Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.829
Filtrar
1.
Radiol Clin North Am ; 57(6): 1083-1091, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31582036

RESUMO

This article reviews the current state of imaging for acute ischemic stroke. Protocolized imaging acquisition using computed tomography in conjunction with coordinated stroke care allows for rapid diagnosis and prompt revascularization. Following the initial evidence to support endovascular therapy for large-vessel occlusion, published between 2014 and 2015, there are now guidelines supporting treatment up to 24 hours after time of onset of symptoms. Neuroimaging remains a central component in diagnosing acute stroke and potentially excluding patients from stroke treatment, as outlined in this article.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Angiografia por Ressonância Magnética/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Humanos , Neuroimagem/métodos
2.
Radiol Clin North Am ; 57(6): 1093-1108, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31582037

RESUMO

Acute stroke is a leading cause of morbidity and mortality in the United States. Acute ischemic strokes have been classified according to The Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification system, and this system aids in proper management. Nearly every patient who presents to a hospital with acute stroke symptoms has some form of emergent imaging. As such, imaging plays an important role in early diagnosis and management. This article reviews the imaging patterns of acute strokes, and how the infarct pattern and imaging characteristics can suggest an underlying cause.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Angiografia por Ressonância Magnética/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/etiologia , Humanos , Fatores de Risco , Doenças Vasculares/complicações , Doenças Vasculares/diagnóstico por imagem
4.
Br J Radiol ; 92(1103): 20190465, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31356106

RESUMO

Increased collagen, or fibrosis, is an important marker of disease and may improve identification of patients at risk. In addition, fibrosis imaging may play an increasing role in guiding therapy and monitoring its effectiveness. MRI is the most frequently used modality to detect, visualize and quantify fibrosis non-invasively. However, standard MRI techniques used to phenotype cardiac fibrosis such as delayed enhancement and extracellular volume determination by T1 mapping, require the administration of gadolinium-based contrast and are particularly difficult to use in patients with cardiac devices such as pacemakers and automatic defibrillators. Therefore, such methods are limited in the serial evaluation of cardiovascular fibrosis as part of chronic disease monitoring. A method to directly measure collagen amount could be of great clinical benefit. In the current review we will discuss the potential of a novel MR technique, ultrashort echo time (UTE) MR, for fibrosis imaging. Although UTE imaging is successfully applied in other body areas such as musculoskeletal applications, there is very limited experience so far in the heart. We will review the established methods and currently available literature, discuss the technical considerations and challenges, show preliminary in vivo images and provide a future outlook on potential applications of cardiovascular UTE.


Assuntos
Sistema Cardiovascular/patologia , Angiografia por Ressonância Magnética/métodos , Artefatos , Meios de Contraste , Fibrose/patologia , Gadolínio , Humanos , Fatores de Tempo
5.
Rev. Soc. Cardiol. Estado de Säo Paulo ; 29(3 Supl): 291-296, jul.-set. 2019. tab, graf
Artigo em Português | LILACS | ID: biblio-1023081

RESUMO

Avaliar a eficácia diagnóstica da angiotomografia coronariana (AC) comparada com a cineangiocoronariografia (CAT). Material e Métodos: Foram avaliados retrospectivamente 146 pacientes submetidos a AC e CAT com angiografia coronariana quantitativa (ACQ), com intervalo médio de um mês entre os exames. O estudo foi realizado no Hospital Cardiológico Costantini. Foram avaliados os fatores de risco da amostra, a localização das lesões e o grau de severidade da obstrução coronariana nos grandes vasos (TCE, DA, CX e CD). Os resultados dos métodos diagnósticos foram comparados pelo coeficiente de correlação de Pearson. A partir dos achados positivos foi realizada a avaliação de correlação entre os métodos perante a severidade das lesões. Resultados: A amostra foi composta predominantemente por homens (73,97%), sendo a hipertensão arterial (HAS) (71,91%) o fator de risco mais frequente. A artéria mais acometida foi a DA. Quanto ao grau de severidade das lesões, os resultados foram os seguintes na comparação entre AC e CAT: lesões discretas com correlação r = 0,23; moderadas com r = 0,53 e severas com r = 0,70. Na comparação entre AC e ACQ: lesões discretas com correlação r = 0,45; moderadas com r = 0,70 e severas com r = 0,67. Conclusão: A AC apresentou moderada com ACQ e CAT em lesões moderadas e severas, e forte correlação na ausência de lesões quando comparada com ACQ


To evaluate the diagnostic efficacy of multislice CT coronary angiotomography compared with coronary cineangiography. Material and Methods: We retrospectively evaluated 146 patients submitted to MSCT and CA with quantitative coronary angiography (QCA), with a mean interval of one month between the exams. The study was carried out at the Costantini Cardiology Hospital. The risk factors for the sample, the location of the lesions and the degree of severity of the coronary obstruction in the large vessels (LCT, AD, CX and RC).The results of the diagnostic methods were compared using Pearson correlation coefficient. From the positive findings, a correlation evaluation was performed between the methods for the severity of the lesions. Results: The sample consisted predominantly of men (73.97%), and hypertension (SAH) (71.91%) was the most frequent risk factor. The most affected artery was AD. Regarding the degree of severity of the lesions, the results were as follows in the comparison between MSCT and CA: mild lesions with correlation r = 0.23, moderate with r = 0.53 and severe with r = 0.70. In the comparison between MSCT and QCA: mild lesions with correlation r = 0.45, moderate with r = 0.70 and severe with r = 0.67. Conclusion: MSCT showed moderate correlation with QCA and CA in moderate and severe lesions, and a strong correlation in the absence of lesions when compared with QCA


