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1.
Lab Invest ; 2020 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-32203152

RESUMO

An ability to characterize the cellular composition and spatial organization of the tumor microenvironment (TME) using multiplexed IHC has been limited by the techniques available. Here we show the applicability of multiplexed ion beam imaging (MIBI) for cell phenotype identification and analysis of spatial relationships across numerous tumor types. Formalin-fixed paraffin-embedded (FFPE) samples from tumor biopsies were simultaneously stained with a panel of 15 antibodies, each labeled with a specific metal isotope. Multi-step processing produced images of the TME that were further segmented into single cells. Frequencies of different cell subsets and the distributions of nearest neighbor distances between them were calculated using this data. A total of 50 tumor specimens from 15 tumor types were characterized for their immune profile and spatial organization. Most samples showed infiltrating cytotoxic T cells and macrophages present amongst tumor cells. Spatial analysis of the TME in two ovarian serous carcinoma images highlighted differences in the degree of mixing between tumor and immune cells across samples. Identification of admixed PD-L1+ macrophages and PD-1+ T cells in an urothelial carcinoma sample allowed for the detailed observations of immune cell subset spatial arrangement. These results illustrate the high-parameter capability of MIBI at a sensitivity and resolution uniquely suited to understanding the complex tumor immune landscape including the spatial relationships of immune and tumor cells and expression of immunoregulatory proteins.

2.
Magn Reson Med ; 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32077521

RESUMO

PURPOSE: Motion artifact limits the clinical translation of high-field MR. We present an optical prospective motion correction system for 7 Tesla MRI using a custom-built, within-coil camera to track an optical marker mounted on a subject. METHODS: The camera was constructed to fit between the transmit-receive coils with direct line of sight to a forehead-mounted marker, improving upon prior mouthpiece work at 7 Tesla MRI. We validated the system by acquiring a 3D-IR-FSPGR on a phantom with deliberate motion applied. The same 3D-IR-FSPGR and a 2D gradient echo were then acquired on 7 volunteers, with/without deliberate motion and with/without motion correction. Three neuroradiologists blindly assessed image quality. In 1 subject, an ultrahigh-resolution 2D gradient echo with 4 averages was acquired with motion correction. Four single-average acquisitions were then acquired serially, with the subject allowed to move between acquisitions. A fifth single-average 2D gradient echo was acquired following subject removal and reentry. RESULTS: In both the phantom and human subjects, deliberate and involuntary motion were well corrected. Despite marked levels of motion, high-quality images were produced without spurious artifacts. The quantitative ratings confirmed significant improvements in image quality in the absence and presence of deliberate motion across both acquisitions (P < .001). The system enabled ultrahigh-resolution visualization of the hippocampus during a long scan and robust alignment of serially acquired scans with interspersed movement. CONCLUSION: We demonstrate the use of a within-coil camera to perform optical prospective motion correction and ultrahigh-resolution imaging at 7 Tesla MRI. The setup does not require a mouthpiece, which could improve accessibility of motion correction during 7 Tesla MRI exams.

4.
IEEE Trans Radiat Plasma Med Sci ; 3(4): 498-503, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31396580

RESUMO

A significant challenge during high-resolution PET brain imaging on PET/MR scanners is patient head motion. This challenge is particularly significant for clinical patient populations who struggle to remain motionless in the scanner for long periods of time. Head motion also affects the MR scan data. An optical motion tracking technique, which has already been demonstrated to perform MR motion correction during acquisition, is used with a list-mode PET reconstruction algorithm to correct the motion for each recorded event and produce a corrected reconstruction. The technique is demonstrated on real Alzheimer's disease patient data for the GE SIGNA PET/MR scanner.

5.
J Neurosurg Spine ; : 1-9, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31277060

RESUMO

OBJECTIVE: Spine MRI is a diagnostic modality for evaluating pediatric CNS tumors. Applying diffusion-weighted MRI (DWI) or diffusion tensor imaging (DTI) to the spine poses challenges due to intrinsic spinal anatomy that exacerbates various image-related artifacts, such as signal dropouts or pileups, geometrical distortions, and incomplete fat suppression. The zonal oblique multislice (ZOOM)-echo-planar imaging (EPI) technique reduces geometric distortion and image blurring by reducing the field of view (FOV) without signal aliasing into the FOV. The authors hypothesized that the ZOOM-EPI method for spine DTI in concert with conventional spinal MRI is an efficient method for augmenting the evaluation of pediatric spinal tumors. METHODS: Thirty-eight consecutive patients (mean age 8 years) who underwent ZOOM-EPI spine DTI for CNS tumor workup were retrospectively identified. Patients underwent conventional spine MRI and ZOOM-EPI DTI spine MRI. Two blinded radiologists independently reviewed two sets of randomized images: conventional spine MRI without ZOOM-EPI DTI, and conventional spine MRI with ZOOM-EPI DTI. For both image sets, the reviewers scored the findings based on lesion conspicuity and diagnostic confidence using a 5-point Likert scale. The reviewers also recorded presence of tumors. Quantitative apparent diffusion coefficient (ADC) measurements of various spinal tumors were extracted. Tractography was performed in a subset of patients undergoing presurgical evaluation. RESULTS: Sixteen patients demonstrated spinal tumor lesions. The readers were in moderate agreement (kappa = 0.61, 95% CI 0.30-0.91). The mean scores for conventional MRI and combined conventional MRI and DTI were as follows, respectively: 3.0 and 4.0 for lesion conspicuity (p = 0.0039), and 2.8 and 3.9 for diagnostic confidence (p < 0.001). ZOOM-EPI DTI identified new lesions in 3 patients. In 3 patients, tractography used for neurosurgical planning showed characteristic fiber tract projections. The mean weighted ADCs of low- and high-grade tumors were 1201 × 10-6 and 865 × 10-6 mm2/sec (p = 0.002), respectively; the mean minimum weighted ADCs were 823 × 10-6 and 474 × 10-6 mm2/sec (p = 0.0003), respectively. CONCLUSIONS: Diffusion MRI with ZOOM-EPI can improve the detection of spinal lesions while providing quantitative diffusion information that helps distinguish low- from high-grade tumors. By adding a 2-minute DTI scan, quantitative diffusion information and tract profiles can reliably be obtained and serve as a useful adjunct to presurgical planning for pediatric spinal tumors.

6.
Eur J Vasc Endovasc Surg ; 58(1S): S1-S109.e33, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31182334

RESUMO

GUIDELINE SUMMARY: Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

7.
J Vasc Surg ; 69(6S): 3S-125S.e40, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31159978

RESUMO

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.


Assuntos
Cardiologia/normas , Medicina Baseada em Evidências/normas , Isquemia/terapia , Doença Arterial Periférica/terapia , Técnicas de Imagem Cardíaca/normas , Doença Crônica , Consenso , Testes de Função Cardíaca/normas , Humanos , Isquemia/diagnóstico , Isquemia/mortalidade , Isquemia/fisiopatologia , Doença Arterial Periférica/diagnóstico , Doença Arterial Periférica/mortalidade , Doença Arterial Periférica/fisiopatologia , Valor Preditivo dos Testes , Fatores de Risco , Terminologia como Assunto , Resultado do Tratamento
9.
Rheumatol Int ; 39(6): 1061-1067, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30888471

RESUMO

Arterial aneurysms are rare manifestations of Behçet Disease (BD) with high morbidity and mortality. This study aimed to investigate the clinical course of BD patients with abdominal aortic aneurysms (AAA). We retrospectively searched charts of BD patients, followed up between 1988 and 2011, to identify those with AAA with at least 6-month clinical and radiological follow-up data. Chart review revealed 12 patients (11 males) with AAA amongst 1224 patients; follow-up data from 11 patients were available. The most common symptoms were lower back and abdominal pain. The only pre-treatment complication was a spontaneous rupture. All but one patient received corticosteroid and cyclophosphamide pulses for the induction, and corticosteroid and azathioprine for the maintenance treatment; one patient received only the maintenance treatment. Two patients had surgical graft interposition, without postoperative complications. Seven patients had endovascular stenting; five of them (71.4%) showed radiological regression after 32.5 (13.4-53.8) months, while four (57%) had clinical improvement after 11.8 (0.2-29.4) months. However, one non-responsive patient developed stent infection and exsanguinated during percutaneous drainage, and one patient developed femoral artery pseudo-aneurysm at the catheter insertion site. Another patient developed a new aneurysm under the maintenance treatment. Medical treatment alone yielded radiological regression in one of two patients. Current immunosuppressive, surgical or endovascular approaches can provide clinical and radiological improvements lately in BD patients with AAA. Furthermore, complication rates seem to be high with interventional approaches. These findings suggest an unmet need for safer alternative treatments.


Assuntos
Corticosteroides/uso terapêutico , Aneurisma da Aorta Abdominal/terapia , Azatioprina/uso terapêutico , Síndrome de Behçet/terapia , Ciclofosfamida/uso terapêutico , Procedimentos Endovasculares , Imunossupressores/uso terapêutico , Stents , Enxerto Vascular , Dor Abdominal , Adulto , Falso Aneurisma/epidemiologia , Aneurisma da Aorta Abdominal/etiologia , Ruptura Aórtica , Síndrome de Behçet/complicações , Feminino , Artéria Femoral , Humanos , Quimioterapia de Indução , Dor Lombar , Quimioterapia de Manutenção , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Infecções Relacionadas à Prótese/epidemiologia , Estudos Retrospectivos , Adulto Jovem
10.
Acta Orthop Traumatol Turc ; 52(6): 409-414, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30274704

RESUMO

OBJECTIVES: This paper aims to evaluate the extremity function and vascular outcome after limb-sparing surgery for extremity musculoskeletal tumors invading vascular structure required reconstruction. METHODS: Of the 507 patients with musculoskeletal tumors, who underwent surgery between 2004 and 2007, 17 (3,3%) patients with major vessel involvement were included in the study. The mean age was 37.8 ± 14.5, with a female/male ratio of 8/9. Thirteen (76.4%) patients had Stage IIb disease, and 2 (11,7%) patients had Stage III disease. In 2 (11,7%) patients have locally aggressive tumor that had Stage 3. Fifteen (88.2%) of the cases involved lower extremity, whilst 2 (11.8%) of them involved upper extremity. An arterial reconstruction was carried out in all patients. Wide tumor resection and endoprosthetic reconstruction were performed in 6 (35.2%) patients. Other 11 (65.8%) patients were treated with wide resection and soft tissue reconstruction. Postoperative data included; perioperative morbidities such as bleeding, infection, graft thrombosis, rupture, metastatic local recurrence and mortality. Ankle brachial index (ABI) and color-flow-duplex-scan (CFDS) were done at the final follow-up of the study, in order to prove the efficacy of reconstruction. Functional outcome was evaluated with International Society of Limb Salvage (ISOLS) criteria. RESULTS: The mean follow-up was of 39 months (range 3-120). Perioperative complications were arterial graft thrombosis occurred in 3 (17.6%) patients treated acutely with thrombectomy, uncontrolled deep wound infection occurred in 2 patients whom extremities were amputated. The most frequent complication after surgery was limb edema according to possibly venous and lymphatic obstruction, staged as C1, C2 and C3 disease was established in 6 patients (two patients in each group), and 1 patient was classified as C6 disease. Three (17.6%) patients had local recurrence (1/3 patient died and 2/3 (11.7%) patients underwent transfemoral amputation). At the last follow-up, 9 (52.9%) patients were alive without evidence of disease, 8 (47.1%) patients were died due to primary disease. There were 8 (47.1%) patients alive with an intact limb. Although functional outcome scores were satisfactory, emotional acceptance scores were low. The limb salvage probability was 74.0%. CONCLUSION: Limb-sparing oncological surgery in musculoskeletal tumors with vascular invasion provides a satisfactory limb function, which may lead to an improved life quality. Arterial reconstruction has a high rate of patency in the long term. The surgeon should be aware of early perioperative complication related to vascular reconstruction and infection that effect on the rate of extremity survival. LEVEL OF EVIDENCE: Level IV, Therapeutic study.


Assuntos
Extremidades , Salvamento de Membro , Recidiva Local de Neoplasia/epidemiologia , Neoplasias de Tecido Conjuntivo e de Tecidos Moles , Complicações Pós-Operatórias , Adulto , Amputação/métodos , Amputação/estatística & dados numéricos , Extremidades/irrigação sanguínea , Extremidades/patologia , Extremidades/fisiopatologia , Extremidades/cirurgia , Feminino , Humanos , Salvamento de Membro/efeitos adversos , Salvamento de Membro/métodos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Neoplasias de Tecido Conjuntivo e de Tecidos Moles/mortalidade , Neoplasias de Tecido Conjuntivo e de Tecidos Moles/patologia , Neoplasias de Tecido Conjuntivo e de Tecidos Moles/cirurgia , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/cirurgia , Procedimentos Cirúrgicos Reconstrutivos/métodos , Recuperação de Função Fisiológica , Estudos Retrospectivos , Resultado do Tratamento , Turquia/epidemiologia , Procedimentos Cirúrgicos Vasculares/métodos
11.
Perfusion ; 33(2): 110-114, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28825352

RESUMO

AIM: Transradial access (TRA) for coronary intervention is increasingly used in current clinical practice. The aim of the present study was to evaluate the hypothesis that cutaneous analgesia before TRA for coronary intervention at a puncture site 30 minutes before puncture can reduce patient discomfort and the incidence of radial artery spasm (RAS). METHODS: Patients (n=104) undergoing planned coronary interventions using TRA were prospectively randomized to receive either 1 mL of 1% lidocaine subcutaneously (n=52) (control group) or subcutaneous lidocaine plus 5% lidocaine cream (n=52) cutaneously 30 minutes before puncture (treatment group). The primary endpoint was angiographically or clinically confirmed RAS. Secondary endpoints were the occurrence of patient discomfort in the forearm during the procedure and access-site crossover to the femoral artery. Patient discomfort was quantified with a visual analogue scale (VAS) score. RESULTS: Fifty-two patients in the treatment group (60.5±9.4 years of age and 16 female) and 52 patients in the control group (60.4±9.7 years of age and 16 female) were included in the final analysis. Radial artery spasm occurrence decreased in the treatment group compared to the control group (26.9% vs 9.6%; p=0.04) accompanied by a VAS score of 3.7±1.8 in the treatment group and 4.9±2.0 in the control group; p=0.02. The access site crossover rate did not differ between the groups (7.6% vs 21.1%; p=0.09). CONCLUSION: Cutaneous analgesia before TRA for coronary interventions is associated with a substantial reduction in the RAS and the procedure-related level of patient discomfort.


Assuntos
Analgesia/métodos , Angiografia Coronária/métodos , Intervenção Coronária Percutânea/métodos , Artéria Radial/efeitos dos fármacos , Espasmo/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
12.
Magn Reson Med ; 79(4): 1911-1921, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28722314

RESUMO

PURPOSE: Optical prospective motion correction substantially reduces sensitivity to motion in neuroimaging of human subjects. However, a major barrier to clinical deployment has been the time-consuming cross-calibration between the camera and MRI scanner reference frames. This work addresses this challenge. METHODS: A single camera was mounted onto the head coil for tracking head motion. Two new methods were developed: (1) a rapid calibration method for camera-to-scanner cross-calibration using a custom-made tool incorporating wireless active markers, and (2) a calibration adjustment method to compensate for table motion between scans. Both methods were tested at 1.5T and 3T in vivo. Simulations were performed to determine the required mechanical tolerance for repositioning of the camera. RESULTS: The rapid calibration method is completed in a short (<30 s) scan, which is carried out only once per installation. The calibration adjustment method requires no extra scan time and runs automatically whenever the system is used. The mechanical tolerance analysis indicates that most motion (90% reduction in voxel displacement) could be corrected even with far larger camera repositioning errors than are observed in practice. CONCLUSION: The methods presented here allow calibration of sufficient quality to be carried out and maintained with no additional technologist workload. Magn Reson Med 79:1911-1921, 2018. © 2017 International Society for Magnetic Resonance in Medicine.


Assuntos
Adenoma/diagnóstico por imagem , Circulação Cerebrovascular , Imagem por Ressonância Magnética/métodos , Neuroimagem/métodos , Dispositivos Ópticos , Neoplasias Hipofisárias/diagnóstico por imagem , Algoritmos , Encéfalo/diagnóstico por imagem , Calibragem , Simulação por Computador , Desenho de Equipamento , Feminino , Cabeça/diagnóstico por imagem , Humanos , Imagem Tridimensional , Masculino , Movimento (Física) , Posicionamento do Paciente , Reprodutibilidade dos Testes , Software , Estresse Mecânico
13.
J Matern Fetal Neonatal Med ; 31(11): 1490-1493, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28420274

RESUMO

AIM: The aim of this study was to compare serum folate, vitamin B12, 25-OH vitamin D, and calcium levels between pregnants with and without fetal anomaly of neural tube origin. METHODS: One hundred seventy-eight pregnants were recruited for this study. Pregnants with and without sonographically detected fetal anomaly of neural tube origin were compared in terms of serum folate, vitamin B12, 25-OH vitamin D, and calcium levels. RESULTS: There were significant differences between groups with regard to age, serum 25 OH vitamin D, 1,25 OH vitamin D, folate, calcium, and B 12 levels. Multivariate regression analyses revealed significant associations between the serum 25 OH vitamin D level, age, and the neural tube defect (NTD). CONCLUSIONS: Vitamin D and the age of pregnants were significantly associated with the NTDs.


Assuntos
Cálcio/sangue , Doenças Fetais/sangue , Ácido Fólico/sangue , Defeitos do Tubo Neural/sangue , Vitamina D/análogos & derivados , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Gravidez , Vitamina D/sangue
15.
Neuroimage ; 153: 97-108, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28359788

RESUMO

INTRODUCTION: Geometric distortions along the phase encode direction caused by off-resonant spins are still a major issue in EPI based functional and diffusion imaging. If the off-resonance map is known it is possible to correct for distortions. Most correction methods operate as a post-processing step on the reconstructed magnitude images. THEORY AND METHODS: Here, we present an algebraic reconstruction method (hybrid-space SENSE) that incorporates a physics based model of off-resonances, phase inconsistencies between k-space segments, and T2*-decay during the acquisition. The method can be used to perform a joint reconstruction of interleaved acquisitions with normal (blip-up) and inverted (blip-down) phase encode direction which results in reduced g-factor penalty. RESULTS: A joint blip-up/down simultaneous multi slice (SMS) reconstruction for SMS-factor 4 in combination with twofold in-plane acceleration leads to a factor of two decrease in maximum g-factor penalty while providing off-resonance and eddy-current corrected images. CONCLUSION: We provide an algebraic framework for reconstructing diffusion weighted EPI data that in addition to the general applicability of hybrid-space SENSE to 2D-EPI, SMS-EPI and 3D-EPI with arbitrary k-space coverage along z, allows for a modeling of arbitrary spatio-temporal effects during the acquisition period like off-resonances, phase inconsistencies and T2*-decay. The most immediate benefit is a reduction in g-factor penalty if an interleaved blip-up/down acquisition strategy is chosen which facilitates eddy current estimation and ensures no loss in k-space encoding in regions with strong off-resonance gradients.


