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1.
PLoS One ; 15(7): e0237092, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32735633

RESUMO

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


Assuntos
Encéfalo/diagnóstico por imagem , Angiografia Cerebral/métodos , Meios de Contraste , Aprendizado Profundo/tendências , Angiografia por Tomografia Computadorizada/métodos , Meios de Contraste/efeitos adversos , Meios de Contraste/farmacologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Estudos Retrospectivos
2.
J Cardiothorac Surg ; 15(1): 107, 2020 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-32448306

RESUMO

BACKGROUND: For many years, percutaneous interventional occlusion of congenital patent ductus arteriosus (PDA) has been completed using radiation and contrast agents. In this study, transthoracic echocardiography without radiation and contrast agents was used to complete percutaneous occlusion of pediatric PDA. METHODS: Thirty-two children (8 males and 24 females) with normal heart function and no other intracardiac deformities were diagnosed with PDA (20 funnel type; 12 tube type), One patient had peripheral facial paralysis, 1 patient had epilepsy, and 1 case had multiple cervical deformities. All procedures were performed in the surgical operating room (without Digital Subtraction Angiography (DSA) equipment) under basic anesthesia through the femoral artery pathway. The procedures were guided by transthoracic echocardiography (TTE) by establishing an orbit with a catheter through the femoral artery to thepatent ductus arteriosus,pulmonary artery and right ventricle. A suitable ventricular septal defect occluder was placed using the femoral artery approach,and the treatment effect was evaluated by echocardiography after occlusion. The Outpatient follow-up was performed at 1, 3 months after the operation. RESULTS: All cases had successful closure of PDA, which took only 35.6 ± 6.4 min. The diameter of the device was 4.8 ± 2.3 mm, and the heart murmur disappeared. There was no shunt between the left pulmonary artery and the descending aortic artery, and the length of hospitalization was 3.4 ± 0.5 days. No other incisions were needed in 32 cases. No occluder was removed, and no residual shunt was found after operation; moreover, no ICU stay was needed, and the mean hospital stay was 3.4 ± 0.5 days. No residual shunt was found at the 1-, 3-month follow-up visit. CONCLUSIONS: PDA closure guided by transthoracic echocardiography via femoral artery puncture is a minimally invasive procedure that avoids injuries due to radiation and contrast agents. This method has wider application prospects in pediatrics.


Assuntos
Cateterismo Cardíaco/métodos , Procedimentos Cirúrgicos Cardíacos/métodos , Meios de Contraste/farmacologia , Permeabilidade do Canal Arterial/cirurgia , Ecocardiografia/métodos , Dispositivo para Oclusão Septal , Cirurgia Assistida por Computador/métodos , Criança , Pré-Escolar , Permeabilidade do Canal Arterial/diagnóstico , Feminino , Artéria Femoral , Humanos , Lactente , Masculino , Resultado do Tratamento
3.
PLoS One ; 15(4): e0231662, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32315336

RESUMO

Early detection of obesity-related glomerulopathy in humans is challenging as it might not be detected by routine biomarkers of kidney function. This study's aim was to use novel kidney biomarkers and contrast-enhanced ultrasound (CEUS) to evaluate the effect of obesity development and weight-loss on kidney function, perfusion, and injury in dogs. Sixteen healthy lean adult beagles were assigned randomly but age-matched to a control group (CG) (n = 8) fed to maintain a lean body weight (BW) for 83 weeks; or to a weight-change group (WCG) (n = 8) fed the same diet to induce obesity (week 0-47), to maintain stable obese weight (week 47-56) and to lose BW (week 56-83). At 8 time points, values of systolic blood pressure (sBP); serum creatinine (sCr); blood urea nitrogen (BUN); serum cystatin C (sCysC); urine protein-to-creatinine ratio (UPC); and urinary biomarkers of glomerular and tubular injury were measured. Glomerular filtration rate (GFR) and renal perfusion using CEUS were assayed (except for week 68). For CEUS, intensity- and time-related parameters representing blood volume and velocity were derived from imaging data, respectively. At 12-22% weight-gain, cortical time-to-peak, representing blood velocity, was shorter in the WCG vs. the CG. After 37% weight-gain, sCysC, UPC, glomerular and tubular biomarkers of injury, urinary immunoglobulin G and urinary neutrophil gelatinase-associated lipocalin, respectively, were higher in the WCG. sBP, sCr, BUN and GFR were not significantly different. After 23% weight-loss, all alterations were attenuated. Early weight-gain in dogs induced renal perfusion changes measured with CEUS, without hyperfiltration, preceding increased urinary protein excretion with potential glomerular and tubular injury. The combined use of routine biomarkers of kidney function, CEUS and site-specific urinary biomarkers might be valuable in assessing kidney health of individuals at risk for obesity-related glomerulopathy in a non-invasive manner.