Assuntos
Humanos , Masculino , Feminino , Doença da Artéria Coronariana/diagnóstico por imagem , Angiografia/métodos , Angiografia Digital/métodos , Angiografia Coronária/métodos , Diagnóstico por Imagem/métodos , Doenças Cardiovasculares/mortalidade , Estudos Retrospectivos , Fatores de Risco , Angiografia por Ressonância Magnética/métodos , Angiografia por Tomografia Computadorizada/métodos , Hipertensão
6.
Medicine (Baltimore) ; 98(30): e16360, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31348236

RESUMO

BACKGROUND AND OBJECTIVE: Ischemic stroke is a foremost cause for disability and death worldwide. This study is conducted in order to compare the diagnostic values between transcranial Doppler ultrasound (ultrasonography), computed tomography (CT), and magnetic resonance imaging (MRI) in patients suffering from ischemic stroke by performing a network meta-analysis. METHODS: We made use of Cochrane Library, PubMed, and Embase in order to obtain literature and papers. The combination analysis of both direct and indirect evidence in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy was conducted so as to assess the odds ratios (ORs) and surface under the cumulative ranking curve (SUCRA) values of the seven different imaging methods. These imaging techniques include ultrasonography, computed tomography (traditional CT, computed tomography angiography [CTA], computed tomography perfusion [CTP]), and MRI (traditional MRI, diffusion-weighted imaging [DWI], magnetic resonance angiography), in order to properly diagnose ischemic stroke patients. RESULTS: Thirteen eligible diagnostic trials were enrolled into this network meta-analysis. The results of the traditional meta-analysis showed that among CT methods, CTP showed higher sensitivity, NPV, and accuracy; among MRI methods, DWI had relatively higher sensitivity, NPV, and accuracy. The results of network meta-analysis showed that DWI had relatively higher sensitivity, NPV, and accuracy when compared with traditional CT, CTA, magnetic resonance angiography and traditional MRI. CTP showed higher SUCRA among CT methods while DWI showed higher SUCRA among MRI methods. A cluster analysis revealed that DWI had the highest diagnostic value in terms of sensitivity, PPV, NPV, and accuracy amongst the aforementioned seven imaging techniques. CONCLUSION: This network meta-analysis provides supporting evidence to the idea that DWI has a higher diagnostic value regarding ischemic stroke among MRI methods, and CTP has a poor diagnostic value among CT methods, which provide therapeutic considerations for Ischemic stroke intervention.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Ultrassonografia Doppler Transcraniana/métodos , Angiografia por Tomografia Computadorizada/métodos , Angiografia por Tomografia Computadorizada/normas , Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Difusão por Ressonância Magnética/normas , Humanos , Angiografia por Ressonância Magnética/métodos , Angiografia por Ressonância Magnética/normas , Imagem por Ressonância Magnética/normas , Meta-Análise em Rede , Valor Preditivo dos Testes , Tomografia Computadorizada por Raios X/normas , Ultrassonografia Doppler Transcraniana/normas
7.
Eur J Radiol ; 116: 84-89, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31153579

RESUMO

OBJECTIVES: The purpose of this study was to evaluate the associations between vertebral artery hypoplasia (VAH) and the morphologic types of spontaneous vertebral artery dissection (sVAD) and to assess the chronological changes of VAH after sVAD. METHODS AND MATERIALS: In this retrospective study, we included 208 patients with 216 sVADs which were diagnosed between January 2003 and June 2017 at two tertiary hospitals. Morphologic types of sVAD were classified into aneurysmal dilatation without stenosis, pearl-and-string appearance, and steno-occlusion without aneurysmal dilatation. Baseline clinical characteristics and sVAD types were compared according to the presence of VAH on initial imaging. For 143 sVAD patients with follow-up imaging available, chronological changes of VAH and their associations with sVAD types were also evaluated. RESULT: VAH was detected in 29 (13.9%) subjects: 18 (8.7%) with ipsilateral VAH and 11 (5.3%) with contralateral VAH to the sVAD site. Primary lesion shape was statistically associated with the presence of VAH (P = 0.001); steno-occlusion without dilatation was more frequently observed in the ipsilateral VAH group (44.4%) than the no-VAH group (20.9%) or contralateral VAH group (0%). Of a total 143 sVAD patients with follow-up imaging available, VAH-like diffuse VA narrowing was newly observed in seven patients and four patients who were initially classified into the VAH group showed their VAH-like appearances resolved. CONCLUSIONS: The presence of VAH may be associated with the morphologic subtype of sVAD and the VA diameter can dynamically change, making it possible for the VAH-like appearance to be induced after a sVAD event.


