Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
Radiol Cardiothorac Imaging ; 6(2): e230073, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38573127

RESUMO

Purpose This special report outlines a retrospective observational study of CT fractional flow reserve (CT-FFR) analysis using dual-source coronary CT angiography (CTA) scans performed without heart rate control and its impact on clinical outcomes. Materials and Methods All patients who underwent clinically indicated coronary CTA between August 2020 and August 2021 were included in this retrospective observational study. Scans were performed in the late systolic to early diastolic period without heart rate control and analyzed at the interpreting physician's discretion. Demographics, coronary CTA features, and rates of invasive coronary angiography (ICA), percutaneous coronary intervention (PCI), myocardial infarction, and all-cause death at 3 months were assessed by chart review. Results During the study period, 3098 patients underwent coronary CTA, of whom 113 with coronary bypass grafting were excluded. Of the remaining 2985 patients, 292 (9.7%) were referred for CT-FFR analysis. Two studies (0.7%) were rejected from CT-FFR analysis, and six (2.1%) analyses did not evaluate the lesion of concern. A total of 160 patients (56.3%) had CT-FFR greater than 0.80. Among patients with significant stenosis at coronary CTA, patients who underwent CT-FFR analysis presented with lower rates of ICA (74.5% vs 25.5%, P = .04) and PCI (78.9% vs 21.1%, P = .05). Conclusion CT-FFR was implemented in patients not requiring heart rate control by using dual-source coronary CTA acquisition and showed the potential to decrease rates of ICA and PCI without compromising safety in patients with significant stenosis and an average heart rate of 65 beats per minute. Keywords: Angiography, CT, CT-Angiography, Fractional Flow Reserve, Cardiac, Heart, Arteriosclerosis Supplemental material is available for this article. © RSNA, 2024.


Assuntos
Reserva Fracionada de Fluxo Miocárdico , Intervenção Coronária Percutânea , Humanos , Centros Médicos Acadêmicos , Constrição Patológica , Tomografia Computadorizada por Raios X
2.
Curr Cardiol Rep ; 23(7): 87, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-34081227

RESUMO

PURPOSE OF REVIEW: Diagnosis of infiltrative cardiomyopathies can be challenging despite differences in clinical manifestations due to overlapping cardiac manifestations. We review the salient findings by cardiac magnetic resonance imaging that aids in diagnosis, as well the potential implications for prognosis and treatment. RECENT FINDINGS: Cardiac magnetic resonance imaging has added substantially to our understanding of various infiltrative cardiomyopathies, and the addition of late gadolinium enhancement imaging and parametric mapping has yielded additional insights regarding potential diagnoses, prognosis, and therapy. Cardiac magnetic resonance imaging should be employed in the setting of suspected hypertrophic or infiltrative cardiomyopathies to aid in diagnosis. In the setting of cardiac amyloidosis and Fabry disease, there is data to suggest that cardiac magnetic resonance imaging is useful for risk stratification as well as for monitoring response to therapy.


Assuntos
Cardiomiopatias , Meios de Contraste , Cardiomiopatias/diagnóstico por imagem , Gadolínio , Humanos , Imageamento por Ressonância Magnética , Miocárdio , Prognóstico
3.
Radiographics ; 41(3): 680-698, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33939541

RESUMO

Transcatheter left atrial appendage (LAA) closure is an alternative to long-term anticoagulation therapy in selected patients with nonvalvular atrial fibrillation who have an increased risk for stroke. LAA closure devices can be implanted by means of either an endocardial or a combined endocardial and epicardial approach. Preprocedural imaging is key to identifying contraindications, accurately sizing the device, and minimizing complications. Transesophageal echocardiography (TEE) has been the reference standard imaging modality to assess the anatomy for LAA closure and to provide intraprocedural guidance. However, CT has emerged as a less-invasive alternative to TEE for pre- and postprocedural imaging. CT is comparable to TEE for exclusion of thrombus but is superior to TEE for the delineation of complex LAA anatomy, measurement for device sizing, and evaluation of pulmonary venous and extracardiac structures. CT provides accurate measurements of the LAA ostial diameter, landing zone diameter, and LAA length, which are vital for accurate sizing of the device. CT allows evaluation of the relationship with the pulmonary veins and other adjacent structures that can be injured during the procedure. CT also simulates procedural fluoroscopic angles and provides evaluation of the interatrial septum, which is punctured during LAA closure. CT also provides a more convenient method for the evaluation of postprocedural complications such as incomplete closure, peridevice leaking, device-related thrombus, and device dislodgement. Online supplemental material is available for this article. ©RSNA, 2021.


