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1.
Mol Carcinog ; 55(6): 1111-7, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26258624

RESUMO

Mitochondria are the primary source of energy generation in human cells. Low mitochondrial DNA (mtDNA) copy number in peripheral blood leukocytes (PBLs) has been associated with obesity and increased risks of several cancers. Since obesity is a significant risk factor for endometrial cancer, we hypothesize that low mtDNA copy number in PBLs is associated with an increased susceptibility to endometrial cancer. Using a Caucasian case-control study, we measured mtDNA copy number in PBLs from 139 endometrial cancer patients and 139 age-matched controls and determined the association of mtDNA copy number with the risk of endometrial cancer using multivariate logistic regression analysis. The normalized mtDNA copy number was significantly lower in endometrial cancer cases (median, 0.84; range, 0.24-2.00) than in controls (median, 1.06; range, 0.64-1.96) (P < 0.001). Dichotomized into high and low groups based on the median mtDNA copy number value in the controls, individuals with low mtDNA copy number had a significantly increased risk of endometrial cancer (adjusted OR, 5.59; 95%CI, 3.05-10.25; P < 0.001) compared to those with high mtDNA copy number. There was a significant dose-response association in tertile analysis. In addition, there was a significant joint effect between lower mtDNA copy number and never smoking, hypertension, diabetes, and obesity in elevating the risk of endometrial cancer. Low mtDNA copy number in PBLs is significantly associated with an increased risk of endometrial cancer in Caucasians. © 2015 Wiley Periodicals, Inc.


Assuntos
Variações do Número de Cópias de DNA , DNA Mitocondrial/sangue , Neoplasias do Endométrio/genética , Mitocôndrias/genética , Idoso , Estudos de Casos e Controles , Neoplasias do Endométrio/sangue , Feminino , Predisposição Genética para Doença , Humanos , Leucócitos/patologia , Pessoa de Meia-Idade , População Branca/genética
2.
Curr Pediatr Rev ; 19(2): 179-186, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35440311

RESUMO

AIMS: We correlate ultrasound, MRI, and clinical findings in neonates with suspected hypoxic ischemic injury. BACKGROUND: Recent advances in neuroimaging have led to improved detection of subtle insults associated with neurodevelopmental outcomes, beyond more historically described lesions such as large hemorrhages and hydrocephalus. OBJECTIVE: In this study, we compare cranial ultrasound to MRI for the evaluation of suspected HIE in preterm infants. METHODS: 147 premature infant patients with paired ultrasound and MRI exams were retrospectively analyzed to compare imaging finding accuracy and clinical value. RESULT: We confirm that ultrasound is highly sensitive and specific for hydrocephalus, ventricular prominence, and gross structural abnormalities. Ultrasound is not a substitute for MRI in cases of small hemorrhages or white matter injury, however, certain US findings were associated with Apgar score and MRI sequelae of HIE. CONCLUSION: Choosing between ultrasound and MRI for preterm neonates at risk for intracranial abnormalities based on their strengths can reduce cost and maximize clinical utility. MRI provides a highly sensitive identification of subtle brain injury, yet ultrasound is correlated with the peripartum clinical picture as measured by Apgar score.


Assuntos
Hidrocefalia , Hipóxia-Isquemia Encefálica , Lactente , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Estudos Retrospectivos , Hipóxia-Isquemia Encefálica/diagnóstico por imagem , Hipóxia-Isquemia Encefálica/patologia , Imageamento por Ressonância Magnética/métodos , Hidrocefalia/patologia , Encéfalo/diagnóstico por imagem
3.
Am J Gastroenterol ; 107(9): 1370-6, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22825363

