Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 152
Filtrar
1.
Zentralbl Chir ; 149(1): 96-115, 2024 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-37816386

RESUMO

The process of implementing early detection of lung cancer with low-dose CT (LDCT) in Germany has gained significant momentum in recent years. It is expected that the ordinance of the Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV) on early detection of lung cancer, which has been commented on by the professional societies, will come into effect by the end of 2023. Based on this regulation, the Federal Joint Committee (G-BA) will set up a program for early lung cancer detection with LDCT in the near future. In this position paper, the specialist societies involved in lung cancer screening present concrete cornerstones for a uniform, structured and quality-assured early detection program for lung cancer in Germany to make a constructive contribution to this process.


Assuntos
Detecção Precoce de Câncer , Neoplasias Pulmonares , Humanos , Tomografia Computadorizada por Raios X , Neoplasias Pulmonares/diagnóstico por imagem , Alemanha , Sociedades Médicas , Programas de Rastreamento
2.
Pneumologie ; 78(1): 15-34, 2024 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-37816379

RESUMO

The process of implementing early detection of lung cancer with low-dose CT (LDCT) in Germany has gained significant momentum in recent years. It is expected that the ordinance of the Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV) on early detection of lung cancer, which has been commented on by the professional societies, will come into effect by the end of 2023. Based on this regulation, the Federal Joint Committee (G-BA) will set up a program for early lung cancer detection with LDCT in the near future. In this position paper, the specialist societies involved in lung cancer screening present concrete cornerstones for a uniform, structured and quality-assured early detection program for lung cancer in Germany to make a constructive contribution to this process.


Assuntos
Detecção Precoce de Câncer , Neoplasias Pulmonares , Humanos , Tomografia Computadorizada por Raios X , Neoplasias Pulmonares/diagnóstico por imagem , Fatores de Risco , Alemanha , Programas de Rastreamento
3.
J Cardiovasc Magn Reson ; 25(1): 22, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-36978131

RESUMO

BACKGROUND: Different software programs are available for the evaluation of 4D Flow cardiovascular magnetic resonance (CMR). A good agreement of the results between programs is a prerequisite for the acceptance of the method. Therefore, the goal was to compare quantitative results from a cross-over comparison in individuals examined on two scanners of different vendors analyzed with four postprocessing software packages. METHODS: Eight healthy subjects (27 ± 3 years, 3 women) were each examined on two 3T CMR systems (Ingenia, Philips Healthcare; MAGNETOM Skyra, Siemens Healthineers) with a standardized 4D Flow CMR sequence. Six manually placed aortic contours were evaluated with Caas (Pie Medical Imaging, SW-A), cvi42 (Circle Cardiovascular Imaging, SW-B), GTFlow (GyroTools, SW-C), and MevisFlow (Fraunhofer Institute MEVIS, SW-D) to analyze seven clinically used parameters including stroke volume, peak flow, peak velocity, and area as well as typically scientifically used wall shear stress values. Statistical analysis of inter- and intrareader variability, inter-software and inter-scanner comparison included calculation of absolute and relative error (ER), intraclass correlation coefficient (ICC), Bland-Altman analysis, and equivalence testing based on the assumption that inter-software differences needed to be within 80% of the range of intrareader differences. RESULTS: SW-A and SW-C were the only software programs showing agreement for stroke volume (ICC = 0.96; ER = 3 ± 8%), peak flow (ICC: 0.97; ER = -1 ± 7%), and area (ICC = 0.81; ER = 2 ± 22%). Results from SW-A/D and SW-C/D were equivalent only for area and peak flow. Other software pairs did not yield equivalent results for routinely used clinical parameters. Especially peak maximum velocity yielded poor agreement (ICC ≤ 0.4) between all software packages except SW-A/D that showed good agreement (ICC = 0.80). Inter- and intrareader consistency for clinically used parameters was best for SW-A and SW-D (ICC = 0.56-97) and worst for SW-B (ICC = -0.01-0.71). Of note, inter-scanner differences per individual tended to be smaller than inter-software differences. CONCLUSIONS: Of all tested software programs, only SW-A and SW-C can be used equivalently for determination of stroke volume, peak flow, and vessel area. Irrespective of the applied software and scanner, high intra- and interreader variability for all parameters have to be taken into account before introducing 4D Flow CMR in clinical routine. Especially in multicenter clinical trials a single image evaluation software should be applied.


