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Evaluation of layer decomposition for multiframe quantitative coronary angiography

MEDICAL PHYSICS 2002年第3期29卷 311-318页

作者： Close, RA Abbey, CK Morioka, CA Whiting, JS Cedars Sinai Med Ctr Div Med Phys & Imaging Los Angeles CA 90048 USA

Multiframe quantitative coronary angiography is typically performed by averaging measurements of artery diameter over multiple frames. This approach reduces errors attributable to random noise but may not reduce systematic errors caused by background structures, nonlinear system response, and motion blur. We attempt to reduce these sources of error by decomposing the image sequence into moving layers, one of which includes the artery. We embed simulated arteries into clinical angiographic sequences so that the true vessel dimensions are known accurately. The measurement tasks are minimum diameter, geometric percent stenosis, and densitometric percent stenosis. We compare measurements for single and multiple raw images, single images with fixed mask subtraction, single and multiple images with layered background subtraction, and time-averaged layer images. We find that both multiframe averaging and layer decomposition significantly improve geometric and densitometric accuracy compared with single-frame measurements. The best results were obtained by averaging measurements from multiple frames of layered background-subtracted images. (C) 2002 American Association of Physicists in Medicine.

关键词： computer-assisted image processing coronary angiography radiographic image enhancement stenosis

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Functional magnetic resonance imaging for neurosurgical planning in neurooncology

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EUROPEAN RADIOLOGY 2004年第7期14卷 1143-1153页

作者： Vlieger, EJ Majoie, CB Leenstra, S den Heeten, GJ Acad Med Ctr Dept Radiol NL-1100 DD Amsterdam Netherlands Acad Med Ctr Dept Neurosurg NL-1100 DD Amsterdam Netherlands

Functional magnetic resonance imaging (fMRI) is a non-invasive technique that is widely available and can be used to determine the spatial relationships between tumor tissue and eloquent brain areas. Within certain limits, this functional information can be applied in the field of neurosurgery as a pre-operative mapping tool to minimize damage to eloquent brain areas. In this article, we review the literature on the use of fMRI for neurosurgical planning. The issues addressed are: (1) stimulation paradigms, (2) the influence of tumors on the blood oxygenation level-dependent (BOLD) signal, (3) post-processing the fMRI time course, (4) integration of fMRI results into neuronavigation systems, (5) the accuracy of fMRI and (6) fMRI compared to intra-operative mapping (IOM).

关键词： functional magnetic resonance imaging computer-assisted image processing neurosurgery neuronavigation brain neoplasm

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Reliability of neuroanatomical measurements in a multisite longitudinal study of youth at risk for psychosis

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HUMAN BRAIN MAPPING 2014年第5期35卷 2424-2434页

作者： Cannon, Tyrone D. Sun, Frank McEwen, Sarah Jacobson Papademetris, Xenophon He, George van Erp, Theo G. M. Jacobson, Aron Bearden, Carrie E. Walker, Elaine Hu, Xiaoping Zhou, Lei Seidman, Larry J. Thermenos, Heidi W. Cornblatt, Barbara Olvet, Doreen M. Perkins, Diana Belger, Aysenil Cadenhead, Kristin Tsuang, Ming Mirzakhanian, Heline Addington, Jean Frayne, Richard Woods, Scott W. McGlashan, Thomas H. Constable, R. Todd Qiu, Maolin Mathalon, Daniel H. Thompson, Paul Toga, Arthur W. Yale Univ Dept Psychol New Haven CT 06520 USA Univ Calif Los Angeles Dept Psychiat & Biobehav Sci Los Angeles CA 90024 USA Yale Univ Dept Diagnost Radiol New Haven CT 06520 USA Yale Univ Dept Biomed Engn New Haven CT 06520 USA Univ Calif Irvine Dept Psychiat & Human Behav Irvine CA 92717 USA Emory Univ Dept Psychiat Atlanta GA 30322 USA Emory Univ Biomed Imaging Technol Ctr Atlanta GA 30322 USA Beth Israel Deaconess Med Ctr Dept Psychiat Boston MA 02215 USA Harvard Univ Sch Med Boston MA USA Zucker Hillside Hosp Dept Psychiat Great Neck NY USA Univ N Carolina Dept Psychiat Chapel Hill NC USA Univ Calif San Diego Dept Psychiat San Diego CA 92103 USA Univ Calgary Dept Psychiat Calgary AB Canada Univ Calgary Dept Radiol Calgary AB Canada Yale Univ Dept Psychiat New Haven CT 06520 USA Univ Calif San Francisco Dept Psychiat San Francisco CA USA Univ Calif Los Angeles Dept Neurol Los Angeles CA 90024 USA

Multisite longitudinal neuroimaging designs are used to identify differential brain structural change associated with onset or progression of disease. The reliability of neuroanatomical measurements over time and across sites is a crucial aspect of power in such studies. Prior work has found that while within-site reliabilities of neuroanatomical measurements are excellent, between-site reliability is generally more modest. Factors that may increase between-site reliability include standardization of scanner platform and sequence parameters and correction for between-scanner variations in gradient nonlinearities. Factors that may improve both between- and within-site reliability include use of registration algorithms that account for individual differences in cortical patterning and shape. In this study 8 healthy volunteers were scanned twice on successive days at 8 sites participating in the North American Prodrome Longitudinal Study (NAPLS). All sites employed 3 Tesla scanners and standardized acquisition parameters. Site accounted for 2 to 30% of the total variance in neuroanatomical measurements. However, site-related variations were trivial (<1%) among sites using the same scanner model and 12-channel coil or when correcting for between-scanner differences in gradient nonlinearity and scaling. Adjusting for individual differences in sulcal-gyral geometries yielded measurements with greater reliabilities than those obtained using an automated approach. Neuroimaging can be performed across multiple sites at the same level of reliability as at a single site, achieving within- and between-site reliabilities of 0.95 or greater for gray matter density in the majority of voxels in the prefrontal and temporal cortical surfaces as well as for the volumes of most subcortical structures. Hum Brain Mapp 35:2424-2434, 2014. (c) 2013 Wiley Periodicals, Inc.

关键词： amygdala reproducibility of results hippocampus cerebral cortex neuroanatomy thalamus computer-assisted image processing magnetic resonance imaging

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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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Automated lesion detection in panoramic dental radiographs

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ORAL RADIOLOGY 2016年第2期32卷 111-118页

作者： Birdal, Ramiz Gorkem Gumus, Ergun Sertbas, Ahmet Birdal, Ilda Sinem Istanbul Univ Dept Comp Engn Istanbul Turkey Istanbul Medeniyet Univ Dept Anat Istanbul Turkey

Objectives Even in the presence of physical indicators like pain, tumor, color, and function loss, determining the exact size or location of acute dental apical diseases is challenging. Even harder to detect is chronic apical periodontitis, which is asymptomatic. In such circumstances, use of dental radiography is especially beneficial. However, radiographs are not sufficient by themselves, and require interpretation by a well-trained dental specialist. Nevertheless, owing to the human factor, mistakes leading to incorrect treatment can be made by specialists because of a wrong diagnosis. This study aimed to introduce an automated dental apical lesion detection methodology by assessing changes in hard tissue structures. The system consists of modules for jaw separation, tooth segmentation, root localization, and lesion detection. Methods Panoramic radiographs are used to improve the process of diagnosis. Unlike the column-sum methodology used in previous studies, the upper and lower jaws are separated using discrete wavelet transformation along with polynomial regression to obtain a better jaw separation curve. Subsequently, angular radial scanning is used to segment the teeth and capture the location of the tooth roots. At the last step, for each detected root, region growing is performed to detect possible lesions surrounding the root apices. Results The results for test samples indicate that use of the above-mentioned methods with proposed threshold selection is an effective way for discriminating anatomic structures from lesions, which is our main concern. Conclusions The findings prove that the proposed methodology can be used efficiently as an assistant for examination of radiographs.

关键词： Endodontics Panoramic radiography Periapical disease computer-assisted image processing computer-assisted diagnosis

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Three-dimensional echocardiography: The gateway to virtual reality!

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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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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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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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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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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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