Assuntos
Angiografia por Ressonância Magnética/métodos , Dissecação da Artéria Vertebral/diagnóstico por imagem , Dissecação da Artéria Vertebral/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Artéria Vertebral/diagnóstico por imagem , Artéria Vertebral/patologia
8.
Medicine (Baltimore) ; 98(23): e15972, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31169728

RESUMO

BACKGROUND: This study aimed to evaluate the value of 3-dimensional pseudocontinuous arterial spin labeling (3D-pcASL) and susceptibility-weighted imaging (SWI) for the early disease-sensitive markers of conversion from amnestic MCI (aMCI) to Alzheimer disease (AD) in this process. METHODS: Forty patients with aMCI and AD respectively were recruited in the study, and 40 healthy subjects were taken as controls. Data were recorded using 3T MR scanner. We assessed the cerebral blood flow (CBF) in 11 different regions of interest, and counted number of microhemorrhages (MB) in 3 regions of brain lobes, bilateral basal ganglia/thalamus, and brain stem/cerebellum, and then investigated correlations between Montreal Cognitive Assessment (MoCA) scores, CBF, and susceptibility-weighted imaging (SWI) features in these 3 groups. RESULTS: The results revealed that for AD patients, the MoCA scores and CBF values in frontal gray matter (FGM), occipital gray matter (OGM), temporal gray matter (TGM), parietal gray matter (PGM), hippocampus, anterior cingulate cortex (ACC), precuneus, posterior cingulate cortex (PCC), precuneus, basal ganglia and thalamus decreased compared with aMCI patients and control group, and significant difference was revealed among the 3 groups. While in cerebellum, statistical significance was only found between AD patients and control group. On SWI, the average numbers of hemorrhage in regions of lobes for AD patients were significantly higher than aMCI patients and control group. The same results occurred in the bilateral basal ganglia/thalamus. We further found the MoCA score was positively correlated with CBF, but negatively correlated with hypointense signal on SWI. CONCLUSION: 3D-pCASL and SWI have promising potential to be biomarkers for conversion from aMCI to AD in this process.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Amnésia/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Angiografia por Ressonância Magnética/métodos , Idoso , Doença de Alzheimer/psicologia , Amnésia/complicações , Circulação Cerebrovascular/fisiologia , Disfunção Cognitiva/complicações , Estudos Transversais , Progressão da Doença , Feminino , Humanos , Imagem Tridimensional , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Medição de Risco/métodos , Marcadores de Spin
9.
J Stroke Cerebrovasc Dis ; 28(7): 1824-1831, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31078388

RESUMO

OBJECTIVE: To assess the reproducibility of 3.0T high-resolution magnetic resonance imaging for the identification and quantification of atherosclerotic plaques in the middle cerebral artery. METHODS: Sixty-nine consecutive patients with ischemic stroke or asymptomatic stenosis (>30%) of the middle cerebral artery underwent 3.0T high-resolution magnetic resonance imaging examinations. Two independent investigators reviewed all images with 1 investigator re-evaluating all images 4 weeks later. Wall characteristics of the middle cerebral artery, including plaque surface morphology, plaque location, plaque components, and burden were identified and measured. RESULTS: Intraobserver and interobserver agreement were all substantial in identifying plaque surface irregularity (k = 0.741, 0.555-0.897; k = 0.685, 0.490-0.843; respectively) and intraplaque hemorrhage (k = 0.654, 0.446-0.838; k = 0.605, 0.369-0.792; respectively). Intraobserver agreement was substantial (k = 0.654) and interobserver agreement was moderate (k = 0.553) for the identification of plaque fibrous caps. The total intraobserver and interobserver reproducibility was almost excellent for the identification of plaque position. With regards to vessel area measurement at the site of maximal lumen narrowing, intraobserver and interobserver reproducibility was excellent (intraclass correlation coefficient was 0.886 and 0.885, respectively) and moderate for lumen area at the site of maximal lumen narrowing (intraclass correlation coefficient was 0.695 and 0.558, respectively). In addition, intraobserver and interobserver reproducibility was excellent for vessel area and lumen area measurements at the reference sites. CONCLUSIONS: The reproducibility of 3.0T high-resolution magnetic resonance imaging for the identification and quantification of artery wall characteristics was overall acceptable. However, the reliability for lumen area measurement at the maximum narrowing site and identification of the fibrous cap needs to be improved.


Assuntos
Angiografia Cerebral/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Arteriosclerose Intracraniana/diagnóstico por imagem , Ataque Isquêmico Transitório/diagnóstico por imagem , Angiografia por Ressonância Magnética/métodos , Artéria Cerebral Média/diagnóstico por imagem , Placa Aterosclerótica , Idoso , Feminino , Fibrose , Humanos , Infarto da Artéria Cerebral Média/patologia , Arteriosclerose Intracraniana/patologia , Ataque Isquêmico Transitório/patologia , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/patologia , Variações Dependentes do Observador , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Índice de Gravidade de Doença
10.
J Headache Pain ; 20(1): 48, 2019 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-31060491