Assuntos
Imageamento por Ressonância Magnética , Software , Humanos , Feminino , Reprodutibilidade dos Testes , Valor Preditivo dos Testes , Aorta
4.
J Endovasc Ther ; 29(2): 181-192, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34362274

RESUMO

PURPOSE: To compare retrograde plantar-arch and transpedal-access approach for revascularization of below-the-knee (BTK) arteries in patients with critical limb ischemia (CLI) after a failed antegrade approach. MATERIALS AND METHODS: Retrospectively we identified 811 patients who underwent BTK revascularization between 1/2014 and 1/2020. In 115/811 patients (14.2%), antegrade revascularization of at least 1 tibial artery had failed. In 67/115 (58.3%), patients retrograde access to the target vessel was achieved via the femoral access and the plantar-arch (PLANTAR-group); and in 48/115 patients (41.7%) retrograde revascularization was performed by an additional retrograde puncture (TRANSPEDAL-group). Comorbidities, presence of calcification at pedal-plantar-loop/transpedal-access-site, and tibial-target-lesion was recorded. Endpoints were technical success (PLANTAR-group: crossing the plantar-arch; TRANSPEDAL-group: intravascular placement of the pedal access sheath), procedural success [residual stenosis <30% after plain old balloon angioplasty (POBA)], and procedural complications limb salvage and survival. Correlations between calcification at access site/tibial-target-lesion and technical/procedural-success were tested. RESULTS: Technical success was achieved in 50/67 (75%) patients of the PLANTAR-group and in 39/48 (81%) patients of the TRANSPEDAL-group (p=0.1). Procedural success was obtained in 23/67 (34%) patients of the PLANTAR-group and in 25/48 (52%) patients of the TRANSPEDAL-group (p=0.04). In 14/49 (29%) cases with calcification at the pedal-plantar loop, technical success was not achieved (p=0.04), and in 33/44 (75%) patients with calcification at the tibial-target-lesion, procedural success was not attained (PLANTAR-group) (p=0.026). In the TRANSPEDAL-group, correlations between calcification at access site/tibial-target-lesion and technical/procedural-success were not observed (p=0.2/p=0.4). In the PLANTAR-group, minor complications occurred in 13/67 (19%) and in the TRANSPEDAL-group in 4/48 patients (8%) (p=0.08). Limb salvage at 12 (18) months was 90% (82%) (PLANTAR-group; 95%CI 15.771-18.061) and 84% (76%) (TRANSPEDAL-group; 95%CI 14.475-17.823) (Log-rank p=0.46). Survival at 12 (18) months was 94% (86%) (PLANTAR-group; 95%CI 16.642-18.337) and 85% (77%) (TRANSPEDAL; 95%CI 14.296-17.621) (Log-rank p=0.098). CONCLUSION: Procedural success was significantly higher using the transpedal-access approach. Calcifications at pedal-plantar loop and target-lesion significantly influenced technical/procedural failure using the plantar-arch approach. No significant difference between both retrograde techniques in terms of feasibility, safety, and limb salvage/survival was found.