RESUMO

OBJECTIVES: Both capsule endoscopy (CE) and angiography have been recommended as first investigation for patients with acute overt obscure gastrointestinal bleeding (OGIB). However, no studies have directly compared the two modalities in patients with overt OGIB. We compared the diagnostic yield and long-term outcomes of patients with overt OGIB randomized to CE or angiogram. METHODS: Consecutive patients presented with acute melena or hematochezia, but nondiagnostic upper and lower endoscopy, were immediately randomized to receive small-bowel CE or angiography. All patients were monitored for rebleeding and anemia for up to 5 years. Primary end point was the diagnostic yield of the assigned investigation. Secondary end points included rebleeding, further transfusion, readmission for bleeding or anemia, and mortality. RESULTS: A total of 60 patients with overt OGIB were randomized. The mean follow-up was 48.5 months. The diagnostic yield of immediate CE was significantly higher than angiography (53.3% vs. 20.0%, P = 0.016). The cumulative risk of rebleeding in the angiography and CE group was 33.3% and 16.7%, respectively (P = 0.10, log-rank test). There was no significant difference in the long-term outcomes between the two groups including further transfusion, hospitalization for rebleeding, and mortality. CONCLUSIONS: In patients with overt OGIB, immediate CE has higher diagnostic yield and comparable long-term outcomes when compared with angiography.


Assuntos
Angiografia , Endoscopia por Cápsula , Hemorragia Gastrointestinal/diagnóstico , Intestino Delgado/diagnóstico por imagem , Melena/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Hemorragia Gastrointestinal/diagnóstico por imagem , Humanos , Masculino , Melena/diagnóstico por imagem , Pessoa de Meia-Idade
4.
Curr Probl Diagn Radiol ; 48(2): 189-192, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29173798

RESUMO

PURPOSE: Computed tomography (CT) has been shown to change management in children on extracorporeal membrane oxygenation (ECMO). Although techniques have been described to transport these critically ill patients to the CT suite in the radiology department, transport out of the intensive care setting is not without risk, and using portable CT is a practical alternative. However, obtaining a CT pulmonary angiogram (CTPA) in a patient on veno-arterial (VA) ECMO presents unique challenges due to bypass of the cardiopulmonary system, which may lead to suboptimal opacification of the pulmonary arteries. METHODS: We describe a method to obtain a diagnostic CTPA study in an infant on VA ECMO in the intensive care unit using portable CT. Our solution involved temporary withholding ECMO and using the venous cannula to deliver a compact contrast bolus to the right atrium to adequately opacify the pulmonary arteries. Special attention was given to the delivery of the contrast bolus, which was given by hand injection, to ensure it coincided with image acquisition and minimized the time ECMO was withheld. RESULTS: We were able to successfully obtain a diagnostic CTPA study in an infant on VA ECMO in the intensive care unit using portable CT. CONCLUSION: This case demonstrates that in select instances CTPA in infants on VA ECMO can be achieved using a portable CT system.


Assuntos
Angiografia por Tomografia Computadorizada/instrumentação , Oxigenação por Membrana Extracorpórea , Insuficiência Cardíaca/diagnóstico por imagem , Unidades de Terapia Intensiva Pediátrica , Pneumonia Necrosante/diagnóstico por imagem , Sistemas Automatizados de Assistência Junto ao Leito , Meios de Contraste , Diagnóstico Diferencial , Ecocardiografia , Humanos , Lactente , Iohexol , Masculino
5.
Stud Health Technol Inform ; 132: 387-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18391327

RESUMO

A force prediction algorithm is proposed to facilitate virtual-reality (VR) based collaborative surgical simulation by reducing the effect of network latencies. State regeneration is used to correct the estimated prediction. This algorithm is incorporated into an adaptive transmission protocol in which auxiliary features such as view synchronization and coupling control are equipped to ensure the system consistency. We implemented this protocol using multi-threaded technique on a cluster-based network architecture.


Assuntos
Algoritmos , Simulação por Computador , Comportamento Cooperativo , Cirurgia Geral , Hong Kong
6.
Stud Health Technol Inform ; 125: 367-72, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17377305

RESUMO

Research on collaborative virtual surgery opens the opportunity for simulating the cooperative work during surgical operations. It is however a challenging task to design and implement a high performance collaborative surgical simulation system because of the difficulty in maintaining a high level of state consistency under limited network transmission capacity. In this paper, we present an adaptive framework using cluster-based hybrid architecture to support real-time collaboration in surgical simulation. In addition to the TCP communication protocol, the framework is also equipped with UDP for multicasting, allowing for a flexible strategy to reduce network latency. A set of techniques was proposed to assure reliable transmission on top of standard yet unreliable multicast protocols. Experimental results demonstrate that this framework can support collaborative surgical simulation with lower network latencies than traditional client-server architecture.


