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Sample records for anterior segment optical

  1. Clinical Applications of Anterior Segment Optical Coherence Tomography

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    Su-Ho Lim

    2015-01-01

    Full Text Available Anterior segment optical coherence tomography (AS-OCT was recently developed and has become a crucial tool in clinical practice. AS-OCT is a noncontact imaging device that provides the detailed structure of the anterior part of the eyes. In this review, the author will discuss the various clinical applications of AS-OCT, such as the normal findings, tear meniscus measurement, ocular surface disease (e.g., pterygium, pinguecula, and scleromalacia, architectural analysis after cataract surgery, post-LASIK keratectasia, Descemet’s membrane detachment, evaluation of corneal graft after keratoplasty, corneal deposits (corneal dystrophies and corneal verticillata, keratitis, anterior segment tumors, and glaucoma evaluation (angle assessment, morphological analysis of the filtering bleb after trabeculectomy, or glaucoma drainage device implantation surgery. The author also presents some interesting cases demonstrated via AS-OCT.

  2. Anterior Segment Tomography with the Cirrus Optical Coherence Tomography

    OpenAIRE

    Rodrigues, Eduardo B.; Margara Johanson; Fernando M Penha

    2012-01-01

    Optical coherence tomography (OCT) is an optical acquisition method to examine biological tissues. In recent years, OCT has become an important imaging technology used in diagnosing and following macular pathologies. Further development enabled application of optical coherence tomography in evaluation of the integrity of the nerve fiber layer, optic nerve cupping, anterior chamber angle, or corneal topography. In this manuscript we overview the use of OCT in the clinical practice to enable co...

  3. Anterior Segment Tomography with the Cirrus Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Eduardo B. Rodrigues

    2012-01-01

    Full Text Available Optical coherence tomography (OCT is an optical acquisition method to examine biological tissues. In recent years, OCT has become an important imaging technology used in diagnosing and following macular pathologies. Further development enabled application of optical coherence tomography in evaluation of the integrity of the nerve fiber layer, optic nerve cupping, anterior chamber angle, or corneal topography. In this manuscript we overview the use of OCT in the clinical practice to enable corneal, iris, ciliary body, and angle evaluation and diagnostics.

  4. Measurement of anterior chamber volume with rotating scheimpflug camera and anterior segment optical coherence tomography

    Institute of Scientific and Technical Information of China (English)

    FU Jing; LI Shu-ning; WANG Xiao-zhen; WU Ge-wei; MU Da-peng; WANG Jian; WANG Ning-li

    2010-01-01

    Background Measurement of anterior segment parameters plays an important role in diagnosis and treatment of glaucoma. The objective of this study was to evaluate the repeatability and reproducibility of anterior chamber volume (ACV) measurements with rotating scheimpflug camera (RSC) and to examine agreement with anterior segment optical coherence tomography (AS-OCT). Methods Thirty nine healthy normal subjects were recruited from the Eye Center of Tongren Hospital. ACV was measured using RSC and AS-OCT in a randomly selected eye for each subject. For RSC measurements, both automatic and manual ACV measurements and 2 independent operators' ACV measurements were obtained. All subjects were invited for 3 visits within a week to evaluate repeatability and reproducibility of ACV measurement by RSC. Agreement was evaluated between RSC and AS-OCT. Results Good repeatability and reproducibility were found for both automatic and manual ACV measurements obtained by RSC. For intrasession repeatability, coefficient of variation (CVw) and intraclass correlation coefficient (ICC) values for automatic were 3.52% and 0.98; the values for manual were 3.44% and 0.97, respectively. For intersession reproducibility, the respective CVw and ICC values were 3.96% and 0.96. Good agreement was also found in 2 operators for both automatic and manual ACV measurements; nevertheless, poor agreement was found between RSC and AS-OCT (95% confidence interval (CI) for agreement of automatic RSC measurement versus AS-OCT were -96.3 to 72.8 μl and 95% CI for agreement of manual RSC measurement versus AS-OCT were between -41.7 to 10.1 μl). Conclusions Both RSC automatic and manual ACV measurements showed good repeatability and reproducibility, and showed comparable agreement between 2 independent operators, but poor agreement was found between RSC and AS-OCT.

  5. Reproducibility of Scleral Spur Identification and Angle Measurements Using Fourier Domain Anterior Segment Optical Coherence Tomography

    OpenAIRE

    Ricardo J. Cumba; Sunita Radhakrishnan; Nicholas P. Bell; Kundandeep S. Nagi; Alice Z. Chuang; Lin, Shan C.; Mankiewicz, Kimberly A.; Feldman, Robert M.

    2012-01-01

    Purpose. To evaluate intraobserver and interobserver agreement in locating the scleral spur landmark (SSL) and anterior chamber angle measurements obtained using Fourier Domain Anterior Segment Optical Coherence Tomography (ASOCT) images. Methods. Two independent, masked observers (SR and AZC) identified SSLs on ASOCT images from 31 eyes with open and nonopen angles. A third independent reader, NPB, adjudicated SSL placement if identifications differed by more than 80  μ m. Nine months later,...

  6. Clinical utility of anterior segment swept-source optical coherence tomography in glaucoma

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    Dewang Angmo

    2016-01-01

    Full Text Available Optical coherence tomography (OCT, a noninvasive imaging modality that uses low-coherence light to obtain a high-resolution cross-section of biological structures, has evolved dramatically over the years. The Swept-source OCT (SS-OCT makes use of a single detector with a rapidly tunable laser as a light source. The Casia SS-1000 OCT is a Fourier-domain, SS-OCT designed specifically for imaging the anterior segment. This system achieves high resolution imaging of 10΅m (Axial and 30΅m (Transverse and high speed scanning of 30,000 A-scans per second. With a substantial improvement in scan speed, the anterior chamber angles can be imaged 360 degrees in 128 cross sections (each with 512 A-scans in about 2.4 seconds. We summarize the clinical applications of anterior segment SS-OCT in Glaucoma. Literature search: We searched PubMed and included Medline using the phrases anterior segment optical coherence tomography in ophthalmology, swept-source OCT, use of AS-OCT in glaucoma, use of swept-source AS-OCT in glaucoma, quantitative assessment of angle, filtering bleb in AS-OCT, comparison of AS-OCT with gonioscopy and comparison of AS-OCT with UBM. Search was made for articles dating 1990 to August 2015.

  7. Evaluation of the Lower Punctum Parameters and Morphology Using Spectral Domain Anterior Segment Optical Coherence Tomography

    OpenAIRE

    Allam, Riham S. H. M.; Ahmed, Rania A.

    2015-01-01

    Purpose. To study features of the lower punctum in normal subjects using spectral domain anterior segment optical coherence tomography (SD AS-OCT). Methods. Observational cross-sectional study that included 147 punctae (76 subjects). Punctae were evaluated clinically for appearance, position, and size. AS-OCT was used to evaluate the punctal shape, contents, and junction with the vertical canaliculus. Inner and outer diameters as well as depth were measured. Results. 24 males and 52 females (...

  8. Handheld, rapidly switchable, anterior/posterior segment swept source optical coherence tomography probe.

    Science.gov (United States)

    Nankivil, Derek; Waterman, Gar; LaRocca, Francesco; Keller, Brenton; Kuo, Anthony N; Izatt, Joseph A

    2015-11-01

    We describe the first handheld, swept source optical coherence tomography (SSOCT) system capable of imaging both the anterior and posterior segments of the eye in rapid succession. A single 2D microelectromechanical systems (MEMS) scanner was utilized for both imaging modes, and the optical paths for each imaging mode were optimized for their respective application using a combination of commercial and custom optics. The system has a working distance of 26.1 mm and a measured axial resolution of 8 μm (in air). In posterior segment mode, the design has a lateral resolution of 9 μm, 7.4 mm imaging depth range (in air), 4.9 mm 6dB fall-off range (in air), and peak sensitivity of 103 dB over a 22° field of view (FOV). In anterior segment mode, the design has a lateral resolution of 24 μm, imaging depth range of 7.4 mm (in air), 6dB fall-off range of 4.5 mm (in air), depth-of-focus of 3.6 mm, and a peak sensitivity of 99 dB over a 17.5 mm FOV. In addition, the probe includes a wide-field iris imaging system to simplify alignment. A fold mirror assembly actuated by a bi-stable rotary solenoid was used to switch between anterior and posterior segment imaging modes, and a miniature motorized translation stage was used to adjust the objective lens position to correct for patient refraction between -12.6 and + 9.9 D. The entire probe weighs less than 630 g with a form factor of 20.3 x 9.5 x 8.8 cm. Healthy volunteers were imaged to illustrate imaging performance. PMID:26601014

  9. [Toxic anterior segment syndrome].

    Science.gov (United States)

    Cornut, P-L; Chiquet, C

    2011-01-01

    Toxic anterior segment syndrome (TASS) is a general term used to describe acute, sterile postoperative inflammation due to a non-infectious substance that accidentally enters the anterior segment at the time of surgery and mimics infectious endophthalmitis. TASS most commonly occurs acutely following anterior segment surgery, typically 12-72h after cataract extraction. Anterior segment inflammation is usually quite severe with hypopyon. Endothelial cell damage is common, resulting in diffuse corneal edema. No bacterium is isolated from ocular samples. The causes of TASS are numerous and difficult to isolate. Any device or substance used during the surgery or in the immediate postoperative period may be implicated. The major known causes include: preservatives in ophthalmic solutions, denatured ophthalmic viscosurgical devices, bacterial endotoxin, and intraocular lens-induced inflammation. Clinical features of infectious and non-infectious inflammation are initially indistinguishable and TASS is usually diagnosed and treated as acute endophthalmitis. It usually improves with local steroid treatment but may result in chronic elevation of intraocular pressure or irreversible corneal edema due to permanent damage of trabecular meshwork or endothelial cells. PMID:21176994

  10. Quantitative Fourier Domain Optical Coherence Tomography Imaging of the Ocular Anterior Segment

    Science.gov (United States)

    McNabb, Ryan Palmer

    Clinical imaging within ophthalmology has had transformative effects on ocular health over the last century. Imaging has guided clinicians in their pharmaceutical and surgical treatments of macular degeneration, glaucoma, cataracts and numerous other pathologies. Many of the imaging techniques currently used are photography based and are limited to imaging the surface of ocular structures. This limitation forces clinicians to make assumptions about the underlying tissue which may reduce the efficacy of their diagnoses. Optical coherence tomography (OCT) is a non-invasive, non-ionizing imaging modality that has been widely adopted within the field of ophthalmology in the last 15 years. As an optical imaging technique, OCT utilizes low-coherence interferometry to produce micron-scale three-dimensional datasets of a tissue's structure. Much of the human body consists of tissues that significantly scatter and attenuate optical signals limiting the imaging depth of OCT in those tissues to only 1-2mm. However, the ocular anterior segment is unique among human tissue in that it is primarily transparent or translucent. This allows for relatively deep imaging of tissue structure with OCT and is no longer limited by the optical scattering properties of the tissue. This goal of this work is to develop methods utilizing OCT that offer the potential to reduce the assumptions made by clinicians in their evaluations of their patients' ocular anterior segments. We achieved this by first developing a method to reduce the effects of patient motion during OCT volume acquisitions allowing for accurate, three dimensional measurements of corneal shape. Having accurate corneal shape measurements then allowed us to determine corneal spherical and astigmatic refractive contribution in a given individual. This was then validated in a clinical study that showed OCT better measured refractive change due to surgery than other clinical devices. Additionally, a method was developed to combine

  11. Comparison of ultrasound biomicroscopy and spectral-domain anterior segment optical coherence tomography in evaluation of anterior segment after laser peripheral iridotomy

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    Ma, Xiao-Yun; Zhu, Dan; Zou, Jun; Zhang, Wen-Jie; Cao, Yi-Lin

    2016-01-01

    AIM To quantitatively assess narrow anterior chamber angle using spectral-domain anterior segment optical coherence tomography (SD-AS-OCT) and ultrasound biomicroscopy (UBM), and to evaluate the correlations and consistency between SD-AS-OCT and UBM. METHODS Fifty-five eyes from 40 patients were examined. Patients were diagnosed with primary angle-closure glaucoma (PACG) remission (11 eyes from 8 patients), primary angle closure (PAC, 20 eyes from 20 patients) and PAC suspect (24 eyes from 12 patients). Each eye was examined by SD-AS-OCT and UBM after laser peripheral iridotomy (LPI). The measurements of SD-AS-OCT were angle open distance (AOD), anterior chamber angle (ACA), trabecular iris angle (TIA), and trabecular iris space area (TISA). UBM measurements were AOD and TIA. Correlations of AOD500 and TIA500 between UBM and AS-OCT were assessed. All parameters were analysed by SPSS 16.0 and MedCalc. RESULTS ACA, TIA and AOD measured by SD-AS-OCT reached a maximum at the temporal quadrant and minimum at the nasal quadrant. TISA reached the maximum at the inferior and minimum at the superior quadrant. Group parameters of AOD500 and AOD750 showed a linear positive correlation, and AOD750 had less variability. UBM outcomes of AOD500 and TIA500 were significantly smaller than those of SD-AS-OCT. The results of the two techniques were correlated at the superior, nasal and inferior quadrants. CONCLUSION Both UBM and SD-AS-OCT are efficient tools for follow-up during the course of PACG. We recommended using parameters at 750 µm anterior to the sclera spur for the screening and follow-up of PACG and PAC. The two methods might be alternatives to each other.

  12. Evaluation of Descemet’s Membrane Detachment Using Anterior Segment Optical Coherence Tomography

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    Halil Hüseyin Çağatay

    2014-10-01

    Full Text Available We report the use of anterior segment optical coherence tomography (ASOCT in Descemet’s membrane detachment (DMD. A patient who developed DMD after uneventful cataract surgery with posterior chamber lens implantation is presented in this case report. At the follow-up examination after cataract surgery, slit-lamp evaluation showed stromal striae, but it was impossible to diagnose the DMD due to the corneal edema. ASOCT imaging of the cornea revealed a DMD, and the patient underwent intracameral air injection to the anterior chamber through the site which was identified as intact by ASOCT. Follow-up ASOCT imaging revealed the reattachment of the Descemet’s membrane and reduced corneal thickness. If DMD is suspected in any cases, ASOCT can be useful to document and follow the postsurgical detachment of DMD and also to determine the site, configuration, and extent of the DMD, thus guiding the treatment method and monitoring the treatment outcome. (Turk J Ophthalmol 2014; 44: 407-9

  13. A case of optic-nerve hypoplasia and anterior segment abnormality associated with facial cleft

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    Miyake T

    2016-07-01

    Full Text Available Tomoko Miyake,1 Shota Kojima,1 Tetsuya Sugiyama,2 Mari Ueki,1 Jun Sugasawa,1 Hidehiro Oku,1 Kensuke Tajiri,1 Yuka Shigemura,3 Koichi Ueda,3 Atsuko Harada,4 Mami Yamasaki,4 Takumi Yamanaka,4 Hidetsuna Utsunomiya,5 Tsunehiko Ikeda1 1Department of Ophthalmology, Osaka Medical College, Takatsuki City, 2Nakano Eye Clinic of Kyoto Medical Co-operative, Kyoto, 3Department of Plastic and Reconstructive Surgery, Osaka Medical College, Takatsuki City, 4Department of Pediatric Neurosurgery, Takatsuki General Hospital, Takatsuki City, 5Department of Radiological Science, International University of Health and Welfare, Graduate School, Fukuoka, Japan Introduction: The incidence of facial cleft is rare and ranges between 1.43 and 4.85 per 100,000 births. To date, there have been few reports of detailed ophthalmologic examinations performed in cases of facial cleft. Here, we report a case of optic-nerve hypoplasia and anterior segment abnormality associated with facial cleft. Case report: A 9-day-old female infant was delivered by cesarian section at 34 weeks of gestational age (the second baby of twins and weighed 2,276 g upon presentation. She had a facial cleft and ectrodactyly at birth. Right eye-dominant blepharophimosis was obvious. Examination of the right eye revealed inferior corneal opacity with vascularization, downward corectopia, and optic-nerve hypoplasia. The corneal diameter was 8 mm in both eyes, and tonometry by use of a Tono-Pen® XL (Reichert Technologies, Depew, NY, USA handheld applanation tonometer revealed that her intraocular pressure was 11–22 mmHg (Oculus Dexter and 8 mmHg (Oculus Sinister. B-mode echo revealed no differences in axial length between her right and left eyes. When she was 15–16 months old, we attempted to examine her eyes before she underwent plastic surgery under general anesthesia. She had a small optic disc in both eyes and the right-eye disc was tilted. After undergoing canthotomy, gonioscopy and ultrasound

  14. Evaluation of the Lower Punctum Parameters and Morphology Using Spectral Domain Anterior Segment Optical Coherence Tomography.

    Science.gov (United States)

    Allam, Riham S H M; Ahmed, Rania A

    2015-01-01

    Purpose. To study features of the lower punctum in normal subjects using spectral domain anterior segment optical coherence tomography (SD AS-OCT). Methods. Observational cross-sectional study that included 147 punctae (76 subjects). Punctae were evaluated clinically for appearance, position, and size. AS-OCT was used to evaluate the punctal shape, contents, and junction with the vertical canaliculus. Inner and outer diameters as well as depth were measured. Results. 24 males and 52 females (mean age 44 ± 14.35 y) were included. Lower punctum was perceived by OCT to be an area with an outer diameter (mean 412.16 ± 163 μm), inner diameter (mean 233.67 ± 138.73 μm), and depth (mean 251.7 ± 126.58 μm). The OCT measured outer punctum diameter was significantly less than that measured clinically (P: 0.000). Seven major shapes were identified. The junction with the vertical canaliculus was detectable in 44%. Fluid was detected in 34%, one of which had an air bubble; however, 63% of punctae showed no contents and 4% had debris. Conclusions. AS-OCT can be a useful tool in understanding the anatomy of the punctum and distal lacrimal system as well as tear drainage physiology. Measuring the punctum size may play a role in plugs fitting. PMID:26090219

  15. Morphological analysis of age-related iridocorneal angle changes in normal and glaucomatous cases using anterior segment optical coherence tomography

    OpenAIRE

    Maruyama Y; Mori K; Ikeda Y; Ueno M; Kinoshita S

    2013-01-01

    Yuko Maruyama, Kazuhiko Mori, Yoko Ikeda, Morio Ueno, Shigeru Kinoshita Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan Purpose: To analyze age-related morphological changes of the iridocorneal angle in normal subjects and glaucomatous cases, using anterior segment optical coherence tomography (AS-OCT). Methods: This study involved 58 eyes of 58 open-angle glaucoma cases and 72 eyes of 72 age-matched normal-open-angle control subjects. Iridocorneal angle s...

  16. Tear fluid signs associated with filtration blebs, as demonstrated by three-dimensional anterior segment optical coherence tomography

    OpenAIRE

    Kojima S; Inoue T.; Kawaji T; Tanihara H

    2014-01-01

    Sachi Kojima, Toshihiro Inoue, Takahiro Kawaji, Hidenobu TaniharaDepartment of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Chuo-ku, Kumamoto, JapanPurpose: To determine the clinical features of tear fluid signs associated with filtration blebs via three-dimensional anterior segment optical coherence tomography (3D AS-OCT).Methods: In total, 152 eyes (130 patients) with glaucoma that underwent trabeculectomy with mitomycin C were evaluated retrospectively. We investigated tea...

  17. Morphology of functioning trabeculectomy blebs using anterior segment optical coherence tomography

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    Mayuri B Khamar

    2014-01-01

    Full Text Available Purpose: To image trabeculectomy blebs using anterior segment optical coherence tomography (AS-OCT, and to correlate the bleb morphologic features at one month postoperatively with bleb function at six months. Materials and Methods: This prospective, observational study included 56 eyes undergoing trabeculectomy with MMC, followed up for minimum of six months. Postoperatively, bleb imaging was done using AS-OCT at one and six month. Bleb morphology was assessed for bleb wall reflectivity, bleb pattern in multiform reflectivity, visibility of drainage route and presence of hyper-reflectivity area. Bleb function was considered successful if IOP was <18 mmHg without medication at six month. Bleb morphology one month postoperatively was correlated with bleb function at six months. Results: At six months successful bleb function was noted in 44 (81.5% eyes. Morphology of bleb at one month showed uniform bleb wall reflectivity in 6 eyes (11% and multiform wall reflectivity in 48 eyes (89%. In eyes with multiform wall reflectivity, microcysts with multiple layers was seen in 26 eyes (48%, microcysts with subconjunctival separation in 12 eyes (22% and only microcyst in 10 eyes (19%. When bleb features at one month were correlated with the bleb function at six months, logistic regression analysis revealed that blebs with multiform reflectivity with multiple internal layers with microcysts were associated with higher chances of success (P < 0.001. Conclusion : AS-OCT demonstrated early bleb morphological features that may be used to predict the functioning of a bleb. Multiform bleb wall reflectivity with a pattern of multiple internal layers and microcysts was associated with increased chances of success of a bleb.

  18. Comparison between a New Optical Biometry Device and an Anterior Segment Optical Coherence Tomographer for Measuring Central Corneal Thickness and Anterior Chamber Depth

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    Jinhai Huang

    2016-01-01

    Full Text Available Purpose. To compare between a new optical biometer (AL-Scan, Nidek Co., Aichi, Japan and an anterior segment optical coherence tomographer (Visante AS-OCT, Carl Zeiss Meditec, Dublin, USA for measuring central corneal thickness (CCT, anterior chamber depth (ACD, and aqueous depth (AD. Methods. Sixty-three eyes of 63 normal subjects were examined with AL-Scan and Visante AS-OCT in this prospective study. One eye per subject was measured three times with both devices to record their CCT, ACD, and AD. All procedures were performed by the same operator. Agreement between the two devices was assessed using paired t-tests, Bland-Altman plots, and 95% limits of agreement (LoA. Results. The mean CCT, ACD, and AD measured by AL-Scan were 538.59±27.37 μm, 3.70±0.30 mm, and 3.16±0.30 mm, respectively. The mean values obtained by the Visante OCT were 536.14±26.61 μm for CCT, 3.71±0.29 mm for ACD, and 3.17±0.29 mm for AD. The mean CCT by the AL-Scan was higher than that obtained by the Visante AS-OCT (difference = 2.45±6.07 μm, P<0.05. The differences in ACD and AD measurements were not statistically significant. The 95% LoA of CCT, ACD, and AD were between −9.44 and 14.35 μm, −0.15 and 0.12 mm, and −0.15 and 0.12 mm, respectively. Conclusions. Since these two devices were comparable for measuring CCT, ACD, and AD, their results can be interchangeably used in the clinic.

  19. Comparison between a New Optical Biometry Device and an Anterior Segment Optical Coherence Tomographer for Measuring Central Corneal Thickness and Anterior Chamber Depth.

    Science.gov (United States)

    Huang, Jinhai; Lu, Weicong; Savini, Giacomo; Chen, Hao; Wang, Chengfang; Yu, Xinxin; Bao, Fangjun; Wang, Qinmei

    2016-01-01

    Purpose. To compare between a new optical biometer (AL-Scan, Nidek Co., Aichi, Japan) and an anterior segment optical coherence tomographer (Visante AS-OCT, Carl Zeiss Meditec, Dublin, USA) for measuring central corneal thickness (CCT), anterior chamber depth (ACD), and aqueous depth (AD). Methods. Sixty-three eyes of 63 normal subjects were examined with AL-Scan and Visante AS-OCT in this prospective study. One eye per subject was measured three times with both devices to record their CCT, ACD, and AD. All procedures were performed by the same operator. Agreement between the two devices was assessed using paired t-tests, Bland-Altman plots, and 95% limits of agreement (LoA). Results. The mean CCT, ACD, and AD measured by AL-Scan were 538.59 ± 27.37 μm, 3.70 ± 0.30 mm, and 3.16 ± 0.30 mm, respectively. The mean values obtained by the Visante OCT were 536.14 ± 26.61 μm for CCT, 3.71 ± 0.29 mm for ACD, and 3.17 ± 0.29 mm for AD. The mean CCT by the AL-Scan was higher than that obtained by the Visante AS-OCT (difference = 2.45 ± 6.07 μm, P LoA of CCT, ACD, and AD were between -9.44 and 14.35 μm, -0.15 and 0.12 mm, and -0.15 and 0.12 mm, respectively. Conclusions. Since these two devices were comparable for measuring CCT, ACD, and AD, their results can be interchangeably used in the clinic. PMID:27403339

  20. Full anterior segment biometry with extended imaging range spectral domain optical coherence tomography at 1340 nm

    OpenAIRE

    Li, Peng; Johnstone, Murray; Ruikang K Wang

    2014-01-01

    Abstract. We demonstrate an extended-imaging-range anterior-segment optical coherence tomography (eAS-OCT) system for the biometric assessment of full AS in human eye. This newly developed eAS-OCT operating at 1340-nm wavelength band is simultaneously capable of an imaging speed of 120 kHz A-line scan rate, an axial resolution of 7.2 μm, and an extended imaging range of up to 16 mm in air. Imaging results from three healthy subjects and one subject with a narrow-angle demonstrate the instrume...

  1. Analysis of iris structure and iridocorneal angle parameters with anterior segment optical coherence tomography in Fuchs' uveitis syndrome.

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    Basarir, Berna; Altan, Cigdem; Pinarci, Eylem Yaman; Celik, Ugur; Satana, Banu; Demirok, Ahmet

    2013-06-01

    To evaluate the differences in the biometric parameters of iridocorneal angle and iris structure measured by anterior segment optical coherence tomography (AS-OCT) in Fuchs' uveitis syndrome (FUS). Seventy-six eyes of 38 consecutive patients with the diagnosis of unilateral FUS were recruited into this prospective, cross-sectional and comparative study. After a complete ocular examination, anterior segment biometric parameters were measured by Visante(®) AS-OCT. All parameters were compared between the two eyes of each patient statistically. The mean age of the 38 subjects was 32.5 ± 7.5 years (18 female and 20 male). The mean visual acuity was lower in eyes with FUS (0.55 ± 0.31) than in healthy eyes (0.93 ± 0.17). The central corneal thickness did not differ significantly between eyes. All iridocorneal angle parameters (angle-opening distance 500 and 750, scleral spur angle, trabecular-iris space (TISA) 500 and 750) except TISA 500 in temporal quadrant were significantly larger in eyes with FUS than in healthy eyes. Anterior chamber depth was deeper in the eyes with FUS than in the unaffected eyes. With regard to iris measurements, iris thickness in the thickest part, iris bowing and iris shape were all statistically different between the affected eye and the healthy eye in individual patients with FUS. However, no statistically significant differences were evident in iris thickness 500 μm, thickness in the middle and iris length. There were significant difference in iris shape between the two eyes of patients with glaucoma. AS-OCT as an imaging method provides us with many informative resultsin the analysis of anterior segment parameters in FUS. PMID:23277205

  2. Comparison of immersion ultrasonography, ultrasound biomicroscopy and anterior segment optical coherence tomography in the evaluation of traumatic phacoceles

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    Harikrishna Vodapalli

    2012-01-01

    Full Text Available Blunt ocular trauma in the elderly can result in anterior dislocation of the crystalline lens into the subconjunctival space (phacocele. Although rare, this presentation can be missed, especially if the patient presents several days after the injury and if the lid is not everted on examination. While a careful clinical examination is adequate in the diagnosis, imaging techniques can be put to use for the accurate location of the associated sclera rupture. We report three cases of post-traumatic phacocele wherein ultrasound biomicroscopy (UBM was compared to the anterior segment optical coherence tomography (AS-OCT and B-scan ultrasonography (B-scan, in order to establish the best imaging tool for this condition. We concluded, based on image quality, that UBM could be the imaging modality of choice to aid in the diagnosis of phacocele.

  3. Correlation of anterior segment optical coherence tomography measurements with graft trephine diameter following descemet stripping automated endothelial keratoplasty

    International Nuclear Information System (INIS)

    To assess repeatability of the Zhongshan Assessment Program (ZAP) software measurement of Anterior Segment Optical Coherence Tomography (ASOCT) images and correlate with graft trephine diameter following Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) Retrospectively evaluated interventional case series. 121 consecutive eyes undergoing DSAEK over a 26 month period underwent ASOCT imaging 1month after their surgery. ASOCT images were processed using ZAP software which measured the graft and cornea parameters including anterior and posterior graft arc length and cord length, posterior cornea arc length (PCAL) and anterior chamber width. The graft measurements showed good repeatability on ASOCT using ZAP with high intra class coefficient and small variation in the coefficient of variation. On ASOCT, the mean recipient PCAL was 12.99+/−0.69mm and the anterior chamber width was 11.16+/−0.57mm. The mean Graft anterior arc length was 9.69+/−0.66mm and the mean Graft anterior cord length was 8.92+/−2.94mm. The mean graft posterior arc length was 9.24+/−0.75mm and the mean graft posterior cord length was 8.15+/−0.57mm. Graft posterior arc length (rho=0.788, p< 0.001) correlated best with intra-operative graft trephine diameter. The mean ratio of posterior graft arc length to PCAL was 0.712 +/− 0.056. We have validated the repeatability of the ZAP software for DSAEK graft measurements from ASOCT images and shown that the graft arc length parameters calculated from the ASOCT images correlate well with the intra-operative graft trephine diameter. This software may help surgeons determine the optimal DSAEK graft size based on pre-operative ASOCT measurements of the recipient eye

  4. Agreement of angle closure assessments between gonioscopy, anterior segment optical coherence tomography and spectral domain optical coherence tomography

    Institute of Scientific and Technical Information of China (English)

    Elton; Lik; Tong; Tay; Vernon; Khet; Yau; Yong; Boon; Ang; Lim; Stelson; Sia; Elizabeth; Poh; Ying; Wong; Leonard; Wei; Leon; Yip

    2015-01-01

    AIM: To determine angle closure agreements between gonioscopy and anterior segment optical coherence tomography(AS-OCT), as well as gonioscopy and spectral domain OCT(SD-OCT). A secondary objective was to quantify inter-observer agreements of AS-OCT and SD-OCT assessments.METHODS: Seventeen consecutive subjects(33 eyes)were recruited from the study hospital’s Glaucoma clinic.Gonioscopy was performed by a glaucomatologist masked to OCT results. OCT images were read independently by 2 other glaucomatologists masked to gonioscopy findings as well as each other’s analyses of OCT images.RESULTS: Totally 84.8% and 45.5% of scleral spurs were visualized in AS-OCT and SD-OCT images respectively(P <0.01). The agreement for angle closure between AS-OCT and gonioscopy was fair at k =0.31(95% confidence interval, CI: 0.03-0.59) and k =0.35(95%CI: 0.07-0.63) for reader 1 and 2 respectively. The agreement for angle closure between SD-OCT and gonioscopy was fair at k =0.21(95% CI: 0.07-0.49) and slight at k =0.17(95% CI: 0.08-0.42) for reader 1 and 2 respectively. The inter-reader agreement for angle closure in AS-OCT images was moderate at 0.51(95% CI: 0.13-0.88). The inter-reader agreement for angle closure in SD-OCT images was slight at 0.18(95% CI: 0.08-0.45).CONCLUSION: Significant proportion of scleral spurs were not visualised with SD-OCT imaging resulting in weaker inter-reader agreements. Identifying other angle landmarks in SD-OCT images will allow more consistent angle closure assessments. Gonioscopy and OCT imaging do not always agree in angle closure assessments but have their own advantages, and should be used together and not exclusively.

  5. Trabecular-iris circumference volume in open angle eyes using swept-source fourier domain anterior segment optical coherence tomography.

    Science.gov (United States)

    Rigi, Mohammed; Blieden, Lauren S; Nguyen, Donna; Chuang, Alice Z; Baker, Laura A; Bell, Nicholas P; Lee, David A; Mankiewicz, Kimberly A; Feldman, Robert M

    2014-01-01

    Purpose. To introduce a new anterior segment optical coherence tomography parameter, trabecular-iris circumference volume (TICV), which measures the integrated volume of the peripheral angle, and establish a reference range in normal, open angle eyes. Methods. One eye of each participant with open angles and a normal anterior segment was imaged using 3D mode by the CASIA SS-1000 (Tomey, Nagoya, Japan). Trabecular-iris space area (TISA) and TICV at 500 and 750 µm were calculated. Analysis of covariance was performed to examine the effect of age and its interaction with spherical equivalent. Results. The study included 100 participants with a mean age of 50 (±15) years (range 20-79). TICV showed a normal distribution with a mean (±SD) value of 4.75 µL (±2.30) for TICV500 and a mean (±SD) value of 8.90 µL (±3.88) for TICV750. Overall, TICV showed an age-related reduction (P = 0.035). In addition, angle volume increased with increased myopia for all age groups, except for those older than 65 years. Conclusions. This study introduces a new parameter to measure peripheral angle volume, TICV, with age-adjusted normal ranges for open angle eyes. Further investigation is warranted to determine the clinical utility of this new parameter. PMID:25210623

  6. Trabecular-Iris Circumference Volume in Open Angle Eyes Using Swept-Source Fourier Domain Anterior Segment Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Mohammed Rigi

    2014-01-01

    Full Text Available Purpose. To introduce a new anterior segment optical coherence tomography parameter, trabecular-iris circumference volume (TICV, which measures the integrated volume of the peripheral angle, and establish a reference range in normal, open angle eyes. Methods. One eye of each participant with open angles and a normal anterior segment was imaged using 3D mode by the CASIA SS-1000 (Tomey, Nagoya, Japan. Trabecular-iris space area (TISA and TICV at 500 and 750 µm were calculated. Analysis of covariance was performed to examine the effect of age and its interaction with spherical equivalent. Results. The study included 100 participants with a mean age of 50 (±15 years (range 20–79. TICV showed a normal distribution with a mean (±SD value of 4.75 µL (±2.30 for TICV500 and a mean (±SD value of 8.90 µL (±3.88 for TICV750. Overall, TICV showed an age-related reduction (P=0.035. In addition, angle volume increased with increased myopia for all age groups, except for those older than 65 years. Conclusions. This study introduces a new parameter to measure peripheral angle volume, TICV, with age-adjusted normal ranges for open angle eyes. Further investigation is warranted to determine the clinical utility of this new parameter.

  7. Morphological analysis of age-related iridocorneal angle changes in normal and glaucomatous cases using anterior segment optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Maruyama Y

    2013-12-01

    Full Text Available Yuko Maruyama, Kazuhiko Mori, Yoko Ikeda, Morio Ueno, Shigeru Kinoshita Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan Purpose: To analyze age-related morphological changes of the iridocorneal angle in normal subjects and glaucomatous cases, using anterior segment optical coherence tomography (AS-OCT. Methods: This study involved 58 eyes of 58 open-angle glaucoma cases and 72 eyes of 72 age-matched normal-open-angle control subjects. Iridocorneal angle structures in nasal and temporal regions and anterior chamber depth (ACD were measured using AS-OCT. Axial length and refractive error were measured by use of an ocular biometer and auto refractor keratometer. Angle opening distance (AOD, angle recess area (ARA, and trabecular-iris space area (TISA, measured at 500 µm (TISA500 and 750 µm (TISA750 distant from the scleral spur, were calculated, in the nasal and temporal regions. A new index, the peripheral angle frame index (PAFI, which represents the peripheral angle structure, was proposed, and was defined as (TISA750-TISA500/TISA500. Results: Refractive power in the glaucoma cases was less than in control cases (P<0.0001. Axial length (P<0.0001 and ACD (P=0.0004 were longer and deeper, respectively, in the glaucoma cases, compared with the control cases. In both control and glaucoma groups, ACD, AOD, ARA, and TISA decreased linearly in an age-dependent manner, while PAFI stayed at relatively constant values throughout the age distribution. AOD in the glaucoma group was longer than in the control group, in both the temporal and nasal regions; ARA and TISA were larger in the glaucoma than in the control group. However, no significant differences in nasal or temporal PAFI were found between the glaucoma and control groups. Conclusion: The findings of this study show that AS-OCT is useful for the quantitative evaluation of age-related changes in peripheral angle structure in glaucoma and control cases. Keywords

  8. Anterior and posterior segment parameters measured with Fourier domain optical coherence tomography in photopic and scotopic conditions

    Science.gov (United States)

    Rampersad, Nishanee; Hansraj, Rekha

    2016-01-01

    Purpose: To compare anterior and posterior segment parameters measured with the iVue-100 optical coherence tomography (OCT) in photopic and scotopic conditions. Methods: Central and peripheral corneal thickness, retinal nerve fiber layer and macula thickness were measured using the iVue-100 OCT in 47 healthy individuals at a higher education institution in photopic (958 lux) and scotopic (0.03 lux) conditions. Results: As the lighting conditions changed from scotopic to photopic, a significant change in pupil size was noted (P < 0.001). However, there was no significant difference in central corneal thickness measurements with this change in surrounding illumination with only the temporal peripheral corneal area showing a significant difference (3.44 μm thinner). No significant differences were found in the retinal nerve fiber layer thickness. A significant decrease in the reading was noted in only the inferior (P = 0.05) and temporal (P = 0.05) inner macula area. Conclusion: Change in the ambient lighting conditions does not result in a clinically significant difference in corneal, retinal nerve fiber layer, and macula thickness when measured with the iVue-100 OCT. PMID:27050349

  9. Efficacy of intacs intrastromal corneal ring segment relative to depth of insertion evaluated with anterior segment optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Hassan Hashemi

    2013-01-01

    Full Text Available Aim: To evaluate the effect of implantation depth of Intacs microthin prescription inserts (Addition Technology Inc, Fremont, California on visual and topographic outcomes in patients with post- laser-assisted in situ keratomileusis (LASIK ectasias. Settings and Design: Retrospective, observational case series. Materials and Methods: In this case series, 16 eyes of 12 patients were evaluated. All cases were post-LASIK ectasia that had undergone intrastromal corneal ring segment (ICRS implantation. The planned insertion depth was 70% of stromal thickness using a manual dissector. At least 12 months postoperatively, all eyes underwent Visante (Carl Zeiss Meditec AS-OCT to determine insertion depth. Cases were categorized into 3 groups based on the measured implantation depth: 40-59% thickness; 60-79% thickness; and ≥80% thickness. Visual, refractive and topographic outcomes were evaluated relative to implantation depth. Results: The lowest improvement in the study parameters ocurred when the implantation depth was ≥80%. In this group, uncorrected visual acuity (UCVA and best spectacle corrected VA (BSCVA improved less than 0.5 lines. Manifest refractive spherical equivalent (MRSE and mean keratometry (Km change was less than 0.5 diopters (D. The greatest improvements were observed with implantation depth of 60-79% where UCVA and BSCVA increased by 4.5 and 2.5 lines respectively, and MRSE and Km changed by approximately 2.00 D. Less improvement was found when ICRS were implanted between 40-59% of stromal thickness. Conclusion: Implantation of ICRS greater than 80% of stromal thickness may have no effect on visual and topographic status.

  10. Toxic Anterior Segment Syndrome (TASS

    Directory of Open Access Journals (Sweden)

    Özlem Öner

    2011-12-01

    Full Text Available Toxic anterior segment syndrome (TASS is a sterile intraocular inflammation caused by noninfectious substances, resulting in extensive toxic damage to the intraocular tissues. Possible etiologic factors of TASS include surgical trauma, bacterial endotoxin, intraocular solutions with inappropriate pH and osmolality, preservatives, denatured ophthalmic viscosurgical devices (OVD, inadequate sterilization, cleaning and rinsing of surgical devices, intraocular lenses, polishing and sterilizing compounds which are related to intraocular lenses. The characteristic signs and symptoms such as blurred vision, corneal edema, hypopyon and nonreactive pupil usually occur 24 hours after the cataract surgery. The differential diagnosis of TASS from infectious endophthalmitis is important. The main treatment for TASS formation is prevention. TASS is a cataract surgery complication that is more commonly seen nowadays. In this article, the possible underlying causes as well as treatment and prevention methods of TASS are summarized. (Turk J Oph thal mol 2011; 41: 407-13

  11. Mild toxic anterior segment syndrome mimicking delayed onset toxic anterior segment syndrome after cataract surgery

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    Su-Na Lee

    2014-01-01

    Full Text Available Toxic anterior segment syndrome (TASS is an acute sterile postoperative anterior segment inflammation that may occur after anterior segment surgery. I report herein a case that developed mild TASS in one eye after bilateral uneventful cataract surgery, which was masked during early postoperative period under steroid eye drop and mimicking delayed onset TASS after switching to weaker steroid eye drop.

  12. Trypan blue dye for anterior segment surgeries

    OpenAIRE

    Jhanji, V; Chan, E.; Das, S.; Zhang, H; Vajpayee, R B

    2011-01-01

    Use of vital dyes in ophthalmic surgery has gained increased importance in the past few years. Trypan blue (TB) has been a popular choice among anterior segment surgeons mainly due to its safety, ease of availability, and remarkable ability to enable an easy surgery in difficult situations mostly related to visibility of the targeted tissue. It is being used in cataract surgery since nearly a decade and its utilization has been extended to other anterior segment surgeries like trabeculectomy ...

  13. Comparative Study of Anterior Eye Segment Measurements with Spectral Swept-Source and Time-Domain Optical Coherence Tomography in Eyes with Corneal Dystrophies

    Directory of Open Access Journals (Sweden)

    Anna K. Nowinska

    2015-01-01

    Full Text Available Purpose. To compare anterior eye segment measurements and morphology obtained with two optical coherence tomography systems (TD OCT, SS OCT in eyes with corneal dystrophies (CDs. Methods. Fifty healthy volunteers (50 eyes and 54 patients (96 eyes diagnosed with CD (epithelial basement membrane dystrophy, EBMD = 12 eyes; Thiel-Behnke CD = 6 eyes; lattice CD TGFBI type = 15 eyes; granular CD type 1 = 7 eyes, granular CD type 2 = 2 eyes; macular CD = 23 eyes; and Fuchs endothelial CD = 31 eyes were recruited for the study. Automated and manual central corneal thickness (aCCT, mCCT, anterior chamber depth (ACD, and nasal and temporal trabecular iris angle (nTIA, tTIA were measured and compared with Bland-Altman plots. Results. Good agreement between the TD and SS OCT measurements was demonstrated for mCCT and aCCT in normal individuals and for mCCT in the CDs group. The ACD, nTIA, and tTIA measurements differed significantly in both groups. TBCD, LCD, and FECD caused increased CCT. MCD caused significant corneal thinning. FECD affected all analyzed parameters. Conclusions. Better agreement between SS OCT and TD OCT measurements was demonstrated in normal individuals compared to the CDs group. OCT provides comprehensive corneal deposits analysis and demonstrates the association of CD with CCT, ACD, and TIA measurements.

  14. Anterior Eye Imaging with Optical Coherence Tomography

    Science.gov (United States)

    Huang, David; Li, Yan; Tang, Maolong

    The development of corneal and anterior segment optical coherence tomography (OCT) technology has advanced rapidly in recently years. The scan geometry and imaging wavelength are both important choices to make in designing anterior segment OCT systems. Rectangular scan geometry offers the least image distortion and is now used in most anterior OCT systems. The wavelength of OCT light source affects resolution and penetration. An optimal choice of the OCT imaging wavelength (840, 1,050, or 1,310 nm) depends on the application of interest. Newer generation Fourier-domain OCT technology can provide scan speed 100-1000 times faster than the time-domain technology. Various commercial anterior OCT systems are available on the market. A wide spectrum of diagnostic and surgical applications using anterior segment OCT had been investigated, including mapping of corneal and epithelial thicknesses, keratoconus screening, measuring corneal refractive power, corneal surgery planning and evaluation in LASIK, intracorneal ring implantation, assessment of angle closure glaucoma, anterior chamber biometry and intraocular lens implants, intraocular lens power calculation, and eye bank donor cornea screening.

  15. Toxic anterior-segment syndrome (TASS

    Directory of Open Access Journals (Sweden)

    Cetinkaya S

    2014-10-01

    Full Text Available Servet Cetinkaya,1 Zeynep Dadaci,2 Hüsamettin Aksoy,3 Nursen Oncel Acir,2 Halil Ibrahim Yener,4 Ekrem Kadioglu5 1Ophthalmology Clinics, Turkish Red Crescent Hospital, Konya, 2Department of Ophthalmology, Faculty of Medicine, Mevlana University, Konya, 3Ophthalmology Clinics, Karaman State Hospital, Karaman, 4Konya Eye Center Hospital, Konya, 5Ophthalmology Clinics, Beyhekim State Hospital, Konya, Turkey Purpose: To evaluate the clinical findings and courses of five patients who developed toxic anterior-segment syndrome (TASS after cataract surgery and investigate the cause.Materials and methods: In May 2010, on the same day, ten patients were operated on by the same surgeon. Five of these patients developed TASS postoperatively.Results: Patients had blurred-vision complaints on the first day after the operation, but no pain. They had different degrees of diffuse corneal edema, anterior-chamber reaction, fibrin, hypopyon, iris atrophies, and dilated pupils. Their vision decreased significantly, and their intraocular pressures increased. Both anti-inflammatory and antiglaucomatous therapies were commenced. Corneal edema and inflammation resolved in three cases; however, penetrating keratoplasty was needed for two cases and additional trabeculectomy was needed for one case. Although full investigations were undertaken at all steps, we could not find the causative agent.Conclusion: TASS is a preventable complication of anterior-segment surgery. Recognition of TASS, differentiating it from endophthalmitis, and starting treatment immediately is important. Controlling all steps in surgery, cleaning and sterilization of the instruments, and training nurses and other operation teams will help us in the prevention of TASS. Keywords: cataract, phacoemulsification, TASS, corneal edema, inflammation

  16. Refraction and eye anterior segment parameters in schizophrenic patients

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    Tongabay Cumurcu

    2015-06-01

    Full Text Available ABSTRACT Purpose: To evaluate the difference in terms of refractive errors and anterior segment parameters between schizophrenic patients and healthy volunteers. Methods: This study compared 70 patients (48 men who were diagnosed with schizophrenia with a control group of 60 (35 men who were similar in terms of age, gender, education, and socioeconomic level. Anterior segment examination was performed using a Scheimflug system. Axial length and lens thickness (LT were measured using optic biometry. The following tests were administered to the psychiatric patient group: Brief Psychiatric Rating Scale (BPRS, Scale for the Assessment of Negative Symptoms (SANS, and Scale for the Assessment of Positive Symptoms (SAPS. Results: Mild myopia was detected in both the schizophrenic and control groups, with no statistically significant difference (p>0.005. Corneal volume (CV, anterior chamber volume (ACV, anterior chamber depth (ACD, and central corneal thickness (CCT values were lower in the schizophrenic group, and there was a statistically significant between-group difference (p=0.026, p=0.014, p=0.048, and p=0.005, respectively. LT was greater in schizophrenics, and the difference was found to be statistically significant (p=0.006. A statistically significant negative correlation was found between SAPS and cylinder values (p=0.008. The axial eye length, cylinder value, pupil diameter, mean keratometric value, and anterior chamber angle revealed no statistically significant difference between the groups (p>0.05. Conclusion: No statistically significant difference was detected in terms of refraction disorders between schizophrenics and the healthy control group, while some differences in anterior chamber parameters were present. These results demonstrate that schizophrenics may exhibit clinical and structural differences in the eye.

  17. 采用AS-OCT测量房角开放度数的一致性分析%Reproducibility of anterior chamber angle measurement with anterior segment optical coherence tomography

    Institute of Scientific and Technical Information of China (English)

    曾阳发; 刘杏; 王涛; 钟毅敏; 何明光

    2008-01-01

    目的 探讨采用眼前段光学相干断层扫描仪(AS-OCT)定量测量房角,并分析其测量一致性.方法 采用AS-OCT对23例受试者(30只眼)的房角进行扫描,分别由测量者甲和乙,以及测量者甲在两个不同的时间点对颞侧房角500μm(AA-500μm)和750μm(AA-750μm)的房角开放度数进行定量测量.采用类内相关系数ICC和95%LoA(95%Limts of Agreement,95% LoA)评价测量的一致性.结果 甲两次测量的AA-500μm和AA-750μm值比较差异均无统计学意义(均P>0.05);甲与乙测量的AA-500μm和AA-750μm值比较差异均无统计学意义(均P>0.05).AA-500μm和AA-750μm测量者内的95%LoA分别为(-5.441,5.281弧度和-7.313、6.020弧度);ICC分别为:0.933,0.907.AA-500μm和AA-750μm测量者间的95%LoA分别为:(-6.098,5.098弧度和-7.877、5.423弧度);ICC分别为0.925,0.887.结论 AS-OCT测量房角开放度数的一致性较好,可以用于定量测量房角开放度数.%Objective To assess reproducibility of anterior segment optical coherencetomography (AS-OCT)to quantify the anterior chamber angle(AA).Methods 23 eyes of 30 subjects were enrolled.Anterior champer angle was scanned using AS-OCT,and the 500μm(AA-500 μm)and 750μm(AA-750μm)temporal anterior champer angle were measured by two ophthalmologists,respectively.And one observer repeatedly measured its in two different times.Analyzing the reproducibility with intraclass correlation coefficient(ICC)and 95%Limts of Agreement(95%LoA).Results The difference in AA-500μm and AA-750μm measurements between two observers were not significant(all P>0.05),and its were also no significant difference between the first and the second measurement for same observer(all P>0.05).The 95%LoA of intraobserver of AA-500μm and AA-750μm were-5.441 to 5.281 degrees and-7.313 to 6.020 degrees,respectively.The ICC server of AA-500μm and AA-750μm were-6.098 to 5.098 degrees and-7.877 to 5.423 degrees,respectively.The ICC of interobserver of AA-500

  18. Comparison of Central Corneal Thickness Measurements Obtained with Ultrasonic Pachymetry and Spectral Domain Anterior Segment OCT

    OpenAIRE

    Kirikkaya, Esin Tunca; Akyuz Unsal, Ayşe İpek; Dogramaci, Mahmut

    2014-01-01

    Aim: To compare central corneal thickness (CCT) measurements obtained with Ultrasonic Pachymetry (USP) and Anterior Segment Optical Coherence Tomography (AS-OCT).Methods: Seventy eight eyes of thirty nine volunteers between 40-60 ages were recruited in this study. Best corrected visual acuity (BCVA), intraocular pressure (IOP) measurements, anterior and posterior segment biomicroscopic examinations of all volunteers were performed. CCT measurements were evaluated with Nidek  UP and Zeiss Cirr...

  19. Clinical applications and limitations of anterior segment optical coherence tomography%眼前节相干光断层扫描技术的临床应用进展

    Institute of Scientific and Technical Information of China (English)

    洪佳旭; 孙兴怀

    2010-01-01

    Optical coherence tomography (OCT) is being employed more and more often to facilitate the diagnosis and management of the anterior eye segment diseases. The cross-sectional imaging capability of its higher resolution allows OCT to measure and visualize clear anatomic structures, specifically in anterior chamber biometry, corneal pachymetric mapping, and anterior chamber angle. Fourier-domain OCT technique which achieves higher speed and higher resolution and time-domain OCT technique have driven their further application in ophthalmological practice. In this review, we describe the principles and characteristics of OCT, summarize the recent utility and the limitations of anterior segment OCT in the pathologies and surgical planning of anterior chamber, cornea and surrounding areas, and prospect its future development.%近年来,相干光断层扫描(OCT)技术在眼前节疾病诊治中的应用飞速发展.由于OCT的分辨率更高、成像效果更好且为无创的非接触测量,所以它在前房参数测量、角膜地形测量及房角测量等方面具有明显的优势.高速、高分辨率的傅立叶OCT技术与传统的时域OCT技术相辅相成,推动和发展OCT在眼科临床中的应用.本文介绍了眼前节OCT的成像原理,结合相应的临床应用展示了OCT在眼前节疾病发病机制研究及诊疗中的价值与局限,并对OCT技术未来的发展进行展望.

  20. Comparison of Hanna and Hessburg-Barron trephine and punch systems using histological, anterior segment optical coherence tomography, and elliptical curve fitting models

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    Moshirfar M

    2011-08-01

    Full Text Available Majid Moshirfar1, Charles M Calvo2, Krista I Kinard1, Lloyd B Williams1, Shameema Sikder3, Marcus C Neuffer11University of Utah, Department of Ophthalmology and Visual Sciences, Salt Lake City, UT, USA; 2University of Nevada, School of Medicine, Las Vegas, NV, USA; 3Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USABackground: This study analyzes the characteristics of donor and recipient tissue preparation between the Hessburg-Barron and Hanna punch and trephine systems by using elliptical curve fitting models, light microscopy, and anterior segment optical coherence tomography (AS-OCT.Methods: Eight millimeter Hessburg-Barron and Hanna vacuum trephines and punches were used on six cadaver globes and six corneal-scleral rims, respectively. Eccentricity data were generated using measurements from photographs of the corneal buttons and were used to generate an elliptical curve fit to calculate properties of the corneal button. The trephination angle and punch angle were measured by digital protractor software from light microscopy and AS-OCT images to evaluate the consistency with which each device cuts the cornea.Results: The Hanna trephine showed a trend towards producing a more circular recipient button than the Barron trephine (ratio of major axis to minor axis, ie, 1.059 ± 0.041 versus 1.110 ± 0.027 (P = 0.147 and the Hanna punch showed a trend towards producing a more circular donor cut than the Barron punch, ie, 1.021 ± 0.022 versus 1.046 ± 0.039 (P = 0.445. The Hanna trephine was demonstrated to have a more consistent trephination angle than the Barron trephine when assessing light microscopy images, ie, ±14.39° (95% confidence interval [CI] 111.9–157.7 versus ±19.38° (95% CI 101.9–150.2, P = 0.492 and OCT images, ie, ± 8.08° (95% CI 106.2–123.3 versus ± 11.16° (95% CI 109.3–132.6, P = 0.306. The angle created by the Hanna punch had less variability than the Barron punch from both the light microscopy

  1. Anterior segment parameters and eyelids in systemic sclerosis.

    Science.gov (United States)

    Sahin Atik, Sevinc; Koc, Feray; Akin Sari, Sirin; Sefi Yurdakul, Nazife; Ozmen, Mustafa; Akar, Servet

    2016-08-01

    To evaluate main numerical parameters of anterior segment and the effects of eyelid skin changes on these parameters in patients with systemic sclerosis (SSc). Thirty-four patients with SSc and 34 healthy individuals were enrolled. Besides full eye examination, anterior segment measurements including anterior chamber depth (ACD), anterior chamber volume, anterior chamber angle width, central corneal thickness, pupil size, corneal volume and keratometry were obtained using a Sirius Scheimpflug/Placido photography-based topography system. Eyelid thickness was evaluated using the scala of the modified Rodnan skin score and the patients were subgrouped with respect to these scores to evaluate the effect of eyelid thickening on the anterior segment parameters. Age and sex distributions of the groups were similar (p > 0.05). SSc patients had steeper and thinner corneas, smaller corneal volumes, narrower, shallower and smaller anterior segments but only the mean ACD value of right eyes was found significantly less than those of the controls (p = 0.047). The mean ACD values of SSc subgroup patients with moderate to severe eyelid thickening (50 %) had lower ACD measurements compared to those of control group. (p = 0.043 for the right eyes, p = 0.070 for the left eyes). However, SSc subgroup patients with none to mild eyelid thickening (50 %) had similar anterior segment parameters with control subjects (p > 0.05). Anterior chamber parameters of the SSc patients could show significant differences. These differences occur parallel to the eyelid changes but not secondary to it. PMID:26694912

  2. Application of Fourier Domain OCT Imaging Technology to the Anterior Segment of the Human Eye

    Science.gov (United States)

    Wojtkowski, Maciej; Marcos, Susana; Ortiz, Sergio; Grulkowski, Ireneusz

    The anterior segment is the front part of the human eye, which forms the optical system and hence directly impacts vision. Traumatic or pathological changes in the anterior segment may lead to vision loss and, in some cases, even blindness. Since the eighteenth century, optical instrumentation for measuring and imaging the anterior segment of the human eye has been developing along with modern ophthalmology. The application of OCT to the anterior segment imaging is particularly of interest, since this could potentially provide substantial complementary information regarding the large-scale architecture of the cornea and the crystalline lens, or on small portions of tissue imaged with high spatial resolutions comparable to regular microscopy. Especially an introduction of Fourier domain detection in OCT has opened new frontiers in OCT ophthalmic applications. The resultant substantial speed improvement enables rapid image acquisition, helping to reduce artifacts due to patient motion. Thus, it is currently possible to perform high-speed, in vivo, three-dimensional volumetric imaging over large scales within a reasonable time limit and without reducing system sensitivity. This chapter describes the state-of the art OCT technology dedicated to anterior segment imaging and indicates all important parameters which are required for optimization of the performance of OCT instrument.

  3. Anterior segment dysgenesis in mosaic Turner syndrome

    OpenAIRE

    Lloyd, I; Haigh, P; Clayton-Smith, J.; Clayton, P.; Price, D.; Ridgway, A; Donnai, D

    1997-01-01

    AIMS/BACKGROUND—Females with Turner syndrome commonly exhibit ophthalmological abnormalities, although there is little information in the literature documenting findings specific to Turner syndrome mosaics. Ophthalmic findings are described in four patients with mosaic Turner syndrome. All had anterior chamber abnormalities and all four had karyotypic abnormalities with a 45, X cell line. The possible relation between the karyotypic and the phenotypic findings in these patients is discussed.
...

  4. Complication of toxic anterior segment syndrome after IOL implantation

    OpenAIRE

    Juan Guo

    2014-01-01

    AIM: To evaluate the treatment process of toxic anterior segment syndrome(TASS)and to found out the effective treatment, aetiological agent and prognosis.METHODS: A total of 6 cases(7 eyes)were suspected with TASS by clinical situations. Bacterial infectious endophthalmitis could be ruled out by anterior chamber and vitreous body paracentesis. All patients were treated with local application of antibiotics and glucocorticoid eyedrops, and some patients were treated with intravitreal injection...

  5. Leech segmental repeats develop normally in the absence of signals from either anterior or posterior segments

    Science.gov (United States)

    Seaver, E. C.; Shankland, M.

    2000-01-01

    We have investigated whether the development of segmental repeats is autonomous in the embryo of the leech Helobdella robusta. The segmental tissues of the germinal band arise from progeny of five stem cells called teloblasts. Asymmetric divisions of the teloblasts form chains of segment founder cells (called primary blast cells) that divide in a stereotypical manner to produce differentiated descendants. Using two distinct techniques, we have looked for potential interactions between neighboring blast cell clones along the anterior-posterior axis. In one technique, we prevented the birth of primary blast cells by injection of DNase I into the teloblast, thereby depriving the last blast cell produced before the ablation of its normal posterior neighbors. We also ablated single blast cells with a laser microbeam, which allowed us to assess potential signals acting on either more anterior or more posterior primary blast cell clones. Our results suggest that interactions along the anterior-posterior axis between neighboring primary blast cell clones are not required for development of normal segmental organization within the blast cell clone. We also examined the possibility that blast cells receive redundant signals from both anterior and posterior neighboring clones and that either is sufficient for normal development. Using double blast cell laser ablations to isolate a primary blast cell clone by removal of both its anterior and its posterior neighbor, we found that the isolated clone still develops normally. These results reveal that the fundamental segmental repeat in the leech embryo, the primary blast cell clone, can develop normally in the apparent absence of signals from adjacent repeats along the anterior-posterior axis.

  6. Síndrome tóxica do segmento anterior Toxic anterior segment syndrome

    Directory of Open Access Journals (Sweden)

    Luiz Filipe de Albuquerque Alves

    2013-02-01

    Full Text Available A síndrome tóxica do segmento anterior (STSA é uma severa reação inflamatória aguda causada por agente não infeccioso que entra no segmento anterior, resultando em lesão celular tóxica com necrose e apoptose mediado por resposta imunológica. Neste relato de caso de STSA são enfatizadas as causas mais comuns para o aparecimento da síndrome, apontam para os cuidados que devem ser tomados no processo de esterilização do material cirúrgico além de revisar a melhor conduta diante desses casos. Em conclusão notou-se que o foco principal deve ser a prevenção, pois o tratamento busca apenas suprimir a resposta inflamatória secundária. O tratamento nos casos de STSA consiste em intensa instilação de esteróides tópicos com seguimento rigoroso e controle de complicações tardias como o glaucoma.Toxic anterior segment syndrome is acute inflammatory reaction caused by a noninfectious substance that enters the anterior segment, resulting in extracellular damage with necrosis and apoptosis during an immune response. We have the report of a case of toxic anterior segment syndrome (TASS, in which the authors seek to emphasize the most common causes of the appearance of these syndrome. They point out the care that must be taken in the process of sterilization of surgical material, in addition to reviewing the best conduct when faced with these cases. In conclusion, it was noted that the main focus should be on prevention, as treatment only seeks to suppress the secondary inflammatory response. Treatment in cases of toxic anterior segment syndrome (TASS consists of intense instillation of topical steroids with strict follow-up and control of late complications such as glaucoma.

  7. Anterior Cervical Corpectomy and Fusion Accelerates Degenerative Disease at Adjacent Vertebral Segments

    OpenAIRE

    Pickett, Gwynedd E.; Duggal, Neil; Theodore, Nicholas; Sonntag, Volker K.H.

    2008-01-01

    Background Anterior cervical corpectomy provides the most direct and thorough surgical approach for anterior decompression when spinal cord compression is found directly behind the vertebral body. However, anterior cervical fusion has been shown to be associated with the development of new degenerative changes at levels immediately adjacent to the fused segments. Th e incidence of adjacent segment disease (ASD) following anterior cervical corpectomy has not been widely reported. We set out to...

  8. Diagnostics of anterior eye segment in cats and dogs

    Directory of Open Access Journals (Sweden)

    Hadži-Milić Milan

    2006-01-01

    Full Text Available Diagnostics of the anterior segment of the eye present the most frequent diagnostics implemented in ophthalmology and by most veterinary practicians as well. This paper presents the complete diagnostics in the most concise form possible. The procedure with animals is presented first, followed by the equipment, and then anamnesis. The following diagnostic methods are presented: examination in a lighted room which include an examination from a distance, taking a smear, the Schirmer tear test (STT, an examination from close by, examination in a dark room which comprises the elementary examinations, such as the use of focal lighting and examination using a direct ophthalmoscope, and special examination in a dark room, such as biomicroscopy, gonioscopy and keratoscopy. Additional examination methods are also included.

  9. Deep Learning Guided Partitioned Shape Model for Anterior Visual Pathway Segmentation.

    Science.gov (United States)

    Mansoor, Awais; Cerrolaza, Juan J; Idrees, Rabia; Biggs, Elijah; Alsharid, Mohammad A; Avery, Robert A; Linguraru, Marius George

    2016-08-01

    Analysis of cranial nerve systems, such as the anterior visual pathway (AVP), from MRI sequences is challenging due to their thin long architecture, structural variations along the path, and low contrast with adjacent anatomic structures. Segmentation of a pathologic AVP (e.g., with low-grade gliomas) poses additional challenges. In this work, we propose a fully automated partitioned shape model segmentation mechanism for AVP steered by multiple MRI sequences and deep learning features. Employing deep learning feature representation, this framework presents a joint partitioned statistical shape model able to deal with healthy and pathological AVP. The deep learning assistance is particularly useful in the poor contrast regions, such as optic tracts and pathological areas. Our main contributions are: 1) a fast and robust shape localization method using conditional space deep learning, 2) a volumetric multiscale curvelet transform-based intensity normalization method for robust statistical model, and 3) optimally partitioned statistical shape and appearance models based on regional shape variations for greater local flexibility. Our method was evaluated on MRI sequences obtained from 165 pediatric subjects. A mean Dice similarity coefficient of 0.779 was obtained for the segmentation of the entire AVP (optic nerve only =0.791 ) using the leave-one-out validation. Results demonstrated that the proposed localized shape and sparse appearance-based learning approach significantly outperforms current state-of-the-art segmentation approaches and is as robust as the manual segmentation. PMID:26930677

  10. Optical Ground Segment Performance Summary

    Science.gov (United States)

    Breidenthal, J.; Xie, H.; Clare, L.

    2016-05-01

    The performance of candidate optical communication systems for deep space that would use a single optical ground station in conjunction with various space terminals is reported here. We considered three potential diameters of ground receive terminals (4, 8, and 12 m) and three potential ground transmit powers (1, 5, and 10 kW). Combinations of ground receive terminals, ground transmit terminals, and spacecraft terminals were assessed for data rate and volume (both uplink and downlink), and for uplink irradiance needed to enable downlink pointing, in the context of a set of 12 design reference missions. Raw physical link performance was assessed assuming clear weather conditions with conservative desert daytime turbulence, using communication link parameters that were optimized according to previously reported methods using the Strategic Optical Link Tool (SOLT). Also, realistic bad weather conditions were considered, assuming a random process that could at any time make transitions between two states: a cloud-free state and a cloudy state that completely interrupts data transmission. We compared the link performance achievable under our assumptions to the anticipated requirements associated with the design reference missions to determine the degree of satisfaction possible with various optical segments. Nine potential operating concepts for an optical communication system were described, and two were evaluated in detail for the Mars 2022 mission opportunity: raw data delivery and automatic repeat request for complete data delivery.

  11. Radial optic neurotomy as a treatment for anterior ischemic optic neuropathy secondary to optic disc drusen

    OpenAIRE

    Pinxten, I; Stalmans, P

    2014-01-01

    Importance: Radial optic neurotomy (RON) was first described by Opremcak as a treatment for patients with central retinal vein occlusion (CRVO). The most common cause of visual loss in patients with optic disc drusen is nonarteritic anterior ischemic optic neuropathy (NAION). The pathogenesis of nonarteritic anterior ischemic optic neuropathy associated with optic disc drusen is assumed to be similar to the compartment-like syndrome described by Opremcak in the case of central retinal vein o...

  12. Radial optic neurotomy as a treatment for anterior ischemic optic neuropathy secondary to optic disc drusen

    OpenAIRE

    Pinxten, Isabel; Stalmans, Peter

    2014-01-01

    [english] Importance: Radial optic neurotomy (RON) was first described by Opremcak as a treatment for patients with central retinal vein occlusion (CRVO). The most common cause of visual loss in patients with optic disc drusen is nonarteritic anterior ischemic optic neuropathy (NAION). The pathogenesis of nonarteritic anterior ischemic optic neuropathy associated with optic disc drusen is assumed to be similar to the compartment-like syndrome described by Opremcak in the case of central retin...

  13. Electro-Optic Segment-Segment Sensors for Radio and Optical Telescopes

    Science.gov (United States)

    Abramovici, Alex

    2012-01-01

    A document discusses an electro-optic sensor that consists of a collimator, attached to one segment, and a quad diode, attached to an adjacent segment. Relative segment-segment motion causes the beam from the collimator to move across the quad diode, thus generating a measureable electric signal. This sensor type, which is relatively inexpensive, can be configured as an edge sensor, or as a remote segment-segment motion sensor.