Assuntos
Glomerulonefrite/metabolismo , Glomérulos Renais/metabolismo , Túbulos Renais/metabolismo , Obesidade/metabolismo , Ganho de Peso/genética , Animais , Biomarcadores/urina , Nitrogênio da Ureia Sanguínea , Meios de Contraste/farmacologia , Creatinina/sangue , Modelos Animais de Doenças , Cães , Taxa de Filtração Glomerular , Glomerulonefrite/etiologia , Glomerulonefrite/patologia , Glomerulonefrite/urina , Humanos , Glomérulos Renais/diagnóstico por imagem , Glomérulos Renais/lesões , Glomérulos Renais/patologia , Túbulos Renais/diagnóstico por imagem , Túbulos Renais/lesões , Túbulos Renais/patologia , Obesidade/complicações , Obesidade/diagnóstico por imagem , Obesidade/patologia , Ultrassonografia , Sistema Urinário/metabolismo , Sistema Urinário/patologia , Ganho de Peso/fisiologia , Perda de Peso/genética , Perda de Peso/fisiologia
5.
Clinics (Sao Paulo) ; 75: e1489, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32130354

RESUMO

OBJECTIVES: Histopathology is the 'gold standard' for diagnosing renal cell carcinoma but is limited by sample size. Contrast-enhanced ultrasound can differentiate malignant and benign lesions, but the Chinese guidelines on the management of renal cell carcinoma do not include this method. The purpose of this study was to compare the diagnostic parameters of contrast-enhanced ultrasound against those of contrast-enhanced computed tomography for detecting kidney lesions, with histopathology considered the reference standard. METHODS: Patients with suspected kidney lesions from prior grayscale ultrasonography and computed tomography were included in the analysis (n=191). The contrast-enhanced ultrasound, contrast-enhanced computed tomography, and histopathology data were collected and analyzed. A solid, enhanced mass was considered a malignant lesion, and an unenhanced mass or cyst was considered a benign lesion. The Bosniak criteria were used to characterize the lesions. RESULTS: Contrast-enhanced ultrasound and contrast-enhanced computed tomography both detected that 151 patients had malignant tumors and 40 patients had benign tumors. No significant differences in the tumors and their subtypes were reported between contrast-enhanced ultrasound and histopathology (p=0.804). Chromophobe renal cell carcinoma was detected through contrast-enhanced computed tomography (n=1), but no such finding was reported by contrast-enhanced ultrasound. A total of 35 cases of papillary renal cell carcinoma were reported through contrast-enhanced ultrasound while 32 were reported through histopathology. CONCLUSIONS: Contrast-enhanced ultrasound might be safe and as accurate as histopathology in diagnosing kidney lesions, especially renal cell carcinoma. Additionally, this study provides additional information over histopathology and has an excellent safety profile. LEVEL OF EVIDENCE: III.


Assuntos
Carcinoma de Células Renais/diagnóstico por imagem , Meios de Contraste/farmacologia , Cistos/diagnóstico por imagem , Neoplasias Renais/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Ultrassonografia/métodos , Carcinoma de Células Renais/metabolismo , Feminino , Humanos , Neoplasias Renais/metabolismo , Masculino , Sensibilidade e Especificidade
6.
PLoS One ; 15(2): e0227649, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32012163

RESUMO

OBJECTIVE: To determine the effect of a linear gadolinium-based contrast agent (GBCA) on the signal intensity (SI) of the deep cerebellar nuclei (DCN) in a retrospective clinical study on dogs after multiple magnetic resonance (MR) examinations with intravenous injections of gadodiamide and LA-ICP-MS analysis of a canine cerebellum after gadodiamide administration. ANIMALS: 15 client-owned dogs of different breeds and additionally 1 research beagle dog cadaver. PROCEDURES: In the retrospective study part, 15 dogs who underwent multiple consecutive MR imaging examinations with intravenous injection of linear GBCA gadodiamide were analyzed. SI ratio differences on unenhanced T1-weighted MR images before and after gadodiamide injections was calculated by subtracting SI ratios between DCN and pons of the first examination from the ratio of the last examination. Additionally, 1 research beagle dog cadaver was used for LA-ICP-MS (Laser ablation inductively coupled plasma mass spectrometry) analysis of gadolinium in the cerebellum as an add-on to another animal study. Descriptive and non-parametrical statistical analysis was performed and a p-value of < 0.05 was considered significant. RESULTS: No statistically significant differences of SI ratios, between DCN and pons, were detectable based on unenhanced T1-weighted MR images. LA-ICP-MS analyses showed between 1.5 to 2.5 µg gadolinium/g tissue in the cerebellum of the examined dog, 35 months after the last of 3 MRI examination with gadodiamide (two examinations at a dose of 1 x 0.1mmol/kg, last examination at a dose of 3 x 0.05mmol/kg). CONCLUSION AND CLINICAL RELEVANCE: Although the retrospective MRI study did not indicate any visible effect of SI increase after multiple gadodiamide exposures, further studies based on LA-ICP-MS showed that the optical threshold was not reached for a potential visible effect. Gadolinium was detectable at a level of 1.5 to 2.5 µg gadolinium/g tissue by using LA-ICP-MS in the cerebellum 35 months after last MRI examination. The general importance of gadolinium retention of subvisible contents requires further investigation.


Assuntos
Encéfalo/diagnóstico por imagem , Núcleos Cerebelares/diagnóstico por imagem , Meios de Contraste/farmacologia , Gadolínio/farmacologia , Administração Intravenosa , Animais , Encéfalo/efeitos dos fármacos , Cães , Humanos , Imagem por Ressonância Magnética
7.
Carbohydr Polym ; 231: 115652, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31888820

RESUMO

Hyaluronan (HA) have been widely used as the ideal biomaterials. It is important to understand their degradation and distribution for better optimization. From a new aspect of using radiotracers, we designed the HA-tyramine-bisphosphonate derivative for dual-labelling with two radionuclides (99mTc and 131I) simultaneously for in vitro and in vivo tracking. This dual-radiolabelled HA derivative can still be non-covalently crosslinked by hydroxyapatites to form injectable gel. The excellent properties of the gel, such as robust, biodegradable, and self-healing capacity were maintained. We firstly proved the possibility to distinguish different radionuclides in the degraded gel using the high-resolution gamma-ray spectrometry. The radiolabelled gel showed lower toxicity than pure hydroxyapatites against various cell lines, while the in vivo results proved that the 99mTc/131I-labelling of the gel was safe and stable enough for imaging and quantitatively tracking. The present method can also be applied for the development of dual-radiolabelled gels from other polysaccharides.


Assuntos
Meios de Contraste/farmacologia , Difosfonatos/química , Géis/química , Radioisótopos/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/farmacologia , Meios de Contraste/química , Difosfonatos/farmacologia , Raios gama , Géis/farmacologia , Humanos , Ácido Hialurônico/química , Radioisótopos do Iodo/química , Radioisótopos do Iodo/farmacologia , Radioisótopos/farmacologia , Análise Espectral , Tecnécio/química , Tecnécio/farmacologia , Engenharia Tecidual/métodos , Tiramina/química , Tiramina/farmacologia
8.
Eur Radiol ; 30(4): 2365-2376, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31900703

RESUMO

OBJECTIVES: We aimed to establish and validate an artificial intelligence-based radiomics strategy for predicting personalized responses of hepatocellular carcinoma (HCC) to first transarterial chemoembolization (TACE) session by quantitatively analyzing contrast-enhanced ultrasound (CEUS) cines. METHODS: One hundred and thirty HCC patients (89 for training, 41 for validation), who received ultrasound examination (CEUS and B-mode) within 1 week before the first TACE session, were retrospectively enrolled. Ultrasonographic data was used for building and validating deep learning radiomics-based CEUS model (R-DLCEUS), machine learning radiomics-based time-intensity curve of CEUS model (R-TIC), and machine learning radiomics-based B-Mode images model (R-BMode), respectively, to predict responses (objective-response and non-response) to TACE with reference to modified response evaluation criteria in solid tumor. The performance of models was compared by areas under the receiver operating characteristic curve (AUC) and the DeLong test was used to compare different AUCs. The prediction robustness was assessed for each model. RESULTS: AUCs of R-DLCEUS, R-TIC, and R-BMode were 0.93 (95% CI, 0.80-0.98), 0.80 (95% CI, 0.64-0.90), and 0.81 (95% CI, 0.67-0.95) in the validation cohort, respectively. AUC of R-DLCEUS shows significant difference compared with that of R-TIC (p = 0.034) and R-BMode (p = 0.039), whereas R-TIC was not significantly different from R-BMode. The performance was highly reproducible with different training and validation cohorts. CONCLUSIONS: DL-based radiomics method can effectively utilize CEUS cines to achieve accurate and personalized prediction. It is easy to operate and holds good potential for benefiting TACE candidates in clinical practice. KEY POINTS: • Deep learning (DL) radiomics-based CEUS model can accurately predict responses of HCC patients to their first TACE session by quantitatively analyzing their pre-operative CEUS cines. • The visualization of the 3D CNN analysis adopted in CEUS model provided direct insight into what computers "see" on CEUS cines, which can help people understand the interpretation of CEUS data. • The proposed prediction method is easy to operate and labor-saving for clinical practice, facilitating the clinical treatment decision of HCCs with very few time costs.


Assuntos
Inteligência Artificial , Carcinoma Hepatocelular/diagnóstico , Quimioembolização Terapêutica/métodos , Meios de Contraste/farmacologia , Neoplasias Hepáticas/diagnóstico , Ultrassonografia/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/terapia , Feminino , Humanos , Neoplasias Hepáticas/terapia , Masculino , Pessoa de Meia-Idade , Curva ROC , Estudos Retrospectivos , Adulto Jovem
9.
Nat Commun ; 11(1): 136, 2020 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-31919353

RESUMO

Targeted manipulations of neural activity are essential approaches in neuroscience and neurology, but monitoring such procedures in the living brain remains a significant challenge. Here we introduce a paramagnetic analog of the drug muscimol that enables targeted neural inactivation to be performed with feedback from magnetic resonance imaging. We validate pharmacological properties of the compound in vitro, and show that its distribution in vivo reliably predicts perturbations to brain activity.


Assuntos
Ondas Encefálicas/fisiologia , Encéfalo/fisiologia , Imagem por Ressonância Magnética/métodos , Muscimol/farmacologia , Animais , Meios de Contraste/farmacologia , Agonistas GABAérgicos/química , Masculino , Muscimol/análogos & derivados , Ratos Sprague-Dawley , Ácido gama-Aminobutírico/química
10.
Nanoscale ; 12(3): 1801-1810, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31898712

RESUMO

Black titanium dioxide (TiO2) nanoparticles have attracted great attention due to their application in photothermal therapy (PTT). However, single-mode phototherapy has the risk of recurrence, and the high-dose laser usually imposed to improve the PTT performance can bring a potential threat to security. Here, polydopamine (PDA)-coated black TiO2 (b-P25@PDA) nanoparticles with a core-shell structure were synthesized for enhanced PTT; then, synergistic phototherapy nanoprobes (b-P25@PDA-Ce6 (Mn)) were constructed by coupling chlorin e6 (Ce6) and chelating Mn2+ for simultaneous photodynamic therapy (PDT)/PTT and magnetic resonance (MR) imaging, in which a low-dose laser was used and imaging-guided phototherapy with high efficiency and high safety was achieved. The prepared nanoprobes showed high photothermal conversion efficiency (32.12%), high reactive oxygen generation and excellent MR imaging. In the 4T1 tumor-bearing nude mouse model, the tumors completely disappeared under the combination of PDT/PTT with a low-dose laser but were only partially inhibited by single PDT and single PTT. The current work developed a multifunctional black TiO2-based nanoprobe for enhanced synergistic PDT/PTT and MR imaging, which will be important for the safe and efficient visualized theranostics of cancers.


Assuntos
Meios de Contraste , Indóis , Imagem por Ressonância Magnética , Neoplasias Mamárias Animais , Manganês , Nanopartículas , Fototerapia , Polímeros , Porfirinas , Titânio , Animais , Linhagem Celular Tumoral , Meios de Contraste/química , Meios de Contraste/farmacologia , Feminino , Indóis/química , Indóis/farmacologia , Neoplasias Mamárias Animais/diagnóstico por imagem , Neoplasias Mamárias Animais/tratamento farmacológico , Manganês/química , Manganês/farmacologia , Camundongos , Nanopartículas/química , Nanopartículas/uso terapêutico , Polímeros/química , Polímeros/farmacologia , Porfirinas/química , Porfirinas/farmacologia , Titânio/química , Titânio/farmacologia
11.
Eur Radiol ; 30(1): 558-570, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31444598

RESUMO

PURPOSE: To enhance clinician's decision-making by diagnosing hepatocellular carcinoma (HCC) in cirrhotic patients with indeterminate liver nodules using quantitative imaging features extracted from triphasic CT scans. MATERIAL AND METHODS: We retrospectively analyzed 178 cirrhotic patients from 27 institutions, with biopsy-proven liver nodules classified as indeterminate using the European Association for the Study of the Liver (EASL) guidelines. Patients were randomly assigned to a discovery cohort (142 patients (pts.)) and a validation cohort (36 pts.). Each liver nodule was segmented on each phase of triphasic CT scans, and 13,920 quantitative imaging features (12 sets of 1160 features each reflecting the phenotype at one single phase or its change between two phases) were extracted. Using machine-learning techniques, the signature was trained and calibrated (discovery cohort), and validated (validation cohort) to classify liver nodules as HCC vs. non-HCC. Effects of segmentation and contrast enhancement quality were also evaluated. RESULTS: Patients were predominantly male (88%) and CHILD A (65%). Biopsy was positive for HCC in 77% of patients. LI-RADS scores were not different between HCC and non-HCC patients. The signature included a single radiomics feature quantifying changes between arterial and portal venous phases: DeltaV-A_DWT1_LL_Variance-2D and reached area under the receiver operating characteristic curve (AUC) of 0.70 (95%CI 0.61-0.80) and 0.66 (95%CI 0.64-0.84) in discovery and validation cohorts, respectively. The signature was influenced neither by segmentation nor by contrast enhancement. CONCLUSION: A signature using a single feature was validated in a multicenter retrospective cohort to diagnose HCC in cirrhotic patients with indeterminate liver nodules. Artificial intelligence could enhance clinicians' decision by identifying a subgroup of patients with high HCC risk. KEY POINTS: • In cirrhotic patients with visually indeterminate liver nodules, expert visual assessment using current guidelines cannot accurately differentiate HCC from differential diagnoses. Current clinical protocols do not entail biopsy due to procedural risks. Radiomics can be used to non-invasively diagnose HCC in cirrhotic patients with indeterminate liver nodules, which could be leveraged to optimize patient management. • Radiomics features contributing the most to a better characterization of visually indeterminate liver nodules include changes in nodule phenotype between arterial and portal venous phases: the "washout" pattern appraised visually using EASL and EASL guidelines. • A clinical decision algorithm using radiomics could be applied to reduce the rate of cirrhotic patients requiring liver biopsy (EASL guidelines) or wait-and-see strategy (AASLD guidelines) and therefore improve their management and outcome.


Assuntos
Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/diagnóstico por imagem , Cirrose Hepática/complicações , Cirrose Hepática/diagnóstico por imagem , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/diagnóstico por imagem , Aprendizado de Máquina , Tomografia Computadorizada por Raios X/métodos , Idoso , Inteligência Artificial , Carcinoma Hepatocelular/patologia , Meios de Contraste/farmacologia , Diagnóstico Diferencial , Feminino , Humanos , Fígado/diagnóstico por imagem , Fígado/patologia , Cirrose Hepática/patologia , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
12.
ACS Appl Mater Interfaces ; 12(1): 312-321, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31840976

RESUMO

Developing a spatiotemporal-controlled nitric oxide (NO) delivery nanoplatform is highly desirable for its biological applications as a tumor inhibitor and antibacterial agent. In this study, a novel multifunctional magnetic nanoplatform {Fe3O4@PDA@Ru-NO@FA} (1) was developed for the near-infrared (NIR) light-controlled release of NO in which a ruthenium nitrosyl (Ru-NO) donor and a folic acid (FA)-directing group were covalently functionalized onto Fe3O4@PDA. Nanoplatform 1 preferentially accumulated in folate receptor-overexpressing cancer cell lines and magnetic field-guided tumor tissue, instantly released NO, and simultaneously produced a prominent photothermal effect upon 808 nm NIR light irradiation, leading to remarkable in vitro and in vivo antitumor efficacy. When nanoplatform 1 was treated only once, the potential MRI contrast agent was sufficient to significantly inhibit or eliminate the tumor tissues in living mice, thus offering opportunities for future NO-involved multimodal cancer therapy. In addition, a NO delivery nanoplatform {Fe3O4@PDA@Ru-NO} was imbedded in the matrix of a chitosan (CS)-poly(vinyl alcohol) (PVA) material to develop a hybrid thermosensitive CS-PVA/NO hydrogel. The CS-PVA/NO hydrogels demonstrated mild (<150 mW cm-2) NIR light-controlled NO delivery and thus produced an efficient antibacterial effect for both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Therefore, these hydrogels have potential as antibacterial dressings for wound bacterial infection treatment.


Assuntos
Antibacterianos/química , Raios Infravermelhos , Óxido Nítrico/química , Rutênio/química , Antibacterianos/farmacologia , Meios de Contraste/química , Meios de Contraste/farmacologia , Sistemas de Liberação de Medicamentos/métodos , Escherichia coli/efeitos dos fármacos , Hidrogéis/química , Staphylococcus aureus/efeitos dos fármacos
13.
Magn Reson Imaging ; 65: 100-108, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31655139

RESUMO

OBJECTIVES: To assess the feasibility of ferumoxytol-enhanced MRI in pregnancy with a nonhuman primate model. MATERIALS AND METHODS: In this prospective study, eleven pregnant rhesus macaques at day 98 ±â€¯5 of gestation were divided into three groups, untreated control (UC) (n = 3), saline control (SC) (n = 4) and interleukin 1 beta (IL-1ß) treated (IT) (n = 4), which were administered with either saline or IL-1ß into the amniotic fluid. All animals were imaged at multiple time points before and after ferumoxytol administration (4 mg/kg). Longitudinal R2* and susceptibility of tissues were obtained using region-of-interest analysis and the longitudinal changes were assessed using linear mixed models and Student's t-test. RESULTS: In fetuses, a slope of 0.3 s-1/day (P = 0.008), 0.00 ppm/day (P = 0.699) and - 0.2 s-1/day (P = 0.023) was observed in liver R2*, liver susceptibility, and lung R2*, respectively. In placentas, R2* and susceptibility increased immediately after ferumoxytol administration (P < 0.001) and decreased to baseline within two days. The mean change from baseline showed no significant difference between the SC group and the IT group at all scan time points. In maternal livers, R2* increased immediately after ferumoxytol administration, further increased at one-day, and then decreased but remained elevated (P < 0.001). The mean change from baseline showed no significant difference between the SC group and the IT group at all scan time points. CONCLUSIONS: This work demonstrates the feasibility of quantitative ferumoxytol-enhanced MRI to measure dynamics of ferumoxytol delivery and washout in the placenta. Stable MRI measurements indicated no evidence of iron deposition in fetal tissues of nonhuman primates after maternal ferumoxytol exposure.


Assuntos
Meios de Contraste/farmacologia , Óxido Ferroso-Férrico/farmacologia , Imagem por Ressonância Magnética , Prenhez , Animais , Estudos de Viabilidade , Feminino , Inflamação , Interleucina-1beta/metabolismo , Ferro/análise , Macaca mulatta , Placenta/efeitos dos fármacos , Gravidez , Estudos Prospectivos
14.
Eur Radiol ; 30(3): 1790-1803, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31844962