Assuntos
Simulação por Computador , Sistemas Computacionais , Comportamento Cooperativo , Cirurgia Geral , Hong Kong
7.
Comput Med Imaging Graph ; 33(7): 559-66, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19524403

RESUMO

Registration of ultrasound volumes is a key issue for the reconstruction of volumetric ultrasound panorama. In this paper, we propose an improved three-dimensional (3D) scale invariant feature transform (SIFT) algorithm to globally register ultrasound volumes acquired from dedicated ultrasound probe, where local deformations are corrected by block-based warping algorithm. Original SIFT algorithm is extended to 3D and improved by combining the SIFT detector with Rohr3D detector to extract complementary features and applying the diffusion distance algorithm for robust feature comparison. Extensive experiments have been performed on both phantom and clinical data sets to demonstrate the effectiveness and robustness of our approach.


Assuntos
Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional , Ultrassonografia/métodos , Algoritmos , Humanos
8.
Artigo em Inglês | MEDLINE | ID: mdl-18982589

RESUMO

The reconstruction of three-dimensional (3D) ultrasound panorama from multiple ultrasound volumes can provide a wide field of view for better clinical diagnosis. Registration of ultrasound volumes has been a key issue for the success of this panoramic process. In this paper, we propose a method to register and stitch ultrasound volumes, which are scanned by dedicated ultrasound probe, based on an improved 3D Scale Invariant Feature Transform (SIFT) algorithm. We propose methods to exclude artifacts from ultrasound images in order to improve the overall performance in 3D feature point extraction and matching. Our method has been validated on both phantom and clinical data sets of human liver. Experimental results show the effectiveness and stability of our approach, and the precision of our method is comparable to that of the position tracker based registration.


Assuntos
Algoritmos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Reconhecimento Automatizado de Padrão/métodos , Ultrassonografia/métodos , Análise de Fourier , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
9.
Artigo em Inglês | MEDLINE | ID: mdl-18982648

RESUMO

Ultrasound-guided biopsy is one of the most fundamental, but difficult, skills to acquire in interventional radiology. Intensive training, especially in the needle insertion, is required for trainee radiologists to perform safe procedures. In this paper, we propose a virtual reality simulation system to facilitate the training of radiologists and physicians in this procedures. Key issues addressed include a 3D anatomical model reconstruction, data fusion of multiple ultrasound volumes and computed tomography (CT), realistic rendering, interactive navigation, and haptic feedbacks in six degrees of freedom (DOF). Simulated ultrasound imagery based on real ultrasound data is presented to users, in real-time, while performing an examination on the needle placement into a virtual anatomical model. Our system delivers a realistic haptic feeling for trainees throughout the simulated needle insertion procedure, permitting repeated practices with no danger to patients.


Assuntos
Biópsia por Agulha/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Robótica/métodos , Tato , Ultrassonografia de Intervenção/métodos , Interface Usuário-Computador , Retroalimentação , Humanos , Aumento da Imagem/métodos , Transdutores
10.
J Vasc Interv Radiol ; 19(1): 95-103, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18192473

RESUMO

PURPOSE: This prospective trial aimed to evaluate the safety and effectiveness of transarterial ethanol ablation (TEA) of intrahepatic lesions of hepatocellular carcinoma (HCC) with a Lipiodol-ethanol mixture. MATERIALS AND METHODS: Seventy-seven patients were recruited and 164 lesions (mean size, 5.2 cm +/- 3.0) were treated. Inclusion criteria included histologic proof of HCC, refusal of (n = 9) or contraindication to (n = 68) surgical resection, Eastern Cooperative Oncology Group performance status no greater than 2, and intrahepatic disease without vascular invasion. The mixture consisted of 33% ethanol by volume, with the total dose of Lipiodol-ethanol mixture limited to 60 mL for each treatment session. The primary endpoint was patient survival. Secondary endpoints were tumor response, adverse effects of treatment, and progression-free survival. Median follow-up time for the whole cohort was 2.3 years. RESULTS: Median overall survival was 2.2 years. Overall survival and progression-free survival rates at 1 year and 2 years were 77.9% and 50.1% and 63.6% and 46.3%, respectively. Complete ablation according to radiologic criteria was achieved in 61 patients (79.2%) and 86% of the 164 treated lesions. Mean tumor volume reduction was 65.22%. Patient survival was significantly better in patients with tumors no larger than 5 cm (Cox proportional-hazards regression, P = .0074). Treatment response was significantly better for patients with tumors no greater than 7 cm (chi2 test, P = .0462; Fisher exact test, P = .0326). Adverse effects included irreversible hepatic decompensation (0.6% of procedures), pain (4.8%), and fever (13.8%). CONCLUSIONS: TEA is a safe and effective means to establish local control of unresectable and resectable intrahepatic lesions of HCC.


Assuntos
Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/métodos , Etanol , Óleo Iodado/administração & dosagem , Neoplasias Hepáticas/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia Digital , Carcinoma Hepatocelular/irrigação sanguínea , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/mortalidade , Quimioembolização Terapêutica/efeitos adversos , Intervalo Livre de Doença , Feminino , Humanos , Neoplasias Hepáticas/irrigação sanguínea , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/mortalidade , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do Tratamento
11.
Artigo em Inglês | MEDLINE | ID: mdl-17354757

RESUMO

Image diffusion can smooth away noise and small-scale structures while retaining important features, thereby enhancing the performances of many image processing algorithms such as image compression, segmentation and recognition. In this paper, we present a novel diffusion algorithm for which the filtering kernels vary according to the perceptual saliency of boundaries in the input images. The boundary saliency is estimated through a saliency measure which is generally determined by curvature changes, intensity gradient and the interaction of neighboring vectors. The connection between filtering kernels and perceptual saliency makes it possible to remove small-scale structures and preserves significant boundaries adaptively. The effectiveness of the proposed approach is validated by experiments on various medical images including the color Chinese Visible Human data set and gray MRI brain images.


Assuntos
Algoritmos , Inteligência Artificial , Encéfalo/anatomia & histologia , Imagem de Difusão por Ressonância Magnética/métodos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Reconhecimento Automatizado de Padrão/métodos , Análise por Conglomerados , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
12.
Eur Radiol ; 15(6): 1168-72, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15538579

RESUMO

PURPOSE: To evaluate in a prospective study the use of a 4F Rosch inferior mesenteric (RIM) catheter for uterine artery embolisation (UAE). MATERIALS AND METHODS: UAE was performed in 72 women over a 37-month period. A 4F RIM braided J-curve 65-cm catheter was used in combination with an angled hydrophilic 150 cm, 0.035" flexible tip guide-wire to catheterise the horizontal portion of both uterine arteries (UA) from a right common femoral artery (CFA) approach. Technical success was defined as successful catheterisation and embolisation of both uterine arteries. Fluorosocpic and procedure times were recorded. RESULTS: Mean subject age=43.7 years (range=25-57 years). Technical success was 98.6% (n=71/72). A single approach via the right CFA was used in 88.9% (n=64/72) and a bilateral CFA approach in 11.1% (n=8/72). Bilateral uterine artery catheterisation using a single 4F RIM catheter via the right CFA approach was successful in 79.2% (n=57/72). Microcatheters were used in 2.8% of patients (n=2/72). Mean fluoroscopic time=13.6+/-5.3 min (mean+/-SD). Mean procedure time=44.2+/-16.5 min. CONCLUSION: High technical success rate for UAE is possible using a single 4F RIM catheter via a unilateral right CFA approach, which obviates the need for Waltman loop formation, reversed curve catheters and complex suture-catheter arrangements.


Assuntos
Embolização Terapêutica/instrumentação , Leiomioma/terapia , Neoplasias Uterinas/terapia , Adulto , Cateterismo/métodos , Feminino , Fluoroscopia , Humanos , Pessoa de Meia-Idade , Radiografia Intervencionista , Resultado do Tratamento
13.
J Vasc Interv Radiol ; 16(10): 1373-7, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16221909

RESUMO

A coaxial technique was introduced for successful embolization of a large fusiform splenic artery aneurysm in a vessel with a large caliber and a great degree of tortuosity. A standard 5-F angioplasty catheter was placed at the immediate afferent artery for occlusion of arterial inflow into the aneurysm, thereby preventing intraaneurysmal hypertension during embolization of the efferent segment. This was followed by coaxial microcatheterization of the immediate efferent segment for coil embolization, and then embolization of the afferent segment. It is postulated that this approach may improve the safety of embolization of large aneurysms with unfavorable morphology by decreasing the pressure on the aneurysm just after closure of the efferent segment.


Assuntos
Aneurisma/terapia , Cateterismo/instrumentação , Artéria Esplênica/patologia , Procedimentos Cirúrgicos Vasculares/métodos , Idoso , Aneurisma/diagnóstico por imagem , Cateterismo/métodos , Feminino , Humanos , Hiperesplenismo/diagnóstico por imagem , Hiperesplenismo/terapia , Cirrose Hepática/diagnóstico por imagem , Cirrose Hepática/terapia , Artéria Esplênica/diagnóstico por imagem , Tomografia Computadorizada por Raios X
14.
Oncology ; 67(2): 174-8, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15539923

RESUMO

A woman with stage IIIb non-small cell lung cancer (NSCLC) developed disease progression with brain metastases during chemotherapy. Due to unusual circumstances, the patient received gefitinib alone, without the use of corticosteroid treatment or radiotherapy. There was a dramatic clinical improvement within 1 week. Follow-up magnetic resonance imaging of the brain 1 month later showed decreases in both the size and number of brain metastases. The patient remains well 9 months after initiation of gefitinib. It is proposed that gefitinib may have a role in treatment of brain metastases from NSCLC.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/secundário , Quinazolinas/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/secundário , Receptores ErbB/antagonistas & inibidores , Feminino , Gefitinibe , Neoplasias Gengivais/tratamento farmacológico , Neoplasias Gengivais/secundário , Humanos , Neoplasias Pulmonares/patologia , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Inibidores de Proteínas Quinases/uso terapêutico , Resultado do Tratamento
15.
Hepatology ; 39(4): 932-8, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15057896

RESUMO

This study aims to compare the therapeutic effectiveness of continuous catheter drainage versus intermittent needle aspiration in the percutaneous treatment of pyogenic liver abscesses. Over a 5-year period, 64 consecutive patients with pyogenic liver abscess were treated with intravenous antibiotics (ampicillin, cefuroxime, and metronidazole) and randomized into two percutaneous treatment groups: continuous catheter drainage (with an 8F multi-sidehole pigtail catheter); and intermittent needle aspiration (18G disposable trocar needle). There was no statistically significant difference between the two groups regarding patient demographics, underlying coexisting disease, abscess size, abscess number, number of loculation of abscess, the presenting clinical symptoms such as fever, abdominal pain, and pretreatment liver function test. Although not statistically significant, the duration of intravenous antibiotics treatment before percutaneous treatment was longer with the catheter group, and the change of antibiotics after the sensitivity test was more frequent with the needle group. The needle group was associated with a higher treatment success rate, a shorter duration of hospital stay, and a lower mortality rate, although this did not reach statistical significance. In conclusion, this study suggests that intermittent needle aspiration is probably as effective as continuous catheter drainage for the treatment of pyogenic liver abscess, although further proof with a large-scale study is necessary. Due to the additional advantages of procedure simplicity, patient comfort, and reduced price, needle aspiration deserves to be considered as a first-line drainage approach.


Assuntos
Drenagem , Abscesso Hepático/terapia , Sucção , Adulto , Cateterismo , Feminino , Seguimentos , Humanos , Tempo de Internação , Abscesso Hepático/mortalidade , Masculino , Agulhas , Estudos Prospectivos , Supuração , Resultado do Tratamento
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