  14. Development of Toxic Anterior Segment Syndrome Immediately after Uneventful Phaco Surgery

    OpenAIRE

    Choi, Jin Seok; Shyn, Kyung Hwan

    2008-01-01

    Purpose We report on 15 cases of suspected toxic anterior segment syndrome after uneventful phaco surgery. Methods We retrospectively reviewed the charts of patients who had developed toxic anterior segment syndrome (TASS) after uneventful phacoemulsification for senile cataracts between April and December of 2005. Clinical features and all possible causes were investigated including irrigating solutions or drugs, surgical instruments or intraocular lenses, sterilization techniques for instru...

  15. Anterior segment and retinal OCT imaging with simplified sample arm using focus tunable lens technology (Conference Presentation)

    Science.gov (United States)

    Grulkowski, Ireneusz; Karnowski, Karol; Ruminski, Daniel; Wojtkowski, Maciej

    2016-03-01

    Availability of the long-depth-range OCT systems enables comprehensive structural imaging of the eye and extraction of biometric parameters characterizing the entire eye. Several approaches have been developed to perform OCT imaging with extended depth ranges. In particular, current SS-OCT technology seems to be suited to visualize both anterior and posterior eye in a single measurement. The aim of this study is to demonstrate integrated anterior segment and retinal SS-OCT imaging using a single instrument, in which the sample arm is equipped with the electrically tunable lens (ETL). ETL is composed of the optical liquid confined in the space by an elastic polymer membrane. The shape of the membrane, electrically controlled by a specific ring, defines the radius of curvature of the lens surface, thus it regulates the power of the lens. ETL can be also equipped with additional offset lens to adjust the tuning range of the optical power. We characterize the operation of the tunable lens using wavefront sensing. We develop the optimized optical set-up with two adaptive operational states of the ETL in order to focus the light either on the retina or on the anterior segment of the eye. We test the performance of the set-up by utilizing whole eye phantom as the object. Finally, we perform human eye in vivo imaging using the SS-OCT instrument with versatile imaging functionality that accounts for the optics of the eye and enables dynamic control of the optical beam focus.

  16. Extended coherence length megahertz FDML and its application for anterior segment imaging.

    Science.gov (United States)

    Wieser, Wolfgang; Klein, Thomas; Adler, Desmond C; Trépanier, Francois; Eigenwillig, Christoph M; Karpf, Sebastian; Schmitt, Joseph M; Huber, Robert

    2012-10-01

    We present a 1300 nm Fourier domain mode locked (FDML) laser for optical coherence tomography (OCT) that combines both, a high 1.6 MHz wavelength sweep rate and an ultra-long instantaneous coherence length for rapid volumetric deep field imaging. By reducing the dispersion in the fiber delay line of the FDML laser, the instantaneous coherence length and hence the available imaging range is approximately quadrupled compared to previously published MHz-FDML setups, the imaging speed is increased by a factor of 16 compared to previous extended coherence length results. We present a detailed characterization of the FDML laser performance. We demonstrate for the first time MHz-OCT imaging of the anterior segment of the human eye. The OCT system provides enough imaging depth to cover the whole range from the top surface of the cornea down to the crystalline lens. PMID:23082303

  17. Anterior ischemic optic neuropathy in association with optic nervehead drusen

    Directory of Open Access Journals (Sweden)

    Bharathi Megur

    2014-01-01

    Full Text Available Optic nerve head drusen (ONHD are incidental ophthalmologic finding in the optic nerve. Patients with ONHD are often asymptomatic, but sometimes present with transient visual obscuration′s (TVO, the reported incidence of which is 8.6%. Optic nerve head drusen are of two types: Superficial; visible and deep. The deep-buried drusen mimic papilledema. Because of the varied presentation deep-buried drusen pose a diagnostic challenge to the ophthalmologists. In young patients, they are mistaken for papilledema as it is clinically difficult to detect a buried drusen in the optic nerve head, but are seen on the surface with aging as the retinal nerve fiber layer thins out. They are observed as pale yellow lesions more often located towards the poles. Clinical examination aided with diagnostic tests like computed tomography (CT orbits and ultrasound B scan can help establish the diagnosis. Herein, we report a rare case of optic nerve head drusen in a young lady, who presented with loss of vision and clinical evaluation and investigations suggested ONHD with anterior ischemic optic neuropathy.

  18. Radiographic Response to Yttrium-90 Radioembolization in Anterior Versus Posterior Liver Segments

    International Nuclear Information System (INIS)

    The purpose of our study was to determine if preferential radiographic tumor response occurs in tumors located in posterior versus anterior liver segments following radioembolization with yttrium-90 glass microspheres. One hundred thirty-seven patients with chemorefractory liver metastases of various primaries were treated with yttrium-90 glass microspheres. Of these, a subset analysis was performed on 89 patients who underwent 101 whole-right-lobe infusions to liver segments V, VI, VII, and VIII. Pre- and posttreatment imaging included either triphasic contrast material-enhanced CT or gadolinium-enhanced MRI. Responses to treatment were compared in anterior versus posterior right lobe lesions using both RECIST and WHO criteria. Statistical comparative studies were conducted in 42 patients with both anterior and posterior segment lesions using the paired-sample t-test. Pearson correlation was used to determine the relationship between pretreatment tumor size and posttreatment tumor response. Median administered activity, delivered radiation dose, and treatment volume were 2.3 GBq, 118.2 Gy, and 1,072 cm3, respectively. Differences between the pretreatment tumor size of anterior and posterior liver segments were not statistically significant (p = 0.7981). Differences in tumor response between anterior and posterior liver segments were not statistically significant using WHO criteria (p = 0.8557). A statistically significant correlation did not exist between pretreatment tumor size and posttreatment tumor response (r = 0.0554, p = 0.4434). On imaging follow-up using WHO criteria, for anterior and posterior regions of the liver, (1) response rates were 50% (PR = 50%) and 45% (CR = 9%, PR = 36%), and (2) mean changes in tumor size were -41% and -40%. In conclusion, this study did not find evidence of preferential radiographic tumor response in posterior versus anterior liver segments treated with yttrium-90 glass microspheres.

  19. AS-OCT与A超测量中央角膜厚度与前房深度的比较%Comparison of central corneal thickness and anterior chamber depth measurements using the Anterior Segment Optical Coherence Tomography and A-scan ultrasonography

    Institute of Scientific and Technical Information of China (English)

    曾阳发; 李彬彬; 黄国富; 李月桃; 何明光

    2009-01-01

    目的 探讨眼前段光学相干断层扫描技术(anteriorsegment optical coherence tomography,AS-OCT)和A型超声波生物测量技术(A超)测量,中央角膜厚度(central corneal thickness,CCT)和前房深度(anterior chamber depth,ACD)的异同.方法 分别采用AS-OCT和A超测量33名(54只眼)正常人的CCT和ACD,分别采用配对t检验、Pearson相关和Bland-Altman方法,分析两种仪器的测量值的差异、相关性和一致性.结果 A超与AS-OCT的CCT值分别为(524.41±23.24)μm、(513.37±22.71)μm,之间的差异有统计学意义(t=15.906,P=0.000),差值均数为(11.04±5.10)μm.两种仪器的CCT值正相关(r=0.976,P=0.000).95%LoA(95% Limts of Agreement)为(-21.03,-1.04)μm,95%LoA的区间范围为19.99μm,为A超CCT平均值的3.81%.A超与AS-OCT的ACD值分别为(2.89±0.29)mm、(3.18±0.26)mm,之间的差异有统计学意义(f=-12.052,P=0.000),差值的均数为(-0.29±0.17)mm.两种仪器的ACD值相关(r=0.803,P=0.000).95%LoA为(-0.63,-0.06)mm,95%LoA的区间范围为0.57mm,为A超ACD平均值的19.72%.结论 AS-OCT的CCT值和ACD值与A超的测量值相关.与A超相比,AS-OCT的CCT测量值更小,而ACD值更大.两种仪器测量CCT的一致性比ACD高.%Objective To assess central corneal thickness(CCT)and anterior chamber depth (ACD) measurements with anterior segment optical coherence tomography (AS-OCT)comparing with A-scan ultrasonography (A-scan US).Methods 54 eyes of 33 normal subjects were enrolled in the study.CCT and ACD were measured using AS-OCT and A-scan US.The measurements of two instruments were analyzed using paired t test,Pearson correlation and Bland-Altman plot,respectively.Results The CCT of AS-OCT and A-scan US were 524.41± 23.24 microm and 513.37± 22.7 microm,respectively.The CCT values measured by A-scan US were significantly greater than AS-OCT, paired difference was 11.04± 5.10 microm (t =15.906, P =0.000).There were a significantly correlation between CCTs value of two instruments (r =0

  20. Clinical implications of anterior S-T segment depression in patients with acute inferior myocardial infarction

    International Nuclear Information System (INIS)

    To assess various factors associated with anterior S-T segment depression during acute inferior myocardial infarction, 47 consecutive patients with electrocardiographic evidence of a first transmural inferior infarction were studied prospectively with radionuclide ventriculography an average of 7.3 hours (range 2.9 to 15.3) after the onset of symptoms. Thirty-nine patients (Group I) had anterior S-T depression in the initial electrocardiogram and 8 (Group II) did not have such reciprocal changes. There was no difference between the two groups in left ventricular end-diastolic or end-diastolic volume index or left ventricular ejection fraction. Stroke volume index was greater in Group I than in Group II. There were no group differences in left ventricular total or regional wall motion scores. A weak correlation existed between the quantities (mV) or inferior S-T segment elevation and reciprocal S-T depression. No relation between anterior S-T segment depression and the left ventricular end-diastolic volume index could be demonstrated; the extent of left ventricular apical and right ventricular wall motion abnormalities, both frequently associated with inferior infarction, did not correlate with the quantity of anterior S-T depression. These data show that anterior S-T segment depression occurs commonly during the early evolution of transmural inferior infarction, is not generally a marker of functionally significant anterior ischemia and cannot be used to predict left ventricular function in individual patients. Anterior S-T segment depression may be determined by reciprocal mechanisms

  1. Risk Factors for the Development of Adjacent Segment Disease Following Anterior Cervical Arthrodesis

    OpenAIRE

    Ezgi Akar; Mehmet Ufuk Akmil; Merih İş

    2015-01-01

    Aim: The aim of this study was to clinically and radiologically evaluate the efficacy of anterior cervical discectomy and fusion (ACDF) in the treatment of adjacent level degeneration. Methods: We retrospectively evaluated 89 patients (55 females, 34 males) who underwent ACDF. Adjacent segment degeneration findings were evaluated by investigating new osteophyte formation, growth of existing osteophytes, ossification of the anterior longitudinal ligament, presence of inter...

  2. Anterior Segmental Distraction Osteogenesis in the Hypoplastic Cleft Maxilla: Report of five cases

    OpenAIRE

    Sruthi Rao (Janardhan); Kotrashetti, S. M.; J. B. Lingaraj; Pinto, P. X.; Keluskar, K. M.; Siddharth Jain; Piyush Sone; Santhosh Rao

    2013-01-01

    Orthognathic surgery and distraction osteogenesis play a prime role in the correction of maxillary hypoplasia in patients with cleft lip and palate (CLP). Advancement of the anterior maxilla alone without interfering with the velopharyngeal sphincter may be advantageous in cleft patients, who more commonly have speech deficits and dental crowding. We present a case series of anterior maxillary segmental distraction for maxillary hypoplasia in 5 CLP patients with a one-year follow-up. A custom...

  3. Anterior segment manifestations of human immunodeficiency virus/acquired immune deficiency syndrome

    Directory of Open Access Journals (Sweden)

    Biswas Jyotirmay

    2008-01-01

    Full Text Available Ocular complications are known to occur as a result of human immunodeficiency virus (HIV disease. They can be severe leading to ocular morbidity and visual handicap. Cytomegalovirus (CMV retinitis is the commonest ocular opportunistic infection seen in acquired immune deficiency syndrome (AIDS. Though posterior segment lesions can be more vision-threatening, there are varied anterior segment manifestations which can also lead to ocular morbidity and more so can affect the quality of life of a HIV-positive person. Effective antiretroviral therapy and improved prophylaxis and treatment of opportunistic infections have led to an increase in the survival of an individual afflicted with AIDS. This in turn has led to an increase in the prevalence of anterior segment and adnexal disorders. Common lesions include relatively benign conditions such as blepharitis and dry eye, to infections such as herpes zoster ophthalmicus and molluscum contagiosum and malignancies such as squamous cell carcinoma and Kaposi′s sarcoma. With the advent of highly active antiretroviral therapy, a new phenomenon known as immune recovery uveitis which presents with increased inflammation, has been noted to be on the rise. Several drugs used in the management of AIDS such as nevirapine or indinavir can themselves lead to severe inflammation in the anterior segment and adnexa of the eye. This article is a comprehensive update of the important anterior segment and adnexal manifestations in HIV-positive patients with special reference to their prevalence in the Indian population.

  4. Anterior ischemic optic neuropathy in patients undergoing hemodialysis

    NARCIS (Netherlands)

    DoorenbosBot, ACC; Geerlings, W; Houtman, IA

    1996-01-01

    Four patients are discussed who underwent hemodialysis and developed anterior ischemic optic neuropathy (AION). Three patients had been treated by hemodialysis for several years. One patient developed bilateral optic neuropathy after the first hemodialysis session, So far, only four hemodialysis pat

  5. TOXIC ANTERIOR SEGMENT SYNDROME (TASS WITH SEVERE PIGMENT DISPERSION

    Directory of Open Access Journals (Sweden)

    Stephen Sudhakar

    2014-09-01

    Full Text Available AIM: To clinically analyze the cases of TASS with severe pigment dispersion following uncomplicated cataract surgery in a tertiary care teaching hospital from January 2011 to January 2013. DESIGN: Retrospective case series study. MATERIALS AND METHODS: The records of all eyes developing TASS with severe pigment dispersion following uncomplicated Cataract surgery were retrospectively reviewed. Clinical outcomes including visual acuity, intraocular pressure and complications were recorded at 1st post-operative day, 7th post-operative day and after six weeks of follow up visits. RESULTS: TASS with severe pigment dis pension was recorded in five out of 1060 patients. All cases were females. Phacoemulsification with foldable IOL was done in 2 patients and Small Incision Cataract Surgery (SICS with in bag posterior chamber IOL was done in three patients. All patients had pain which was less severe when compared to the amount of inflammation. Visual acuity ranged from 6/36 to perception of light. All the five patients had rim to rim corneal edema which was seen from the first post-operative day and persisted at six weeks follow up. Pupils were dilated and fixed in all patients. Intraocular pressure was raised in four out of five patients who poorly responded to medical treatment. Dense pigment clumps were seen in the corneal endothelium and on the surgical wound site after one week in three out of five patients and increased at 6 weeks of follow up. Visual acuity did not improve in any of the patient even with treatment. The reduced visual acuity was due to worsening corneal edema and dense pigment clumping in corneal endothelium. CONCLUSION: TASS with severe pigment dispersion has more complication than routine TASS. The complication are due to dense pigment clumping in cornea and angle of anterior chamber causing corneal endothelial de-compensation and raised Intraocular pressure, which persisted even after the inflammation subsided. Although the

  6. Effects of 1% cyclopentolate hydrochloride on anterior segment parameters obtained with Pentacam in young adults

    Directory of Open Access Journals (Sweden)

    Ceyhun Arici

    2014-08-01

    Full Text Available Purpose: To investigate the effects of topically applied 1% cyclopentolate hydrochloride on anterior segment parameters obtained with a Pentacam rotating Scheimpflug camera in healthy young adults. Methods: Anterior segment analyses of 25 eyes from 25 young adults (Group 1, before and after 45 min of 1% cyclopentolate hydrochloride application, were performed. For a control group (cycloplegia-free, Group 2, 24 eyes of 24 age- and sex-matched healthy cases were evaluated twice at 45 min intervals. The results obtained from the groups were compared statistically. Results: The mean ages of the groups were 23.04 ± 3.42 (range, 18-29 and 22.4 ± 2.05 (range, 18-27 years for Groups 1 and 2, respectively (p=0.259. In Group 1, measurements between the two analyses were significantly different for the values of anterior chamber depth (ACD, anterior chamber angle (ACA, and anterior chamber volume (ACV (p<0.05, whereas no statistical difference was found for the central corneal thickness (CCT and keratometry (K1, K2 measurements. In Group 2, none of these parameters were statistically different between the two analyses. Conclusions: Topically applied 1% cyclopentolate hydrochloride caused an increase in the ACD and ACV values, and a decrease in the ACA value. However, it had no significant effect on the CCT and keratometry measurements. It is important to consider these effects when using the Pentacam device on young adults with cycloplegia and when applying it for various reasons.

  7. Anterior Overgrowth in Primary Curves, Compensatory Curves and Junctional Segments in Adolescent Idiopathic Scoliosis

    Science.gov (United States)

    van Stralen, Marijn; Chu, Winnie C. W.; Lam, Tsz-Ping; Ng, Bobby K. W.; Vincken, Koen L.; Cheng, Jack C. Y.; Castelein, René M.

    2016-01-01

    Introduction Although much attention has been given to the global three-dimensional aspect of adolescent idiopathic scoliosis (AIS), the accurate three-dimensional morphology of the primary and compensatory curves, as well as the intervening junctional segments, in the scoliotic spine has not been described before. Methods A unique series of 77 AIS patients with high-resolution CT scans of the spine, acquired for surgical planning purposes, were included and compared to 22 healthy controls. Non-idiopathic curves were excluded. Endplate segmentation and local longitudinal axis in endplate plane enabled semi-automatic geometric analysis of the complete three-dimensional morphology of the spine, taking inter-vertebral rotation, intra-vertebral torsion and coronal and sagittal tilt into account. Intraclass correlation coefficients for interobserver reliability were 0.98–1.00. Coronal deviation, axial rotation and the exact length discrepancies in the reconstructed sagittal plane, as defined per vertebra and disc, were analyzed for each primary and compensatory curve as well as for the junctional segments in-between. Results The anterior-posterior difference of spinal length, based on “true” anterior and posterior points on endplates, was +3.8% for thoracic and +9.4% for (thoraco)lumbar curves, while the junctional segments were almost straight. This differed significantly from control group thoracic kyphosis (-4.1%; Plumbar lordosis (+7.8%; Plumbar curves). Conclusions Excess anterior length of the spine in AIS has been described as a generalized growth disturbance, causing relative anterior spinal overgrowth. This study is the first to demonstrate that this anterior overgrowth is not a generalized phenomenon. It is confined to the primary as well as the compensatory curves, the junctional zones do not exhibit this growth discrepancy, however, they are straight. PMID:27467745

  8. Bilateral anterior ischaemic optic neuropathy associated with optic disc drusen and systemic hypotension.

    OpenAIRE

    C. Michaelson; Behrens, M; Odel, J

    1989-01-01

    We report a case of bilateral anterior ischaemic optic neuropathy in a 23-year-old woman which was probably attributable to optic disc drusen and systemic hypotension related to peritoneal dialysis for renal failure.

  9. Identification of the segmental artery feeding the anterior spinal artery. Correlation between helical CT and angiography

    International Nuclear Information System (INIS)

    We investigated whether identification of the segmental artery feeding the anterior spinal artery (ASA) is possible by single-slice helical CT. Enhanced CT and angiography were performed in 14 patients with retroperitoneal, liver, or bone tumor. A single-slice helical CT scanner with 7 mm collimation and a 1.0 helical pitch was used. Scanning was started 25 to 30 sec after an intravenous injection of 100 ml of contrast medium at a rate of 3.0 ml/sec. We predicted the segmental artery feeding the ASA in all 14 patients using enhanced CT images. In 12 of the 14 patients, the segmental artery feeding the ASA was angiographically identified. In 7 of these 12 patients, the level of the segmental artery feeding the ASA identified on segmental arteriogram was the same level as that predicted by enhanced CT. In the remaining 5 patients, the level of the segmental artery feeding the ASA identified on segmental arteriogram was one level higher or lower than the predicted spinal level. We could identify the segmental artery feeding the ASA by detailed examination and interpretation of single-slice helical CT images. (author)

  10. Intravitreal Bevacizumab in Nonarteritic Anterior Ischemic Optic Neuropathy

    Directory of Open Access Journals (Sweden)

    Ebadollah Heidari

    2014-01-01

    Full Text Available Purpose: To evaluate the effect of intravitreal injection of Bevacizumab on improving visual function in patients with Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION. Methods: In a prospective interventional case series, 11 eyes with vision loss due to (NAION in less than 15 days of attack were studied. Visual acuity, perimetry and optic nerve head changes were evaluated 1 week post-intravitreal injection of 1.25mg/0.1 mL Bevacizumab. Results: 5 of patients had improved visual acuity. In all patients optic disc edema resolved either completely or remarkably in 1 week, but there was no significant change in perimetric values. Conclusion: This case series suggest that intravitreal injection of Bevacizumab may be beneficial in treatment of NAION. Keywords: Intravitreal Bevacizumab; Non-arteritic anterior ischemic optic neuropathy; Perimetry 

  11. A case of anterior ischemic optic neuropathy associated with uveitis

    Directory of Open Access Journals (Sweden)

    Sugahara M

    2013-05-01

    Full Text Available Michitaka Sugahara, Takayuki Fujimoto, Kyoko Shidara, Kenji Inoue, Masato Wakakura Inouye Eye Hospital, Tokyo, Japan Introduction: Here, we describe a patient who presented with anterior ischemic optic neuropathy (AION and subsequently developed uveitis. Case: A 69-year-old man was referred to our hospital and initially presented with best-corrected visual acuities (BCVA of 20/40 (right eye and 20/1000 (left eye and relative afferent pupillary defect. Slit-lamp examination revealed no signs of ocular inflammation in either eye. Fundus examination revealed left-eye swelling and a pale superior optic disc, and Goldmann perimetry revealed left-eye inferior hemianopia. The patient was diagnosed with nonarteritic AION in the left eye. One week later, the patient returned to the hospital because of vision loss. The BCVA of the left eye was so poor that the patient could only count fingers. Slit-lamp examination revealed 1+ cells in the anterior chamber and the anterior vitreous in both eyes. Funduscopic examination revealed vasculitis and exudates in both eyes. The patient was diagnosed with bilateral panuveitis, and treatment with topical betamethasone was started. No other physical findings resulting from other autoimmune or infectious diseases were found. No additional treatments were administered, and optic disc edema in the left eye improved, and the retinal exudates disappeared in 3 months. The patient's BCVA improved after cataract surgery was performed. Conclusion: Panuveitis most likely manifests after the development of AION. Keywords: anterior ischemic optic neuropathy, uveitis

  12. Posterior high sacral segmental disconnection prior to anterior en bloc exenteration for recurrent rectal cancer.

    Science.gov (United States)

    Brown, K G M; Solomon, M J; Austin, K K S; Lee, P J; Stalley, P

    2016-06-01

    This article describes a novel technique for en bloc resection of locally recurrent rectal cancer that invades the high sacral bone (above S3). The involved segment of the sacrum is mobilised with osteotomes during an initial posterior approach before an anterior abdominal phase where the segment of sacral bone is delivered with the specimen. This allows en bloc resection of the involved sacrum while preserving uninvolved distal and contralateral sacral bone and nerve roots. The goal is to obtain a clear bony margin and offer a chance of cure while improving functional outcomes by maintaining pelvic stability and minimising neurological deficit. PMID:27000857

  13. Anterior segment developmental anomalies in a 33-week-old fetus with MIDAS syndrome.

    Science.gov (United States)

    Herwig, Martina C; Loeffler, Karin U; Gembruch, Ulrich; Kuchelmeister, Klaus; Müller, Annette M

    2014-01-01

    We report anterior segment abnormalities in both eyes of a 33-week-old fetus endorsing the diagnosis of MIDAS (microphthalmia, dermal aplasia, and sclerocornea) syndrome. After abortion, the fetus was examined by a standard pediatric autopsy that included macroscopic and microscopic examination of both eyes. Postmortem findings included craniofacial stigmata (such as hypertelorism, a flat nose and low-set ears) and an agenesis of the corpus callosum. Array comparative genomic hybridization revealed a deletion of the short arm of the X chromosome (region Xp22.2 to p22.32). Ophthalmopathologic examination of the eyes revealed microphthalmia with anterior segment developmental anomalies, in particular sclerocornea and Peters' anomaly, respectively. General pathology findings plus the ocular findings allowed the diagnosis of MIDAS syndrome. A discussion of differential diagnoses is provided. This case report indicates that ophthalmopathologic investigation of fetal eyes can be of great value for the further classification of syndromes. PMID:25291437

  14. Toxic anterior segment syndrome after uncomplicated cataract surgery possibly associated with intracamaral use of cefuroxime

    OpenAIRE

    Cakir, Burcin

    2015-01-01

    Burçin Çakir, Erkan Celik, Nilgün Özkan Aksoy, Özlem Bursali, Turgay Uçak, Erdinç Bozkurt, Gursoy AlagozSakarya University Education and Research Hospital, Sakarya, TurkeyPurpose: To report toxic anterior segment syndrome (TASS) after cataract surgery possibly associated with intracameral use of cefuroxime.Methods: We conducted a retrospective chart review and analysis on the pre- and postoperative conditions of the subjec...

  15. A New Potential Cause in the Development of Toxic Anterior Segment Syndrome: Fibrin Glue

    OpenAIRE

    Selçuk Sızmaz; Cem Küçükerdönmez; Altuğ Çetinkaya; Yonca Aydın Akova

    2014-01-01

    Objectives: To present a potential cause for toxic anterior segment syndrome (TASS). Materials and Methods: We report 4 cases of TASS that occurred following uneventful phacoemulsification and intraocular lens implantation. Results: The 4 cases were the first consecutive 2 cases of 2 different surgery days, 5 months apart. The most prominent sign of TASS was limbus-to-limbus corneal edema. Pain and/or intraocular pressure rise were also common. All surgical and presurgical procedu...

  16. Eye hydrodynamics and anatomical topographic features of anterior eye segment before and following cataract phacoemulsification

    OpenAIRE

    Yu. A. Gusev; S. M. Makkaeva; E. V. Maslova; E. B. Tretyak

    2014-01-01

    Different aspects of eye hydrodynamics before and following complicated cataract surgery as well as its impact on IOP levels are observed. Trabecular and uveoscleral outflow features, anterior eye segment anatomy and topography, associations between accommodation and aqueous humor outflow regulation in elderly patients are analyzed. Besides, optimal clinical refraction and IOL model selection are of special importance in cataract and glaucomapatients

  17. Risk Factors for the Development of Adjacent Segment Disease Following Anterior Cervical Arthrodesis

    Directory of Open Access Journals (Sweden)

    Ezgi Akar

    2015-06-01

    Full Text Available Aim: The aim of this study was to clinically and radiologically evaluate the efficacy of anterior cervical discectomy and fusion (ACDF in the treatment of adjacent level degeneration. Methods: We retrospectively evaluated 89 patients (55 females, 34 males who underwent ACDF. Adjacent segment degeneration findings were evaluated by investigating new osteophyte formation, growth of existing osteophytes, ossification of the anterior longitudinal ligament, presence of intervertebral disc space narrowing, sagittal alignment and range of motion (ROM using serial radiographs and magnetic resonance imaging. Results: The mean age of the 89 patients was 41.3 (24-76 years. The mean follow-up duration was 34.3 (12-64 months. Radiographic evidence of adjacent segment degeneration was observed in 12 patients (13.4%. Nine (75% patients had new complaints. Of the patients who had degenerative changes, 7 were (58% were male, 5 (42% were female; the mean age was 46 (30- 62 years. It was observed that the level of fusion and the number of fusion did not increase the adjacent segment degeneration. All of 12 patients were observed to have a non lordotic cervical spine and increased ROM. Conclusion: Development of degeneration at the level adjacent to region anterior cervical discectomy and fusion performed is higher compared to non-adjacent levels. The level of fusion and the number of fusion levels have no effect on the development of degeneration. (The Medical Bulletin of Haseki 2015; 53:120-3

  18. Failure of the human lumbar motion-segments resulting from anterior shear fatigue loading.

    Science.gov (United States)

    Skrzypiec, Daniel M; Nagel, Katrin; Sellenschloh, Kay; Klein, Anke; Püschel, Klaus; Morlock, Michael M; Huber, Gerd

    2016-08-01

    An in-vitro experiment was designed to investigate the mode of failure following shear fatigue loading of lumbar motion-segments. Human male lumbar motion-segments (age 32-42 years, n=6) were immersed in Ringer solution at 37°C and repeatedly loaded, using a modified materials testing machine. Fatigue loading consisted of a sinusoidal shear load from 0 N to 1,500 N (750 N±750 N) applied to the upper vertebra of the motion-segment, at a frequency of 5 Hz. During fatigue experiments, several failure events were observed in the dynamic creep curves. Post-test x-ray, CT and dissection revealed that all specimens had delamination of the intervertebral disc. Anterior shear fatigue predominantly resulted in fracture of the apophyseal processes of the upper vertebrae (n=4). Exposure to the anterior shear fatigue loading caused motion-segment instability and resulted in vertebral slip corresponding to grade I and 'mild' grade II spondylolisthesis, as observed clinically. PMID:26829975

  19. Anterior maxillary osteotomy: A technical note for superior repositioning: A bird wing segment

    Directory of Open Access Journals (Sweden)

    V Sadesh Kannan

    2014-01-01

    Full Text Available Aim: The aim of this study is to evaluate the efficacy of a single piece bird wing osteotectomy segment during anterior maxillary osteotomy (AMO markedly reduces the duration of the surgery by nearly one-half of the time during bone removal with the conventional method thereby reducing the kinking effect to the palatal pedicle and gives good perfusion to the anterior segment. Materials and Methods: This study was conducted at Karpaga Vinayaga Institute of Dental Sciences composing of 20 patients in which male: female ratio was 8:12, with a mean age of 25-30 years. This bird wing segment technique is performed following presurgical orthodontics under the guidance of clinical assessment of the gummy smile with an incisal show when the lip is at repose (vertical maxillary excess, especially for the calculated amount of superior repositioning. It is calculated by subtracting 2 mm from the total amount of an incisor show when the lip is at repose. The normal incisal show when the lip is at repose is 2 mm. After conventional primary AMO cut was performed, the precise calculated. Results: All our cases were tested positive for pulp vitality, no relapse, and minimal edema and with no changes in the bite or dentoalveolar relation followed until 1 year postoperatively indicating a good perfusion to the anterior segment and all the patients were satisfied esthetically and free of complaints. Conclusion: This simple technique allows the precise amount of calculated bone removal in a single piece from the nasal floor markedly reduces the duration of the surgery by nearly one-half of the time during bone removal with the conventional method there by reducing the kinking effect to the palatal pedicle and maintains good perfusion.

  20. The changes of inflammatory cytokines and their clinical significance in patients of inferior ST-segment elevation acute myocardial infarction with anterior ST-segment depression

    Institute of Scientific and Technical Information of China (English)

    叶明

    2014-01-01

    Objective To investigate the level of Hs-CRP,Fib,IL-6,TNF-α,MDA,SOD,and analyze the correlation between the level of plasma inflammatory cytokines and clinical significance in patients with anterior ST-segment depression.Methods We chose 360 patients with inferior ST Segment elavation acute myocardial infarction from May 2007 to Sep 2012 in emergency department of

  1. Can intramuscular corticosteroid injection cause nonarteritic anterior ischemic optic neuropathy?

    OpenAIRE

    Bakbak B; Ozturk BT; Gedik S; Koktekir BE; Gonul S

    2013-01-01

    Berker Bakbak, Banu Turgut Ozturk, Sansal Gedik, Bengu Ekinci Koktekir, Saban Gonul Selcuk University Medical Faculty, Department of Ophthalmology, Konya, Turkey Abstract: A 56-year-old man noted a sudden decrease of vision in his right eye 4 hours after intramuscular triamcinolone acetonide (TA) injection. A diagnosis of unilateral nonarteritic anterior ischemic optic neuropathy (NAION) was made, and the patient was counseled to discontinue using TA. Examination for possible risk factors rev...

  2. Comparison of high-resolution Scheimpflug and high-frequency ultrasound biomicroscopy to anterior-segment OCT corneal thickness measurements

    Directory of Open Access Journals (Sweden)

    Kanellopoulos AJ

    2013-11-01

    Full Text Available Anastasios John Kanellopoulos,1,2 George Asimellis1 1Laservision.gr Eye Institute, Athens, Greece; 2New York University Medical School, New York, NY, USA Background: The purpose of this study was to compare and correlate central corneal thickness in healthy, nonoperated eyes with three advanced anterior-segment imaging systems: a high-resolution Scheimpflug tomography camera (Oculyzer II, a spectral-domain anterior-segment optical coherence tomography (AS-OCT system, and a high-frequency ultrasound biomicroscopy (HF-UBM system. Methods: Fifty eyes randomly selected from 50 patients were included in the study. Inclusion criteria were healthy, nonoperated eyes examined consecutively by the same examiner. Corneal imaging was performed by three different methods, ie, Oculyzer II, spectral-domain AS-OCT, and FH-UBM. Central corneal thickness measurements were compared using scatter diagrams, Bland-Altman plots (with bias and 95% confidence intervals, and two-paired analysis. Results: The coefficient of determination (r2 between the Oculyzer II and AS-OCT measurements was 0.895. Likewise, the coefficient was 0.893 between the Oculyzer II and HF-UBM and 0.830 between the AS-OCT and HF-UBM. The trend line coefficients of linearity were 0.925 between the Oculyzer II and the AS-OCT, 1.006 between the Oculyzer II and HF-UBM, and 0.841 between the AS-OCT and HF-UBM. The differences in average corneal thickness between the three pairs of CCT measurements were –6.86 µm between the Oculyzer II and HF-UBM, –12.20 µm between the AS-OCT and Oculyzer II, and +19.06 µm between the HF-UBM and AS-OCT. Conclusion: The three methods used for corneal thickness measurement are highly correlated. Compared with the Scheimplug and ultrasound devices, the AS-OCT appears to report a more accurate, but overally thinner corneal pachymetry. Keywords: anterior eye segment, high-frequency ultrasound biomicroscopy, optical coherence tomography, high-resolution Pentacam

  3. 超声乳化白内障吸除联合人工晶状体植入术后眼前节相干光断层扫描观察%Slit lamp optical coherence tomography study of anterior segment changes after phacoemulsification and foldable intraocular lens implantation

    Institute of Scientific and Technical Information of China (English)

    晏丕松; 张振平; 林浩添; 吴文捷; 柏凌

    2009-01-01

    目的 应用裂隙灯显微镜眼前节相干光断层扫描(OCT)观察超声乳化白内障吸除联合人工晶状体(IOL)植入术后眼前节组织的变化情况,探讨手术对眼前节结构的影响.方法 前瞻性系列病例研究.使用海德堡公司裂隙灯显微镜眼前节OCT观察40例(44只眼)行超声乳化白内障吸除联合IOL植入术患者术前和术后1 d、1周、2周及1个月的眼前节组织变化情况.对所测量的数据进行重复测量设计资料的方差分析,用LSD法进行两两比较.结果 中央及切口处角膜在术后第1天全部患者均明显增厚(与术前相比增厚分别为99.59μm,234.57μm;P=0.490),中央角膜厚度至术后1个月可恢复术前水平,而切口处角膜厚度还较术前厚约19.25μm(P=0.001);前房深度(ACD)和各项反映前房角宽度的指标(AOD500、AOD750、TISA500、TISA750)在术后各观察时间点,均较术前明显加深和加宽(均P0.05).结论 裂隙灯显微镜眼前节OCT可客观、定量评价白内障手术对眼前节形态特征的影响.%Objective To investigate quantitative changes of the anterior segment configuration after clear corneal incision phacoemulsification and foldable intraocular lens (IOL) implantation with slit-lamp-adapted optical coherence tomography (SL-OCT). Methods In prospective consecutive case series, clear corneal incision phacoemulsification and foldable intraocular lens implantation were performed in 44 eyes of 40 patients. The changes of the anterior segment configuration were performed by SL-OCT before and 1 day, 1 week, 2 weeks and 1 month after surgery. SPSS 16.0 software was used to analyze statistical difference. Results For all patients, the central corneal thickness (CCT) and the incisional corneal thickness (ICT) increased significantly 1 day after surgery ( CCT increased 99. 59 μm, ICT increased 234. 57 μm;P = O. 490). At 1 month, the CCT almost had returned to baseline, but the ICT had been ticker about 19. 25 μm than

  4. Intravitreal Bevacizumab in Nonarteritic Anterior Ischemic Optic Neuropathy

    OpenAIRE

    Ebadollah Heidari; Mohammad Reza Niyousha; Reza Heidari; Babak Rahimi-Aradabili; Farzad Hami Adl; Nooshin Bazzazi

    2014-01-01

    Purpose: To evaluate the effect of intravitreal injection of Bevacizumab on improving visual function in patients with Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION). Methods: In a prospective interventional case series, 11 eyes with vision loss due to (NAION) in less than 15 days of attack were studied. Visual acuity, perimetry and optic nerve head changes were evaluated 1 week post-intravitreal injection of 1.25mg/0.1 mL Bevacizumab. Results: 5 of patients had improved visual acui...

  5. Automatic intraocular lens segmentation and detection in optical coherence tomography images.

    Science.gov (United States)

    Gillner, Melanie; Eppig, Timo; Langenbucher, Achim

    2014-05-01

    We present a new algorithm for automatic segmentation and detection of an accommodative intraocular lens implanted in a biomechanical eye model. We extracted lens curvature and position. The algorithm contains denoising and fan correction by a multi-level calibration routine. The segmentation is realized by an adapted canny edge detection algorithm followed by a detection of lens surface with an automatic region of interest search to suppress non-optical surfaces like the lens haptic. The optical distortion of lens back surface is corrected by inverse raytracing. Lens geometry was extracted by a spherical fit. We implemented and demonstrated a powerful algorithm for automatic segmentation, detection and surface analysis of intraocular lenses in vitro. The achieved accuracy is within the expected range determined by previous studies. Future improvements will include the transfer to clinical anterior segment OCT devices. PMID:23928353

  6. Toxic anterior segment syndrome after uncomplicated cataract surgery possibly associated with intracamaral use of cefuroxime

    OpenAIRE

    Çakır B; Celik E; Aksoy NÖ; Bursalı Ö; Uçak T; Bozkurt E; Alagoz G

    2015-01-01

    Burçin Çakir, Erkan Celik, Nilgün Özkan Aksoy, Özlem Bursali, Turgay Uçak, Erdinç Bozkurt, Gursoy AlagozSakarya University Education and Research Hospital, Sakarya, TurkeyPurpose: To report toxic anterior segment syndrome (TASS) after cataract surgery possibly associated with intracameral use of cefuroxime.Methods: We conducted a retrospective chart review and analysis on the pre- and postoperative conditions of the subjects who had developed TASS.Re...

  7. Can intramuscular corticosteroid injection cause nonarteritic anterior ischemic optic neuropathy?

    Directory of Open Access Journals (Sweden)

    Bakbak B

    2013-03-01

    Full Text Available Berker Bakbak, Banu Turgut Ozturk, Sansal Gedik, Bengu Ekinci Koktekir, Saban Gonul Selcuk University Medical Faculty, Department of Ophthalmology, Konya, Turkey Abstract: A 56-year-old man noted a sudden decrease of vision in his right eye 4 hours after intramuscular triamcinolone acetonide (TA injection. A diagnosis of unilateral nonarteritic anterior ischemic optic neuropathy (NAION was made, and the patient was counseled to discontinue using TA. Examination for possible risk factors revealed controlled hypertension. Final visual acuity was finger counting at 1 m, and the optic disc was pale in his right eye. This is the first reported case of unilateral NAION that has occurred in a patient after intramuscular corticosteroid injection. Although a cause-and-effect relationship is difficult to prove, the short duration between the TA injection and the NAION is noteworthy. The history of corticosteroid injection should be questioned in cases with predisposing conditions such as hypertension. Keywords: ischemic optic neuropathy, corticosteroids, optic disc edema

  8. Adjustable muscle plication: a new surgical technique for strabismic patients with high risk for anterior segment ischemia

    Institute of Scientific and Technical Information of China (English)

    Carlos; Laria; David; P.Pi?ero

    2015-01-01

    <正>INTRODUCTION Anterior ciliary arteries provide 70%of the vascular supply of the anterior segment.A significant interruption of the vascular flow of these arteries increases the risk for anterior ischemia.Although the frequency of this special condition is low after strabismus surgery(1:13 000)[1],its effects may involve substantial visual problems[2].We report the successful outcome of a new surgical approach for strabismus management in a case of high risk for anterior ischemia.Specifically,we show the correction of the horizontal ocular deviation by means of an adjustable muscle

  9. Characterization of rat model of acute anterior uveitis using optical coherence tomography angiography

    Science.gov (United States)

    Choi, Woo June; Pepple, Kathryn L.; Zhi, Zhongwei; Wang, Ruikang K.

    2015-03-01

    Uveitis, or ocular inflammation, is a cause of severe visual impairment. Rodent models of uveitis are powerful tools used to investigate the pathological mechanisms of ocular inflammation and to study the efficacy of new therapies prior to human testing. In this paper, we report the utility of spectral-domain optical coherence tomography (SD-OCT) angiography in characterizing the inflammatory changes induced in the anterior segment of a rat model of uveitis. Acute anterior uveitis (AAU) was induced in two rats by intravitreal injection of a killed mycobacterial extract. One of them received a concurrent periocular injection of steroids to model a treatment effect. OCT imaging was performed prior to inflammation induction on day 0 (baseline), and 2 days post-injection (peak inflammation). Baseline and inflamed images were compared. OCT angiography identified swelling of the cornea, inflammatory cells in the anterior and posterior chambers, a fibrinous papillary membrane, and dilation of iris vessels in the inflamed eyes when compared to baseline images. Steroid treatment was shown to prevent the changes associated with inflammation. This is a novel application of anterior OCT imaging in animal models of uveitis, and provides a high resolution, in vivo assay for detecting and quantifying ocular inflammation and the response to new therapies.

  10. Efficacy of highly hydrophilic soft contact lenses for persistent corneal epithelial defects after anterior segment surgery

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    Zhi-Wei Peng

    2015-02-01

    Full Text Available AIM:To investigate the efficacy of highly hydrophilic soft contact lenses for persistent corneal epithelial defects.METHODS:In this retrospective case analysis, 28 patients(28 eyeswith persistent corneal epithelial defects after anterior segment surgery from January 2011 to June 2013 in our hospital were reviewed. After regular treatment for at least 2wk, the persistent corneal epithelial defects were treated with highly hydrophilic soft contact lenses, until the corneal epithelial healing. Continued to wear the same lens no more than 3wk, or in need of replacement the new one. All cases were followed up for 6mo. Key indicators of corneal epithelial healling, corneal fluorescein staining and ocular symptoms improvement were observed.RESULTS: Twenty-one eyes were cured(75.00%, markedly effective in 5 eyes(17.86%, effective in 2 eyes(7.14%, no invalid cases, the total efficiency of 100.00%. Ocular symptoms of 25 cases(89.29%relieved within 2d, the rest 3 cases(10.71%relieved within 1wk. The corneal epithelial of 6 cases(21.43%repaired in 3wk, 13 cases(46.43%in 6wk, 7 cases(25.00%in 9wk, 2 cases(7.14%over 12wk. There were no signs of secondary infection. And no evidence of recurrence in 6mo. CONCLUSION: Highly hydrophilic soft contact lenses could repair persistent corneal epithelial defects after anterior segment surgery significantly, while quickly and effectively relieve a variety of ocular irritation.

  11. Changes in intraocular pressure and anterior segment morphometry after uneventful phacoemulsification cataract surgery.

    LENUS (Irish Health Repository)

    Dooley, I

    2012-02-01

    PURPOSE: To study changes in anterior segment morphometry after uneventful phacoemulsification cataract surgery, and to investigate whether there is a relationship between any observed changes and intraocular pressure (IOP) reduction after the procedure. METHODS: The anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), central corneal thickness (CCT), and IOP were measured in 101 non-glaucomatous eyes before and after uneventful phacoemulsification cataract surgery. RESULTS: After cataract surgery, the mean ACD, ACV, and ACA values increased by 1.08 mm, 54.4 mm(3), and 13.1 degrees , respectively, and the mean IOP (corrected for CCT) decreased by 3.2 mm Hg. The predictive value of a previously described index (preoperative ACD\\/preoperative IOP (corrected for CCT) or CPD ratio) for IOP (corrected for CCT) reduction after cataract surgery was confirmed, reflected in an r(2) value of 23.3% between these two parameters (P<0.001). Other indices predictive of IOP reduction after cataract surgery were also identified, including preoperative IOP\\/preoperative ACV and preoperative IOP\\/preoperative ACA, reflected in r(2) values of 13.7 and 13.7%, respectively (P<0.001 and P<0.001, respectively). CONCLUSIONS: Our study confirms the predictive value of the CPD ratio for IOP reduction after cataract surgery, and may contribute to the decision-making process in patients with glaucoma or ocular hypertension. Furthermore, two novel indices of preoperative parameters that are predictive for IOP reduction after cataract surgery were identified, and enhance our understanding of the mechanisms underlying IOP changes after this procedure.

  12. Coil embolization in precommunicating (A1) segment aneurysms of anterior cerebral artery

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Dae; Ahn, Jun Hyong; Jung, Seung Chai; Kim, Chang Hun [Seoul National University Hospital, Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Kang, Hyun-Seung; Kim, Jeong Eun [Seoul National University Hospital, Seoul National University College of Medicine, Department of Neurosurgery, 28 Yongon-dong, Jongno-gu, Seoul (Korea, Republic of); Son, Young Je [Seoul National University Boramae Hospital, Seoul National University College of Medicine, Department of Neurosurgery, Seoul (Korea, Republic of); Han, Moon Hee [Seoul National University Hospital, Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Hospital, Seoul National University College of Medicine, Department of Neurosurgery, 28 Yongon-dong, Jongno-gu, Seoul (Korea, Republic of)

    2014-03-15

    Precommunicating (A1) segment aneurysms of the anterior cerebral artery are rare and often pose technical challenges for coil embolization due to their distinctive configurations. Clinical and radiologic outcomes of treating such aneurysms through endovascular coil embolization are presented herein. Data accruing prospectively from May 2002 to August 2013 yielded 48 patients harboring 50 A1 segment aneurysms, each classified as proximal, middle, or distal by location. Clinical outcome of the patients and morphological outcome of the aneurysms were assessed, with emphasis on technical aspects of treatment. The aneurysms studied occupied either proximal (n = 39), middle (n = 6), or distal (n = 5). Proximal aneurysms were largely directed posteriorly (80 %), and most (97 %) were devoid of branches. Middle and distal aneurysms were associated with the medial lenticulostriate artery, cortical branches, or fenestrations. The preshaped ''S'' and steam-shaped ''S'' microcatheters facilitated aneurysm selection in 60 % of lesions. Single-microcatheter technique was most commonly applied for coil embolization (62 %), followed by balloon protection (16 %). Successful aneurysmal occlusion could be achieved in 76 % of the patients, with no procedure-related morbidity and mortality. At final follow-up (mean interval, 29.9 months), stable aneurysmal occlusion was sustained in 93 % of the patients (40/43). A1 segment aneurysms are amenable to safe and efficacious endovascular coil embolization by adjusting procedural strategy to accommodate distinctive anatomic configurations. (orig.)

  13. A New Potential Cause in the Development of Toxic Anterior Segment Syndrome: Fibrin Glue

    Directory of Open Access Journals (Sweden)

    Selçuk Sızmaz

    2014-08-01

    Full Text Available Objectives: To present a potential cause for toxic anterior segment syndrome (TASS. Materials and Methods: We report 4 cases of TASS that occurred following uneventful phacoemulsification and intraocular lens implantation. Results: The 4 cases were the first consecutive 2 cases of 2 different surgery days, 5 months apart. The most prominent sign of TASS was limbus-to-limbus corneal edema. Pain and/or intraocular pressure rise were also common. All surgical and presurgical procedures were checked after the first outbreak, whereas the second outbreak required further investigation. Fibrin glue remnants from preceding pterygium surgery with conjunctival autografting were found to be the potential cause. Despite intensive corticosteroid therapy, corneal edema did not resolve in 2 patients who underwent keratoplasty. Conclusion: TASS is a sight-threatening condition which requires thorough investigation for prevention of new cases. All steps must be carefully revised. (Turk J Ophthalmol 2014; 44: 280-3

  14. Comparative study on the effect of anterior and posterior decompression in the treatment of multi-segmental cervical spondylotic myelopathy

    Institute of Scientific and Technical Information of China (English)

    Liang Li; Mei-Lin Jiang; Xiao-Jun Yang

    2016-01-01

    Objective: To analyze and compare the clinical efficacy of anterior and posterior decompression in the treatment of multi-segmental cervical spondylotic myelopathy (MCSM), providing certain guidance for the clinical treatment. Methods:A total of 72 patients with MCSM who were admitted in our hospital from September, 2012 to October, 2014 were included in the study and divided into the anterior group (n=37) and the posterior group (n=35) according to different surgical methods. The patients in the anterior group were given anterior cervical discectomy fusion (ACDF) and anterior cervical corpectomy fusion (ACCF), while the patients in the posterior group were given laminoplasty (LP). The general materials, surgical materials, and postoperative functional recovery in the two groups were compared. Results:The comparison of gender, age, course, preoperative JOA score, follow-up time, and affected segment between the two groups was not statistically significant. The operation time in the anterior group was significantly longer than that in the posterior group, but the intraoperative amount of bleeding was significantly less than that in the posterior group. The postoperative spinal cord function in the two groups was significantly improved when compared with before operation;moreover, the improved degree in the anterior group was more obvious. The postoperative cervical physiological curvature in the anterior group was significantly increased, but in the posterior group was significantly reduced. The comparison of the occurrence rate of postoperative complications between the two groups was not statistically significant. Conclusions:The anterior and posterior surgeries in the treatment of MCSM can significantly improve the postoperative spinal cord function, among which the anterior surgery can effectively recover the cervical physiological curvature. It is recommended that an appropriate surgical method should be reasonably selected by comprehensively considering the

  15. Automated detection of inflammatory cells in whole anterior chamber of a uveitis mouse from swept-source optical coherence tomography images

    Science.gov (United States)

    Choi, Woo June; Pepple, Kathryn L.; Wang, Ruikang K.

    2016-03-01

    Cell grading in a rodent anterior chamber is essential for anterior inflammation evaluation in preclinical vision research. This paper describes a computerized method for detection and counting of the anterior chamber cells from swept-source optical coherence tomography (SS-OCT) images of a experimental rodent model of uveitis. The volumetric anterior segment OCT data is obtained from 100 kHz SS-OCT imaging of mouse eye in vivo. For the OCT cross-sections, each OCT structural image is de-speckled and binarized. After removal of cornea, iris, and crystalline lens structures connected to the binary image border, an area thresholding is then employed for each labeled region to isolate only celllike objects in the anterior chamber, followed by roundness estimation of the objects to identify potential cell candidates in the data. Eventually, the cell candidates are counted and graded as total number of cells in the anterior chamber.

  16. Toxic anterior segment syndrome after uncomplicated cataract surgery possibly associated with intracamaral use of cefuroxime

    Directory of Open Access Journals (Sweden)

    Çakır B

    2015-03-01

    Full Text Available Burçin Çakir, Erkan Celik, Nilgün Özkan Aksoy, Özlem Bursali, Turgay Uçak, Erdinç Bozkurt, Gursoy AlagozSakarya University Education and Research Hospital, Sakarya, TurkeyPurpose: To report toxic anterior segment syndrome (TASS after cataract surgery possibly associated with intracameral use of cefuroxime.Methods: We conducted a retrospective chart review and analysis on the pre- and postoperative conditions of the subjects who had developed TASS.Results: The patient group consisted of 17 patients. Tyndallization and fibrin fibers were positive in all eyes. In four eyes, hypopyon formation developed. These reactions diminished on the third day and fully resolved 1 week after the operations with the use of intensive topical steroid and mydriatic therapy. To determine the etiology of TASS, infusion fluid, viscoelastics, and intracameral antibiotic agent were changed respectively. After changing intracameral antibiotic agent from cefuroxime axetile to moxifloxacin no new cases of TASS were diagnosed.Conclusion: All agents injected into the anterior chamber can cause TASS. Ophthalmologists and operating room staff need to pay careful attention to all drugs and irrigating solutions.Keywords: phacoemulsification, fibrin reaction, drug toxicity

  17. Anterior ST segment depression in acute inferior myocardial infarction as a marker of greater inferior, apical, and posterolateral damage

    International Nuclear Information System (INIS)

    The clinical significance of anterior precordial ST segment depression during acute inferior myocardial infarction was evaluated in 67 consecutive patients early after onset of symptoms with gated blood pool scans, thallium-201 perfusion images, and 12-lead ECGs. Patients with anterior ST depression (n = 33) had depressed mean values for left ventricular ejection fraction (54 +/- 2% [mean +/- S.E.M.] vs 59 +/- 2%; p = 0.02), cardiac index (3.1 +/- 0.2 vs 3.6 +/- 0.2 L/m2; p = 0.03), and ratio of systolic blood pressure to end-systolic volume (2.0 +/- 0.1 vs 2.5 +/- 0.3 mm Hg/ml; p = 0.04) compared to patients with no anterior ST depression (n = 34). Patients with anterior ST depression had (1) lower mean wall motion values for the inferior, apical, and inferior posterolateral segments (p less than 0.05) and (2) greater reductions in thallium-201 uptake in the inferior and posterolateral regions (p less than 0.05). However, anterior and septal (1) wall motion and (2) thallium-201 uptake were similar in patients with and without ST depression. Thus, anterior precordial ST segment depression in patients with acute inferior wall myocardial infarction represents more than a reciprocal electrical phenomenon. It identifies patients with more severe wall motion impairment and greater hypoperfusion of the inferior and adjacent segments. The poorer global left ventricular function in these patients is a result of more extensive inferior infarction and not of remote septal or anterior injury

  18. Right anterior segmental hepatic duct emptying directly into the cystic duct in a living donor

    Directory of Open Access Journals (Sweden)

    Yasunao Ishiguro, Masanobu Hyodo, Takehito Fujiwara, Yasunaru Sakuma, Nobuyuki Hojo, Koichi Mizuta, Hideo Kawarasaki, Alan T Lefor, Yoshikazu Yasuda

    2010-08-01

    Full Text Available A 35-year-old mother was scheduled to be the living donor for liver transplantation to her second son, who suffered from biliary atresia complicated with biliary cirrhosis at the age of 2 years. The operative plan was to recover the left lateral segment of the mother’s liver for living donor transplantation. With the use of cholangiography at the time of surgery, we found the right anterior segmental duct (RASD emptying directly into the cystic duct, and the catheter passed into the RASD. After repairing the incision in the cystic duct, transplantation was successfully performed. Her postoperative course was uneventful. Biliary anatomical variations were frequently encountered, however, this variation has very rarely been reported. If the RASD was divided, the repair would be very difficult because the duct will not dilate sufficiently in an otherwise healthy donor. Meticulous preoperative evaluation of the living donor’s biliary anatomy, especially using magnetic resonance cholangiography and careful intraoperative techniques, is important to prevent bile duct injury and avoid the risk to the healthy donor.

  19. Evaluation of Anterior Segment Parameter Changes Using the Sirius after Uneventful Phacoemulsification

    Science.gov (United States)

    Şimşek, Ali; Çapkın, Musa; Bilak, Şemsettin; Güler, Mete; Reyhan, Ali Hakim

    2016-01-01

    noncontact, noninvasive, and comfortable system for patients that is highly reliable and repeatable for anterior segment measurements. PMID:27478351

  20. Biomedical sensing and imaging for the anterior segment of the eye

    Science.gov (United States)

    Eom, Tae Joong; Yoo, Young-Sik; Lee, Yong-Eun; Kim, Beop-Min; Joo, Choun-Ki

    2015-07-01

    Eye is an optical system composed briefly of cornea, lens, and retina. Ophthalmologists can diagnose status of patient's eye from information provided by optical sensors or images as well as from history taking or physical examinations. Recently, we developed a prototype of optical coherence tomography (OCT) image guided femtosecond laser cataract surgery system. The system combined a swept-source OCT and a femtosecond (fs) laser and afford the 2D and 3D structure information to increase the efficiency and safety of the cataract procedure. The OCT imaging range was extended to achieve the 3D image from the cornea to lens posterior. A prototype of OCT image guided fs laser cataract surgery system. The surgeons can plan the laser illumination range for the nuclear division and segmentation, and monitor the whole cataract surgery procedure using the real time OCT. The surgery system was demonstrated with an extracted pig eye and in vivo rabbit eye to verify the system performance and stability.

  1. Unilateral Acute Anterior Ischemic Optic Neuropathy in a Patient with an Already Established Diagnosis of Bilateral Optic Disc Drusen

    OpenAIRE

    Ziya Ayhan; Aylin Yaman; Meltem Söylev Bajin; Osman Saatci, A

    2015-01-01

    Optic disc drusen (ODD) are calcific deposits that form in the optic nerve head secondary to abnormalities in axonal metabolism and degeneration. Anterior ischemic optic neuropathy, central retinal artery, and vein occlusion are among the rare vascular complications of disc drusen. We reported the clinical course of a 51-year-old patient with a unilateral acute nonarteritic anterior ischemic optic neuropathy (NAION) who received the diagnosis of bilateral optic disc drusen five years earlier ...

  2. Evaluation of Changes in Anterior Segment Configuration by Ultrasound Biomicroscopy after Phacoemulsification and Foldable Intraocular Lens Implantation

    Directory of Open Access Journals (Sweden)

    ilhami Salcan

    2011-08-01

    Full Text Available Purpose: To quantify the configuration changes in anterior segment structures after cataract extraction using ultrasound biomicroscopy (UBM. Material and Method: 33 eyes of 33 patients (21 male, 12 female; mean age: 69.0±8.3 years with senile or presenile cataracts undergoing cataract surgery were prospectively studied. UBM was performed for each patient before and 1 month after surgery. At each UBM examination, axial images of the anterior chamber and radial sections of the angle in four quadrants were obtained. The measurements were performed by using the calipers included in the equipment software and UBM Pro2000® software. Results: After cataract surgery, we determined statistically significant increases in anterior chamber depth and angle parameters (p=0.001. We found that the postoperative increases in anterior chamber depth, angle recess area, angle opening distance 250 and angle opening distance 500 were 1.3, 1.4, 1.7 and 1.5 times, respectively, when compared with the preoperative levels. Decreases in acceleration and increases in y-intercept were determined in 4 quadrants postoperatively by of linear regression analysis of anterior chamber angle and these were also statistically significant (p=0.001. Discussion: UBM gives both qualitative and quantitative valuable information about anterior segment structures. We think that UBM may be a useful tool for evaluation of patients with cataract and occludable and/or narrow angles undergoing cataract surgery for therapeutic purpose. (Turk J Ophthalmol 2011; 41: 200-6

  3. Improved Large Segmented Optics Fabrication Using Magnetorheological Finishing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Primary mirrors for large aperture telescopes (> 10 m) are collections of smaller (1-2 m), typically hexagonal, often aspheric, optical segments. NASA's next...

  4. Improved Large Segmented Optics Fabrication Using Magnetorheological Finishing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Primary mirrors for large aperture telescopes (>10m) are collections of smaller (1-2m), typically hexagonal, often aspheric, optical segments. NASA?s next...

  5. Advanced Lightweight Metal Matrix Composite Segmented Optic Manufacture Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Design, manufacture and test a flat segmented mirror made of optical grade AlBeMet 162 material and fusion bonded through the use of E Beam welding to demonstrate...

  6. Evaluation of anterior segment parameters using pentacam in silicone oil-injected patients after pars plana vitrectomy

    Directory of Open Access Journals (Sweden)

    Burcu Çalik

    2013-01-01

    Full Text Available Background: The aim of this study is to evaluate anterior segment changes with Pentacam Scheimpflug camera after pars plana vitrectomy (PPV and silicone oil injection. Materials and Methods: In all, 44 eyes of 44 patients who underwent PPV by one surgeon were evaluated with Pentacam preoperatively, first week, and first month after surgery. The patients were divided into two groups, eyes with silicone injection after PPV and eyes with PPV and no endotamponade. Main outcome measures were preoperative and postoperative anterior chamber volume (ACV, anterior chamber depth (ACD, anterior chamber angle (ACA, and central corneal thickness (CCT obtained with pentacam. Results: Each group consisted of 22 patients. In both groups no significant difference was detected among preop and postop changes in ACV and ACA values ( p > 0.05. The increase in ACD in silicone oil-injected group and the decrease in ACD in PPV group at postop 1 week were statistically significant ( p < 0.05. The increase in CCT in silicone oil-injected group at postop 1 week and then decrease in postop 1 month were also significant ( p < 0.05. Surgically induced astigmatism (SIA was 3.7 Dioptry (D in silicone oil-injected group and 2.4 D in PPV group at postop 1 week. SIA decreased to 1.7 D and 1.5 D, respectively, at postop 1 month. Changes in SIA were significant ( p < 0.05. Conclusion: PPV effects cornea and anterior segment. Changes in cornea and anterior segment after PPV seem to return to preoperative values among 1 month after surgery.

  7. A novel method for measuring anterior segment area of the eye on ultrasound biomicroscopic images using photoshop.

    Directory of Open Access Journals (Sweden)

    Zhonghao Wang

    Full Text Available To describe a novel method for quantitative measurement of area parameters in ocular anterior segment ultrasound biomicroscopy (UBM images using Photoshop software and to assess its intraobserver and interobserver reproducibility.Twenty healthy volunteers with wide angles and twenty patients with narrow or closed angles were consecutively recruited. UBM images were obtained and analyzed using Photoshop software by two physicians with different-level training on two occasions. Borders of anterior segment structures including cornea, iris, lens, and zonules in the UBM image were semi-automatically defined by the Magnetic Lasso Tool in the Photoshop software according to the pixel contrast and modified by the observers. Anterior chamber area (ACA, posterior chamber area (PCA, iris cross-section area (ICA and angle recess area (ARA were drawn and measured. The intraobserver and interobserver reproducibilities of the anterior segment area parameters and scleral spur location were assessed by limits of agreement, coefficient of variation (CV, and intraclass correlation coefficient (ICC.All of the parameters were successfully measured by Photoshop. The intraobserver and interobserver reproducibilities of ACA, PCA, and ICA were good, with no more than 5% CV and more than 0.95 ICC, while the CVs of ARA were within 20%. The intraobserver and interobserver reproducibilities for defining the spur location were more than 0.97 ICCs. Although the operating times for both observers were less than 3 minutes per image, there was significant difference in the measuring time between two observers with different levels of training (p<0.001.Measurements of ocular anterior segment areas on UBM images by Photoshop showed good intraobserver and interobserver reproducibilties. The methodology was easy to adopt and effective in measuring.

  8. MPLS over Segmented WDM Optical Packet Switching Networks

    Directory of Open Access Journals (Sweden)

    Hakim Mellah

    2006-01-01

    Full Text Available Wavelength Division Multiplexing (WDM is a promising solution for data transport in future all-optical wide area networks. Such networks consist of fibers joined by dynamically controllable cross-connects which provide purely optical transport between pairs of network access stations. Optical packet switching (OPS is optical switching with the finest granularity. Incoming packets are switched all-optically without being converted to electrical signal. There are two categories of OPS networks. Slotted (synchronous OPS networks, in which all the packets have the same size and unslotted (asynchronous OPS networks, where packets may or may not have the same size. In this study we propose to integrate MPLS over slotted OPS networks by aggregating optical packets into a labeled optical burst. The burst has a fixed number of packets (segments. The number of segments in each burst is encoded in the experimental field of the MPLS header.

  9. Segmentation of the Optic Disc in 3-D OCT Scans of the Optic Nerve Head

    OpenAIRE

    Lee, Kyungmoo; Niemeijer, Meindert; Garvin, Mona K.; Kwon, Young H.; Sonka, Milan; Abràmoff, Michael D.

    2009-01-01

    Glaucoma is the second leading ocular disease causing blindness due to gradual damage to the optic nerve and resultant visual field loss. Segmentations of the optic disc cup and neuroretinal rim can provide important parameters for detecting and tracking this disease. The purpose of this study is to describe and evaluate a method that can automatically segment the optic disc cup and rim in spectral-domain 3-D OCT (SD-OCT) volumes. Four intraretinal surfaces were segmented using a fast multisc...

  10. Ocular Drug Delivery - New Strategies for Targeting Anterior and Posterior Segments of the Eye.

    Science.gov (United States)

    Fangueiro, Joana F; Veiga, Francisco; Silva, Amelia M; Souto, Eliana B

    2016-01-01

    The ocular delivery of drugs encounters several limitations because of the dynamic and static barriers of the human's eye anatomy and physiology. The poor bioavailability of drugs are mainly related to the topical administration, i.e. eye drops which is the most common drug dosage form for the treatment of eye pathologies. Precorneal factors and drug limitations related to its solubility and susceptibility for physicochemical degradation could be the main reasons for the poor permeation and uptake in the ocular mucosa. Pathologies affecting the anterior and posterior segment of the eye are thereafter difficult to be treated and, given the chronic and degenerative nature of some of these injuries, it is crucial to improve drugs therapeutic effect. Nanotechnology-based delivery systems could be a suitable approach to overcome these limitations. Some of the most important colloidal systems are highlighted in this review, such as the use of mucoadhesive polymers, prodrugs, nanogels, liposomes, microemulsions, lipid and polymeric nanoparticles, cyclodextrins, dendrimers and nanocrystals, along with their clinical and therapeutic relevance for the administration of drugs for ocular delivery. PMID:26675225

  11. Imaging the anterior eye with dynamic-focus swept-source optical coherence tomography

    Science.gov (United States)

    Su, Johnny P.; Li, Yan; Tang, Maolong; Liu, Liang; Pechauer, Alex D.; Huang, David; Liu, Gangjun

    2015-12-01

    A custom-built dynamic-focus swept-source optical coherence tomography (SS-OCT) system with a central wavelength of 1310 nm was used to image the anterior eye from the cornea to the lens. An electrically tunable lens was utilized to dynamically control the positions of focusing planes over the imaging range of 10 mm. The B-scan images were acquired consecutively at the same position but with different focus settings. The B-scan images were then registered and averaged after filtering the out-of-focus regions using a Gaussian window. By fusing images obtained at different depth focus locations, high-resolution and high signal-strength images were obtained over the entire imaging depth. In vivo imaging of human anterior segment was demonstrated. The performance of the system was compared with two commercial OCT systems. The human eye ciliary body was better visualized with the dynamic-focusing SS-OCT system than using the commercial 840 and 1310 nm OCT systems. The sulcus-to-sulcus distance was measured, and the result agreed with that acquired with ultrasound biomicroscopy.