RESUMO

BACKGROUND: Sildenafil and calcitonin gene-related peptide both dilate the intradural segments of the middle meningeal artery measured with 3.0 tesla (T) MR angiography. Here we hypothesized that an increase in field strength to 7.0 T and concomitant enhanced voxel resolution would lower variance in measurements of dilation in the intradural middle meningeal artery. METHODS: Five subjects completed two sessions at respectively 3.0 T and 7.0 T. Each session comprised MR angiography scans once before and twice after administration of sildenafil, calcitonin gene-related peptide or placebo in a three-way, crossover, double-blind, placebo-controlled design. RESULTS: Standard deviations of arterial circumference revealed no difference between 3.0 T and 7.0 T measurements (p = 0.379). We found a decrease in standard deviation from our original angiography analysis software (QMra) to a newer (LAVA) software package (p < 0.001). Furthermore, we found that the dilation after sildenafil and calcitonin gene-related peptide were comparable between 3.0 T and 7.0 T. CONCLUSIONS: Our findings suggest no gain from the increase in voxel resolution but cemented dilatory findings from earlier. The implemented software update improved variance in circumference measurements in the intradural middle meningeal artery, which should be exploited in future studies. TRIAL REGISTRATION: The study is part of a parent study, which is registered at ClinicalTrials.gov ( NCT03143465 ).


Assuntos
Peptídeo Relacionado com Gene de Calcitonina/farmacologia , Angiografia Cerebral/métodos , Angiografia por Ressonância Magnética/métodos , Artérias Meníngeas/diagnóstico por imagem , Transtornos de Enxaqueca/diagnóstico por imagem , Citrato de Sildenafila/farmacologia , Adulto , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Encéfalo/efeitos dos fármacos , Peptídeo Relacionado com Gene de Calcitonina/uso terapêutico , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Masculino , Artérias Meníngeas/efeitos dos fármacos , Transtornos de Enxaqueca/tratamento farmacológico , Transtornos de Enxaqueca/fisiopatologia , Citrato de Sildenafila/uso terapêutico , Adulto Jovem
11.
Eur J Radiol ; 113: 165-173, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30927943

RESUMO

PURPOSE: To evaluate the feasibility and accuracy of a combined magnetic resonance angiography (MRA) - magnetic resonance venography (MRV) protocol using contrast agents with blood pool properties, gadofosveset trisodium and gadobenate dimeglumine, in the evaluation of pulmonary embolus (PE) and deep venous thrombosis (DVT) as compared to the standard clinical reference imaging modalities; computed tomography pulmonary angiography (CTPA) and color-coded Duplex ultrasound (DUS). MATERIALS AND METHODS: This prospective clinical study recruited patients presenting to the emergency department with clinical suspicion for PE and scheduled for a clinically indicated CTPA. We performed both MRA of the chest for the evaluation of PE as well as MRV of the pelvis and thighs to evaluate for DVT using a single contrast injection. MRA-MRV data was compared to the clinical reference standard CTPA and DUS, respectively. RESULTS: A total of 40 patients were recruited. The results on a per-patient basis comparing MRA to CTPA for pulmonary embolus yielded 100% sensitivity and 97% specificity. There was a small subset of patients that underwent clinical DUS to evaluate for DVT, which demonstrated a sensitivity and specificity of 100% for MRV. CONCLUSIONS: This single-center, preliminary study using contrast agents with blood pool properties to perform a relatively rapid combined MRA-MRV exam to image for PE and above knee DVT shows potential as an alternative imaging choice to CTPA. Further large-scale, multicentre studies are warranted.


Assuntos
Embolia Pulmonar/diagnóstico , Trombose Venosa/diagnóstico , Adulto , Angiografia por Tomografia Computadorizada/métodos , Meios de Contraste , Estudos de Viabilidade , Feminino , Gadolínio , Humanos , Angiografia por Ressonância Magnética/métodos , Masculino , Meglumina/análogos & derivados , Pessoa de Meia-Idade , Compostos Organometálicos , Pelve , Flebografia/métodos , Estudos Prospectivos , Exposição à Radiação/prevenção & controle , Sensibilidade e Especificidade , Tórax
12.
Eur J Radiol ; 113: 217-224, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30927950

RESUMO

INTRODUCTION: T1 and T2 mapping have been shown to be reliable markers of interstitial myocardial fibrosis, edema, and inflammation. The aim of this study was to evaluate myocardial involvement in acute phase Takotsubo syndrome using native and post-contrast T1 mapping, ECV fraction, and T2 mapping. MATERIAL AND METHODS: We investigated 14 patients with acute Takotsubo syndrome and 14 healthy controls. CMR included cine imaging, black-blood STIR imaging, early and late gadolinium enhancement imaging, native and post-contrast T1 mapping, and T2 mapping. Wall motion, T2 ratio, early gadolinium enhancement ratio, extracellular volume fraction, T1 and T2 relaxation times were analyzed. RESULTS: Patients had significantly impaired left ventricular function (46 ± 10%) and acute wall motion abnormalities compared with controls (62 ± 2%). Native T1 and T2 values, T2 ratio, and ECV fraction were significantly higher in patients compared with controls. In patients, native T1 and T2 values as well as T2 ratio were significantly higher in segments with abnormal wall motion compared with normokinetic segments. Native T1 values, T2 relaxation times, T2 ratio, and ECV fraction were significantly higher, post-contrast T1 relaxation times significantly lower in segments with abnormal wall motion compared with segments of controls; except for T2 ratio and post-contrast T1 relaxation times this also held true for patients' segments with normal wall motion. CONCLUSIONS: Native T1 and T2 mapping, as well as ECV fraction, discriminate between visually affected vs. unaffected segments in patients with acute Takotsubo syndrome and reveal significant T1 and T2 tissue changes even in visually unaffected segments. Thus, mapping may allow for better detection in convalescent stages of disease and additionally may have the potential to serve as a marker of disease progress. These preliminary findings warrant further investigation in a larger patient cohort.


