RESUMO
Sorriso gengival é comumente conhecido pela exposição excessiva das gengivas ao sorrir, acarretando assim na diminuição das coroas dos elementos. No que tange a etiologia dessa condição, ela se apresenta de maneiras diversas e sua identificação é fundamental para o desenvolvimento de um plano de tratamento eficaz. O planejamento clínico pode ser feito usando uma abordagem dinâmica e digital do sorriso, como softwares, exames de imagem, modelos virtuais 3D e guias cirúrgicos, melhorando a qualidade e precisão do tratamento, oferecendo diversos benefícios aos pacientes. Sendo assim esse estudo teve como objetivo demonstrar a importância dos processos digitais no planejamento e correção do sorriso gengival. Paciente queixou-se da desproporção do sorriso, caracterizado por coroas curtas nas regiões de pré-molares e incisivos ligadamente com a exposição excessiva da gengiva ao sorrir. Após estudos clínicos e de imagem, a etiologia foi diagnosticada como erupção passiva alterada, tipo I (fenótipo espesso). O tratamento de escolha foi o remodelamento gengival associado à osteotomia e osteoplastia obtendo assim uma maior precisão no tratamento, sendo confeccionado um guia cirúrgico duplo. Sendo assim, é possível contemplar que o planejamento digital permite uma maior previsibilidade da execução, compatibilidade em relação a expectativa do paciente e profissional, além da total individualização do caso, tornando os resultados mais favoráveis e exatos e minimizando as chances de iatrogenias(AU)
Gummy smile is commonly known for exposing the gums to the smile, thereby increasing the crowns elevation of the elements. Regarding a condition, it presents itself in different ways and its identification is fundamental for the development of a treatment plan. The clinician can be done using a dynamic and digital approach to image treatment, such as software, imaging exams, various 3D virtual models and elaborate guides, improving the quality and precision of treatment, offering benefits to patients. Therefore, this study aimed to demonstrate the importance of digital processes in planning and correcting the gummy smile. Patient complained of disproportion of the smile, facing the regions of premolar crowns and incisors of the smile, facing the exposure of the gingiva when smiling. After clinical and imaging exams, the diagnostic studies were diagnosed as passive eruption, type I (phenotype and specific). The choice of choice was remodeling associated with surgery treatment and surgery treatment, thus providing a greater precision in the treatment, being a double guide elaborated. Therefore, it is possible that the digital is possible a predictability of execution, compatibility in relation to patient and professional care, in addition to the greater possibility of individualization planning than it allows, making the results more planned as possibilities and exactly the iatrogenic(AU)
Assuntos
Humanos , Feminino , Adulto , Planejamento , Gengivoplastia , Osteotomia , Dente Pré-Molar , Coroas , Imageamento Tridimensional , GengivaRESUMO
The registration of preoperative magnetic resonance (MR) images and intraoperative ultrasound (US) images is very important in the planning of brain tumor surgery and during surgery. Considering that the two-modality images have different intensity range and resolution, and the US images are degraded by lots of speckle noises, a self-similarity context (SSC) descriptor based on local neighborhood information was adopted to define the similarity measure. The ultrasound images were considered as the reference, the corners were extracted as the key points using three-dimensional differential operators, and the dense displacement sampling discrete optimization algorithm was adopted for registration. The whole registration process was divided into two stages including the affine registration and the elastic registration. In the affine registration stage, the image was decomposed using multi-resolution scheme, and in the elastic registration stage, the displacement vectors of key points were regularized using the minimum convolution and mean field reasoning strategies. The registration experiment was performed on the preoperative MR images and intraoperative US images of 22 patients. The overall error after affine registration was (1.57 ± 0.30) mm, and the average computation time of each pair of images was only 1.36 s; while the overall error after elastic registration was further reduced to (1.40 ± 0.28) mm, and the average registration time was 1.53 s. The experimental results show that the proposed method has prominent registration accuracy and high computational efficiency.
Assuntos
Imageamento Tridimensional , Cirurgia Assistida por Computador , Humanos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Ultrassonografia/métodos , Algoritmos , Cirurgia Assistida por Computador/métodosRESUMO
Magnetic resonance (MR) imaging is an important tool for prostate cancer diagnosis, and accurate segmentation of MR prostate regions by computer-aided diagnostic techniques is important for the diagnosis of prostate cancer. In this paper, we propose an improved end-to-end three-dimensional image segmentation network using a deep learning approach to the traditional V-Net network (V-Net) network in order to provide more accurate image segmentation results. Firstly, we fused the soft attention mechanism into the traditional V-Net's jump connection, and combined short jump connection and small convolutional kernel to further improve the network segmentation accuracy. Then the prostate region was segmented using the Prostate MR Image Segmentation 2012 (PROMISE 12) challenge dataset, and the model was evaluated using the dice similarity coefficient (DSC) and Hausdorff distance (HD). The DSC and HD values of the segmented model could reach 0.903 and 3.912 mm, respectively. The experimental results show that the algorithm in this paper can provide more accurate three-dimensional segmentation results, which can accurately and efficiently segment prostate MR images and provide a reliable basis for clinical diagnosis and treatment.
Assuntos
Próstata , Neoplasias da Próstata , Masculino , Humanos , Próstata/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Imageamento Tridimensional/métodos , Neoplasias da Próstata/diagnóstico por imagemRESUMO
Selective dorsal rhizotomy (SDR) is a difficult, risky, and sophisticated operation, in which a laminectomy should not only expose an adequate surgical field of view but also protect the patient's spinal nerves from injury. Digital models play an important role in the pre-and intra-operation of SDR, because they can not only make doctors more familiar with the anatomical structure of the surgical site, but also provide precise surgical navigation coordinates for the manipulator. This study aims to create a 3D digital model of a patient-specific lumbar vertebra that can be used for planning, surgical navigation, and training of the SDR operation. The 3D printing model is also manufactured for more effective work during these processes. Traditional orthopedic digital models rely almost entirely on computed tomography (CT) data, which is less sensitive to soft tissues. Fusion of the bone structure from CT and the neural structure from magnetic resonance imaging (MRI) is the key element for the model reconstruction in this study. The patient's specific 3D digital model is reconstructed for the real appearance of the surgical area and shows the accurate measurement of inter-structural distances and regional segmentation, which can effectively help in the preoperative planning and training of SDR. The transparent bone structure material of the 3D-printed model allows surgeons to clearly distinguish the relative relationship between the spinal nerve and the vertebral plate of the operated segment, enhancing their anatomical understanding and spatial sense of the structure. The advantages of the individualized 3D digital model and its accurate relationship between spinal nerve and bone structures make this method a good choice for preoperative planning of SDR surgery.
Assuntos
Imageamento Tridimensional , Impressão Tridimensional , Humanos , Imageamento Tridimensional/métodos , Vértebras Lombares , Tomografia Computadorizada por Raios X , Imageamento por Ressonância MagnéticaRESUMO
The aim of the present study was to develop a 3D digital image-analysis method to quantitatively assess gingival changes after clear-aligner orthodontic therapy. Using teeth as fixed reference points, 3D image analysis tools have been used to quantify mucosal level changes after specific therapies. This technology has not been applied to orthodontic therapy, primarily because orthodontic tooth movement precludes using teeth as fixed reference points. Rather than superimposing the pre- and posttherapy volumes for the entire dentition, the methodology presented herein superimposed the pre- and post-therapy volumes for individual teeth. The lingual tooth surfaces, which remained unaltered, were used as fixed references. Intraoral scans taken before and after clear-aligner orthodontic therapy were imported for comparison. Volumes were created for each 3D image and were superimposed in a 3D image-analysis software that allowed quantitative measurements. The results demonstrated this technique's ability to measure very small changes in the apicocoronal position of the gingival zenith, as well as alterations of gingival margin thickness, following clear-aligner orthodontic therapy. The present 3D image-analysis method offers a useful tool for investigating the periodontal dimensional and positional changes that accompany orthodontic therapy.
Assuntos
Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Humanos , Projetos Piloto , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Técnicas de Movimentação Dentária , Gengiva/diagnóstico por imagemRESUMO
BACKGROUND: Lung cross-section is one of the emphases and challenges in sectional anatomy. Identification of the complex arrangement of intrapulmonary tubes such as bronchi, arteries, and veins in the lungs requires the spatial imagination of students. Three-dimensional (3D) printing has become increasingly used in anatomy education. This study aimed to analyze the effectiveness of 3D-printed specimens used for the experimental teaching of sectional anatomy. METHODS: A digital thoracic dataset was obtained and input into a 3D printer to print multicolor specimens of the pulmonary segment after software processing. As research subjects, 119 undergraduate students majoring in medical imaging from classes 5-8 in the second-year were chosen. In the lung cross-section experiment course, 59 students utilized 3D printed specimens in conjunction with traditional instruction as the study group, while 60 students received traditional teaching as the control group. Preclass and postclass tests, course grading, and questionnaire surveys were used to assess instructional efficacy. RESULTS: We obtained a set of pulmonary segment specimens for teaching. The students in the study group scored better in the postclass test than those in the control group (P < 0.05), and the students in the study group scored higher in satisfaction with the teaching content and spatial thinking for sectional anatomy than those in the control group (P < 0.05). The course grades and excellence rates in the study group exceeded those in the control group (P < 0.05). CONCLUSION: The application of high-precision multicolor 3D-printed specimens of lung segments in experimental teaching of sectional anatomy can improve teaching effectiveness and is worth adopting and promoting in sectional anatomy courses.
Assuntos
Avaliação Educacional , Estudantes de Medicina , Humanos , Imageamento Tridimensional/métodos , Anatomia Transversal , Impressão Tridimensional , Pulmão/diagnóstico por imagemRESUMO
The leaf phenotypic traits of plants have a significant impact on the efficiency of canopy photosynthesis. However, traditional methods such as destructive sampling will hinder the continuous monitoring of plant growth, while manual measurements in the field are both time-consuming and laborious. Nondestructive and accurate measurements of leaf phenotypic parameters can be achieved through the use of 3D canopy models and object segmentation techniques. This paper proposed an automatic branch-leaf segmentation pipeline based on lidar point cloud and conducted the automatic measurement of leaf inclination angle, length, width, and area, using pear canopy as an example. Firstly, a three-dimensional model using a lidar point cloud was established using SCENE software. Next, 305 pear tree branches were manually divided into branch points and leaf points, and 45 branch samples were selected as test data. Leaf points were further marked as 572 leaf instances on these test data. The PointNet++ model was used, with 260 point clouds as training input to carry out semantic segmentation of branches and leaves. Using the leaf point clouds in the test dataset as input, a single leaf instance was extracted by means of a mean shift clustering algorithm. Finally, based on the single leaf point cloud, the leaf inclination angle was calculated by plane fitting, while the leaf length, width, and area were calculated by midrib fitting and triangulation. The semantic segmentation model was tested on 45 branches, with a mean Precisionsem, mean Recallsem, mean F1-score, and mean Intersection over Union (IoU) of branches and leaves of 0.93, 0.94, 0.93, and 0.88, respectively. For single leaf extraction, the Precisionins, Recallins, and mean coverage (mCoV) were 0.89, 0.92, and 0.87, respectively. Using the proposed method, the estimated leaf inclination, length, width, and area of pear leaves showed a high correlation with manual measurements, with correlation coefficients of 0.94 (root mean squared error: 4.44°), 0.94 (root mean squared error: 0.43 cm), 0.91 (root mean squared error: 0.39 cm), and 0.93 (root mean squared error: 5.21 cm2), respectively. These results demonstrate that the method can automatically and accurately measure the phenotypic parameters of pear leaves. This has great significance for monitoring pear tree growth, simulating canopy photosynthesis, and optimizing orchard management.
Assuntos
Imageamento Tridimensional , Pyrus , Imageamento Tridimensional/métodos , Árvores , Plantas , Folhas de PlantaRESUMO
Tissue dynamics play critical roles in many physiological functions and provide important metrics for clinical diagnosis. Capturing real-time high-resolution 3D images of tissue dynamics, however, remains a challenge. This study presents a hybrid physics-informed neural network algorithm that infers 3D flow-induced tissue dynamics and other physical quantities from sparse 2D images. The algorithm combines a recurrent neural network model of soft tissue with a differentiable fluid solver, leveraging prior knowledge in solid mechanics to project the governing equation on a discrete eigen space. The algorithm uses a Long-short-term memory-based recurrent encoder-decoder connected with a fully connected neural network to capture the temporal dependence of flow-structure-interaction. The effectiveness and merit of the proposed algorithm is demonstrated on synthetic data from a canine vocal fold model and experimental data from excised pigeon syringes. The results showed that the algorithm accurately reconstructs 3D vocal dynamics, aerodynamics, and acoustics from sparse 2D vibration profiles.
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Redes Neurais de Computação , Prega Vocal , Animais , Cães , Prega Vocal/fisiologia , Imageamento Tridimensional , Algoritmos , FísicaRESUMO
BACKGROUND: Neuroanatomy is the most abstract and complex anatomy. Neurosurgeons have to spend plenty of time mastering the nuances of the autopsy. However, the laboratory that can meet the requirements of neurosurgery microanatomy is only owned by several large medical colleges because it is an expensive affair. Thus, laboratories worldwide are searching for substitutes,but the reality and local details might not meet the exact requirements of the anatomical structure. Herein, we compared the traditional teaching mode, the 3D image generated by the current advanced hand-held scanner and our self-developed 2D image fitting 3D imaging method in the comparative study of neuroanatomy education. METHODS: To examine the efficacy of two-dimensional fitting three-dimensional imaging techniques in neuroanatomy education. 60 clinical students of grade 2020 in Wannan Medical College were randomly divided into traditional teaching group, hand held scanner 3D imaging group and 2D fitting 3D method group, with 20 students in each group.First, the modeling images of the hand held scanner 3D imaging group and the 2D fitting 3D method group are analyzed and compared, and then the teaching results of the three groups are evaluated by objective and subjective evaluation methods. The objective evaluation is in the form of examination papers, unified proposition and unified score; The subjective evaluation is conducted in the form of questionnaires to evaluate. RESULTS: The modeling and image analysis of the current advanced hand-held 3D imaging scanner and our self-developed 2D fitting 3D imaging method were compared.The images (equivalent to 1, 10, and 40 × magnification) of the model points and polygons using the Cinema 4D R19 virtual camera of 50, 500, and 2000 mm showed 1,249,955 points and 2,500,122 polygons in the skull data obtained using the hand-held scanner. The 3D model data of the skull consisted of 499,914 points, while the number of polygons reached up to 60,000,000, which was about fourfold that of the hand-held 3D scanning. This model used 8 K mapping technology, and hand-held scanner 3D imaging 3D scanning modeling used a 0.13 K map based on the map data, thereby indicating that the 2D fitting 3D imaging method is delicate and real. Comparative analysis of general data of three groups of students.The comparison of test results, clinical practice assessment and teaching satisfaction of the three groups shows that the performance of hand held scanner 3D imaging group is better than that of traditional teaching group (P < 0.01), and that of 2D fitting 3D method group is significantly better than that of traditional teaching group (P < 0.01). CONCLUSIONS: The method used in this study can achieve real reduction. Compared to hand-held scanning, this method is more cost-effective than the cost of the equipment and the results. Moreover, the post-processing is easy to master, and the autopsy can be performed easily after learning, negating the need to seek professional help. It has a wide application prospect in teaching.
Assuntos
Imageamento Tridimensional , Neuroanatomia , Humanos , Neuroanatomia/educação , Aprendizagem , Avaliação Educacional , EscolaridadeRESUMO
BACKGROUND: Since the popularization of computed tomography (CT) technology, the detection rate of pulmonary ground glass nodules (GGNs) with imaging follow-up as the main management method has increased significantly. The purpose of this study is to quantitatively analyze the changes of pulmonary GGNs during the follow-up process with three-dimensional reconstruction technology, explore the natural progression of pulmonary GGNs, and provide effective basis for clinical guidance for patients to conduct reasonable management of nodules. METHODS: A total of 115 cases of pulmonary GGNs with regular follow-up in the Combined Outpatient Department of Zhoushan Hospital from March 2015 to November 2022 were enrolled. Quantitative imaging features of nodules were extracted by semi-automatic segmentation of 3D Slicer software to evaluate the growth of nodules and clinical intervention during follow-up. RESULTS: The average baseline age of the patients was (56.9±10.1) yr. The mean follow-up time was (48.8±18.9) months. The two-dimensional diameter of baseline CT scan was (7.9±2.9) mm, and the maximum three-dimensional diameter was (10.1±3.4) mm. The two-dimensional diameter of the last CT scan was (9.9±4.7) mm, and the maximum three-dimensional diameter was (11.4±5.1) mm. A total of 27 cases (23.5%) showed an increase during follow-up, with a median volume doubling time of 822 days and a median mass doubling time of 1,007 days. 32 cases were surgically resected, including 6 cases of invasive adenocarcinoma (IAC), 16 cases of minimally invasive adenocarcinoma (MIA), 8 cases of adenocarcinoma in situ (AIS) and 2 cases of atypical adenomatous hyperplasia (AAH). Five nodules underwent surgical intervention due to the progression of two-dimensional diameter, which was pathologically confirmed as pre-invasive lesions, but their three-dimensional maximum diameter showed no significant change. Nodular morphology, lobulated sign, spiculated sign and vacuole signs all promoted the growth of nodules in univariate analysis. There were significant differences in age, baseline diameter, mean CT value, median CT value, 10% and 90% percentile CT number between the growth group and the stable group (P<0.05). Multivariate Logistic regression analysis showed that age and average CT value were risk factors for nodule growth (P<0.05). Receiver-operating characteristic (ROC) curve analysis results indicated that the age ≥63 years old, the baseline three-dimensional maximum diameter ≥9.2 mm, and the average CT value ≥-507.8 HU were more likely to accelerate the growth of GGNs. The maximum three-dimensional diameter ≥14.4 mm and the average CT value ≥-495.7 HU may be a higher malignant probability. CONCLUSIONS: GGNs show an inert growth process, and the use of three-dimensional measurements during follow-up is of greater significance. For persistent glass grinding nodules ≥63 years old, the baseline three-dimensional maximum diameter ≥9.2 mm, and the average CT value ≥-507.8 HU are more likely to increase. However, most nodules still have good prognosis after progression, and long-term follow-up is safe.
Assuntos
Adenocarcinoma , Neoplasias Pulmonares , Nódulos Pulmonares Múltiplos , Humanos , Pessoa de Meia-Idade , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/cirurgia , Neoplasias Pulmonares/patologia , Imageamento Tridimensional , Invasividade Neoplásica , Estudos Retrospectivos , Nódulos Pulmonares Múltiplos/diagnóstico por imagem , Nódulos Pulmonares Múltiplos/cirurgia , Nódulos Pulmonares Múltiplos/patologia , Adenocarcinoma/patologiaRESUMO
Objective: To investigate the feasibility of MRI three-dimensional (3D) reconstruction model in quantifying glenoid bone defect by comparing with CT 3D reconstruction model measurement. Methods: Forty patients with shoulder anterior dislocation who met the selection criteria between December 2021 and December 2022 were admitted as study participants. There were 34 males and 6 females with an average age of 24.8 years (range, 19-32 years). The injury caused by sports injury in 29 cases and collision injury in 6 cases, and 5 cases had no obvious inducement. The time from injury to admission ranged from 4 to 72 months (mean, 28.5 months). CT and MRI were performed on the patients' shoulder joints, and a semi-automatic segmentation of the images was done with 3D slicer software to construct a glenoid model. The length of the glenoid bone defect was measured on the models by 2 physicians. The intra-group correlation coefficient ( ICC) was used to evaluate the consistency between the 2 physicians, and Bland-Altman plots were constructed to evaluate the consistency between the 2 methods. Results: The length of the glenoid bone defects measured on MRI 3D reconstruction model was (3.83±1.36) mm/4.00 (0.58, 6.13) mm for physician 1 and (3.91±1.20) mm/3.86 (1.39, 5.96) mm for physician 2. The length of the glenoid bone defects measured on CT 3D reconstruction model was (3.81±1.38) mm/3.80 (0.60, 6.02) mm for physician 1 and (3.99±1.19) mm/4.00 (1.68, 6.38) mm for physician 2. ICC and Bland-Altman plot analysis showed good consistency. The ICC between the 2 physicians based on MRI and CT 3D reconstruction model measurements were 0.73 [95% CI (0.54, 0.85)] and 0.80 [95% CI (0.65, 0.89)], respectively. The 95% CI of the difference between the two measurements of physicians 1 and 2 were (-0.46, 0.49) and (-0.68, 0.53), respectively. Conclusion: The measurement of glenoid bone defect based on MRI 3D reconstruction model is consistent with that based on CT 3D reconstruction model. MRI can be used instead of CT to measure glenoid bone defects in clinic, and the soft tissue of shoulder joint can be observed comprehensively while reducing radiation.
Assuntos
Instabilidade Articular , Luxação do Ombro , Articulação do Ombro , Masculino , Feminino , Humanos , Adulto Jovem , Adulto , Imageamento Tridimensional/métodos , Tomografia Computadorizada por Raios X/métodos , Articulação do Ombro/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodosRESUMO
INTRODUCTION: Rotator cuff tear (RCT) is a challenging and common musculoskeletal disease. Magnetic resonance imaging (MRI) is a commonly used diagnostic modality for RCT, but the interpretation of the results is tedious and has some reliability issues. In this study, we aimed to evaluate the accuracy and efficacy of the 3-dimensional (3D) MRI segmentation for RCT using a deep learning algorithm. METHODS: A 3D U-Net convolutional neural network (CNN) was developed to detect, segment, and visualize RCT lesions in 3D, using MRI data from 303 patients with RCTs. The RCT lesions were labeled by two shoulder specialists in the entire MR image using in-house developed software. The MRI-based 3D U-Net CNN was trained after the augmentation of a training dataset and tested using randomly selected test data (training: validation: test data ratio was 6:2:2). The segmented RCT lesion was visualized in a three-dimensional reconstructed image, and the performance of the 3D U-Net CNN was evaluated using the Dice coefficient, sensitivity, specificity, precision, F1-score, and Youden index. RESULTS: A deep learning algorithm using a 3D U-Net CNN successfully detected, segmented, and visualized the area of RCT in 3D. The model's performance reached a 94.3% of Dice coefficient score, 97.1% of sensitivity, 95.0% of specificity, 84.9% of precision, 90.5% of F1-score, and Youden index of 91.8%. CONCLUSION: The proposed model for 3D segmentation of RCT lesions using MRI data showed overall high accuracy and successful 3D visualization. Further studies are necessary to determine the feasibility of its clinical application and whether its use could improve care and outcomes.
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Aprendizado Profundo , Lesões do Manguito Rotador , Humanos , Imageamento Tridimensional/métodos , Lesões do Manguito Rotador/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Algoritmos , Imageamento por Ressonância Magnética/métodosRESUMO
Investigating organ biology often requires methodologies to induce genetically distinct clones within a living tissue. However, the 3D nature of clones makes sample image analysis challenging and slow, limiting the amount of information that can be extracted manually. Here we develop PECAn, a pipeline for image processing and statistical data analysis of complex multi-genotype 3D images. PECAn includes data handling, machine-learning-enabled segmentation, multivariant statistical analysis, and graph generation. This enables researchers to perform rigorous analyses rapidly and at scale, without requiring programming skills. We demonstrate the power of this pipeline by applying it to the study of Minute cell competition. We find an unappreciated sexual dimorphism in Minute cell growth in competing wing discs and identify, by statistical regression analysis, tissue parameters that model and correlate with competitive death. Furthermore, using PECAn, we identify several genes with a role in cell competition by conducting an RNAi-based screen.
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Carya , Animais , Competição entre as Células , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional , Aprendizado de MáquinaRESUMO
Exact placement of bone conduction implants requires avoidance of critical structures. Existing guidance technologies for intraoperative placement have lacked widespread adoption given accessibility challenges and significant cognitive loading. The purpose of this study is to examine the application of augmented reality (AR) guided surgery on accuracy, duration, and ease on bone conduction implantation. Five surgeons surgically implanted two different types of conduction implants on cadaveric specimens with and without AR projection. Pre- and postoperative computer tomography scans were superimposed to calculate centre-to-centre distances and angular accuracies. Wilcoxon signed-rank testing was used to compare centre-to-centre (C-C) and angular accuracies between the control and experimental arms. Additionally, projection accuracy was derived from the distance between the bony fiducials and the projected fiducials using image guidance coordinates. Both operative time (4.3 ± 1.2 min. vs. 6.6 ± 3.5 min., p = 0.030) and centre-to-centre distances surgery (1.9 ± 1.6 mm vs. 9.0 ± 5.3 mm, p < 0.001) were significantly less in augmented reality guided surgery. The difference in angular accuracy, however, was not significantly different. The overall average distance between the bony fiducial markings and the AR projected fiducials was 1.7 ± 0.6 mm. With direct intraoperative reference, AR-guided surgery enhances bone conduction implant placement while reduces operative time when compared to conventional surgical planning.
Assuntos
Realidade Aumentada , Cirurgia Assistida por Computador , Humanos , Cirurgia Assistida por Computador/métodos , Condução Óssea , Imageamento Tridimensional/métodos , Marcadores FiduciaisRESUMO
BACKGROUND: Computer-aided design/manufacturing (CAD/CAM) technology was developed to improve surgical accuracy and minimize errors in surgical planning and orthognathic surgery. However, its accurate implementation during surgery remains a challenge. Hence, we compared the accuracy and stability of conventional orthognathic surgery and the novel modalities, such as virtual simulation and three-dimensional (3D) titanium-printed customized surgical osteotomy guides and plates. METHODS: This prospective study included 12 patients who were willing to undergo orthognathic surgery. The study group consisted of patients who underwent orthognathic two-jaw surgery using 3D-printed patient-specific plates processed by selective laser melting and an osteotomy guide; orthognathic surgery was also performed by the surgeon directly bending the ready-made plate in the control group. Based on the preoperative computed tomography images and intraoral 3D scan data, a 3D virtual surgery plan was implemented in the virtual simulation module, and the surgical guide and bone fixation plate were fabricated. The accuracy and stability were evaluated by comparing the results of the preoperative virtual simulation (T0) to those at 7 days (T1) and 6 months (T2) post-surgery. RESULT: The accuracy (ΔT1âT0) and stability (ΔT2âT1) measurements, using 11 anatomical references, both demonstrated more accurate results in the study group. The mean difference of accuracy for the study group (0.485 ± 0.280 mm) was significantly lower than in the control group (1.213 ± 0.716 mm) (P < 0.01). The mean operation time (6.83 ± 0.72 h) in the control group was longer than in the study group (5.76 ± 0.43 h) (P < 0.05). CONCLUSION: This prospective clinical study demonstrated the accuracy, stability, and effectiveness of using virtual preoperative simulation and patient-customized osteotomy guides and plates for orthognathic surgery.
Assuntos
Cirurgia Ortognática , Procedimentos Cirúrgicos Ortognáticos , Humanos , Titânio , Estudos Prospectivos , Procedimentos Cirúrgicos Ortognáticos/métodos , Desenho Assistido por Computador , Imageamento TridimensionalRESUMO
For integral stereo imaging systems based on lens arrays, the cross-mixing of erroneous light rays between adjacent lenses seriously affects the quality of the reconstructed light field. In this paper, we proposed a light field reconstruction method based on the human eye viewing mechanism, which incorporates simplified human eye imaging into the integral imaging system. First, the light field model for specified viewpoint is established, and the distribution of the light source for each viewpoint is accurately calculated for the EIA generation algorithm of fixed viewpoint. Second, according to the ray tracing algorithm in this paper, non-overlapping EIA based on the human eye viewing mechanism is designed to suppress the amount of crosstalk rays fundamentally. The actual viewing clarity is improved with the same reconstructed resolution. Experimental results verify the effectiveness of the proposed method. The SSIM value is higher than 0.93, which verifies that the viewing angle range is increased to 62°.
Assuntos
Imageamento Tridimensional , Lentes , Humanos , Imageamento Tridimensional/métodos , AlgoritmosRESUMO
Line confocal (LC) microscopy is a fast 3D imaging technique, but its asymmetric detection slit limits resolution and optical sectioning. To address this, we propose the differential synthetic illumination (DSI) method based on multi-line detection to enhance the spatial resolution and optical sectioning capability of the LC system. The DSI method allows the imaging process to simultaneously accomplish on a single camera, which ensures the rapidity and stability of the imaging process. DSI-LC improves X- and Z-axis resolution by 1.28 and 1.26 times, respectively, and optical sectioning by 2.6 times compared to LC. Furthermore, the spatially resolved power and contrast are also demonstrated by imaging pollen, microtubule, and the fiber of the GFP fluorescence-labeled mouse brain. Finally, Video-rate imaging of zebrafish larval heart beating in a 665.6 × 332.8 µm2 field-of-view is achieved. DSI-LC provides a promising approach for 3D large-scale and functional imaging in vivo with improved resolution, contrast, and robustness.
Assuntos
Iluminação , Peixe-Zebra , Animais , Camundongos , Iluminação/métodos , Microscopia Confocal/métodos , Imageamento Tridimensional , PólenRESUMO
PURPOSE: To make a comparative estimation of the positional accuracy of dental implants inserted using selective laser melting and computerised stackable surgical guides produced through digital light processing for patients with maxillary terminal dentition. MATERIALS AND METHODS: Twenty-four dental implants were inserted in partially edentulous patients who were treated for tooth loss and required fixed prosthodontic rehabilitation. Virtually designed prosthetically driven fixation bases with stackable surgical osteotomy guides were used for bone reduction after tooth extraction and osteotomy preparation, respectively. The inserted implants were divided into two equal groups according to the type of surgical guide used, either cobalt-chromium guides fabricated through selective laser melting or resin guides produced by digital light processing. The final actual implant position was compared to the preoperative planned position and the coronal and apical deviations were calculated in millimetres, and angular deviation measurements in degrees. RESULTS: A t test was used for comparison (P < 0.05). The mean coronal, apical and angular deviation for the implants positioned using a stackable guide made by digital light processing were greater than those for implants positioned using cobalt-chromium guides fabricated through selective laser melting. Highly significant differences were found between both groups for all the measurements. CONCLUSIONS: Within the limitations of this study, cobalt-chromium stackable surgical guides produced by selective laser melting are more accurate than resin guides produced through digital light processing.
Assuntos
Implantes Dentários , Cirurgia Assistida por Computador , Humanos , Implantação Dentária Endóssea , Dentição , Imageamento Tridimensional , Desenho Assistido por Computador , LasersRESUMO
BACKGROUND: Changes in liver magnetic resonance imaging T1 relaxation times are associated with histologic inflammation and fibrosis. OBJECTIVE: To compare liver T1 measurements obtained using a novel single-breath-hold 3-dimensional (3D) whole-liver T1 estimation method (3D-QALAS) to standard-of-care 2-dimensional (2D) modified Look-Locker (2D-MOLLI) measurements. METHODS: With institutional review board approval, research magnetic resonance imaging examinations were performed in 19 participants at 1.5 T. T1 relaxometry of the liver was performed using a novel 3D whole-liver T1 estimation method (3D-QALAS) as well as a 2D modified Look-Locker (2D-MOLLI) method. The 3D method covered the entire liver in a single breath hold, whereas 2D imaging was performed at 4 anatomic levels in 4 consecutive breath holds. T1 measurements from parametric maps were obtained by a single operator, and region-of-interest area-weighted mean T1 values were calculated. Pearson correlation ( r ) was used to assess correlation between T1 estimation methods, and the paired t test and Bland-Altman analysis were used to compare agreement in T1 measurements. RESULTS: In 18 participants (1 participant was excluded from analysis because of respiratory motion artifacts on 3D-QALAS images), 2D-MOLLI and 3D-QALAS mean T1 measurements were strongly correlated ( r = 0.95, [95% CI: 0.87-0.98]; P < 0.0001). 2D-MOLLI T1 values were significantly longer than 3D-QALAS values (647.2 ± 87.3 milliseconds vs. 554.7 ± 75.8 milliseconds; P < 0.0001) with mean bias = 92.5 milliseconds (95% limits of agreement, 36.8, 148.2 milliseconds). CONCLUSION: Whole-liver T1 measurements obtained using a novel single-breath-hold 3D T1 estimation method correlate with a standard-of-care multiple consecutive-breath-hold 2D single-slice method but demonstrate systematic bias that should be considered or corrected when used in a clinical or research setting.
Assuntos
Imageamento Tridimensional , Imageamento por Ressonância Magnética , Humanos , Imageamento por Ressonância Magnética/métodos , Imageamento Tridimensional/métodos , Suspensão da Respiração , Fibrose , Fígado/diagnóstico por imagem , Reprodutibilidade dos Testes , Imagens de FantasmasRESUMO
OBJECTIVE: Although amide proton transfer-weighted (APTw) imaging is reported by 2-dimensional (2D) spin-echo-based sequencing, 3-dimensional (3D) APTw imaging can be obtained by gradient-echo-based sequencing. The purpose of this study was to compare the efficacy of APTw imaging between 2D and 3D imaging in patients with various brain tumors. METHODS: A total of 49 patients who had undergone 53 examinations [5 low-grade gliomas (LGG), 16 high-grade gliomas (HGG), 6 malignant lymphomas, 4 metastases, and 22 meningiomas] underwent APTw imaging using 2D and 3D sequences. The magnetization transfer ratio asymmetry (MTR asym ) was assessed by means of region of interest measurements. Pearson correlation was performed to determine the relationship between MTR asym for the 2 methods, and Student's t test to compare MTR asym for LGG and HGG. The diagnostic accuracy to differentiate HGG from LGG of the 2 methods was compared by means of the McNemar test. RESULTS: Three-dimensional APTw imaging showed a significant correlation with 2D APTw imaging ( r = 0.79, P < 0.0001). The limits of agreement between the 2 methods were -0.021 ± 1.42%. The MTR asym of HGG (2D: 1.97 ± 0.96, 3D: 2.11 ± 0.95) was significantly higher than those of LGG (2D: 0.46 ± 0.89%, P < 0.01; 3D: 0.15 ± 1.09%, P < 0.001). The diagnostic performance of the 2 methods to differentiate HGG from LGG was not significantly different ( P = 1). CONCLUSIONS: The potential capability of 3D APTw imaging is equal to or greater than that of 2D APTw imaging and is considered at least as valuable in patients with brain tumors.