  12. Extensive molecular differences between anterior- and posterior-half-sclerotomes underlie somite polarity and spinal nerve segmentation

    Directory of Open Access Journals (Sweden)

    Keynes Roger J

    2009-05-01

    Full Text Available Abstract Background The polarization of somite-derived sclerotomes into anterior and posterior halves underlies vertebral morphogenesis and spinal nerve segmentation. To characterize the full extent of molecular differences that underlie this polarity, we have undertaken a systematic comparison of gene expression between the two sclerotome halves in the mouse embryo. Results Several hundred genes are differentially-expressed between the two sclerotome halves, showing that a marked degree of molecular heterogeneity underpins the development of somite polarity. Conclusion We have identified a set of genes that warrant further investigation as regulators of somite polarity and vertebral morphogenesis, as well as repellents of spinal axon growth. Moreover the results indicate that, unlike the posterior half-sclerotome, the central region of the anterior-half-sclerotome does not contribute bone and cartilage to the vertebral column, being associated instead with the development of the segmented spinal nerves.

  13. Spontaneous resolution of a flow-related ophthalmic-segment aneurysm after treatment of anterior cranial fossa dural arteriovenous fistula

    Directory of Open Access Journals (Sweden)

    Kevin Reinard

    2014-01-01

    Full Text Available Background: The natural history of proximal, feeding-artery aneurysms after successful obliteration of high-grade, anterior cranial fossa dural arteriovenous fistulas (dAVFs has not been well documented. Case Description: A 52-year-old Caucasian male presented with an unruptured anterior cranial fossa (dAVF and an associated aneurysm. Cerebral angiography revealed a large, contralateral, carotid-ophthalmic segment aneurysm, enlarged feeding ophthalmic arteries, as well as cortical venous drainage. Successful surgical obliteration of the dAVF was undertaken to eliminate the risk of hemorrhage. Conclusion: The carotid-ophthalmic aneurysm regressed significantly after surgical obliteration of the dAVF and a follow-up, planned coiling procedure to address the carotid-ophthalmic aneurysm was abandoned. This represents the first reported case of a near complete, spontaneous resolution of an unruptured carotid-ophthalmic aneurysm associated with a high-grade anterior cranial fossa dAVF.

  14. Resolution Enhancement by Incorporating Segmentation-based Optical Flow Estimation

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    Osama A. Omer

    2012-06-01

    Full Text Available In this paper, the problem of recovering a high-resolution frame from a sequence of low-resolution frames is considered. High-resolution reconstruction process highly depends on image registration step. Typical resolution enhancement techniques use global motion estimation technique. However, in general, video frames cannot be related through global motion due to the arbitrary individual pixel movement between frame pairs. To overcome this problem, we propose to employ segmentation-based optical flow estimation technique for motion estimation with a modified model for frame alignment. To do that, we incorporate the segmentation with the optical flow estimation in two-stage optical flow estimation. In the first stage, a reference image is segmented into homogeneous regions. In the second stage, the optical flow is estimated for each region rather than pixels or blocks. Then, the frame alignment is accomplished by optimizing the cost function that consists of L1-norm of the difference between the interpolated low-resolution (LR frames and the simulated LR frames. The experimental results demonstrate that using segmentation-based optical flow estimation in motion estimation step with the modified alignment model works better than other motion models such as affine, and conventional optical flow motion models.

  15. Image segmentation by nonlinear filtering of optical Hough transform.

    Science.gov (United States)

    Fernández, Ariel; Flores, Jorge L; Alonso, Julia R; Ferrari, José A

    2016-05-01

    The identification and extraction (i.e., segmentation) of geometrical features is crucial in many tasks requiring image analysis. We present a method for the optical segmentation of features of interest from an edge enhanced image. The proposed method is based on the nonlinear filtering (implemented by the use of a spatial light modulator) of the generalized optical Hough transform and is capable of discriminating features by shape and by size. The robustness of the method against noise in the input, low contrast, or overlapping of geometrical features is assessed, and experimental validation of the working principle is presented. PMID:27140381

  16. Robust optic nerve segmentation on clinically acquired CT

    Science.gov (United States)

    Panda, Swetasudha; Asman, Andrew J.; DeLisi, Michael P.; Mawn, Louise A.; Galloway, Robert L.; Landman, Bennett A.

    2014-03-01

    The optic nerve is a sensitive central nervous system structure, which plays a critical role in many devastating pathological conditions. Several methods have been proposed in recent years to segment the optic nerve automatically, but progress toward full automation has been limited. Multi-atlas methods have been successful for brain segmentation, but their application to smaller anatomies remains relatively unexplored. Herein we evaluate a framework for robust and fully automated segmentation of the optic nerves, eye globes and muscles. We employ a robust registration procedure for accurate registrations, variable voxel resolution and image fieldof- view. We demonstrate the efficacy of an optimal combination of SyN registration and a recently proposed label fusion algorithm (Non-local Spatial STAPLE) that accounts for small-scale errors in registration correspondence. On a dataset containing 30 highly varying computed tomography (CT) images of the human brain, the optimal registration and label fusion pipeline resulted in a median Dice similarity coefficient of 0.77, symmetric mean surface distance error of 0.55 mm, symmetric Hausdorff distance error of 3.33 mm for the optic nerves. Simultaneously, we demonstrate the robustness of the optimal algorithm by segmenting the optic nerve structure in 316 CT scans obtained from 182 subjects from a thyroid eye disease (TED) patient population.

  17. Optical coherence tomography plaque characterization in a patient with ST segment elevation myocardial infarction after cocaine intake.

    Science.gov (United States)

    Hansen, Morten Steen Svarer; Antonsen, Lisbeth; Jensen, Lisette Okkels

    2016-01-01

    A 28-year old man presented to the Emergency Department with malaise after cocaine intake. After arrival he developed retrosternal chest pain and the electrocardiogram showed ST segment elevations in V1-V2 and ST segment depressions in V5-V6. An acute coronary angiogram revealed a focal non-occlusive lesion with thrombus in the left anterior descending artery. Supplementary optical coherence tomography (OCT) detected plaque erosion with adherent thrombus to be the responsible underlying pathophysiological mechanism. The patient received an effective antithrombotic regimen. Repeat angiogram with additional OCT one month later documented thrombus resolution and complete restoration of the previously eroded coronary vascular surface area. PMID:26905053

  18. Thallium-201 evidence that anterior ST segment depression during early acute inferior myocardial infarction reflects septal or posterolateral ischemic injury

    International Nuclear Information System (INIS)

    The pathogenesis of anterior (ANT) ST segment depression (ST decreasing) during acute inferior myocardial infarction (IMI) remains controversial. To evaluate the role of septal (S) or posterolateral (PL) ischemic injury (IS), resting thallium-201 (T1-201) scintigrams closely timed to ECG findings (mean 21+-21 minutes) were evaluated in 49 consecutive pts during the first 5 hrs of a first acute IMI. ANT ST decreasing (any lead V1-V4) of ≥ 1.0 mm was considered significant. All 49 pts had inferior T1-201 defects. In all 38 pts with ANT ST decreasing, there was T1-201 evidence of PL and/or S IS. In 9 of 11 pts without ANT ST decreasing, IS was confined to the inferior wall. The magnitude of inferior lead ST segment elevation correlated well with ST decreasing in leads 1 and AVL (r=0.88) and poorly with ST decreasing in anterior leads (r=0.32, supporting the concept that in acute IMI, ST decreasing in 1 and AVL is a reciprocal electrical phenomenon, but that ANT ST decreasing has a different pathogenesis. Thus the authors conclude that anterior ST depression in acute inferior myocardial infarction is associated with additional septal and/or posterolateral ischemic injury and does not reflect a benign reciprocal electrical phenomenon

  19. Software design of segment optical transmitter for indoor free-space optical networks

    Science.gov (United States)

    Latal, Jan; Vitasek, Jan; Koudelka, Petr; Siska, Petr; Liner, Andrej; Hajek, Lukas; Vanderka, Ales; Vasinek, Vladimir; Lucki, Michal

    2015-01-01

    During recent years, there has been rapid development in optical networks. This includes not only fiber optical networks but also free space optical networks. The free space optical networks can be divided into indoor and outdoor ones. The indoor free space optical networks have been experiencing dramatic progress in the last years, allowed by the newest IEEE norm 802.15.7, which enabled development of different types of transmitter receivers, modulation formats, etc. The team of authors is dealing with software design of segment optical transmitters for an indoor free space optical network based on the multi-mode optical 50/125 or 62.5/125 μm fiber. Simulated data are then evaluated from the point of view of optical intensity uniform distribution and space spot light size radiating from segment optical transmitter.

  20. From acoustic segmentation to language processing: evidence from optical imaging

    Directory of Open Access Journals (Sweden)

    Hellmuth Obrig

    2010-06-01

    Full Text Available During language acquisition in infancy and when learning a foreign language, the segmentation of the auditory stream into words and phrases is a complex process. Intuitively, learners use ‘anchors’ to segment the acoustic speech stream into meaningful units like words and phrases. Regularities on a segmental (e.g., phonological or suprasegmental (e.g., prosodic level can provide such anchors. Regarding the neuronal processing of these two kinds of linguistic cues a left hemispheric dominance for segmental and a right hemispheric bias for suprasegmental information has been reported in adults. Though lateralization is common in a number of higher cognitive functions, its prominence in language may also be a key to understanding the rapid emergence of the language network in infants and the ease at which we master our language in adulthood. One question here is whether the hemispheric lateralization is driven by linguistic input per se or whether non-linguistic, especially acoustic factors, ‘guide’ the lateralization process. Methodologically, fMRI provides unsurpassed anatomical detail for such an enquiry. However, instrumental noise, experimental constraints and interference with EEG assessment limit its applicability, pointedly in infants and also when investigating the link between auditory and linguistic processing. Optical methods have the potential to fill this gap. Here we review a number of recent studies using optical imaging to investigate hemispheric differences during segmentation and basic auditory feature analysis in language development.

  1. Doenças do segmento anterior ocular associadas a lentes de contato Contact lens-associated ocular anterior segment diseases

    Directory of Open Access Journals (Sweden)

    Murilo Barreto Souza

    2008-12-01

    Full Text Available A disponibilidade de lentes de contato cada vez mais confortáveis e toleráveis favoreceu não só a ampliação das indicações, mas também o aumento do número de seus usuários. Como conseqüência deste fato as complicações associadas ao uso de lentes de contato são cada vez mais comuns, e representam um problema de grande prevalência na prática clínica. O objetivo deste estudo é revisar as principais doenças e alterações do segmento anterior e superfície ocular associadas ao uso de lentes de contato.Nowadays, contact lenses have shown a larger variety of options in order to meet the needs of different patients. They have become more frequent in the clinical practice and, consequently, the complications related to contact lenses have been more common. This review attempted to describe the main alterations and diseases of the cornea and anterior segment associated with contact lens wearers.

  2. Recurrent progressive anterior segment fibrosis syndrome following a descemet-stripping endothelial keratoplasty in an infant with congenital aniridia

    Directory of Open Access Journals (Sweden)

    Mihir Kothari

    2014-01-01

    Full Text Available Progressive anterior segment fibrosis syndrome (ASFS, after intraocular surgery in older children (≥9 years and adults with congenital aniridia, is described in the literature. In this report, we describe an unique case of ASFS in an infant with congenital aniridia following a combined trabeculotomy-ectomy and its recurrence after a descemet stripping endothelial keratoplasty. The ophthalmologists should be well aware of this entity and warn the parents about its possibilities. Use of immunomodulators or prolonged anti-inflammatory therapy may be considered to prevent its occurrence.

  3. Biomechanical effects of polyaxial pedicle screw fixation on the lumbosacral segments with an anterior interbody cage support

    Directory of Open Access Journals (Sweden)

    Chen Hsiang-Ho

    2007-03-01

    Full Text Available Abstract Background Lumbosacral fusion is a relatively common procedure that is used in the management of an unstable spine. The anterior interbody cage has been involved to enhance the stability of a pedicle screw construct used at the lumbosacral junction. Biomechanical differences between polyaxial and monoaxial pedicle screws linked with various rod contours were investigated to analyze the respective effects on overall construct stiffness, cage strain, rod strain, and contact ratios at the vertebra-cage junction. Methods A synthetic model composed of two ultrahigh molecular weight polyethylene blocks was used with four titanium pedicle screws (two in each block and two rods fixation to build the spinal construct along with an anterior interbody cage support. For each pair of the construct fixed with polyaxial or monoaxial screws, the linked rods were set at four configurations to simulate 0°, 7°, 14°, and 21° lordosis on the sagittal plane, and a compressive load of 300 N was applied. Strain gauges were attached to the posterior surface of the cage and to the central area of the left connecting rod. Also, the contact area between the block and the cage was measured using prescale Fuji super low pressure film for compression, flexion, lateral bending and torsion tests. Results Our main findings in the experiments with an anterior interbody cage support are as follows: 1 large segmental lordosis can decrease the stiffness of monoaxial pedicle screws constructs; 2 polyaxial screws rather than monoaxial screws combined with the cage fixation provide higher compression and flexion stiffness in 21° segmental lordosis; 3 polyaxial screws enhance the contact surface of the cage in 21° segmental lordosis. Conclusion Polyaxial screws system used in conjunction with anterior cage support yields higher contact ratio, compression and flexion stiffness of spinal constructs than monoaxial screws system does in the same model when the spinal segment

  4. Evaluation of the Changes in Anterior Segment Morphology After Laser Peripheral Iridotomy Through One-Year Follow-Up

    Directory of Open Access Journals (Sweden)

    Ulviye Yiğit

    2014-01-01

    Full Text Available Objectives: To evaluate the long-term changes in anterior segment morphology after laser peripheral iridotomy (LPI in eyes with primary angle-closure suspect (PACS, primary angle closure (PAC, and primary angle-closure glaucoma (PACG using Scheimpflug camera (SC. Materials and Methods: Fifty-six eyes of 30 patients diagnosed as PACS, PAC, and PACG were included prospectively in this study. In addition to full ophthalmic examination and intraocular pressure (IOP assessment, anterior-posterior length (AxL values of the eyes were recorded. With use of SC, average anterior chamber angle (AACA, central anterior chamber depth (CACD, and anterior chamber volume (ACV were documented preoperatively and at 1 month, 3 months, 6 months, and 12 months after LPI. The results have been evaluated statistically. Results: There was no statistically significant difference between the groups in terms of mean age, gender, and AxL (p>0.05. AACA, CACD, and ACV measurements showed significant difference between baseline and months 1.3, 6, and 12 in all groups (p<0.05. AACA was statistically significantly decreased between months 6 and 12 in PACS group; between months 1 and 12, months 3 and 12, months 6 and 12 in PAC and PACG groups (p<0.05. CACD measurements demonstrated statistically significant decrease between months 6 and 12 in PAC group, between months 3 and 6, months 3 and 12 in PACG group (p<0.05. ACV was statistically significantly decreased between months 6 and 12 in PAC group, between months 1 and 12, months 3 and 12 in PACG group (p<0.05. Conclusion: LPI led to dramatic changes in anterior segment morphology. In our study, the course of the changes caused by LPI was observed through one-year follow-up with SC. In the early period, a positive effect on all parameters was detected. The trends in the course of measurements should be followed up for longer time in larger series to investigate whether the changes show continuity or not. (Turk J Ophthalmol 2014

  5. Technical note: Endoscopic resection of a dermoid cyst anchored to the anterior optic chiasm

    Directory of Open Access Journals (Sweden)

    Yuichiro Yoneoka, MD, PhD

    2014-06-01

    Conclusion: To the best of our knowledge, ours is the only case of a dermoid cyst anchored to the anterior optic chiasma, which was visually confirmed under endoscopic observation. After surgery, the patient presented a transient impairment of the visual field, which was not evident at four month follow-up. It will contribute to a similar case, in which surgeons hesitate to make an incision in the optic chiasm. A subtotal excision should be considered in cases of dermoid cysts anchored to the anterior optic chiasm, because all the previously reported cases of suprasellar dermoid cysts are young people or those who have a relatively long life expectancy.

  6. The spinal nail: a new implant for short-segment anterior instrumentation of the thoracolumbar spine.

    Science.gov (United States)

    Dawson, J M; DeBoer, D K; Spengler, D M; Schwartz, H S

    1996-08-01

    The biomechanics of a new spinal implant were evaluated and its dependence on an anterior strut graft was determined. Six fresh-frozen adult porcine spines were used. An L3 corpectomy was created. The spinal nail was inserted intraosseously into the middle column of the L2-L4 vertebral bodies in a trough. Implant drill holes were made for proximal and distal locking bolts in L2 and L4. A locking plate bridged the L2 and L4 trough and anchored the exposed ends of the locking bolts. Testing was performed in axial compression, torsion, and flexion. The axial and torsional stability of the spine instrumented with the spinal nail are similar to results with other devices when used with anterior strut grafting. The axial and flexural stiffnesses of the instrumented spine are independent of strut grafting. This study suggests that this device may be useful for reconstruction of the anterior spine because of instability. PMID:8877956

  7. A case of superior segmental optic hypoplasia accompanied by a glaucomatous optic neuropathy

    OpenAIRE

    Ohguro, Hiroshi

    2008-01-01

    Ikuyo Ohguro, Hiroshi OhguroDepartment of Ophthalmology, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, JapanAbstract: This is the first case report of a bilateral superior segmental optic hypoplasia (SSOH) accompanied by a glaucomatous optic neuropathy (GON). A 47-year-old man incidentally diagnosed as having bilateral SSOH, simultaneously disclosed glaucomatous optic disc appearances, including enlargements of the cup of the optic nerve heads and a thinning of the infero-...

  8. Anterior segment study with the pentacam scheimpflug camera in refractive surgery candidates

    Directory of Open Access Journals (Sweden)

    Masih Hashemi

    2013-01-01

    Conclusions: Myopic eyes had steeper corneas than hyperopic eyes and anterior chamber measurements were significantly higher in the myopic eyes. In myopic eyes, AE max and PE max and K max measurements were higher, and ACD measurements were lower in the astigmatic groups.

  9. Evaluation of ultrasonic biomicroscopy results in anterior eye segment before and after cataract surgery

    OpenAIRE

    Ciftci S.; Simsek A.

    2012-01-01

    Ali Simsek,1 Süleyman Ciftci21Department of Ophthalmology, Faculty of Medicine, Adiyaman University, Adiyaman, Turkey; 2Department of Ophthalmology, Diyarbakir Training and Research Hospital, Diyarbakir, TurkeyBackground: The aim of this study was to assess the value of ultrasonic biomicroscopy in reporting decreases in intraocular pressure resulting from changes in anterior chamber depth and angle after phacoemulsification and intracapsular lens implantation in patients with catarac...

  10. Tyndallometric evaluation of the inflammatory response to the procedures in the anterior segment

    Science.gov (United States)

    Zarnowski, Tomasz; Chmiel, Malgorzata; Machowicz-Matejko, Eulalia; Zagorski, Zbigniew

    1998-10-01

    The purpose of this study was to quantify noninvasively, with the use of laser-flare meter, the alterations of the blood-aqueous barrier following phacoemulsification, extracapsular cataract extraction (ECCE), trabeculectomy and phacotrabeculectomy. Aqueous flare measurements were performed using laser-flare meter (Kowa FM-500). The device allows noninvasive, quantitative determination of aqueous protein concentration by recording the scatter of a helium- neon laser light scanned into the anterior chamber. Anterior chamber flare expressed as photon counts per millisecond was also estimated preoperatively, one and three days postoperatively, in two groups of cataractous eyes: 75 eyes after `divide and conquer' phacoemulsification with continuous curvilinear capsulorhexis, 43 eyes after extracapsular cataract extraction with `can opener' capsulotomy. Moreover, two groups of eyes following trabeculectomy (12 eyes) and phacotrabeculectomy (12 eyes) were also examined one, three and seven days postoperatively. We observed significantly lower anterior chamber flare measurements following phacoemulsification (32.0 - 1 day, 16.4 - 3 days postop) than after ECCE (64.6 and 40.2, respectively; P Phacoemulsification with curvilinear capsulorhexis induced less severe blood-aqueous breakdown than ECCE with `can opener' capsulotomy. Eventually, it can be suggested that phacoemulsification, as a less traumatizing technique might be preferable in high risk eyes (with diabetes, glaucoma, uveitis) that are more susceptible to postoperative inflammation and consecutive complications.

  11. Distribution of pseudoexfoliation material on anterior segment structures in human autopsy eyes after cataract surgery with intraocular lens implantation.

    Science.gov (United States)

    Schmack, Ingo; Auffarth, Gerd Uwe

    2016-06-01

    The purpose of the study was to evaluate the distribution and amount of pseudoexfoliation material (PXM) on anterior segment structures in pseudophakic human autopsy eyes with pseudoexfoliation (PEX) syndrome and to study its impact on fixation and decentration of posterior chamber intraocular lenses (IOLs). Sixteen human autopsy eyes (donor age [mean ± SD] 77.5 ± 8.6 years; range, 70-90 years) with history of cataract surgery and PEX syndrome were analyzed for distribution and accumulation of PXM on structures of the anterior segment by light microscopy. Quantitative IOL decentration measurements were performed using the Miyake-Apple posterior view technique. All 16 eyes displayed IOLs which were either fixed symmetrically in the capsular bag (n = 8) or asymmetrically with one haptic in the sulcus and one in the bag (n = 7) or at the pars plicata of the ciliary body (n = 1). In the majority, PXM was found around the pars plicata (average grade: 1.6 ± 0.53 µm) and the lens capsule (average grade: 1.05 ± 0.46 µm). Minor amounts were detected at the pars plana and the trabecular meshwork. IOL decentration measurements ranged from 0.51 ± 0.35 (symmetrical-fixation) to 0.61 ± 0.43 mm (asymmetrical-fixation). There was only a weak statistically not significant correlation in regard to the amount of PXM and IOL decentration and between PXM distribution and the IOL fixation site. PXM contributes to weakening of the suspensory apparatus of the crystalline lens. Although PXM induced tissue alterations predispose for a broad spectrum of intra- and postoperative complications, the amount and distribution of PXM on different anterior segment structures showed only a weak correlation to IOL decentration or fixation location. PMID:26307751

  12. Analysis of Fundus Photography and Fluorescein Angiography in Nonarteritic Anterior Ischemic Optic Neuropathy and Optic Neuritis

    Science.gov (United States)

    Kim, Min Kyung

    2016-01-01

    Purpose We evaluated fundus and fluorescein angiography (FAG) findings and characteristics that can help distinguish nonarteritic anterior ischemic optic neuropathy (NAION) from optic neuritis (ON). Methods Twenty-three NAION patients and 17 ON with disc swelling patients were enrolled in this study. We performed fundus photography and FAG. The disc-swelling pattern, hyperemia grade, presence of splinter hemorrhages, cotton-wool spots, artery/vein ratio and degree of focal telangiectasia were investigated. The FAG findings for each patient were compared with respect to the following features: the pattern of disc leakage in the early phase, arteriovenous (artery/vein) transit time (second), and the presence and pattern of the filling delay. Results Cotton-wool spots, focal telangiectasia, and venous congestion were more common in the affected eyes of NAION patients. Upon FAG, 76.5% of the patients in the ON group exhibited normal choroidal circulation. However, 56.5% of patients in the NAION group demonstrated abnormal filling defects, such as peripapillary, generalized, or watershed zone filling delays. Conclusions Fundus findings, including cotton-wool spots, focal telangiectasia, and venous congestion in the affected eye, may be clues that can be used to diagnose NAION. In addition, choroidal insufficiencies on FAG could be also helpful in differentiating NAION from ON. PMID:27478356

  13. Should steroids be offered to patients with nonarteritic anterior ischemic optic neuropathy (NAION)?

    OpenAIRE

    Lee, Andrew G.; Biousse, Valérie

    2010-01-01

    The treatment of nonarteritic anterior optic neuropathy remains very limited and disappointing. Recent publications have suggested that oral steroids as well as intravitreal injections of steroids might be helpful to accelerate resolution of disc edema and improve visual outcome. However, the use of steroids to treat acute NAION remains largely debated.

  14. Neuropatia óptica isquêmica anterior e poliarterite nodosa: relato de caso Anterior ischemic optic neuropathy and polyarteritis nodosa: case report

    OpenAIRE

    Christie Michelle Graf; Thelma Larocca Skare; Carlos Augusto Moreira

    2006-01-01

    Descreve-se uma paciente com diagnóstico de poliarterite nodosa, em tratamento com citostáticos e corticosteróides que desenvolveu neuropatia óptica isquêmica anterior, uma manifestação considerada bastante rara para esta doença.We describe a patient with polyarteritis nodosa being treated with cytostatics and corticosteroids who developed an anterior ischemic optic neuropathy, a rare manifestation of this pathology.

  15. Neuropatia óptica isquêmica anterior e poliarterite nodosa: relato de caso Anterior ischemic optic neuropathy and polyarteritis nodosa: case report

    Directory of Open Access Journals (Sweden)

    Christie Michelle Graf

    2006-02-01

    Full Text Available Descreve-se uma paciente com diagnóstico de poliarterite nodosa, em tratamento com citostáticos e corticosteróides que desenvolveu neuropatia óptica isquêmica anterior, uma manifestação considerada bastante rara para esta doença.We describe a patient with polyarteritis nodosa being treated with cytostatics and corticosteroids who developed an anterior ischemic optic neuropathy, a rare manifestation of this pathology.

  16. Retinal Blood Vessel Segmentation with Optic Disc Pixels Exclusion

    Directory of Open Access Journals (Sweden)

    Randy Cahya Wihandika

    2013-06-01

    Full Text Available The morphological changes of retinal blood vessels are important indicators used to diagnose and monitor the progression of various diseases. A number of retinal blood vessel segmentation methods have been introduced, including the line operator based methods, which have shown satisfactory results. However, the basic line operator method cannot discriminate the pixels around the retinal optic disc, resulting in false classification of those pixels. In this paper, we integrate the detection of pixels around the retinal optic disc to the line operator method so that those pixels can be excluded from the vessel pixels. The method is evaluated on the widely used retinal dataset, the DRIVE dataset. The results demonstrate that the proposed method has made improvements over the basic and the multi-scale line detector with accuracy and area under curve of 0.942 and 0.9521, respectively.

  17. Automatic optic disc segmentation based on image brightness and contrast

    Science.gov (United States)

    Lu, Shijian; Liu, Jiang; Lim, Joo Hwee; Zhang, Zhuo; Tan, Ngan Meng; Wong, Wing Kee; Li, Huiqi; Wong, Tien Yin

    2010-03-01

    Untreated glaucoma leads to permanent damage of the optic nerve and resultant visual field loss, which can progress to blindness. As glaucoma often produces additional pathological cupping of the optic disc (OD), cupdisc- ratio is one measure that is widely used for glaucoma diagnosis. This paper presents an OD localization method that automatically segments the OD and so can be applied for the cup-disc-ratio based glaucoma diagnosis. The proposed OD segmentation method is based on the observations that the OD is normally much brighter and at the same time have a smoother texture characteristics compared with other regions within retinal images. Given a retinal image we first capture the ODs smooth texture characteristic by a contrast image that is constructed based on the local maximum and minimum pixel lightness within a small neighborhood window. The centre of the OD can then be determined according to the density of the candidate OD pixels that are detected by retinal image pixels of the lowest contrast. After that, an OD region is approximately determined by a pair of morphological operations and the OD boundary is finally determined by an ellipse that is fitted by the convex hull of the detected OD region. Experiments over 71 retinal images of different qualities show that the OD region overlapping reaches up to 90.37% according to the OD boundary ellipses determined by our proposed method and the one manually plotted by an ophthalmologist.

  18. [Techniques for preparing postmortem human eyes to perform anterior segment intraocular surgery].

    Science.gov (United States)

    Vargas, L G; Werner, L; Pandey, S K; Werner, L P; Schmidbauer, J M; Zuleta, V; Escobar-Gómez, M; Apple, D J

    2003-02-01

    We describe different methods to prepare postmortem human or animal eyes used at the Center for Research in Ocular Therapeutics and Biodevices at the Storm Eye Institute, Medical University of South Carolina, Charleston, SC, USA. These techniques have been utilized for performing different surgical procedures (phacoemulsification, extracapsular cataract extraction, etc.), and for training of surgeons in-transition. Performing these techniques in the wet-laboratory contributed to improve surgical skills to perform the critical steps of the phacoemulsification surgery. Pathological evaluation of pseudophakic postmortem human eyes using the Miyake-Apple posterior view and histology was helpful to analyze postoperative complications of cataract surgery (anterior capsule opacification and posterior capsule opacification) secondary to postoperative proliferation of lens epithelial cells into the capsular bag. Modifications in the surgical techniques and/or lens design may be helpful to reduce these postoperative complications. Implantation of various aphakic and phakic intraocular lenses in postmortem human eyes as well as animal eyes was helpful to analyze the sizing and fitting of new lens designs within the eye. PMID:12647248

  19. Anaesthesia in various anterior segment complications of sub-Tenon surgeries

    International Nuclear Information System (INIS)

    Objective: The sub-Tenon's space is a potential space between the capsule and the sclera. This study evaluated complications from sub-Tenon's anaesthesia in different corneal and anterior chamber ophthalmic surgical procedures. Methods: The prospective cross-sectional study was carried out at the Baqai Medical University, Karachi, from March 2010 to August 2011, and comprised 149 patients for various minor and major intraocular surgeries. All the patients were operated under sub-Tenon is anaesthesia, administered in the inferio-nasal quadrant with a 19G cannula. Their complications were noted on a specific proforma. Data was analysed for frequencies of complications. SPSS 13 was used for statistical analysis. Results: There were 82 (55%) males and 67 (45%) females who underwent surgery. There were 89 (59.7%) right eyes and 60 (40%) left eyes. The commonest surgery was phaco-emulsification (n=79; 53%), followed by extracapsular cataract extraction with intraocular lens implantation (n=33; 22.1%). Subconjuctival haemorrhage (n=75; 50.3%) was the commonest complication, and the least common was pain during injection (n=9; 6%). Conclusion: There was no incidence of life-threatening or sight-threatening complications. The procedure was almost pain free and can be simply, safely and effectively given by the beginners with due precautions. (author)

  20. Extended coherence length megahertz FDML and its application for anterior segment imaging

    OpenAIRE

    Wieser, Wolfgang; Klein, Thomas; Adler, Desmond C.; Trépanier, Francois; Eigenwillig, Christoph M.; Karpf, Sebastian; Schmitt, Joseph M.; Huber, Robert

    2012-01-01

    We present a 1300 nm Fourier domain mode locked (FDML) laser for optical coherence tomography (OCT) that combines both, a high 1.6 MHz wavelength sweep rate and an ultra-long instantaneous coherence length for rapid volumetric deep field imaging. By reducing the dispersion in the fiber delay line of the FDML laser, the instantaneous coherence length and hence the available imaging range is approximately quadrupled compared to previously published MHz-FDML setups, the imaging speed is increase...

  1. Instrumentation of a new direction sensitive segmented optical module

    International Nuclear Information System (INIS)

    An efficiency increase in the intermediate energy region for an underwater neutrino telescope could be an important development to gain better sensitivity in the study of the physical processes concerning the deep universe and to have a useful tool for better detector calibration with atmospheric neutrinos. A new, direction sensitive, segmented optical module (OM) is under development in Genova, in the framework of the NEMO experiment, part of the KM3NET European network. According to preliminary simulations, this kind of device can-together with a dedicated track reconstruction strategy-improve by a significant factor the telescope sensitivity at low and intermediate energies. This OM will feature a newly developed 10 in. Hamamatsu 4-anode photomultiplier (PMT) coupled to dedicated electronics to be integrated in the NEMO readout chain. The first directional OMs will be installed at the NEMO test site during the preliminary phase of the experiment.

  2. Anterior Ischaemic Optic Neuropathy in Patient with Rheumatoid Arthritis – Case Report

    OpenAIRE

    Perić, S; Cerovski, B.; Perić, P.

    2001-01-01

    This case report presents a patient with long-lasting rheumatoid arthritis (RA) of fourth clinical grade, having ocular complications. RA was diagnosed according to current modified ARA criteria from 1987. Upon admission to the Department of Ophthalmology clinical examination revealed anterior ischaemic optic neuropathy (AION), which is not characteristic manifestation of RA in the eye. The occurrence of AION in patients with RA has been explained in literature as a secondary m...

  3. Bilateral Simultaneous Nonarteritic Anterior Ischemic Optic Neuropathy after Ingestion of Sildenafil for Erectile Dysfunction

    OpenAIRE

    Anna Tarantini; Alessandra Faraoni; Francesca Menchini; Paolo Lanzetta

    2012-01-01

    Purpose. To describe a patient who developed bilateral, simultaneous nonarteritic anterior ischemic optic neuropathy (NAION) after ingestion of Sildenafil citrate (Viagra) for erectile dysfunction. Methods. Observational case report. Results. A 60-year-old diabetic man noted sudden decrease of vision in both eyes 16 hours after his third consecutive 50 mg daily Sildenafil ingestion. A diagnosis of bilateral NAION was made and he was treated for three days with methylprednisolone 1 g/d intrave...

  4. Efficacy of Optical Internal Urethrotomy and Intralesional Injection of Vatsala-Santosh PGI Tri-Inject (Triamcinolone, Mitomycin C, and Hyaluronidase in the Treatment of Anterior Urethral Stricture

    Directory of Open Access Journals (Sweden)

    Santosh Kumar

    2014-01-01

    Full Text Available Purpose. To study the efficacy of optical internal urethrotomy with intralesional injection of Vatsala-Santosh PGI tri-inject (triamcinolone, mitomycin C, and hyaluronidase in the treatment of anterior urethral stricture. Material and Methods. A total of 103 patients with symptomatic anterior urethral stricture were evaluated on the basis of clinical history, physical examination, uroflowmetry, and retrograde urethrogram preoperatively. All patients were treated with optical internal urethrotomy followed by injection of tri-inject at the urethrotomy site. Tri-inject was prepared by diluting the combination of triamcinolone 40 mg, mitomycin C 2 mg, and hyaluronidase 3000 in 5–10 mL of saline according to length of stricture. An indwelling 18 Fr silicone catheter was left in place for a period of 7–21 days. All patients were followed up for 6–18 months postoperatively on the basis of history, uroflowmetry, and, if required, retrograde urethrogram and micturating urethrogram every 3 months. Results. The overall recurrence rate after first OIU is 19.4% (20 out of 103 patients, that is, a success rate of 80.6%. Overall recurrence rate after second procedure was 5.8% (6 out of 103 patients, that is, a success rate of 94.2%. Conclusion. Optical internal urethrotomy with intralesional injection of Vatsala-Santosh PGI tri-inject (triamcinolone, mitomycin C, and hyaluronidase is a safe and effective minimally invasive therapeutic modality for short segment anterior urethral strictures.

  5. Anterior maxillary segmental distraction in the treatment of severe maxillary hypoplasia secondary to cleft lip and palate

    Science.gov (United States)

    Li, Hongliang; Dai, Jiewen; Si, Jiawen; Zhang, Jianfei; Wang, Minjiao; Shen, Steve Guofang; Yu, Hongbo

    2015-01-01

    Anterior maxillary segmental distraction (AMSD) is an effective surgical procedure in the treatment of maxillary hypoplasia secondary to cleft lip and palate. Its unique advantage of preserving velopharyngeal function makes this procedure widely applied. In this study, the application of AMSD was described and its long-term stability was explored. Eight patients with severe maxillary hypoplasia secondary to CLP were included in this study. They were treated with AMSD using rigid external distraction (RED) device. Cephalometric analysis was performed twice at three time points for evaluation: before surgery (T1), after distraction (T2), and 2 years after treatment (T3). One-way analysis of variance was used to assess the differences statistically. All the distractions completed smoothly, and maxilla was distracted efficiently. The value of SNA, NA-FH, Ptm-A, U1-PP, overjet and PP (ANS-PNS) increased significantly after the AMSD procedure (P 0.05). Changes of palatopharyngeal depth and soft palatal length were insignificant. AMSD with RED device provided an effective way to correct maxillary hypoplasia secondary to CLP, extended the palatal and arch length, avoided damage on velopharyngeal closure function and reduced the relapse rate. It is a promising and valuable technique in this potentially complicated procedure. PMID:26629107

  6. Application of a stand-alone anchored spacer in noncontiguous anterior cervical arthrodesis with radiologic analysis of the intermediate segment.

    Science.gov (United States)

    Shi, Sheng; Liu, Zu-De; You, Wen-Jie; Ouyang, Yue-Ping; Li, Xin-Feng; Qian, Lie; Zhong, Gui-Bin

    2016-03-01

    The purpose of this study was to describe the clinical features of noncontiguous cervical degenerative disc disease (cDDD), investigate the efficacy and complications of a stand-alone anchored spacer (SAAS) for patients with noncontiguous cDDD, and present radiologic analysis of the intermediate segment (IS) after skip-level fusion. Nineteen consecutive patients with noncontiguous cDDD who underwent skip-level anterior cervical discectomy and fusion (ACDF) with SAAS from January 2010 to December 2012 were enrolled in this study. Clinical outcomes were assessed preoperatively and at 24 months postoperatively using the Japanese Orthopaedic Association score, Neck Disability Index, and Visual Analog Scale. Overall cervical alignment (OCA) of the cervical spine, and the range of motion (ROM), intervertebral disc height (IDH), disc signal intensity and disc protrusion of IS were measured and compared before and after surgery. Clinical outcomes significantly improved compared to preoperative scores. The OCA was corrected and maintained at 24 months postoperatively compared with preoperative values (p0.05). However, decreased signal intensity on T2-weighted MRI was evidenced in three mobile IS at final follow-up (20.0%). Skip-level ACDF with SAAS may be an efficacious option for the treatment of noncontiguous cDDD. PMID:26597607

  7. Coating Thin Mirror Segments for Lightweight X-ray Optics

    Science.gov (United States)

    Chan, Kai-Wing; Sharpe, Marton V.; Zhang, William; Kolosc, Linette; Hong, Melinda; McClelland, Ryan; Hohl, Bruce R.; Saha, Timo; Mazzarellam, James

    2013-01-01

    Next generations lightweight, high resolution, high throughput optics for x-ray astronomy requires integration of very thin mirror segments into a lightweight telescope housing without distortion. Thin glass substrates with linear dimension of 200 mm and thickness as small as 0.4 mm can now be fabricated to a precision of a few arc-seconds for grazing incidence optics. Subsequent implementation requires a distortion-free deposition of metals such as iridium or platinum. These depositions, however, generally have high coating stresses that cause mirror distortion. In this paper, we discuss the coating stress on these thin glass mirrors and the effort to eliminate their induced distortion. It is shown that balancing the coating distortion either by coating films with tensile and compressive stresses, or on both sides of the mirrors is not sufficient. Heating the mirror in a moderately high temperature turns out to relax the coated films reasonably well to a precision of about a second of arc and therefore provide a practical solution to the coating problem.

  8. Large-scale segmentation errors in optical gratings and their unique effect onto optical scattering spectra

    Science.gov (United States)

    Heusinger, Martin; Flügel-Paul, Thomas; Zeitner, Uwe-Detlef

    2016-08-01

    In this paper, we analyze the influence of large-scale segmentation errors in the morphology of high-performance optical gratings. It is thus assumed that the optical grating under consideration (typical lateral extends S are 10-1000 mm) can be spatially decomposed into a great many but unique sub-segments (≪ S; typical extends are 10-100 μm). Any violation of the perfect periodicity will result in the generation of stray light, especially Rowland ghosts, which radiate into a small angular region around the grating's diffraction orders. In this paper, we focus on three different kinds of segmentation errors. On the one hand, there are statistic as well as deterministic alignment errors between otherwise perfect sub-segments. On the other hand, we analyze the effect of chirping of geometrical parameters, i.e., the groove width, within every sub-segment. Most importantly, we find that the particular type of imperfection results in a unique characteristic of the according stray light spectrum which thus acts as a fingerprint. We come to this conclusion on three different ways. First, we rely on a simple theoretical model that is based on scalar diffraction theory. Second, we have performed rigorous numerical simulations for a high aspect ratio purely dielectric spectrometer grating (period = {667} nm). Third, the very same grating was then fabricated by e-beam lithography and its stray light spectrum was measured with a purposely designed optical setup. Eventually, all different routes to analyze the problem turn out to be in very good agreement, and we are confident that stray light measurements can be used as an important tool in the detection of fabrication imperfections.

  9. Automatic segmentation of the optic nerve head for deformation measurements in video rate optical coherence tomography

    Science.gov (United States)

    Hidalgo-Aguirre, Maribel; Gitelman, Julian; Lesk, Mark Richard; Costantino, Santiago

    2015-11-01

    Optical coherence tomography (OCT) imaging has become a standard diagnostic tool in ophthalmology, providing essential information associated with various eye diseases. In order to investigate the dynamics of the ocular fundus, we present a simple and accurate automated algorithm to segment the inner limiting membrane in video-rate optic nerve head spectral domain (SD) OCT images. The method is based on morphological operations including a two-step contrast enhancement technique, proving to be very robust when dealing with low signal-to-noise ratio images and pathological eyes. An analysis algorithm was also developed to measure neuroretinal tissue deformation from the segmented retinal profiles. The performance of the algorithm is demonstrated, and deformation results are presented for healthy and glaucomatous eyes.

  10. Comparison of the Deep Optic Nerve Head Structure between Normal-Tension Glaucoma and Nonarteritic Anterior Ischemic Optic Neuropathy

    Science.gov (United States)

    Kim, Tae-Woo; Hwang, Jeong-Min

    2016-01-01

    Purpose To compare the deep optic nerve head (ONH) structure between normal-tension glaucoma (NTG) and nonarteritic anterior ischemic optic neuropathy (NAION) and also in healthy subjects as a control using enhanced depth imaging (EDI) spectral-domain optical coherence tomography (SD-OCT). Methods This prospective cross-sectional study included 21 NAION patients who had been diagnosed as NAION at least 6 months prior to study entry, and 42 NTG patients and 42 healthy controls who were matched with NAION patients in terms of age, intraocular pressure (IOP), and optic disc area. The retinal nerve fiber layer (RNFL) thickness in the affected sector was also matched between NAION and NTG patients. The ONH was imaged using SD-OCT with the EDI technique. The anterior lamina cribrosa surface depth (LCD) and average prelaminar tissue (PT) thickness were measured in a sector of interest in each eye and compared among the three groups. Results In the sector-matched comparison, LCD was largest in NTG patients, followed by NAION patients, while PT was thinner in NTG patients than in NAION patients (all P < 0.001). NAION patients had a comparable LCD and a thinner PT relative to normal controls (P = 0.170 and < 0.001, respectively). Conclusion The deep ONH configuration is strikingly different between NTG and NAION. The differing features provide comparative insight into the pathophysiology of the two diseases, and may be useful for differential diagnosis. PMID:27035660

  11. Comparison of Physiologic versus Pharmacologic Mydriasis on Anterior Chamber Angle Measurements Using Spectral Domain Optical Coherence Tomography.

    Science.gov (United States)

    Dastiridou, Anna I; Pan, Xiaojing; Zhang, ZhouYuan; Marion, Kenneth M; Francis, Brian A; Sadda, Srinivas R; Chopra, Vikas

    2015-01-01

    Purpose. To compare the effects of physiologic versus pharmacologic pupil dilation on anterior chamber angle (ACA) measurements obtained with spectral domain optical coherence tomography (SD-OCT). Methods. Forty eyes from 20 healthy, phakic individuals with open angles underwent anterior segment OCT imaging under 3 pupillary states: (1) pupil constricted under standard room lighting, (2) physiologic mydriasis in a darkened room, and (3) postpharmacologic mydriasis. Inferior angle Schwalbe's line-angle opening distance (SL-AOD) and SL-trabecular-iris-space area (SL-TISA) were computed for each eye and pupillary condition by masked, certified Reading Center graders using customized grading software. Results. SL-AOD and SL-TISA under pupillary constriction to room light were 0.87 ± 0.31 mm and 0.33 ± 0.14 mm(2), respectively; decreased to 0.75 ± 0.29 mm (P < 0.01) and 0.29 ± 0.13 mm(2)  (P < 0.01), respectively, under physiologic mydriasis; and increased to 0.90 ± 0.38 mm (P < 0.01) and 0.34 ± 0.17 mm(2)  (P = 0.06) under pharmacologic mydriasis compared to baseline. Conclusions. Using SD-OCT imaging, pharmacologic mydriasis yielded the widest angle opening, whereas physiologic mydriasis yielded the most angle narrowing in normal individuals with open iridocorneal angles. Accounting for the state of the pupil and standardizing the lighting condition would appear to be of importance for future studies of the angle. PMID:25878896

  12. Comparison of Physiologic versus Pharmacologic Mydriasis on Anterior Chamber Angle Measurements Using Spectral Domain Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Anna I. Dastiridou

    2015-01-01

    Full Text Available Purpose. To compare the effects of physiologic versus pharmacologic pupil dilation on anterior chamber angle (ACA measurements obtained with spectral domain optical coherence tomography (SD-OCT. Methods. Forty eyes from 20 healthy, phakic individuals with open angles underwent anterior segment OCT imaging under 3 pupillary states: (1 pupil constricted under standard room lighting, (2 physiologic mydriasis in a darkened room, and (3 postpharmacologic mydriasis. Inferior angle Schwalbe’s line-angle opening distance (SL-AOD and SL-trabecular-iris-space area (SL-TISA were computed for each eye and pupillary condition by masked, certified Reading Center graders using customized grading software. Results. SL-AOD and SL-TISA under pupillary constriction to room light were 0.87±0.31 mm and 0.33±0.14 mm2, respectively; decreased to 0.75±0.29 mm P<0.01 and 0.29±0.13 mm2  P<0.01, respectively, under physiologic mydriasis; and increased to 0.90±0.38 mm P<0.01 and 0.34±0.17 mm2  P=0.06 under pharmacologic mydriasis compared to baseline. Conclusions. Using SD-OCT imaging, pharmacologic mydriasis yielded the widest angle opening, whereas physiologic mydriasis yielded the most angle narrowing in normal individuals with open iridocorneal angles. Accounting for the state of the pupil and standardizing the lighting condition would appear to be of importance for future studies of the angle.

  13. Strain gauge ambiguity sensor for segmented mirror active optical system

    Science.gov (United States)

    Wyman, C. L.; Howe, T. L. (Inventor)

    1974-01-01

    A system is described to measure alignment between interfacing edges of mirror segments positioned to form a segmented mirror surface. It serves as a gauge having a bending beam with four piezoresistive elements coupled across the interfaces of the edges of adjacent mirror segments. The bending beam has a first position corresponding to alignment of the edges of adjacent mirror segments, and it is bendable from the first position in a direction and to a degree dependent upon the relative misalignment between the edges of adjacent mirror segments to correspondingly vary the resistance of the strain guage. A source of power and an amplifier are connected in circuit with the strain gauge whereby the output of the amplifier varies according to the misalignment of the edges of adjacent mirror segments.

  14. Reproducibility and Agreement Between 2 Spectral Domain Optical Coherence Tomography Devices for Anterior Chamber Angle Measurements

    OpenAIRE

    Marion, Kenneth M.; Maram, Jyotsna; Pan, Xiaojing; Dastiridou, Anna; Zhang, ZhouYuan; Ho, Alex; Francis, Brian A; Sadda, Srinivas R.; Chopra, Vikas

    2015-01-01

    Purpose: To compare anterior chamber angle parameters based on the location of Schwalbe line (SL) from 2 spectral domain optical coherence tomography (SD-OCT) instruments and to measure their reproducibility. Methods: Forty-two eyes from 21 normal, healthy participants underwent imaging of the inferior irido-corneal angle with the Spectralis and Cirrus SD-OCT under tightly controlled low-light conditions. SL-angle opening distance (SL-AOD) and SL-trabecular iris space area (SL-TISA) were meas...

  15. Use of Fourier-Domain Optical Coherence Tomography to Evaluate Anterior Stromal Opacities in Donor Corneas

    Directory of Open Access Journals (Sweden)

    Matthew R. Bald

    2013-01-01

    Full Text Available Purpose. To evaluate Fourier-domain optical coherence tomography (FD-OCT as an adjunct to traditional slit lamp examination of donor corneas with suspected Anterior Stromal Opacities. Methods. Seven corneas suspected of having anterior stromal opacities by slit lamp examination were evaluated with FD-OCT. Each cornea was evaluated to confirm the presence of opacity and, if present, the depth of opacity was measured. Results. The opacity depth ranged from 82 μm to 624 μm. The initial slit lamp impressions of five of the seven corneas were confirmed by OCT. In two corneas, the OCT findings were different from the initial slit lamp impressions. Slit lamp examination of the first cornea gave the impression of anterior stromal scarring, but OCT showed that the opacity was limited to the epithelium. Slit lamp examination of the second cornea suggested opacity limited to the epithelium, but OCT identified significant sub-Bowman's scarring. In all cases, the Eye Bank Technicians reported that the location and depth of corneal opacity were more sharply defined by OCT than by slit lamp. Conclusion. The high resolution of OCT makes it easier to determine the location of corneal opacities compared to slit lamp examinations. This enhanced visualization can improve decisions regarding transplant suitability of donor corneas.

  16. Perioperative Complications Prognosis Based on Local Neurocirculatory and Trophic Changes in the Anterior Eye Segment in Pseudoexfoliation Syndrome (Report II

    Directory of Open Access Journals (Sweden)

    A.V. Petrayevsky

    2009-03-01

    Full Text Available ABSTRACT Purpose To develop clinical method of prognosis of cataract surgery possible complications in pseudoexfoliation syndrome (PES patients convenient for routine practice of the ophthalmosurgeon. Material and methods We examined 111 patients (111 eyes between the ages of 58 and 76, who were operated for cataract. Of those, 66 patients (66 eyes had cataract combined with PES and 45 patients (45 eyes had cataract without PES signs. We used the following examination methods: visometry, eye anterior segment biomicroscopy with estimation of severity of iris trophic changes and pseudoexfoliation signs according to special classification schemes, computer tonography, ultrasonic biometry, ophthalmometry, vasotonometry in anterior ciliary arteries (ACA, and pupil cycle time (PCT calculation. The patients with cataract were operated by extracapsular extraction using corneal access in 60% of cases, and by mechanical phacofragmentation using scleral access in 40% of cases. All patients were implanted posterior chamber intraocular lenses (IOL. In the patients with cataract and PES we additionally used intracapsular extraction with implantation IOL RSP3 in 15% of cases. Results In operated patients, we recorded such complications of cataract sur gery as lens posterior capsule rupture, zonula fibers rupture, fibrinoidtype reactions, and postoperative ocular hypertension. The rate of complications was higher in PES patients (37,9% and lower in patients without PES (17,8%. An average PCT was 1840±82 ms in PES against 1186±35 ms without PES. ACA blood pressure in the PES-patients was 44,1±1,0 mm Hg against 53,1±0,98 mm Hg in the patients without PES. The rate of iris trophic changes was significantly higher in PES-patients than in the patients without PES. The rate of complications depended on frequency and severity of iris trophic changes and intensity of PES. Most of complicated cases were observed in the PES-patients with III–IV grade of PES

  17. Bilateral simultaneous nonarteritic anterior ischemic optic neuropathy in a patient with alcoholic liver disease

    Directory of Open Access Journals (Sweden)

    Shikha Talwar Bassi

    2014-01-01

    Full Text Available A 53-year-old man with a history of alcoholism since 10 years admitted for jaundice elsewhere developed bilateral simultaneous decrease in vision in both the eyes 4 days after admission. His best-corrected visual acuity was 20/20 in both eyes. Visual field evaluation revealed an inferior altitudinal defect in both the eyes. Optic disc appearance, visual fields, and optical coherence tomography of discs were suggestive of nonarteritic anterior ischemic optic neuropathy (NAION in both the eyes. Liver function tests revealed elevated serum bilirubin and hepatic enzymes. He was negative for hepatitis B virus (HBV and hepatitis C virus (HCV infection. Abdominal ultrasound revealed no focal hepatic lesion, and carotid doppler revealed no arteriosclerosis. A diagnosis of bilateral ischemic optic neuropathy associated with alcoholic hepatitis was made. Bilateral simultaneous NAION has been previously reported in perioperative visual loss, HCV infection, and interferon treatment. This is the first case report of bilateral simultaneous NAION in alcoholic hepatitis in the absence of associated infective viral hepatitis. We explore the pathophysiology of ischemic optic neuropathy in liver disease. An early intervention to correct the risk factors leading to NAION may help in preventing this vision-threatening complication in patients with chronic liver disease.

  18. Impact of Indocyanine Green Concentration, Exposure Time, and Degree of Dissolution in Creating Toxic Anterior Segment Syndrome: Evaluation in a Rabbit Model

    Science.gov (United States)

    Khoramnia, Ramin; Uwe Auffarth, Gerd

    2016-01-01

    Purpose. To investigate the role of indocyanine green (ICG) dye as a causative material of toxic anterior segment syndrome (TASS) in an experimental rabbit model. Method. Eight eyes of four rabbits were allocated to this study. Capsular staining was performed using ICG dye, after which the anterior chamber was irrigated with a balanced salt solution. The effects of different concentrations (control, 0.25, 0.5, and 1.0%), exposure times (10 and 60 seconds), and the degree of dissolution (differently vortexed) were investigated. The analysis involved anterior segment photography, ultrasound pachymetry, prostaglandin assay (PGE2 Parameter Assay, R&D systems, Inc.), and scanning electron microscopy of each iris. Result. There was no reaction in the control eye. A higher aqueous level of PGE2 and more severe inflammatory reaction were observed in cases of eyes with higher concentration, longer exposure time, and poorly dissolved dye. Additionally, scanning electron microscopy revealed larger and coarser ICG particles. Conclusion. TASS occurrence may be associated with the concentration, exposure time, and degree of dissolution of ICG dye during cataract surgery. PMID:27478634

  19. Automated segmentation of the optic disc from stereo color photographs using physiologically plausible features

    NARCIS (Netherlands)

    Abramoff, M.D.; Alward, W.L.M.; Greenlee, E.C.; Shuba, L.; Kim, Chan Y.; Fingert, J.H.; Kwon, Y.H.

    2007-01-01

    PURPOSE. To evaluate a novel automated segmentation algorithm for cup-to-disc segmentation from stereo color photographs of patients with glaucoma for the measurement of glaucoma progression. METHODS. Stereo color photographs of the optic disc were obtained by using a fixed stereo-base fundus camera

  20. The segmentation of the HMD market: optics for smart glasses, smart eyewear, AR and VR headsets

    Science.gov (United States)

    Kress, Bernard; Saeedi, Ehsan; Brac-de-la-Perriere, Vincent

    2014-09-01

    This paper reviews the various optical technologies that have been developed to implement HMDs (Head Mounted Displays), both as AR (Augmented Reality) devices, VR (Virtual Reality) devices and more recently as smart glasses, smart eyewear or connected glasses. We review the typical requirements and optical performances of such devices and categorize them into distinct groups, which are suited for different (and constantly evolving) market segments, and analyze such market segmentation.

  1. Segmentation of anterior cruciate ligament in knee MR images using graph cuts with patient-specific shape constraints and label refinement.

    Science.gov (United States)

    Lee, Hansang; Hong, Helen; Kim, Junmo

    2014-12-01

    We propose a graph-cut-based segmentation method for the anterior cruciate ligament (ACL) in knee MRI with a novel shape prior and label refinement. As the initial seeds for graph cuts, candidates for the ACL and the background are extracted from knee MRI roughly by means of adaptive thresholding with Gaussian mixture model fitting. The extracted ACL candidate is segmented iteratively by graph cuts with patient-specific shape constraints. Two shape constraints termed fence and neighbor costs are suggested such that the graph cuts prevent any leakage into adjacent regions with similar intensity. The segmented ACL label is refined by means of superpixel classification. Superpixel classification makes the segmented label propagate into missing inhomogeneous regions inside the ACL. In the experiments, the proposed method segmented the ACL with Dice similarity coefficient of 66.47±7.97%, average surface distance of 2.247±0.869, and root mean squared error of 3.538±1.633, which increased the accuracy by 14.8%, 40.3%, and 37.6% from the Boykov model, respectively. PMID:25305694

  2. A Case of Schizencephaly and Septo-Optic Dysplasia Presenting with Anterior Encephalocele

    Directory of Open Access Journals (Sweden)

    Kaveh FADAKAR

    2013-01-01

    Full Text Available How to cite this article: Fadakar K, Dadkhahfar S, Esmaeili A, Keyhanidoust Z. A Case of Schizencephaly and Septo-Optic Dysplasia Presenting with Anterior Encephalocele. Iran J Child Neurol Autumn 2012; 6(4:47-50. AbstractSchizencephaly is a rare central nervous system disorder with variable presentations. Here we report a patient with a huge bilateral schizencephaly and septo-optic dysplasia presenting with anterior encephalocele. References:Yakovlev PI, Wadsworth RC. Schizencephalies; a study of the congenital clefts in the cerebral mantle; clefts with hydrocephalus and lips separated. J Neuropathol Exp Neurol. 1946 Jul;5(3:169-206.Yakovlev PI, Wadsworth RC. Schizencephalies; a study of the congenital clefts in the cerebral mantle; clefts with fused lips. J Neuropathol Exp Neurol. 1946 Apr;5:116-30.Brunelli S, Faiella A, Capra V, Nigro V, Simeone A,Cama A et al. Germline mutations in the homeobox gene EMX2 in patients with severe schizencephaly. Nat Genet. 1996 Jan;12(1:94-6.Montenegro MA, Guerreiro MM, Lopes-Cendes I,Guerreiro CA, Cendes F. Interrelationship of genetics and prenatal injury in the genesis of malformations of cortical development. Arch Neurol. 2002 Jul;59(7:1147-53.Granata T, Freri E, Caccia C, Setola V, Taroni F,Battaglia G. Schizencephaly: clinical spectrum, epilepsy, and pathogenesis. J Child Neurol. 2005 Apr;20(4:313-8.Lee HK, Kim JS, Hwang YM, Lee MJ, Choi CG, Suh DC et al. Location of the primary motor cortex in schizencephaly. AJNR Am J Neuroradiol. 1999 Jan;20(1:163-6.De Morsier G. [Studies on malformation of cranio-encephalic sutures. III. Agenesis of the septum lucidum with malformation of the optic tract]. Schweiz Arch Neurol Psychiatr. 1956;77(1:267-92.Hoyt WF, Kaplan SL, Grumbach MM, Glaser JS. Septo-optic dysplasia and pituitary dwarfism. Lancet. 1970 Apr;1(7652:893-4.Webb EA, Dattani MT. Septo-optic dysplasia. Eur J Hum Genet. 2010 Apr;18(4:393-7.Ellenberger C Jr, Runyan TE

  3. Length-adaptive graph search for automatic segmentation of pathological features in optical coherence tomography images

    Science.gov (United States)

    Keller, Brenton; Cunefare, David; Grewal, Dilraj S.; Mahmoud, Tamer H.; Izatt, Joseph A.; Farsiu, Sina

    2016-07-01

    We introduce a metric in graph search and demonstrate its application for segmenting retinal optical coherence tomography (OCT) images of macular pathology. Our proposed "adjusted mean arc length" (AMAL) metric is an adaptation of the lowest mean arc length search technique for automated OCT segmentation. We compare this method to Dijkstra's shortest path algorithm, which we utilized previously in our popular graph theory and dynamic programming segmentation technique. As an illustrative example, we show that AMAL-based length-adaptive segmentation outperforms the shortest path in delineating the retina/vitreous boundary of patients with full-thickness macular holes when compared with expert manual grading.

  4. THE RHEO-OPTICAL FTIR STUDY OF POLYESTER-POLYETHER SEGMENTED COPOLYMER

    Institute of Scientific and Technical Information of China (English)

    WEN Zaiqing; SHEN Deyan; ZHAO Hengqi

    1988-01-01

    The polyester-polyether segmented copolymer has been investigated by rheo-optical FTIR during stretching for the information on strain induced crystallization of soft segment chains, hard and soft chain orientation.At room temperature 15℃, the soft segment chains of polyester-polyether being to crystallize at 220% strain and the degree of crystallization increase with draw ratio, but there will not be any soft segment chains crystallization above 21℃ even at higher strain. The average orientation of hard segment chains are higher than that of the soft chain at high strain level, both are positive oriented into the stretching direction at allover strain level. This indicates that the hard segment chains are dispersed into the elastomeric phase and without forming spherulite.

  5. Bilateral Simultaneous Nonarteritic Anterior Ischemic Optic Neuropathy after Ingestion of Sildenafil for Erectile Dysfunction

    Science.gov (United States)

    Tarantini, Anna; Faraoni, Alessandra; Menchini, Francesca; Lanzetta, Paolo

    2012-01-01

    Purpose. To describe a patient who developed bilateral, simultaneous nonarteritic anterior ischemic optic neuropathy (NAION) after ingestion of Sildenafil citrate (Viagra) for erectile dysfunction. Methods. Observational case report. Results. A 60-year-old diabetic man noted sudden decrease of vision in both eyes 16 hours after his third consecutive 50 mg daily Sildenafil ingestion. A diagnosis of bilateral NAION was made and he was treated for three days with methylprednisolone 1 g/d intravenously, followed by oral prednisone 75 mg/d. Final visual acuity was 20/50 right eye (OD) and 20/20 left eye (OS). He had preexisting diabetes. Conclusion. This is the first reported case of simultaneous bilateral NAION occurred in a diabetic patient early after Sildenafil intake. Patients with predisposing conditions such as diabetes have to be warned against the use of PDE inhibitors. PMID:22481954

  6. A NEW DECODER OF SYNCHRONOUS OPTICAL CODE DIVISION MULTIPLE ACCESS SYSTEMS USING SEGMENTED CORRELATION

    Institute of Scientific and Technical Information of China (English)

    Li Ou; Wu Jiangxing; Lan Julong

    2001-01-01

    A new segmented correlating decoder of synchronous optical CDMA using modified prime sequence codes is proposed. The performance of the proposed system is analyzed under the assumption of Poisson shot noise model for the receiver photodetector. The decoder technique is shown to be more effective to improve the bit error probability performance than the method using an optical hard-limiter.

  7. Development of Extended-Depth Swept Source Optical Coherence Tomography for Applications in Ophthalmic Imaging of the Anterior and Posterior Eye

    Science.gov (United States)

    Dhalla, Al-Hafeez Zahir

    Optical coherence tomography (OCT) is a non-invasive optical imaging modality that provides micron-scale resolution of tissue micro-structure over depth ranges of several millimeters. This imaging technique has had a profound effect on the field of ophthalmology, wherein it has become the standard of care for the diagnosis of many retinal pathologies. Applications of OCT in the anterior eye, as well as for imaging of coronary arteries and the gastro-intestinal tract, have also shown promise, but have not yet achieved widespread clinical use. The usable imaging depth of OCT systems is most often limited by one of three factors: optical attenuation, inherent imaging range, or depth-of-focus. The first of these, optical attenuation, stems from the limitation that OCT only detects singly-scattered light. Thus, beyond a certain penetration depth into turbid media, essentially all of the incident light will have been multiply scattered, and can no longer be used for OCT imaging. For many applications (especially retinal imaging), optical attenuation is the most restrictive of the three imaging depth limitations. However, for some applications, especially anterior segment, cardiovascular (catheter-based) and GI (endoscopic) imaging, the usable imaging depth is often not limited by optical attenuation, but rather by the inherent imaging depth of the OCT systems. This inherent imaging depth, which is specific to only Fourier Domain OCT, arises due to two factors: sensitivity fall-off and the complex conjugate ambiguity. Finally, due to the trade-off between lateral resolution and axial depth-of-focus inherent in diffractive optical systems, additional depth limitations sometimes arises in either high lateral resolution or extended depth OCT imaging systems. The depth-of-focus limitation is most apparent in applications such as adaptive optics (AO-) OCT imaging of the retina, and extended depth imaging of the ocular anterior segment. In this dissertation, techniques for

  8. Three-dimensional choroidal segmentation in spectral OCT volumes using optic disc prior information

    Science.gov (United States)

    Hu, Zhihong; Girkin, Christopher A.; Hariri, Amirhossein; Sadda, SriniVas R.

    2016-03-01

    Recently, much attention has been focused on determining the role of the peripapillary choroid - the layer between the outer retinal pigment epithelium (RPE)/Bruchs membrane (BM) and choroid-sclera (C-S) junction, whether primary or secondary in the pathogenesis of glaucoma. However, the automated choroidal segmentation in spectral-domain optical coherence tomography (SD-OCT) images of optic nerve head (ONH) has not been reported probably due to the fact that the presence of the BM opening (BMO, corresponding to the optic disc) can deflect the choroidal segmentation from its correct position. The purpose of this study is to develop a 3D graph-based approach to identify the 3D choroidal layer in ONH-centered SD-OCT images using the BMO prior information. More specifically, an initial 3D choroidal segmentation was first performed using the 3D graph search algorithm. Note that varying surface interaction constraints based on the choroidal morphological model were applied. To assist the choroidal segmentation, two other surfaces of internal limiting membrane and innerouter segment junction were also segmented. Based on the segmented layer between the RPE/BM and C-S junction, a 2D projection map was created. The BMO in the projection map was detected by a 2D graph search. The pre-defined BMO information was then incorporated into the surface interaction constraints of the 3D graph search to obtain more accurate choroidal segmentation. Twenty SD-OCT images from 20 healthy subjects were used. The mean differences of the choroidal borders between the algorithm and manual segmentation were at a sub-voxel level, indicating a high level segmentation accuracy.