Assuntos
Cardiomiopatia de Takotsubo/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Cardiomiopatias/patologia , Meios de Contraste , Feminino , Fibrose/patologia , Gadolínio , Humanos , Angiografia por Ressonância Magnética/métodos , Imagem Cinética por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Valor Preditivo dos Testes , Estudos Prospectivos , Cardiomiopatia de Takotsubo/fisiopatologia , Função Ventricular Esquerda/fisiologia
13.
Eur J Radiol ; 113: 51-58, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30927959

RESUMO

BACKGROUND: Systolic strain and peak-early diastolic strain rate (PEDSR) measure subclinical cardiac dysfunction. These parameters can be derived from cardiovascular magnetic resonance (CMR) cine images using new software packages, but the comparative test-retest reproducibility of these software in disease states is unknown. This study compared the test-retest reproducibility of strain measures derived from two software packages (feature-tracking software (FT) and tissue-tracking (TT)) in disease populations with preserved ejection fractions. METHODS: This was a prospective study of 10 patients with aortic stenosis (AS), 10 haemodialysis patients and 10 diabetic patients at 1.5 and 3-Tesla. 30 subjects underwent test-retest reproducibility scans of global circumferential strain (GCS), global longitudinal strain (GLS), circumferential-PEDSR and longitudinal-PEDSR calculated using TT and FT software. RESULTS: Test-retest reproducibility of GCS and GLS were similar for FT and TT across patient groups. Coefficient of variability (CoV) for FT-derived GCS 8.1%, 5% and 7.9% for AS, diabetic and haemodialysis patients, compared to 3.3%, 9.2% and 5.4% for TT-derived GCS, with CoV for FT-derived GLS 8%, 6.4% and 8.2% for AS, diabetic and haemodialysis patients, compared to 5.3%, 4.8% and 7% for TT-derived GLS). Reproducibility of FT-derived circumferential and longitudinal-PEDSR was worse than TT-derived circumferential and longitudinal-PEDSR (CoV for FT-derived circumferential-PEDSR 18.2%, 18% and 17.4% for AS, diabetic and haemodialysis patients, compared to 6.1%, 11.7% and 11% for TT-derived circumferential-PEDSR with CoV for FT-derived longitudinal PEDSR 18.2%, 18.9%, 18.3% for AS, diabetic and haemodialysis patients, compared to 8.9%, 9.1% and 11.4% for TT-derived longitudinal-PEDSR). Bland-Altman analysis revealed no systematic bias with tighter limits of agreement for TT-derived strain measures. CONCLUSIONS: Reproducibility of GCS and GLS are excellent with FT and TT software across diseases. TT had superior test-retest reproducibility for quantification of longitudinal and circumferential-PEDSR than FT-derived PEDSR across diseases.


Assuntos
Estenose da Valva Aórtica/diagnóstico , Software , Idoso , Estenose da Valva Aórtica/fisiopatologia , Feminino , Humanos , Angiografia por Ressonância Magnética/métodos , Imagem Cinética por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Estresse Fisiológico/fisiologia , Volume Sistólico/fisiologia
14.
Int J Cardiovasc Imaging ; 35(7): 1339-1346, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30949869

RESUMO

To describe a novel time-resolved magnetic resonance angiography (TR-MRA) postprocessing technique using the time-resolved angiography with interleaved stochastic trajectories (TWIST) method to evaluate the pulmonary veins and left atrium in adults with congenital heart disease undergoing cardiac MRI. Institutional ethics committee approved the study. 21 consecutive adult patients (14 female, 7 male patients, mean age 28 years) with known congenital heart disease who underwent a cardiac MRI were included. Post-processing of the TR-MRA sequences created novel "subtracted" datasets. Two independent observers reviewed the conventional TWIST and novel subtracted TWIST data sets in source and maximum intensity projection (MIP) coronal reformats to assess visualization of the pulmonary veins and left atrium based on a 5-point scale. Quantitative signal to noise (SNR) comparison was performed. TR-MRA yielded diagnostic image data in 20/21 patients (95.2%). The novel "subtracted" TR-MRA technique improved visualization of the pulmonary veins and left atrium compared to the source TR-MRA sequence in 16/20 patients (mean scores 3.34 ± 0.69 vs. 2.92 ± 0.69, p < 0.008). Further improved visualization of the pulmonary veins and left atrium was observed in the subtracted MIP TWIST sequences compared to the MIP TWIST images (mean scores 4.43 ± 0.80 vs. 3.02 ± 0.87 vs., p < 0.001). No significant SNR difference between the source and novel subtracted group was observed (85.4 vs. 70.4, p = 0.57). Compared to source TR-MRA images, subtraction of TR-MRA images is a novel postprocessing technique that improves visualization of the pulmonary veins and left atrium in a substantial number of patients.