Assuntos
Mapeamento Encefálico/métodos , Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Imagem Ecoplanar , Artefatos , Imagem de Difusão por Ressonância Magnética/métodos , Humanos , Processamento de Imagem Assistida por Computador , Modelos Neurológicos , Processamento de Sinais Assistido por Computador
16.
Magn Reson Imaging ; 39: 44-52, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28137627

RESUMO

Head motion is an unsolved problem in magnetic resonance imaging (MRI) studies of the brain. Real-time tracking using a camera has recently been proposed as a way to prevent head motion artifacts. As compared to navigator-based approaches that use MRI data to detect and correct motion, optical motion correction works independently of the MRI scanner, thus providing low-latency real-time motion updates without requiring any modifications to the pulse sequence. The purpose of this study was two-fold: 1) to demonstrate that prospective optical motion correction using an optical camera mitigates artifacts from head motion in three-dimensional pseudo-continuous arterial spin labeling (3D PCASL) acquisitions and 2) to assess the effect of latency differences between real-time optical motion tracking and navigator-style approaches (such as PROMO). An optical motion correction system comprising a single camera and a marker attached to the patient's forehead was used to track motion at a rate of 60fps. In the presence of motion, continuous tracking data from the optical system was used to update the scan plane in real-time during the 3D-PCASL acquisition. Navigator-style correction was simulated by using the tracking data from the optical system and performing updates only once per repetition time. Three normal volunteers and a patient were instructed to perform continuous and discrete head motion throughout the scan. Optical motion correction yielded superior image quality compared to uncorrected images or images using navigator-style correction. The standard deviations of pixel-wise CBF differences between reference and non-corrected, navigator-style-corrected and optical-corrected data were 14.28, 14.35 and 11.09mL/100g/min for continuous motion, and 12.42, 12.04 and 9.60mL/100g/min for discrete motion. Data obtained from the patient revealed that motion can obscure pathology and that application of optical prospective correction can successfully reveal the underlying pathology in the presence of head motion.


Assuntos
Encéfalo/diagnóstico por imagem , Aumento da Imagem/métodos , Imagem por Ressonância Magnética/métodos , Artérias , Artefatos , Voluntários Saudáveis , Humanos , Movimento (Física) , Estudos Prospectivos , Marcadores de Spin
17.
Indian J Pharmacol ; 48(4): 355-359, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27756943

RESUMO

OBJECTIVES: Dual antiplatelet therapy (DAPT), consisting of clopidogrel and aspirin, is the main-stay treatment of acute coronary syndromes (ACS). However, major adverse cardiovascular events may occur even in patients undergoing DAPT, and this has been related to the variable pharmacodynamic efficacy of these drugs, especially clopidogrel. Platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) are novel inflammatory markers for cardiovascular risk stratification, which may reflect an inflammatory state and thus high on-treatment platelet reactivity (HPR). METHODS: We investigated the usefulness of PLR and NLR in predicting HPR in clopidogrel-treated patients with ACS. A total of 244 patients were enrolled in this study, and 43 of them were nonresponsive to clopidogrel. RESULTS: Logistic regression analysis indicated that PLR was significantly associated with HPR (P < 0.001). Using a cutoff level of 331, PLR predicted HPR with a sensitivity of 73% and a specificity of 69% (odds ratio: 376.15, 95% confidence interval = 37.813-3741.728 P < 0.001, receiver operating characteristic curve: 0.885). CONCLUSIONS: We suggest that more attention should be paid to the PLR values of these patients on admission to identify individuals who may not benefit from clopidogrel during the course of ACS.


Assuntos
Síndrome Coronariana Aguda/tratamento farmacológico , Plaquetas/citologia , Linfócitos/citologia , Neutrófilos/citologia , Inibidores da Agregação de Plaquetas/uso terapêutico , Ticlopidina/análogos & derivados , Síndrome Coronariana Aguda/sangue , Síndrome Coronariana Aguda/imunologia , Biomarcadores , Contagem de Células Sanguíneas , Clopidogrel , Resistência a Medicamentos , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Ticlopidina/uso terapêutico
18.
Heart Views ; 17(2): 69-71, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27512536

RESUMO

Fibromuscular dysplasia (FMD) is a nonatherosclerotic and noninflammatory arterial disease that commonly affects the renal and carotid arteries. The primary target in treating patients with renal artery FMD is the control of blood pressure in order to prevent end-organ damage, which can be caused by poorly controlled hypertension. Invasive endovascular treatment should be taken into consideration both when hypertension cannot be controlled with medication. According to current opinion, hypertension attributed to renal artery FMD is often successfully treated solely with percutaneous renal balloon angioplasty (PRBA), with no requirement for stent implantation under most circumstances. However, an FMD recurrence after PRBA occurs frequently in these patients.

19.
Bull Environ Contam Toxicol ; 97(3): 439-45, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27435977

RESUMO

Perchlorate is a chemical pollutant that inhibits iodide uptake and may possibly impair thyroid function. Our previous study found widespread perchlorate exposure in non-pregnant, non-lactating, healthy women residing in Istanbul. The aim of this study is to assess the relative amounts of perchlorate exposure attributable to consumption of municipal water, bottled water and boxed milk available in Istanbul. Only trace levels of perchlorate were found in treated municipal water (58 % detectable, mean = 0.13 µg/L, maximum = 0.75 µg/L) and bottled water (7.4 % detectable, mean = 

Assuntos
Água Potável/química , Exposição Ambiental/análise , Leite/química , Percloratos/análise , Animais , Humanos , Iodetos/metabolismo , Turquia
20.
Vasa ; 45(5): 387-93, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27351418

RESUMO

BACKGROUND: Carotid artery stenting (CAS) is currently used as an alternative treatment to carotid endarterectomy (CEA). The objective of this study was to analyse our 5-year experience performing CAS. Secondarily, we sought to determine independent risk factors which predict periprocedural complications. PATIENTS AND METHODS: A total of 146 patients who underwent 153 CAS procedures were analysed. The majority of patients (123, 84.2%) had symptomatic carotid stenosis. Demographic and interventional data, angiographic lesion characteristics, and periprocedural complications were recorded. Using univariate and multivariate logistic regression analyses, risk factors associated with adverse clinical outcomes were determined. RESULTS: Periprocedural neurological complications, including four (2.7 %) major strokes, three (2 %) transient ischaemic attacks, one (0.7%) amaurosis fugax, and two (1.3 %) cases of hyperperfusion syndrome occurred in ten (6.8%) patients. The incidence of periprocedural complications significantly increased in female patients (r = 0.214, p = 0.009) and patients with longer lesions (r = 0.183, p = 0.027), contralateral stenosis ≥50 % (r = 0.222, p = 0.007), the presence of complicated plaques (r = 0.478, p < 0.001) and inadequate glycaemic control (r = 0.259, p = 0.002). Multivariate regression analysis also determined four variables to be potential independent risk factors for 30-day adverse events: higher age (Odds ratio [OR] = 1.283; 95 % CI, 1.051 to 1.566, p = 0.014); longer lesions (OR = 1.459, 95 % CI, 1.124 to 1.893, p = 0.004); higher tortuosity index (OR = 1.015, 95 % CI, 1.001 to 1.030, p = 0.034), and the presence of complicated plaque morphology (OR = 4.321, 95 % CI, 1.621 to 10.23, p = 0.001). CONCLUSIONS: Patient and lesion characteristics including age, lesion length, complicated plaque morphology and tortuosity index, may be associated with periprocedural complications.


Assuntos
Angioplastia/efeitos adversos , Angioplastia/instrumentação , Estenose das Carótidas/terapia , Stents , Fatores Etários , Idoso , Estenose das Carótidas/diagnóstico por imagem , Distribuição de Qui-Quadrado , Angiografia por Tomografia Computadorizada , Feminino , Humanos , Modelos Logísticos , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Medição de Risco , Fatores de Risco , Resultado do Tratamento , Turquia , Ultrassonografia Doppler Dupla
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