  9. Assessment of Anterior Segment Changes in Pseudophakic Eyes, Using Ultrasonic Biomicroscopic Imaging, after Pars Plana Vitrectomy with Silicone Oil or Gas Tamponade

    Science.gov (United States)

    Kızılay, Osman

    2016-01-01

    Objective. To evaluate the morphological changes of the anterior segment using ultrasonic biomicroscopy (UBM) imaging in pseudophakic patients who underwent pars plana vitrectomy (PPV) with silicone oil or gas (C3F8) internal tamponade agent injection. Method. This prospective study included pseudophakic patients with planned PPV, divided into two groups according to internal tamponade agent: those in which silicone oil was used (n = 27, Group 1) and those in which gas (C3F8) was used (n = 24, Group 2). UBM measurements were performed in the supine position before and one week after surgery. Results. In patients of Group 1, postoperative trabecular meshwork-ciliary process distance (T-CPD) and iris-ciliary process distance (I-CPD), according to preoperative values, were found to be statistically significantly reduced, and postoperative mean value of scleral thickness (ST) and intraocular pressure (IOP), according to preoperative value, was found to be statistically significantly increased. In patients of Group 2, postoperative mean values of anterior chamber depth (ACD), ciliary body thickness (CBT), T-CPD, I-CPD, and IOP, according to preoperative values, were found to be statistically significantly reduced. Preoperatively, in Group 2 patients, according to Group 1 patients, TIA and IOP were found to be statistically significantly increased. Preoperative and postoperative IOP between the measured parameters with UBM showed no statistically significant correlation. Conclusions. Gases cause more morphological changes in the anterior segment structures. It is thought that complications such as increased intraocular pressure can be seen more frequently for this reason. PMID:27298733

  10. An optical approach to validate ultrasound surface segmentation of the heart

    Science.gov (United States)

    Wang, Bo; Schlaefer, Alexander; Zhang, Zhenxi

    2014-09-01

    The patient specific geometry of the heart is of interest for a number of diagnostic methods, e.g., when modeling the inverse electrocardiography (ECG) problem. One approach to get images of the heart is three-dimensional ultrasound. However, segmentation of the surface is complicated and segmentation methods are typically validated against manually drawn contours. This requires considerable expert knowledge. Hence, we have developed a setup that allows studying the accuracy of image segmentation from cardiac ultrasound. Using an optical tracking system, we have measured the three-dimensional surface of an isolated porcine heart. We studied whether the actual geometry can be reconstructed from both optical and ultrasound images. We illustrate the use of our approach in quantifying the segmentation result for a three-dimensional region-based active contour algorithm.

  11. Arteritic anterior ischemic optic neuropathy associated with chronic myelomonocytic leukemia (CMML: A case report

    Directory of Open Access Journals (Sweden)

    Miriam García Fernández

    2015-02-01

    Full Text Available Introduction: Ocular involvement in patients with CMML is rarely reported, owing in part to the fact that the severe illness faced by many of these patients limits the feasibility of ocular examinations. Nevertheless, post-mortem examination of the eyes of patients without ophthalmological symptoms and diagnosis of CMML, has revealed ocular infiltration of atypical cells. Case report: A 72-year-old man presented with two days of left-sided blurring of vision and an episode of transient visual obscuration associated to periorbitary pain. A relative afferent pupillary defect was present in the LE. Fundus examination revealed optic disc swelling in LE. The erythrocyte sedimentation rate (ESR was 120 mm (1st hour and C-reactive protein was 7.8. Complementary examinations yielded normal findings. A presumptive diagnosis of arteritic anterior ischemic optic neuropathy (AAION was made. Treatment with endovenous bolus of methylprednisolone, followed by slow-tapering of oral steroids, was started, without improvement. Temporal artery biopsy confirmed the diagnosis. Conclusions: To our knowledge, this is the second case in peer-reviewed literature reporting the association between AAION and CMML. A possible explanation is the fact that small vessel vasculitis, of unclear pathogenesis so far, complicates approximately 10% of CMML and presents as cutaneous vasculitis and lupus-like syndromes. Therefore, this may be in relation with the vasculitis of the short posterior ciliary arteries which happens in cases of AAION.

  12. Central Corneal Thickness Measurements in Nonarteritic Anterior Ischemic Optic Neuropathy Patients: A Controlled Study

    Directory of Open Access Journals (Sweden)

    Haneen Jabaly-Habib

    2014-01-01

    Full Text Available Purpose. To measure central corneal thickness (CCT in patients with history of nonarteritic anterior ischemic optic neuropathy (NAION. Patients and Methods. Patients older than 40 years with a history of NAION (group 1 were prospectively evaluated including full eye examination and central corneal thickness (CCT pachymetry. Patients with a history of intraocular surgery, corneal disease, glaucoma, and contact lens wear were excluded. Measurements were also performed in a gender and age matched control group (group 2. Results. Thirty-one eyes of 31 NAION patients in group 1 were included and 30 eyes of 30 participants in group 2. There were 15 men in group 1 and 9 in group 2 P=0.141, and mean age of the patients was 59±10 years in group 1 versus 61±11 years in group 2 P=0.708. Mean CCT was 539±30 microns in group 1 and 550±33 microns in group 2 P=0.155. Conclusion. Patients with NAION have no special characteristic of CCT in contrast to the crowded optic disc known to be a significant anatomic risk factor for NAION. More studies should be carried out to investigate CCT and other structure related elements in NAION patients.

  13. Segmented X-Ray Optics for Future Space Telescopes

    Science.gov (United States)

    McClelland, Ryan S.

    2013-01-01

    Lightweight and high resolution mirrors are needed for future space-based X-ray telescopes to achieve advances in high-energy astrophysics. The slumped glass mirror technology in development at NASA GSFC aims to build X-ray mirror modules with an area to mass ratio of approx.17 sq cm/kg at 1 keV and a resolution of 10 arc-sec Half Power Diameter (HPD) or better at an affordable cost. As the technology nears the performance requirements, additional engineering effort is needed to ensure the modules are compatible with space-flight. This paper describes Flight Mirror Assembly (FMA) designs for several X-ray astrophysics missions studied by NASA and defines generic driving requirements and subsequent verification tests necessary to advance technology readiness for mission implementation. The requirement to perform X-ray testing in a horizontal beam, based on the orientation of existing facilities, is particularly burdensome on the mirror technology, necessitating mechanical over-constraint of the mirror segments and stiffening of the modules in order to prevent self-weight deformation errors from dominating the measured performance. This requirement, in turn, drives the mass and complexity of the system while limiting the testable angular resolution. Design options for a vertical X-ray test facility alleviating these issues are explored. An alternate mirror and module design using kinematic constraint of the mirror segments, enabled by a vertical test facility, is proposed. The kinematic mounting concept has significant advantages including potential for higher angular resolution, simplified mirror integration, and relaxed thermal requirements. However, it presents new challenges including low vibration modes and imperfections in kinematic constraint. Implementation concepts overcoming these challenges are described along with preliminary test and analysis results demonstrating the feasibility of kinematically mounting slumped glass mirror segments.

  14. Adjacent segment disease after anterior cervical decompression and fusion: analysis of risk factors on X-ray and magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    Zhao Yanbin; Sun Yu; Zhou Feifei; Wang Shaobo; Zhang Fengshan; Pan Shengfa

    2014-01-01

    Background Adjacent segment disease (ASD) is common after cervical fusion.The aim of this study was to evaluate the risk factors for ASD on X-ray and magnetic resonance imaging (MRI).Methods Patients included in this study had received revision surgeries after developing symptomatic ASD following anterior decompression and fusion.A control group that had not developed ASD was matched 1:1 by follow-up time and fusion segments.Plate-to-disc distances (PDDs),developmental cervical canal stenosis on X-ray,cervical disc degeneration grading,and cervical disc bulge impingements on preoperative MRI were measured and compared between the ASD group and the control group.Results Thirty-four patients with complete radiographic data were included in the ASD group.The causative segments of ASD included nine cases of C3-4,18 cases of C4-5,three cases of C5-6,and four cases of C6-7.The ASD occurred at the upper adjacent segments in 26 patients and at the lower adjacent segments in eight patients.PDD distributions were similar between the ASD group and the control group.Developmental cervical canal stenosis was a risk factor for ASD,with an odd ratio value of 2.88.Preoperative cervical disc degenerations on MRI were similar between the ASD group and the control group.In the upper-level ASD group,the disc bulge impingement was (19.7±9.7)%,which was significantly higher than that of the control group of (11.8±4.8)%.Conclusions ASD was more likely to develop above the index level of fusion.Developmental cervical canal stenosis and greater disc bulge impingement may be risk factors for the development of ASD.

  15. Improvement of optical properties of synchrotron radiation by undulator segmentation and phase control

    International Nuclear Information System (INIS)

    Two simple schemes to improve optical properties of undulator radiation (UR) are reported. One is to suppress the intensity of higher harmonics, and the other is to obtain variable polarization. Both of them are based on a segmentation of undulator and control of the relative phase between segments. A simple analysis of UR emitted from the segmented undulator is made to explain the principle of the two schemes, which is followed by a detailed discussion on the effects of the finite emittance of the electron beam and angular acceptance of the beamline. Several practical examples are shown to reveal the effectiveness of the proposed schemes. (author)

  16. End-to-End Assessment of a Large Aperture Segmented Ultraviolet Optical Infrared (UVOIR) Telescope Architecture

    Science.gov (United States)

    Feinberg, Lee; Bolcar, Matt; Liu, Alice; Guyon, Olivier; Stark,Chris; Arenberg, Jon

    2016-01-01

    Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance.

  17. Establishing an experimental model of photodynamic induced anterior ischemic optic neuropathy

    Institute of Scientific and Technical Information of China (English)

    Runsheng Wang; Xiaodi Wang; Peilin Lü; Jianwei Bai; Jianzhou Wang; Xiaoqin Lei; Xiaoliang Zhou; Hongfen Sun; Aizhu Pan

    2006-01-01

    BACKGROUND: Scholars have supposed to establish animal models of optic neuropathy by pressing and partially amputating optic nerve, increasing intraocular pressure and injecting vasoconstrictor, etc., but the models are greatly different from anterior ischemia optic neuropathy. Therefore, a more ideal method is needed to establish animal model of anterior ischemic optic neuropathy (AION).OBJECTIVE: To establish AION models in rats, observe the functional changes of fundus, fundus fluorescein angiography (FFA), optical coherence tomography (OCT), flash visual evoked potential (F-VEP), and histopathologically confirm its reliability.DESIGN: A randomized control trial.SETTINGS: Department of Ophthalmology, Xi'an Fourth Hospital; Xi'an Institute of Ocular Fundus Diseases.MATERIALS: The experiments were carried out in the research room of Xi'an Institute of Ocular Fundus Diseases from February 2005 to May 2006. Thirty healthy male SD rats of 4-5 weeks old, weighing 140-160 g,were provided by the animal experimental center of the Fourth Military Medical University of Chinese PLA [SCXK (Military)2002-005], and those without eye disease examined by slit lamp and direct ophthalmoscope after mydriasis were enrolled. The conditions for feeding mice without special pathogen were strictly followed.The rats were randomly divided into blank control group (n =5), laser group (n =5), hematoporphyrin derivative (HPD) group and AION group (n =15), each group was numbered randomly. For each rat, the right eye was taken as the experimental eye, and the left one as the control one.METHODS: In the AION group, the rats were injected with HPD (10 mg/kg) via caudal vein, and then the optic discs were exposed to krypton red (647 nm, 80 mV) for 120 s, and the rats were in avoidance of light for 2 weeks postoperatively. Rats in the laser group were only exposed to krypton red (647 nm, 80 mV) for 120 s, and in avoidance of light for 2 weeks postoperatively; Those in the HPD group were only

  18. Viewpoint-independent 3D object segmentation for randomly stacked objects using optical object detection

    International Nuclear Information System (INIS)

    This work proposes a novel approach to segmenting randomly stacked objects in unstructured 3D point clouds, which are acquired by a random-speckle 3D imaging system for the purpose of automated object detection and reconstruction. An innovative algorithm is proposed; it is based on a novel concept of 3D watershed segmentation and the strategies for resolving over-segmentation and under-segmentation problems. Acquired 3D point clouds are first transformed into a corresponding orthogonally projected depth map along the optical imaging axis of the 3D sensor. A 3D watershed algorithm based on the process of distance transformation is then performed to detect the boundary, called the edge dam, between stacked objects and thereby to segment point clouds individually belonging to two stacked objects. Most importantly, an object-matching algorithm is developed to solve the over- and under-segmentation problems that may arise during the watershed segmentation. The feasibility and effectiveness of the method are confirmed experimentally. The results reveal that the proposed method is a fast and effective scheme for the detection and reconstruction of a 3D object in a random stack of such objects. In the experiments, the precision of the segmentation exceeds 95% and the recall exceeds 80%. (paper)

  19. Reattachment of a Fractured Anterior Tooth Segment With Pulp Exposure via Er:YAG and Nd:YAG Lasers

    Directory of Open Access Journals (Sweden)

    Fornaini

    2015-11-01

    Full Text Available Introduction The reattachment of a dental fragment may be performed for treatment of traumatized anterior teeth, both in cases of simple coronal fracture (enamel and superficial dentin and in those with complicated coronal fracture (deep dentin with pulp exposure. A major part of this procedure is the adhesion technique, which was described for the first time by Buonocore in 1955. This clinical case demonstrates the use of Er:YAG and Nd:YAG lasers in fragment reattachment of a traumatically fractured anterior tooth with pulp exposure, describes their advantages and highlights the steps involved in their use. Case Presentation A 14-year-old patient who came to our clinic with a traumatic crown fracture of the permanent, right central incisor is described. The patient had preserved the fragment that had broken off into his mouth and it was rebonded to the tooth using lasers (LightWalker device; Fotona, Ljubljana, Slovenia with the following parameters: Er:YAG, SSP mode; 200 mJ; 10 Hz; quasi-contact tipless handpiece; Nd:YAG, SP mode; 4 W; 40 Hz; 300 μm contact fiber. The whole procedure was performed without the need for anesthesia. Conclusions The patient reported that he did not feel pain or discomfort throughout the intervention. Follow-up visits performed after one, three, six, twelve, and sixteen months demonstrated vitality of the tooth the absence of complications, as well as good esthetic results. Laser technology may be used in the treatment of traumatic anterior teeth injury with advantages in terms of quality of the restoration, esthetic results, and patient comfort.

  20. Diode Laser 810 Nm as a Potential Treatment to Improve Visual Function in Nonarteritic Anterior Ischemic Optic Neuropathy (NAION

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Heidari

    2011-01-01

    Full Text Available Nonarteritic anterior ischemic optic neuropathy (NAION is one of the most widespread visually disabling diseases in the middle-aged and elderly population. The optic nerve damage appears to result from a perfusion insufficiency in the short posterior ciliary arteries leading to infarction of the retrolaminar portion of the optic disc. Induced Heat shock protein (Hsp is known to have neuroprotective effects against ischemic injury of the central nervous system in mammals. Transpupillary thermotherapy (TTT application to the optic nerve head induces Hsp70 expression. We hypothesize that Transpupillary thermotherapy (TTT could be a novel method for improving and preserving the function of the optic nerve fibers in the eye with NAION. An 810-nm diode laser beam is focused to the center of the optic nerve head to induce Hsp. Controlled prospective and randomized clinical trial is necessary to confirm conclusively the effectiveness of this method.

  1. Neural organization and visual processing in the anterior optic tubercle of the honeybee brain.

    Science.gov (United States)

    Mota, Theo; Yamagata, Nobuhiro; Giurfa, Martin; Gronenberg, Wulfila; Sandoz, Jean-Christophe

    2011-08-10

    The honeybee Apis mellifera represents a valuable model for studying the neural segregation and integration of visual information. Vision in honeybees has been extensively studied at the behavioral level and, to a lesser degree, at the physiological level using intracellular electrophysiological recordings of single neurons. However, our knowledge of visual processing in honeybees is still limited by the lack of functional studies of visual processing at the circuit level. Here we contribute to filling this gap by providing a neuroanatomical and neurophysiological characterization at the circuit level of a practically unstudied visual area of the bee brain, the anterior optic tubercle (AOTu). First, we analyzed the internal organization and neuronal connections of the AOTu. Second, we established a novel protocol for performing optophysiological recordings of visual circuit activity in the honeybee brain and studied the responses of AOTu interneurons during stimulation of distinct eye regions. Our neuroanatomical data show an intricate compartmentalization and connectivity of the AOTu, revealing a dorsoventral segregation of the visual input to the AOTu. Light stimuli presented in different parts of the visual field (dorsal, lateral, or ventral) induce distinct patterns of activation in AOTu output interneurons, retaining to some extent the dorsoventral input segregation revealed by our neuroanatomical data. In particular, activity patterns evoked by dorsal and ventral eye stimulation are clearly segregated into distinct AOTu subunits. Our results therefore suggest an involvement of the AOTu in the processing of dorsoventrally segregated visual information in the honeybee brain. PMID:21832175

  2. Comparison of central corneal thickness measurements between anterior chamber-optical coherence tomography and ultrasonic pachymeter

    International Nuclear Information System (INIS)

    Objective: To assess the agreement of central corneal thickness (CCT) measured by anterior chamber-optical coherence tomography (AC-OCT) and ultrasonic pachymeter and provide an objective basis for clinical application of AC-OCT. Methods: CCT of 150 college student volunteers (300 eyes) measured by two devices were obtained. The data was analyzed by paired t test and Pearson correlation analysis. Bland-Altman plot and Mountain plot were used to assess the agreement. Results: The mean CCT values were (530.05 ± 33.611) μm measured by AC-OCT and (543.68 ± 35.088) μm measured by ultrasonic pachymeter. Regression analysis showed a high correlation between the values obtained by both devices (r=0.960, P<0.001). Compared with AC-OCT, ultrasonic pachymeter overestimated the CCT by a mean of 13.62 μm. The two modalities had incomparable results. Conclusion: It is important to be noted in clinical practice that the measurements acquired by these two modalities are not directly interchangeable. However, the CCT measurements by the AC-OCT and ultrasonic pachymeter are highly correlated. AC-OCT is an effective method to observe the changes of the corneal thickness in the long term. (authors)

  3. A Closed Form Solution to Segment 3D Motion Using Straight-line Optical Flow

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing; SHI Fan-huai; MA Wen-juan; LIU Yun-cai

    2008-01-01

    A closed form solution to the problem of segmenting multiple 3D motion models was proposed fromstraight-line optical flow. It introduced the multibody line optical flow constraint (MLOFC), a polynomial equation relating motion models and line parameters. The motion models can be obtained analytically as the derivative of the MLOFC at the corresponding line measurement, without knowing the motion model associated with that line. Experiments on real and synthetic sequences were also presented.

  4. An Intelligent Segmented Burst Assembly Mechanism in Optical Burst Switching Networks

    Institute of Scientific and Technical Information of China (English)

    XIE Yi-Yuan; ZHANG Jian-Guo

    2008-01-01

    We focus on the burst assembly mechanism and propose a new intelligent method in which the burst is assembled from several internet protocol (IP) packets in which the number of IP packets is changed according to the traffic load and the burst is segmented into several parts, called the ISOBS mechanism. The average burst assembly time of the ISOBS mechanism decreases as compared with the fixed-assembly-time and fixed-assembly-time-and-length mechanisms. The loss ratio decreases 50% as compared with the general optical burst switching (OBS) mechanism. The last segment can carry high quality of service (QOS) information. We can achieve that the loss ratio of the last segment is almost zero when the traffic load is less than 0.05. When the traffic load is 0.9, the loss ratio of the last segment is 0.0041. The ISOBS can support to transmit different QOS data.

  5. An Intelligent Segmented Burst Assembly Mechanism in Optical Burst Switching Networks

    International Nuclear Information System (INIS)

    We focus on the burst assembly mechanism and propose a new intelligent method in which the burst is assembled from several internet protocol (IP) packets in which the number of IP packets is changed according to the traffic load and the burst is segmented into several parts, called the ISOBS mechanism. The average burst assembly time of the ISOBS mechanism decreases as compared with the fixed-assembly-time and fixed-assembly-time-and-length mechanisms. The loss ratio decreases 50% as compared with the general optical burst switching (OBS) mechanism. The last segment can carry high quality of service (QOS) information. We can achieve that the loss ratio of the last segment is almost zero when the traffic load is less than 0.05. When the traffic load is 0.9, the loss ratio of the last segment is 0.0041. The ISOBS can support to transmit different QOS data. (fundamental areas of phenomenology (including applications))

  6. Overview of segmented glass optics development for the Constellation-X hard X-ray telescope

    DEFF Research Database (Denmark)

    Hailey, C.J; Christensen, Finn Erland; Craig, W.W.;

    2002-01-01

    We report recent work on segmented glass optics for the Constellation-H hard x-ray telescope. This effort seeks to both improve the figure of the free-standing glass substrates, and to refine a newly-developed mounting technology for the substrates. We discuss metrology on recently characterized...

  7. Lumen Segmentation in Intravascular Optical Coherence Tomography Using Backscattering Tracked and Initialized Random Walks.

    Science.gov (United States)

    Guha Roy, Abhijit; Conjeti, Sailesh; Carlier, Stéphane G; Dutta, Pranab K; Kastrati, Adnan; Laine, Andrew F; Navab, Nassir; Katouzian, Amin; Sheet, Debdoot

    2016-03-01

    Intravascular imaging using ultrasound or optical coherence tomography (OCT) is predominantly used to adjunct clinical information in interventional cardiology. OCT provides high-resolution images for detailed investigation of atherosclerosis-induced thickening of the lumen wall resulting in arterial blockage and triggering acute coronary events. However, the stochastic uncertainty of speckles limits effective visual investigation over large volume of pullback data, and clinicians are challenged by their inability to investigate subtle variations in the lumen topology associated with plaque vulnerability and onset of necrosis. This paper presents a lumen segmentation method using OCT imaging physics-based graph representation of signals and random walks image segmentation approaches. The edge weights in the graph are assigned incorporating OCT signal attenuation physics models. Optical backscattering maxima is tracked along each A-scan of OCT and is subsequently refined using global graylevel statistics and used for initializing seeds for the random walks image segmentation. Accuracy of lumen versus tunica segmentation has been measured on 15 in vitro and 6 in vivo pullbacks, each with 150-200 frames using 1) Cohen's kappa coefficient (0.9786 ±0.0061) measured with respect to cardiologist's annotation and 2) divergence of histogram of the segments computed with Kullback-Leibler (5.17 ±2.39) and Bhattacharya measures (0.56 ±0.28). High segmentation accuracy and consistency substantiates the characteristics of this method to reliably segment lumen across pullbacks in the presence of vulnerability cues and necrotic pool and has a deterministic finite time-complexity. This paper in general also illustrates the development of methods and framework for tissue classification and segmentation incorporating cues of tissue-energy interaction physics in imaging. PMID:25700476

  8. Impending anterior ischemic optic neuropathy with elements of retinal vein occlusion in a patient on interferon for polycythemia vera

    OpenAIRE

    Rue KS; Hirsch LK; Sadun AA

    2012-01-01

    Kelly S Rue, Louis K Hirsch, Alfredo A SadunDepartment of Neuro-Ophthalmology, Doheny Eye Institute and Keck School of Medicine, University of Southern California, Los Angeles, CA, USAAbstract: We describe the course and likely pathophysiology of impending anterior ischemic optic neuropathy (AION) and retinal vein occlusion in a 56-year-old man with polycythemia vera managed with interferon alpha for 2 years. Our patient presented with decreased vision, scintillating scotomata, and floaters. ...

  9. The Association between Diabetes Mellitus and Nonarteritic Anterior Ischemic Optic Neuropathy: A Systematic Review and Meta-Analysis

    OpenAIRE

    CHEN Ting; Song, Delu; Shan, Guangliang; Wang, Ke; Wang, Yiwei; Ma, Jin; Zhong, Yong

    2013-01-01

    Background The association of diabetes mellitus (DM) with nonarteritic anterior ischemic optic neuropathy (NAION) has been inconclusive. Purpose To determine whether DM is associated with an increased risk of NAION. Methods A comprehensive literature search was performed for published studies reporting both DM and NAION based on PubMed and EMBASE. After reviewing characteristics of all the included studies systematically, meta-analytical method was employed to calculate the pooled odds ratio ...

  10. Optic atrophy, necrotizing anterior scleritis and keratitis presenting in association with Streptococcal Toxic Shock Syndrome: a case report

    Directory of Open Access Journals (Sweden)

    Papageorgiou Konstantinos I

    2008-02-01

    Full Text Available Abstract Introduction We report a case of optic atrophy, necrotizing anterior scleritis and keratitis presenting in a patient with Streptococcal Toxic Shock Syndrome. Case presentation A 43-year-old woman developed streptococcal toxic shock syndrome secondary to septic arthritis of her right ankle. Streptococcus pyogenes (b-haemolyticus Group A was isolated from blood cultures and joint aspirate. She was referred for ophthalmology review as her right eye became injected and the pupil had become unresponsive to light whilst she was in the Intensive Therapy Unit (ITU. The iris appeared atrophic and was mid-dilated with no direct or consensual response to light. Three zones of sub-epithelial opacification where noted in the cornea. There where extensive posterior synechiae. Indirect ophthalmoscopy showed a pale right disc. The vision was reduced to hand movements (HM. A diagnosis of optic atrophy was made secondary to post-streptococcal uveitis. She subsequently developed a necrotizing anterior scleritis. Conclusion This case illustrates a previously unreported association of optic atrophy, necrotizing anterior scleritis and keratitis in a patient with post-streptococcal uveitis. This patient had developed Streptococcal Toxic Shock Syndrome secondary to septic arthritis. We recommend increased awareness of the potential risks of these patients developing severe ocular involvement.

  11. Fast retinal layer segmentation of spectral domain optical coherence tomography images

    Science.gov (United States)

    Zhang, Tianqiao; Song, Zhangjun; Wang, Xiaogang; Zheng, Huimin; Jia, Fucang; Wu, Jianhuang; Li, Guanglin; Hu, Qingmao

    2015-09-01

    An approach to segment macular layer thicknesses from spectral domain optical coherence tomography has been proposed. The main contribution is to decrease computational costs while maintaining high accuracy via exploring Kalman filtering, customized active contour, and curve smoothing. Validation on 21 normal volumes shows that 8 layer boundaries could be segmented within 5.8 s with an average layer boundary error macular degeneration cases to yield similar or significantly better accuracy and is 37 times faster. The proposed method could be a potential tool to clinically quantify the retinal layer boundaries.

  12. An Automatic Optic Disk Detection and Segmentation System using Multi-level Thresholding

    OpenAIRE

    KARASULU, B.

    2014-01-01

    Optic disk (OD) boundary localization is a substantial problem in ophthalmic image processing research area. In order to segment the region of OD, we developed an automatic system which involves a multi-level thresholding. The OD segmentation results of the system in terms of average precision, recall and accuracy for DRIVE database are 98.88%, 99.91%, 98.83%, for STARE database are 98.62%, 97.38%, 96.11%, and for DIARETDB1 database are 99.29%, 99.90%, 99.20%, respectively. Th...

  13. End-to-End Assessment of a Large Aperture Segmented Ultraviolet Optical Infrared (UVOIR) Telescope Architecture

    Science.gov (United States)

    Feinberg, Lee; Rioux, Norman; Bolcar, Matthew; Liu, Alice; Guyon, Oliver; Stark, Chris; Arenberg, Jon

    2016-01-01

    Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10^-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance. These efforts are combined through integrated modeling, coronagraph evaluations, and Exo-Earth yield calculations to assess the potential performance of the selected architecture. In addition, we discusses the scalability of this architecture to larger apertures and the technological tall poles to enabling it.

  14. Relation of Left Ventricular Mass and Infarct Size in Anterior Wall ST-Segment Elevation Acute Myocardial Infarction (from the EMBRACE STEMI Clinical Trial).

    Science.gov (United States)

    Daaboul, Yazan; Korjian, Serge; Weaver, W Douglas; Kloner, Robert A; Giugliano, Robert P; Carr, Jim; Neal, Brandon J; Chi, Gerald; Cochet, Madeleine; Goodell, Laura; Michalak, Nathan; Rusowicz-Orazem, Luke; Alkathery, Turky; Allaham, Haytham; Routray, Sujit; Szlosek, Donald; Jain, Purva; Gibson, C Michael

    2016-09-01

    Biomarker measures of infarct size and myocardial salvage index (MSI) are important surrogate measures of clinical outcomes after a myocardial infarction. However, there is variability in infarct size unaccounted for by conventional adjustment factors. This post hoc analysis of Evaluation of Myocardial Effects of Bendavia for Reducing Reperfusion Injury in Patients With Acute Coronary Events (EMBRACE) ST-Segment Elevation Myocardial Infarction (STEMI) trial evaluates the association between left ventricular (LV) mass and infarct size as assessed by areas under the curve for creatine kinase-MB (CK-MB) and troponin I release over the first 72 hours (CK-MB area under the curve [AUC] and troponin I [TnI] AUC) and the MSI. Patients with first anterior STEMI, occluded left anterior descending artery, and available LV mass measurement in EMBRACE STEMI trial were included (n = 100) (ClinicalTrials.govNCT01572909). MSI, end-diastolic LV mass on day 4 cardiac magnetic resonance, and CK-MB and troponin I concentrations were evaluated by a core laboratory. After saturated multivariate analysis, dominance analysis was performed to estimate the contribution of each independent variable to the predicted variance of each outcome. In multivariate models that included age, gender, body surface area, lesion location, smoking, and ischemia time, LV mass remained independently associated with biomarker measures of infarct size (CK-MB AUC p = 0.02, TnI AUC p = 0.03) and MSI (p = 0.003). Dominance analysis demonstrated that LV mass accounted for 58%, 47%, and 60% of the predicted variances for CK-MB AUC, TnI AUC, and MSI, respectively. In conclusion, LV mass accounts for approximately half of the predicted variance in biomarker measures of infarct size. It should be considered as an adjustment variable in studies evaluating infarct size. PMID:27392509

  15. Engrafted human induced pluripotent stem cell-derived anterior specified neural progenitors protect the rat crushed optic nerve.

    Directory of Open Access Journals (Sweden)

    Leila Satarian

    Full Text Available BACKGROUND: Degeneration of retinal ganglion cells (RGCs is a common occurrence in several eye diseases. This study examined the functional improvement and protection of host RGCs in addition to the survival, integration and neuronal differentiation capabilities of anterior specified neural progenitors (NPs following intravitreal transplantation. METHODOLOGY/PRINCIPAL FINDINGS: NPs were produced under defined conditions from human induced pluripotent stem cells (hiPSCs and transplanted into rats whose optic nerves have been crushed (ONC. hiPSCs were induced to differentiate into anterior specified NPs by the use of Noggin and retinoic acid. The hiPSC-NPs were labeled by green fluorescent protein or a fluorescent tracer 1,1' -dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI and injected two days after induction of ONC in hooded rats. Functional analysis according to visual evoked potential recordings showed significant amplitude recovery in animals transplanted with hiPSC-NPs. Retrograde labeling by an intra-collicular DiI injection showed significantly higher numbers of RGCs and spared axons in ONC rats treated with hiPSC-NPs or their conditioned medium (CM. The analysis of CM of hiPSC-NPs showed the secretion of ciliary neurotrophic factor, basic fibroblast growth factor, and insulin-like growth factor. Optic nerve of cell transplanted groups also had increased GAP43 immunoreactivity and myelin staining by FluoroMyelin™ which imply for protection of axons and myelin. At 60 days post-transplantation hiPSC-NPs were integrated into the ganglion cell layer of the retina and expressed neuronal markers. CONCLUSIONS/SIGNIFICANCE: The transplantation of anterior specified NPs may improve optic nerve injury through neuroprotection and differentiation into neuronal lineages. These NPs possibly provide a promising new therapeutic approach for traumatic optic nerve injuries and loss of RGCs caused by other diseases.

  16. Risk of Nonarteritic Anterior Ischemic Optic Neuropathy Following End-Stage Renal Disease.

    Science.gov (United States)

    Chang, Yuh-Shin; Weng, Shih-Feng; Chang, Chun; Wang, Jhi-Joung; Su, Shih-Bin; Huang, Chien-Cheng; Wang, Jiu-Yao; Jan, Ren-Long

    2016-03-01

    To investigate the risk of nonarteritic anterior ischemic optic neuropathy (NAION) following end-stage renal disease (ESRD).A retrospective, nationwide, matched cohort study.ESRD patients identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 585.The study cohort included 93,804 ESRD patients registered with the Taiwan National Health Insurance Research Database between January 2000 and December 2009. An age- and sex-matched control group comprised 93,804 patients (case:control = 1:1) selected from the Taiwan Longitudinal Health Insurance Database 2000. Information for each patient was collected from the index date until December 2011. The incidence and risk of NAION were compared between the ESRD and control groups. The adjusted hazard ratio (HR) for NAION after adjustment for potential confounders was obtained by a Cox proportional hazard regression analysis. A Kaplan-Meier analysis was used to calculate the cumulative incidence rate of NAION.The incidence of NAION following ESRD.In total, 133 ESRD patients (0.14%) and 51 controls (0.05%) had NAION (P leading to a significantly elevated risk of NAION in the ESRD patients compared with the controls (incidence rate ratio = 3.14, 95% confidence interval [CI] = 2.11-4.67). After adjustment for potential confounders including diabetes mellitus, hypertension, hypotension, hyperlipidemia, and 2-way interaction terms between any 2 factors, ESRD patients were 3.12 times more likely to develop NAION than non-ESRD patients in the full cohort (adjusted HR = 3.12, 95% CI = 2.10-4.64). Additionally, patients with hypertension and hyperlipidemia showed higher incidence rates of NAION in the ESRD group compared with the controls: 2.31 (95% CI = 1.40-3.82) for hypertension and 2.72 (95% CI = 1.14-6.50) for hyperlipidemia.ESRD increased the risk of NAION, which is an interdisciplinary emergency. Close collaboration between nephrologists and

  17. Signaling-based path-segment protection in mesh optical networks

    Institute of Scientific and Technical Information of China (English)

    Yueming Lu; Chao Zou; Qiushi Wang; Yuefeng Ji

    2011-01-01

    Path protections have become increasingly important for current mesh optical networks because fast restorations in generalized multiprotocol label switching (GMPLS) networks are uncertain. However, setting up additional disjoint paths to protect connections leads to more path setup blocking and signaling collisions. We analyze signaling collisions, path blocking and blocking probability, as well as calculate node-to-node blocking probabilities. A signaling-based path-segment protection (PSP) is proposed, which integrates segment protections and path protections as well as enhances the performance of path protections and ring protections. The setup of PSP connections causes less blocking probability than the setup of path protection connections in the simulations.%Path protections have become increasingly important for current mesh optical networks because fast restorations in generalized multiprotocol label switching (GMPLS) networks are uncertain.However,setting up additional disjoint paths to protect connections leads to more path setup blocking and signaling collisions.We analyze signaling collisions,path blocking and blocking probability,as well as calculate node-to-node blocking probabilities.A signaling-based path-segment protection (PSP) is proposed,which integrates segment protections and path protections as well as enhances the performance of path protections and ring protections.The setup of PSP connections causes less blocking probability than the setup of path protection connections in the simulations.Recently,with the emergence of new protection and restoration methods,mesh topologies have gradually replaced ring topologies,especially in optical transport networks (OTNs)[1],automatically switched optical networks (ASONs)[2],generalized multiprotocol label switching (GMPLS) protocol networks[3,4],and packet transport networks (PTNs)[5].However,fast restoration methods currently face some challenges in China.

  18. Continuous Beam Steering From A Segmented Liquid Crystal Optical Phased Array

    Science.gov (United States)

    Pouch, John; Nguyen, Hung; Miranda, Felix; Titus, Charles M.; Bos, Philip J.

    2002-01-01

    Optical communications to and from deep space probes will require beams possessing divergence on the order of a microradian, and must be steered with sub-microradian precision. Segmented liquid crystal spatial phase modulators, a type of optical phased array, are considered for this ultra-high resolution beam steering. It is shown here that in an ideal device of this type, there are ultimately no restrictions on the angular resolution. Computer simulations are used to obtain that result, and to analyze the influence of beam truncation and substrate flatness on the performance of this type of device.

  19. Total thoracoscopic lung segmentectomy of anterior basal segment of the right lower lobe (RS8 for NSCLC stage IA (case report

    Directory of Open Access Journals (Sweden)

    Nakajiima Tomohiro

    2011-09-01

    Full Text Available Abstract A 69-year-old woman with a pulmonary nodule in anterior basal segment of the right lower lobe (RS8 was referred to our department. The diameter of the tumor was 12 mm, and it had increased over a few months. First, video-assisted thoracoscopic lung surgery (VATS biopsy of the pulmonary nodule was carried out. Frozen section examination of this nodule confirmed the diagnosis of bronchioloalveolar carcinoma (BAC. Segmentectomy of RS8 with lower mediastinal node dissection (ND2a-1 was performed. The intersegmental plane was identified using the intersegmental veins as landmarks and the demarcation between the resected (inflated and preserved (collapsed lungs. Electrocautery at 70 watts was used to divide the intersegmental plane. A vessel sealing system was used to seal and cut the pulmonary arteries. Postoperative histopathological examination revealed that the tumor was T1aN0M0 BAC, and the minimal distance between the surgical margin and the tumor edge was 15 mm. The patient was discharged from hospital on postoperative day 5 without any complications.

  20. Volume Averaging of Spectral-Domain Optical Coherence Tomography Impacts Retinal Segmentation in Children

    Science.gov (United States)

    Trimboli-Heidler, Carmelina; Vogt, Kelly; Avery, Robert A.

    2016-01-01

    Purpose To determine the influence of volume averaging on retinal layer thickness measures acquired with spectral-domain optical coherence tomography (SD-OCT) in children. Methods Macular SD-OCT images were acquired using three different volume settings (i.e., 1, 3, and 9 volumes) in children enrolled in a prospective OCT study. Total retinal thickness and five inner layers were measured around an Early Treatment Diabetic Retinopathy Scale (ETDRS) grid using beta version automated segmentation software for the Spectralis. The magnitude of manual segmentation required to correct the automated segmentation was classified as either minor (12 and 26 and 48 lines adjusted or could not adjust due to poor image quality). The frequency of each edit classification was assessed for each volume setting. Thickness, paired difference, and 95% limits of agreement of each anatomic quadrant were compared across volume density. Results Seventy-five subjects (median age 11.8 years, range 4.3–18.5 years) contributed 75 eyes. Less than 5% of the 9- and 3-volume scans required more than minor manual segmentation corrections, compared with 71% of 1-volume scans. The inner (3 mm) region demonstrated similar measures across all layers, regardless of volume number. The 1-volume scans demonstrated greater variability of the retinal nerve fiber layer (RNLF) thickness, compared with the other volumes in the outer (6 mm) region. Conclusions In children, volume averaging of SD-OCT acquisitions reduce retinal layer segmentation errors. Translational Relevance This study highlights the importance of volume averaging when acquiring macula volumes intended for multilayer segmentation.

  1. Accurate and reliable segmentation of the optic disc in digital fundus images.

    Science.gov (United States)

    Giachetti, Andrea; Ballerini, Lucia; Trucco, Emanuele

    2014-07-01

    We describe a complete pipeline for the detection and accurate automatic segmentation of the optic disc in digital fundus images. This procedure provides separation of vascular information and accurate inpainting of vessel-removed images, symmetry-based optic disc localization, and fitting of incrementally complex contour models at increasing resolutions using information related to inpainted images and vessel masks. Validation experiments, performed on a large dataset of images of healthy and pathological eyes, annotated by experts and partially graded with a quality label, demonstrate the good performances of the proposed approach. The method is able to detect the optic disc and trace its contours better than the other systems presented in the literature and tested on the same data. The average error in the obtained contour masks is reasonably close to the interoperator errors and suitable for practical applications. The optic disc segmentation pipeline is currently integrated in a complete software suite for the semiautomatic quantification of retinal vessel properties from fundus camera images (VAMPIRE). PMID:26158034

  2. Individual tree segmentation over large areas using airborne LiDAR point cloud and very high resolution optical imagery

    OpenAIRE

    Qin, Y.; Ferraz, A.; C. Mallet; Iovan, Corina

    2015-01-01

    Timely and accurate measuremen ts of forest parameters are critical for ecosystem studies, sustainable forest resources management, monitoring and planning. This paper presents a processing chain for individual tree segmentation over large areas with airborne LiDAR 3D point cloud and very high resolution (VHR) optical imagery. The proposed processing chain consists of fo rest stand level delineation with optical imagery, individual tree segmentation with Canopy ...

  3. Fibre segment interferometry using code-division multiplexed optical signal processing for strain sensing applications

    International Nuclear Information System (INIS)

    A novel optical signal processing scheme for multiplexing fibre segment interferometers is proposed. The continuous-wave, homodyne technique combines code-division multiplexing with single-sideband modulation. It uses only one electro-optic phase modulator to achieve both range separation and quadrature interferometric phase measurement. This scheme is applied to fibre segment interferometry, where a number of long-gauge length interferometric fibre sensors are formed by subtracting pairs of signals from equidistantly placed, weak back reflectors. In this work we give a detailed account of the signal processing involved and, in particular, explore aspects such as electronic bandwidth requirements, noise, crosstalk and linearity, which are important design considerations. A signal bandwidth of ±20 kHz permits the resolution of phase change rates of 2.5 × 104 rad s−1 for each of the four 16.5 m long segments in our setup. We show that dynamic strain resolutions below 0.2 nanostrain Hz−0.5 at 2 m sensor gauge length are achievable, even with an inexpensive diode laser. When used in applications that require only relative strain change measurements, this scheme compares well to more established techniques and can provide high-fidelity yet cost-effective measurements. (paper)

  4. An Automatic Optic Disk Detection and Segmentation System using Multi-level Thresholding

    Directory of Open Access Journals (Sweden)

    KARASULU, B.

    2014-05-01

    Full Text Available Optic disk (OD boundary localization is a substantial problem in ophthalmic image processing research area. In order to segment the region of OD, we developed an automatic system which involves a multi-level thresholding. The OD segmentation results of the system in terms of average precision, recall and accuracy for DRIVE database are 98.88%, 99.91%, 98.83%, for STARE database are 98.62%, 97.38%, 96.11%, and for DIARETDB1 database are 99.29%, 99.90%, 99.20%, respectively. The experimental results show that our system works properly on retinal image databases with diseased retinas, diabetic signs, and a large degree of quality variability.

  5. Extremely Lightweight Segmented Membrane Optical Shell Fabrication Technology for Future IR to Optical Telescope Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose that the Membrane Optical Shell Technology (MOST) substrate fabrication approach be extended with a specific focus on advanced off-axis very light...

  6. James Webb Space Telescope segment phasing using differential optical transfer functions

    CERN Document Server

    Codona, Johanan L

    2015-01-01

    Differential Optical Transfer Function (dOTF) is an image-based, non-iterative wavefront sensing method that uses two star images with a single small change in the pupil. We describe two possible methods for introducing the required pupil modification to the JWST, one using a small (segment's actuator and another that uses small misalignments of NIRCam's filter wheel. While both methods should work with NIRCam, the actuator method will allow both MIRI and NIRISS to be used for segment phasing, which is new functionality. Since the actuator method requires only small displacements, it should provide a fast and safe phasing alternative that reduces mission risk and can be performed frequently for alignment monitoring and maintenance. Since a single actuator modification can be seen by all three cameras, it should be possible to calibrate the non-common-path aberrations between them. Large segment discontinuities can be measured using dOTFs in two filter bands. Using two im...

  7. Spectral Clustering for Unsupervised Segmentation of Lower Extremity Wound Beds Using Optical Images.

    Science.gov (United States)

    Dhane, Dhiraj Manohar; Krishna, Vishal; Achar, Arun; Bar, Chittaranjan; Sanyal, Kunal; Chakraborty, Chandan

    2016-09-01

    Chronic lower extremity wound is a complicated disease condition of localized injury to skin and its tissues which have plagued many elders worldwide. The ulcer assessment and management is expensive and is burden on health establishment. Currently accurate wound evaluation remains a tedious task as it rely on visual inspection. This paper propose a new method for wound-area detection, using images digitally captured by a hand-held, optical camera. The strategy proposed involves spectral approach for clustering, based on the affinity matrix. The spectral clustering (SC) involves construction of similarity matrix of Laplacian based on Ng-Jorden-Weiss algorithm. Starting with a quadratic method, wound photographs were pre-processed for color homogenization. The first-order statistics filter was then applied to extract spurious regions. The filter was selected based on the performance, evaluated on four quality metrics. Then, the spectral method was used on the filtered images for effective segmentation. The segmented regions were post-processed using morphological operators. The performance of spectral segmentation was confirmed by ground-truth pictures labeled by dermatologists. The SC results were additionally compared with the results of k-means and Fuzzy C-Means (FCM) clustering algorithms. The SC approach on a set of 105 images, effectively delineated targeted wound beds yielding a segmentation accuracy of 86.73 %, positive predictive values of 91.80 %, and a sensitivity of 89.54 %. This approach shows the robustness of tool for ulcer perimeter measurement and healing progression. The article elucidates its potential to be incorporated in patient facing medical systems targeting a rapid clinical assistance. PMID:27520612

  8. Impending anterior ischemic optic neuropathy with elements of retinal vein occlusion in a patient on interferon for polycythemia vera

    Directory of Open Access Journals (Sweden)

    Rue KS

    2012-10-01

    Full Text Available Kelly S Rue, Louis K Hirsch, Alfredo A SadunDepartment of Neuro-Ophthalmology, Doheny Eye Institute and Keck School of Medicine, University of Southern California, Los Angeles, CA, USAAbstract: We describe the course and likely pathophysiology of impending anterior ischemic optic neuropathy (AION and retinal vein occlusion in a 56-year-old man with polycythemia vera managed with interferon alpha for 2 years. Our patient presented with decreased vision, scintillating scotomata, and floaters. Fundus examination findings and results of a fluorescein angiogram led to the diagnosis of impending AION and retinal vein occlusion. Considering that both polycythemia vera and interferon have possible influences on vascular occlusion and optic disc edema, we stopped interferon treatment and immediately attempted to treat the polycythemia vera empirically with pentoxifylline and any interferon-associated inflammation with prednisone. Our patient experienced complete resolution of fundus abnormalities and return of normal vision within 3 weeks, which may be attributed to our successful treatment of both etiologies. Thus, further study is warranted to elucidate the treatment of both polycythemia vera and interferon-induced impending AION.Keywords: optic disc edema, interferon alpha, vascular occlusion, Roth spot, autoantibody, pentoxifylline

  9. Application of Multifractal Analysis to Segmentation of Water Bodies in Optical and Synthetic Aperture Radar Satellite Images

    OpenAIRE

    Martin, Victor Manuel San; Figliola, Alejandra

    2016-01-01

    A method for segmenting water bodies in optical and synthetic aperture radar (SAR) satellite images is proposed. It makes use of the textural features of the different regions in the image for segmentation. The method consists in a multiscale analysis of the images, which allows us to study the images regularity both, locally and globally. As results of the analysis, coarse multifractal spectra of studied images and a group of images that associates each position (pixel) with its correspondin...

  10. Automated segmentation and characterization of esophageal wall in vivo by tethered capsule optical coherence tomography endomicroscopy.

    Science.gov (United States)

    Ughi, Giovanni J; Gora, Michalina J; Swager, Anne-Fré; Soomro, Amna; Grant, Catriona; Tiernan, Aubrey; Rosenberg, Mireille; Sauk, Jenny S; Nishioka, Norman S; Tearney, Guillermo J

    2016-02-01

    Optical coherence tomography (OCT) is an optical diagnostic modality that can acquire cross-sectional images of the microscopic structure of the esophagus, including Barrett's esophagus (BE) and associated dysplasia. We developed a swallowable tethered capsule OCT endomicroscopy (TCE) device that acquires high-resolution images of entire gastrointestinal (GI) tract luminal organs. This device has a potential to become a screening method that identifies patients with an abnormal esophagus that should be further referred for upper endoscopy. Currently, the characterization of the OCT-TCE esophageal wall data set is performed manually, which is time-consuming and inefficient. Additionally, since the capsule optics optimally focus light approximately 500 µm outside the capsule wall and the best quality images are obtained when the tissue is in full contact with the capsule, it is crucial to provide feedback for the operator about tissue contact during the imaging procedure. In this study, we developed a fully automated algorithm for the segmentation of in vivo OCT-TCE data sets and characterization of the esophageal wall. The algorithm provides a two-dimensional representation of both the contact map from the data collected in human clinical studies as well as a tissue map depicting areas of BE with or without dysplasia. Results suggest that these techniques can potentially improve the current TCE data acquisition procedure and provide an efficient characterization of the diseased esophageal wall. PMID:26977350

  11. New variational image decomposition model for simultaneously denoising and segmenting optical coherence tomography images

    International Nuclear Information System (INIS)

    Optical coherence tomography (OCT) imaging plays an important role in clinical diagnosis and monitoring of diseases of the human retina. Automated analysis of optical coherence tomography images is a challenging task as the images are inherently noisy. In this paper, a novel variational image decomposition model is proposed to decompose an OCT image into three components: the first component is the original image but with the noise completely removed; the second contains the set of edges representing the retinal layer boundaries present in the image; and the third is an image of noise, or in image decomposition terms, the texture, or oscillatory patterns of the original image. In addition, a fast Fourier transform based split Bregman algorithm is developed to improve computational efficiency of solving the proposed model. Extensive experiments are conducted on both synthesised and real OCT images to demonstrate that the proposed model outperforms the state-of-the-art speckle noise reduction methods and leads to accurate retinal layer segmentation. (paper)

  12. Cervicoplastia anterior Anterior cervicoplasty

    Directory of Open Access Journals (Sweden)

    Lucas Gomes Patrocínio

    2004-10-01

    Full Text Available Muitos pacientes buscam correção estética da frouxidão da pele do pescoço, depósito de gordura na região submentoneana ou bandas de platisma. Em grande parte dos casos a ação medial, via cervicoplastia anterior é necessária. OBJETIVO: Demonstrar a casuística e avaliar os resultados e complicações com a técnica de cervicoplastia anterior no Serviço de Otorrinolaringologia da Universidade Federal de Uberlândia. FORMA DE ESTUDO: Relato de série. PACIENTES E MÉTODOS: Quarenta e dois pacientes, entre 39 e 65 anos de idade, sendo 40 (95,2% do sexo feminino e 2 (4,8% do masculino, foram submetidos a cervicoplastia anterior. Retrospectivamente foram avaliados resultados e complicações. RESULTADOS: Destes, 34 apresentaram resultados satisfatórios, 4 apresentaram déficit estético notado somente pelo cirurgião, 3 apresentaram déficit estético notado somente pelo paciente e 1 apresentou déficit estético necessitando cirurgia revisional. Ao estudo fotográfico, todos os pacientes apresentaram melhora do perfil cervical, redução das bandas de platisma e da frouxidão da pele, estabilização da musculatura cervical e acentuação do ângulo cervicomental, em graus variados. Houve complicação em 2 casos (discreto serohematoma e cicatriz um pouco alargada. CONCLUSÃO: A cervicoplastia, associada ou não à tração lateral pela ritidoplastia, é uma técnica que produz resultados satisfatórios na grande maioria dos casos.Many patients look for aesthetic correction of the laxity of neck skin, submandibular fat deposit or platisma bands. In a large part of the cases, medial action, through anterior cervicoplasty is necessary. AIM: To demonstrate the casuistic and to evaluate the results and complications with anterior cervicoplasty technique in the Otorhinolaryngology Service of the Federal University of Uberlândia. STUDY DESIGN: Serie report. PATIENTS AND METHODS: Forty-two patients, between 39 and 65 years of age, being 40 (95

  13. Spontaneous Scleral Perforation of an Anterior Chamber Intraocular Lens

    Science.gov (United States)

    Spierer, Oriel; O'Brien, Terrence P.

    2016-01-01

    A routine eye examination of a 69-year-old man revealed a scleral perforation of one of the haptics of the anterior chamber intraocular lens (AC IOL) which had been implanted many years ago. The patient was asymptomatic with good visual acuity. His history was negative for any trauma, eye rubbing, topical corticosteroid use, or autoimmune disease. The horizontal and vertical white-to-white diameters of the cornea in the right eye were 11.5 and 10.5 mm, respectively. Anterior segment optical coherence tomography showed the anterior chamber length to be 12.28 mm horizontally and 10.63 mm vertically. The patient underwent an IOL exchange, and the length of the explanted AC IOL was measured to be 12 mm. We speculate that the AC IOL, which was vertically aligned, was oversized. This case demonstrates the need for proper sizing and positioning of an AC IOL. In complex cases where AC IOL may be used, measuring the horizontal and vertical lengths of the anterior chamber by anterior segment optical coherence tomography prior to surgery may be useful.

  14. Semi-Automatic Segmentation of Optic Radiations and LGN, and Their Relationship to EEG Alpha Waves

    Science.gov (United States)

    Descoteaux, Maxime; Bernier, Michaël; Garyfallidis, Eleftherios; Whittingstall, Kevin

    2016-01-01

    At rest, healthy human brain activity is characterized by large electroencephalography (EEG) fluctuations in the 8-13 Hz range, commonly referred to as the alpha band. Although it is well known that EEG alpha activity varies across individuals, few studies have investigated how this may be related to underlying morphological variations in brain structure. Specifically, it is generally believed that the lateral geniculate nucleus (LGN) and its efferent fibres (optic radiation, OR) play a key role in alpha activity, yet it is unclear whether their shape or size variations contribute to its inter-subject variability. Given the widespread use of EEG alpha in basic and clinical research, addressing this is important, though difficult given the problems associated with reliably segmenting the LGN and OR. For this, we employed a multi-modal approach and combined diffusion magnetic resonance imaging (dMRI), functional magnetic resonance imaging (fMRI) and EEG in 20 healthy subjects to measure structure and function, respectively. For the former, we developed a new, semi-automated approach for segmenting the OR and LGN, from which we extracted several structural metrics such as volume, position and diffusivity. Although these measures corresponded well with known morphology based on previous post-mortem studies, we nonetheless found that their inter-subject variability was not significantly correlated to alpha power or peak frequency (p >0.05). Our results therefore suggest that alpha variability may be mediated by an alternative structural source and our proposed methodology may in general help in better understanding the influence of anatomy on function such as measured by EEG or fMRI. PMID:27383146

  15. Semi-Automatic Segmentation of Optic Radiations and LGN, and Their Relationship to EEG Alpha Waves.

    Directory of Open Access Journals (Sweden)

    Emmanuelle Renauld

    Full Text Available At rest, healthy human brain activity is characterized by large electroencephalography (EEG fluctuations in the 8-13 Hz range, commonly referred to as the alpha band. Although it is well known that EEG alpha activity varies across individuals, few studies have investigated how this may be related to underlying morphological variations in brain structure. Specifically, it is generally believed that the lateral geniculate nucleus (LGN and its efferent fibres (optic radiation, OR play a key role in alpha activity, yet it is unclear whether their shape or size variations contribute to its inter-subject variability. Given the widespread use of EEG alpha in basic and clinical research, addressing this is important, though difficult given the problems associated with reliably segmenting the LGN and OR. For this, we employed a multi-modal approach and combined diffusion magnetic resonance imaging (dMRI, functional magnetic resonance imaging (fMRI and EEG in 20 healthy subjects to measure structure and function, respectively. For the former, we developed a new, semi-automated approach for segmenting the OR and LGN, from which we extracted several structural metrics such as volume, position and diffusivity. Although these measures corresponded well with known morphology based on previous post-mortem studies, we nonetheless found that their inter-subject variability was not significantly correlated to alpha power or peak frequency (p >0.05. Our results therefore suggest that alpha variability may be mediated by an alternative structural source and our proposed methodology may in general help in better understanding the influence of anatomy on function such as measured by EEG or fMRI.

  16. 25G玻璃体切割系统在眼前节手术中的应用进展%25-gauge vitrectomy system for the surgery of eye anterior segment

    Institute of Scientific and Technical Information of China (English)

    张影影; 张立贵

    2012-01-01

    25 G经结膜无缝合玻璃体切割系统的出现,标志着微创玻璃体切割手术取得了突破性进展,该系统在一些眼底疾病的治疗中已取得令人满意的疗效,随着对其不断改进,目前已逐步应用到眼前节手术中,尤其在儿童白内障手术中经角巩膜缘或扁平部行后囊膜切开联合前段玻璃体切割术更突显其微创优势.本文就25 G玻璃体切割系统的工作原理和优点、在眼前节手术中的临床应用及其潜在并发症等作一综述.%One of the most revolutionary developments in vitreoretinal surgery is 25-gauge transconjunctival sutureless vitrectomy.Its use in the treatment of retina diseases has achieved signifcant effects.With the improvement of surgical technique,it has been developed for application to the operation of eye anterior segment,especially for pediatric cataract surgery,during which posterior capsulotomy and anterior vitrectomy are performed via a corneoscleral limbal or pars plana approach with it.This paper summaries the principle,advantages,indications and the potential accomplications of 25-gauge transconjunctival sutureless vitrectomy system for the surgery of eye anterior segment.

  17. Localization and segmentation of optic disc in retinal images using circular Hough transform and grow-cut algorithm

    Science.gov (United States)

    Abdullah, Muhammad; Barman, Sarah A.

    2016-01-01

    Automated retinal image analysis has been emerging as an important diagnostic tool for early detection of eye-related diseases such as glaucoma and diabetic retinopathy. In this paper, we have presented a robust methodology for optic disc detection and boundary segmentation, which can be seen as the preliminary step in the development of a computer-assisted diagnostic system for glaucoma in retinal images. The proposed method is based on morphological operations, the circular Hough transform and the grow-cut algorithm. The morphological operators are used to enhance the optic disc and remove the retinal vasculature and other pathologies. The optic disc center is approximated using the circular Hough transform, and the grow-cut algorithm is employed to precisely segment the optic disc boundary. The method is quantitatively evaluated on five publicly available retinal image databases DRIVE, DIARETDB1, CHASE_DB1, DRIONS-DB, Messidor and one local Shifa Hospital Database. The method achieves an optic disc detection success rate of 100% for these databases with the exception of 99.09% and 99.25% for the DRIONS-DB, Messidor, and ONHSD databases, respectively. The optic disc boundary detection achieved an average spatial overlap of 78.6%, 85.12%, 83.23%, 85.1%, 87.93%, 80.1%, and 86.1%, respectively, for these databases. This unique method has shown significant improvement over existing methods in terms of detection and boundary extraction of the optic disc.

  18. Localization and segmentation of optic disc in retinal images using circular Hough transform and grow-cut algorithm.

    Science.gov (United States)

    Abdullah, Muhammad; Fraz, Muhammad Moazam; Barman, Sarah A

    2016-01-01

    Automated retinal image analysis has been emerging as an important diagnostic tool for early detection of eye-related diseases such as glaucoma and diabetic retinopathy. In this paper, we have presented a robust methodology for optic disc detection and boundary segmentation, which can be seen as the preliminary step in the development of a computer-assisted diagnostic system for glaucoma in retinal images. The proposed method is based on morphological operations, the circular Hough transform and the grow-cut algorithm. The morphological operators are used to enhance the optic disc and remove the retinal vasculature and other pathologies. The optic disc center is approximated using the circular Hough transform, and the grow-cut algorithm is employed to precisely segment the optic disc boundary. The method is quantitatively evaluated on five publicly available retinal image databases DRIVE, DIARETDB1, CHASE_DB1, DRIONS-DB, Messidor and one local Shifa Hospital Database. The method achieves an optic disc detection success rate of 100% for these databases with the exception of 99.09% and 99.25% for the DRIONS-DB, Messidor, and ONHSD databases, respectively. The optic disc boundary detection achieved an average spatial overlap of 78.6%, 85.12%, 83.23%, 85.1%, 87.93%, 80.1%, and 86.1%, respectively, for these databases. This unique method has shown significant improvement over existing methods in terms of detection and boundary extraction of the optic disc. PMID:27190713

  19. Segmental anterior cervical decompression with fusion for treating multilevel cervical myelopathy%颈前路分节段减压融合治疗多节段颈椎病

    Institute of Scientific and Technical Information of China (English)

    林昊; 何仿; 李健; 崔庆元; 陈小强; 田纪伟

    2011-01-01

    Objective To evaluate the clinical value of the segmental anterior cervical decompression with fusion for treating multilevel cervical myelopathy.Methods 24 patients of multilevel cervical myelopathy with 3 or 4 consecutive segments were treated with segmental anterior cervical decompression with fusion.All patientst' cervical plain films,magnetic resonance imaging( MRI ) on preoperation and cervical plain films on postoperation were ohserved.The JOA scores of preoperation and 3 months postoperatively were collected.Results 24 cases were followed up from 3 months to 48 months, average 28 months.All patients improved their functional status in different degree.No complications such as graft nonunion and graft suhsidence occurred.The mean preoperative JOA score of all patients was ( 8.20 ±2.26 ),the postoperative of 3 months was ( 13.50 ± 1.28 ) , the average JOA recovery rate was 60.2%.Fusion rate was 100%.Conclusions The segmental anterior cervical decompression with fusion for treating multilevel cervical myelopathy appears to be effective in decompressing spinal cord, improving nerve functional status and restoring lordosis to the cervical spine with high fusion rate and fewer complications.%目的 评价颈前路分节段减压植骨融合术治疗多节段颈椎病的临床疗效.方法 对24例连续3或4个节段病变的颈椎病患者采用分节段减压融合术治疗.均行术前X线、MRI和术后X线片检查.均于术前及术后3个月进行JOA评分.结果 24例均获随访,时间3~48(28±20)个月.患者功能均有不同程度的改善.无植骨块不愈合、内置物下沉等并发症发生.JOA评分术前平均为(8.20±2.26)分,术后3个月平均为(13.50±1.28),改善率为60.2%,植骨融合率100%.结论 颈椎前路分节段减压融合术具有减压彻底、术后神经功能恢复好、恢复颈椎曲度、融合率高、并发症少等优点.

  20. Reversal of segmental hypokinesis by coronary angioplasty in patients with unstable angina, persistent T wave inversion, and left anterior descending coronary artery stenosis. Additional evidence for myocardial stunning in humans

    International Nuclear Information System (INIS)

    To evaluate the significance of persistent negative T waves during severe ischemia, we prospectively studied 62 patients admitted for unstable angina without evidence of recent or ongoing myocardial infarction. A critical stenosis on the left anterior descending coronary artery (LAD), considered as the culprit lesion, was successfully treated by percutaneous transluminal coronary angioplasty (PTCA). The patients were divided into two groups according to the admission electrocardiogram: T NEG group (n = 32) had persistent negative T waves, and the T POS group (n = 30) had normal positive T waves on precordial leads. The two groups had similar baseline clinical, hemodynamic, and angiographic characteristics. All patients underwent a complete clinical and angiographic evaluation (coronary arteriography and left ventriculography) before undergoing PTCA and 8 +/- 3 months later. Left ventricular anterior wall motion was evaluated by the percent shortening of three areas (S1, S2, and S3) considered as LAD-related segments on left ventriculograms. Before PTCA, there was no significant difference in global ejection fraction between the two groups despite a significant depression in anterior mean percent area shortening in the T NEG compared with the T POS group (S1, 44 versus 54, p less than 0.01; S2, 39 versus 48, p less than 0.01; S3, 44 versus 50, NS). At repeated angiography, the anterior mean percent area shortening improved significantly in the T NEG group (S1, from 44 to 61, p less than 0.001; S2, from 39 to 58, p less than 0.001; S3, from 44 to 61, p less than 0.001)

  1. Object-Based Canopy Gap Segmentation and Classification: Quantifying the Pros and Cons of Integrating Optical and LiDAR Data

    Directory of Open Access Journals (Sweden)

    Jian Yang

    2015-11-01

    Full Text Available Delineating canopy gaps and quantifying gap characteristics (e.g., size, shape, and dynamics are essential for understanding regeneration dynamics and understory species diversity in structurally complex forests. Both high spatial resolution optical and light detection and ranging (LiDAR remote sensing data have been used to identify canopy gaps through object-based image analysis, but few studies have quantified the pros and cons of integrating optical and LiDAR for image segmentation and classification. In this study, we investigate whether the synergistic use of optical and LiDAR data improves segmentation quality and classification accuracy. The segmentation results indicate that the LiDAR-based segmentation best delineates canopy gaps, compared to segmentation with optical data alone, and even the integration of optical and LiDAR data. In contrast, the synergistic use of two datasets provides higher classification accuracy than the independent use of optical or LiDAR (overall accuracy of 80.28% ± 6.16% vs. 68.54% ± 9.03% and 64.51% ± 11.32%, separately. High correlations between segmentation quality and object-based classification accuracy indicate that classification accuracy is largely dependent on segmentation quality in the selected experimental area. The outcome of this study provides valuable insights of the usefulness of data integration into segmentation and classification not only for canopy gap identification but also for many other object-based applications.

  2. The role of prosthesis design on segmental biomechanics: Semi-constrained versus unconstrained prostheses and anterior versus posterior centre of rotation

    OpenAIRE

    Wilke, Hans-Joachim; Schmidt, René; Richter, Marcus; Schmoelz, Werner; Reichel, Heiko; Cakir, Balkan

    2010-01-01

    The purpose of this study was to evaluate the influence of different implant designs of total lumbar disc replacements on the segmental biomechanics of the lumbar spine. The unconstrained Charité, the semi-constrained Prodisc and a semi-constrained Prototype with more posterior centre of rotation than the Prodisc were tested in vitro using six human, lumbar spines L2–L5. The segmental lordosis was measured on plain radiographs and the range of motion (ROM) for all six degrees of freedom with ...

  3. Intravitreal Injection of a Rho-Kinase Inhibitor (Fasudil) for Recent-Onset Nonarteritic Anterior Ischemic Optic Neuropathy.

    Science.gov (United States)

    Sanjari, Nasrin; Pakravan, Mohammad; Nourinia, Ramin; Esfandiari, Hamed; Hafezi-Moghadam, Ali; Zandi, Souska; Nakao, Shintaro; Shah-Heidari, Mohamamad-Hassan; Jamali, Arsia; Yaseri, Mehdi; Ahmadieh, Hamid

    2016-06-01

    This study evaluated the effects of intravitreal injection of fasudil (IVF), a Rho-kinase inhibitor, in cases of recent-onset nonarteritic anterior ischemic optic neuropathy (NAION). In this interventional case series, 13 eyes of 13 patients diagnosed with NAION within 14 days of onset were included. The affected eyes received a 0.025 mg/0.05 mL IVF. Functional and structural outcomes were assessed 1 and 3 months following treatment. Best corrected visual acuity (BCVA) was the main outcome measured, with mean deviation (MD) index of the VF test and peripapillary retinal nerve fiber layer thickness as secondary measures. There was a statistically significant improvement in the patients' BCVA 1 and 3 months following IVF; BCVA improved from 1.69 ± 0.55 logMAR at baseline to 0.98 ± 0.47 and 0.93 ± 0.51 logMAR at 1 and 3 months, respectively (P = .004). The change in BCVA was not significant between month 1 and month 3 (P = .22). Peripapillary retinal nerve fiber layer thickness decreased from 173.5 ± 29.28 µm in the baseline evaluation to 85.8 ± 8.8 µm at 1 month, and 62.9 ± 5.97 µm at 3 months (P = .003). MD values changed from 24.60 ± 3.80 to 21.0 ± 6.10 and 20.5 ± 6.50 at 1 and 3 months, respectively (P = .007 and .005, respectively). This pilot study suggests that IVF may be an effective treatment for patients with recent-onset NAION. Larger studies are required to establish the therapeutic role of fasudil for NAION. PMID:26444290

  4. Combined use of high-definition and volumetric optical coherence tomography for the segmentation of neural canal opening in cases of optic nerve edema

    Science.gov (United States)

    Wang, Jui-Kai; Kardon, Randy H.; Garvin, Mona K.

    2015-03-01

    In cases of optic-nerve-head edema, the presence of the swelling reduces the visibility of the underlying neural canal opening (NCO) within spectral-domain optical coherence tomography (SD-OCT) volumes. Consequently, traditional SD-OCT-based NCO segmentation methods often overestimate the size of the NCO. The visibility of the NCO can be improved using high-definition 2D raster scans, but such scans do not provide 3D contextual image information. In this work, we present a semi-automated approach for the segmentation of the NCO in cases of optic disc edema by combining image information from volumetric and high-definition raster SD-OCT image sequences. In particular, for each subject, five high-definition OCT B-scans and the OCT volume are first separately segmented, and then the five high-definition B-scans are automatically registered to the OCT volume. Next, six NCO points are placed (manually, in this work) in the central three high-definition OCT B-scans (two points for each central B-scans) and are automatically transferred into the OCT volume. Utilizing a combination of these mapped points and the 3D image information from the volumetric scans, a graph-based approach is used to identify the complete NCO on the OCT en-face image. The segmented NCO points using the new approach were significantly closer to expert-marked points than the segmented NCO points using a traditional approach (root mean square differences in pixels: 5.34 vs. 21.71, p < 0.001).

  5. Application of Multifractal Analysis to Segmentation of Water Bodies in Optical and Synthetic Aperture Radar Satellite Images

    CERN Document Server

    Martin, Victor Manuel San

    2016-01-01

    A method for segmenting water bodies in optical and synthetic aperture radar (SAR) satellite images is proposed. It makes use of the textural features of the different regions in the image for segmentation. The method consists in a multiscale analysis of the images, which allows us to study the images regularity both, locally and globally. As results of the analysis, coarse multifractal spectra of studied images and a group of images that associates each position (pixel) with its corresponding value of local regularity (or singularity) spectrum are obtained. Thresholds are then applied to the multifractal spectra of the images for the classification. These thresholds are selected after studying the characteristics of the spectra under the assumption that water bodies have larger local regularity than other soil types. Classifications obtained by the multifractal method are compared quantitatively with those obtained by neural networks trained to classify the pixels of the images in covered against uncovered b...

  6. Segmentation and quantification of retinal lesions in age-related macular degeneration using polarization-sensitive optical coherence tomography

    Science.gov (United States)

    Baumann, Bernhard; Götzinger, Erich; Pircher, Michael; Sattmann, Harald; Schütze, Christopher; Schlanitz, Ferdinand; Ahlers, Christian; Schmidt-Erfurth, Ursula; Hitzenberger, Christoph K.

    2010-11-01

    We present polarization-sensitive optical coherence tomography (PS-OCT) for quantitative assessment of retinal pathologies in age-related macular degeneration (AMD). On the basis of the polarization scrambling characteristics of the retinal pigment epithelium, novel segmentation algorithms were developed that allow one to segment pathologic features such as drusen and atrophic zones in dry AMD as well as to determine their dimensions. Results from measurements in the eyes of AMD patients prove the ability of PS-OCT for quantitative imaging based on the retinal features polarizing properties. Repeatability measurements were performed in retinas diagnosed with drusen and geographic atrophy in order to evaluate the performance of the described methods. PS-OCT appears as a promising imaging modality for three-dimensional retinal imaging and ranging with additional contrast based on the structures' tissue-inherent polarization properties.

  7. Bilateral ocular abnormalities in a wild stranded harp seal (Phoca groenlandica) suggestive of anterior segment dysgenesis and persistent hyperplastic primary vitreous.

    Science.gov (United States)

    Erlacher-Reid, Claire; Colitz, Carmen M H; Abrams, Ken; Smith, Ainsley; Tuttle, Allison D

    2011-06-01

    A male yearling harp seal (Phoca groenlandica) stranded and was brought to Mystic Aquarium & Institute for Exploration's Seal Rescue and Rehabilitation Center. The seal presented with a bilateral pendular vertical nystagmus, negative menace response, and a positive palpebral response. Ophthalmological examination by slit lamp biomicroscopy revealed perilimbal corneal edema, excessive iridal surface structures, pupils that appeared to be shaped improperly (dyscoria), and suspected cataracts. Attempts to dilate the pupils with both dark-lighted conditions and repeated dosages of 10% phenylephrine and 1% atropine ophthalmic solution in each eye (OU) were unsuccessful. Ocular ultrasonography findings suggested bilateral cataracts with flattened anterior-posterior (A-P) diameter and possible persistent hyperplastic primary vitreous. It is possible that these structural congenital abnormalities could produce further ocular complications for this seal including uveitis, secondary glaucoma, retinal detachment, and/or vitreal hemorrhage in the future. This case demonstrates the importance of a thorough ophthalmological examination in stranded wild animals, especially if their symptoms appear neurological. PMID:22946409

  8. Automatic Registration Method for Optical Remote Sensing Images with Large Background Variations Using Line Segments

    Directory of Open Access Journals (Sweden)

    Xiaolong Shi

    2016-05-01

    Full Text Available Image registration is an essential step in the process of image fusion, environment surveillance and change detection. Finding correct feature matches during the registration process proves to be difficult, especially for remote sensing images with large background variations (e.g., images taken pre and post an earthquake or flood. Traditional registration methods based on local intensity probably cannot maintain steady performances, as differences are significant in the same area of the corresponding images, and ground control points are not always available in many disaster images. In this paper, an automatic image registration method based on the line segments on the main shape contours (e.g., coastal lines, long roads and mountain ridges is proposed for remote sensing images with large background variations because the main shape contours can hold relatively more invariant information. First, a line segment detector called EDLines (Edge Drawing Lines, which was proposed by Akinlar et al. in 2011, is used to extract line segments from two corresponding images, and a line validation step is performed to remove meaningless and fragmented line segments. Then, a novel line segment descriptor with a new histogram binning strategy, which is robust to global geometrical distortions, is generated for each line segment based on the geometrical relationships,including both the locations and orientations of theremaining line segments relative to it. As a result of the invariance of the main shape contours, correct line segment matches will have similar descriptors and can be obtained by cross-matching among the descriptors. Finally, a spatial consistency measure is used to remove incorrect matches, and transformation parameters between the reference and sensed images can be figured out. Experiments with images from different types of satellite datasets, such as Landsat7, QuickBird, WorldView, and so on, demonstrate that the proposed algorithm is

  9. Performance evaluation of automated segmentation software on optical coherence tomography volume data.

    Science.gov (United States)

    Tian, Jing; Varga, Boglarka; Tatrai, Erika; Fanni, Palya; Somfai, Gabor Mark; Smiddy, William E; Debuc, Delia Cabrera

    2016-05-01

    Over the past two decades a significant number of OCT segmentation approaches have been proposed in the literature. Each methodology has been conceived for and/or evaluated using specific datasets that do not reflect the complexities of the majority of widely available retinal features observed in clinical settings. In addition, there does not exist an appropriate OCT dataset with ground truth that reflects the realities of everyday retinal features observed in clinical settings. While the need for unbiased performance evaluation of automated segmentation algorithms is obvious, the validation process of segmentation algorithms have been usually performed by comparing with manual labelings from each study and there has been a lack of common ground truth. Therefore, a performance comparison of different algorithms using the same ground truth has never been performed. This paper reviews research-oriented tools for automated segmentation of the retinal tissue on OCT images. It also evaluates and compares the performance of these software tools with a common ground truth. PMID:27159849

  10. Nursing of slit-lamp anterior segment processing system in treatments of corneal foreign body%裂隙灯眼前段处理系统在角膜异物中的应用及护理

    Institute of Scientific and Technical Information of China (English)

    李伍英; 丛日昌

    2010-01-01

    目的 探讨裂隙灯眼前段处理系统在治疗角膜异物中的应用及护理.方法 将120例患者随机分为对照组(n=60)和实验组(n=60),对照组采用传统检查治疗方法 .实验组应用配置佳能PowerShotA720IS型数码照相机(1 200万像素)SLM型裂隙灯显微镜检查角膜异物的位置,并在不同角度下进行照相(放大倍率×10,×16,×20).结果 实验组患者对医护人员信任度和满意度高于对照组,差异有统计学意义(P<0.05).结论 裂隙灯眼前段处理系统的应用为角膜异物伤的患者提供直接定性依据,给患者了解自身病情带来便利,同时进行相关的护理,达到较理想的效果.%Objective To explore the application and nursing of slit-lamp anterior segment processing system in treatments of corneal foreign body. Methods Totally, 120 cases were divided into the control group and the experimental group randomly, the 60 cases of control group received the traditional treatment and the other 60 cases received the Canon PowerShotA720IS numerical code camera (12,000,000 picture elements)SLM slit lamp to show the position of corneal foreign body, and were carried on some photographs under different angles ( the enlargement ratio ×10, ×16, ×20). Results The rate of credibility and satisfaction to the medical care personnel in experimental group were higher than that in control group, the difference has statistical significance. Conclusions The application of slit-lamp anterior segment processing system provides the direct qualitative basis for the patients. It's convenient for patients to understand their state of the illness, and at the same time, it will achieve the ideal effect when carrying on the relative nursing.

  11. Hybrid Surgery术式治疗颈前路多节段脊髓型颈椎病的临床分析%Clinic analysis of Hybrid Surgery to treat multi segmental anterior cervical spondylotic myelopathy

    Institute of Scientific and Technical Information of China (English)

    福嘉欣; 江汉; 江毅; 肖联平; 田永刚

    2015-01-01

    Objective To investigate the effect of corpectomy decompression by subtotal vertebrectomy and fusion of adjacent segmental artificial disc replacement through anterior intervertenral spance (Hybrid Surgery) in the anteriorcervical spondylotic myelopathy treatment . Methods Hybrid Surgery were operated on 18 patients who suffered from anterior cervi⁃cal spondylotic myelopathy . Follow up of 1-50 months. Patient’s conditions were assessed according to the Japanese Associ⁃ation for Department of orthopedics assessment score (JOA score) before and after operation. Effects of Hybrid operation were assessed by the improvement of JOA score, Odom’s follow-up grade and cervical mobility . Results The JOA scores of all 18 operated patients were improved from 10.6 ± 1.7 before operation to 13.5 ± 2.4 after operation. And the difference is statistically significant (t=1.314, P 0.05). Conclusion Hybrid Surgery of anterior cervical decompression and fusion can both improve the nerve function and preserve cervical mobility.%目的:探讨颈椎前路经椎间隙或椎体次全切除减压植骨融合联合邻近节段人工间盘置换(Hybrid Surgery)在颈前路多节段脊髓型颈椎病治疗中的效果。方法应用Hybrid Surgery术式治疗颈前路多节段脊髓型颈椎病患者18例。随访1~50个月,手术前后根据日本骨科协会评估分数(JOA)进行评分。通过JOA评分的改善情况, Odom’s分级随访结果及颈椎活动度的变化评价Hybrid Surgery的效果。结果18例术后JOA评分(13.5±2.4)分高于术前(10.6±1.7)分,差异有统计学意义(t=1.314,P0.05)。结论 Hybrid Surgery术式颈前路充分减压融合,既可改善患者神经功能,又可保留一定程度上的颈椎活动度。

  12. Ophthalmohelioses and peripheral light focusing by the anterior eye

    Science.gov (United States)

    Coroneo, Minas T.

    1994-07-01

    A coincidence of the locations of foci of scattered light in the anterior eye with the usual locations of common sun-related eye conditions has been observed. These phenomena may explain the pathogenesis of pterygium and the initial location of certain cortical lens opacities and eyelid malignancies. Human and bovine eyes were used to demonstrate that the anterior eye acts as a side-on lens system. Light incident at the temporal limbus can be concentrated at the nasal limbus or beyond or at the nasal crystalline lens equator. The main pathways of light are transcameral and this is demonstrated by the use of baffles. Although this phenomenon is obvious with visible light, focusing of light at 308nm can be demonstrated. Computer-assisted optical ray tracing in a standard human anterior segment model showed that the peak intensity at the distal limbus is approximately twenty times that of the incident light intensity. The degree of limbal focusing is determined by corneal shape and anterior chamber depth. Such light focusing may be particularly injurious to corneal and lenticular epithelial stem cells. These observations provide circumstantial evidence that peripheral refraction phenomena are involved in the pathogenesis of the anterior ophthalmohelioses. Adequate lateral protection of the eye from increasing ultraviolet insolation may be prudent.

  13. A CASE OF ANGLE - CLOSURE GLAUCOMA SECONDARY TO CHRONIC ANTERIOR UVEITIS

    Directory of Open Access Journals (Sweden)

    Pandu

    2015-05-01

    Full Text Available Elevation of intraocular pressure secondary to intraocular inflammation frequently presents a diagnostic & therapeutic challenge. Secondary glaucoma is more common in chronic anterior uveitis. We present a case of the same, a 25 years old female presented with headache and redness in right eye. She gives history of gradual loss of vision in both eyes 15 years back. On examination there was no perception of light in both eyes and pupillary reactions were absent in both eyes. Anterior segment of right eye showed circumciliary congestion, corneal edema, peripheral anterior synechiae, Aqueous flare of grade 1+, annular posterior synechiae with complicated cataract. Anterior segment of left eye showed shallow anterior chamber with closed angles and complicated cataract. A clinical diagnosis of secondary angle closure glaucoma was made. Once IOP was under control she underwent synechotomy and lens extraction in right eye and lens extraction in left eye. Post operatively corneal edema and congestion resolved. Fundus examination revealed glaucomatous optic atrophy. Thus, prompt and early treatment of anterior uveitis is needed to prevent secondary angle closure glaucoma. We report a case of secondary angle closure glaucoma in a young female patient.

  14. Edge Control in Large Segmented Optics Using Zeeko Polishing Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The fabrication of very large optical telescopes for space astronomy can be prohibitively costly due to the immense weight and size of monolithic primary mirrors....

  15. A dual purpose optical truss laser metrology system for a space-based far-IR segmented telescope: Figure maintenance and pointing control

    Science.gov (United States)

    Lau, Kenneth

    1992-01-01

    To obtain imaging performance as for monolithic mirrors, large segmented reflectors used for astronomy must be actively aligned and pointed to extreme levels of precision. A system concept for a dual purpose optical truss laser metrology system is described which is used for both figure and alignment maintenance and telescope pointing. A two-stage figure active control approach was developed for several proposed spaceborne far infrared segmented telescopes, one of which is the 10-20 meters Large Deployable Reflector (LDR). The first active control stage, the figure initialization control system, aligns the optical elements (i.e., the primary segments, secondary and focal plane assembly) based on images obtained. The second stage, the figure maintenance control system, maintains the alignment between re-initializations using measurements provided by laser interferometers arranged in an optical truss configuration. It measures the relative positions and alignments of the telescope segments so that a controller can reposition them appropriately. The application of this optical truss for figure maintenance control is the subject of the first part of this paper. The second portion of this paper discusses the application of the optical truss to telescope pointing. Here, the laser metrology system is used to transfer pointing information from an external fine guidance sensor (FGS) to the telescope optical boresight as defined by the primary mirror, secondary mirror, and focal plane assembly. Thus, any alignment variations between the two boresights can be observed and accounted for.

  16. Active figure maintenance control using an optical truss laser metrology system for a space-based far-IR segmented telescope

    Science.gov (United States)

    Lau, Kenneth; Breckenridge, Bill; Nerheim, Noble; Redding, David

    1992-01-01

    A two-stage active control approach was developed addressing the figure control problem for a spaceborne FIR telescope, the Precision Segmented Reflectors Focus Moderate Mission Telescope (FMMT). The first active control stage aligns the optical segments based on images; attention is here given to the second stage, active figure maintenance control system, which maintains the alignment of the optical elements between initializations to hold the mirror figure steady while obtaining data and fixes translational and rotational changes of the optical segments induced by long-term thermal drifts of the support structure. Errors are expected to be 10-100 microns at the nodes of the primary backup structure over the course of an orbit. An rms performance of 0.8 microns of wavefront error can be expected during the maintenance function based on specified nominal sensor noises, actuator accuracies, and system environments. A performance of less than 0.3 microns rms can be expected, based on advanced components.

  17. Automated detection of kinks from blood vessels for optic cup segmentation in retinal images

    Science.gov (United States)

    Wong, D. W. K.; Liu, J.; Lim, J. H.; Li, H.; Wong, T. Y.

    2009-02-01

    The accurate localization of the optic cup in retinal images is important to assess the cup to disc ratio (CDR) for glaucoma screening and management. Glaucoma is physiologically assessed by the increased excavation of the optic cup within the optic nerve head, also known as the optic disc. The CDR is thus an important indicator of risk and severity of glaucoma. In this paper, we propose a method of determining the cup boundary using non-stereographic retinal images by the automatic detection of a morphological feature within the optic disc known as kinks. Kinks are defined as the bendings of small vessels as they traverse from the disc to the cup, providing physiological validation for the cup boundary. To detect kinks, localized patches are first generated from a preliminary cup boundary obtained via level set. Features obtained using edge detection and wavelet transform are combined using a statistical approach rule to identify likely vessel edges. The kinks are then obtained automatically by analyzing the detected vessel edges for angular changes, and these kinks are subsequently used to obtain the cup boundary. A set of retinal images from the Singapore Eye Research Institute was obtained to assess the performance of the method, with each image being clinically graded for the CDR. From experiments, when kinks were used, the error on the CDR was reduced to less than 0.1 CDR units relative to the clinical CDR, which is within the intra-observer variability of 0.2 CDR units.

  18. Anterior tarsaltunnelsyndrom

    DEFF Research Database (Denmark)

    Miliam, Palle B; Basse, Peter N

    2009-01-01

    Anterior tarsal tunnel syndrome is a rare entrapment neuropathy of the deep peroneal nerve beneath the extensor retinaculum of the ankle. It may be rare because it is underrecognized clinically.We present a case regarding a 29-year-old man, drummer, who for one and a half year experienced clinical...

  19. Object-Based Canopy Gap Segmentation and Classification: Quantifying the Pros and Cons of Integrating Optical and LiDAR Data

    OpenAIRE

    Jian Yang; Trevor Jones; John Caspersen; Yuhong He

    2015-01-01

    Delineating canopy gaps and quantifying gap characteristics (e.g., size, shape, and dynamics) are essential for understanding regeneration dynamics and understory species diversity in structurally complex forests. Both high spatial resolution optical and light detection and ranging (LiDAR) remote sensing data have been used to identify canopy gaps through object-based image analysis, but few studies have quantified the pros and cons of integrating optical and LiDAR for image segmentation and ...

  20. 应用25G玻璃体切除术治疗白内障术后眼前段拥挤征%25-Gauge transconjunctival sutureless vitrectomy for crowded anterior segment after cataract surgery.

    Institute of Scientific and Technical Information of China (English)

    李雯; 荣翱

    2012-01-01

    Objective To investigate the application of 25-gauge transconjunctival sutureless vitrectomy system(25GTSV)on the treatment of crowded anterior segment(CAS)after phacoemulsification and intraocular lens implantation.Methods 15 cases(15 eyes)of CAS after cataract surgery were treated with posterior capsulotomy and anterior segment vitrectomy with 25GTSV.The follow-up periods were 6 ~ 12months[(8.0 ± 1.5)months].The visual acuity,intraocular pressure(IOP)and the depth of anterior chamber were recorded,the condition of cornea,pupil,intraocular lens and complication were observed.Results All operations were successful.The visual acuity of all cases were improved in different degree after treatment.The best corrected visual acuity before treatment,1 week after treatment and at the end of the followup period was(0.05 ± 0.02),(0.2 ± 0.1)and(0.4 ± 0.1)respectively.There were significant difference before and after treatment(t =0.00,P =0.00).The mean IOP 1 week after treatment and at the end of the follow-up period was(17.3 ± 1.8)mmHg and(16.5 ± 1.3)mmHg respectively.They were lower obviously than the mean IOP before surgery which was(40.1 ± 7.5)mmHg.There were significant difference between them(t =0.00,P =0.00).The mean depth of anterior chamber before treatment,1 week after treatment and at the end of the follow-up period was(0.69 ±0.17)mm,(2.7 1 ±0.43)mm and(2.85 ±0.52)mm respectively.There were significant difference before and after treatment(t =0.00,P =0.00).After surgery,the edema of cornea disappeared,the pupil is round and a round hyalomere with diameter of 3.0 ~ 4.0 mmwas formed at the center of lens ' posterior capsule in all eyes.No obvious complications were observed intraoperatively and postoperatively.Conclusion 25GTSV with micro-incision can release and cure CAS after cataract surgery effectively and safely.%目的 评价25G经结膜无缝合玻璃体切除手术系统(25G TSV)在白内障行超声乳化联合人工晶状体植入术后眼前

  1. Optical measurements of phase steps in segmented mirrors - fundamental precision limits

    CERN Document Server

    Noethe, L

    2006-01-01

    Phase steps are an important type of wavefront aberrations generated by large telescopes with segmented mirrors. In a closed-loop correction cycle these phase steps have to be measured with the highest possible precision using natural reference stars, that is with a small number of photons. In this paper the classical Fisher information of statistics is used for calculating the Cramer-Rao bound, which determines the limit to the precision with which the height of the steps can be estimated in an unbiased fashion with a given number of photons and a given measuring device. Four types of measurement devices are discussed: a Shack-Hartmann sensor with one small cylindrical lenslet covering a sub-aperture centred over a border, a modified Mach-Zehnder interferometer, a Foucault test, and a curvature sensor. The Cramer-Rao bound is calculated for all sensors under ideal conditions, that is narrowband measurements without additional noise or disturbances apart from the photon shot noise. This limit is compared with...

  2. Toxic anterior-segment syndrome (TASS)

    OpenAIRE

    Cetinkaya, Servet

    2014-01-01

    Servet Cetinkaya,1 Zeynep Dadaci,2 Hüsamettin Aksoy,3 Nursen Oncel Acir,2 Halil Ibrahim Yener,4 Ekrem Kadioglu5 1Ophthalmology Clinics, Turkish Red Crescent Hospital, Konya, 2Department of Ophthalmology, Faculty of Medicine, Mevlana University, Konya, 3Ophthalmology Clinics, Karaman State Hospital, Karaman, 4Konya Eye Center Hospital, Konya, 5Ophthalmology Clinics, Beyhekim State Hospital, Konya, Turkey Purpose: To evaluate the clinical findings and courses of five patients who dev...

  3. Toxic anterior-segment syndrome (TASS)

    OpenAIRE

    Cetinkaya S; Dadaci Z; Aksoy H; Acir NO; Yener HI; Kadioglu E

    2014-01-01

    Servet Cetinkaya,1 Zeynep Dadaci,2 Hüsamettin Aksoy,3 Nursen Oncel Acir,2 Halil Ibrahim Yener,4 Ekrem Kadioglu5 1Ophthalmology Clinics, Turkish Red Crescent Hospital, Konya, 2Department of Ophthalmology, Faculty of Medicine, Mevlana University, Konya, 3Ophthalmology Clinics, Karaman State Hospital, Karaman, 4Konya Eye Center Hospital, Konya, 5Ophthalmology Clinics, Beyhekim State Hospital, Konya, Turkey Purpose: To evaluate the clinical findings and courses of five patients who develop...

  4. Multivendor Spectral-Domain Optical Coherence Tomography Dataset, Observer Annotation Performance Evaluation, and Standardized Evaluation Framework for Intraretinal Cystoid Fluid Segmentation.

    Science.gov (United States)

    Wu, Jing; Philip, Ana-Maria; Podkowinski, Dominika; Gerendas, Bianca S; Langs, Georg; Simader, Christian; Waldstein, Sebastian M; Schmidt-Erfurth, Ursula M

    2016-01-01

    Development of image analysis and machine learning methods for segmentation of clinically significant pathology in retinal spectral-domain optical coherence tomography (SD-OCT), used in disease detection and prediction, is limited due to the availability of expertly annotated reference data. Retinal segmentation methods use datasets that either are not publicly available, come from only one device, or use different evaluation methodologies making them difficult to compare. Thus we present and evaluate a multiple expert annotated reference dataset for the problem of intraretinal cystoid fluid (IRF) segmentation, a key indicator in exudative macular disease. In addition, a standardized framework for segmentation accuracy evaluation, applicable to other pathological structures, is presented. Integral to this work is the dataset used which must be fit for purpose for IRF segmentation algorithm training and testing. We describe here a multivendor dataset comprised of 30 scans. Each OCT scan for system training has been annotated by multiple graders using a proprietary system. Evaluation of the intergrader annotations shows a good correlation, thus making the reproducibly annotated scans suitable for the training and validation of image processing and machine learning based segmentation methods. The dataset will be made publicly available in the form of a segmentation Grand Challenge. PMID:27579177

  5. Optical granulometric analysis of sedimentary deposits by color segmentation-based software: OPTGRAN-CS

    Science.gov (United States)

    Chávez, G. Moreno; Sarocchi, D.; Santana, E. Arce; Borselli, L.

    2015-12-01

    The study of grain size distribution is fundamental for understanding sedimentological environments. Through these analyses, clast erosion, transport and deposition processes can be interpreted and modeled. However, grain size distribution analysis can be difficult in some outcrops due to the number and complexity of the arrangement of clasts and matrix and their physical size. Despite various technological advances, it is almost impossible to get the full grain size distribution (blocks to sand grain size) with a single method or instrument of analysis. For this reason development in this area continues to be fundamental. In recent years, various methods of particle size analysis by automatic image processing have been developed, due to their potential advantages with respect to classical ones; speed and final detailed content of information (virtually for each analyzed particle). In this framework, we have developed a novel algorithm and software for grain size distribution analysis, based on color image segmentation using an entropy-controlled quadratic Markov measure field algorithm and the Rosiwal method for counting intersections between clast and linear transects in the images. We test the novel algorithm in different sedimentary deposit types from 14 varieties of sedimentological environments. The results of the new algorithm were compared with grain counts performed manually by the same Rosiwal methods applied by experts. The new algorithm has the same accuracy as a classical manual count process, but the application of this innovative methodology is much easier and dramatically less time-consuming. The final productivity of the new software for analysis of clasts deposits after recording field outcrop images can be increased significantly.

  6. CTA study on relationship between dominant A1 segment and the anterior communicating artery aneurysm%大脑前动脉 A1段优势征与前交通动脉瘤关系的 CTA 研究

    Institute of Scientific and Technical Information of China (English)

    王洪生; 陈晓峰; 陈斌; 殷尚炯; 赵佩林; 王志明

    2015-01-01

    目的:探讨大脑前动脉水平段( A1段)优势征与前交通动脉瘤( ACoAA )形成的关系。方法分析173例患者的64排CT血管成像(CTA)检查资料,并按CTA结果分为ACoAA组(83例)与正常对照组(90例)。观察指标:有无动脉瘤,动脉瘤的部位、形态、大小和瘤颈宽度、瘤顶指向及瘤体与周围结构的关系等,判定结果与手术及DSA结果进行对照。同时观察大脑前动脉A1段是否发育不良或缺如,是否存在一侧大脑前动脉A1段优势征。结果 ACoAA组中显示一侧大脑前动脉A1段优势征者的比率达80.7%,明显高于正常对照组的16.7%(P<0.05)。结论一侧大脑前动脉A1段优势征,另一侧A1段发育不良或缺如与ACoAA的发生有密切关系。%Objective To investigate the relationship between the dominant A 1 segment and presence of the anterior communicating artery aneurysm .Methods The data of 64-slice computed tomography angiography ( CTA ) of 173 cases were analysed retrospectively .The 173 cases were divided into anterior communicating artery aneurysm (ACoAA) group(83 cases) and control group (90 cases).The observation items were the presence of aneurysm and the location , shape, size, neck, axis point of every one aneurysm and the relationship of aneurysms to parent vessels and other branches and bone structure .The results of aneurysms were compared with clipping or coiling , at the same time, to observe the A1 segment of anterior cerebral artery whether had dysplasia or absence , whether existed the dominance of A 1 segment of anterior cerebral artery .Results The rate of display the dominance of A1 segment of anterior cerebral artery (80.7%) in the ACoAA group was higher than that in the control group (16.7%) ( P <0.05 ).Conclusion The development of the anterior communicating artery aneurysm closely related with the the dominance of A 1 segment of anterior cerebral artery and the dysplasia or

  7. The observation of anterior segment morphological changes in eyes with primary angle closure after LPI by using UBM%原发性前房角关闭行LPI后眼前节形态学的UBM观察

    Institute of Scientific and Technical Information of China (English)

    吴杨杨; 宋胜仿; 刘世纯; 李春华; 张永烨; 吕莎

    2014-01-01

    观察原发性前房角关闭(primary angle closure, PAC)行YAG激光周边虹膜切除术(laser peripheral iridotomy, LPI)后眼前节形态学的变化。方法:选择2012年3月至2013年3月在我院诊断为PAC并行LPI的患者28例(48眼)为研究对象,应用超声生物显微镜(ultrasound biomicroscopy, UBM),观察LPI术前及术后1天、1周、1个月及3个月各时间点颞上、正上、正下、颞侧、鼻侧共5个位点的房角开放距离(angle opening distance, AOD500)、小梁虹膜夹角(trabecu-lar-iris angle, TIA)、小梁睫状体距离(trabecular ciliary process distance, TCPD)、虹膜睫状体距离(iris ciliary process distance , ICPD)、虹膜晶体夹角(iris lens angle, ILA)、虹膜晶体接触距离(iris lens process distance, ILCD)、虹膜厚度1(iris thickness, ITl)、IT2、IT3以及中央前房深度(cental depth distance, ACD)的变化。结果:AOD500、TIA:术后较术前均增大(P<0.05);术后1周大于术后其余时间点(P>0.05)。TCPD:除个别位点较术前增加(P>0.05),其余时间点相应位点较术前增加(P<0.05);术后1周大于术后其余时间点(P>0.05)。ILA:术后较术前均减小(P<0.05);术后1天至术后3个月逐渐增大(P>0.05)。ILCD:术后较术前均增大(P<0.05),术后1天至术后3个月逐渐减小(P>0.05);IT1、IT2、IT3:术后较术前均减小(P<0.05);术后各时间点间比较(P>0.05)。ACD:术后较术前增加(P>0.05)。 LPI术前及术后各时间点平均ILA与平均ILCD的相关性显示二者呈高度负相关。结论:PAC患者行LPI术后周边前房明显加深,虹膜膨隆和瞳孔阻力减轻,但术后3个月内眼前节形态并不稳定,个别参考值有不同程度的回退,LPI术后有必要进行长期随访观察。%Objective To evaluate the changes in the anterior segment morphology by using ultrasound biomicroscopy (UBM) after YAG laser

  8. A segmented scintillator-lead photon calorimeter using a double wavelength shifter optical readout system

    International Nuclear Information System (INIS)

    The construction and performance of a prototype scintillator-lead photon calorimeter using a double wavelength shifter optical readout is described. The calorimeter is divided into four individual cells consisting of 44 layers of 3 mm lead plus 1 cm thick scintillator. The edges of each scintillator plate are covered by acrylic bars doped with a wavelength shifting material. The light produced in each scintillator plate is first converted in these bars, then converted a second time in a set of acrylic rods which run longitudinally through the calorimeter along the corners of each calorimeter cell. A photomultiplier is attached to each of these rods at the back end of the calorimeter. The energy resolution obtained with incident in the energy range 2-30 GeV is sigma/E = 0.12/√E. The uniformity of response across the front face of each cell was measured. Showers within each cell can be localised with an accuracy of better than sigma = 7 mm. (orig.)

  9. 原发性前房角关闭激光周边虹膜切除术后前房角的改变%Evaluation of changes in anterior segment morphology of primary angle closure after laser peripheral iridotomy

    Institute of Scientific and Technical Information of China (English)

    张英; 田祥; 潘乐

    2012-01-01

    Objective To discover primary angle closure (PAC) in eyes of anatomic narrow angle (ANA),evaluate quantify changes of the PAC in anterior segment morphology after laser iridotomy using ultrasound biomicroscopy (UBM) and explore the therapy of primary angle closure.Methods Prospective interventive observational case series.Twenty-eight eyes of patients presented PAC in the Department of Ophthalmology at Zunyi Medical College Hospital.PAC was presented on iris contacting with trabecular meshwork temporally in one UBM image.The PAC eyes were examined again by UBM in the both same light conditions and items at two weeks after laser peripheral iridotomy (LPI).Results The rate of PAC was significantly decreased after LPI in the same condition,the rate of PAC was 96.43% before LPI in dark condition,and it was significantly dropped down to 32.14% after LPI (x2 =14.45,P <0.05).In light condition,it was cut down from 67.86% to 7.14% after LPI (x2 =15.06,P <0.05).The AOD500 and TIA were increased after LPI (P <0.001),it indicated that the angle of PAC was widened after LPI.The ILCD of PAC was also added after LPI,but the ILA was decreased after LPI (P <0.001).This phenomenon suggested that the pupillary block was relieved after care of LPI.The IT1 was thinner in laser site quadrant in dark condition after LPI which combined Nd-YAG and green laser (P <0.05).There were no significant changes of the ACD (P >0.05).The ICPD was reduced in dark after LPI (t =2.519,P =0.012).The pupillary block was relieved; it leaded to iris caving backward.But the TCPD was added in light after LPI (t =-2.967,P =0.003).It suggested that the ciliary body removed towards the back after LPI.Conclusions LPI produces a significant widening of the peripheral anterior chamber angle and reducing the power of pupillary block for major PAC eyes,which have not peripheral anterior synechia,but not deeping the central anterior chamber distance.LPI can prevent most PAC from developing to PACG

  10. Perawatan Ortodontik Gigi Anterior Berjejal dengan Tulang Alveolar yang Tipis

    Directory of Open Access Journals (Sweden)

    Miesje K. Purwanegara

    2015-09-01

    Full Text Available Anterior teeth movement in orthodontic treatment is limited to labiolingual direction by very thin alveolar bone. An uncontrolled anterior tooth movement to labiolingual direction can cause alveolar bone perforation at its root segment. This case report is to remind us that alveolar bone thickness limits orthodontc tooth movement. A case of crowded anterior teeth with thin alveolar bone in malocclusion I is reported. This case is treated using adgewise orthodontic appliance. Protraction of anterior teeth is anticipated due to thin alveolar bone on the anterior surface. The conclusion is although the alveolar bone surrounding the crowded anterior teeth is thin, by controlling the movement the teeth reposition is allowed.

  11. Sipunculans and segmentation

    DEFF Research Database (Denmark)

    Wanninger, Andreas; Kristof, Alen; Brinkmann, Nora

    2009-01-01

    Comparative molecular, developmental and morphogenetic analyses show that the three major segmented animal groups- Lophotrochozoa, Ecdysozoa and Vertebrata-use a wide range of ontogenetic pathways to establish metameric body organization. Even in the life history of a single specimen, different...... mechanisms may act on the level of gene expression, cell proliferation, tissue differentiation and organ system formation in individual segments. Accordingly, in some polychaete annelids the first three pairs of segmental peripheral neurons arise synchronously, while the metameric commissures of the ventral...... nervous system form in anterior-posterior progression. Contrary to traditional belief, loss of segmentation may have occurred more often than commonly assumed, as exemplified in the sipunculans, which show remnants of segmentation in larval stages but are unsegmented as adults. The developmental...

  12. Comparison of retinal thickness by Fourier-domain optical coherence tomography and OCT retinal image analysis software segmentation analysis derived from Stratus optical coherence tomography images

    Science.gov (United States)

    Tátrai, Erika; Ranganathan, Sudarshan; Ferencz, Mária; Debuc, Delia Cabrera; Somfai, Gábor Márk

    2011-05-01

    Purpose: To compare thickness measurements between Fourier-domain optical coherence tomography (FD-OCT) and time-domain OCT images analyzed with a custom-built OCT retinal image analysis software (OCTRIMA). Methods: Macular mapping (MM) by StratusOCT and MM5 and MM6 scanning protocols by an RTVue-100 FD-OCT device are performed on 11 subjects with no retinal pathology. Retinal thickness (RT) and the thickness of the ganglion cell complex (GCC) obtained with the MM6 protocol are compared for each early treatment diabetic retinopathy study (ETDRS)-like region with corresponding results obtained with OCTRIMA. RT results are compared by analysis of variance with Dunnett post hoc test, while GCC results are compared by paired t-test. Results: A high correlation is obtained for the RT between OCTRIMA and MM5 and MM6 protocols. In all regions, the StratusOCT provide the lowest RT values (mean difference 43 +/- 8 μm compared to OCTRIMA, and 42 +/- 14 μm compared to RTVue MM6). All RTVue GCC measurements were significantly thicker (mean difference between 6 and 12 μm) than the GCC measurements of OCTRIMA. Conclusion: High correspondence of RT measurements is obtained not only for RT but also for the segmentation of intraretinal layers between FD-OCT and StratusOCT-derived OCTRIMA analysis. However, a correction factor is required to compensate for OCT-specific differences to make measurements more comparable to any available OCT device.

  13. Structural Alterations of Segmented Macular Inner Layers in Aquaporin4-Antibody-Positive Optic Neuritis Patients in a Chinese Population.

    Directory of Open Access Journals (Sweden)

    Chunxia Peng

    Full Text Available This study aimed to analyse the structural injury of the peripapillary retinal nerve fibre layer (pRNFL and segmented macular layers in optic neuritis (ON in aquaporin4-antibody (AQP4-Ab seropositivity(AQP4-Ab-positiveON patients and in AQP4-Ab seronegativity (AQP4-Ab-negative ON patients in order to evaluate their correlations with the best-corrected visual acuity (BCVA and the value of the early diagnosis of neuromyelitis optica (NMO.This is a retrospective, cross-sectional and control observational study.In total, 213 ON patients (291 eyes and 50 healthy controls (HC (100 eyes were recruited in this study. According to a serum AQP4-Ab assay, 98 ON patients (132 eyes were grouped as AQP4-Ab-positive ON and 115 ON patients (159 eyes were grouped as AQP4-Ab-negative ON cohorts. All subjects underwent scanning with spectralis optical coherence tomography (OCT and BCVA tests. pRNFL and segmented macular layer measurements were analysed.The pRNFL thickness in AQP4-Ab-positive ON eyes showed a more serious loss during 0-2 months (-27.61μm versus -14.47 μm and ≥6 months (-57.91μm versus -47.19μm when compared with AQP4-Ab-negative ON eyes. AQP4-Ab-positive ON preferentially damaged the nasal lateral pRNFL. The alterations in the macular ganglion cell layer plus the inner plexiform layer (GCIP in AQP4-Ab-positive ON eyes were similar to those in AQP4-Ab-negative ON eyes. AQP4-Ab-positive ON eyes had entirely different injury patterns in the inner nuclear layer (INL compared with AQP4-Ab-negative ON eyes during the first 6 months after the initial ON attack. These differences were as follows: the INL volume of AQP4-Ab-positive ON eyes had a gradual growing trend compared with AQP4-Ab-negative ON eyes, and it increased rapidly during 0-2 months, reached its peak during 2-4 months, and then decreased gradually. The pRNFL and GCIP in AQP4-Ab-positive ON eyes had positive correlations with BCVA. When the pRNFL thickness decreased to 95%CI (50.77

  14. ANTERIOR OSTEOPHYTE IDENTIFICATION IN CERVICAL VERTEBRAE

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    A. T. Chougale

    2011-06-01

    Full Text Available Radiologist always examines X-ray to determine abnormal changes in cervical, lumbar & thoracic vertebrae. Osteophyte (bony growth may appear at the corners of vertebrae so that vertebral shape becomes abnormal. This paper presents the idea from Image processing techniques such as customised Hough transform which will be used for segmentation which should be independent of rotation, scale, noise & shape. This segmented image will be then used for computing size invariant, convex hull based features to differentiate normal cervical vertebrae from cervical vertebrae containing anterior osteophyte. This approach effectively finds anterior osteophytes in cervical vertebrae.

  15. Evaluation of holmium laser versus cold knife in optical internal urethrotomy for the management of short segment urethral stricture

    Directory of Open Access Journals (Sweden)

    Sudhir Kumar Jain

    2014-01-01

    Conclusion: Both modalities are effective in providing immediate relief to patients with single and short segment (<2 cm long urethral strictures but more sustained response was attained with Cold knife urethrotomy.

  16. Uveítes anteriores associadas a doenças sistêmicas Anterior uveitis associated to systemic diseases

    Directory of Open Access Journals (Sweden)

    Maria Angélica Pavão Dimantas

    2003-01-01

    Full Text Available As uveítes anteriores são caracterizadas pela inflamação preponderante do segmento anterior do olho. Hiperemia conjuntival, reação de câmara anterior com células e "flare", precipitados ceráticos e sinéquias posteriores são sinais que compõem o quadro inflamatório. Aspectos clínicos de algumas doenças sistêmicas envolvidas na etiologia das uveítes anteriores serão abordados neste artigo.Anterior uveitis describes a disease predominantly limited to the anterior segment of the eye. Conjunctival hyperemia, anterior chamber cell and flare, keratic precipitates, and iris abnormalities including posterior synechiae characterize the inflammation. This article discusses clinical aspects of the systemic diseases that cause anterior uveitis with review of the literature.

  17. Phacoemulsification in anterior megalophthalmos.

    Science.gov (United States)

    Lee, Graham A; Hann, Joshua V; Braga-Mele, Rosa

    2006-07-01

    This case outlines the phacoemulsification technique used to overcome the challenge of the hyperdeep anterior chamber, weak zonules, abnormal anterior capsule, and large capsular bag. Key steps included trypan blue staining of the anterior capsule, a large capsulorhexis, prolapse of the nucleus into the anterior chamber with phacoemulsification anterior to the capsulorhexis, and a posterior chamber-placed iris-clip intraocular lens. Successful visual rehabilitation is achievable in these anatomically challenging eyes. PMID:16857490

  18. Application of Zero-P interbody fusion in degenerative disease at the adjacent segments after anterior cervical fusion%Zero-P椎间融合术在治疗颈前路融合术后相邻节段退变性疾病中的应用

    Institute of Scientific and Technical Information of China (English)

    程彩霞; 卢旭华; 谢宁; 郭翔; 郭群峰; 倪斌

    2012-01-01

    Objective To investigate the clinical outcomes of Zero-P interbody fusion in the treatment of degenerative disease at the adjacent segments after anterior cervical decompression and fusion with internal fixation. Methods Sixteen patients with degenerative diseases at adjacent segments after anterior cervical decompression and fusion with internal fixation received Zero-P anterior cervical interbody fusion. Japanese Orthopaedic Association ( JOA) scores were compared before and after the operation. Postoperative dysphagia and intervertebral fusion were observed. Results Postoperative JOA score was significantly increased as compared with preoperative score (P<0.05). No dysphagia occurred and all the patients obtained solid fusion. Conclusion The mid- and short-term curative effect is satisfactory for the Zero-P intervertebral fusion in the treatment of cervical degenerative disease in the adjacent segments after anterior cervical fusion.%目的 探讨采用Zero-P椎间融合术治疗颈前路减压融合内固定术后相邻节段退变性疾病的疗效.方法 对16例颈前路减压融合内固定术后发生相邻节段退变性疾病的患者采用Zero-P行颈前路椎间融合术,比较患者手术前后日本骨科学会(Japanese Orthopaedic Association,JOA)评分,观察患者术后吞咽困难发生情况及椎间融合情况.结果 患者术后JOA评分较术前提高,差异有统计学意义(P<0.05),未发生吞咽困难,所有患者均获得牢固融合.结论 采用Zero-P椎间融合术治疗颈前路融合术后相邻节段退变性疾病中短期疗效较好.

  19. Double anterior chamber in a patient with glaucoma and microspherophakia

    Directory of Open Access Journals (Sweden)

    Hamid Khakshoor

    2011-01-01

    Full Text Available We report the case of a 16-year-old woman with microspherophakia and secondary open angle glaucoma. The patient presented with a membrane dividing the anterior chamber into two segments without edema or Descemet′s membrane detachment. Slit lamp biomicroscopy, Pentacam, and specular microscopy images were obtained. Double anterior chamber is primarily found in patients with anterior chamber anomalies when there is no history of surgery or trauma.

  20. Anorgasmia in anterior spinal cord syndrome.

    OpenAIRE

    Berić, A; Light, J K

    1993-01-01

    Three male and two female patients with anorgasmia and dissociated sensory loss due to an anterior spinal cord syndrome are described. Clinical, neurophysiological and quantitative sensory evaluation revealed preservation of the large fibre dorsal column functions from the lumbosacral segments with concomitant severe dysfunction or absence of the small fibre neospinothalamic mediated functions. These findings indicate a role for the spinothalamic system in orgasm.

  1. RETAINED STONE PIECE IN ANTERIOR CHAMBER

    Directory of Open Access Journals (Sweden)

    ZvornicaninJasmin, Nadarevic-VodencarevicAmra

    2015-04-01

    Full Text Available ABSTRACT We read with interest the article by Surekha et al. regarding the retained stone piece in anterior chamber. Similar to the results of previous studies, the authors found that delayed intraocular foreign body (IOFB management can result in good visual outcome without an apparent increased risk of endophthalmitis or other deleterious side effects. However, the authors failed to explain the exact reason for the diminution of vision in patients left eye. It is unclear what the uncorrected visual acuity was and what kind of correction was used, more precisely type and amount of cylinder, given the presence of the corneal opacity. Since the size of the IOFB is approximately 4x4x1mm, significant irido-corneal angle changes resulting in intraocular pressure raise and optic nerve head damage can be expected. Traumatic glaucoma following open globe injury can occur in 2.7 to 19% of cases, with several risk factors associated with glaucoma development (advanced age, poor visual acuity at presentation,perforating rather than penetrating ocular injury,lens injury, presence of vitreous hemorrhage and presence of an IOFB. Earlier reportsof latetraumaticoptic neuropathy onset, even after several years, indicate that this possibility cannot be completely ruled out too. Therefore, repeated intraocular pressure measurements, gonioscopy, pupillary reaction assessment, together with through posterior segment examination including visual field and optical coherence tomography examinations can be useful in determining the possible optic nerve damage as one of the possible reasons for visual acuity reduction. The authors did not suggest any operative treatment at this time. However, it should bear in mind that the inert anterior chamber IOFB could be a risk factor for non-infectious endophthalmitis development even after many years. Also, long term retained anterior chamber foreign body leads to permanent endothelial cell loss and can even result in a corneal

  2. Anterior Myocardial Infarction Associated with Myocardial Bridging in a Young Man

    OpenAIRE

    Ngow, HA; Wan Khairina, WMN

    2010-01-01

    A 43-year-old man presented with acute extensive anterior ST-segment elevation myocardial infarction. During coronary angiogram, a segment of myocardial bridging was noted in the mid-segment of left anteriordescending artery. The association of myocardial bridging and an anterior ST segment elevation is rarely reported in the medical literature. Myocardial bridging is caused by systolic compression of a coronary artery by overlying myocardium tissue. It is a rare coronary artery anomaly, whic...

  3. Risk factors and treatment strategy for adjacent segment diseases after anterior cervical decompression and fusion%颈椎前路融合术后邻近节段退变性疾病的原因分析及治疗策略

    Institute of Scientific and Technical Information of China (English)

    王洪立; 姜建元; 吕飞舟; 马晓生; 夏新雷; 王立勋

    2014-01-01

    目的 探讨颈椎前路融合术后邻近节段退变性疾病的发生原因及治疗策略.方法 对2005年12月至2012年8月颈椎前路减压融合术后并发邻近节段退变性疾病的14例进行回顾性分析.男10例,女4例,初次手术年龄36~68岁,平均(52.0±11.0)岁.测量初次手术后颈椎整体曲度、手术节段局部曲度、钢板与上、下间隙的距离.二次手术时对节段数量≤2个且不伴严重后纵韧带或黄韧带骨化的9例采用颈椎前路减压融合内固定术,对节段数量≥3个且不伴明显后凸畸形、排列不稳及严重黄韧带骨化的3例采用颈椎后路减压椎管扩大成形术,对伴有明显后凸畸形、排列不稳且因技术原因无法行前路减压及合并严重黄韧带骨化的2例采用颈椎后路全椎板切除减压融合术.结果 初次术后邻近节段退变性疾病的发生时间为(9.3±4.4)年,二次手术时患者年龄(61.3±12.4)岁.初次术后颈椎整体曲度与手术节段局部曲度分别为12.4°±10.8°、1.5°±6.8°;钢板与上、下间隙的距离分别为(0.9±1.8)mm、(3.8±3.2) mm.二次术后平均随访(30.4±17.8)个月,末次随访时日本骨科学会颈椎病疗效评分改善率为73.9%±9.7%.结论 钢板与邻近间隙距离过小、手术节段局部曲度恢复不良可能是前路融合术后邻近节段退变性疾病的发生原因;二次手术方案的选择应根据病变累及节段、致压因素、颈椎曲度等因素进行综合分析.%Objective To investigate the risk factors and treatment strategy in treating adjacent segment diseases (ASD) after anterior cervical decompression and fusion.Methods Fourteen patients with ASD after anterior cervical decompression and fusion from December 2005 to August 2012 were analyzed.The overall curvature of the cervical spine,local curvature of surgical segments,and the distances between the plate and the upper and lower intervertebral space were measured and analyzed.10 males

  4. Segmentation error and macular thickness measurements obtained with spectral-domain optical coherence tomography devices in neovascular age-related macular degeneration

    Directory of Open Access Journals (Sweden)

    Moosang Kim

    2013-01-01

    Full Text Available Purpose: To evaluate frequency and severity of segmentation errors of two spectral-domain optical coherence tomography (SD-OCT devices and error effect on central macular thickness (CMT measurements. Materials and Methods: Twenty-seven eyes of 25 patients with neovascular age-related macular degeneration, examined using the Cirrus HD-OCT and Spectralis HRA + OCT, were retrospectively reviewed. Macular cube 512 × 128 and 5-line raster scans were performed with the Cirrus and 512 × 25 volume scans with the Spectralis. Frequency and severity of segmentation errors were compared between scans. Results: Segmentation error frequency was 47.4% (baseline, 40.7% (1 month, 40.7% (2 months, and 48.1% (6 months for the Cirrus, and 59.3%, 62.2%, 57.8%, and 63.7%, respectively, for the Spectralis, differing significantly between devices at all examinations (P < 0.05, except at baseline. Average error score was 1.21 ± 1.65 (baseline, 0.79 ± 1.18 (1 month, 0.74 ± 1.12 (2 months, and 0.96 ± 1.11 (6 months for the Cirrus, and 1.73 ± 1.50, 1.54 ± 1.35, 1.38 ± 1.40, and 1.49 ± 1.30, respectively, for the Spectralis, differing significantly at 1 month and 2 months (P < 0.02. Automated and manual CMT measurements by the Spectralis were larger than those by the Cirrus. Conclusions: The Cirrus HD-OCT had a lower frequency and severity of segmentation error than the Spectralis HRA + OCT. SD-OCT error should be considered when evaluating retinal thickness.

  5. Clinical outcomes of selective anterior cervical corpectomy combined with segmental disectomy and fusion for treating three-level cervical myelopathy%前路选择性椎体切除结合单间隙减压植骨融合术治疗三节段脊髓型颈椎病的临床疗效

    Institute of Scientific and Technical Information of China (English)

    曹涌; 张烽; 陈向东; 姜星杰

    2011-01-01

    Objective To evaluate the clinical outcomes of selective anterior cervical corpectomy combined with segmental disectomy and fusion for treating three-level cervical myelopathy. Methods Thirtee patients of multilevel cervical myelopathy with 3 consecutive segments were treated with anterior cervical corpectomy combined with segmental disectomy and fusion. Study parameters included JOA score and grading the Odom criteria. The sagittal segmental alignment of fusion levels was measured using the Cobb method before and after surgery. Graft fusion rate was observed during final follow up. Results The patients were followed up for 12 to 39 months. The JOA score of 13 patients was higher three months after surgery than that before[(14. 6± 1.0) points vs. (11.1 ± 1.0) points] (P<0. 01). Surgical results of Odom criteria were excellent in 8 cases, good in 3 cases, fair in 2 cases. Graft fusion rate was 100%. Radiograph analysis indicated that the Cobb angle of mean segmental lordosis was 3.7 degrees before, 10.7 degrees one week later and 10.4 degrees during the final follow up. Conclusion Selective anterior cervical corpectomy combined with segmental disectomy and fusion results in high fusion rates with sufficient decompression in the treatment of three-level cervical myelopathy.%目的 分析颈前路选择性椎体次全切除十单间隙减压植骨融合术治疗三节段脊髓型颈椎病的临床疗效.方法 13例脊髓型颈椎病患者行颈前路选择性椎体次全切除十单间隙减压、自体髂骨植骨、钢板内固定术.分析术前及随访时的日本骨科协会(JOA)评分,记录术后Odom分级.测量术前、术后1周及末次随访时颈椎侧位X线片,观察术后颈椎植骨融合率、颈椎曲度(Cobb角)维持、症状及功能改善率.结果 13例患者随访12~39个月,术后3个月JOA评分为(14.6±1.0)分,明显高于术前的(11.1±1.0)分(P<0.01).术后Odom分级:优8例,良3例,一般2例,植骨融合率100%.

  6. 前后段联合手术及硅油填充治疗高度近视黄斑孔视网膜脱离的疗效观察%The therapeutic effect of combined surgery of anterior and posterior segment and silicon oil tamponade on macular hole retinal detachment in eyes with high myopia

    Institute of Scientific and Technical Information of China (English)

    陈伟奇; 张责华; 胡一骏; 郑建龙

    2009-01-01

    Objective To observe the therapeutic effect of combined surgery of anterior and posterior segment and silicon oil tamponade on macular hole retinal detachment in eyes with high myopia. Methods The clinical data of 48 high myopia patients (48 eyes) with macular hole retinal detachment were retrospectively analyzed. Retinal detachment was mainly at the posterior pole; macular hole was confirmed by non-contact Hruby lens and optical coherence tomography (OCT). Phacoemulsification combined with pars plana vitrectomy and silicon oil tamponade were performed to all patients, of which 41 had undergone internal limiting membrane peeling, and 23 had intraocular lens implanting. The oil had been removed 3.5-48.0 months after the first surgery and OCT had been performed before the removal. The follow-up period after the removal of the silicon oil was more than 1 year. Results The edge of the macular hole could not be seen under the non-contact Hruby lens 1 week after the surgery in all but 5 patients, and the visual acuity improved. The silicon oil had been removed in all of the 48 patients; the OCT scan before the removal showed that the closed macular holes can be in U shape (8 eyes), V shape (6 eyes) or W shape (23 eyes). About 13-38 months after the oil removal, retinal detachment recurred in 2 patients with the W-shaped holes. At the end of the follow-up period, 16 patients (33.3%) had U or V-shaped macular holes, and 32 patients (66.7%) had W-shaped macular holes. The rate of retinal reattachment was 100%. Conclusion Combined surgery of anterior and posterior segment and silicon oil tamponade is effective on macular hole retinal detachment in eyes with high myopia.%目的 观察前后段联合手术及硅油充填治疗高度近视黄斑孔视网膜脱离临床疗效.方法 回顾分析前后段联合手术及硅油充填治疗高度近视黄斑孔视网膜脱离患者48例48只眼的临床资料.患者均有高度近视史,视网膜脱离以后极部为主.裂隙灯

  7. Evaluation of holmium laser versus cold knife in optical internal urethrotomy for the management of short segment urethral stricture

    OpenAIRE

    Sudhir Kumar Jain; Ram Chandra Murthy Kaza; Bipin Kumar Singh

    2014-01-01

    Objectives: Sachse cold knife is conventionally used for optical internal urethrotomy intended to manage urethral strictures and Ho: YAG laser is an alternative to it. The aim of this study was to evaluate the role of urethral stricture treatment outcomes, efficacy, and complications using cold knife and Ho: YAG (Holmium laser) for optical internal urethrotomy Materials and Methods: In this prospective study included, 90 male patients age >18 years, with diagnosis of urethral stricture ad...

  8. EVENT SEGMENTATION

    OpenAIRE

    Zacks, Jeffrey M.; Swallow, Khena M.

    2007-01-01

    One way to understand something is to break it up into parts. New research indicates that segmenting ongoing activity into meaningful events is a core component of ongoing perception, with consequences for memory and learning. Behavioral and neuroimaging data suggest that event segmentation is automatic and that people spontaneously segment activity into hierarchically organized parts and sub-parts. This segmentation depends on the bottom-up processing of sensory features such as movement, an...

  9. Sutureless femtosecond anterior lamellar keratoplasty: A 1-year follow-up study

    Directory of Open Access Journals (Sweden)

    Rohit Shetty

    2014-01-01

    Full Text Available Aim: To study the safety and efficacy of sutureless femtosecond anterior lamellar keratoplasty (FALK in patients with corneal stromal opacities. Materials and Methods: Eleven eyes of 11 consecutive patients with corneal stromal opacities involving < 250 μ due to various pathologies were included in the study. Preoperatively, all underwent anterior segment imaging with spectral domain optical coherence tomography (SD-OCT (Bioptigen Inc., Durham, North Carolina, USA to measure the depth of the stromal opacity. All patients underwent FALK, and bandage contact lens was placed for a period of 2 weeks. Postoperatively, uncorrected visual acuity, best corrected visual acuity (BCVA, and SD-OCT evaluation were performed. Results: All patients showed significant improvement in BCVA. The mean postoperative BCVA (in decimals improved from 0.11 ± 0.06 preoperatively to 0.59 ± 0.08. There were no intraoperative or significant postoperative complications that were noticed. Conclusion: FALK is a safe and effective alternative to deep anterior lamellar keratoplasty or penetrating keratoplasty in the treatment of anterior stromal opacities.

  10. Segmentation: Identification of consumer segments

    DEFF Research Database (Denmark)

    Høg, Esben

    2005-01-01

    It is very common to categorise people, especially in the advertising business. Also traditional marketing theory has taken in consumer segments as a favorite topic. Segmentation is closely related to the broader concept of classification. From a historical point of view, classification has its...... analysed possible segments in the market. Results show that the statistical model used identified two segments - a segment of so-called "fish lovers" and another segment called "traditionalists". The "fish lovers" are very fond of eating fish and they actually prefer fish to other dishes. The...... origin in other sciences as for example biology, anthropology etc. From an economic point of view, it is called segmentation when specific scientific techniques are used to classify consumers to different characteristic groupings. What is the purpose of segmentation? For example, to be able to obtain a...

  11. Reliability and reproducibility of macular segmentation using a custom-built optical coherence tomography retinal image analysis software

    Science.gov (United States)

    Cabrera Debuc, Delia; Somfai, Gábor Márk; Ranganathan, Sudarshan; Tátrai, Erika; Ferencz, Mária; Puliafito, Carmen A.

    2009-11-01

    We determine the reliability and reproducibility of retinal thickness measurements with a custom-built OCT retinal image analysis software (OCTRIMA). Ten eyes of five healthy subjects undergo repeated standard macular thickness map scan sessions by two experienced examiners using a Stratus OCT device. Automatic/semi automatic thickness quantification of the macula and intraretinal layers is performed using OCTRIMA software. Intraobserver, interobserver, and intervisit repeatability and reproducibility coefficients, and intraclass correlation coefficients (ICCs) per scan are calculated. Intraobserver, interobserver, and intervisit variability combined account for less than 5% of total variability for the total retinal thickness measurements and less than 7% for the intraretinal layers except the outer segment/ retinal pigment epithelium (RPE) junction. There is no significant difference between scans acquired by different observers or during different visits. The ICCs obtained for the intraobserver and intervisit variability tests are greater than 0.75 for the total retina and all intraretinal layers, except the inner nuclear layer intraobserver and interobserver test and the outer plexiform layer, intraobserver, interobserver, and intervisit test. Our results indicate that thickness measurements for the total retina and all intraretinal layers (except the outer segment/RPE junction) performed using OCTRIMA are highly repeatable and reproducible.

  12. Anterior ischemic optic neuropathy: a comparison of the optic disc area of patients with the arteritic and non-arteritic forms of the disease and that of normal controls Neuropatia óptica isquêmica anterior: estudo comparativo da área do disco óptico de pacientes com as formas arterítica e não-arterítica da doença e de controles normais

    Directory of Open Access Journals (Sweden)

    Mário Luiz Ribeiro Monteiro

    2006-12-01

    Full Text Available PURPOSE: To evaluate the optic disc area of patients with non-arteritic anterior ischemic optic neuropathy (NA-AION and arteritic anterior ischemic optic neuropathy (A-AION and compare the results between each other and with those from controls in order to verify the existence and the magnitude of anatomical factors predisposing to the development of anterior ischemic optic neuropathy. METHODS: This is a case-controlled study of the optic disc area of 24 consecutive patients affected with NA-AION, 13 patients with A-AION and 24 consecutive healthy normals, sex- and age-matched with the patients with the NA-AION group. Measurements of optic disc area were performed for each studied group using disc photographs projected, measured and corrected for the refractive error and the keratometric readings, according to Littmann's method in each studied group. The results were compared using variance analysis. RESULTS: The mean areas and standard deviations of the optic discs from patients with NA-AION, A-AION and normals were respectively 1.99 ± 0.35 mm², 2.29 ± 0.39 mm² and 2.49 ± 0.53 mm². The statistical analysis revealed that the mean areas of the optic disc of patients with NA-AION were significantly different from those of normal controls. No statistical difference was found between A-AION and normal controls. CONCLUSION: NA-AION occurs predominantly in small discs while the arteritic form of the disease shows no such preference. Factors related to optic disc structure play a role in the pathophysiology of NA-AION. The occurrence of AION in large optic optic discs should raise the suspicion of temporal arteritis. On the other hand, small optic disc areas do not rule out that vasculitis.OBJETIVO: Calcular a área do disco óptico de pacientes com neuropatia óptica isquêmica anterior não arterítica (NOIA-NA e com neuropatia óptica isquêmica anterior por arterite temporal (NOIA-A comparando os resultados entre si e com o grupos controle

  13. Improving image segmentation performance and quantitative analysis via a computer-aided grading methodology for optical coherence tomography retinal image analysis

    Science.gov (United States)

    Cabrera Debuc, Delia; Salinas, Harry M.; Ranganathan, Sudarshan; Tátrai, Erika; Gao, Wei; Shen, Meixiao; Wang, Jianhua; Somfai, Gábor M.; Puliafito, Carmen A.

    2010-07-01

    We demonstrate quantitative analysis and error correction of optical coherence tomography (OCT) retinal images by using a custom-built, computer-aided grading methodology. A total of 60 Stratus OCT (Carl Zeiss Meditec, Dublin, California) B-scans collected from ten normal healthy eyes are analyzed by two independent graders. The average retinal thickness per macular region is compared with the automated Stratus OCT results. Intergrader and intragrader reproducibility is calculated by Bland-Altman plots of the mean difference between both gradings and by Pearson correlation coefficients. In addition, the correlation between Stratus OCT and our methodology-derived thickness is also presented. The mean thickness difference between Stratus OCT and our methodology is 6.53 μm and 26.71 μm when using the inner segment/outer segment (IS/OS) junction and outer segment/retinal pigment epithelium (OS/RPE) junction as the outer retinal border, respectively. Overall, the median of the thickness differences as a percentage of the mean thickness is less than 1% and 2% for the intragrader and intergrader reproducibility test, respectively. The measurement accuracy range of the OCT retinal image analysis (OCTRIMA) algorithm is between 0.27 and 1.47 μm and 0.6 and 1.76 μm for the intragrader and intergrader reproducibility tests, respectively. Pearson correlation coefficients demonstrate R2>0.98 for all Early Treatment Diabetic Retinopathy Study (ETDRS) regions. Our methodology facilitates a more robust and localized quantification of the retinal structure in normal healthy controls and patients with clinically significant intraretinal features.

  14. 节段型严重颈椎后纵韧带骨化症前路、后路手术的疗效比较与选择策略%Anterior or posterior approach for segmental severe ossification of posterior longitudinal ligament of the cervical spine: the efficacy and selection strategy

    Institute of Scientific and Technical Information of China (English)

    雷涛; 申勇; 王林峰; 丁文元; 张为; 张迪

    2013-01-01

    Objective To investigate the efficacy and selection of anterior and posterior approaches for segmental severe ossification of posterior longitudinal ligament (OPLL)of the cervical spine.Method From January 2007 to May 2011,59 patients with segmental severe OPLL underwent surgical treatment,including 41 males and 18 females,with an average age of 55.7 years.Among them,24 patients underwent anterior corpectomy and fusion,and 35 patients underwent laminectomy and lateral mass screw fixation.In two groups,the operation time,intraoperative blood loss,change of cervical curvature,neck axial symptoms,and JOA (Japanese Orthopaedic Association) score were recorded and compared.Result All patients were followed up for 12 to 18 months (average,15.4 months).The average JOA score in anterior approach group increased from preoperative 7.33 ± 1.09 to 13.63±0.82 at final follow-up,with an average improvement rate of 65.16% ±7.50%; the average JOA score in posterior approach group increased from preoperative 7.20 ± 1.05 to 12.23 ± 1.11 at final follow-up,with an improvement rate of 51.46%±9.64%; and the difference between two groups was statistically significant.Immediately after the operation,the segmental curvature of the operative site was 5.38°±1.14° in anterior approach group and 3.89°±1.65° in posterior approach group,and the difference was statistically significant.At final follow-up,the rate of neck axial symptoms was 20.83% in anterior approach group and 51.43% in posterior approach group,and the difference was also statistically significant.Conclusion For severe OPLL with not more than 3 segments of ossification,the anterior approach can remove the ossified mass directly,get a better neurological recovery,provide a good biomechanical alignment,and decrease the postoperative axial symptoms.However,posterior laminectomy and lateral mass screw fixation also can obtain enough decompression and maintain the segmental curvature.%目的 探讨前路和

  15. 前部缺血性视神经病变并发视网膜分支动脉阻塞1例%A case of branch retinal artery obstruction complicated after anterior ischemic optic neuropathy

    Institute of Scientific and Technical Information of China (English)

    Ungsoo Samuel Kim; Hyoung-Seok Kim; Young Ju Lew

    2011-01-01

    AIM: To report a case of branch retinal artery obstruction (BRAO) complicated after anterior ischemic optic neuropathy (AION).METHODS: A 42-year-old woman who complained of visual disturbance was performed ophthalmological examinations such as fundus photography, fluorescent angiography (FAG) and visual field test. RESULTS: At first visit, disc swelling was noted and arterial circulation was intact, however, 1 week after onset, the inferior branch retinal artery began to shrink and the flame hemorrhage intensified. Sixteen months later, the optic disc evidenced an atrophic change; additionally, a ghost vessel in the inferior branch retinal artery was found.CONCLUSION: We report a case of complications of BRAO arising after AION which caused the mechanical compression on the arterial circulation.%目的:报告1例前部缺血性视神经病变(anterior ischemic optic neuropathy,AION)并发视网膜分支动脉阻塞(branch retinal artery obstruction,BRAO).方法:患者,女,42岁,因视力障碍进行如下眼科检查:眼底照相、荧光血管造影(fluorescent angiography,FAG)和视野测试.结果:第一次就诊时,患者视盘肿胀,动脉循环完整,发病1wk后,视网膜下支动脉开始萎缩并火焰状出血加剧.16mo后,视盘呈萎缩性改变,此外,发现视网膜下分支动脉血管影一条.结论:AION并发BRAO可造成动脉循环的机械性压迫.