Assuntos
Átrios do Coração/diagnóstico por imagem , Cardiopatias Congênitas/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Angiografia por Ressonância Magnética/métodos , Imagem Cinética por Ressonância Magnética/métodos , Flebografia/métodos , Veias Pulmonares/diagnóstico por imagem , Adolescente , Adulto , Estudos de Casos e Controles , Feminino , Átrios do Coração/anormalidades , Humanos , Masculino , Valor Preditivo dos Testes , Estudos Prospectivos , Veias Pulmonares/anormalidades , Processos Estocásticos , Fatores de Tempo , Adulto Jovem
15.
J Clin Neurosci ; 64: 98-100, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30952556

RESUMO

Vasculitis of the central nervous system is a rare and poorly understood disease of the brain and spinal cord. Cerebral angiography is the radiological gold standard for diagnosis in patients with compatible clinical findings. However, advances in the quality of noninvasive neuroimaging techniques of cerebral and spinal vasculature such as magnetic resonance angiography (MRA) and computed tomography angiography (CTA) may obviate the need for invasive catheter angiography. We reviewed our institutional experience at Jackson Memorial Hospital between 2011 and 2016 to assess the utility of performing a cerebral digital subtraction angiogram (DSA) in the management of suspected vasculitis. In 16 (59%) of the 27 patients who underwent both noninvasive imaging and DSA, neither imaging studies showed any evidence of vasculitis. Despite these negative studies, 2 patients were treated empirically with immunosuppressants based on clinical symptoms and laboratory findings. 10 (37%) patients demonstrated irregularities on MRA and findings were confirmed by DSA in 6 of these patients. All 6 of these patients were treated, however, 2 of the 4 patients with abnormal MRA and normal DSA were also started on immunosuppressive therapy despite negative DSA. In conclusion, invasive catheter-based angiography may be of limited benefit in the diagnosis and management of PCNSV when considered in the context of clinical and laboratory findings and MRA or CTA results. Further large studies are necessary to determine whether non-invasive imaging can replace DSA.


Assuntos
Angiografia Digital/métodos , Angiografia Cerebral/métodos , Neuroimagem/métodos , Vasculite do Sistema Nervoso Central/diagnóstico por imagem , Adulto , Idoso , Angiografia por Tomografia Computadorizada/métodos , Feminino , Humanos , Angiografia por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade
16.
Eur J Radiol ; 114: 6-13, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31005178

RESUMO

BACKGROUND: This study was designed to investigate the agreement of 2D transthoracic echocardiography (2D TTE) with cardiovascular magnetic resonance imaging (CMR) in a contemporary population of ST-elevation myocardial infarction (STEMI) patients. METHODS: In this subanalysis of the GIPS-III trial, a randomized controlled trial investigating the administration of metformin in STEMI patients to prevent reperfusion injury, we studied 259 patients who underwent same-day CMR and 2D TTE assessments four months after hospitalization for a first STEMI. Bland-Altman analyses were performed to assess agreement between LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), LV ejection fraction (LVEF), and LV mass measurements. Sensitivity and specificity of 2D TTE to detect categories of LVEF (≤35%, 35-50%, ≥50%) was determined. Linear regression of absolute differences in measurements between imaging modalities was used to investigate whether patient characteristics impact measurement bias. RESULTS: Pairwise difference (bias) and 95% limits of agreement between CMR and 2D TTE measurements were +84 (37, 147) ml for LVEDV, +39 (6, 85) ml for LVESV, -1.1 ± 13.5% for LVEF, and -75 (-154, -14) g for LV mass. Sensitivity and specificity of 2D TTE to detect subjects with moderately depressed LVEF (35-50%) as measured by CMR were 52% and 88% respectively. We observed a significant effect of enzymatic infarct size on bias between 2D TTE and CMR in measuring LVESV and LVEF (P = 0.029, P = 0.001 respectively), of age and sex on bias between 2D TTE and CMR in measuring LV mass (P = 0.027, P < 0.001) and LVEDV (P = 0.001, P = 0.039), and of heart rate on bias between 2D TTE and CMR in LV volume measurements (P = 0.004, P = 0.016). CONCLUSIONS: Wide limits of agreement, underestimation of LV volumes and overestimation of LV mass was observed when comparing 2D TTE to CMR. Enzymatic infarct size, age, sex, and heart rate are potential sources of bias between imaging modalities.