Assuntos
Doença Arterial Periférica , Artérias da Tíbia , Isquemia Crônica Crítica de Membro , Humanos , Isquemia/diagnóstico por imagem , Isquemia/terapia , Salvamento de Membro , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/terapia , Estudos Retrospectivos , Artérias da Tíbia/diagnóstico por imagem , Resultado do Tratamento
5.
J Vasc Interv Radiol ; 33(4): 384-391.e7, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34958860

RESUMO

PURPOSE: To evaluate the feasibility and accuracy of a radiation-free implantation of a thoracic aortic stent graft employing fiberoptic and electromagnetic tracking in an anthropomorphic phantom. MATERIALS AND METHODS: An anthropomorphic phantom was manufactured based on computed tomography (CT) angiography data from a patient. An aortic stent graft application system was equipped with a fiber Bragg gratings and 3 electromagnetic sensors. The stent graft was navigated in the phantom by 3 interventionalists using the tracking data generated by both technologies. One implantation procedure was performed. The technical success of the procedure was evaluated using digital subtraction angiography and CT angiography (before and after the intervention). Tracking accuracy was determined at various anatomical landmarks based on separately acquired fluoroscopic images. The mean/maximum errors were measured for the stent graft application system and the tip/end of the stent graft. RESULTS: The procedure resulted in technical success with a mean error below 3 mm for the entire application system and <2 mm for the position of the tip of the stent graft. Navigation/implantation and handling of the device were rated sufficiently accurate and on par with comparable, routinely used stent graft application systems. CONCLUSIONS: The study demonstrates successful stent graft implantation during a thoracic endovascular aortic repair procedure employing advanced guidance techniques and avoiding fluoroscopic imaging. This is an essential step in facilitating the implantation of stent grafts and reducing the health risks associated with ionizing radiation during endovascular procedures.


Assuntos
Aneurisma da Aorta Abdominal , Aneurisma da Aorta Torácica , Implante de Prótese Vascular , Procedimentos Endovasculares , Aneurisma da Aorta Abdominal/cirurgia , Aneurisma da Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/cirurgia , Prótese Vascular , Fenômenos Eletromagnéticos , Humanos , Imageamento Tridimensional , Stents , Resultado do Tratamento
6.
Acta Radiol ; 62(5): 586-593, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32678675

RESUMO

BACKGROUND: Detection of breast cancer in women with high breast densities is a clinical challenge. PURPOSE: To study the influence of different degrees of breast density on the sensitivity of contrast-enhanced breast magnetic resonance imaging (CE-BMRI) versus X-ray mammography (XRM). MATERIAL AND METHODS: We performed an additional analysis of two large Phase III clinical trials (G1; G2) which included women with histologically proven breast cancers, called "index cancers." Additional cancers were detected during image reading. We compared the sensitivity of CE-BMRI and XRM in women with different breast densities (ACR A→D; Version 5). For each study, six blinded readers evaluated the images. Results are given as the "Median Reader." RESULTS: A total of 774 patients were included, 169 had additional cancers. While sensitivity of CE-BMRI for detecting all index cancers was independent of breast density (ACR A→D) (G1: 83%→83%; G2: 91%→91%) the sensitivity of XRM declined (ACR A→D) (G1: 79%→62%; G2: 82%→64%). Thus, the sensitivity difference between both imaging modalities in ACR A breasts of 3% (G1) and 9% (G2) increased to 21% (G1) and 26% (G2) in ACR D breasts. Sensitivity of CE-BMRI for detecting at least one additional cancer increased with increasing breast density (ACR A→D) (G1: 50%→73%, G2: 57%→81%). XRM's sensitivity decreased (G1: 34%→20%) or remained stable (G2: 24%→25%). CONCLUSION: CE-BMRI showed significantly higher sensitivity compared to XRM.


