RESUMO
BACKGROUND AND PURPOSE: Multi-disciplinary Team (MDT) meetings are widely regarded as the 'gold standard' of lung cancer care. MDTs improve adherence to clinical guidelines for lung cancer patients. In this study, we describe and compare lung cancer MDTs in Denmark and Norway by combining national surveys and the MDT-Metric for the Observation of Decision-making (MDT-MODe) instrument. MATERIALS AND METHOD: Identical surveys were sent out to all lung cancer MDT centers in Denmark and Norway by the Danish Lung Cancer Group and the Norwegian Lung Cancer Group. Six MDT centers, three in Denmark and three in Norway, were observed using the MDT-MODe instrument. RESULTS AND INTERPRETATION: We found similar organization of MDT meetings in both countries, with the main difference being more local MDT meetings in Norway. All lung cancer MDTs were chaired by respiratory physicians and attended by a radiologist. Other members included oncologists, pathologists, thoracic surgeons, specialist nurses, nuclear medicine specialists and junior doctors. Overall, members reported that they had sufficient time for preparation and attending MDT meetings. With the MDT-MODe instrument it was found that the MDT chairs, surgeons, oncologists, radiologists all contributed positively to case discussion. Comorbidities were included in the discussion of most patients while the patient's view and psychosocial issues were less often discussed. A treatment decision was reached in 79.7% of cases discussed. In conclusion, we found similar settings and overall good quality concerning lung cancer MDT meetings in Denmark and Norway.
Assuntos
Neoplasias Pulmonares , Equipe de Assistência ao Paciente , Humanos , Noruega/epidemiologia , Dinamarca , Neoplasias Pulmonares/terapia , Equipe de Assistência ao Paciente/organização & administração , Inquéritos e Questionários , Comunicação InterdisciplinarRESUMO
INTRODUCTION: The established method for assessment of mediastinal and hilar lymph nodes is endobronchial ultrasound bronchoscopy (EBUS) with needle aspirations. Previously, we presented an electromagnetic navigation platform for this purpose. There were several issues with the permanent electromagnetic tracking (EMT) sensor attachment on the tip of the experimental EBUS bronchoscope. The purpose was to develop a device for on-site attachment of the EMT sensor. MATERIAL AND METHODS: A clip-on EMT sensor attachment device was 3D-printed in Ultem™ and attached to an EBUS bronchoscope. A specially designed ultrasound probe calibration adapter was developed for on-site and quick probe calibration. Navigation accuracy was studied using a wire cross water phantom and clinical feasibility was tested in a healthy volunteer. RESULTS: The device attached to the EBUS bronchoscope increased its diameter from 6.9 mm to 9.5 mm. Average preclinical navigation accuracy was 3.9 mm after adapter calibration. The maneuvering of the bronchoscope examining a healthy volunteer was adequate without harming the respiratory epithelium, and the device stayed firmly attached. CONCLUSION: Development, calibration and testing of a clip-on EMT sensor attachment device for EBUS bronchoscopy was successfully demonstrated. Acceptable accuracy results were obtained, and the device is ready to be tested in patient studies.
Assuntos
Broncoscopia , Neoplasias Pulmonares , Broncoscopia/métodos , Fenômenos Eletromagnéticos , Humanos , Neoplasias Pulmonares/patologia , Linfonodos/patologia , Instrumentos Cirúrgicos , ÁguaRESUMO
OBJECTIVE: Endoluminal visualization in virtual and video bronchoscopy lacks information about the surrounding structures, and the traditional 2 D axial, coronal and sagittal CT views can be difficult to interpret. To address this challenge, we previously introduced a novel visualization technique, Anchored to Centerline Curved Surface, for navigated bronchoscopy. The current study compares the ACCuSurf to the standard ACS CT views as planning and guiding tools in a phantom study. MATERIAL AND METHODS: Bronchoscope operators navigated in physical phantom guided by virtual realistic image data constructed by fusion of CT dataset of phantom and anonymized patient CT data. We marked four different target positions within the virtual image data and gave 12 pulmonologists the task to navigate, with either ACCuSurf or ACS as guidance, to the corresponding targets in the physical phantom. RESULTS: Using ACCuSurf reduced the planning time and increased the grade of successful navigation significantly compared to ACS. CONCLUSION: The phantom setup with virtual patient image data proved realistic according to the pulmonologists. ACCuSurf proved superior to ACS regarding planning time and navigation success grading. Improvements on visualisation or display techniques may consequently improve both planning and navigated bronchoscopy and thus contribute to more precise lung diagnostics.