Assuntos
Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico , Fármacos Cardiovasculares/administração & dosagem , Esquema de Medicação , Ecocardiografia/métodos , Feminino , Ventrículos do Coração/diagnóstico por imagem , Humanos , Angiografia por Ressonância Magnética/métodos , Masculino , Metformina/administração & dosagem , Pessoa de Meia-Idade , Imagem Multimodal/métodos , Traumatismo por Reperfusão Miocárdica/diagnóstico , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Reprodutibilidade dos Testes , Infarto do Miocárdio com Supradesnível do Segmento ST/tratamento farmacológico , Sensibilidade e Especificidade , Disfunção Ventricular Esquerda/diagnóstico
17.
Neuroradiol J ; 32(3): 173-178, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30973290

RESUMO

PURPOSE: To optimize the post-label delay in single-phase arterial spin labeling (SP-ASL) using multi-phase ASL in 4-dimensional magnetic resonance angiography (4D-MRA). METHODS: Ten healthy volunteers (six men, four women; age range, 24-37 years; mean, 29.1) were enrolled. 4D-MRA and SP-ASL were performed on a 3T magnetic resonance imaging (MRI) scanner. Signal intensities in four cerebral arterial territories (anterior cerebral artery, middle cerebral artery, posterior cerebral artery, and whole area) were measured using both 4D-MRA and SP-ASL, and peak time of maximum intensity through each technique was recorded. Regression analysis was used to determine the correlation between the peak times using 4D-MRA and those using SP-ASL, and the regression function obtained was used to estimate the peak time for SP-ASL (optimum post-label delay) from that obtained for 4D-MRA. RESULTS: The peak time in anterior cerebral artery territory for SP-ASL was expressed as 1.19 + 0.30 × (peak time of 4D-MRA) s, ( p = 0.017, r2 = 0.14). The peak time in middle cerebral artery territory for SP-ASL was 0.96 + 0.58 × (peak time of 4D-MRA) s, ( p < 0.001, r2 = 0.32). The peak time in posterior cerebral artery territory for SP-ASL was expressed as 0.92 + 0.58 × (peak time of 4D-MRA) s, ( p < 0.001, r2 = 0.33). The peak time in whole brain for SP-ASL was expressed as 1.04 + 0.46 × (peak time of 4D-MRA) s, ( p < 0.001, r2 = 0.25). CONCLUSION: The peak time values at 4D-MRA showed potential for use in predicting the optimum post-label delay of SP-ASL.


Assuntos
Artérias Cerebrais/diagnóstico por imagem , Angiografia por Ressonância Magnética/métodos , Marcadores de Spin , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Fatores de Tempo
18.
Am J Vet Res ; 80(5): 480-489, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31034269

RESUMO

OBJECTIVE: To assess visualization of the intracranial arteries and internal carotid artery (ICA) on 3-D time-of-flight (TOF) magnetic resonance angiography (MRA) images obtained at 1.5 T and to investigate factors that affect the image quality of those arteries in dogs. ANIMALS: 39 dogs with idiopathic epilepsy. PROCEDURES: Each dog underwent 3-D TOF MRA, and 5 pairs of intracranial arteries, the basilar artery, and both ICAs were evaluated. Each artery was assigned an image-quality score on a scale of 0 to 3, where 0 = poor and 3 = excellent. Multivariable regression analysis was used to assess whether age, body weight (BW), serum total cholesterol concentration, intracranial volume (ICV), and mean arterial pressure were significantly associated with the image quality of each vessel. RESULTS: In all dogs, the image-quality score was 2 or 3 for the proximal middle cerebral arteries, basilar artery, and caudal aspect of the caudal communicating arteries. In some dogs, the rostral cerebellar arteries, rostral aspect of the caudal communicating arteries, and middle and rostral aspects of the ICA were poorly visualized. For various arteries, image quality was negatively associated with age and positively associated with BW and ICV. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that 3-D TOF MRA images obtained at 1.5 T did not consistently and clearly delineate the ICA and narrow or peripheral intracranial arteries of dogs; therefore, careful attention is required when such images are assessed. Patient age, BW, and ICV can also affect the image quality of some intracranial arteries on 3-D TOF MRA images. (Am J Vet Res 2019;80:480-489).


Assuntos
Artérias Cerebrais/diagnóstico por imagem , Doenças do Cão/diagnóstico por imagem , Epilepsia/veterinária , Angiografia por Ressonância Magnética/veterinária , Animais , Encéfalo/irrigação sanguínea , Cães , Epilepsia/diagnóstico por imagem , Epilepsia/patologia , Feminino , Imagem Tridimensional/métodos , Imagem Tridimensional/veterinária , Angiografia por Ressonância Magnética/métodos , Masculino
19.
Int J Cardiovasc Imaging ; 35(8): 1453-1463, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30937683