Assuntos
Densidade da Mama , Neoplasias da Mama/diagnóstico por imagem , Imageamento por Ressonância Magnética , Mamografia , Idoso , Meios de Contraste , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Sensibilidade e Especificidade
7.
J Cardiovasc Magn Reson ; 22(1): 17, 2020 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-32089132

RESUMO

This document is an update to the 2013 publication of the Society for Cardiovascular Magnetic Resonance (SCMR) Board of Trustees Task Force on Standardized Protocols. Concurrent with this publication, 3 additional task forces will publish documents that should be referred to in conjunction with the present document. The first is a document on the Clinical Indications for CMR, an update of the 2004 document. The second task force will be updating the document on Reporting published by that SCMR Task Force in 2010. The 3rd task force will be updating the 2013 document on Post-Processing. All protocols relative to congenital heart disease are covered in a separate document.The section on general principles and techniques has been expanded as more of the techniques common to CMR have been standardized. A section on imaging in patients with devices has been added as this is increasingly seen in day-to-day clinical practice. The authors hope that this document continues to standardize and simplify the patient-based approach to clinical CMR. It will be updated at regular intervals as the field of CMR advances.


Assuntos
Doenças Cardiovasculares/diagnóstico por imagem , Protocolos Clínicos/normas , Imageamento por Ressonância Magnética/normas , Consenso , Humanos , Valor Preditivo dos Testes
8.
J Card Surg ; 34(12): 1452-1457, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31638731

RESUMO

BACKGROUND AND AIM OF THE STUDY: Aortic hemodynamics influence the integrity of the vessel wall and cardiac afterload. The aim of this study was to compare hemodynamics distal to biological (BV) and mechanical aortic valve (MV) replacements by in vitro 4D Flow MRI excluding confounding factors of in-vivo testing potentially influencing hemodynamics. METHODS: Two BV (Perimount MagnaEase [Carpentier-Edwards], Trifecta [Abbott]) and two MV (On-X [CryoLife], prototype trileaflet valve) were scanned in a flexible aortic phantom at 3T using a recommended 4D Flow MR sequence. A triphasic aortic flow profile with blood-mimicking fluid was established. Using GTFlow (Gyrotools), area and velocity of the ejection jet were measured. Presence and extent of sinus vortices and secondary flow patterns were graded on a 0 to 3 scale. RESULTS: A narrow, accelerated central ejection jet (Area = 27 ± 7% of vessel area, Velocity = 166 ± 13 cm/s; measured at sinotubular junction) was observed in BV as compared to MV (Area = 53 ± 13%, Velocity = 109 ± 21 cm/s). As opposed to MV, the jet distal to BV impacted the outer curvature of the ascending aorta and resulted in large secondary flow patterns (BV: n = 4, grades 3, 3, 2, 1; MV: n = 1, grade 1). Sinus vortices only formed distal to MV. Although physiologically configured, they were larger than normal (grade 3). CONCLUSIONS: In contrast to mechanical valves, biological valve replacements induced accelerated and increased flow patterns deviating from physiological ones. While it remains speculative whether this increases the risk of aneurysm formation through wall shear stress changes, findings are contrasted by almost no secondary flow patterns and typical, near-physiological sinus vortex formation distal to mechanical valves.


Assuntos
Valva Aórtica/diagnóstico por imagem , Valva Aórtica/fisiologia , Próteses Valvulares Cardíacas , Imageamento por Ressonância Magnética/métodos , Aorta Torácica/diagnóstico por imagem , Aorta Torácica/fisiologia , Hemodinâmica , Humanos , Técnicas In Vitro
9.
J Endovasc Ther ; 24(4): 521-524, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28457200

RESUMO

PURPOSE: To report a rendezvous technique for subintimal revascularization of a chronic total occlusion (CTO) of the superficial femoral artery (SFA). TECHNIQUE: This maneuver is appropriate after failure to cross a long SFA CTO via intra- and subintimal approaches from the ipsilateral femoral as well as retrograde posterior tibial artery (PTA) access sites. After predilation of the subintimal space from the femoral access, a reentry device was placed at the level of the first popliteal artery segment. A balloon was delivered via the retrograde PTA access and inflated at the corresponding level of the reentry device. The balloon was punctured with the needle of the reentry device under fluoroscopic control, and a 0.014-inch guidewire was placed within the punctured balloon. The balloon and the antegrade guidewire were retracted from the retrograde access while the guidewire was gently pushed from the femoral site. Conventional balloon angioplasty of the SFA occlusion was performed via the femoral access, followed by overlapping stent-graft implantation. Complete revascularization of the CTO was documented. CONCLUSION: In selected cases a transfemoral reentry device-assisted puncture of a retrogradely inserted balloon within the subintimal space may facilitate a rendezvous and revascularization if standard techniques to cross long CTOs have failed.