Assuntos
Apêndice Atrial , Fibrilação Atrial , Acidente Vascular Cerebral , Apêndice Atrial/diagnóstico por imagem , Apêndice Atrial/cirurgia , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/cirurgia , Ecocardiografia Transesofagiana , Humanos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/etiologia , Tomografia Computadorizada por Raios X , Resultado do Tratamento
4.
Opt Express ; 29(7): 9699-9710, 2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33820124

RESUMO

Polymer photonic circuits offer a versatile platform for various applications, including communication, sensing and optical signal processing. Though polymers offer broadband, linear and nonlinear optical properties, the coupling between an optical fibre and a polymer waveguide has been a challenge. In this work, we propose and demonstrate a wafer-scale vertical coupling scheme for polymer waveguides. The scheme uses a silicon nitride grating coupler with an inverse taper to couple between an optical fibre and a SU8 polymer waveguide. We demonstrate a maximum coupling efficiency of -3.55 dB in the C-band and -2.92 dB in the L-band with a 3-dB bandwidth of 74 and 80 nm, respectively. A detailed design and simulation, fabrication, and characterisation results are presented. The scheme demonstrates a scalable and efficient surface grating approach for polymer photonic integrated circuits.

5.
Bone Marrow Transplant ; 56(1): 121-128, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32623447

RESUMO

Sinusoidal obstruction syndrome (SOS) is a serious complication of hematopoietic stem cell transplantation (HSCT). Sirolimus plus tacrolimus is an accepted regimen for graft-versus-host disease (GVHD) prophylaxis, with both agents implicated as risk factors for SOS. We analyzed 260 consecutive patients who underwent allogeneic HSCT following myeloablative conditioning using total body irradiation (TBI)-based (n = 151) or chemotherapy only (n = 109) regimens, with sirolimus plus tacrolimus for GVHD prophylaxis. SOS occurred in 28 patients at a median of 22 (range, 12-58) days. Mean sirolimus trough levels were higher between days 11 and 20 following transplant in patients who developed SOS (10.3 vs. 8.5 ng/ml, P = 0.008), with no significant difference in mean trough levels between days 0 and 10 (P = 0.67) and days 21-30 (P = 0.37). No differences in mean tacrolimus trough levels during the same time intervals were observed between those developing SOS and others. On multivariable analysis, a mean sirolimus trough level ≥ 9 ng/ml between days 11 and 20 increased the risk of SOS (hazard ratio 3.68, 95% CI: 1.57-8.67, P = 0.003), together with a longer time from diagnosis to transplant (P = 0.004) and use of TBI (P = 0.006). Our results suggest that mean trough sirolimus levels ≥ 9 ng/mL between days 11 and 20 post transplant may increase the risk of SOS and should be avoided.


Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Hepatopatia Veno-Oclusiva , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/prevenção & controle , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Hepatopatia Veno-Oclusiva/etiologia , Humanos , Sirolimo/efeitos adversos , Condicionamento Pré-Transplante/efeitos adversos , Transplante Homólogo
6.
Radiographics ; 40(6): 1528-1553, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33001784