RESUMO

To compare contrast-enhanced magnetic resonance angiography (ceMRA) and 3D steady-state free precession (SSFP) during systole and diastole for assessment of the right ventricle outflow tract (RVOT) in patients considered for percutaneous pulmonary valve implantation (PPVI) after tetralogy of Fallot (TOF) repair. We retrospectively evaluated 89 patients (male: 45, mean age 19 ± 8 years), who underwent cardiac-MRI after surgical TOF-repair. Datasets covering the whole heart in systole and diastole were acquired using ECG-gated 3D SSFP and non-gated ceMRA. Measurements were performed in SSFP-sequences and in ceMRA in the narrowest region of the RVOT to obtain the minimum, maximum and effective diameter. Invasive balloon sizing as the gold standard was available in 12 patients. The minimum diameter in diastolic SSFP, systolic SSFP and ceMRA were 21.4 mm (± 6.1 mm), 22.6 mm (± 6.2 mm) and 22.6 mm (± 6.0 mm), respectively. Maximum diameter was 29.9 mm (± 9.5 mm), 30.0 mm (± 7.0 mm) and 28.8 mm (± 8.1 mm) respectively. The effective diameter was 23.2 mm (± 5.7 mm), 27.4 mm (± 6.7 mm) and 24.4 mm (± 6.2 mm), differing significantly between diastole and systole (p < 0.0001). Measurements in ECG-gated SSFP showed a better inter- and intraobserver variability compared to measurements in non-ECG-gated ceMRA. Comparing invasive balloon sizing with our analysis, we found the highest correlation coefficients for the maximum and effective diameter measured in systolic SSFP (R = 0.99 respectively). ECG-gated 3D SSFP enables the identification and characterization of a potential landing zone for PPVI. The maximum and effective systolic diameter allow precise sizing for PPVI. Patients with TOF-repair could benefit from cardiac MRI before PPVI.


Assuntos
Cateterismo Cardíaco/métodos , Procedimentos Cirúrgicos Cardíacos , Implante de Prótese de Valva Cardíaca/métodos , Ventrículos do Coração/diagnóstico por imagem , Angiografia por Ressonância Magnética/métodos , Imagem por Ressonância Magnética/métodos , Insuficiência da Valva Pulmonar/diagnóstico por imagem , Estenose da Valva Pulmonar/diagnóstico por imagem , Valva Pulmonar/diagnóstico por imagem , Tetralogia de Fallot/cirurgia , Adolescente , Adulto , Valvuloplastia com Balão , Cateterismo Cardíaco/instrumentação , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Técnicas de Imagem de Sincronização Cardíaca , Criança , Meios de Contraste/administração & dosagem , Eletrocardiografia , Feminino , Próteses Valvulares Cardíacas , Implante de Prótese de Valva Cardíaca/instrumentação , Ventrículos do Coração/fisiopatologia , Humanos , Interpretação de Imagem Assistida por Computador , Imagem Tridimensional , Masculino , Variações Dependentes do Observador , Valor Preditivo dos Testes , Desenho de Prótese , Valva Pulmonar/fisiopatologia , Valva Pulmonar/cirurgia , Insuficiência da Valva Pulmonar/etiologia , Insuficiência da Valva Pulmonar/fisiopatologia , Insuficiência da Valva Pulmonar/cirurgia , Estenose da Valva Pulmonar/etiologia , Estenose da Valva Pulmonar/fisiopatologia , Estenose da Valva Pulmonar/cirurgia , Reprodutibilidade dos Testes , Estudos Retrospectivos , Tetralogia de Fallot/diagnóstico por imagem , Tetralogia de Fallot/fisiopatologia , Resultado do Tratamento , Função Ventricular Direita , Adulto Jovem
20.
Radiat Oncol ; 14(1): 65, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30992043

RESUMO

BACKGROUND: The differential diagnosis between radiation necrosis, tumor recurrence and tumor progression is crucial for the evaluation of treatment response and treatment planning. The appearance of treatment-induced tissue necrosis on conventional Magnetic Resonance Imaging (MRI) is similar to brain tumor recurrence and it could be difficult to differentiate the two entities on follow-up MRI examinations. Dynamic Susceptibility Contrast-enhanced (DSC) and Dynamic Contrast-Enhanced (DCE) are MRI perfusion techniques that use an exogenous, intravascular, non-diffusible gadolinium-based contrast agent. The aim of this study was to compare the diagnostic accuracy of DSC and DCE perfusion MRI in the differential diagnosis between radiation necrosis and tumor recurrence, in the follow-up of primary and metastatic intra-axial brain tumors after Stereotactic RadioSurgery (SRS) performed with CyberKnife. METHODS: A total of 72 enhancing lesions (57 brain metastases and 15 primary brain tumors) were analyzed with DCE and DSC, by means of MRI acquisition performed by 1,5 Tesla MR scanner. The statistical relationship between the diagnosis of tumor recurrence or radiation necrosis, decided according to clinicoradiologically criteria, rCBV and Ktrans was evaluated by the point-biserial correlation coefficient respectively. RESULTS: The statistical analysis showed a correlation between the diagnosis of radiation necrosis or recurrent tumor with Ktrans (rpb = 0.54, p < 0.001) and with rCBV (rpb = 0.37, p = 0.002). The ROC analysis of rCBV values demonstrated a good classification ability in differentiating radiation necrosis from tumour recurrence as well as the Ktrans. The optimal cut-off value for rCBV was k = 1.23 with 0.88 of sensitivity and 0.75 of specificity while for Ktrans was k = 28.76 with 0.89 of sensitivity and 0.97 of specificity. CONCLUSIONS: MRI perfusion techniques, particularly DCE, help in the differential diagnosis by tumor recurrence and radiation necrosis during the follow-up after radiosurgery.


Assuntos
Neoplasias Encefálicas/secundário , Meios de Contraste , Angiografia por Ressonância Magnética/métodos , Radiocirurgia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Encefálicas/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Curva ROC , Estudos Retrospectivos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA