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Three-dimensional echocardiography: The gateway to virtual reality!

ECHOCARDIOGRAPHY-A JOURNAL OF CARDIOVASCULAR ULTRASOUND AND ALLIED TECHNIQUES 1999年第5期16卷 417-423页

作者： Bruining, N Roelandt, JRTC Grunst, G Berlage, T Waldinger, J Mumm, B Erasmus Med Ctr Rotterdam Dept Cardiol Thoraxctr Rotterdam Netherlands

Virtual reality (VR) is one of the latest developments in cardiac three-dimensional (3-D) ultrasound. A VR heart model linked to 3-D echocardiographic image datasets provides the observers spatial information regarding a 3-D image dataset and prevents the "lost in space effect" in difficult and relevant coupled diseases when integrated into 3-D reconstruction software. Standardized echocardiographic views can be selected within the integrated developed VR heart model, and this is the first step to automatic 3-D computations with minimal operator interaction. VR heart models open exciting opportunities in. the field of teaching echocardiographic cardiology, diagnosis, and examinable states.

关键词： echocardiography computer-assisted image processing heart diseases

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Mean S1 inlet and outlet view angles are not safe for all individuals according to three-dimensional tomographic measurements

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JOURNAL OF ORTHOPAEDIC RESEARCH 2024年第3期42卷 671-677页

作者： Tanoglu, Oguzhan Gokgoz, Mehmet Burak Subasi, Izzet Ozay Arican, Gokhun Kockara, Nizamettin Buca Seyfi Demirsoy Res & Training Hosp Dept Orthopaed & Traumatol TR-35390 Izmir Turkiye Erzincan Binali Yildirim Univ Dept Orthopaed & Traumatol Erzincan Turkiye Yuksek Ihtisas Univ Dept Orthopaed & Traumatol Ankara Turkiye

Although there are many studies evaluating optimal inlet and outlet angles required for the correct placement of S1 iliosacral screws, there is no study evaluating reliability and feasibility of these angles for all individuals on three-dimensional (3D) anatomical models. A total of 100 women and 100 men were selected randomly. A vertical line was created according to long axis of the tomography device on which patient was lying in supine position. The automatized best-fit planes were created on superior and inferior endplates, anterior cortex including notch region and posterior cortex of first sacral vertebrae using 3D imaging software to measure mean inlet and outlet angles. We observed no statistically significant difference between gender groups in terms of inlet and outlet angles. Mean inlet view is obtained for anterior cortex of S1 in 22.5 +/- 9.5(degrees) and for posterior cortex in 46.5 +/- 9.3(degrees). Mean fluoroscopic view angle of S1 for superior outlet is 40.3 +/- 7.6 and for inferior outlet is 46.9 +/- 8.8. Mean anterior and posterior S1 inlet view angles do not accurately visualize anterior cortex of 74 (37%) and posterior cortex of 66 (33%) individuals. Mean superior and inferior S1 outlet view angles do not accurately visualize superior endplate of 74 (37%) and inferior endplate of 56 (28%) individuals. Due to individual alterations of spatial position of sacrum, mean inlet and outlet view angles of S1 are not sufficient to visualize the iliosacral screws under fluoroscopy in many individuals.

关键词： computer-assisted image processing fracture fixation sacrum three-dimensional imaging tomography

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Lesion detection on a combined "All-in-One" window compared to conventional window settings in thoracic oncology chest CT examinations

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DIAGNOSTIC AND INTERVENTIONAL IMAGING 2020年第1期101卷 25-33页

作者： Snoeckx, A. Vuylsteke, P. Broeckx, B. J. G. Carpentier, K. Corthouts, R. Luyckx, E. A. Nicolay, S. Hoyweghen, A. V. Spinhoven, M. J. Cant, J. Parizel, P. M. Antwerp Univ Hosp Dept Radiol Wilrijkstr 10 B-2650 Edegem Belgium Univ Antwerp Wilrijkstr 10 B-2650 Edegem Belgium Agfa Med Imaging B-2640 Mortsel Belgium Univ Ghent B-9820 Merelbeke Belgium