Assuntos
Angioplastia com Balão/instrumentação , Artéria Femoral , Doença Arterial Periférica/terapia , Artéria Poplítea , Dispositivos de Acesso Vascular , Idoso de 80 Anos ou mais , Angiografia Digital , Angioplastia com Balão/efeitos adversos , Doença Crônica , Constrição Patológica , Desenho de Equipamento , Artéria Femoral/diagnóstico por imagem , Artéria Femoral/fisiopatologia , Humanos , Masculino , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/fisiopatologia , Artéria Poplítea/diagnóstico por imagem , Artéria Poplítea/fisiopatologia , Punções , Radiografia Intervencionista , Stents , Resultado do Tratamento
12.
J Magn Reson Imaging ; 42(2): 505-14, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25430957

RESUMO

BACKGROUND: To evaluate the benefit (additional flow information), image quality, and diagnostic accuracy of a dynamic magnetic resonance angiography (MRA) combining high spatial and temporal resolution for the preinterventional assessment of acute aortic dissection. METHODS: Nineteen patients (12 men, 7 women; aged 32-78 years) with acute aortic dissection underwent contrast-enhanced four-dimensional (4D) MRA and 3D conventional high-resolution MRA (3D MRA) within one examination on a 1.5 Tesla MR system. Both MRA datasets for each patient were evaluated and compared for image quality and visualization of vascular details on a 5-point scale (5 = excellent image quality, 1 = nondiagnostic image quality). In addition, presence and relevance of additional hemodynamic information (flow direction and organ perfusion delay) gained by dynamic MRA were assessed. RESULTS: Conventional 3D MRA provided significantly higher values for image quality of the aorta and aortic side branches compared with dynamic MRA (aorta: 4.3 versus 3.3; P = 0.006 side branches: 4.2 versus 3.3; P = 0.02). However, in 10 of the 19 patients (53%) the additionally available information on flow dynamics due to dynamic MRA (e.g., delayed perfusion of parenchymal organs) led to a change in therapy planning and realization. CONCLUSION: Dynamic MRA is a technique that combines functional flow and morphological information. Thus, the combination of 3D and dynamic MRA provides all requested information for treatment planning in patients suffering from acute aortic dissection.


Assuntos
Aneurisma Aórtico/patologia , Aneurisma Aórtico/fisiopatologia , Dissecção Aórtica/patologia , Dissecção Aórtica/fisiopatologia , Velocidade do Fluxo Sanguíneo , Angiografia por Ressonância Magnética/métodos , Doença Aguda , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
Invest Radiol ; 59(5): 345-358, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-37972293

RESUMO

BACKGROUND: Gadobutrol has been administered more than 100 million times worldwide, since February 1998, that is, over the last 25 years. Numerous clinical studies in a broad range of indications document the long-term experience with gadobutrol. OBJECTIVE: The aim of this study was to provide a literature-based overview on gadobutrol's efficacy in 9 approved indications and use in children. MATERIALS AND METHODS: Efficacy results in patients of all age groups including sensitivity, specificity, accuracy, and positive/negative predictive values were identified by a systematic literature search on Embase until December 31, 2022. Nine approved indications were considered: central nervous system (CNS), magnetic resonance angiography (MRA), breast, heart, prostate, kidney, liver, musculoskeletal, whole body, and various indications in children. RESULTS: Sixty-five publications (10 phase III, 2 phase IV, 53 investigator-initiated studies) reported diagnostic efficacy results obtained from 7806 patients including 271 children, at 369 centers worldwide. Indication-specific sensitivity ranges were 59%-98% (CNS), 53%-100% (MRA), 80%-100% (breast), 64%-90% (heart), 64%-96% (prostate), 71-85 (kidney), 79%-100% (liver), 53%-98% (musculoskeletal), and 78%-100% (children). Indication-specific specificity ranges were 75%-100% (CNS), 64%-99% (MRA), 58%-98% (breast), and 47%-100% (heart). CONCLUSIONS: The evaluated body of evidence, consisting of 65 studies with 7806 patients, including 271 children and 7535 adults, showed that gadobutrol is an efficacious magnetic resonance imaging contrast agent for all age groups in various approved indications throughout the whole body.


Assuntos
Compostos Organometálicos , Masculino , Adulto , Criança , Humanos , Compostos Organometálicos/uso terapêutico , Imageamento por Ressonância Magnética/métodos , Angiografia por Ressonância Magnética/métodos , Meios de Contraste , Resultado do Tratamento
14.
Invest Radiol ; 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38426761

RESUMO

BACKGROUND: The macrocyclic gadolinium-based contrast agent gadobutrol was introduced to the market in February 1998. Over the last 25 years, gadobutrol has been administered more than 100 million times worldwide providing a wealth of data related to safety. OBJECTIVE: The aim of this study was to perform a thorough review and status update on gadobutrol's safety. MATERIALS AND METHODS: Safety data from the clinical phase II-IV program and postmarketing surveillance were descriptively analyzed from February 1998 until December 31, 2022. Literature on special at-risk populations and specific safety aspects was critically summarized. RESULTS: Forty-five clinical phase II-IV studies recruited 7856 patients receiving gadobutrol. Drug-related adverse events (AEs) were reported in 3.4% and serious AEs in <0.1% of patients. Nausea (0.7%) and dysgeusia (0.4%) were the most reported AEs. All other drug-related AEs occurred ≤0.3%. After more than 100 million gadobutrol administrations, overall adverse drug reactions (ADRs) from postmarketing surveillance (including clinical trials) were rare with an overall reporting rate of 0.0356%, hypersensitivity reactions (0.0147%), nausea (0.0032%), vomiting (0.0025%), and dyspnea (0.0010%). All other ADRs were <0.001%. No trend for higher rates of AEs was found in patients with reduced renal or liver function. Seven clinical studies reported safety findings in 7292 children ≤18 years, thereof 112 newborns/toddlers younger than 2 years. Overall, 61 ADRs (0.84%) were reported, including 3 serious ones. Adverse events in patients ≥65 years of age ("elderly") were significantly less frequent than in younger patients. A total of 4 reports diagnostic of or consistent with nephrogenic systemic fibrosis have been received. No causal relationship has been established between clinical signs and symptoms and the presence of small amounts of gadolinium in the body in patients with normal renal function after use of gadobutrol. CONCLUSIONS: More than 100 million administrations worldwide have shown gadobutrol's well-established benefit-risk profile in any approved indication and populations.

15.
Methods Inf Med ; 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38262476

RESUMO

OBJECTIVES: In this paper, an artificial intelligence-based algorithm for predicting the optimal contrast medium dose for computed tomography (CT) angiography of the aorta is presented and evaluated in a clinical study. The prediction of the contrast dose reduction is modelled as a classification problem using the image contrast as the main feature. METHODS: This classification is performed by random decision forests (RDF) and k-nearest-neighbor methods (KNN). For the selection of optimal parameter subsets all possible combinations of the 22 clinical parameters (age, blood pressure, etc.) are considered using the classification accuracy and precision of the KNN classifier and RDF as quality criteria. Subsequently, the results of the evaluation were optimized by means of feature transformation using regression neural networks (RNN). These were used for a direct classification based on regressed Hounsfield units as well as preprocessing for a subsequent KNN classification. RESULTS: For feature selection, an RDF model achieved the highest accuracy of 84.42% and a KNN model achieved the best precision of 86.21%. The most important parameters include age, height, and hemoglobin. The feature transformation using an RNN considerably exceeded these values with an accuracy of 90.00% and a precision of 97.62% using all 22 parameters as input. However, also the feasibility of the parameter sets in routine clinical practice has to be considered, because some of the 22 parameters are not measured in routine clinical practice and additional measurement time of 15 to 20 minutes per patient is needed. Using the standard feature set available in clinical routine the best accuracy of 86.67% and precision of 93.18% was achieved by the RNN. CONCLUSION: We developed a reliable hybrid system that helps radiologists determine the optimal contrast dose for CT angiography based on patient-specific parameters.