Assuntos
Broncoscopia/métodos , Pulmão/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Humanos , Imagens de Fantasmas , PneumologistasRESUMO
OBJECTIVE: In flexible endoscopy techniques, such as bronchoscopy, there is often a challenge visualizing the path from start to target based on preoperative data and accessing these during the procedure. An example of this is visualizing only the inside of central airways in bronchoscopy. Virtual bronchoscopy (VB) does not meet the pulmonologist's need to detect, define and sample the frequent targets outside the bronchial wall. Our aim was to develop and study a new visualization technique for navigated bronchoscopy. MATERIAL AND METHODS: We extracted the shortest possible path from the top of the trachea to the target along the airway centerline and a corresponding auxiliary route in the opposite lung. A surface structure between the centerlines was developed and displayed. The new technique was tested on non-selective CT data from eight patients using artificial lung targets. RESULTS: The new display technique anchored to centerline curved surface (ACCuSurf) made it easy to detect and interpret anatomical features, targets and neighboring anatomy outside the airways, in all eight patients. CONCLUSIONS: ACCuSurf can simplify planning and performing navigated bronchoscopy, meets the challenge of improving orientation and register the direction of the moving endoscope, thus creating an optimal visualization for navigated bronchoscopy.
Assuntos
Broncoscopia , Processamento de Imagem Assistida por Computador , Neoplasias Pulmonares/diagnóstico , Algoritmos , Biópsia , Humanos , Imageamento Tridimensional , Neoplasias Pulmonares/patologia , Técnicas Estereotáxicas , Tomografia Computadorizada por Raios XRESUMO
Endobronchial ultrasound (EBUS) is used in the minimally invasive sampling of thoracic lymph nodes. In lung cancer staging, the accurate assessment of mediastinal structures is essential but challenged by variations in anatomy, image quality, and operator-dependent image interpretation. This study aimed to automatically detect and segment mediastinal lymph nodes and blood vessels employing a novel U-Net architecture-based approach in EBUS images. A total of 1161 EBUS images from 40 patients were annotated. For training and validation, 882 images from 30 patients and 145 images from 5 patients were utilized. A separate set of 134 images was reserved for testing. For lymph node and blood vessel segmentation, the mean ± standard deviation (SD) values of the Dice similarity coefficient were 0.71 ± 0.35 and 0.76 ± 0.38, those of the precision were 0.69 ± 0.36 and 0.82 ± 0.22, those of the sensitivity were 0.71 ± 0.38 and 0.80 ± 0.25, those of the specificity were 0.98 ± 0.02 and 0.99 ± 0.01, and those of the F1 score were 0.85 ± 0.16 and 0.81 ± 0.21, respectively. The average processing and segmentation run-time per image was 55 ± 1 ms (mean ± SD). The new U-Net architecture-based approach (EBUS-AI) could automatically detect and segment mediastinal lymph nodes and blood vessels in EBUS images. The method performed well and was feasible and fast, enabling real-time automatic labeling.
RESUMO
BACKGROUND AND OBJECTIVE: Patients suspected to have lung cancer, undergo endobronchial ultrasound bronchoscopy (EBUS) for the purpose of diagnosis and staging. For presumptive curable patients, the EBUS bronchoscopy is planned based on images and data from computed tomography (CT) images and positron emission tomography (PET). Our study aimed to evaluate the feasibility of a multimodal electromagnetic navigation platform for EBUS bronchoscopy, integrating ultrasound and segmented CT, and PET scan imaging data. METHODS: The proof-of-concept study included patients with suspected lung cancer and pathological mediastinal/hilar lymph nodes identified on both CT and PET scans. Images obtained from these two modalities were segmented to delineate target lymph nodes and then incorporated into the CustusX navigation platform. The EBUS bronchoscope was equipped with a sensor, calibrated, and affixed to a 3D printed click-on device positioned at the bronchoscope's tip. Navigation accuracy was measured postoperatively using ultrasound recordings. RESULTS: The study enrolled three patients, all presenting with suspected mediastinal lymph node metastasis (N1-3). All PET-positive lymph nodes were displayed in the navigation platform during the EBUS procedures. In total, five distinct lymph nodes were sampled, yielding malignant cells from three nodes and lymphocytes from the remaining two. The median accuracy of the navigation system was 7.7 mm. CONCLUSION: Our study introduces a feasible multimodal electromagnetic navigation platform that combines intraoperative ultrasound with preoperative segmented CT and PET imaging data for EBUS lymph node staging examinations. This innovative approach holds promise for enhancing the accuracy and effectiveness of EBUS procedures.
Assuntos
Broncoscopia , Estudos de Viabilidade , Neoplasias Pulmonares , Tomografia por Emissão de Pósitrons , Humanos , Broncoscopia/métodos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Masculino , Tomografia por Emissão de Pósitrons/métodos , Idoso , Feminino , Pessoa de Meia-Idade , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Tomografia Computadorizada por Raios X/métodos , Metástase Linfática/diagnóstico por imagem , Ultrassonografia/métodosRESUMO
The purpose of this study was to evaluate the accuracy of a method for estimating the tip position of a fiber optic shape-sensing (FOSS) integrated instrument being inserted through a bronchoscope. A modified guidewire with a multicore optical fiber was inserted into the working channel of a custom-made catheter with three electromagnetic (EM) sensors. The displacement between the instruments was manually set, and a point-based method was applied to match the position of the EM sensors to corresponding points on the shape. The accuracy was evaluated in a realistic bronchial model. An additional EM sensor was used to sample the tip of the guidewire, and the absolute deviation between this position and the estimated tip position was calculated. For small displacements between the tip of the FOSS integrated tool and the catheter, the median deviation in estimated tip position was ≤5 mm. For larger displacements, deviations exceeding 10 mm were observed. The deviations increased when the shape sensor had sharp curvatures relative to more straight shapes. The method works well for clinically relevant displacements of a biopsy tool from the bronchoscope tip, and when the path to the lesion has limited curvatures. However, improvements must be made to our configuration before pursuing further clinical testing.
Assuntos
Broncoscopia , Fenômenos Eletromagnéticos , Broncoscopia/métodos , Imagens de Fantasmas , CatéteresRESUMO
PURPOSE: The authors have studied the accuracy and robustness of a prototype electromagnetic window field generator (WFG) in an interventional radiology suite with a robotic C-arm. The overall purpose is the development of guidance systems combining real-time imaging with tracking of flexible instruments for bronchoscopy, laparoscopic ultrasound, endoluminal surgery, endovascular therapy, and spinal surgery. METHODS: The WFG has a torus shape, which facilitates x-ray imaging through its centre. The authors compared the performance of the WFG to that of a standard field generator (SFG) under the influence of the C-arm. Both accuracy and robustness measurements were performed with the C-arm in different positions and poses. RESULTS: The system was deemed robust for both field generators, but the accuracy was notably influenced as the C-arm was moved into the electromagnetic field. The SFG provided a smaller root-mean-square position error but was more influenced by the C-arm than the WFG. The WFG also produced smaller maximum and variance of the error. CONCLUSIONS: Electromagnetic (EM) tracking with the new WFG during C-arm based fluoroscopy guidance seems to be a step forward, and with a correction scheme implemented it should be feasible.
Assuntos
Magnetismo/instrumentação , Cirurgia Assistida por Computador/instrumentação , Instrumentos Cirúrgicos , Desenho de Equipamento , Análise de Falha de EquipamentoRESUMO
Electromagnetic guided bronchoscopy is a new field of research, essential for the development of advanced investigation of the airways and lung tissue. Consecutive problem-based solutions and refinements are urgent requisites to achieve improvements. For that purpose, our intention is to build a complete research platform for electromagnetic guided bronchoscopy. The experimental interventional electromagnetic field tracking system in conjunction with a C-arm cone beam CT unit is presented in this paper. The animal model and the navigation platform performed well and the aims were achieved; the 3D localization of foreign bodies and their navigated and tracked removal, assessment of tracking accuracy that showed a high level of precision, and assessment of image quality. The platform may prove to be a suitable platform for further research and development and a full-fledged electromagnetic guided bronchoscopy navigation system. The inclusion of the C-arm cone beam CT unit in the experimental setup adds a number of new possibilities for diagnostic procedures and accuracy measurements. Among other future challenges that need to be solved are the interaction between the C-arm and the electromagnetic navigation field, as we demonstrate in this feasibility study.
Assuntos
Broncoscopia/métodos , Tomografia Computadorizada de Feixe Cônico/métodos , Fenômenos Eletromagnéticos , Animais , Estudos de Viabilidade , Modelos Animais , SuínosRESUMO
PURPOSE: The aim of this paper is to show how a specialized planning and guidance application called Fraxinus, can be built on top of the CustusX platform (www.custusx.org), which is an open source image-guided intervention software platform. Fraxinus has been customized to meet the clinical needs in navigated bronchoscopy. METHODS: The application requirements for Fraxinus were defined in close collaboration between research scientists, software developers and clinicians (pulmonologists), and built on top of CustusX. Its superbuild system downloads specific versions of the required libraries and builds them for the application in question, including the selected plugins. New functionality is easily added through the plugin framework. The build process enables the creation of specialized applications, adding additional documentation and custom configurations. The toolkit's libraries offer building blocks for image-guided applications. An iterative development process was applied, where the clinicians would test and provide feedback during the entire process. RESULTS: Fraxinus has been developed and is released as an open source planning and guidance application built on top of CustusX. It is highly specialized for bronchoscopy. The proposed workflow is adapted to the different steps in this procedure. The user interface of CustusX has been modified to enhance information, quality assurance and user friendliness with the intention to increase the overall yield for the patient. As the workflow of the procedure is relatively constant, some actions are predicted and automatically performed by the application, according to the requirements from the clinicians. CONCLUSIONS: The CustusX platform facilitates development of new and specialized applications. The toolkit supports the process and makes important extension and injection points available for customization.
Assuntos
Algoritmos , Broncoscopia/métodos , Software , Interface Usuário-Computador , HumanosRESUMO
PURPOSE: Electromagnetic tracking is a core platform technology in the navigation and visualisation of image-guided procedures. The technology provides high tracking accuracy in non-line-of-sight environments, allowing instrument navigation in locations where optical tracking is not feasible. EMT can be beneficial in applications such as percutaneous radiofrequency ablation for the treatment of hepatic lesions where the needle tip may be obscured due to difficult liver environments (e.g subcutaneous fat or ablation artefacts). Advances in the field of EMT include novel methods of improving tracking system accuracy, precision and error compensation capabilities, though such system-level improvements cannot be readily incorporated in current therapy applications due to the 'blackbox' nature of commercial tracking solving algorithms. METHODS: This paper defines a software framework to allow novel EMT designs, and improvements become part of the global design process for image-guided interventions. An exemplary framework is implemented in the Python programming language and demonstrated with the open-source Anser EMT system. The framework is applied in the preclinical setting though targeted liver ablation therapy on an animal model. RESULTS: The developed framework was tested with the Anser EMT electromagnetic tracking platform. Liver tumour targeting was performed using the tracking framework with the CustusX navigation platform using commercially available electromagnetically tracked needles. Ablation of two tumours was performed with a commercially available ablation system. Necropsy of the tumours indicated ablations within 5 mm of the tumours. CONCLUSIONS: An open-source framework for electromagnetic tracking was presented and effectively demonstrated in the preclinical setting. We believe that this framework provides a structure for future advancement in EMT system in and customised instrument design.
Assuntos
Ablação por Cateter/métodos , Fenômenos Eletromagnéticos , Neoplasias Hepáticas/cirurgia , Cirurgia Assistida por Computador/métodos , Algoritmos , Animais , Biópsia por Agulha , Desenho de Equipamento , Feminino , Fígado/cirurgia , Agulhas , Reprodutibilidade dos Testes , Software , SuínosRESUMO
INTRODUCTION: Endobronchial ultrasound with transbronchial needle aspiration (EBUS-TBNA) has become an important diagnostic tool for the pulmonologist. Learning this procedure and maintaining technical skills requires continuous practice and evaluation. OBJECTIVES: The aims of the study were a retrospective evaluation of the diagnostic quality of the EBUS-technique and the learning profile of the endoscopy team during the first years (2007-2013) of experience in an unselected population. METHODS: EBUS-TBNA procedures were analysed for clinical data, including results from surgery or clinical/radiological follow-up for at least 6 months. Rapid on-site cytological evaluation (ROSE) was introduced on regular basis the forth year. RESULTS: A total of 711 EBUS-TBNA from 635 patients were included. The percentage of representative EBUS-TBNA initially decreased the first years (minimum 60,9%), before increased to a final result of 82,4%. There was a lower proportion of representative EBUS-TBNA in the benign group (76,8%) vs the malignant group (85,8%). A significant increase in the proportion of representative EBUS-TBNA was seen after ROSE had been introduced. The major indications were diagnosing/staging of lung cancer (54%) and mediastinal lymphadenopathy of unknown cause (25,7%). The sensitivity detecting malignancy was 94,9%, negative predictive value 81,2% and diagnostic accuracy 95,8%. During the study period the percentage of re-examinations with EBUS-TBNA declined from 18,0% to 8,2%. CONCLUSION: After an initial run-in period with declining results, the overall diagnostic yield of EBUS-TBNA increased and reached acceptable levels. These results underline the importance of continuously evaluation of our own results when new methods are implemented in clinical practice.
Assuntos
Competência Clínica , Educação de Pós-Graduação em Medicina , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico/métodos , Aprendizagem , Neoplasias Pulmonares/diagnóstico , Pneumologia/educação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Brônquios , Criança , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Adulto JovemRESUMO
BACKGROUND: Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is the endoscopic method of choice for confirming lung cancer metastasis to mediastinal lymph nodes. Precision is crucial for correct staging and clinical decision-making. Navigation and multimodal imaging can potentially improve EBUS-TBNA efficiency. AIMS: To demonstrate the feasibility of a multimodal image guiding system using electromagnetic navigation for ultrasound bronchoschopy in humans. METHODS: Four patients referred for lung cancer diagnosis and staging with EBUS-TBNA were enrolled in the study. Target lymph nodes were predefined from the preoperative computed tomography (CT) images. A prototype convex probe ultrasound bronchoscope with an attached sensor for position tracking was used for EBUS-TBNA. Electromagnetic tracking of the ultrasound bronchoscope and ultrasound images allowed fusion of preoperative CT and intraoperative ultrasound in the navigation software. Navigated EBUS-TBNA was used to guide target lymph node localization and sampling. Navigation system accuracy was calculated, measured by the deviation between lymph node position in ultrasound and CT in three planes. Procedure time, diagnostic yield and adverse events were recorded. RESULTS: Preoperative CT and real-time ultrasound images were successfully fused and displayed in the navigation software during the procedures. Overall navigation accuracy (11 measurements) was 10.0 ± 3.8 mm, maximum 17.6 mm, minimum 4.5 mm. An adequate sample was obtained in 6/6 (100%) of targeted lymph nodes. No adverse events were registered. CONCLUSIONS: Electromagnetic navigated EBUS-TBNA was feasible, safe and easy in this human pilot study. The clinical usefulness was clearly demonstrated. Fusion of real-time ultrasound, preoperative CT and electromagnetic navigational bronchoscopy provided a controlled guiding to level of target, intraoperative overview and procedure documentation.
Assuntos
Broncoscopia/métodos , Endossonografia/métodos , Biópsia Guiada por Imagem/métodos , Neoplasias Pulmonares/patologia , Idoso , Broncoscopia/efeitos adversos , Broncoscopia/instrumentação , Endossonografia/instrumentação , Estudos de Viabilidade , Humanos , Biópsia Guiada por Imagem/instrumentação , Imagem Multimodal/instrumentação , Imagem Multimodal/métodos , Complicações Pós-Operatórias , Tomografia Computadorizada por Raios X/instrumentação , Tomografia Computadorizada por Raios X/métodosRESUMO
PURPOSE: One of the major challenges in electromagnetic navigated bronchoscopy is the navigation accuracy. An initial rigid image-to-patient registration may not be optimal for the entire lung volume, as the lung tissue anatomy is likely to have shifted since the time of computer tomography (CT) acquisition. The accuracy of the initial rigid registration will also be affected throughout the procedure by breathing, coughing, patient movement and tissue displacements due to pressure from bronchoscopy tools. A method to minimize the negative impact from these factors by updating the registration locally during the procedure is needed and suggested in this paper. METHODS: The intraoperative local registration method updates the initial registration by optimization in an area of special interest, for example, close to a biopsy position. The local registration was developed through an adaptation of a previously published registration method used for the initial registration of CT to the patient anatomy. The method was tested in an experimental breathing phantom setup, where respiratory movements were induced by a robotic arm. Deformations were also applied to the phantom to see if the local registration could compensate for these. RESULTS: The local registration was successfully applied in all 15 repetitions, five in each of the three parts of the airway phantom. The mean registration accuracy was improved from 11.8-19.4 mm to 4.0-6.7 mm, varying to some degree in the different segments of the airway model. CONCLUSIONS: A local registration method, to update and improve the initial image-to patient registration during navigated bronchoscopy, was developed. The method was successfully tested in a breathing phantom setup. Further development is needed to make the method more automatic. It must also be verified in human studies.
Assuntos
Broncoscopia , Imagens de Fantasmas , Biópsia , Fenômenos Eletromagnéticos , Humanos , Pulmão/diagnóstico por imagem , Respiração , Tomografia Computadorizada por Raios XRESUMO
PURPOSE: Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) of mediastinal lymph nodes is essential for lung cancer staging and distinction between curative and palliative treatment. Precise sampling is crucial. Navigation and multimodal imaging may improve the efficiency of EBUS-TBNA. We demonstrate a novel EBUS-TBNA navigation system in a dedicated airway phantom. METHODS: Using a convex probe EBUS bronchoscope (CP-EBUS) with an integrated sensor for electromagnetic (EM) position tracking, we performed navigated CP-EBUS in a phantom. Preoperative computed tomography (CT) and real-time ultrasound (US) images were integrated into a navigation platform for EM navigated bronchoscopy. The coordinates of targets in CT and US volumes were registered in the navigation system, and the position deviation was calculated. RESULTS: The system visualized all tumor models and displayed their fused CT and US images in correct positions in the navigation system. Navigating the EBUS bronchoscope was fast and easy. Mean error observed between US and CT positions for 11 target lesions (37 measurements) was [Formula: see text] mm, maximum error was 5.9 mm. CONCLUSION: The feasibility of our novel navigated CP-EBUS system was successfully demonstrated. An EBUS navigation system is needed to meet future requirements of precise mediastinal lymph node mapping, and provides new opportunities for procedure documentation in EBUS-TBNA.
Assuntos
Broncoscopia/métodos , Endossonografia/métodos , Neoplasias Pulmonares/diagnóstico por imagem , Linfonodos/diagnóstico por imagem , Metástase Linfática/diagnóstico por imagem , Mediastino/diagnóstico por imagem , Fenômenos Eletromagnéticos , Humanos , Neoplasias Pulmonares/patologia , Linfonodos/patologia , Metástase Linfática/patologia , Mediastino/patologia , Imagem Multimodal , Estadiamento de Neoplasias , Imagens de Fantasmas , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Malignant airway obstruction is a feared complication and will most probably occur more frequently in the future because of increasing cancer incidence and increased life expectancy in cancer patients. Minimal invasive treatment using airway stents represents a meaningful and life-saving palliation. We present a new removable airway stent for improved individualised treatment. METHODS: To our knowledge, the new airway stent is the world's first knitted and uncovered self-expanding metal stent, which can unravel and be completely removed. In an in vivo model using two anaesthetised and spontaneously breathing pigs, we deployed and subsequently removed the stents by unravelling the device. The procedures were executed by flexible bronchoscopy in an acute and a chronic setting - a 'proof-of-principle' study. RESULTS: The new stent was easily and accurately deployed in the central airways, and it remained fixed in its original position. It was easy to unravel and completely remove from the airways without clinically significant complications. During the presence of the stent in the chronic study, granulation tissue was induced. This tissue disappeared spontaneously with the removal. CONCLUSIONS: The new removable stent functioned according to its purpose and unravelled easily, and it was completely removed without significant technical or medical complications. Induced granulation tissue disappeared spontaneously. Further studies on animals and humans are needed to define its optimal indications and future use.
RESUMO
INTRODUCTION: Our motivation is increased bronchoscopic diagnostic yield and optimized preparation, for navigated bronchoscopy. In navigated bronchoscopy, virtual 3D airway visualization is often used to guide a bronchoscopic tool to peripheral lesions, synchronized with the real time video bronchoscopy. Visualization during navigated bronchoscopy, the segmentation time and methods, differs. Time consumption and logistics are two essential aspects that need to be optimized when integrating such technologies in the interventional room. We compared three different approaches to obtain airway centerlines and surface. METHOD: CT lung dataset of 17 patients were processed in Mimics (Materialize, Leuven, Belgium), which provides a Basic module and a Pulmonology module (beta version) (MPM), OsiriX (Pixmeo, Geneva, Switzerland) and our Tube Segmentation Framework (TSF) method. Both MPM and TSF were evaluated with reference segmentation. Automatic and manual settings allowed us to segment the airways and obtain 3D models as well as the centrelines in all datasets. We compared the different procedures by user interactions such as number of clicks needed to process the data and quantitative measures concerning the quality of the segmentation and centrelines such as total length of the branches, number of branches, number of generations, and volume of the 3D model. RESULTS: The TSF method was the most automatic, while the Mimics Pulmonology Module (MPM) and the Mimics Basic Module (MBM) resulted in the highest number of branches. MPM is the software which demands the least number of clicks to process the data. We found that the freely available OsiriX was less accurate compared to the other methods regarding segmentation results. However, the TSF method provided results fastest regarding number of clicks. The MPM was able to find the highest number of branches and generations. On the other hand, the TSF is fully automatic and it provides the user with both segmentation of the airways and the centerlines. Reference segmentation comparison averages and standard deviations for MPM and TSF correspond to literature. CONCLUSION: The TSF is able to segment the airways and extract the centerlines in one single step. The number of branches found is lower for the TSF method than in Mimics. OsiriX demands the highest number of clicks to process the data, the segmentation is often sparse and extracting the centerline requires the use of another software system. Two of the software systems performed satisfactory with respect to be used in preprocessing CT images for navigated bronchoscopy, i.e. the TSF method and the MPM. According to reference segmentation both TSF and MPM are comparable with other segmentation methods. The level of automaticity and the resulting high number of branches plus the fact that both centerline and the surface of the airways were extracted, are requirements we considered particularly important. The in house method has the advantage of being an integrated part of a navigation platform for bronchoscopy, whilst the other methods can be considered preprocessing tools to a navigation system.
Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador , Pulmão/diagnóstico por imagem , Radiografia Torácica , Tomografia Computadorizada por Raios X , Humanos , Software , Interface Usuário-ComputadorRESUMO
PURPOSE: Electromagnetic based navigated bronchoscopy using preoperative CT images has reached the clinic during the last decade. One of the challenges is the "CT to patient anatomy alignment" of the CT images acquired days or even weeks ahead of bronchoscopy. An automatic registration method, without manual registration of anatomical landmarks, was developed, implemented, and evaluated in the current study. METHODS: The registration method aligns automatically the preoperative CT images to the patient's anatomy during the initial part of the bronchoscopy. The algorithm is a modified version of an iterative closest point algorithm, which in addition to the positions also utilizes the orientation of the bronchoscope and the running direction of the CT centerline. The method was evaluated both by model-based simulated bronchoscopies and by clinical data from six real bronchoscopies. In the clinical evaluation, an electromagnetic position sensor was placed temporarily in the working channel close to the tip of a conventional bronchoscope. Position data, which were acquired while the bronchoscope was moving inside the airways, were registered to the centerline extracted from the airways in the CT image. RESULTS: A mean registration accuracy of 3.0 ± 1.4 mm was found when simulating bronchoscopies. In the clinical part of the study, the registration method was successfully applied to the data from all six patients. The positions of the bronchoscope tip aligned to the CT centerline with a mean distance range 4.7-6.5 mm. CONCLUSIONS: The authors have developed and evaluated an automatic registration algorithm for electromagnetic navigated bronchoscopy. It functioned to its purpose and did not affect the workflow for the bronchoscopic investigation of the six patients included in the study.