RESUMO

Transcatheter mitral valve replacement (TMVR) is a catheter-based interventional technique for treating mitral valve disease in patients who are at high risk for open mitral valve surgery and with unfavorable anatomy for minimally invasive edge-to-edge transcatheter mitral valve repair. There are several TMVR devices with different anchoring mechanisms, delivered by either transapical or transseptal approaches. Transthoracic echocardiography is the first-line imaging modality used for characterization and quantification of mitral valve disorders. CT is complementary to echocardiography and has several advantages, including high isotropic spatial resolution, good temporal resolution, large field of view, multiplanar reconstruction capabilities, and rapid turnaround time. CT is essential for multiple aspects of preprocedural planning. Accurate and reproducible techniques to prescribe the mitral annulus at CT have been described from which important measurements such as the area, perimeter, trigone-trigone distance, intercommissural distance, and septolateral distance are obtained. The neo-left ventricular outflow tract (LVOT) can be simulated by placing a virtual prosthesis in the CT data to predict the risk of TMVR-induced LVOT obstruction. The anatomy of the landing zone and subvalvular apparatus as well as the relationship of the virtual device to adjacent structures such as the coronary sinus and left circumflex coronary artery can be evaluated. CT also stimulates procedural fluoroscopic angles. CT can be used to evaluate the chest wall for transapical access and the atrial septum for transseptal access. Follow-up CT is useful in identifying complications such as LVOT obstruction, paravalvular leak, pseudoaneurysm, and valve embolization. Online supplemental material is available for this article. ©RSNA, 2020.


Assuntos
Cateterismo Cardíaco , Implante de Prótese de Valva Cardíaca/métodos , Próteses Valvulares Cardíacas , Insuficiência da Valva Mitral/cirurgia , Estenose da Valva Mitral/cirurgia , Tomografia Computadorizada por Raios X , Humanos , Insuficiência da Valva Mitral/diagnóstico por imagem , Estenose da Valva Mitral/diagnóstico por imagem , Complicações Pós-Operatórias/diagnóstico por imagem
7.
Radiographics ; 40(3): 629-652, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32281902

RESUMO

Coronary CT angiography is now established as the first-line diagnostic imaging test to exclude coronary artery disease (CAD) in the population at low to intermediate risk. Wide variability exists in both the reporting of coronary CT angiography and the interpretation of these reports by referring physicians. The CAD Reporting and Data System (CAD-RADS) is sponsored by multiple societies and is a collaborative effort to provide standard classification of CAD, which is then integrated into patient clinical care. The main goals of the CAD-RADS are to decrease variability among readers; enhance communication between interpreting and referring clinicians, allowing collaborative determination of the best course of patient care; and generate consistent data for auditing, data mining, quality improvement, research, and education. There are several scenarios in which the CAD-RADS guidelines are ambiguous or do not provide definite recommendations for further management of CAD. The authors discuss the CAD-RADS categories and modifiers, highlight a variety of complex or ambiguous scenarios, and provide recommendations for managing these scenarios. Online supplemental material is available for this article. ©RSNA, 2020 See discussion on this article by Aviram and Wolak.


Assuntos
Angiografia por Tomografia Computadorizada/normas , Angiografia Coronária/normas , Doença da Artéria Coronariana/diagnóstico por imagem , Documentação/normas , Registros Eletrônicos de Saúde/normas , Doença da Artéria Coronariana/classificação , Humanos , América do Norte , Guias de Prática Clínica como Assunto , Reprodutibilidade dos Testes
8.
Sci Rep ; 9(1): 18821, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31827148

RESUMO

Silicon Nitride (SiN) is emerging as a promising material for a variety of integrated photonic applications. Given its low index contrast however, a key challenge remains to design efficient couplers for the numerous platforms in SiN photonics portfolio. Using a combination of bottom reflector and a chirp generating algorithm, we propose and demonstrate high efficiency, grating couplers on two distinct SiN platforms. For a partially etched grating on 500 nm thick SiN, a calculated peak efficiency of -0.5 dB/coupler is predicted, while for a fully etched grating on 400 nm thick SiN, an efficiency of -0.4 dB/coupler is predicted. Experimentally measured coupling efficiencies are observed to be -1.17 and -1.24 dB/coupler for the partial and fully etched grating couplers respectively in the C-L band region. Furthermore, through numerical simulations, it is shown that the chirping algorithm can be implemented in eight additional combinations comprising SiN film thickness between 300-700 nm as well as alternate claddings, to achieve a per coupler loss between -0.33 to -0.65 dB.

9.
Radiographics ; 39(4): 932-956, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31150303

RESUMO

Replacement with a prosthetic heart valve (PHV) remains the definitive surgical procedure for management of severe cardiac valve disease. PHV dysfunction is uncommon but can be a life-threatening condition. The broad hemodynamic and pathophysiologic manifestations of PHV dysfunction are stenosis, regurgitation, and a stuck leaflet. Specific structural abnormalities that cause PHV dysfunction include prosthetic valve-patient mismatch, structural failure, valve calcification, dehiscence, paravalvular leak, infective endocarditis, abscess, pseudoaneurysm, abnormal connections, thrombus, hypoattenuating leaflet thickening, and pannus. Multiple imaging modalities are available for evaluating a PHV and its dysfunction. Transthoracic echocardiography is often the first-line imaging modality, with additional modalities such as transesophageal echocardiography, CT, MRI, cine fluoroscopy, and nuclear medicine used for further characterization and establishing a specific cause. The authors review PHVs and the role of imaging modalities in evaluation of PHV dysfunction and illustrate the imaging appearances of different complications. Online supplemental material is available for this article. ©RSNA, 2019.


Assuntos
Doenças das Valvas Cardíacas/diagnóstico por imagem , Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas/efeitos adversos , Complicações Pós-Operatórias/diagnóstico por imagem , Dissecção Aórtica/diagnóstico por imagem , Falso Aneurisma/diagnóstico por imagem , Bioprótese/efeitos adversos , Calcinose/diagnóstico por imagem , Cinerradiografia/métodos , Constrição Patológica , Ecocardiografia/métodos , Endocardite/diagnóstico por imagem , Doenças das Valvas Cardíacas/etiologia , Doenças das Valvas Cardíacas/fisiopatologia , Hemodinâmica , Humanos , Imageamento por Ressonância Magnética/métodos , Imagem Multimodal/métodos , Complicações Pós-Operatórias/etiologia , Desenho de Prótese , Falha de Prótese , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único/métodos , Deiscência da Ferida Operatória/diagnóstico por imagem
10.
Radiol Clin North Am ; 57(1): 85-111, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30454820

RESUMO

The prevalence of adult congenital heart disease (ACHD) is increasing due to advances in surgical techniques, anesthesia, and perioperative care. Imaging plays an important role, not only in the surveillance of ACHD, but also in the initial evaluation of cases that have escaped detection early in life and present with symptoms later in adulthood. In this article, we review the role of computed tomography in the comprehensive evaluation of ACHD.


Assuntos
Cardiopatias Congênitas/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Meios de Contraste , Humanos
11.
Abdom Radiol (NY) ; 43(4): 998-1012, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29332247

RESUMO

Computed tomography (CT) and magnetic resonance imaging (MRI) are two of the workhorse modalities of abdominopelvic radiology. However, these modalities are not without patient- and technique-specific limitations that may prevent a timely and accurate diagnosis. Contrast-enhanced ultrasound (CEUS) is an effective, rapid, and cost-effective imaging modality with expanding clinical utility in the United States. In this pictorial essay, we provide a case-based discussion demonstrating the practical advantages of CEUS in evaluating a variety of pathologies in which CT or MRI was precluded or insufficient. Through these advantages, CEUS can serve a complementary role with CT and MRI in comprehensive abdominopelvic radiology.


Assuntos
Abdome/diagnóstico por imagem , Meios de Contraste/administração & dosagem , Ultrassonografia/métodos , Abdome/patologia , Humanos , Imageamento por Ressonância Magnética/métodos , Tomografia Computadorizada por Raios X/métodos , Estados Unidos
12.
J Clin Oncol ; 34(36): 4445-4446, 2016 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-27621392
13.
Biomed Res Int ; 2015: 943618, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26425563