RESUMO

OBJECTIVES: We compared the value of ferumoxytol (FMX)- and gadolinium (Gd)-enhanced MRI for assessment of sarcomas in paediatric/adolescent patients and hypothesised that tumour size and morphological features can be equally well assessed with both protocols. METHODS: We conducted a retrospective study of paediatric/adolescent patients with newly diagnosed bone or soft tissue sarcomas and both pre-treatment FMX- and Gd-MRI scans, which were maximal 4 weeks apart. Both protocols included T1- and T2-weighted sequences. One reader assessed tumour volumes, signal-to-noise ratios (SNR) of the primary tumour and adjacent tissues and contrast-to-noise ratios (CNR) of FMX- and Gd-MRI scans. Additionally, four readers scored FMX- and Gd-MRI scans according to 15 diagnostic parameters, using a Likert scale. The results were pooled across readers and compared between FMX- and Gd-MRI scans. Statistical methods included multivariate analyses with different models. RESULTS: Twenty-two patients met inclusion criteria (16 males, 6 females; mean age 15.3 ± 5.0). Tumour volume was not significantly different on T1-LAVA (p = 0.721), T1-SE (p = 0.290) and T2-FSE (p = 0.609) sequences. Compared to Gd-MRI, FMX-MRI demonstrated significantly lower tumour SNR on T1-LAVA (p < 0.001), equal tumour SNR on T1-SE (p = 0.104) and T2-FSE (p = 0.305), significantly higher tumour-to-marrow CNR (p < 0.001) on T2-FSE as well as significantly higher tumour-to-liver (p = 0.021) and tumour-to-vessel (p = 0.003) CNR on T1-LAVA images. Peritumoural and marrow oedema enhanced significantly more on Gd-MRI compared to FMX-MRI (p < 0.001/p = 0.002, respectively). Tumour thrombi and neurovascular bundle involvement were assessed with a significantly higher confidence on FMX-MRI (both p < 0.001). CONCLUSIONS: FMX-MRI provides equal assessment of the extent of bone and soft tissue sarcomas compared to Gd-MRI with improved tumour delineation and improved evaluation of neurovascular involvement and tumour thrombi. Therefore, FMX-MRI is a possible alternative to Gd-MRI for tumour staging in paediatric/adolescent sarcoma patients. KEY POINTS: • Ferumoxytol can be used as an alterative to gadolinium chelates for MRI staging ofpaediatric sarcomas. • Ferumoxytol-enhanced MRI provides equal assessment of tumour size and other diagnostic parameters compared to gadolinium chelate-enhanced MRI. • Ferumoxytol-enhanced MRI provides improved delineation of sarcomas from bone marrow, liver and vessels compared to gadolinium chelate-enhanced MRI.


Assuntos
Óxido Ferroso-Férrico/farmacologia , Gadolínio DTPA/farmacologia , Imagem por Ressonância Magnética/métodos , Sarcoma/diagnóstico , Adolescente , Adulto , Quelantes/farmacologia , Criança , Meios de Contraste/farmacologia , Feminino , Hematínicos/farmacologia , Humanos , Masculino , Estudos Retrospectivos , Adulto Jovem
15.
Eur Radiol ; 30(4): 2091-2102, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31858204

RESUMO

OBJECTIVE: This study aimed to assess material-specific iodine and fat images for diagnosis of clear cell renal cell carcinoma (cc-RCC) compared to papillary RCC (p-RCC) and other renal masses. MATERIALS AND METHODS: With IRB approval, we identified histologically confirmed solid renal masses that underwent rapid-kVp-switch DECT between 2016 and 2018: 25 cc-RCC (7 low grade versus 18 high grade), 11 p-RCC, and 6 other tumors (2 clear cell papillary RCC, 2 chromophobe RCC, 1 oncocytoma, 1 renal angiomyomatous tumor). A blinded radiologist measured iodine and fat concentration on material-specific iodine-water and fat-water basis pair images. Comparisons were performed between groups using univariate analysis and diagnostic accuracy calculated by ROC. RESULTS: Iodine concentration was higher in cc-RCC (6.14 ± 1.79 mg/mL) compared to p-RCC (1.40 ± 0.54 mg/mL, p < 0.001), but not compared to other tumors (5.0 ± 2.2 mg/mL, p = 0.370). Intratumoral fat was seen in 36.0% (9/25) cc-RCC (309.6 ± 234.3 mg/mL [71.1-762.3 ng/mL]), 9.1% (1/11) papillary RCC (97.11 mg/mL), and no other tumors (p = 0.036). Iodine concentration ≥ 3.99 mg/mL achieved AUC and sensitivity/specificity of 0.88 (CI 0.76-1.00) and 92.31%/82.40% to diagnose cc-RCC. To diagnose p-RCC, iodine concentration ≤ 2.5 mg/mL achieved AUC and sensitivity/specificity of 0.99 (0.98-1.00) and 100%/100%. The presence of intratumoral fat had AUC 0.64 (CI 0.53-0.75) and sensitivity/specificity of 34.6%/93.8% to diagnose cc-RCC. A logistic regression model combining iodine concentration and presence of fat increased AUC to 0.91 (CI 0.81-1.0) with sensitivity/specificity of 80.8%/93.8% to diagnose cc-RCC. CONCLUSION: Iodine concentration values are highly accurate to differentiate clear cell RCC from papillary RCC; however, they overlap with other tumors. Fat-specific images may improve differentiation of clear cell RCC from other avidly enhancing tumors. KEY POINTS: • Clear cell renal cell carcinoma (RCC) has significantly higher iodine concentration than papillary RCC, but there is an overlap in values comparing clear cell RCC to other renal tumors. • Iodine concentration ≤ 2.5 mg/mL is highly accurate to differentiate papillary RCC from clear cell RCC and other renal tumors. • The presence of microscopic fat on material-specific fat images was specific for clear cell RCC, helping to differentiate clear cell RCC from other avidly enhancing renal tumors.


Assuntos
Carcinoma de Células Renais/diagnóstico , Iodo/farmacologia , Neoplasias Renais/diagnóstico , Estadiamento de Neoplasias/métodos , Tomografia Computadorizada por Raios X/métodos , Tecido Adiposo , Idoso , Meios de Contraste/farmacologia , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Estudos Retrospectivos
16.
ACS Appl Mater Interfaces ; 11(50): 46437-46450, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31804795

RESUMO

Clinical translation of photoacoustic imaging (PAI) has been limited by the lack of near-infrared (NIR) contrast agents with low toxicity required for regulatory approval. Herein, J aggregates of indocyanine green (ICG) with strong NIR absorbance were encapsulated at high loadings within small 77 nm polymersomes (nanocapsules) composed of poly(lactide-co-glycolide-b-poly(ethylene glycol)) (PLGA-b-PEG) bilayers, thus enabling PAI of of breast and ovarian cancer cells with high specificity and a sensitivity at the level of ∼100 total cells. All of the major components of the polymersomes are FDA approved and used in the clinic. During formation of polymersomes with a water-in-oil-in-water double emulsion process, loss of ICG from the ICG J aggregates was minimized by coating them with a layer of branched polyethylenimine and by providing excess "sacrificial" ICG to adsorb at the oil-water interfaces. The encapsulated J aggregates were protected against dissociation by the polymersome shell for 24 h in 100% fetal bovine serum, after which the polymersomes biodegraded and the J aggregates dissociated to ICG monomers.


Assuntos
Meios de Contraste/farmacologia , Verde de Indocianina/farmacologia , Imagem Molecular , Técnicas Fotoacústicas , Animais , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Meios de Contraste/química , Emulsões/química , Emulsões/farmacologia , Feminino , Humanos , Verde de Indocianina/química , Camundongos , Camundongos Nus , Nanocápsulas/química , Óleos/química , Neoplasias Ovarianas/diagnóstico por imagem , Neoplasias Ovarianas/patologia , Polietilenoglicóis/química , Poliglactina 910/química , Água/química
17.
Medicine (Baltimore) ; 98(50): e18236, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31852088

RESUMO

BACKGROUND: This study aims to assess the impact of contrast-enhanced transcranial Doppler ultrasound (cTCD) diagnosis for young adult with cryptogenic stroke (CS). METHODS: This study will analyze data from case-controlled studies investigating the impact of cTCD diagnosis for young adult with CS. A comprehensive literature search will be performed from PUBMED, EMBASE, Cochrane Library, Web of Science, Cumulative Index to Nursing and Allied Health Literature, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, and Wanfang Data from their inceptions up to the August 1, 2019. All databases will be searched with no language limitations. Two researchers will independently carry out study selection, data collection, and study quality assessment. Any discrepancies between two researchers will be solved by a third researcher. We will apply RevMan 5.3 software and Stata 12.0 software for statistical analysis. RESULTS: Outcomes consist of sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio for determination of cTCD diagnosis for young adult with CS. CONCLUSION: The results of this study may summarize up-to-date evidence of cTCD diagnosis for young adult with CS. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42019145641.


Assuntos
Meios de Contraste/farmacologia , Acidente Vascular Cerebral/diagnóstico , Ultrassonografia Doppler Transcraniana/métodos , Humanos , Curva ROC , Reprodutibilidade dos Testes , Adulto Jovem
18.
ACS Appl Mater Interfaces ; 11(50): 46637-46644, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31747242

RESUMO

Metallofullerenes have attracted considerable attention as potential novel noninvasive high-relaxivity magnetic resonance contrast agents. However, the applications of metallofullerenes as stimuli-responsive biosensors to monitor biological processes are still scarce. Herein, manganese-fullerenes core-shell nanocomposites are prepared via a facile one-pot approach to achieve GSH-activatable magnetic resonance/fluorescence bimodal imaging functions. The nanocomposites initially have a FRET-induced quenched fluorescence, and water-resisting stimulated low T1-MRI contrast. Upon exposure to GSH, collapse of the outer MnO2 shell led to reconstruction of the nanoprobes and subsequently resulted in multicolor fluorescence recovery and longitudinal (T1) relaxivity enhancement (r1 value up to 29.8 mM-1 s-1 at 0.5 T based on Mn ion). Our work demonstrates feasibility of using fullerenes to fabricate activatable probes for molecular imaging of GSH, which may promote the development of new fullerene-based stimuli-responsive multimodal probes for the detection and regulation of particular biological processes in vivo.


Assuntos
Técnicas Biossensoriais , Fulerenos/química , Glutationa/isolamento & purificação , Imagem Molecular/métodos , Animais , Meios de Contraste/química , Meios de Contraste/farmacologia , Fluorescência , Glutationa/química , Humanos , Íons/química , Imagem por Ressonância Magnética , Manganês/química , Compostos de Manganês/química , Metais/química , Camundongos , Microscopia Eletrônica de Transmissão/métodos , Nanocompostos/química
19.
BMC Gastroenterol ; 19(1): 187, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31727083

RESUMO

BACKGROUND: Hepatic epithelioid hemangioendothelioma (HEH) is rare; it is reported in < 1 person in 1,000,000 individuals. For accurate diagnosis, information regarding multiple graphic modalities in HEH is required. However, there is very little information concerning Sonazoid® contrast enhanced ultrasonography (CEUS) in HEH. CASE PRESENTATION: The present report describes the histologically proven three HEH cases evaluated using Sonazoid® CEUS. Case 1 was a 33-year-old female patient with no relevant past medical history, who experienced right upper quadrant pain. Conventional abdominal US revealed multiple low echoic liver nodules with vague borderlines. In CEUS, the vascularity of the nodules was similar to that seen in the neighboring normal liver. Later in the portal venous and late phases (PVLP) and post vascular phase, washout of Sonazoid® was detected in the nodules. Case 2 was a 93-year-old female patient with a previous medical history including operations for breast cancer and ovary cancer in her 50's. Conventional abdominal US revealed multiple low echoic nodules, some of which contained cystic lesions. In the early vascular phase of CEUS, nodules excluding the central anechoic regions were enhanced from peripheral sites. Although the enhancement inside the nodules persisted in both the PVLP and post vascular phase, anechoic areas in the center of some nodules were not enhanced at all. Case 3 was a 39-year-old male patient presented with right upper-quadrant pain, without any relevant past medical history. Conventional abdominal US revealed multiple low echoic liver nodules. In the early vascular phase of CEUS, nodules were gradually enhanced from the peripheral sites as ringed enhancement. Sonazoid®was washed out from the nodules in the PVLP and post vascular phase. CONCLUSIONS: The most important feature was peripheral enhancement in the early vascular phase. In case 2, the enhancement of the parenchyma of liver nodules persisted even in the PVLP; indicating the lower degree of malignant potential than others. Actually, the tumors did not extend without any treatment in case 2. Since case 2 is the first case report of HEH with cystic lesions, in patients with liver nodules including cystic lesions, HEH is a potential diagnosis.


Assuntos
Compostos Férricos/farmacologia , Hemangioendotelioma Epitelioide , Ferro/farmacologia , Neoplasias Hepáticas , Óxidos/farmacologia , Ultrassonografia/métodos , Adulto , Idoso de 80 Anos ou mais , Meios de Contraste/farmacologia , Diagnóstico Diferencial , Feminino , Hemangioendotelioma Epitelioide/diagnóstico , Hemangioendotelioma Epitelioide/patologia , Humanos , Aumento da Imagem/métodos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/patologia , Masculino , Imagem de Perfusão
20.
BMC Med Imaging ; 19(1): 83, 2019 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-31653206

RESUMO

BACKGROUND: Magnetic resonance arthrography (MRA) requires intra-articular injection of gadolinium-based diluted paramagnetic contrast material. To our knowledge, gadobenate dimeglumine (Gd-BOPTA) has never been used for intra-articular applications. Our aim was to test in vitro different concentrations of Gd-BOPTA to be potentially used to perform MRA. METHODS: Gd-BOPTA was diluted in saline (NaCl 0.9%) to achieve different concentrations (4 mmol/l; 2 mmol/l; 1 mmol/l; 0.67 mmol/l; 0.5 mmol/l). Six sets of five sterile pipes were prepared with 5 ml of each solution, five sets added with 0.5 ml of fresh synovial fluid. Two separate pipes were prepared with 5 ml of gadopentetate dimeglumine (Gd-DTPA) at 2 mmol/l, one pipe added with 0.5 ml of synovial fluid. Pipes were imaged using a T1-weighted sequence at 1.5 T. For each pipe, signal intensity (SI) in arbitrary units (au) was measured. RESULTS: SI reproducibility range was 86-99%. Mean Gd-BOPTA SI in pipes containing synovial fluid increased from 1236 ± 8au (0.5 mmol/l) up to 1610 ± 44au (1 mmol/l) and down to 1405 ± 33au (4 mmol/l). Mean Gd-BOPTA SI in pipes without synovial fluid increased from 1184 ± 29au (0.5 mmol/l) up to 1530 ± 38au (1 mmol/l), and down to 1347 ± 39au (4 mmol/l). SI of pipes without synovial fluid was lower than that of pipes with synovial fluid for both Gd-BOPTA and Gd-DTPA (P ≤ 0.002). Regarding pipes with synovial fluid, mean Gd-DTPA SI at 2 mmol/l was 1246 ± 27au. Compared with Gd-BOPTA, SI was not different at 0.5 mmol/l (- 0.2%, P = 0.587) while it was higher (P < 0.001) at all other concentrations (range + 13.3%[4 mmol/l] - + 28.3%[1 mmol/l]). Regarding pipes without synovial fluid, mean Gd-DTPA SI at 2 mmol/l was 1275 ± 56au. Compared with Gd-BOPTA, SI was lower at 0.5 mmol/l (- 6.8%,P < 0.001), while it was higher (P < 0.001) at all other concentrations (range + 6.1%[4 mmol/l] - + 19.6% [1 mmol/l]). CONCLUSIONS: In vitro, Gd-BOPTA at 1 mmol/ had a + 28% SI increase in comparison to Gd-DTPA 2 mmol/l. SI similar to Gd-DTPA can be obtained using one fourth concentration of Gd-BOPTA.


Assuntos
Artrografia/métodos , Meios de Contraste/administração & dosagem , Meglumina/análogos & derivados , Compostos Organometálicos/administração & dosagem , Líquido Sinovial/diagnóstico por imagem , Idoso , Meios de Contraste/farmacologia , Feminino , Humanos , Técnicas In Vitro , Injeções Intra-Articulares , Imagem por Ressonância Magnética/métodos , Masculino , Meglumina/administração & dosagem , Meglumina/farmacologia , Pessoa de Meia-Idade , Compostos Organometálicos/farmacologia , Reprodutibilidade dos Testes
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