16.
Rofo ; 196(2): 134-153, 2024 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-37816377

RESUMO

The process of implementing early detection of lung cancer with low-dose CT (LDCT) in Germany has gained significant momentum in recent years. It is expected that the ordinance of the Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV) on the early detection of lung cancer, which has been commented on by the professional societies, will come into effect by the end of 2023. Based on this regulation, the Federal Joint Committee (G-BA) will set up a program for early lung cancer detection with LDCT in the near future. In this position paper, the specialist societies involved in lung cancer screening present key points for a uniform, structured and quality-assured early detection program for lung cancer in Germany to make a constructive contribution to this process. CITATION FORMAT: · Vogel-Claussen J, Blum TG, Andreas S et al. Position paper on the implementation of a nationally organized program in Germany for the early detection of lung cancer in high-risk populations using low-dose CT screening including the management of screening findings requiring further workup. Fortschr Röntgenstr 2024; 196: DOI 10.1055/a-2178-2846.


Assuntos
Detecção Precoce de Câncer , Neoplasias Pulmonares , Humanos , Tomografia Computadorizada por Raios X , Neoplasias Pulmonares/diagnóstico por imagem , Fatores de Risco , Alemanha , Programas de Rastreamento
17.
Magn Reson Med ; 69(6): 1761-7, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22829518

RESUMO

Magnetic particle imaging has emerged as a new technique for the visualization and quantification of superparamagnetic iron oxide nanoparticles. It seems to be a very promising application for cardiovascular interventional radiology. A prerequisite for interventions is the artifact-free visualization of the required instruments and implants. Various commercially available catheters, guide wires, and a catheter experimentally coated with superparamagnetic iron oxide nanoparticles were tested regarding their signal characteristics using magnetic particle spectroscopy to evaluate their performance in magnetic particle imaging. The results indicate that signal-generating and non-signal-generating instruments can be distinguished. Furthermore, coating or loading non-signal-generating instruments with superparamagnetic iron oxide nanoparticles seems to be a promising approach, but optimized nanoparticles need yet to be developed.


Assuntos
Artefatos , Cateteres Cardíacos , Dextranos , Imagem por Ressonância Magnética Intervencionista/instrumentação , Nanopartículas de Magnetita , Meios de Contraste , Desenho de Equipamento , Análise de Falha de Equipamento , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
18.
Eur Radiol ; 23(1): 298-306, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22777620

RESUMO

OBJECTIVES: Multi-station contrast-enhanced magnetic resonance angiography (MRA) is considered as the imaging investigation of first choice in patients suffering from peripheral arterial occlusive disease. In order to overcome venous overlay and to gain dynamic flow information as provided by digital subtraction angiography (DSA), we developed a triple injection protocol for high-resolution MRA of the entire peripheral vascular system, applying time-resolved (TR) four-dimensional (4D) MRA sequences. METHODS: Ten patients underwent three-station TR-MRA of the pelvis and lower extremities with DSA as reference standard. Both investigations were compared concerning stenosis on a segment-by-segment basis. Furthermore, 28 consecutive patients underwent the same MR-only imaging protocol. All images were evaluated concerning image quality (1 = non-diagnostic, 4 = excellent), venous overlay (from none up to substantial) and time to venous enhancement (very early/early/normal/late). RESULTS: Three-station TR-MRA proved feasible and was comparable with DSA in 282 vessel segments, with underestimation grade of stenosis in four segments and overestimation in four segments, respectively. In 32/38 patients no venous overlay was noted; in six patients there was mild venous overlay. Image quality was rated excellent or good in most cases. CONCLUSIONS: TR-MRA provides morphological and functional information without any timing issues due to optimal arterial enhancement at high spatial resolution without venous overlay.