RESUMO

Introduction of cisplatin based chemotherapy has revolutionized the treatment of germ cell tumors. A common side effect of multiday cisplatin chemotherapy is severe nausea and vomiting. Considerable progress has been made in the control of these side effects since the introduction of cisplatin based chemotherapy in the 1970s. Germ cell tumor which is a model for a curable neoplasm has also turned into an excellent testing ground to develop effective strategies to prevent chemotherapy induced nausea and vomiting (CINV) in multiday cisplatin based regimens. The use of combination of a 5-hydroxytryptamine (HT)3 receptor antagonist, a neurokinin-1 (NK1) antagonist, and dexamethasone has greatly improved our ability to prevent and control acute and delayed CINV. Mechanism and pattern of CINV with multiday chemotherapy may differ from those in single day chemotherapy and therefore efficacy of antiemetic drugs as observed in single day chemotherapy may not be applicable. There are only few randomized clinical trials with special emphasis on multiday chemotherapy. Further studies are essential to determine the efficacy, optimal dose, and duration of the newer agents and combinations in multiday cisplatin based chemotherapy.


Assuntos
Cisplatino/efeitos adversos , Náusea/induzido quimicamente , Náusea/terapia , Vômito/induzido quimicamente , Vômito/terapia , Esquema de Medicação , Quimioterapia Combinada/efeitos adversos , Humanos , Náusea/fisiopatologia , Antagonistas do Receptor 5-HT3 de Serotonina/uso terapêutico , Vômito/fisiopatologia
14.
Sex Transm Dis ; 42(2): 68-70, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25585063

RESUMO

18-Fluorine fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) has been shown to have use in the diagnosis of inflammatory and infectious diseases in addition to its primary use in cancer. We describe a case of early neurosyphilis that initially presented as symmetric, generalized lymphadenopathy on PET/CT. We conclude that PET/CT may play a role in evaluating targeted diagnostic interventions, disease extent, and treatment efficacy for disseminated syphilis.


Assuntos
Fluordesoxiglucose F18 , Linfadenite/diagnóstico por imagem , Neurossífilis/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Baixa Visão/diagnóstico por imagem , Corticosteroides/administração & dosagem , Antibacterianos/administração & dosagem , Diagnóstico Diferencial , Humanos , Injeções Intraoculares , Linfadenite/complicações , Masculino , Pessoa de Meia-Idade , Neurossífilis/complicações , Penicilina G/administração & dosagem , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Baixa Visão/tratamento farmacológico , Baixa Visão/etiologia , Imagem Corporal Total
15.
SAGE Open Med Case Rep ; 2: 2050313X14548094, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-27489652

RESUMO

Arterio-ureteral fistulae are abnormal connections between an artery and the ureter and carry a high mortality. We present two cases of arterio-ureteral fistulae that presented with life-threatening hematuria. Both patients were treated with endovascular covered stent placement.

16.
J Registry Manag ; 37(4): 137-40, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21688742

RESUMO

This study assessed comparability of the directly coded Summary Stage 2000 and the Collaborative Stage (CS) Derived Summary Stage 2000 (SS2000) using 2001-2004 data from 40 population-based cancer registries in the United States that met the high quality criteria. The likelihood ratio test was employed to determine whether stage differences between 2003 (pre-CS) and 2004 (CS) were attributable to 2001-2004 linear trends, decreases in percentage of unknown stage cases, or both. Statistically significant differences in stage distribution between 2003 and 2004 were observed for 30 out of the 34 cancer sites. For 4 cancer sites, the differences were attributable to 2001-2004 linear trends of stage distribution. For 8 cancer sites, the differences were attributable to decreases in percentage of unknown stage cases alone or in combination with the temporal trends of stage distribution. For the remaining 18 cancer sites, either (1) no linear trends of stage distribution were identified or (2) the combination of the decline in cases with unknown stage plus linear trends did not explain the stage differences between 2003 and 2004. By comparing the SS2000 and CS manuals, we found differences in coding definitions for direct extension and/or lymph node involvement for all cancer sites except cancers of the breast, cervix, and cranial nervous and other nervous system. Evidence showed that the stage differences between 2003 and 2004 may be attributable in part to the implementation of the CS System for some cancer sites.


Assuntos
Neoplasias/patologia , Programa de SEER , Feminino , Humanos , Incidência , Funções Verossimilhança , Masculino , Estadiamento de Neoplasias , Neoplasias/epidemiologia , Estados Unidos/epidemiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...