered statistically significant. The analyses showed good to excellent agreement of both kurtosis tensor- and diffusion tensor-derived MK-Curve-corrected metrics (ICC values: 0.77-0.98 and 0.87-0.98, respectively), with the exception of two DKI-derived metrics (axial kurtosis in the cortex: ICC = 0.68, and radial kurtosis in deep gray matter: ICC = 0.544). Non-MK-Curve-corrected kurtosis tensor-derived metrics ranged from 0.01 to 0.52 and diffusion tensor-derived metrics from 0.06 to 0.66, indicating poor to moderate reliability. No structural bias was observed in the BA plots for any of the diffusion metrics. In conclusion, MK-Curve-corrected DKI metrics of the human brain can be reliably acquired in white and gray matter at 3 T and DKI metrics have good to excellent agreement in a test-retest setting.


Assuntos
Imagem de Tensor de Difusão , Substância Branca , Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Imagem de Tensor de Difusão/métodos , Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética , Substância Branca/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética
5.
Invest Radiol ; 58(2): 131-138, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-35926077

RESUMO

OBJECTIVES: In spinal cord injury (SCI), the primary mechanical injury is followed by secondary sequelae that develop over the subsequent months and manifests in biochemical, functional, and microstructural alterations, at the site of direct injury but also in the spinal cord tissue above and below the actual lesion site. Noninvasive magnetic resonance spectroscopy (MRS) can be used to assess biochemical modulation occurring in the secondary injury phase, in addition to and supporting conventional MRI, and might help predict and improve patient outcome. In this article, we aimed to examine the metabolic levels in the pons of subacute SCI by means of in vivo proton MRS at 3 T and explore the association to clinical scores. MATERIALS AND METHODS: In this prospective study, between November 2015 and February 2018, single-voxel short-echo MRS data were acquired in healthy controls and in SCI subjects in the pons once during rehabilitation. Besides the single-point MRS examination, in addition, in participants with SCI, the clinical status (ie, motor, light touch, and pinprick scores) was assessed twice: (1) around the MRS session (approximately 10 weeks postinjury) and (2) before discharge (at approximately 9 months postinjury). The group differences were assessed with Kruskal-Wallis test, the post hoc comparison was assessed with Wilcoxon rank sum test, and the clinical correlations were conducted with Spearman rank correlation test. Bayes factor calculations completed the statistical part providing relevant evidence values. RESULTS: Twenty healthy controls (median age, 50 years; interquartile range, 41-55 years; 18 men) and 18 subjects with traumatic SCI (median age, 50 years; interquartile range, 32-58 years; 16 men) are included. Group comparison showed an increase of total N -acetylaspartate and combined glutamate and glutamine levels in complete SCI and a reduction of total creatine in incomplete paraplegic SCI. The proton MRS-based glutathione levels at baseline correlate to the motor score improvement during rehabilitation in incomplete subacute SCI. CONCLUSIONS: This exploratory study showed an association of the metabolite concentration of glutathione in the pons assessed at approximately 10 weeks after injury with the improvements of the motor score during the rehabilitation. Pontine glutathione levels in subjects with traumatic subacute incomplete SCI acquired remote from the injury site correlate to clinical score and might therefore be beneficial in the rehabilitation assessments.


Assuntos
Prótons , Traumatismos da Medula Espinal , Masculino , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Teorema de Bayes , Traumatismos da Medula Espinal/diagnóstico por imagem , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/patologia , Ponte/diagnóstico por imagem , Ponte/patologia
6.
Sci Rep ; 12(1): 20874, 2022 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-36463248

RESUMO

After spinal cord injury (SCI), reorganization processes and changes in brain connectivity occur. Besides the sensorimotor cortex, the subcortical areas are strongly involved in motion and executive control. This exploratory study focusses on the cerebellum and vermis. Resting-state functional magnetic resonance imaging (fMRI) was performed. Between-group differences were computed using analysis of covariance and post-hoc tests for the seed-based connectivity measure with vermis and cerebellum as regions of interest. Twenty participants with complete SCI (five subacute SCI, 15 with chronic SCI) and 14 healthy controls (HC) were included. Functional connectivity (FC) was lower in all subjects with SCI compared with HC in vermis IX, right superior frontal gyrus (pFDR = 0.008) and right lateral occipital cortex (pFDR = 0.036). In addition, functional connectivity was lower in participants with chronic SCI compared with subacute SCI in bilateral cerebellar crus I, left precentral- and middle frontal gyrus (pFDR = 0.001). Furthermore, higher amplitude of low-frequency fluctuations (ALFF) was found in the left thalamus in individuals with subacute SCI (pFDR = 0.002). Reduced FC in SCI indicates adaptation with associated deficit in sensory and motor function. The increased ALFF in subacute SCI might reflect reorganization processes in the subacute phase.


Assuntos
Doença Enxerto-Hospedeiro , Córtex Sensório-Motor , Traumatismos da Medula Espinal , Humanos , Traumatismos da Medula Espinal/diagnóstico por imagem , Cerebelo/diagnóstico por imagem , Lobo Occipital
7.
Sci Rep ; 8(1): 16844, 2018 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-30442977

RESUMO

The aim of the study was to investigate the signal-intensity-(SI)-ratio changes in the basal ganglia, the pulvinar thalami (PN), and the dentate nucleus (DN) using frontal white matter (FWM) as reference area, in patients with multiple sclerosis after frequent administrations of gadobutrol. A control group (group I) was compared to three stratified patient groups (group II: mean applications of gadobutrol 3.7; group III: 7.5 applications; group IV: 13.8 applications). SI-ratios of the pallidum, putamen, caudate nucleus, and pulvinar thalami were calculated with: 1. FWM, and 2. PN. DN-to-pons and DN-to-FWM ratios were also calculated. The most significant SI-ratio-changes were found by comparing group I and IV for both reference values. However, by using FWM as reference an SI-ratio increase was observed, while an SI-ratio decrease was seen if referenced to the PN. DN-to-FWM showed an SI-ratio increase, too. The PN revealed a significant SI-ratio increase itself, correlating with the number of gadolinium applications, when referenced to FWM. Therefore, SI-ratio calculations using the thalamus as reference might be flawed. In addition, a minor gadolinium accumulation is possible, if FWM was used as reference area. Further studies are necessary to verify our results.


Assuntos
Substância Cinzenta/diagnóstico por imagem , Imageamento por Ressonância Magnética , Esclerose Múltipla/tratamento farmacológico , Compostos Organometálicos/administração & dosagem , Compostos Organometálicos/uso terapêutico , Processamento de Sinais Assistido por Computador , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Adulto , Estudos de Coortes , Feminino , Substância Cinzenta/patologia , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade
8.
World Neurosurg ; 113: 108-109, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29452321

RESUMO

Open magnetic resonance imaging of a 45-year-old man with panic disorder showed a sinus pericranii (SP). Examination of the scalp revealed a discolored scalp mass, and magnetic resonance venography displayed a hypoplastic straight sinus with persistent falcine sinus. SP is a venous anomaly consisting of a transosseous vascular channel connecting an intracranial sinus with subgaleal veins. High venous pressure in the late embryonic stage, as with a hypoplastic straight sinus, has been hypothesized to predispose affected individuals to develop other venous anomalies (i.e., falcine sinus). Because there is no major venous outflow through this accessory SP in an asymptomatic adult, no intervention was recommended for our patient.


Assuntos
Cavidades Cranianas/patologia , Seio Pericrânio/patologia , Cavidades Cranianas/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Couro Cabeludo/patologia , Seio Pericrânio/diagnóstico por imagem
9.
J Neurosurg ; 128(4): 1006-1014, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28409735

RESUMO

OBJECTIVE Cerebral hyperperfusion syndrome (CHS) is a rare but devastating complication of carotid endarterectomy (CEA). This study sought to determine whether quantitative hemodynamic assessment using MR angiography can stratify CHS risk. METHODS In this prospective trial, patients with internal carotid artery (ICA) stenosis were randomly selected for pre- and postoperative quantitative phase-contrast MR angiography (QMRA). Assessment was standardized according to a protocol and included Doppler/duplex sonography, MRI, and/or CT angiography and QMRA of the intra- and extracranial supplying arteries of the brain. Clinical and radiological data were analyzed to identify CHS risk factors. RESULTS Twenty-five of 153 patients who underwent CEA for ICA stenosis were randomly selected for pre- and postoperative QMRA. QMRA data showed a 2.2-fold postoperative increase in blood flow in the operated ICA (p < 0.001) and a 1.3-fold increase in the ipsilateral middle cerebral artery (MCA) (p = 0.01). Four patients had clinically manifested CHS. The mean flow increases in the patients with CHS were significantly higher than in the patients without CHS, both in the ICA and MCA (p < 0.001). Female sex and a low preoperative diastolic blood pressure were the clearest clinical risk factors for CHS, whereas the flow differences and absolute postoperative flow values in the ipsilateral ICA and MCA were identified as potential radiological predictors for CHS. CONCLUSIONS Cerebral blood flow in the ipsilateral ICA and MCA as assessed by QMRA significantly increased after CEA. Higher mean flow differences in ICA and MCA were associated with the development of CHS. QMRA might have the potential to become a noninvasive, operator-independent screening tool for identifying patients at risk for CHS.


Assuntos
Transtornos Cerebrovasculares/diagnóstico por imagem , Angiografia por Ressonância Magnética/métodos , Idoso , Idoso de 80 Anos ou mais , Estenose das Carótidas/complicações , Estenose das Carótidas/cirurgia , Angiografia Cerebral , Artérias Cerebrais/diagnóstico por imagem , Circulação Cerebrovascular , Transtornos Cerebrovasculares/cirurgia , Endarterectomia das Carótidas/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Neurocirúrgicos/métodos , Complicações Pós-Operatórias/diagnóstico por imagem , Valor Preditivo dos Testes , Estudos Prospectivos , Medição de Risco , Síndrome , Ultrassonografia Doppler Dupla , Ultrassonografia Doppler Transcraniana
10.
Front Neurol ; 8: 437, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28894432

RESUMO

BACKGROUND: Behavioral changes are common in patients with multiple sclerosis (MS), however not as readily recognized as cognitive impairments. OBJECTIVE: The aim of this study was to analyze behavioral changes and its relation to disease characteristics, disability, and cognitive impairments in patients with MS. METHOD: This is a single-center cross-sectional study. A detailed neuropsychological examination, including the Frontal Systems Behavior Scale (FrSBe), the Beck depression inventory (BDI), and the Wuerzburg Fatigue Inventory for Multiple Sclerosis (WEIMuS) test, was performed. FrSBe results were correlated with disease characteristics, disability, and cognitive assessments. RESULTS: 66 patients were enrolled (mean age: 43.4 years; disease duration: 9.3 years; Expanded Disability Status Scale: 3.0). Up to one third of patients showed behavioral changes in at least one domain or the total score of the FrSBe. Patients were mildly affected with regard to cognitive functioning. Consistent correlation was found between behavioral changes and fatigue (WEIMuS) and depressive symptoms (BDI), but not with disease characteristics, disability, or cognitive functions. There was an increase of behavioral changes on all FrSBe scales in the current status compared to the retrospectively rated status before disease onset. Self- and family ratings with regard to current behavioral changes were similar. CONCLUSION: Behavioral changes are common in otherwise mildly affected MS patients with up to one third being affected. In this patient cohort, behavioral changes occur largely independent of disease characteristics, physical disability, and cognitive functioning but correlate with both fatigue and depressive symptoms. Therefore, they should be tested specifically.

11.
Swiss Med Wkly ; 147: w14454, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28770549

RESUMO

BACKGROUND: The imaging method most frequently employed to identify brain areas involved in neuronal processing of nociception and brain pain perception is blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI). Arterial spin labelling (ASL), in contrast, offers advantages when slow varying changes in brain function are investigated. Chronic pelvic pain syndrome (CPPS) is a disorder of, mostly, young males that leads to altered pain perceptions in structures related to the pelvis. We aimed to investigate the potential of ASL to monitor longitudinal cranial blood flow (CBF) changes in patients with CPPS. METHODS: In a randomised, placebo-controlled, double-blind single centre trial, we investigated treatment effects in CPPS after 12 weeks in patients that underwent sono-electro-magnetic therapy vs placebo. We investigated changes of CBF related to treatment outcome using pseudo-continuous arterial spin labelling (pCASL)-MRI. RESULTS: We observed CBF downregulation in the prefrontal cortex and anterior cingulate cortex and upregulation in the dorsolateral prefrontal cortex in responders. Nonresponders presented with CBF upregulation in the hippocampus. In patients with a history of CPPS of less than 12 months, there were significant correlations between longitudinal CBF changes and the Chronic Prostatitis Symptom Index pain subscore within the joint clusters anterior cingulate cortex and left anterior prefrontal cortex in responders, and the right hippocampus in nonresponders. CONCLUSIONS: We demonstrated therapy-related and stimulus-free longitudinal CBF changes in core areas of the pain matrix using ASL. ASL may act as a complementary noninvasive method to functional MRI and single-photon emission computed tomography / positron emission tomography, especially in the longitudinal assessment of pain response in clinical trials.


Assuntos
Encéfalo/fisiopatologia , Circulação Cerebrovascular/fisiologia , Dor Crônica/terapia , Imageamento por Ressonância Magnética/métodos , Dor Pélvica/terapia , Adulto , Fatores Etários , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Marcadores de Spin , Resultado do Tratamento
12.
Biomed Res Int ; 2016: 9578139, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26885524

RESUMO

PURPOSE: The purpose of this study was to investigate statistical differences with MR perfusion imaging features that reflect the dynamics of Gadolinium-uptake in MS lesions using dynamic texture parameter analysis (DTPA). METHODS: We investigated 51 MS lesions (25 enhancing, 26 nonenhancing lesions) of 12 patients. Enhancing lesions (n = 25) were prestratified into enhancing lesions with increased permeability (EL+; n = 11) and enhancing lesions with subtle permeability (EL-; n = 14). Histogram-based feature maps were computed from the raw DSC-image time series and the corresponding texture parameters were analyzed during the inflow, outflow, and reperfusion time intervals. RESULTS: Significant differences (p < 0.05) were found between EL+ and EL- and between EL+ and nonenhancing inactive lesions (NEL). Main effects between EL+ versus EL- and EL+ versus NEL were observed during reperfusion (mainly in mean and standard deviation (SD): EL+ versus EL- and EL+ versus NEL), while EL- and NEL differed only in their SD during outflow. CONCLUSION: DTPA allows grading enhancing MS lesions according to their perfusion characteristics. Texture parameters of EL- were similar to NEL, while EL+ differed significantly from EL- and NEL. Dynamic texture analysis may thus be further investigated as noninvasive endogenous marker of lesion formation and restoration.


Assuntos
Meios de Contraste/administração & dosagem , Gadolínio/administração & dosagem , Imageamento por Ressonância Magnética , Esclerose Múltipla/diagnóstico por imagem , Imagem de Perfusão/métodos , Adulto , Idoso , Suscetibilidade a Doenças , Feminino , Humanos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/patologia
13.
Acta Radiol Open ; 4(12): 2058460115617353, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26668757

RESUMO

We report a case of a 9-year-old boy presenting with spastic-dystonic movement disorder of the right arm. MRI showed vast unilateral left-sided polymicrogyria (PMG) with perisylvian, temporal, frontal, and parietal location. Corresponding to the distinctly reduced gyration, the focal pattern of cortical veins in susceptibility weighted imaging (SWI) was absent due to missing sulcal depth. In contrast, adjacent regions with sufficient sulcal depth revealed a pattern with numerically increased and finer cortical veins. Therefore, with its atypical venous pattern SWI indicates an abnormal parenchymal anatomy and might be an additional helpful tool for diagnosing PMG.

14.
Neuroradiology ; 57(10): 1045-54, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26319999

RESUMO

INTRODUCTION: Diagnostic tools to show emboli reliably and protection techniques against embolization when employing stent retrievers are necessary to improve endovascular stroke therapy. The aim of the present study was to investigate iatrogenic emboli using susceptibility-weighted imaging (SWI) in an open series of patients who had been treated with stent retriever thrombectomy using emboli protection techniques. METHODS: Patients with anterior circulation stroke examined with MRI before and after stent retriever thrombectomy were assessed for iatrogenic embolic events. Thrombectomy was performed in flow arrest and under aspiration using a balloon-mounted guiding catheter, a distal access catheter, or both. RESULTS: In 13 of 57 patients (22.8%) post-interventional SWI sequences detected 16 microemboli. Three of them were associated with small ischemic lesions on diffusion-weighted imaging (DWI). None of the microemboli were located in a new vascular territory, none showed clinical signs, and all 13 patients have been rated as Thrombolysis in Cerebral Infarction (TICI) 2b (n = 3) or 3 (n = 10). Retrospective reevaluation of the digital subtraction angiography (DSA) detected discrete flow stagnation nearby the iatrogenic microemboli in four patients with a positive persistent collateral sign in one. CONCLUSION: Our study demonstrates two things: First, SWI seems to be more sensitive to detect emboli than DWI and DSA and, second, proximal or distal protected stent retriever thrombectomy seems to prevent iatrogenic embolization into new vascular territories during retraction of the thrombus, but not downstream during mobilization of the thrombus. Both techniques should be investigated and refined further.


Assuntos
Embolia Intracraniana/prevenção & controle , Trombose Intracraniana/patologia , Trombose Intracraniana/cirurgia , Imageamento por Ressonância Magnética/métodos , Trombólise Mecânica/instrumentação , Stents , Idoso , Angiografia Digital/métodos , Remoção de Dispositivo/instrumentação , Análise de Falha de Equipamento , Feminino , Humanos , Doença Iatrogênica/prevenção & controle , Embolia Intracraniana/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Desenho de Prótese , Resultado do Tratamento
15.
Int J Stroke ; 10(6): 887-92, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26121371

RESUMO

BACKGROUND: We prospectively investigated temporal and spatial evolution of intramural hematomas in patients with acute spontaneous internal carotid artery dissection using repeated magnetic resonance imaging over six-months. AIM: The aim of the present study was to assess dynamic changes of intramural hematoma in patients with acute spontaneous internal carotid artery dissection at multiple follow-up time-points with T1w, PD/T2w, and magnetic resonance angiography. METHODS: We performed serial multiparametric magnetic resonance imaging in 10 patients with spontaneous internal carotid artery dissection on admission, at days 1, 3, 7-14 and at months 1·5, 3, and 6. We calculated the volume and extension of the hyperintense intramural hematoma using T1w and PD/T2w fat suppressed sequences and assessed the degree of stenosis due to the hematoma using magnetic resonance angiography. RESULTS: Mean interval from symptom onset to first magnetic resonance imaging was two-days (SD 2·7). Two patients presented with ischemic stroke, three with transient ischemic attacks, and five with pain and local symptoms only. Nine patients had a transient increase of the intramural hematoma volume, mainly up to day 10 after symptom onset. Fifty percent had a transient increase in the degree of the internal carotid artery stenosis on MRA, one resulting in a temporary occlusion. Lesions older than one-week were predominantly characterized by a shift from iso- to hyperintese signal on T2w images. At three-month follow-up, intramural hematoma was no longer detectable in 80% of patients and had completely resolved in all patients after six-months. CONCLUSIONS: Spatial and temporal dynamics of intramural hematomas after spontaneous internal carotid artery dissection showed an early volume increase with concomitant progression of the internal carotid artery stenosis in 5 of 10 patients. Although spontaneous internal carotid artery dissection overall carries a good prognosis with spontaneous hematoma resorption in all our patients, early follow-up imaging may be considered, especially in case of new clinical symptoms.


Assuntos
Dissecação da Artéria Carótida Interna/patologia , Hematoma/patologia , Isquemia Encefálica/patologia , Isquemia Encefálica/fisiopatologia , Dissecação da Artéria Carótida Interna/fisiopatologia , Estenose das Carótidas/patologia , Estenose das Carótidas/fisiopatologia , Angiografia Cerebral , Bases de Dados Factuais , Progressão da Doença , Feminino , Seguimentos , Hematoma/fisiopatologia , Humanos , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Acidente Vascular Cerebral/patologia , Acidente Vascular Cerebral/fisiopatologia
17.
Resuscitation ; 88: 75-80, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25576980

RESUMO

OBJECTIVE: In susceptibility-weighted imaging (SWI) in the normal brain, cortical veins appear hypointense due to paramagnetic properties of deoxy-hemoglobin. Global cerebral anoxia decreases cerebral oxygen metabolism, thereby increasing oxy-hemoglobin levels in cerebral veins. We hypothesized that a lower cerebral oxygen extraction fraction in comatose patients with non-neonatal hypoxic-ischemic encephalopathy (IHE) produces a pattern of global rarefied or pseudo-diminished cortical veins due to higher oxy-hemoglobin. PURPOSE: (1) To investigate the topographic relationship between susceptibility effects in cortical veins and related diffusion restrictions on diffusion-weighted imaging (DWI) in patients with IHE. (2) To relate imaging findings to patterns of altered resting activity on surface EEG. METHODS: Twenty-three IHE patients underwent MRI. EEG patterns were used to classify the depth of coma. Regional vs. global susceptibility changes on SWI and patterns of DWI restrictions were compared with the depth of coma. RESULTS: All patients exhibited areas of restricted cortical diffusion and SWI abnormalities. The dominant DWI restrictions encompassed widespread areas along the precuneus, frontal and parietal association cortices and basal ganglia. For SWI, nineteen patients had generalized bi-hemispherical patterns, the EEG patterns correlated with coma grades III-V. Four patients had focal decreases of deoxy-hemoglobin following DWI restrictions; associated with normal EEGs. CONCLUSION: Focal patterns of diamagnetic effects on SWI according to relative decreases in deoxy-hemoglobin due to reduced metabolic demand are associated with normal EEG in IHE patients. Global patterns indicated increased depth of coma and widespread cortical damage. CLINICAL RELEVANCE: The results indicate a potential diagnostic value of SWI in patients with IHE.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Parada Cardíaca/complicações , Hipóxia-Isquemia Encefálica/diagnóstico , Adulto , Idoso , Reanimação Cardiopulmonar , Feminino , Parada Cardíaca/terapia , Humanos , Hipóxia-Isquemia Encefálica/etiologia , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos
18.
Radiol Case Rep ; 10(1): 1010, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-27408655

RESUMO

A 63-year-old man with right hemiparesis was found (on MRI) to have an expansive intramedullary tumorous lesion at the C2-C3 level. After complete neurosurgical tumor resection, the tumor was histologically categorized as an intermediate grade of intramedullary melanocytoma, an uncommon neoplasm. Based on this peculiar case and review of the literature, radical surgical resection appears to be the therapy of choice for intramedullary melanocytomas. However, their high recurrence rate and aggressive behavior suggest the need for close followup with serial MRI.

19.
Stroke ; 45(11): 3430-2, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25293657

RESUMO

BACKGROUND AND PURPOSE: The aim of this prospective study was to assess vascular integrity after stent-retriever thrombectomy. METHODS: Dissection, contrast medium extravasation, and vasospasm were evaluated in 23 patients after thrombectomy with biplane or 3D-digital subtraction angiography and 3-Tesla vessel wall MRI. RESULTS: Vasospasm was detected angiographically in 10 patients, necessitating intra-arterial nimodipine in 2 of them. Contrast extravasation, intramural hemorrhage, or iatrogenic dissection were not detected on multimodal MRI in any patient even after Y-double stent-retriever technique. CONCLUSIONS: Our findings suggest that clinically relevant vessel wall injuries occur rarely after stent-retriever thrombectomy.


Assuntos
Angiografia Cerebral , Artérias Cerebrais/diagnóstico por imagem , Imageamento por Ressonância Magnética , Stents , Acidente Vascular Cerebral/cirurgia , Trombectomia/métodos , Angiografia Cerebral/métodos , Estudos de Coortes , Humanos , Imageamento por Ressonância Magnética/métodos , Estudos Prospectivos , Stents/efeitos adversos , Acidente Vascular Cerebral/diagnóstico por imagem , Trombectomia/efeitos adversos , Resultado do Tratamento , Vasoespasmo Intracraniano/diagnóstico por imagem , Vasoespasmo Intracraniano/etiologia
20.
Eur Radiol ; 24(11): 2980-8, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25097124

RESUMO

OBJECTIVE: To investigate pathological findings in the susceptibility weighted imaging (SWI) of patients experiencing convulsive (CSE) or non-convulsive status epilepticus (NCSE) with focal hyperperfusion in the acute setting. METHODS: Twelve patients (six with NCSE confirmed by electroencephalogram (EEG) and six patients with CSE with seizure event clinically diagnosed) underwent MRI in this acute setting (mean time between onset of symptoms and MRI was 3 h 8 min), including SWI, dynamic susceptibility contrast MR imaging (DSC) and diffusion-weighted imaging (DWI). MRI sequences were retrospectively evaluated and compared with EEG findings (10/12 patients), and clinical symptoms. RESULTS: Twelve out of 12 (100 %) patients showed a focal parenchymal area with pseudo-narrowed cortical veins on SWI, associated with focal hyperperfused areas (increased cerebral blood flow (CBF) and mean transit time (MTT) shortening), and cortical DWI restriction in 6/12 patients (50 %). Additionally, these areas were associated with ictal or postical EEG patterns in 8/10 patients (80 %). Most frequent acute clinical findings were aphasia and/or hemiparesis in eight patients, and all of them showed pseudo-narrowed veins in those parenchymal areas responsible for these symptoms. CONCLUSION: In this study series with CSE and NCSE patients, SWI showed focally pseudo-narrowed cortical veins in hyperperfused and ictal parenchymal areas. Therefore, SWI might have the potential to identify an ictal region in CSE/NCSE. KEY POINTS: • The focal ictal brain regions show hyperperfusion in DSC MR-perfusion imaging. • SWI shows focally diminished cortical veins in hyperperfused ictal regions. • SWI has the potential to identify a focal ictal region in CSE/NCSE.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Hemodinâmica/fisiologia , Estado Epiléptico/fisiopatologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Encéfalo/patologia , Circulação Cerebrovascular , Criança , Pré-Escolar , Eletroencefalografia , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Fluxo Sanguíneo Regional , Estudos Retrospectivos , Estado Epiléptico/diagnóstico , Adulto Jovem
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