Purpose: The purpose of this study was to investigate if lesion detection using a single "All-in-One" (AIO) window was non-inferior to lesion detection on conventional window settings in thoracic oncology chest computed tomography (CT) examinations. Materials and methods: In a retrospective study, 50 consecutive chest CT examinations of 50 patients (31 men, 19 women;mean age 64 +/- 10 [SD] years, range: 35-82 years) containing 417 lesions, were reviewed by 6 radiologists, subdivided into 2 groups of 3 radiologists each, with similar levels of expertise in each group (senior staff member, junior staff member and radiology resident). All examinations were reviewed in conventional or AIO window settings by one of the groups. A 'lesion' was defined as any abnormality seen on the chest CT examination, including both benign and malignant lesions, findings in chest and upper abdomen, and measurable and non-measurable disease. Lesions were listed as 'missed' when they were not seen by at least two out of three observers. F-tests were used to evaluate the significance of the variables of interest within a mixed model framework and kappa statistics to report interobserver agreement. Results: On a reader level, 54/417 lesions (12.9%) were not detected by the senior staff member reading the studies in conventional window settings and 45/417 (10.8%) by the senior staff member reading the AIO images. For the junior staff member and radiology resident this was respectively 55/417 (13.2%) and 67/417 (16.1%) for the conventional window settings and 43/417 (10.3%) and 61/417 (14.6%) for the AIO window. On a lesion level, 68/417 (16.3%) were defined as 'missed' lesions (lesions not detected by at least 2 readers): 21/68 (30.9%) on the AIO-window, 30/68 (44.1%) on conventional views and 17/68 (25.0%) on both views. The use of the AIO window did not result in an increase of missed lesions (P> 0.99). Interobserver agreement in both groups was similar (P=0.46). Regarding lesions that were

关键词： Diagnosis Computed tomography (CT) computer-assisted image processing computer-assisted image interpretation Lung neoplasms

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Two-dimensional sectioned images and three-dimensional surface models for learning the anatomy of the female pelvis

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ANATOMICAL SCIENCES EDUCATION 2013年第5期6卷 316-323页

作者： Shin, Dong Sun Jang, Hae Gwon Hwang, Sung Bae Har, Dong-Hwan Moon, Young Lae Chung, Min Suk Ajou Univ Dept Anat Sch Med Suwon 441749 South Korea Ajou Univ Grad Sch Informat & Commun Suwon 441749 South Korea Kyungbuk Coll Dept Phys Therapy Youngju South Korea Chung Ang Univ Grad Sch Adv Imaging Sci Multimedia & Film Seoul South Korea Chosun Univ Hosp Dept Orthoped Kwangju South Korea

In the Visible Korean project, serially sectioned images of the pelvis were made from a female cadaver. Outlines of significant structures in the sectioned images were drawn and stacked to build surface models. To improve the accessibility and informational content of these data, a five-step process was designed and implemented. First, 154 pelvic structures were outlined with additional surface reconstruction to prepare the image data. Second, the sectioned and outlined images (in a browsing software) as well as the surface models (in a PDF file) were placed on the Visible Korean homepage in a readily-accessible format. Third, all image data were visualized with interactive elements to stimulate creative learning. Fourth, two-dimensional (2D) images and three-dimensional (3D) models were superimposed on one another to provide context and spatial information for students viewing these data. Fifth, images were designed such that structure names would be shown when the mouse pointer hovered over the 2D images or the 3D models. The state-of-the-art sectioned images, outlined images, and surface models, arranged and systematized as described in this study, will aid students in understanding the anatomy of female pelvis. The graphic data accompanied by corresponding magnetic resonance images and computed tomographs are expected to promote the production of 3D simulators for clinical practice. Anat Sci Educ 6: 316-323. (c) 2013 American Association of Anatomists.

关键词： anatomic models computer-assisted image processing female pelvis three-dimensional imaging user-computer interface visible human projects

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Application of two segmentation protocols during the processing of virtual images in rapid prototyping: ex vivo study with human dry mandibles

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CLINICAL ORAL INVESTIGATIONS 2013年第9期17卷 2113-2118页

作者： Ferraz, Eduardo Gomes Safira Andrade, Lucio Costa dos Santos, Aline Rode Torregrossa, Vinicius Rabelo Fischer Rubira-Bullen, Izabel Regina Sarmento, Viviane Almeida Univ Fed Bahia Sch Dent BR-41110150 Salvador BA Brazil State Univ Sao Paulo Bauru Sch Dent BR-17012101 Bauru SP Brazil Univ Estadual Feira de Santana Sch Dent Feira De Santana BA Brazil

The aim of this study was to evaluate the accuracy of virtual three-dimensional (3D) reconstructions of human dry mandibles, produced from two segmentation protocols ("outline only" and "all-boundary lines"). Twenty virtual three-dimensional (3D) images were built from computed tomography exam (CT) of 10 dry mandibles, in which linear measurements between anatomical landmarks were obtained and compared to an error probability of 5 %. The results showed no statistically significant difference among the dry mandibles and the virtual 3D reconstructions produced from segmentation protocols tested (p = 0,24). During the designing of a virtual 3D reconstruction, both "outline only" and "all-boundary lines" segmentation protocols can be used. Virtual processing of CT images is the most complex stage during the manufacture of the biomodel. Establishing a better protocol during this phase allows the construction of a biomodel with characteristics that are closer to the original anatomical structures. This is essential to ensure a correct preoperative planning and a suitable treatment.

关键词： X-ray computed tomography computer-assisted image processing Three-dimensional imaging Rapid prototyping

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ULTRASTRUCTURAL MORPHOMETRIC ANALYSIS OF HUMAN BLOOD-PLATELETS EXPOSED TO MINIMAL HANDLING PROCEDURES

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APMIS 1992年第10期100卷 922-929页

作者： ROGER, M HUITFELDT, HS HOVIG, T Institute of Pathology Rikshospitalet Oslo Norway.

A detailed morphometric study of normal human blood platelets is described. The purpose has been to evaluate the morphological characteristics of platelets exposed to minimal handling procedures in order to obtain an optimal basis for the appraisal of platelets in disease. Blood from 10 healthy volunteers was collected directly into buffered glutaraldehyde and processed for electron microscopy. This platelet fixation procedure resulted in excellent preservation of resting platelet ultrastructure with one exception: the dense bodies. Compared to platelets fixed following washing procedures, our directly fixed platelets comprised fewer pseudopods and contained more glycogen. An unexpected feature of the open canalicular system was the apparent release of blisters interpreted as microvesicles. Employing a computerized image analyzer, 300 of the platelets were examined morphologically. The morphometric data thus obtained were analyzed statistically, resulting in a set of standard values for morphological characteristics of human platelets which we have found useful in subsequent evaluations of platelet morphology in disease. Significant inter-individual variance was, however, detected in two instances, in the section area of the alpha granules, as well as the area fraction of platelet sections occupied by channels of the open canalicular system (OCS). This should be taken into consideration when appraising platelet ultrastructure in health and disease.

关键词： BLOOD PLATELETS ELECTRON MICROSCOPY computer-assisted image processing MORPHOMETRIC ANALYSIS CELL COMMUNICATION

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DEVELOPMENT AND EVALUATION OF A HEAD-CONTROLLED HUMAN-computer INTERFACE WITH MOUSE-LIKE FUNCTIONS FOR PHYSICALLY DISABLED USERS

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CLINICS 2009年第10期64卷 975-981页

作者： Martins Pereira, Cesar Augusto Bolliger Neto, Raul Reynaldo, Ana Carolina de Miranda Luzo, Maria Candida Oliveira, Reginaldo Perilo Univ Sao Paulo Fac Med Musculoskeletal Syst Med Res Lab LIM 41 Hosp ClinOrthopaed & Traumatol Inst Sao Paulo Brazil Univ Sao Paulo Fac Med Occupat Therapy Div Orthopaed & Traumatol InstHosp Clin Sao Paulo Brazil

OBJECTIVES: The objectives of this study were to develop a pointing device controlled by head movement that had the same functions as a conventional mouse and to evaluate the performance of the proposed device when operated by quadriplegic users. METHODS: Ten individuals with cervical spinal cord injury participated in functional evaluations of the developed pointing device. The device consisted of a video camera, computer software, and a target attached to the front part of a cap, which was placed on the user's head. The software captured images of the target coming from the video camera and processed them with the aim of determining the displacement from the center of the target and correlating this with the movement of the computer cursor. Evaluation of the interaction between each user and the proposed device was carried out using 24 multidirectional tests with two degrees of difficulty. RESULTS: According to the parameters of mean throughput and movement time, no statistically significant differences were observed between the repetitions of the tests for either of the studied levels of difficulty. CONCLUSIONS: The developed pointing device adequately emulates the movement functions of the computer cursor. It is easy to use and can be learned quickly when operated by quadriplegic individuals.

关键词： Quadriplegia computer peripherals computer systems computer-assisted image processing Task performance and analysis

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Registration-based semi-automatic assessment of aortic diameter growth rate from contrast-enhanced computed tomography outperforms manual quantification

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EUROPEAN RADIOLOGY 2022年第3期32卷 1997-2009页

作者： Dux-Santoy, Lydia Rodriguez-Palomares, Jose F. Teixido-Tura, Gisela Ruiz-Munoz, Aroa Casas, Guillem Valente, Filipa Servato, Maria Luz Galian-Gay, Laura Gutierrez, Laura Gonzalez-Alujas, Teresa Fernandez-Galera, Ruben Evangelista, Arturo Ferreira-Gonzalez, Ignacio Guala, Andrea Vall Hebron Inst Recerca VHIR Barcelona Spain Inst Salud Carlos III CIBER CV Madrid Spain Hosp Univ Vall Hebron Dept Cardiol Paseo Vall Hebron 119-129 Barcelona 08035 Spain Univ Autenoma Barcelona Bellaterra Spain Inst Corazon Quironsalud Teknon Barcelona Spain Inst Salud Carlos III CIBER Epidemiol & Salud Publ CIBERESP Madrid Spain

Objectives Manual assessment of aortic diameters on double-oblique reformatted computed tomography angiograms (CTA) is considered the current standard, although the reproducibility for growth rates has not been reported. Deformable registration of CTA has been proposed to provide 3D aortic diameters and growth maps, but validation is lacking. This study aimed to quantify accuracy and inter-observer reproducibility of registration-based and manual assessment of aortic diameters and growth rates. Methods Forty patients with >= 2 CTA acquired at least 6 months apart were included. Aortic diameters and growth rate were obtained in the aortic root and the entire thoracic aorta using deformable image registration by two independent observers, and compared with the current standard at typical anatomical landmarks. Results Compared with manual assessment, the registration-based technique presented low bias (0.46 mm), excellent agreement (ICC = 0.99), and similar inter-observer reproducibility (ICC = 0.99 for both) for aortic diameters;and low bias (0.10 mm/year), good agreement (ICC = 0.82), and much higher inter-observer reproducibility for growth rates (root: ICC = 0.96 vs 0.68;thoracic aorta: ICC = 0.96 vs 0.80). Registration-based growth rate reproducibility over a 6-month-long follow-up was similar to that obtained by manual assessment after 2.7 years (LoA = [-0.01, 0.33] vs [-0.13, 0.21] mm/year, respectively). Mapping of diameter and growth rate was highly reproducible (ICC > 0.9) in the whole thoracic aorta. Conclusions Registration-based assessment of aortic dilation on CTA is accurate and substantially more reproducible than the current standard, even at follow-up as short as 6 months, and provides robust 3D mapping of aortic diameters and growth rates beyond the pre-established anatomic landmarks.

关键词： Aortic aneurysm Dilatation Computed tomography angiography computer-assisted image processing

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Optimising central venous catheter placement by comparing cavoatrial junction position to chest X-ray landmarks: A cross-sectional study using CT chest reconstruction

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JOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY 2024年第6期68卷 667-672页

作者： Kandasamy, Mayooran Xue, Stanley McGregor, Nigel Xiang, Hao Concord Repatriat Gen Hosp Dept Radiol Sydney NSW Australia Univ New South Wales Sydney NSW Australia

Introduction: Central venous catheter (CVC) tip placement guided by chest X-ray (CXR) landmarks is currently prone to inconsistency and malpositioning. This study aims to better define the relationship between the cavoatrial junction (CAJ) and selected X-ray landmarks. Methods: Chest CTs of 100 patients were retrospectively assessed. CT images were converted to a 'virtual CXR' using a digital workstation, enabling simultaneous localisation of the CAJ and evaluation of CXR landmarks. Vertical distances between the CAJ and selected landmarks were measured for each patient. Measurements were assessed for correlation with age and compared between age groups and sexes. Results: The mean vertical distance of the following landmarks above the CAJ was found: the carina (46.2 mm), the intersection of the bronchus intermedius and the right heart border (7.6 mm) and the superior inflection of the right heart border (Sup-RHB) (13.0 mm). The maximum lateral bulge of the right heart border (Lat-RHB) was 18.4 mm below the CAJ. A new landmark: the mid-superior right heart border, defined as the mid-point between the Sup-RHB and Lat-RHB, was the closest to the CAJ, lying 2.6 mm below the CAJ. Conclusion: We propose that the CVC tip can be placed at the mid-superior right heart border landmark.

关键词： anatomic landmarks central venous catheters computer-assisted image processing thoracic radiography vascular access devices

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Automatic differentiation of placental perfusion compartments by time-to-peak analysis in mice

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PLACENTA 2015年第3期36卷 255-261页

作者： Kording, F. Forkert, N. D. Sedlacik, J. Adam, G. Hecher, K. Arck, P. Remus, C. C. Univ Med Ctr Hamburg Eppendorf Dept Diagnost & Intervent Radiol Ctr Radiol & Endoscopy D-20246 Hamburg Germany Univ Calgary Calgary AB T2N 1N4 Canada Univ Med Ctr Hamburg Eppendorf Ctr Radiol & Endoscopy Dept Diagnost & Intervent Neuroradiol D-20246 Hamburg Germany Univ Med Ctr Hamburg Eppendorf Ctr Obstet & Paediat Dept Obstet & Fetal Med D-20246 Hamburg Germany

Introduction: The aim of this study was to develop an automatic differentiation of two perfusion compartments within the mouse placenta based on times of maximal contrast enhancement for a detailed and reproducible perfusion assessment. Methods: Placentas (n = 17) from pregnant BALB/c mice (n = 10) were examined in vivo at 7T on gestation day 16.5. Corona] dual-echo 3D TI-weighted gradient-echo sequences were acquired after application of contrast agent for dynamic MRI. An adapted gamma variate function was fitted to the discrete contentration time curves to evaluate the effect of noise on perfusion and segmentation results. Time-to-peak maps based on fitted and discrete curves of each placenta were used to classify each voxel into the high- or low-blood flow compartment using k-means clustering. Perfusion analysis was performed using the steepest slope model and also applied to fitted and discrete curves. Results were compared to manually defined compartments from two independent observers using the Dice coefficient D. Results: Manually defined placental areas of high-flow and low-flow were similar to the automatic segmentation for discrete (D = 0.76/0.75;D = 0.76/0.79) and fitted (D = 0.80/0.80;D = 0.81/0.82) concentration time curves. Mean perfusion values of discrete and fitted curves ranged in the high-flow compartment from 134 to 142 ml/min/100 ml (discrete) vs. 138-143 ml/min/100 ml (fitted) and in the low-flow compartment from 91 to 94 ml/min/100 ml (discrete) vs. 74-82 ml/min/100 ml (fitted). Discussion: Our novel approach allows the automatic differentiation of perfusion compartments of the mouse placenta. The approach may overcome limitations of placental perfusion analyses caused by tissue heterogeneity and a potentially biased selection of regions of interest. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Magnetic resonance imaging Placenta Perfusion computer-assisted image processing

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