  16. Bilateral anterior shoulder dislocation

    OpenAIRE

    Meena, Sanjay; Saini, Pramod; Singh, Vivek; Kumar, Ramakant; Trikha, Vivek

    2013-01-01

    Shoulder dislocations are the most common major joint dislocations encountered in the emergency departments. Bilateral shoulder dislocations are rare and of these, bilateral posterior shoulder dislocations are more prevalent than bilateral anterior shoulder dislocations. Bilateral anterior shoulder dislocation is very rare. We present a case of 24-year-old male who sustained bilateral anterior shoulder dislocation following minor trauma, with associated greater tuberosity fracture on one side...

  17. Segmental neurofibromatosis

    OpenAIRE

    Galhotra, Virat; Sheikh, Soheyl; Jindal, Sanjeev; Singla, Anshu

    2014-01-01

    Segmental neurofibromatosis is a rare disorder, characterized by neurofibromas or cafι-au-lait macules limited to one region of the body. Its occurrence on the face is extremely rare and only few cases of segmental neurofibromatosis over the face have been described so far. We present a case of segmental neurofibromatosis involving the buccal mucosa, tongue, cheek, ear, and neck on the right side of the face.

  18. Reactive histiocytosis of the orbit and posterior segment in a dog.

    Science.gov (United States)

    Pumphrey, Stephanie A; Pizzirani, Stefano; Pirie, Christopher G; Sato, Amy F; Buckley, Faith I

    2013-05-01

    We present a case of reactive histiocytic disease involving the orbit, optic nerve, retina, and choroid in a Border Collie dog initially presenting for vision loss. Long-term partial return of vision has been achieved with systemic immunosuppression. Anterior segment and ocular surface manifestations of reactive histiocytic disease in dogs are relatively common. Posterior segment and orbital involvement, however, are minimally documented in the existing literature. To the authors' knowledge, this is the first report of disease confined to the orbit and posterior segment as well as the first report of vision loss as a presenting complaint for reactive histiocytic disease. Clinical, magnetic resonance imaging, cytologic, and histopathologic findings are reviewed. PMID:22853429

  19. Anterior surgery for the treatment of acute single segment 30 cases of cervical disc%前路手术治疗急性单节段颈椎间盘突出30例

    Institute of Scientific and Technical Information of China (English)

    吴成如; 张诗虎

    2013-01-01

    目的 研究探讨前路颈椎间盘切除+椎间融合器+钛板内固定治疗急性颈椎间盘突出症的效果.方法 采用前路手术对我科2008-03-2011-03收治的30例急性颈椎间盘突出症患者进行治疗,所有患者均获得平均15个月的随访,根据术后摄片及JOA评分判断疗效.结果 在随访过程中,所有患者均未出现临床并发症,术后摄片显示均获得骨性融合,依据JOA评分标准:优(改善率大于75%)20例,良(改善率50~75%)8例,好转(改善率25~50%)2例.结论 该方法治疗急性颈椎间盘突出症可达到充分减压、重建颈椎生理曲度、恢复椎间隙高度、椎体间高融合率、颈椎牢固固定的作用.而且该术式操作简单,手术时间短、出血少、并发症少,是治疗急性颈椎间盘突出一种可靠方法.%Objective research and discuss the effect of the treatment of acute cervical disc herniation by using anterior cervical discectomy, Intervertebral fusion and Internal fixation with titanium plate. Methods 30 cases of patients with acute cervical disc herniation in our department in March 2008-March 2011 were treated by using anterior surgery,all patients received an average of 15 months of follow-up visit,then judge the curative effect according to postoperative radiography and JOA scores. Results In the process of follow-up, all patients did not show clinical complications, postoperative radiography showed bony fusion,according to JOA scoring criteria, optimal (improvement rate more than 75%) 20 cases, fine (improvement rate 50%~75%) 8 cases,improved (improvement rate 25%-50%) 2 cases. Conclusion the treatment of acute cervical disc herniation can achieve full decompression, reconstruction of cervical physiological curvature, restore interverte-bral disc height,high fusion rate between the vertebral bodies, cervical vertebra firmly fixed. And the operation is simple,short operation time,less bleeding,fewer complications,so the treatment of acute

  20. Progress report (interface segment)

    International Nuclear Information System (INIS)

    Full text: 1. Presentations and status reports. T. Fukahori (JAEA) reported on the plans for the www interface layout. Discussions included which functions were needed for new RIPL-3 web pages. The results are summarized in next section. 2. Layout of the interfaces and retrieval tools and web. RIPL-3 home page will include some description about RIPL-3 and link to the Technical report in pdf-format. The web page for 'mass' segment contains same contents as RIPL-2 except the removal of the information about ground state deformation. The abundance data will be replaced by data from the new BNL wallet card (2005 version). The Q-value calculation tool will be also improved. The 'Nuclear Matter Density' will be renamed 'Nucleon Density Distribution'. 'Levels' segment will be same as before, and the deformation parameters for excited levels will be moved from 'optical' segment and given the name 'deformation'. 'Resonances' segment will be same as before - may be replaced with the new Mughabghab tables. 'Optical' segment will be same as before, and the deformation parameters for excited levels will be moved to 'optical' segment and given the name 'deformation'. The optical model calculation with ECIS and OPTMAN will be considered and double-folding calculation tool will possibly be provided. 'Densities' segment will be same as before, and the plotting programs will be checked. The 3-7 sets of combination of GC, BSFG, GSFM with/without enhancement factors will be given. 'Gamma' segment will be same as before, with addition of MLO and theoretical GDR calculation. 'Fission' segment will be same as before, and 'Exp.' will be renamed. New barrier evaluations will be added, for example, transition (2+) states. The fission spectrum calculation tool (codes and inputs) may be added. The fundamental format will be kept as before. For new items such as deformed 'nucleon density distribution', double-folding potential, evaluated fission barrier (extension into 3 or more) and fission

  1. Segmental Neurofibromatosis

    Directory of Open Access Journals (Sweden)

    Yesudian Devakar

    1997-01-01

    Full Text Available Segmental neurofibromatosis is a rare variant of neurofibromatosis in which the lesions are confined to one segment or dermatome of the body. They resemble classical neurofibromas in their morphology, histopathology and electron microscopy. However, systemic associations are usually absent. We report one such case with these classical features.

  2. Anterior Cruciate Ligament (ACL) Injuries

    Science.gov (United States)

    ... Help a Friend Who Cuts? Anterior Cruciate Ligament (ACL) Injuries KidsHealth > For Teens > Anterior Cruciate Ligament (ACL) ... and Recovery Coping With an ACL Injury About ACL Injuries A torn anterior cruciate ligament (ACL) is ...

  3. MARKET SEGMENTATION

    Directory of Open Access Journals (Sweden)

    Munaga Ramakrishna Mohan Rao

    2015-01-01

    Full Text Available Market segmentation is a marketing strategy that involves dividing a broad target market into subsets of consumers, businesses, or countries who have common needs and priorities, and then designing and implementing strategies to target them. Market segmentation strategies may be used to identify the target customers, and provide supporting data for positioning to achieve a marketing plan objective. Businesses may develop product differentiation strategies, or an undifferentiated approach, involving specific products or product lines depending on the specific demand and attributes of the target segment.

  4. Treatment of lumbosacral spinal tuberculosis by one-stage anterior debridement and fusion combined with dual screw-rod anterior instrumentation underneath the iliac vessel

    OpenAIRE

    Zhang, Ting; He, Xijing; Li, Haopeng; Xu, Siyue

    2016-01-01

    Background There has been no consensus regarding what is the optimal means of treating lumbosacral segment tuberculosis. The aim of this study was to evaluate the clinical outcomes of our newly developed one-stage anterior debridement and fusion combined with dual screw-rod construct anterior instrument underneath the iliac vessels for lumbosacral spinal tuberculosis. Methods We retrospectively reviewed 22 patients with lumbosacral spinal tuberculosis who underwent one-stage anterior debridem...

  5. Anterior cervical plating

    Directory of Open Access Journals (Sweden)

    Gonugunta V

    2005-01-01

    Full Text Available Although anterior cervical instrumentation was initially used in cervical trauma, because of obvious benefits, indications for its use have been expanded over time to degenerative cases as well as tumor and infection of the cervical spine. Along with a threefold increase in incidence of cervical fusion surgery, implant designs have evolved over the last three decades. Observation of graft subsidence and phenomenon of stress shielding led to the development of the new generation dynamic anterior cervical plating systems. Anterior cervical plating does not conclusively improve clinical outcome of the patients, but certainly enhances the efficacy of autograft and allograft fusion and lessens the rate of pseudoarthrosis and kyphosis after multilevel discectomy and fusions. A review of biomechanics, surgical technique, indications, complications and results of various anterior cervical plating systems is presented here to enable clinicians to select the appropriate construct design.

  6. Anterior knee pain

    Science.gov (United States)

    Patellofemoral syndrome; Chondromalacia patella; Runner's knee; Patellar tendinitis; Jumper's knee ... or playing soccer). You have flat feet. Anterior knee pain is more ... skiers, bicyclists, and soccer players who exercise often ...

  7. Anterior knee pain

    Science.gov (United States)

    ... or playing soccer). You have flat feet. Anterior knee pain is more common in: People who are overweight People who have had a dislocation, fracture, or other injury to the kneecap Runners, jumpers, ...

  8. Comparison of anterior cervical discectomy and fusion and anterior cervical corpectomy and fusion for the treatment of multi-segmental cervical spondylotic myelopathy%前路椎间盘切除减压融合与椎体次全切除减压融合治疗多节段颈椎病疗效比较

    Institute of Scientific and Technical Information of China (English)

    吴畏; 朱天亮

    2014-01-01

    目的:比较前路椎间盘减压融合( ACDF)与前路椎体次全切除减压融合( ACCF)治疗多节段颈椎病的效果。方法将138例多节段脊髓型颈椎病患者按照治疗方式的不同分为观察组(行ACDF治疗)和对照组(行ACCF治疗),比较两组手术时间、术中出血量、术后住院时间、术前与术后6个月颈椎总活动度、颈椎曲度、颈椎节段性高度及JOA评分。结果手术时间:观察组(128.3±32.4)min,对照组(163.2±43.6)min;术中出血量:观察组(161.4±122.5)ml,对照组(319.2±308.7)ml;以上指标观察组均少于对照组(P0.05)。术后颈椎曲度:观察组23.5°±7.4°,对照组16.1°±7.2°;椎间节段性高度:观察组5.6°±0.4°,对照组4.7°±0.8°;以上指标两组比较差异有统计学意义(P0. 05 ) . Postoperative cervical curvature: the observation group was 23. 5° ± 7. 4°, the control group was 16. 1° ± 7. 2°;intervertebral segmental height:observation group was 5. 6° ± 0. 4°, the control group was 4. 7° ± 0. 8°; between these indicators there were statistically significant differences between groups ( P <0. 05 ) . Conclusions Compared with ACCF, ACDF has shorter operative time, less blood loss, cervical physiological curvature and height of intervertebral segment recovered well, but there is no statistically significant differences on postoperative hospital stay time, postoperative JOA score and cervical total activity.

  9. MARKET SEGMENTATION

    OpenAIRE

    Munaga Ramakrishna Mohan Rao

    2015-01-01

    Market segmentation is a marketing strategy that involves dividing a broad target market into subsets of consumers, businesses, or countries who have common needs and priorities, and then designing and implementing strategies to target them. Market segmentation strategies may be used to identify the target customers, and provide supporting data for positioning to achieve a marketing plan objective. Businesses may develop product differentiation strategies, or an undifferentiated approach, inv...

  10. Fingerprint Segmentation

    OpenAIRE

    Jomaa, Diala

    2009-01-01

    In this thesis, a new algorithm has been proposed to segment the foreground of the fingerprint from the image under consideration. The algorithm uses three features, mean, variance and coherence. Based on these features, a rule system is built to help the algorithm to efficiently segment the image. In addition, the proposed algorithm combine split and merge with modified Otsu. Both enhancements techniques such as Gaussian filter and histogram equalization are applied to enhance and improve th...

  11. Clinical research on segmental invisible technique with mini-implant for en-masse retraction of maxillary anterior teeth%片段隐形矫治器结合微种植体内收上前牙的临床研究

    Institute of Scientific and Technical Information of China (English)

    金丽飞; 黄一慧; 弓国梁; 林新平

    2016-01-01

    Objective To evaluate the clinical efficiency of segmental invisible technique with mini-implant for en-masse retraction of maxillary anterior teeth on the aspect of vertical and torque in the treatment of bimaxillary protrusion. Methods Twelve subjects with upper dental alveolar bone protrusion were selected for this study. Arch-dimension variables were evaluated by cephalometric and dental models before and after orthodontic retraction. All data were analyzed by SPSS 20. 0 software. Results For vertical control, U1E-PP was increased by 0. 78 mm, U1AP-PP was decreased by 0. 29 mm, while the change of U1CR-PP showed no significant difference ( P>0. 05). For sagittal control, all the anterior teeth showed a decreased torque with canine displaying uprighting. Conclusion Segmen-tal invisible technique with mini-implant is efficient in the vertical and torque control of anterior teeth in the treatment of bimaxillary protrusion, and it can demonstrate invisible and aesthetic orthodontic effects.%目的:评估片段隐形矫治器结合微种植体矫治前突患者时对上前牙垂直向和转矩方面的控制效果。方法选取12例双牙槽前突患者,通过测量治疗前后X线头颅定位侧位片上颌前牙矢状向与垂直向的变化值,以及模型上的转矩变化值,使用SPSS 20.0软件进行统计分析。结果治疗后上切牙切缘至腭平面距离U1E-PP增加0.78 mm,上切牙根尖点至腭平面距离U1AP-PP减小0.29 mm,上切牙阻抗中心至腭平面距离U1CR-PP的变化无统计学差异(P>0.05),上切牙阻抗中心的位置基本不变;治疗后的上前牙转矩值减少,尖牙出现直立趋势。结论片段隐形矫治技术治疗前突患者对其上前牙的垂直向和转矩控制较好,总体获得了良好的治疗效果,并且在治疗期间充分发挥了隐形、美观的矫治效果。

  12. 人工椎间盘置换加颈前路椎体次全切减压植骨融合术治疗多节段颈椎病%Artificial Disc Replacement Combined with Anterior Cervical Decompression and Autograft Bone Fusion for the Treatment of Multi-segment Cervical Spondylosis

    Institute of Scientific and Technical Information of China (English)

    廖维峰; 肖晟; 黄象望; 刘向阳; 张毅; 向铁城

    2014-01-01

    [目的]探讨人工椎间盘置换加颈前路椎体次全切减压植骨融合术治疗多节段颈椎病的临床疗效。[方法]湖南省人民医院2008年2月至2012年6月收治的12例多节段颈椎病手术病例,均行人工椎间盘置换加颈前路椎体次全切减压植骨融合术,随访时间为12~18个月,平均随访15.5个月,均摄术前、术后及末次随访时的颈椎正侧位及颈椎过伸过屈位X线片及磁共振检查,观察植骨融合、内固定及人工椎间盘的情况,以JO A评分评价神经功能改善情况。[结果]所有病例内置物无松动、移位,植骨融合时间在3~6个月,平均4.9个月。置换间隙活动度术后1年时为12.5°±5.0°,与术前(12.3°±4.9°)比较无统计学差异(P>0.05)。术前JOA 评分平均为9.3分,术后6个月时平均为16.1分,平均改善率为91.2%。[结论]人工椎间盘置换加颈前路椎体次全切减压植骨融合术治疗多节段颈椎病近期疗效满意,是治疗多节段颈椎病的一种可行方法。%[Objective]To explore the clinical efficacy of cervical artificial disc replacement combined with anterior cervical decompression and autograft bone fusion for the treatment of multi -segment cervical spon-dylosis .[Methods]Twelve patients with multi- segment cervical spondylosis operated in Hunan provincial people's hospital from Feb .2008 to June 2012 underwent cervical artificial disc replacement combined with an-terior cervical decompression and autograft bone fusion .The follow up time was 12~18 months(average 15 .5 months) .Cervical MRI and X-ray films of cervical normal lateral position ,hyperextension and hyperflexion position were performed before and after operation and at the last time of follow up .Bone fusion ,internal fixa-tion and artificial disc were observed .JOA score was used to evaluate the improvement of neurological func-tion .[Results]No loosening and displacement of

  13. Congenital anterior urethral diverticulum.

    Science.gov (United States)

    Singh, Sanjeet Kumar; Ansari, Ms

    2014-09-01

    Congenital anterior urethral diverticulum (CAUD) may be found all along the anterior urethra and may present itself at any age, from infant to adult. Most children with this condition present with difficulty in initiating micturition, dribbling of urine, poor urinary stream, or urinary tract infection. A careful history will reveal that these children never had a good urinary stream since birth, and the telltale sign is a cystic swelling of the penile urethra. In this paper, we present two cases of CAUD that were managed by excision of the diverticulum with primary repair. PMID:26328174

  14. Corneal Segmentation Analysis Increases Glaucoma Diagnostic Ability of Optic Nerve Head Examination, Heidelberg Retina Tomograph's Moorfield's Regression Analysis, and Glaucoma Probability Score.

    Science.gov (United States)

    Saenz-Frances, F; Jañez, L; Berrozpe-Villabona, C; Borrego-Sanz, L; Morales-Fernández, L; Acebal-Montero, A; Mendez-Hernandez, C D; Martinez-de-la-Casa, J M; Santos-Bueso, E; Garcia-Sanchez, J; Garcia-Feijoo, J

    2015-01-01

    Purpose. To study whether a corneal thickness segmentation model, consisting in a central circular zone of 1 mm radius centered at the corneal apex (zone I) and five concentric rings of 1 mm width (moving outwards: zones II to VI), could boost the diagnostic accuracy of Heidelberg Retina Tomograph's (HRT's) MRA and GPS. Material and Methods. Cross-sectional study. 121 healthy volunteers and 125 patients with primary open-angle glaucoma. Six binary multivariate logistic regression models were constructed (MOD-A1, MOD-A2, MOD-B1, MOD-B2, MOD-C1, and MOD-C2). The dependent variable was the presence of glaucoma. In MOD-A1, the predictor was the result (presence of glaucoma) of the analysis of the stereophotography of the optic nerve head (ONH). In MOD-B1 and MOD-C1, the predictor was the result of the MRA and GPS, respectively. In MOD-B2 and MOD-C2, the predictors were the same along with corneal variables: central, overall, and zones I to VI thicknesses. This scheme was reproduced for model MOD-A2 (stereophotography along with corneal variables). Models were compared using the area under the receiver operator characteristic curve (AUC). Results. MOD-A1-AUC: 0.771; MOD-A2-AUC: 0.88; MOD-B1-AUC: 0.736; MOD-B2-AUC: 0.845; MOD-C1-AUC: 0.712; MOD-C2-AUC: 0.838. Conclusion. Corneal thickness variables enhance ONH assessment and HRT's MRA and GPS diagnostic capacity. PMID:26180641

  15. Biological activity is the likely origin of the intersection between the photoreceptor inner and outer segments of the rat retina as determined by optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Yamauchi Y

    2011-11-01

    Full Text Available Yasuyuki Yamauchi, Hiromichi Yagi, Yoshihiko Usui, Keisuke Kimura, Tsuyoshi Agawa, Rintaro Tsukahara, Naoyuki Yamakawa, Hiroshi GotoDepartment of Ophthalmology, Tokyo Medical University Hospital, Tokyo, JapanBackground: Recent research on macular diseases has prompted investigations into the condition of the intersection between the photoreceptor inner and outer segments (IS/OS and the relationship with retinal photoreceptor abnormalities. Although the origin of the IS/OS in optical coherence tomography (OCT images is unclear, it may be related to either the cellular activity of the photoreceptors or the structure of the OS disks. To address this question, we compared the IS/OS status in OCT images of rat retinas before and after euthanasia.Methods: OCT images were taken before and after euthanasia in four eyes of two Brown Norway rats. After the OCT images were taken, the rats were used for histopathological studies to confirm that retinal structures were intact.Results: Before euthanasia, the IS/OS and external limiting membrane (ELM line were clearly identifiable on the OCT images. However, after euthanasia, neither the IS/OS nor the ELM line was evident in three out of four eyes, and a faint IS/OS and an ELM line were identified in one eye. Histopathological analysis did not show any abnormalities in the retina in any of the four eyes.Conclusion: The origin of the IS/OS identified in OCT images is likely related to the biological activities of the photoreceptor cells.Keywords: IS/OS, OCT, histopathology, biological activity

  16. Diffusion MR Imaging of Postoperative Bilateral Acute Ischemic Optic Neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Kannan, Anusha; Srinivasan, Sivasubramanian [Khoo Teck Puat Hospital, Singapore (Singapore)

    2012-09-15

    We read with great interest, the case report on ischemic optic neuropathy (1). We would like to add a few points concerning the blood supply of the optic nerve and the correlation with the development of post-operative ischemic neuropathy. Actually, the perioperative or post-operative vision loss (postoperative ischemic neuropathy) is most likely due to ischemic optic neuropathy. Ischemic optic neuropathy (2) is classified as an anterior ischemic optic neuropathy (AION) and posterior ischemic optic neuropathy (PION). This classification is based on the fact that blood supply (2) to the anterior segment of the optic nerve (part of the optic nerve in the scleral canal and the optic disc) is supplied by short posterior ciliary vessels or anastamotic ring branches around the optic nerve. The posterior part of the optic canal is relatively less perfused, and is supplied by ophthalmic artery and central fibres are perfused by a central retinal artery. So, in the post-operative period, the posterior part of the optic nerve is more vulnerable for ischemia, especially, after major surgeries (3), one of the theories being hypotension or anaemia (2) and resultant decreased perfusion. The onset of PION is slower than the anterior ischemic optic neuropathy. AION on the other hand, is usually spontaneous (idiopathic) or due to arteritis, and is usually sudden in its onset. The reported case is most likely a case of PION. The role of imaging, especially the diffusion weighted magnetic resonance imaging, is very important because the ophthalmoscopic findings in early stages of PION is normal, and it may delay the diagnosis. On the other hand, edema of the disc is usually seen in the early stages of AION.

  17. Anterior vaginal wall repair

    Science.gov (United States)

    ... symptoms will go away. This improvement will often last for years. Alternative Names A/P repair; Vaginal wall repair; Anterior and/ ... writing by ADAM Health Solutions. About MedlinePlus Site Map FAQs Contact ... Institutes of Health Page last updated: 23 August 2016

  18. Dirofilaria in the anterior chamber: A rare occurrence

    Directory of Open Access Journals (Sweden)

    Rupali Chopra

    2012-01-01

    Full Text Available Dirofilariasis is a parasitic infection of the carvivores that may present as a zoonotic infestation in humans. Systemic involvement in man is subcutaneous, pulmonary, or ocular. We report a rare occurrence of ocular dirofilariasis in a 25-year-old male patient who presented with pain and redness in the eye. A live, white, coiled, and highly motile worm was present in the anterior chamber. The worm, however, could not be detected in the anterior chamber, posterior segment, or the angle of the anterior chamber when the patient was taken to the operating room for surgical removal of the worm. The patient was made to lie prone till the worm reappeared in the anterior chamber and was removed by paracentesis. The worm was identified as Dirofilaria repens on the basis of microscopic and histopathological examination.

  19. Segmental neurofibromatosis

    OpenAIRE

    Yesudian Devakar; Krishnan S. G. S; Jayaraman M; Janaki V R; Yesudian Patrick

    2014-01-01

    Segmental neurofibromatosis or type V neurofibromatosis is a rare genodermatosis characterized by neurofibromas, café-au-lait spots and neurofibromas limited to a circumscribed body region. The disease may be associated with systemic involvement and malignancies. The disorder has not been reported yet in the Polish medical literature. A 63-year-old Caucasian woman presented with a 20-year history of multiple, flesh colored, dome-shaped, soft to firm nodules situated in the right lumbar region...

  20. Language Segmentation

    OpenAIRE

    Alfter, David

    2015-01-01

    Language segmentation consists in finding the boundaries where one language ends and another language begins in a text written in more than one language. This is important for all natural language processing tasks. The problem can be solved by training language models on language data. However, in the case of low- or no-resource languages, this is problematic. I therefore investigate whether unsupervised methods perform better than supervised methods when it is difficult or impossible to trai...

  1. Anterior cruciate ligament (ACL) injury

    Science.gov (United States)

    Cruciate ligament injury - anterior; ACL injury; Knee injury - anterior cruciate ligament (ACL) ... confirm the diagnosis. It may also show other knee injuries. First aid for an ACL injury may include: ...

  2. Comb-like optical transmission spectra generated from one-dimensional two-segment-connected two-material waveguide networks optimized by genetic algorithm

    International Nuclear Information System (INIS)

    In this Letter, a one-dimensional (1D) two-segment-connected two-material waveguide network (TSCTMWN) is designed to produce comb-like frequency passbands, where each waveguide segment is composed of normal and anomalous dispersion materials and the length ratio of sub-waveguide segments is optimized by genetic algorithm (GA). It is found that 66 comb-like frequency passbands are created in the second frequency unit, maximal relative width difference of which is less than 2×10−5. It may be useful for the designing of dense wavelength division multiplexings (DWDMs) and multi-channel filters, etc., and provide new applications for GA.

  3. Agreement of anterior chamber angle examination by slit lamp optical coherence tomography and gonioscopy%裂隙灯前节OCT与房角镜检查前房角度数一致性分析

    Institute of Scientific and Technical Information of China (English)

    朱洪丽

    2013-01-01

    Objective To explore the agreement of anterior chamber angle examination by slit lamp optical coherence tomography (SL-OCT) and gonioscope.Methods Twenty-six patients with primary glaucoma (52 eyes) and 16 normal persons (32 eyes) were included.Anterior chamber angle was measured with SL-OCT and gonioscope in turns for temporal,nasal,superior and inferior quadrant.Results of two methods were analyzed and the data were analyzed with Pearson correlation coefficient and Kappa value.Results The Pearson Helation coefficient of the two methods was 0.86 (P =0.00) and the Kappa value was 0.75 (P=0.00).The specificity and sensitivity of detecting occludable angle were 94.7% and 89.4%.Conclusions Anterior chamber angle examination with SL-OCT and gonioscope are well consistent.The specificity and sensitivity for SL-OCT in detecting occludable angle is satisfying.SL-OCT can be regard as an objective assistant method for the diagnosis of angle closure glaucoma.%目的 探讨裂隙灯前节OCT与房角镜检查前房角的一致性,以便更准确地评价这一新的客观前节成像方法.方法 对2010年11月至2011年11月在沈阳市第四人民医院眼科选择原发性青光眼患者26例(52只眼)及正常人16名(32只眼).在同一暗室中依次对其双眼颞侧、鼻侧、上方、下方4个象限进行裂隙灯前节OCT和房角镜检查,采用Shaffer法与Scheie法结合的分级系统记录前房角度数,应用Pearson相关分析及Kappa值对两种检查结果进行一致性检验.结果 两种方法检查房角结果的Pearson相关系数为0.86 (P =0.00),Kappa值为0.75(P=0.00),检测可关闭房角(即房角镜检查Shaffer分级≤2级)的敏感性和特异性分别为94.7%和89.4%.结论 裂隙灯前节OCT与房角镜检查一致性好,检测可关闭房角的特异性和敏感性较高,可作为青光眼辅助诊断的客观检查手段.

  4. Donor disc attachment assessment with intraoperative spectral optical coherence tomography during descemet stripping automated endothelial keratoplasty

    Directory of Open Access Journals (Sweden)

    Edward Wylegala

    2013-01-01

    Full Text Available Optical coherence tomography has already been proven to be useful for pre- and post-surgical anterior eye segment assessment, especially in lamellar keratoplasty procedures. There is no evidence for intraoperative usefulness of optical coherence tomography (OCT. We present a case report of the intraoperative donor disc attachment assessment with spectral-domain optical coherence tomography in case of Descemet stripping automated endothelial keratoplasty (DSAEK surgery combined with corneal incisions. The effectiveness of the performed corneal stab incisions was visualized directly by OCT scan analysis. OCT assisted DSAEK allows the assessment of the accuracy of the Descemet stripping and donor disc attachment.

  5. Biomarkers and special features of oxidative stress in the anterior segment of the eye linked to lens cataract and the trabecular meshwork injury in primary open-angle glaucoma: challenges of dual combination therapy with N-acetylcarnosine lubricant eye drops and oral formulation of nonhydrolyzed carnosine.

    Science.gov (United States)

    Babizhayev, Mark A

    2012-02-01

    The implication of oxidative stress associated with increased oxidant production in mammalian and human cells characterized by the release of free radicals, resulting in cellular degeneration, is involved in many ocular diseases, such as age-related macular degeneration, retinopathy of prematurity, retinal light damage, primary open-angle glaucoma (POAG), and cataract. Cataract is the leading cause of blindness, accounting for 50% of blindness worldwide. Glaucoma, the leading cause of irreversible blindness, is considered as a progressive optic neuropathy often caused by elevated intraocular pressure (IOP) consequent to abnormally high resistance to aqueous humor (AH) drainage via the trabecular meshwork (TM) and Schlemm's canal. Morphological and biochemical analyses of the TM of patients with POAG revealed the loss of cells, increased accumulation of extracellular matrix proteins (ECM), changes in the cytoskeleton, cellular senescence, and the process of subclinical inflammation. The TM is the target tissue of glaucoma in the anterior chamber, and the development and progression of glaucoma are accompanied by the accumulation of oxidative damage in this tissue. The separate studies were conducted to comparatively evaluate the sensitivity to oxidative stress and lipid peroxidation (LPO) of anterior chamber tissues including TM. Accumulation of the primary, secondary, and end products of LPO (diene and triene conjugates, Schiff's bases) was noted in the studied extracts. Significant differences in the levels of all mentioned LPO products in comparison with the control were observed. The data may be considered as an evidence of LPO participation in the destruction of the trabecule and Schlemm's canal in POAG. Treatment of TM cells with oxidative stress induced POAG-typical changes such as ECM accumulation, cell death, disarrangement of the cytoskeleton, advanced senescence, and the release of inflammatory markers. By pretreatment with antioxidants, prostaglandin

  6. Anterior Cruciate Ligament Injury

    OpenAIRE

    Vilaseca, Tomas; Chahla, Jorge; Rodriguez, Gustavo Gomez; Arroquy, Damián; Herrera, Gonzalo Perez; Orlowski, Belen; Carboni, Martín

    2015-01-01

    Objectives: The objective of this study was to analyze whether it is more frequent the presence of a decreased range of motion in the hips of recreational athletes with primary injury of the anterior cruciate ligament (ACL) than in a control group of volunteers without knee pathology. Methods: We included prospectively recreational athletes between 18 and 40 years with an acute ACL injury between January 2011 and January 2013. They were compared with a control group of volunteers recreational...

  7. Anterior Decompression and Anterior Instrumentation of Tuberculosis of Cervicothoracic Spine by Cervicomanubrial Approach

    Directory of Open Access Journals (Sweden)

    Anant Kumar Garg

    2012-04-01

    Full Text Available Background: Evaluation of result of anterior cervical approach with manubriotomy and anterior instrumentation in tuberculosis of cervicothoracic spine in terms of the neurological recovery, reconstruction of spine and prevention of deformity along with relief of pain. Materials and Methods: All five patients with cervicothoracic caries spine had surgery through anterior cervical approach with manubriotomy in our hospital and underwent excision of the involved vertebrae and intervertebral discs followed by anterior spinal reconstruction with titanium spacer cage filled with cancellous iliac crest bone graft and Orion plate with locking screw. Antitubercular drugs were administered for 12 months. The follow-up period ranged from 12 to 36 months. Results: Analysis of result was done on the basis of clinical and radiological criteria. Clinical assessment based on Frankel grade and modified JOA score showed significant improvement from preoperative findings. Radiological assessment showed osteointegration, no spinal instability and no progression of the deformity. The pain control, based on visual analog scale changed from a pre-operative average of 7.5 to 2 at the last follow-up thereby indicating significant improvement and all patients returned to preoperative functional status. One patient had transient hoarseness of voice. No other complication had been encountered in the immediate post operative and during the follow-up period. Conclusions: Our study showed that anterior cervical approach with manubriotomy and anterior insertion of titanium cage, filled with autogenous bone graft, secured with locking plate instrumentation has a successful role in the eradication of infection, neurological recovery, segmental spinal reconstruction and it also reduces surgical time, blood loss, and surgical complications and approach related comorbidity in follow up period. Level of Evidence- Level 4, Case series

  8. Segmental neurofibromatosis.

    Science.gov (United States)

    Sobjanek, Michał; Dobosz-Kawałko, Magdalena; Michajłowski, Igor; Pęksa, Rafał; Nowicki, Roman

    2014-12-01

    Segmental neurofibromatosis or type V neurofibromatosis is a rare genodermatosis characterized by neurofibromas, café-au-lait spots and neurofibromas limited to a circumscribed body region. The disease may be associated with systemic involvement and malignancies. The disorder has not been reported yet in the Polish medical literature. A 63-year-old Caucasian woman presented with a 20-year history of multiple, flesh colored, dome-shaped, soft to firm nodules situated in the right lumbar region. A histopathologic evaluation of three excised tumors revealed neurofibromas. No neurological and ophthalmologic symptoms of neurofibromatosis were diagnosed. PMID:25610358

  9. Brookhaven segment interconnect

    International Nuclear Information System (INIS)

    We have performed a high energy physics experiment using a multisegment Brookhaven FASTBUS system. The system was composed of three crate segments and two cable segments. We discuss the segment interconnect module which permits communication between the various segments

  10. Artificial cervical disc replacement and anterior cervical decompression and fusion for the treatment of single segmental cervical disc herniation:a 3-year follow-up%颈椎人工间盘置换与前路减压融合修复单节段颈椎间盘突出症:3年随访

    Institute of Scientific and Technical Information of China (English)

    程俊杰; 眭江涛; 马原; 田慧中

    2015-01-01

    stages. Artificial disc replacement can not only play a role in mitigation of cervical disease neurological symptoms and signs, but also maintain stability and semental activity of cervical spine, and reduce secondary adjacent segmental degeneration. These two methods which applied in cervical degenerative intervertebral disc herniation stil remain controversial. OBJECTIVE:To investigate the short-term effect of artificial cervical disc replacement and anterior cervical decompression and fusion for the treatment of single segmental cervical disc herniation. METHODS:Total y 48 patients with single segment radiculopathy or myelopathy cervical diseases induced by cervical disc herniation that required surgery and received a three-month fol ow-up were included and retrospectively analyzed. These patients were divided into replacement group (n=21) and fusion group (n=27) according to the different repair programs. Patients in the replacement group were subjected to Prestige LP cervical artificial disc replacement, and patients in the fusion group were subjected to disc fusion using interbody fusion cage of Johnson or al ogeneic fibularing. They were fol owed up at 1 week, 3, 6, 12, 24, 36 months after treatment. Complications were recorded during the fol ow-up. The pain of patients was evaluated using neck and upper limb pain visual analogue scale scores. The therapeutic effect was evaluated using Japanese Orthopaedic Association (JOA) score. The clinical symptoms improvement and daily functional status of patients after treatment were evaluated using cervical disability index. RESULTS AND CONCLUSION:During the final fol ow-up, the fusion rate in fusion group was 93%(25/27). Comparisons between groups:at the 1 week and final fol ow-up after treatment, the visual analog scale scores of neck and upper limbs and cervical dysfunction indexes were al lower than those before treatment;the Japanese Orthopaedic Association scores were higher than those before treatment (P0.05). The

  11. Is it possible to differentiate between Takotsubo cardiomyopathy and acute anterior ST-elevation myocardial infarction?

    DEFF Research Database (Denmark)

    Vervaat, Fabienne E; Christensen, Thomas E; Smeijers, Loes;

    2015-01-01

    INTRODUCTION: Several studies have investigated the ability of the twelve-lead electrocardiogram (ECG) to reliably distinguish Takotsubo cardiomyopathy (TC) from an acute anterior ST-segment elevation myocardial infarction (STEMI). In these studies, only ECG changes were required - ST-segment dev......INTRODUCTION: Several studies have investigated the ability of the twelve-lead electrocardiogram (ECG) to reliably distinguish Takotsubo cardiomyopathy (TC) from an acute anterior ST-segment elevation myocardial infarction (STEMI). In these studies, only ECG changes were required - ST...

  12. New Imaging Methods in Eye Tumors - Ultrasound Biomicroscopy, Optic Coherence Tomography, and Fundus Autofluorescence

    Directory of Open Access Journals (Sweden)

    Ahmet Murat Sarıcı

    2014-09-01

    Full Text Available Several ancillary tests could be used in the diagnosis, treatment, and management of complications of eye tumors. Among those, ultrasound biomicroscopy has a particular role in the evaluation of anterior segment tumors. Optic coherence tomography and fundus autofluorescence have values in determining the architecture of posterior segment tumors and the effects of tumors on the adjacent structures. However, it should be noted that those tests have a meaning when they are evaluated together with the clinical features of the lesions. (Turk J Ophthalmol 2014; 44: Supplement 66-70

  13. Segmentation of knee injury swelling on infrared images

    Science.gov (United States)

    Puentes, John; Langet, Hélène; Herry, Christophe; Frize, Monique

    2011-03-01

    Interpretation of medical infrared images is complex due to thermal noise, absence of texture, and small temperature differences in pathological zones. Acute inflammatory response is a characteristic symptom of some knee injuries like anterior cruciate ligament sprains, muscle or tendons strains, and meniscus tear. Whereas artificial coloring of the original grey level images may allow to visually assess the extent inflammation in the area, their automated segmentation remains a challenging problem. This paper presents a hybrid segmentation algorithm to evaluate the extent of inflammation after knee injury, in terms of temperature variations and surface shape. It is based on the intersection of rapid color segmentation and homogeneous region segmentation, to which a Laplacian of a Gaussian filter is applied. While rapid color segmentation enables to properly detect the observed core of swollen area, homogeneous region segmentation identifies possible inflammation zones, combining homogeneous grey level and hue area segmentation. The hybrid segmentation algorithm compares the potential inflammation regions partially detected by each method to identify overlapping areas. Noise filtering and edge segmentation are then applied to common zones in order to segment the swelling surfaces of the injury. Experimental results on images of a patient with anterior cruciate ligament sprain show the improved performance of the hybrid algorithm with respect to its separated components. The main contribution of this work is a meaningful automatic segmentation of abnormal skin temperature variations on infrared thermography images of knee injury swelling.

  14. Quantitative assessment of rat corneal thickness and morphology during stem cell therapy by high-speed optical coherence tomography

    Science.gov (United States)

    Lal, Cerine; McGrath, James; Subhash, Hrebesh; Rani, Sweta; Ritter, Thomas; Leahy, Martin

    2016-03-01

    Optical Coherence Tomography (OCT) is a non-invasive 3 dimensional optical imaging modality that enables high resolution cross sectional imaging in biological tissues and materials. Its high axial and lateral resolution combined with high sensitivity, imaging depth and wide field of view makes it suitable for wide variety of high resolution medical imaging applications at clinically relevant speed. With the advent of swept source lasers, the imaging speed of OCT has increased considerably in recent years. OCT has been used in ophthalmology to study dynamic changes occurring in the cornea and iris, thereby providing physiological and pathological changes that occur within the anterior segment structures such as in glaucoma, during refractive surgery, lamellar keratoplasty and corneal diseases. In this study, we assess the changes in corneal thickness in the anterior segment of the eye during wound healing process in a rat corneal burn model following stem cell therapy using high speed swept source OCT.

  15. Continuous intraoperative OCT guided management of post-deep anterior lamellar keratoplasty descemet’s membrane detachme

    Directory of Open Access Journals (Sweden)

    Namrata Sharma

    2016-04-01

    Full Text Available Continuous intraoperative optical coherence tomography (iOCT integrated into the operating microscope is a new modification in the current operating microscope to aid in the surgical procedures involving both the anterior and the posterior segment. This helps in intraoperative planning, modification of the surgical steps if required and confirmation of the surgical endpoint in the operating room itself. iOCT was used for the successful management of descemet’s membrane detachment (DMD following deep anterior lamellar keratoplasty (DALK with intracameral injection of 20% Sulphur hexafluoride. The gas was injected under direct visualization through the microscope with continuous real time monitoring of the change in height of the detached Descemet’s membrane (DM. Additionally stab incisions were given through the anterior cornea due to the presence of residual fluid above the DM which was visible on continuous iOCT images. This led to the successful apposition of the DM which otherwise would have remained detached due to the residual fluid. This highlights the importance of continuous iOCT monitoring of the ophthalmic surgical procedures in order to produce a successful anatomical outcome of the surgery without disruption of the surgical procedure.

  16. Anterior knee pain

    International Nuclear Information System (INIS)

    Anterior knee pain is a common complain in all ages athletes. It may be caused by a large variety of injuries. There is a continuum of diagnoses and most of the disorders are closely related. Repeated minor trauma and overuse play an important role for the development of lesions in Hoffa's pad, extensor mechanism, lateral and medial restrain structures or cartilage surface, however usually an increase or change of activity is referred. Although the direct relation of cartilage lesions, especially chondral, and pain is a subject of debate these lesions may be responsible of early osteoarthrosis and can determine athlete's prognosis. The anatomy and biomechanics of patellofemoral joint is complex and symptoms are often unspecific. Transient patellar dislocation has MR distinct features that provide evidence of prior dislocation and rules our complication. However, anterior knee pain more often is related to overuse and repeated minor trauma. Patella and quadriceps tendon have been also implicated in anterior knee pain, as well as lateral or medial restraint structures and Hoffa's pad. US and MR are excellent tools for the diagnosis of superficial tendons, the advantage of MR is that permits to rule out other sources of intraarticular derangements. Due to the complex anatomy and biomechanic of patellofemoral joint maltracking is not fully understood; plain films and CT allow the study of malalignment, new CT and MR kinematic studies have promising results but further studies are needed. Our purpose here is to describe how imaging techniques can be helpful in precisely defining the origin of the patient's complaint and thus improve understanding and management of these injuries

  17. The anterior cingulate cortex

    Directory of Open Access Journals (Sweden)

    Pavlović D.M.

    2009-01-01

    Full Text Available The anterior cingulate cortex (ACC has a role in attention, analysis of sensory information, error recognition, problem solving, detection of novelty, behavior, emotions, social relations, cognitive control, and regulation of visceral functions. This area is active whenever the individual feels some emotions, solves a problem, or analyzes the pros and cons of an action (if it is a right decision. Analogous areas are also found in higher mammals, especially whales, and they contain spindle neurons that enable complex social interactions. Disturbance of ACC activity is found in dementias, schizophrenia, depression, the obsessive-compulsive syndrome, and other neuropsychiatric diseases.

  18. Longitudinal Evaluation of Cornea With Swept-Source Optical Coherence Tomography and Scheimpflug Imaging Before and After Lasik

    OpenAIRE

    Tommy C. Y. Chan; Biswas, Sayantan; Yu, Marco; Jhanji, Vishal

    2015-01-01

    Abstract Swept-source optical coherence tomography (OCT) is the latest advancement in anterior segment imaging. There are limited data regarding its performance after laser in situ keratomileusis (LASIK). We compared the reliability of swept-source OCT and Scheimpflug imaging for evaluation of corneal parameters in refractive surgery candidates with myopia or myopic astigmatism. Three consecutive measurements were obtained preoperatively and 1 year postoperatively using swept-source OCT and S...

  19. Optical coherence tomography and autofluorescence findings in chronic phototoxic maculopathy secondary to snow-reflected solar radiation

    Directory of Open Access Journals (Sweden)

    Dhananjay Shukla

    2015-01-01

    Full Text Available A professional mountain trekker presented with gradual, moderate visual decline in one eye. The subnormal vision could not be explained by the examination of anterior and posterior segment of either eye, which was unremarkable. Optical coherence tomography and autofluorescence imaging revealed subtle defects in the outer retina, which correlated with the extent of visual disturbance. A novel presentation of retinal phototoxicity due to indirect solar radiation reflected from snow in inadequately protected eyes of a chronically exposed subject is reported.

  20. Optic disc boundary segmentation from diffeomorphic demons registration of monocular fundus image sequences versus 3D visualization of stereo fundus image pairs for automated early stage glaucoma assessment

    Science.gov (United States)

    Gatti, Vijay; Hill, Jason; Mitra, Sunanda; Nutter, Brian

    2014-03-01

    Despite the current availability in resource-rich regions of advanced technologies in scanning and 3-D imaging in current ophthalmology practice, world-wide screening tests for early detection and progression of glaucoma still consist of a variety of simple tools, including fundus image-based parameters such as CDR (cup to disc diameter ratio) and CAR (cup to disc area ratio), especially in resource -poor regions. Reliable automated computation of the relevant parameters from fundus image sequences requires robust non-rigid registration and segmentation techniques. Recent research work demonstrated that proper non-rigid registration of multi-view monocular fundus image sequences could result in acceptable segmentation of cup boundaries for automated computation of CAR and CDR. This research work introduces a composite diffeomorphic demons registration algorithm for segmentation of cup boundaries from a sequence of monocular images and compares the resulting CAR and CDR values with those computed manually by experts and from 3-D visualization of stereo pairs. Our preliminary results show that the automated computation of CDR and CAR from composite diffeomorphic segmentation of monocular image sequences yield values comparable with those from the other two techniques and thus may provide global healthcare with a cost-effective yet accurate tool for management of glaucoma in its early stage.

  1. Segmentation of Handwritten Text in Gurmukhi Script

    Directory of Open Access Journals (Sweden)

    Rajiv K. Sharma

    2008-09-01

    Full Text Available Character segmentation is an important preprocessing step for text recognition.The size and shape of characters generally play an important role in the processof segmentation. But for any optical character recognition (OCR system, thepresence of touching characters in textual as well handwritten documents furtherdecreases correct segmentation as well as recognition rate drastically. Becauseone can not control the size and shape of characters in handwritten documentsso the segmentation process for the handwritten document is too difficult. Wetried to segment handwritten text by proposing some algorithms, which wereimplemented and have shown encouraging results. Algorithms have beenproposed to segment the touching characters. These algorithms have shown areasonable improvement in segmenting the touching handwritten characters inGurmukhi script.

  2. Review of 31 cases of anterior thoracolumbar fixation with the anterior thoracolumbar locking plate system.

    Science.gov (United States)

    Wilson, J A; Bowen, S; Branch, C L; Meredith, J W

    1999-07-15

    Anterior fixation devices for the thoracolumbar spine have gained wide acceptance as viable alternatives to long-segment posterior fixation in cases of thoracolumbar spine trauma. This review was undertaken to evaluate the safety and efficacy of the Synthes anterior thoracolumbar locking plate (ATLP) system. Over a 3-year period, 31 patients with unstable traumatic fractures of the thoracolumbar spine underwent corpectomy, placement of a structural bone graft, and anterior fixation in which the Synthes ATLP system was used. Long-term follow-up data were obtained in 29 patients. Two patients were lost to follow up, one at 4 months and the other at 1 year. In the remaining patients, the average length of follow up was 20 months. In all patients radiographic evidence of solid bone fusion was demonstrated on follow-up plain x-ray films, and there were no signs or symptoms of pseudarthrosis. No patient suffered neurological deterioration as a result of surgery, and there was relatively little morbidity associated with this plating system. To date, none of the patients in this study has developed any delayed complications related to the fixation device. In one patient, who had sustained a severe flexion injury, loosening of the anterior fixation device occurred, and the patient developed progressive kyphosis, which required a posterior stabilization procedure. These results appear slightly better than those obtained in published studies in which other anterior plating systems were used, indicating that this system is safe and effective in the treatment of unstable fractures of the thoracolumbar spine. PMID:16918232

  3. Multidisciplinary management of anterior diastemata

    DEFF Research Database (Denmark)

    Furuse, Adilson Yoshio; Herkrath, Fernando José; Franco, Eduardo Jacomino;

    2007-01-01

    Anterior diastemata may compromise the harmony of a patient's smile. Consideration of etiologic factors, previous gingival conditioning, and individual treatment planning are essential in the proper management of anterior diastemata. An integrated orthodontic-restorative approach may enhance the...... aesthetic results when orthodontic therapy itself is not feasible. This article presents integrated orthodonticrestorative solutions of anterior diastemata, associated with the conditioning of the gingival tissue with composite resin, and discusses the most relevant aspects related to their etiology and...

  4. Anterior cruciate ligament reconstruction with double bundle versus single bundle: experimental study Reconstrução do ligamento cruzado anterior com duplo feixe versus feixe único: estudo experimental

    OpenAIRE

    Roberto F. Mota e Albuquerque; Sandra Umeda Sasaki; Marco Martins Amatuzzi; Fabio Janson Angelini

    2007-01-01

    OBJECTIVE: To test an intra-articular reconstruction of the anterior cruciate ligament of the knee in 10 human cadavers by replacing 2 anterior cruciate ligament bundles, with the purpose of producing a surrogate that would be structurally more similar to the anatomy of the anterior cruciate ligament and would provide the knee with more stability. METHODS: We reconstructed the anteromedial and posterolateral bundles using a quadriceps muscle tendon graft that included a patellar bone segment....

  5. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Ninth Edition Optics: Ninth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommen

  6. Anterior cruciate ligament reconstruction

    International Nuclear Information System (INIS)

    This paper determines the efficacy of MR imaging in evaluation of the anterior cruciate ligament (ACL) following reconstructive surgery. Forty-three MR examinations were performed in 33 patients who had undergone previous arthroscopic ACL reconstruction with patellar bone-tendon- bone autografts (postoperative period, 1-24 months; mean, 5.2 months). Of the 40 studies performed in clinically stable knees (30 patients), MR demonstrated a well-defined, signal void ACL graft in 36. Of the three studies performed in three patients with clinical ACL laxity or suspected tear, the neoligament was of intermediate definition in one and nondiscernible in the other two. As in the native knee, buckling of the PCL was suggestive of ACL insufficiency. Bone tunnel placement, patellar tendon changes, and joint effusions were also evaluated

  7. Anterior hip pain.

    Science.gov (United States)

    O'Kane, J W

    1999-10-15

    Anterior hip pain is a common complaint with many possible causes. Apophyseal avulsion and slipped capital femoral epiphysis should not be overlooked in adolescents. Muscle and tendon strains are common in adults. Subsequent to accurate diagnosis, strains should improve with rest and directed conservative treatment. Osteoarthritis, which is diagnosed radiographically, generally occurs in middle-aged and older adults. Arthritis in younger adults should prompt consideration of an inflammatory cause. A possible femoral neck stress fracture should be evaluated urgently to prevent the potentially significant complications associated with displacement. Patients with osteitis pubis should be educated about the natural history of the condition and should undergo physical therapy to correct abnormal pelvic mechanics. "Sports hernias," nerve entrapments and labral pathologic conditions should be considered in athletic adults with characteristic presentations and chronic symptoms. Surgical intervention may allow resumption of pain-free athletic activity. PMID:10537384

  8. Change pattern of somatosensory-evoked potentials after occlusion of segmental vessels: possible indicator for spinal cord ischemia

    OpenAIRE

    Wu, Liang; Qiu, Yong; Ling, Weiqi; Shen, Qin

    2005-01-01

    Paraplegia was reported after occlusion of the segmental vessels during anterior spinal surgery. The aim of this study was to investigate the effect of occlusion of the segmental vessels on the somatosensory-evoked potential (SEP) monitoring and analyze its potential risk for cord ischemia. Thirty-one patients with thoracic scoliosis underwent anterior spinal surgery. T5–T11 segmental vessels on the convexity were occluded with microvascular clamps at the point 2 cm from the intravertebra for...

  9. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... and E-poly antioxidant-infused technology during a hip replacement through the anterior supine intramuscular approach. “OR- ... Dr. Keith Berend perform an anterior approach total hip replacement with the patient on a regular OR ...

  10. Expression of segment polarity genes in brachiopods supports a non-segmental ancestral role of engrailed for bilaterians.

    Science.gov (United States)

    Vellutini, Bruno C; Hejnol, Andreas

    2016-01-01

    The diverse and complex developmental mechanisms of segmentation have been more thoroughly studied in arthropods, vertebrates and annelids-distantly related animals considered to be segmented. Far less is known about the role of "segmentation genes" in organisms that lack a segmented body. Here we investigate the expression of the arthropod segment polarity genes engrailed, wnt1 and hedgehog in the development of brachiopods-marine invertebrates without a subdivided trunk but closely related to the segmented annelids. We found that a stripe of engrailed expression demarcates the ectodermal boundary that delimits the anterior region of Terebratalia transversa and Novocrania anomala embryos. In T. transversa, this engrailed domain is abutted by a stripe of wnt1 expression in a pattern similar to the parasegment boundaries of insects-except for the expression of hedgehog, which is restricted to endodermal tissues of the brachiopod embryos. We found that pax6 and pax2/5/8, putative regulators of engrailed, also demarcate the anterior boundary in the two species, indicating these genes might be involved in the anterior patterning of brachiopod larvae. In a comparative phylogenetic context, these findings suggest that bilaterians might share an ancestral, non-segmental domain of engrailed expression during early embryogenesis. PMID:27561213

  11. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Eighth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommended for engineering st

  12. Endoscopic anterior decompression in cervical disc disease

    Directory of Open Access Journals (Sweden)

    Yad Ram Yadav

    2014-01-01

    Full Text Available Background: Although microscopic anterior cervical discectomy with or without fusion are common surgical procedures for treatment of cervical herniated discs, loss of disc height, pseudarthrosis, and adjacent disc degeneration are some of the problems associated with it. This study is aimed to evaluate results of endoscopic microforaminotomy in cervical disc diseases. Materials and Methods: A prospective study of 50 patients of mono segmental soft or hard disc causing myeloradiculopathy was undertaken. A visual analogue scale (VAS for neck and arm pain and functional outcomes using the Nurick grading system were assessed. There were 28, 12, 8, and 2 patients at C5-6, C6-7, C4-5, and C3-4 levels disc diseases, respectively. Patients with two or more level disc, instabilities, disc extending more than half vertebral body height, and previous operation at the same segment were excluded. Results: Age ranged from 21 to 67 years. Average postoperative reduction in disc height, operating time, and blood loss was 1.1 mm, 110 minutes, and 30 ml, respectively. Average pre-operative VAS score for arm pain and Nurick grading was 7.6 and 2.7, which improved to 1.9 and 0.82, respectively. All patients improved; 1, 2, 3 grade improvement was seen in 10, 27, and 10 patients, respectively. There was no significant complication or any mortality. Conclusion: Although longer follow up of large number of patients is required, endoscopic microforaminotomy is a safe and an effective alternative to microscopic anterior discectomy with or without fusion.

  13. Anterior Cervical Osteophytes Causing Dysphagia and Dyspnea: An Uncommon Entity Revisited

    OpenAIRE

    Giger, Roland; Dulguerov, Pavel; Payer, Michael

    2007-01-01

    Large anterior cervical osteophytes can occur in degeneration of the cervical spine or in diffuse idiopathic skeletal hyperostosis (DISH). We present the case of an 83-year-old patient with progressive dysphagia and acute dyspnea, necessitating emergency tracheotomy. Voluminous anterior cervical osteophytes extending from C3 to C7 and narrowing the pharyngoesophageal segment by external compression and bilateral vocal fold immobility were diagnosed radiologically and by fiberoptic laryngoscop...

  14. Central corneal thickness and anterior chamber depth measurement by Sirius® Scheimpflug tomography and ultrasound

    OpenAIRE

    Jorge J; Rosado JL; Díaz-Rey JA; González-Méijome JM

    2013-01-01

    J Jorge,1 JL Rosado,2 JA Díaz-Rey,1 JM González-Méijome11Clinical and Experimental Optometry Research Laboratory, Center of Physics (Optometry), School of Sciences, University of Minho, Braga, 2Opticlinic, Lisboa, PortugalBackground: The purpose of this study was to compare the accuracy of the new Sirius® Scheimpflug anterior segment examination device for measurement of central corneal thickness (CCT) and anterior chamber depth (ACD) with that of CCT ...

  15. Shape of the anterior cornea : Comparison of height data from 4 corneal topographers

    NARCIS (Netherlands)

    de Jong, Tim; Sheehan, Matthew T.; Dubbelman, Michiel; Koopmans, Steven A.; Jansonius, Nomdo M.

    2013-01-01

    PURPOSE: To compare the ability of clinical corneal topographers to describe the shape of the anterior cornea for optical modeling. SETTING: University Medical Center Groningen, Groningen, Netherlands. DESIGN: Cross-sectional study. METHODS: The anterior corneal shape of healthy subjects was assesse

  16. Probabilistic retinal vessel segmentation

    Science.gov (United States)

    Wu, Chang-Hua; Agam, Gady

    2007-03-01

    Optic fundus assessment is widely used for diagnosing vascular and non-vascular pathology. Inspection of the retinal vasculature may reveal hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. Due to various imaging conditions retinal images may be degraded. Consequently, the enhancement of such images and vessels in them is an important task with direct clinical applications. We propose a novel technique for vessel enhancement in retinal images that is capable of enhancing vessel junctions in addition to linear vessel segments. This is an extension of vessel filters we have previously developed for vessel enhancement in thoracic CT scans. The proposed approach is based on probabilistic models which can discern vessels and junctions. Evaluation shows the proposed filter is better than several known techniques and is comparable to the state of the art when evaluated on a standard dataset. A ridge-based vessel tracking process is applied on the enhanced image to demonstrate the effectiveness of the enhancement filter.

  17. Fabrication, performance, and figure metrology of epoxy-replicated aluminum foils for hard x-ray focusing multilayer-coated segmented conical optics

    Science.gov (United States)

    Jimenez-Garate, Mario A.; Craig, William W.; Hailey, Charles J.; Christensen, Finn E.; Hussain, Ahsen M.

    2000-11-01

    We fabricated x-ray mirrors for hard x-ray (>= 10 keV) telescopes using multilayer coatings and an improved epoxy- replicated aluminum foil (ERAF) nonvacuum technology. The ERAF optics have approximately 1 arcmin axial figure half- power diameter (HPD) and passed environmental testing. Reflectivity measurements at 8 keV on ERAFs with and without multilayer coatings show a 4.4 to 4.8 angstroms room mean square microroughness for correlation lengths EQ 15 micrometers . To reduce the dominant contribution of mirror assembly and large-scale distortion in the overall telescope HPD, we designed a figure metrology system and a new mounting technique. We describe a cylindrical metrology system built for fast axial and roundness figure measurement of hard x-ray conical optics. These developments lower cost and improve the optics performance of the HEFT (high-energy focusing telescope) and Constellation-X missions.

  18. Fabrication, performance, and figure metrology of epoxy-replicated aluminum foils for hard x-ray focusing multilayer-coated segmented conical optics

    DEFF Research Database (Denmark)

    Jimenez-Garate, M.A.; Craig, W.W.; Hailey, C.J.; Christensen, Finn Erland; Hussain, A.

    2000-01-01

    We fabricated x-ray mirrors for hard x-ray (greater than or equal to 10 keV) telescopes using multilayer coatings and an improved epoxy-replicated aluminum foil (ERAF) nonvacuum technology. The ERAF optics have similar to1 arcmin axial figure half-power diameter (HPD) and passed environmental...... testing. Reflectivity measurements at 8 keV on ERAFs with and without multilayer coatings show a 4.4 to 4.8 A root mean square (rms) microroughness for correlation lengths less than or equal to 15 mum. To reduce the dominant contribution of mirror assembly and large-scale distortion in the overall...... telescope HPD, we designed a figure metrology system and a new mounting technique. We describe a cylindrical metrology system built for fast axial and roundness figure measurement of hard x-ray conical optics. These developments lower cost and improve the optics performance of the HEFT (high-energy focusing...

  19. Abnormal origin of the ophthalmic artery from the anterior cerebral artery: Neuroradiological and intraoperative findings

    International Nuclear Information System (INIS)

    A 7-year old male child with an abnormal ophthalmic artery arising from the A1 segment of the anterior cerebral artery is described. The patient suffered growth inhibition which was thought to be caused by a craniobasal cystic lesion affecting the hypothalamus. Preoperative angiograms revealed no vascular abnormalities. The right ophthalmic artery, however, could not be identified. During resection of a large arachnoid cyst the ophthalmic artery was found to arise from the A1 segment of the anterior cerebral artery. To the best of our knowledge, this exact anomaly has not previously been reported. The clinical, neuroradiological and intraoperative findings are presented. (orig.)

  20. Corticotomy and compression osteogenesis in the posterior maxilla for treating severe anterior open bite.

    Science.gov (United States)

    Kanno, T; Mitsugi, M; Furuki, Y; Kozato, S; Ayasaka, N; Mori, H

    2007-04-01

    A new technique is described for outpatient treatment of anterior open bite. The compression osteogenesis method with a two-stage corticotomy was used in the posterior maxilla to treat a woman with severe anterior open bite. Three-week post-surgical compression using anchor plates and elastics repositioned the posterior maxillary bone/teeth segments by 7 mm to the ideal superior position. The patient had a stable skeletal position of the maxilla at 14-month follow-up with satisfactory results and no complications after orthodontic treatment. This technique appears to be an efficient option for treating patients with anterior open bite. PMID:17110086

  1. Tissue Segmentation of Brain MRI

    Czech Academy of Sciences Publication Activity Database

    Dvořák, P.; Bartušek, Karel; Mikulka, J.

    Berlin: IEEE, 2014, s. 482-485. ISBN 978-80-214-4983-1. ISSN 1805-5435. [TSP 2014. International Conference on Telecommunications and Signal Processing /37./. Berlín (DE), 01.07.2014-03.07.2014] R&D Projects: GA ČR GAP102/12/1104 Institutional support: RVO:68081731 Keywords : Brain * Gaussian Mixture Model * GMM * Image segmentation * Magnetic Resonance Subject RIV: BH - Optics, Masers, Lasers

  2. Optical Coherence Tomography Guided Percutaneous Coronary Intervention With Nobori Stent Implantation in Patients With Non-ST-Segment-Elevation Myocardial Infarction (OCTACS) Trial

    DEFF Research Database (Denmark)

    Antonsen, Lisbeth; Thayssen, Per; Maehara, Akiko;

    2015-01-01

    BACKGROUND: Incomplete strut coverage has been documented an important histopathologic morphometric predictor for later thrombotic events. This study sought to investigate whether optical coherence tomography (OCT)-guided percutaneous coronary intervention with Nobori biolimus-eluting stent impla...... 6-month follow-up in comparison with angiographic guidance alone. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02272283....

  3. STUDY ON VARIATIONS OF INFERIOR SEGMENTAL BRANCH OF RENAL ARTERY

    Directory of Open Access Journals (Sweden)

    Chandragirish S

    2014-11-01

    Full Text Available Background: The segmental arteries of the kidney supply the organ in such a way that, each renal pole receives its own artery while, the anterior portion between the poles is supplied by an upper and lower segmental vessel. These two arteries also include in their territory the lateral edge of the kidney and adjacent to the strip of parenchyma on the dorsal or posterior aspect of the organ. The knowledge of inferior segmental branch of renal artery is very important for surgeries in its distribution area in kidney. Materials and Methods: 100 kidneys (Fifty pairs intact with abdominal aorta were collected from department of Forensic medicine, JSS Medical College and Mysore Medical College. For study of segmental variation Corrosion cast technique method was used. The variations of inferior segmental branch of renal artery were observed and recorded. Results: In present study type I inferior segmental branch of renal artery were found in - 59% cases, type II in - 6% cases, type III in - 28% cases, type IV in - 2% cases. Conclusion: The inferior segmental artery from the anterior division of the renal artery is the commonest event –arising in 59%. This is Type I, the normal type. It arises from the renal artery (28% or from the posterior division (6% or from the aorta (2%. The knowledge of inferior segmental branch of renal artery helpful in kidney transplantation and renal surgery because these type of surgeries success mainly depends on arterial ligations.

  4. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... Taperloc Microplasty stem and E-poly antioxidant-infused technology during a hip replacement through the anterior supine ... renewed interest at this time due to several advantages that it brings. The approach that is performed ...

  5. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... an anterior approach total hip replacement with the patient on a regular OR table supine. My name ... less invasive without being small incision surgery. Obese patients can be easier due to less distribution of ...

  6. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... it to have any real negative or deleterious effect by removing the anterior capsule. Now I would ... is what happens with one of the competitive designs. Like I told you, I just take a ...

  7. Anterior approach for knee arthrography

    International Nuclear Information System (INIS)

    Objective. To develop a new method of magnetic resonance arthrography (MRA) of the knee using an anterior approach analogous to the portals used for knee arthroscopy.Design. An anterior approach to the knee joint was devised mimicking anterior portals used for knee arthroscopy. Seven patients scheduled for routine knee MRA were placed in a decubitus position and under fluoroscopic guidance a needle was advanced from a position adjacent to the patellar tendon into the knee joint. After confirmation of the needle tip location, a dilute gadolinium solution was injected.Results and conclusion. All the arthrograms were technically successful. The anterior approach to knee MRA has greater technical ease than the traditional approach with little patient discomfort. (orig.)

  8. Carotid-anterior cerebral artery anastomosis on MR angiography: a university hospital-based study

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, Akira; Saito, Naoko; Okada, Yoshitaka; Inoue, Kaiji [Saitama Medical University International Medical Center, Department of Diagnostic Radiology, Hidaka, Saitama (Japan)

    2012-01-15

    Rarely in the anterior circulation, an anastomosis of the carotid and anterior cerebral arteries occurs when an anomalous branch arises from the ophthalmic segment of the internal carotid artery and anastomoses with the A1-A2 junction of the anterior communicating artery. Right-side predominance is known. To our knowledge, the incidence of carotid-anterior cerebral artery anastomosis has not been reported, so we researched cases in our institution records to determine incidence and investigated characteristic features of the condition on magnetic resonance (MR) angiography. To isolate such cases, we retrospectively reviewed cranial MR angiographic images of 3,491 consecutive patients in our institution. We found three cases with carotid-anterior cerebral artery anastomosis (two men, one woman), representing an incidence of 0.086%. The anastomosis was on the right in all three cases. A normal A1 segment of the anterior cerebral artery (ACA) was present in two cases but could not be identified in the remaining case on MR angiographic images that included source images. Two of the three patients demonstrated associated arterial variations in their carotid systems. On MR angiography, we observed a 0.086% incidence of carotid-anterior cerebral artery anastomosis in our institution and reaffirmed the right-side predominance of this anomaly. We found a high frequency of other associated arterial variations in the carotid system. (orig.)

  9. Amodal Instance Segmentation

    OpenAIRE

    Li, Ke; Malik, Jitendra

    2016-01-01

    We consider the problem of amodal instance segmentation, the objective of which is to predict the region encompassing both visible and occluded parts of each object. Thus far, the lack of publicly available amodal segmentation annotations has stymied the development of amodal segmentation methods. In this paper, we sidestep this issue by relying solely on standard modal instance segmentation annotations to train our model. The result is a new method for amodal instance segmentation, which rep...

  10. What Segments Equity Markets?

    OpenAIRE

    Geert Bekaert; Harvey, Campbell R.; Christian Lundblad; Stephan Siegel

    2009-01-01

    We propose a new, valuation-based measure of world equity market segmentation. While we observe decreased levels of segmentation in many developing countries, the level of segmentation is still significant. In contrast to previous research, we characterize the factors that account for variation in market segmentation both through time as well as across countries. While a country’s regulation with respect to foreign capital flows is important in determining its level of segmentation, we find t...

  11. Travoprost Induced Granulomatous Anterior Uveitis

    OpenAIRE

    Patrick Chiam

    2011-01-01

    Purpose. To report a case of granulomatous anterior uveitis caused by travoprost. Methods. Single observational case report. Results. A 71-year-old who was fit and healthy presented with bilateral granulomatous anterior uveitis 2 months after he was started on travoprost in both eyes. There was no past history of uveitis. Blood test and radiological investigation were unremarkable. Travoprost was stopped. The uveitis resolved on topical steroid treatment. A rechallenge with travoprost was att...

  12. Update on anterior ankle impingement

    OpenAIRE

    Vaseenon, Tanawat; Amendola, Annunziato

    2012-01-01

    Anterior ankle impingement results from an impingement of the ankle joint by a soft tissue or osteophyte formation at the anterior aspect of the distal tibia and talar neck. It often occurs secondary to direct trauma (impaction force) or repetitive ankle dorsiflexion (repetitive impaction and traction force). Chronic ankle pain, swelling, and limitation of ankle dorsiflexion are common complaints. Imaging is valuable for diagnosis of the bony impingement but not for the soft tissue impingemen...

  13. Anterior chamber depth during hemodialysis

    Directory of Open Access Journals (Sweden)

    Gracitelli CPB

    2013-08-01

    Full Text Available Carolina Pelegrini Barbosa Gracitelli,1 Francisco Rosa Stefanini,1 Fernando Penha,1 Miguel Ângelo Góes,2 Sérgio Antonio Draibe,2 Maria Eugênia Canziani,2 Augusto Paranhos Junior1 1Ophthalmology Department, 2Division of Nephrology, Federal University of São Paulo – UNIFESP, São Paulo, Brazil Background: Exacerbation of chronic glaucoma or acute glaucoma is occasionally observed in patients undergoing hemodialysis (HD because of anterior chamber depth changes during this therapy. Purpose: To evaluate anterior chamber depth and axial length in patients during HD sessions. Methods: A total of 67 eyes of 35 patients were prospectively enrolled. Axial length and anterior chamber depth were measured using ultrasonic biometry, and these measures were evaluated at three different times during HD sessions. Body weight and blood pressure pre- and post-HD were also measured. Results: There was no difference in the axial length between the three measurements (P = 0.241. We observed a significantly decreased anterior chamber depth (P = 0.002 during HD sessions. Conclusion: Our results support the idea that there is a change in anterior chamber depth in HD sessions. Keywords: anterior chamber, hemodialysis, axial length, acute angle-closure glaucoma

  14. Load Rate of Facet Joints at the Adjacent Segment Increased After Fusion

    Institute of Scientific and Technical Information of China (English)

    Hui Li; Bao-Qing Pei; Jin-Cai Yang; Yong Hai; De-Yu Li; Shu-Qin Wu

    2015-01-01

    Background:The cause of the adjacent segment degeneration (ASD) after fusion remains unknown.It is reported that adjacent facet joint stresses increase after anterior cervical discectomy and fusion.This increase of stress rate may lead to tissue injury.Thus far,the load rate of the adjacent segment facet joint after fusion remains unclear.Methods:Six C2-C7 cadaveric spine specimens were loaded under four motion modes:Flexion,extension,rotation,and lateral bending,with a pure moment using a 6° robot arm combined with an optical motion analysis system.The Tecscan pressure test system was used for testing facet joint pressure.Results:The contact mode of the facet joints and distributions of the force center during different motions were recorded.The adjacent segment facet joint forces increased faster after fusion,compared with intact conditions.While the magnitude of pressures increased,there was no difference in distribution modes before and after fusion.No pressures were detected during flexion.The average growth velocity during extension was the fastest and was significantly faster than lateral bending.Conclusions:One of the reasons for cartilage injury was the increasing stress rate of loading.This implies that ASD after fusion may be related to habitual movement before and after fusion.More and faster extension is disadvantageous for the facet joints and should be reduced as much as possible.

  15. Postnatal development of the anterior skull base and nasal septum: CT study

    International Nuclear Information System (INIS)

    To know the normal CT appearance of the anterior skull base and nasal septum after birth. Coronal CT scans with a helical mode were performed from the nasal bone to the sphenoid sinus in 99 children whose ages ranged from 27 days to 14 years. We investigated the CT appearance of the developing anterior skull base and nasal septum with particular attention to the anteroposterior length of the anterior skull base and the ossification patterns of the cribriform plate, perpendicular plate, crista galli, and vomer. The anteroposterior length of the anterior skull base statistically significantly increased with age. The cribriform plate showed partial or complete ossification in at least one segment at more than 3 months of age and in all three segments at more than 6 months of age. Ossification of the cribriform plate occurred earlier in the middle segment than in the anterior and posterior segments. It began exclusively in the region of the lateral mass of the ethmoid and proceeded medially toward the crista galli. Partial ossification of the perpendicular plate was noted as early as 9 months of age, and complete ossification as early as 13 months of age. All children at 18 months and older showed at least partial ossification of the perpendicular plate. Partial ossification of the crista galli was noted as early as 27 days of age, and complete ossification as early as 3 months of age. CT showed complete ossification of the crista galli in all but two children at 6 months and older. The superior aspect of the vomer exhibited a V- or Y-shape on all CT scans in 66%(65/99) of children at any age. It appeared as an undivided single lump anteriorly and a V or Y posteriorly in 34%(34/99). Knowledge of the normal developing patterns of ossification of the anterior skull base and nasal septum could help prevent errors in interpreting CT scans in this region, especially in infants and young children

  16. Pituitary Adenoma Segmentation

    CERN Document Server

    Egger, Jan; Kuhnt, Daniela; Freisleben, Bernd; Nimsky, Christopher

    2011-01-01

    Sellar tumors are approximately 10-15% among all intracranial neoplasms. The most common sellar lesion is the pituitary adenoma. Manual segmentation is a time-consuming process that can be shortened by using adequate algorithms. In this contribution, we present a segmentation method for pituitary adenoma. The method is based on an algorithm we developed recently in previous work where the novel segmentation scheme was successfully used for segmentation of glioblastoma multiforme and provided an average Dice Similarity Coefficient (DSC) of 77%. This scheme is used for automatic adenoma segmentation. In our experimental evaluation, neurosurgeons with strong experiences in the treatment of pituitary adenoma performed manual slice-by-slice segmentation of 10 magnetic resonance imaging (MRI) cases. Afterwards, the segmentations were compared with the segmentation results of the proposed method via the DSC. The average DSC for all data sets was 77.49% +/- 4.52%. Compared with a manual segmentation that took, on the...

  17. Study on the design and Zernike aberrations of a segmented mirror telescope

    Institute of Scientific and Technical Information of China (English)

    Jiang Zhen-Yu; Li Lin; Huang Yi-Fan

    2009-01-01

    The segmented mirror telescope is widely used. The aberrations of segmented mirror systems are different from single mirror systems. This paper uses the Fourier optics theory to analyse the Zernike aberrations of segmented mirror systems. It concludes that the Zernike aberrations of segmented mirror systems obey the linearity theorem. The design of a segmented space telescope and segmented schemes are discussed, and its optical model is constructed. The computer simulation experiment is performed with this optical model to verify the suppositions. The experimental results confirm the correctness of the model.

  18. Travoprost Induced Granulomatous Anterior Uveitis

    Science.gov (United States)

    Chiam, Patrick

    2011-01-01

    Purpose. To report a case of granulomatous anterior uveitis caused by travoprost. Methods. Single observational case report. Results. A 71-year-old who was fit and healthy presented with bilateral granulomatous anterior uveitis 2 months after he was started on travoprost in both eyes. There was no past history of uveitis. Blood test and radiological investigation were unremarkable. Travoprost was stopped. The uveitis resolved on topical steroid treatment. A rechallenge with travoprost was attempted in one eye. The inflammation recurred in this eye only. This subsided with the cessation of travoprost alone without topical steroid. Conclusion. This is the first case report of travoprost causing granulomatous anterior uveitis. The uveitis recurred with a rechallenge. Changing the prostaglandin analogue to another topical treatment may be adequate to cease the inflammation. PMID:22606464

  19. Anterior ST depression with acute transmural inferior infarction due to posterior infarction. A vectorcardiographic and scintigraphic study

    International Nuclear Information System (INIS)

    The hypothesis that anterior ST segment depression represents concomitant posterior infarction was tested in 49 patients admitted with a first transmural inferior myocardial infarction. Anterior ST depression was defined as 0.1 mV or more ST depression in leads V1, V2 or V3 on an electrocardiogram recorded within 18 hours of infarction. Serial vectorcardiograms and technetium pyrophosphate scans were obtained. Eighty percent of the patients (39 of 49) had anterior ST depression. Of these 39 patients, 34% fulfilled vectorcardiographic criteria for posterior infarction, and 60% had pyrophosphate scanning evidence of posterior infarction. Early anterior ST depression was neither highly sensitive (84%) nor specific (20%) for the detection of posterior infarction as defined by pyrophosphate imaging. Of patients with persistent anterior ST depression (greater than 72 hours), 87% had posterior infarction detected by pyrophosphate scan. In patients with inferior myocardial infarction, vectorcardiographic evidence of posterior infarction correlated poorly with pyrophosphate imaging data. Right ventricular infarction was present on pyrophosphate imaging in 40% of patients with pyrophosphate changes of posterior infarction but without vectorcardiographic evidence of posterior infarction. It is concluded that: 1) the majority of patients with acute inferior myocardial infarction have anterior ST segment depression; 2) early anterior ST segment depression in such patients is not a specific marker for posterior infarction; and 3) standard vectorcardiographic criteria for transmural posterior infarction may be inaccurate in patients with concomitant transmural inferior myocardial infarction or right ventricular infarction, or both

  20. Multi-segmental neurofibromatosis

    OpenAIRE

    Kumar Sudhir; Kumar Ravi

    2004-01-01

    Neurofibromatosis (NF), one of the commonest phakomatoses, is characterized by varied clinical manifestations. Segmental NF is one of the uncommon subtypes of NF. We report a young adult presenting with asymptomatic skin lesions- neurofibromas and café-au-lait macules- over localized areas of the lower back, affecting more than one segment. None of the family members were found to have features of segmental NF. Segmental NF may be misdiagnosed as a birthmark or remain undiagnosed for l...

  1. Anterior spinal artery syndrome of the cervical hemicord.

    Science.gov (United States)

    Baumgartner, R W; Waespe, W

    1992-01-01

    Three patients developed signs of a unilateral cervical cord lesion 6 to 36 h after the acute onset of severe cervico-brachial pain. The neurological deficit progressed over 6 to 18 h. On the painful side a central Horner's syndrome, a hemiparesis with plegia of the hand, and a slight pallhypaesthesia were found. On the opposite side thermhypaesthesia and hypalgesia were noted with a level at the dermatome C5 or C6. T2-weighted MR images revealed in one patient a small area of increased signal intensity restricted to one half of the cervical cord, and electromyography in another patient showed after 6 months evidence of segmental chronic denervation. Both abnormalities were found at the clinically expected level. The findings are consistent with a small infarction of the cervical cord in the perfusion territory of a central (sulco-commissural) artery, a duplicated anterior spinal artery or an anterior spinal branch of the vertebral artery. PMID:1315578

  2. Automatic Melody Segmentation

    NARCIS (Netherlands)

    Rodríguez López, Marcelo

    2016-01-01

    The work presented in this dissertation investigates music segmentation. In the field of Musicology, segmentation refers to a score analysis technique, whereby notated pieces or passages of these pieces are divided into “units” referred to as sections, periods, phrases, and so on. Segmentation analy

  3. Color image segmentation

    Science.gov (United States)

    McCrae, Kimberley A.; Ruck, Dennis W.; Rogers, Steven K.; Oxley, Mark E.

    1994-03-01

    The most difficult stage of automated target recognition is segmentation. Current segmentation problems include faces and tactical targets; previous efforts to segment these objects have used intensity and motion cues. This paper develops a color preprocessing scheme to be used with the other segmentation techniques. A neural network is trained to identify the color of a desired object, eliminating all but that color from the scene. Gabor correlations and 2D wavelet transformations will be performed on stationary images; and 3D wavelet transforms on multispectral data will incorporate color and motion detection into the machine visual system. The paper will demonstrate that color and motion cues can enhance a computer segmentation system. Results from segmenting faces both from the AFIT data base and from video taped television are presented; results from tactical targets such as tanks and airplanes are also given. Color preprocessing is shown to greatly improve the segmentation in most cases.

  4. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... during a hip replacement through the anterior supine intramuscular approach. “OR-Live,” the vision of improving health. ... the approach are operating through an internervous and intramuscular anatomic interval. It’s not necessary to detach any ...

  5. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... got coming out in “JBJS,” the early six-week recovery is dramatically different between a direct lateral abductor splitting approach and this anterior supine approach. Let me get this head on. My experience, these patients have full leg control in about 24 hours. Yeah. They can get out of bed and ...

  6. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... the anterior supine intramuscular approach. “OR-Live,” the vision of improving health. Good evening and welcome to ... should know that this is done under direct vision. Yeah. You are seeing everything you’re doing. ...

  7. Segmental mode of neural patterning in sipuncula

    DEFF Research Database (Denmark)

    Kristof, Alen; Wollesen, Tim; Wanninger, Andreas

    2008-01-01

    anterior-posterior progression. In late-stage larvae, the two serotonergic axons of the VNCs fuse, the commissures disappear, and one additional pair of perikarya is formed. These cells (ten in total) migrate toward one another, eventually forming two clusters of five cells each. These neural......-remodeling processes result in the single nonmetameric CNS of the adult sipunculan. Our data confirm the segmental ancestry of Sipuncula and render Phascolosoma a textbook example for the Haeckelian hypothesis of ontogenetic recapitulation of the evolutionary history of a species [8]....

  8. Improved document image segmentation algorithm using multiresolution morphology

    Science.gov (United States)

    Bukhari, Syed Saqib; Shafait, Faisal; Breuel, Thomas M.

    2011-01-01

    Page segmentation into text and non-text elements is an essential preprocessing step before optical character recognition (OCR) operation. In case of poor segmentation, an OCR classification engine produces garbage characters due to the presence of non-text elements. This paper describes modifications to the text/non-text segmentation algorithm presented by Bloomberg,1 which is also available in his open-source Leptonica library.2The modifications result in significant improvements and achieved better segmentation accuracy than the original algorithm for UW-III, UNLV, ICDAR 2009 page segmentation competition test images and circuit diagram datasets.

  9. 前节光学相干断层扫描仪观察原发性闭角型青光眼激光虹膜周边切除术后前房形态的改变%Anterior segment optical coherence tomography for detecting the morphological changes of anterior chamber in patients with primary angle closure glaucoma after laser peripheral iridotomy

    Institute of Scientific and Technical Information of China (English)

    史强; 谢安明; 张小玲

    2014-01-01

    目的 通过前节光学相干断层扫描仅(AS-OCT)观察原发性闭角型青光眼(PACG)激光虹膜周边切除术(LPI)后前房形态的改变.方法 30例(30只眼)PACG患者均行LPI,于行LPI前、后1周使用AS-OCT检查前房深度(ACD)、晶状体膨隆高度(CLR)、房角开放距离(AOD)、虹膜小梁空间面积(TISA)及瞳孔直径(PD),观察LPI前后前房形态的改变.结果 手术前眼压为(15.923±2.028)mmHg(1 mmHg =0.133 kPa),术后1周为(14.523±1.650)mmHg,术后1周眼压显著低于术前,差异有统计学意义(P<0.05).LPI前患者ACD、CLR、PD与手术后1周比较,差异均无统计学意义(P>0.05).LPI后1周患者鼻侧AOD500、颞侧AOD500、鼻侧AOD750、颞侧AOD750、鼻侧TISA500、颞侧TISA500、鼻侧TISA750、颞侧TISA750及双侧平均AOD500、AOD750、TISA500、TISA750均显著大于手术前,差异均有统计学意义(P<0.01).结论 LPI可以显著改善PACG患者眼前房结构,AS-OCT可以客观准确地观察PACG患者的前房形态.

  10. Application of multiple intraoperative monitoring techniques in microsurgery for anterior communicating aneurysms

    Directory of Open Access Journals (Sweden)

    NI Wei

    2012-02-01

    Full Text Available Objective To evaluate the efficacy of combined multiple intraoperative monitoring techniques including transcranial Doppler (TCD, indocyanine green angiography (ICGA and neuroelectrophysiological monitoring consisting of somatosensory evoked potential (SEP and motor evoked potential (MEP in the surgical management of anterior communicating aneurysm. Methods Clinical data were analyzed for the 23 patients who underwent microsurgery for anterior communicating aneurysms with assistance of combined multiple intraoperative monitoring techniques. Twenty-three patients [12 males, 11 females; mean age 52 (range 44-63 years] underwent aneurysm clipping via modified pterional approach. Total vein anaesthesia was used for all patients. Propofol, fentanyl and scoline were administrated before intubation. Remifentanil and propofol were used throughout the procedure. Internal carotid artery and A1 segment of anterior cerebral artery were exposed successively. The parent artery, perforating artery and aneurysm were carefully recognized after the A1 segment was temporarily occluded. The temporary clip was removed after the aneurysm being clipped. Neuroelectrophysiological monitoring, ICGA and TCD were applied for intraoperative monitoring. Results All of the 23 aneurysms were successfully clipped. MEP changes were seen in 6 patients during the temporary occlusion of A1 segment, which directed neurosurgeon to pause for its recovery. TCD and ICGA detected A2 segment or anterior communicating artery stenosis in 2 patients and residual aneurysm in 1 patient during clipping procedure, which directed neurosurgeons to readjust aneurysmal clips. Postoperative transient hemiparalysis were observed in 1 patient with modified Rankin Scale level 1 at discharge. No hemorrhagic or ischemic events were observed in other 22 patients with modified Rankin Scale level 0 at discharge. Conclusion Combined multiple intraoperative monitoring techniques may provide important

  11. Retinal Optical Coherence Tomography Imaging

    Science.gov (United States)

    Drexler, Wolfgang; Fujimoto, James G.

    The eye is essentially transparent, transmitting light with only minimal optical attenuation and scattering providing easy optical access to the anterior segment as well as the retina. For this reason, ophthalmic and especially retinal imaging has been not only the first but also most successful clinical application for optical coherence tomography (OCT). This chapter focuses on the development of OCT technology for retinal imaging. OCT has significantly improved the potential for early diagnosis, understanding of retinal disease pathogenesis, as well as monitoring disease progression and response to therapy. Development of ultrabroad bandwidth light sources and high-speed detection techniques has enabled significant improvements in ophthalmic OCT imaging performance, demonstrating the potential of three-dimensional, ultrahigh-resolution OCT (UHR OCT) to perform noninvasive optical biopsy of the living human retina, i.e., the in vivo visualization of microstructural, intraretinal morphology in situ approaching the resolution of conventional histopathology. Significant improvements in axial resolution and speed not only enable three-dimensional rendering of retinal volumes but also high-definition, two-dimensional tomograms, topographic thickness maps of all major intraretinal layers, as well as volumetric quantification of pathologic intraretinal changes. These advances in OCT technology have also been successfully applied in several animal models of retinal pathologies. The development of light sources emitting at alternative wavelengths, e.g., around #1,060 nm, not only enabled three-dimensional OCT imaging with enhanced choroidal visualization but also improved OCT performance in cataract patients due to reduced scattering losses in this wavelength region. Adaptive optics using deformable mirror technology, with unique high stroke to correct higher-order ocular aberrations, with specially designed optics to compensate chromatic aberration of the human eye, in

  12. 38 CFR 3.379 - Anterior poliomyelitis.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Anterior poliomyelitis. 3... Specific Diseases § 3.379 Anterior poliomyelitis. If the first manifestations of acute anterior poliomyelitis present themselves in a veteran within 35 days of termination of active military service, it...

  13. Segmentation with Area Constraints

    OpenAIRE

    Niethammer, Marc; Zach, Christopher

    2012-01-01

    Image segmentation approaches typically incorporate weak regularity conditions such as boundary length or curvature terms, or use shape information. High-level information such as a desired area or volume, or a particular topology are only implicitly specified. In this paper we develop a segmentation method with explicit bounds on the segmented area. Area constraints allow for the soft selection of meaningful solutions, and can counteract the shrinking bias of length-based regularization. We ...

  14. Automatic Melody Segmentation

    OpenAIRE

    Rodríguez López, Marcelo

    2016-01-01

    The work presented in this dissertation investigates music segmentation. In the field of Musicology, segmentation refers to a score analysis technique, whereby notated pieces or passages of these pieces are divided into “units” referred to as sections, periods, phrases, and so on. Segmentation analysis is a widespread practice among musicians: performers use it to help them memorise pieces, music theorists and historians use it to compare works, music students use it to understand the composi...

  15. Spectral mesh segmentation

    OpenAIRE

    Liu, Rong

    2009-01-01

    Polygonal meshes are ubiquitous in geometric modeling. They are widely used in many applications, such as computer games, computer-aided design, animation, and visualization. One of the important problems in mesh processing and analysis is segmentation, where the goal is to partition a mesh into segments to suit the particular application at hand. In this thesis we study structural-level mesh segmentation, which seeks to decompose a given 3D shape into parts according to human intuition. We t...

  16. Comparison of adjacent segment degeneration five years after single level cervical fusion and cervical arthroplasty:a retrospective controlled study

    Institute of Scientific and Technical Information of China (English)

    SUN Yu; ZHAO Yan-bin; PAN Sheng-fa; ZHOU Fei-fei; CHEN Zhong-qiang; LIU Zhong-jun

    2012-01-01

    Background Cervical arthroplasty is indicated to preserve cervical motion and prevent accelerated adjacent segment degeneration.Whether accelerated adjacent segment degeneration is prevented in the long term is unclear.This trial compared adjacent segment degeneration in Bryan disc arthroplasty with that in anterior cervical decompression and fusion five years after the surgery.Methods We studied patients with single level degenerative cervical disc disease.The extent of adjacent segment degeneration was estimated from lateral X-rays.Results Twenty-six patients underwent single level Bryan disc arthroplasty and twenty-four patients underwent single level anterior cervical decompression and fusion.All patients were followed up for an average of sixty months.In the Bryan arthroplasty group,nine(17.6%)segments developed adjacent segment degeneration,which was significantly lower than that(60.4%)in the anterior cervical decompression and fusion group.Eleven segments in the Bryan arthroplasty group developed heterotopic ossification according to McAfee's classification and two segments had range of motion less than 2°.In the heterotopic ossification group,four(19.5%)segments developed adjacent segment degeneration,similar to the number in the non-heterotopic ossification group(16.7%).Adjacent segment degeneration rate was 50% in gradeⅣ?group but 11.8% in gradeⅡ?to Ⅲ.Conclusions Adjacent segment degeneration was accelerated after anterior cervical decompression and fusion.However,Bryan disc arthroplasty avoided accelerated adjacent segment degeneration by preserving motion.Patients with gradeⅣ?heterotopic ossification lost motion,and the rate of adjacent segment degeneration was higher than that in patients without heterotopic ossification.

  17. A combined segmenting and non-segmenting approach to signal quality estimation for ambulatory photoplethysmography.

    Science.gov (United States)

    Wander, J D; Morris, D

    2014-12-01

    Continuous cardiac monitoring of healthy and unhealthy patients can help us understand the progression of heart disease and enable early treatment. Optical pulse sensing is an excellent candidate for continuous mobile monitoring of cardiovascular health indicators, but optical pulse signals are susceptible to corruption from a number of noise sources, including motion artifact. Therefore, before higher-level health indicators can be reliably computed, corrupted data must be separated from valid data. This is an especially difficult task in the presence of artifact caused by ambulation (e.g. walking or jogging), which shares significant spectral energy with the true pulsatile signal. In this manuscript, we present a machine-learning-based system for automated estimation of signal quality of optical pulse signals that performs well in the presence of periodic artifact. We hypothesized that signal processing methods that identified individual heart beats (segmenting approaches) would be more error-prone than methods that did not (non-segmenting approaches) when applied to data contaminated by periodic artifact. We further hypothesized that a fusion of segmenting and non-segmenting approaches would outperform either approach alone. Therefore, we developed a novel non-segmenting approach to signal quality estimation that we then utilized in combination with a traditional segmenting approach. Using this system we were able to robustly detect differences in signal quality as labeled by expert human raters (Pearson's r = 0.9263). We then validated our original hypotheses by demonstrating that our non-segmenting approach outperformed the segmenting approach in the presence of contaminated signal, and that the combined system outperformed either individually. Lastly, as an example, we demonstrated the utility of our signal quality estimation system in evaluating the trustworthiness of heart rate measurements derived from optical pulse signals. PMID:25407849

  18. A combined segmenting and non-segmenting approach to signal quality estimation for ambulatory photoplethysmography

    International Nuclear Information System (INIS)

    Continuous cardiac monitoring of healthy and unhealthy patients can help us understand the progression of heart disease and enable early treatment. Optical pulse sensing is an excellent candidate for continuous mobile monitoring of cardiovascular health indicators, but optical pulse signals are susceptible to corruption from a number of noise sources, including motion artifact. Therefore, before higher-level health indicators can be reliably computed, corrupted data must be separated from valid data. This is an especially difficult task in the presence of artifact caused by ambulation (e.g. walking or jogging), which shares significant spectral energy with the true pulsatile signal. In this manuscript, we present a machine-learning-based system for automated estimation of signal quality of optical pulse signals that performs well in the presence of periodic artifact. We hypothesized that signal processing methods that identified individual heart beats (segmenting approaches) would be more error-prone than methods that did not (non-segmenting approaches) when applied to data contaminated by periodic artifact. We further hypothesized that a fusion of segmenting and non-segmenting approaches would outperform either approach alone. Therefore, we developed a novel non-segmenting approach to signal quality estimation that we then utilized in combination with a traditional segmenting approach. Using this system we were able to robustly detect differences in signal quality as labeled by expert human raters (Pearson’s r = 0.9263). We then validated our original hypotheses by demonstrating that our non-segmenting approach outperformed the segmenting approach in the presence of contaminated signal, and that the combined system outperformed either individually. Lastly, as an example, we demonstrated the utility of our signal quality estimation system in evaluating the trustworthiness of heart rate measurements derived from optical pulse signals. (paper)

  19. Unsupervised Texture Segmentation

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Mikeš, Stanislav

    Vienna : In-Tech, 2008 - (Yin, P.), s. 227-248 ISBN 978-953-7619-24-4 R&D Projects: GA AV ČR 1ET400750407; GA MŠk 1M0572; GA ČR GA102/08/0593 Grant ostatní: GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : texture segmentation * image segmentation * unsupervised segmentation Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2008/RO/haindl-unsupervised texture segmentation .pdf

  20. Universal Numeric Segmented Display

    CERN Document Server

    Azad, Md Abul kalam; Kamruzzaman, S M

    2010-01-01

    Segmentation display plays a vital role to display numerals. But in today's world matrix display is also used in displaying numerals. Because numerals has lots of curve edges which is better supported by matrix display. But as matrix display is costly and complex to implement and also needs more memory, segment display is generally used to display numerals. But as there is yet no proposed compact display architecture to display multiple language numerals at a time, this paper proposes uniform display architecture to display multiple language digits and general mathematical expressions with higher accuracy and simplicity by using a 18-segment display, which is an improvement over the 16 segment display.

  1. Pediatric anterior cruciate ligament reconstruction

    OpenAIRE

    McConkey, Mark O.; Bonasia, Davide Edoardo; Amendola, Annunziato

    2011-01-01

    An increasing number of anterior cruciate ligament (ACL) injuries are seen in children now than in the past due to increased sports participation. The natural history of ACL deficient knees in active individuals, particularly in children is poor. Surgical management of ACL deficiency in children is complex due to the potential risk of injury to the physis and growth disturbance. Delaying ACL reconstruction until maturity is possible but risks instability episodes and intra-articular damage. S...

  2. Anterior impingement syndrome in dancers

    OpenAIRE

    O’Kane, John William; Kadel, Nancy

    2007-01-01

    Anterior impingement is a common problem in dancers occurring primarily secondary to the repetitive forced ankle dorsiflexion inherent in ballet. Symptoms generally occur progressively and may respond to conservative treatment including addressing biomechanical faults that contribute to the problem. As impingement progresses, movements essential to ballet may become impossible and arthroscopic ankle surgery is often effective for both diagnosis and treatment, allowing athletes to return to da...

  3. 激光周边虹膜切除术后前房及房角形态评价方法的研究进展%Evaluation methods of anterior chamber and angle structures after laser peripheral iridotomy

    Institute of Scientific and Technical Information of China (English)

    林仲; 张袆草

    2011-01-01

    Laser peripheral iridotomy ( LPI) is one of the main therapy for glaucoma due to its reliable efficacy of widening peripheral angle and therefore decreasing intraocular pressure by partially relieving pupillary block. The parameters of the anterior chamber angle following the LPI are the main evaluation indexes. At present,the detecting and diagnosis technique for the anterior chamber angle is deeply advancing, including gonioscopy, ultrasound biomicroscopy, anterior segment optical coherence tomography and Pentacam. These methods offer some useful parameters and also present with some limits in the application respectively in the evaluation of anterior chamber and angle structure. This review focuses on the application of Methods mentioned above and morphologic changes of anterior chamber and angle structure following the LPI.%激光周边虹膜切除术(LPI)通过部分解除瞳孔阻滞,增宽周边前房角,降低眼压而成为青光眼治疗的重要手段之一.LPI术后前房角形态的检测参数是评价LPI治疗效果的主要指标.随着检测手段的进步,目前对LPI手术前后前房及房角形态的评价正在逐渐深入.已有的房角检查方法包括前房角镜、超声生物显微镜(UBM)、眼前节OCT(AS.OCT)以及Pentacam等,每种方法均可获得其各自的评价参数,但也存在一定限制.就LPI术后上述检查方法在评价前房及房角形态方面的应用价值进行总结,同时总结LPI术后前房和前房角结构的变化.

  4. Optical coherence tomography a clinical and technical update

    CERN Document Server

    Cunha-Vaz, José

    2012-01-01

    Optical Coherence Tomography represents the ultimate noninvasive  ocular imaging technique although being in the field for over two-decades. This book encompasses both medical and technical developments and recent achievements. Here, the authors cover the field of application from the anterior to the posterior ocular segments (Part I) and present a comprehensive review on the development of OCT. Important developments towards  clinical applications are covered in Part II, ranging from the adaptive optics to the integration on a slit-lamp, and passing through new structural  and functional information extraction from OCT data. The book is intended to be informative, coherent and comprehensive for both the medical and technical communities and aims at easing the communication between the two fields and bridging the gap between the two scientific communities.

  5. Esthetic, occlusal, and periodontal rehabilitation of anterior teeth with minimum thickness porcelain laminate veneers.

    Science.gov (United States)

    da Cunha, Leonardo Fernandes; Pedroche, Lorena Oliveira; Gonzaga, Carla Castiglia; Furuse, Adilson Yoshio

    2014-12-01

    Ceramic veneers of minimum thickness provide satisfactory esthetic outcomes while preserving the dental structure. Dental ceramics can both improve the esthetic appearance and reestablish the strength and function of teeth. In worn anterior teeth, functional surfaces, for example, anterior and lateral guidance, can be restored effectively. The characteristics of dental ceramics, such as color stability and mechanical and optical properties, make this material a good choice for indirect restorations, especially when optimum function and esthetics are required. This clinical report presents an occlusal, periodontal, and restorative solution with minimum thickness glass ceramic veneers for worn anterior teeth with multiple diastemas. PMID:25156092

  6. Anatomic variations of anterior cerebral artery cortical branches.

    Science.gov (United States)

    Stefani, M A; Schneider, F L; Marrone, A C; Severino, A G; Jackowski, A P; Wallace, M C

    2000-01-01

    The anterior cerebral artery (ACA) is a major vessel responsible for the blood supply to the interhemispheric region. The ACA segment after the anterior communicating artery (AComA) origin is called the distal ACA and has central and cortical branches. The cortical branches are distributed in the different regions of the orbital and medial part of the brain. The objects of this study are the anatomical variations found in the distal ACA. In 76 hemispheres the ACA distal branches were injected with latex and dissected under microscope magnification. Vessel diameters and distances between vessel origins and anterior communicating artery were recorded and analyzed. Microsurgical dissection was carried out to demonstrate anatomic variations of these vessels. Average diameter of ACA at origin was 2.61 +/- 0.34 mm and average diameter of cortical branches diameter ranged from 0.79 +/- 0.27 mm to 1.84 +/- 0.3 mm. Distances between vessel origin and AComA ranged from 7.68 +/- 3.91 mm (orbitofrontal) to 112.6 +/- 11.63 mm (inferior internal parietal). This study found anatomical variations: a single (azygos) ACA was present in one case and three in three cases. Crossing branches of the distal ACA to the contralateral hemisphere were present in 26% of the cases. In some cases a single ACA may supply the posterior hemispheric region through crossing branches. This calls attention to potential bilateral brain infarcts due to a single unilateral ACA occlusion. PMID:10873213

  7. Segmentation, advertising and prices

    NARCIS (Netherlands)

    Galeotti, Andrea; Moraga-Gonzalez, Jose Luis

    2008-01-01

    This paper explores the implications of market segmentation on firm competitiveness. In contrast to earlier work, here market segmentation is minimal in the sense that it is based on consumer attributes that are completely unrelated to tastes. We show that when the market is comprised by two consume

  8. Multi-segmental neurofibromatosis

    Directory of Open Access Journals (Sweden)

    Kumar Sudhir

    2004-11-01

    Full Text Available Neurofibromatosis (NF, one of the commonest phakomatoses, is characterized by varied clinical manifestations. Segmental NF is one of the uncommon subtypes of NF. We report a young adult presenting with asymptomatic skin lesions- neurofibromas and café-au-lait macules- over localized areas of the lower back, affecting more than one segment. None of the family members were found to have features of segmental NF. Segmental NF may be misdiagnosed as a birthmark or remain undiagnosed for long periods of time, as the patients are often asymptomatic. Moreover, the clinical features are highly variable and range from a small area of skin involvement to involvement over the entire half of the body. This variation is explained by the fact that segmental NF is thought to arise from a postzygotic NF1 gene mutation, leading to somatic mosaicism. We have also reviewed the relevant literature on this subject.

  9. Multi-segmental neurofibromatosis

    Directory of Open Access Journals (Sweden)

    Kumar Sudhir

    2004-01-01

    Full Text Available Neurofibromatosis (NF, one of the commonest phakomatoses, is characterized by varied clinical manifestations. Segmental NF is one of the uncommon subtypes of NF. We report a young adult presenting with asymptomatic skin lesions- neurofibromas and café-au-lait macules- over localized areas of the lower back, affecting more than one segment. None of the family members were found to have features of segmental NF. Segmental NF may be misdiagnosed as a birthmark or remain undiagnosed for long periods of time, as the patients are often asymptomatic. Moreover, the clinical features are highly variable and range from a small area of skin involvement to involvement over the entire half of the body. This variation is explained by the fact that segmental NF is thought to arise from a postzygotic NF1 gene mutation, leading to somatic mosaicism. We have also reviewed the relevant literature on this subject.

  10. Synthetic cornea: biocompatibility and optics

    Science.gov (United States)

    Parel, Jean-Marie A.; Kaminski, Stefan; Fernandez, Viviana; Alfonso, E.; Lamar, Peggy; Lacombe, Emmanuel; Duchesne, Bernard; Dubovy, Sander; Manns, Fabrice; Rol, Pascal O.

    2002-06-01

    Purpose. Experimentally find a method to provide a safe surgical technique and an inexpensive and long lasting mesoplant for the restoration of vision in patients with bilateral corneal blindness due to ocular surface and stromal diseases. Methods. Identify the least invasive and the safest surgical technique for synthetic cornea implantation. Identify the most compatible biomaterials and the optimal shape a synthetic cornea must have to last a long time when implanted in vivo. Results. Penetrating procedures were deemed too invasive, time consuming, difficult and prone to long term complications. Therefore a non-penetrating delamination technique with central trephination was developed to preserve the integrity of Descemet's membrane and the anterior segment. Even though this approach limits the number of indications, it is acceptable since the majority of patients only have opacities in the stroma. The prosthesis was designed to fit in the removed tissue plane with its skirt fitted under the delaminated stroma. To improve retention, the trephination wall was made conical with the smallest opening on the anterior surface and a hat-shaped mesoplant was made to fit. The skirt was perforated in its perimeter to allow passage of nutrients and tissues ingrowths. To simplify the fabrication procedure, the haptic and optic were made of the same polymer. The intrastromal biocompatibility of several hydrogels was found superior to current clinically used PMMA and PTFE materials. Monobloc mesoplants made of 4 different materials were implanted in rabbits and followed weekly until extrusion occurred. Some remained optically clear allowing for fundus photography. Conclusions. Hydrogel synthetic corneas can be made to survive for periods longer than 1 year. ArF excimer laser photoablation studies are needed to determine the refractive correction potential of these mesoplants. A pilot FDA clinical trial is needed to assess the mesoplant efficacy and very long-term stability.

  11. SEGMENTATION OF CHARACTERS WITHOUT MODIFIERS FROM A PRINTED BANGLA TEXT

    OpenAIRE

    Fakruddin Ali Ahmed

    2013-01-01

    Optical Character Recognition (OCR) is one of the fundamental research areas of image processing and pattern recognition field. The performance accuracy of an OCR system depends on the proper segmentation of the characters. This paper is concerned with the segmentation of printed bangla characters without modifiers for optical character recognition (OCR) system. The basic steps needed for developing an OCR system also have been discussed.

  12. SEGMENTATION OF CHARACTERS WITHOUT MODIFIERS FROM A PRINTED BANGLA TEXT

    Directory of Open Access Journals (Sweden)

    Fakruddin Ali Ahmed

    2013-02-01

    Full Text Available Optical Character Recognition (OCR is one of the fundamental research areas of image processing and pattern recognition field. The performance accuracy of an OCR system depends on the proper segmentation of the characters. This paper is concerned with the segmentation of printed bangla characters without modifiers for optical character recognition (OCR system. The basic steps needed for developing an OCR system also have been discussed.

  13. Optical coherence tomography based microangiography for quantitative monitoring of structural and vascular changes in a rat model of acute uveitis in vivo: a preliminary study

    Science.gov (United States)

    Choi, Woo June; Pepple, Kathryn L.; Zhi, Zhongwei; Wang, Ruikang K.

    2015-01-01

    Uveitis models in rodents are important in the investigation of pathogenesis in human uveitis and the development of appropriate therapeutic strategies for treatment. Quantitative monitoring of ocular inflammation in small animal models provides an objective metric to assess uveitis progression and/or therapeutic effects. We present a new application of optical coherence tomography (OCT) and OCT-based microangiography (OMAG) to a rat model of acute anterior uveitis induced by intravitreal injection of a killed mycobacterial extract. OCT/OMAG is used to provide noninvasive three-dimensional imaging of the anterior segment of the eyes prior to injection (baseline) and two days post-injection (peak inflammation) in rats with and without steroid treatments. OCT imaging identifies characteristic structural and vascular changes in the anterior segment of the inflamed animals when compared to baseline images. Characteristics of inflammation identified include anterior chamber cells, corneal edema, pupillary membranes, and iris vasodilation. In contrast, no significant difference from the control is observed for the steroid-treated eye. These findings are compared with the histology assessment of the same eyes. In addition, quantitative measurements of central corneal thickness and iris vessel diameter are determined. This pilot study demonstrates that OCT-based microangiography promises to be a useful tool for the assessment and management of uveitis in vivo.

  14. Evolution of anterior Hox regulatory elements among chordates

    Directory of Open Access Journals (Sweden)

    Natale Alfonso

    2011-11-01

    Full Text Available Abstract Background The Hox family of transcription factors has a fundamental role in segmentation pathways and axial patterning of embryonic development and their clustered organization is linked with the regulatory mechanisms governing their coordinated expression along embryonic axes. Among chordates, of particular interest are the Hox paralogous genes in groups 1-4 since their expression is coupled to the control of regional identity in the anterior nervous system, where the highest structural diversity is observed. Results To investigate the degree of conservation in cis-regulatory components that form the basis of Hox expression in the anterior nervous system, we have used assays for transcriptional activity in ascidians and vertebrates to compare and contrast regulatory potential. We identified four regulatory sequences located near the CiHox1, CiHox2 and CiHox4 genes of the ascidian Ciona intestinalis which direct neural specific domains of expression. Using functional assays in Ciona and vertebrate embryos in combination with sequence analyses of enhancer fragments located in similar positions adjacent to Hox paralogy group genes, we compared the activity of these four Ciona cis-elements with a series of neural specific enhancers from the amphioxus Hox1-3 genes and from mouse Hox paralogous groups 1-4. Conclusions This analysis revealed that Kreisler and Krox20 dependent enhancers critical in segmental regulation of the hindbrain appear to be specific for the vertebrate lineage. In contrast, neural enhancers that function as Hox response elements through the action of Hox/Pbx binding motifs have been conserved during chordate evolution. The functional assays reveal that these Hox response cis-elements are recognized by the regulatory components of different and extant species. Together, our results indicate that during chordate evolution, cis-elements dependent upon Hox/Pbx regulatory complexes, are responsible for key aspects of

  15. Absence of scalenus anterior muscle.

    OpenAIRE

    Murakami S; Horiuchi K; Yamamoto C; Ohtsuka A; Murakami T.

    2003-01-01

    A rare anomaly of the scalenus muscles is described. In this case, the right scalenus anterior muscle was absent. As a substitute for this muscle, some aberrant muscle slips arose from the lower vertebrae and descended in front of the ventral rami of the lower cervical nerves. These aberrant slips then ran between the ventral rami of the the eighth cervical and first thoracic nerves, and were fused with the right scalenus medius muscle. Thus, the subclavian artery and vein ran in front of the...

  16. Lesiones del ligamento cruzado anterior

    OpenAIRE

    Alejandro Álvarez López; Yenima García Lorenzo

    2015-01-01

    Fundamento: el ligamento cruzado anterior desempeña un papel muy importante en la estabili-dad de la rodilla. La incidencia de esta afección es alta en pacientes que practican deportes de contacto y de no ser tratados de forma adecuada, los resultados son desfavorables. Objetivo: profundizar en los factores necesarios para el tratamiento adecuado de enfermos con esta lesión y evitar las complicaciones. Método: se realizó una revisión bibliográfica de un total de 300 artículos publicados en Pu...

  17. Pancreas and cyst segmentation

    Science.gov (United States)

    Dmitriev, Konstantin; Gutenko, Ievgeniia; Nadeem, Saad; Kaufman, Arie

    2016-03-01

    Accurate segmentation of abdominal organs from medical images is an essential part of surgical planning and computer-aided disease diagnosis. Many existing algorithms are specialized for the segmentation of healthy organs. Cystic pancreas segmentation is especially challenging due to its low contrast boundaries, variability in shape, location and the stage of the pancreatic cancer. We present a semi-automatic segmentation algorithm for pancreata with cysts. In contrast to existing automatic segmentation approaches for healthy pancreas segmentation which are amenable to atlas/statistical shape approaches, a pancreas with cysts can have even higher variability with respect to the shape of the pancreas due to the size and shape of the cyst(s). Hence, fine results are better attained with semi-automatic steerable approaches. We use a novel combination of random walker and region growing approaches to delineate the boundaries of the pancreas and cysts with respective best Dice coefficients of 85.1% and 86.7%, and respective best volumetric overlap errors of 26.0% and 23.5%. Results show that the proposed algorithm for pancreas and pancreatic cyst segmentation is accurate and stable.

  18. Segmentation of Color Images Based on Different Segmentation Techniques

    OpenAIRE

    Purnashti Bhosale; Aniket Gokhale

    2013-01-01

    In this paper, we propose an Color image segmentation algorithm based on different segmentation techniques. We recognize the background objects such as the sky, ground, and trees etc based on the color and texture information using various methods of segmentation. The study of segmentation techniques by using different threshold methods such as global and local techniques and they are compared with one another so as to choose the best technique for threshold segmentation. Further segmentation...

  19. Segmentation of consumer's markets and evaluation of market's segments

    OpenAIRE

    ŠVECOVÁ, Iveta

    2013-01-01

    The goal of this bachelor thesis was to explain a possibly segmentation of consumer´s markets for a chosen company, and to present a suitable goods offer, so it would be suitable to the needs of selected segments. The work is divided into theoretical and practical part. First part describes marketing, segmentation, segmentation of consumer's markets, consumer's market, market's segments a other terms. Second part describes an evaluation of questionnaire survey, discovering of market's segment...

  20. Segmentation of ribs in digital chest radiographs

    Science.gov (United States)

    Cong, Lin; Guo, Wei; Li, Qiang

    2016-03-01

    Ribs and clavicles in posterior-anterior (PA) digital chest radiographs often overlap with lung abnormalities such as nodules, and cause missing of these abnormalities, it is therefore necessary to remove or reduce the ribs in chest radiographs. The purpose of this study was to develop a fully automated algorithm to segment ribs within lung area in digital radiography (DR) for removal of the ribs. The rib segmentation algorithm consists of three steps. Firstly, a radiograph was pre-processed for contrast adjustment and noise removal; second, generalized Hough transform was employed to localize the lower boundary of the ribs. In the third step, a novel bilateral dynamic programming algorithm was used to accurately segment the upper and lower boundaries of ribs simultaneously. The width of the ribs and the smoothness of the rib boundaries were incorporated in the cost function of the bilateral dynamic programming for obtaining consistent results for the upper and lower boundaries. Our database consisted of 93 DR images, including, respectively, 23 and 70 images acquired with a DR system from Shanghai United-Imaging Healthcare Co. and from GE Healthcare Co. The rib localization algorithm achieved a sensitivity of 98.2% with 0.1 false positives per image. The accuracy of the detected ribs was further evaluated subjectively in 3 levels: "1", good; "2", acceptable; "3", poor. The percentages of good, acceptable, and poor segmentation results were 91.1%, 7.2%, and 1.7%, respectively. Our algorithm can obtain good segmentation results for ribs in chest radiography and would be useful for rib reduction in our future study.

  1. Multimodal Range Image Segmentation

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Žid, Pavel

    Vienna : I-Tech Education and Publishing, Vienna, 2007 - (Obinata, G.; Dutta, A.), s. 25-46 ISBN 978-3-902613-05-9 R&D Projects: GA AV ČR 1ET400750407; GA MŠk 1M0572; GA AV ČR IAA2075302 EU Projects: European Commission(XE) 507752 - MUSCLE Grant ostatní: GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : Range segmentation * unsupervised segmentation Subject RIV: BD - Theory of Information http://s.i-techonline.com/Book/Vision-Systems- Segmentation - and -Pattern-Recognition/ISBN978-3-902613-05-9.html

  2. Unsupervised Dynamic Textures Segmentation

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Mikeš, Stanislav

    Vol. I. Heidelberg : Springer, 2013 - (Wilson, R.; Bors, A.; Hancock, E.; Smith , W.), s. 433-440 ISBN 978-3-642-40260-9. ISSN 0302-9743. - (Lecture Notes in Computer Science. 8047). [International Conference on Computer Analysis of Images and Patterns (CAIP 2013) /15./. York (GB), 27.08.2013-29.08.2013] Institutional support: RVO:67985556 Keywords : dynamic texture segmentation * unsupervised segmentation Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2013/RO/haindl-unsupervised dynamic textures segmentation.pdf

  3. MEDICAL IMAGE SEGMENTATION

    Directory of Open Access Journals (Sweden)

    Madhavi Latha

    2010-07-01

    Full Text Available Image segmentation is an essential but critical component in low level vision image analysis, pattern recognition, and in robotic systems. It is one of the most difficult and challenging tasks in image processing which determines the quality of the final result of the image analysis. Image segmentation is the process of dividing an image into different regions such that each region is homogeneous. Various image segmentation algorithms are discussed. Some examples in different image formats are presented and overall results discussed and compared considering different parameters.

  4. Anterior chest wall examination reviewed

    Directory of Open Access Journals (Sweden)

    F. Trotta

    2011-09-01

    Full Text Available Anterior chest wall involvement is not infrequently observed within inflammatory arthropaties, particularly if one considers seronegative spondiloarthritides and SAPHO syndrome. Physical examination is unreliable and conventional X-rays analysis is an unsatisfactory tool during diagnostic work-up of this region. Scintigraphic techniques yield informations both on the activity and on the anatomical extent of the disease while computerized tomography visualize the elementary lesions, such as erosions, which characterize the process. Moreover, when available, magnetic resonance imaging couple the ability to finely visualize such lesions with the possibility to show early alterations and to characterize the “activity” of the disease, presenting itself as a powerful tool both for diagnosis and follow-up. This review briefly shows the applications of imaging techniques for the evaluation of the anterior chest wall focusing on what has been done in the SAPHO syndrome which can be considered prototypical for this regional involvement since it is the osteo-articular target mainly affected by the disease.

  5. Dolor anterior de la rodilla

    Directory of Open Access Journals (Sweden)

    Alejandro Álvarez López

    2010-01-01

    Full Text Available Introducción:el dolor anterior de la rodilla constituye una importante causa de consulta en la especialidad de Ortopedia y Traumatología. La incidencia de otras enfermedades relacionadas con este síntoma es cada vez mayor, ejemplo de ello es la condromalacia de rótula, tendinitis patelar, osteoartritis patelofemoral entre otras, el diagnóstico de estas enfermedades se debe al cúmulo de experiencia y a la introducción de técnicas y equipos imagenológicos de avanzada. Desarrollo: se realizó una revisión bibliográfica sobre el dolor anterior de la rodilla, con especial énfasis en las teorías involucradas en su fisiopatología, entre las que se encuentran la mala-alineación patelo-femoral, equilibrio de la homeostasis tisular y aumento de la presión intra-ósea, además de brindar brevemente el cuadro clínico de la enfermedad. Para finalizar se expone el enfoque terapéutico que se basa fundamentalmente en el tratamiento conservador, se mencionan además las modalidades de tratamiento quirúrgico.

  6. Segmentation of antiperspirants and deodorants

    OpenAIRE

    Král, Tomáš

    2009-01-01

    The goal of Master's Thesis on topic Segmentation of antiperspirants and deodorants is to discover differences in consumer's behaviour, determinate and describe segments of consumers based on these differences and propose marketing strategy for the most attractive segments. Theoretical part describes market segmentation in general, process of segmentation and segmentation criteria. Analytic part characterizes Czech market of antiperspirants and deodorants, analyzes ACNielsen market data and d...

  7. Image segmentation survey

    Science.gov (United States)

    Haralick, R. M.

    1982-01-01

    The methodologies and capabilities of image segmentation techniques are reviewed. Single linkage schemes, hybrid linkage schemes, centroid linkage schemes, histogram mode seeking, spatial clustering, and split and merge schemes are addressed.

  8. Segmentation of SAR images

    Science.gov (United States)

    Kwok, Ronald

    1989-01-01

    The statistical characteristics of image speckle are reviewed. Existing segmentation techniques that have been used for speckle filtering, edge detection, and texture extraction are sumamrized. The relative effectiveness of each technique is briefly discussed.

  9. Chromosome condensation and segmentation

    International Nuclear Information System (INIS)

    Some aspects of chromosome condensation in mammalians -humans especially- were studied by means of cytogenetic techniques of chromosome banding. Two further approaches were adopted: a study of normal condensation as early as prophase, and an analysis of chromosome segmentation induced by physical (temperature and γ-rays) or chemical agents (base analogues, antibiotics, ...) in order to show out the factors liable to affect condensation. Here 'segmentation' means an abnormal chromosome condensation appearing systematically and being reproducible. The study of normal condensation was made possible by the development of a technique based on cell synchronization by thymidine and giving prophasic and prometaphasic cells. Besides, the possibility of inducing R-banding segmentations on these cells by BrdU (5-bromodeoxyuridine) allowed a much finer analysis of karyotypes. Another technique was developed using 5-ACR (5-azacytidine), it allowed to induce a segmentation similar to the one obtained using BrdU and identify heterochromatic areas rich in G-C bases pairs

  10. International EUREKA: Initialization Segment

    International Nuclear Information System (INIS)

    The Initialization Segment creates the starting description of the uranium market. The starting description includes the international boundaries of trade, the geologic provinces, resources, reserves, production, uranium demand forecasts, and existing market transactions. The Initialization Segment is designed to accept information of various degrees of detail, depending on what is known about each region. It must transform this information into a specific data structure required by the Market Segment of the model, filling in gaps in the information through a predetermined sequence of defaults and built in assumptions. A principal function of the Initialization Segment is to create diagnostic messages indicating any inconsistencies in data and explaining which assumptions were used to organize the data base. This permits the user to manipulate the data base until such time the user is satisfied that all the assumptions used are reasonable and that any inconsistencies are resolved in a satisfactory manner

  11. Positioning of anterior teeth in removable dentures

    Directory of Open Access Journals (Sweden)

    Strajnić Ljiljana

    2002-01-01

    Full Text Available Introduction The aim of this paper was to present methods of placement of artificial anterior teeth in edentulous individuals. The following review takes account of the majority of papers published during the last 100 years. The review has been divided into sections regarding the method used to determine the position of artificial anterior teeth. Geometric aspect Gysi (1895-1920 produced the first scientific theory about the position of artificial anterior teeth. Physiognomic theory The aim of this theory is to find the most natural position for artificial anterior teeth for each individual. Camper's "face angle" as a physiognomic criterion, has been introduced in papers of Wehrli (1961, Marxhors (1966, Tanzer (1968, Lombardi (1973. Esthetic aspect Important names in the field of dental esthetics are: Schön and Singer (1961, Arnheim (1965, Krajiček (1969, Tanzer (1968, Lombardi (1973, Goldstein (1976. They have introduced principles of visual aspects for selection of contours, dimension and position of artificial anterior teeth. Constitution aspect Flagg (1880, Williams (1913 and Hrauf (1957, 1958, have considered body constitution and individual characteristics regarding position of artificial anterior teeth. Physiological theory In 1971, Marxhors pointed to the fact that the position of artificial teeth corresponds with the function of the surrounding soft tissue and from the aspect of physiognomy as well. Phonetic aspect According to Silverman (1962 artificial anterior teeth are nearest when we pronounce the sound "S". Cephalometrical research Rayson (1970, Watson (1989, Strajnić Lj. (1999, Bassi F. (2001 have presented cephalometric radiographic analyses of natural anterior teeth compared with cephalometric radiographic analyses of artificial anterior teeth. A review of dental literature shows several factors suggesting modalities which should determine the position of artificial anterior teeth. Numerous methods have been designed for

  12. Pharyngocutaneous fistula after anterior cervical spine surgery

    OpenAIRE

    Sansur, Charles A.; Early, Stephen; Reibel, James; Arlet, Vincent

    2009-01-01

    Pharyngocutaneous fistulae are rare complications of anterior spine surgery occurring in less than 0.1% of all anterior surgery cases. We report a case of a 19 year old female who sustained a C6 burst fracture with complete quadriplegia. She was treated urgently with a C6 corpectomy with anterior cage and plating followed by posterior cervical stabilization at another institution. Post operatively she developed a pharyngocutaneous fistula that failed to heal despite several attempts of closu...

  13. Model-based segmentation

    OpenAIRE

    Heimann, Tobias; Delingette, Hervé

    2011-01-01

    This chapter starts with a brief introduction into model-based segmentation, explaining the basic concepts and different approaches. Subsequently, two segmentation approaches are presented in more detail: First, the method of deformable simplex meshes is described, explaining the special properties of the simplex mesh and the formulation of the internal forces. Common choices for image forces are presented, and how to evolve the mesh to adapt to certain structures. Second, the method of point...

  14. Segmental Neurofibromatosis: Atypical Localisation

    OpenAIRE

    Filiz Topaloğlu Demir; Burçe Can; Berkant Oman; İlkin Zindancı; Tülay Zenginkinet; Mukaddes Kavala

    2015-01-01

    Neurofibromatosis (NF) is a genetic disease leading pathological findings in skin, soft tissue, bone and nervous system by affecting neural crest cells. Due to its heterogeneity neurofibromatosis was divided into eight different subgroups (NF-I NF-VIII) by Riccardi. Segmental neurofibromatosis (NF type V) is characterized by cutaneous neurofibromas and Café-au-lait spots limited with a segment of dermatome. Here we report this case with numerous, painless cutaneous nodules showing extension f...

  15. Expectation Maximization Segmentation

    OpenAIRE

    Bergman, Niclas

    1998-01-01

    This report reviews the Expectation Maximization EM algorithm and applies it to the data segmentation problem yielding the Expectation Maximization Segmentation EMS algorithm The EMS algorithm requires batch processing of the data and can be applied to mode switching or jumping linear dynamical state space models The EMS algorithm consists of an optimal fusion of fixed interval Kalman smoothing and discrete optimization. The next section gives a short introduction to the EM algorithm with som...

  16. Beer Market Segmentation

    OpenAIRE

    Koulová, Tereza

    2012-01-01

    The goal of the master's thesis is to find out similarities or differences among consumers in the Czech beer market by using primary and secondary research and content analysis. The thesis contains two parts, the theoretical and the practical one. Market segmentation, marketing research and Czech beer market are described in the theoretical part. The practical part includes market segmentation by using secondary data (agency data MML-TGI with Data Analyzer software), primary data (own researc...

  17. Segmentation of industrial markets

    OpenAIRE

    Drugă, Petruţa

    2011-01-01

    The business marketing manager performs on a market consisting of many different types of industrial customers with different needs. Only when this aggregate market is split into meaningful categories, the business marketing strategist can react suitably and usefully to the unique needs. After the determination process of the segments has ended, then the marketer must estimate the demand for every segment. Accurate projections of future possible sales represent one of ...

  18. Adjacent segment disease.

    Science.gov (United States)

    Virk, Sohrab S; Niedermeier, Steven; Yu, Elizabeth; Khan, Safdar N

    2014-08-01

    EDUCATIONAL OBJECTIVES As a result of reading this article, physicians should be able to: 1. Understand the forces that predispose adjacent cervical segments to degeneration. 2. Understand the challenges of radiographic evaluation in the diagnosis of cervical and lumbar adjacent segment disease. 3. Describe the changes in biomechanical forces applied to adjacent segments of lumbar vertebrae with fusion. 4. Know the risk factors for adjacent segment disease in spinal fusion. Adjacent segment disease (ASD) is a broad term encompassing many complications of spinal fusion, including listhesis, instability, herniated nucleus pulposus, stenosis, hypertrophic facet arthritis, scoliosis, and vertebral compression fracture. The area of the cervical spine where most fusions occur (C3-C7) is adjacent to a highly mobile upper cervical region, and this contributes to the biomechanical stress put on the adjacent cervical segments postfusion. Studies have shown that after fusion surgery, there is increased load on adjacent segments. Definitive treatment of ASD is a topic of continuing research, but in general, treatment choices are dictated by patient age and degree of debilitation. Investigators have also studied the risk factors associated with spinal fusion that may predispose certain patients to ASD postfusion, and these data are invaluable for properly counseling patients considering spinal fusion surgery. Biomechanical studies have confirmed the added stress on adjacent segments in the cervical and lumbar spine. The diagnosis of cervical ASD is complicated given the imprecise correlation of radiographic and clinical findings. Although radiological and clinical diagnoses do not always correlate, radiographs and clinical examination dictate how a patient with prolonged pain is treated. Options for both cervical and lumbar spine ASD include fusion and/or decompression. Current studies are encouraging regarding the adoption of arthroplasty in spinal surgery, but more long

  19. Automated segmentation of the human hippocampus along its longitudinal axis.

    Science.gov (United States)

    Lerma-Usabiaga, Garikoitz; Iglesias, Juan Eugenio; Insausti, Ricardo; Greve, Douglas N; Paz-Alonso, Pedro M

    2016-09-01

    The human hippocampal formation is a crucial brain structure for memory and cognitive function that is closely related to other subcortical and cortical brain regions. Recent neuroimaging studies have revealed differences along the hippocampal longitudinal axis in terms of structure, connectivity, and function, stressing the importance of improving the reliability of the available segmentation methods that are typically used to divide the hippocampus into its anterior and posterior parts. However, current segmentation conventions present two main sources of variability related to manual operations intended to correct in-scanner head position across subjects and the selection of dividing planes along the longitudinal axis. Here, our aim was twofold: (1) to characterize inter- and intra-rater variability associated with these manual operations and compare manual (landmark based) and automatic (percentage based) hippocampal anterior-posterior segmentation procedures; and (2) to propose and test automated rotation methods based on approximating the hippocampal longitudinal axis to a straight line (estimated with principal component analysis, PCA) or a quadratic Bézier curve (fitted with numerical methods); as well as an automated anterior-posterior hippocampal segmentation procedure based on the percentage-based method. Our results reveal that automated rotation and segmentation procedures, used in combination or independently, minimize inconsistencies generated by the accumulation of manual operations while providing higher statistical power to detect well-known effects. A Matlab-based implementation of these procedures is made publicly available to the research community. Hum Brain Mapp 37:3353-3367, 2016. © 2016 Wiley Periodicals, Inc. PMID:27159325

  20. Segmental neurofibromatosis and malignancy.

    Science.gov (United States)

    Dang, Julie D; Cohen, Philip R

    2010-01-01

    Segmental neurofibromatosis is an uncommon variant of neurofibromatosis type I characterized by neurofibromas and/or café-au-lait macules localized to one sector of the body. Although patients with neurofibromatosis type I have an associated increased risk of certain malignancies, malignancy has only occasionally been reported in patients with segmental neurofibromatosis. The published reports of patients with segmental neurofibromatosis who developed malignancy were reviewed and the characteristics of these patients and their cancers were summarized. Ten individuals (6 women and 4 men) with segmental neurofibromatosis and malignancy have been reported. The malignancies include malignant peripheral nerve sheath tumor (3), malignant melanoma (2), breast cancer (1), colon cancer (1), gastric cancer (1), lung cancer (1), and Hodgkin lymphoma (1). The most common malignancies in patients with segmental neurofibromatosis are derived from neural crest cells: malignant peripheral nerve sheath tumor and malignant melanoma. The incidence of malignancy in patients with segmental neurofibromatosis may approach that of patients with neurofibromatosis type I. PMID:21137621

  1. Skin Images Segmentation

    Directory of Open Access Journals (Sweden)

    Ali E. Zaart

    2010-01-01

    Full Text Available Problem statement: Image segmentation is a fundamental step in many applications of image processing. Skin cancer has been the most common of all new cancers detected each year. At early stage detection of skin cancer, simple and economic treatment can cure it mostly. An accurate segmentation of skin images can help the diagnosis to define well the region of the cancer. The principal approach of segmentation is based on thresholding (classification that is lied to the problem of the thresholds estimation. Approach: The objective of this study is to develop a method to segment the skin images based on a mixture of Beta distributions. We assume that the data in skin images can be modeled by a mixture of Beta distributions. We used an unsupervised learning technique with Beta distribution to estimate the statistical parameters of the data in skin image and then estimate the thresholds for segmentation. Results: The proposed method of skin images segmentation was implemented and tested on different skin images. We obtained very good results in comparing with the same techniques with Gamma distribution. Conclusion: The experiment showed that the proposed method obtained very good results but it requires more testing on different types of skin images.

  2. Herniation of the anterior lens capsule

    Directory of Open Access Journals (Sweden)

    Pereira Nolette

    2007-01-01

    Full Text Available Herniation of the anterior lens capsule is a rare abnormality in which the capsule bulges forward in the pupillary area. This herniation can be mistaken for an anterior lenticonus where both the capsule and the cortex bulge forward. The exact pathology behind this finding is still unclear. We report the clinical, ultrasound biomicroscopy (UBM and histopathological findings of a case of herniation of the anterior lens capsule. UBM helped to differentiate this entity from anterior lenticonus. Light microscopy revealed capsular splitting suggestive of capsular delamination and collection of fluid (aqueous in the area of herniation giving it a characteristic appearance.

  3. Perawatan Gigitan Terbalik Anterior Dengan Menggunakan Inclined Plane

    OpenAIRE

    Siregar, Wilda A.

    2008-01-01

    Gigitan terbalik anterior adalah suatu anomali posisi gigi anterior atas yang lebih ke lingual dibandingkan gigi anterior bawah. Anomali gigitan terbalik anterior dapat ditemui pada periode gigi sulung, gigi bercampur, dan gigi permanen. Faktor etiologi gigitan terbalik anterior dibedakan atas dental, fungsional atau skeletal. Untuk menentukan etiologi dari anomali gigitan terbalik anterior perlu dilakukan diagnosa yang tepat. Perawatan gigitan terbalik anterior ini dapat dilakukan de...

  4. Ocular perfusion pressure and hemodynamics analysis in non-arteritic anterior ischemic optic neuropathy and idiopathic optic neuritis%非炎性前部缺血性视神经病变和特发性视神经炎眼灌注压与眼部血流动力学研究

    Institute of Scientific and Technical Information of China (English)

    王欣玲; 李雪姣; 阎启昌

    2014-01-01

    Objective To compare the Ocular perfusion pressure (OPP) and ocular hemodynamics of patients with non-arteritic anterior ischemic optic neuropathy (NAION) and idiopathic optic neuritis (ION),and analyze their relationship with fixation features.Methods It was a retrospective case study.Data were collected in patients with NAION and ION who were treated in Department of Ophthalmology,the Fourth Affiliated Hospital,China Medical University from March 2011 to May 2013.OPP and ocular hemodynamics were analyzed,as well as the ages,gender,and systemic diseases after these patients were divided as the central fixation group and the extra-central fixation one on the basis of ocular fixation features.The reason making the differences were thought over.Results There were 21 NAION cases (21 eyes,14 for central fixation and 7 for extra-central fixation) and 21 ION ones (21 eyes,8 for central fixation and 13 for extra-central fixation).The peak systolic velocity (PSV) of posterior ciliary artery (PCA) and central retinal artery (CRA) were significantly decreased in the NAION group comparing with the ION group in central fixation eyes (t =12.49,P =0.00; t =14.25,P =0.00).In the extra-central fixation eyes,the sitting mean artery pressure (MAP) of brachial artery and OPP were significantly increased in the NAION group,and the PSV of PCA and CRA were significantly decreased in the NAION group (t =6.41,P =0.02; t =5.66,P =0.03; t =8.47,P =0.01; t =11.32,P =0.00).However,the PSV of PCA and CRA were significantly decreased in the NAION group when the fixation features were excluded from the classification criteria and all kinds of vision was regarded totally as central fixation vision (t =5.81,P =0.02; t =9.20,P =0.00).Conclusions The fixation features of NAION and ION eyes can be classified as central fixation and extra-central fixation.The comparisons of OPP and ocular hemodynamics should be classified according to the fixation features.%目的 比较非炎性前部缺血性视神

  5. Anterior cervical osteophytes causing dysphagia and dyspnea: an uncommon entity revisited.

    Science.gov (United States)

    Giger, Roland; Dulguerov, Pavel; Payer, Michael

    2006-10-01

    Large anterior cervical osteophytes can occur in degeneration of the cervical spine or in diffuse idiopathic skeletal hyperostosis (DISH). We present the case of an 83-year-old patient with progressive dysphagia and acute dyspnea, necessitating emergency tracheotomy. Voluminous anterior cervical osteophytes extending from C3 to C7 and narrowing the pharyngoesophageal segment by external compression and bilateral vocal fold immobility were diagnosed radiologically and by fiberoptic laryngoscopy. Surgical removal of all osteophytes led to the resolution of symptoms. Dyspnea with or without dysphagia caused by hypertrophic anterior cervical osteophytes is an uncommon entity. The exhaustive diagnostic workup proposed in the literature could be simplified by using fiberoptic laryngoscopy and dynamic videofluoroscopy. The causes, treatment, and outcome are discussed. PMID:17216390

  6. Absence of scalenus anterior muscle.

    Directory of Open Access Journals (Sweden)

    Murakami S

    2003-06-01

    Full Text Available A rare anomaly of the scalenus muscles is described. In this case, the right scalenus anterior muscle was absent. As a substitute for this muscle, some aberrant muscle slips arose from the lower vertebrae and descended in front of the ventral rami of the lower cervical nerves. These aberrant slips then ran between the ventral rami of the the eighth cervical and first thoracic nerves, and were fused with the right scalenus medius muscle. Thus, the subclavian artery and vein ran in front of the aberrant slips, together with the ventral ramus of the first thoracic nerve. The aberrant muscle slips issued 2 accessory bundles. One bundle ran between the ventral rami of the fourth and fifth cervical nerves and was fused with the scalenus medius muscle; the other bundle ran between the ventral rami of the fifth and sixth cervical nerves and was fused with the scalenus medius muscle.

  7. Rediscovering market segmentation.

    Science.gov (United States)

    Yankelovich, Daniel; Meer, David

    2006-02-01

    In 1964, Daniel Yankelovich introduced in the pages of HBR the concept of nondemographic segmentation, by which he meant the classification of consumers according to criteria other than age, residence, income, and such. The predictive power of marketing studies based on demographics was no longer strong enough to serve as a basis for marketing strategy, he argued. Buying patterns had become far better guides to consumers' future purchases. In addition, properly constructed nondemographic segmentations could help companies determine which products to develop, which distribution channels to sell them in, how much to charge for them, and how to advertise them. But more than 40 years later, nondemographic segmentation has become just as unenlightening as demographic segmentation had been. Today, the technique is used almost exclusively to fulfill the needs of advertising, which it serves mainly by populating commercials with characters that viewers can identify with. It is true that psychographic types like "High-Tech Harry" and "Joe Six-Pack" may capture some truth about real people's lifestyles, attitudes, self-image, and aspirations. But they are no better than demographics at predicting purchase behavior. Thus they give corporate decision makers very little idea of how to keep customers or capture new ones. Now, Daniel Yankelovich returns to these pages, with consultant David Meer, to argue the case for a broad view of nondemographic segmentation. They describe the elements of a smart segmentation strategy, explaining how segmentations meant to strengthen brand identity differ from those capable of telling a company which markets it should enter and what goods to make. And they introduce their "gravity of decision spectrum", a tool that focuses on the form of consumer behavior that should be of the greatest interest to marketers--the importance that consumers place on a product or product category. PMID:16485810

  8. Multisegmental cervical ossification of the posterior longitudinal ligament: Anterior vs posterior approach

    OpenAIRE

    Jain Subodh; Salunke Pravin; Vyas K; Behari Sanjay; Banerji Deepu; Jain Vijendra

    2005-01-01

    Aims : To determine the surgical approach in patients with multisegmental (four or more segments) OPLL of the cervical spine. Methods and Materials : Data of 27 patients who had undergone either an anterior (corpectomy with excision of OPLL and interbody fusion=14 patients) or posterior approach (laminectomy=12, laminoplasty=1 patient) for the multisegmental cervical OPLL was analyzed retrospectively. The patients in each group were statistically similar in respect to preoperative factors su...

  9. Evolution of anterior Hox regulatory elements among chordates

    OpenAIRE

    Natale Alfonso; Sims Carrie; Chiusano Maria L; Amoroso Alessandro; D'Aniello Enrico; Fucci Laura; Krumlauf Robb; Branno Margherita; Locascio Annamaria

    2011-01-01

    Abstract Background The Hox family of transcription factors has a fundamental role in segmentation pathways and axial patterning of embryonic development and their clustered organization is linked with the regulatory mechanisms governing their coordinated expression along embryonic axes. Among chordates, of particular interest are the Hox paralogous genes in groups 1-4 since their expression is coupled to the control of regional identity in the anterior nervous system, where the highest struc...

  10. Segmentation of the foveal microvasculature using deep learning networks

    Science.gov (United States)

    Prentašić, Pavle; Heisler, Morgan; Mammo, Zaid; Lee, Sieun; Merkur, Andrew; Navajas, Eduardo; Beg, Mirza Faisal; Šarunić, Marinko; Lončarić, Sven

    2016-07-01

    Accurate segmentation of the retinal microvasculature is a critical step in the quantitative analysis of the retinal circulation, which can be an important marker in evaluating the severity of retinal diseases. As manual segmentation remains the gold standard for segmentation of optical coherence tomography angiography (OCT-A) images, we present a method for automating the segmentation of OCT-A images using deep neural networks (DNNs). Eighty OCT-A images of the foveal region in 12 eyes from 6 healthy volunteers were acquired using a prototype OCT-A system and subsequently manually segmented. The automated segmentation of the blood vessels in the OCT-A images was then performed by classifying each pixel into vessel or nonvessel class using deep convolutional neural networks. When the automated results were compared against the manual segmentation results, a maximum mean accuracy of 0.83 was obtained. When the automated results were compared with inter and intrarater accuracies, the automated results were shown to be comparable to the human raters suggesting that segmentation using DNNs is comparable to a second manual rater. As manually segmenting the retinal microvasculature is a tedious task, having a reliable automated output such as automated segmentation by DNNs, is an important step in creating an automated output.

  11. Segmented conjugated polymers

    Indian Academy of Sciences (India)

    G Padmanaban; S Ramakrishnan

    2003-08-01

    Segmented conjugated polymers, wherein the conjugation is randomly truncated by varying lengths of non-conjugated segments, form an interesting class of polymers as they not only represent systems of varying stiffness, but also ones where the backbone can be construed as being made up of chromophores of varying excitation energies. The latter feature, especially when the chromophores are fluorescent, like in MEHPPV, makes these systems particularly interesting from the photophysics point of view. Segmented MEHPPV- samples, where x represents the mole fraction of conjugated segments, were prepared by a novel approach that utilizes a suitable precursor wherein selective elimination of one of the two eliminatable groups is affected; the uneliminated units serve as conjugation truncations. Control of the composition x of the precursor therefore permits one to prepare segmented MEHPPV- samples with varying levels of conjugation (elimination). Using fluorescence spectroscopy, we have seen that even in single isolated polymer chains, energy migration from the shorter (higher energy) chromophores to longer (lower energy) ones occurs – the extent of which depends on the level of conjugation. Further, by varying the solvent composition, it is seen that the extent of energy transfer and the formation of poorly emissive inter-chromophore excitons are greatly enhanced with increasing amounts of non-solvent. A typical S-shaped curve represents the variation of emission yields as a function of composition suggestive of a cooperative collapse of the polymer coil, reminiscent of conformational transitions seen in biological macromolecules.

  12. Bootstrapping structured page segmentation

    Science.gov (United States)

    Ma, Huanfeng; Doermann, David S.

    2003-01-01

    In this paper, we present an approach to the bootstrap learning of a page segmentation model. The idea evolves from attempts to segment dictionaries that often have a consistent page structure, and is extended to the segmentation of more general structured documents. In cases of highly regular structure, the layout can be learned from examples of only a few pages. The system is first trained using a small number of samples, and a larger test set is processed based on the training result. After making corrections to a selected subset of the test set, these corrected samples are combined with the original training samples to generate bootstrap samples. The newly created samples are used to retrain the system, refine the learned features and resegment the test samples. This procedure is applied iteratively until the learned parameters are stable. Using this approach, we do not need to initially provide a large set of training samples. We have applied this segmentation to many structured documents such as dictionaries, phone books, spoken language transcripts, and obtained satisfying segmentation performance.

  13. Totally thrombosed giant anterior communicating artery aneurysm

    Directory of Open Access Journals (Sweden)

    V R Roopesh Kumar

    2015-01-01

    Full Text Available Giant anterior communicating artery aneurysmsarerare. Apatient presented with visual dysfunction, gait ataxia and urinary incontinence. MRI showed a giant suprasellar mass.At surgery, the lesion was identified as being an aneurysm arising from the anterior communicating artery.The difficulty in preoperative diagnosis and relevant literature are reviewed.

  14. Anterior capsular rupture following blunt ocular injury

    OpenAIRE

    Gremida, Anas; Kassem, Iris; Traish, Aisha

    2011-01-01

    A 10-year-old boy suffered a large, oblique anterior capsular tear following blunt injury to his right eye. The boy was followed daily for hyphema resolution and progressive traumatic cataract formation. After the hyphema had resolved, the lens was removed using an anterior approach and an intraocular lens was placed with excellent visual outcome.

  15. Dentulous Appliance for Upper Anterior Edentulous Span

    OpenAIRE

    Chalakkal, Paul; Devi, Ramisetty Sabitha; Srinivas, G Vijay; Venkataramana, Pammi

    2013-01-01

    This article discusses about a fixed dentulous appliance that was constructed to replace the primary upper anterior edentulous span in a four year old girl. It constituted a design, whereby the maxillary primary second molars were used to support the appliance through bands and a wire that contained an acrylic flange bearing trimmed acrylic teeth, anteriorly. The appliance was functionally and aesthetically compliant.

  16. Anterior cervical hypertrichosis: a sporadic case.

    Science.gov (United States)

    Bostan, Sezen; Yaşar, Şirin; Serdar, Zehra Aşiran; Gizlenti, Sevda

    2016-03-01

    Anterior cervical hypertrichosis is a very rare form of primary localized hypertrichosis. It consists of a tuft of terminal hair on the anterior neck just above the laryngeal prominence. The etiology is still unknown. In this article, we reported a 15-year-old female patient who presented to our clinic with a complaint of hypertrichosis on the anterior aspect of the neck for the last five years. Her past medical history revealed no pathology except for vesicoureteral reflux. On the basis of clinical presentation, our patient was diagnosed with anterior cervical hypertrichosis and she was considered to be a sporadic case due to lack of other similar cases in familial history. To date, 33 patients with anterior cervical hypertrichosis have been reported. Anterior cervical hypertrichosis can be associated with other abnormalities, but it frequently presents as an isolated defect (70%). The association of vesicoureteral reflux and anterior cervical hypertrichosis which was observed in our patient might be coincidental. So far, no case of anterior cervical hypertrichosis associated with vesicoureteral reflux has been reported in the literature. PMID:27103865

  17. Cooperative processes in image segmentation

    Science.gov (United States)

    Davis, L. S.

    1982-01-01

    Research into the role of cooperative, or relaxation, processes in image segmentation is surveyed. Cooperative processes can be employed at several levels of the segmentation process as a preprocessing enhancement step, during supervised or unsupervised pixel classification and, finally, for the interpretation of image segments based on segment properties and relations.

  18. Optic disc oedema

    DEFF Research Database (Denmark)

    Nielsen, Marianne Kromann; Hamann, Steffen

    2014-01-01

    Optic disc oedema describes the nonspecific, localized swelling of the optic nerve head regardless of aetiology. Therefore, differentiating among the various aetiologies depends on a thorough history and knowledge of the clinical characteristics of the underlying conditions. Papilloedema strictly...... refers to optic disc oedema as a consequence of elevated intracranial pressure. It is usually a bilateral condition and visual function is preserved until late. Optic disc oedema caused by an anterior optic neuropathy is usually unilateral and accompanied by the loss of visual function....

  19. Texture Segmentation Benchmark

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Mikeš, Stanislav

    Los Alamitos : IEEE Press, 2008, s. 2933-2936. ISBN 978-1-4244-2174-9. [19th International Conference on Pattern Recognition. Tampa (US), 07.12.2008-11.12.2008] R&D Projects: GA AV ČR 1ET400750407; GA MŠk 1M0572; GA ČR GA102/07/1594; GA ČR GA102/08/0593 Grant ostatní: GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : texture segmentation * image segmentation * benchmark Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2008/RO/haindl-texture segmentation benchmark.pdf

  20. Nasal palatal: segment complex

    Directory of Open Access Journals (Sweden)

    Lourdes Romera

    2015-10-01

    Full Text Available This paper focuses on the nature of a segment which is always problematical —the palatal nasal. Phonetic results found in the acoustic, perceptive and articulate spheres, showing the different features of this nasal with regards to others, are the point of departure for a brief reflection on the phonological nature of this segment, taking into account the feature geometry and the articulatory phonology. It concludes by considering the palatal nasal /?/ as a complex segment formed by /n+j/ and the imputation, to temporary effects, of a degree of major o minor assimilation and gestural overlapping during effective perception of /?/, of /n+j/ or of /n+i/.

  1. Segmentation of complex document

    Directory of Open Access Journals (Sweden)

    Souad Oudjemia

    2014-06-01

    Full Text Available In this paper we present a method for segmentation of documents image with complex structure. This technique based on GLCM (Grey Level Co-occurrence Matrix used to segment this type of document in three regions namely, 'graphics', 'background' and 'text'. Very briefly, this method is to divide the document image, in block size chosen after a series of tests and then applying the co-occurrence matrix to each block in order to extract five textural parameters which are energy, entropy, the sum entropy, difference entropy and standard deviation. These parameters are then used to classify the image into three regions using the k-means algorithm; the last step of segmentation is obtained by grouping connected pixels. Two performance measurements are performed for both graphics and text zones; we have obtained a classification rate of 98.3% and a Misclassification rate of 1.79%.

  2. Microscopic Halftone Image Segmentation

    Institute of Scientific and Technical Information of China (English)

    WANG Yong-gang; YANG Jie; DING Yong-sheng

    2004-01-01

    Microscopic halftone image recognition and analysis can provide quantitative evidence for printing quality control and fault diagnosis of printing devices, while halftone image segmentation is one of the significant steps during the procedure. Automatic segmentation on microscopic dots by the aid of the Fuzzy C-Means (FCM) method that takes account of the fuzziness of halftone image and utilizes its color information adequately is realized. Then some examples show the technique effective and simple with better performance of noise immunity than some usual methods. In addition, the segmentation results obtained by the FCM in different color spaces are compared, which indicates that the method using the FCM in the f1f2f3 color space is superior to the rest.

  3. Large Telescope Segmented Primary Mirror Alignment

    Science.gov (United States)

    Rud, Mayer

    2010-01-01

    A document discusses a broadband (white light) point source, located at the telescope Cassegrain focus, which generates a cone of light limited by the hole in the secondary mirror (SM). It propagates to the aspheric null-mirror, which is optimized to make all the reflected rays to be normal to the primary mirror (PM) upon reflection. PM retro-reflects the rays back through the system for wavefront analysis. The point source and the wavefront analysis subsystems are all located behind the PM. The PM phasing is absolute (white light) and does not involve the SM. A relatively small, aspheric null-mirror located near the PM center of curvature has been designed to deliver the high level of optical wavefront correction. The phasing of the segments is absolute due to the use of a broadband source. The segmented PM is optically aligned independently and separately from the SM alignment. The separation of the PM segments alignment from the PM to the SM, and other telescope optics alignments, may be a significant advantage, eliminating the errors coupling. The point source of this concept is fully cooperative, unlike a star or laser-generated guide-star, providing the necessary brightness for the optimal S/N ratio, the spectral content, and the stable on-axis position. This concept can be implemented in the lab for the PM initial alignment, or made to be a permanent feature of the space-based or groundbased telescope.

  4. Illumination Invariant Unsupervised Segmenter

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Mikeš, Stanislav; Vácha, Pavel

    Los Alamitos : IEEE, 2009, s. 4025-4028. ISBN 978-1-4244-5655-0. ISSN 1522-4880. [ICIP 2009. Cairo (EG), 07.11.2009-11.11.2009] R&D Projects: GA MŠk 1M0572; GA ČR GA102/08/0593 Grant ostatní: GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : unsupervised image segmentation * Illumination Invariants Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2009/RO/haindl-illumination invariant unsupervised segmenter.pdf

  5. Segmental Neurofibromatosis: Atypical Localisation

    Directory of Open Access Journals (Sweden)

    Filiz Topaloğlu Demir

    2015-06-01

    Full Text Available Neurofibromatosis (NF is a genetic disease leading pathological findings in skin, soft tissue, bone and nervous system by affecting neural crest cells. Due to its heterogeneity neurofibromatosis was divided into eight different subgroups (NF-I NF-VIII by Riccardi. Segmental neurofibromatosis (NF type V is characterized by cutaneous neurofibromas and Café-au-lait spots limited with a segment of dermatome. Here we report this case with numerous, painless cutaneous nodules showing extension from the shoulder to the dorsal aspect of the right hand, since it a rare case.

  6. Range Video Segmentation

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Žid, Pavel; Holub, Radek

    Los Alamitos : IEEE, 2010, s. 369-372. ISBN 978-1-4244-7166-9. [10th International Conference on Information Sciences, Signal Processing and their Applications. Kuala Lumpur (MY), 10.05.2010-13.05.2010] R&D Projects: GA MŠk 1M0572; GA ČR GA102/08/0593 Grant ostatní: GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : Range segmentation * Markov random fields Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2010/RO/haindl-range video segmentation.pdf

  7. Unsupervised Image Segmentation Contest

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Mikeš, Stanislav

    Stockholm: IEEE Computer Society, 2014, s. 1484-1489. ISBN 978-1-4799-5208-3. ISSN 1051-4651. [ICPR 2014 - The 22nd International Conference on Pattern Recognition. Stockholm (SE), 24.08.2014-28.08.2014] R&D Projects: GA ČR(CZ) GA14-10911S Institutional support: RVO:67985556 Keywords : unsupervised image segmentation * color image segmentation algorithms * content-based image retrieval Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2014/RO/haindl-0431256.pdf

  8. Remote Sensing Segmentation Benchmark

    Czech Academy of Sciences Publication Activity Database

    Mikeš, Stanislav; Haindl, Michal; Scarpa, G.

    Piscataway, NJ : IEEE Press, 2012, s. 1-4. ISBN 978-1-4673-4960-4. [IAPR Workshop on Pattern Recognition in Remote Sensing (PRRS). Tsukuba Science City (JP), 11.11.2012] R&D Projects: GA ČR GAP103/11/0335; GA ČR GA102/08/0593 Grant ostatní: CESNET(CZ) 409/2011 Keywords : remote sensing * segmentation * benchmark Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2013/RO/mikes-remote sensing segmentation benchmark.pdf

  9. Anterior Shoulder Instability with Concomitant Superior Labrum from Anterior to Posterior (SLAP) Lesion Compared to Anterior Instability without SLAP Lesion

    Science.gov (United States)

    Durban, Claire Marie C.; Kim, Je Kyun; Kim, Sae Hoon

    2016-01-01

    Background The aims of this study were to investigate the clinical characteristics of patients with combined anterior instability and superior labrum from anterior to posterior (SLAP) lesions, and to analyze the effect of concomitant SLAP repair on surgical outcomes. Methods We retrospectively reviewed patients who underwent arthroscopic stabilization for anterior shoulder instability between January 2004 and March 2013. A total of 120 patients were available for at least 1-year follow-up. Forty-four patients with reparable concomitant detached SLAP lesions (group I) underwent combined SLAP and anterior stabilization, and 76 patients without SLAP lesions (group II) underwent anterior stabilization alone. Patient characteristics, preoperative and postoperative pain scores, Rowe scores, and shoulder ranges of motion were compared between the 2 groups. Results Patients in group I had higher incidences of high-energy trauma (p = 0.03), worse preoperative pain visual analogue scale (VAS) (p = 0.02), and Rowe scores (p = 0.04). The postoperative pain VAS and Rowe scores improved equally in both groups without significant differences. Limitation in postoperative range of motion was similar between the groups (all p-value > 0.05). Conclusions Anterior instability with SLAP lesion may not be related to frequent episodes of dislocation but rather to a high-energy trauma. SLAP fixation with anterior stabilization procedures did not lead to poor functional outcomes if appropriate surgical techniques were followed. PMID:27247742

  10. Optimizing Anterior En Masse Retraction with Miniscrew Anchorage

    Directory of Open Access Journals (Sweden)

    Pavankumar Janardan Vibhute

    2011-01-01

    Full Text Available In severely protrusive patients, skeletal anchorage from miniscrew is often used to avoid anchorage loss with preferred miniscrew location near centre of resistance (Cres of posterior teeth. Biomechanical requirement for directing retraction force towards Cres of posterior teeth demands the insertion of miniscrew in loose mucosa, where risk of infection and failure increases. In addition, undesirable biomechanical side effects on anterior and posterior segments may be possible in all three planes, when continuous arch sliding mechanics are installed with miniscrew anchorage. This paper describes technique of molar-stabilizing power arm (MSPA for simultaneous intrusion and retraction of anteriors with miniscrew placement at attached gingiva between 1st molar and 2nd premolar. Advantages of this technique include (i the need of miniscrews placement in loose mucosa apically near the Cres of the posterior teeth is eliminated, (ii the risk of infection and miniscrew failure is lowered since the miniscrew is placed in attached gingiva rather than the loose mucosa, and (iii by adjusting vertical length or replacing MSPA, alteration of the retraction force vector is possible in all three planes; thus, need of removal and repositioning of the miniscrew (e.g., in correction of occlusal cant can be eliminated.

  11. Optimizing anterior en masse retraction with miniscrew anchorage.

    Science.gov (United States)

    Vibhute, Pavankumar Janardan

    2011-01-01

    In severely protrusive patients, skeletal anchorage from miniscrew is often used to avoid anchorage loss with preferred miniscrew location near centre of resistance (Cres) of posterior teeth. Biomechanical requirement for directing retraction force towards Cres of posterior teeth demands the insertion of miniscrew in loose mucosa, where risk of infection and failure increases. In addition, undesirable biomechanical side effects on anterior and posterior segments may be possible in all three planes, when continuous arch sliding mechanics are installed with miniscrew anchorage. This paper describes technique of molar-stabilizing power arm (MSPA) for simultaneous intrusion and retraction of anteriors with miniscrew placement at attached gingiva between 1st molar and 2nd premolar. Advantages of this technique include (i) the need of miniscrews placement in loose mucosa apically near the Cres of the posterior teeth is eliminated, (ii) the risk of infection and miniscrew failure is lowered since the miniscrew is placed in attached gingiva rather than the loose mucosa, and (iii) by adjusting vertical length or replacing MSPA, alteration of the retraction force vector is possible in all three planes; thus, need of removal and repositioning of the miniscrew (e.g., in correction of occlusal cant) can be eliminated. PMID:22567438

  12. Optic Nerve Sheath Meningioma Masquerading as Optic Neuritis

    OpenAIRE

    Alroughani, R.; Behbehani, R

    2016-01-01

    Optic neuritis is a common presentation of demyelinating disorders such as multiple sclerosis. It typically presents with acute painful monocular vision loss, whereas chronic optic neuropathy can be caused by compressive lesions along the anterior visual pathway, genetic, toxic, or nutritional causes. We report an unusual presentation mimicking optic neuritis, which was subsequently diagnosed as optic nerve sheath meningioma (ONSM). Misinterpretation of white matter lesions on MRI of brain an...

  13. 3D spectral imaging system for anterior chamber metrology

    Science.gov (United States)

    Anderson, Trevor; Segref, Armin; Frisken, Grant; Frisken, Steven

    2015-03-01

    Accurate metrology of the anterior chamber of the eye is useful for a number of diagnostic and clinical applications. In particular, accurate corneal topography and corneal thickness data is desirable for fitting contact lenses, screening for diseases and monitoring corneal changes. Anterior OCT systems can be used to measure anterior chamber surfaces, however accurate curvature measurements for single point scanning systems are known to be very sensitive to patient movement. To overcome this problem we have developed a parallel 3D spectral metrology system that captures simultaneous A-scans on a 2D lateral grid. This approach enables estimates of the elevation and curvature of anterior and posterior corneal surfaces that are robust to sample movement. Furthermore, multiple simultaneous surface measurements greatly improve the ability to register consecutive frames and enable aggregate measurements over a finer lateral grid. A key element of our approach has been to exploit standard low cost optical components including lenslet arrays and a 2D sensor to provide a path towards low cost implementation. We demonstrate first prototypes based on 6 Mpixel sensor using a 250 μm pitch lenslet array with 300 sample beams to achieve an RMS elevation accuracy of 1μm with 95 dB sensitivity and a 7.0 mm range. Initial tests on Porcine eyes, model eyes and calibration spheres demonstrate the validity of the concept. With the next iteration of designs we expect to be able to achieve over 1000 simultaneous A-scans in excess of 75 frames per second.

  14. Operative treatment via anterior approaches for cervicothoracic vertebrae tumors: surgical techniques and primary outcome

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: To sum up 7 patients with cervicothoracic vertebrae tumors (C7 to T3) from March 1999 and May 2002, who underwent operative treatment via anterior approaches. Methods :The anterior approaches included low anterior cervical approach and high transthoracic approach. In 5 cases of segments of T1 and above involved, the low anterior cervical approaches were adopted, otherwise the high transthoracic approaches were used(2 cases). Excision of tumor was carried out according to demands of the Weinstein-Boriani-Biagini (WBB) staging system. Spine stability was reconstructed by bone autografting and instrumentation. There were 4 cases of primary tumor and 3 of metastases. Their mean age was 45.1 years (23 to 66). The mean follow up was 18.9 months (3 to 45). Results were evaluated by occurrence of complications, improvement of symptoms, local recurrence and mortality. Results: All patients stood surgery well. No significant complications occurred during and after operation. Local pain was significantly alleviated and neurological deficit was improved at least one Frankel grade. Three patients died.Local tumor control was obtained in 6 patients (85.7 %) until the end of follow-up. Conclusion:Our experience showed that via low anterior cervical approach and high transthoracic approach, the cervicothoracic vertebrae tumor could be excised safely and adequately. Moreover, excision of tumor according to the WBB surgical staging system and reconstruction of spine stability have made great contribution to local tumor control and the neurological function improvement.

  15. Anterior migration of dexamethasone implant in a pseudophakic patient with intact posterior capsule

    Directory of Open Access Journals (Sweden)

    Nilufer Kocak

    2014-01-01

    Full Text Available Intravitreal application of Ozurdex ® (Allergan, Inc., Irvine, CA, USA which is a biodegradable, sustained-release dexamethasone implant has been reported to be effective in the treatment of macular edema. Migration of such implant into the anterior chamber has been recently described in cases without perfect zonular or the posterior capsular integrity. Herein, we report the first case with anterior migration of Ozurdex ® implant that mislocated just behind the intraocular lens (IOL in an intact capsular bag. It is thought that such implant migrated anteriorly towards into the posterior chamber through weak zonules as the present case had a medical history of uneventful phacoemulsification surgery with the implantation of posterior chamber IOL. However, the migrated implant was well tolerated since there was no sign of the corneal complication, rise in intraocular pressure, and anterior chamber reaction. Close follow-up was scheduled to find out any signs of anterior segment pathology. Meanwhile dexamethasone implant completely degraded at the 4 th month of postoperative follow-up.

  16. Severe anterior uveitis associated with idiopathic dacryoadenitis in diabetes mellitus patient

    Directory of Open Access Journals (Sweden)

    Takahashi YY

    2011-05-01

    Full Text Available Yasuhiro Takahashi¹, Hirohiko Kakizaki¹, Akihiro Ichinose², Masayoshi Iwaki¹¹Department of Ophthalmology, Aichi Medical University, Nagakute, Aichi, Japan; ²Department of Plastic Surgery, Kobe University, Kobe, Hyogo, JapanAbstract: A 38-year-old woman with diabetes mellitus complained of acute visual loss in the left eye (20/200 and swollen left upper eyelid. Slit lamp examination of the left eye revealed ciliary injection, posterior synechia iritis, numerous inflammatory cells, and fibrin exudates in the anterior chamber. T1-weighted enhanced magnetic resonance imaging demonstrated left lacrimal gland enhancement with inflammatory spread to the left anterior ocular segment. Blood examination showed increased blood sugar but the other components were within normal limits. The patient was treated with steroid pulse therapy (methylprednisolone 1 g/day × 3 days under a blood sugar control regimen in consultation with an endocrinologist, after which additional peribulbar injection of triamcinolone acetonide (40 mg was performed. Resolution of the anterior uveitis and the dacryoadenitis was obtained after 2 months and there was no recurrence 1 year after the therapy. This is a rare case of severe anterior uveitis caused by idiopathic dacryoadenitis in a patient with diabetes mellitus.Keywords: anterior uveitis, idiopathic dacryoadenitis, diabetes mellitus, magnetic resonance imaging, steroid

  17. SEPTO-OPTICDYSPLASIA WITH AN ANTERIOR ENCEPHALOCELE AND INTACT SEPTUM PELLUCIDUM: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Z. Razavi

    2008-10-01

    Full Text Available ObjectiveThe diagnosis of de Morsier syndrome or septo-optic dysplasia is made on the basis of the diagnosis of optic nerve hypoplasia. Septo-optic dysplasia is defined by a variable combination of dysgenesis of midline brain structures including optic nerve hypoplasia and hypothalamic-pituitary dysfunction often associated with a wide variety of brain malformations of cortical development.The importance of direct ophthalmoscopy of optic nerve abnormalities is stressed, as well as of magnetic resonance imaging, which has become a guideline in the classification of  this syndrome This article reports a 19-year-old female with bilateral optic nerve  hypoplasia,anterior encephalocele and intact septum pellucidum. She was diagnosed withdiabetes insipidus, short stature and the history of seizure.Keywords: De morsier syndrome, Septo-optic dysplasia, Encephalocele, Short stature, Optic nerve hypoplasia

  18. The impact of implantation technique on frontal and sagittal alignment in total lumbar disc replacement: a comparison of anterior versus oblique implantation

    OpenAIRE

    Schmidt, René; Obertacke, U; Nothwang, J.; C. Ulrich; Nowicki, J.; Reichel, H; Cakir, B

    2010-01-01

    The concept of total lumbar disc replacement (TDR) is gaining acceptance due to good clinical short-term outcome. Standard implantation is strict anterior, which poses especially above the segment L5/S1 sometimes difficulties due to the vessel configuration. Therefore, oblique implantable TDR have been invented. In oblique implantation the anterior longitudinal ligament (ALL) is only partially resected, with additional partial resection of lateral annulus fibers. This could have an impact on ...

  19. The LOFT Ground Segment

    DEFF Research Database (Denmark)

    Bozzo, E.; Antonelli, A.; Argan, A.;

    2014-01-01

    we summarize the planned organization of the LOFT ground segment (GS), as established in the mission Yellow Book 1 . We describe the expected GS contributions from ESA and the LOFT consortium. A review is provided of the planned LOFT data products and the details of the data flow, archiving and...

  20. Unsupervised Image Segmentation

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Mikeš, Stanislav

    2014-01-01

    Roč. 36, č. 4 (2014), s. 23-23 R&D Projects: GA ČR(CZ) GA14-10911S Institutional support: RVO:67985556 Keywords : unsupervised image segmentation Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2014/RO/haindl-0434412.pdf

  1. Dictionary Based Image Segmentation

    DEFF Research Database (Denmark)

    Dahl, Anders Bjorholm; Dahl, Vedrana Andersen

    2015-01-01

    We propose a method for weakly supervised segmentation of natural images, which may contain both textured or non-textured regions. Our texture representation is based on a dictionary of image patches. To divide an image into separated regions with similar texture we use an implicit level sets...

  2. Active Optics in Modern, Large Optical Telescopes

    OpenAIRE

    Noethe, Lothar

    2001-01-01

    Active optics is defined as the control of the shape and the alignment of the components of an optical system at low temporal frequencies. For modern large telescopes with flexible monolithic or segmented primary mirrors and also flexible structures this technique is indispensable to reach a performance which is either diffraction limited for an operation in space or limited by the atmosphere for an operation on the ground. This article first describes the theory of active optics, both of the...

  3. Anterior retropharyngeal approach to the cervical spine.

    OpenAIRE

    Behari S; Banerji D; Trivedi P; Jain V; Chhabra D

    2001-01-01

    The anterior retropharyngeal approach (ARPA) accesses anteriorly situated lesions from the clivus to C3, in patients with a short neck, Klippel Feil anomaly or those in whom the C2-3 and C3-4 disc spaces are situated higher in relation to the hyoid bone and the angle of mandible where it is difficult to approach this region using the conventional anterior approach, due to the superomedial obliquity of the trajectory. The ARPA avoids the potentially contaminated oropharyngeal cavity providing ...

  4. Mini-open anterior lumbar interbody fusion.

    Science.gov (United States)

    Gandhoke, Gurpreet S; Ricks, Christian; Tempel, Zachary; Zuckerbraun, Brian; Hamilton, D Kojo; Okonkwo, David O; Kanter, Adam S

    2016-07-01

    In deformity surgery, anterior lumbar interbody fusion provides excellent biomechanical support, creates a broad surface area for arthrodesis, and induces lordosis in the lower lumbar spine. Preoperative MRI, plain radiographs, and, when available, CT scan should be carefully assessed for sacral slope as it relates to pubic symphysis, position of the great vessels (especially at L4/5), disc space height, or contraindication to an anterior approach. This video demonstrates the steps in an anterior surgical procedure with minimal open exposure. The video can be found here: https://youtu.be/r3bC4_vu1hQ . PMID:27364424

  5. Linear and nonlinear properties of segmented waveguides

    International Nuclear Information System (INIS)

    This dissertation deals with Periodically Segmented Waveguides (PSW), which are applied on KTiOP04 (KTP) crystals, by chemical ion-exchange process. In these waveguides, the crystal polarity and refractive index are periodically modulated to obtain Quasi Phase Matching (QPM) between the fundamental and second-harmonic waves. PSW is a relatively new optical device which exhibits unique optical properties in comparison with a continuous waveguide. The possibility of utilizing the KTP-PSW as a compact, cw, blue-violet, source by doubling infra-red light, is the main motivation for studying the optical properties of KTP segmented waveguides. Nevertheless, much attention in this work is also given to the study of linear optical properties of KTP-PSW, most of which, to my best knowledge, has not been studied yet. Controlling and understanding the linear optical properties of KTP-PSW, are required, for applying the PSW as an optical device by its own, and for control and characterization of the non-linear optical properties of the waveguide. In this work the dependence of the linear optical properties of KTP-PSW on geometrical parameters (period size, duty cycle and waveguide width) were studied. The experimental measured parameters include the PSW near field and the Bragg reflections, which appear due lo the grating structure of the waveguide. The possibility of controlling the wavelength and intensity, of the segmented waveguide Bragg reflections of regular period and super-period, is shown theoretically and experimentally. An unexpected dependence was found, by the experimental measurement, between the index profile and the ion-exchanged segment area,. The segmented waveguide dispersion curve, neff(λ) in the infra-red region was found, A main part of the research work is dedicated to the study of nonlinear characteristics of PSW. The different factors, which effect the Second Harmonic Generation (SHG), are measured experimentally and analyzed. The experimental results

  6. Speckle reduction in optical coherence tomography imaging by affine-motion image registration

    Science.gov (United States)

    Alonso-Caneiro, David; Read, Scott A.; Collins, Michael J.

    2011-11-01

    Signal-degrading speckle is one factor that can reduce the quality of optical coherence tomography images. We demonstrate the use of a hierarchical model-based motion estimation processing scheme based on an affine-motion model to reduce speckle in optical coherence tomography imaging, by image registration and the averaging of multiple B-scans. The proposed technique is evaluated against other methods available in the literature. The results from a set of retinal images show the benefit of the proposed technique, which provides an improvement in signal-to-noise ratio of the square root of the number of averaged images, leading to clearer visual information in the averaged image. The benefits of the proposed technique are also explored in the case of ocular anterior segment imaging.

  7. 非动脉炎性前部缺血性视神经病变24h动态血压的初步分析%Preliminary analysis on 24-hour ambulatory blood pressure monitoring of 19 patients with non-arteritic anterior ischemic optic neuropathy

    Institute of Scientific and Technical Information of China (English)

    梅晓白; 范坷; 魏世辉

    2012-01-01

    OBJECTIVE To conduct the preliminary analysis of the characteristics of 24-hour ambulatory blood pressure monitoring (ABPM) of the 19 patients with non-arteritic anterior ischemic optic neuropathy (NAION).METHODS Chose 19 cases of NA10N group and normal control group respectively, and recorded its 24-hour systolic, diastolic and mean arterial pressure, then portrayed the curve and analyzed the morning blood pressure surge (MBPS). RESULTS The daytime systolic blood pressure of 19 cases with NAION was lower than the normal group(P<0.01); The diastolic blood pressure of the day and the night was higher than the normal group(P<0.01); The blood pressure curves concluded seven non-dippers and eleven reverse-dippers. MBPS values were measured (MBPS==35 mmHg, 3cases; 10 mmHg =MBPS<35 mmHg, llcases; 0=MBPS<10 mmHg, 2cases, MBPS<0, 3cases). CONCLUSIONS NAION patients with low systolic blood pressure in the daytime, high diastolic blood pressure in the day and the night, reverse-dippers and non-dippers of the blood pressure curve, low morning blood pressure surge were all the possible risk factors damaging target organ, and further researches are needed.%目的 初步分析非动脉炎性前部缺血性视神经病变(non-arteritic anterior ischaemic optic neuropathy,NAION)患者的24h动态血压(ambulatory blood pressure monitoring,ABPM)特点.方法 选取NAION患者19例作为病例组,同期健康体检者19例作为正常对照组,分别记录其24h的收缩压、舒张压和平均动脉压,描绘其动态曲线并分类,分析血压晨峰情况.结果 19例NAION患者日间收缩压低于正常对照组(P<0.01),昼夜的舒张压均高于正常组(P<0.01);血压变化曲线中有7例为非勺型,其余均为反勺型;血压晨峰(morning blood pressure surge,MBPS)值>35mmHg者3例,≥10mmHg~<35mmHg者11例,≥0mmHg~<10mmHg者2例,<0mmHg者3例.结论 NAION患者的日间低收缩压、昼夜高舒张压、反勺型和非勺型血压曲线、低血

  8. Surface Figure Metrology for CELT Primary Mirror Segments

    Energy Technology Data Exchange (ETDEWEB)

    Sommargren, G; Phillion, D; Seppala, L; Lerner, S

    2001-02-27

    The University of California and California Institute of Technology are currently studying the feasibility of building a 30-m segmented ground based optical telescope called the California Extremely Large Telescope (CELT). The early ideas for this telescope were first described by Nelson and Mast and more recently refined by Nelson. In parallel, concepts for the fabrication of the primary segments were proposed by Mast, Nelson and Sommargren where high risk technologies were identified. One of these was the surface figure metrology needed for fabricating the aspheric mirror segments. This report addresses the advanced interferometry that will be needed to achieve 15nm rms accuracy for mirror segments with aspheric departures as large as 35mm peak-to-valley. For reasons of cost, size, measurement consistency and ease of operation we believe it is desirable to have a single interferometer that can be universally applied to each and every mirror segment. Such an instrument is described in this report.

  9. Segmentation by Large Scale Hypothesis Testing - Segmentation as Outlier Detection

    DEFF Research Database (Denmark)

    Darkner, Sune; Dahl, Anders Lindbjerg; Larsen, Rasmus;

    2010-01-01

    We propose a novel and efficient way of performing local image segmentation. For many applications a threshold of pixel intensities is sufficient but determine the appropriate threshold value can be difficult. In cases with large global intensity variation the threshold value has to be adapted lo...... segmentation of the corpus callosum. Comparing the methods corpus callosum segmentation to manual segmentation an average dice score of 0.86 is obtained over 40 images....

  10. Judging the quality of customer segments: segmentation effectiveness

    OpenAIRE

    Dibb, Sally; Simkin, Lyndon

    2010-01-01

    Market segmentation is well established in marketing theory and applied by organisations from all industry sectors. Despite widespread use, developing and implementing segmentation schemes is rarely problem free. Testing the quality and robustness of segments is one of the difficulties which marketers face. The literature describes segment quality criteria which are intended to help with this task, yet there is little evidence of their deployment and efficacy in practice. Using a longitudinal...

  11. Secondary anterior crocodile shagreen of Vogt.

    Science.gov (United States)

    Tripathi, R C; Bron, A J

    1975-01-01

    The clincopathological features and pathogenesis of secondary mosaic degeneration of the cornea (anterior crocodile shagreen of Vogt) are described. The structural basis for the normal anterior corneal mosaic pattern seems to lie in the particular arrangement of many prominent collagen lamellae of the anterior stroma that thake an oblique course to gain insertion into Bowman's layer. Since, at normal intraocular pressure, Bowman's layer is under tension, when viewed from the anterior surface the cornea appears smooth. By releasing the tension, however, a reproducible polygonal ridge pattern becomes manifest. It is suggested that a prolonged phthisical state of the eye is one condition wherein the mosaic pattern may become permanent and that, as a secondary event, this is followed by irregular calcification of Bowman's layer which particularly involves the ridges projecting into the epithelium. Biomicroscopically these ridges corresponded to the branching reticular arrangement of the mosaic opacities. Images PMID:1079137

  12. Anterior Cervical Discectomy and Fusion with Plating

    Medline Plus

    Full Text Available Anterior Cervical Discectomy and Fusion with Plating Broward Health Medical Center Fort Lauderdale, FL November 17, 2011 I'm Dr. Matthew Moore, head of the Spine Care Center here at North Broward Medical Center. And ...

  13. Development of a segmented grating mount system for FIREX-1

    International Nuclear Information System (INIS)

    A mount system for segmented meter-sized gratings has been developed, which has a high precision grating support mechanism and drive mechanism to minimize both deformation of the optical surfaces and misalignments in setting a segmented grating for obtaining sufficient performance of the pulse compressor. From analytical calculations, deformation of the grating surface is less than 1/20 lambda RMS and the estimated drive resolution for piston and tilt drive of the segmented grating is 1/20 lambda, which are both compliant with the requirements for the rear-end subsystem of FIREX-1

  14. Hemodynamic patterns of anterior communicating artery aneurysms: a possible association with rupture

    Science.gov (United States)

    Castro, Marcelo A.; Putman, Christopher M.; Cebral, Juan R.

    2007-03-01

    The aim of this study is to characterize the different flows present at anterior communicating artery (AcoA) aneurysms and investigate possible associations with rupture. For that purpose, patient-specific computational models of 26 AcoA aneurysms were constructed from 3D rotational angiography images. Bilateral images were acquired in 15 patients who had both A1 segments of the anterior cerebral arteries and models were created by fusing the reconstructed left and right arterial trees. Computational fluid dynamics simulations were performed under pulsatile flow conditions. Visualizations of the flow velocity pattern were created to classify the aneurysms into the following flow types: A) inflow from both A1 segments, B) flow jet in the parent artery splits into three secondary jets, one enters the aneurysm and the other two are directed to the A2 segments, C) the parent artery jet splits into two secondary jets, one is directed to one of the A2 segments and the other enters the aneurysm before being directed to the other A2 segment, and D) the parent artery jet enters the aneurysm before being directed towards the A2 segments. The maximum wall shear stress in the aneurysm at the systolic peak (MWSS) was calculated. Most aneurysms in group A were unruptured and had the lowest MWSS. Group B had the same number of unruptured and ruptured aneurysms, and a low MWSS. Groups C and D had high rupture ratios, being the average MWSS significantly higher in group C. Finally, it was found that the MWSS was higher for ruptured aneurysms of all flow types.

  15. Unsupervised Mammograms Segmentation

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Mikeš, Stanislav

    Los Alamitos : IEEE Press, 2008, s. 676-679. ISBN 978-1-4244-2174-9. [19th International Conference on Pattern Recognition. Tampa (US), 07.12.2008-11.12.2008] R&D Projects: GA AV ČR 1ET400750407; GA MŠk 1M0572; GA AV ČR IAA2075302 EU Projects: European Commission(XE) 507752 - MUSCLE Grant ostatní: GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : mammography * cancer detection * image unsupervised segmentation * Markov random fields Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2008/RO/haindl-unsupervised mammograms segmentation .pdf

  16. Segment fuel rods

    International Nuclear Information System (INIS)

    Purpose: To maintain the integrity of segment fuel rods without causing power spikes in adjacent fuel rods. Constitution: Power spikes are generated in the portions in adjacent with end plugs of segment fuel elements shielded welding zircaloy end plugs, because water/uranium ratio is locally increased due to the absence of pellets at the bonding end plugs to increase the neutron moderating effect thereby increasing the thermal neutron fluxes to rise the reactivity. This can be prevented most effectively by absorbing excess neutron absorbers. In view of the above, the purpose can be attained either by incorporating high neutron absorbing material at the bonding end plug, or constituting the bonding end plug itself with neutron absorbing material. (Kamimura, M.)

  17. Segmentation Using Symmetry Deviation

    DEFF Research Database (Denmark)

    Hollensen, Christian; Højgaard, L.; Specht, L.;

    2011-01-01

    the 10 hypopharyngeal cancer patients to find anatomical symmetry and evaluate it against the standard deviation of the normal patients to locate pathologic volumes. Combining the information with an absolute PET threshold of 3 Standard uptake value (SUV) a volume was automatically delineated. The...... overlap of automated segmentations on manual contours was evaluated using concordance index and sensitivity for the hypopharyngeal patients. The resulting concordance index and sensitivity was compared with the result of using a threshold of 3 SUV using a paired t-test. Results: The anatomical and...... overlap concordance index and sensitivity of respectively 0.43±0.15 and 0.56±0.18 was acquired. It was compared to the concordance index of segmentation using absolute threshold of 3 SUV giving respectively 0.41±0.16 and 0.51±0.19 for concordance index and sensitivity yielding p-values of 0.33 and 0...

  18. Scintillation counter, segmented shield

    International Nuclear Information System (INIS)

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  19. Market segmentation: Venezuelan ADRs

    Directory of Open Access Journals (Sweden)

    Urbi Garay

    2012-12-01

    Full Text Available The control on foreign exchange imposed by Venezuela in 2003 constitute a natural experiment that allows researchers to observe the effects of exchange controls on stock market segmentation. This paper provides empirical evidence that although the Venezuelan capital market as a whole was highly segmented before the controls were imposed, the shares in the firm CANTV were, through their American Depositary Receipts (ADRs, partially integrated with the global market. Following the imposition of the exchange controls this integration was lost. Research also documents the spectacular and apparently contradictory rise experienced by the Caracas Stock Exchange during the serious economic crisis of 2003. It is argued that, as it happened in Argentina in 2002, the rise in share prices occurred because the depreciation of the Bolívar in the parallel currency market increased the local price of the stocks that had associated ADRs, which were negotiated in dollars.

  20. Unsupervised Texture Segmentation

    OpenAIRE

    Haindl, Michal; Mikes, Stanislav

    2008-01-01

    We discussed three efficient and robust methods for unsupervised texture segmentation with unknown number of classes based on the underlying Markovian and GM texture models and their modifications for medical mammographics and remote sensing applications, respectively. Although these algorithm use the random field type models they are fast because they use efficient recursive or pseudo-likelihood parameter estimation of the underlying texture models and therefore they are much faster than the...

  1. Functional Outcomes of Primary Anterior Cruciate Ligament Reconstruction with Tibialis Anterior Allograft

    OpenAIRE

    Başar, Selda; Büyükafşar, Enes; Hazar, Zeynep; Ataoğlu, Baybars; Kanatlı, Ulunay

    2014-01-01

    Objectives: Allografts have potential advantages in primary anterior cruciate ligament reconstruction (ACLR), including the absence of donor site morbidity, shorter operative times, improved cosmesis, and easier rehabilitation. There is limited and conflicting outcome data for ACLR with tibialis anterior allograft. The purpose of this study was to evaluate the functional outcomes of ACLR with tibialis anterior allograft. Methods: We retrospectively evaluated patients underwent ACLR using with...

  2. Musical Sheet Segmentation

    Directory of Open Access Journals (Sweden)

    Vinaya V

    2014-05-01

    Full Text Available Music has had an important role in human life from time immemorial. Music has been shared in two ways aurally and as written documents known as musical notes or musical scores. Many ancient cultures have used musical symbols to represent melodies and lyrics but none of them is as comprehensive as a written language or document. Thus the knowledge of ancient music is limited to a few fragments which are mostly unpublished. Hence to preserve such music we need to introduce a computerized system to digitalize and to decode the musical symbol images and reconstruct it as new score which will be in machine readable format. Here the machine readable format is MIDI. Prior to converting the musical symbols into MIDI format, musical sheets need to be segmented for isolating the musical symbols. Since synthetically generated musical sheets are used here, the segmentation process can be carried out using recursive graph cut method. Here we discuss the initial few steps such as staff line removal, text removal and segmentation of musical sheet.

  3. LBP-Based Segmentation of Defocus Blur.

    Science.gov (United States)

    Xin Yi; Eramian, Mark

    2016-04-01

    Defocus blur is extremely common in images captured using optical imaging systems. It may be undesirable, but may also be an intentional artistic effect, thus it can either enhance or inhibit our visual perception of the image scene. For tasks, such as image restoration and object recognition, one might want to segment a partially blurred image into blurred and non-blurred regions. In this paper, we propose a sharpness metric based on local binary patterns and a robust segmentation algorithm to separate in- and out-of-focus image regions. The proposed sharpness metric exploits the observation that most local image patches in blurry regions have significantly fewer of certain local binary patterns compared with those in sharp regions. Using this metric together with image matting and multi-scale inference, we obtained high-quality sharpness maps. Tests on hundreds of partially blurred images were used to evaluate our blur segmentation algorithm and six comparator methods. The results show that our algorithm achieves comparative segmentation results with the state of the art and have big speed advantage over the others. PMID:26886995

  4. A Survey of Semantic Segmentation

    OpenAIRE

    Thoma, Martin

    2016-01-01

    This survey gives an overview over different techniques used for pixel-level semantic segmentation. Metrics and datasets for the evaluation of segmentation algorithms and traditional approaches for segmentation such as unsupervised methods, Decision Forests and SVMs are described and pointers to the relevant papers are given. Recently published approaches with convolutional neural networks are mentioned and typical problematic situations for segmentation algorithms are examined. A taxonomy of...

  5. Segmentation of Noisy Discrete Surfaces

    OpenAIRE

    Provot, Laurent; Debled-Rennesson, Isabelle

    2008-01-01

    International audience We propose in this paper a segmentation process that can deal with noisy discrete objects. A flexible approach considering arithmetic discrete planes with a variable width is used to avoid the over-segmentation that might happen when classical segmentation algorithms based on regular discrete planes are used to decompose the surface of the object. A method to choose a seed and different segmentation strategies according to the shape of the surface are also proposed.

  6. Market segmentation in behavioral perspective.

    OpenAIRE

    Wells, V.K.; Chang, S W; Oliveira-Castro, J.M.; J. Pallister

    2010-01-01

    A segmentation approach is presented using both traditional demographic segmentation bases (age, social class/occupation, and working status) and a segmentation by benefits sought. The benefits sought in this case are utilitarian and informational reinforcement, variables developed from the Behavioral Perspective Model (BPM). Using data from 1,847 consumers and from a total of 76,682 individual purchases, brand choice and price and reinforcement responsiveness were assessed for each segment a...

  7. Lesiones del ligamento cruzado anterior

    Directory of Open Access Journals (Sweden)

    Alejandro Álvarez López

    2015-01-01

    Full Text Available Fundamento: el ligamento cruzado anterior desempeña un papel muy importante en la estabili-dad de la rodilla. La incidencia de esta afección es alta en pacientes que practican deportes de contacto y de no ser tratados de forma adecuada, los resultados son desfavorables. Objetivo: profundizar en los factores necesarios para el tratamiento adecuado de enfermos con esta lesión y evitar las complicaciones. Método: se realizó una revisión bibliográfica de un total de 300 artículos publicados en Pubmed, Hinari y Medline mediante el localizador de información Endnote, de ellos se utilizaron 52 citas selecciona-das para realizar la revisión, 48 de ellas de los últimos cinco años donde se incluyeron seis libros. Desarrollo: se discuten los aspectos relacionados con el diagnóstico clínico e imaginológico. Se aborda la clasificación de esta lesión en cuanto a varios aspectos como: tiempo, lesión de ligamentos u ósea, aislada o combinada y parcial o total. Se mencionan los parámetros para obtener resultados satisfac-torios al considerar factores como la edad del enfermo, lesiones asociadas y tiempo de la lesión. Se relacio-nan los requisitos para la selección del implante y se mostró las ventajas y desventajas de cada tipo de in-jerto. Las complicaciones de esta cirugía están relacionadas con la técnica quirúrgica y médicas. Conclusiones: las lesiones del ligamento son entidades traumáticas que afectan por lo general a pacientes jóvenes. Para lograr un resultado satisfactorio en el tratamiento es necesario el conocimiento de su anatomía, clasificación, tipo de injerto a emplear según sus ventajas y desventajas.

  8. Market Segmentation for Information Services.

    Science.gov (United States)

    Halperin, Michael

    1981-01-01

    Discusses the advantages and limitations of market segmentation as strategy for the marketing of information services made available by nonprofit organizations, particularly libraries. Market segmentation is defined, a market grid for libraries is described, and the segmentation of information services is outlined. A 16-item reference list is…

  9. Segmenting the Adult Education Market.

    Science.gov (United States)

    Aurand, Tim

    1994-01-01

    Describes market segmentation and how the principles of segmentation can be applied to the adult education market. Indicates that applying segmentation techniques to adult education programs results in programs that are educationally and financially satisfying and serve an appropriate population. (JOW)

  10. Automatic segmentation method which divides a cerebral artery tree in time-of-flight MR-angiography into artery segments

    Science.gov (United States)

    Takemura, Akihiro; Suzuki, Masayuki; Harauchi, Hajime; Okumura, Yusuke; Umeda, Tokuo

    2006-03-01

    To achieve sufficient accuracy and robustness, 2D/3D registration methods between DSA and MRA of the cerebral artery require an automatic extraction method that can isolate wanted segments from the cerebral artery tree. Here, we described an automatic segmentation method that divides the cerebral artery tree in time-of-flight magnetic resonance angiography (TOF-MRA) into each artery. This method requires a 3D dataset of the cerebral artery tree obtained by TOF-MRA. The processes of this method are: 1) every branch in the cerebral artery tree is labeled with a unique index number, 2) the 3D center of the Circle of Willis is determined using 2D and 3D templates, and 3) the labeled branches are classified with reference to the 3D territory map of cerebral arteries centered on the Circle of Willis. This method classifies all branches into internal carotid arteries (ICA), basilar artery (BA), middle cerebral artery (MCA), a1 segment of anterior cerebral artery (ACA(A1)), other segments of the anterior cerebral artery (ACA), posterior communication artery (PcomA), and posterior cerebral artery (PCA). In the eleven cases examined, the numbers of correctly segmented pixels in each branch were counted and the percentages based on the total number of pixels of the artery were calculated. Manually classified arteries of each case were used as references. Mean percentages were: ACA, 87.6%; R-ACA(A1), 44.9%; L-ACA(A1), 30.4%; R-MC, 82.4%; L-MC, 79.0%; R-PcomA, 0.5%; L-PcomA, 0.0%; R-PCA, 77.2%; L-PCA, 80.0%; R-ICA, 78.6%; L-ICA, 93.05; BA, 77.1%; and total arteries, 78.9%.

  11. Comparison of properties of segmented copolyetheresteramides containing uniform aramid segments with commercial segmented copolymers

    NARCIS (Netherlands)

    Niesten, M.C.E.J.; Gaymans, R.J.

    2001-01-01

    The thermal (using differential scanning calorimetry), dynamic mechanical (using a dynamic mechanical analyzer), and mechanical properties of segmented copolyetheresteramides with aramid units of uniform length (TT) and poly(tetramethylene oxide) (PTMO) segments were compared to those of commercial

  12. Shape-Memory Properties of Segmented Polymers Containing Aramid Hard Segments and Polycaprolactone Soft Segments

    OpenAIRE

    Arno Kraft; Louis Garnier; Lechmann, Maria C.; Christian Schuh; Kerstin Schuh

    2010-01-01

    A series of segmented multiblock copolymers containing aramid hard segments and extended polycaprolactone soft segments (with an Mn of 4,200 or 8,200 g mol–1) was prepared and tested for their shape-memory properties. Chain extenders were essential to raise the hard segment concentration so that an extended rubbery plateau could be observed. Dynamic mechanical thermal analysis provided a useful guide in identifying (i) the presence of a rubbery plateau, (ii) the flow temperature, and (iii) th...

  13. SEGMENTATION USING MULTISCALE MORPHOLOGICAL RECONSTRUCTION

    Directory of Open Access Journals (Sweden)

    NANMOZHI.R

    2013-04-01

    Full Text Available Image segmentation is a crucial step in the field of image processing and pattern recognition. Segmentation allows the identification of structures in an image which can be utilized for further processing. This paper proposes a technique for object segmentation from its background. We utilized both region-based and object-based segmentation capabilities to handle the object segmentation for large-scale database images in a robust and principled manner. MultiScalE Graylevel mOrphological recoNstructions (SEGON is used for segmenting an image. SEGON roughly identifies the background and object regions in the image. To further refine the boundaries of the objects mean-shift segmentation technique is applied on the SEGON processed image. Accuracy of segmentation is evaluated by computing structural similarity index (SSIM, for the image segmented with and without using SEGON. Images collected from Corel, Caltech, PASCAL, UCID and CMU-PIE databases are utilized for this work. Experimental results showed that the proposed object segmentation method outperforms the state-of-the-art image segmentation techniques.

  14. Segmentation of Unstructured Datasets

    Science.gov (United States)

    Bhat, Smitha

    1996-01-01

    Datasets generated by computer simulations and experiments in Computational Fluid Dynamics tend to be extremely large and complex. It is difficult to visualize these datasets using standard techniques like Volume Rendering and Ray Casting. Object Segmentation provides a technique to extract and quantify regions of interest within these massive datasets. This thesis explores basic algorithms to extract coherent amorphous regions from two-dimensional and three-dimensional scalar unstructured grids. The techniques are applied to datasets from Computational Fluid Dynamics and from Finite Element Analysis.

  15. Floating anterior lens capsule: an unusual case of true exfoliation

    OpenAIRE

    Riffle, John

    2010-01-01

    A rare case of delamination and replication of the anterior lens capsule into prominent floating folds in the anterior chamber approximately 55 years after a penetrating injury to the eye and anterior lens capsule is reported. Classically, true exfoliation of the anterior lens capsule has been reported in individuals who have been exposed to intense heat over a prolonged period. However, more recently cases of true exfoliation of the anterior lens capsule have been reported in patients who ha...

  16. Assessment of Optic Nerve Impairment in Patients with Neuromyelitis Optica by MR Diffusion Tensor Imaging.

    Directory of Open Access Journals (Sweden)

    Zhiye Chen

    Full Text Available Diffusion tensor imaging (DTI has been used for the evaluation of the white matter integrity. In this study, we evaluated optic nerve impairment in patients with neuromyelitis optica (NMO using DTI.Optic nerve DTI were performed on 28 NMO patients and 38 normal controls. Fractional anisotropy (FA values were measured in the anterior, middle, and posterior parts of the intraorbital optic nerve segment. For the posterior intraorbital optic nerve, FA values of BI (0.20±0.07, MI (0.24±0.16, and NA (0.25±0.14 decreased significantly compared with that of NC (0.43±0.07 (P<0.05, and ROC analysis demonstrated that the area under the curve (AUC measurements for BI vs. NC, MI vs. NC, NA vs. NC, and NMO (including BI, MI, and NA vs. NC were 0.99, 0.93, 0.88, and 0.96, respectively. The corresponding diagnostic sensitivities of ROC analysis were 100%, 80%, 80%, and 91%; and the specificities were 93%, 97%, 91%, and 93%.Decreased FA value in the intraorbital optic nerve, especially in the posterior part of the nerve, was demonstrated as a characteristic MR feature for NMO-related optic nerve impairment.

  17. Clinical outcomes of pars plicata anterior vitrectomy: 2-year results

    Directory of Open Access Journals (Sweden)

    Priya Narang

    2015-01-01

    Full Text Available Purpose: To demonstrate the safety and outcome of a surgical approach that uses pars plicata site for anterior vitrectomy during phacoemulsification procedure complicated by posterior capsule rupture and residual cortical matter. Design: Single center, retrospective, interventional, noncomparative study. Materials and Methods: Medical records of a consecutive series of 35 eyes of 35 patients who underwent pars plicata anterior vitrectomy (PPAV were reviewed. The main outcome measures were corrected and uncorrected distance visual acuity (CDVA, UDVA, early and late postoperative complications and intraocular pressure (IOP. Ultrasound biomicroscopic (UBM evaluation of sclerotomy site and spectral domain optical coherence tomography analysis for central macular thickness (CMT was performed. The final visual outcome at 2 years was evaluated. Results: At 2 years follow-up, the mean postoperative UDVA (logarithm of the minimum angle of resolution [logMAR] and CDVA (logMAR was 0.49 ± 0.26 and 0.19 ± 0.14, respectively. There was no significant change in the IOP (P = 0.061 and the mean CMT at 2 years was 192.5 ± 5.54 mm. The postoperative UBM image of the sclerotomy site at 8 weeks demonstrated a clear wound without any vitreous adhesion or incarceration. Intraoperative hyphema was seen in 1 (2.8% case and postoperative uveitis was seen in 2 (5.7% cases, which resolved with medications. No case of an iatrogenic retinal break or retinal detachment was reported. Conclusions: PPAV enables a closed chamber approach, allows thorough cleanup of vitreous in the pupillary plane and anterior chamber and affords better access to the subincisional and retropupillary cortical remnant with a significant visual outcome and an acceptable complication rate.

  18. Aphasia following anterior cerebral artery occlusion

    International Nuclear Information System (INIS)

    We have report two cases of aphasia that had infarcts in the distribution of the left or right anterior cerebral artery, as confirmed by computed tomography. Case 1 is a right-handed, 65-year-old man in whom computerized tomographic scanning revealed an infarction of the territory of the left anterior cerebral artery after the clipping of the anterior communicating artery aneurysm. The standard language test of aphasia (SLTA) revealed non-fluent aphasia with dysarthria, good comprehension, almost normal repetition with good articulation, and a defectiveness in writing. This syndrome was considered an instance of transcortical motor aphasia. Although three years had passed from the onset, his aphasia did not show any improvement. Case 2 is a 37-year-old man who is right-handed but who can use his left hand as well. He was admitted because of subarachnoid hemorrhage from an anterior communicating aneurysm. Because of postoperative spasm, an infarction in the distribution of the right anterior cerebral artery developed. He was totally unable to express himself vocally, but he could use written language quite well to express his ideas and had a good comprehension of spoken language. This clinical picture was considered that of an aphemia. After several weeks, his vocalization returned, but the initial output was still hypophonic. (J.P.N.)

  19. Superficial temporal artery to proximal posterior cerebral artery bypass through the anterior temporal approach

    Directory of Open Access Journals (Sweden)

    Satoru Takeuchi

    2015-01-01

    Full Text Available Background: The superficial temporal artery (STA to proximal posterior cerebral artery (PCA (P2 segment bypass is one of the most difficult procedures to perform because the proximal PCA is located deep and high within the ambient cistern. STA to proximal PCA bypass is usually performed through a subtemporal approach or posterior transpetrosal approach, and rarely through a transsylvian approach. The aim of this study was to describe the operative technique of STA to proximal PCA bypass through a modified transsylvian approach (anterior temporal approach. Methods: STA to proximal PCA bypass was performed through an anterior temporal approach in three patients with intracranial aneurysm. We describe the details of the surgical technique. Results: The STA was successfully anastomosed to the proximal PCA in all cases. One patient suffered hemiparesis and aphasia due to infarction in the anterior thalamoperforating artery territory. Conclusions: STA to proximal PCA bypass can be performed through an anterior temporal approach in selected patients. We recommend that every precaution, including complete hemostasis, placement of cellulose sponges beneath the recipient artery to elevate the site of the anastomosis, and placement of a continuous drainage tube at the bottom of the operative field to avoid blood contamination during the anastomosis, should be taken to shorten the temporary occlusion time.

  20. SEPTO-OPTICDYSPLASIA WITH AN ANTERIOR ENCEPHALOCELE AND INTACT SEPTUM PELLUCIDUM: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Z. Razavi

    2008-06-01

    Full Text Available ObjectiveThe diagnosis of de Morsier syndrome or septo-optic dysplasia is made on the basis of the diagnosis of optic nerve hypoplasia. Septo-optic dysplasia is defined by a variable combination of dysgenesis of midline brain structures including optic nerve hypoplasia and hypothalamic-pituitary dysfunction often associated with a wide variety of brain malformations of cortical development.The importance of direct ophthalmoscopy of optic nerve abnormalities is stressed, as well as of magnetic resonance imaging, which has become a guideline in the classification of  this syndrome This article reports a 19-year-old female with bilateral optic nerve  hypoplasia,anterior encephalocele and intact septum pellucidum. She was diagnosed withdiabetes insipidus, short stature and the history of seizure.