Assuntos
Arteriopatias Oclusivas/diagnóstico , Angiografia por Ressonância Magnética/métodos , Doenças Vasculares Periféricas/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia Digital , Meios de Contraste , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Organometálicos
19.
Eur Radiol ; 23(9): 2392-404, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23645330

RESUMO

OBJECTIVES: To evaluate time-resolved interleaved stochastic trajectories (TWIST) contrast-enhanced 4D magnetic resonance angiography (MRA) and compare it with 3D FLASH MRA in patients with congenital heart and vessel anomalies. METHODS: Twenty-six patients with congenital heart and vessel anomalies underwent contrast-enhanced MRA with both 3D FLASH and 4D TWIST MRA. Images were subjectively evaluated regarding total image quality, artefacts, diagnostic value and added diagnostic value of 4D dynamic imaging. Quantitative comparison included signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and vessel sharpness measurements. RESULTS: Three-dimensional FLASH MRA was judged to be significantly better in terms of image quality (4.0 ± 0.6 vs 3.4 ± 0.6, P < 0.05) and artefacts (3.8 ± 0.4 vs 3.3 ± 0.5, P < 0.05); no difference in diagnostic value was found (4.2 ± 0.4 vs 4.0 ± 0.4); important additional functional information was found in 21/26 patients. SNR and CNR were higher in the pulmonary trunk in 4D TWIST, but slightly higher in the systemic arteries in 3D FLASH. No difference in vessel sharpness delineation was found. CONCLUSIONS: Although image quality was inferior compared with 3D FLASH MRA, 4D TWIST MRA yields robust images and added diagnostic value through dynamic acquisition was found. Thus, 4D TWIST MRA is an attractive alternative to 3D FLASH MRA. KEY POINTS: • New magnetic resonance angiography (MRA) techniques are increasingly introduced for congenital cardiovascular problems. • Time-resolved angiography with interleaved stochastic trajectories (TWIST) is an example. • Four-dimensional TWIST MRA provided inferior image quality compared to 3D FLASH MRA but without significant difference in vessel sharpness. • Four-dimensional TWIST MRA gave added diagnostic value.


Assuntos
Meios de Contraste/farmacologia , Cardiopatias Congênitas/patologia , Angiografia por Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Artefatos , Criança , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Razão Sinal-Ruído , Fatores de Tempo
20.
J Cardiovasc Magn Reson ; 15: 91, 2013 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-24103764

RESUMO

This document is an update to the 2008 publication of the Society for Cardiovascular Magnetic Resonance (SCMR) Board of Trustees Task Force on Standardized Protocols. Since the time of the original publication, 3 additional task forces (Reporting, Post-Processing, and Congenital Heart Disease) have published documents that should be referred to in conjunction with the present document. The section on general principles and techniques has been expanded as more of the techniques common to CMR have been standardized. There is still a great deal of development in the area of tissue characterization/mapping, so these protocols have been in general left as optional. The authors hope that this document continues to standardize and simplify the patient-based approach to clinical CMR. It will be updated at regular intervals as the field of CMR advances.


Assuntos
Doenças Cardiovasculares/diagnóstico , Imageamento por Ressonância Magnética/normas , Doenças Cardiovasculares/fisiopatologia , Doenças Cardiovasculares/terapia , Humanos , Valor Preditivo dos Testes , Prognóstico
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa