Mesiodistal tooth angulation to segmental occlusal plane in panoramic radiography
International Nuclear Information System (INIS)
Kim, Jae Duk; Kim, Jin Soo; You, Choong Hyun
2005-01-01
To evaluate the stability of the segmental occlusal plane and anatomical line as the reference line for measuring the mesiodistal tooth angulation in panoramic radiography and to determine the mean angle and the range of the mesiodistal tooth angulation in Korean population with normal occlusions. Twenty nine subjects (15 men, 14 women) with normal occlusion were selected. A total of 29 panoramic radiograms were taken at normal head position and then 10 images of 5 subjects selected were repeatedly taken with repositioning 2 times at each of the head down (V-shaped occlusion) and up (horizontal occulsion) for evaluation of stability of adopted reference lines by using PM2002CC (Planmeca, Finland). The images were traced with adoption of two test reference lines and the long axes of the teeth. The mesial angles formed by each reference line and the long axes of the teeth were measured and analyzed. With anatomical reference line, the mesiodistal tooth angulations of the molars showed the significant difference by over 5 degree between the normal and each changed head position. With segmented occlusal reference line, deviations of mesiodistal tooth angulations by the two changed head positions were less than 1 degree. The means, standard deviations, and maximum and minimum values of mesiodistal tooth angulations to segmental occlusal reference line on panoramic radiography were determined. It would appear that mesiodistal tooth angulations to segmental occlusal plane as reference line in panograms are predictable as standards of normal occlusion and useful for evaluation of tooth arrangement between adjacent teeth.
Mesiodistal tooth angulation to segmental occlusal plane in panoramic radiography
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Kim, Jae Duk; Kim, Jin Soo; You, Choong Hyun [Chosun University College of Medicine, Kwangju (Korea, Republic of)
2005-03-15
To evaluate the stability of the segmental occlusal plane and anatomical line as the reference line for measuring the mesiodistal tooth angulation in panoramic radiography and to determine the mean angle and the range of the mesiodistal tooth angulation in Korean population with normal occlusions. Twenty nine subjects (15 men, 14 women) with normal occlusion were selected. A total of 29 panoramic radiograms were taken at normal head position and then 10 images of 5 subjects selected were repeatedly taken with repositioning 2 times at each of the head down (V-shaped occlusion) and up (horizontal occulsion) for evaluation of stability of adopted reference lines by using PM2002CC (Planmeca, Finland). The images were traced with adoption of two test reference lines and the long axes of the teeth. The mesial angles formed by each reference line and the long axes of the teeth were measured and analyzed. With anatomical reference line, the mesiodistal tooth angulations of the molars showed the significant difference by over 5 degree between the normal and each changed head position. With segmented occlusal reference line, deviations of mesiodistal tooth angulations by the two changed head positions were less than 1 degree. The means, standard deviations, and maximum and minimum values of mesiodistal tooth angulations to segmental occlusal reference line on panoramic radiography were determined. It would appear that mesiodistal tooth angulations to segmental occlusal plane as reference line in panograms are predictable as standards of normal occlusion and useful for evaluation of tooth arrangement between adjacent teeth.
Yosano, Akira; Katakura, Akira; Takaki, Takashi; Shibahara, Takahiko
2009-05-01
In this study, we investigated how method of mandibular fixation influenced longterm postoperative stability of the maxilla in Class III cases. In particular, we investigated change in the maxillary occlusal plane after Occlusal Plane Alteration. Therefore, we focused on change in the palatal plane to evaluate stability of the maxillary occlusal plane, as the position of the palatal plane affects the maxillary occlusal plane. This study included 16 patients diagnosed with mandibular protrusion. Alteration of the occlusal plane was achieved by clockwise rotation of the maxilla by Le Fort I osteotomy and mandibular setback was performed by bilateral sagittal split ramus osteotomy. We analyzed and examined lateral cephalometric radiographs taken at 1 month, 3 months, 6 months, and 1 year after surgery. Stability achieved by two methods of mandibular fixation was compared. In one group of patients (group S) titanium screws were used, and in the other group (group P) titanium-locking mini-plates were used. No significant displacement was recognized in group S, whereas an approximately 0.7mm upward vertical displacement was recognized in the anterior nasal spine in group P. As a result, not only the angle of the palatal plane and S-N plane, but also occlusal plane angle in group P showed a greater decrease than that in group S. The results suggest that fixing the mandible with screws yielded greater stability of the maxilla and maxillary occlusal plane than fixing the mandible with titanium plates.
Occlusal plane location in edentulous patients: a review.
Shetty, Sanath; Zargar, Nazia Majeed; Shenoy, Kamalakanth; Rekha, V
2013-09-01
Occlusal plane orientation is an important factor in the construction of a complete denture. Occlusal plane could be oriented using landmarks in the mandibular arch as well as in the maxillary arch. In the mandibular arch there are few landmarks which could be used to orient the occlusal plane like the retromolar pad, corner of the lips (lower lip length) whereas the maxillary arch has a number of landmarks, of which the ala-tragal line is the most commonly used and the same being the most controversial. In the following article different landmarks and its accuracy for orientating the occlusal plane in an edentulous subject as studied by various authors has been discussed.
A study of parallelism of the occlusal plane and ala-tragus line.
Sadr, Katayoun; Sadr, Makan
2009-01-01
Orientation of the occlusal plane is one of the most important clinical procedures in prostho-dontic rehabilitation of edentulous patients. The aim of this study was to define the best posterior reference point of ala-tragus line for orientation of occlusal plane for complete denture fabrication. Fifty-three dental students (27 females and 26 males) with complete natural dentition and Angel's Class I occlusal relationship were selected. The subjects were photographed in natural head position while clenching on a Fox plane. After tracing the photographs, the angles between the following lines were measured: the occlusal plane (Fox plane) and the superior border of ala-tragus, the occlusal plane (Fox plane) and the middle of ala-tragus as well as the occlusal plane (Fox plane) and the inferior border of ala-tragus. Descriptive statistics, one sample t-test and independent t-test were used. P value less than 0.05 was considered significant. There was no parallelism between the occlusal plane and ala-tragus line with three different posterior ends and one sample t-test showed that the angles between them were significantly different from zero (pplane. The superior border of the tragus is suggested as the posterior reference for ala-tragus line.
A cephalometric study to determine the plane of occlusion in completely edentulous patients.
Hindocha, Amit D; Vartak, Vikas N; Bhandari, Aruna J; Dudani, Mohit T
2013-01-01
Determination of the plane of occlusion in completely edentulous patients with the help of the ala-tragus line (Camper's plane) may be questioned. An attempt to devise an alternative method to determine the orientation of the plane of occlusion was made. Cephalometric analysis was used to identify whether a correlation exists between the plane of occlusion of dentulous Indian individuals and other stable cranial landmarks. A negative correlation was found to exist between the occlusal Plane-FH plane angle and the porion-nasion-anterior nasal spine (PoNANS) angle. From the derived mathematical correlation, it was concluded that the angulation of the occlusal plane in completely edentulous subjects may be determined by taking a cephalogram at the diagnostic stage. Further, the clinical applicability of the derived mathematical formula (while determining the plane of occlusion) was tested on completely edentulous patients.
Al Quran, Firas A M; Hazza'a, Abdalla; Al Nahass, Nabeel
2010-12-01
This study aimed at determining the most reliable ala-tragus line as a guide for the orientation of the occlusal plane in complete denture patients by use of cephalometric landmarks on dentate volunteers. Analysis was made for prosthodontically related craniofacial reference lines and angles of lateral cephalometric radiographs taken for 47 dentate adults. Variables were determined and data were analyzed using SPSS (SPSS, Inc., Chicago, IL). Occlusal plane angle formed between the occlusal plane and Camper's plane had the lowest mean value in the angle formed with Camper's I, which represents the measure taken from the superior border of the tragus of the ear with a score of 2.1°. The highest was measured in the angle formed with Camper's III with a score of 6.1°, while the angle formed with Camper's II was 3.2°. The differences between the three planes in relation to the occlusal plane was significant (p < 0.001). The superior border of the tragus with the inferior border of the ala of the nose was most accurate in orienting the occlusal plane. © 2010 by The American College of Prosthodontists.
[A cephalometric study on determining the orientation of occlusal plane].
Xie, J; Zhao, Y; Chao, Y; Luo, W
1993-12-01
A study of the parallel relationship between the occlusal plane and the line connecting nasal alar and tragus was made in 90 dentulous cases by using cephalometry. The results show that the line connecting the inferior point of nasal alar and the mid-point of tragus runs much more parallel with the occlusal plane. The regression equation reveals a "line of closest fitting". It was used in the prosthetic treatment for 50 edentulous patients with good clinical results. The line connecting the inferior point of nasal alar and the mid-point of tragus therefore represents a proper reference plane for determining occlusal plane and hence should be still a valuable index in clinical dentistry.
DEFF Research Database (Denmark)
Blæhr, Tue Lindberg; Jensen, Thomas; Due, Karen Margrethe
2014-01-01
OBJECTIVES: To assess the short term dental and skeletal stability of the anterior maxillary segment after segmental Le Fort I osteotomy with postoperative skeletal elastic fixation with or without occlusal splint. MATERIAL AND METHODS: 29 consecutive patients underwent segmental Le Fort I...... osteotomy and elastic skeletal fixation was applied. Patients were divided into two groups according to whether a fixed occlusal splint was used for six weeks (group A) or dismounted perioperatively (group B). Changes in landmarks and reference planes between the two timepoints were estimated on lateral.......83 to 1.69°). There was no statistically significant difference in stability between the two groups at the P value 0.05. CONCLUSIONS: The skeletal anterior fixation with postoperative elastics for eight weeks may not compromise the early postoperative dental and skeletal stability of the anterior segment...
Williamson, Richard A; Williamson, Anne E; Bowley, John; Toothaker, Randy
2004-03-01
The stability of mandibular complete dentures may be improved by reducing the transverse forces on the denture base through linear (noninterceptive) occlusion, selecting an occlusal plane that reduces horizontal vectors of force at occlusal contact, and utilizing a central bearing intraoral gothic arch tracing to record jaw relations. This article is intended to acquaint the reader with one technique for providing stable complete denture prostheses using the aforementioned materials, devices, and procedures.
Occlusal plane rotation: aesthetic enhancement in mandibular micrognathia.
Rosen, H M
1993-06-01
Patients afflicted with extreme degrees of mandibular micrognathia typically have vertically deficient rami as well as sagittally deficient mandibular bodies. This results in deficient posterior facial height, an obtuse gonial angle, excessively steep occlusal and mandibular planes, and a compensatory increase in anterior facial height. The entire maxillomandibular complex is overrotated in a clockwise direction. Standard orthognathic surgical correction fails to address this rotational deformity. As a consequence, the achieved projection of the lower face is inadequate, posterior facial height is further reduced, and occlusal and mandibular planes remain steep. Eleven patients with severe mandibular micrognathia underwent a surgical correction involving occlusal plane rotation to its normal orientation relative to Frankfort horizontal. This was accomplished by Le Fort I osteotomy to shorten the anterior maxilla (creating open bites in seven patients and making preexisting open bites worse in four patients) and sagittal split ramus osteotomies to advance and rotate the mandibular body counterclockwise, thus closing the surgically produced open bite. Counterclockwise rotation of the mandible afforded significantly greater sagittal displacement at the B point (mean 17 mm) than at the first molar (mean 10 mm) and produced adequate degrees of projection of the lower face when accompanied by a modest sliding genioplasty (mean 6.9 mm). Total advancement at the pogonion was a mean of 25.2 mm. In addition, posterior facial height was preserved, and mandibular and occlusal planes were normalized to mean angles of 27 and 10 degrees, respectively. At follow-up, which ranged from 9 to 24 months with a mean of 14.1 months, the mean sagittal relapse at the B point was 1.9 mm. Although heretofore considered unstable and therefore not clinically accepted, maxillomandibular counterclockwise rotation to normalize the occlusal plane rotational deformity provides stable, aesthetically
Esthetic smile preferences and the orientation of the maxillary occlusal plane.
Kattadiyil, Mathew T; Goodacre, Charles J; Naylor, W Patrick; Maveli, Thomas C
2012-12-01
The anteroposterior orientation of the maxillary occlusal plane has an important role in the creation, assessment, and perception of an esthetic smile. However, the effect of the angle at which this plane is visualized (the viewing angle) in a broad smile has not been quantified. The purpose of this study was to assess the esthetic preferences of dental professionals and nondentists by using 3 viewing angles of the anteroposterior orientation of the maxillary occlusal plane. After Institutional Review Board approval, standardized digital photographic images of the smiles of 100 participants were recorded by simultaneously triggering 3 cameras set at different viewing angles. The top camera was positioned 10 degrees above the occlusal plane (camera #1, Top view); the center camera was positioned at the level of the occlusal plane (camera #2, Center view); and the bottom camera was located 10 degrees below the occlusal plane (camera #3, Bottom view). Forty-two dental professionals and 31 nondentists (persons from the general population) independently evaluated digital images of each participant's smile captured from the Top view, Center view, and Bottom view. The 73 evaluators were asked individually through a questionnaire to rank the 3 photographic images of each patient as 'most pleasing,' 'somewhat pleasing,' or 'least pleasing,' with most pleasing being the most esthetic view and the preferred orientation of the occlusal plane. The resulting esthetic preferences were statistically analyzed by using the Friedman test. In addition, the participants were asked to rank their own images from the 3 viewing angles as 'most pleasing,' 'somewhat pleasing,' and 'least pleasing.' The 73 evaluators found statistically significant differences in the esthetic preferences between the Top and Bottom views and between the Center and Bottom views (Pgender, profession, and race. The esthetic preference for the maxillary occlusal plane was influenced by the viewing angle with the
Functional Aesthetic Occlusal Plane (FAOP)
Câmara, Carlos Alexandre; Martins, Renato Parsekian
2016-01-01
ABSTRACT Introduction: A reasonable exposure of incisors and gingival tissues is generally considered more attractive than excess or lack of exposure. A reasonable gingival exposure is considered to be around 0 to 2 mm when smiling and 2-4 mm exposure of the maxillary incisor edge when the lips are at rest. Objective: The aim of this paper is to present the Functional Aesthetic Occlusal Plane (FAOP), which aims to help in the diagnosis of the relationships established among molars, incisors...
Use of digital photography in the reconstruction of the occlusal plane orientation
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Robert Antonić,
2009-08-01
Full Text Available Aim This study evaluated whether the occlusal plane measurementson digital photographs were reliable for the reconstructionof occlusal plane.Methods Forty-two subjects (25 female and 17 male subjects,aged 19 to 30 years with all teeth and Angle Class I participated.Irreversible hydrocolloid impressions were made and the castswere poured in dental stone (ISO Type I and finally mounted inthe S.A.M. 2 “P”, articulator (S.A.M. Praezisiontechnik, GmbH,Munich, Germany by a quick mount face-bow transfer. Lateraldigital photographs were taken from a distance of 1.5 m in a naturalhead position with a subject in erect posture. A Fox plane wasplaced over the maxillary dental arch. A quick-mounting face-bowwas positioned. The angles between the articulator horizontalplane and the occlusal plane (AHP-OP, as well as those betweenthe face bow and the Fox plane (FB-FP were measured, and thesignificance of the difference between the means was tested by thet-test (p<0.05.Results The mean value of AHP-OP angle was 8.56 ± 3.1 degreesand the mean value of FB-FP angle was 8.80 ± 4.2 degrees. Therewas no significant difference between the male and the female subjects(p<0.05. There was no significant difference between AHPOPand FB-FP angles (p<0.05.Conclusion Measurements of occlusal plane inclination fromdigital photographs could be helpful in future prosthodontic reconstructiontreatment.
Treatment of Class III malocclusion: the key role of the occlusal plane.
Raymond, Jean-Louis; Matern, Olivier; Grollemund, Bruno; Bacon, William
2010-01-01
Patients with a Class III malocclusion generally present with a counterclockwise inclination of the occlusal plane, converging with Camper's line towards the front. This slope has an effect on mandibular movement (forward posture) and on chewing mechanisms in general. As dysfunctional mastication is likely to influence facial growth and inter-arch stability negatively, early orthopedic therapy of the occlusal unbalance concurrent with Class III malocclusion is justified. The aim of this article is to present a method of Class III treatment based on a correct re-orientation of the occlusal plane in order to achieve an optimal masticatory mechanism, essential for stability of early treatment outcomes. Copyright © 2010 Società Italiana di Ortodonzia (SIDO). Published by Elsevier Srl. All rights reserved.
DEFF Research Database (Denmark)
Jørgensen, B; Tønnesen, K H; Nielsen, J D
1991-01-01
Segmentally enclosed thrombolysis (SET) was performed immediately following 34 percutaneous transluminal angioplasties (PTAs) for femoropopliteal occlusions. The dilated segment was sealed off with a double balloon catheter, and recombinant tissue plasminogen activator (rt-PA) 1 mg/ml and heparin...
A cephalometric study to determine the plane of occlusion in completely edentulous patients: part I.
Hindocha, Amit D; Vartak, Vikas N; Bhandari, Aruna J; Dudani, Mohit
2010-12-01
To determine the relationship between the plane of occlusion and the Camper's line (ala-tragus line). Lateral cephalograms of 105 dentulous subjects were obtained after outlining the tragus and the base of the ala of the nose with radiopaque markers. Tracings of the cephalograms were done and the relationship between the plane of occlusion and the Camper's line (ala-tragus line) was noted. The most common tragal reference as a posterior landmark for determination of plane of occlusion was found to be below inferior (in 30.48% of subjects), and inferior (in 24.76% of subjects). The least common tragal reference was found to be above superior (in 3.82% of subjects) followed by superior of tragus and the point between superior and middle of the tragus (in 6.66% of subjects). The tragal reference in this study population was more towards the inferior of the tragus, with most of the times being below the inferior border. Therefore, the orientation of the plane of occlusion using the superior of tragus as a posterior landmark (according to the widely accepted definition of Camper's line) may be considered to be questionable. Further, the use of the tragus as a posterior landmark for the orientation of the plane of occlusion may be questioned on the basis of the findings of this study.
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M GHOREYSHIAN
2002-09-01
Full Text Available Introduction. Pain and the need for controlling it is a determinant factor in dental treatment procedures. One of the most common methods of local anesthesia in mandibular area is infra alveolar nerve block which has failure rate of 5% to 15%. The purpose of this study was to locate the optimal needle entrance point in order to achieve a fast, deep and durable anesthesia with minimal anesthetic consumption. Methods. This cross-sectional study has been performed on 38 cadavers of Iranian males with approximate age of more than 17 years. old. They had normal occlusion and at least 2 molars in each quadrant of the mandible if a sample was edentulous in one quadrant of the mandible or in the opposite jaw; or when a severe tilt in mandi bular dentition was present and in the case of mandibular or condylar fracture, the sample was excluded from the study. Distance between lingual and occlusal plane was measured by a device with two parallel plates. The precision of the measurment was 1mm. Data was analysed by the use of SPSS software. Results. On the right side, the average distance between lingual and occlusal plane was 2.4 ± 4.4 (Mean ± SD and on the left side, was 2:r.4.4 which there was no significant difference between right and left sides (P value=0.9. Discussion. In this study the human body is used and the best point for entrance of the needle for inferior alveolar nerve block technique is located at 8mm above the occlusal plane. At this point the anesthetic solution will be evacuated in the nearest position to the inferior alveolar never.
Changes of occlusal plane inclination after orthodontic treatment in different dentoskeletal frames.
Li, Jin-le; Kau, Chung; Wang, Min
2014-06-25
The inclination of the occlusal plane (OP) is related to facial types and experiences physiological growth-related changes. The aims of this research were to determine if there were any differences in the inclination of OP in subjects with three types of skeletal malocclusion and to investigate the characteristics and differences of functional occlusal plane (FOP) compared to bisected occlusal plane (BOP). A sample of 90 Caucasians patients was skeletal-classified into three (n = 30), and pre- and post-treatment cephalograms were digitized. Six linear and 8 angular cephalometric measurements were selected. The changes of OP inclination within each group and the differences among the three groups pre- and post-treatment were compared with paired t test and ANOVA test, respectively. The comparison and correlation between BOP and FOP were analyzed with paired t test and coefficient of correlation, respectively. The BOP angle increased in all of the three groups but only had statistically significant differences in skeletal class II patients in a mean of 1.51° (p stability (p > 0.05) in all three groups. The inclination of FOP was closely related to that of BOP (p stability in orthodontically treated patients with all three skeletal patterns.
Sahoo, S; Singh, D; Raghav, D; Singh, G; Sarin, A; Kumar, P
2014-05-01
Accurate occlusal plane orientation is an essential factor in the fabrication of complete denture prosthesis. Over the years, it has received a number of methodologies by several researchers utilizing various anatomical landmarks however none of them is considered as perfect that could orient ideal occlusal plane. The presented literature review is an attempt to enlighten historical perspectives, pioneer researches, different controversies, difficulties and current trends for re-establishment of lost occlusal plane in edentulous patients. An extensive literature search was performed using Medline/PubMed interface and other scholarly research bibliographic databases using Medical Subject Headings. Studies describing research studies, case series and assorted clinical reports were retrieved and evaluated from 1963 to 2013. Most of the studies have suggest and evidence to consider Camper's plane for artificial orientation of occlusal plane however there is a substantial lack of genuine long term studies and authentic data that could recommend a single reliable landmark for perfect occlusal plane reorientation in a variety of cases.
Yoon, Stephan S; Cheong, Chan; Preisser, John; Jun, Sangho; Chang, Brian M; Wright, Robert F
2014-08-01
Total occlusal convergence of crown preparation is an important didactic and clinical concept in dental education. The purpose of this study was to compare the discrepancy between the total occlusal convergence of dental students' typodont crown preparations and the ideal range (4 to 10 degrees) in 3 different regions of the mouth and in 4 different planes of the teeth. The dental students of the Class of 2012 at Harvard School of Dental Medicine were asked to prepare typodont teeth for crowns on 3 different teeth, the maxillary left central incisor (ceramic), mandibular left first molar (complete metal), and mandibular left first premolar (metal ceramic), during their third year preclinical summative examination and the Comprehensive Clinical Examination in their fourth year. Eighteen students prepared 3 teeth in their third and fourth years, whereas 19 students participated only in their fourth year, for a total of 55 sets of 3 teeth. By using custom fit die bases to reproduce the position, a novel procedure of measuring each tooth was accomplished in 4 different planes: the faciolingual, mesiodistal, mesiofacial-distolingual, and mesiolingual-distofacial. The total occlusal convergence of each image was measured with a computer screen protractor. The gingival 2 mm of the axial wall was used to determine the taper of each wall. Linear mixed model analysis was used to estimate and compare the total occlusal convergences of different teeth and planes (α=.05). Bonferroni corrections were used to adjust for post hoc multiple comparisons. The mean total occlusal convergence varied by tooth and plane (2-way interaction; Pplanes; the model-predicted 99% CIs for the total occlusal convergence were as follows: faciolingual (12.7, 19.4), mesiodistal (14.0, 19.3), mesiofacial-distolingual (13,4, 19.4), and mesiolingual-distofacial (13.7, 19.1). For the central incisor, 99% CIs for the total occlusal convergence were (15.9, 24.4) for the faciolingual measurement, providing
Mesiodistal angulation of the lateral teeth to the functional occlusal plane in normal occlusions
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Hiroshi Ueda
2016-01-01
Full Text Available Introduction: Crowding is a malocclusion with irregularly positioned teeth caused by arch length discrepancy (ALD. Its incidence is high compared with the various malocclusions. In a previous study the crowns of the maxillary lateral teeth had erupted mesially in relation to the functional occlusal plane (FOP in patients with Angle Class I malocclusion and highly erupted canines, which had been uprighted by non-extraction orthodontic treatment, yet these results were based on only two cases evaluated by using plaster models. Therefore, the aim of this study was to assess the mesiodistal angulations of both maxillary and mandibular teeth relative to the FOP in normal occlusion by means of cephalograms and identifying the teeth axial factors contributing to the normal dentitions with the least ALD. Materials and Methods: Thirty Japanese young adult patients (6 males, 24 females with normal occlusion were selected to participate in this study; cephalograms were procured from each and the FOP was used as a reference plane for measuring the changes in the axial angulation along with other indicators of vertical growth. Results: Progressive mesial tipping of the maxillary lateral teeth was observed. First premolars tended to express this more than the second premolars but the tipping values were roughly 90° relative to the FOP on the first molars. Conclusion: The maxillary lateral teeth are more mesially angulated compared to the mandibular ones relative to the FOP. Furthermore, progressive mesial tipping of the maxillary lateral teeth was detected, of which axial angulations were significantly correlated to each other, in spite the mandibular premolars and molars being angulated in a similar fashion.
[Occlusal plane control in hyperdivergents: regarding one case].
Rerhrhaye, Wiam; Zaoui, Fatima; Aalloula, El Housseine
2009-06-01
Management of occlusal plane inclination in the sagittal dimension is one of the main concerns of practitioners. Inclination maintenance or correction can condition the success and stability of treatment. By means of a clinical case, we will attempt to discuss the different aspects of management from diagnosis to treatment, bearing in mind the local and regional context. The adopted treatment plan takes into consideration the functional and esthetic issues specific to Moroccan patients without neglecting soft tissue harmony.
Farret, Marcel Marchiori; Farret, Milton M. Benitez
2016-01-01
ABSTRACT Introduction: A canted occlusal plane presents an unesthetic element of the smile. The correction of this asymmetry has been typically considered difficult by orthodontists, as it requires complex mechanics and may sometimes even require orthognathic surgery. Objective: This paper outlines the case of a 29-year-old woman with Class II malocclusion, pronounced midline deviation and accentuated occlusal plane inclination caused by mandibular deciduous molar ankylosis. Methods: The patient was treated with a miniplate used to provide anchorage in order to intrude maxillary teeth and extrude mandibular teeth on one side, thus eliminating asymmetry. Class II was corrected on the left side by means of distalization, anchored in the miniplate as well. On the right side, maxillary first premolar was extracted and molar relationship was kept in Class II, while canines were moved to Class I relationship. The patient received implant-prosthetic rehabilitation for maxillary left lateral incisor and mandibular left second premolar. Results: At the end of treatment, Class II was corrected, midlines were matched and the canted occlusal plane was totally corrected, thereby improving smile function and esthetics. PMID:27409658
Koller, M M; Merlini, L; Spandre, G; Palla, S
1992-07-01
The aim of this study was to compare two methods used to orientate the occlusal plane (OP) and to determine the vertical dimension of occlusion (VDO). In method A the VDO was established by means of the rest position, the minimal speaking distance, and the patient's profile. Method B used a newly developed registration pin assembly. The VDO was registered using a silicone occlusion rim and the swallowing technique. The results were compared to the values of the new dentures. Three standardized lateral radiographs were taken at the VDO obtained with methods A, B, and at that of the final dentures. On each radiograph the orientation of the OP to the Camper plane and the VDO were measured by two investigators independently. The results indicated no statistically significant differences between the mean VDO with method A and B compared with the new dentures (P greater than 0.05). With both methods it was not possible to orientate the OP parallel to the Camper plane. None of the occlusal planes of the new dentures were parallel either. Their OP diverged on average by 7 degrees dorso-caudally. The time spent with method B to orient the OP and to determine the VDO was significantly lower than with method A (17-50 min).
Blæhr, Tue Lindberg; Jensen, Thomas; Due, Karen Margrethe; Neumann-Jensen, Bjarne
2014-07-01
To assess the short term dental and skeletal stability of the anterior maxillary segment after segmental Le Fort I osteotomy with postoperative skeletal elastic fixation with or without occlusal splint. 29 consecutive patients underwent segmental Le Fort I osteotomy and elastic skeletal fixation was applied. Patients were divided into two groups according to whether a fixed occlusal splint was used for six weeks (group A) or dismounted perioperatively (group B). Changes in landmarks and reference planes between the two timepoints were estimated on lateral cephalometric radiographs. The upper incisor had a mean intrusion of -0.56 mm (SD 0.77; range -2.04 to 1.08 mm) and a mean posterior movement of -0.93 mm (SD 1.03; range -2.52 to 0.96 mm). The mean change in the axial inclination of the upper incisor was -0.33° (SD 2.56; range -6° to 4°) (95% CI: -1.75 to 1.08°). Group B: The upper incisor had a mean intrusion of -0.13 mm (SD 1.36; range -1.92 to 3.6 mm) and a mean anterior movement of 0.11 mm (SD 1.78; range -2.88 to 3.84 mm). The mean change in the axial inclination of the upper incisor was -0.07° (SD 3.05; range -5° to 5°) (95% CI: -1.83 to 1.69°). There was no statistically significant difference in stability between the two groups at the P value 0.05. The skeletal anterior fixation with postoperative elastics for eight weeks may not compromise the early postoperative dental and skeletal stability of the anterior segment in segmental Le Fort I osteotomy.
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Tue Lindberg
2014-10-01
Full Text Available Objectives: To assess the short term dental and skeletal stability of the anterior maxillary segment after segmental Le Fort I osteotomy with postoperative skeletal elastic fixation with or without occlusal splint. Material and Methods: 29 consecutive patients underwent segmental Le Fort I osteotomy and elastic skeletal fixation was applied. Patients were divided into two groups according to whether a fixed occlusal splint was used for six weeks (group A or dismounted perioperatively (group B. Changes in landmarks and reference planes between the two timepoints were estimated on lateral cephalometric radiographs. Results: Group A: The upper incisor had a mean intrusion of -0.56 mm (SD 0.77; range -2.04 to 1.08 mm and a mean posterior movement of -0.93 mm (SD 1.03; range -2.52 to 0.96 mm. The mean change in the axial inclination of the upper incisor was -0.33° (SD 2.56; range -6° to 4° (95% CI: -1.75 to 1.08°. Group B: The upper incisor had a mean intrusion of -0.13 mm (SD 1.36; range -1.92 to 3.6 mm and a mean anterior movement of 0.11 mm (SD 1.78; range -2.88 to 3.84 mm. The mean change in the axial inclination of the upper incisor was -0.07° (SD 3.05; range -5° to 5° (95% CI: -1.83 to 1.69°. There was no statistically significant difference in stability between the two groups at the P value 0.05. Conclusions: The skeletal anterior fixation with postoperative elastics for eight weeks may not compromise the early postoperative dental and skeletal stability of the anterior segment in segmental Le Fort I osteotomy.
International Nuclear Information System (INIS)
Smith, H.J.; Singh, B.N.; Norris, R.M.; John, M.B.; Hurley, P.J.
1975-01-01
The relationship between regional blood flow and epicardial S-T segment elevation was studied in 26 open-chest anesthetized dogs with left anterior coronary artery ligations. Changes in myocardial blood flow, measured with 15 +- 5 μ (diameter) microspheres labeled with 141 Ce, 85 Sr, and 169 Yb, were correlated with summated S-T segment elevations 15 minutes, 1 hour, and 2 hours after coronary artery occlusion. In normal areas, myocardial blood flow was 113 +- 5 ml/min 100 g -1 and summated S-T segment elevation was 0.3 +- 0.2 mv. Fifteen minutes after coronary artery occlusion in 26 dogs, S-T segment elevation was 5.7 +- 0.7 mv over the center of the infarct and myocardial blood flow was 10 +- 1 ml/min 100 g -1 ; over the border zone, myocardial blood flow was 63 +- 4 ml/min 100 g -1 and S-T segment elevation was 3.1 +- 0.1 mv. One third of the areas with a myocardial blood flow of 10 ml/min 100 g -1 or less had no S-T segment elevation. In the center and border zones of the infarct in 9 dogs, myocardial blood flow increased from 11 +- 2 and 67 +- 8 ml/min 100 g -1 15 minutes after occlusion to 20 +- 4 and 84 +- 12 ml/min 100 g -1 , respectively, 2 hours after coronary artery occlusion. These increases were not associated with a significant reduction in summated S-T segment elevation. The results do not suggest a simple quantitative relationship between epicardial S-T segment elevation and myocardial blood flow following acute coronary artery occlusion
Directory of Open Access Journals (Sweden)
NR Yuliawati Zenab
2009-07-01
Full Text Available The purpose of this study was to find out whether there were changes in occlusal plane inclination after fixed orthodontic treatment of bimaxillary protrusion cases where extraction of four first premolars was needed using the standard Edgewise appliances. The sample was fourteen orthodontic patients, aged above sixteen years old, no sexual discrimination, treated with fixed appliances at Orthodontic Specialist Clinic Faculty of Dentistry Universitas Padjadjaran. The method was a pre-post design which compared occlusal plane inclination obtained from tracings of lateral cephalograms before and after orthodontic treatment. The results were calculated with the paired t-test analysis. The study revealed that there were no significant changes in occlusal plane inclination after the orthodontic treatment.
Directory of Open Access Journals (Sweden)
Marcel Marchiori Farret
Full Text Available ABSTRACT Introduction: A canted occlusal plane presents an unesthetic element of the smile. The correction of this asymmetry has been typically considered difficult by orthodontists, as it requires complex mechanics and may sometimes even require orthognathic surgery. Objective: This paper outlines the case of a 29-year-old woman with Class II malocclusion, pronounced midline deviation and accentuated occlusal plane inclination caused by mandibular deciduous molar ankylosis. Methods: The patient was treated with a miniplate used to provide anchorage in order to intrude maxillary teeth and extrude mandibular teeth on one side, thus eliminating asymmetry. Class II was corrected on the left side by means of distalization, anchored in the miniplate as well. On the right side, maxillary first premolar was extracted and molar relationship was kept in Class II, while canines were moved to Class I relationship. The patient received implant-prosthetic rehabilitation for maxillary left lateral incisor and mandibular left second premolar. Results: At the end of treatment, Class II was corrected, midlines were matched and the canted occlusal plane was totally corrected, thereby improving smile function and esthetics.
Subintimal stent placement in patients with long segment occlusion of the iliac artery
Energy Technology Data Exchange (ETDEWEB)
Yu, Ho Jung; Kim, Young Hwan; Kim, Si Hyung; Ko, Sung Min; Choi, Jin Soo; Lee, Hyun Jin; Kim, Hyung Tae; Jo, Won Hyun [Dongsan Medical Center, Keimyung University College of Medicine, Daegu (Korea, Republic of); Kim, Yong Joo [Andong General Hospital, Andong (Korea, Republic of)
2008-01-15
We evaluated the technical feasibility and clinical efficacy of subintimal stent placement for long segment occlusion of the iliac artery. From March 2003 to February 2007, subintimal stent placement for long segment occlusion of the iliac artery of 24 limbs in 22 patients was analyzed retrospectively. Endovascular access was performed via the ipsilateral femoral artery in 7 cases, via the contralateral femoral artery in 6 cases, via both femoral arteries in 10 cases and via the brachial artery in one case. The SAFARI (subintimal arterial flossing with antegrade-retrograde intervention) technique using a microcatheter was performed to recannalize iliac artery occlusion in three cases. Medical records were reviewed for the collection of follow-up data. The stent patency rate was analyzed by use of the Kaplan-Meier method. Subintimal stent placement was technically successful in 23 of 24 procedures (95.8%). The mean ankle-brachial index (ABI) increased form 0.26 to 0.82. The Fontaine classification was improved after stent placement in all patients. Major complications occurred in four procedures: three distal embolizations and one arterial rupture. All of the complications were successfully treated by endovascular intervention. The primary stent patency rates at 6-months, 1-, 2-and 3-years were 95%, 88%, 88% and 88%, respectively. Subintimal stent placement is a safe and effective treatment for long segment occlusion of the iliac artery.
[A new method to orthodontically correct dental occlusal plane canting: wave-shaped arch].
Zheng, X; Hu, X X; Ma, N; Chen, X H
2017-02-18
To introduce a technique of second order wave-shaped arch wire to orthodontically treat dental occlusal plane canting (DOPC) with left-right interactive anchorage, and to test its clinical efficacy. Among the permanent dentition malocclusion patients who showed no obvious facial asymmetry, we screened for patients who showed anterior occlusal plane canting (AOPC) after routine orthodontic examination, treatment planning, MBT fixed appliance installation and serial arch wires alignment. Each patient had been clinically appraised in frontal view by 2 orthodontists and the patient him/herself; if all 3 agreed that the AOPC was obvious, the patient was included. By this means, we included 37 patients, including 10 males and 27 females; the average age was (21.9±5.2) years. To correct AOPC, opposite direction equal curvature second order rocking-chair curve was bent on each side of 0.46 mm×0.56 mm stainless steel edgewise wire. With reference to normal occlusal plane, a curve toward the occlusal surface was made to extrude under-erupted teeth on one side while a curve toward the gingiva was made to intrude over-erupted teeth on the other side, so that the arch wire was made into a wave shape in vertical dimension. Before and after application of wave-shaped arch wire, frontal facial photographs were taken when the patient's mouth was open slightly with lips retracted to show anterior occlusal plane (AOP) clearly. An AOP was constructed by connecting the center of the slot in the medial edge of canine bracket on each side in the photograph. The angles between the bipupillary plane(BPP) and the constructed AOP were measured in ImageJ1-48v software and the angle differences before and after treatment were compared with paired Wilcoxon test in SPSS 10.0 software. The wave-shaped arch could correct AOPC effectively in 3 to 10 months time with an average of 5.5±1.7 months; the angles between AOP and BBP before treatment ranged from 2.90° to 6.12° with a median of 4.01
Acceleration of planes segmentation using normals from previous frame
Gritsenko, Pavel; Gritsenko, Igor; Seidakhmet, Askar; Abduraimov, Azizbek
2017-12-01
One of the major problem in integration process of robots is to make them able to function in a human environment. In terms of computer vision, the major feature of human made rooms is the presence of planes [1, 2, 20, 21, 23]. In this article, we will present an algorithm dedicated to increase speed of a plane segmentation. The algorithm uses information about location of a plane and its normal vector to speed up the segmentation process in the next frame. In conjunction with it, we will address such aspects of ICP SLAM as performance and map representation.
Directory of Open Access Journals (Sweden)
Milton Edson Miranda
Full Text Available INTRODUCTION: In patients with Bruxism, the attrition can result in excessive occlusal wear that exceeds the compensatory mechanism and loss of occlusion vertical dimension occurs. OBJECTIVE: The purpose of this article is to show the importance of re-establishing an adequate occlusal plane for the non treated arch by means of a fixed acrylic overlay, compatible with the prosthetic treatment of the arch to be rehabilitated. An upper maxillary fixed acrylic overlay restored the patient’s occlusal plane in an appropriate vertical dimension of occlusion together with a fixed prosthesis in the mandible, supported by five dental implants. CONCLUSION: When there is severe wear due to dental attrition in one of the arches, it is important to re-establish the occlusal plane and compensation curves in conjunction with the prosthetic treatment of the arch to be rehabilitated.
Kumar, Sandeep; Garg, Sandeep; Gupta, Seema
2013-02-01
The purpose of this study was to determine accurately the part of the tragus to be used to form the Ala-Tragal line or Camper's line in orthognathic profile patients. 150 dentate subjects with age of 18-40 years with orthognathic profile were sampled. Life-size lateral digital photographs of the face with fox plane were taken in natural head position. Different angles between Eye-Ear plane and occlusal plane (OT1-OP), Eye-Ear plane and ala-superior border of tragus (OT1-AT1), Eye-Ear plane and ala-middle border of tragus (OT1-AT2) and Eye-Ear plane and ala-inferior border of tragus (OT1-AT3) were calculated using computer software package, AutoCAD 2004. From the three angles formed by the Eye-ear plane (OT1 or FH plane) and the ala-tragal lines, the one closest to the angle formed between Eye-Ear plane (OT1) and occlusal plane (OP) was used to determine the occlusal plane of orientation. The obtained results were subjected to ANOVA F test, Tukey's Honestly significant difference test, followed by Karl Pearson coefficient of correlation test. P values of less than 0.05 were taken as statistically significant. The mean of base line angle i.e. OT1-OP angle (11.96 ± 4.36) was found to be close to OT1-AT2 angle (13.67 ± 1.93) and OT1-AT3 angle (10.31 ± 2.03), but OT1-OP angle was found to be more closer to OT1-AT3 angle. Comparison of mean angles showed that OT1-OP angle in both males (11.68) and females (12.51) is close to OT1-AT3 angle (males- 11.01, females- 11.95). The line joining from ala to the lower border of the tragus was parallel to the occlusal plane in 53.3% of the subjects. There was no influence of the sex on the level of occlusal plane.
International Nuclear Information System (INIS)
Lou Wensheng; Gu Jianping; He Xu; Chen Liang; Chen Guoping; Su Haobo; Song Jinhua; Wang Tao; Xu Ke
2011-01-01
Objective: To discuss the clinical value of subintimal angioplasty in treating long segment occlusion of superficial femoral artery and to observe its midterm results. Methods: Subintimal angioplasty was performed in 45 patients with long segment occlusion of superficial femoral artery, whose clinical presentation was intermittent claudication or critical limb ischemia. The primary patency, limb salvage and factors influencing long-term patency were observed, and the clinical data were analyzed. Results: Of the total 45 cases, the subintimal angioplasty was successfully accomplished in 43. The success rate of antegrade approach technique via the superficial femoral artery was 80% (n=36), the occlusion was recanalized by using retrograde approach technique via ipsilateral popliteal artery in 7 case. The total technical success rate was 95.6%. The primary patency in 43 successful cases at 6, 12, 24 and 36 months was 85.7%, 69.0% 57.3% and 50.9%, respectively. No statistically significant difference in primary patency existed between the group of intermittent claudication and the group of critical limb ischemia (P>0.05). Statistically significant prediction factors for primary patency included the number of the run off vessels below the knee and the length of the occlusion (P<0.05). Conclusion: Subintimal angioplasty is an effective procedure for the treatment of long segment occlusions of superficial femoral artery with satisfactory mid-term results. (authors)
Energy Technology Data Exchange (ETDEWEB)
Wei, Li-Ming; Zhu, Yue-Qi; Zhang, Pei-Lei; Lu, Hai-Tao; Zhao, Jun-Gong [Shanghai Jiaotong University Affiliated Sixth People' s Hospital, Department of Diagnostic and Interventional Radiology, Shanghai (China); Liu, Fang [Shanghai Jiaotong University Affiliated Sixth People' s Hospital, Department of Endocrinology, Shanghai (China)
2018-03-15
To investigate morphological characteristics used to predict recanalisation strategies in long-segment (>10 cm) femoral chronic total occlusion (LSF-CTO) angioplasty. We retrospectively evaluated a range of morphological CTA and DSA features in patients who underwent recanalisation of LSF-CTO. The stage of CTO was classified into early (3-12 months) and late (>12 months) according to estimated duration. Characteristics including stump morphology, lesion length and calcification, proximal side branches, collaterals circulation, runoff vessels and concomitant arterial occlusion were used as predictors, and multivariate logistic regression analysis was performed to identify variables associated with late-stage CTO and retrograde technique. A total of 119 patients with 137 CTOs in 137 limbs were enrolled. Overall, successful recanalisation was achieved in 122 CTOs (89.1%). Flush occlusion [odds ratio (OR) 2.958; 95% confidence interval (CI) 1.172-7.465; p = 0.022], large collateral (OR 2.778; 95% CI 1.201-6.427; p = 0.017) and TransAtlantic Inter-Society Consensus II class D (TASC D) lesion (OR 1.743; 95% CI 1.019-2.981; p = 0.042) were predictors for late-stage CTO. Flush occlusion (OR 75.278; 95% CI 10.664-531.384; p < 0.001) and large collateral (OR 23.213; 95% CI 3.236-166.523; p = 0.002) were associated with high likelihood for retrograde approach. Flush occlusion and large collateral were associated with a CTO at late-stage which may require retrograde recanalisation. (orig.)
Segmented focal plane detector for light and heavy ions
International Nuclear Information System (INIS)
Wolfs, F.L.H.; Bryan, D.C.; Kurz, K.L.; Herrick, D.M.; Perera, P.A.A.; White, C.A.
1992-01-01
A segmented focal plane detector for an Enge split-pole spectrograph has been developed for the study of breakup reactions at very low relative energies. It consists of a 61 cm long segmented position-sensitive parallel plate avalanche counter backed by a large Bragg curve detector. A segmented plastic scintillator is mounted behind the anode of the Bragg curve detector and is used for particle identification of low-ionizing particles. The dead space between the two sections of the focal plane detector is 2.5 mm. The intrinsic position resolution of the detector is 1 mm. The intrinsic energy resolution depends on the energy of the incident ion and can be as good as 0.55%. The nuclear charge and mass resolutions are 0.3 e and 0.3 u, respectively. (orig.)
Microstrip Resonator for High Field MRI with Capacitor-Segmented Strip and Ground Plane
DEFF Research Database (Denmark)
Zhurbenko, Vitaliy; Boer, Vincent; Petersen, Esben Thade
2017-01-01
) segmenting stripe and ground plane of the resonator with series capacitors. The design equations for capacitors providing symmetric current distribution are derived. The performance of two types of segmented resonators are investigated experimentally. To authors’ knowledge, a microstrip resonator, where both......, strip and ground plane are capacitor-segmented, is shown here for the first time....
Computer-generated holograms by multiple wavefront recording plane method with occlusion culling.
Symeonidou, Athanasia; Blinder, David; Munteanu, Adrian; Schelkens, Peter
2015-08-24
We propose a novel fast method for full parallax computer-generated holograms with occlusion processing, suitable for volumetric data such as point clouds. A novel light wave propagation strategy relying on the sequential use of the wavefront recording plane method is proposed, which employs look-up tables in order to reduce the computational complexity in the calculation of the fields. Also, a novel technique for occlusion culling with little additional computation cost is introduced. Additionally, the method adheres a Gaussian distribution to the individual points in order to improve visual quality. Performance tests show that for a full-parallax high-definition CGH a speedup factor of more than 2,500 compared to the ray-tracing method can be achieved without hardware acceleration.
An efficient global energy optimization approach for robust 3D plane segmentation of point clouds
Dong, Zhen; Yang, Bisheng; Hu, Pingbo; Scherer, Sebastian
2018-03-01
Automatic 3D plane segmentation is necessary for many applications including point cloud registration, building information model (BIM) reconstruction, simultaneous localization and mapping (SLAM), and point cloud compression. However, most of the existing 3D plane segmentation methods still suffer from low precision and recall, and inaccurate and incomplete boundaries, especially for low-quality point clouds collected by RGB-D sensors. To overcome these challenges, this paper formulates the plane segmentation problem as a global energy optimization because it is robust to high levels of noise and clutter. First, the proposed method divides the raw point cloud into multiscale supervoxels, and considers planar supervoxels and individual points corresponding to nonplanar supervoxels as basic units. Then, an efficient hybrid region growing algorithm is utilized to generate initial plane set by incrementally merging adjacent basic units with similar features. Next, the initial plane set is further enriched and refined in a mutually reinforcing manner under the framework of global energy optimization. Finally, the performances of the proposed method are evaluated with respect to six metrics (i.e., plane precision, plane recall, under-segmentation rate, over-segmentation rate, boundary precision, and boundary recall) on two benchmark datasets. Comprehensive experiments demonstrate that the proposed method obtained good performances both in high-quality TLS point clouds (i.e., http://SEMANTIC3D.NET)
3D knee segmentation based on three MRI sequences from different planes.
Zhou, L; Chav, R; Cresson, T; Chartrand, G; de Guise, J
2016-08-01
In clinical practice, knee MRI sequences with 3.5~5 mm slice distance in sagittal, coronal, and axial planes are often requested for the knee examination since its acquisition is faster than high-resolution MRI sequence in a single plane, thereby reducing the probability of motion artifact. In order to take advantage of the three sequences from different planes, a 3D segmentation method based on the combination of three knee models obtained from the three sequences is proposed in this paper. In the method, the sub-segmentation is respectively performed with sagittal, coronal, and axial MRI sequence in the image coordinate system. With each sequence, an initial knee model is hierarchically deformed, and then the three deformed models are mapped to reference coordinate system defined by the DICOM standard and combined to obtain a patient-specific model. The experimental results verified that the three sub-segmentation results can complement each other, and their integration can compensate for the insufficiency of boundary information caused by 3.5~5 mm gap between consecutive slices. Therefore, the obtained patient-specific model is substantially more accurate than each sub-segmentation results.
Arzola, Leidimar Carballo; Esteban, Marcos T Rodríguez; Niebla, Javier García
2016-01-01
The isolated right ventricular infarction is a rare entity. Our case presented a selective occlusion of an acute marginal branch that supplies the right ventricular free wall with isolated ST elevation in precordial leads simulating an occlusion of the left anterior descending artery and without pseudonormalization in inferior due to the non-involvement of the main branch in the ischemic process. Our case clearly illustrates a rare differential diagnosis when a new ST segment elevation appears in earlier precordial leads in patients with symptoms of myocardial ischemia. Copyright © 2016 Elsevier Inc. All rights reserved.
Park, Hyo-Sang; Kim, Ji-Yeun; Kwon, Tae-Geon
2010-11-01
To increase stability and mandibular setback movement, surgical maxillary impaction is normally performed with mandibular setback surgery in treating adult skeletal Class III patients. This article demonstrates the use of microimplants for anchorage to intrude molars and the resultant rotation of the maxillary occlusal plane clockwise to increase the surgical mandibular setback and reduce the posterior vertical dimension instead of maxillary surgical impaction. A 21-year-old man with mandibular prognathism was treated with mandibular setback surgery that included orthodontic treatment for decompensation. Microimplants placed into the palatal alveolar bone between the maxillary first and second molars were used to intrude the maxillary posterior teeth and change the occlusal plane clockwise. This produced 4 mm more of distal movement of the chin during mandibular setback surgery compared with the surgical prediction with no change in the occlusal plane. These results were similar to those of 2-jaw surgery with maxillary posterior impaction. The intrusion of the maxillary posterior teeth with microimplants might prevent the need for maxillary surgery in adult skeletal Class III patients. Copyright © 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.
Wedged-shaped, segmental changes in the liver caused by occlusion of a single hepatic vein
International Nuclear Information System (INIS)
Kanazawa, Susumu; Akaki, Shiro; Yasui, Kotaro; Tanaka, Akio; Hiraki, Yoshio
1997-01-01
We evaluated wedged-shaped, segmental changes in the liver caused by occlusion of a single hepatic vein in seven patients. The causes of occlusion were due to liver tumors in three patients, metastasis of the right adrenal gland in one, and postoperative changes in three. Changes included low attenuating on unenhanced CT, high attenuation on enhanced CT, low signal intensity on T1-weighted MRI, high signal intensity on T2-weighted MRI, high signal intensity on enhanced MRI, dense hepatogram and retrograde arterioportal shunt on hepatic arteriography. MRI and hepatic arteriography are more sensitive than CT in demonstration of those changes. (author)
Postoperative stability of 2-jaw surgery with clockwise rotation of the occlusal plane.
Bang, Sung-Moon; Kwon, Yong-Dae; Kim, Su-Jung; Lee, Baek-Soo; Choi, Byung-Joon; Ohe, Joo-Young; Suh, Joon-Ho
2012-03-01
The objective of this study was to investigate the skeletal stability after Le Fort I osteotomy with clockwise rotation and bilateral sagittal split osteotomy. The sample consisted of 31 young Korean patients who were treated with Le Fort I osteotomy with clockwise rotation and setback bilateral sagittal split osteotomy. The lateral cephalographs were obtained before surgery (T1), right after surgery (T2), and on an average of 6.23 months after the operation (T3). The horizontal and vertical relations of landmarks to the reference line and soft tissue changes were evaluated. During the T2 - T1 period, there was superior and anterior movement of the posterior part (PNS, UMD) and advancement and impaction of the anterior part (ANS, A point, UIE) of the maxilla. The mandible was moved superiorly and posteriorly. During the T3 - T2 period, maxillary segment showed counterclockwise rotational relapse. The posterior part was relatively stable especially in the vertical position and the anterior part moved in the posterior and superior directions. Mandibular landmarks showed forward relapse in the horizontal aspect and superior relapse in the vertical aspect. The posterior part (PNS and UMD) showed a significantly higher stability rate (>70%) in the vertical aspect and the anterior part of the maxilla (ANS, A point) demonstrated a significantly lower value (occlusal plane showed stable results especially in the maxillary posterior landmarks. The clockwise rotational movement can be beneficial to increase skeletal stability and facial aesthetics in Asians.
A framework for classification and segmentation of branch retinal artery occlusion in SD-OCT
Guo, Jingyun; Shi, Fei; Zhu, Weifang; Chen, Haoyu; Chen, Xinjian
2016-03-01
Branch retinal artery occlusion (BRAO) is an ocular emergency which could lead to blindness. Quantitative analysis of BRAO region in the retina is very needed to assessment of the severity of retinal ischemia. In this paper, a fully automatic framework was proposed to classify and segment BRAO based on 3D spectral-domain optical coherence tomography (SD-OCT) images. To the best of our knowledge, this is the first automatic 3D BRAO segmentation framework. First, a support vector machine (SVM) based classifier is designed to differentiate BRAO into acute phase and chronic phase, and the two types are segmented separately. To segment BRAO in chronic phase, a threshold-based method is proposed based on the thickness of inner retina. While for segmenting BRAO in acute phase, a two-step segmentation is performed, which includes the bayesian posterior probability based initialization and the graph-search-graph-cut based segmentation. The proposed method was tested on SD-OCT images of 23 patients (12 of acute and 11 of chronic phase) using leave-one-out strategy. The overall classification accuracy of SVM classifier was 87.0%, and the TPVF and FPVF for acute phase were 91.1%, 5.5%; for chronic phase were 90.5%, 8.7%, respectively.
Simulation research on the process of large scale ship plane segmentation intelligent workshop
Xu, Peng; Liao, Liangchuang; Zhou, Chao; Xue, Rui; Fu, Wei
2017-04-01
Large scale ship plane segmentation intelligent workshop is a new thing, and there is no research work in related fields at home and abroad. The mode of production should be transformed by the existing industry 2.0 or part of industry 3.0, also transformed from "human brain analysis and judgment + machine manufacturing" to "machine analysis and judgment + machine manufacturing". In this transforming process, there are a great deal of tasks need to be determined on the aspects of management and technology, such as workshop structure evolution, development of intelligent equipment and changes in business model. Along with them is the reformation of the whole workshop. Process simulation in this project would verify general layout and process flow of large scale ship plane section intelligent workshop, also would analyze intelligent workshop working efficiency, which is significant to the next step of the transformation of plane segmentation intelligent workshop.
LOPES, Ana Cristina Távora de Albuquerque; TÉO, Mirela Anne Quartaroli; CORRÊA, Mônica Grazieli; ISHIKIRIAMA, Bella Luna Colombini; CAMPOS, Mirella Lindoso Gomes
2016-01-01
Abstract Introduction Primary occlusal trauma (OT) is an injury of the periodontium with normal height as a result of occlusal forces which exceed their adaptive capacity. Objective To evaluate, histometrically, the alveolar bone loss in the furcation region of rats experimentally submitted to 2 models of occlusal overload. Material and method 45 animals randomly divided into 3 groups: Occlusal Interference (OI, n = 15) - fixing an orthodontic wire segment on the occlusal surface of the fi...
Coro, Jorge C; Velasquez, Roberto L; Coro, Ivette M; Wheeler, Timothy T; McGorray, Susan P; Sato, Sadao
2016-07-01
The purpose of this study was to examine the relationship of the 3-dimensional (3D) posterior occlusal plane (POP) and the mandibular 3D spatial position. The relationship of the POP to mandibular morphology was also investigated. Retrospective data from a convenience sample of pretreatment diagnostic cone-beam computed tomography scans were rendered using InVivo software (Anatomage, San Jose, Calif). The sample consisted of 111 subjects (51 male, 60 female) and included growing and nongrowing subjects of different races and ethnicities. The 3D maxillary POP was defined by selecting the cusp tips of the second premolars and the second molars on the rendered images of the subjects. The angles made by this plane, in reference to the Frankfort horizontal plane, were measured against variables that described the mandibular position in the coronal, sagittal, and axial views. The POP was also compared with bilateral variables that described mandibular morphology. There were significant differences of the POP among the different skeletal malocclusions (P <0.0001). The POP showed significant correlations with mandibular position in the sagittal (P <0.0001), coronal (P <0.05), and axial (P <0.05) planes. The POP also showed a significant correlation with mandibular morphology (P <0.0001). These findings suggest that there is a distinct and significant relationship between the 3D POP and the mandibular spatial position and its morphology. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.
Directory of Open Access Journals (Sweden)
Bo Xu
2015-12-01
Full Text Available RANdom SAmple Consensus (RANSAC is a widely adopted method for LiDAR point cloud segmentation because of its robustness to noise and outliers. However, RANSAC has a tendency to generate false segments consisting of points from several nearly coplanar surfaces. To address this problem, we formulate the weighted RANSAC approach for the purpose of point cloud segmentation. In our proposed solution, the hard threshold voting function which considers both the point-plane distance and the normal vector consistency is transformed into a soft threshold voting function based on two weight functions. To improve weighted RANSAC’s ability to distinguish planes, we designed the weight functions according to the difference in the error distribution between the proper and improper plane hypotheses, based on which an outlier suppression ratio was also defined. Using the ratio, a thorough comparison was conducted between these different weight functions to determine the best performing function. The selected weight function was then compared to the existing weighted RANSAC methods, the original RANSAC, and a representative region growing (RG method. Experiments with two airborne LiDAR datasets of varying densities show that the various weighted methods can improve the segmentation quality differently, but the dedicated designed weight functions can significantly improve the segmentation accuracy and the topology correctness. Moreover, its robustness is much better when compared to the RG method.
Segmental osteotomies of the maxilla.
Rosen, H M
1989-10-01
Multiple segment Le Fort I osteotomies provide the maxillofacial surgeon with the capabilities to treat complex dentofacial deformities existing in all three planes of space. Sagittal, vertical, and transverse maxillomandibular discrepancies as well as three-dimensional abnormalities within the maxillary arch can be corrected simultaneously. Accordingly, optimal aesthetic enhancement of the facial skeleton and a functional, healthy occlusion can be realized. What may be perceived as elaborate treatment plans are in reality conservative in terms of osseous stability and treatment time required. The close cooperation of an orthodontist well-versed in segmental orthodontics and orthognathic surgery is critical to the success of such surgery. With close attention to surgical detail, the complication rate inherent in such surgery can be minimized and the treatment goals achieved in a timely and predictable fashion.
International Nuclear Information System (INIS)
Lee, Ho Yun; Chung, Jin Wook; Lee, Jeong Min; Yoon, Chang Jin; Lee, Whal; Jae, Hwan Jun; Yin, Yong Hu; Kang, Sung Gwon; Park, Jae Hyung
2007-01-01
The conventional method of dividing hepatic segment 2 (S2) and 3 (S3) is subjective and CT interpretation is unclear. The purpose of our study was to test the validity of our hypothesis that the actual plane dividing S2 and S3 is a vertical plane of equal distance from the S2 and S3 portal veins in clinical situations. We prospectively performed thin-section iodized-oil CT immediately after segmental chemoembolization of S2 or S3 in 27 consecutive patients and measured the angle of intersegmental plane on sagittal multiplanar reformation (MPR) images to verify its vertical nature. Our hypothetical plane dividing S2 and S3 is vertical and equidistant from the S2 and S3 portal veins (vertical method). To clinically validate this, we retrospectively collected 102 patients with small solitary hepatocellular carcinomas (HCC) on S2 or S3 the segmental location of which was confirmed angiographically. Two reviewers predicted the segmental location of each tumor at CT using the vertical method independently in blind trials. The agreement between CT interpretation and angiographic results was analyzed with Kappa values. We also compared the vertical method with the horizontal one. In MPR images, the average angle of the intersegmental plane was slanted 15 degrees anteriorly from the vertical plane. In predicting the segmental location of small HCC with the vertical method, the Kappa value between CT interpretation and angiographic result was 0.838 for reviewer 1 and 0.756 for reviewer 2. Inter-observer agreement was 0.918. The vertical method was superior to the horizontal method for localization of HCC in the left lobe (p < 0.0001 for reviewers 1 and 2). The proposed vertical plane equidistant from S2 and S3 portal vein is simple to use and useful for dividing S2 and S3 of the liver
Selective Segmentation for Global Optimization of Depth Estimation in Complex Scenes
Directory of Open Access Journals (Sweden)
Sheng Liu
2013-01-01
Full Text Available This paper proposes a segmentation-based global optimization method for depth estimation. Firstly, for obtaining accurate matching cost, the original local stereo matching approach based on self-adapting matching window is integrated with two matching cost optimization strategies aiming at handling both borders and occlusion regions. Secondly, we employ a comprehensive smooth term to satisfy diverse smoothness request in real scene. Thirdly, a selective segmentation term is used for enforcing the plane trend constraints selectively on the corresponding segments to further improve the accuracy of depth results from object level. Experiments on the Middlebury image pairs show that the proposed global optimization approach is considerably competitive with other state-of-the-art matching approaches.
[Occlusal anomalies in the deciduous and mixed bites].
Legovic, M; Mady, L
1998-01-01
In 311 examines (177 boys and 134 girls) with primary dentition and 535 examinees (285 boys and 250 girls) with mixed dentition in Istria--Croatia, the frequency of orthodontic and occlusive anomalies in regard of space plane and premature extraction of c, m1 and m2 are investigated. The orthodontic anomalies are defected in 46.95%, premature loss in 11.25% and occlusive anomalies in 40.85% of examinees with primary dentition, while in mixed dentition the 58.69% of examinees have orthodontic anomaly, the 17.20% premature loss and the 48.97% of examinees have occlusal anomaly. In both phases of dentition the most frequent are occlusive anomalies in the following planes: sagittal, vertical and sagittal-vertical.
Cao, Jun; Lu, Hai-Tao; Wei, Li-Ming; Zhao, Jun-Gong; Zhu, Yue-Qi
2016-04-01
To assess the technical feasibility and efficacy of the rendezvous technique, a type of subintimal retrograde wiring, for the treatment of long-segmental chronic total occlusions above the knee following unsuccessful standard angioplasty. The rendezvous technique was attempted in eight limbs of eight patients with chronic total occlusions above the knee after standard angioplasty failed. The clinical symptoms and ankle-brachial index were compared before and after the procedure. At follow-up, pain relief, wound healing, limb salvage, and the presence of restenosis of the target vessels were evaluated. The rendezvous technique was performed successfully in seven patients (87.5%) and failed in one patient (12.5%). Foot pain improved in all seven patients who underwent successful treatment, with ankle-brachial indexes improving from 0.23 ± 0.13 before to 0.71 ± 0.09 after the procedure (P rendezvous technique is a feasible and effective treatment for chronic total occlusions above the knee when standard angioplasty fails. © The Author(s) 2015.
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Sugihara, Fumie; Murata, Satoru; Ueda, Tatsuo; Yasui, Daisuke; Yamaguchi, Hidenori; Miki, Izumi; Kumita, Shin-ichiro [Nippon Medical School, Department of Radiology, Center for Advanced Medical Technology, Tokyo (Japan); Kawamoto, Chiaki [Nippon Medical School, Department of Internal Medicine, Tokyo (Japan); Uchida, Eiji [Nippon Medical School, Department of Surgery, Tokyo (Japan)
2017-06-15
To investigate haemodynamic changes in hepatocellular carcinoma (HCC) and liver under hepatic artery occlusion. Thirty-eight HCC nodules in 25 patients were included. Computed tomography (CT) during hepatic arteriography (CTHA) with and without balloon occlusion of the hepatic artery was performed. CT attenuation and enhancement volume of HCC and liver with and without balloon occlusion were measured on CTHA. Influence of balloon position (segmental or subsegmental branch) was evaluated based on differences in HCC-to-liver attenuation ratio (H/L ratio) and enhancement volume of HCC and liver. In the segmental group (n = 20), H/L ratio and enhancement volume of HCC and liver were significantly lower with balloon occlusion than without balloon occlusion. However, in the subsegmental group (n = 18), H/L ratio was significantly higher and liver enhancement volume was significantly lower with balloon occlusion; HCC enhancement volume was similar with and without balloon occlusion. Rate of change in H/L ratio and enhancement volume of HCC and liver were lower in the segmental group than in the subsegmental group. There were significantly more perfusion defects in HCC in the segmental group. Hepatic artery occlusion causes haemodynamic changes in HCC and liver, especially with segmental occlusion. (orig.)
Percutaneous Treatment of Intrahepatic Biliary Leak: A Modified Occlusion Balloon Technique
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Nasser, Felipe; Rocha, Rafael Dahmer, E-mail: rafaeldrocha@gmail.com; Falsarella, Priscila Mina; Motta-Leal-Filho, Joaquim Maurício da; Azevedo, André Arantes; Valle, Leonardo Guedes Moreira; Cavalcante, Rafael Noronha; Garcia, Rodrigo Gobbo; Affonso, Breno Boueri; Galastri, Francisco Leonardo [Hospital Israelita Albert Einstein, Department of Interventional Radiology (Brazil)
2016-05-15
PurposeTo report a novel modified occlusion balloon technique to treat biliary leaks.MethodsA 22-year-old female patient underwent liver transplantation with biliary-enteric anastomosis. She developed thrombosis of the common hepatic artery and extensive ischemia in the left hepatic lobe. Resection of segments II and III was performed and a biliary-cutaneous leak originating at the resection plane was identified in the early postoperative period. Initial treatment with percutaneous transhepatic drainage was unsuccessful. Therefore, an angioplasty balloon was coaxially inserted within the biliary drain and positioned close to the leak.ResultsThe fistula output abruptly decreased after the procedure and stopped on the 7th day. At the 3-week follow-up, cholangiography revealed complete resolution of the leakage.ConclusionThis novel modified occlusion balloon technique was effective and safe. However, greater experience and more cases are necessary to validate the technique.
MICELLI, Ana Lígia Piza; BUARQUE E SILVA, Wilkens Aurélio; ANDRADE E SILVA, Frederico; BUARQUE E SILVA, Lígia Luzia; ALVES, Josué Nogueira; CASSELLI, Denise de Sa Maia
2015-01-01
When the shape, structure, and/or function of one of the parts of the components of the stomatognathic system change, structural and physiological changes also occur to absorb or compensate the consequent loads. Hence, an insightful rehabilitation of this type of patient involves essential procedures, such as: correct orientation of the occlusal plane, determination of the vertical dimension of occlusion, and a stable and healthy maxillomandibular relationship, since the nonobservance of thes...
Roberts, W Eugene; Viecilli, Rodrigo F; Chang, Chris; Katona, Thomas R; Paydar, Nasser H
2015-12-01
In the absence of adequate animal or in-vitro models, the biomechanics of human malocclusion must be studied indirectly. Finite element analysis (FEA) is emerging as a clinical technology to assist in diagnosis, treatment planning, and retrospective analysis. The hypothesis tested is that instantaneous FEA can retrospectively simulate long-term mandibular arch retraction and occlusal plane rotation for the correction of a skeletal Class III malocclusion. Seventeen published case reports were selected of patients treated with statically determinate mechanics using posterior mandible or infrazygomatic crest bone screw anchorage to retract the mandibular arch. Two-dimensional measurements were made for incisor and molar movements, mandibular arch rotation, and retraction relative to the maxillary arch. A patient with cone-beam computed tomography imaging was selected for a retrospective FEA. The mean age for the sample was 23.3 ± 3.3 years; there were 7 men and 10 women. Mean incisor movements were 3.35 ± 1.55 mm of retraction and 2.18 ± 2.51 mm of extrusion. Corresponding molar movements were retractions of 4.85 ± 1.78 mm and intrusions of 0.85 ± 2.22 mm. Retraction of the mandibular arch relative to the maxillary arch was 4.88 ± 1.41 mm. Mean posterior rotation of the mandibular arch was -5.76° ± 4.77° (counterclockwise). The mean treatment time (n = 16) was 36.2 ± 15.3 months. Bone screws in the posterior mandibular region were more efficient for intruding molars and decreasing the vertical dimension of the occlusion to close an open bite. The full-cusp, skeletal Class III patient selected for FEA was treated to an American Board of Orthodontics Cast-Radiograph Evaluation score of 24 points in about 36 months by en-masse retraction and posterior rotation of the mandibular arch: the bilateral load on the mandibular segment was about 200 cN. The mandibular arch was retracted by about 5 mm, posterior rotation was about 16.5°, and molar intrusion was about 3
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Markandeya Rao
2015-12-01
Full Text Available BACKGROUND & OBJECTIVES The Electrocardiogram remains a crucial tool in the identification and management of acute myocardial infarction. A detailed analysis of patterns of ST-segment elevation may influence decisions regarding the perfusion therapy. This study was undertaken to identify the culprit vessel from ECG in patients with acute ST elevation myocardial infarction and correlate with coronary angiogram. MATERIALS & METHODS This is a prospective study, conducted on 126 patients in Osmania General Hospital, Hyderabad. Patients with ST segment elevation from ECG was evaluated to identify culprit vessel and later correlated with coronary angiogram. RESULTS Amongst 126 patients in this study, 70 patients had anterior wall and 56 patients had inferior wall myocardial infarction. ST> 1mm in V4R, ST V3/ST LIII Lead II was the most sensitive and ratio of STV3/STLIII >1.2 was the most specific criteria. ST in inferior leads > 1mm had maximum sensitivity in localizing occlusion in proximal D1 occlusion proximal to S1 as well. Absence of ST i in inferior leads is the most sensitive criteria in occlusion distal to S1 as well as in distal D1 in AWMI. CONCLUSION The admission ECG in patients with ST elevation AMI is valuable not only for determining early reperfusion treatment, but also provides important information to guide clinical decision-making.
Wang, Rong; Xu, Xin
2015-12-01
To compare the effect of 2 methods of occlusion adjustment on occlusal balance and muscles of mastication in patients with dental implant restoration. Twenty patients, each with a single edentulous posterior dentition with no distal dentition were selected, and divided into 2 groups. Patients in group A underwent original occlusion adjustment method and patients in group B underwent occlusal plane reduction technique. Ankylos implants were implanted in the edentulous space in each patient and restored with fixed prosthodontics single unit crown. Occlusion was adjusted in each restoration accordingly. Electromyograms were conducted to determine the effect of adjustment methods on occlusion and muscles of mastication 3 months and 6 months after initial restoration and adjustment. Data was collected and measurements for balanced occlusal measuring standards were obtained, including central occlusion force (COF), asymmetry index of molar occlusal force(AMOF). Balanced muscles of mastication measuring standards were also obtained including measurements from electromyogram for the muscles of mastication and the anterior bundle of the temporalis muscle at the mandibular rest position, average electromyogram measurements of the anterior bundle of the temporalis muscle at the intercuspal position(ICP), Astot, masseter muscle asymmetry index, and anterior temporalis asymmetry index (ASTA). Statistical analysis was performed using Student 's t test with SPSS 18.0 software package. Three months after occlusion adjustment, parameters of the original occlusion adjustment method were significantly different between group A and group B in balanced occlusal measuring standards and balanced muscles of mastication measuring standards. Six months after occlusion adjustment, parameters of the original occlusion adjustment methods were significantly different between group A and group B in balanced muscles of mastication measuring standards, but was no significant difference in balanced
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Ikeda, Yohei; Yoshimura, Norihiko; Hori, Yoshiro; Horii, Yosuke; Ishikawa, Hiroyuki; Yamazaki, Motohiko; Noto, Yoshiyuki; Aoyama, Hidefumi
2014-01-01
Highlights: • The proportion of preserved PE lesions in the non-occlusive group was 76.7% (33/43). • HUs of the iodine map were significantly higher in the non-occlusive group than in the occlusive group. • There was no significant difference in HUs between the non-occlusive and corresponding normal group. - Abstract: Purpose: The aim of this study was to determine if lung perfusion blood volume (lung PBV) with non-occlusive pulmonary embolism (PE) differs quantitatively and visually from that with occlusive PE and to investigate if lung PBV with non-occlusive PE remains the same as that without PE. Materials and methods: Totally, 108 patients suspected of having acute PE underwent pulmonary dual-energy computed tomography angiography (DECTA) between April 2011 and January 2012. Presence of PE on DECTA was evaluated by one radiologist. Two radiologists visually evaluated the PE distribution (segmental or subsegmental) and its nature (occlusive or non-occlusive) on DECTA and classified perfusion in lung PBV as “decreased,” “slightly decreased,” and “preserved”. Two radiologists used a lung PBV application to set a region of interest (ROI) in the center of the lesion and measured HU values of an iodine map. In the same slice as the ROI of the lesion and close to the lesion, another ROI was set in the normal perfusion area without PE, and HUs were measured. The proportion of lesions was compared between the occlusive and non-occlusive groups. HUs were compared among the occlusive, non-occlusive, and corresponding normal groups. Results: Twenty-five patients had 80 segmental or subsegmental lesions. There were 37 and 43 lesions in the occlusive and non-occlusive groups, respectively. The proportion of decreased lesions was 73.0% (27/37) in the occlusive group, while that of preserved lesions in the non-occlusive group was 76.7% (33/43). There was a significant difference in the proportion of lesions (P < 0.001) between the two groups. HUs of the
Occlusion Issues in Early Renaissance Art
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Barbara Gillam
2011-12-01
Full Text Available Early Renaissance painters innovatively attempted to depict realistic three-dimensional scenes. A major problem was to produce the impression of overlap for surfaces that occlude one another in the scene but are adjoined in the picture plane. Much has been written about perspective in art but little about occlusion. Here I examine some of the strategies for depicting occlusion used by early Renaissance painters in relation to ecological considerations and perceptual research. Perceived surface overlap is often achieved by implementing the principle that an occluding surface occludes anything behind it, so that occlusion perception is enhanced by a lack of relationship of occluding contour to occluded contours. Some well-known figure-ground principles are also commonly used to stratify adjoined figures. Global factors that assist this stratification include the placement of figures on a ground plane, a high viewpoint, and figure grouping. Artists of this period seem to have differed on whether to occlude faces and heads, often carefully avoiding doing so. Halos were either eliminated selectively or placed oddly to avoid such occlusions. Finally, I argue that the marked intransitivity in occlusion by architecture in the paintings of Duccio can be related to the issue of perceptual versus cognitive influences on the visual impact of paintings.
Titschack, J.; Baum, D.; Matsuyama, K.; Boos, K.; Färber, C.; Kahl, W.-A.; Ehrig, K.; Meinel, D.; Soriano, C.; Stock, S. R.
2018-06-01
During the last decades, X-ray (micro-)computed tomography has gained increasing attention for the description of porous skeletal and shell structures of various organism groups. However, their quantitative analysis is often hampered by the difficulty to discriminate cavities and pores within the object from the surrounding region. Herein, we test the ambient occlusion (AO) algorithm and newly implemented optimisations for the segmentation of cavities (implemented in the software Amira). The segmentation accuracy is evaluated as a function of (i) changes in the ray length input variable, and (ii) the usage of AO (scalar) field and other AO-derived (scalar) fields. The results clearly indicate that the AO field itself outperforms all other AO-derived fields in terms of segmentation accuracy and robustness against variations in the ray length input variable. The newly implemented optimisations improved the AO field-based segmentation only slightly, while the segmentations based on the AO-derived fields improved considerably. Additionally, we evaluated the potential of the AO field and AO-derived fields for the separation and classification of cavities as well as skeletal structures by comparing them with commonly used distance-map-based segmentations. For this, we tested the zooid separation within a bryozoan colony, the stereom classification of an ophiuroid tooth, the separation of bioerosion traces within a marble block and the calice (central cavity)-pore separation within a dendrophyllid coral. The obtained results clearly indicate that the ideal input field depends on the three-dimensional morphology of the object of interest. The segmentations based on the AO-derived fields often provided cavity separations and skeleton classifications that were superior to or impossible to obtain with commonly used distance-map-based segmentations. The combined usage of various AO-derived fields by supervised or unsupervised segmentation algorithms might provide a promising
Bruxism in children and transverse plane of occlusion: is there a relationship or not?
Nahás-Scocate, Ana Carla Raphaelli; Coelho, Fernando Vusberg; de Almeida, Viviane Chaves
2014-01-01
To assess the occurrence of bruxism in deciduous dentition and a potential association between the habit and the presence or absence of posterior crossbite. A total of 940 patient files were assessed. They were gathered from the archives of University of São Paulo City--UNICID; however, 67 patient files were dismissed for not meeting the inclusion criteria. Therefore, 873 children, males and females, comprised the study sample. They were aged between 2-6 years old and came from six different public primary schools from the east of the city of São Paulo. Data were collected through questionnaires answered by parents/guardians and by clinical examinations carried out in the school environment in order to obtain the occlusal characteristics in the transverse direction. First, a descriptive statistical analysis of all variables was performed (age, sex, race, posterior crossbite, bruxism, headache and restless sleep); then, the samples were tested by means of chi-square test with significance level set at 0.05%. A logistic regression model was applied to identify the presence of bruxism. The prevalence of this parafunctional habit was of 28.8%, with 84.5% of patients showing no posterior crossbite. Regarding the association of bruxism with crossbite, significant results were not found. Children with restless sleep have 2.1 times more chances of developing bruxism, whereas children with headache have 1.5 more chances. Transverse plane of occlusion was not associated with the habit of bruxism.
Bruxism in children and transverse plane of occlusion: Is there a relationship or not?
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Ana Carla Raphaelli Nahás-Scocate
2014-10-01
Full Text Available OBJECTIVE: To assess the occurrence of bruxism in deciduous dentition and a potential association between the habit and the presence or absence of posterior crossbite. METHODS: A total of 940 patient files were assessed. They were gathered from the archives of University of São Paulo City - UNICID; however, 67 patient files were dismissed for not meeting the inclusion criteria. Therefore, 873 children, males and females, comprised the study sample. They were aged between 2-6 years old and came from six different public primary schools from the east of the city of São Paulo. Data were collected through questionnaires answered by parents/guardians and by clinical examinations carried out in the school environment in order to obtain the occlusal characteristics in the transverse direction. First, a descriptive statistical analysis of all variables was performed (age, sex, race, posterior crossbite, bruxism, headache and restless sleep; then, the samples were tested by means of chi-square test with significance level set at 0.05%. A logistic regression model was applied to identify the presence of bruxism. RESULTS: The prevalence of this parafunctional habit was of 28.8%, with 84.5% of patients showing no posterior crossbite. Regarding the association of bruxism with crossbite, significant results were not found. Children with restless sleep have 2.1 times more chances of developing bruxism, whereas children with headache have 1.5 more chances. CONCLUSION: Transverse plane of occlusion was not associated with the habit of bruxism.
Pittschieler, Elisabeth; Foltin, Andrea; Falkensammer, Frank; Figl, Michael; Birkfellner, Wolfgang; Jonke, Erwin; Bantleon, Hans-Peter
2016-01-01
The aim of this study was to investigate the hamulus-incisive-papilla (HIP) plane as an alternative for transferring the three-dimensional position of a patient's maxilla to an articulator. Camper, Frankfurt horizontal, occlusal, and HIP planes were evaluated in 21 patients' computed tomography scans and compared to one another. Analysis of variance showed significant differences between all planes, with the HIP plane being closest to the occlusal plane (HIP-OP: 0.6 ± 4.0 degrees). Frankfurt and Camper planes, being more peripheral, showed higher geometric asymmetries. The HIP plane, when used for articulator mounting, results in a closer and more technically reliable patient relationship in a clinical and laboratory context.
Endovascular Treatment Strategies in Aortoiliac Occlusion
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Ozkan, Ugur; Oguzkurt, Levent; Tercan, Fahri; Gumus, Burcak
2009-01-01
The aim of this study was to report our experience in endovascular treatment of total aortoiliac occlusion. Five patients who underwent endovascular recanalization procedures including manual aspiration thrombectomy, balloon angioplasty, and stent placement for total aortoiliac occlusion in a 4-year period were reviewed retrospectively. The mean age of patients was 51 years (range, 43 to 58 years). All patients had abdominal aorta and bilateral common iliac artery occlusion with or without external iliac artery occlusion. All patients either had a contraindication to surgery or refused it. Initial technical success was obtained in four of five (80%) patients. Endovascular techniques were successful in four patients who had good distal runoff and short-segment aortoiliac occlusion, but failed in a patient who had the worst distal runoff and long-segment aortoiliac occlusion. We observed two major complications, one of which was bilateral rupture of the common iliac arteries treated with covered stent placement. Another patient had extension of intra-aortic thrombus into the iliac stent after primary stenting. This was successfully treated with manual aspiration thrombectomy. Aortic and iliac stents remained patent during the follow-up period (median, 18 months; range, 3 to 26 months) in four patients. Primary patency rates at 6, 12, and 24 months were all 80%. In conclusion, endovascular treatment can be an alternative for aortoiliac occlusion in selected patients. Short- to midterm follow-up so far is satisfactory. Removal of intra-aortic thrombus with manual aspiration thrombectomy before balloon angioplasty and/or stenting is possible and a good alternative to thrombolysis.
Collateral Circulation in Chronic Total Occlusions - An Interventional Perspective
Choo, Gim-Hooi
2015-01-01
Human coronary collaterals are inter-coronary communications that are believed to be present from birth. In the presence of chronic total occlusions, recruitment of flow via these collateral anastomoses to the arterial segment distal to occlusion provide an alternative source of blood flow to the myocardial segment at risk. This mitigates the ischemic injury. Clinical outcome of coronary occlusion ie. severity of myocardial infarction/ischemia, impairment of cardiac function and possibly survival depends not only on the acuity of the occlusion, extent of jeopardized myocardium, duration of ischemia but also to the adequacy of collateral circulation. Adequacy of collateral circulation can be assessed by various methods. These coronary collateral channels have been used successfully as a retrograde access route for percutaneous recanalization of chronic total occlusions. Factors that promote angiogenesis and further collateral remodeling ie. arteriogenesis have been identified. Promotion of collateral growth as a therapeutic target in patients with no suitable revascularization option is an exciting proposal.
Collateral Circulation in Chronic Total Occlusions - an interventional perspective.
Choo, Gim-Hooi
2015-09-09
Human coronary collaterals are inter-coronary communications that are believed to be present from birth. In the presence of chronic total occlusions, recruitment of flow via these collateral anastomoses to the arterial segment distal to occlusion provide an alternative source of blood flow to the myocardial segment at risk. This mitigates the ischemic injury. Clinical outcome of coronary occlusion ie. severity of myocardial infarction/ischemia, impairment of cardiac function and possibly survival depends not only on the acuity of the occlusion, extent of jeopardized myocardium, duration of ischemia but also to the adequacy of collateral circulation. Adequacy of collateral circulation can be assessed by various methods. These coronary collateral channels have been used successfully as a retrograde access route for percutaneous recanalization of chronic total occlusions. Factors that promote angiogenesis and further collateral remodeling ie. arteriogenesis have been identified. Promotion of collateral growth as a therapeutic target in patients with no suitable revascularization option is an exciting proposal.
Yusuf, Imran H; Peirson, Stuart N; Patel, Chetan K
2012-03-01
To evaluate whether occlusive intraocular lenses (IOLs) produced by several manufacturers for clinical use equivalently transmit near-infrared (IR) light for scanning laser ophthalmoscopy (SLO) or optical coherence tomography (OCT) imaging. Nuffield Laboratory of Ophthalmology, Oxford University, United Kingdom. Evaluation of diagnostic test or technology. The study evaluated 6 black IOLs of 2 designs: 3 poly(methyl methacrylate) (PMMA) and 3 iris-claw anterior chamber IOLs. Each IOL was placed between a broad-spectrum white light source and a spectroradiometer to generate transmission spectra. Transmission in the near-IR range was examined using an 850 nm light-emitting diode. Scanning laser ophthalmoscopy or OCT imaging using Spectralis spectral-domain SLO or OCT was attempted through occlusive IOLs in a model eye. Artisan iris-claw and MS 612 PMMA occlusive IOLs totally occluded all wavelengths of light, including in the near IR range in which SLO and OCT imaging systems operate. It was not possible to capture SLO or OCT images through the iris-claw and PMMA occlusive IOLs in a model eye. Results suggest the property of near-IR transmission that permits SLO or OCT imaging through occlusive IOLs is restricted to the Morcher range of occlusive IOLs. Patients with non-near IR transmitting IOLs will not be able to receive detailed posterior segment monitoring with SLO or OCT. This finding may have a significant impact on preoperative occlusive IOL selection and the management of current patients with occlusive IOLs. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.
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Ana Cristina Távora de Albuquerque LOPES
Full Text Available Abstract Introduction Primary occlusal trauma (OT is an injury of the periodontium with normal height as a result of occlusal forces which exceed their adaptive capacity. Objective To evaluate, histometrically, the alveolar bone loss in the furcation region of rats experimentally submitted to 2 models of occlusal overload. Material and method 45 animals randomly divided into 3 groups: Occlusal Interference (OI, n = 15 - fixing an orthodontic wire segment on the occlusal surface of the first lower molar; Occlusal Overload (OO, n = 15 - wearing of the cusps of the lower contralateral molars, the second and third molars next to the first molar that had its dimensions maintained; Negative Control (NC, n = 15 - evaluation of the initial dimensions of the periodontal ligament (PL. Five animals / group were sacrificed after 14, 21 and 28 days. Result Intergroup evaluation showed significant bone loss in OI (p0.05. The thickness of the PL remained stable in NC (p>0.05. Conclusion OI and OO were effective in the experimental reproduction of OT, and OI promoted greater alveolar bone loss compared to OO, showing that the impact of occlusal overload in OI increased the extent of the OT injury.
Christensen, L V; Rassouli, N M
1995-12-01
Frontal plane mandibular rotations and corresponding hemimandibular translations were studied in vitro by using direct observations of a human cadaver mandible and in vivo by using the indirect observations of rotational electrognathography. A comparison between the two methods showed that rotational electrognathography erred in measuring the clinically relevant hemimandibular translations resulting from mandibular rotations having a unilateral molar point (simulated occlusal interference) as the pivot of frontal plane torque. In vitro frontal plane rotations about a unilateral mandibular molar tooth (simulated occlusal interference) suggested that the resulting hemimandibular upward translations of the lateral portion of the mandibular condyle, contralateral to the molar tooth, would cause considerable compressive loading of the temporomandibular joint disc.
Range camera on conveyor belts: estimating size distribution and systematic errors due to occlusion
Blomquist, Mats; Wernersson, Ake V.
1999-11-01
When range cameras are used for analyzing irregular material on a conveyor belt there will be complications like missing segments caused by occlusion. Also, a number of range discontinuities will be present. In a frame work towards stochastic geometry, conditions are found for the cases when range discontinuities take place. The test objects in this paper are pellets for the steel industry. An illuminating laser plane will give range discontinuities at the edges of each individual object. These discontinuities are used to detect and measure the chord created by the intersection of the laser plane and the object. From the measured chords we derive the average diameter and its variance. An improved method is to use a pair of parallel illuminating light planes to extract two chords. The estimation error for this method is not larger than the natural shape fluctuations (the difference in diameter) for the pellets. The laser- camera optronics is sensitive enough both for material on a conveyor belt and free falling material leaving the conveyor.
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Budi Yuli Setianto
2017-04-01
Full Text Available Current guidelines for the management of patients with acute coronary syndromes (ACSs focus on the electrocardiogram to divide patients into ST-elevation acute myocardial infarction (STEMI or non-ST-elevation acute myocardial infarction (NSTEMI/unstable angina (UA. Patients with STEMI in the earliest time will receive reperfusion therapy to destruct occlusive thrombus. An ST segment elevation is the ‘sine qua non’ for diagnosing acute total coronary occlusion causing transmural myocardial infarction. Left circumflex coronary artery (LCx occlusion is often categorized as NSTEMI because of the absence of significant ST-elevation on the 12 lead standard electrocardiogram. An ST segment elevation is presented in fewer than 50% of patients with LCx total occlusion, such that the reperfusion therapy is delayed. We reported a 77 years old woman whom being diagnosed with NSTEMI because a 12 lead electrocardiogram showed ST segment depression in lead V2-V5. On coronary angiography, we found a total occlusion in the LCx artery as the culprit lession.
International Nuclear Information System (INIS)
Shin, Sang June; Koh, Young Hwan; Cha, Joo Hee; Kim, Hyu Beom; Chung, Jin Wook; Park, Jae Hyung
2000-01-01
To compare the diagnostic value of gadolinium-enhanced MR angiography with that of conventional digital subtraction angiography for the evaluation of lower extremity arterial occlusive diseases. In 26 patients with symptomatic lower extremity arterial occlusive disease, both conventional digital subtraction angiography (DSA) and gadolinium-enhanced MR angiography (CE-MRA) were performed during the same week. MR angiography was performed using three-dimensional gradient-echo acquisition before, and two sequential acquisitions after, the administration of gadolinium (0.2 mmol/kg). In 23 patients, two separate, contiguous areas were scanned using additional doses. In three patients, only one field with a suspicious lesion was scanned. Three radiologists independently analyzed the CE-MRA and DSA findings of each vascular segment (20 segments per arterial tree) for the presence of obstructive lesions; the grade assigned was either mild or none (less than 50%), stenotic (50%-99%), or occlusion (100%). From among a total of 462 segments, DSA detected 99 which were significantly narrowed (stenosis, 33; occlusion, 66). Using MR angiography, 102 segments (stenosis 39; occlusion, 63) were identified, and 94 lesions (stenosis, 32; occlusion, 62) were graded correctly. Seven lesions were overestimated and four were underestimated. For the detection of hemodynamically significant stenosis or occlusions using MR angiography, sensitivity, specificity, and diagnostic accuracy were 95%, 98%, and 98% (G=3D0.995, P less than 0.001), respectively. To prove the absence of lesions, we repeated DSA in two patients with arterial spasm due to puncture. Three occluded segments seen on DSA, which revealed intact segments on MR angiography, suggested slow distal flow after reconstitution. For the evaluation of lower extremity arterial occlusive disease, the diagnostic value of gadolinium-enhanced MR angiography is comparable with that of digital subtraction angiography. The advantages of the
Localization of root canal orifices in mandibular second molars in relation to occlusal dimension.
Gorduysus, O; Nagas, E; Cehreli, Z C; Gorduysus, M; Yilmaz, Z
2009-11-01
To evaluate the localization and distribution of canal orifices of mandibular second molar teeth in relation to the mesio-distal and bucco-lingual dimensions of coronal tissue. Fifty extracted mandibular second molar teeth were embedded into plaster blocks with their vertical axes aligned perpendicular to the horizontal plane. The teeth were photographed digitally from the occlusal aspect under 12 x magnification. Thereafter, the occlusal halves of crowns were sectioned off to expose the root canal orifices. The teeth were than photographed under the same magnification, after which the pre- and post-sectioning images of each specimen were stacked into a single file. To plot the coordinate of each canal orifice, a 0.5-mm grid analytical plane was mounted digitally on the stack so that the x- and y-axes of the plane were superimposed on the mesiodistal and buccolingual axes (bisectors) of the tooth crowns. Localization and distribution of the coordinates of the canal orifices were evaluated using the chi-square test (P = 0.05). Only one tooth displayed a single root canal orifice, located in the mesiobuccal-distolingual 'centre' of the occlusal surface. The majority of mandibular second molars had three orifices (72%), followed by those with two (16%) and four (10%). The distal canal was located lingual to the centre of the occlusal plane. The distal canal was located lingual to the centre of the occlusal plane of mandibular second molars. The possibility of observing more divergent localizations and orifice numbers should not be overlooked in clinical practice.
Babaev, Anvar; Gokhale, Rohit; Zavlunova, Susanna; Attubato, Michael
2016-11-01
We describe a novel approach for the endovascular treatment of femoral artery occlusion as a result of Angio-Seal closure device deployment. Angio-Seal is the most commonly used vascular closure device following percutaneous coronary and peripheral catheterizations worldwide. A rare complication of Angio-Seal deployment is an occlusion of the femoral artery leading to limb ischemia requiring revascularization. Given its unique ability to cut both atherosclerotic plaque and the Angio-Seal anchor with a collagen plug at operator-directed planes, TurboHawk/HawkOne atherectomy device can be a fast and effective approach to treat Angio-Seal-associated femoral artery occlusions. We studied 13 consecutive patients who developed Angio-Seal-associated femoral artery occlusions that occurred from 3 hours to several weeks after catheterization. These patients were successfully treated with TurboHawk/HawkOne directional atherectomy followed by balloon angioplasty with no complications. During a mean follow-up period of 20.4 ± 17.3 months, 12 patients remained claudication free with no evidence of obstructive arterial disease of the treated segment on imaging studies. One patient developed restenosis that was treated with repeat atherectomy and balloon angioplasty following which he was asymptomatic at follow-up. The use of directional atherectomy followed by balloon angioplasty is a quick, safe, and effective endovascular approach to treating Angio-Seal-associated femoral artery occlusions. It is associated with an excellent success rate, no complications, and good midterm outcomes.
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Valentina Graci
2016-03-01
Conclusion: Hip and knee kinematics differed across different segment definitions including or excluding the greater trochanter marker, especially in the transverse plane. Therefore when considering whether to include the greater trochanter in the thigh segment model when using a surface markers to calculate 3D kinematics for movement assessment, it is important to have a clear understanding of the effect of different marker sets and segment models in use.
Nikita Sinha; K Mahendranadh Reddy; Nidhi Gupta; Y M Shastry
2017-01-01
Purpose: Occlusal plane (OP) differs considerably in participants with skeletal Class I and Class II participants. In this study, cephalometrics has been used to help in the determination of orientation of the OP utilizing the nonresorbable bony anatomic landmarks in skeletal Class II participants and an attempt has been made to predict and examine the OP in individuals with skeletal class II jaw relationship. Materials and Methods: One hundred dentulous participants with skeletal Class II...
Saber, Hamidreza; Narayanan, Sandra; Palla, Mohan; Saver, Jeffrey L; Nogueira, Raul G; Yoo, Albert J; Sheth, Sunil A
2017-11-10
Endovascular thrombectomy has demonstrated benefit for patients with acute ischemic stroke from proximal large vessel occlusion. However, limited evidence is available from recent randomized trials on the role of thrombectomy for M2 segment occlusions of the middle cerebral artery (MCA). We conducted a systematic review and meta-analysis to investigate clinical and radiographic outcomes, rates of hemorrhagic complications, and mortality after M2 occlusion thrombectomy using modern devices, and compared these outcomes against patients with M1 occlusions. Recanalization was defined as Thrombolysis in Cerebral Infarction (TICI) 2b/3 or modified TICI 2b/3. A total of 12 studies with 1080 patients with M2 thrombectomy were included in our analysis. Functional independence (modified Rankin Scale 0-2) rate was 59% (95% CI 54% to 64%). Mortality and symptomatic intracranial hemorrhage rates were 16% (95% CI 11% to 23%) and 10% (95% CI 6% to 16%), respectively. Recanalization rates were 81% (95% CI 79% to 84%), and were equally comparable for stent-retriever versus aspiration (OR 1.05; 95% CI 0.91 to 1.21). Successful M2 recanalization was associated with greater rates of favorable outcome (OR 4.22; 95% CI 1.96 to 9.1) compared with poor M2 recanalization (TICI 0-2a). There was no significant difference in recanalization rates for M2 versus M1 thrombectomy (OR 1.05; 95% CI 0.77 to 1.42). This meta-analysis suggests that mechanical thrombectomy for M2 occlusions that can be safely accessed is associated with high functional independence and recanalization rates, but may be associated with an increased risk of hemorrhage. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Rubio-Bueno, P; Landete, P; Ardanza, B; Vázquez, L; Soriano, J B; Wix, R; Capote, A; Zamora, E; Ancochea, J; Naval-Gías, L
2017-11-01
Maxillomandibular advancement (MMA) can be effective for managing obstructive sleep apnoea (OSA); however, limited information is available on the predictor surgical variables. This study investigated whether normalization of the mandibular occlusal plane (MOP) was a determinant factor in curing OSA. Patients with moderate or severe OSA who underwent MMA were evaluated by preoperative and postoperative three-dimensional (3D) scans and polysomnograms. The postoperative value of MOP and the magnitude of skeletal advancement were the predictor variables; change in the apnoea-hypopnoea index (AHI) was the main outcome variable. Thirty-four subjects with a mean age of 41±14years and 58,8% female were analysed. The Epworth Sleepiness Scale (ESS) was 17.4±5.4 and AHI was 38.3±10.7 per hour before surgery. Postoperative AHI was 6.5±4.3 per hour (P<0.001) with 52.94% of the patients considered as cured, and 47.06% suffering from a mild residual OSA with ESS 0.8±1.4 (P<0.001). 3D changes revealed a volume increase of 106.3±38.8%. The mandible was advanced 10.4±3.9mm and maxilla 4.9±3.2mm. MOP postoperative value was concluded to be the best predictor variable. Treatment planning should include MOP normalization and a mandibular advancement between 6 and 10mm. The maxillary advancement would depend on the desired aesthetic changes and final occlusion. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Sachse, Tina; Schwestka-Polly, Rainer; Flieger, Stefanie; Wiechmann, Dirk
2012-05-21
The role of occlusion concerning temporomandibular disorder is still unclear but seems to be the only component of the stomathognathic system dentists are able to change morphologically. The aim of the paper is to describe the orthodontist's approach for transferring and maintaining a therapeutic splint position into permanent occlusion using a fully customized lingual appliance. Fixed acrylic bite planes on lower molars were used to maintain a symptom-free condyle position prior to orthodontic treatment. Silicone impressions of the arches including the fixed bite planes were used for the Incognito laboratory procedure. Two digital setups were made. One setup represents the target occlusion. A second setup including the bite planes was used to fabricate an additional set of lower molar brackets. In the leveling stage all teeth except the lower molars were settled to maintain the therapeutic condyle position. Finally, the fixed bite planes were stepwise removed and molar brackets were replaced to establish the permanent occlusion planned with the first setup. The advantage of an individual lingual appliance consists in the high level of congruence between the fabricated setups and the final clinical result. Both the individual scope for design and the precision of the appliance were vitally important in the treatment of a patient with a functional disorder of the masticatory system.
Endovascular treatment in proximal and intracranial carotid occlusion 9 hours after symptom onset
International Nuclear Information System (INIS)
Jakubowska, Malgorzata M.; Michels, Peter; Mueller-Jensen, Axel; Leppien, Andreas; Eckert, Bernd
2008-01-01
A debate is emerging over whether the treatment time window in acute stroke can be extended beyond 6 h if penumbral tissue can be identified. Treatment decisions are very difficult in cases of tandem proximal carotid occlusion with arterioarterial intracranial embolism. We enter this debate with the present report on a case of atherosclerotic proximal carotid occlusion and resulting periocclusional carotid T embolism that was successfully treated 9 h after symptom onset. The case of a 68-year-old man with fluctuating symptoms of right-hemispheric stroke is presented (NIHSS score 12-20 on admission). CT angiography demonstrated proximal carotid occlusion and periocclusional embolism of the entire internal carotid artery (ICA) including the carotid T segment. Penumbral tissue was diagnosed by nonenhanced and perfusion CT imaging 7.5 h after symptom onset. Treatment was initiated 9 h after symptom onset by passing the proximal occlusion with a microcatheter and local administration of recombinant tissue plasminogen activator (rt-PA) into the carotid T segment at the level of posterior communicating artery (PCoA) origin. Recanalization of the ICA and middle cerebral artery was accomplished within 1 h by flow establishment via the PCoA. The atherosclerotic proximal ICA occlusion was not stented due to the risk of embolism from remnant thrombi in the petrous and cavernous ICA segments. Follow-up MRI showed only mild haemorrhagic infarct transformation of the initial infarct core. The patient was discharged from hospital 18 days after treatment with NIHSS score 5. If penumbral tissue can be conclusively identified, endovascular treatment in proximal and intracranial tandem occlusion can be successful, even in treatments initiated 6-9 h after stroke onset. If the intracranial flow after recanalization can be established via the circle of Willis, the underlying proximal ICA occlusion may not require treatment. (orig.)
Endovascular treatment in proximal and intracranial carotid occlusion 9 hours after symptom onset
Energy Technology Data Exchange (ETDEWEB)
Jakubowska, Malgorzata M.; Michels, Peter; Mueller-Jensen, Axel [Asklepios Clinic Altona, Department of Neurology, Hamburg (Germany); Leppien, Andreas; Eckert, Bernd [Asklepios Clinic Altona, Department of Neuroradiology, Hamburg (Germany)
2008-07-15
A debate is emerging over whether the treatment time window in acute stroke can be extended beyond 6 h if penumbral tissue can be identified. Treatment decisions are very difficult in cases of tandem proximal carotid occlusion with arterioarterial intracranial embolism. We enter this debate with the present report on a case of atherosclerotic proximal carotid occlusion and resulting periocclusional carotid T embolism that was successfully treated 9 h after symptom onset. The case of a 68-year-old man with fluctuating symptoms of right-hemispheric stroke is presented (NIHSS score 12-20 on admission). CT angiography demonstrated proximal carotid occlusion and periocclusional embolism of the entire internal carotid artery (ICA) including the carotid T segment. Penumbral tissue was diagnosed by nonenhanced and perfusion CT imaging 7.5 h after symptom onset. Treatment was initiated 9 h after symptom onset by passing the proximal occlusion with a microcatheter and local administration of recombinant tissue plasminogen activator (rt-PA) into the carotid T segment at the level of posterior communicating artery (PCoA) origin. Recanalization of the ICA and middle cerebral artery was accomplished within 1 h by flow establishment via the PCoA. The atherosclerotic proximal ICA occlusion was not stented due to the risk of embolism from remnant thrombi in the petrous and cavernous ICA segments. Follow-up MRI showed only mild haemorrhagic infarct transformation of the initial infarct core. The patient was discharged from hospital 18 days after treatment with NIHSS score 5. If penumbral tissue can be conclusively identified, endovascular treatment in proximal and intracranial tandem occlusion can be successful, even in treatments initiated 6-9 h after stroke onset. If the intracranial flow after recanalization can be established via the circle of Willis, the underlying proximal ICA occlusion may not require treatment. (orig.)
Kondo, E
1998-12-01
This case report analyzes long-term occlusal stability that can be achieved in Class II, Division 1, deep bite cases with active treatment finished during the period of maxillomandibular growth. The analysis was designed to identify occlusal features common to two cases at the end of active treatment and to study how the occlusion changed with growth and jaw movement to achieve stability. The following occlusal features were shared by the two cases at the end of active treatment: (1) AB plane and axes of the maxillary and mandibular posterior teeth were perpendicular to functional occlusal plane; (2) the axis of the lower incisor was almost perpendicular to DC-L1i line; (3) the anterior occlusion was overcorrected to or near an edge-to-edge relationship. Items 1 and 2 remained unchanged throughout the follow-up periods, regardless of growth status, and the overjet and overbite increased during maxillomandibular growth after treatment. During the period of mandibular growth alone, after the end of retention, the axes of maxillary incisors tipped labially; as a result, F line became parallel to CDM line by the end of growth. The labial tipping of maxillary incisors brought the lower incisal edge into contact with or extremely near the inflection point (Bp).1 By the end of growth, the tangent of Bp became parallel to or coincident with DC-L1i line and perpendicular to the axis of the lower incisor, and the DC-L1i lines at various times posttreatment were almost parallel to each other in the two cases. Overjet increased as the maxillary incisors tipped labially, providing proper protrusive and retrusive paths for mandibular guidance. The angle between the functional occlusal plane and CDM line stayed almost the same as at the end of active treatment in the two cases, suggesting a possible change in the angle of eminence in harmony with the functional occlusal plane. These factors apparently contributed to the long-term occlusal stability in the two cases.
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Min Hwang
2018-01-01
Full Text Available Abstract Background This study was performed to evaluate the treatment effects of the antero-posterior lingual retractor (APLR, focusing on the 3-dimensional (3D tooth movement of the maxillary anterior teeth and their alveolar bone levels. Methods En masse retraction was performed using either the C-lingual retractor (CLR, C-group, n = 9 or the antero-posterior lingual retractor (APLR, AP-group, n = 8. We evaluated 3D movement of the maxillary anterior teeth and alveolar bone levels, root length of the central incisors, long axes of the maxillary canines, and occlusal plane changes from CBCT images. Results After retraction, the central incisors were more significantly intruded and their root apex was more retracted in the AP-group. The long axis of the canine was well maintained in the AP-group. There were no differences in the steepness of occlusal plane and the incidence of alveolar bone loss or of root resorption during en masse retraction with the two retractors. Conclusions The clockwise bowing effect of the anterior segment was less with the APLR, which prevented unwanted canine movement.
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Sachse Tina
2012-05-01
Full Text Available Abstract Introduction The role of occlusion concerning temporomandibular disorder is still unclear but seems to be the only component of the stomathognathic system dentists are able to change morphologically. The aim of the paper is to describe the orthodontist’s approach for transferring and maintaining a therapeutic splint position into permanent occlusion using a fully customized lingual appliance. Methods Fixed acrylic bite planes on lower molars were used to maintain a symptom-free condyle position prior to orthodontic treatment. Silicone impressions of the arches including the fixed bite planes were used for the Incognito laboratory procedure. Two digital setups were made. One setup represents the target occlusion. A second setup including the bite planes was used to fabricate an additional set of lower molar brackets. In the leveling stage all teeth except the lower molars were settled to maintain the therapeutic condyle position. Finally, the fixed bite planes were stepwise removed and molar brackets were replaced to establish the permanent occlusion planned with the first setup. Results and discussion The advantage of an individual lingual appliance consists in the high level of congruence between the fabricated setups and the final clinical result. Both the individual scope for design and the precision of the appliance were vitally important in the treatment of a patient with a functional disorder of the masticatory system.
International Nuclear Information System (INIS)
Zhao, Kai; Yan, Xingpeng; Jiang, Xiaoyu; Huang, Yingqing
2015-01-01
A spatial frequency index method is proposed to cull occlusion and generate a hologram. Object points with the same spatial frequency are put into a set for their mutual occlusion. The hidden surfaces of the three-dimensional (3D) scene are quickly removed through culling the object points that are furthest from the hologram plane in the set. The phases of plane wave, which are only interrelated with the spatial frequencies, are precomputed and stored in a table. According to the spatial frequency of the object points, the phases of plane wave for generating fringes are obtained directly from the table. Three 3D scenes are chosen to verify the spatial frequency index method. Both numerical simulation and optical reconstruction are performed. Experimental results demonstrate that the proposed method can cull the hidden surfaces of the 3D scene correctly. The occlusion effect of the 3D scene can be well reproduced. The computational speed is better than that obtained using conventional methods but is still time-consuming. (paper)
Depicting Occlusion in Early Renaissance Art
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Barbara Gillam
2011-05-01
Full Text Available The artist attempting to give the impression of three-dimensional relationships must convey somehow that one surface is in front of another. There is a large and venerable literature in Psychology on this subject, showing how figure-ground, border ownership and amodal completion and continuation are determined but there is almost no discussion of how artist's have recruited these and other principles to create convincing impressions of occlusion. Even Gombrich (Art & Illusion 1960 only considers the situation in which a figure has to be imagined from very partial cues, not how juxtaposed elements in art are parsed perceptually into occluding and occluded surfaces. In this paper I shall discuss approaches to occlusion present in early Renaissance art and the degree to which the principles now well-known to Psychologists were discovered and used, as artists increasingly depicted naturalistic scenes. Among the preoccupations of these artists, as indicated by their work, were whether and how much to occlude faces (and the related issue of the management of haloes, occlusion of and by architectural features, and the importance or otherwise of transitivity in occlusion relationships within the scene. They also clearly used the ground plane, high viewpoints and arrangements of contour terminations, as well as more conventional figural cues, to disambiguate perceived occlusion or to avoid the confusion of multiple surfaces.
Treatment of lower extremity arterial occlusive through retrograde access
International Nuclear Information System (INIS)
Liu Xueqiang; Guo Pingfan; Zhang Jinchi; Cai Fanggang
2012-01-01
Objective: To explore the clinical significance of retrograde access for the interventional treatment of lower extremity arterial occlusive diseases when the occluded segment of lower extremity artery could not be reached through antegrade access. Methods: Twenty-seven cases (male 17, female 10; age range 32-89 years) were retrospectively investigated, including 18 with lower limb arteriosclerosis obliterans, 7 with diabetic foot and 2 with thromboangiitis obliterans. According to the Fontaine staging, 6 cases were classified as Fontaine Ⅱ, 11 were classified as Fontaine Ⅲ and 10 were classified as Fontaine Ⅳ. All cases underwent endovascular operation through antegrade access first with an attempt to cross the occlusive segment, but in vain. So retrograde access was tried via puncture of pedis dorsalis or posterior tibial artery or exposure of lateral branches of posterior tibial artery, peroneal artery or dorsal artery by open surgery,which followed by Percutaneous transluminal angiography and (or) stenting. Results: The operation through retrograde access was successful in all cases with obvious improvement of ischemic symptoms. Hematoma at the puncture site occurred in 3 patients, and paresthesia of toes occurred in 1 after dorsalis pedis arteriotomy. No severe perioperative complication occurred. The average ankle brachial index increased from 0.37 ± 0.11 preoperatively to 0.85 ± 0.12 postoperatively. Conclusions: Retrograde access could be used as an alternative strategy in lower extremity arterial occlusive diseases when the occluded segment could not reach through antegrade access. (authors)
Watson, James T
2008-01-01
Crown dimensions and occlusal surface wear rate and wear plane were evaluated using paired first and second mandibular molars from a sample of 84 Early Agricultural period (1600 B.C.-A.D. 200) skeletons from northwest Mexico. Although this period represents a major shift in subsistence strategies in the Sonoran Desert, from food-foraging to agriculture, archaeological and dental pathology studies have identified this period as one of relative dietary stability. It was therefore predicted that very little variation in occlusal wear would have occurred between the early phase (San Pedro: 1600-800 B.C.) and late phase (Cienega: 800 B.C.-A.D. 200). Comparison of crown diameters identified some phenotypic differences between sexes but not between archaeological phases. Molar occlusal surfaces were then divided into four quadrants, and wear scores recorded for each quadrant. Principle axis analysis was performed between total wear scores of paired, adjacent first and second mandibular molars to assess rate and occlusal wear plane over time. The analysis demonstrated that both wear rate and wear plane increased from the early to the late phase of the Early Agricultural period. These results indicate that although diet may have indeed remained stable during this period in the Sonoran Desert increases in the rate of wear and wear plane may reflect changes in food-processing techniques. It is suggested that more intensive processing of agricultural products during the Cienega phase simultaneously softened the diet to create more tooth-contact wear and introduced more grit to cause faster and more angled wear on the molar occlusal surfaces. (c) 2007 Wiley-Liss, Inc.
DEFF Research Database (Denmark)
Tønnesen, K H; Holstein, P; Andersen, E
1991-01-01
dilatation of femoro-popliteal occlusions, the balloons were inflated on both sides of the lesion. The dilated segment was then isolated from the circulation. Through a sideport between the balloons 5 mg of tissue type plasminogen activator and 1000 IU of heparin were installed within the segment for 30 min...
Liu, Hai-Wei; Han, Ya-Ling; Jin, Quan-Min; Wang, Xiao-Zeng; Ma, Ying-Yan; Wang, Geng; Wang, Bin; Xu, Kai; Li, Yi; Chen, Shao-Liang
2018-06-20
Very few data have been reported for ST-segment elevation myocardial infarction (STEMI) caused by unprotected left main coronary artery (ULMCA) occlusion, and very little is known about the results of this subgroup of patients who underwent primary percutaneous coronary intervention (PCI). The aim of this study was to determine the clinical features and outcomes of patients with STEMI who underwent primary PCI for acute ULMCA occlusion. From January 2000 to February 2014, 372 patients with STEMI caused by ULMCA acute occlusion (ULMCA-STEMI) who underwent primary PCI at one of two centers were enrolled. The 230 patients with non-ST-segment elevation MI (NSTEMI) caused by ULMCA lesion (ULMCA-NSTEMI) who underwent emergency PCI were designated the control group. The main indexes were the major adverse cardiac events (MACEs) in-hospital, at 1 month, and at 1 year. Compared to the NSTEMI patients, the patients with STEMI had significantly higher rates of Killip class≥III (21.2% vs. 3.5%, χ 2 = 36.253, P 0.05) and TVR (all P > 0.05) in the intervals of 0-1 month as well as 1 month to 1 year. The results of Cox regression analysis showed that the differences in the independent predictors for MACE included the variables of Killip class ≥ III and intra-aortic balloon pump support for the STEMI patients and the variables of previous MI, ULMCA distal bifurcation, and 2-stent for distal ULMCA lesions for the NSTEMI patients. Compared to the NSTEMI patients, the patients with STEMI and ULMCA lesions still remain at a much higher risk for adverse events at 1 year, especially on 1 month. If a successful PCI procedure is performed, the 1-year outcomes in those patients might improve.
DEFF Research Database (Denmark)
Rasmussen, Marianne N P; Hornbak, Malene; Larsen, Stine S
2013-01-01
Background/Aims: In response to experimental stroke, a characteristic functional and expressional upregulation of contractile G-protein-coupled receptors has been uncovered in the affected cerebral vasculature; however, the mechanism initiating this phenomenon remains unknown. Methods: Using...... a model of permanent distal occlusion of rat middle cerebral arteries, we investigated whether there was a regional difference in receptor-mediated contractility of segments located upstream and downstream of the occlusion site. The contractile response to endothelin, angiotensin and 5-hydroxytryptamine...... receptor stimulation was studied by sensitive wire myograph. Results: Only downstream segments exhibited an augmented contractile response to stimulation with each of the three ligands, with the response towards sarafotoxin 6c being especially augmented compared to sham, upstream and contralateral controls...
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Nodari Franco
2011-08-01
Full Text Available Abstract Background The ergotamine tartrate associated with certain categories of drugs can lead to critical ischemia of the extremities. Discontinuation of taking ergotamine is usually sufficient for the total regression of ischemia, but in some cases it could be necessary thrombolytic and anticoagulant therapy to avoid amputation. Case report A woman of 62 years presented with a severe pain left forearm appeared 10 days ago, with a worsening trend. The same symptoms appeared after 5 days also in the right forearm. Physical examination showed the right arm slightly hypothermic, with radial reduced pulse in presence of reduced sensitivity. The left arm was frankly hypothermic, pulse less on radial and with an ulnar humeral reduced pulse, associated to a decreased sensitivity and motility. Clinical history shows a chronic headache for which the patient took a daily basis for years Cafergot suppository (equivalent to 3.2 mg of ergotamine. From about ten days had begun therapy with itraconazole for vaginal candidiasis. The Color-Doppler ultrasound shown arterial thrombosis of the upper limbs (humeral and radial bilateral, with minimal residual flow to the right and no signal on the humeral and radial left artery. Results Angiography revealed progressive reduction in size of the axillary artery and right humeral artery stenosis with right segmental occlusions and multiple hypertrophic collateral circulations at the elbow joint. At the level of the right forearm was recognizable only the radial artery, decreased in size. Does not recognize the ulnar, interosseous artery was thin. To the left showed progressive reduction in size of the distal subclavian and humeral artery, determined by multiple segmental steno-occlusion with collateral vessels serving only a thin hypotrophic interosseous artery. Arteriographic findings were compatible with systemic drug-induced disease. The immediate implementation of thrombolysis, continued for 26 hours, with
In Situ 3D Segmentation of Individual Plant Leaves Using a RGB-D Camera for Agricultural Automation
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Chunlei Xia
2015-08-01
Full Text Available In this paper, we present a challenging task of 3D segmentation of individual plant leaves from occlusions in the complicated natural scene. Depth data of plant leaves is introduced to improve the robustness of plant leaf segmentation. The low cost RGB-D camera is utilized to capture depth and color image in fields. Mean shift clustering is applied to segment plant leaves in depth image. Plant leaves are extracted from the natural background by examining vegetation of the candidate segments produced by mean shift. Subsequently, individual leaves are segmented from occlusions by active contour models. Automatic initialization of the active contour models is implemented by calculating the center of divergence from the gradient vector field of depth image. The proposed segmentation scheme is tested through experiments under greenhouse conditions. The overall segmentation rate is 87.97% while segmentation rates for single and occluded leaves are 92.10% and 86.67%, respectively. Approximately half of the experimental results show segmentation rates of individual leaves higher than 90%. Nevertheless, the proposed method is able to segment individual leaves from heavy occlusions.
Ambient Occlusion Effects for Combined Volumes and Tubular Geometry
Schott, M.; Martin, T.; Grosset, A. V. P.; Smith, S. T.; Hansen, C. D.
2013-01-01
This paper details a method for interactive direct volume rendering that computes ambient occlusion effects for visualizations that combine both volumetric and geometric primitives, specifically tube-shaped geometric objects representing streamlines, magnetic field lines or DTI fiber tracts. The algorithm extends the recently presented the directional occlusion shading model to allow the rendering of those geometric shapes in combination with a context providing 3D volume, considering mutual occlusion between structures represented by a volume or geometry. Stream tube geometries are computed using an effective spline-based interpolation and approximation scheme that avoids self-intersection and maintains coherent orientation of the stream tube segments to avoid surface deforming twists. Furthermore, strategies to reduce the geometric and specular aliasing of the stream tubes are discussed.
Ambient Occlusion Effects for Combined Volumes and Tubular Geometry
Schott, M.
2013-06-01
This paper details a method for interactive direct volume rendering that computes ambient occlusion effects for visualizations that combine both volumetric and geometric primitives, specifically tube-shaped geometric objects representing streamlines, magnetic field lines or DTI fiber tracts. The algorithm extends the recently presented the directional occlusion shading model to allow the rendering of those geometric shapes in combination with a context providing 3D volume, considering mutual occlusion between structures represented by a volume or geometry. Stream tube geometries are computed using an effective spline-based interpolation and approximation scheme that avoids self-intersection and maintains coherent orientation of the stream tube segments to avoid surface deforming twists. Furthermore, strategies to reduce the geometric and specular aliasing of the stream tubes are discussed.
DEFF Research Database (Denmark)
Jørgensen, B; Tønnesen, K H; Bülow, J
1989-01-01
To establish whether re-occlusion of the femoral artery could be prevented, in 6 consecutive patients undergoing percutaneous transluminal angioplasty (PTA) for superficial femoral artery occlusion the recanalised segment was isolated, with a 7-French double-balloon catheter. 5 mg recombined huma...
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Daniel Amaral Alves Marlière
2018-01-01
Full Text Available Dentofacial deformities (DFD presenting mainly as Class III malocclusions that require orthognathic surgery as a part of definitive treatment. Class III patients can have obvious signs such as increasing the chin projection and chin throat length, nasolabial folds, reverse overjet, and lack of upper lip support. However, Class III patients can present different facial patterns depending on the angulation of occlusal plane (OP, and only bite correction does not always lead to the improvement of the facial esthetic. We described two Class III patients with different clinical features and inclination of OP and had undergone different treatment planning based on 6 clinical features: (I facial type; (II upper incisor display at rest; (III dental and gingival display on smile; (IV soft tissue support; (V chin projection; and (VI lower lip projection. These patients were submitted to orthognathic surgery with different treatment plannings: a clockwise rotation and counterclockwise rotation of OP according to their facial features. The clinical features and OP inclination helped to define treatment planning by clockwise and counterclockwise rotations of the maxillomandibular complex, and two patients undergone to bimaxillary orthognathic surgery showed harmonic outcomes and stables after 2 years of follow-up.
Karadeli, E; Tarhan, N C; Ulu, E M Kayahan; Tutar, N U; Basaran, O; Coskun, M; Niron, E A
2009-01-01
To evaluate failing hemodialysis fistula complications using 16-detector MDCTA, and to assess the accuracies of different 3D planes. Thirty patients (16 men, 14 women, aged 27-79 years) were referred for hemodialysis access dysfunction. Thirty-one MDCTA exams were done prior to fistulography. For MDCTA, contrast was administered (2mL/kg at 5mL/s) via a peripheral vein in the contralateral arm. Axial MIP, coronal MIP, and VRT images were constructed. Venous complications were evaluated on axial source images, on each 3D plane, and on all-planes together. Results were analyzed using McNemar test. Axial MIP, VRT and all-planes evaluations were most sensitive for fistula site detection (93%). Coronal MIP had the highest sensitivity, specificity and accuracy (35%, 96%, and 85%, respectively) for detecting venous stenosis. VRT and all-planes had the highest sensitivity and accuracy for detecting aneurysms (100%). All-planes and axial MIP were most sensitive for detecting venous occlusion (61% and 54%). Comparisons of detection frequencies for each venous pathology between the five categories of MDCTA revealed no significant differences (P>0.05). MDCTA additionally showed 3 partially thrombosed aneurysms, 4 anastomosis site stenosis and 12 arterial complications. MDCTA overall gives low sensitivity for detection of central vein stenosis and moderate sensitivity for occlusion. For most pathology, all-planes evaluation of MDCTA gives highest sensitivity and accuracy rates when compared to other planes. For venous stenosis and occlusion, MDCTA should be considered when ultrasonography and fistulography are inconclusive. MDCTA is helpful in identifying aneurysms, collaterals, partial venous thromboses and additional arterial, anastomosis site pathologies.
International Nuclear Information System (INIS)
Okuda, Katsuya; Nakajima, Masahiro; Kakudo, Kenji
2009-01-01
Relapse is sometimes observed during the postoperative course following sagittal split ramus osteotomy which is widely used to correct jaw deformities. Relapse may be caused by biomechanical factors such as the postoperative occlusal force. We evaluated serial changes in the stress distribution associated with postoperative occlusal force and jaw-closing pressure on the mandible and osteosynthesis plate using three-dimensional finite element analysis. Based on CT data, we produced mandibular models 1, 3, 6, and 12 months after sagittal split ramus osteotomy, and subjected them to simulated occlusal force and jaw-closing pressure. Changes in equivalent stress in the proximal and distal segments, at the osteosynthesis site, and the fixation plate were evaluated by three-dimensional finite element analysis. The equivalent stresses in the proximal and distal segments slightly increased over time from 1 to 12 months after the operation. In particular, marked stress concentration was observed at the anterior border of the ramus at each measurement area. Stress at the osteosynthesis site increased from 1 to 6 months after the operation, but decreased after 12 months. As a result of postoperative occlusal forces and jaw-closing pressure, stress was concentrated at the anterior border of the ramus in the proximal segment. Between 3 and 6 months after the operation, tensile stress was concentrated at the upper and lower ends of the osteotomy line at the osteosynthesis site. These biomechanical findings indicate the application of clockwise stress on the distal segment up to 6 months after the operation. We concluded that sagittal split ramus osteotomy runs the risk of relapse between 3 and 6 months after the operation. (author)
Ifesanya, J U; Adeyemi, A T; Otuyemi, O D
2014-09-01
Conjoint analysis of orthodontic patients using the Subspinale (A-point) Nasion-Supramentale (B point) (ANB) angle and the Wits appraisal is popular in many practices. This study aimed to present reference values for the Wits appraisal among Nigerians using three horizontal reference planes namely the bisected occlusal plane (BOP), the functional occlusal plane (FOP) and the maxillomandibular angle bisector (MM° bisector) plane. It also assessed the relationship of the Wits appraisal with the ANB angle and its interaction with clinical measures of sagittal skeletal relations among subjects with malocclusion. One hundred participants with normal occlusion and 120 with malocclusion were recruited in the study. Cephalometric radiographs were taken for all participants. Each radiograph was manually traced on a 0.003 matted cellulose acetate tracing paper using a sharpened 2H pencil. The Wits appraisal and ANB angle were determined. Data was analyzed using SPSS version 19. The mean age was 20.7 ± 4.9 years for those with normal occlusion and 18.8 ± 6.5 years in the malocclusion group. There were 91 (41.4%) males and 129 (58.6%) females. Mean values for the Wits appraisal using the BOP as reference, was--1.27 ± 2.91mm, with the FOP, it was -3.54 ± 3.24mm, while with the MM° bisector plane, it was--.75? ± .94mm. The ANB angle showed highest correlation with the MM'°bisector plane Wits value(Pplane Wits appraisal.
Aye, Thandar; Phan, Thanh Trung; Muir, Douglas Findlay; Linker, Nicholas John; Hartley, Richard; Turley, Andrew John
2017-10-01
This new laser facilitated 'inside-out' technique was used for transvenous pacemaker insertion in a pacemaker-dependent patient with bilateral subclavian occlusion and a failed epicardial system who is not suitable for a transfemoral approach. Procedure was undertaken under general anaesthesia with venous access obtained from right femoral vein and left axillary vein. 7F multipurpose catheter was used to enter proximal edge of the occluded segment of subclavian vein via femoral approach, which then supported stiff angioplasty wires and microcatheters to tunnel into the body of occlusion. When encountered with impenetrable resistance, 1.4 mm Excimer laser helped delivery of a Pilot 200 wire, which then progressed towards the distal edge of occlusion. Serial balloon dilatations allowed wire tracked into subintimal plane, advanced towards left clavicle using knuckle wire technique, which was then externalized with blunt dissection from infraclavicular pocket area. It was later changed to Amplatz superstiff wire exiting from both ends to form a rail, which ultimately allowed passage of pacing leads after serial balloon dilatation from clavicular end. Our hybrid 'inside-out' technique permitted transvenous pacemaker insertion without complication and this is, to our knowledge, the first case using laser in this context. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.
Cheong, Jieun; Hwang, Yu-Sun; Jung, Bock-Yung
2018-03-13
In the full-mouth rehabilitation of a patient with severely collapsed occlusion, a multidisciplinary approach including prosthodontics, orthodontics, endodontics, and surgery could provide better esthetic and functional results. Orthodontic treatment aiming for stable occlusion that meets the standard requirement of functional occlusion, enables the maintenance of occlusal function, and guarantees long-term stability on the basis of periodontal health was attempted. The essential element of this protocol is careful treatment planning based on the optimal sequence pursuing functional occlusion. © 2018 by the American College of Prosthodontists.
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Sogabe, Shu; Satomi, Junichiro; Tada, Yoshiteru; Kanematsu, Yasuhisa; Kuwayama, Kazuyuki; Yagi, Kenji; Yoshioka, Shotaro; Mizobuchi, Yoshifumi; Mure, Hideo; Yamaguchi, Izumi; Kitazato, Keiko T.; Nagahiro, Shinji; Abe, Takashi; Harada, Masafumi; Yamamoto, Nobuaki; Kaji, Ryuji
2017-01-01
Arterial spin labeling (ASL) involves perfusion imaging using the inverted magnetization of arterial water. If the arterial arrival times are longer than the post-labeling delay, labeled spins are visible on ASL images as bright, high intra-arterial signals (IASs); such signals were found within occluded vessels of patients with acute ischemic stroke. The identification of the occluded segment in the internal carotid artery (ICA) is crucial for endovascular treatment. We tested our hypothesis that high IASs on ASL images can predict the occluded segment. Our study included 13 patients with acute ICA occlusion who had undergone angiographic and ASL studies within 48 h of onset. We retrospectively identified the high IAS on ASL images and angiograms and recorded the occluded segment and the number of high IAS-positive slices on ASL images. The ICA segments were classified as cervical (C1), petrous (C2), cavernous (C3), and supraclinoid (C4). Of seven patients with intracranial ICA occlusion, five demonstrated high IASs at C1-C2, suggesting that high IASs could identify stagnant flow proximal to the occluded segment. Among six patients with extracranial ICA occlusion, five presented with high IASs at C3-C4, suggesting that signals could identify the collateral flow via the ophthalmic artery. None had high IASs at C1-C2. The mean number of high IAS-positive slices was significantly higher in patients with intra- than extracranial ICA occlusion. High IASs on ASL images can identify slow stagnant and collateral flow through the ophthalmic artery in patients with acute ICA occlusion and help to predict the occlusion site. (orig.)
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Sogabe, Shu; Satomi, Junichiro; Tada, Yoshiteru; Kanematsu, Yasuhisa; Kuwayama, Kazuyuki; Yagi, Kenji; Yoshioka, Shotaro; Mizobuchi, Yoshifumi; Mure, Hideo; Yamaguchi, Izumi; Kitazato, Keiko T.; Nagahiro, Shinji [Tokushima University Graduate School, Department of Neurosurgery, Tokushima (Japan); Abe, Takashi; Harada, Masafumi [Tokushima University Graduate School, Department of Radiology, Tokushima (Japan); Yamamoto, Nobuaki; Kaji, Ryuji [Tokushima University Graduate School, Department of Clinical Neurosciences, Institute of Biomedical Biosciences, Tokushima (Japan)
2017-06-15
Arterial spin labeling (ASL) involves perfusion imaging using the inverted magnetization of arterial water. If the arterial arrival times are longer than the post-labeling delay, labeled spins are visible on ASL images as bright, high intra-arterial signals (IASs); such signals were found within occluded vessels of patients with acute ischemic stroke. The identification of the occluded segment in the internal carotid artery (ICA) is crucial for endovascular treatment. We tested our hypothesis that high IASs on ASL images can predict the occluded segment. Our study included 13 patients with acute ICA occlusion who had undergone angiographic and ASL studies within 48 h of onset. We retrospectively identified the high IAS on ASL images and angiograms and recorded the occluded segment and the number of high IAS-positive slices on ASL images. The ICA segments were classified as cervical (C1), petrous (C2), cavernous (C3), and supraclinoid (C4). Of seven patients with intracranial ICA occlusion, five demonstrated high IASs at C1-C2, suggesting that high IASs could identify stagnant flow proximal to the occluded segment. Among six patients with extracranial ICA occlusion, five presented with high IASs at C3-C4, suggesting that signals could identify the collateral flow via the ophthalmic artery. None had high IASs at C1-C2. The mean number of high IAS-positive slices was significantly higher in patients with intra- than extracranial ICA occlusion. High IASs on ASL images can identify slow stagnant and collateral flow through the ophthalmic artery in patients with acute ICA occlusion and help to predict the occlusion site. (orig.)
[Complete denture occlusion considered from occlusal contacts during mastication].
Suzuki, Tetsuya
2004-12-01
Few reports describe the functional superiority of full balanced occlusion to that of lingualized occlusion. Recently, a bilateral balanced scheme has been much more generally applied than a unilateral balanced scheme in lingualized occlusion as well as in full balanced occlusion. Occlusal contacts on the non-chewing side occur earlier than on the chewing side;in the order of second molar, first molar, and then premolars. The contact on the balancing side contributes to the prevention of denture dislocation and guidance from eccentric positions to the centric occlusal position during mastication. Therefore, bilateral balanced occlusion was shown to be effective for denture stability during mastication with complete dentures. Today's typical edentulous patients have greater mean age than in the past, and thus are seen with severe alveolar bone resorption, thin mucosa and sometimes abnormalities of the maxillomandibular relation. Their occlusal positions are often unstable and changeable after insertion of complete dentures. Because lingualized occlusion allows for easier accommodation and correction, lingualized occlusion is more suitable for such cases than full balanced occlusion, which requires a strict occlusal relationship. In light of the standard Japanese diet, there is some doubt about why lingualized occlusion might be suitable for Japanese edentulous patients in terms of the sense of mastication. A method of evaluating the sense of mastication needs to be established.
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Jung, Seung Eun; Shinn, Kyung Sub; Kim, Hak Hee; Mun, Seok Hwan; Lee, Young Joon; Lee, Bae Young; Choi, Byung Gil; Lee, Jae Mun; Lee, Hee Jeong
1999-01-01
To evaluate the efficacy of power Doppler ultrasonography (PDUS) in depicting renal infarction in rabbits during experimental renal segmental arterial occlusion, and to compare the results with those of CT scanning. In 28 rabbits weighing 2.5 4kg, the segmental renal artery was occluded through the left main renal artery by embolization with Ivalon (Nycomed, Paris, France). Power Doppler ultrasonography and spiral CT scanning were performed before and at 2, 5, 8, 15, and 24 hours, and 3 and 7 days after occlusion of the segmental renal artery. The location of infarcted areas and collaterals, as seen on PDUS and CT scans, was evaluated by two radiologists. In all cases, as seen on power Doppler ultrasonography, infarcted areas-when compared with normal parenchyma, clearly demonstrated wedge-shaped perfusion defects in the kidney. The location of the lesion closely corresponded to the location seen during CT scanning. After renal arterial occlusion, transiently congested capsular arteries, which were named 'capsular sign', were seen in 63% of rabbits in the two and five-hour groups. No significant cortical rim sign was demonstrated on power Doppler ultrasonography, though it was noted on spiral CT at 15 and 24 hours, and 3 and 7 days after renal arterial occlusion. Power Doppler ultrasonography was useful for the diagnosis of renal infarction. Congested capsular artery seen in the early stage of renal infarction might be a characteristic finding of this condition, as seen on power Doppler ultrasonography
Robust moving ship detection using context-based motion analysis and occlusion handling
Bao, X.; Zinger, S.; Wijnhoven, R.G.J.; With, de P.H.N.
2013-01-01
This paper proposes an original moving ship detection approach in video surveillance systems, especially con- centrating on occlusion problems among ships and vegetation using context information. Firstly, an over- segmentation is performed to divide and classify by SVM (Support Vector Machine)
[Relationship between Occlusal Discomfort Syndrome and Occlusal Threshold].
Munakata, Motohiro; Ono, Yumie; Hayama, Rika; Kataoka, Kanako; Ikuta, Ryuhei; Tamaki, Katsushi
2016-03-01
Occlusal dysesthesia has been defined as persistent uncomfortable feelings of intercuspal position continuing for more than 6 months without evidence of physical occlusal discrepancy. The problem often occurs after occlusal intervention by dental care. Although various dental treatments (e. g. occlusal adjustment, orthodontic treatment and prosthetic reconstruction) are attempted to solve occlusal dysesthesia, they rarely reach a satisfactory result, neither for patients nor dentists. In Japan, these symptoms are defined by the term "Occlusal discomfort syndrome" (ODS). The aim of this study was to investigate the characteristics of ODS with the simple occlusal sensory perceptive and discriminative test. Twenty-one female dental patients with ODS (mean age 55.8 ± 19.2 years) and 21 age- and gender-matched dental patients without ODS (mean age 53.1 ± 16.8 years) participated in the study. Upon grinding occlusal registration foils that were stacked to different thicknesses, participants reported the thicknesses at which they recognized the foils (recognition threshold) and felt discomfort (discomfort threshold). Although there was no significant difference in occlusal recognition thresholds between the two patient groups, the discomfort threshold was significantly smaller in the patients with ODS than in those without ODS. Moreover, the recognition threshold showed an age-dependent increase in patients without ODS, whereas it remained comparable between the younger (patient subgroups with ODS. These results suggest that occlusal discomfort threshold rather than recognition threshold is an issue in ODS. The foil grinding procedure is a simple and useful method to evaluate occlusal perceptive and discriminative abilities in patients with ODS.
Comparison of partial and complete arterial occlusion models for studying intestinal ischemia
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Parks, D.A.; Grogaard, B.; Granger, D.N.
1982-01-01
Mucosal albumin clearance was measured in jejunal segments of dogs under control conditions and following complete or partial arterial occlusion of varying durations (1, 2, 3, or 4 hours). The rate of albumin clearance was estimated from the luminal perfusion rate and the activity of protein bound 125 I in the perfusate and plasma. Partial and total arterial occlusions of 60 minutes to 4 hours' duration produced significant increases in mucosal albumin clearance. The magnitude of the rise in albumin clearance was directly related to the duration of ischemia in both total and partial arterial occlusion models. However, the magnitude of the increase in albumin clearance was significantly greater with total arterial occlusion for any given duration of ischemia. The albumin clearance results obtained in the present study compare favorably with previously reported morphologic changes in the intestinal mucosa produced by both total and partial occlusion of the superior mesenteric artery. The agreement between morphologic and physiologic measurements indicates that mucosal albumin clearance may be a useful tool for studying the pathophysiology of intestinal ischemia
Vives-Borrás, Miquel; Jorge, Esther; Amorós-Figueras, Gerard; Millán, Xavier; Arzamendi, Dabit; Cinca, Juan
2018-01-01
Simultaneous ischemia in two myocardial regions is a potentially lethal clinical condition often unrecognized whose corresponding electrocardiographic (ECG) patterns have not yet been characterized. Thus, this study aimed to determine the QRS complex and ST-segment changes induced by concurrent ischemia in different myocardial regions elicited by combined double occlusion of the three main coronary arteries. For this purpose, 12 swine were randomized to combination of 5-min single and double coronary artery occlusion: Group 1: left Circumflex (LCX) and right (RCA) coronary arteries ( n = 4); Group 2: left anterior descending artery (LAD) and LCX ( n = 4) and; Group 3: LAD and RCA ( n = 4). QRS duration and ST-segment displacement were measured in 15-lead ECG. As compared with single occlusion, double LCX+RCA blockade induced significant QRS widening of about 40 ms in nearly all ECG leads and magnification of the ST-segment depression in leads V1-V3 (maximal 228% in lead V3, p ST-segment elevation in precordial leads (maximal attenuation of 60% in lead V3 in LAD+LCX and 86% in lead V5 in LAD+RCA, p ST-segment elevation in leads V7-V9 was a specific sign of single LCX occlusion. In conclusion, concurrent infero-lateral ischemia was associated with a marked summation effect of the ECG changes previously elicited by each single ischemic region. By contrast, a cancellation effect on ST-segment changes with no QRS widening was observed when the left anterior descending artery was involved.
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Lauenstein, T.C.; Heusner, T.A.; Antoch, G.; Hamami, M.; Bockisch, A.; Ertle, J.; Schlaak, J.F.; Gerken, G.
2011-01-01
Radioembolization using 90yttrium is an emerging therapy option for unresectable liver malignancies. In order to reduce the number of yttrium injections, endovascular occlusion of a segmental hepatic artery has been proposed. The aim of this study was to assess whether sufficient vascular redistribution of the occluded liver segments through intrahepatic collaterals can be observed. 27 patients with hepatocellular carcinoma (n = 16) or hepatic metastases (n = 11) were studied. Hepatic angiography was performed on average 16 days prior to radioembolization. The segment II/III artery (n = 9) or the segment IV artery (n = 18) was occluded using coils. Technectium-99m-labeled macroaggregated albumin (99mTc-MAA) was injected into the right and the remaining part of the left hepatic artery in order to identify any hepatic volume not included in the perfused area. Patients underwent a SPECT/CT on average 1 h after the 99mTc-MAA injection. Two radiologists evaluated the SPECT/CT scans regarding the presence of non-perfused hepatic segments. Furthermore, hepatic perfusion was assessed by digital subtraction angiography (DSA) on the day of radioembolization. In 16 / 27 patients (59 %) a perfusion of the occluded liver segment was visible on the SPECT/CT scan. In 8 / 11 patients without flow redistribution at the time of the SPECT/CT, perfusion of the occluded segment through hepatic collaterals was observed during angiography prior to radioembolization. Hence, flow redistribution was eventually found in 24 / 27 patients (89 %). Flow redistribution after the occlusion of intrahepatic arteries prior to radioembolization can be successfully induced in the majority of patients with anatomical variants of the hepatic arteries. (orig.)
Experimental animal study of a novel radiofrequency endovascular occlusion device.
Zacharoulis, Dimitris; Lazoura, Olga; Rountas, Christos; Katsimboulas, Michael; Mantzianas, George; Tzovaras, George; Habib, Nagy
2011-07-01
The purpose of this study was to present a radiofrequency (RF) endovascular occlusion device (ie, Habib VesCoag Catheter; EMcision Ltd, London, UK) and to evaluate safety and efficacy of the device for complete occlusion of normal porcine vessels. The study included 20 pigs. In each pig, a segmental branch of the right hepatic artery, a branch of the splenic artery, and a branch of one of the renal arteries were catheterized. A single or multiple applications of RF energy were performed until vessel occlusion was achieved. Fifteen days later, angiography was repeated to assess vessel patency. The vessels were then excised for pathological analysis. Vessels 2.5 to 6 mm in diameter were treated. Complete occlusion with a single attempt was achieved using a mean amount of energy of 110.67 J in vessels 2.5 to 3 mm, 111.67 J in vessels 3.5 to 4 mm, and 116.63 J in vessels 5 to 6 mm in diameter and was confirmed by angiography at the 15-day follow-up. Vascular occlusion can be effectively and safely achieved by endovascular application of RF energy to normal porcine arteries using the Habib VesCoag catheter. Copyright © 2011 Elsevier Inc. All rights reserved.
Wiens, Jonathan P; Priebe, Jennifer W
2014-01-01
Occlusion is the foundation for clinical success in fixed, removable, and implant prosthodontic treatment. Understanding those principles is critical when restoring a patient's occlusion. Many philosophies, devices, and theories of occlusion have evolved based on anecdotal clinical observations and applied geometric perceptions. The literature has reported these classic and contemporary occlusal concepts. As evidence-based dentistry emerged, it championed scrutiny of previously held beliefs, resulting in the abandonment of many pragmatic, yet beneficial occlusal procedures. The impetus toward scientific discovery, whereby factual information might be universally applied in dental education and clinical practice, has renewed interest in occlusal studies. Copyright © 2014 Elsevier Inc. All rights reserved.
Superior mesenteric arterial branch occlusion causing partial jejunal ischemia: a case report
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Van De Winkel Nele
2012-02-01
Full Text Available Abstract Introduction Ischemic bowel disease comprises both mesenteric ischemia and colonic ischemia. Mesenteric ischemia can be divided into acute and chronic ischemia. These are two separate entities, each with their specific clinical presentation and diagnostic and therapeutic modalities. However, diagnosis may be difficult due to the vague symptomatology and subtle signs. Case presentation We report the case of a 68-year-old Caucasian woman who presented with abdominal discomfort, anorexia, melena and fever. A physical examination revealed left lower quadrant tenderness and an irregular pulse. Computed tomography of her abdomen as well as computed tomography enterography, enteroscopy, angiography and small bowel enteroclysis demonstrated an ischemic jejunal segment caused by occlusion of a branch of the superior mesenteric artery. The ischemic segment was resected and an end-to-end anastomosis was performed. The diagnosis of segmental small bowel ischemia was confirmed by histopathological study. Conclusion Mesenteric ischemia is a pathology well-known by surgeons, gastroenterologists and radiologists. Acute and chronic mesenteric ischemia are two separate entities with their own specific clinical presentation, radiological signs and therapeutic modalities. We present the case of a patient with symptoms and signs of chronic mesenteric ischemia despite an acute etiology. To the best of our knowledge, this is the first report presenting a case of acute mesenteric ischemia with segmental superior mesenteric artery occlusion.
Nazir, Nazia; Sujesh, M; Kumar, Ravi; Sreenivas, P
2012-01-01
The precision of an arbitrary face-bow in accurately transferring the orientation of the maxillary cast to the articulator has been questioned because the maxillary cast is mounted in relation to arbitrary measurements and anatomic landmarks that vary among individuals. This study was intended to evaluate the sagittal inclination of mounted maxillary casts on two semi-adjustable articulator/face-bow systems in comparison to the occlusal cant on lateral cephalograms. Maxillary casts were mounted on the Hanau and Girrbach semi-adjustable articulators following face-bow transfer with their respective face-bows. The sagittal inclination of these casts was measured in relation to the fixed horizontal reference plane using physical measurements. Occlusal cant was measured on lateral cephalograms. SPSS software (version 11.0, Chicago, IL, USA) was used for statistical analysis. Repeated measures analysis of variance and Tukey's tests were used to evaluate the results (P occlusal cant on the articulators and cephalogram revealed statistically significant differences. Occlusal plane was steeper on Girrbach Artex articulator in comparison to the Hanau articulator. Within the limitations of this study, it was found that the sagittal inclination of the mounted maxillary cast achieved with Hanau articulator was closer to the cephalometric occlusal cant as compared to that of the Girrbach articulator. Among the two articulators and face-bow systems, the steepness of sagittal inclination was greater on Girrbach semi-adjustable articulator. Different face-bow/articulator systems could result in different orientation of the maxillary cast, resulting in variation in stability, cuspal inclines and cuspal heights.
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Kim, Gun Soo; Kim, Seul Kee; Baek, Byeong Hyeon; Lee, Youn Young; Yoon, Woong [Dept. of Radiology, Chonnam National University Medical School, Chonnam National University Hospital, Gwangju (Korea, Republic of)
2017-04-15
To compare the characteristics and outcomes of multimodal endovascular therapy (EVT) in patients with acute basilar artery occlusion (BAO) with and without underlying intracranial atherosclerotic stenosis (ICAS). We retrospectively analyzed the data from 50 patients with acute BAO who were treated with EVT. The baseline characteristics and outcomes of patients with and without ICAS were compared. Patients with ICAS underwent intracranial angioplasty or stenting after mechanical thrombectomy. Thirty percent of the patients (15/50) had underlying ICAS at the occlusion site. On pretreatment diffusion-weighted imaging (DWI), bilateral thalamic infarction was less frequently found in patients with ICAS (0% vs. 25.7%, p = 0.03). Occlusion in the proximal segment of the basilar artery was more common in patients with ICAS (60% vs. 5.7%, p < 0.001), whereas occlusion in the distal segment of the basilar artery was more common in patients without ICAS (26.7% vs. 91.4%, p < 0.001). There were no significant differences in the rates of successful revascularization, 3-month modified Rankin Scale scores of 0–2, symptomatic hemorrhage, and mortality between the two groups. ICAS was common in patients with acute stroke due to BAO. The occlusion site and the presence or absence of bilateral thalamic infarction on pretreatment DWI might help predict the underlying ICAS in patients with acute BAO.
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Kim, Gun Soo; Kim, Seul Kee; Baek, Byeong Hyeon; Lee, Youn Young; Yoon, Woong
2017-01-01
To compare the characteristics and outcomes of multimodal endovascular therapy (EVT) in patients with acute basilar artery occlusion (BAO) with and without underlying intracranial atherosclerotic stenosis (ICAS). We retrospectively analyzed the data from 50 patients with acute BAO who were treated with EVT. The baseline characteristics and outcomes of patients with and without ICAS were compared. Patients with ICAS underwent intracranial angioplasty or stenting after mechanical thrombectomy. Thirty percent of the patients (15/50) had underlying ICAS at the occlusion site. On pretreatment diffusion-weighted imaging (DWI), bilateral thalamic infarction was less frequently found in patients with ICAS (0% vs. 25.7%, p = 0.03). Occlusion in the proximal segment of the basilar artery was more common in patients with ICAS (60% vs. 5.7%, p < 0.001), whereas occlusion in the distal segment of the basilar artery was more common in patients without ICAS (26.7% vs. 91.4%, p < 0.001). There were no significant differences in the rates of successful revascularization, 3-month modified Rankin Scale scores of 0–2, symptomatic hemorrhage, and mortality between the two groups. ICAS was common in patients with acute stroke due to BAO. The occlusion site and the presence or absence of bilateral thalamic infarction on pretreatment DWI might help predict the underlying ICAS in patients with acute BAO
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Nelson, R.C.; Chemzmar, J.L.; Sugarbaker, P.H.; Bernardino, M.E.
1989-01-01
Using cross-sectional images to localize tumors to specific hepatic segments before resection might be difficult because the transverse scissura, an important segmental landmark, is approximately parallel to the axial plane. Since this plane is parallel to the main right and left portal pedicles, the authors postulated that they could localize lesions above this plane to segments 2,4A,7, or 8, and below this plane to segments 3, 4B,5, or 6. The authors have retrospectively evaluated, in a blinded fashion, 24 hepatic masses in 13 patients who underwent CTA-portography and subsequent tumor resection. Using this scheme, they have accurately predicted the primary segmental location in 22 (92%) of 24 surgically confirmed lesions
Small bowel volvulus in pregnancy with associated superior mesenteric artery occlusion.
Esterson, Yonah B; Villani, Robert; Dela Cruz, Ronald A; Friedman, Barak; Grimaldi, Gregory M
Here we report the case of a pregnant 28-year-old who presented with acute upper abdominal pain. CT demonstrated midgut volvulus with short segment occlusion of the superior mesenteric artery (SMA). Emergent detorsion of the small bowel was performed, at which time underlying intestinal malrotation was discovered. Following detorsion, the SMA had a bounding pulse and did not require thrombectomy or revascularization. Fewer than 25 cases of midgut volvulus during pregnancy have been reported over the past 20years. To our knowledge, this is the first report of maternal midgut volvulus in which imaging captures the resultant occlusion of the SMA. Copyright © 2017 Elsevier Inc. All rights reserved.
NCC-RANSAC: a fast plane extraction method for 3-D range data segmentation.
Qian, Xiangfei; Ye, Cang
2014-12-01
This paper presents a new plane extraction (PE) method based on the random sample consensus (RANSAC) approach. The generic RANSAC-based PE algorithm may over-extract a plane, and it may fail in case of a multistep scene where the RANSAC procedure results in multiple inlier patches that form a slant plane straddling the steps. The CC-RANSAC PE algorithm successfully overcomes the latter limitation if the inlier patches are separate. However, it fails if the inlier patches are connected. A typical scenario is a stairway with a stair wall where the RANSAC plane-fitting procedure results in inliers patches in the tread, riser, and stair wall planes. They connect together and form a plane. The proposed method, called normal-coherence CC-RANSAC (NCC-RANSAC), performs a normal coherence check to all data points of the inlier patches and removes the data points whose normal directions are contradictory to that of the fitted plane. This process results in separate inlier patches, each of which is treated as a candidate plane. A recursive plane clustering process is then executed to grow each of the candidate planes until all planes are extracted in their entireties. The RANSAC plane-fitting and the recursive plane clustering processes are repeated until no more planes are found. A probabilistic model is introduced to predict the success probability of the NCC-RANSAC algorithm and validated with real data of a 3-D time-of-flight camera-SwissRanger SR4000. Experimental results demonstrate that the proposed method extracts more accurate planes with less computational time than the existing RANSAC-based methods.
International Nuclear Information System (INIS)
Behnes, Michael; Akin, Ibrahim; Sartorius, Benjamin; Fastner, Christian; El-Battrawy, Ibrahim; Borggrefe, Martin; Haubenreisser, Holger; Meyer, Mathias; Schoenberg, Stefan O.; Henzler, Thomas
2016-01-01
A standardized imaging proposal evaluating implanted left atrial appendage (LAA) occlusion devices by cardiac computed tomography angiography (cCTA) has never been investigated. cCTA datasets were acquired on a 3 rd generation dual-source CT system and reconstructed with a slice thickness of 0.5 mm. An interdisciplinary evaluation was performed by two interventional cardiologists and one radiologist on a 3D multi-planar workstation. A standardized multi-planar reconstruction algorithm was developed in order to assess relevant clinical aspects of implanted LAA occlusion devices being outlined within a pictorial essay. The following clinical aspects of implanted LAA occlusion devices were evaluated within the most appropriate cCTA multi-planar reconstruction: (1) topography to neighboring structures, (2) peri-device leaks, (3) coverage of LAA lobes, (4) indirect signs of neo-endothelialization. These are illustrated within concise CT imaging examples emphasizing the potential value of the proposed cCTA imaging algorithm: Starting from anatomical cCTA planes and stepwise angulation planes perpendicular to the base of the LAA devices generates an optimal LAA Occluder View for post-implantation Evaluation (LOVE). Aligned true axial, sagittal and coronal LOVE planes offer a standardized and detailed evaluation of LAA occlusion devices after percutaneous implantation. This pictorial essay presents a standardized imaging proposal by cCTA using multi-planar reconstructions that enables systematical follow-up and comparison of patients after LAA occlusion device implantation. The online version of this article (doi:10.1186/s12880-016-0127-y) contains supplementary material, which is available to authorized users
Directory of Open Access Journals (Sweden)
Nazia Nazir
2012-01-01
Full Text Available Context: The precision of an arbitrary face-bow in accurately transferring the orientation of the maxillary cast to the articulator has been questioned because the maxillary cast is mounted in relation to arbitrary measurements and anatomic landmarks that vary among individuals. Aim: This study was intended to evaluate the sagittal inclination of mounted maxillary casts on two semi-adjustable articulator/face-bow systems in comparison to the occlusal cant on lateral cephalograms. Materials and Methods: Maxillary casts were mounted on the Hanau and Girrbach semi-adjustable articulators following face-bow transfer with their respective face-bows. The sagittal inclination of these casts was measured in relation to the fixed horizontal reference plane using physical measurements. Occlusal cant was measured on lateral cephalograms. SPSS software (version 11.0, Chicago, IL, USA was used for statistical analysis. Repeated measures analysis of variance and Tukey′s tests were used to evaluate the results (P < 0.05. Results: Comparison of the occlusal cant on the articulators and cephalogram revealed statistically significant differences. Occlusal plane was steeper on Girrbach Artex articulator in comparison to the Hanau articulator. Conclusion: Within the limitations of this study, it was found that the sagittal inclination of the mounted maxillary cast achieved with Hanau articulator was closer to the cephalometric occlusal cant as compared to that of the Girrbach articulator. Among the two articulators and face-bow systems, the steepness of sagittal inclination was greater on Girrbach semi-adjustable articulator. Different face-bow/articulator systems could result in different orientation of the maxillary cast, resulting in variation in stability, cuspal inclines and cuspal heights.
Regarding optical coherence tomography grading of ischemia in central retinal venous occlusion
Directory of Open Access Journals (Sweden)
Tripathy K
2017-02-01
Full Text Available Koushik TripathyDepartment of Vitreoretina and Uvea, ICARE Eye Hospital & Postgraduate Institute, Noida, Uttar Pradesh, IndiaThe author read with interest the article by Browning et al.1 The author humbly wants to discuss a few facts.1. The article1 discusses grading of retinal ischemia based on optical coherence tomography features in central retinal venous occlusion. As coexisting central retinal arterial occlusion or cilioretinal arterial occlusion may also cause inner retinal hyper-reflectivity, exclusion of such cases is an important consideration before implicating central retinal venous occlusion for the ischemia. Extensive intraretinal hemorrhages are other important hindrances to the evaluation of the perfusion status of the retina using both fluorescein angiogram and optical coherence tomography.2. It would be interesting to know the gonioscopic findings, especially neovascularization of the anterior chamber angle if it was performed at presentation and during the follow-ups.3. The manuscript documented that the incidence of anterior segment neovascularization at 1 year was 8.9% in severe ischemia group.1 The incidence of anterior segment neovascularization in perfused groups was higher (15.4% and 17.6% for mild and moderate ischemia, respectively. Although the sample size was low, such findings are contrary to the literature2 and require further discussion. Authors' replyDavid J Browning, Omar S Punjabi, Chong LeeDepartment of Ophthalmology, Charlotte Eye, Ear, Nose and Throat Associates, P.A., Charlotte, NC, USA We thank Dr Tripathy for his interest in our article and would respond to his above-mentioned points.1. We agree that excluding eyes with cilioretinal artery and central retinal artery occlusions is necessary to be able to attribute inner retinal reflectivity changes to central retinal vein occlusion. Cilioretinal artery occlusion is associated with a band of ischemic retinal whitening and central retinal artery occlusion
Henriques, J.P.; Hoebers, L.P.; Ramunddal, T.; Laanmets, P.; Eriksen, E.; Bax, M.; Ioanes, D.; Suttorp, M.J.; Strauss, B.H.; Barbato, E.; Nijveldt, R.; Rossum, A.C. van; Marques, K.M.; Elias, J.; Dongen, I.M. van; Claessen, B.E.; Tijssen, J.G.; Schaaf, R.J. van der; Boer, M.J. de; et al.,
2016-01-01
BACKGROUND: In 10% to 15% of patients with ST-segment elevation myocardial infarction (STEMI), concurrent coronary chronic total occlusion (CTO) in a non-infarct-related artery is present and is associated with increased morbidity and mortality. OBJECTIVES: The EXPLORE (Evaluating Xience and Left
Lederman, K H; Clayton, J A
1983-07-01
An earlier study of 50 patients with occlusions restored by fixed partial dentures indicated a high percent (68%) of TMJ dysfunction. Occlusal interferences can play a significant role in causing TMJ dysfunction. To determine the significance of occlusal interferences, occlusal splints were placed in 10 of these restored patients who had moderate to severe dysfunction. The PRI was used to detect the presence or absence of TMJ dysfunction. The PRI TMJ dysfunction scores were reduced in all 10 patients after use of the occlusal splint. Five of the patients achieved reproducible tracings (no TMJ dysfunction) during the experiment time of 7 months. The occlusion of two patients was adjusted to eliminate the need for the occlusal splint. Patients who wore the splint 24 hours a day showed a significant (0.0004 level) reduction in TMJ dysfunction. Those patients who did not wear the splint regularly or had high levels of stress had PRI scores that varied. This finding indicates that the occlusal splint is not a treatment, as its removal permits reactivation of the occlusal interference. Resolution of dysfunction did not occur until occlusal interferences were removed. The changes in PRI scores to different dysfunction categories (none, slight, moderate, and severe) for the experimental group were significant at the 0.01 level. A control group of five patients had similar pantographic tracings but no other treatment. Their PRI scores varied, but there was no significant change in PRI scores or dysfunction categories. It was concluded that occlusal interferences were active causes of TMJ dysfunction in 10 of 36 patients in a population with restored occlusions.
Gamifying Video Object Segmentation.
Spampinato, Concetto; Palazzo, Simone; Giordano, Daniela
2017-10-01
Video object segmentation can be considered as one of the most challenging computer vision problems. Indeed, so far, no existing solution is able to effectively deal with the peculiarities of real-world videos, especially in cases of articulated motion and object occlusions; limitations that appear more evident when we compare the performance of automated methods with the human one. However, manually segmenting objects in videos is largely impractical as it requires a lot of time and concentration. To address this problem, in this paper we propose an interactive video object segmentation method, which exploits, on one hand, the capability of humans to identify correctly objects in visual scenes, and on the other hand, the collective human brainpower to solve challenging and large-scale tasks. In particular, our method relies on a game with a purpose to collect human inputs on object locations, followed by an accurate segmentation phase achieved by optimizing an energy function encoding spatial and temporal constraints between object regions as well as human-provided location priors. Performance analysis carried out on complex video benchmarks, and exploiting data provided by over 60 users, demonstrated that our method shows a better trade-off between annotation times and segmentation accuracy than interactive video annotation and automated video object segmentation approaches.
[Occlusal schemes of complete dentures--a review of the literature].
Tarazi, E; Ticotsky-Zadok, N
2007-01-01
movements). Linear occlusion scheme occludes cuspless teeth with anatomic teeth that have been modified (bladed teeth) in order to achieve linear occlusal contacts. Linear contacts are the pin-point contacts of the tips of the cusps of the bladed teeth against cuspless teeth that create a plane. The specific design of positioning upper modified teeth on the upper denture and non anatomic teeth on the lower one is called lingualized occlusion. It is characterized by contacts of only the lingual (palatinal, to be more accurate) cusps of the upper teeth with the lower teeth. The lingualized occlusal scheme provides better aesthetics than the monoplane occlusion scheme, and better stability (in the case of resorbed residual ridges) than bilateral occlusion scheme of anatomic teeth. The results of studies that compared different occlusal schemes may well be summarized as inconclusive. However, it does seem that patients preferred anatomic or semi-anatomic (modified) teeth, and that chewing efficiency with anatomic and modified teeth was better than with non anatomic teeth. Similar results were found in studies of occlusal schemes of implant-supported lower dentures opposed by complete upper dentures. There isn't one occlusal scheme that fits all patients in need of complete dentures, in fact, in many cases more than one occlusal scheme might be adequate. Selection of an occlusal scheme for a patient should include correlation of the characteristics of the patient with those of the various occlusal schemes. The characteristics of the patient include: height and width of the residual ridge, aesthetic demands of the patient, skeletal relations (class I/II/III), neuromuscular control, and tendency for para-functional activity. The multiple characteristics of the occlusal schemes were reviewed in this article. Considering all of those factors in relation to a specific patient, the dentist should be able to decide on the most suitable occlusal scheme for the case.
Occlusal management for a patient with aural symptoms of unknown etiology: a case report
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Torii Kengo
2007-09-01
Full Text Available Abstract Background Although the discrepancy between the habitual occlusal position (HOP and the flat bite plate-induced occlusal position (BPOP (regarded as the muscular physiological reference position has been recently reported to be related to symptoms of temporomandibular disorders (TMDs, it still remains unclear whether the occlusal equilibration in the reference position is effective to resolve TMD-related discrepancy and symptoms. Aural symptoms (otalgia, tinnitus, vertigo et cetera have been included under TMD symptoms. Methods To examine the effect of occlusal equilibration for the treatment of TMDs, occlusal equilibration was performed for a patient with aural symptoms (otalgia, tinnitus and vertigo of unknown etiology in the right ear. An occlusal analysis was performed on this patient with dental models mounted on an articulator after relieving painful symptoms by an appliance therapy and a discrepancy was identified (p Results At completion of treatment, the discrepancy was not significant (p > 0.25, and the patient's right condyle had shifted 2.8 mm posteromedially in the horizontal plane, and the left condyle had shifted 1.0 mm laterally in the voluntarily closed position from the previous HOP. The aural symptoms of the patient were resolved, and there has been no recurrence to date after a two-year follow-up period. Conclusion An occlusal analysis should be performed in patients exhibiting TMD symptoms to identify the presence or absence of any discrepancy between the HOP and the BPOP. If a discrepancy exists, occlusal equilibration should be attempted in the reference position.
Fatic, Nikola; Jaffer, Usman; Ivana, Saicic; Gordana, Globarevic-Vukcevic; Markovic, Dragan; Kostic, Dusan; Davidovic, Lazar
2017-10-01
The clinical spectrum of internal carotid artery occlusion ranges from being a completely asymptomatic occlusion to a devastating stroke or death. The prevalence of asymptomatic internal carotid artery occlusion is unknown, particularly for bilateral occlusion. The distal branches of the external carotid artery anastomose with distal branches of the internal carotid artery provide important sources of collateral circulation to the brain. Stenosis of the external carotid artery with ipsilateral/bilateral internal occlusion may result in ischemic sequelae. Coiling or kinking of the vertebral artery is a rare morphological entity that is infrequently reported because it remains asymptomatic and has no clinical relevance. Currently, there is little evidence to support management strategies for this disease entity and no official recommendations for asymptomatic bilateral carotid artery occlusion. We present a case of a 62-year-old female with asymptomatic bilateral internal carotid artery occlusion, bilateral external carotid artery stenoses, and bilateral kinking of the vertebral artery at the V2 segment, who has been successfully managed conservatively for over 5 years. An individualized approach to management of patients with bilateral internal carotid artery occlusion, especially in combination with external carotid artery stenosis and elongation malformations of the vertebral artery is key to a successful strategy. Copyright © 2017 Elsevier Inc. All rights reserved.
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Olivier Lezoray
2011-05-01
Full Text Available In this paper, an approach to the segmentation of microscopic color images is addressed, and applied to medical images. The approach combines a clustering method and a region growing method. Each color plane is segmented independently relying on a watershed based clustering of the plane histogram. The marginal segmentation maps intersect in a label concordance map. The latter map is simplified based on the assumption that the color planes are correlated. This produces a simplified label concordance map containing labeled and unlabeled pixels. The formers are used as an image of seeds for a color watershed. This fast and robust segmentation scheme is applied to several types of medical images.
CT identification of bronchopulmonary segments: 50 normal subjects
International Nuclear Information System (INIS)
Osbourne, D.; Vock, P.; Godwin, J.D.; Silverman, P.M.
1984-01-01
A systematic evaluation of the fissures, segmental bronchi and arteries, bronchopulmonary segments, and peripheral pulmonary parenchyma was made from computed tomographic (CT) scans of 50 patients with normal chest radiographs. Seventy percent of the segmental bronchi and 76% of the segmental arteries were identified. Arteries could be traced to their sixth- and seventh-order branches; their orientation to the plane of the CT section allowed gross identification and localization of bronchopulmonary segments
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Tonev, I.; Zechirov, B.; Stanoev, D.; Velikov, C.; Smilkova, D.
2015-01-01
Full text: Diseases of the upper limb arteries are significantly rarer than those of the lower limbs but they are not causes and due to the lack of diagnostic algorithms are often missed. the symptoms are not typical except for those in acute thrombosis. The complaints in acute thrombosis is strong, sudden pain in the limb or part of it, bruising or paleness of the ischemic area and a lack of pulsation. Diagnosis is fairly easy – clinical events, difference in blood pressure or a lack of blood pressure in the affected limb, a total lack of blood pressure or a difference in the pressure in the left and right arm. Then complaints in stenosis and chronic occlusions is significantly less pronounced and is expressed as weakness in the affected limb, heaviness, bluish or paleness. If the proximal segments are affected Still’s syndrome is often observed. The complaints is not decisive for diagnosis. A difference in blood pressure of more than 20 mm Hg and an echodoppler examination of the arteries are the main criteria for directing the patients for angiography. Contrast CT and MRT are not used often. treatment is vascular surgery and endovascular. In acute thrombosis priority takes vascular surgery through extraction of the thrombi with Fogerty catheters, and in chronical stenosis and occlusions – dilation and stenting. Clinical cases: Case 1 – Revascularization of artery brachialis, radialis and ulnaris after acute occlusion L.Y., 77 years old. Complains of sharp pain and bruising of right forearm since two hours before hospitalization. A lack of blood flow was identified using palpation and echodoppler. After a diagnostic angiography , thrombaspiration was undertaken, through a leading catheter, recovering blood flow in both arteries and stenting of the proximal segment of artery radialis. Case 2: Revascularization of Trunkus brachiocefalicus K.P., 65 years old. Suffering from bradypsychia for several months. Bradypsychia becomes worse after manual labor
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Zhiva Taherpour
2013-05-01
Full Text Available Please cite this article as: Taherpour Z, Seyedian M, Alasti M. Simultaneous right coronary artery spasm in a patient with Anterior ST-Segment Elevation Myocardial Infarction: a case report. Novel Biomed 2013;1:29-33.Simultaneous occlusion of two vessels causing infarction at different territories is an uncommon finding. We report simultaneous right ventricular and anterior ST-segment elevation myocardial infarction in a previously healthy young man.The angiographic results demonstrated the simultaneous occlusion of the right and left coronary arteries because of simultaneous occlusion of left anterior descending artery (LADA and spasm of right coronary artery (RCA. In this patient, we found simultaneous ST elevations in right and precordial leads so everyone should be careful about all leads of the surface electrocardiogram for decision making in the management of a patient.
Godefroy, J N; Yardin, M
1991-06-01
The effects of occlusal interference on masticatory cycles have been studied in twenty nine volunteers with complete natural dentition, using an electromagnetic pantograph (Sirognatograph, Siemens A.G.). After a one week recall, a decrease in speed motion was noted and the range of cycles in the horizontal plane had been altered.
Stereovision-Based Object Segmentation for Automotive Applications
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Fu Shan
2005-01-01
Full Text Available Obstacle detection and classification in a complex urban area are highly demanding, but desirable for pedestrian protection, stop & go, and enhanced parking aids. The most difficult task for the system is to segment objects from varied and complicated background. In this paper, a novel position-based object segmentation method has been proposed to solve this problem. According to the method proposed, object segmentation is performed in two steps: in depth map ( - plane and in layered images ( - planes. The stereovision technique is used to reconstruct image points and generate the depth map. Objects are detected in the depth map. Afterwards, the original edge image is separated into different layers based on the distance of detected objects. Segmentation performed in these layered images can be easier and more reliable. It has been proved that the proposed method offers robust detection of potential obstacles and accurate measurement of their location and size.
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Ingrid Madeira de Barros Nunes
2007-01-01
Full Text Available OBJETIVO: este trabalho objetiva verificar as alterações do plano oclusal funcional de Ricketts, utilizando as variáveis que orientam este plano nas análises cefalométricas de Ricketts e Schawrz-Faltin, em pacientes portadores de má oclusão de Classe II de Angle, 1ª divisão, associada ao retrognatismo mandibular, cuja terapêutica indicada tenha sido a Bionatorterapia. METODOLOGIA: a amostra coletada neste estudo retrospectivo consta de 128 telerradiografias em norma lateral de 64 indivíduos retrovertidos, neutrovertidos e provertidos, de ambos os gêneros, no estágio de desenvolvimento da oclusão em fase mista ou permanente jovem. A faixa etária dos indivíduos selecionados para o estudo variou entre 7 anos e 1 mês a 13 anos e 2 meses no momento T1, sendo a média inicial de 10 anos de idade. A média de duração do tratamento foi de 19,7 meses. RESULTADOS E CONCLUSÃO: os resultados mostraram comportamentos distintos do plano oclusal, conforme o tipo facial retrovertido, neutrovertido ou provertido. O controle do plano oclusal na Bionatorterapia, pelo manejo do Bionator conforme o tipo facial de cada paciente, por meio de desgastes seletivos no acrílico e conseqüente erupção diferenciada dos dentes, pode influenciar favoravelmente o crescimento geral da face em cada tipo facial.AIM: This work aims to verify the changes of Ricketts functional occlusal plane making use of variables which guide this same plane in the cephalometric analysis of Ricketts and Schwarz-Faltin among patients with Class II, division 1 malocclusion, associated to mandible retrognathism, whose therapy indicated has been Bionatortherapy. METHODS: The sample collected in this retrospective survey has 128 lateral cephalograms of 64 retroverted, neutroverted and proverted individuals, of both genders, at the stage of developing occlusion, either in mixed phase or permanent young. The age scale of individuals selected by the survey goes from 7 years and 1
Wang, Chen; Yin, Xinmin
2012-10-01
The aim of this study was to characterize occlusal stability in young adults with temporomandibular disorder (TMD). Thirty-one patients (aged 19-31 years) with complete natural dentition and Angle class I occlusion who exhibited TMD were compared with 31 age- and sex-matched healthy control subjects. The occlusal registrations were performed using the T-Scan II occlusal imaging and analysis system. Center of occlusal force, asymmetry index of occlusal force, maximal movement of COF, premature contacts, clusion time, and disclusion time were recorded. Compared with control subjects, TMD subjects had a significantly higher frequency of premature contacts (16/32, 50.0%) and greater bilateral asymmetry in the occlusal force. Furthermore, prolonged clusion time and disclusion time also were observed in TMD subjects. These results suggest that a significant association exists between occlusal stability and TMD in young adults. Copyright © 2012 Elsevier Inc. All rights reserved.
Occlusion of the artery of Percheron: an unusual cause of bilateral stroke.
Anderson, Clare; O'Brien, Richard
2012-11-19
The artery of Percheron is a rare anatomical variant whereby a single vessel arising from the proximal segment of one posterior cerebral artery supplies both medial thalami. This is a rare example of a single arterial supply to brain structures on both sides of the midline. Occlusion of the artery of Percheron results in bilateral medial thalamic infarction, which is manifest clinically as gaze paresis, cognitive disturbance and altered consciousness. The presentation can mimic subarachnoid haemorrhage, drug intoxication, encephalitis and other inflammatory or infective conditions. The presentation is similar to the 'top of the basilar syndrome' and early recognition should prompt further investigation for underlying stroke aetiologies and consideration can be given to thrombolysis if vascular occlusion can be confirmed.
Electrical impedance along connective tissue planes associated with acupuncture meridians
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Hammerschlag Richard
2005-05-01
Full Text Available Abstract Background Acupuncture points and meridians are commonly believed to possess unique electrical properties. The experimental support for this claim is limited given the technical and methodological shortcomings of prior studies. Recent studies indicate a correspondence between acupuncture meridians and connective tissue planes. We hypothesized that segments of acupuncture meridians that are associated with loose connective tissue planes (between muscles or between muscle and bone visible by ultrasound have greater electrical conductance (less electrical impedance than non-meridian, parallel control segments. Methods We used a four-electrode method to measure the electrical impedance along segments of the Pericardium and Spleen meridians and corresponding parallel control segments in 23 human subjects. Meridian segments were determined by palpation and proportional measurements. Connective tissue planes underlying those segments were imaged with an ultrasound scanner. Along each meridian segment, four gold-plated needles were inserted along a straight line and used as electrodes. A parallel series of four control needles were placed 0.8 cm medial to the meridian needles. For each set of four needles, a 3.3 kHz alternating (AC constant amplitude current was introduced at three different amplitudes (20, 40, and 80 μAmps to the outer two needles, while the voltage was measured between the inner two needles. Tissue impedance between the two inner needles was calculated based on Ohm's law (ratio of voltage to current intensity. Results At the Pericardium location, mean tissue impedance was significantly lower at meridian segments (70.4 ± 5.7 Ω compared with control segments (75.0 ± 5.9 Ω (p = 0.0003. At the Spleen location, mean impedance for meridian (67.8 ± 6.8 Ω and control segments (68.5 ± 7.5 Ω were not significantly different (p = 0.70. Conclusion Tissue impedance was on average lower along the Pericardium meridian, but not
Ersoz, M Giray; Ture, Gamze
2018-04-01
To report the youngest female carrier of Fabry disease, complicated by cilioretinal artery occlusion and anterior ischemic optic neuropathy (AION). Case report. An 11-year-old girl was referred to our clinic with painless, acute loss of vision in her right eye. Posterior segment examination and fluorescein angiography revealed cilioretinal artery occlusion and AION. Systemic evaluations were unremarkable, except for a low blood α-galactosidase A enzyme level of 242.27 pmol/spot*20 h (reference range: 450-2000 pmol/spot*20 h). The patient was diagnosed with female carrier of Fabry disease. Retinal vascular occlusions are rare in childhood, and Fabry disease may present with retinal vascular occlusion. Ophthalmological examinations may be contributing for early detection of the disease. To the best of our knowledge, this is the first report of a child female carrier of Fabry disease, complicated by cilioretinal artery occlusion and AION.
A neural model of visual figure-ground segregation from kinetic occlusion.
Barnes, Timothy; Mingolla, Ennio
2013-01-01
Freezing is an effective defense strategy for some prey, because their predators rely on visual motion to distinguish objects from their surroundings. An object moving over a background progressively covers (deletes) and uncovers (accretes) background texture while simultaneously producing discontinuities in the optic flow field. These events unambiguously specify kinetic occlusion and can produce a crisp edge, depth perception, and figure-ground segmentation between identically textured surfaces--percepts which all disappear without motion. Given two abutting regions of uniform random texture with different motion velocities, one region appears to be situated farther away and behind the other (i.e., the ground) if its texture is accreted or deleted at the boundary between the regions, irrespective of region and boundary velocities. Consequently, a region with moving texture appears farther away than a stationary region if the boundary is stationary, but it appears closer (i.e., the figure) if the boundary is moving coherently with the moving texture. A computational model of visual areas V1 and V2 shows how interactions between orientation- and direction-selective cells first create a motion-defined boundary and then signal kinetic occlusion at that boundary. Activation of model occlusion detectors tuned to a particular velocity results in the model assigning the adjacent surface with a matching velocity to the far depth. A weak speed-depth bias brings faster-moving texture regions forward in depth in the absence of occlusion (shearing motion). These processes together reproduce human psychophysical reports of depth ordering for key cases of kinetic occlusion displays. Copyright © 2012 Elsevier Ltd. All rights reserved.
Communication: Two types of flat-planes conditions in density functional theory.
Yang, Xiaotian Derrick; Patel, Anand H G; Miranda-Quintana, Ramón Alain; Heidar-Zadeh, Farnaz; González-Espinoza, Cristina E; Ayers, Paul W
2016-07-21
Using results from atomic spectroscopy, we show that there are two types of flat-planes conditions. The first type of flat-planes condition occurs when the energy as a function of the number of electrons of each spin, Nα and Nβ, has a derivative discontinuity on a line segment where the number of electrons, Nα + Nβ, is an integer. The second type of flat-planes condition occurs when the energy has a derivative discontinuity on a line segment where the spin polarization, Nα - Nβ, is an integer, but does not have a discontinuity associated with an integer number of electrons. Type 2 flat planes are rare-we observed just 15 type 2 flat-planes conditions out of the 4884 cases we tested-but their mere existence has implications for the design of exchange-correlation energy density functionals. To facilitate the development of functionals that have the correct behavior with respect to both fractional number of electrons and fractional spin polarization, we present a dataset for the chromium atom and its ions that can be used to test new functionals.
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Kunz, Wolfgang G.; Sommer, Wieland H.; Meinel, Felix G.; Ertl-Wagner, Birgit; Thierfelder, Kolja M. [Ludwig-Maximilian-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); Havla, Lukas; Dietrich, Olaf [Ludwig-Maximilian-University Hospital Munich, Josef Lissner Laboratory for Biomedical Imaging of the Institute for Clinical Radiology, Munich (Germany); Dorn, Franziska [Ludwig-Maximilian-University Hospital Munich, Department of Neuroradiology, Munich (Germany); Buchholz, Grete [Ludwig-Maximilian-University Hospital Munich, Department of Neurology, Munich (Germany)
2017-06-15
To determine the detection rate of intracranial vessel occlusions using CT perfusion-based wavelet-transformed angiography (waveletCTA) in acute ischemic stroke patients, in whom single-phase CTA (spCTA) failed to detect an occlusion. Subjects were selected from a cohort of 791 consecutive patients who underwent multiparametric CT including whole-brain CT perfusion. Inclusion criteria were (1) significant cerebral blood flow (CBF) deficit, (2) no evidence of vessel occlusion on spCTA and (3) follow-up-confirmed acute ischemic infarction. waveletCTA was independently analysed by two readers regarding presence and location of vessel occlusions. Logistic regression analysis was performed to identify predictors of waveletCTA-detected occlusions. Fifty-nine patients fulfilled the inclusion criteria. Overall, an occlusion was identified using waveletCTA in 31 (52.5 %) patients with negative spCTA. Out of 47 patients with middle cerebral artery infarction, 27 occlusions (57.4 %) were detected by waveletCTA, mainly located in the M2 (15) and M3 segments (8). The presence of waveletCTA-detected occlusions was associated with larger CBF deficit volumes (odds ratio (OR) = 1.335, p = 0.010) and shorter times from symptom onset (OR = 0.306, p = 0.041). waveletCTA is able to detect spCTA occult vessel occlusions in about half of acute ischemic stroke patients and may potentially identify more patients eligible for endovascular therapy. (orig.)
International Nuclear Information System (INIS)
Rodriguez, Javier; Alvarez, Luisa F; Marino, Martha E and others
2004-01-01
Fractal geometry is a chapter of mathematics that allows the measurement of irregularity in natural objects. The adequate measures in order to characterize the forms of the human body are the fractal dimensions. Coronary ramification is a fractal object, which enables the diagnosis of occlusive arterial disease by the measurement of an arterial segment obtained by coronary angiography, without measuring the impact of the obstruction in the whole ramification. Fractal dimension evaluates the irregularity of the whole coronary ramification. The right anterior oblique projection (RAO) of the left coronary ramifications (LCR) obtained through arteriography is evaluated with fractal dimensions, using the box counting method. Images of the ramification between systole and diastole were measured in 14 patients, 7 of them without occlusive arterial disease, group 1, and 7 with severe occlusive arterial disease, group 2. Patients without occlusive arterial disease showed a greater variability in the fractal dimensions sequence evaluated with the net difference, being in general this difference other than zero
Isozaki, Makoto; Arai, Hiroshi; Neishi, Hiroyuki; Kitai, Ryuhei; Kikuta, Ken-Ichiro
2016-10-01
We report the case of a 49-year-old man with underlying hypertension who developed diplopia lasting 2 months. Magnetic resonance imaging and digital subtraction angiography showed multi-lobular unruptured aneurysms in the P2 portion of the posterior cerebral artery (PCA) migrating into the interpeduncular cistern of the midbrain. Because the shapes of the aneurysms were serpentine fusiform and the posterior communicating artery (PCoA) was the fetal type, we planned anastomosis of the occipital artery to the P4 portion of the PCA followed by endovascular obliteration of the parent artery including the aneurysms. Endovascular treatment was performed via a femoral approach one week after the anastomosis. Super-selective balloon test occlusion (BTO) of the PCoA was performed by using an occlusion balloon microcatheter before endovascular treatment. Occlusion of the proximal segment of the PCoA induced disturbance of consciousness of the patient. Occlusion of the distal segment other than the first point of the PCoA did not induce any neurological symptoms. The information from this super-selective BTO helped us to perform precise endovascular obliteration. The aneurysm was successfully obliterated, and the diplopia almost disappeared in a few months. Super-selective BTO of the PCoA might be a useful method for preventing ischemic complications due to occlusion of invisible perforators.
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Ueno, Koji; Anzai, Toshihisa; Jinzaki, Masahiro
2009-01-01
The relationship between the epicardial fat volume measured by 64-slice multidetector computed tomography (MDCT) and the extension and severity of coronary atherosclerosis was investigated. Both MDCT and conventional coronary angiography (CAG) were performed in 71 consecutive patients who presented with effort angina. The volume of epicardial adipose tissue (EAT) was measured by MDCT. The severity of coronary atherosclerosis was assessed by evaluating the extension of coronary plaques in 790 segments using MDCT data, and the percentage diameter stenosis in 995 segments using CAG data. The estimated volume of EAT indexed by body surface area was defined as VEAT. Increased VEAT was associated with advanced age, male sex, degree of metabolic alterations, a history of acute coronary syndrome (ACS) and the presence of total occlusions, and showed positive correlation with the stenosis score r=0.28, P=0.02) and the atheromatosis score (r=0.67, P 3 /m 2 ) to be the strongest independent determinant of the presence of total occlusions odds ratio 4.64. P=0.02). VEAT correlates with the degree of metabolic alterations and coronary atheromatosis. Excessive accumulation of EAT might contribute to the development of ACS and coronary total occlusions. (author)
Optimization of the static occlusion by "occlusal surface settling" in the Cerec 3D software.
Späth, C; Kordass, B
2006-04-01
The adjustment of the static occlusion can be automated in computer-based systems. The Cerec 3D software makes it possible to take preformed occlusal surfaces from a database and adapt them to the antagonist. In this adaptation (settling), the CAD occlusal surface "settles" as whole or each cusp individually into the occlusal surface of the antagonist until stable occlusion is reached. Two occlusal surface shapes were compared: Vita Physiodens and Lee Culp. An index was formed from the number, quality, and position of the occlusal contacts for 35 model cases (25 molars, 10 premolars). With regard to the settling of the total occlusal surfaces, there were no differences between the two occlusal surface shapes. In "cusp settling" of the molars, Vita Physiodens performed significantly better. In the comparison of the 1st with the 3rd settling process, significant improvements occurred the 3rd time in many cases when settling individual cusps, but in clearly fewer cases in the settling process of the total occlusal surface. The Lee Culp tooth occlusion improved especially after the 3rd settling process of individual cusps. It is therefore expedient to combine both settling versions with one another.
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Song, Xiao Li [Dept. of Radiology, Chonnam National University Medical School, Gwangju (Korea, Republic of); Zhu, Yue Qi; Lu, Hai Tao; Lui, Fang; Wei, Li Ming; Kang, Heoung Keun; Zhao, Jun Gong [Shanghai Jiao Tong University Affiliated Sixth People' s Hospital, Shanghai (China)
2016-11-15
To prospectively investigate predictors for good restoration of blood flow of below-the-knee (BTK) chronic total occlusions (CTOs) after endovascular therapy in diabetes mellitus (DM) patients. A total of 120 long-segmental (≥ 5 cm) BTK, CTOs in 81 patients who underwent recanalization were included in this study. After angioplasty, blood-flow restoration was assessed using modified thrombolysis in myocardial ischemia grades and classified as good flow (grade 3) and poor flow (grade 1/2). One hundred and six CTOs with successful recanalization were divided into a good flow group (GFG; n = 68) and poor flow group (PFG; n = 38). Multivariate logistic regression analyses were undertaken to determine independent predictors of blood-flow restoration. Receiver operating characteristic curves were constructed to determine the best cutoff value. The prevalence of target-lesion restenosis during follow-up was compared between two groups. Univariate analyses suggested that CTOs in GFG were characterized by lighter limb ischemia (p = 0.03), shorter course of ischemic symptoms (p < 0.01) and lesion length (p = 0.04), more frequent use of intraluminal angioplasty (p = 0.03), and higher runoff score (p < 0.01) than those in PFG. Multivariate regression analyses suggested that distal runoffs (p = 0.001; odds ratio [OR], 10.32; 95% confidence interval [CI]: 4.082-26.071) and lesion length (p < 0.001; OR, 1.26; 95% CI: 1.091-1.449) were independent predictors for good flow restoration. Kaplan-Meier analyses at 12 months showed a higher prevalence of non-restenosis in GFG (p < 0.01). Distal runoffs and lesion length are independent predictors for good flow restoration for long-segmental BTK, CTOs in DM patients who receive endovascular therapy.
Zhu, Ming; Chai, Gang; Zhang, Yan; Ma, Xiaofei; Gan, Jiliang
2011-09-01
An augmented reality tool allows for visual tracking of real anatomic structures in superposition with volume-rendered computed tomographic or magnetic resonance imaging scans and thus can be used for navigated translocation of important structures during operation. In this feasibility study, ARToolKit was used in mandibular angle oblique split osteotomy to define the cutting planes according to an operative plan. We overlay the operative plan on the model of a mandible made by rapid prototyping technology, and the technology was successfully used in 15 patients. Before the operation, all patients underwent computed tomographic scan, and dental casts were prepared by surgeons. Then, surgeons make the occlusal splint according to a dental cast to fix the marker, which can be recognized by the ARToolKit. The occlusal splint and marker were transformed to three-dimensional data using a laser scanner, and a programmer that runs on a personal computer named Rapidform matches the marker and the mandible image to generate the virtual image. By this step, the virtual image describing the marker, occlusal splint, and the mandible image of the patient are integrated. During the operation, the operative plan was overlaid on the rapid prototyping model of the mandible as soon as the ARToolKit recognized the marker. The technology was successfully used in 15 patients; the virtual image of the mandible and the cutting-plane both overlaid the real model of the mandible. This study has reported a new and effective way for mandibular angle oblique split osteotomy, and using occlusal splint might be a powerful option for the registration of augmented reality. Augmented reality tools like ARToolKit may be helpful for control of maxillary translocation in orthognathic surgery.
International Nuclear Information System (INIS)
Nicholson, Tony
1998-01-01
Purpose: To determine whether percutaneous transluminal angioplasty (PTA) and enclosed thrombolysis (ET) is superior to PTA alone in the treatment of femoropopliteal occlusions. Methods: Twenty-five patients with 5-15-cm-long occlusions in the femoropopliteal segments, with otherwise normal run-in arteries and at least one normal tibioperoneal artery to the foot, were randomized to ET/PTA or PTA alone. Ankle brachial systolic index (ABI) was measured before the procedure and at 24 hr and 12 months after the procedure, when a duplex scan was also carried out. End points in the study were patency at, or repeat intervention before, 12 months. Results: Procedures were successful in 23 of 25 patients. There was one immediate occlusion of tibioperoneal arteries, and one early reocclusion of a reopened segment in the ET/PTA group. There was one early reocclusion in the PTA group. At 12 months patency was 70% and 69.2% in the ET/PTA and PTA groups respectively. Covariant analysis showed no significant difference in ABI between the two groups at any of the three measurement times. Conclusion: This trial demonstrated no difference between ET/PTA and PTA alone in femoropopliteal occlusions associated with normal proximal arteries and at least one normal tibioperoneal artery
Efficient Depth Map Compression Exploiting Segmented Color Data
DEFF Research Database (Denmark)
Milani, Simone; Zanuttigh, Pietro; Zamarin, Marco
2011-01-01
performances is still an open research issue. This paper presents a novel compression scheme that exploits a segmentation of the color data to predict the shape of the different surfaces in the depth map. Then each segment is approximated with a parameterized plane. In case the approximation is sufficiently...
Segmentation by Large Scale Hypothesis Testing - Segmentation as Outlier Detection
DEFF Research Database (Denmark)
Darkner, Sune; Dahl, Anders Lindbjerg; Larsen, Rasmus
2010-01-01
a microscope and we show how the method can handle transparent particles with significant glare point. The method generalizes to other problems. THis is illustrated by applying the method to camera calibration images and MRI of the midsagittal plane for gray and white matter separation and segmentation......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...... locally. We propose a method based on large scale hypothesis testing with a consistent method for selecting an appropriate threshold for the given data. By estimating the background distribution we characterize the segment of interest as a set of outliers with a certain probability based on the estimated...
Use of Nitinol Stents Following Recanalization of Central Venous Occlusions in Hemodialysis Patients
International Nuclear Information System (INIS)
Rajan, Dheeraj K.; Saluja, Jasdeep S.
2007-01-01
Purpose. To retrospectively review the patency of endovascular interventions with nitinol stent placement for symptomatic central venous occlusions in hemodialysis patients. Methods. A retrospective review of all patients who underwent endovascular interventions for dysfunctional hemodialysis grafts and fistulas was performed from April 2004 to August 2006. A total of 6 patients presented with arm and/or neck and facial swelling and left brachiocephalic vein occlusion. The study group consisted of 3 men and 3 women with a mean age of 79.5 years (SD 11.2 years). Of these 6 patients, 1 had a graft and 5 had fistulas in the left arm. The primary indication for nitinol stent placement was technical failure of angioplasty following successful traversal of occluded central venous segments. Patency was assessed from repeat fistulograms and central venograms performed when patients redeveloped symptoms or were referred for access dysfunction determined by the ultrasound dilution technique. No patients were lost to follow-up. Results. Nitinol stent placement to obtain technically successful recanalization of occluded venous segments was initially successful in 5 of 6 patients (83%). In 1 patient, incorrect stent positioning resulted in partial migration to the superior vena cava requiring restenting to prevent further migration. Clinical success was observed in all patients (100%). Over the follow-up period, 2 patients underwent repeat intervention with angioplasty alone. Primary patency was 83.3% (95% CI 0.5-1.2) at 3 months, and 66.7% at 6 and 12 months (0.2-1.1, 0.1-1.2). Secondary patency was 100% at 12 months with 3 patients censored over that time period. Mean primary patency was 10.4 months with a mean follow-up of 12.4 months. No complications related to recanalization of the occluded central venous segments were observed. Conclusion. Our initial experience has demonstrated that use of nitinol stents for central venous occlusion in hemodialysis patients is
Cache-Oblivious Red-Blue Line Segment Intersection
DEFF Research Database (Denmark)
Arge, Lars; Mølhave, Thomas; Zeh, Norbert
2008-01-01
We present an optimal cache-oblivious algorithm for finding all intersections between a set of non-intersecting red segments and a set of non-intersecting blue segments in the plane. Our algorithm uses $O(\\frac{N}{B}\\log_{M/B}\\frac{N}{B}+T/B)$ memory transfers, where N is the total number...... of segments, M and B are the memory and block transfer sizes of any two consecutive levels of any multilevel memory hierarchy, and T is the number of intersections....
Communication: Two types of flat-planes conditions in density functional theory
Energy Technology Data Exchange (ETDEWEB)
Yang, Xiaotian Derrick; Patel, Anand H. G.; González-Espinoza, Cristina E.; Ayers, Paul W. [Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario LBS 4M1 (Canada); Miranda-Quintana, Ramón Alain [Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario LBS 4M1 (Canada); Laboratory of Computational and Theoretical Chemistry, Faculty of Chemistry, University of Havana, Havana (Cuba); Heidar-Zadeh, Farnaz [Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario LBS 4M1 (Canada); Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 (S3), 9000 Gent (Belgium); Center for Molecular Modeling, Ghent University, Technologiepark 903, 9052 Zwijnaarde (Belgium)
2016-07-21
Using results from atomic spectroscopy, we show that there are two types of flat-planes conditions. The first type of flat-planes condition occurs when the energy as a function of the number of electrons of each spin, N{sub α} and N{sub β}, has a derivative discontinuity on a line segment where the number of electrons, N{sub α} + N{sub β}, is an integer. The second type of flat-planes condition occurs when the energy has a derivative discontinuity on a line segment where the spin polarization, N{sub α} – N{sub β}, is an integer, but does not have a discontinuity associated with an integer number of electrons. Type 2 flat planes are rare—we observed just 15 type 2 flat-planes conditions out of the 4884 cases we tested—but their mere existence has implications for the design of exchange-correlation energy density functionals. To facilitate the development of functionals that have the correct behavior with respect to both fractional number of electrons and fractional spin polarization, we present a dataset for the chromium atom and its ions that can be used to test new functionals.
Analysis of a kinetic multi-segment foot model. Part I: Model repeatability and kinematic validity.
Bruening, Dustin A; Cooney, Kevin M; Buczek, Frank L
2012-04-01
Kinematic multi-segment foot models are still evolving, but have seen increased use in clinical and research settings. The addition of kinetics may increase knowledge of foot and ankle function as well as influence multi-segment foot model evolution; however, previous kinetic models are too complex for clinical use. In this study we present a three-segment kinetic foot model and thorough evaluation of model performance during normal gait. In this first of two companion papers, model reference frames and joint centers are analyzed for repeatability, joint translations are measured, segment rigidity characterized, and sample joint angles presented. Within-tester and between-tester repeatability were first assessed using 10 healthy pediatric participants, while kinematic parameters were subsequently measured on 17 additional healthy pediatric participants. Repeatability errors were generally low for all sagittal plane measures as well as transverse plane Hindfoot and Forefoot segments (median<3°), while the least repeatable orientations were the Hindfoot coronal plane and Hallux transverse plane. Joint translations were generally less than 2mm in any one direction, while segment rigidity analysis suggested rigid body behavior for the Shank and Hindfoot, with the Forefoot violating the rigid body assumptions in terminal stance/pre-swing. Joint excursions were consistent with previously published studies. Copyright © 2012 Elsevier B.V. All rights reserved.
Soslow, Jonathan H; Usoro, Emem; Wang, Li; Parra, David A
2016-04-01
Aneurysmal dilation of the right ventricular outflow tract complicates assessment of right ventricular function in patients with repaired tetralogy of Fallot. Tricuspid annular plane systolic excursion is commonly used to estimate ejection fraction. We hypothesised that tricuspid annular plane systolic excursion measured by cardiac MRI approximates global and segmental right ventricular function, specifically right ventricular sinus ejection fraction, in children with repaired tetralogy of Fallot. Tricuspid annular plane systolic excursion was measured retrospectively on cardiac MRIs in 54 patients with repaired tetralogy of Fallot. Values were compared with right ventricular global, sinus, and infundibular ejection fractions. Tricuspid annular plane systolic excursion was indexed to body surface area, converted into a fractional value, and converted into published paediatric Z-scores. Tricuspid annular plane systolic excursion measurements had good agreement between observers. Right ventricular ejection fraction did not correlate with the absolute or indexed tricuspid annular plane systolic excursion and correlated weakly with fractional tricuspid annular plane systolic excursion (r=0.41 and p=0.002). Segmental right ventricular function did not appreciably improve correlation with any of the tricuspid annular plane systolic excursion measures. Paediatric Z-scores were unable to differentiate patients with normal and abnormal right ventricular function. Tricuspid annular plane systolic excursion measured by cardiac MRI correlates poorly with global and segmental right ventricular ejection fraction in children with repaired tetralogy of Fallot. Tricuspid annular plane systolic excursion is an unreliable approximation of right ventricular function in this patient population.
Elsman, P; van't Hof, AWJ; Hoorntje, JCA; de Boer, MJ; Borm, GF; Suryapranata, H; Ottervanger, JP; Gosselink, AM; Zijlstra, F; Dambrink, Jan Hendrik Everwijn
2006-01-01
In acute myocardial infarction that is treated with thrombolysis, proximal coronary artery occlusion is associated with worse prognosis, irrespective of the infarcted artery. Primary percutaneous coronary intervention (PCI) is currently the treatment of choice for ST-segment elevation acute
Kothari, L K; Gupta, A S
1978-02-01
In 15 human subjects, the vasa deferentia were occluded by applying two tantalum clips on one side and by conventional vasectomy with silk ligatures on the other. After 2 weeks, the occluded segments were recovered for histopathologic examination of serial sections. Obstructing the seminal tract did not, as such, produce any significant change in the vas: the distal and proximal segments appeared to be essentially similar and normal. At the actual site of occlusion, however, tantalum clips produced marked flattening of the tube, complete loss of lining epithelium, distortion of the muscular lamellae, and areas of hemorrhage. The lumen was converted into a narrow slit. Under the ligatures, the damage was largely confined to denudation of the mucosal epithelium. The mucosa of the intersegment left unexcised between two clips showed hyalinization, invasion by macrophages, and degeneration of the epithelium. The changes under the clips suggest that, although clip occlusion may offer several advantages, sterility cannot be reversed merely by removing the clips. The mechanisms of these changes, different in the case of clips and ligatures, are discussed and some possible long-term consequences are considered.
Traumatic occlusion of the anterior cerebral artery--case report.
Ishibashi, A; Kubota, Y; Yokokura, Y; Soejima, Y; Hiratsuka, T
1995-12-01
A 71-year-old female presented with posttraumatic occlusion of the anterior cerebral artery (ACA) after a road accident in which she was hit in the mid-frontal region. Initial computed tomography (CT) demonstrated frontal skull fractures and pneumocephalus. High density areas were also identified in the right basal cisterns, suggesting traumatic subarachnoid hemorrhage. She was alert on admission, but with attendant shock due to crush wounds. Her condition rapidly deteriorated and an emergency amputation of her left leg was performed. After aggressive treatment with transfusion and infusion, her systolic pressure increased to 120 mmHg. Her consciousness remained disturbed. Serial CT disclosed hemorrhagic infarction in the entire medial side of the right frontal lobe. Magnetic resonance angiography demonstrated decreased flow voids in the bilateral A1 segments and right ACA, and a basilar artery aneurysm, which was unruptured clinically. Three weeks after the injury, she regained consciousness. Six months later, she had motor aphasia and left upper extremity weakness. The clinicopathological mechanism causing the traumatic occlusion of the ACA in the present case was probably dissecting aneurysm.
de Chantal, Marilyn; Diodati, Jean G; Nasmith, James B; Amyot, Robert; LeBlanc, A Robert; Schampaert, Erick; Pharand, Chantal
2006-12-01
ST-segment depression is commonly seen in patients with acute coronary syndromes. Most authors have attributed it to transient reductions in coronary blood flow due to nonocclusive thrombus formation on a disrupted atherosclerotic plaque and dynamic focal vasospasm at the site of coronary artery stenosis. However, ST-segment depression was never reproduced in classic animal models of coronary stenosis without the presence of tachycardia. We hypothesized that ST-segment depression occurring during acute coronary syndromes is not entirely explained by changes in epicardial coronary artery resistance and thus evaluated the effect of a slow, progressive epicardial coronary artery occlusion on the ECG and regional myocardial blood flow in anesthetized pigs. Slow, progressive occlusion over 72 min (SD 27) of the left anterior descending coronary artery in 20 anesthetized pigs led to a 90% decrease in coronary blood flow and the development of ST-segment elevation associated with homogeneous and transmural myocardial blood flow reductions, confirmed by microspheres and myocardial contrast echocardiography. ST-segment depression was not observed in any ECG lead before the development of ST-segment elevation. At normal heart rates, progressive epicardial stenosis of a coronary artery results in myocardial ischemia associated with homogeneous, transmural reduction in regional myocardial blood flow and ST-segment elevation, without preceding ST-segment depression. Thus, in coronary syndromes with ST-segment depression and predominant subendocardial ischemia, factors other than mere increases in epicardial coronary resistance must be invoked to explain the heterogeneous parietal distribution of flow and associated ECG changes.
Longmuir, Susannah; Pfeifer, Wanda; Scott, William; Olson, Richard
2013-01-01
To investigate the incidence and characteristics of occlusion amblyopia with prescribed full-time patching and determine its effect on long-term visual acuity outcomes. The records of patients younger than 10 years diagnosed as having amblyopia between 1970 and 2000 were retrospectively reviewed. Patients were prescribed full-time occlusion and observed until completion of therapy. Of 597 patients treated for amblyopia by full-time patching, 115 were diagnosed as having occlusion amblyopia (19.3%). Seventy-five percent (86 of 115) developed occlusion amblyopia during the first episode of full-time patching. Occlusion amblyopia occurred more frequently in children prescribed full-time patching at an earlier age (P = .0002), with an odds ratio of 8.56 (95% confidence interval: 2.73, 26.84) in children younger than 36 months and 2.66 (95% confidence interval: 0.96, 7.37) in children between 36 and 59 months old. Seven of the patients with occlusion amblyopia did not reverse fixation and continued to fixate with the initially amblyopic eye after treatment. Final visual acuity in these eyes with occlusion amblyopia was 20/30 or better. After cessation of treatment, the final interocular difference in visual acuity was less in patients with a history of occlusion amblyopia (P = .003). Occlusion amblyopia occurred at all ages, but the incidence decreased with increasing age. Patients who developed occlusion amblyopia with prescribed full-time occlusion had less interocular visual acuity difference than patients who did not, suggesting that development of occlusion amblyopia can indicate the potential for the development of better vision in the originally amblyopic eye. Copyright 2013, SLACK Incorporated.
The lingualized occlusion of complete denture
Institute of Scientific and Technical Information of China (English)
BEN Wei-hong; Eleni Roumanas
2008-01-01
This article reviews the literatures dealing with the lingualized occlusion of complete denture including the origin,development and research. Lingualized occlusion is a valuable concept because many advantages of anatomic and nonanatomic occlusions are retained,satisfactory occlusion is easily obtained,balanced occlusion can be accomplished.
CAD/CAM splints for the functional and esthetic evaluation of newly defined occlusal dimensions.
Edelhoff, Daniel; Schweiger, Josef; Prandtner, Otto; Trimpl, Johannes; Stimmelmayr, Michael; Güth, Jan-Frederik
2017-01-01
Pretreatment with occlusal splints is a crucial step in a structured treatment approach for a complex rehabilitation that changes the vertical dimension of occlusion. Meticulous patient compliance is one of the essential prerequisites for overall treatment success. However, patient compliance is all too often insufficient due to esthetic, phonetic, and functional limitations when using conventional occlusal splints in one arch. Modern production technologies now allow the use of tooth-colored occlusal splints made of polycarbonate, whose quality and material properties are quite distinct from those of conventionally manufactured splints made of transparent polymethyl methacrylate (PMMA). These materials, produced under standardized polymerization conditions, are extremely homogenous, which provides benefits such as a greater accuracy of fit by eliminating the polymerization shrinkage, greater long-term stability of shapes and shades, better biocompatibility, less wear, and a more favorable esthetic appearance. In addition, tooth-colored polycarbonate splints can be fabricated very thin without significantly increasing the fracture risk, thanks to the flexibility of the material. The improved wearing comfort combined with acceptable esthetics result in significantly improved patient compliance in terms of a "23-hour splint." By providing separate splints for the maxilla and mandible in the case of major alterations of the vertical dimension of occlusion, the esthetic and functional aspects defined by the wax-up can be completely transferred to the removable splints for a "test drive" by the patient, reversibly, and under realistic conditions. This dual-splint approach additionally facilitates segmental transfer into the definitive restoration.
Occlusion of the artery of Percheron: an unusual cause of bilateral stroke
Anderson, Clare; O'Brien, Richard
2012-01-01
The artery of Percheron is a rare anatomical variant whereby a single vessel arising from the proximal segment of one posterior cerebral artery supplies both medial thalami. This is a rare example of a single arterial supply to brain structures on both sides of the midline. Occlusion of the artery of Percheron results in bilateral medial thalamic infarction, which is manifest clinically as gaze paresis, cognitive disturbance and altered consciousness. The presentation can mimic subarachnoid h...
Occlusal stability in shortened dental arches.
Witter, D J; Creugers, N H; Kreulen, C M; de Haan, A F
2001-02-01
Shortened dental arches consisting of anterior and premolar teeth have been shown to meet oral functional demands. However, the occlusal stability may be at risk as a result of tooth migration. The aim of this nine-year study was to investigate occlusal stability in shortened dental arches as a function over time. Occlusal stability indicators were: 'interdental spacing', 'occlusal contacts of anterior teeth in Intercuspal Position', 'overbite', 'occlusal tooth wear', and 'alveolar bone support'. Subjects with shortened dental arches (n = 74) were compared with subjects with complete dental arches (controls, n = 72). Repeated-measurement regression analyses were applied to assess age-dependent variables in the controls and to relate the occlusal changes to the period of time since the treatment that led to the shortened dental arches. Compared with complete dental arches, shortened dental arches had similar overbite and occlusal tooth wear. They showed more interdental spacing in the premolar regions, more anterior teeth in occlusal contact, and lower alveolar bone scores. Since the differences remained constant over time, we conclude that shortened dental arches can provide long-term occlusal stability. Occlusal changes were self-limiting, indicating a new occlusal equilibrium.
Energy Technology Data Exchange (ETDEWEB)
Tabuchi, Kenji [Dokkyo Univ. School of Medicine, Mibu, Tochigi (Japan)
2000-03-01
To assess the characteristics of blood flow measurement with MR Angiography (MRA) to evaluate the status of vascular stenoses, two or three dimensional time-of-flight MRA and velocity-encoded cine MR were performed in the 230 segments of 35 patients, with abdominal and peripheral arterial occlusive diseases. In 11 of these 35 patients digital subtraction angiography was additionally underwent, and the stenotic findings was compared with MRA. There were 17 segments in which the velocity could not be measured, because the blood flow exceeded the upper limit of peak-encoded velocity (VENC) which was set at 120 cm/sec. Therefore, it is necessary to set the upper limit of VENC at higher than 120 cm/sec. There were 11 stenotic findings in DSA and 20 stenotic findings in MRA. Pulsatility Index (PI=(max velocity-min. velocity)/average velocity) were used for evaluating the blood flow waveform, and there were significant difference between the 11 stenotic findings of DSA and the others'. In summery, MRA was considered as useful examination to assess the degree of the vascular stenoses in abdominal and peripheral arterial occlusive disease. (author)
Limitations and pitfalls of Couinaud's segmentation of the liver in transaxial Imaging
Energy Technology Data Exchange (ETDEWEB)
Strunk, H; Textor, J; Willinek, W [Department of Radiology, University of Bonn, Sigmund Freud-Strasse 25, 53105, Bonn (Germany); Stuckmann, G [Department of Radiology, Kantonsspital Winterthur (Switzerland)
2003-11-01
The segmental anatomy of the human liver has become a matter of increasing interest to the radiologist, especially in view of the need for an accurate preoperative localization of focal hepatic lesions. In this review article first an overview of the different classical concepts for delineating segmental and subsegmental anatomy on US, transaxial CT, and MR images is given. Essentially, these procedures are based on Couinaud's concept of three vertical planes that divide the liver into four segments and of a transverse scissura that further subdivides the segments into two subsegments each. In a second part, the limitations of these methods are delineated and discussed with the conclusion that if exact preoperative localization of hepatic lesions is needed, tumor must be located relative to the avascular planes between the different portal territories. (orig.)
Limitations and pitfalls of Couinaud's segmentation of the liver in transaxial Imaging
International Nuclear Information System (INIS)
Strunk, H.; Textor, J.; Willinek, W.; Stuckmann, G.
2003-01-01
The segmental anatomy of the human liver has become a matter of increasing interest to the radiologist, especially in view of the need for an accurate preoperative localization of focal hepatic lesions. In this review article first an overview of the different classical concepts for delineating segmental and subsegmental anatomy on US, transaxial CT, and MR images is given. Essentially, these procedures are based on Couinaud's concept of three vertical planes that divide the liver into four segments and of a transverse scissura that further subdivides the segments into two subsegments each. In a second part, the limitations of these methods are delineated and discussed with the conclusion that if exact preoperative localization of hepatic lesions is needed, tumor must be located relative to the avascular planes between the different portal territories. (orig.)
Vertebrobasilar Artery Occlusion
Directory of Open Access Journals (Sweden)
Schoen, Jessica
2011-05-01
Full Text Available The presentation of vertebrobasilar artery occlusion varies with the cause of occlusion and location of ischemia. This often results in delay in diagnosis. Areas of the brain supplied by the posterior circulation are difficult to visualize and usually require angiography or magnetic resonance imaging. Intravenous thrombolysis and local-intra arterial thrombolysis are the most common treatment approaches used. Recanalization of the occluded vessel significantly improves morbidity and mortality. Here we present a review of the literature and a case of a patient with altered mental status caused by vertebrobasilar artery occlusion. [West J Emerg Med. 2011;12(2:233-239.
Acute Thrombotic Coronary Occlusion in a Patient with Coronary Artery Anomaly
Directory of Open Access Journals (Sweden)
Beganu Elena
2017-09-01
Full Text Available Patients with coronary artery anomalies are more susceptible to develop acute thrombotic coronary occlusions due to the abnormal anatomy of these arteries and the disturbance of the pathophysiological mechanisms that lead to an accelerated atherosclerosis development. The following article presents the case of a 64-year-old female patient diagnosed with anterior ST-segment elevation myocardial infarction. The patient underwent primary percutaneous coronary intervention, which revealed the absence of the right coronary artery and separated origins of the left anterior descending artery and the left circumflex artery from the aorta.
Micaceous occlusions in kaolinite observed by ultramicrotomy and high resolution electron microscopy
Energy Technology Data Exchange (ETDEWEB)
Lee, S Y [Univ. of Wisconsin, Madison; Jackson, M L; Brown, J L
1975-01-01
The layer structure of kaolinite from Twiggs, Georgia, and fire-clay type kaolinite (Frantex B, from France, particle size separates 2 0.2 ..mu..m was studied by high resolution electron microscopy after embedment in Spurr low-viscosity Epoxy media and thin sectioning normal to the (001) planes by an ultramicrotome. Images of the (001) planes (viewed edge-on) of both kaolinites were spaced at 7 A and generally aligned in parallel, with occasional bending into more widely spaced images of about 10 A interval. Some of the 10 A images converged to 7 A at one or both ends, forming ellipse-shaped islands 80 to 130 A thick and 300 to 500 A long. The island areas and interleaved 10 A layers between 7 A layers may represent a residue of incomplete weathering of mica to kaolinite. The proportions of micaceous occlusions were too small and the layer sequences too irregular to be detected by X-ray diffraction. The lateral continuity of the layers through the 7-10-7 A sequence in a kaolinite particle would partially interrupt or prevent expansion in dimethyl sulfoxide (DMSO) and other kaolinite intercalating media. Discrete mica particles were also observed with parallel images at 10 A, as impurities in both kaolinites. The small K content of the chemical analyses of the kaolinite samples is accounted for as interlayer K, not only in discrete mica particles but also in the micaceous occlusions.
Wide-band segmented power distribution networks
Tereshchenko, O.V.; Buesink, Frederik Johannes Karel; Leferink, Frank Bernardus Johannes
2013-01-01
This paper discusses a novel design of Power Distribution Network (PDN). By physical structuring of the power plane into repetitive symmetrical and asymmetrical segments of varying size, suppression of the propagation of unwanted noise throughout the PDN over a wide frequency range is achieved.
Contralateral Occlusion Test: The effect of external ear canal occlusion on hearing thresholds.
Reis, Luis Roque; Fernandes, Paulo; Escada, Pedro
Bedside testing with tuning forks may decrease turnaround time and improve decision making for a quick qualitative assessment of hearing loss. The purpose of this study was to quantify the effects of ear canal occlusion on hearing, in order to decide which tuning fork frequency is more appropriate to use for quantifying hearing loss with the Contralateral Occlusion Test. Twenty normal-hearing adults (forty ears) underwent sound field pure tone audiometry with and without ear canal occlusion. Each ear was tested with the standard frequencies. The contralateral ear was suppressed with by masking. Ear occlusion was performed by two examiners. Participants aged between 21 and 30 years (25.6±3.03 years) showed an increase in hearing thresholds with increasing frequencies from 19.94dB (250Hz) to 39.25dB (2000Hz). The threshold difference between occluded and unoccluded conditions was statistically significant and increased from 10.69dB (250Hz) to 32.12dB (2000Hz). There were no statistically significant differences according to gender or between the examiners. The occlusion effect increased the hearing thresholds and became more evident with higher frequencies. The occlusion method as performed demonstrated reproducibility. In the Contralateral Occlusion Test, 256Hz or 512Hz tuning forks should be used for diagnosis of mild hearing loss, and a 2048Hz tuning fork should be used for moderate hearing loss. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.
REGISTRATION OF OVERLAPPING 3D POINT CLO UDS USING EXTRACTED LINE SEGMENTS
Directory of Open Access Journals (Sweden)
Poręba Martyna
2014-12-01
Full Text Available The registration of 3D point clouds collected from different scanner positions is necessary in order to avoid occlusions, ensure a full coverage of areas, and collect useful data for analyzing an d documenting the surrounding environment. This procedure involves three main stages: 1 choosing appropriate features, which can be reliably extracted; 2 matching conjugate primitives; 3 estimating the transformation parameters. Currently, points and spheres are most frequently chosen as the registration features. However, due to limited point cloud resolution, proper identification and precise measurement of a common point within the overlapping laser data is almost impossible. One possible solution to this problem may be a registration process based on the Iterative Closest Point (ICP algorithm or its variation. Alternatively, planar and linear feature - based registration techniques can also be applied. In this paper, we propose the use of line segments obtained from intersecting planes modelled within individual scans. Such primitives can be easily extracted even from low - density point clouds. Working with synthetic data, several existing line - based registration methods are evaluated according to their robustness to noise and the precision of the estimated transformation parameters. For the purpose of quantitative assessment, an accuracy criterion based on a modified Hausdorff distance is defined. Since a n automated matching of segments is a challenging task that influences the correctness of the transformation parameters, a correspondence - finding algorithm is developed. The tests show that our matching algorithm provides a correct pairing with an accuracy of 99 % at least, and about 8% of omitted line pairs.
International Nuclear Information System (INIS)
Zeleňák, Kamil; Šinák, Igor; Janík, Ján; Mikolajčík, Anton; Mištuna, Dušan
2013-01-01
Acute superior mesenteric artery (SMA) occlusion is a life-threatening disease, and acute intestinal ischemia develops from the sudden decrease in perfusion to the intestines. The key to saving the patient’s life is early diagnosis, and prompt revascularization of the SMA can prevent intestinal infarction and decrease the risk of bowel segment necrosis. Computed tomographic angiography may be useful for rapid diagnosis. We report recanalization of an SMA occlusion in an 80-year-old man with a combination of intraarterial thrombolysis and mechanical thrombectomy with a carotid filter.
Computerized occlusal analysis in bruxism
Directory of Open Access Journals (Sweden)
Lazić Vojkan
2006-01-01
Full Text Available Introduction. Sleep bruxism as nocturnal parafunction, also known as tooth grinding, is the most common parasomnia (sleep disorder. Most tooth grinding occurs during rapid eye movement - REM sleep. Sleep bruxism is an oral habit characterized by rhythmic activity of the masticatory muscles (m. masseter that causes forced contact between dental surfaces during sleep. Sleep bruxism has been associated with craniomandibular disorders including temporomandibular joint discomfort, pulpalgia, premature loss of teeth due to excessive attrition and mobility, headache, muscle ache, sleep interruption of an individual and problems with removable and fixed denture. Basically, two groups of etiological factors can be distinguished, viz., peripheral (occlusal factors and central (pathophysiological and psychological factors. The role of occlusion (occlusal discrepancies as the causative factor is not enough mentioned in relation to bruxism. Objective. The main objective of this paper was to evaluate the connection between occlusal factors and nocturnal parafunctional activities (occlusal disharmonies and bruxism. Method. Two groups were formed- experimental of 15 persons with signs and symptoms of nocturnal parafunctional activity of mandible (mean age 26.6 years and control of 42 persons with no signs and symptoms of bruxism (mean age 26.3 yrs.. The computerized occlusal analyses were performed using the T-Scan II system (Tekscan, Boston, USA. 2D occlusograms were analyzed showing the occlusal force, the center of the occlusal force with the trajectory and the number of antagonistic tooth contacts. Results. Statistically significant difference of force distribution was found between the left and the right side of the arch (L%-R% (t=2.773; p<0.02 in the group with bruxism. The difference of the centre of occlusal force - COF trajectory between the experimental and control group was not significant, but the trajectory of COF was longer in the group of
Christensen, L V; Rassouli, N M
1995-11-01
In 12 subjects, a pliable, yet unbreakable, intercuspal interference (aluminum shim onlay splint; uniform height of 0.25 mm) was placed between either the right or left maxillary and mandibular second premolars and first molars. During brief and forceful biting (dynamic chewing stroke of about 20 kg force) the interference emulated a semisoft food bolus, and at the end of biting (subsequent static clenching stroke of about 20 kg force) it emulated a rigid metal interference. During dynamic/static biting, rotational electrognathography measured maximum frontal and horizontal plane torque of the right and left mandibular condyles. Eleven subjects (92%) showed frontal plane upward rotation (mean of 1.0 degree) of the condyle contralateral to the interference, and one subject (8%) showed frontal plane upward rotation (0.4 degree) of the condyle ipsilateral to the interference. Two subjects (17%) showed no horizontal plane rotation; seven subjects (58%) showed backward rotation (mean of 0.4 degree) of the condyle contralateral to the interference; and three subjects (25%) showed backward rotation (mean of 0.3 degree) of the condyle ipsilateral to the interference. It is suggested that, in the presence of an occlusal interference, mastication may have both short- and long-term detrimental effects.
Energy Technology Data Exchange (ETDEWEB)
Nam, Se Jin; Kim, Eun Kyung [Dept. of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul (Korea, Republic of)
2014-10-15
We report a case of middle-aged woman incidentally diagnosed with Takayasu arteritis during the ultrasonography of a thyroid gland nodule. Prominent collaterals of the thyroidal arteries and a thin common carotid artery with mural thickening and deficient intraluminal flow signals were initially depicted on the ultrasonography with color Doppler. Subsequent magnetic resonance angiography and computed tomography aortography confirmed the diagnosis with the imaging features of a bilateral long segment common carotid artery occlusion and segmental stenosis of the left subclavian artery in addition to the suggestive physical findings.
Graph-based surface reconstruction from stereo pairs using image segmentation
Bleyer, Michael; Gelautz, Margrit
2005-01-01
This paper describes a novel stereo matching algorithm for epipolar rectified images. The method applies colour segmentation on the reference image. The use of segmentation makes the algorithm capable of handling large untextured regions, estimating precise depth boundaries and propagating disparity information to occluded regions, which are challenging tasks for conventional stereo methods. We model disparity inside a segment by a planar equation. Initial disparity segments are clustered to form a set of disparity layers, which are planar surfaces that are likely to occur in the scene. Assignments of segments to disparity layers are then derived by minimization of a global cost function via a robust optimization technique that employs graph cuts. The cost function is defined on the pixel level, as well as on the segment level. While the pixel level measures the data similarity based on the current disparity map and detects occlusions symmetrically in both views, the segment level propagates the segmentation information and incorporates a smoothness term. New planar models are then generated based on the disparity layers' spatial extents. Results obtained for benchmark and self-recorded image pairs indicate that the proposed method is able to compete with the best-performing state-of-the-art algorithms.
International Nuclear Information System (INIS)
Shiffman, Smadar; Rubin, Geoffrey D.; Schraedley-Desmond, Pamela; Napel, Sandy
2003-01-01
Two-dimensional intensity-based methods for the segmentation of blood vessels from computed-tomography-angiography data often result in spurious segments that originate from other objects whose intensity distributions overlap with those of the vessels. When segmented images include spurious segments, additional methods are required to select segments that belong to the target vessels. We describe a method that allows experts to select vessel segments from sequences of segmented images with little effort. Our method uses ellipse-overlap criteria to differentiate between segments that belong to different objects and are separated in plane but are connected in the through-plane direction. To validate our method, we used it to extract vessel regions from volumes that were segmented via analysis of isolabel-contour maps, and showed that the difference between the results of our method and manually-edited results was within inter-expert variability. Although the total editing duration for our method, which included user-interaction and computer processing, exceeded that of manual editing, the extent of user interaction required for our method was about a fifth of that required for manual editing
Variational mesh segmentation via quadric surface fitting
Yan, Dongming; Wang, Wen Ping; Liu, Yang; Yang, Zhouwang
2012-01-01
We present a new variational method for mesh segmentation by fitting quadric surfaces. Each component of the resulting segmentation is represented by a general quadric surface (including plane as a special case). A novel energy function is defined to evaluate the quality of the segmentation, which combines both L2 and L2 ,1 metrics from a triangle to a quadric surface. The Lloyd iteration is used to minimize the energy function, which repeatedly interleaves between mesh partition and quadric surface fitting. We also integrate feature-based and simplification-based techniques in the segmentation framework, which greatly improve the performance. The advantages of our algorithm are demonstrated by comparing with the state-of-the-art methods. © 2012 Elsevier Ltd. All rights reserved.
Variational mesh segmentation via quadric surface fitting
Yan, Dongming
2012-11-01
We present a new variational method for mesh segmentation by fitting quadric surfaces. Each component of the resulting segmentation is represented by a general quadric surface (including plane as a special case). A novel energy function is defined to evaluate the quality of the segmentation, which combines both L2 and L2 ,1 metrics from a triangle to a quadric surface. The Lloyd iteration is used to minimize the energy function, which repeatedly interleaves between mesh partition and quadric surface fitting. We also integrate feature-based and simplification-based techniques in the segmentation framework, which greatly improve the performance. The advantages of our algorithm are demonstrated by comparing with the state-of-the-art methods. © 2012 Elsevier Ltd. All rights reserved.
Basilar artery occlusive disease in stroke survivors in a multiethnic population.
Ciríaco, Jovana Gobbi Marchesi; Leite, Claudia da Costa; dMartin, Maria a Graça Morais; Barros, Cristiano Venturim; Puglia, Paulo; Caldas, José Guilherme Pereira; Scaff, Milberto; Conforto, Adriana Bastos
2010-04-01
To describe clinical, radiological findings, and outcome in a multiethnic population of stroke survivors with basilar artery occlusive disease (BAOC). Forty patients with infarcts in the basilar artery (BA) territory, alive 30 days after the ictus, participated in the study. BA stenosis (>50%) or occlusion was shown by magnetic resonance or digital subtraction angiography in all patients. Demographical, clinical and radiological characteristics were described. Modified Rankin Scale (MRS) scores at 30 days and 6 months after the ischemic event were evaluated. Association between demographical, clinical, radiological features and outcome were analyzed with Chi-square and Fisher's exact tests. MRS scores at 30 days and 6 months were compared with the Wilcoxon test. Sixty percent of the patients were men, and 33% were Afro-Brazilian. Mean age was 55.8+/-12.9 years. Most (90%) had multiple vascular risk factors. Stroke was preceded by TIA in 48% of the patients, and 80% had a history of arterial hypertension. The most common neurological symptom was vertigo/dizziness (60%) and the sign, hemiparesis (60%). Most of the infarcts were located in the pons (85%) and the BA middle third was the most frequently affected segment (33%). BA occlusion occurred in 58% of the patients. More severe vascular occlusive lesions were present in Whites (p=0.002) and in patients with involvement of the middle third of the BA (p=0.021). Large-artery atherosclerosis was the most common stroke etiology (88%) and was more frequent in older patients (p<0.001). Most patients were treated with anticoagulation. MRS scores improved significantly at 6 months (p<0.001); at this time, 78% of the patients had MRS scores between 0 and 2. We observed different results compared with other series: greater proportion of Afro-descendents, higher frequency of atherosclerosis and BA occlusion. Rates of preceding TIAs and good outcome at 6 months were similar to previously published data. These results represent
Directory of Open Access Journals (Sweden)
Lillian Lami Enone
2017-01-01
Full Text Available Background: This study aimed to evaluate the clinical performance of nanocomposites in a Nigerian adult population. Resin composites are becoming the preferred direct restorative material in restoring occlusal and proximo-occlusal cavities due to their aesthetic properties and good clinical service. Materials and Methods: This was a clinical study evaluating the clinical performance of a nanohybrid resin composite in the restoration of occlusal and proximo-occlusal cavities in Nigerian adults. This study was done in the Conservative Dentistry Clinic of the Lagos State University Teaching Hospital, Ikeja, from April 2014 to September 2015. The restorations were evaluated immediately at baseline, 3, 6 and 12 months postoperatively for colour match, marginal discolouration, surface roughness, anatomical form, marginal adaptation, retention, post-operative sensitivity and secondary caries using the modified USPHS criteria. Statistical analysis was performed using Fisher's exact test and a 5% level of significance was considered statistically significant. Results: Males had more proximo-occlusal (26.7 than occlusal (6.7 cavities while the females (43.3 had more occlusal cavities. The nanohybrid occlusal restorations had 100% alpha scores at baseline for anatomical form which dropped to 93.3% at 12 months with 6.7% of the restorations scoring Bravo, whereas all nanohybrid proximo-occlusal restorations had 100% alpha scores from baseline to the 12-month review. All occlusal and proximo-occlusal restorations evaluated for surface texture and marginal adaptation had alpha scores at baseline which dropped to 93.3% at 12 months. Conversely, all nanohybrid occlusal and proximo-occlusal restorations scored 100% for colour match and retention, sensitivity and secondary caries from baseline to 12 months. Conclusion: The clinical performance of natural elegance nanohybrid resin composite (Henry Schein® was satisfactory in the restoration of occlusal and
Study of automated segmentation of the cerebellum and brainstem on brain MR images
International Nuclear Information System (INIS)
Hayashi, Norio; Matsuura, Yukihiro; Sanada, Shigeru; Suzuki, Masayuki
2005-01-01
MR imaging is an important method for diagnosing abnormalities of the brain. This paper presents an automated method to segment the cerebellum and brainstem for brain MR images. MR images were obtained from 10 normal subjects (male 4, female 6; 22-75 years old, average 31.0 years) and 15 patients with brain atrophy (male 3, female 12; 62-85 years of age, average 76.0 years). The automated method consisted of the following four steps: segmentation of the brain on original images, detection of an upper plane of the cerebellum using the Hough transform, correction of the plane using three-dimensional (3D) information, and segmentation of the cerebellum and brainstem using the plane. The results indicated that the regions obtained by the automated method were visually similar to those obtained by a manual method. The average rates of coincidence between the automated method and manual method were 83.0±9.0% in normal subjects and 86.4±3.6% in patients. (author)
International Nuclear Information System (INIS)
Kau, Thomas; Eicher, Wolfgang; Reiterer, Christian; Niedermayer, Martin; Rabitsch, Egon; Hausegger, Klaus A.; Senft, Birgit
2011-01-01
To evaluate the accuracy of dual-energy CT angiography (DE-CTA) maximum intensity projections (MIPs) in symptomatic peripheral arterial occlusive disease (PAOD). In 58 patients, DE-CTA of the lower extremities was performed on dual-source CT. In a maximum of 35 arterial segments, severity of the most stenotic lesion was graded (<10%, 10-49% and 50-99% luminal narrowing or occlusion) independently by two radiologists, with DSA serving as the reference standard. In DSA, 52.3% of segments were significantly stenosed or occluded. Agreement of DE-CTA MIPs with DSA was good in the aorto-iliac and femoro-popliteal regions (κ = 0.72; κ = 0.66), moderate in the crural region (κ = 0.55), slight in pedal arteries (κ = 0.10) and very good in bypass segments (κ = 0.81). Accuracy was 88%, 78%, 74%, 55% and 82% for the respective territories and moderate (75%) overall, with good sensitivity (84%) and moderate specificity (67%). Sensitivity and specificity was 82% and 76% in claudicants and 84% and 61% in patients with critical limb ischaemia. While correlating well with DSA above the knee, accuracy of DE-CTA MIPs appeared to be moderate in the calf and largely insufficient in calcified pedal arteries, especially in patients with critical limb ischaemia. (orig.)
Velazquez-Pupo, Roxana; Sierra-Romero, Alberto; Torres-Roman, Deni; Shkvarko, Yuriy V.; Romero-Delgado, Misael
2018-01-01
This paper presents a high performance vision-based system with a single static camera for traffic surveillance, for moving vehicle detection with occlusion handling, tracking, counting, and One Class Support Vector Machine (OC-SVM) classification. In this approach, moving objects are first segmented from the background using the adaptive Gaussian Mixture Model (GMM). After that, several geometric features are extracted, such as vehicle area, height, width, centroid, and bounding box. As occlusion is present, an algorithm was implemented to reduce it. The tracking is performed with adaptive Kalman filter. Finally, the selected geometric features: estimated area, height, and width are used by different classifiers in order to sort vehicles into three classes: small, midsize, and large. Extensive experimental results in eight real traffic videos with more than 4000 ground truth vehicles have shown that the improved system can run in real time under an occlusion index of 0.312 and classify vehicles with a global detection rate or recall, precision, and F-measure of up to 98.190%, and an F-measure of up to 99.051% for midsize vehicles. PMID:29382078
Recurrence of amblyopia after occlusion therapy.
Bhola, Rahul; Keech, Ronald V; Kutschke, Pamela; Pfeifer, Wanda; Scott, William E
2006-11-01
To determine the stability of visual acuity (VA) after a standardized occlusion regimen in children with strabismic and/or anisometropic amblyopia. Retrospective, population-based, consecutive observational case series. Four hundred forty-nine patients younger than 10 years who underwent an occlusion trial for amblyopia and were observed until there was a recurrence of amblyopia or for a maximum of 1 year after decrease or cessation of occlusion therapy. We performed a retrospective chart review of all patients treated by occlusion therapy for strabismic and/or anisometropic amblyopia at our institution over a 34-year period. Of the 1621 patients identified in our database, 449 met the eligibility criteria and were included in this study. Patients having at least a 2 logarithm of the minimum angle of resolution (logMAR)-level improvement in VA by optotypes or a change from unmaintained to maintained fixation preference during the course of occlusion therapy were included. A recurrence of amblyopia was defined as > or =2 logMAR levels of VA reduction or reversal of fixation preference within 1 year after a decrease or cessation of occlusion therapy. Recurrence of amblyopia after a decrease or cessation of occlusion therapy and its relationship with patient age and VA of the amblyopic eye at the time of decrease or cessation of occlusion therapy. Of 653 occlusion trials, 179 (27%) resulted in recurrence of amblyopia. The recurrence was found to be inversely correlated with patient age. There was no statistically significant association between the recurrence of amblyopia and VA of the amblyopic eye at the end of maximal occlusion therapy. There is a clinically important risk of amblyopia recurrence when occlusion therapy is decreased before the age of 10 years. The risk of recurrence is inversely correlated with age (P<0.0001).
Impact of posterior communicating artery on basilar artery steno-occlusive disease.
Hong, J M; Choi, J Y; Lee, J H; Yong, S W; Bang, O Y; Joo, I S; Huh, K
2009-12-01
Acute brainstem infarction with basilar artery (BA) occlusive disease is the most fatal type of all ischaemic strokes. This report investigates the prognostic impact of the posterior communicating artery (PcoA) and whether its anatomy is a safeguard or not. Consecutive patients who had acute brainstem infarction with at least 50% stenosis of BA upon CT angiography (CTA) were studied. The configuration of PcoA was divided into two groups upon CTA: "textbook" group (invisible PcoA with good P1 and P2 segment) and "fetal-variant of PcoA" group (only visible PcoA with absent P1 segment). Baseline demographics, radiological findings and stroke mechanisms were analysed. A multiple regression analysis was performed to predict clinical outcome at 30 days (modified Rankin disability Scale (mRSPcoA (26 bilateral, 18 unilateral). By multiple logistic regression analysis, the atherosclerotic mechanism (OR 18.0; 95% CI 3.0 to 107.0) and presence of fetal-variant PcoA (OR 5.1; 95% CI 1.4 to 18.8) were independent predictors for good prognosis and initial NIH stroke scale score (OR 1.24 per one-point increase; 95% CI 1.1 to 1.4) for poor prognosis. Fetal-variant PcoA appears to act as a safeguard against ischaemic insult in acute stroke victims involving the brainstem with BA occlusive disease. This result can be explained by the fact that patients with fetal-variant PcoA have a smaller area of posterior circulation and a possibility of retrograde filling into the upper brainstem through the fetal-variant PcoA.
International Nuclear Information System (INIS)
Oka, Yoshihisa; Kusunoki, Katsusuke; Nochide, Ichiro; Igase, Keiji; Harada, Hironobu; Sadamoto, Kazuhiko; Nagasawa, Kiyoshi
2001-01-01
The usefulness for evaluation of cerebral hemodynamics using time-resolved projection MRA was studied in normal volunteers and patients of cerebrovascular diseases. Six normal volunteers and ten patients with cerebrovascular occlusive diseases including 6 of IC occlusion and 4 of post EC/IC bypass surgery underwent time-resolved projection MRA on a 1.5 T clinical MRI system. Projection angiograms are acquired with 2D-fast SPGR sequence with a time resolution of approximately one image per second, 40 images being acquired consecutively before and after bolus injection Gd-DTPA. And all images were calculated by complex subtraction from the background mask in a work station. In normal volunteers, the quality of images of time-resolved projection MRA was satisfactory. The arteries from internal carotid artery through M2 segment of middle cerebral artery and all major venous systems were well portrayed. In 4 cases of IC occlusion who were assessed the collateral flow through the anterior communicating artery and posterior communicating artery, there were delayed to demonstrate the ipsilateral MCA. However, in 2 cases of IC occlusion that were assessed the collateral flow through leptomeningeal anastomosis, ipsilateral MCA and collateral circulation were not demonstrated. In all patients of post EC/IC bypass surgery, the patency of EC/IC bypass could be evaluated as properly with time-resolved projection MRA as 3D-TOF MRA. Although the temporal and spatial resolutions are insufficient, time-resolved projection MRA was power-full non-invasive method to evaluate the cerebral hemodynamics vis the basal communicating arteries in IC occlusion and identify the patency of EC/IC bypass. (author)
Soslow, Jonathan H.; Usoro, Emem; Wang, Li; Parra, David A.
2015-01-01
Background Aneurysmal dilation of the right ventricular outflow tract complicates assessment of right ventricular function in patients with repaired tetralogy of Fallot. Tricuspid annular plane systolic excursion is commonly used to estimate ejection fraction. We hypothesized that tricuspid annular plane systolic excursion measured by cardiac magnetic resonance imaging approximates global and segmental right ventricular function, specifically right ventricular sinus ejection fraction, in pediatric patients with repaired tetralogy of Fallot. Methods Tricuspid annular plane systolic excursion was measured retrospectively on cardiac magnetic resonance images in 54 patients with repaired tetralogy of Fallot. Values were compared with right ventricular global, sinus, and infundibular ejection fractions. Tricuspid annular plane systolic excursion was: 1) indexed to body surface area, 2) converted into a fractional value, and 3) converted into published pediatric Z-scores. Results Tricuspid annular plane systolic excursion measurements had good agreement between observers. Right ventricular ejection fraction did not correlate with the absolute or indexed tricuspid annular plane systolic excursion and correlated weakly with fractional tricuspid annular plane systolic excursion (r=0.41 and p=0.002). Segmental right ventricular function did not appreciably improve correlation with any of the tricuspid annular plane systolic excursion measures. Pediatric Z-scores were unable to differentiate patients with normal and abnormal right ventricular function. Conclusions Tricuspid annular plane systolic excursion measured on cardiac magnetic resonance imaging correlates poorly with global and segmental right ventricular ejection fraction in pediatric patients with repaired tetralogy of Fallot. Tricuspid annular plane systolic excursion is an unreliable approximation of right ventricular function in this patient population. PMID:26279488
H-Ransac a Hybrid Point Cloud Segmentation Combining 2d and 3d Data
Adam, A.; Chatzilari, E.; Nikolopoulos, S.; Kompatsiaris, I.
2018-05-01
In this paper, we present a novel 3D segmentation approach operating on point clouds generated from overlapping images. The aim of the proposed hybrid approach is to effectively segment co-planar objects, by leveraging the structural information originating from the 3D point cloud and the visual information from the 2D images, without resorting to learning based procedures. More specifically, the proposed hybrid approach, H-RANSAC, is an extension of the well-known RANSAC plane-fitting algorithm, incorporating an additional consistency criterion based on the results of 2D segmentation. Our expectation that the integration of 2D data into 3D segmentation will achieve more accurate results, is validated experimentally in the domain of 3D city models. Results show that HRANSAC can successfully delineate building components like main facades and windows, and provide more accurate segmentation results compared to the typical RANSAC plane-fitting algorithm.
Abdul-rahman R. Abdel-karim; Minh Vo; Michael L. Main; J. Aaron Grantham
2016-01-01
Interventricular septal hematoma is a rare complication of retrograde chronic total occlusion (CTO) percutaneous coronary interventions (PCI) with a typically benign course. Here we report two cases of interventricular septal hematoma and coronary-cameral fistula development after right coronary artery (RCA) CTO-PCI using a retrograde approach. Both were complicated by development of ST-segment elevation and chest pain. One case was managed actively and the other conservatively, both with a f...
DEFF Research Database (Denmark)
Hansen, Mie Østergaard
annoyances and the objective measurements were analysed. Persons suffering from tinnitus behaved differently than person without tinnitus. The latter group showed significant relations between the measured occlusion effect, hearing loss and the personal of occlusion. The actual sensation level is also...
Limitations and pitfalls of Couinaud's segmentation of the liver in transaxial Imaging
Energy Technology Data Exchange (ETDEWEB)
Strunk, H.; Textor, J.; Willinek, W. [Department of Radiology, University of Bonn, Sigmund Freud-Strasse 25, 53105, Bonn (Germany); Stuckmann, G. [Department of Radiology, Kantonsspital Winterthur (Switzerland)
2003-11-01
The segmental anatomy of the human liver has become a matter of increasing interest to the radiologist, especially in view of the need for an accurate preoperative localization of focal hepatic lesions. In this review article first an overview of the different classical concepts for delineating segmental and subsegmental anatomy on US, transaxial CT, and MR images is given. Essentially, these procedures are based on Couinaud's concept of three vertical planes that divide the liver into four segments and of a transverse scissura that further subdivides the segments into two subsegments each. In a second part, the limitations of these methods are delineated and discussed with the conclusion that if exact preoperative localization of hepatic lesions is needed, tumor must be located relative to the avascular planes between the different portal territories. (orig.)
[Temporomandibular joint, occlusion and bruxism].
Orthlieb, J D; Ré, J P; Jeany, M; Giraudeau, A
2016-09-01
Temporomandibular joint and dental occlusion are joined for better and worse. TMJ has its own weaknesses, sometimes indicated by bad functional habits and occlusal disorders. Occlusal analysis needs to be addressed simply and clearly. The term "malocclusion" is not reliable to build epidemiological studies, etiologic mechanisms or therapeutic advice on this "diagnosis". Understanding the impact of pathogenic malocclusion is not just about occlusal relationships that are more or less defective, it requires to locate them within the skeletal framework, the articular and behavioural context of the patient, and above all to assess their impact on the functions of the masticatory system. The TMJ-occlusion couple is often symbiotic, developing together in relation to its environment, compensating for its own shortcomings. However, a third partner may alter this relationship, such as bruxism, or more generally oral parafunctions, trauma or an interventionist practitioner. Copyright © 2016 Elsevier Masson SAS. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Noguchi, Osamu; Iwasa, Satoshi; Kohno, Norio; Nozaki, Miwako (Kiryu Kohsei General Hospital, Gunma (Japan))
1994-10-01
We report a patient who developed occlusion of the intracranial major arteries induced by radiation therapy for craniopharyngioma. The patient, a 9-year-old boy, presented with deterioration of vision, nausea and vomiting. He underwent a right ventriculo-peritoneal shunt operation, and the tumor was partially removed. Postoperatively, he received focal radiation therapy with total of 60 Gy. Preoperative cerebral angiography, cerebral vessels had no sigh of occlusive lesion or stenosis. One year after irradiation, he started to have repeated cerebral ischemic attacks. But no regrowth of the tumor was detected on CT scans. Two years and 8 months after irradiation, he suddenly had right hemiparesis. Cerebral angiography revealed severe stenosis of the right anterior cerebral artery (precommunicating segment), middle cerebral artery (horizontal portion) and terminal portion of the right carotid artery. Left carotid angiography showed complete occlusion of the terminal portion of the internal carotid artery and collateral vessels from the middle meningeal artery to the middle cerebral artery through the shunt burr hole. He has been treated conservatively and is doing well except for slight right hemiparesis. Our experience shows that the risk of occlusive cerebrovasculopathy after radiation therapy should be taken into account, especially in children. (author).
Treatment of temporomandibular disorder using occlusal splint
Directory of Open Access Journals (Sweden)
Agus Dahlan
2009-03-01
Full Text Available Background: Patient suffering from occlusal abnormality is usually detected months or even years when the acute patient visits a dentist, and generally the patient does not receive direct treatment upon his complaints since minimum information is available on this type of treatment. In general, the dentist provides medication only or conducts incorrect selective grinding where in fact, the patient does not feel better from the previous conditions. Purpose: The objective of this study is to discuss the treatment on the dysfunctional temporomandibular joint followed by orofacial pain caused by occlusal disorder using occlusal splint. Case: In this case, a forty three years old male having trouble with the joint on the left jaw followed by orofacial pain caused by occlusal disorder. Case Management: Initial treatment with occlusal splint makes the patient comfortable and recovers from his complaints since the patient could restructure the chewing muscles. This treatment will be more successful if the dentist has the knowledge to use and choose occlusal splint method properly. Occlusal Splint could be used as a supporting therapy and consideration as one of the therapies to avoid the unwanted side effects. The use of occlusal splint is meant as an alternative of the main therapy in overcoming the problem of occlusal splint. Conclusion: Finally, therapy with occlusal splint is very effective as an alternative treatment to handle the dysfunction of temporomandibular joint caused by occlusion.
Williams, Ann
Thrombotic catheter occlusion is a common complication associated with central venous catheters (CVCs). A wide variety of needleless connectors that differ greatly in design and function are available for use with CVCs; however, there are a limited number of studies comparing the catheter occlusion rate associated with differently designed needleless connectors. This retrospective observational study compared occlusion rates associated with a split-septum neutral-displacement needleless connector versus those of a solid-surface neutral-reflux needleless connector in patients undergoing home infusion therapy. The neutral-reflux needleless connector was associated with a significant reduction in occlusion rate and thrombolytic use versus the neutral-displacement needleless connector.
Hydrogel based occlusion systems
Stam, F.A.; Jackson, N.; Dubruel, P.; Adesanya, K.; Embrechts, A.; Mendes, E.; Neves, H.P.; Herijgers, P.; Verbrugghe, Y.; Shacham, Y.; Engel, L.; Krylov, V.
2013-01-01
A hydrogel based occlusion system, a method for occluding vessels, appendages or aneurysms, and a method for hydrogel synthesis are disclosed. The hydrogel based occlusion system includes a hydrogel having a shrunken and a swollen state and a delivery tool configured to deliver the hydrogel to a
Real-Time Facial Segmentation and Performance Capture from RGB Input
Saito, Shunsuke; Li, Tianye; Li, Hao
2016-01-01
We introduce the concept of unconstrained real-time 3D facial performance capture through explicit semantic segmentation in the RGB input. To ensure robustness, cutting edge supervised learning approaches rely on large training datasets of face images captured in the wild. While impressive tracking quality has been demonstrated for faces that are largely visible, any occlusion due to hair, accessories, or hand-to-face gestures would result in significant visual artifacts and loss of tracking ...
International Nuclear Information System (INIS)
Ramjas, Greg; Thurley, Peter; Habib, Said
2008-01-01
Endovascular treatment of iliac artery occlusions can be unsuccessful due to a failure to break back into the true lumen, and lesions without a proximal stump can be particularly problematic. True lumen re-entry catheters have not been previously used for this type of lesion. The authors report eight patients, five males and three females, with lifestyle-limiting intermittent claudication referred for endovascular treatment. Imaging demonstrated unilateral chronic total occlusion of the common iliac artery in six patients and two patients with short patent stumps at the origin of the occluded common iliac artery. Endovascular therapy was initially unsuccessful due to an inability to re-enter the true lumen after crossing the occlusion in the subintimal plane. With the assistance of the Outback LTD catheter it was possible to achieve continuity of the dissecting tract with the true lumen, thus facilitating successful primary stenting in all eight patients. To our knowledge this is the first report of the use of the Outback LTD catheter in this type of lesion
Complex neurological symptoms in bilateral thalamic stroke due to Percheron artery occlusion.
Caruso, Paola; Manganotti, Paolo; Moretti, Rita
2017-01-01
The artery of Percheron is a rare anatomical variant where a single thalamic perforating artery arises from the proximal posterior cerebral artery (P1 segment) between the basilar artery and the posterior communicating artery and supplies the rostral mesencephalon and both paramedian territories of the thalami. Almost one-third of human brains present this variant. Occlusion of the artery of Percheron mostly results in a bilateral medial thalamic infarction, which usually manifests with altered consciousness (including coma), vertical gaze paresis, and cognitive disturbance. The presentation is similar to the "top of the basilar syndrome", and early recognition should be prompted. We describe the case of a young female with this vessel variant who experienced a bilateral thalamic stroke. Magnetic resonance angiography demonstrated bilateral thalamic infarcts and a truncated artery of Percheron. Occlusion of the vessel was presumably due to embolism from a patent foramen ovale. Thrombolysis was performed, with incomplete symptom remission, cognitive impairment, and persistence of speech disorders. Early recognition and treatment of posterior circulation strokes is mandatory, and further investigation for underlying stroke etiologies is needed.
Vanacker, Peter; Heldner, Mirjam R; Amiguet, Michael; Faouzi, Mohamed; Cras, Patrick; Ntaios, George; Arnold, Marcel; Mattle, Heinrich P; Gralla, Jan; Fischer, Urs; Michel, Patrik
2016-06-01
Endovascular treatment for acute ischemic stroke with a large vessel occlusion was recently shown to be effective. We aimed to develop a score capable of predicting large vessel occlusion eligible for endovascular treatment in the early hospital management. Retrospective, cohort study. Two tertiary, Swiss stroke centers. Consecutive acute ischemic stroke patients (1,645 patients; Acute STroke Registry and Analysis of Lausanne registry), who had CT angiography within 6 and 12 hours of symptom onset, were categorized according to the occlusion site. Demographic and clinical information was used in logistic regression analysis to derive predictors of large vessel occlusion (defined as intracranial carotid, basilar, and M1 segment of middle cerebral artery occlusions). Based on logistic regression coefficients, an integer score was created and validated internally and externally (848 patients; Bernese Stroke Registry). None. Large vessel occlusions were present in 316 patients (21%) in the derivation and 566 (28%) in the external validation cohort. Five predictors added significantly to the score: National Institute of Health Stroke Scale at admission, hemineglect, female sex, atrial fibrillation, and no history of stroke and prestroke handicap (modified Rankin Scale score, < 2). Diagnostic accuracy in internal and external validation cohorts was excellent (area under the receiver operating characteristic curve, 0.84 both). The score performed slightly better than National Institute of Health Stroke Scale alone regarding prediction error (Wilcoxon signed rank test, p < 0.001) and regarding discriminatory power in derivation and pooled cohorts (area under the receiver operating characteristic curve, 0.81 vs 0.80; DeLong test, p = 0.02). Our score accurately predicts the presence of emergent large vessel occlusions, which are eligible for endovascular treatment. However, incorporation of additional demographic and historical information available on hospital arrival
Postural stability and occlusal status among Japanese elderly.
Song-Yu, Xuan; Rodis, Omar M M; Ogata, Sagiri; Can-Hu, Jin; Nishimura, Michiko; Matsumura, Seishi
2012-06-01
There are still no data available on the relationship between postural stability and occlusal status among the elderly. To examine relationships between postural stability and occlusal status through a cohort study among elderly Japanese. Oral examination, occlusal status, postural stability and a questionnaire were conducted and given to 87 community-dwelling Japanese at enrolment. The average occlusal pressure of the female group was statistically higher than the male group while average occlusal pressure and postural stability length were lesser in the group with more remaining teeth. Postural stability area and number of remaining teeth showed statistically significant correlations. Postural stability length was lesser in the group with strong occlusal force. Furthermore, the number of decayed teeth was fewer in the good hygiene group. This study identified a close relationship between occlusal status and postural stability of Japanese older individuals. Occlusal hypofunction was observed more in those with occlusal problems, and a decrease in their occlusal functions resulted in postural instability. © 2011 The Gerodontology Society and John Wiley & Sons A/S.
Li, C.; Li, F.; Liu, Y.; Li, X.; Liu, P.; Xiao, B.
2012-07-01
Building 3D reconstruction based on ground remote sensing data (image, video and lidar) inevitably faces the problem that buildings are always occluded by vegetation, so how to automatically remove and repair vegetation occlusion is a very important preprocessing work for image understanding, compute vision and digital photogrammetry. In the traditional multispectral remote sensing which is achieved by aeronautics and space platforms, the Red and Near-infrared (NIR) bands, such as NDVI (Normalized Difference Vegetation Index), are useful to distinguish vegetation and clouds, amongst other targets. However, especially in the ground platform, CIR (Color Infra Red) is little utilized by compute vision and digital photogrammetry which usually only take true color RBG into account. Therefore whether CIR is necessary for vegetation segmentation or not has significance in that most of close-range cameras don't contain such NIR band. Moreover, the CIE L*a*b color space, which transform from RGB, seems not of much interest by photogrammetrists despite its powerfulness in image classification and analysis. So, CIE (L, a, b) feature and support vector machine (SVM) is suggested for vegetation segmentation to substitute for CIR. Finally, experimental results of visual effect and automation are given. The conclusion is that it's feasible to remove and segment vegetation occlusion without NIR band. This work should pave the way for texture reconstruction and repair for future 3D reconstruction.
An Ensemble of 2D Convolutional Neural Networks for Tumor Segmentation
DEFF Research Database (Denmark)
Lyksborg, Mark; Puonti, Oula; Agn, Mikael
2015-01-01
Accurate tumor segmentation plays an important role in radiosurgery planning and the assessment of radiotherapy treatment efficacy. In this paper we propose a method combining an ensemble of 2D convolutional neural networks for doing a volumetric segmentation of magnetic resonance images....... The segmentation is done in three steps; first the full tumor region, is segmented from the background by a voxel-wise merging of the decisions of three networks learned from three orthogonal planes, next the segmentation is refined using a cellular automaton-based seed growing method known as growcut. Finally......, within-tumor sub-regions are segmented using an additional ensemble of networks trained for the task. We demonstrate the method on the MICCAI Brain Tumor Segmentation Challenge dataset of 2014, and show improved segmentation accuracy compared to an axially trained 2D network and an ensemble segmentation...
Directory of Open Access Journals (Sweden)
Michael D. Rivers-Bowerman, MD, MSc, FRCPC
2017-09-01
Full Text Available A 50-year-old male with right upper quadrant symptoms and hepatic dysfunction was found to have multiple dilated hepatic veins (HVs with intrahepatic collateralization and membranous occlusion of the intrahepatic inferior vena cava (IVC consistent with primary Budd–Chiari syndrome. Venacavograms depicted drainage of the intrahepatic collaterals through a left-sided HV entering the IVC above the level of the occlusion. Sharp recanalization of the membranous IVC occlusion was performed with an occlusion balloon as a needle target under echocardiographic monitoring followed by balloon angioplasty with restoration of IVC patency. Clinical, laboratory, and venographic procedural success has been demonstrated to 9 months with minimal residual stenosis.
A new method of evaluating posterior occlusion and its relation to posttreatment occlusal changes.
Parkinson, C E; Buschang, P H; Behrents, R G; Throckmorton, G S; English, J D
2001-11-01
The purpose of this study was to assess the relationship between posterior occlusion and posttreatment changes in other occlusal variables. Pretreatment (T1), posttreatment (T2), and postretention (T3) records were obtained for 49 Class I (n = 23) and Class II (n = 26) extraction cases. Overbite, overjet, mandibular incisor irregularity, right and left molar deviations, midline deviation, and mandibular arch length were measured, and occlusal registrations were made of each set of dental casts. The proximity of posterior occlusal surfaces was measured as the contact or near-contact areas at or below 300 microm thickness, based on the optical densities of scanned images of the posterior occlusal registrations. The treatment changes for overbite, overjet, right and left molar deviation, and arch length were significantly greater in the Class II group, and the reductions in incisor irregularity were greater in the Class I group. No other class differences were found. Overbite, overjet, and incisor irregularity increased after treatment, and arch length continued to decrease, with no significant class differences. Contact and near-contact areas at or below 300 microm constituted 7% of the functional occlusal table for both classes at the end of treatment, having decreased significantly in both groups (21% in Class I and 29% in Class II) during treatment. Because contact and near-contact areas increased in some patients and decreased in others, there were no significant posttreatment changes. Negative correlations were found between contact and near-contact areas at T2 and changes in overjet from T2 to T3, and between contact and near-contact areas at T3 and changes in overbite from T2 to T3. No relationships were found between posterior contact and near-contact area and incisor irregularity. We concluded that (1) the area of actual and near contacts at or below 300 microm decreased significantly with treatment, indicating that, despite excellent treatment results by
Occlusion Handling in Videos Object Tracking: A Survey
International Nuclear Information System (INIS)
Lee, B Y; Liew, L H; Cheah, W S; Wang, Y C
2014-01-01
Object tracking in video has been an active research since for decades. This interest is motivated by numerous applications, such as surveillance, human-computer interaction, and sports event monitoring. Many challenges related to tracking objects still remain, this can arise due to abrupt object motion, changing appearance patterns of objects and the scene, non-rigid object structures and most significant are occlusion of tracked object be it object-to-object or object-to-scene occlusions. Generally, occlusion in object tracking occur under three situations: self-occlusion, inter-object occlusion by background scene structure. Self-occlusion occurs most frequently while tracking articulated objects when one part of the object occludes another. Inter-object occlusion occurs when two objects being tracked occlude each other whereas occlusion by the background occurs when a structure in the background occludes the tracked objects. Typically, tracking methods handle occlusion by modelling the object motion using linear and non-linear dynamic models. The derived models will be used to continuously predicting the object location when a tracked object is occluded until the object reappears. Example of these method are Kalman filtering and Particle filtering trackers. Researchers have also utilised other features to resolved occlusion, for example, silhouette projections, colour histogram and optical flow. We will present some result from a previously conducted experiment when tracking single object using Kalman filter, Particle filter and Mean Shift trackers under various occlusion situation in this paper. We will also review various other occlusion handling methods that involved using multiple cameras. In a nutshell, the goal of this paper is to discuss in detail the problem of occlusion in object tracking and review the state of the art occlusion handling methods, classify them into different categories, and identify new trends. Moreover, we discuss the important
Occlusion Handling in Videos Object Tracking: A Survey
Lee, B. Y.; Liew, L. H.; Cheah, W. S.; Wang, Y. C.
2014-02-01
Object tracking in video has been an active research since for decades. This interest is motivated by numerous applications, such as surveillance, human-computer interaction, and sports event monitoring. Many challenges related to tracking objects still remain, this can arise due to abrupt object motion, changing appearance patterns of objects and the scene, non-rigid object structures and most significant are occlusion of tracked object be it object-to-object or object-to-scene occlusions. Generally, occlusion in object tracking occur under three situations: self-occlusion, inter-object occlusion by background scene structure. Self-occlusion occurs most frequently while tracking articulated objects when one part of the object occludes another. Inter-object occlusion occurs when two objects being tracked occlude each other whereas occlusion by the background occurs when a structure in the background occludes the tracked objects. Typically, tracking methods handle occlusion by modelling the object motion using linear and non-linear dynamic models. The derived models will be used to continuously predicting the object location when a tracked object is occluded until the object reappears. Example of these method are Kalman filtering and Particle filtering trackers. Researchers have also utilised other features to resolved occlusion, for example, silhouette projections, colour histogram and optical flow. We will present some result from a previously conducted experiment when tracking single object using Kalman filter, Particle filter and Mean Shift trackers under various occlusion situation in this paper. We will also review various other occlusion handling methods that involved using multiple cameras. In a nutshell, the goal of this paper is to discuss in detail the problem of occlusion in object tracking and review the state of the art occlusion handling methods, classify them into different categories, and identify new trends. Moreover, we discuss the important
Saito, Daiji; Yasuhara, Koichiro; Takeda, Hikaru; Hyodo, Tatuo; Yamada, Nobuyuki; Uchida, Toshiaki; Haraoka, Shoichi; Nagashima, Hideo
1982-01-01
Changes in the stenotic resistance of a coronary artery following brief coronary occlusion were studied in the anesthetized open-chest dog. A critical coronary stenosis was constructed by tying a thick string around the circumflex coronary artery (LCx) near its origin. The LCx was occluded for 5, 10, 15, 20 and 30 seconds with and without coronary stenosis then the reactive hyperemia was observed. In the absence of the stenosis, resistance of the segment of the large coronary artery remained ...
Occlusion-Aware View Interpolation
Directory of Open Access Journals (Sweden)
Ince Serdar
2008-01-01
Full Text Available Abstract View interpolation is an essential step in content preparation for multiview 3D displays, free-viewpoint video, and multiview image/video compression. It is performed by establishing a correspondence among views, followed by interpolation using the corresponding intensities. However, occlusions pose a significant challenge, especially if few input images are available. In this paper, we identify challenges related to disparity estimation and view interpolation in presence of occlusions. We then propose an occlusion-aware intermediate view interpolation algorithm that uses four input images to handle the disappearing areas. The algorithm consists of three steps. First, all pixels in view to be computed are classified in terms of their visibility in the input images. Then, disparity for each pixel is estimated from different image pairs depending on the computed visibility map. Finally, luminance/color of each pixel is adaptively interpolated from an image pair selected by its visibility label. Extensive experimental results show striking improvements in interpolated image quality over occlusion-unaware interpolation from two images and very significant gains over occlusion-aware spline-based reconstruction from four images, both on synthetic and real images. Although improvements are obvious only in the vicinity of object boundaries, this should be useful in high-quality 3D applications, such as digital 3D cinema and ultra-high resolution multiview autostereoscopic displays, where distortions at depth discontinuities are highly objectionable, especially if they vary with viewpoint change.
Occlusion-Aware View Interpolation
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Janusz Konrad
2009-01-01
Full Text Available View interpolation is an essential step in content preparation for multiview 3D displays, free-viewpoint video, and multiview image/video compression. It is performed by establishing a correspondence among views, followed by interpolation using the corresponding intensities. However, occlusions pose a significant challenge, especially if few input images are available. In this paper, we identify challenges related to disparity estimation and view interpolation in presence of occlusions. We then propose an occlusion-aware intermediate view interpolation algorithm that uses four input images to handle the disappearing areas. The algorithm consists of three steps. First, all pixels in view to be computed are classified in terms of their visibility in the input images. Then, disparity for each pixel is estimated from different image pairs depending on the computed visibility map. Finally, luminance/color of each pixel is adaptively interpolated from an image pair selected by its visibility label. Extensive experimental results show striking improvements in interpolated image quality over occlusion-unaware interpolation from two images and very significant gains over occlusion-aware spline-based reconstruction from four images, both on synthetic and real images. Although improvements are obvious only in the vicinity of object boundaries, this should be useful in high-quality 3D applications, such as digital 3D cinema and ultra-high resolution multiview autostereoscopic displays, where distortions at depth discontinuities are highly objectionable, especially if they vary with viewpoint change.
Inference of segmented color and texture description by tensor voting.
Jia, Jiaya; Tang, Chi-Keung
2004-06-01
A robust synthesis method is proposed to automatically infer missing color and texture information from a damaged 2D image by (N)D tensor voting (N > 3). The same approach is generalized to range and 3D data in the presence of occlusion, missing data and noise. Our method translates texture information into an adaptive (N)D tensor, followed by a voting process that infers noniteratively the optimal color values in the (N)D texture space. A two-step method is proposed. First, we perform segmentation based on insufficient geometry, color, and texture information in the input, and extrapolate partitioning boundaries by either 2D or 3D tensor voting to generate a complete segmentation for the input. Missing colors are synthesized using (N)D tensor voting in each segment. Different feature scales in the input are automatically adapted by our tensor scale analysis. Results on a variety of difficult inputs demonstrate the effectiveness of our tensor voting approach.
Application of photogrammetry for analysis of occlusal contacts.
Shigeta, Yuko; Hirabayashi, Rio; Ikawa, Tomoko; Kihara, Takuya; Ando, Eriko; Hirai, Shinya; Fukushima, Shunji; Ogawa, Takumi
2013-04-01
The conventional 2D-analysis methods for occlusal contacts provided limited information on tooth morphology. This present study aims to detect 3D positional information of occlusal contacts from 2D-photos via photogrammetry. We propose an image processing solution for analysis of occlusal contacts and facets via the black silicone method and a photogrammetric technique. The occlusal facets were reconstructed from a 2D-photograph data-set of inter-occlusal records into a 3D image via photogrammetry. The configuration of the occlusal surface was reproduced with polygons. In addition, the textures of the occlusal contacts were mapped to each polygon. DIFFERENCE FROM CONVENTIONAL METHODS: Constructing occlusal facets with 3D polygons from 2D-photos with photogrammetry was a defining characteristic of this image processing technique. It allowed us to better observe findings of the black silicone method. Compared with conventional 3D analysis using a 3D scanner, our 3D models did not reproduce the detail of the anatomical configuration. However, by merging the findings of the inter-occlusal record, the deformation of mandible and the displacement of periodontal ligaments under occlusal force were reflected in our model. EFFECT OR PERFORMANCE: Through the use of polygons in the conversion of 2D images to 3D images, we were able to define the relation between the location and direction of the occlusal contacts and facets, which was difficult to detect via conventional methods. Through our method of making a 3D polygon model, the findings of inter-occlusal records which reflected the jaw/teeth behavior under occlusal force could be observed 3-dimensionally. Copyright © 2012 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.
Directory of Open Access Journals (Sweden)
Estevan Isaac
2015-09-01
Full Text Available In taekwondo, there is a lack of consensus about how the kick sequence occurs. The aim of this study was to analyse the peak velocity (resultant and value in each plane of lower limb segments (thigh, shank and foot, and the time to reach this peak velocity in the kicking lower limb during the execution of the roundhouse kick technique. Ten experienced taekwondo athletes (five males and five females; mean age of 25.3 ±5.1 years; mean experience of 12.9 ±5.3 years participated voluntarily in this study performing consecutive kicking trials to a target located at their sternum height. Measurements for the kinematic analysis were performed using two 3D force plates and an eight camera motion capture system. The results showed that the proximal segment reached a lower peak velocity (resultant and in each plane than distal segments (except the peak velocity in the frontal plane where the thigh and shank presented similar values, with the distal segment taking the longest to reach this peak velocity (p < 0.01. Also, at the instant every segment reached the peak velocity, the velocity of the distal segment was higher than the proximal one (p < 0.01. It provides evidence about the sequential movement of the kicking lower limb segments. In conclusion, during the roundhouse kick in taekwondo inter-segment motion seems to be based on a proximo-distal pattern.
Current possibilities in occlusal caries management
Directory of Open Access Journals (Sweden)
Hrvoje Jurić
2013-11-01
Full Text Available Dental caries is a multifactorial disease that affects most populations throughout the world and it is still the primary cause of oral pain and tooth loss. The occlusal surfaces of posterior teeth are the most vulnerable sites for dental caries due to their anatomy. Therefore, the aim of the following article is to summarize current knowledge on occlusal caries development and the possibilities of its prevention. Although the overall caries rate today has fallen for populations in industrialized countries, the rate of occlusal surface caries has not decreased. This may be explained with fact that topically applied fluorides and their mode of action prevent caries better on smooth than on occlusal surfaces. As we know, tooth decay of first permanent molars causes a great deal of different short and long term difficulties for patients. Therefore, there is a continuous need for implementation of programs for caries prevention in permanent teeth. Nowadays, we like to treat our patients by minimally invasive methods. A very important step in our effective preventive treatment is sealing pits and fissures as a cornerstone of occlusal caries management. Reliable assessment of caries activity is also very important for defining treatment needs and plans. A very important decision, which should be made during occlusal caries management, is the selection of restorative material according to the treatment plan. Conclusion. Current possibilities in occlusal caries prevention and management are very effective. Therefore, dentists today do not have any excuse for avoiding the philosophy of Minimally Invasive Dentistry, especially when we talk about caries management of occlusal surfaces in permanent molars.
[Evaluation of accuracy of virtual occlusal definition in Angle class I molar relationship].
Wu, L; Liu, X J; Li, Z L; Wang, X
2018-02-18
To evaluate the accuracy of virtual occlusal definition in non-Angle class I molar relationship, and to evaluate the clinical feasibility. Twenty pairs of models of orthognathic patients were included in this study. The inclusion criteria were: (1) finished with pre-surgical orthodontic treatment and (2) stable final occlusion. The exclusion criteria were: (1) existence of distorted teeth, (2) needs for segmentation, (3) defect of dentition except for orthodontic extraction ones, and (4) existence of tooth space. The tooth-extracted test group included 10 models with two premolars extracted during preoperative orthodontic treatment. Their molar relationships were not Angle class I relationship. The non-tooth-extracted test group included another 10 models without teeth extracted, therefore their molar relationships were Angle class I. To define the final occlusion in virtual environment, two steps were included: (1) The morphology data of upper and lower dentition were digitalized by surface scanner (Smart Optics/Activity 102; Model-Tray GmbH, Hamburg, Germany); (2) the virtual relationships were defined using 3Shape software. The control standard of final occlusion was manually defined using gypsum models and then digitalized by surface scanner. The final occlusion of test group and control standard were overlapped according to lower dentition morphology. Errors were evaluated by calculating the distance between the corresponding reference points of testing group and control standard locations. The overall errors for upper dentition between test group and control standard location were (0.51±0.18) mm in non-tooth-extracted test group and (0.60±0.36) mm in tooth-extracted test group. The errors were significantly different between these two test groups (P0.05); and the accuracy of non-tooth-extracted group was significantly smaller than 1 mm (Pdefinition of none class I molar relationship is higher than that of class I relationship, with an accuracy of 1 mm
International Nuclear Information System (INIS)
Sato, Manabu; Kidooka, Minoru
1982-01-01
A case of occlusion of the left Heubner's artery in a right-handed, 51-year-old man is reported. Cardinal clinical features were transient right hemiparesis and mental disturbance, especially intellectual defect. Low density areas were found at CT in the globus pallidus, putamen, anterior limb of the internal capsule and a part of the caudate nucleus. It is well known that the occlusion of the Heubner's artery causes transient motor paresis of upper extremity on the contralaterl side. However, in the case where the Heubner's artery is remarkably well developed when compared with the medial striate arteries as was the case in this patient, it should be noted that the occlusion of the Heubner's artery may well causes grave mental disturbance, in addition. (author)
Occlusal considerations for dental implant restorations.
Bergmann, Ranier H
2014-01-01
When placed, dental implants are put into an ever-changing oral environment in which teeth can continue to migrate. Yet, the implants themselves are ankylosed. This can lead to occlusal instability. Teeth may continue to erupt, leaving the implants in infraocclusion. Teeth may move mesially away from an implant, requiring modification to close an open contact point. Friction in the connection between teeth and implants can lead to intrusion of teeth and damage to the periodontal attachment apparatus. Implant occlusion with shallow incisal guidance minimizes lateral and tipping forces. Cross-arch stabilization allows the best distribution of occlusal forces. The choice of restorative materials influences long-term occlusal stability.
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Chiwata Ichiro
2010-03-01
Full Text Available Abstract Background Many researchers have not accepted the use of occlusal treatments for temporomandibular disorders (TMDs. However, a recent report described a discrepancy between the habitual occlusal position (HOP and the bite plate-induced occlusal position (BPOP and discussed the relation of this discrepancy to TMD. Therefore, the treatment outcome of evidence-based occlusal adjustments using the bite plate-induced occlusal position (BPOP as a muscular reference position should be evaluated in patients with TMD. Methods The BPOP was defined as the position at which a patient voluntarily closed his or her mouth while sitting in an upright posture after wearing an anterior flat bite plate for 5 minutes and then removing the plate. Twenty-one patients with TMDs underwent occlusal adjustment using the BPOP. The occlusal adjustments were continued until bilateral occlusal contacts were obtained in the BPOP. The treatment outcomes were evaluated using the subjective dysfunction index (SDI and the Helkimo Clinical Dysfunction Index (CDI before and after the occlusal adjustments; the changes in these two indices between the first examination and a one-year follow-up examination were then analyzed. In addition, the difference between the HOP and the BPOP was three-dimensionally measured before and after the treatment. Results The percentage of symptom-free patients after treatment was 86% according to the SDI and 76% according to the CDI. The changes in the two indices after treatment were significant (p 0.1. Conclusion Although the results of the present study should be confirmed in other studies, a randomized clinical trial examining occlusal adjustments using the BPOP as a reference position appears to be warranted.
Bolkas, Dimitrios; Martinez, Aaron
2018-01-01
Point-cloud coordinate information derived from terrestrial Light Detection And Ranging (LiDAR) is important for several applications in surveying and civil engineering. Plane fitting and segmentation of target-surfaces is an important step in several applications such as in the monitoring of structures. Reliable parametric modeling and segmentation relies on the underlying quality of the point-cloud. Therefore, understanding how point-cloud errors affect fitting of planes and segmentation is important. Point-cloud intensity, which accompanies the point-cloud data, often goes hand-in-hand with point-cloud noise. This study uses industrial particle boards painted with eight different colors (black, white, grey, red, green, blue, brown, and yellow) and two different sheens (flat and semi-gloss) to explore how noise and plane residuals vary with scanning geometry (i.e., distance and incidence angle) and target-color. Results show that darker colors, such as black and brown, can produce point clouds that are several times noisier than bright targets, such as white. In addition, semi-gloss targets manage to reduce noise in dark targets by about 2-3 times. The study of plane residuals with scanning geometry reveals that, in many of the cases tested, residuals decrease with increasing incidence angles, which can assist in understanding the distribution of plane residuals in a dataset. Finally, a scheme is developed to derive survey guidelines based on the data collected in this experiment. Three examples demonstrate that users should consider instrument specification, required precision of plane residuals, required point-spacing, target-color, and target-sheen, when selecting scanning locations. Outcomes of this study can aid users to select appropriate instrumentation and improve planning of terrestrial LiDAR data-acquisition.
Bunc, Matjaž; Kocijančič, Igor J.; Pregelj, Rado; Dolenc, Vinko V.
2010-01-01
Embolic occlusion of cerebral arteries is a major cause for stroke. Intravenous thrombolysis showed positive results in this condition, however even when strict criteria are used, the risk of hemorrhagic transformation is possible. Microsurgical embolectomy has been described earlier. Purpose. We performed multimodal therapy of cerebral artery occlusion. Case Report. We present a case of a 49-year-old female patient who—according to the National Institute of Health Stroke Scale (NIHSS)—was rated as 19 due to acute occlusion of the horizontal segment of the left middle cerebral artery (MCA). After failed i.v. thrombolysis, only a part of the clot could be evacuated by the endovascular approach—without restoration of blood flow. Normal patency of the left MCA was re-established after stenting. Within 72 hours, the patient had an NIHSS score of 14, with a small haematoma in the left hemisphere. Conclusion. In our case multimodal therapy combining i.v. thrombolysis, mechanical disruption of thrombus, MCA stenting and platelet function antagonists, resulted in successful recanalization of the acutely occluded left MCA. PMID:20671974
Bunc, Matjaz; Kocijancic, Igor J; Pregelj, Rado; Dolenc, Vinko V
2010-01-01
Embolic occlusion of cerebral arteries is a major cause for stroke. Intravenous thrombolysis showed positive results in this condition, however even when strict criteria are used, the risk of hemorrhagic transformation is possible. Microsurgical embolectomy has been described earlier. Purpose. We performed multimodal therapy of cerebral artery occlusion. Case Report. We present a case of a 49-year-old female patient who-according to the National Institute of Health Stroke Scale (NIHSS)-was rated as 19 due to acute occlusion of the horizontal segment of the left middle cerebral artery (MCA). After failed i.v. thrombolysis, only a part of the clot could be evacuated by the endovascular approach-without restoration of blood flow. Normal patency of the left MCA was re-established after stenting. Within 72 hours, the patient had an NIHSS score of 14, with a small haematoma in the left hemisphere. Conclusion. In our case multimodal therapy combining i.v. thrombolysis, mechanical disruption of thrombus, MCA stenting and platelet function antagonists, resulted in successful recanalization of the acutely occluded left MCA.
Effect of glove occlusion on the skin barrier
DEFF Research Database (Denmark)
Tiedemann, Daniel; Clausen, Maja Lisa; John, Swen Malthe
2016-01-01
that the negative effect of occlusion in itself is limited, and that only extensive and long-term occlusion will cause barrier impairment. However, studies investigating combined effect of occlusion and exposure to soaps/detergents indicate that occlusion significantly enhances the skin barrier damage caused...... by detergents/soaps in a dose-response fashion....
Occlusal features and need for orthodontic treatment in persons with osteogenesis imperfecta
Binh, Ho Duy; Nguyen, Khac Minh; Maasalu, Katre; Kõks, Sulev; Märtson, Aare; Saag, Mare; Jagomägi, Triin
2017-01-01
Abstract The aim of the study was to (a) analyse dental occlusion and determine the need for orthodontic treatment of persons with osteogenesis imperfecta (OI) in comparison with the healthy population and (b) investigate the associations between OI and malocclusion. A case‐control study included 26 OI persons and 400 healthy participants (control group). Occlusal features and the need for orthodontic treatment were defined according to Dental Health Component‐Index of Orthodontic Treatment Need and Dental Aesthetic Index. Results showed that Angle Class I, II, and III relationship was found in 23.1%, 3.8%, and 73.1% of OI group, and in the control group, it was 67%, 17.5%, and 15.5%, respectively. OI group had significantly higher prevalence of reverse overjet >1 mm (76.9%), missing teeth (42.3%), posterior crossbite (34.6%), and open bite >2 mm (19.2%) compared to the control group (8.5%, 2.2%, 6.2%, and 3.5%, respectively). OI group had less incisal segment crowding and more incisal segment spacing than the control group (p 1 mm (OR = 13.3, 95% CI = 3.9–44.7, p < .001), Angle Class III malocclusion (OR = 8.0, 95% CI = 2.0–30.8, p = .003), and missing teeth (OR = 4.7, 95% CI = 1.0–22.4, p = .049). In conclusion, there is the high probability of malocclusion in OI persons. Persons with OI require early orthodontic treatment because of significant correlation of OI disease with Angle Class III malocclusion, reverse overjet, and missing teeth. PMID:29744175
Elias, Joëlle; van Dongen, Ivo M; Hoebers, Loes P; Ouweneel, Dagmar M; Claessen, Bimmer E P M; Råmunddal, Truls; Laanmets, Peep; Eriksen, Erlend; van der Schaaf, René J; Ioanes, Dan; Nijveldt, Robin; Tijssen, Jan G; Hirsch, Alexander; Henriques, José P S
2017-07-19
The Evaluating Xience and left ventricular function in PCI on occlusiOns afteR STEMI (EXPLORE) trial did not show a significant benefit of percutaneous coronary intervention (PCI) of the concurrent chronic total occlusion (CTO) in ST-segment elevation myocardial infarction (STEMI) patients on global left ventricular (LV) systolic function. However a possible treatment effect will be most pronounced in the CTO territory. Therefore, we aimed to study the effect of CTO PCI compared to no-CTO PCI on the recovery of regional LV function, particularly in the CTO territory. Using cardiovascular magnetic resonance (CMR) we studied 180 of the 302 EXPLORE patients with serial CMR (baseline and 4 months follow-up). Segmental wall thickening (SWT) was quantified on cine images by an independent core laboratory. Dysfunctional segments were defined as SWT PCI compared to no-CTO PCI (ΔSWT 17 ± 27% vs 11 ± 23%, p = 0.03). This recovery was most pronounced in the dysfunctional but viable segments(TEI PCI compared with no-CTO PCI is associated with a greater recovery of regional systolic function in the CTO territory, especially in the dysfunctional but viable segments. Further research is needed to evaluate the use of CMR in selecting post-STEMI patients for CTO PCI and the effect of regional LV function recovery on clinical outcome. Trialregister.nl NTR1108 , Date registered NTR: 30-okt-2007.
[High-frequency components of occlusal sound in sliding movement].
Nagai, K
1990-03-01
We postulated that high-frequency components of the occlusal sound occurring due to the characteristic vibration of teeth can be useful data for confirmation of the stability in occlusion, and studied the high-frequency components in the cases both of an experimental sliding movement and a normal occlusion. The results obtained were as follows. 1. A study on high-frequency components of the occlusal sound in an experimental sliding movement. 1) A study on wave type of the occlusal sound revealed one damped oscillation in an impact form and two in a slide form. 2) Spectrum analysis of the damped oscillation showed a similar spectrum pattern with a peak existing between 16KHz or more and 17KHz or less in both impact and slide cases. 2. A study on high-frequency components of the occlusal sound in a normal occlusion case. 1) The wave type in occlusal sound we have observed in a normal occlusion group and in a prosthetic or operative group was as follows: One damped oscillation shown in an impact form and two damped oscillation in a slide form which were the same as those shown in the case where an interference device was attached. 2) Duration of the sliding movement was short in a normal occlusion group, but was prolonged in a prosthetic or operative group. 3) The incidence of the wave type in occlusal sound was 56.7% in a prosthetic or operative group as compared to 87.8% in a normal occlusion group in an impact form. In contrast, the incidence was 43.3% in a prosthetic or operative group as compared to 12.2% in a normal occlusion group in a slide form. Such difference in the incidence between the wave types suggested that high-frequency components of occlusal sound can be an index for judgement of the stability in occlusion.
Stent Graft in Managing Juxta-Renal Aortoiliac Occlusion
International Nuclear Information System (INIS)
Prabhudesai, V.; Mitra, K.; West, D. J.; Dean, M. R. E.
2003-01-01
Endovascular procedures are frequently used as an alternative to surgical bypass in aortic and iliac occlusion. Stents have revolutionized the scope of such endovascular procedures, but there are few reports of stents or stent grafts in occlusive juxta-renal aortic occlusion. We present a case where such occlusion was managed by use of a stent graft with successful outcome
Fish tracking by combining motion based segmentation and particle filtering
Bichot, E.; Mascarilla, L.; Courtellemont, P.
2006-01-01
In this paper, we suggest a new importance sampling scheme to improve a particle filtering based tracking process. This scheme relies on exploitation of motion segmentation. More precisely, we propagate hypotheses from particle filtering to blobs of similar motion to target. Hence, search is driven toward regions of interest in the state space and prediction is more accurate. We also propose to exploit segmentation to update target model. Once the moving target has been identified, a representative model is learnt from its spatial support. We refer to this model in the correction step of the tracking process. The importance sampling scheme and the strategy to update target model improve the performance of particle filtering in complex situations of occlusions compared to a simple Bootstrap approach as shown by our experiments on real fish tank sequences.
Roof planes detection via a second-order variational model
Benciolini, Battista; Ruggiero, Valeria; Vitti, Alfonso; Zanetti, Massimo
2018-04-01
The paper describes a unified automatic procedure for the detection of roof planes in gridded height data. The procedure exploits the Blake-Zisserman (BZ) model for segmentation in both 2D and 1D, and aims to detect, to model and to label roof planes. The BZ model relies on the minimization of a functional that depends on first- and second-order derivatives, free discontinuities and free gradient discontinuities. During the minimization, the relative strength of each competitor is controlled by a set of weight parameters. By finding the minimum of the approximated BZ functional, one obtains: (1) an approximation of the data that is smoothed solely within regions of homogeneous gradient, and (2) an explicit detection of the discontinuities and gradient discontinuities of the approximation. Firstly, input data is segmented using the 2D BZ. The maps of data and gradient discontinuities are used to isolate building candidates and planar patches (i.e. regions with homogeneous gradient) that correspond to roof planes. Connected regions that can not be considered as buildings are filtered according to both patch dimension and distribution of the directions of the normals to the boundary. The 1D BZ model is applied to the curvilinear coordinates of boundary points of building candidates in order to reduce the effect of data granularity when the normals are evaluated. In particular, corners are preserved and can be detected by means of gradient discontinuity. Lastly, a total least squares model is applied to estimate the parameters of the plane that best fits the points of each planar patch (orthogonal regression with planar model). Refinement of planar patches is performed by assigning those points that are close to the boundaries to the planar patch for which a given proximity measure assumes the smallest value. The proximity measure is defined to account for the variance of a fitting plane and a weighted distance of a point from the plane. The effectiveness of the
Afifi, Ahmed; Nakaguchi, Toshiya; Tsumura, Norimichi
2010-03-01
In many medical applications, the automatic segmentation of deformable organs from medical images is indispensable and its accuracy is of a special interest. However, the automatic segmentation of these organs is a challenging task according to its complex shape. Moreover, the medical images usually have noise, clutter, or occlusion and considering the image information only often leads to meager image segmentation. In this paper, we propose a fully automated technique for the segmentation of deformable organs from medical images. In this technique, the segmentation is performed by fitting a nonlinear shape model with pre-segmented images. The kernel principle component analysis (KPCA) is utilized to capture the complex organs deformation and to construct the nonlinear shape model. The presegmentation is carried out by labeling each pixel according to its high level texture features extracted using the overcomplete wavelet packet decomposition. Furthermore, to guarantee an accurate fitting between the nonlinear model and the pre-segmented images, the particle swarm optimization (PSO) algorithm is employed to adapt the model parameters for the novel images. In this paper, we demonstrate the competence of proposed technique by implementing it to the liver segmentation from computed tomography (CT) scans of different patients.
Segmentation and Classification of Burn Color Images
National Research Council Canada - National Science Library
Acha, Begonya
2001-01-01
.... In the classification part, we take advantage of color information by clustering, with a vector quantization algorithm, the color centroids of small squares, taken from the burnt segmented part of the image, in the (V1, V2) plane into two possible groups, where V1 and V2 are the two chrominance components of the CIE Lab representation.
Neuromuscular dentistry: Occlusal diseases and posture.
Khan, Mohd Toseef; Verma, Sanjeev Kumar; Maheshwari, Sandhya; Zahid, Syed Naved; Chaudhary, Prabhat K
2013-01-01
Neuromuscular dentistry has been a controversial topic in the field of dentistry and still remains debatable. The issue of good occlusion and sound health has been repeatedly discussed. Sometimes we get complains of sensitive teeth and sometimes of tired facial muscles on getting up in the morning. Owing to the intimate relation of masticatory apparatus with the cranium and cervico-scapular muscular system, the disorders in any system, draw attention from concerned clinicians involved in management, to develop an integrated treatment protocol for the suffering patients. There may be patients reporting to the dental clinics after an occlusal restoration or extraction, having pain in or around the temporomandibular joint, headache or neck pain. Although their esthetic demands must not be undermined during the course of treatment plan, whenever dental treatment of any sort is planned, occlusion/bite should be given prime importance. Very few dentist are able to diagnose the occlusal disease and of those who diagnose many people resort to aggressive treatment modalities. This paper aims to report the signs of occlusal disease, and discuss their association with TMDs and posture.
Research on spatial-variant property of bistatic ISAR imaging plane of space target
International Nuclear Information System (INIS)
Guo Bao-Feng; Wang Jun-Ling; Gao Mei-Guo
2015-01-01
The imaging plane of inverse synthetic aperture radar (ISAR) is the projection plane of the target. When taking an image using the range-Doppler theory, the imaging plane may have a spatial-variant property, which causes the change of scatter’s projection position and results in migration through resolution cells. In this study, we focus on the spatial-variant property of the imaging plane of a three-axis-stabilized space target. The innovative contributions are as follows. 1) The target motion model in orbit is provided based on a two-body model. 2) The instantaneous imaging plane is determined by the method of vector analysis. 3) Three Euler angles are introduced to describe the spatial-variant property of the imaging plane, and the image quality is analyzed. The simulation results confirm the analysis of the spatial-variant property. The research in this study is significant for the selection of the imaging segment, and provides the evidence for the following data processing and compensation algorithm. (paper)
DEFF Research Database (Denmark)
Agerskov, K; Henriksen, O; Tønnesen, K H
1981-01-01
The effect of head-up tilt on leg blood flow and segmental arterial blood pressures was studied in 21 patients with occlusion or severe stenosis of the common or superficial femoral artery. Arterial pressure was measured directly in the brachial artery, common femoral artery and popliteal artery....... Relative change in blood flow in the leg during tilt was estimated by changes in arterio-venous oxygen differences and by the indicator dilution technique in nine patients. Head-up tilt caused a decrease in leg blood flow of 36% corresponding to an increase in total vascular resistance of 57%. Tilt did...... not change the pressure gradient from femoral to popliteal artery in the patients with occlusion of the superficial femoral artery, indicating that the flow resistance offered by the collateral arteries had increased. In a bilateral sympathectomised patient the increase in collateral resistance was almost...
Epulis and pyogenic granuloma with occlusal interference
Directory of Open Access Journals (Sweden)
Widowati Witjaksono
2005-06-01
Full Text Available In dental clinic of Hospital University Science Malaysia (HUSM, there were cases with Localized Gingival Enlargement (LGE in the oral cavity with occlusal interference. In this study, three cases were observed. They were a 13 - year- old female with fibrous lge around 31 and 32 with occlusal interference in protrusive movement due to X bite, a 15 - year – old female with pyogenic granuloma near 11 & 21 with occlusal interference due to deep bite; and a 24 – year – old female who was eight months in pregnancy with pyogenic granuloma on the 34-35 and severe generalized pregnancy gingivitis with occlusal interference in centric occlusion and lateral movement. Clinical and histopathological diagnosis of the first case showed fibrous epulis, whereas the second and third cases disclosed pyogenic granuloma. Chronic trauma of the gingiva due to occlusal interference was assumed to be the cause of those LGE in case 1 and 2, while in case 3 poor oral hygiene and chronic trauma were assumed to be the etiologic factors.
Deep Learning-Based Iris Segmentation for Iris Recognition in Visible Light Environment
Directory of Open Access Journals (Sweden)
Muhammad Arsalan
2017-11-01
Full Text Available Existing iris recognition systems are heavily dependent on specific conditions, such as the distance of image acquisition and the stop-and-stare environment, which require significant user cooperation. In environments where user cooperation is not guaranteed, prevailing segmentation schemes of the iris region are confronted with many problems, such as heavy occlusion of eyelashes, invalid off-axis rotations, motion blurs, and non-regular reflections in the eye area. In addition, iris recognition based on visible light environment has been investigated to avoid the use of additional near-infrared (NIR light camera and NIR illuminator, which increased the difficulty of segmenting the iris region accurately owing to the environmental noise of visible light. To address these issues; this study proposes a two-stage iris segmentation scheme based on convolutional neural network (CNN; which is capable of accurate iris segmentation in severely noisy environments of iris recognition by visible light camera sensor. In the experiment; the noisy iris challenge evaluation part-II (NICE-II training database (selected from the UBIRIS.v2 database and mobile iris challenge evaluation (MICHE dataset were used. Experimental results showed that our method outperformed the existing segmentation methods.
International Nuclear Information System (INIS)
He Xu; Gu Jianping; Lou Wensheng; Chen Liang; Chen Guoping; Su Haobo; Song Jinhua; Wang Tao; Xu Ke
2011-01-01
Objective: To discuss the application of retrograde popliteal artery puncturing under X-ray guidance in the interventional therapy for superficial femoral artery occlusion. Methods: Retrograde popliteal artery puncturing under X-ray guidance was carried out in nine patients with long-segment occlusion of superficial femoral artery as antegrade recanalization via femoral artery approach had failed in them. After retrograde route was successfully established, the balloon dilation and subsequent stent placement for occluded vessel were performed. Results: The technical success was obtained in all patients. The occluded superficial femoral arteries were reopened and the symptoms of intermittent claudication disappeared. No serious complications such as injuries of adjacent nerves or vessels occurred. The ankle-brachial index (ABI) increased from preoperative (0.38±0.13) to postoperative (0.92±0.11) with the difference being statistically significant (P<0.01). A follow-up period lasting for 2-16 months was conducted. Eleven months after the treatment, intermittent claudication recurred in one case, and CT angiography showed that the distal part of the stent was narrowed. The symptoms were improved after percutaneous transcatheter angioplasty was performed again. Conclusion: Retrograde popliteal artery puncturing under X-ray guidance is an effective and safe technique for the treatment of superficial femoral artery long-segment occlusion with stent placement, especially for patients in whom antegrade recanalization via femoral artery approach fails. (authors)
International Nuclear Information System (INIS)
Huey, B.L.; Beller, G.A.; Kaiser, D.L.; Gibson, R.S.
1988-01-01
Forty consecutive patients with creatine kinase-MB confirmed myocardial infarction due to circumflex artery occlusion (Group 1) were prospectively evaluated and compared with 107 patients with infarction due to right coronary artery occlusion (Group 2) and 94 with left anterior descending artery occlusion (Group 3). All 241 patients underwent exercise thallium-201 scintigraphy, radionuclide ventriculography, 24 h Holter electrocardiographic (ECG) monitoring and coronary arteriography before hospital discharge and were followed up for 39 +/- 18 months. There were no significant differences among the three infarct groups in age, gender, number of risk factors, prevalence and type of prior infarction, Norris index, Killip class and frequency of in-hospital complications. Acute ST segment elevation was present in only 48% of patients in Group 1 versus 71 and 72% in Groups 2 and 3, respectively (p = 0.012), and 38% of patients with a circumflex artery-related infarct had no significant ST changes (that is, elevation or depression) on admission (versus 21 and 20% for patients in Groups 2 and 3, respectively) (p = 0.001). Abnormal R waves in lead V1 were more common in Group 1 than in Group 2 (p less than 0.003) as was ST elevation in leads I, aVL and V4 to V6 (p less than or equal to 0.048). These differences in ECG findings between Group 1 and 2 patients correlated with a significantly higher prevalence of posterior and lateral wall asynergy in the group with a circumflex artery-related infarct. Infarct size based on peak creatine kinase levels and multiple radionuclide variables was intermediate in Group 1 compared with that in Group 2 (smallest) and Group 3 (largest). During long-term follow-up, the probability of recurrent cardiac events was similar in the three infarct groups
Estimation of Absorbed Dose in Occlusal Radiography
International Nuclear Information System (INIS)
Yoo, Young Ah; Choi, Karp Shick; Lee, Sang Han
1990-01-01
The purpose of this study was to estimate absorbed dose of each important anatomic site of phantom (RT-210 Head and Neck Section R, Humanoid Systems Co., U.S.A.) head in occlusal radiography. X-radiation dosimetry at 12 anatomic sites in maxillary anterior topography, maxillary posterior topography, mandibular anterior cross-section, mandibular posterior cross-section, mandibular anterior topographic, mandibular posterior topographic occlusal projection was performed with calcium sulfate thermoluminescent dosimeters under 70 Kvp and 15 mA, 1/4 second (8 inch cone ) and 1 second (16 inch cone) exposure time. The results obtained were as follows: Skin surface produced highest absorbed dose ranged between 3264 mrad and 4073 mrad but there was little difference between projections. In maxillary anterior topographic occlusal radiography, eyeballs, maxillary sinuses, and pituitary gland sites produced higher absorbed doses than those of other sites. In maxillary posterior topographic occlusal radiography, exposed eyeball site and exposed maxillary sinus site produced high absorbed doses. In mandibular anterior cross-sectional occlusal radiography, all sites were produced relatively low absorbed dose except eyeball sites. In Mandibular posterior cross-sectional occlusal radiography, exposed eyeball site and exposed maxillary sinus site were produced relatively higher absorbed doses than other sites. In mandibular anterior topographic occlusal radiography, maxillary sinuses, submandibular glands, and thyroid gland sites produced high absorbed doses than other sites. In mandibular posterior topographic occlusal radiography, submandibular gland site of the exposed side produced high absorbed dose than other sites and eyeball site of the opposite side produced relatively high absorbed dose.
Combined surface and volumetric occlusion shading
Schott, Matthias O.; Martin, Tobias; Grosset, A. V Pascal; Brownlee, Carson; Hollt, Thomas; Brown, Benjamin P.; Smith, Sean T.; Hansen, Charles D.
2012-01-01
In this paper, a method for interactive direct volume rendering is proposed that computes ambient occlusion effects for visualizations that combine both volumetric and geometric primitives, specifically tube shaped geometric objects representing streamlines, magnetic field lines or DTI fiber tracts. The proposed algorithm extends the recently proposed Directional Occlusion Shading model to allow the rendering of those geometric shapes in combination with a context providing 3D volume, considering mutual occlusion between structures represented by a volume or geometry. © 2012 IEEE.
Combined surface and volumetric occlusion shading
Schott, Matthias O.
2012-02-01
In this paper, a method for interactive direct volume rendering is proposed that computes ambient occlusion effects for visualizations that combine both volumetric and geometric primitives, specifically tube shaped geometric objects representing streamlines, magnetic field lines or DTI fiber tracts. The proposed algorithm extends the recently proposed Directional Occlusion Shading model to allow the rendering of those geometric shapes in combination with a context providing 3D volume, considering mutual occlusion between structures represented by a volume or geometry. © 2012 IEEE.
Ghosn, Carole Abi; Zogheib, Carla; Makzoumé, Joseph E
2012-09-01
Definitions of the ala-tragus line (ATL) cause confusion, because the exact points of reference for this line do not agree. This study determined the relationship between the prosthetic occlusal plane (OP) corresponding to the lateral borders of the tongue and ATL which was established by using the inferior border of the ala of the nose and (1) the superior border of the tragus (ATL 1), (2) the tip (ATL 2) and (3) the inferior border of the tragus (ATL 3). Neutral zone moldings using phonation and autopolymerizing acrylic resin were recorded and leveled with the lateral borders of the tongue. Lateral cephalometric radiographs were taken of each subject by a standard method. Tracings were obtained on acetate paper to show the prosthetic OP and the three ATLs. The relationship between the prosthetic OP and each of ATL was measured for each subject. Mean and standard deviation values were then calculated for the relationship. Statistical analysis was performed using repeated measure analysis of variance followed by Bonferroni pairwise comparisons and Student's t-test (α = 0.05). Significant difference was found between the three mean angles (p = 0.001). There was no significant difference between the mean angle (5.00° ± 4.38) formed by OP and ATL 2, and the mean angle (4.90° ± 3.50) formed by OP and ATL 3 (p = 1.00) which revealed the smallest. The findings of this study indicated that ATLs, extending from the inferior border of the ala of the nose to (1) the tip of the tragus of the ear, and (2) the inferior border of the tragus presented the closest relationship to the prosthetic OP corresponding to the lateral borders of the tongue. When the ATL is used for orientation of the OP in denture construction, it would seem preferable to define it as running from the inferior border of the ala of the nose to the tip or to the inferior border of the tragus of the ear.
Biomechanics of occlusion--implications for oral rehabilitation.
Peck, C C
2016-03-01
The dental occlusion is an important aspect of clinical dentistry; there are diverse functional demands ranging from highly precise tooth contacts to large crushing forces. Further, there are dogmatic, passionate and often diverging views on the relationship between the dental occlusion and various diseases and disorders including temporomandibular disorders, non-carious cervical lesions and tooth movement. This study provides an overview of the biomechanics of the masticatory system in the context of the dental occlusion's role in function. It explores the adaptation and precision of dental occlusion, its role in bite force, jaw movement, masticatory performance and its influence on the oro-facial musculoskeletal system. Biomechanics helps us better understand the structure and function of biological systems and consequently an understanding of the forces on, and displacements of, the dental occlusion. Biomechanics provides insight into the relationships between the dentition, jaws, temporomandibular joints, and muscles. Direct measurements of tooth contacts and forces are difficult, and biomechanical models have been developed to better understand the relationship between the occlusion and function. Importantly, biomechanical research will provide knowledge to help correct clinical misperceptions and inform better patient care. The masticatory system demonstrates a remarkable ability to adapt to a changing biomechanical environment and changes to the dental occlusion or other components of the musculoskeletal system tend to be well tolerated. © 2015 John Wiley & Sons Ltd.
Dental occlusion and temporomandibular disorders.
Stone, J Caitlin; Hannah, Andrew; Nagar, Nathan
2017-10-27
Data sourcesMedline, Scopus and Google Scholar.Study selectionTwo reviewers selected studies independently. English language clinical studies assessing the association between temporomandibular disorders (TMD) and features of dental occlusion were considered.Data extraction and synthesisStudy quality was assessed based on the Newcastle-Ottawa Scale (NOS) and a narrative synthesis was presented.ResultsIn all 25 studies (17 case-control, eight comparative) were included. Overall there was a high variability between occlusal features and TMD diagnosis. Findings were consistent with a lack of clinically relevant association between TMD and dental occlusion. Only two studies were associated with TMD in the majority (≥50%) of single variable analyses in patient populations. Only mediotrusive interferences are associated with TMD in the majority of multiple variable analyses.ConclusionsThe findings support the absence of a disease-specific association, there is no ground to hypothesise a major role for dental occlusion in the pathophysiology of TMDs. Dental clinicians are thus encouraged to move forward and abandon the old-fashioned gnathological paradig.
Directory of Open Access Journals (Sweden)
Viola William Keddeas
2017-06-01
Conclusion: Both global and regional peak longitudinal systolic strain can offer accurate, feasible, and non-invasive predictor for acute coronary artery occlusion in patients with non ST elevation myocardial infarction who may benefit from early revascularization.
The Sentinel 4 focal plane subsystem
Hohn, Rüdiger; Skegg, Michael P.; Hermsen, Markus; Hinger, Jürgen; Williges, Christian; Reulke, Ralf
2017-09-01
The Sentinel 4 instrument is an imaging spectrometer, developed by Airbus under ESA contract in the frame of the joint European Union (EU)/ESA COPERNICUS program with the objective of monitoring trace gas concentrations. Sentinel 4 will provide accurate measurements of key atmospheric constituents such as ozone, nitrogen dioxide, sulfur dioxide, formaldehyde, as well as aerosol and cloud properties. Sentinel 4 is unique in being the first geostationary UVN mission. The SENTINEL 4 space segment will be integrated on EUMETSAT's Meteosat Third Generation Sounder satellite (MTG-S). Sentinel 4 will provide coverage of Europe and adjacent regions. The Sentinel 4 instrument comprises as a major element two Focal Plane Subsystems (FPS) covering the wavelength ranges 305 nm to 500 nm (UVVIS) and 750 nm to 775 nm (NIR) respectively. The paper describes the Focal Plane Subsystems, comprising the detectors, the optical bench and the control electronics. Further the design and development approach will be presented as well as first measurement results of FPS Qualification Model.
Renovascular hypertension due to insufficient collateral flow in segmental artery occulusion
International Nuclear Information System (INIS)
Park, Y. H.; Lee, S. Y.; Kim, S. H.; Sohn, H. S.; Chung, S. K.
2001-01-01
We report a case in which a 33-year-old woman with renovascular hypertension due to insufficient collateral flow in segmental renal artery occlusion demonstrated abnormality on captopril renal scintigram. Baseline renal scintigram with DTPA showed normal perfusion and excretion in left kidney and captopril renal scintigram with DTPA showed a focal area of decreased perfusion and delayed clearance in lower half of left kidney, suggesting segmental renal artery stenosis. Selective left renal arteriography showed complete obstruction in proximal portion of anterior segmental artery with multiple small collateral vessels from posterior segmental artery and capsular artery and delayed opacification in lower half of left kidney. These findings are suggestive of segmental hypoperfusion due to insufficient collateral blood flow resulting to positive captopril response. Patient's blood pressure have been controlled well with ACE (angiotensin converting enzyme) inhibitor and calcium channel blocker for 2 year. Follow-up baseline renal scintigram with MAG3 showed normal perfusion and excretion in left kidney and captopril renal scintigram with MAG3 showed a focal area of decreased perfusion and delayed clearance in lower lateral portion of left kidney, which was smaller size than that of previous renal scintigram. And captopril renal scintigram with DMSA demonstrated a small area of decreased DMSA uptake on this lesion compared to baseline DMSA scintigram
Segmentation of radiographic images under topological constraints: application to the femur.
Gamage, Pavan; Xie, Sheng Quan; Delmas, Patrice; Xu, Wei Liang
2010-09-01
A framework for radiographic image segmentation under topological control based on two-dimensional (2D) image analysis was developed. The system is intended for use in common radiological tasks including fracture treatment analysis, osteoarthritis diagnostics and osteotomy management planning. The segmentation framework utilizes a generic three-dimensional (3D) model of the bone of interest to define the anatomical topology. Non-rigid registration is performed between the projected contours of the generic 3D model and extracted edges of the X-ray image to achieve the segmentation. For fractured bones, the segmentation requires an additional step where a region-based active contours curve evolution is performed with a level set Mumford-Shah method to obtain the fracture surface edge. The application of the segmentation framework to analysis of human femur radiographs was evaluated. The proposed system has two major innovations. First, definition of the topological constraints does not require a statistical learning process, so the method is generally applicable to a variety of bony anatomy segmentation problems. Second, the methodology is able to handle both intact and fractured bone segmentation. Testing on clinical X-ray images yielded an average root mean squared distance (between the automatically segmented femur contour and the manual segmented ground truth) of 1.10 mm with a standard deviation of 0.13 mm. The proposed point correspondence estimation algorithm was benchmarked against three state-of-the-art point matching algorithms, demonstrating successful non-rigid registration for the cases of interest. A topologically constrained automatic bone contour segmentation framework was developed and tested, providing robustness to noise, outliers, deformations and occlusions.
Segmentation of radiographic images under topological constraints: application to the femur
International Nuclear Information System (INIS)
Gamage, Pavan; Xie, Sheng Quan; Delmas, Patrice; Xu, Wei Liang
2010-01-01
A framework for radiographic image segmentation under topological control based on two-dimensional (2D) image analysis was developed. The system is intended for use in common radiological tasks including fracture treatment analysis, osteoarthritis diagnostics and osteotomy management planning. The segmentation framework utilizes a generic three-dimensional (3D) model of the bone of interest to define the anatomical topology. Non-rigid registration is performed between the projected contours of the generic 3D model and extracted edges of the X-ray image to achieve the segmentation. For fractured bones, the segmentation requires an additional step where a region-based active contours curve evolution is performed with a level set Mumford-Shah method to obtain the fracture surface edge. The application of the segmentation framework to analysis of human femur radiographs was evaluated. The proposed system has two major innovations. First, definition of the topological constraints does not require a statistical learning process, so the method is generally applicable to a variety of bony anatomy segmentation problems. Second, the methodology is able to handle both intact and fractured bone segmentation. Testing on clinical X-ray images yielded an average root mean squared distance (between the automatically segmented femur contour and the manual segmented ground truth) of 1.10 mm with a standard deviation of 0.13 mm. The proposed point correspondence estimation algorithm was benchmarked against three state-of-the-art point matching algorithms, demonstrating successful non-rigid registration for the cases of interest. A topologically constrained automatic bone contour segmentation framework was developed and tested, providing robustness to noise, outliers, deformations and occlusions. (orig.)
Segmentation of radiographic images under topological constraints: application to the femur
Energy Technology Data Exchange (ETDEWEB)
Gamage, Pavan; Xie, Sheng Quan [University of Auckland, Department of Mechanical Engineering (Mechatronics), Auckland (New Zealand); Delmas, Patrice [University of Auckland, Department of Computer Science, Auckland (New Zealand); Xu, Wei Liang [Massey University, School of Engineering and Advanced Technology, Auckland (New Zealand)
2010-09-15
A framework for radiographic image segmentation under topological control based on two-dimensional (2D) image analysis was developed. The system is intended for use in common radiological tasks including fracture treatment analysis, osteoarthritis diagnostics and osteotomy management planning. The segmentation framework utilizes a generic three-dimensional (3D) model of the bone of interest to define the anatomical topology. Non-rigid registration is performed between the projected contours of the generic 3D model and extracted edges of the X-ray image to achieve the segmentation. For fractured bones, the segmentation requires an additional step where a region-based active contours curve evolution is performed with a level set Mumford-Shah method to obtain the fracture surface edge. The application of the segmentation framework to analysis of human femur radiographs was evaluated. The proposed system has two major innovations. First, definition of the topological constraints does not require a statistical learning process, so the method is generally applicable to a variety of bony anatomy segmentation problems. Second, the methodology is able to handle both intact and fractured bone segmentation. Testing on clinical X-ray images yielded an average root mean squared distance (between the automatically segmented femur contour and the manual segmented ground truth) of 1.10 mm with a standard deviation of 0.13 mm. The proposed point correspondence estimation algorithm was benchmarked against three state-of-the-art point matching algorithms, demonstrating successful non-rigid registration for the cases of interest. A topologically constrained automatic bone contour segmentation framework was developed and tested, providing robustness to noise, outliers, deformations and occlusions. (orig.)
Occlusion classifiers for picture rate conversion
Bartels, C.L.L.; Haan, de G.; Rabbani, Majid
2009-01-01
Occlusion detection is an essential ingredient in high quality picture rate up-conversion and view interpolation applications. Many integrated approaches to occlusion detection and classification have been proposed, particularly in the stereo literature. However, due to their high complexity and
Landriel, Federico; Baccanelli, Matteo; Hem, Santiago; Vecchi, Eduardo; Bendersky, Mariana; Yampolsky, Claudio
2017-01-01
Spinal radiculomedullary artery aneurysms are extremely rare. Treatment should be tailored to clinical presentation, distal aneurysm flow, and lesion anatomical features. When a surgical occlusion is planned, it is necessary to evaluate whether intraoperative monitoring (IOM) should be considered as an indispensable tool to prevent potential spinal cord ischemia. We present a patient with symptoms and signs of spinal subarachnoid hemorrhage resulting from the rupture of a T4 anterior radiculomedullary aneurysm who underwent open surgical treatment under motor evoked potential (MEP) monitoring. Due to the aneurysmal fusiform shape and preserved distal flow, the afferent left anterior radiculomedullary artery was temporarily clipped; 2 minutes after the clamping, the threshold stimulation level rose higher than 100 V, and at minute 3, MEPs amplitude became attenuated over 50%. This was considered as a warning criteria to leave the vessel occlusion. The radiculomedullary aneurysm walls were reinforced and wrapped with muscle and fibrin glue to prevent re-bleeding. The patient awoke from general anesthesia without focal neurologic deficit and made an uneventful recovery with complete resolution of her symptoms and signs. This paper attempts to build awareness of the possibility to cause or worsen a neurological deficit if a radiculomedullary aneurysm with preserved distal flow is clipped or embolized without an optimal IOM control. We report in detail MEP monitoring during the occlusion of a unilateral T4 segmental artery that supplies an anterior radiculomedullary artery aneurysm.
Application of morphological bit planes in retinal blood vessel extraction.
Fraz, M M; Basit, A; Barman, S A
2013-04-01
The appearance of the retinal blood vessels is an important diagnostic indicator of various clinical disorders of the eye and the body. Retinal blood vessels have been shown to provide evidence in terms of change in diameter, branching angles, or tortuosity, as a result of ophthalmic disease. This paper reports the development for an automated method for segmentation of blood vessels in retinal images. A unique combination of methods for retinal blood vessel skeleton detection and multidirectional morphological bit plane slicing is presented to extract the blood vessels from the color retinal images. The skeleton of main vessels is extracted by the application of directional differential operators and then evaluation of combination of derivative signs and average derivative values. Mathematical morphology has been materialized as a proficient technique for quantifying the retinal vasculature in ocular fundus images. A multidirectional top-hat operator with rotating structuring elements is used to emphasize the vessels in a particular direction, and information is extracted using bit plane slicing. An iterative region growing method is applied to integrate the main skeleton and the images resulting from bit plane slicing of vessel direction-dependent morphological filters. The approach is tested on two publicly available databases DRIVE and STARE. Average accuracy achieved by the proposed method is 0.9423 for both the databases with significant values of sensitivity and specificity also; the algorithm outperforms the second human observer in terms of precision of segmented vessel tree.
The role of "rescue saccades" in tracking objects through occlusions.
Zelinsky, Gregory J; Todor, Andrei
2010-12-29
We hypothesize that our ability to track objects through occlusions is mediated by timely assistance from gaze in the form of "rescue saccades"-eye movements to tracked objects that are in danger of being lost due to impending occlusion. Observers tracked 2-4 target sharks (out of 9) for 20 s as they swam through a rendered 3D underwater scene. Targets were either allowed to enter into occlusions (occlusion trials) or not (no occlusion trials). Tracking accuracy with 2-3 targets was ≥ 92% regardless of target occlusion but dropped to 74% on occlusion trials with four targets (no occlusion trials remained accurate; 83%). This pattern was mirrored in the frequency of rescue saccades. Rescue saccades accompanied approximatlely 50% of the Track 2-3 target occlusions, but only 34% of the Track 4 occlusions. Their frequency also decreased with increasing distance between a target and the nearest other object, suggesting that it is the potential for target confusion that summons a rescue saccade, not occlusion itself. These findings provide evidence for a tracking system that monitors for events that might cause track loss (e.g., occlusions) and requests help from the oculomotor system to resolve these momentary crises. As the number of crises increase with the number of targets, some requests for help go unsatisfied, resulting in degraded tracking.
Clinical Aspects of Combination of Ceramic and Acrylic Occlusal Surfaces
Directory of Open Access Journals (Sweden)
Z. Ozhohan
2017-03-01
Full Text Available The objective of the research was to develop and substantiate the methods of constructing the occlusal surfaces when manufacturing aesthetic fixed restorations through the combination of different materials. Materials and methods. The study included 65 patients with ceramic and acrylic occlusal surfaces of aesthetic fixed dental prostheses. Group I included 21 patients with a combination of ceramic and acrylic occlusal surfaces. Group II included 22 patients with a combination of ceramic occlusal surfaces. Group III included 22 patients with a combination of acrylic occlusal surfaces. The patients were observed 3, 6 and 12 months after prosthetic repair. Results. The greatest increase in the occlusal contact surface area of fixed restorations was observed in Group I, that is, when combining dental prostheses with ceramic and acrylic occlusal surfaces. Considering uneven abrasion of the occlusal surfaces, we do not recommend to combine different materials when veneering the occlusal surface of the antagonistic teeth. Conclusions. This study demonstrated the important role of the correct combination of materials when veneering the occlusal surfaces. Physical and chemical properties of materials, namely the abrasion resistance play a significant role in the long-term denture functioning. The smallest increase in the occlusal contact surface area was observed in Group II when combining ceramic occlusal surfaces. It was due to a good abrasion resistance of ceramics as compared to acrylic resin as well as the presence of the glazed layer which prevents the premature abrasion of the occlusal surfaces of the antagonistic teeth due to lower surface roughness. The combination of acrylic resin and ceramics when constructing the occlusal surfaces of fixed restorations in Group I demonstrated the highest rate of the increase in the occlusal contact surface area – 9.93%. It was due to a low hardness of acrylic resin and its high surface roughness. In
The prevalence of questionable occlusal caries
DEFF Research Database (Denmark)
Makhija, Sonia K; Gilbert, Gregg H; Funkhouser, Ellen
2012-01-01
Questionable occlusal caries (QOC) can be defined as clinically suspected caries with no cavitation or radiographic evidence of occlusal caries. To the authors' knowledge, no one has quantified the prevalence of QOC, so this quantification was the authors' objective in conducting this study...
Computed tomography in basilar artery occlusion in childhood
International Nuclear Information System (INIS)
Mori, Koreaki; Miwa, Soichi; Handa, Hajime
1978-01-01
A case of basilar artery occlusion in a 13-year-old boy is presented. Eighteen other cases of such occlusion in childhood in the relevant literature were analyzed, and then all nineteen cases were compared to adult cases. In comparison with adult cases, the following points were clear: (1) In children as well as in adults, basilar artery occlusion is more common in males. (2) As is well known, arteriosclerosis is the commonest cause in adults. In children, however, idiopathic and/or congenital occlusion are more common causes. (3) The main clinical manifestations in childhood as well as in maturity are consciousness disturbance, hemiplegia or quadriplegia, and pupillary abnormalities. (4) An occlusion of the proximal third of the basilar artery is common in adults, whereas an occlusion of the middle third is common in childhood. (5) Diagnosis is based on clinical manifestations, cerebral angiography, and computed tomography. (6) In contrast to the poor prognosis in adults, the prognosis is fairly in children. (author)
DEFF Research Database (Denmark)
Aludden, Hanna Cecilia; Jensen, Thomas
2016-01-01
Ankylosis is the abnormal adhesion of alveolar bone to dentin or cementum and commonly seen after traumatic dental injuries. Treatment of impacted and ankylosed teeth solely by orthodontics alignment may be challenging. Consequently, several treatment alternatives have been proposed for the manag....... A dentoalveolar segmental osteotomy with immediate repositioning of an upper canine was performed. One year after final orthodontic treatment a satisfying occlusal and esthetic treatment outcome was obtained....
Atashrazm, Parsa; Alavijeh, Leila Zamani; Afshar, Maryam Sadat Sadrzadeh
2011-03-01
Occlusal errors during acryl processing affect the retention and stability of complete dentures. The aim of the present study was to assess the influence of a short curing technique on the number of occlusal contacts and the occlusal vertical dimension (OVD) of complete dentures. Complete dentures were prepared. The number of occlusal contacts was recorded in centric relation (CR) using 60 µ articulation paper. The OVD was recorded with the waxed trial denture in place. Dentures were then invested and processed with compression molding and short cure water bath technique. The number of occlusal contacts was recorded again. The amount of pin opening was measured for all of the complete dentures on the articulator. Data were analyzed with paired t-test to determine the alterations. The mean number of occlusal contacts before and after processing was 10.9 ± 2.4 and 6.3 ± 3.1 respectively (4.7 ± 1.9 decrease; p negative effect on the morphologic pattern of artificial teeth of complete dentures and thus should be used carefully.
A study on occlusal stability in shortened dental arches.
Sarita, Paulo T N; Kreulen, Cees M; Witter, Dick J; van't Hof, Martin; Creugers, Nico H J
2003-01-01
The aim of this study was to verify the hypothesis that shortened dental arches constitute a risk to occlusal stability. Using cluster samples, 725 subjects with shortened dental arches comprising intact anterior regions and zero to eight occluding pairs of posterior teeth and 125 subjects with complete dental arches were selected. Subjects with shortened dental arches were classified into eight categories according to arch length and symmetry. Parameters for occlusal stability were interdental spacing, occlusal tooth wear, occlusal contact of incisors in intercuspal position, and vertical and horizontal overlap. Additionally, tooth mobility and overeruption of unopposed teeth were assessed. Influence of independent variables (dental arch category, age, gender, and residence) on the parameters for occlusal stability was assessed by one-way ANOVA and Tukey's multiple range tests. Extreme shortened dental arches (zero to two pairs of occluding premolars) had significantly more interdental spacing, occlusal contact of incisors, and vertical overlap compared to complete dental arches. Occlusal wear and prevalence of mobile teeth were highest in these categories. The category with three to four occluding premolars had significantly more interdental spacing and, for the older age group, more anterior teeth in occlusal contact compared to complete dental arches. Age was consistently associated with increased changes in occlusal integrity. Signs of increased risk to occlusal stability seemed to occur in extreme shortened dental arches, whereas no such evidence was found for intermediate categories of shortened dental arches.
A 3D freehand ultrasound system for multi-view reconstructions from sparse 2D scanning planes.
Yu, Honggang; Pattichis, Marios S; Agurto, Carla; Beth Goens, M
2011-01-20
A significant limitation of existing 3D ultrasound systems comes from the fact that the majority of them work with fixed acquisition geometries. As a result, the users have very limited control over the geometry of the 2D scanning planes. We present a low-cost and flexible ultrasound imaging system that integrates several image processing components to allow for 3D reconstructions from limited numbers of 2D image planes and multiple acoustic views. Our approach is based on a 3D freehand ultrasound system that allows users to control the 2D acquisition imaging using conventional 2D probes.For reliable performance, we develop new methods for image segmentation and robust multi-view registration. We first present a new hybrid geometric level-set approach that provides reliable segmentation performance with relatively simple initializations and minimum edge leakage. Optimization of the segmentation model parameters and its effect on performance is carefully discussed. Second, using the segmented images, a new coarse to fine automatic multi-view registration method is introduced. The approach uses a 3D Hotelling transform to initialize an optimization search. Then, the fine scale feature-based registration is performed using a robust, non-linear least squares algorithm. The robustness of the multi-view registration system allows for accurate 3D reconstructions from sparse 2D image planes. Volume measurements from multi-view 3D reconstructions are found to be consistently and significantly more accurate than measurements from single view reconstructions. The volume error of multi-view reconstruction is measured to be less than 5% of the true volume. We show that volume reconstruction accuracy is a function of the total number of 2D image planes and the number of views for calibrated phantom. In clinical in-vivo cardiac experiments, we show that volume estimates of the left ventricle from multi-view reconstructions are found to be in better agreement with clinical
Wollman, Adam J. M.; Miller, Helen; Foster, Simon; Leake, Mark C.
2016-10-01
Staphylococcus aureus is an important pathogen, giving rise to antimicrobial resistance in cell strains such as Methicillin Resistant S. aureus (MRSA). Here we report an image analysis framework for automated detection and image segmentation of cells in S. aureus cell clusters, and explicit identification of their cell division planes. We use a new combination of several existing analytical tools of image analysis to detect cellular and subcellular morphological features relevant to cell division from millisecond time scale sampled images of live pathogens at a detection precision of single molecules. We demonstrate this approach using a fluorescent reporter GFP fused to the protein EzrA that localises to a mid-cell plane during division and is involved in regulation of cell size and division. This image analysis framework presents a valuable platform from which to study candidate new antimicrobials which target the cell division machinery, but may also have more general application in detecting morphologically complex structures of fluorescently labelled proteins present in clusters of other types of cells.
Panda, Rashmi; Puhan, N B; Panda, Ganapati
2018-02-01
Accurate optic disc (OD) segmentation is an important step in obtaining cup-to-disc ratio-based glaucoma screening using fundus imaging. It is a challenging task because of the subtle OD boundary, blood vessel occlusion and intensity inhomogeneity. In this Letter, the authors propose an improved version of the random walk algorithm for OD segmentation to tackle such challenges. The algorithm incorporates the mean curvature and Gabor texture energy features to define the new composite weight function to compute the edge weights. Unlike the deformable model-based OD segmentation techniques, the proposed algorithm remains unaffected by curve initialisation and local energy minima problem. The effectiveness of the proposed method is verified with DRIVE, DIARETDB1, DRISHTI-GS and MESSIDOR database images using the performance measures such as mean absolute distance, overlapping ratio, dice coefficient, sensitivity, specificity and precision. The obtained OD segmentation results and quantitative performance measures show robustness and superiority of the proposed algorithm in handling the complex challenges in OD segmentation.
Energy Technology Data Exchange (ETDEWEB)
Matsumoto, Kenji; Ehara, Shoichi; Hasegawa, Takao; Sakaguchi, Mikumo; Shimada, Kenei [Osaka City University Graduate School of Medicine, Department of Cardiovascular Medicine, Abeno-ku, Osaka (Japan)
2017-09-15
To evaluate the association between duration of the coronary occlusion and high-intensity signal (HIS) on noncontrast T1-weighted imaging using a 1.5-T magnetic resonance imager among patients with angiographic coronary total occlusion. The signal intensity of the coronary target area divided by the signal intensity of the left ventricular muscle near the target area at each site (TMR) was measured. Areas with a TMR >1.0 were defined as HIS. Thirty five lesions from 33 patients were divided into the following three groups: subacute occlusion (up to 3 months; n = 7), short-duration chronic total occlusion (SD-CTO: 3-6 months; n = 9) and long-duration CTO (LD-CTO: ≥6 months; n = 19). All subacute occlusion lesions showed a HIS within the occlusion site. Among patients with CTO, the frequency of a HIS within the occlusion site was significantly higher in SD-CTO than in LD-CTO lesions (p = 0.013). In multivariate analyses, only an occlusion duration of less than 6 months was an independent factor associated with the presence of HIS (odds ratio 7.6, 95% CI 1.1-54.5; p = 0.044). The presence of a HIS in the occlusion site was associated more with SD-CTO than with LD-CTO among patients with CTO. (orig.)
International Nuclear Information System (INIS)
Matsumoto, Kenji; Ehara, Shoichi; Hasegawa, Takao; Sakaguchi, Mikumo; Shimada, Kenei
2017-01-01
To evaluate the association between duration of the coronary occlusion and high-intensity signal (HIS) on noncontrast T1-weighted imaging using a 1.5-T magnetic resonance imager among patients with angiographic coronary total occlusion. The signal intensity of the coronary target area divided by the signal intensity of the left ventricular muscle near the target area at each site (TMR) was measured. Areas with a TMR >1.0 were defined as HIS. Thirty five lesions from 33 patients were divided into the following three groups: subacute occlusion (up to 3 months; n = 7), short-duration chronic total occlusion (SD-CTO: 3-6 months; n = 9) and long-duration CTO (LD-CTO: ≥6 months; n = 19). All subacute occlusion lesions showed a HIS within the occlusion site. Among patients with CTO, the frequency of a HIS within the occlusion site was significantly higher in SD-CTO than in LD-CTO lesions (p = 0.013). In multivariate analyses, only an occlusion duration of less than 6 months was an independent factor associated with the presence of HIS (odds ratio 7.6, 95% CI 1.1-54.5; p = 0.044). The presence of a HIS in the occlusion site was associated more with SD-CTO than with LD-CTO among patients with CTO. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Chen, Xiaoyi; Li, Dongye [Capital Medical University and Beijing Institute for Brain Disorders, Center for Brain Disorders Research, Beijing (China); Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); Zhao, Huilin [Shanghai Jiao Tong University, Department of Radiology, Renji Hospital, School of Medicine, Shanghai (China); Chen, Zhensen; Qiao, Huiyu; He, Le; Li, Rui [Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); Cui, Yuanyuan [PLA General Hospital, Department of Radiology, Beijing (China); Zhou, Zechen [Philips Research China, Healthcare Department, Beijing (China); Yuan, Chun [Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); University of Washington, Department of Radiology, Seattle, WA (United States); Zhao, Xihai [Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); Beijing Institute for Brain Disorders, Center for Stroke, Beijing (China)
2017-05-15
Significant stenosis or occlusion in carotid arteries may lead to diffuse wall thickening (DWT) in the arterial wall of downstream. This study aimed to investigate the correlation between proximal internal carotid artery (ICA) steno-occlusive disease and DWT in ipsilateral petrous ICA. Symptomatic patients with atherosclerotic stenosis (>0%) in proximal ICA were recruited and underwent carotid MR vessel wall imaging. The 3D motion sensitized-driven equilibrium prepared rapid gradient-echo (3D-MERGE) was acquired for characterizing the wall thickness and longitudinal extent of the lesions in petrous ICA and the distance from proximal lesion to the petrous ICA. The stenosis degree in proximal ICA was measured on the time-of-flight (TOF) images. In total, 166 carotid arteries from 125 patients (mean age 61.0 ± 10.5 years, 99 males) were eligible for final analysis and 64 showed DWT in petrous ICAs. The prevalence of severe DWT in petrous ICA was 1.4%, 5.3%, 5.9%, and 80.4% in ipsilateral proximal ICAs with stenosis category of 1%-49%, 50%-69%, 70%-99%, and total occlusion, respectively. Proximal ICA stenosis was significantly correlated with the wall thickness in petrous ICA (r = 0.767, P < 0.001). Logistic regression analysis showed that proximal ICA stenosis was independently associated with DWT in ipsilateral petrous ICA (odds ratio (OR) = 2.459, 95% confidence interval (CI) 1.896-3.189, P < 0.001). Proximal ICA steno-occlusive disease is independently associated with DWT in ipsilateral petrous ICA. (orig.)
International Nuclear Information System (INIS)
Chen, Xiaoyi; Li, Dongye; Zhao, Huilin; Chen, Zhensen; Qiao, Huiyu; He, Le; Li, Rui; Cui, Yuanyuan; Zhou, Zechen; Yuan, Chun; Zhao, Xihai
2017-01-01
Significant stenosis or occlusion in carotid arteries may lead to diffuse wall thickening (DWT) in the arterial wall of downstream. This study aimed to investigate the correlation between proximal internal carotid artery (ICA) steno-occlusive disease and DWT in ipsilateral petrous ICA. Symptomatic patients with atherosclerotic stenosis (>0%) in proximal ICA were recruited and underwent carotid MR vessel wall imaging. The 3D motion sensitized-driven equilibrium prepared rapid gradient-echo (3D-MERGE) was acquired for characterizing the wall thickness and longitudinal extent of the lesions in petrous ICA and the distance from proximal lesion to the petrous ICA. The stenosis degree in proximal ICA was measured on the time-of-flight (TOF) images. In total, 166 carotid arteries from 125 patients (mean age 61.0 ± 10.5 years, 99 males) were eligible for final analysis and 64 showed DWT in petrous ICAs. The prevalence of severe DWT in petrous ICA was 1.4%, 5.3%, 5.9%, and 80.4% in ipsilateral proximal ICAs with stenosis category of 1%-49%, 50%-69%, 70%-99%, and total occlusion, respectively. Proximal ICA stenosis was significantly correlated with the wall thickness in petrous ICA (r = 0.767, P < 0.001). Logistic regression analysis showed that proximal ICA stenosis was independently associated with DWT in ipsilateral petrous ICA (odds ratio (OR) = 2.459, 95% confidence interval (CI) 1.896-3.189, P < 0.001). Proximal ICA steno-occlusive disease is independently associated with DWT in ipsilateral petrous ICA. (orig.)
Computing the Maximum Detour of a Plane Graph in Subquadratic Time
DEFF Research Database (Denmark)
Wulff-Nilsen, Christian
2008-01-01
Let G be a plane graph where each edge is a line segment. We consider the problem of computing the maximum detour of G, defined as the maximum over all pairs of distinct points p and q of G of the ratio between the distance between p and q in G and the distance |pq|. The fastest known algorithm...
Modeling self-occlusions in dynamic shape and appearance tracking
Yang, Yanchao
2013-12-01
We present a method to track the precise shape of a dynamic object in video. Joint dynamic shape and appearance models, in which a template of the object is propagated to match the object shape and radiance in the next frame, are advantageous over methods employing global image statistics in cases of complex object radiance and cluttered background. In cases of complex 3D object motion and relative viewpoint change, self-occlusions and disocclusions of the object are prominent, and current methods employing joint shape and appearance models are unable to accurately adapt to new shape and appearance information, leading to inaccurate shape detection. In this work, we model self-occlusions and dis-occlusions in a joint shape and appearance tracking framework. Experiments on video exhibiting occlusion/dis-occlusion, complex radiance and background show that occlusion/dis-occlusion modeling leads to superior shape accuracy compared to recent methods employing joint shape/appearance models or employing global statistics. © 2013 IEEE.
Jurling, Alden S; Fienup, James R
2014-03-01
Extending previous work by Thurman on wavefront sensing for segmented-aperture systems, we developed an algorithm for estimating segment tips and tilts from multiple point spread functions in different defocused planes. We also developed methods for overcoming two common modes for stagnation in nonlinear optimization-based phase retrieval algorithms for segmented systems. We showed that when used together, these methods largely solve the capture range problem in focus-diverse phase retrieval for segmented systems with large tips and tilts. Monte Carlo simulations produced a rate of success better than 98% for the combined approach.
Optimization of coronagraph design for segmented aperture telescopes
Jewell, Jeffrey; Ruane, Garreth; Shaklan, Stuart; Mawet, Dimitri; Redding, Dave
2017-09-01
The goal of directly imaging Earth-like planets in the habitable zone of other stars has motivated the design of coronagraphs for use with large segmented aperture space telescopes. In order to achieve an optimal trade-off between planet light throughput and diffracted starlight suppression, we consider coronagraphs comprised of a stage of phase control implemented with deformable mirrors (or other optical elements), pupil plane apodization masks (gray scale or complex valued), and focal plane masks (either amplitude only or complex-valued, including phase only such as the vector vortex coronagraph). The optimization of these optical elements, with the goal of achieving 10 or more orders of magnitude in the suppression of on-axis (starlight) diffracted light, represents a challenging non-convex optimization problem with a nonlinear dependence on control degrees of freedom. We develop a new algorithmic approach to the design optimization problem, which we call the "Auxiliary Field Optimization" (AFO) algorithm. The central idea of the algorithm is to embed the original optimization problem, for either phase or amplitude (apodization) in various planes of the coronagraph, into a problem containing additional degrees of freedom, specifically fictitious "auxiliary" electric fields which serve as targets to inform the variation of our phase or amplitude parameters leading to good feasible designs. We present the algorithm, discuss details of its numerical implementation, and prove convergence to local minima of the objective function (here taken to be the intensity of the on-axis source in a "dark hole" region in the science focal plane). Finally, we present results showing application of the algorithm to both unobscured off-axis and obscured on-axis segmented telescope aperture designs. The application of the AFO algorithm to the coronagraph design problem has produced solutions which are capable of directly imaging planets in the habitable zone, provided end
Influence of denture adhesives on occlusion and disocclusion times.
Abdelnabi, Mohamed Hussein; Swelem, Amal Ali; Al-Dharrab, Ayman A
2016-03-01
The effectiveness of adhesives in enhancing several functional aspects of complete denture performance has been well established. The direct influence of adhesives on occlusal contact simultaneity has not yet been investigated. The purpose of this crossover clinical trial was to evaluate quantitatively the influence of adhesives on occlusal balance by recording timed occlusal contacts; namely occlusion time (OT) and disocclusion time during right (DT-right) and left (DT-left) excursions by using computerized occlusal analysis. A crossover clinical trial was adopted. Assessments were carried out while participants (n=49) wore their dentures first without then with adhesives. Computerized occlusal analysis using the T-Scan III system was conducted to perform baseline computer-guided occlusal adjustment for conventionally fabricated dentures. Retention and stability assessment using the modified Kapur index and recording of OT and DT-right and DT-left values using the T-Scan III were subsequently carried out for all dentures, first without adhesives and then after application of adhesive. All T-Scan procedures were carried out by the same clinician. Wilcoxon signed-rank test was used to analyze the Kapur index scores and occlusal parameters (α=.05). Stability and retention of conventional dentures ranged initially from good to very good. However, adhesive application resulted in significant improvement (PAdhesives significantly decreased OT and DT durations in initially well-fitting complete dentures with fairly well balanced occlusion, and further enhanced denture stability and occlusal contact simultaneity. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.
Predictors of early stent occlusion among plastic biliary stents.
Khashab, Mouen A; Kim, Katherine; Hutfless, Susan; Lennon, Anne Marie; Kalloo, Anthony N; Singh, Vikesh K
2012-09-01
A major disadvantage of plastic biliary stents is their short patency rates. The aim of this study was to identify predictors of early stent occlusion among patients receiving conventional plastic biliary stents. Early stent occlusion was defined as worsening cholestatic liver test results of a severity sufficiently significant to warrant ERCP with stent exchange prior to the planned stent exchange, or as symptoms of cholangitis. The association of cumulative stent diameter, demographics, stricture location, procedure indication, Charlson comorbidity index, history of prior early stent occlusion, presence of gallbladder, and performance of sphincteromy with the occurrence of early stent occlusion was studied using logistic regression and multivariate analysis. Our patient cohort comprised 343 patients (mean age 59.3 years) who underwent 561 ERCP procedures with the placement of one or more plastic biliary stents (mean number of stents per procedure 1.2, mean total diameter of stents per procedure 12 Fr). Early stent occlusion occurred in 73 (13 %) procedures. Female gender was protective against early stent occlusion (adjusted OR 0.54, 95 % CI 0.32-0.90, p = 0.02), while hilar stricture location was independently associated with a significantly increased risk of early stent occlusion (adjusted OR 3.41, 95 % CI 1.68-6.90, p = 0.0007). Early occlusion of conventional biliary stents occurred in 13 % of cases. While female gender decreased the risk of early stent occlusion, hilar stricture location was a significant predictor of early stent occlusion. Our results suggest that physicians should consider early elective stent exchange in patients with hilar strictures.
[Case report of occlusal treatment with full mouth reconstruction].
Oizumi, Makoto
2008-07-01
A 70-year-old woman presented with a complaint of masticatory pain and disturbance. She had collapse of occlusal support and vertical dimension decrease. This case used provisional restoration for increasing vertical dimension and reconstruction of anterior guidance. After confirming occlusal stability, she was treated with fixed prosthesis and removable partial dentures. This patient was followed for 6 and a half years with no prosthetic complications, because the reconstruction of bilateral occlusal support and anterior guidance were performed. It is important to reconstruct the occlusal support and anterior guidance in cases of prosthetic treatment of occlusal collapse.
Occlusal stability in shortened dental arches.
Witter, D.J.; Creugers, N.H.J.; Kreulen, C.M.; Haan, A. de
2001-01-01
Shortened dental arches consisting of anterior and premolar teeth have been shown to meet oral functional demands. However, the occlusal stability may be at risk as a result of tooth migration. The aim of this nine-year study was to investigate occlusal stability in shortened dental arches as a
Morita, Takumi; Hiraba, Katsunari; Matsunaga, Tomoko; Ito, Yu; Maruo, Hisanobu; Kurita, Kenichi
2016-06-01
Tooth contact does not occur on the balancing side during mastication. Hence, it is possible that the presence of occlusal interference on the balancing side causes mandibular rotation followed by atypical condylar movement because the jaw-closing muscle activity on the working side is greater than on the balancing side. The aim of the present study was to investigate the relationship between occlusal contact on the balancing side and condylar movement during mastication. EMG activity of the masseter (MS), lateral pterygoid (LP) and digastric (DG) muscles and jaw movements were recorded. Condylar movements in the sagittal plane were recorded using a high speed charge-coupled device (CCD) camera. Incisal point movements were recorded using a magnet on the mentum and a magnetometric sensor on the nasal bone. A removable biting plate was used to introduce an artificial occlusal interference on the balancing side. Nine of the 10 rabbits showed large postero-inferior condylar movement (Pi-Cm) when a biting plate was applied on the balancing side. Five rabbits showed very small Pi-Cm when a biting plate was applied on the balancing side. In the small Pi-Cm group, MS activity decreased markedly and LP and DG transient activity appeared in the early occlusal phase in the presence of the biting plate. Interference on the balancing side always caused Pi-Cm on the ipsilateral side during mastication. However, the degree of Pi-Cm was often decreased by a jaw opening reflex response. Copyright © 2016 Elsevier Ltd. All rights reserved.
Depth estimation of complex geometry scenes from light fields
Si, Lipeng; Wang, Qing
2018-01-01
The surface camera (SCam) of light fields gathers angular sample rays passing through a 3D point. The consistency of SCams is evaluated to estimate the depth map of scene. But the consistency is affected by several limitations such as occlusions or non-Lambertian surfaces. To solve those limitations, the SCam is partitioned into two segments that one of them could satisfy the consistency constraint. The segmentation pattern of SCam is highly related to the texture of spatial patch, so we enforce a mask matching to describe the shape correlation between segments of SCam and spatial patch. To further address the ambiguity in textureless region, a global method with pixel-wise plane label is presented. Plane label inference at each pixel can recover not only depth value but also local geometry structure, that is suitable for light fields with sub-pixel disparities and continuous view variation. Our method is evaluated on public light field datasets and outperforms the state-of-the-art.
Influence of the quality of the finished occlusion on postretention occlusal relapse.
de Freitas, Karina Maria Salvatore; Janson, Guilherme; de Freitas, Marcos Roberto; Pinzan, Arnaldo; Henriques, José Fernando Castanha; Pinzan-Vercelino, Célia Regina Maio
2007-10-01
In this study, we aimed to evaluate the influence of the quality of the finished occlusion on postretention occlusal stability. The sample comprised 87 patients with Class I malocclusion, treated with extraction of the 4 first premolars and edgewise mechanics; they were divided into 2 groups, according to the quality of their finished occlusions. Group 1 included 44 subjects (23 boys, 21 girls) with posttreatment peer assessment rating (PAR) scores from 0 to 5. The mean pretreatment age was 13.74 years (SD 2.14). The mean treatment time was 1.92 years (SD 0.57), the mean retention time was 1.75 years (SD 0.96), and the mean time of posttreatment evaluation was 5.17 years (SD 1.82). Group 2 included 43 subjects (22 boys, 21 girls) with posttreatment PAR scores greater than 5. The mean initial age was 13.34 years (SD 1.35). The mean treatment time was 2.20 years (SD 0.66), the mean retention time was 1.77 years (SD 0.78), and the mean posttreatment evaluation was 5.47 years (SD 1.60). The PAR and the Little irregularity indexes were measured on the dental casts at pretreatment, posttreatment, and postretention. Intergroup comparisons were made with independent t tests, and the Pearson correlation coefficient was applied to the PAR score for the whole sample at the times evaluated. Well-finished patients had lower posttreatment and postretention PAR scores and greater changes during the treatment and posttreatment periods than did the poorly finished patients. For the Little irregularity index, the only difference between the groups was at the posttreatment stage; group 1 had a smaller irregularity score than group 2. The correlation coefficients showed that the greater the treatment changes, the smaller the posttreatment PAR score and the greater the relapse. But the higher the posttreatment PAR score, the higher the postretention PAR score. It was concluded that the greater the quality of the orthodontic finished occlusion, the greater are the treatment changes and
Siebert, Eberhard; Bohner, Georg; Zweynert, Sarah; Maus, Volker; Mpotsaris, Anastasios; Liebig, Thomas; Kabbasch, Christoph
2018-04-12
To describe the clinical and radiological characteristics, frequency, technical aspects and outcome of endovascular treatment of acute basilar artery occlusion (ABO) in the setting of vertebrobasilar steno-occlusive disease. Retrospective analysis of databases of two universitary stroke centers including all consecutive patients from January 2013 until May 2017 undergoing thrombectomy for a) acute stroke due to basilar artery occlusion and either significant basilar artery stenosis or vertebral artery stenosis/occlusion as well as b) presumed embolic basilar artery occlusions. Demographics, stroke characteristics, time metrics, recanalization results and outcome were recorded. Interventional strategies were evaluated concerning the thrombectomy technique, additional angioplasty, type of approach with respect to lesion pattern (ipsilateral to steno-occlusive VA lesion: dirty road or contralateral: clean road) and sequence of actions. Out of 157 patients treated for ABO 38 (24.2%) had associated significant vertebrobasilar steno-occlusive lesions. An underlying significant basilar artery stenosis was present in 23.7% and additionally significant steno-occlusive vertebral lesions were present in 81.5%. Thrombectomy was performed with primary aspiration in 15.8% and with stent-retrievers in 84.2%. Successful revascularization (TICI 2b-3) was achieved in 86.8%. In 52.6% additional stent angioplasty was performed, in 7.9% balloon angioplasty only. The clean road approach was used in 22.5% of cases, the dirty road in 77.4%. Final modified Rankin scale (mRS) was 0-2 in 6 patients (15.8%) and 3-5 in 32 (84.2%). The in-hospital mortality was 36.8%. There were no statistically significant differences in outcome compared to presumed cases of embolisms. Endovascular treatment of ABO with underlying significant vertebrobasilar steno-occlusive lesions is effective and reasonably safe. Specific procedural strategies apply depending on individual patient pathology and anatomy
[Gnathosonics study of the occlusal stability of orthodontic patients].
Jiang, Ruo-Ping; Tyson, Kenneth W
2008-02-18
To analysis the stability of the occlusion before and after the orthodontic treatment by gnathosonics; To evaluate the reliability of the stethoscope method by comparing the subjective(stethoscopy) and objective(digital occlusal sound recording) methods of checking the occlusal sound. Sixty-four new patients with malocclusion were selected as the before treatment group, these patients were not subject to any previous orthodontic treatment, facial surgery or injury; the treatment complete group included 15 patients who were just debonded the fixed appliance. Both stethoscope and digital occlusal sound recording were used to evaluate the occlusal sound. The occlusal stability before and after orthodontic treatment was compared depending on the results from the objective examination. The stability of the occlusion between different types of malocclusion before treatment was compared also. The veracity and reliability of the stethoscope method were analysis using the objective method as the golden standard. (1) 43.75%(28/64) of the 64 new patients showed unstable occlusal sound. ANOVA test showed that there were no statistically significant differences between the unstable rates in different type of malocclusion. (2) 40% (6/15) of the 15 treatment complete patients had unstable occlusions. (3) There were no statistically significant differences between the unstable rate pre- and post-treatment. (4) The veracity of the stethoscopes was 81.01% (64/79). (5) Kappa test showed that the stethoscopes and the digital recording method were consistent; the Kappa value was 0.488, Pocclusion rate between the two groups, and between the different types of malocclusion before treatment. (2) Using stethoscopes method to check the occlusal sound is reliable. The veracity could be improved significantly with increased experiences.
Directory of Open Access Journals (Sweden)
Pawan Kumar
2013-01-01
Full Text Available Extruded middle segment of radius with open segmental fracture both bone forearm and dislocation of ipsilateral elbow is a rare injury. A 12-year-old child presented to us within 4 hours following fall from tree. The child′s mother was carrying a 12-cm-long extruded soiled segment of radius. The extruded bone was thoroughly washed. The medullary cavity was properly syringed with antiseptic solution. The bone was autoclaved and put in the muscle plane of the distal forearm after debridement of the wound. After 5 days, a 2.5-mm K-wire was introduced by retrograde method into the proximal radius by passing through the extruded segment. Another 2.5-mm K-wire was passed in ulna. The limb was evaluated clinicoradiologically every 2 weeks. The wound was healed by primary intention. At 4 months, the reposed bone appeared less dense radiologically and K-wire seemed to be out of the bone. In the subsequent months, the roentgenograms show remodeling of the extruded fragment. After 20 weeks, the K-wires were removed (first ulnar and then radial. Complete union was achieved with full range of movement except loss of few degrees of extension of elbow and thumb. This case is reported to show a good outcome following successful incorporation of an extruded segment of radius in an open fracture.
Concepts of occlusion in prosthodontics: A literature review, part I
Directory of Open Access Journals (Sweden)
V Rangarajan
2015-01-01
Full Text Available Occlusion and its relationship to the function of the stomatognathic system have been widely studied in dentistry since many decades. This series of articles describe about occlusion in the complete denture, fixed partial denture, and implants. Part I and II of this articles series describe concepts and philosophies of occlusion in complete denture. So far, available research has not concluded a superior tooth form or occlusal scheme to satisfy the requirements of completely edentulous patients with respect to comfort, mastication, phonetics, and esthetics. Since then, several balanced and nonbalanced articulation concepts were proposed in the literature. A balanced articulation appears to be most appropriate because of tooth contacts observed during nonfunctional activities of patients. This article discusses about evolution of different concepts of occlusion and occlusal schemes in complete denture occlusion.
International Nuclear Information System (INIS)
Deng Min; Ma Qianjun; Song Jianping
2005-01-01
Objective: The aim of this study is to address the pertinence between the tombstoning electrocardiographic pattern of ST-segment change and infracted artery orientation in acute myocardial infarction. Methods: The study investigated 104 patients with AMI, who subsequently underwent angiography. In this population, 19 patients had a definite tombstoning pattern on their admission ECG. Results: Between tombstoning ECGs and non-tombstoning, campared CAG, the results were as follows: tombstoning ECGs were more strongly associated with anterior infarction and significantly influence the left anterior descending (LAD) artery (P<0.001); LAD occlusions were significantly more severe, mostly proximal (P<0.05, P<0.01); tombstoning ECGs were significantly greater incidence of occlusion of multivessel coronary artery (P<0.05). Conclusions: Although tombstoning ECGs correlates with the occlusion of a high-grade stenosis of the proximal LAD and severe abnormal ventricle wall motion, it is still greatly necessary to reperfuse and revascularize so as to ameliorate the prognosis. (authors)
International Nuclear Information System (INIS)
Feaster, S.H.; Powers, A.; Laws, E.R.
1990-01-01
This paper demonstrates the reliability of transcranial Doppler (TCD) US in the evaluation of the adequacy of collateral vessel cerebral blood flow in patients being considered for carotid ligation or occlusion. TCD was utilized in 12 patients in an attempt to study collateral vessel blood flow during endovascular balloon occlusion of a carotid artery. This was correlated with TCD measurements performed during manual carotid compression and with cerebral angiography. Changes of blood flow velocity were measured in the ipsilateral MCA and ACA. Excellent correlation was noted between the TCD measurements during manual carotid compression and actual endovascular balloon occlusion. There was also qualitative agreement with the cross-compression angiogram
Bassier, M.; Bonduel, M.; Van Genechten, B.; Vergauwen, M.
2017-11-01
Point cloud segmentation is a crucial step in scene understanding and interpretation. The goal is to decompose the initial data into sets of workable clusters with similar properties. Additionally, it is a key aspect in the automated procedure from point cloud data to BIM. Current approaches typically only segment a single type of primitive such as planes or cylinders. Also, current algorithms suffer from oversegmenting the data and are often sensor or scene dependent. In this work, a method is presented to automatically segment large unstructured point clouds of buildings. More specifically, the segmentation is formulated as a graph optimisation problem. First, the data is oversegmented with a greedy octree-based region growing method. The growing is conditioned on the segmentation of planes as well as smooth surfaces. Next, the candidate clusters are represented by a Conditional Random Field after which the most likely configuration of candidate clusters is computed given a set of local and contextual features. The experiments prove that the used method is a fast and reliable framework for unstructured point cloud segmentation. Processing speeds up to 40,000 points per second are recorded for the region growing. Additionally, the recall and precision of the graph clustering is approximately 80%. Overall, nearly 22% of oversegmentation is reduced by clustering the data. These clusters will be classified and used as a basis for the reconstruction of BIM models.
Relationship of Occlusal Schemes with the Occurrence of Temporomandibular Disorders
Directory of Open Access Journals (Sweden)
Dina H. Sugiaman
2013-07-01
Full Text Available Masticatory system is a complex functional unit of the body responsible for mastication, speech, and deglutition process. Temporomandibular disorders (TMD is used to describe all functional disturbances of the masticatory system. The etiology of TMD is multifactorial, such as occlusal disharmony and emotional stress. The relationship between occlusion and TMD has been highly debated in dentistry, one of the occlusal factors is the occlusal scheme. Occlusal schemes are defined as bilateral canine guidance, unilateral canine guidance, group function and balanced occlusion. However, studies about the relationship of occlusal schemes and the occurrence of the TMD are still limited and remained controversial. Objective: To investigate the relationship of occlusal schemes witht he occurrence of TMD. Methods: A cross-sectional study was conducted at the Faculty of Dentistry, Uniiversitas Indonesia. A total of 127 students were included in this study. Subjects were examined based on Clinical Helkimo Index and divided into TMD and non-TMD groups. Subjects were categorized as non-TMD groups if the value of the clinical Helkimo index was 0 and as TMD group when the value ranged between 1-25. Results: Balanced occlusion schemes has a greater risk of TMD occurrence with odds ratio value 5.6 and 95% confidence interval 1.188 to 26.331 (p=0.021. Conclusion: Balanced occlusion has a significant relationship with the occurrence of TMD.
Gravitational Couplings for Gop-Planes and y-Op-Planes
Giraldo, Juan Fernando Ospina
2000-01-01
The Wess-Zumino actions for generalized orientifold planes (GOp-planes) and y-deformed orientifold planes (yOp-planes) are presented and two series power expantions are realized from whiches processes that involves GOp-planes,yOp-planes, RR-forms, gravitons and gaugeons, are obtained. Finally non-standard GOp-planes and y-Op-planes are showed.
Part-time occlusion therapy for amblyopia in older children.
Singh, Inderpreet; Sachdev, Nishant; Brar, Gagandeep S; Kaushik, Sushmita
2008-01-01
To compare the efficacy of part-time versus full-time occlusion for treatment of amblyopia in children aged 7-12 years. Prospective interventional case series. One hundred children between 7-12 years of age with anisometropic (57), strabismic (25) and mixed (18) unilateral amblyopia were randomized (simple randomization) into four groups (25 each) to receive two hours, four hours, six hours or full-time occlusion therapy. Children were regularly followed up at six-weekly intervals for a minimum of three visits. Intragroup visual improvement was analyzed using paired t-test while intergroup comparisons were done using ANOVA and unpaired t-test. All four groups showed significant visual improvement after 18 weeks of occlusion therapy ( P amblyopia therapy with 11 eyes (44%), 17 eyes (68%), 22 eyes (88%) and 23 eyes (92%) being amblyopia responders in the four groups respectively, with the least number of responders in the two hours group. In mild to moderate amblyopia (vision 20/30 to 20/80), there was no significant difference in visual outcome among the four groups ( P =0.083). However, in severe amblyopia (vision 20/100 or worse), six hours ( P =0.048) and full-time occlusion ( P =0.027) treatment were significantly more effective than two hours occlusion. All grades of part-time occlusion are comparable to full-time occlusion in effectiveness of treatment for mild to moderate amblyopia in children between 7-12 years of age unlike in severe amblyopia, where six hours and full-time occlusion were more effective than two hours occlusion therapy.
Hydrocolloid occlusion for the treatment of neurovascular corns
DEFF Research Database (Denmark)
Petersen, Lars Jelstrup; Beck, Jan Walther; Reumert, L N
1991-01-01
The goal of this study was to determine the effect of hydrocolloid occlusion on neurovascular corns. The design was an observer-blinded, randomized, controlled study. Thirty consecutive patients participated in the trial. The patients received curettage alone or curettage with hydrocolloid...... occlusion. Six treatments were given over 12 weeks. A follow-up examination was performed 3 months after termination of the trial. Outcome measures were the size of the corns, a discomfort score, and an overall judgment of the trial. The results demonstrated no benefit of occlusion for symptoms or signs...... of neurovascular corns. The patients treated with occlusion were, however, generally more satisfied than the conventional group....
Radiation Retinopathy Associated with Central Retinal Vein Occlusion
Institute of Scientific and Technical Information of China (English)
Yan; Liu; FengWen
2007-01-01
Purpose: To report a case of radiation retinopathy associated with central retinal vein occlusion.Methods: The clinical features and fundus fluorescein angiography of this case were analyzed.Results: The patient had been treated with radiotherapy for her nasopharyngeal carcinoma, and presented with sudden visual loss in the left eye. The funduscopic examination and fluorescein angiography showed the features of radiation retinopathy in both eyes, and central retinal vein occlusion in the left eye.Conclusions: Radiation retinopathy can be associated with central retinal vein occlusion in the same eye, and it seems that the endothelial cell loss caused by radiation retinopathy may lead to retinal vein occlusion.
Volumetric ambient occlusion for real-time rendering and games.
Szirmay-Kalos, L; Umenhoffer, T; Toth, B; Szecsi, L; Sbert, M
2010-01-01
This new algorithm, based on GPUs, can compute ambient occlusion to inexpensively approximate global-illumination effects in real-time systems and games. The first step in deriving this algorithm is to examine how ambient occlusion relates to the physically founded rendering equation. The correspondence stems from a fuzzy membership function that defines what constitutes nearby occlusions. The next step is to develop a method to calculate ambient occlusion in real time without precomputation. The algorithm is based on a novel interpretation of ambient occlusion that measures the relative volume of the visible part of the surface's tangent sphere. The new formula's integrand has low variation and thus can be estimated accurately with a few samples.
Makita, Toshio; Suzuki, Kenji; Takizawa, Kaname; Ootomo, Tatsushi; Inoue, Naoto; Meguro, Taiichirou
2014-04-01
A 75-year-old hemodialysis patient with right critical limb ischemia received endovascular therapy for a chronic total occlusion (CTO) in a diffusely calcified superficial femoral artery (SFA). During a retrograde approach, a Brockenbrough needle (BN) was able to penetrate the calcified hard plaque formed in the middle segment of the CTO. Moreover, bougie dilatation with the BN allowed balloon crossing and stent deployment, even after failure to pass a 2.0-mm monorail balloon across the plaque. These results suggest that the BN offers a new therapeutic option in the penetration and modification of severely calcified CTO in SFA.
2016-03-01
aorta extending from the lowest renal artery to the aortic bifurcation. Despite the anatomic plausibility of Stannard’s technical description, it is...resuscitative thoracotomy. Zone II is the paravisceral segment and was proposed as a potential no-occlusion zone, while Zone III represents the infra- renal ...not a clinical report, simply an anatomic recommendation based on zones of aortic perfusion. The rationale behind REBOA follows the understanding
Saliency-aware food image segmentation for personal dietary assessment using a wearable computer
International Nuclear Information System (INIS)
Chen, Hsin-Chen; Jia, Wenyan; Li, Yuecheng; Sun, Mingui; Sun, Xin; Li, Zhaoxin; Fernstrom, John D; Burke, Lora E; Baranowski, Thomas
2015-01-01
Image-based dietary assessment has recently received much attention in the community of obesity research. In this assessment, foods in digital pictures are specified, and their portion sizes (volumes) are estimated. Although manual processing is currently the most utilized method, image processing holds much promise since it may eventually lead to automatic dietary assessment. In this paper we study the problem of segmenting food objects from images. This segmentation is difficult because of various food types, shapes and colors, different decorating patterns on food containers, and occlusions of food and non-food objects. We propose a novel method based on a saliency-aware active contour model (ACM) for automatic food segmentation from images acquired by a wearable camera. An integrated saliency estimation approach based on food location priors and visual attention features is designed to produce a salient map of possible food regions in the input image. Next, a geometric contour primitive is generated and fitted to the salient map by means of multi-resolution optimization with respect to a set of affine and elastic transformation parameters. The food regions are then extracted after contour fitting. Our experiments using 60 food images showed that the proposed method achieved significantly higher accuracy in food segmentation when compared to conventional segmentation methods. (paper)
Saliency-aware food image segmentation for personal dietary assessment using a wearable computer
Chen, Hsin-Chen; Jia, Wenyan; Sun, Xin; Li, Zhaoxin; Li, Yuecheng; Fernstrom, John D.; Burke, Lora E.; Baranowski, Thomas; Sun, Mingui
2015-02-01
Image-based dietary assessment has recently received much attention in the community of obesity research. In this assessment, foods in digital pictures are specified, and their portion sizes (volumes) are estimated. Although manual processing is currently the most utilized method, image processing holds much promise since it may eventually lead to automatic dietary assessment. In this paper we study the problem of segmenting food objects from images. This segmentation is difficult because of various food types, shapes and colors, different decorating patterns on food containers, and occlusions of food and non-food objects. We propose a novel method based on a saliency-aware active contour model (ACM) for automatic food segmentation from images acquired by a wearable camera. An integrated saliency estimation approach based on food location priors and visual attention features is designed to produce a salient map of possible food regions in the input image. Next, a geometric contour primitive is generated and fitted to the salient map by means of multi-resolution optimization with respect to a set of affine and elastic transformation parameters. The food regions are then extracted after contour fitting. Our experiments using 60 food images showed that the proposed method achieved significantly higher accuracy in food segmentation when compared to conventional segmentation methods.
International Nuclear Information System (INIS)
Itai, Y.; Moss, A.A.; Goldberg, H.I.
1982-01-01
Dynamic computed tomography of hepatic tumors revealed a transient attenuation difference of the liver in a lobar or segmental distribution in three cases. The difference was most prominent during the hepatogram phase. It was attributed to siphonage of arterial blood by hepatic tumors in two cases, while an increase of arterial flow induced by portal vein occlusion was inferred in the other case. Results indicate dynamic computed tomography will be usful in analysis of geometrical hemodynamics
Tajstra, Mateusz; Hawranek, Michał; Desperak, Piotr; Ciślak, Aneta; Gąsior, Mariusz
2017-10-03
A chronic total occlusion in a non-infarct-related artery is an independent predictor of mortality in non-ST elevation myocardial infarction. There are no mortality data about the impact of a chronic total occlusion in patients with non-ST elevation myocardial infarction according to gender. The purpose of this study was to evaluate the prevalence of the chronic total occlusion in in men and women and examine its impact on clinical outcomes. Data from consecutive patients with multivessel coronary artery disease treated in a high-volume center between 2006 and 2012 were included in a prospective registry and divided according to gender and the presence of chronic total occlusion. All of the analyzed patients were followed up for at least 24 months, with all-cause mortality defined as the primary endpoint. Among the 515 patients who fulfilled the inclusion criteria, 32.8% were female. In the female arm, the 24-month mortality for the groups with and without chronic total occlusion was similar (18.9% and 14.7%, respectively; p = 0.47). In contrast, in the male arm, the occurrence of chronic total occlusion was associated with higher 24-month mortality (24.3% vs. 13.4%; p = 0.009). Multivariate analysis of the male arm revealed a trend toward a positive association between the occurrence of chronic total occlusion and 24-month mortality (HR 1.62; 95% CI 0.93-2.83; p = 0.087). The presence of chronic total occlusion in men is associated with an adverse long-term prognosis, whereas in women this effect was not observed.
Part-time occlusion therapy for amblyopia in older children
Directory of Open Access Journals (Sweden)
Singh Inderpreet
2008-01-01
Full Text Available Aim: To compare the efficacy of part-time versus full-time occlusion for treatment of amblyopia in children aged 7-12 years. Materials and Methods: Prospective interventional case series. One hundred children between 7-12 years of age with anisometropic (57, strabismic (25 and mixed (18 unilateral amblyopia were randomized (simple randomization into four groups (25 each to receive two hours, four hours, six hours or full-time occlusion therapy. Children were regularly followed up at six-weekly intervals for a minimum of three visits. Statistical Analysis: Intragroup visual improvement was analyzed using paired t-test while intergroup comparisons were done using ANOVA and unpaired t-test. Results: All four groups showed significant visual improvement after 18 weeks of occlusion therapy ( P < 0.001. Seventy-three (73% of the total 100 eyes responded to amblyopia therapy with 11 eyes (44%, 17 eyes (68%, 22 eyes (88% and 23 eyes (92% being amblyopia responders in the four groups respectively, with the least number of responders in the two hours group. In mild to moderate amblyopia (vision 20/30 to 20/80, there was no significant difference in visual outcome among the four groups ( P =0.083. However, in severe amblyopia (vision 20/100 or worse, six hours ( P =0.048 and full-time occlusion ( P =0.027 treatment were significantly more effective than two hours occlusion. Conclusion: All grades of part-time occlusion are comparable to full-time occlusion in effectiveness of treatment for mild to moderate amblyopia in children between 7-12 years of age unlike in severe amblyopia, where six hours and full-time occlusion were more effective than two hours occlusion therapy.
[Study on retention and stability of linear occlusal complete dentures].
Zhang, Ping; Xu, Jun
2003-01-01
To learn retention and stability of linear occlusal complete dentures by investigating the subjective feelings of patient and the value of retention force. Static retention forces of maxillary and mandibular dentures were measured for 25 patients wearing linear occlusal dentures by using Hz-1 retention dynamometer. The subjective feelings of patients in functional state were gained simultaneously through questionnaire. Linear occlusal dentures demonstrate good retention in static and dynamic state. Among patients with severe resorption of residual ridge (RRR), mandibular linear occlusal dentures (shown good retentive subjective feelings) demonstrate significantly smaller retention force than those with slight or medium degree of RRR. There is no correlation between the subjective feelings and the values of retention forces of mandibular dentures. The subjective feelings of patients wearing new linear occlusal dentures are much better than that of old anatomic occlusal dentures. Linear occlusal dentures improve the performances of dentures by enhancing their stability during mastication movement.
Energy Technology Data Exchange (ETDEWEB)
Jambon, E.; Petitpierre, F. [Pellegrin Hospital, Department of Radiology (France); Brizzi, V.; Dubuisson, V. [Pellegrin Hospital, Department of Surgery (France); Bras, Y. Le; Grenier, N.; Cornelis, F., E-mail: cornelisfrancois@gmail.com [Pellegrin Hospital, Department of Radiology (France)
2017-02-15
PurposeTo retrospectively investigate the safety and efficacy of hybrid proximal coiling of various medium-sized vessels (4 to 8 mm) using the Penumbra Occlusion Device (POD).Materials and MethodsFrom October 2014 to February 2016, 37 proximal embolizations were performed with PODs in 36 patients (mean age: 50.8, range: 10–86; 29 male, 7 female). Vessel occlusions were achieved under fluoroscopic guidance using a 2.7 French microcatheter. Among the 36 vessels targeted, 16 were splenic arteries, 11 renal arteries, 4 mesenteric arteries, 3 arteriovenous fistulae, 1 iliac artery, and 1 gonadal vein. Intermittent follow-up angiography was performed to assess the flow for final occlusion. Outcomes and complications were assessed by clinical and/or imaging follow-up.ResultsTo produce proximal occlusion of the intended vessels, the POD was used alone in 19 embolizations (51.4 %). In 12 procedures (32.4 %), POD was used as a coil constrainer to secure the coil construct. In 6 procedures (16.2 %), additional embolic devices were used to achieve vessel occlusion after initial POD deployment. After a mean follow-up of 3.2 months, no POD migration was observed but two complications occurred (5.4 %): one post embolic syndrome and one extensive infarction with splenic abscess.ConclusionThe POD system allows safe and effective proximal embolization of medium-sized vessels in a variety of clinical settings.
Experimental occlusal interference induces long-term masticatory muscle hyperalgesia in rats.
Cao, Ye; Xie, Qiu-Fei; Li, Kai; Light, Alan R; Fu, Kai-Yuan
2009-08-01
Temporomandibular joint or related masticatory muscle pain represents the most common chronic orofacial pain condition. Patients frequently report this kind of pain after dental alterations in occlusion. However, lack of understanding of the mechanisms of occlusion-related temporomandibular joint and muscle pain prevents treating this problem successfully. To explore the relationship between improper occlusion (occlusal interference) and masticatory muscle pain, we created an occlusal interference animal model by directly bonding a crown to a maxillary molar to raise the masticating surface of the tooth in rats. We raised the occlusal surface to three different heights (0.2, 0.4, and 0.6mm), and for one month we quantitatively measured mechanical nociceptive thresholds of the temporal and masseter muscles on both sides. Results showed a stimulus-response relationship between the height of occlusal interference and muscle hyperalgesia. Removal of the crown 6 days after occlusal interference showed that the removal at this time could not terminate the 1 month duration of mechanical hyperalgesia in the masticatory muscles. Lastly, we systemically administered NMDA antagonist MK801 (0.2, 0.1, and 0.05 mg/kg) to the treated rats and found that MK801 dose dependently attenuated the occlusal interference-induced hyperalgesia. These findings suggest that occlusal interference is directly related to masticatory muscle pain, and that central sensitization mechanisms are involved in the maintenance of the occlusal interference-induced mechanical hyperalgesia.
ST–Segment elevation: Not always an acute coronary syndrome
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Érico Costa
2017-01-01
Full Text Available Cardiac tumors can be primary or metastatic, the latter being more frequent and usually of pulmonary or hematologic origin. These patients’ clinical signs are non-specific and the electrocardiogram (ECG can assume many patterns, among which, ST-segment elevation. Nevertheless, associated occlusion of the coronary arteries is rare in these situations.We present a 79-year-old woman with a history of pulmonary neoplasia who was admitted to the emergency department due to atypical chest pain, cough and worsening dyspnea in the previous 3 days. The ECG revealed an ST-segment elevation in the anterolateral and inferolateral leads, despite normal blood work, namely normal troponin. Due to the disparity between the patient’s symptoms and the ECG findings, a decision was made not to proceed to primary angioplasty, but to further investigate with echocardiography, which revealed a mass localized in the anterolateral and inferolateral left ventricle walls, confirmed by computed tomography. The patient was admitted in the medical ward for symptomatic management. Her clinical condition gradually deteriorated due to the disease’s natural evolution and she died two weeks later.This case highlights the importance to keep in mind differential diagnoses to acute coronary syndromes, when a ST-segment elevation is encountered on an ECG.
Collation of chewing efficiency and dentures with diverse occlusal schemes
Directory of Open Access Journals (Sweden)
Vijay Kumar Peddinti
2017-01-01
Full Text Available Background: Rehabilitation of an edentulous patient nurtures satisfaction and this lies in the chewing ability provided by the prosthesis. Aim: To evaluate and compare the masticatory efficiencies of complete dentures with different occlusal schemes. Materials and Methods: Fourteen completely edentulous patients from the age group of 50-70 years were selected according to the inclusion criteria followed in this study. The dentures were made with three different occlusal schemes, i.e., anatomic occlusion without balancing, anatomic occlusion with balancing, and lingualized occlusion and stored in water till the date of denture insertion. Post-insertion instructions were given to the patients at the time of delivery of the dentures. Patients were recalled after seven days and then masticatory efficiency was performed. The test was performed using boiled peanuts and Sieve system. Statistical Analysis: One-way analysis of variance (ANOVA test and unpaired t-test were carried out. Results: The obtained masticatory efficiency values with anatomic occlusion without balancing, anatomic occlusion with balancing, and lingualized occlusion LO were analyzed using one-way ANOVA test and unpaired “t” test. The tests showed that lingualized scheme had highest masticatory efficiency. Conclusion: Within the scope of this study, it can be concluded that the masticatory efficiency will be generally higher in patients provided with complete dentures fabricated using the lingualized occlusal scheme.
Compliance with occlusion therapy for childhood amblyopia.
Wallace, Michael P; Stewart, Catherine E; Moseley, Merrick J; Stephens, David A; Fielder, Alistair R
2013-09-17
Explore compliance with occlusion treatment of amblyopia in the Monitored and Randomized Occlusion Treatment of Amblyopia Studies (MOTAS and ROTAS), using objective monitoring. Both studies had a three-phase protocol: initial assessment, refractive adaptation, and occlusion. In the occlusion phase, participants were instructed to dose for 6 hours/day (MOTAS) or randomized to 6 or 12 hour/day (ROTAS). Dose was monitored continuously using an occlusion dose monitor (ODM). One hundred and fifty-two patients (71 male, 81 female; 122 Caucasian, 30 non-Caucasian) of mean ± SD age 68 ± 18 months participated. Amblyopia was defined as an interocular acuity difference of at least 0.1 logMAR and was associated with anisometropia in 50, strabismus in 44, and both (mixed) in 58. Median duration of occlusion was 99 days (interquartile range 72 days). Mean compliance was 44%, mean proportion of days with no patch worn was 42%. Compliance was lower (39%) on weekends compared with weekdays (46%, P = 0.04), as was the likelihood of dosing at all (52% vs. 60%, P = 0.028). Compliance was lower when attendance was less frequent (P amblyopia type, and severity were not associated with compliance. Mixture modeling suggested three subpopulations of patch day doses: less than 30 minutes; doses that achieve 30% to 80% compliance; and doses that achieve around 100% compliance. This study shows that compliance with patching treatment averages less than 50% and is influenced by several factors. A greater understanding of these influences should improve treatment outcome. (ClinicalTrials.gov number, NCT00274664).
Object tracking by occlusion detection via structured sparse learning
Zhang, Tianzhu
2013-06-01
Sparse representation based methods have recently drawn much attention in visual tracking due to good performance against illumination variation and occlusion. They assume the errors caused by image variations can be modeled as pixel-wise sparse. However, in many practical scenarios these errors are not truly pixel-wise sparse but rather sparsely distributed in a structured way. In fact, pixels in error constitute contiguous regions within the object\\'s track. This is the case when significant occlusion occurs. To accommodate for non-sparse occlusion in a given frame, we assume that occlusion detected in previous frames can be propagated to the current one. This propagated information determines which pixels will contribute to the sparse representation of the current track. In other words, pixels that were detected as part of an occlusion in the previous frame will be removed from the target representation process. As such, this paper proposes a novel tracking algorithm that models and detects occlusion through structured sparse learning. We test our tracker on challenging benchmark sequences, such as sports videos, which involve heavy occlusion, drastic illumination changes, and large pose variations. Experimental results show that our tracker consistently outperforms the state-of-the-art. © 2013 IEEE.
International Nuclear Information System (INIS)
Wong, Yon Cheong; Wu, Cheng Hsien; Wang, Li Jen; Chen, Huan Wu; Lin, Being Chuan; Huang, Chen Chih
2013-01-01
To compare the ancillary CT findings between superior mesenteric artery thromboembolism (SMAT) and superior mesenteric vein thrombosis (SMVT), and to determine the independent CT findings of life-threatening mesenteric occlusion. Our study was approved by the institution review board. We included 43 patients (21 SMAT and 22 SMVT between 1999 and 2008) of their median age of 60.0 years, and retrospectively analyzed their CT scans. Medical records were reviewed for demographics, management, surgical pathology diagnosis, and outcome. We compared CT findings between SMAT and SMVT groups. Multivariate analysis was conducted to determine the independent CT findings of life-threatening mesenteric occlusion. Of 43 patients, 24 had life-threatening mesenteric occlusion. Death related to mesenteric occlusion was 32.6%. A thick bowel wall (p < 0.001), mesenteric edema (p < 0.001), and ascites (p = 0.009) were more frequently associated with SMVT, whereas diminished bowel enhancement (p = 0.003) and paralytic ileus (p = 0.039) were more frequent in SMAT. Diminished bowel enhancement (OR = 20; p = 0.007) and paralytic ileus (OR = 16; p = 0.033) were independent findings suggesting life-threatening mesenteric occlusion. The ancillary CT findings occur with different frequencies in SMAT and SMVT. However, the independent findings indicating life-threatening mesenteric occlusion are diminished bowel wall enhancement and paralytic ileus.
International Nuclear Information System (INIS)
Oster, Z.H.; Som, P.; Zamora, P.O.
1989-01-01
A new method for diagnosing mesenteric vaso-occlusive bowel disease with the use of radioimmunoscintigraphy was developed and tested in experimental models of arterial and venous disease, as well as in a model simulating bowel strangulation. The method involves the use of a monoclonal antibody fragment mixture that binds to platelets. The antibody was labeled with technetium-99m, and imaging was performed with a gamma camera in the planar and single photon emission computed tomography modes. This method allowed visualization of areas of ischemia of 1-6 hours duration in bowel loops in 19 dogs 90-180 minutes after injection of the radiolabeled antibody. No bowel radioactivity accumulation occurred in dogs that underwent the same surgical procedure but were given a nonspecific Tc-99m-labeled antibody or in normal dogs given the specific antibody. It appears that the radiolabeled antibody used, which has higher reactivity with human platelets than with dog platelets, will be a good agent for noninvasive diagnosis of mesenteric vaso-occlusive disease in humans. It may also play a role in the intraoperative determination of the extent and location of ischemic bowel segments
Stent Recanalization of Chronic Portal Vein Occlusion in a Child
International Nuclear Information System (INIS)
Cwikiel, Wojciech; Solvig, Jan; Schroder, Henrik
2000-01-01
An 8-year-old boy with a 21/2 year history of portal hypertension and repeated bleedings from esophageal varices, was referred for treatment. The 3.5-cm-long occlusion of the portal vein was passed and the channel created was stabilized with a balloon-expandable stent; a portosystemic stent-shunt was also created. The portosystemic shunt closed spontaneously within 1 month, while the recanalized segment of the portal vein remained open. The pressure gradient between the intrahepatic and extrahepatic portal vein branches dropped from 17 mmHg to 0 mmHg. The pressure in the portal vein dropped from 30 mmHg to 17 mmHg and the bleedings stopped. The next dilation of the stent was performed 12 months later due to an increased pressure gradient; the gastroesophageal varices disappeared completely. Further dilation of the stent was planned after 2, 4, and 6 years
Influence of stapling the intersegmental planes on lung volume and function after segmentectomy.
Tao, Hiroyuki; Tanaka, Toshiki; Hayashi, Tatsuro; Yoshida, Kumiko; Furukawa, Masashi; Yoshiyama, Koichi; Okabe, Kazunori
2016-10-01
Dividing the intersegmental planes with a stapler during pulmonary segmentectomy leads to volume loss in the remnant segment. The aim of this study was to assess the influence of segment division methods on preserved lung volume and pulmonary function after segmentectomy. Using image analysis software on computed tomography (CT) images of 41 patients, the ratio of remnant segment and ipsilateral lung volume to their preoperative values (R-seg and R-ips) was calculated. The ratio of postoperative actual forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) per those predicted values based on three-dimensional volumetry (R-FEV1 and R-FVC) was also calculated. Differences in actual/predicted ratios of lung volume and pulmonary function for each of the division methods were analysed. We also investigated the correlations of the actual/predicted ratio of remnant lung volume with that of postoperative pulmonary function. The intersegmental planes were divided by either electrocautery or with a stapler in 22 patients and with a stapler alone in 19 patients. Mean values of R-seg and R-ips were 82.7 (37.9-140.2) and 104.9 (77.5-129.2)%, respectively. The mean values of R-FEV1 and R-FVC were 103.9 (83.7-135.1) and 103.4 (82.2-125.1)%, respectively. There were no correlations between the actual/predicted ratio of remnant lung volume and pulmonary function based on the division method. Both R-FEV1 and R-FVC were correlated not with R-seg, but with R-ips. Stapling does not lead to less preserved volume or function than electrocautery in the division of the intersegmental planes. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
Bookshelf faulting and transform motion between rift segments of the Northern Volcanic Zone, Iceland
Green, R. G.; White, R. S.; Greenfield, T. S.
2013-12-01
Plate spreading is segmented on length scales from 10 - 1,000 kilometres. Where spreading segments are offset, extensional motion has to transfer from one segment to another. In classical plate tectonics, mid-ocean ridge spreading centres are offset by transform faults, but smaller 'non-transform' offsets exist between slightly overlapping spreading centres which accommodate shear by a variety of geometries. In Iceland the mid-Atlantic Ridge is raised above sea level by the Iceland mantle plume, and is divided into a series of segments 20-150 km long. Using microseismicity recorded by a temporary array of 26 three-component seismometers during 2009-2012 we map bookshelf faulting between the offset Askja and Kverkfjöll rift segments in north Iceland. The micro-earthquakes delineate a series of sub-parallel strike-slip faults. Well constrained fault plane solutions show consistent left-lateral motion on fault planes aligned closely with epicentral trends. The shear couple across the transform zone causes left-lateral slip on the series of strike-slip faults sub-parallel to the rift fabric, causing clockwise rotations about a vertical axis of the intervening rigid crustal blocks. This accommodates the overall right-lateral transform motion in the relay zone between the two overlapping volcanic rift segments. The faults probably reactivated crustal weaknesses along the dyke intrusion fabric (parallel to the rift axis) and have since rotated ˜15° clockwise into their present orientation. The reactivation of pre-existing rift-parallel weaknesses is in contrast with mid-ocean ridge transform faults, and is an important illustration of a 'non-transform' offset accommodating shear between overlapping spreading segments.
Segmentation of liver tumors on CT images
International Nuclear Information System (INIS)
Pescia, D.
2011-01-01
This thesis is dedicated to 3D segmentation of liver tumors in CT images. This is a task of great clinical interest since it allows physicians benefiting from reproducible and reliable methods for segmenting such lesions. Accurate segmentation would indeed help them during the evaluation of the lesions, the choice of treatment and treatment planning. Such a complex segmentation task should cope with three main scientific challenges: (i) the highly variable shape of the structures being sought, (ii) their similarity of appearance compared with their surrounding medium and finally (iii) the low signal to noise ratio being observed in these images. This problem is addressed in a clinical context through a two step approach, consisting of the segmentation of the entire liver envelope, before segmenting the tumors which are present within the envelope. We begin by proposing an atlas-based approach for computing pathological liver envelopes. Initially images are pre-processed to compute the envelopes that wrap around binary masks in an attempt to obtain liver envelopes from estimated segmentation of healthy liver parenchyma. A new statistical atlas is then introduced and used to segmentation through its diffeomorphic registration to the new image. This segmentation is achieved through the combination of image matching costs as well as spatial and appearance prior using a multi-scale approach with MRF. The second step of our approach is dedicated to lesions segmentation contained within the envelopes using a combination of machine learning techniques and graph based methods. First, an appropriate feature space is considered that involves texture descriptors being determined through filtering using various scales and orientations. Then, state of the art machine learning techniques are used to determine the most relevant features, as well as the hyper plane that separates the feature space of tumoral voxels to the ones corresponding to healthy tissues. Segmentation is then
Multi-segment foot kinematics and plantar fascia strain during treadmill and overground running
Sinclair, Jonathan Kenneth; Taylor, Paul John; Vincent, Hayley
2014-01-01
Although physiologically beneficial, running is known to be associated with a high incidence of chronic injuries. Excessive coronal and transverse plane motions of the foot segments and strain experienced by the plantar fascia are linked to the development of a number of chronic injuries. This study examined differences in multi-segment foot kinematics and plantar fascia strain during treadmill and overground running. Twelve male recreational runners ran at 4.0 m.s-1 in both treadmill and ove...
Kinematic repeatability of a multi-segment foot model for dance.
Carter, Sarah L; Sato, Nahoko; Hopper, Luke S
2018-03-01
The purpose of this study was to determine the intra and inter-assessor repeatability of a modified Rizzoli Foot Model for analysing the foot kinematics of ballet dancers. Six university-level ballet dancers performed the movements; parallel stance, turnout plié, turnout stance, turnout rise and flex-point-flex. The three-dimensional (3D) position of individual reflective markers and marker triads was used to model the movement of the dancers' tibia, entire foot, hindfoot, midfoot, forefoot and hallux. Intra and inter-assessor reliability demonstrated excellent (ICC ≥ 0.75) repeatability for the first metatarsophalangeal joint in the sagittal plane. Intra-assessor reliability demonstrated excellent (ICC ≥ 0.75) repeatability during flex-point-flex across all inter-segmental angles except for the tibia-hindfoot and hindfoot-midfoot frontal planes. Inter-assessor repeatability ranged from poor to excellent (0.5 > ICC ≥ 0.75) for the 3D segment rotations. The most repeatable measure was the tibia-foot dorsiflexion/plantar flexion articulation whereas the least repeatable measure was the hindfoot-midfoot adduction/abduction articulation. The variation found in the inter-assessor results is likely due to inconsistencies in marker placement. This 3D dance specific multi-segment foot model provides insight into which kinematic measures can be reliably used to ascertain in vivo technical errors and/or biomechanical abnormalities in a dancer's foot motion.
Vertical dimensional stability and rigidity of occlusal registration materials.
Walker, Mary P; Wu, Edis; Heckman, M Elizabeth; Alderman, Nicholas
2009-01-01
Dimensionally accurate occlusal registration records are essential for restorative dentistry; moreover, since records are not used immediately or may be used more than once, the registration material should exhibit accuracy over time (a concept known as dimensional stability). It has been speculated that materials with increased hardness or rigidity should produce more accurate registration records due to an increased resistance to distortion. This study compared the rigidity and associated dimensional accuracy of a recently marketed bisacrylic occlusal registration material and a vinyl polysiloxane (VPS). Maxillary and mandibular typodont arches were mounted on a plasterless articulator from which teeth No. 3, 13, and 15 had been removed to simulate edentulous spaces. After preparing teeth No. 2, 4, 12, and 14 as bridge abutments, the remaining teeth were equilibrated selectively to produce even anterior contact. Four digital photographs were taken to make vertical interarch measurements at four locations (teeth No. 3, 7, 10, and 14). Following initial photos (controls), 10 interocclusal records were made using each registration material, with material placed only in the segments in which teeth were prepared. The records were used for mounting the maxillary arch against the mandibular arch after 48, 72, and 120 hours. There were significant effects on vertical dimensional change related to arch location, material, and mounting time. Both materials demonstrated significantly larger posterior vertical openings than anterior vertical openings, while the bisacrylate produced a larger posterior opening than VPS at 48 and 72 hours and a larger anterior opening at all mounting times. There also was a significant difference in hardness/rigidity due to material and measurement time; at all measurement times, bisacrylate exhibited a significantly higher hardness number.
Macchi, Veronica; Picardi, Edgardo; Inferrera, Antonino; Porzionato, Andrea; Crestani, Alessandro; Novara, Giacomo; De Caro, Raffaele; Ficarra, Vincenzo
2018-02-01
The aim of the present anatomic and radiologic study was to evaluate the location, extension, and characteristics of the Brödel's plane and eventually define its different patterns. We evaluated 15 human normal kidneys sampled from unembalmed cadavers without clinical history or anatomical evidence of renal diseases. Kidneys with the surrounding perirenal fat tissue were removed en bloc with the abdominal segment of the aorta. The renal artery was injected with acrylic and radiopaque resins. A CT examination of the injected kidneys was performed. After the imaging acquisition, the specimens were treated with sodium hydroxide for removal of the parenchyma to obtain the vascular casts. All the CT images were elaborated using dedicated three-dimensional (3D) software with the aim to improve the possibility to identify the Brödel's plane. The avascular plane was identified directly on the vascular casts and confirmed on the corresponding 3D images. The avascular plane was located in all cases medially to the lateral convex border of the kidneys. The recorded mean distance was 2.04 cm (range 1.8-2.4 cm). Three patterns of distribution of the Brödel's line were identified. In five (33.3%) cases the avascular plane was extended from the apical to the inferior segment of the kidneys (type 1); in six (40%) from the superior to the inferior segment (type 2); and in four (26.7%) from the apical to the middle segment (type 3). Fourth and fifth order vessels crossing the Brödel's line were detected in all the analyzed cases. The renal avascular plane showed a different extension allowing us to cluster three different patterns. Preoperative identification of the Brödel's line patterns could help surgeons to minimize hemorrhagic complications during percutaneous and surgical procedures requiring an incision of the renal parenchyma such as traditional or robot-assisted nephrolithotomy or partial nephrectomy for endophytic renal tumors. Radiologic studies validated that
Tian, Shu; Zhang, Ye; Yan, Yiming; Su, Nan
2016-10-01
Segmentation of real-world remote sensing images is a challenge due to the complex texture information with high heterogeneity. Thus, graph-based image segmentation methods have been attracting great attention in the field of remote sensing. However, most of the traditional graph-based approaches fail to capture the intrinsic structure of the feature space and are sensitive to noises. A ℓ-norm regularization-based graph segmentation method is proposed to segment remote sensing images. First, we use the occlusion of the random texture model (ORTM) to extract the local histogram features. Then, a ℓ-norm regularized low-rank and sparse representation (LNNLRS) is implemented to construct a ℓ-regularized nonnegative low-rank and sparse graph (LNNLRS-graph), by the union of feature subspaces. Moreover, the LNNLRS-graph has a high ability to discriminate the manifold intrinsic structure of highly homogeneous texture information. Meanwhile, the LNNLRS representation takes advantage of the low-rank and sparse characteristics to remove the noises and corrupted data. Last, we introduce the LNNLRS-graph into the graph regularization nonnegative matrix factorization to enhance the segmentation accuracy. The experimental results using remote sensing images show that when compared to five state-of-the-art image segmentation methods, the proposed method achieves more accurate segmentation results.
Gevers, S.; Heijtel, D.; Ferns, S. P.; van Ooij, P.; van Rooij, W. J.; van Osch, M. J.; van den Berg, R.; Nederveen, A. J.; Majoie, C. B.
2012-01-01
BACKGROUND AND PURPOSE: Therapeutic carotid occlusion is an established technique for treatment of large and giant aneurysms of the (CA, in patients with synchronous venous filling on angiography during BTO. Concern remains that hemodynamic alterations after permanent occlusion will predispose the
Preprosthetic therapy utilizing a temporary occlusal acrylic splint: a case report.
Badel, Tomislav; Kraljeviç, Sonja; Panduriç, Josip; Marotti, Miljenko
2004-05-01
This case report describes the complex occlusal rehabilitation of a patient with signs and symptoms of temporomandibular disorders with utilization of an occlusal acrylic splint as a means of initial treatment for neuromuscular reprogramming and repositioning of the condyle within the mandibular fossa for occlusal stability, thus allowing adaptation to a new occlusal vertical dimension.
A hybrid segmentation method for partitioning the liver based on 4D DCE-MR images
Zhang, Tian; Wu, Zhiyi; Runge, Jurgen H.; Lavini, Cristina; Stoker, Jaap; van Gulik, Thomas; Cieslak, Kasia P.; van Vliet, Lucas J.; Vos, Frans M.
2018-03-01
The Couinaud classification of hepatic anatomy partitions the liver into eight functionally independent segments. Detection and segmentation of the hepatic vein (HV), portal vein (PV) and inferior vena cava (IVC) plays an important role in the subsequent delineation of the liver segments. To facilitate pharmacokinetic modeling of the liver based on the same data, a 4D DCE-MR scan protocol was selected. This yields images with high temporal resolution but low spatial resolution. Since the liver's vasculature consists of many tiny branches, segmentation of these images is challenging. The proposed framework starts with registration of the 4D DCE-MRI series followed by region growing from manually annotated seeds in the main branches of key blood vessels in the liver. It calculates the Pearson correlation between the time intensity curves (TICs) of a seed and all voxels. A maximum correlation map for each vessel is obtained by combining the correlation maps for all branches of the same vessel through a maximum selection per voxel. The maximum correlation map is incorporated in a level set scheme to individually delineate the main vessels. Subsequently, the eight liver segments are segmented based on three vertical intersecting planes fit through the three skeleton branches of HV and IVC's center of mass as well as a horizontal plane fit through the skeleton of PV. Our segmentation regarding delineation of the vessels is more accurate than the results of two state-of-the-art techniques on five subjects in terms of the average symmetric surface distance (ASSD) and modified Hausdorff distance (MHD). Furthermore, the proposed liver partitioning achieves large overlap with manual reference segmentations (expressed in Dice Coefficient) in all but a small minority of segments (mean values between 87% and 94% for segments 2-8). The lower mean overlap for segment 1 (72%) is due to the limited spatial resolution of our DCE-MR scan protocol.
Intravitreal triamcinolone acetonide injections in the treatment of retinal vein occlusions.
Roth, Daniel B; Cukras, Catherine; Radhakrishnan, Ravi; Feuer, William J; Yarian, David L; Green, Stuart N; Wheatley, Harold M; Prenner, Jonathan
2008-01-01
To report the visual acuity response after intravitreal triamcinolone injection in patients with macular edema due to retinal vein occlusions. Retrospective nonrandomized interventional series of 172 consecutive patients with macular edema due to retinal vein occlusions who were treated with intravitreal triamcinolone acetonide injection. Patients underwent Snellen visual acuity testing and ophthalmoscopic examination at baseline and 1, 3, 6, and 12 months after intravitreal triamcinolone acetonide injection. All subtypes of retinal vein occlusions showed significant improvements in mean visual acuity 1 month after injection. This improvement in visual acuity was maintained over the 12-month period for all but the central retinal vein occlusion group. Seventy-one (41.3%) of the 172 patients received more than one intravitreal triamcinolone injection for unresolved or recurrent macular edema. This study demonstrates a benefit associated with intravitreal triamcinolone acetonide injection for retinal vein occlusions that was maintained by patients with branch retinal vein occlusions and hemiretinal vein occlusions over a 12-month period. Visual acuity improvement was not maintained in patients with central retinal vein occlusions with this course of treatment.
Progression of Diabetic Capillary Occlusion: A Model.
Directory of Open Access Journals (Sweden)
Xiao Fu
2016-06-01
Full Text Available An explanatory computational model is developed of the contiguous areas of retinal capillary loss which play a large role in diabetic maculapathy and diabetic retinal neovascularization. Strictly random leukocyte mediated capillary occlusion cannot explain the occurrence of large contiguous areas of retinal ischemia. Therefore occlusion of an individual capillary must increase the probability of occlusion of surrounding capillaries. A retinal perifoveal vascular sector as well as a peripheral retinal capillary network and a deleted hexagonal capillary network are modelled using Compucell3D. The perifoveal modelling produces a pattern of spreading capillary loss with associated macular edema. In the peripheral network, spreading ischemia results from the progressive loss of the ladder capillaries which connect peripheral arterioles and venules. System blood flow was elevated in the macular model before a later reduction in flow in cases with progression of capillary occlusions. Simulations differing only in initial vascular network structures but with identical dynamics for oxygen, growth factors and vascular occlusions, replicate key clinical observations of ischemia and macular edema in the posterior pole and ischemia in the retinal periphery. The simulation results also seem consistent with quantitative data on macular blood flow and qualitative data on venous oxygenation. One computational model applied to distinct capillary networks in different retinal regions yielded results comparable to clinical observations in those regions.
A system for the acquisition and segmentation of plane static images in nuclear medicine
International Nuclear Information System (INIS)
Fideles, Ederson Lacerda.
1994-09-01
In nuclear medicine an image is obtained by employing a radioactive compound that is selectively fixed by the organ or tissue under study. In the traditional exams a radiation detector and a oscilloscope are used to obtain analog images of the organs that can be visualized directly or printed in film. In the modern approach, computers are used in the processing of the images obtained. In the present work an A/D board was developed to be used with an IBM compatible PC (XT or AT) for the acquisition of planar static images generated by the gamma camera. Pre-processing routines were developed to prepare the images for the image processing routines developed for the image segmentation. For this segmentation task thresholding methods were used based on the optimization of a certain criterion based on the histogram in such a way that the object can be separated from the background. (author). 25 refs., 26 figs
Does compliance with amblyopia management improve following supervised occlusion treatment?
El-Ghrably, I A; Longville, D; Gnanaraj, L
2007-01-01
To demonstrate improvement in compliance following supervised occlusion therapy for amblyopia in children who had failed to respond to outpatient treatment. Retrospective review of the visual outcome of 30 children who were admitted to an ophthalmology ward for 1-day intensive supervised occlusion. These children had documented poor compliance and previously failed to respond to the outpatient occlusion treatment. During their stay a trained ophthalmology nurse educated parents regarding amblyopia and the benefits of occlusion therapy. Visual acuity (VA) of the amblyopic and fellow eyes was recorded on admission, discharge, and at each subsequent visit. The compliance was recorded from parent's history and also indirectly by noticing improvement in vision. The mean supervised occlusion was 7.4 hours (range 4-12 hours). The compliance with occlusion therapy improved in 23 children (77%) after discharge. The mean duration of occlusion after discharge improved to 4 hours (range 1-12 hours). The mean follow-up was 18 months (range 4-24 months). Though there was no dramatic improvement in VA at discharge there was a statistically significant improvement in VA between admission and last recorded VA (pocclusion following discharge, 21 (91%) gained at least one line of acuity in their amblyopic eye on the last assessment of their VA and five of them achieved 6/12. Of the seven children who did not comply with occlusion following discharge, only one patient gained one line improvement in his amblyopic eye. This study shows that supervised occlusion treatment and parental education was effective in children who had initially failed traditional outpatient treatment.
Li, J N; Zhang, L J; He, Y; Chen, Y L; Huang, R C; Lyu, S Z; Song, X T
2017-07-24
Objective: Late gadolinium enhancement(LGE) cardiac magnetic resonance imaging(CMR) was used to evaluate the myocardial viability of chronic total occlusion(CTO) in patients with coronary heart disease and to observe the relationship between collateral circulation and myocardium viability in these patients. Methods: This retrospective study included 40 patients with CTO diagnosed by invasive coronary angiography (CAG) from September 2015 to June 2016 in our department, all patients performed CMR examination within one week after CAG.The collateral circulation of CTO was graded with Rentrop classification as follows: poor or no collateral circulation group, moderate collateral circulation group and good collateral circulation group.According to CMR images, the delayed enhancement transmural extent of myocardial segments were scored, the ventricular wall motion of the myocardial segment were graded, and the wall motion score index (WMSI) was calculated.Spearman correlation analysis was used to analyze the relationship between the delayed enhancement transmural extent of myocardial segments and WMSI. Results: In the no or poor collateral group of 6 myocardial regions, 1 myocardial region had viable myocardium and 3 myocardial regions had no viable myocardium; in the moderate collateral group of 16 myocardial regions, 11 myocardial regions had viable myocardium and 5 myocardial regions had no viable myocardium; in the good collateral group of 24 myocardial regions, 21 myocardial regions had viable myocardium and 3 myocardial regions had no viable myocardium, there was significant difference between the groups ( P =0.002). The WMSI of poor or no collateral circulation group, moderate collateral circulation group and good collateral circulation group were 1.54±0.50, 1.21±0.34 and 1.26±0.40, respectively, there was no significant difference between the groups ( P =0.063). Spearman correlation analysis showed that the extent of delayed enhancement transmural extent of
Occlusion detection via structured sparse learning for robust object tracking
Zhang, Tianzhu
2014-01-01
Sparse representation based methods have recently drawn much attention in visual tracking due to good performance against illumination variation and occlusion. They assume the errors caused by image variations can be modeled as pixel-wise sparse. However, in many practical scenarios, these errors are not truly pixel-wise sparse but rather sparsely distributed in a structured way. In fact, pixels in error constitute contiguous regions within the object’s track. This is the case when significant occlusion occurs. To accommodate for nonsparse occlusion in a given frame, we assume that occlusion detected in previous frames can be propagated to the current one. This propagated information determines which pixels will contribute to the sparse representation of the current track. In other words, pixels that were detected as part of an occlusion in the previous frame will be removed from the target representation process. As such, this paper proposes a novel tracking algorithm that models and detects occlusion through structured sparse learning. We test our tracker on challenging benchmark sequences, such as sports videos, which involve heavy occlusion, drastic illumination changes, and large pose variations. Extensive experimental results show that our proposed tracker consistently outperforms the state-of-the-art trackers.
van de Hoef, Tim P.; Nijveldt, Robin; van der Ent, Martin; Neunteufl, Thomas; Meuwissen, Martijn; Khattab, Ahmed; Berger, Rudolf; Kuijt, Wichert J.; Wykrzykowska, Joanna; Tijssen, Jan G. P.; van Rossum, Albert C.; Stone, Gregg W.; Piek, Jan J.
2015-01-01
Pressure-controlled intermittent coronary sinus occlusion (PICSO) may improve myocardial perfusion after pPCI. We evaluated the safety and feasibility of PICSO after pPCI for STEMI, and explored its effects on infarct size and myocardial function. Thirty patients were enrolled following successful
DEFF Research Database (Denmark)
Einholm, Anja P.; Andersen, Jens Peter; Vilsen, Bente
2007-01-01
In this review we summarize mutagenesis work on the structure-function relationship of transmembrane segment M1 in the Na(+),K(+)-ATPase and the sarco(endo)plasmic reticulum Ca(2+)-ATPase. The original hypothesis that charged residues in the N-terminal part of M1 interact with the transported...... cations can be rejected. On the other hand hydrophobic residues in the middle part of M1 turned out to play crucial roles in Ca(2+) interaction/occlusion in Ca(2+)-ATPase and K(+) interaction/occlusion in Na(+),K(+)-ATPase. Leu(65) of the Ca(2+)-ATPase and Leu(99) of the Na(+),K(+)-ATPase, located...... of the extracytoplasmic gate in both the Ca(2+)-ATPase and the Na(+),K(+)-ATPase. Udgivelsesdato: 2007-Dec...
Directory of Open Access Journals (Sweden)
Abdel Aziz A. Jaffan
2013-01-01
Full Text Available Endovascular recanalization of chronic total aortoiliac occlusion is technically challenging. Inability to reenter the true aortic lumen, following retrograde iliac recanalization, is one of the most common causes of failure. We describe a case of a total aortoiliac occlusion where balloon occlusion of the right common iliac artery, following its recanalization from a brachial approach, was used to facilitate antegrade recanalization of the occluded contralateral left common iliac artery.
A change in humidification system can eliminate endotracheal tube occlusion.
Doyle, Alex; Joshi, Manasi; Frank, Peter; Craven, Thomas; Moondi, Parvez; Young, Peter
2011-12-01
Inadequate airway humidification can result in endotracheal tube occlusion. There is evidence that heat and moisture exchangers (HMEs) are more prone to endotracheal tube occlusion than heated humidifiers (HHs) that contain a heated wire circuit. We aimed to compare the incidence of endotracheal tube occlusion while introducing a new dual-heated wire circuit HH in place of an established hydrophobic HME. This was a prospective observational study. All patients who required intubation were included in our analysis. Univariate statistical analysis was performed using a Fisher exact test. P humidification exclusively by HH. In the subsequent 18-month period, there were no further episodes of endotracheal tube occlusion. Our study demonstrates that there is a significant increase in the incidence of endotracheal tube occlusion when using a hydrophobic HME compared with an HH and that using a dual-heated wire circuit HH can eliminate endotracheal tube occlusion. Copyright © 2011 Elsevier Inc. All rights reserved.
Retinal vein occlusion: pathophysiology and treatment options
Karia, Niral
2010-01-01
Niral KariaDepartment of Ophthalmology, Southend Hospital, Prittlewell Chase, Westcliff on Sea, Essex, United KingdomAbstract: This paper reviews the current thinking about retinal vein occlusion. It gives an overview of its pathophysiology and discusses the evidence behind the various established and emerging treatment paradigms.Keywords: central, hemispheric, branch, retinal vein occlusion, visual loss
Multichannel prototype of coordinate detector based on segmented straws
International Nuclear Information System (INIS)
Gusakov, Yu.V.; Davkov, V.I.; Davkov, K.I.; Zhukov, I.A.; Lutsenko, V.M.; Myalkovskij, V.V.; Peshekhonov, V.D.; Savenkov, A.A.
2010-01-01
The design and assembly technology of a detector prototype based on segmented straws is considered. The granularity of the prototype is 4 cm 2 . The prototype has a sensitive area of 400 x 200 mm, and contains two straw planes displaced against each other by 2 mm. The number of registration channels is 360. Preliminary results of the bench study of the prototype are presented
Hepatic veno-occlusive disease associated with comfrey ingestion.
Yeong, M L; Swinburn, B; Kennedy, M; Nicholson, G
1990-01-01
A 23 year old man presented with hepatic veno-occlusive disease and severe portal hypertension and subsequently died from liver failure. Light microscopy and hepatic angiography showed occlusion of sublobular veins and small venous radicles of the liver, associated with widespread haemorrhagic necrosis of hepatocytes. The patient had been on a predominantly vegetarian diet and, prior to his illness, took comfrey leaves which are known to contain hepatotoxic pyrrolizidine alkaloids. Comfrey is widely used as a herbal remedy, but so far has only been implicated in two other documented cases of human hepatic veno-occlusive disease. A possible causal association of comfrey and this patient's veno-occlusive disease is suggested by the temporal relationship of the ingestion of comfrey to his presentation, the histological changes in the liver and the exclusion of other known causes of the disease.
[Single- and multi-unit fixed dental prostheses in relation to the occlusal system].
Witter, D J; Gerritsen, A E; van Spijker, A; Creugers, N H J
2013-02-01
Occlusion concepts based on functional aspects offer more solid ground in the diagnostic process and in the treatment of (reduced) dentitions than morphologically and mechanically oriented occlusion concepts. Nevertheless, for occlusal reconstruction morphologically oriented guidelines are necessary. These guidelines are based on the border movements and positions of the mandible in the orofacial system, and on the location and modelling of the occlusal contacts in the occlusal system. The modelling of single- and multi-unit fixed dental prostheses must harmonize with the occlusal system. Moreover, an important feature is the relation of the anterior teeth which enables mutually protected occlusion. Characteristics of a healthy orofacial and occlusal system are: absence of pathology, perceived sufficient oral functions, variability inform and function, and adaptive capacity. When designing single- or multiunit fixed dental prostheses, a pragmatic starting point is to maintain the existing occlusion and the existing speech pattern unless arguments can be provided for alterations. The occlusal design should aim at optimizing oral functions, such as mandibular and occlusal stability.
Acute pancreatitis during sickle cell vaso-occlusive painful crisis.
Ahmed, Shahid; Siddiqui, Anita K; Siddiqui, Rina K; Kimpo, Miriam; Russo, Linda; Mattana, Joseph
2003-07-01
Sickle cell disease is characterized by chronic hemolytic anemia and vaso-occlusive painful crisis. The vascular occlusion in sickle cell disease is a complex process and accounts for the majority of the clinical manifestations of the disease. Abdominal pain is an important component of vaso-occlusive painful crisis and may mimic diseases such as acute appendicitis and cholecystitis. Acute pancreatitis is rarely included as a cause of abdominal pain in patients with sickle cell disease. When it occurs it may result form biliary obstruction, but in other instances it might be a consequence of microvessel occlusion causing ischemia. In this series we describe four cases of acute pancreatitis in patients with sickle cell disease apparently due to microvascular occlusion and ischemic injury to the pancreas. All patients responded to conservative management. Acute pancreatitis should be considered in the differential diagnosis of abdominal pain in patients with sickle cell disease. Copyright 2003 Wiley-Liss, Inc.
Zhao, Ke; Mai, Qing-Qing; Wang, Xiao-Dong; Yang, Wen; Zhao, Li
2013-11-01
To systematically review clinical outcomes of different occlusal designs of complete dentures. Using a various key words, an electronic search of clinical trials published in English and Chinese literature was performed from four databases: Medline/PubMed, EMBASE, Cochrane Library, and CBM. Furthermore, a manual searching of the relevant journals and the bibliographies of reviews was performed. General satisfaction, masticatory ability, retention, and stability were major criteria for the evaluation of the outcomes. Studies met these criteria were selected for a full-text reading. The whole processes were performed by two reviewers independently. This systematic review started with 1030 articles, which were finally narrowed down to seven, according to the inclusion criteria. The following occlusal designs were included and analyzed: anatomic occlusion, balanced occlusion, canine guidance occlusion, lingualized occlusion, monoplane occlusion, and bilateral-balanced and canine-guided design. Three of the seven studies showed that lingualized occlusion had ratings of higher patients' satisfaction than other occlusion designs. On the other hand, the canine-guided occlusion dentures demonstrated equal or better clinical performances than bilateral-balanced dentures. Because of the heterogeneity and bias of the studies, it was not possible to analyze the data statistically. Lingualized occlusion and canine-guided occlusion can be successfully applied in the fabrication of complete dentures. Canine guided occlusion has also been shown to be satisfactory. More well-controlled randomized trials are needed regarding canine-guided occlusion and the relationship between alveolar ridge resorption, different occlusal schemes and patient satisfaction. The conventional prosthodontic wisdom that complete dentures require a balanced occlusal design is not supported by the included literature. A suitable occlusal scheme would be a critical factor for a successful complete denture
Particle filters, a quasi-Monte-Carlo-solution for segmentation of coronaries.
Florin, Charles; Paragios, Nikos; Williams, Jim
2005-01-01
In this paper we propose a Particle Filter-based approach for the segmentation of coronary arteries. To this end, successive planes of the vessel are modeled as unknown states of a sequential process. Such states consist of the orientation, position, shape model and appearance (in statistical terms) of the vessel that are recovered in an incremental fashion, using a sequential Bayesian filter (Particle Filter). In order to account for bifurcations and branchings, we consider a Monte Carlo sampling rule that propagates in parallel multiple hypotheses. Promising results on the segmentation of coronary arteries demonstrate the potential of the proposed approach.
The correction of occlusal vertical dimension on tooth wear
Directory of Open Access Journals (Sweden)
Rostiny Rostiny
2007-12-01
Full Text Available The loss of occlusal vertical dimension which is caused by tooth wear is necessarily treated to regain vertical dimension. Correctional therapy should be done as early possible. In this case, simple and relatively low cost therapy was performed. In unserve loss of occlusal vertical dimension, partial removable denture could be used and the improvement of lengthening anterior teeth using composite resin to improve to regain vertical dimensional occlusion.
Influence of occlusal contact area on cusp defection and stress distribution.
Costa, Anna Karina Figueiredo; Xavier, Thaty Aparecida; Paes-Junior, Tarcisio José Arruda; Andreatta-Filho, Oswaldo Daniel; Borges, Alexandre Luiz Souto
2014-11-01
The purpose of this study was to evaluate the effect of occlusal contact area for loading on the cuspal defection and stress distribution in a first premolar restored with a high elastic modulus restorative material. The Rhinoceros 4.0 software was used for modeling the three-dimensional geometries of dental and periodontal structures and the inlay restoration. Thus, two different models, intact and restored teeth with three occlusal contact areas, 0.1, 0.5 and 0.75 mm(2), on enamel at the occlusal surface of buccal and lingual cusps. Finite element analysis (FEA) was performed with the program ANSYS (Workbench 13.0), which generated a mesh with tetrahedral elements with greater refinement in the regions of interest, and was constrained at the bases of cortical and trabecular bone in all axis and loaded with 100 N normal to each contact area. To analysis of maximum principal stress, the smaller occlusal contact area showed greater compressive stress in region of load application for both the intact and inlay restored tooth. However, tensile stresses at the occlusal isthmus were similar for all three tested occlusal contact areas (60 MPa). To displacement of the cusps was higher for teeth with inlay (0.46-0.48 mm). For intact teeth, the smaller contact area showed greater displacement (0.10 mm). For teeth with inlays, the displacement of the cusps were similar in all types of occlusal area. Cuspal displacement was higher in the restored tooth when compared to the intact tooth, but there were no significant variations even with changes in the occlusal contact area. RELEVANCE CLINICAL: Occlusal contacts have a great influence on the positioning of teeth being able to maintain the position and stability of the mandible. Axial loads would be able to generate more uniform stress at the root presenting a greater concentration of load application in the point and the occlusal surface. Thus, is necessary to analyze the relationship between these occlusal contacts as dental
A method for smoothing segmented lung boundary in chest CT images
Yim, Yeny; Hong, Helen
2007-03-01
To segment low density lung regions in chest CT images, most of methods use the difference in gray-level value of pixels. However, radiodense pulmonary vessels and pleural nodules that contact with the surrounding anatomy are often excluded from the segmentation result. To smooth lung boundary segmented by gray-level processing in chest CT images, we propose a new method using scan line search. Our method consists of three main steps. First, lung boundary is extracted by our automatic segmentation method. Second, segmented lung contour is smoothed in each axial CT slice. We propose a scan line search to track the points on lung contour and find rapidly changing curvature efficiently. Finally, to provide consistent appearance between lung contours in adjacent axial slices, 2D closing in coronal plane is applied within pre-defined subvolume. Our method has been applied for performance evaluation with the aspects of visual inspection, accuracy and processing time. The results of our method show that the smoothness of lung contour was considerably increased by compensating for pulmonary vessels and pleural nodules.
Quantifying coordination among the rearfoot, midfoot, and forefoot segments during running.
Takabayashi, Tomoya; Edama, Mutsuaki; Yokoyama, Erika; Kanaya, Chiaki; Kubo, Masayoshi
2018-03-01
Because previous studies have suggested that there is a relationship between injury risk and inter-segment coordination, quantifying coordination between the segments is essential. Even though the midfoot and forefoot segments play important roles in dynamic tasks, previous studies have mostly focused on coordination between the shank and rearfoot segments. This study aimed to quantify coordination among rearfoot, midfoot, and forefoot segments during running. Eleven healthy young men ran on a treadmill. The coupling angle, representing inter-segment coordination, was calculated using a modified vector coding technique. The coupling angle was categorised into four coordination patterns. During the absorption phase, rearfoot-midfoot coordination in the frontal planes was mostly in-phase (rearfoot and midfoot eversion with similar amplitudes). The present study found that the eversion of the midfoot with respect to the rearfoot was comparable in magnitude to the eversion of the rearfoot with respect to the shank. A previous study has suggested that disruption of the coordination between the internal rotation of the shank and eversion of the rearfoot leads to running injuries such as anterior knee pain. Thus, these data might be used in the future to compare to individuals with foot deformities or running injuries.
Li, Xuejiao; Cao, Ye; Xie, Qiufei
2014-10-01
To investigate the relationship between the existence of occlusal interference and masticatory muscle hyperalgesia by exploring the stimulus-response relationship between the duration of occlusal interference and masticatory muscle mechanical withdrawal threshold. Occlusal interference with 0.4 mm-thick crowns on rat molars was removed under anaesthesia at 2, 3, 4, 5, and 6 d after wear, and masticatory muscle mechanical withdrawal threshold was tested at 1, 3, 5, 7, 10, 14, 21 and 28 d. Decreased mechanical withdrawal thresholds were detected in temporal muscles and masseter muscles on both sides following occlusal interference (P 0.05). No significant differences were detected between the contralateral side with the ipsilateral side (P occlusal interference at 5 d, and the existence of the occlusal interference is positively correlated with the duration of the mechanical hyperalgesia.
Left atrial appendage occlusion
Directory of Open Access Journals (Sweden)
Ahmad Mirdamadi
2013-01-01
Full Text Available Left atrial appendage (LAA occlusion is a treatment strategy to prevent blood clot formation in atrial appendage. Although, LAA occlusion usually was done by catheter-based techniques, especially percutaneous trans-luminal mitral commissurotomy (PTMC, it can be done during closed and open mitral valve commissurotomy (CMVC, OMVC and mitral valve replacement (MVR too. Nowadays, PTMC is performed as an optimal management of severe mitral stenosis (MS and many patients currently are treated by PTMC instead of previous surgical methods. One of the most important contraindications of PTMC is presence of clot in LAA. So, each patient who suffers of severe MS is evaluated by Trans-Esophageal Echocardiogram to rule out thrombus in LAA before PTMC. At open heart surgery, replacement of the mitral valve was performed for 49-year-old woman. Also, left atrial appendage occlusion was done during surgery. Immediately after surgery, echocardiography demonstrates an echo imitated the presence of a thrombus in left atrial appendage area, although there was not any evidence of thrombus in pre-pump TEE. We can conclude from this case report that when we suspect of thrombus of left atrial, we should obtain exact history of previous surgery of mitral valve to avoid misdiagnosis clotted LAA, instead of obliterated LAA. Consequently, it can prevent additional evaluations and treatments such as oral anticoagulation and exclusion or postponing surgeries including PTMC.
Design of the Monitored Occlusion Treatment of Amblyopia Study (MOTAS)
Stewart, C E; Fielder, A R; Stephens, D A; Moseley, M J
2002-01-01
Background/aims: The effectiveness of occlusion therapy for the treatment of amblyopia is a research priority. The authors describe the design of the Monitored Occlusion Treatment for Amblyopia Study (MOTAS) and its methodology. MOTAS will determine the dose-response relation for occlusion therapy as a function of age and category of amblyopia.
Directory of Open Access Journals (Sweden)
Mason lll JO
2015-06-01
Full Text Available John O Mason III,1,2 Shyam A Patel,1 Richard M Feist,1,2 Michael A Albert Jr,1,2 Carrie Huisingh,1 Gerald McGwin Jr,1,3 Martin L Thomley1,2 1Department of Ophthalmology, University of Alabama School of Medicine, Birmingham, AL, USA; 2Retina Consultants of Alabama, Callahan Eye Foundation Hospital, Birmingham, AL, USA; 3Department of Epidemiology, School of Public Health, University of Alabama at Birmingham, Birmingham, AL, USA Purpose: To investigate the ocular neovascularization (ONV rate in eyes with a branch retinal artery occlusion (BRAO or a central retinal artery occlusion (CRAO, and to study factors that may influence the ONV rate secondary to CRAO.Methods: This was a retrospective case series of consecutive patients (286 total eyes: 83 CRAOs and 203 BRAOs who were diagnosed with a retinal artery occlusion from 1998 to 2013 at the Retina Consultants of Alabama and University of Alabama at Birmingham, Birmingham, AL, USA. Generalized estimating equations were used to evaluate the association between hypothesized risk factors and ONV development.Results: Twelve (14.5% of the 83 eyes with a CRAO developed ONV. Eleven of 12 eyes (91.7% had iris neovascularization, ten of 12 eyes (83.3% had neovascular glaucoma, and two of 12 eyes (16.7% had neovascularization of the optic disc. The average time for ONV development secondary to CRAO was 30.7 days, ranging from the date of presentation to 137 days. Only two (<1.0% of the 203 eyes with a BRAO developed iris neovascularization. Diabetes mellitus type 2 was a risk factor for ONV development following a CRAO with an adjusted odds ratio of 5.2 (95% confidence interval: 1.4–19.8 (P=0.02.Conclusion: ONV is an important complication of CRAO and is a less-frequent complication of BRAO. Patients with a CRAO, especially those with diabetes mellitus type 2, should be closely monitored for the first 6 months for ONV. Keywords: neovascularization, neovascular glaucoma, retinal artery occlusion, central
Sinha, Nikita; Reddy, K Mahendranadh; Gupta, Nidhi; Shastry, Y M
2017-01-01
Occlusal plane (OP) differs considerably in participants with skeletal Class I and Class II participants. In this study, cephalometrics has been used to help in the determination of orientation of the OP utilizing the nonresorbable bony anatomic landmarks in skeletal Class II participants and an attempt has been made to predict and examine the OP in individuals with skeletal class II jaw relationship. One hundred dentulous participants with skeletal Class II malocclusion who came to the hospital for correcting their jaw relationship participated in the study. Their right lateral cephalogram was taken using standardized procedures, and all the tracings were manually done by a single trained examiner. The cephalograms which were taken for the diagnostic purpose were utilized for the study, and the patient was not exposed to any unnecessary radiation. The numerical values obtained from the cephalograms were subjected to statistical analysis. Pearson's correlation of orientation of the OP in Class II edentulous participants. Pearson's correlation coefficient and linear regression analysis were performed, and a high correlation was found between A2 and (A2 + B2)/(B2 + C2) with " r " value of 0.5. A medium correlation was found between D2 and (D2 + E2)/(E2 + F2) with " r " value of 0.42. The formula obtained for posterior reference frame through linear regression equation was y = 0.018* × +0.459 and the formula obtained for anterior reference frame was y1 = 0.011* × 1 + 0.497. It was hypothesized that by substituting these formulae in the cephalogram obtained from the Class II edentate individual, the OP can be obtained and verified. It was concluded that cephalometrics can be useful in examining the orientation of OP in skeletal Class II participants.
Vasilenko, Yu V; Kim, A I; Kotov, S A
2002-11-01
The mechanism of extravasal occlusion of blood vessels with titanic clips "Atrauclip" and "Ligaclip extra" was studied in order to reveal indications and contraindications to their use. Occlusion with the clips of both types was ineffective in vessels with a diameter of >7.0 mm. Arteritis or the presence of an intravascular occlusion facility in the vessel were also the contraindications for clip occlusion. In overcases the procedure of occlusion with titanic clips was efficient and atraumatic.
Treatment of hemobilia by transcatheter vascular occlusion
International Nuclear Information System (INIS)
Vaughan, R.; Roesch, J.; Keller, F.S.; Antonovic, R.; Veterans Administration Medical Center, Portland, OR
1984-01-01
Four cases of hemobilia treated by transcatheter arterial occlusion are presented and reviewed with 30 similar cases reported in the literature. Transcatheter vascular occlusion successfully controlled hemorrhage in all 34 patients. No obvious liver parenchymal damage appeared in 26 patients; transient elevation of liver enzymes occurred in 6 patients (18%) including one in our series; two of the patients reviewed died of acute hepatic insufficiency following nonselective hepatic artery embolization. Hemobilia should be considered when gastrointestinal hemorrhage occurs after abdominal trauma, liver biopsy or other manipulative liver procedures. Hepatic angiography establishes the diagnosis and selective vascular occlusion is the treatment of choice for control of intractable or recurrent hemorrhage. Techniques and precautions for the diagnosis and transcatheter therapy of hemobilia are discussed. (orig.)
Mechanism of vaso-occlusion in sickle cell anemia
Lei, Huan; Karniadakis, George
2012-11-01
Vaso-occlusion crisis is one of the key hallmark of sickle cell anemia. While early studies suggested that the crisis is caused by blockage of a single elongated cell, recent experimental investigations indicate that vaso-occlusion is a complex process triggered by adhesive interactions among different cell groups in multiple stages. Based on dissipative particle dynamics, a multi-scale model for the sickle red blood cells (SS-RBCs), accounting for diversity in both shapes and cell rigidities, is developed to investigate the mechanism of vaso-occlusion crisis. Using this model, the adhesive dynamics of single SS-RBC was investigated in arterioles. Simulation results indicate that the different cell groups (deformable SS2 RBCs, rigid SS4 RBCs, leukocytes, etc.) exhibit heterogeneous adhesive behavior due to the different cell morphologies and membrane rigidities. We further simulate the tube flow of SS-RBC suspensions with different cell fractions. The more adhesive SS2 cells interact with the vascular endothelium and further trap rigid SS4 cells, resulting in vaso-occlusion in vessels less than 15 μm . Under inflammation, adherent leukocytes may also trap SS4 cells, resulting in vaso-occlusion in even larger vessels. This work was supported by the NSF grant CBET-0852948 and the NIH grant R01HL094270.
Arterial occlusive disease after radiotherapy
International Nuclear Information System (INIS)
Piedbois, P.; Mazeron, J.J.; Le Bourgeois, J.P.; Becquemin, J.P.; Blanc, I.; Lange, F.; Melliere, D.
1990-01-01
Fourteen cases of arterial occlusion or severe narrowing following radiotherapy are studied in order to assess the possible etiological role of such therapy in arterial lesion. Surgical results are also discussed in terms of long-term efficacy. The average time of occurrence after radiotherapy was 8 years post-radiotherapy. This series includes 7 supra-aortic trunk stenoses and 7 abdominal aorta trunk stenoses. The doses received in the volumes iradiated ranged from 47 to 70 Gy with standard fractionation. Association of atherosclerotic risk factors was present in 12 patients, but stenoses were usually confined to irradiated areas, and at imes occurred in uncommon sites. Surgical management included 11 by-passes, 2 endarterectomies and one percutaneous transluminal angioplasty. All patients experienced immediate and satisfactory functional improvements. Three patients were re-operated on because of the re-occlusion of the by-pass and graft infection. On the whole, stenoses in previously irradiated areas showed no particular difficulties for surgical treatment. It was concluded that radiotherapy seems to be a definite risk factor for arterial occlusion or narrowing, especially in association in association with atherosclerotic risk factors. (author). 45 refs.; 3 figs.; 2 tabs
Directory of Open Access Journals (Sweden)
Rahmad Hidayat
2015-04-01
Full Text Available Bit-Plane Complexity Segmentation (BPCS is a fairly new steganography technique. The most important process in BPCS is the calculation of complexity value of a bit-plane. The bit-plane complexity is calculated by looking at the amount of bit changes contained in a bit-plane. If a bit-plane has a high complexity, the bi-plane is categorized as a noise bit-plane that does not contain valuable information on the image. Classification of the bit-plane using the set cripst set (noise/not is not fair, where a little difference of the value will significantly change the status of the bit-plane. The purpose of this study is to apply the principles of fuzzy sets to classify the bit-plane into three sets that are informative, partly informative, and the noise region. Classification of the bit-plane into a fuzzy set is expected to classify the bit-plane in a more objective approach and ultimately message capacity of the images can be improved by using the Mamdani fuzzy inference to take decisions which bit-plane will be replaced with a message based on the classification of bit-plane and the size of the message that will be inserted. This research is able to increase the capability of BPCS steganography techniques to insert a message in bit-pane with more precise so that the container image quality would be better. It can be seen that the PSNR value of original image and stego-image is only slightly different.
International Nuclear Information System (INIS)
Jan, S.; Khan, M.N.; Karim, S.; Khan, M.T.; Hussain, Z.; Khan, S.; Nazim, M.
2010-01-01
Vascular endothelial growth factor plays major role in ocular angio genesis and retinal edema production and is a step forward in the management of ocular neovascularization and retinal edematous pathologies. To determine the efficacy and safety of intra-vitreal Avastin (Bevacizumab) in cases having central retinal vein occlusion. All patients with central retinal occlusion occurring in the past 3 months and seen between the study period were included in the study. Diagnosis of central retinal vein occlusion was made clinically by slit lamp biomicroscopy with 78D examination Patients who had received any treatment for and eyes which already had developed Anterior Segment Neovascularization, Neovascularization elsewhere or Neovascularization on disc at presentation were excluded. Dose of 0.05 ml (1.25mg) of Avastin (Bevacizumab) was used as intra vitreal injection every month for 3 months in cases that presented within a month of occlusion and less injections were given in dose presenting later. Follow-up was done at 30th, 60th, 90th and 120th day after the onset of disease. Visual outcome was defined as Snellen's or LogMar Best Corrected Visual Acuity at final follow up, of 120th day, compared to the visual acuity at presentation. Data were analyzed by SPSS version 17. Total of 17 eyes of 17 patients were included in this study. Eleven (64.7%) patients were males while 6(35.3%) were females. Total of 40 intra-vitreal injections of Avastin were given to patients with a mean of 2.35 injections per eye. Good visual outcome was achieved in 10(58.8%) eyes, while 7(41.2%) had stable visual outcome. Mean initial Best Corrected Visual Acuity (LogMar) in all 17 eyes was 1.79(SD+0.87) which significantly improved to a mean of 1.18 (SD+0.77) at final follow up. Mean improvement in Best Corrected Visual Acuity (LogMar) after paired sample test in all patients at final follow up on day 120 was 0.61(SD+0.84). Retinal hemorrhages and macular edema decreased clinically on
Sealing Occlusal Dentin Caries in Permanent Molars
DEFF Research Database (Denmark)
Qvist, Vibeke; Borum, Mette Kit; Møller, Kirsten Dynes
2017-01-01
The purpose of this study was to investigate the possibility of postponing restorative intervention of manifest occlusal caries in young, permanent dentition by non-invasive sealing. This RCT-designed study included 521 occlusal lesions in 521 patients aged 6 to 17 y. Based on clinical and radiog......The purpose of this study was to investigate the possibility of postponing restorative intervention of manifest occlusal caries in young, permanent dentition by non-invasive sealing. This RCT-designed study included 521 occlusal lesions in 521 patients aged 6 to 17 y. Based on clinical...... longevity of sealings and restorations until retreatments, and 3) compare effectiveness of sealings and restorations to halt caries progression in sealed lesions and beneath restorations. Furthermore, we aimed to identify factors influencing longevity and the effectiveness of sealings and restorations.......001). The median survival time for sealings not replaced by restorations was 7.3 y (CI, 6.4 y to NA). Survival of sealings was increased in patients with low caries risk and/or excellent oral hygiene, second molars compared with first molars, and lesions not extending the middle one-third of the dentin. Survival...
Bilateral retinal vein occlusion and rubeosis irides: lessons to learn.
Md Noh, Umi Kalthum; Ahem, Amin; Mustapha, Mushawiahti
2013-01-01
Uncontrolled hypertension is well- known to give rise to systemic complications involving multiple central organs. Artherosclerosis leads to damage of the retinal vessels wall, contributing to venous stasis, thrombosis and finally, occlusion. Retinal vein occlusions compromise vision through development of ischaemic maculopathy, macular oedema, and rubeotic glaucoma. Laser photocoagulation remains the definitive treatment for ischaemic vein occlusion with secondary neovascularization. Timely treatment with anti- vascular endothelial growth factor prevents development of rubeotic glaucoma. We hereby report an unusual case of bilateral retinal vein occlusion complicated by rubeosis irides, which was successfully managed to improve vision and prevent rubeotic glaucoma.
Comorbidity in patients with branch retinal vein occlusion
DEFF Research Database (Denmark)
Bertelsen, Mette; Linneberg, Allan; Rosenberg, Thomas
2012-01-01
To evaluate comorbidity before and after the diagnosis of branch retinal vein occlusion to determine whether it is a consequence of arterial thickening and therefore could serve as a diagnostic marker for other comorbidities and to evaluate the risk factors for the development of such occlusion....
Factors affecting root curvature of mandibular first molar
International Nuclear Information System (INIS)
Choi, Hang Moon; Yi, Won Jin; Heo, Min Suk; Kim, Jung Hwa; Choi, Soon Chul; Park, Tae Won
2006-01-01
To find the cause of root curvature by use of panoramic and lateral cephalometric radiograph. Twenty six 1st graders whose mandibular 1st molars just emerged into the mouth were selected. Panoramic and lateral cephalometric radiograph were taken at grade 1 and 6, longitudinally. In cephalometric radio graph, mandibular plane angle, ramus-occlusal place angle, gonial angle, and gonion-gnathion distance(Go-Gn distance) were measured. In panoramic radiograph, elongated root length and root angle were measured by means of digital subtraction radiography. Occlusal plane-tooth axis angle was measured, too. Pearson correlations were used to evaluate the relationships between root curvature and elongated length and longitudinal variations of all variables. Multiple regression equation using related variables was computed. The pearson correlation coefficient between curved angle and longitudinal variations of occlusal plane-tooth axis angle and ramus-occlusal plane angle was 0.350 and 0.401, respectively (p 1 +0.745X 2 (Y: root angle, X 1 : variation of occlusal plane-tooth axis angle, X 2 : variation of ramus-occlusal plane angle). It was suspected that the reasons of root curvature were change of tooth axis caused by contact with 2nd deciduous tooth and amount of mesial and superior movement related to change of occlusal plane
Occlusion-Aware Fragment-Based Tracking With Spatial-Temporal Consistency.
Sun, Chong; Wang, Dong; Lu, Huchuan
2016-08-01
In this paper, we present a robust tracking method by exploiting a fragment-based appearance model with consideration of both temporal continuity and discontinuity information. From the perspective of probability theory, the proposed tracking algorithm can be viewed as a two-stage optimization problem. In the first stage, by adopting the estimated occlusion state as a prior, the optimal state of the tracked object can be obtained by solving an optimization problem, where the objective function is designed based on the classification score, occlusion prior, and temporal continuity information. In the second stage, we propose a discriminative occlusion model, which exploits both foreground and background information to detect the possible occlusion, and also models the consistency of occlusion labels among different frames. In addition, a simple yet effective training strategy is introduced during the model training (and updating) process, with which the effects of spatial-temporal consistency are properly weighted. The proposed tracker is evaluated by using the recent benchmark data set, on which the results demonstrate that our tracker performs favorably against other state-of-the-art tracking algorithms.
Celiac artery stenosis/occlusion treated by interventional radiology
International Nuclear Information System (INIS)
Ikeda, Osamu; Tamura, Yoshitaka; Nakasone, Yutaka; Yamashita, Yasuyuki
2009-01-01
Severe stenosis/occlusion of the proximal celiac trunk due to median arcuate ligament compression (MALC), arteriosclerosis, pancreatitis, tumor invasion, and celiac axis agenesis has been reported. However, clinically significant ischemic bowel disease attributable to celiac axis stenosis/occlusion appears to be rare because the superior mesenteric artery (SMA) provides for rich collateral circulation. In patients with celiac axis stenosis/occlusion, the most important and frequently encountered collateral vessels from the SMA are the pancreaticoduodenal arcades. Patients with celiac artery stenosis/occlusion are treated by interventional radiology (IR) via dilation of the pancreaticoduodenal arcade. In patients with dilation of the pancreaticoduodenal arcade on SMA angiograms, IR through this artery may be successful. Here we provide several tips on surmounting these difficulties in IR including transcatheter arterial chemoembolization for hepatocellular carcinoma, an implantable port system for hepatic arterial infusion chemotherapy to treat metastatic liver tumors, coil embolization of pancreaticoduodenal artery aneurysms, and arterial stimulation test with venous sampling for insulinomas.
Celiac artery stenosis/occlusion treated by interventional radiology
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Ikeda, Osamu [Department of Diagnostic Radiology, Kumamoto University Graduate School of Medical and Pharmaceutical Sciences, 1-1-1, Honjo Kumamoto 860-8505 (Japan)], E-mail: osamu-3643ik@do9.enjoy.ne.jp; Tamura, Yoshitaka; Nakasone, Yutaka; Yamashita, Yasuyuki [Department of Diagnostic Radiology, Kumamoto University Graduate School of Medical and Pharmaceutical Sciences, 1-1-1, Honjo Kumamoto 860-8505 (Japan)
2009-08-15
Severe stenosis/occlusion of the proximal celiac trunk due to median arcuate ligament compression (MALC), arteriosclerosis, pancreatitis, tumor invasion, and celiac axis agenesis has been reported. However, clinically significant ischemic bowel disease attributable to celiac axis stenosis/occlusion appears to be rare because the superior mesenteric artery (SMA) provides for rich collateral circulation. In patients with celiac axis stenosis/occlusion, the most important and frequently encountered collateral vessels from the SMA are the pancreaticoduodenal arcades. Patients with celiac artery stenosis/occlusion are treated by interventional radiology (IR) via dilation of the pancreaticoduodenal arcade. In patients with dilation of the pancreaticoduodenal arcade on SMA angiograms, IR through this artery may be successful. Here we provide several tips on surmounting these difficulties in IR including transcatheter arterial chemoembolization for hepatocellular carcinoma, an implantable port system for hepatic arterial infusion chemotherapy to treat metastatic liver tumors, coil embolization of pancreaticoduodenal artery aneurysms, and arterial stimulation test with venous sampling for insulinomas.
International Nuclear Information System (INIS)
Winter-Warnars, Hillegonda A.O.; Graaf, Yolanda van der; Mali, Willem P.T.M.
1996-01-01
Purpose: Comparison of the relative values of the ankle-arm index (AAI) at rest and after exercise, angiography, and duplex ultrasonography for the follow-up of percutaneous transluminal angioplasty (PTA) in patients with peripheral vascular disease. Methods: Thirty-two patients were prospectively followed after technically and clinically successful PTA of a femoropopliteal occlusion. The patency of the femoropopliteal artery was assessed for 1 year using AAI measurements at rest and after exercise; duplex ultrasonography at 4, 12, 24, 36, and 52 weeks; and angiography at 3 and 12 months after PTA. Results: Patency was highly dependent on the measurement technique. The cumulative patency after 1 year determined with the AAI at rest and during exercise, by angiography, and by duplex ultrasonography was 74%, 19%, 31%, and 32%, respectively. Seventy-five percent of the restenoses occurred at the site of the treated occlusion. Conclusion: Duplex ultrasonography is most suitable for this assessment, as it causes no patient discomfort and the specificity is better than AAI after exercise because vascular disease in other, proximal segments does not interfere with the results
Does partial occlusion promote normal binocular function?
Li, Jingrong; Thompson, Benjamin; Ding, Zhaofeng; Chan, Lily Y L; Chen, Xiang; Yu, Minbin; Deng, Daming; Hess, Robert F
2012-10-03
There is growing evidence that abnormal binocular interactions play a key role in the amblyopia syndrome and represent a viable target for treatment interventions. In this context the use of partial occlusion using optical devices such as Bangerter filters as an alternative to complete occlusion is of particular interest. The aims of this study were to understand why Bangerter filters do not result in improved binocular outcomes compared to complete occlusion, and to compare the effects of Bangerter filters, optical blur and neutral density (ND) filters on normal binocular function. The effects of four strengths of Bangerter filters (0.8, 0.6, 0.4, 0.2) on letter and vernier acuity, contrast sensitivity, stereoacuity, and interocular suppression were measured in 21 observers with normal vision. In a subset of 14 observers, the partial occlusion effects of Bangerter filters, ND filters and plus lenses on stereopsis and interocular suppression were compared. Bangerter filters did not have graded effect on vision and induced significant disruption to binocular function. This disruption was greater than that of monocular defocus but weaker than that of ND filters. The effect of the Bangerter filters on stereopsis was more pronounced than their effect on monocular acuity, and the induced monocular acuity deficits did not predict the induced deficits in stereopsis. Bangerter filters appear to be particularly disruptive to binocular function. Other interventions, such as optical defocus and those employing computer generated dichoptic stimulus presentation, may be more appropriate than partial occlusion for targeting binocular function during amblyopia treatment.
Video steganography based on bit-plane decomposition of wavelet-transformed video
Noda, Hideki; Furuta, Tomofumi; Niimi, Michiharu; Kawaguchi, Eiji
2004-06-01
This paper presents a steganography method using lossy compressed video which provides a natural way to send a large amount of secret data. The proposed method is based on wavelet compression for video data and bit-plane complexity segmentation (BPCS) steganography. BPCS steganography makes use of bit-plane decomposition and the characteristics of the human vision system, where noise-like regions in bit-planes of a dummy image are replaced with secret data without deteriorating image quality. In wavelet-based video compression methods such as 3-D set partitioning in hierarchical trees (SPIHT) algorithm and Motion-JPEG2000, wavelet coefficients in discrete wavelet transformed video are quantized into a bit-plane structure and therefore BPCS steganography can be applied in the wavelet domain. 3-D SPIHT-BPCS steganography and Motion-JPEG2000-BPCS steganography are presented and tested, which are the integration of 3-D SPIHT video coding and BPCS steganography, and that of Motion-JPEG2000 and BPCS, respectively. Experimental results show that 3-D SPIHT-BPCS is superior to Motion-JPEG2000-BPCS with regard to embedding performance. In 3-D SPIHT-BPCS steganography, embedding rates of around 28% of the compressed video size are achieved for twelve bit representation of wavelet coefficients with no noticeable degradation in video quality.
Frictionless segmented mechanics for controlled space closure.
Andrade, Ildeu
2017-02-01
Extraction spaces may be needed to achieve specific orthodontic goals of positioning the dentition in harmony with the craniofacial complex. However, the fundamental reality that determines the occlusion final position is the control exerted by the orthodontist while closing the extraction spaces. A specific treatment objective may require the posterior teeth to remain in a constant position anteroposteriorly as well as vertically, while the anterior teeth occupy the entire extraction site. Another treatment objective may require the opposite, or any number of intentional alternatives of extraction site closure. The present case report describes a simple controlled segmented mechanic system that permitted definable and predictable force systems to be applied and allowed to predict the treatment outcome with confidence. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO) in partial fulfillment of the requirements for Diplomate certification.
CT findings of middle cerebral artery occlusion
International Nuclear Information System (INIS)
Shiokawa, Yoshiaki; Saito, Isamu; Segawa, Hiromu; Fujimaki, Takamitsu; Tsutsumi, Kazuo
1987-01-01
In each case, we selected the CT scan showing the maximum extent of the low-density area (LDA) during the course of the occlusion and classified the findings into the following five types: basal ganglia type, extensive subcortical type, hemispheric type, branch type, and normal (no LDA) type. The angiographic occlusion sites of MCA were divided into 4 patterns; the origin of MCA, the distal M1 portion, MCA trifurcation, and one branch of the M2. The overall mortality rate was 33 %, while the morbidity rate was 53 %. The older the patient, the poorer the prognosis. In the 17 cases of MCA-origin occlusion, 12 cases (71 %) showed the basal ganglia type of LDA; their prognoses varied. In the 12 cases of MCA trifurcation occlusion, 10 cases (83 %) revealed an extensive subcortical type of LDA, and all showed a poor prognosis. In the MCA occlusion, the angiography-CT correlation seemed to depend on where and how the occlusion had occurred. Cerebral thrombosis frequently occurred at the origin of MCA, while cerebral embolism was more usually found to occlude the MCA trifurcation. In order to assess the collateral circulation quantitatively, we determined the IC-M2 time, that is, the conduction time of the contrast media from the intracranial carotid siphone (IC) to the insular portion of the MCA (M2) through the leptomeningeal anastomosis. Of the 29 cases admitted within 24 hours after the onset and which yet showed no LDA on the initial CT scan, all 13 cases with IC-M2 times of less than 5 seconds showed the basal ganglia type of LDA. On the other hand, the 16 cases with IC-M2 times of more than 5 seconds always demonstrated a large LDA, of either the extensive subcortical type or the hemispheric type. This IC-M2 time is useful in anticipating the extent of infarction before a CT scan demonstrates LDA and in predicting a patient's prognosis in the acute stage. (J.P.N.)
CT findings of middle cerebral artery occlusion
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Shiokawa, Yoshiaki; Saito, Isamu; Segawa, Hiromu; Fujimaki, Takamitsu; Tsutsumi, Kazuo
1987-04-01
In each case, we selected the CT scan showing the maximum extent of the low-density area (LDA) during the course of the occlusion and classified the findings into the following five types: basal ganglia type, extensive subcortical type, hemispheric type, branch type, and normal (no LDA) type. The angiographic occlusion sites of MCA were divided into 4 patterns; the origin of MCA, the distal M1 portion, MCA trifurcation, and one branch of the M2. The overall mortality rate was 33 %, while the morbidity rate was 53 %. The older the patient, the poorer the prognosis. In the 17 cases of MCA-origin occlusion, 12 cases (71 %) showed the basal ganglia type of LDA; their prognoses varied. In the 12 cases of MCA trifurcation occlusion, 10 cases (83 %) revealed an extensive subcortical type of LDA, and all showed a poor prognosis. In the MCA occlusion, the angiography-CT correlation seemed to depend on where and how the occlusion had occurred. Cerebral thrombosis frequently occurred at the origin of MCA, while cerebral embolism was more usually found to occlude the MCA trifurcation. In order to assess the collateral circulation quantitatively, we determined the IC-M2 time, that is, the conduction time of the contrast media from the intracranial carotid siphone (IC) to the insular portion of the MCA (M2) through the leptomeningeal anastomosis. Of the 29 cases admitted within 24 hours after the onset and which yet showed no LDA on the initial CT scan, all 13 cases with IC-M2 times of less than 5 seconds showed the basal ganglia type of LDA. On the other hand, the 16 cases with IC-M2 times of more than 5 seconds always demonstrated a large LDA, of either the extensive subcortical type or the hemispheric type. This IC-M2 time is useful in anticipating the extent of infarction before a CT scan demonstrates LDA and in predicting a patient's prognosis in the acute stage. (J.P.N.).
Occlusal accommodation and mouthguards for prevention of orofacial trauma.
Geary, Julian Lindsay; Clifford, Thomas Joseph; Kinirons, Martin James
2009-01-01
The aim of this study was to investigate the effect of two types of occlusal accommodation on the arch separation in centric and eccentric arch positions and to assess the opposing tooth contacts in professionally made, thermoformed sports mouthguards. Maxillary and mandibular alginate impressions, a wax interocclusal record of centric occlusion together with maxillary/condylar face-bow registrations, were recorded clinically for 10 undergraduate dental students who are sports activist volunteers of the School of Medicine and Dentistry, Queen's University Belfast. Two ethylene vinyl acetate thermoformed maxillary mouthguards were made for each player (N = 20) using a standardised procedure. Ten mouthguards served both as the control (i.e. the non-accommodated) group and also the accommodated, occlusally 'imprinted' group. The other 10 mouthguards served as the accommodated, occlusally 'ground' group. Casts were articulated, each non-accommodated and accommodated mouthguard was seated and the extent of the interocclusal opening was recorded in all three arch relationships. The number of mouthguard and mandibular tooth contacts were also recorded in each position. The increased vertical occlusal dimension that was found in the presence of non-accommodated mouthguards equated to the full-sheet thickness of the material that was used to form the mouthguards. Only mouthguards accommodated by grinding retained high levels of occlusal contact in all arch relationships that were tested. Within the limitations of this study, the modification of the occlusal surface made by flat grinding reduced the arch separation in eccentric movements and increased the opposing tooth contacts in custom-made mouthguards. This may contribute to increased comfort, compliance and the protective effect of these appliances thus resulting in a reduction of injuries to the teeth, arches and soft tissues.
Occlusion-amblyopia following high dose oral levodopa combined with part time patching
Mihir Kothari
2014-01-01
Part time occlusion therapy is not reported to cause occlusion (reverse) amblyopia. However, when combined with high dose oral levodopa, an increase in the plasticity of the visual cortex can lead to occlusion amblyopia. In this case report, we describe a six year old child who developed occlusion amblyopia following part time patching combined with oral levodopa.
Occlusion-amblyopia following high dose oral levodopa combined with part time patching.
Kothari, Mihir
2014-12-01
Part time occlusion therapy is not reported to cause occlusion (reverse) amblyopia. However, when combined with high dose oral levodopa, an increase in the plasticity of the visual cortex can lead to occlusion amblyopia. In this case report, we describe a six year old child who developed occlusion amblyopia following part time patching combined with oral levodopa.
Shape tracking with occlusions via coarse-to-fine region-based sobolev descent
Yang, Yanchao
2015-05-01
We present a method to track the shape of an object from video. The method uses a joint shape and appearance model of the object, which is propagated to match shape and radiance in subsequent frames, determining object shape. Self-occlusions and dis-occlusions of the object from camera and object motion pose difficulties to joint shape and appearance models in tracking. They are unable to adapt to new shape and appearance information, leading to inaccurate shape detection. In this work, we model self-occlusions and dis-occlusions in a joint shape and appearance tracking framework. Self-occlusions and the warp to propagate the model are coupled, thus we formulate a joint optimization problem. We derive a coarse-to-fine optimization method, advantageous in tracking, that initially perturbs the model by coarse perturbations before transitioning to finer-scale perturbations seamlessly. This coarse-to-fine behavior is automatically induced by gradient descent on a novel infinite-dimensional Riemannian manifold that we introduce. The manifold consists of planar parameterized regions, and the metric that we introduce is a novel Sobolev metric. Experiments on video exhibiting occlusions/dis-occlusions, complex radiance and background show that occlusion/dis-occlusion modeling leads to superior shape accuracy. © 2014 IEEE.
Oda, Masafumi; Yoshino, Kenichi; Tanaka, Tatsurou; Shiiba, Shunji; Makihara, Eri; Miyamoto, Ikuya; Nogami, Shinnosuke; Kito, Shinji; Wakasugi-Sato, Nao; Matsumoto-Takeda, Shinobu; Nishimura, Shun; Murakami, Keita; Koga, Masahiro; Kawagishi, Shigenori; Yoshioka, Izumi; Masumi, Shin-Ichi; Kimura, Mitsutaka; Morimoto, Yasuhiro
2014-10-10
The purpose of this study was to use functional magnetic resonance imaging (fMRI) to quantify changes in brain activity during experimental occlusal interference. Fourteen healthy volunteers performed a rhythmical tapping occlusion task with experimental occlusal interference of the right molar tooth at 0 mm (no occlusion), 0.5 mm, and 0.75 mm. The blood-oxygen-level dependent (BOLD) signal was quantified using statistical parametric mapping and compared between rest periods and task periods. In tapping tasks with experimental occlusal interference of 0.75 mm or 0.5 mm, there was clear activation of the contralateral teeth-related primary sensory cortex and Brodmann's area 46. At 0 and 30 minutes after removal of the experimental occlusal interference, the activation clearly appeared in the bilateral teeth-related primary sensory cortices and Brodmann's area 46. At 60 minutes after the removal of the experimental occlusal interference, the activation of Brodmann's area 46 had disappeared, and only the bilateral teeth-related primary sensory cortices were active. The present results suggest that adjustments for experimental occlusal interference can be objectively evaluated using fMRI. We expect that this method of evaluating adjustments in occlusal interference, combined with fMRI and the tapping task, could be applied clinically in the future.
Carotid near-occlusion frequently has high peak systolic velocity on Doppler ultrasound
Energy Technology Data Exchange (ETDEWEB)
Khangure, Simon R.; Machnowska, Matylda; Fox, Allan J.; Hojjat, Seyed-Parsa; Aviv, Richard I. [Sunnybrook Health Sciences Centre, Department of Medical Imaging, Neuroradiology Division, Toronto, ON (Canada); University of Toronto, Department of Medical Imaging, Division of Neuroimaging, Toronto (Canada); Benhabib, Hadas [Sunnybrook Health Sciences Centre, Department of Medical Imaging, Neuroradiology Division, Toronto, ON (Canada); Groenlund, Christer [Umeaa University, Department of Radiation Sciences, Biomedical Engineering, Umeaa (Sweden); Herod, Wendy [Department of Surgery, Sunnybrook Health Sciences Centre, Toronto (Canada); Maggisano, Robert [Department of Surgery, Sunnybrook Health Sciences Centre, Toronto (Canada); University of Toronto, Division of Vascular Surgery, Department of Surgery, Toronto (Canada); Sjoeberg, Anders [Umeaa University, Department of Radiation Sciences, Biomedical Engineering, Umeaa (Sweden); Umeaa University, Department of Pharmacology and Clinical Neuroscience, Umeaa (Sweden); Wester, Per [Umeaa University, Department of Public Health and Clinical Medicine, Umeaa (Sweden); Karolinska Institutet Danderyds Hospital, Department of Clinical Sciences, Stockholm (Sweden); Hopyan, Julia [University of Toronto, Division of Neurology, Department of Medicine, Toronto (Canada); Johansson, Elias [Umeaa University, Department of Pharmacology and Clinical Neuroscience, Umeaa (Sweden); Umeaa University, Department of Public Health and Clinical Medicine, Umeaa (Sweden)
2018-01-15
Carotid near-occlusion is a tight atherosclerotic stenosis of the internal carotid artery (ICA) resulting in decrease in diameter of the vessel lumen distal to the stenosis. Near-occlusions can be classified as with or without full collapse, and may have high peak systolic velocity (PSV) across the stenosis, mimicking conventional > 50% carotid artery stenosis. We aimed to determine how frequently near-occlusions have high PSV in the stenosis and determine how accurately carotid Doppler ultrasound can distinguish high-velocity near-occlusion from conventional stenosis. Included patients had near-occlusion or conventional stenosis with carotid ultrasound and CT angiogram (CTA) performed within 30 days of each other. CTA examinations were analyzed by two blinded expert readers. Velocities in the internal and common carotid arteries were recorded. Mean velocity, pulsatility index, and ratios were calculated, giving 12 Doppler parameters for analysis. Of 136 patients, 82 had conventional stenosis and 54 had near-occlusion on CTA. Of near-occlusions, 40 (74%) had high PSV (≥ 125 cm/s) across the stenosis. Ten Doppler parameters significantly differed between conventional stenosis and high-velocity near-occlusion groups. However, no parameter was highly sensitive and specific to separate the groups. Near-occlusions frequently have high PSV across the stenosis, particularly those without full collapse. Carotid Doppler ultrasound does not seem able to distinguish conventional stenosis from high-velocity near-occlusion. These findings question the use of ultrasound alone for preoperative imaging evaluation. (orig.)
Object tracking by occlusion detection via structured sparse learning
Zhang, Tianzhu; Ghanem, Bernard; Xu, Changsheng; Ahuja, Narendra
2013-01-01
occlusion through structured sparse learning. We test our tracker on challenging benchmark sequences, such as sports videos, which involve heavy occlusion, drastic illumination changes, and large pose variations. Experimental results show that our tracker
Robust 3D Face Recognition in the Presence of Realistic Occlusions
Alyuz, Nese; Gökberk, B.; Spreeuwers, Lieuwe Jan; Veldhuis, Raymond N.J.; Akarun, Lale
2012-01-01
Facial occlusions pose significant problems for automatic face recognition systems. In this work, we propose a novel occlusion-resistant three-dimensional (3D) facial identification system. We show that, under extreme occlusions due to hair, hands, and eyeglasses, typical 3D face recognition systems
Discordant relationship between Essure microinsert position and tubal occlusion.
Hou, Melody Y
2016-07-27
Hysteroscopic sterilisation with Essure requires confirmation of tubal occlusion by hysterosalpingogram or microinsert position by transvaginal sonography 3 months after placement before women can rely on the method for pregnancy prevention. A 39-year-old woman underwent hysteroscopic sterilisation via Essure, with successful bilateral tubal occlusion documented on hysterosalpingogram. She had a subsequent unintended pregnancy and termination, and presented with persistent pelvic pain and other non-specific symptoms. She underwent a laparoscopic-assisted vaginal hysterectomy with bilateral salpingectomy, with complete resolution of her symptoms. Pathological evaluation demonstrated a perforated Essure microinsert and ipsilateral tubal occlusion, and a correctly placed Essure microinsert with ipsilateral tubal patency. Clinicians should be cautious about the assumption that correctly placed microinserts based on ultrasonography, hysterosalpingogram or laparoscopic evaluation assures occlusion success. 2016 BMJ Publishing Group Ltd.
Adaptive Self-Occlusion Behavior Recognition Based on pLSA
Directory of Open Access Journals (Sweden)
Hong-bin Tu
2013-01-01
Full Text Available Human action recognition is an important area of human action recognition research. Focusing on the problem of self-occlusion in the field of human action recognition, a new adaptive occlusion state behavior recognition approach was presented based on Markov random field and probabilistic Latent Semantic Analysis (pLSA. Firstly, the Markov random field was used to represent the occlusion relationship between human body parts in terms an occlusion state variable by phase space obtained. Then, we proposed a hierarchical area variety model. Finally, we use the topic model of pLSA to recognize the human behavior. Experiments were performed on the KTH, Weizmann, and Humaneva dataset to test and evaluate the proposed method. The compared experiment results showed that what the proposed method can achieve was more effective than the compared methods.
Hairy Slices: Evaluating the Perceptual Effectiveness of Cutting Plane Glyphs for 3D Vector Fields.
Stevens, Andrew H; Butkiewicz, Thomas; Ware, Colin
2017-01-01
Three-dimensional vector fields are common datasets throughout the sciences. Visualizing these fields is inherently difficult due to issues such as visual clutter and self-occlusion. Cutting planes are often used to overcome these issues by presenting more manageable slices of data. The existing literature provides many techniques for visualizing the flow through these cutting planes; however, there is a lack of empirical studies focused on the underlying perceptual cues that make popular techniques successful. This paper presents a quantitative human factors study that evaluates static monoscopic depth and orientation cues in the context of cutting plane glyph designs for exploring and analyzing 3D flow fields. The goal of the study was to ascertain the relative effectiveness of various techniques for portraying the direction of flow through a cutting plane at a given point, and to identify the visual cues and combinations of cues involved, and how they contribute to accurate performance. It was found that increasing the dimensionality of line-based glyphs into tubular structures enhances their ability to convey orientation through shading, and that increasing their diameter intensifies this effect. These tube-based glyphs were also less sensitive to visual clutter issues at higher densities. Adding shadows to lines was also found to increase perception of flow direction. Implications of the experimental results are discussed and extrapolated into a number of guidelines for designing more perceptually effective glyphs for 3D vector field visualizations.
New focal plane detector system for the broad range spectrometer
International Nuclear Information System (INIS)
Sjoreen, T.P.
1984-01-01
A focal plane detector system consisting of a vertical drift chamber, parallel plate avalanche counters, and an ionization chamber with segmented anodes has been installed in the Broad Range Spectrometer at the Holifield Facility at Oak Ridge. The system, which has been designed for use with light-heavy ions with energies ranging from 10 to 25 MeV/amu, has a position resolution of approx. 0.1 mm, a scattering angle resolution of approx. 3 mrad, and a mass resolution of approx. 1/60
International Nuclear Information System (INIS)
Yurtsever, U.
1988-01-01
It is well known that when two precisely plane-symmetric gravitational waves propagating in an otherwise flat background collide, they focus each other so strongly as to produce a curvature singularity. This paper is the first of several devoted to almost-plane gravitational waves and their collisions. Such waves are more realistic than plane waves in having a finite but very large transverse size. In this paper we review some crucial features of the well-known exact solutions for colliding plane waves and we argue that one of these features, the breakdown of ''local inextendibility'' can be regarded as nongeneric. We then introduce a new framework for analyzing general colliding plane-wave spacetimes; we give an alternative proof of a theorem due to Tipler implying the existence of singularities in all generic colliding plane-wave solutions; and we discuss the fact that the recently constructed Chandrasekhar-Xanthopoulos colliding plane-wave solutions are not strictly plane symmetric and thus do not satisfy the conditions and the conclusion of Tipler's theorem
Crack Front Segmentation and Facet Coarsening in Mixed-Mode Fracture
Chen, Chih-Hung; Cambonie, Tristan; Lazarus, Veronique; Nicoli, Matteo; Pons, Antonio J.; Karma, Alain
2015-12-01
A planar crack generically segments into an array of "daughter cracks" shaped as tilted facets when loaded with both a tensile stress normal to the crack plane (mode I) and a shear stress parallel to the crack front (mode III). We investigate facet propagation and coarsening using in situ microscopy observations of fracture surfaces at different stages of quasistatic mixed-mode crack propagation and phase-field simulations. The results demonstrate that the bifurcation from propagating a planar to segmented crack front is strongly subcritical, reconciling previous theoretical predictions of linear stability analysis with experimental observations. They further show that facet coarsening is a self-similar process driven by a spatial period-doubling instability of facet arrays.
In-plane and cross-plane thermal conductivities of molybdenum disulfide
International Nuclear Information System (INIS)
Ding, Zhiwei; Pei, Qing-Xiang; Zhang, Yong-Wei; Jiang, Jin-Wu
2015-01-01
We investigate the in-plane and cross-plane thermal conductivities of molybdenum disulfide (MoS 2 ) using non-equilibrium molecular dynamics simulations. We find that the in-plane thermal conductivity of monolayer MoS 2 is about 19.76 W mK −1 . Interestingly, the in-plane thermal conductivity of multilayer MoS 2 is insensitive to the number of layers, which is in strong contrast to the in-plane thermal conductivity of graphene where the interlayer interaction strongly affects the in-plane thermal conductivity. This layer number insensitivity is attributable to the finite energy gap in the phonon spectrum of MoS 2 , which makes the phonon–phonon scattering channel almost unchanged with increasing layer number. For the cross-plane thermal transport, we find that the cross-plane thermal conductivity of multilayer MoS 2 can be effectively tuned by applying cross-plane strain. More specifically, a 10% cross-plane compressive strain can enhance the thermal conductivity by a factor of 10, while a 5% cross-plane tensile strain can reduce the thermal conductivity by 90%. Our findings are important for thermal management in MoS 2 based nanodevices and for thermoelectric applications of MoS 2 . (paper)
Occlusion-amblyopia following high dose oral levodopa combined with part time patching
Directory of Open Access Journals (Sweden)
Mihir Kothari
2014-01-01
Full Text Available Part time occlusion therapy is not reported to cause occlusion (reverse amblyopia. However, when combined with high dose oral levodopa, an increase in the plasticity of the visual cortex can lead to occlusion amblyopia. In this case report, we describe a six year old child who developed occlusion amblyopia following part time patching combined with oral levodopa.
Improving prediction of recanalization in acute large-vessel occlusive stroke.
Vanacker, P; Lambrou, D; Eskandari, A; Maeder, P; Meuli, R; Ntaios, G; Michel, P
2014-06-01
Recanalization in acute ischemic stroke with large-vessel occlusion is a potent indicator of good clinical outcome. To identify easily available clinical and radiologic variables predicting recanalization at various occlusion sites. All consecutive, acute stroke patients from the Acute STroke Registry and Analysis of Lausanne (2003-2011) who had a large-vessel occlusion on computed tomographic angiography (CTA) (< 12 h) were included. Recanalization status was assessed at 24 h (range: 12-48 h) with CTA, magnetic resonance angiography, or ultrasonography. Complete and partial recanalization (corresponding to the modified Treatment in Cerebral Ischemia scale 2-3) were grouped together. Patients were categorized according to occlusion site and treatment modality. Among 439 patients, 51% (224) showed complete or partial recanalization. In multivariate analysis, recanalization of any occlusion site was most strongly associated with endovascular treatment, including bridging therapy (odds ratio [OR] 7.1, 95% confidence interval [CI] 2.2-23.2), and less so with intravenous thrombolysis (OR 1.6, 95% CI 1.0-2.6) and recanalization treatments performed beyond guidelines (OR 2.6, 95% CI 1.2-5.7). Clot location (large vs. intermediate) and tandem pathology (the combination of intracranial occlusion and symptomatic extracranial stenosis) were other variables discriminating between recanalizers and non-recanalizers. For patients with intracranial occlusions, the variables significantly associated with recanalization after 24 h were: baseline National Institutes of Health Stroke Scale (NIHSS) (OR 1.04, 95% CI 1.02-1.1), Alberta Stroke Program Early CT Score (ASPECTS) on initial computed tomography (OR 1.2, 95% CI 1.1-1.3), and an altered level of consciousness (OR 0.2, 95% CI 0.1-0.5). Acute endovascular treatment is the single most important factor promoting recanalization in acute ischemic stroke. The presence of extracranial vessel stenosis or occlusion decreases
Bonmati, Ester; Hu, Yipeng; Gibson, Eli; Uribarri, Laura; Keane, Geri; Gurusami, Kurinchi; Davidson, Brian; Pereira, Stephen P; Clarkson, Matthew J; Barratt, Dean C
2018-06-01
Navigation of endoscopic ultrasound (EUS)-guided procedures of the upper gastrointestinal (GI) system can be technically challenging due to the small fields-of-view of ultrasound and optical devices, as well as the anatomical variability and limited number of orienting landmarks during navigation. Co-registration of an EUS device and a pre-procedure 3D image can enhance the ability to navigate. However, the fidelity of this contextual information depends on the accuracy of registration. The purpose of this study was to develop and test the feasibility of a simulation-based planning method for pre-selecting patient-specific EUS-visible anatomical landmark locations to maximise the accuracy and robustness of a feature-based multimodality registration method. A registration approach was adopted in which landmarks are registered to anatomical structures segmented from the pre-procedure volume. The predicted target registration errors (TREs) of EUS-CT registration were estimated using simulated visible anatomical landmarks and a Monte Carlo simulation of landmark localisation error. The optimal planes were selected based on the 90th percentile of TREs, which provide a robust and more accurate EUS-CT registration initialisation. The method was evaluated by comparing the accuracy and robustness of registrations initialised using optimised planes versus non-optimised planes using manually segmented CT images and simulated ([Formula: see text]) or retrospective clinical ([Formula: see text]) EUS landmarks. The results show a lower 90th percentile TRE when registration is initialised using the optimised planes compared with a non-optimised initialisation approach (p value [Formula: see text]). The proposed simulation-based method to find optimised EUS planes and landmarks for EUS-guided procedures may have the potential to improve registration accuracy. Further work will investigate applying the technique in a clinical setting.
Krucoff, M W; Parente, A R; Bottner, R K; Renzi, R H; Stark, K S; Shugoll, R A; Ahmed, S W; DeMichele, J; Stroming, S L; Green, C E
1988-06-01
Multilead ST-segment recordings taken during percutaneous transluminal coronary angioplasty (PTCA) could function as an individualized noninvasive template or "fingerprint," useful in evaluating transient ischemic episodes after leaving the catheterization laboratory. To evaluate the reproducibility of such ST-segment patterns over time, these changes were analyzed in patients grouped according to the time between occlusion and reocclusion. For the patients in group 1, the study required comparing their "fingerprints" in repeat balloon inflation during PTCA (reocclusion in less than 1 hour), for those in group 2, comparing ST "fingerprints" during PTCA with ST changes during spontaneous early myocardial infarction (reocclusion in 24 hours) and in group 3, comparing ST "fingerprints" with ST changes during repeat PTCA for restenosis greater than 1 month after the initial PTCA. The ST "fingerprints" among the 20 patients in group 1 were identical in 14 cases (70%) and clearly related in another 4 (20%). Of the 23 patients in group 2, 12 (52%) had the same and 8 (35%) had related patterns. Of 19 patients in group 3, 8 (42% had the same pattern and 8 (42%) had related patterns. Thus, ST fingerprints were the same or clearly related with reocclusion in the same patient from less than 1 hour to greater than 1 month after initial occlusion in 87% of patients overall, in 90% in less than 1 hour, in 87% in less than 24 hours and in 84% greater than 1 month later. Multilead pattern ST-segment "fingerprints" may serve as a noninvasive marker for detecting site-specific reocclusion.
Hypothalamic digoxin, hemispheric chemical dominance, and mesenteric artery occlusion.
Kurup, Ravi Kumar; Kurup, Paramesware Achutha
2003-12-01
The role of the isoprenoid pathway in vascular thrombosis, especially mesenteric artery occlusion and its relation to hemispheric dominance, was assessed in this study. The following parameters were measured in patients with mesenteric artery occlusion and individuals with right hemispheric, left hemispheric, and bihemispheric dominance: (1) plasma HMG CoA reductase, digoxin, dolichol, ubiquinone, and magnesium levels; (2) tryptophan/tyrosine catabolic patterns; (3) free radical metabolism; (4) glycoconjugate metabolism; and (5) membrane composition. In patients with mesenteric artery occlusion there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels, low ubiquinone, and elevated free radical levels. The RBC membrane Na(+)-K+ ATPase activity and serum magnesium were decreased. There was also an increase in tryptophan catabolites and reduction in tyrosine catabolites in the serum. There was an increase in cholesterol:phospholipid ratio and a reduction in glycoconjugate level of RBC membrane in these patients. The biochemical patterns obtained in mesenteric artery occlusion is similar to those obtained in left-handed/right hemispheric dominant individuals by the dichotic listening test. But all the patients with mesenteric artery occlusion were right-handed/left hemispheric dominant by the dichotic listening test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. Mesenteric artery occlusion occurs in right hemispheric chemically dominant individuals and is a reflection of altered brain function. Hemispheric chemical dominance may thus control the risk for developing vascular thrombosis in individuals.
Increased carboxyhemoglobin level during liver resection with inflow occlusion.
Godai, Kohei; Hasegawa-Moriyama, Maiko; Kuniyoshi, Tamotsu; Matsunaga, Akira; Kanmura, Yuichi
2013-04-01
Controlling stress responses associated with ischemic changes due to bleeding and ischemia/reperfusion injury is essential for anesthetic management. Endogenous carboxyhemoglobin (COHb) is produced in the oxidative degradation of heme proteins by the stress-response enzyme heme oxygenase. Although the COHb level is elevated in critically ill patients, changes in endogenous COHb during anesthesia have not been well investigated. Therefore, we evaluated changes in endogenous COHb levels in patients undergoing liver resections with inflow occlusion. Levels of COHb were significantly increased after the Pringle maneuver. The inflow occlusion time in patients with increased COHb after the Pringle maneuver (∆COHb > 0.3 %) was significantly longer than in patients without increased COHb (∆COHb < 0.3 %) (P = 0.01). In addition, COHb changes were correlated with inflow occlusion time (P = 0.005, R(2) = 0.21). Neither total blood loss, transfusion volume of packed red blood cells, operation time, nor anesthetic time differed between patients with and without increased COHb. The results indicated that endogenous COHb levels were increased by inflow occlusion in patients undergoing liver resections, which suggests that changes in COHb may correlate with hepatic ischemia/reperfusion injury induced by inflow occlusion.
Globally Optimal Segmentation of Permanent-Magnet Systems
DEFF Research Database (Denmark)
Insinga, Andrea Roberto; Bjørk, Rasmus; Smith, Anders
2016-01-01
Permanent-magnet systems are widely used for generation of magnetic fields with specific properties. The reciprocity theorem, an energy-equivalence principle in magnetostatics, can be employed to calculate the optimal remanent flux density of the permanent-magnet system, given any objective...... remains unsolved. We show that the problem of optimal segmentation of a two-dimensional permanent-magnet assembly with respect to a linear objective functional can be reduced to the problem of piecewise linear approximation of a plane curve by perimeter maximization. Once the problem has been cast...
Wilbrink, H.A.
1982-01-01
In this paper we develop a theory for nearaffine planes analogous to the theory of ordinary affine translation planes. In a subsequent paper we shall use this theory to give a characterization of a certain class of Minkowski planes.
Sickle cell vaso-occlusion in an animal model
International Nuclear Information System (INIS)
Kurantsin-Mills, J.; Jacobs, H.M.; Lessin, L.S.
1987-01-01
Sickle cell disease is clinically characterized with vaso-occlusive painful crisis which is pleomorphic in terms of frequency of occurrence. The intracellular polymerization of deoxygenated hemoglobin S increases the internal viscosity of the sickle cells exponentially, concurrent with binding of hemoglobin S to the membrane and discocyte-drepanocyte transformation. As a result, the red cells in sickle cell disease are heterogenous with cells of varying density and mean corpuscular hemoglobin concentration which alter the rheological features of the blood in the microcirculation. The cellular, physiological, biochemical and rheological factors that contribute to the vaso-occlusive events are not completely understood. Nonetheless, recent clinical studies have demonstrated that a certain fraction of the dense cells disappear during sickle cell painful crisis. In an attempt to elucidate some of the cellular and rheological factors involved in the initiation of vaso-occlusion, the authors have employed intravital videomicroscopy and radionuclide imaging of indium-III labeled sickle cells to determine the dynamics and sites of vaso-occlusion using the rat exchanged-transfused with sickle (HbSS) erythrocytes as a model
[Occlusion and posture: is there evidence of correlation?].
Michelotti, A; Manzo, P; Farella, M; Martina, R
1999-11-01
The observation that the masticatory system and the postural body regulating system are anatomically and functionally related, has led to postulate several hypotheses of correlation between occlusal and postural disturbances. In the last decade, these arguments have gained a great social impact, also because they have been broadly spread by the mass-media. As a consequence, there has been a growing number of patients seeking concomitant occlusal and postural treatments. The aim of this study was to review critically the current evidence of correlation between the two systems; this in order to address clinical issues for the management of patients. Methodology of the studies reviewed has been evaluated according to the criteria suggested by Storey and Rugh 20 rif. Although there are some evidences of correlation between occlusion and posture, this appears limited to the cranio-cervical tract of the column and tends to disappear when descending in cranio-caudal direction. On the basis of this review of the literature, it's not advisable to treat postural imbalance by means of occlusal treatment or vice versa, particularly if the therapeutic modalities are irreversible.
Automatic decomposition of a complex hologram based on the virtual diffraction plane framework
International Nuclear Information System (INIS)
Jiao, A S M; Tsang, P W M; Lam, Y K; Poon, T-C; Liu, J-P; Lee, C-C
2014-01-01
Holography is a technique for capturing the hologram of a three-dimensional scene. In many applications, it is often pertinent to retain specific items of interest in the hologram, rather than retaining the full information, which may cause distraction in the analytical process that follows. For a real optical image that is captured with a camera or scanner, this process can be realized by applying image segmentation algorithms to decompose an image into its constituent entities. However, because it is different from an optical image, classic image segmentation methods cannot be applied directly to a hologram, as each pixel in the hologram carries holistic, rather than local, information of the object scene. In this paper, we propose a method to perform automatic decomposition of a complex hologram based on a recently proposed technique called the virtual diffraction plane (VDP) framework. Briefly, a complex hologram is back-propagated to a hypothetical plane known as the VDP. Next, the image on the VDP is automatically decomposed, through the use of the segmentation on the magnitude of the VDP image, into multiple sub-VDP images, each representing the diffracted waves of an isolated entity in the scene. Finally, each sub-VDP image is reverted back to a hologram. As such, a complex hologram can be decomposed into a plurality of subholograms, each representing a discrete object in the scene. We have demonstrated the successful performance of our proposed method by decomposing a complex hologram that is captured through the optical scanning holography (OSH) technique. (papers)
Computer modeling of occlusal surfaces of posterior teeth with the CICERO CAD/CAM system.
Olthoff, L W; Van Der Zel, J M; De Ruiter, W J; Vlaar, S T; Bosman, F
2000-08-01
Static and dynamic occlusal interference frequently needs to be corrected by selective grinding of the occlusal surface of conventional cast and ceramic-fused-to-metal restorations. CAD/CAM techniques allow control of the dimensional contours of these restorations. However, parameters responsible for the occlusal form need to be determined. In most articulators, these parameters are set as default values. Which technique is best for minimizing the introduction of occlusal interference in restorations has not been determined. This study investigated differences in crown structure of a crown designed in static occlusion (STA) with designs adapted for dynamic occlusal interferences. Therefore, values from an optoelectronic registration system (String-Condylocomp, KAVO), an occlusal generated path (OGP) technique and default settings (DEF) were used in the CICERO CAD/CAM system. Morphology of CON, DEF, and OGP crowns was compared with that of the STA crown with respect to differences in a buccolingual section and frequency of occlusal distances in an interocclusal range of 1 mm, measured from the occlusal surface of the crown. All crown types fulfilled the esthetic and morphologic criteria for restorations in clinical dentistry. Difference in the morphology of the OGP crown, compared with that of the STA crown, was greater than that for the CON and DEF crowns. These differences were seen especially in the distobuccal part of the occlusal surface; however, the number of occlusal contacts was considered sufficient to stabilize occlusion. Functional occlusion, adapted to dynamic occlusion in a CICERO crown for the first mandibular molar, can be obtained using data acquired with the String-Condylocomp registration system. The OGP technique was preferred to other techniques because of the simplicity of the technique for eliminating potential problems with opposing teeth during motion. However, this is achieved at the cost of fewer points of contact during occlusion than
A new user-assisted segmentation and tracking technique for an object-based video editing system
Yu, Hong Y.; Hong, Sung-Hoon; Lee, Mike M.; Choi, Jae-Gark
2004-03-01
This paper presents a semi-automatic segmentation method which can be used to generate video object plane (VOP) for object based coding scheme and multimedia authoring environment. Semi-automatic segmentation can be considered as a user-assisted segmentation technique. A user can initially mark objects of interest around the object boundaries and then the user-guided and selected objects are continuously separated from the unselected areas through time evolution in the image sequences. The proposed segmentation method consists of two processing steps: partially manual intra-frame segmentation and fully automatic inter-frame segmentation. The intra-frame segmentation incorporates user-assistance to define the meaningful complete visual object of interest to be segmentation and decides precise object boundary. The inter-frame segmentation involves boundary and region tracking to obtain temporal coherence of moving object based on the object boundary information of previous frame. The proposed method shows stable efficient results that could be suitable for many digital video applications such as multimedia contents authoring, content based coding and indexing. Based on these results, we have developed objects based video editing system with several convenient editing functions.
Directory of Open Access Journals (Sweden)
David Zhiwei Law
2014-01-01
Full Text Available A 52-year-old Chinese gentleman presented with right eye floaters and photopsia over one week. His visual acuities were 20/20 bilaterally. Posterior segment examination showed a right eye swollen optic disc and central retinal vein occlusion (CRVO associated with an area of subretinal hemorrhage adjacent to the optic disc. Fundus fluorescein (FA and indocyanine green angiographies (ICGA of the right eye did not demonstrate choroidal neovascularization (CNV, polypoidal choroidal vasculopathy (PCV, or retinal ischemia. Ultrasound B-scan revealed optic disc drusen (ODD. In view of good vision and absence of CNV, he was managed conservatively with spontaneous resolution after two months. Commonly, ODD may directly compress and mechanically rupture subretinal vessels at the optic disc, resulting in peripapillary subretinal hemorrhage, as was likely the case in our patient. Mechanical impairment of peripapillary circulation also results in retinal ischemia and may trigger the development of choroidal neovascularization (CNV and/or polypoidal choroidal vasculopathy (PCV, leading to subretinal haemorrhage. Compromise in central venous outflow with increased retinal central venous pressure from the direct mechanical effects of enlarging ODD results in central retinal vein occlusion (CRVO. Patients with subretinal hemorrhage and CRVO from ODD should be monitored closely for the development of potentially sight-threatening complications.
Zhang, Shujun; Su, Yanfei; Chen, Haisong
2017-08-01
To study the value of a retrograde flow sign and the collateral circulation on CT angiography (CTA) for the differential diagnosis of chronic total occlusion from subtotal occlusion of the femoropopliteal artery (FPA). 50 patients with obstruction of the FPA underwent CTA and digital subtraction angiography examinations of the lower limbs. The frequency of a retrograde flow sign and collateral circulation on CTA in chronic total and subtotal occlusion was noted and analyzed, with the results of digital subtraction angiography as a standard to judge total or subtotal occlusion. The decreasing CT value from the distal to proximal direction on CTA suggests the existence of retrograde flow. There were significant differences in the occurrence rates of a retrograde flow sign on CTA in the chronic total and subtotal obstruction groups (X 2 = 13.1, p collateral circulation sign (X 2 = 13.5, p collateral circulation sign to diagnose chronic total obstruction of the FPA had a sensitivity of 92.3% and specificity of 89.8%. The retrograde flow sign combined with a collateral circulation sign is of great clinical value for differentiation of chronic total stenosis from severe stenosis (subtotal occlusion) of the FPA. Advances in knowledge: A retrograde flow sign combined with a collateral circulation sign is of great clinical value to differentiate between chronic total stenosis and severe stenosis (subtotal occlusion) of the FPA.
International Nuclear Information System (INIS)
Varma, Amit H.; Malushte, Sanjeev R.; Sener, Kadir C.; Lai, Zhichao
2014-01-01
Steel-concrete (SC) composite walls being considered and used as an alternative to conventional reinforced concrete (RC) walls in safety-related nuclear facilities due to their construction economy and structural efficiency. However, there is a lack of standardized codes for SC structures, and design guidelines and approaches are still being developed. This paper presents the development and verification of: (a) mechanics based model, and (b) detailed nonlinear finite element model for predicting the behavior and failure of SC wall panels subjected to combinations of in-plane forces. The models are verified using existing test results, and the verified models are used to explore the behavior of SC walls subjected to combinations of in-plane forces and moments. The results from these investigations are used to develop an interaction surface in principle force (S p1 –S p2 ) space that can be used to design or check the adequacy of SC wall panels. The interaction surface is easy to develop since it consists of straight line segments connecting anchor points defined by the SC wall section strengths in axial tension, in-plane shear, and compression. Both models and the interaction surface (for design) developed in this paper are recommended for future work. However, in order to use these approaches, the SC wall section should be detailed with adequate shear connector and tie bar strength and spacing to prevent non-ductile failure modes
The pinwheel pupil discovery: exoplanet science & improved processing with segmented telescopes
Breckinridge, James Bernard
2018-01-01
In this paper, we show that by using a “pinwheel” architecture for the segmented primary mirror and curved supports for the secondary mirror, we can achieve a near uniform diffraction background in ground and space large telescope systems needed for high SNR exoplanet science. Also, the point spread function will be nearly rotationally symmetric, enabling improved digital image reconstruction. Large (>4-m) aperture space telescopes are needed to characterize terrestrial exoplanets by direct imaging coronagraphy. Launch vehicle volume constrains these apertures are segmented and deployed in space to form a large mirror aperture that is masked by the gaps between the hexagonal segments and the shadows of the secondary support system. These gaps and shadows over the pupil result in an image plane point spread function that has bright spikes, which may mask or obscure exoplanets.These telescope artifact mask faint exoplanets, making it necessary for the spacecraft to make a roll about the boresight and integrate again to make sure no planets are missed. This increases integration time, and requires expensive space-craft resources to do bore-sight roll.Currently the LUVOIR and HabEx studies have several significant efforts to develop special purpose A/O technology and to place complex absorbing apodizers over their Hex pupils to shape the unwanted diffracted light. These strong apodizers absorb light, decreasing system transmittance and reducing SNR. Implementing curved pupil obscurations will eliminate the need for the highly absorbing apodizers and thus result in higher SNR.Quantitative analysis of diffraction patterns that use the pinwheel architecture are compared to straight hex-segment edges with a straight-line secondary shadow mask to show a gain of over a factor of 100 by reducing the background. For the first-time astronomers are able to control and minimize image plane diffraction background “noise”. This technology will enable 10-m segmented
Driver, Brian E; Khalil, Ayesha; Henry, Timothy; Kazmi, Faraz; Adil, Amina; Smith, Stephen W
Precordial normal variant ST elevation (NV-STE), previously often called "early repolarization," may be difficult to differentiate from subtle ischemic STE due to left anterior descending (LAD) occlusion. We previously derived and validated a logistic regression formula that was far superior to STE alone for differentiating the two entities on the ECG. The tool uses R-wave amplitude in lead V4 (RAV4), ST elevation at 60 ms after the J-point in lead V3 (STE60V3) and the computerized Bazett-corrected QT interval (QTc-B). The 3-variable formula is: 1.196 x STE60V3 + 0.059 × QTc-B - 0.326 × RAV4 with a value ≥23.4 likely to be acute myocardial infarction (AMI). Adding QRS voltage in V2 (QRSV2) would improve the accuracy of the formula. 355 consecutive cases of proven LAD occlusion were reviewed, and those that were obvious ST elevation myocardial infarction were excluded. Exclusion was based on one straight or convex ST segment in V2-V6, 1 millimeter of summed inferior ST depression, any anterior ST depression, Q-waves, "terminal QRS distortion," or any ST elevation >5 mm. The NV-STE group comprised emergency department patients with chest pain who ruled out for AMI by serial troponins, had a cardiologist ECG read of "NV-STE," and had at least 1 mm of STE in V2 and V3. R-wave amplitude in lead V4 (RAV4), ST elevation at 60 ms after the J-point in lead V3 (STE60V3) and the computerized Bazett-corrected QT interval (QTc-B) had previously been measured in all ECGs; physicians blinded to outcome then measured QRSV2 in all ECGs. A 4-variable formula was derived to more accurately classify LAD occlusion vs. NV-STE and optimize area under the curve (AUC) and compared with the previous 3-variable formula. There were 143 subtle LAD occlusions and 171 NV-STE. A low QRSV2 added diagnostic utility. The derived 4-variable formula is: 0.052*QTc-B - 0.151*QRSV2 - 0.268*RV4 + 1.062*STE60V3. The 3-variable formula had an AUC of 0.9538 vs. 0.9686 for the 4-variable formula (p = 0
Branch retinal artery occlusion in Susac's syndrome
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Ricardo Evangelista Marrocos de Aragão
2015-02-01
Full Text Available Susac's syndrome is a rare disease attribuited to a microangiopathy involving the arterioles of the cochlea, retina and brain. Encefalopathy, hearing loss, and visual deficits are the hallmarks of the disease. Visual loss is due to multiple, recurrent branch arterial retinal occlusions. We report a case of a 20-year-old women with Susac syndrome presented with peripheral vestibular syndrome, hearing loss, ataxia, vertigo, and vision loss due occlusion of the retinal branch artery.
Pathophysiological aspects of sickle cell vaso-occlusion
International Nuclear Information System (INIS)
Nagel, R.L.
1987-01-01
This book contains over 30 selections. Some of the titles are: An Animal Model for Sickle Cell Vaso-Occlusion: A Study Using NMR and Technetium Imaging; Sickle-Cell Vaso-Occlusion in an Animal Model: Intravital Microscopy and Radionuclide Imaging of Selective Sequestration of Dense Cells; Magnetic Resonance Imaging, Percentage of Dense Cells, and Serum Prostanoids as Tools for Objective Assessment of Pain Crisis: A Preliminary Report; and Painful Crisis and Dense Echinocytes: Effects of Hydration and Vasodilators
Frictionless segmented mechanics for controlled space closure
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Ildeu Andrade Jr
Full Text Available ABSTRACT Extraction spaces may be needed to achieve specific orthodontic goals of positioning the dentition in harmony with the craniofacial complex. However, the fundamental reality that determines the occlusion final position is the control exerted by the orthodontist while closing the extraction spaces. A specific treatment objective may require the posterior teeth to remain in a constant position anteroposteriorly as well as vertically, while the anterior teeth occupy the entire extraction site. Another treatment objective may require the opposite, or any number of intentional alternatives of extraction site closure. The present case report describes a simple controlled segmented mechanic system that permitted definable and predictable force systems to be applied and allowed to predict the treatment outcome with confidence. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO in partial fulfillment of the requirements for Diplomate certification.
Image Based Solution to Occlusion Problem for Multiple Robots Navigation
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Taj Mohammad Khan
2012-04-01
Full Text Available In machine vision, occlusions problem is always a challenging issue in image based mapping and navigation tasks. This paper presents a multiple view vision based algorithm for the development of occlusion-free map of the indoor environment. The map is assumed to be utilized by the mobile robots within the workspace. It has wide range of applications, including mobile robot path planning and navigation, access control in restricted areas, and surveillance systems. We used wall mounted fixed camera system. After intensity adjustment and background subtraction of the synchronously captured images, the image registration was performed. We applied our algorithm on the registered images to resolve the occlusion problem. This technique works well even in the existence of total occlusion for a longer period.
Microfluidics for investigating vaso-occlusions in sickle cell disease.
Horton, Renita E
2017-07-01
SCD stems from amutation in the beta globin gene. Upon deoxygenation, hemoglobin polymerizes and triggers RBC remodeling. This phenomenon is central to SCD pathogenesis as individuals suffering from the disease are plagued by painful vaso-occlusive crises episodes. These episodes are the result of a combination of processes including inflammation, thrombosis, and blood cell adhesion to the vascular wall which leads to blockages within the vasculature termed vaso-occlusions. Vaso-occlusive episodes deprive tissues of oxygen and are a major contributor to SCD-related complications; unfortunately, the complex mechanisms that contribute to vaso-occlusions are not well understood. Vaso-occlusions can occur in post-capillary venules; hence, the microvasculature is a prime target for SCD therapies. Traditional in vitro systems poorly recapitulate architectural and dynamic flow properties of in vivo systems. However, microfluidic devices can capture features of the native vasculature such as cellular composition, flow, geometry, and ECM presentation. This review, although not comprehensive, highlights microfluidic approaches that aim to improve our current understanding of the pathophysiological mechanisms surrounding SCD. Microfluidic platforms can aid in identifying factors that may contribute to disease severity and can serve as suitable test beds for novel treatment strategies which may improve patient outcomes. © 2017 John Wiley & Sons Ltd.
Occlusal factors are not related to self-reported bruxism.
Manfredini, Daniele; Visscher, Corine M; Guarda-Nardini, Luca; Lobbezoo, Frank
2012-01-01
To estimate the contribution of various occlusal features of the natural dentition that may identify self-reported bruxers compared to nonbruxers. Two age- and sex-matched groups of self-reported bruxers (n = 67) and self-reported nonbruxers (n = 75) took part in the study. For each patient, the following occlusal features were clinically assessed: retruded contact position (RCP) to intercuspal contact position (ICP) slide length ( 4 mm, a deep bite), horizontal overlap (> 4 mm was considered a large horizontal overlap), incisor dental midline discrepancy (bruxism (dependent variable). Accuracy values to predict self-reported bruxism were unacceptable for all occlusal variables. The only variable remaining in the final regression model was laterotrusive interferences (P = .030). The percentage of explained variance for bruxism by the final multiple regression model was 4.6%. This model including only one occlusal factor showed low positive (58.1%) and negative predictive values (59.7%), thus showing a poor accuracy to predict the presence of self-reported bruxism (59.2%). This investigation suggested that the contribution of occlusion to the differentiation between bruxers and nonbruxers is negligible. This finding supports theories that advocate a much diminished role for peripheral anatomical-structural factors in the pathogenesis of bruxism.
Comparison of three facebow/semi-adjustable articulator systems for planning orthognathic surgery.
O'Malley, A M; Milosevic, A
2000-06-01
Our aim was to measure the steepness of the occlusal plane produced by three different semi-adjustable articulators: the Dentatus Type ARL, Denar MkII, and the Whipmix Quickmount 8800, and to assess the influence of possible systematic errors in positioning of study casts on articulators that are used to plan orthognathic surgery. Twenty patients (10 skeletal class II, and 10 skeletal class III) who were having pre-surgical orthodontics at Liverpool University Dental Hospital were studied. The measurement of the steepness of the occlusal plane was taken as the angle between the facebow bite-fork and the horizontal arm of the articulator. This was compared with the angle of the maxillary occlusal plane to the Frankfort plane as measured on lateral cephalometry (the gold standard). The Whipmix was closest to the gold standard as it flattened the occlusal plane by only 2 degrees (P<0.05). The results of the Denar and Dentatus differed significantly from those of the cephalogram as they flattened the occlusal plane by 5 degrees and 6. 5 degrees (P<0.01), respectively. Clinicians are encouraged to verify the steepness of the occlusal plane on mounted study casts before the technician makes the model. Copyright 2000 The British Association of Oral and Maxillofacial Surgeons.
Oda, Masafumi; Yoshino, Kenichi; Tanaka, Tatsurou; Shiiba, Shunji; Makihara, Eri; Miyamoto, Ikuya; Nogami, Shinnosuke; Kito, Shinji; Wakasugi-Sato, Nao; Matsumoto-Takeda, Shinobu; Nishimura, Shun; Murakami, Keita; Koga, Masahiro; Kawagishi, Shigenori; Yoshioka, Izumi
2014-01-01
Background The purpose of this study was to use functional magnetic resonance imaging (fMRI) to quantify changes in brain activity during experimental occlusal interference. Methods Fourteen healthy volunteers performed a rhythmical tapping occlusion task with experimental occlusal interference of the right molar tooth at 0 mm (no occlusion), 0.5 mm, and 0.75 mm. The blood-oxygen-level dependent (BOLD) signal was quantified using statistical parametric mapping and compared between rest period...
de Castro-Filho, Antonio; Lamas, Edgar Stroppa; Meneguz-Moreno, Rafael A; Staico, Rodolfo; Siqueira, Dimytri; Costa, Ricardo A; Braga, Sergio N; Costa, J Ribamar; Chamié, Daniel; Abizaid, Alexandre
2017-06-01
The present study examined the association between Multicenter CTO Registry in Japan (J-CTO) score in predicting failure of percutaneous coronary intervention (PCI) correlating with the estimated duration of chronic total occlusion (CTO). The J-CTO score does not incorporate estimated duration of the occlusion. This was an observational retrospective study that involved all consecutive procedures performed at a single tertiary-care cardiology center between January 2009 and December 2014. A total of 174 patients, median age 59.5 years (interquartile range [IQR], 53-65 years), undergoing CTO-PCI were included. The median estimated occlusion duration was 7.5 months (IQR, 4.0-12.0 months). The lesions were classified as easy (score = 0), intermediate (score = 1), difficult (score = 2), and very difficult (score ≥3) in 51.1%, 33.9%, 9.2%, and 5.7% of the patients, respectively. Failure rate significantly increased with higher J-CTO score (7.9%, 20.3%, 50.0%, and 70.0% in groups with J-CTO scores of 0, 1, 2, and ≥3, respectively; PJ-CTO score predicted failure of CTO-PCI independently of the estimated occlusion duration (P=.24). Areas under receiver-operating characteristic curves were computed and it was observed that for each occlusion time period, the discriminatory capacity of the J-CTO score in predicting CTO-PCI failure was good, with a C-statistic >0.70. The estimated duration of occlusion had no influence on the J-CTO score performance in predicting failure of PCI in CTO lesions. The probability of failure was mainly determined by grade of lesion complexity.
A novel method to determine perineal artery occlusion among male bicyclists.
Parthiban, Sujeeth; Hotaling, James M; Kathrins, Martin; Baftiri, Amit P; Freels, Sally; Niederberger, Craig S
2015-01-01
Background. Perineal pressure due to bicycle riding has been associated with erectile dysfunction. We developed a novel method to measure the occlusive force exerted over the perineal arteries and determined perineal artery occlusion by a variety of seat designs. Methods. Doppler ultrasonography facilitated perineal artery localization and determination of the force required for perineal artery occlusion in 20 healthy men. Flexiforce(®) sensors were affixed over the proximal and distal aspects of the perineal arteries bilaterally. Individuals completed bicycle rides in the road- and stationary-settings with six distinct seat designs, including those with and without an anterior "nose." Results. The occlusion time proportion of the total ride time was calculated for each trial. The overall occlusion time proportion was 0.59 (95% CI [0.45-0.73]) across all seats and settings. The "no-nose" bicycle seat and the stationary-setting demonstrated significantly lower occlusion proportion times than the traditional nose bicycle seat and road-setting, respectively. However, all bicycle seats yielded an occlusion time proportion of 0.41 or greater. Discussion. Our method of real-time, non-invasive force measurement localized to the perineal arteries may be used to validate future bicycle seat design. It also underscores the significant risk of perineal artery insufficiency in men who are avid bicyclists. This risk may be minimized by using newer "no-nose" bicycle seats.
Comparisons of Hysterosalpingography and Laparoscopy Results in the Diagnosis of Tubal Occlusion
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Rafet Duraker
2011-03-01
Full Text Available Objective: The compliance rate between the hysterosalpingography (HSG and laparoscopy (L/S results in patients who diagnosed tubal occlusion on the HSG was investigated. Also, the incidence of endometriosis was evaluated in the study population. Material and Methods: Medical records of 139 women who were underwent L/S for the investigation of the tubal occlusion were reviewed retrospectively. The concordance rate between the HSG and L/S was investigated. The incidence of endometriosis in patients with no tubal pathology was compared with patients with unilaterally and bilaterally tubal occlusion. Results: Mean age of the women was 31.8±5.7years, mean BMI was measured as 24.6±4.6 kg/m2, and gravida 0 (0-5, mean infertility period was 30.7±3.7 months. Tubal occlusion was confirmed after the L/S in 38.8% of the patients (n=38 who has unilaterally tubal occlusion on the HSG. However, 58.8% (n=20 of the patients who were diagnosed as bilaterally tubal occlusion on the HSG was confirmed with the L/S. The misdiagnosis rate of the HSG was significantly high in women with unilaterally tubal occlusions compared with bilaterally tubal occlusions [(respectively, 61.2%, 51.2% (p: 0.001]. Endometriosis was observed in 28.4% of the patients who had patent tubes and in 13.9% of the patients in the unilaterally tubal occlusion group and and in 22.7% of the patients in the bilaterally tubal occlusion group. But the difference was not statistically significant when groups were compared according to the rate of endometriosis (p=0.24. Conclusion: HSG is the first step diagnostic test for the assessment of the fallopian tubes. Although L/S is more invasive technique than HSG, L/S with chromopertubation is the gold standard test for identifying periadnexal adhesive disease and endometriosis.
Endobronchial Occlusion Stent: A Preliminary Experimental Study
Energy Technology Data Exchange (ETDEWEB)
Choi, Yo Won; Jeong, Woo Kyoung; Lee, Seoung Hoon; Heo, Jeong Nam; Jeon, Seok Chol [Hanyang University College of Medicine, Seoul (Korea, Republic of); Ko, Gi Young; Song, Ho Young [University of Ulsan College of Medicine, Ulsan (Korea, Republic of)
2010-04-15
To evaluate the safety and the technical feasibility of the use of an endobronchial occlusion stent and to get preliminary data for the development of the optimal material required for endobronchial occlusions. A commercialized, self-expandable tracheobronchial stent was modified; one half had a polyurethane cover with an occluded end and the other half was uncovered with a flaring configuration. The occluded end was placed such that it would face the distal lung. Under fluoroscopic guidance, seven stents were placed at the lower lobar bronchus in 6 mini-pigs. The bronchial obstruction was examined immediately after stent placement. Chest radiographs were taken at days 1, 7, 14, and 28 after stent placement and the removed airways from two, two, one, and one mini-pigs sacrificed on corresponding days were examined for the maintenance of bronchial obstruction. Stents were successfully placed and induced the immediate bronchial obstruction in all mini-pigs. Five of seven airways with occlusion stents maintained an obstruction until the mini-pigs were sacrificed. Proximal stent migration occurred in two mini-pigs (29%), and pulmonary consolidations were observed distal to four of the stents (57%). The placement of an endobronchial occlusion stent and the obstruction of targeted bronchi seem to be feasible, but an add-on check valve should be considered to prevent stent migration and obstructive pneumonia
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Koskinen, Suvi Maaria [University of Helsinki, Clinicum, Department of Neurosciences (Finland); University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, Helsinki (Finland); Silvennoinen, Heli; Valanne, Leena [University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, Helsinki (Finland); Ijaes, Petra; Nuotio, Krista; Lindsberg, Perttu J. [University of Helsinki and Helsinki University Hospital, Neurology, Clinical Neurosciences, Helsinki (Finland); University of Helsinki, Molecular Neurology, Research Programs Unit, Helsinki (Finland); Soinne, Lauri [University of Helsinki and Helsinki University Hospital, Neurology, Clinical Neurosciences, Helsinki (Finland)
2017-04-15
Near-occlusion of the internal carotid artery (ICA) is a significant luminal diameter (LD) reduction beyond a tight atherosclerotic carotid stenosis (CS). Recognition of even subtle near-occlusions is essential to prevent underestimation of the stenosis degree. Our goal was to investigate the prevalence of near-occlusion among CS patients using a single standard criterion to facilitate its recognition, even when distal ICA LD reduction is not visually evident in computed tomography angiography (CTA). We analysed carotid artery CTAs of 467 patients with moderate-to-severe CS scheduled for endarterectomy. We performed measurements of the bilateral distal ICA LDs from thin axial source images and utilized a 1.0 mm intra-individual side-to-side distal ICA LD difference to distinguish near-occlusions, based on a previous study, aware of the vagaries of measurement. For analysis stratification, we excluded cases with significant carotid pathology affecting LD measurements. We discovered 126 near-occlusions fulfilling our criterion of ipsilateral near-occlusion: the mean LD side-to-side difference (mm) with 95% confidence interval being 1.8 (1.6, 1.9) and a standard deviation of 0.8 mm. Among the 233 cases not meeting our near-occlusion criterion, we found 140 moderate (50-69%) and 93 severe (70-99%) ipsilateral stenoses. The utilization of 1.0 mm cut-off value for the intra-individual distal ICA LD side-to-side difference to distinguish atherosclerotic ICA near-occlusion leads to a relatively high incidence of near-occlusion. In CTA, recently suggested to be used for near-occlusion diagnosis, a discriminatory 1.0 mm cut-off value could function as a pragmatic tool to enhance the detection of even subtle near-occlusions. (orig.)
A Hierarchical Building Segmentation in Digital Surface Models for 3D Reconstruction
Directory of Open Access Journals (Sweden)
Yiming Yan
2017-01-01
Full Text Available In this study, a hierarchical method for segmenting buildings in a digital surface model (DSM, which is used in a novel framework for 3D reconstruction, is proposed. Most 3D reconstructions of buildings are model-based. However, the limitations of these methods are overreliance on completeness of the offline-constructed models of buildings, and the completeness is not easily guaranteed since in modern cities buildings can be of a variety of types. Therefore, a model-free framework using high precision DSM and texture-images buildings was introduced. There are two key problems with this framework. The first one is how to accurately extract the buildings from the DSM. Most segmentation methods are limited by either the terrain factors or the difficult choice of parameter-settings. A level-set method are employed to roughly find the building regions in the DSM, and then a recently proposed ‘occlusions of random textures model’ are used to enhance the local segmentation of the buildings. The second problem is how to generate the facades of buildings. Synergizing with the corresponding texture-images, we propose a roof-contour guided interpolation of building facades. The 3D reconstruction results achieved by airborne-like images and satellites are compared. Experiments show that the segmentation method has good performance, and 3D reconstruction is easily performed by our framework, and better visualization results can be obtained by airborne-like images, which can be further replaced by UAV images.
Optical gain and absorption of 420 nm InGaN-based laser diodes grown on m-plane GaN substrate
Shen, Chao
2014-01-01
Segmented contact method was utilized to measure the gain and absorption spectra at below and above threshold for 420nm m-plane InGaN/GaN laser diode with a comparatively higher peak modal gain of 29.2 cm-1.
Sixty-eight years of experimental occlusal interference studies: what have we learned?
Clark, G T; Tsukiyama, Y; Baba, K; Watanabe, T
1999-12-01
Understanding is needed regarding the effect that occlusal interferences have on the teeth, periodontium, and especially on jaw function. This article summarizes research in which experimental occlusal interferences have been placed on the teeth of animals and human volunteers. Data from 18 human and 10 animals studies were reviewed. Experimental occlusal interferences were grouped into those that alter intercuspal position and those contacting on lateral jaw movement only. The outcome of these interferences were analyzed according to their local pulpal-periodontal, jaw function, or bruxism effects. Experimental occlusal interferences in maximum intercuspation had a deleterious effect on periodontal and pulpal tissues of the affected tooth; sometimes this produces a disruption of smooth jaw function and occasionally jaw muscle pain and clicking. Experimental occlusal interferences that contact only in a lateral jaw movement are infrequently harmful to jaw function. Furthermore, no reliable evidence demonstrates that occlusal interferences can cause nocturnal bruxism, or stop it. Transient local tooth pain, loosening of the tooth, a slight change in postural muscle tension levels, chewing stroke patterns, and sometimes a clicking joint can be induced by an experimental occlusal interference. Because such findings are present in relatively asymptomatic patients, these data do not prove that occlusal interferences are causally related to a chronic jaw muscle pain or temporomandibular joint dysfunction problems.
Outflow occlusion for circulatory arrest in dogs "Outfow occlusion" para parada circulatória em cães
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James N.B.M. de Andrade
2009-02-01
Full Text Available The purpose of this study was to evaluate the possibility of producing circulatory arrest by occlusion of the pulmonary trunk as an alternative to the venous inflow occlusion through the left hemithorax. Eight healthy mongrel dogs were divided in two groups. Group I underwent 4 minutes of outflow occlusion and Group II was submitted to 8 minutes of circulatory arrest. Outflow occlusion was performed through left thoracotomy and pericardiotomy by passing a Rumel tourniquet around the pulmonary trunk. Physical examination, electrocardiography, echocardiography, blood gas analyses, hemodynamic, and oxygen transport variables were obtained before and after the procedure. The dogs from Group I did not have any clinical, electrocardiographic, echocardiographic, or hemo-dynamic abnormalities after anesthetic recover. In the Group II, only one dog survived, which had no clinical, electrocardiographic, or echocardiographic abnormalities. In this last dog, just after releasing the occlusion, it was detected increases in the following parameters: heart rate (HR, systolic, diastolic and mean arterial blood pressure (SAP; DAP; MAP, pulmonary artery pressure (PAP, pulmonary wedge pressure (PWP, central venous pressure (CVP, cardiac output (CO, systolic index (SI, cardiac index (CI, left and right ventricular stroke work (LVSW; RVSW, oxygen delivery index (DO2, oxygen consumption index (VO2, and oxygen extraction (O2 ext. Moreover, the oxygen content of arterial and mixed venous blood (CaO2; CvO2, and the arterial and mixed venous partial pressure of oxygen (PaO2; PvO2 were decreased 5 minutes after circulatory arrest. Outflow occlusion is a feasible surgical procedure for period of 4 minutes of circulatory arrest.O objetivo deste estudo foi avaliar a possibilidade de se produzir uma parada circulatória pela oclusão do tronco pulmonar, como alternativa ao "inflow occlusion", pelo hemitórax esquerdo. Oito cães sem raça definida foram divididos em dois
Effects of occlusal inclination and loading on mandibular bone remodeling: a finite element study.
Rungsiyakull, Chaiy; Rungsiyakull, Pimdeun; Li, Qing; Li, Wei; Swain, Michael
2011-01-01
To provide a preliminary understanding of the biomechanics with respect to the effect of cusp inclination and occlusal loading on the mandibular bone remodeling. Three different cusp inclinations (0, 10, and 30 degrees) of a ceramic crown and different occlusal loading locations (central fossa and 1- and 2-mm offsets horizontally) were taken into account to explore the stresses and strains transferred from the crown to the surrounding dental bone through the implant. A strain energy density obtained from two-dimensional plane-strain finite element analysis was used as the mechanical stimulus to drive cancellous and cortical bone remodeling in a buccolingual mandibular section. Different ceramic cusp inclinations had a significant effect on bone remodeling responses in terms of the change in the average peri-implant bone density and overall stability. The remodeling rate was relatively high in the first few months of loading and gradually decreased until reaching its equilibrium. A larger cusp inclination and horizontal offset (eg, 30 degrees and 2-mm offset) led to a higher bone remodeling rate and greater interfacial stress. The dental implant superstructure design (in terms of cusp inclination and loading location) determines the load transmission pattern and thus largely affects bone remodeling activities. Although the design with a lower cusp inclination recommended in previous studies may reduce damage and fracture failure, it could, to a certain extent, compromise bone engagement and long-term stability.
Anterior Segmental Distraction Osteogenesis in the Hypoplastic Cleft Maxilla
Rao (Janardhan), Sruthi; Kotrashetti, S. M.; Lingaraj, J. B.; Pinto, P. X.; Keluskar, K. M.; Jain, Siddharth; Sone, Piyush; Rao, Santhosh
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-made tooth-borne distraction device with a hyrax screw positioned anteroposteriorly was used. The evaluation comprised of hard and soft tissue analysis and speech assessment. A stable occlusion with positive overjet and correction of dental-crowding without extraction was achieved at one year post-distraction. Facial profile and lip support improved. There was no deterioration in speech. PMID:23984033
Early endovascular treatment of superior mesenteric occlusion secondary to thromboemboli.
Jia, Z; Jiang, G; Tian, F; Zhao, J; Li, S; Wang, K; Wang, Y; Jiang, L; Wang, W
2014-02-01
To evaluate our early experience with endovascular revascularization in patients with acute thromboembolic occlusion of the superior mesenteric artery (SMA). A retrospective review was conducted of all patients who underwent endovascular revascularization for acute thromboembolic SMA occlusion from May 2005 to May 2012. Endovascular revascularization was performed using aspiration, intra-arterial thrombolysis, and adjunctive stent-placement techniques. Laparotomy was performed if the patient developed clinical signs of advanced bowel ischemia after endovascular procedure. Twenty-one patients underwent endovascular revascularization for acute thromboembolic SMA occlusion. All presented with acute-onset abdominal pain. Three patients had rebound tenderness before the procedure. Computed tomography angiography revealed complete occlusion in seven cases and incomplete occlusion in 14 cases, with no evidence of free gas or bowel necrosis. The median duration from onset of symptoms to revascularization was 8.7 ± 4.1 hours (range, 2-18 hours). Completely successful endovascular revascularization occurred in six cases (aspiration alone, 3 cases; combined aspiration and urokinase, 3 cases); partial success was achieved in 15 cases (aspiration alone, 4 cases; combined aspiration and urokinase, 10 cases; and combined aspiration, urokinase, and stent placement, 1 case). Laparotomy was required in five patients, all of whom had SMA main trunk complete occlusion and required small bowel resection. The 30-day mortality for all patients was 9.5%. During a median follow-up of 26 months, 15 patients remained asymptomatic, three patients reported occasional abdominal pain, and one patient had temporary short-bowel syndrome. Percutaneous revascularization is a promising alternative to surgery for acute SMA occlusion in selected patients who have no signs of advanced bowel ischemia. Early diagnosis followed by prompt endovascular intervention with close postprocedural monitoring is
Interventional treatment for the occlusive hepatic veins in Budd-Chiari syndrome
International Nuclear Information System (INIS)
Zhang Xitong; Xu Ke; Feng Bo; Su Hongying; Li Hong; Zu Maoheng; Cui Jingguo; Yang Xueliang; Zhao Jinxu; Chen Kai
2003-01-01
Objective: To evaluate the interventional methods for occlusive hepatic veins in Budd-Chiari syndrome and its mid and long-term effects. Methods: Forty-two patients (male 17 cases and female 25 cases) aged from 18 to 57 years old (mean 34.5 years) were studied. The liver functions were Child A in 23 cases, Child B in 6 cases, and Child C in 13 cases, respectively. A total of 92 hepatic veins were occluded. Among them, 29 left hepatic veins, 24 middle hepatic veins, 36 right hepatic veins, and 3 accessory hepatic veins were occluded. Thirty-four patients were accompanied with the stenotic or occlusive inferior vena cave (IVC) . The interventional methods included: (1) recanalization of occlusive hepatic veins (by transjugular, transfemoral, and percutaneous transhepatic route, or the combination of above three methods); (2) percutaneous transluminal angioplasty; (3) self-expanding stent implantation. The occlusive IVC in 32 patients also accepted PTA and/or stent implantation. Results: The successful recanalization was carried out in forty hepatic veins in 40 patients. PTA of occlusive veins was followed by stent implantation in 8 patients. The pressure of hepatic veins dropped from 34.5 cm H 2 O (25.0-48.0 cm H 2 O) to 22.0 cm H 2 O (12.0-35.0 cm H 2 O) after intervention (T=11.50, P < 0.01). The symptoms and pathological signs improved obviously in 32 cases and improved partly in 8 cases. During the follow-up period from 1 month to 54 months (mean 27.5 months), one cases died of liver function failure at one month after intervention. The re-intervention of occlusive veins in two cases were performed and the better results were acquired again. Five cases didn't accept re-intervention. Neither recurrence of symptoms nor re-occlusion of hepatic veins was found in the other 32 patients. Conclusion: (1) Multiple and synthetical interventional methods for the occlusive hepatic veins in Budd-Chiari syndrome can be utilized. (2) The intervention of hepatic vein is mini
Clinical Decision Support Model to Predict Occlusal Force in Bruxism Patients.
Thanathornwong, Bhornsawan; Suebnukarn, Siriwan
2017-10-01
The aim of this study was to develop a decision support model for the prediction of occlusal force from the size and color of articulating paper markings in bruxism patients. We used the information from the datasets of 30 bruxism patients in which digital measurements of the size and color of articulating paper markings (12-µm Hanel; Coltene/Whaledent GmbH, Langenau, Germany) on canine protected hard stabilization splints were measured in pixels (P) and in red (R), green (G), and blue (B) values using Adobe Photoshop software (Adobe Systems, San Jose, CA, USA). The occlusal force (F) was measured using T-Scan III (Tekscan Inc., South Boston, MA, USA). The multiple regression equation was applied to predict F from the P and RGB. Model evaluation was performed using the datasets from 10 new patients. The patient's occlusal force measured by T-Scan III was used as a 'gold standard' to compare with the occlusal force predicted by the multiple regression model. The results demonstrate that the correlation between the occlusal force and the pixels and RGB of the articulating paper markings was positive (F = 1.62×P + 0.07×R -0.08×G + 0.08×B + 4.74; R 2 = 0.34). There was a high degree of agreement between the occlusal force of the patient measured using T-Scan III and the occlusal force predicted by the model (kappa value = 0.82). The results obtained demonstrate that the multiple regression model can predict the occlusal force using the digital values for the size and color of the articulating paper markings in bruxism patients.
Clinical Decision Support Model to Predict Occlusal Force in Bruxism Patients
Thanathornwong, Bhornsawan
2017-01-01
Objectives The aim of this study was to develop a decision support model for the prediction of occlusal force from the size and color of articulating paper markings in bruxism patients. Methods We used the information from the datasets of 30 bruxism patients in which digital measurements of the size and color of articulating paper markings (12-µm Hanel; Coltene/Whaledent GmbH, Langenau, Germany) on canine protected hard stabilization splints were measured in pixels (P) and in red (R), green (G), and blue (B) values using Adobe Photoshop software (Adobe Systems, San Jose, CA, USA). The occlusal force (F) was measured using T-Scan III (Tekscan Inc., South Boston, MA, USA). The multiple regression equation was applied to predict F from the P and RGB. Model evaluation was performed using the datasets from 10 new patients. The patient's occlusal force measured by T-Scan III was used as a ‘gold standard’ to compare with the occlusal force predicted by the multiple regression model. Results The results demonstrate that the correlation between the occlusal force and the pixels and RGB of the articulating paper markings was positive (F = 1.62×P + 0.07×R –0.08×G + 0.08×B + 4.74; R2 = 0.34). There was a high degree of agreement between the occlusal force of the patient measured using T-Scan III and the occlusal force predicted by the model (kappa value = 0.82). Conclusions The results obtained demonstrate that the multiple regression model can predict the occlusal force using the digital values for the size and color of the articulating paper markings in bruxism patients. PMID:29181234
Occlusion detection via structured sparse learning for robust object tracking
Zhang, Tianzhu; Ghanem, Bernard; Xu, Changsheng; Ahuja, Narendra
2014-01-01
occlusion through structured sparse learning. We test our tracker on challenging benchmark sequences, such as sports videos, which involve heavy occlusion, drastic illumination changes, and large pose variations. Extensive experimental results show that our
Effect of occlusal contact stability on the jaw closing point during tapping movements.
Nishigawa, Keisuke; Suzuki, Yoshitake; Ishikawa, Teruaki; Bando, Eiichi
2012-04-01
We studied the relationship between tapping point reproducibility and stability of occlusal contacts at maximum intercuspation. Tapping movements of 12 adult volunteers who had dentition with natural teeth were recorded, and distances between the tapping point (TP) and the intercuspal position (ICP) at the incisal point were calculated. Occlusal contacts at the ICP of individual subjects were also evaluated with black-colored silicone impression material. The correlation between TP-ICP distance and occlusal contact stability was studied. TP-ICP distance exhibited negative correlations with the total number of teeth showing occlusal contact at the ICP. Standard deviations of TP-ICP distance also negatively correlated with the extension of occlusal contact area over dentition. This finding indicates that occlusal contacts at the ICP affect the kinematic behavior of tapping movements. The results of this study also suggest that jaw movement data may provide useful clinical information for the evaluation of occlusal contact at ICP. Copyright © 2011 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.
Reconstruction-based Digital Dental Occlusion of the Partially Edentulous Dentition
Zhang, Jian; Xia, James J.; Li, Jianfu; Zhou, Xiaobo
2016-01-01
Partially edentulous dentition presents a challenging problem for the surgical planning of digital dental occlusion in the field of craniomaxillofacial surgery because of the incorrect maxillomandibular distance caused by missing teeth. We propose an innovative approach called Dental Reconstruction with Symmetrical Teeth (DRST) to achieve accurate dental occlusion for the partially edentulous cases. In this DRST approach, the rigid transformation between two symmetrical teeth existing on the left and right dental model is estimated through probabilistic point registration by matching the two shapes. With the estimated transformation, the partially edentulous space can be virtually filled with the teeth in its symmetrical position. Dental alignment is performed by digital dental occlusion reestablishment algorithm with the reconstructed complete dental model. Satisfactory reconstruction and occlusion results are demonstrated with the synthetic and real partially edentulous models. PMID:26584502
Veno-occlusive disease of the colon - CT findings
International Nuclear Information System (INIS)
Rademaker, J.
1998-01-01
Venous occlusion is a rare cause of ischemic bowel disease and is usually brought about by thrombosis that may occur as a complication of systemic disorders like systemic lupus erythematosus, Behcet disease or Churg-Strauss syndrome. This report describes a patient with veno-occlusive disease of the colon caused by lymphocytic phlebitis. Typical CT findings included homogeneous bowel wall thickening and vascular engorgement. (orig.) (orig.)
Bilateral Internal Carotid Artery Occlusion Associated with the Antiphospholipid Antibody Syndrome
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Pria Anand
2014-03-01
Full Text Available A 39-year-old woman presented with a right-hemispheric stroke 1 year after she had suffered a left-hemispheric stroke. Her diagnostic workup was notable for bilateral occlusions of the internal carotid arteries at their origins and a positive lupus anticoagulant antibody test. There was no evidence of carotid dissection or another identifiable cause for her carotid occlusions. These findings suggest that the antiphospholipid antibody syndrome may be implicated in the pathological changes that resulted in occlusions of the extracranial internal carotid arteries. Young stroke patients who present with unexplained internal carotid artery occlusions may benefit from testing for the presence of antiphospholipid antibodies.
Endovascular management of inferior vena cava filter thrombotic occlusion.
Branco, Bernardino C; Montero-Baker, Miguel F; Espinoza, Eduardo; Gamero, Maria; Zea-Vera, Rodrigo; Labropoulos, Nicos; Leon, Luis R
2018-01-01
Objective Inferior vena cava occlusion is a potentially life-threatening complication related to caval filters. We present our experience with filter-induced inferior vena cava occlusion in order to assess the feasibility, safety, and effectiveness of endovascular management. Methods A retrospective review of all patients undergoing inferior vena cava filter placement over a 60-month study period was performed. From this cohort, a total of 10 cases of inferior vena cava occlusion after filter placement were identified. Demographics, clinical data, procedures, and outcomes were extracted. Patients were followed to the last clinic visit or until they died. Results One-hundred eighty filters were placed by our group practice during the study period. Of those, a total of 10 patients were identified. Overall, there were 7 males; the mean age was 57.1 years (25-78 years). The median time between inferior vena cava filter placement and filter occlusion was 105 days (range 5-4745 days). All patients were clinically symptomatic at the time of their presentation. Nine out of 10 patients were successfully managed endovascularly. Trellis™-8 thrombectomy was the most common endovascular strategy performed ( n = 9). Four patients had balloon angioplasty, two of those with stent placement for chronically occluded inferior vena cava/iliac veins. No thromboembolic complications developed during a median follow-up period of 233 days (range 4-1083 days). Conclusions Endovascular management of inferior vena cava occlusion is feasible, safe, and effective in decreasing thrombus burden in the presence of an inferior vena cava filter. Further studies evaluating long-term inferior vena cava patency and optimal surveillance regimen after endovascular management of filter-related inferior vena cava occlusion are warranted.
International Nuclear Information System (INIS)
Karlish, S.J.D.; Goldshleger, R.; Stein, W.D.
1990-01-01
Tryptic digestion of pig renal Na/K-ATPase in the presence of Rb and absence of Ca ions removes about half of the protein but leaves a stable 19-kDa membrane-embedded fragment derived from the α chain, a largely intact β chain, and essentially normal Rb- and Na-occlusion capacity. Subsequent digestion with trypsin in the presence of Ca or absence of Rb ions leads to rapid loss of the 19-kDa fragment and a parallel loss of Rb occlusion, demonstrating that the fragment is essential for occlusion. The N-terminal sequence of the 19-kDa fragment is Asn-Pro-Lys-Thr-Asp-Lys-Leu-Val-Asn-Glu-Arg-Leu-Ile-Ser-Met-Ala, beginning at residue 830 and extending toward the C terminus. Membranes containing the 19-kDa fragment have the following functional properties. (i) ATP-dependent functions are absent. (ii) The apparent affinity for occluding Rb is unchanged, the affinity for Na is lower than in the control enzyme, and activation is now strongly sigmoidal rather than hyperbolic. (iii) Membranes containing the 19-kDa fragment can be reconstituted into phospholipid vesicles and sustain slow Rb-Rb exchange. Thus the transport pathway is retained. The authors conclude that cation occlusion sites and the transport pathway within transmembrane segments are quite separate from the ATP binding sites, located on the cytoplasmic domain of the α chain. Interactions between cation and ATP sites, the heart of active transport, must be indirect - mediated, presumably, by conformational changes of the protein
Energy Technology Data Exchange (ETDEWEB)
Karlish, S.J.D.; Goldshleger, R. (Weizmann Institute of Science, Rehovot (Israel)); Stein, W.D. (Hebrew Univ. Jerusalem (Israel))
1990-06-01
Tryptic digestion of pig renal Na/K-ATPase in the presence of Rb and absence of Ca ions removes about half of the protein but leaves a stable 19-kDa membrane-embedded fragment derived from the {alpha} chain, a largely intact {beta} chain, and essentially normal Rb- and Na-occlusion capacity. Subsequent digestion with trypsin in the presence of Ca or absence of Rb ions leads to rapid loss of the 19-kDa fragment and a parallel loss of Rb occlusion, demonstrating that the fragment is essential for occlusion. The N-terminal sequence of the 19-kDa fragment is Asn-Pro-Lys-Thr-Asp-Lys-Leu-Val-Asn-Glu-Arg-Leu-Ile-Ser-Met-Ala, beginning at residue 830 and extending toward the C terminus. Membranes containing the 19-kDa fragment have the following functional properties. (i) ATP-dependent functions are absent. (ii) The apparent affinity for occluding Rb is unchanged, the affinity for Na is lower than in the control enzyme, and activation is now strongly sigmoidal rather than hyperbolic. (iii) Membranes containing the 19-kDa fragment can be reconstituted into phospholipid vesicles and sustain slow Rb-Rb exchange. Thus the transport pathway is retained. The authors conclude that cation occlusion sites and the transport pathway within transmembrane segments are quite separate from the ATP binding sites, located on the cytoplasmic domain of the {alpha} chain. Interactions between cation and ATP sites, the heart of active transport, must be indirect - mediated, presumably, by conformational changes of the protein.
Surgical treatment of chronic occlusive in peripheral arteries (Review of 100 cases
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H. AHRARI
1977-01-01
Full Text Available The purpose of this article is to diseuse the philosophy of our approch to the severely ischemic extremity and ourcurrent methods of treatment. 1 - The natural history of artheriosclerotic arterial obstruction should always be borne in mind. There is no doubt that many people have some degree of arterial stenosis or obstrcction and never suffer symptoms, either because of the reduced demand due to senility or because they are prepared to tolerate minor inconveniences which do not significantly interfere with their lives or livelihood. It should also be remembered that a proportion of patients with claudication improve spontaneously ever a time scale extending to many months or years. Taylor and Cale (1962, in a long term follow up of patients with untreated intermittent claudication, found spontaneous relief of symptoms in 39 per cent of the cases, no change in 45% and 16% worsening. Because of this it is impossible to lay down precise rules concerning the treatment of patients with intermittent claudication. It would be wrong to advise major arterial surgery in an elderly patient with extensive main' vessel disease and relatively mild claudication, and equally wrong to deny surgical treatment to an active younger patient with a we 11 localized arterial lesion. It is superfuous to add that anyhow, the surgery must not make the patient worse. 2- In a survey of a decade of experience, the arterioplastie treatment of occlusive disease seems to fall int three groups based on the anatomic distribution of the lesion. (Ref, 13. A - These in whom the obstructive disease is limited to the aortoiliac segments of the arterial tree supplying the leg. B - Those with both aort-iliao and femoral arterial disease. C - These with only femoropopliteal or proximal part of the popliteal arteries. Results in both the aorto-iliac and femoral arterial disease operations were in general satisfactory. The good early results of aorto-iliac operations showed only a
Investigation of Primary Mirror Segment's Residual Errors for the Thirty Meter Telescope
Seo, Byoung-Joon; Nissly, Carl; Angeli, George; MacMynowski, Doug; Sigrist, Norbert; Troy, Mitchell; Williams, Eric
2009-01-01
The primary mirror segment aberrations after shape corrections with warping harness have been identified as the single largest error term in the Thirty Meter Telescope (TMT) image quality error budget. In order to better understand the likely errors and how they will impact the telescope performance we have performed detailed simulations. We first generated unwarped primary mirror segment surface shapes that met TMT specifications. Then we used the predicted warping harness influence functions and a Shack-Hartmann wavefront sensor model to determine estimates for the 492 corrected segment surfaces that make up the TMT primary mirror. Surface and control parameters, as well as the number of subapertures were varied to explore the parameter space. The corrected segment shapes were then passed to an optical TMT model built using the Jet Propulsion Laboratory (JPL) developed Modeling and Analysis for Controlled Optical Systems (MACOS) ray-trace simulator. The generated exit pupil wavefront error maps provided RMS wavefront error and image-plane characteristics like the Normalized Point Source Sensitivity (PSSN). The results have been used to optimize the segment shape correction and wavefront sensor designs as well as provide input to the TMT systems engineering error budgets.
Induction of intestinal ischemia reperfusion injury by portal vein outflow occlusion in rats
International Nuclear Information System (INIS)
Vincenti, M.; Behrends, M.; Hirose, Ryutaro; Liu, T.; Niemann, C.U.; Dang, K.; Park, Y.H.; Blasi-Ibanez, A.; Serkova, N.J.
2010-01-01
Intestinal ischemia can occur from mesenteric artery (MA) occlusion and portal vein (PV) occlusion. The degree and mechanisms of ischemia/reperfusion (I/R) injury in these conditions may differ. Metabolic changes are seen early in I/R. This study compares tissue histology, inflammation, and metabolic response during small bowel I/R due to superior MA or PV occlusion. Anesthetized male Wistar rats (250-300 g) underwent laparotomy followed by MA or PV occlusion for 40 min. After 120 min of reperfusion, small bowel tissue was collected. The expression of heat shock protein (HSP)-32 and HSP70 was evaluated to compare physiological stress responses between groups. Metabolic profiles were obtained using 1 H-nuclear magnetic resonance spectroscopy (NMR)-based quantitative metabolomics. Histological injury of small bowel was graded from 0 (normal) to 4 (extensive ischemic damage). Protein expression of HSP32 and HSP70 increased when compared to sham but was not different in the MA I/R and PV I/R groups. Metabolic profiles demonstrated decreased glucose levels and highly elevated tissue lactate and amino acids and fatty acids following I/R, with more pronounced changes with PV occlusion. Lipid peroxidation was equally increased in both groups, while depletion of reduced glutathione (GSH) was more severe with MA occlusion. The epithelial necrosis score was higher with MA (3.5±0.6) than with PV occlusion (2.3±0.8). Histological injury of the intestine is less pronounced following PV occlusion, most likely due to higher oxygen and substrate availability during I/R by PV occlusion. This conclusion is supported by a more pronounced metabolic synthetic response (increased glycolysis and fatty acid and amino acid accumulation) with PV occlusion, while oxidative stress was higher with MA occlusion. The inflammatory response showed little difference between the groups. (author)
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Sunanda Vashisth
2014-01-01
Full Text Available A frequency plane phase mask based on Devil’s vortex structure has been used for image encryption using the fractional Mellin transform. The phase key for decryption is obtained by an iterative phase retrieval algorithm. The proposed scheme has been validated for grayscale secret target images, by numerical simulation. The efficacy of the scheme has been evaluated by computing mean-squared-error between the secret target image and the decrypted image. Sensitivity analysis of the decryption process to variations in various encryption parameters has been carried out. The proposed encryption scheme has been seen to exhibit reasonable robustness against occlusion attack.
3D contrast-enhanced MR portography and direct X-ray portography: a correlation study
International Nuclear Information System (INIS)
Lin Jiang; Zhou Kangrong; Chen Zuang; Wang Jianhua; Yan Ziping; Wang Yixiang, J.
2003-01-01
Our objective was to compare 3D contrast-enhanced MR portography (3D CE MRP) on a 1.5-T MR imager with direct X-ray portography. Twenty-six consecutive patients underwent 3D CE MRP with in-plane resolution of 1.4 or 1.8 mm, and direct X-ray portography. The findings of these two methods were evaluated and compared. The main portal vein (PV), right PV with its anterior and posterior segmental branches, and left PV including its sagittal segment were shown clearly without diagnostic problem in all cases on MRP. The main PV appearance was accordant with MRP and X-ray. For intrahepatic PVs, the results agreed in 21 patients but disagreed in 5 patients. In 1 patient with a huge tumor in right liver, the right posterior PV was classified as occluded at MRP, but diffusely narrowed at X-ray. The findings of left intrahepatic PV were discordant in 3 patients with hepatocelluar carcinoma in the left lobe. The MRP demonstrated complete occlusion of the left PVs, whereas X-ray showed proximal narrowing and distal occlusion. In another patient with hepatocelluar carcinoma, a small non-occlusive thrombus involving the sagittal segment of the left PV was seen on MRP but not on X-ray. With demonstration of varices and portosystemic shunts, MRP showed results similar to those of X-ray, except one recanalized para-umbilical vein was excluded from the field of view at MRP due to the patient's limited ability of breathholding. The 3D CE MRP correlated well with direct X-ray portography in most cases, it was limited in distinguishing narrowing of an intrahepatic PV from occlusion, but it showed advantage in demonstrating small thrombus within PV. (orig.)
Pemakaian Inclined Bite Plane untuk Koreksi Gigitan Terbalik Interior pada Anak
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Debrania Santoso
2012-12-01
of inclined bite plane can corrected anterior crossbite. Case. Two girls with anterior crossbite cases are examined and from the anamnesis is known that the first child has a bad habit pushing chin and the second child pushing tongue to the lower anterior teeth. Treatment of case is to use the inclined bite plane every day while awake and sleeping except when eating and brushing teeth. Conclusion. The anterior crossbite of the first child is corrected after 8 weeks treatment and 5 weeks treatment for the second child. The occlusion of the second child is better than the first child.
Ladwiniec, Andrew; Cunnington, Michael S; Rossington, Jennifer; Thackray, Simon; Alamgir, Farquad; Hoye, Angela
2016-05-01
The aim of this study was to compare microvascular resistance under both baseline and hyperemic conditions immediately after percutaneous coronary intervention (PCI) of a chronic total occlusion (CTO) with an unobstructed reference vessel in the same patient Microvascular dysfunction has been reported to be prevalent immediately after CTO PCI. However, previous studies have not made comparison with a reference vessel. Patients with a CTO may have global microvascular and/or endothelial dysfunction, making comparison with established normal values misleading. After successful CTO PCI in 21 consecutive patients, coronary pressure and flow velocity were measured at baseline and hyperemia in distal segments of the CTO/target vessel and an unobstructed reference vessel. Hemodynamics including hyperemic microvascular resistance (HMR), basal microvascular resistance (BMR), and instantaneous minimal microvascular resistance at baseline and hyperemia were calculated and compared between reference and target/CTO vessels. After CTO PCI, BMR was reduced in the target/CTO vessel compared with the reference vessel: 3.58 mm Hg/cm/s vs 4.94 mm Hg/cm/s, difference -1.36 mm Hg/cm/s (-2.33 to -0.39, p = 0.008). We did not detect a difference in HMR: 1.82 mm Hg/cm/s vs 2.01 mm Hg/cm/s, difference -0.20 (-0.78 to 0.39, p = 0.49). Instantaneous minimal microvascular resistance correlated strongly with the length of stented segment at baseline (r = 0.63, p = 0.005) and hyperemia (r = 0.68, p = 0.002). BMR is reduced in a recanalized CTO in the immediate aftermath of PCI compared to an unobstructed reference vessel; however, HMR appears to be preserved. A longer stented segment is associated with increased microvascular resistance. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Occlusal Grinding Pattern during Sleep Bruxism and Temporomandibular Disorder
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Yeni Wijaya
2013-09-01
Full Text Available Sleep Bruxism is a significant etiology of temporomandibular disorder (TMD and causes many dental or oral problems such as tooth wear or facet. There is no study analyzing the relationship between sleep bruxism and TMD. Objective: To investigate any relationship between occlusal grinding pattern during sleep bruxism and temporomandibular disorder. Methods: A cross-sectional study involving 30 sleep bruxism patients attended the Faculty Dentistry Universitas Indonesia Teaching Hospital (RSGMP FKG UI. Completion of 2 forms of ID-TMD index and questionnaire from American Academy of Sleep Medicine were done. BruxChecker was fabricated and used for two nights to record the occlusal grinding pattern. The occlusal grinding pattern was categorized into laterotrusive grinding (LG and mediotrusive side. Further divisons of LG were: incisor-canine (IC, incisor-caninepremolar (ICP and incisor-canine-premolar-molar (ICPM. Mediotrusive side was classified as mediotrusive contact (MC and mediotrusive grinding (MG. Results: It was found that occlusal grinding pattern in non-TMD subjects were IC+MC, in subjects with mild TMD were ICP+MG and in subjects with moderate TMD were ICP+MG and ICPM+MG. TMJ was more significantly affected by ICP and ICPM grinding pattern than that of IC. Conclusion: There was a significant relationship between occlusal grinding pattern during sleep bruxism and TMD.DOI: 10.14693/jdi.v20i2.149
Stability of anterior open-bite treatment with occlusal adjustment.
Janson, Guilherme; Crepaldi, Marcus Vinicius; Freitas, Karina Maria Salvatore; de Freitas, Marcos Roberto; Janson, Waldyr
2010-07-01
In this study, we aimed to evaluate the long-term stability of anterior open-bite treatment with occlusal adjustment and the dentinal sensitivity caused by this procedure in the long term. The sample comprised 17 open-bite patients who experienced relapse of the negative vertical overbite after orthodontic treatment and were retreated with occlusal adjustment. The cephalometric changes were evaluated on lateral cephalograms obtained before and after the occlusal adjustment and in the long term (mean, 3.4 years after occlusal adjustment). Dentinal sensitivity was also evaluated before the occlusal adjustment, and 1.35 months, 4.61 months, and 3.4 years later. The cephalometric statuses between the 3 evaluations were compared with analysis of variance (ANOVA) and Tukey tests. The percentages of clinically significant relapse were calculated. To compare dentinal sensitivity at the several stages, nonparametric Friedman and Wilcoxon tests were performed. Statistically significant relapse of anterior open bite occurred in 33.3% of the patients. Those who had the procedure before 21 years of age were most likely to experience relapse. Dentinal sensitivity remained within the normal range in the long term. Despite the statistically significant relapse of anterior open bite, clinically significant stability was found in 66.7% of the patients. Copyright (c) 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.
Some Considerations Regarding Plane to Plane Parallelism Error Effects in Robotic Systems
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Stelian Alaci
2015-06-01
Full Text Available The paper shows that by imposing the parallelism constraint between the measured plane and the reference plane, the position of the current plane is not univocal specified and is impossible to specify the way to attain the parallelism errors imposed by accuracy constrains. The parameters involved in the calculus of plane to plane parallelism error can be used to set univocal the relative position between the two planes.
[Single- and multi-unit fixed dental prostheses in relation to the occlusal system
Witter, D.J.; Gerritsen, A.E.; Spijker, A. van 't; Creugers, N.H.J.
2013-01-01
Occlusion concepts based on functional aspects offer more solid ground in the diagnostic process and in the treatment of (reduced) dentitions than morphologically and mechanically oriented occlusion concepts. Nevertheless, for occlusal reconstruction morphologically oriented guidelines are
AN ADAPTIVE APPROACH FOR SEGMENTATION OF 3D LASER POINT CLOUD
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Z. Lari
2012-09-01
Full Text Available Automatic processing and object extraction from 3D laser point cloud is one of the major research topics in the field of photogrammetry. Segmentation is an essential step in the processing of laser point cloud, and the quality of extracted objects from laser data is highly dependent on the validity of the segmentation results. This paper presents a new approach for reliable and efficient segmentation of planar patches from a 3D laser point cloud. In this method, the neighbourhood of each point is firstly established using an adaptive cylinder while considering the local point density and surface trend. This neighbourhood definition has a major effect on the computational accuracy of the segmentation attributes. In order to efficiently cluster planar surfaces and prevent introducing ambiguities, the coordinates of the origin's projection on each point's best fitted plane are used as the clustering attributes. Then, an octree space partitioning method is utilized to detect and extract peaks from the attribute space. Each detected peak represents a specific cluster of points which are located on a distinct planar surface in the object space. Experimental results show the potential and feasibility of applying this method for segmentation of both airborne and terrestrial laser data.
Morita, Takumi; Hiraba, Katsunari; Matsunaga, Tomoko; Ito, Yu; Maruo, Hisanobu; Kurita, Kenichi
2015-03-01
The mandible can be modelled as a triangular plate supported at two joints and the point of occlusion. The mandible is stable if the vector of the jaw-closing muscle forces lies within the triangle of support. If this vector lies outside of the triangle of support, one of the three contact points will tend to separate as the mandible rotates around a line connecting the other two points. Here, we examined whether postero-inferior condylar movements (Pi-Cm) due to mandibular rotation may occur during fictive mastication in anaesthetized rabbits. EMG activities of the masseter (MS) and lateral pterygoid (LP) muscles and movements of the condyle and incisal points were recorded. Condylar movements in the sagittal plane were recorded using a high speed CCD camera. Pi-Cm were observed on the working side during occlusal phase in half of the rabbits (altered-movement group), if the biting point was restricted at the posterior most tooth (M3) on the working side using a metal biting plate. Pi-Cm appeared in the period between the estimated maximum force of the MS and the LP during late occlusal phase. The MS EMG ratio between the working and balancing sides in the altered-movement group was significantly less than that in the unaltered-movement group. Since the space lying between the condyle and the articular eminence expanded during the Pi-Cm, it is likely that the posterior band of the articular disc tended to slip anteriorly. The clinical significance of the Pi-Cm is discussed concerning the anterior dislocation of the disc in patients with TMJ disorder. Copyright © 2014 Elsevier Ltd. All rights reserved.
A novel method to determine perineal artery occlusion among male bicyclists
Parthiban, Sujeeth; Hotaling, James M.; Kathrins, Martin; Baftiri, Amit P.; Freels, Sally; Niederberger, Craig S.
2015-01-01
Background. Perineal pressure due to bicycle riding has been associated with erectile dysfunction. We developed a novel method to measure the occlusive force exerted over the perineal arteries and determined perineal artery occlusion by a variety of seat designs. Methods. Doppler ultrasonography facilitated perineal artery localization and determination of the force required for perineal artery occlusion in 20 healthy men. Flexiforce? sensors were affixed over the proximal and distal aspects ...
Psychosocial distress of part-time occlusion in children with intermittent exotropia.
Kim, Ungsoo Samuel; Park, Subin; Yoo, Hee Jeong; Hwang, Jeong-Min
2013-01-01
To evaluate the psychosocial distress of part-time occlusion therapy in intermittent exotropia. A total of 25 children (15 males and 10 females, aged 3 to 7 years, mean age 4.7 years) with intermittent exotropia were enrolled. Behavioral and psychosocial problems were assessed by the Korean Child Behavior Checklist (K-CBCL), which consists of eight categories of withdrawal, somatic problems, depression/anxiety, social problems, thought problems, attention problems, delinquent behavior, and aggressive behavior, and the Amblyopia Treatment Index (ATI). The ATI was designed to evaluate the three factors of compliance, adverse effect, and social stigma. The Parenting Stress Index (PSI) is a parent self-report designed to identify potentially dysfunctional parent-child systems. The K-CBCL was obtained before and after occlusion therapy, and the ATI and PSI were taken from parents only after occlusion therapy. We evaluated the change on the K-CBCL and the correlation between the K-CBCL and ATI. The attention problem assessed by the K-CBCL significantly decreased after occlusion therapy. On the ATI, the social stigma was relatively lower than compliance and adverse effect factors (Likert scale 2.64, 3.11, and 3.11, respectively). The somatic problem assessed by the K-CBCL and compliance on the ATI were significantly correlated (p = 0.014). There was no significant change in percentile scores of each subscale (parental dominant scale and child dominant scale) of the PSI. Total stress index before and after occlusion therapy was 97.16 ± 8.38 and 97.00 ± 8.16 respectively (p = 0.382). Occlusion therapy may influence the psychosocial impact on intermittent exotropia patients. Part-time occlusion significantly decreased the attention problem in children with intermittent strabismus. Children with a high somatic problem score on the KCBCL showed poor compliance to the part-time occlusion.
Minimally invasive lung volume reduction treated with bronchi occlusion emphysema model
International Nuclear Information System (INIS)
Zhou Dayong; Shen Liming; Shen Junkang; Jin Yiqi; Chen Lei; Huang Xianchen
2007-01-01
Objective: To evaluate the efficacy and feasibility of the coil-and-glue method for the reduction of lung volume in rabbit emphysema model. Methods: Sixteen rabbits of emphysema model were divided into the occlusion group(n=10), in which both anterior bronchi were occluded using the coil-and- glue method, and the control group (n=6). The maximal static pressure of airway (P max ), peak expiratory flow (PEF), end-expiratory volume (EEV) and pressure of oxygen (PO 2 ) were measured at ante- emphysema, post-emphysema, 1 week and 4 week after occlusion respectively. The expectoration (or migration) of coil and collapse of lung were also investigated. Results: P max was (20.0±1.3) and (17.1± 1.4) cm H 2 O (1 cm H 2 O=0.098 kPa) in the occlusion group at ante-emphysema and post-emphysema respectively. P max was (19.2±1.4) cm H 2 O in the occlusion group in the 1 week after the occlusion, while (17.1±1.5)cm H 2 O in the control group (F=6.68, P max was (19.2±1.4) cm H 2 O in the occlusion group, while (16.6±1.2) cm H 2 O in the control group (F=12.10, P max , in the 1 week and 4 week after occlusion were higher than those at post-emphysema (P<0.01, respectively); EEV at post-emphysema was higher than that at ante-emphysema (P<0.01). Conclusion: Coil-and-glue occlusion method for lung volume reduction in rabbit emphysema model can improve the pulmonary function, which can be relatively long lasting. (authors)
A Vision Chip for Color Segmentation and Pattern Matching
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Ralph Etienne-Cummings
2003-06-01
Full Text Available A 128(H × 64(V × RGB CMOS imager is integrated with region-of-interest selection, RGB-to-HSI transformation, HSI-based pixel segmentation, (36bins × 12bits-HSI histogramming, and sum-of-absolute-difference (SAD template matching. Thirty-two learned color templates are stored and compared to each image. The chip captures the R, G, and B images using in-pixel storage before passing the pixel content to a multiplying digital-to-analog converter (DAC for white balancing. The DAC can also be used to pipe in images for a PC. The color processing uses a biologically inspired color opponent representation and an analog lookup table to determine the Hue (H of each pixel. Saturation (S is computed using a loser-take-all circuit. Intensity (I is given by the sum of the color components. A histogram of the segments of the image, constructed by counting the number of pixels falling into 36 Hue intervals of 10 degrees, is stored on a chip and compared against the histograms of new segments using SAD comparisons. We demonstrate color-based image segmentation and object recognition with this chip. Running at 30 fps, it uses 1 mW. To our knowledge, this is the first chip that integrates imaging, color segmentation, and color-based object recognition at the focal plane.
Veno-occlusive disease of the colon - CT findings
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Rademaker, J [Department of Radiology I, Medical School Hannover (Germany)
1998-10-01
Venous occlusion is a rare cause of ischemic bowel disease and is usually brought about by thrombosis that may occur as a complication of systemic disorders like systemic lupus erythematosus, Behcet disease or Churg-Strauss syndrome. This report describes a patient with veno-occlusive disease of the colon caused by lymphocytic phlebitis. Typical CT findings included homogeneous bowel wall thickening and vascular engorgement. (orig.) (orig.) With 1 fig., 4 refs.
松田, 岳; 後藤, 崇晴; 柏原, 稔也; 市川, 哲雄
2015-01-01
The maxillomandibular registration is one of important processes to achieve patientsatisfaction with the function and esthetics for complete denture fabrication. Over the years, clinical decision of vertical and horizontal jaw relationship has been mainly discussed in the maxillomandibular registration. With regard to the occlusal plane setting, many clinicians have believed to decide the occlusal plane parallel to Camper's plane, however there is little information on the effect of occlusal ...
Retinal artery occlusion during carotid artery stenting with distal embolic protection device.
Kohara, Kotaro; Ishikawa, Tatsuya; Kobayashi, Tomonori; Kawamata, Takakazu
2018-01-01
Retinal artery occlusion associated with carotid artery stenosis is well known. Although it can also occur at the time of carotid artery stenting, retinal artery occlusion via the collateral circulation of the external carotid artery is rare. We encountered two cases of retinal artery occlusion that were thought to be caused by an embolus from the external carotid artery during carotid artery stenting with a distal embolic protection device for the internal carotid artery. A 71-year-old man presented with central retinal artery occlusion after carotid artery stenting using the Carotid Guardwire PS and a 77-year-old man presented with branch retinal artery occlusion after carotid artery stenting using the FilterWire EZ. Because additional new cerebral ischaemic lesions were not detected in either case by postoperative diffusion-weighted magnetic resonance imaging, it was highly likely that the debris that caused retinal artery occlusion passed through not the internal carotid artery but collaterals to retinal arteries from the external carotid artery, which was not protected by a distal embolic protection device. It is suggested that a distal protection device for the internal carotid artery alone cannot prevent retinal artery embolisation during carotid artery stenting and protection of the external carotid artery is important to avoid retinal artery occlusion.
Influence of occlusal loading on peri-implant clinical parameters. A pilot study.
Pellicer-Chover, Hilario; Viña-Almunia, José; Romero-Millán, Javier; Peñarrocha-Oltra, David; García-Mira, Berta; Peñarrocha-Diago, María
2014-05-01
To investigate the relation between occlusal loading and peri-implant clinical parameters (probing depth, bleeding on probing, gingival retraction, width of keratinized mucosa, and crevicular fluid volume) in patients with implant-supported complete fixed prostheses in both arches. This clinical study took place at the University of Valencia (Spain) dental clinic. It included patients attending the clinic for regular check-ups during at least 12 months after rehabilitation of both arches with implant-supported complete fixed ceramo-metallic prostheses. One study implant and one control implant were established for each patient using the T-Scan®III computerized system (Tesco, South Boston, USA). The maxillary implant closest to the point of maximum occlusal loading was taken as the study implant and the farthest (with least loading) as the control. Occlusal forces were registered with the T-Scan® III and then occlusal adjustment was performed to distribute occlusal forces correctly. Peri-implant clinical parameters were analyzed in both implants before and two and twelve months after occlusal adjustment. Before occlusal adjustment, study group implants presented a higher mean volume of crevicular fluid (51.3 ± 7.4 UP) than the control group (25.8 ± 5.5 UP), with statistically significant difference. Two months after occlusal adjustment, there were no significant differences between groups (24.6 ± 3.8 UP and 26 ± 4.5 UP respectively) (p=0.977). After twelve months, no significant differences were found between groups (24.4 ± 11.1 UP and 22.5 ± 8.9 UP respectively) (p=0.323). For the other clinical parameters, no significant differences were identified between study and control implants at any of the study times (p>0.05). Study group implants receiving higher occlusal loading presented significantly higher volumes of crevicular fluid than control implants. Crevicular fluid volumes were similar in both groups two and twelve months after occlusal adjustment.
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Chung, Mi Sun [Chung-Ang University College of Medicine, Department of Radiology, Chung-Ang University Hospital, Seoul (Korea, Republic of); Yang, Dong Hyun; Seo, Joon Beom; Kang, Joon-Won; Lim, Tae-Hwan [Asan Medical Center, University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Kim, Young-Hak; Kang, Soo-Jin; Jung, Joonho [Asan Medical Center, University of Ulsan College of Medicine, Heart Institute, Seoul (Korea, Republic of); Kim, Namkug [Asan Medical Center, University of Ulsan College of Medicine, Department of Convergence Medicine, Seoul (Korea, Republic of); Heo, Seung-Ho [Asan Medical Center, University of Ulsan College of Medicine, Asan institute for Life Science, Seoul (Korea, Republic of); Baek, Seunghee [Asan Medical Center, University of Ulsan College of Medicine, Department of Clinical Epidemiology and Biostatistics, Seoul (Korea, Republic of); Choi, Byoung Wook [Yonsei University, Department of Diagnostic Radiology, College of Medicine, Seoul (Korea, Republic of)
2017-10-15
To validate a method for performing myocardial segmentation based on coronary anatomy using coronary CT angiography (CCTA). Coronary artery-based myocardial segmentation (CAMS) was developed for use with CCTA. To validate and compare this method with the conventional American Heart Association (AHA) classification, a single coronary occlusion model was prepared and validated using six pigs. The unstained occluded coronary territories of the specimens and corresponding arterial territories from CAMS and AHA segmentations were compared using slice-by-slice matching and 100 virtual myocardial columns. CAMS more precisely predicted ischaemic area than the AHA method, as indicated by 95% versus 76% (p < 0.001) of the percentage of matched columns (defined as percentage of matched columns of segmentation method divided by number of unstained columns in the specimen). According to the subgroup analyses, CAMS demonstrated a higher percentage of matched columns than the AHA method in the left anterior descending artery (100% vs. 77%; p < 0.001) and mid- (99% vs. 83%; p = 0.046) and apical-level territories of the left ventricle (90% vs. 52%; p = 0.011). CAMS is a feasible method for identifying the corresponding myocardial territories of the coronary arteries using CCTA. (orig.)
Visual Acuity Improvement in Continuous vs Divided Occlusion in Anisometropic Amblyopia.
Irfani, Irawati; Feriyanto, Feri; Oktarima, Primawita; Kartasasmita, Arief
2018-01-01
To compare visual acuity improvement between continuous and split part-time occlusion for the treatment of moderate and severe anisometropic amblyopia. Randomised clinical trials in 6 - 13 y.o children with moderate and severe anisometropic amblyopia. Each patient was consecutively selected with continuous or split part-time occlusion. Best corrected visual acuity's improvement was followed up to six weeks and statistical data were analyzed using chi square and unpaired t-test. Best corrected visual acuity's improvement was comparable between continuous and split part-time occlusion (0.20±0.27 vs 0.21±0.25; p = 0.79). Split part-time occlusion may be considered as an alternative treatment for moderate and severe anisometropic amblyopia treatment.
Influence of dental occlusion on postural control and plantar pressure distribution.
Scharnweber, Benjamin; Adjami, Frederic; Schuster, Gabriele; Kopp, Stefan; Natrup, Jörg; Erbe, Christina; Ohlendorf, Daniela
2017-11-01
The number of studies investigating correlations between the temporomandibular system and body posture, postural control or plantar pressure distribution is continuously increasing. If a connection can be found, it is often of minor influence or for only a single parameter. However, small subject groups are critical. This study was conducted to define correlations between dental parameters, postural control and plantar pressure distribution in healthy males. In this study, 87 male subjects with an average age of 25.23 ± 3.5 years (ranging from 18 to 35 years) were examined. Dental casts of the subjects were analyzed. Postural control and plantar pressure distribution were recorded by a force platform. Possible orthodontic and orthopedic factors of influence were determined by either an anamnesis or a questionnaire. All tests performed were randomized and repeated three times each for intercuspal position (ICP) and blocked occlusion (BO). For a statistical analysis of the results, non-parametric tests (Wilcoxon-Matched-Pairs-Test, Kruskall-Wallis-Test) were used. A revision of the results via Bonferroni-Holm correction was considered. ICP increases body sway in the frontal (p ≤ 0.01) and sagittal planes (p ≤ 0.03) compared to BO, whereas all other 29 correlations were independent of the occlusion position. For both of the ICP or BO cases, Angle-class, midline-displacement, crossbite, or orthodontic therapy were found to have no influence on postural control or plantar pressure distribution (p > 0.05). However, the contact time of the left foot decreased (p ≤ 0.001) while detecting the plantar pressure distribution in each position. Persistent dental parameters have no effect on postural sway. In addition, postural control and plantar pressure distribution have been found to be independent postural criteria.
An Automatic Occlusion Device for Remote Control of Tumor Tissue Ischemia
El-Dahdah, Hamid; Wang, Bei; He, Guanglong; Xu, Ronald X.
2015-01-01
We developed an automatic occlusion device for remote control of tumor tissue ischemia. The device consists of a flexible cannula encasing a shape memory alloy wire with its distal end connected to surgical suture. Regional tissue occlusion was tested on both the benchtop and the animal models. In the benchtop test, the occlusion device introduced quantitative and reproducible changes of blood flow in a tissue simulating phantom embedding a vessel simulator. In the animal test, the device generated a cyclic pattern of reversible ischemia in the right hinder leg tissue of a black male C57BL/6 mouse. We also developed a multimodal detector that integrates near infrared spectroscopy and electron paramagnetic resonance spectroscopy for continuous monitoring of tumor tissue oxygenation, blood content, and oxygen tension changes. The multimodal detector was tested on a cancer xenograft nude mouse undergoing reversible tumor ischemia. The automatic occlusion device and the multi-modal detector can be potentially integrated for closed-loop feedback control of tumor tissue ischemia. Such an integrated occlusion device may be used in multiple clinical applications such as regional hypoperfusion control in tumor resection surgeries and thermal ablation processes. In addition, the proposed occlusion device can also be used as a research tool to understand tumor oxygen transport and hemodynamic characteristics. PMID:20082532
The effect of experimental stress and experimental occlusal interference on masseteric EMG activity.
McGlynn, F D; Bichajian, C; Tira, D E; Lundeen, H C; Mahan, P E; Nicholas, B V
1989-01-01
This experiment attempted to study the separate and combined effects of occlusal interference and transient stress on masseteric activity among eight nonclinical human subjects. Before each of two sessions, subjects were fitted with an occlusal interference or an occlusally inert (control) molar clasp. During each session they viewed horrific and idyllic videotapes while masseter EMG was recorded bilaterally. Electrodermal measures validated that the horrific videotapes were stressful. Studies showed that the occlusal variable worked less well. The EMG was elevated contralateral to both clasps and during videotape viewing. The EMG effects from videotape viewing were relatively pronounced without the occlusal interference. Research implications are discussed.
Intradomain phase transitions in flexible block copolymers with self-aligning segments
Burke, Christopher J.; Grason, Gregory M.
2018-05-01
We study a model of flexible block copolymers (BCPs) in which there is an enlthalpic preference for orientational order, or local alignment, among like-block segments. We describe a generalization of the self-consistent field theory of flexible BCPs to include inter-segment orientational interactions via a Landau-de Gennes free energy associated with a polar or nematic order parameter for segments of one component of a diblock copolymer. We study the equilibrium states of this model numerically, using a pseudo-spectral approach to solve for chain conformation statistics in the presence of a self-consistent torque generated by inter-segment alignment forces. Applying this theory to the structure of lamellar domains composed of symmetric diblocks possessing a single block of "self-aligning" polar segments, we show the emergence of spatially complex segment order parameters (segment director fields) within a given lamellar domain. Because BCP phase separation gives rise to spatially inhomogeneous orientation order of segments even in the absence of explicit intra-segment aligning forces, the director fields of BCPs, as well as thermodynamics of lamellar domain formation, exhibit a highly non-linear dependence on both the inter-block segregation (χN) and the enthalpy of alignment (ɛ). Specifically, we predict the stability of new phases of lamellar order in which distinct regions of alignment coexist within the single mesodomain and spontaneously break the symmetries of the lamella (or smectic) pattern of composition in the melt via in-plane tilt of the director in the centers of the like-composition domains. We further show that, in analogy to Freedericksz transition confined nematics, the elastic costs to reorient segments within the domain, as described by the Frank elasticity of the director, increase the threshold value ɛ needed to induce this intra-domain phase transition.
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Shin, Byung Seok; Ahn, Moon Sang [Chungnam National University Hospital, Daejeon (Korea, Republic of); Park, Mi Hyun [Dept. of Radiology, Dankook University Hospital, Cheonan (Korea, Republic of); Jeon, Gyeong Sik [Dept. of Radiology, CHA Bundang Medical Center, CHA University College of Medicine, Seongnam (Korea, Republic of); Lee, Byung Mo [Dept. of Surgery, Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of); Lee, Ki Chang [Dept. of Veterinary Radiology, Chonbuk National University College of VeterinaryMedicine, Seoul (Korea, Republic of); Kim, Ho Jun [Dept. of Radiology, Konyang University Hospital, Daejeon (Korea, Republic of); Ohm, Joon Young [Dept. of Radiology, Bucheon St. Mary Hospital, The Catholic University of Korea College of Medicine, Bucheon (Korea, Republic of)
2012-04-15
To compare the ablation zone after radiofrequency ablation (RFA) with saturated saline preinjection and renal artery occlusion in canine kidneys. RFA was induced in the kidneys of six mongrel dogs. A total of 24 ablation zones were induced using a 1-cm tip internally cooled needle electrode in three groups: RFA (Control group), RFA with 0.5 mL saturated saline preinjection (SS group), and RFA with renal artery occlusion by atraumatic vascular clamp (Occlusion group). Ablation zone diameters were measured along transverse and longitudinal sections of the needle axis, and volumes were calculated. Temperature, applied voltage, current, and impedance during RFA were recorded automatically. The RFA zone volume was the largest in the SS group (1.33 {+-} 0.34 cm{sup 3}), followed by the Occlusion group (1.07 {+-} 0.38 cm{sup 3}) and then the Control group (0.62 {+-} 0.09 cm{sup 3}). Volumes for the SS and Occlusion groups were significantly larger than those for the Control group (p = 0.001, p = 0.012). There was no significant difference in volumes between the SS and Occlusion groups (p = 0.178). Saturated saline preinjection is as effective as renal arterial occlusion for expanding the ablation zone. RFA with saturated saline preinjection could help to treat large renal tumors.
International Nuclear Information System (INIS)
Shin, Byung Seok; Ahn, Moon Sang; Park, Mi Hyun; Jeon, Gyeong Sik; Lee, Byung Mo; Lee, Ki Chang; Kim, Ho Jun; Ohm, Joon Young
2012-01-01
To compare the ablation zone after radiofrequency ablation (RFA) with saturated saline preinjection and renal artery occlusion in canine kidneys. RFA was induced in the kidneys of six mongrel dogs. A total of 24 ablation zones were induced using a 1-cm tip internally cooled needle electrode in three groups: RFA (Control group), RFA with 0.5 mL saturated saline preinjection (SS group), and RFA with renal artery occlusion by atraumatic vascular clamp (Occlusion group). Ablation zone diameters were measured along transverse and longitudinal sections of the needle axis, and volumes were calculated. Temperature, applied voltage, current, and impedance during RFA were recorded automatically. The RFA zone volume was the largest in the SS group (1.33 ± 0.34 cm 3 ), followed by the Occlusion group (1.07 ± 0.38 cm 3 ) and then the Control group (0.62 ± 0.09 cm 3 ). Volumes for the SS and Occlusion groups were significantly larger than those for the Control group (p = 0.001, p = 0.012). There was no significant difference in volumes between the SS and Occlusion groups (p = 0.178). Saturated saline preinjection is as effective as renal arterial occlusion for expanding the ablation zone. RFA with saturated saline preinjection could help to treat large renal tumors.
International Nuclear Information System (INIS)
Siablis, Dimitrios; Karnabatidis, Dimitrios; Katsanos, Konstantinos; Ravazoula, Panagiota; Kraniotis, Pantelis; Kagadis, George C.
2005-01-01
Purpose: Filter devices are already employed for the protection of carotid, coronary and renal distal vascular bed during endovascular procedures. This is a pilot study investigating their feasibility, safety and distal emboli protection capability during recanalization of lower extremities' acute and subacute occlusions. Materials and methods: Study population included 16 patients, 11 with a subacute arterial occlusion and 5 with an acute episode. The Trap filter (Microvena, USA) and its successor the Spider filter (EV3, USA) were utilized. Subacute occlusions were dealt with standard angioplasty and stenting procedures, while acute ones were managed primarily with Angiojet rheolytic thrombectomy. Outflow arterial tree was checked angiographically in-between consequent procedural steps. Embolic material collected after filter recovery was analyzed histopathologically. Patients' follow-up was scheduled at 1 month. Results: Seventeen filter baskets were applied in the recanalization of 16 target lesions in total. Mean length of the occluded segments was 6.1 (range: 2-15 cm; S.D. = 3.7 cm). Mean in situ time of the filters was 38.75 min (range: 20-60 min; S.D. 12.71 min). Technical success rate of deployment and utilization of the filtration devices was 100% (17/17). Procedural success rate of the recanalization was 100% (16/16) without any clinical or angiographic evidence of periprocedural distal embolization. Macroscopic particulate debris was extracted from all the filters (17/17) containing fresh thrombus, calcification minerals, cholesterol and fibrin. Mean diameter of the largest particle per specimen was 1702.80 (range: 373.20-4680.00 μm; S.D. 1155.12 μm). No adverse clinical events occurred at 1-month follow-up with 100% limb salvage (16/16). Conclusion: The application of outflow protection filters is safe, feasible and efficacious in hindering distal embolization complications and safeguarding the distal capillary bed. Nevertheless, this is a pilot study
Interdisciplinary treatment of bruxism with an occlusal splint and cognitive behavioral therapy.
Trindade, Marilene; Orestes-Cardoso, Silvana; de Siqueira, Teresa Cristina
2015-01-01
The etiology of bruxism is associated with exogenous factors, such as occlusal interference, stress, and anxiety, as well as endogenous factors involving neurotransmitters of the basal ganglia. Due to the multifactorial etiology of bruxism, interdisciplinary treatment involving professionals from different healthcare fields has been proposed. The aim of the present study was to compare 2 groups of patients with bruxism (11 in each group) treated with either an occlusal splint combined with cognitive behavioral therapy or an occlusal splint alone. Surface electromyography of the masseter and anterior temporal muscles at rest was performed before and after treatment. The mean amplitude of activity of all muscles was lower after treatment, except for the right anterior temporal muscle in the group treated with an occlusal splint alone. Mean amplitudes were greater in the anterior temporal muscles than in the masseter muscles. Significantly greater improvement was found in the group exposed to cognitive behavioral therapy (P < 0.05; analysis of variance and Student t tests). Therefore, the combination of occlusal splint and psychological therapy was more effective at achieving muscle relaxation than occlusal splint use alone.
Acute internal carotid artery occlusion after carotid endarterectomy
Directory of Open Access Journals (Sweden)
Masatoshi Yunoki
2016-09-01
Full Text Available We report two cases of acute carotid artery (CA occlusion following carotid endarterectomy (CEA. Case 1: a 58-year-old man was admitted with transient right-sided hemiparesis. Magnetic resonance imaging (MRI and MR angiography (MRA revealed cerebral infarction in the left cerebral hemisphere and left CA stenosis. Ten days after admission, he underwent CEA. 24 h after surgery, he developed right hemiplegia. MRI and MRA demonstrated a slightly enlarged infarction and left internal carotid artery (ICA occlusion. Emergency reoperation was performed and complete recanalization achieved. The patient made a clinically significant recovery. Case 2: a 65 year-old man underwent a right-sided CEA for an asymptomatic 80% CA stenosis. 48 h after surgery, his family noticed he was slightly disorientated. MRI and MRA revealed multiple infarctions and right ICA occlusion. He was treated with antiplatelet therapy without reoperation because sufficient cross-flow from the left ICA through the anterior communicating artery was demonstrated by angiography, and his neurological symptoms were mild. His symptoms gradually alleviated and he was discharged 14 days after surgery. With ICA occlusion after CEA, immediate re-operation is mandatory with severe neurological symptoms, whereas individualized judgement is needed when the symptoms are mild.
Cerebral blood flow measurement in cerebrovascular occlusive diseases
International Nuclear Information System (INIS)
Yanagihara, T.; Wahner, H.W.
1984-01-01
In order to evaluate cerebral blood flow (CBF) patterns among individual patients with increased statistical confidence, CBF measurements were carried out using the 133Xe-inhalation method and external head detectors. F1 values representing gray matter flow from 3 to 6 head detectors were averaged to form 16 different regions for each cerebral hemisphere. Normative values were obtained from 46 healthy volunteers, and data from individual regions were analyzed for absolute blood flow rates (ml/100g/min), for concordance between right and left hemispheres and as percent of mean hemispheric flow. CBF measurements were then carried out among 37 patients with cerebrovascular occlusive diseases, and results were compared with normative values. A high incidence of abnormal flows were detected among symptomatic patients with intracranial arterial stenosis or occlusion and those with extracranial internal carotid artery occlusion. By using the above method for data analysis, it was possible to delineate hypoperfused areas among these patients. Even though the 133Xe-inhalation method has inherent limitations, this is a practical and safe method for measurement of CBF which can provide reliable information useful for management of patients with cerebrovascular occlusive diseases, particularly when the results are presented with statistical confidence
Directory of Open Access Journals (Sweden)
Andreas Ebneter
Full Text Available Retinal vein occlusion is a leading cause of visual impairment. Experimental models of this condition based on laser photocoagulation of retinal veins have been described and extensively exploited in mammals and larger rodents such as the rat. However, few reports exist on the use of this paradigm in the mouse. The objective of this study was to investigate a model of branch and central retinal vein occlusion in the mouse and characterize in vivo longitudinal retinal morphology alterations using spectral domain optical coherence tomography. Retinal veins were experimentally occluded using laser photocoagulation after intravenous application of Rose Bengal, a photo-activator dye enhancing thrombus formation. Depending on the number of veins occluded, variable amounts of capillary dropout were seen on fluorescein angiography. Vascular endothelial growth factor levels were markedly elevated early and peaked at day one. Retinal thickness measurements with spectral domain optical coherence tomography showed significant swelling (p<0.001 compared to baseline, followed by gradual thinning plateauing two weeks after the experimental intervention (p<0.001. Histological findings at day seven correlated with spectral domain optical coherence tomography imaging. The inner layers were predominantly affected by degeneration with the outer nuclear layer and the photoreceptor outer segments largely preserved. The application of this retinal vein occlusion model in the mouse carries several advantages over its use in other larger species, such as access to a vast range of genetically modified animals. Retinal changes after experimental retinal vein occlusion in this mouse model can be non-invasively quantified by spectral domain optical coherence tomography, and may be used to monitor effects of potential therapeutic interventions.
Koffijberg, H.; Buskens, E.; Rinkel, G. J. E.
Background Aneurysm occlusion after subarachnoid haemorrhage (SAH) aims to improve outcome by reducing the rebleeding risk. With increasing age, overall prognosis decreases, and the complications of aneurysm occlusion increase. The balance of risks for aneurysm occlusion in elderly SAH patients in
Implications of natural occlusion of ventilated racks on ammonia and sanitation practices.
Creamer, Michelle A; Petty, Joann; Martin, Tara; Bergdall, Valerie; Hickman-Davis, Judy M
2014-03-01
Examination of ventilated rat racks prior to semiannual sanitation revealed silicone nozzles and ventilation ports that were partially or completely occluded with granular debris. We subsequently sought to document performance standards for rack sanitation and investigate the effect of ventilation port occlusion on rack function and animal husbandry practices. We hypothesized that individually ventilated cages with occluded airflow would require more frequent cage changes, comparable to those for static cages (that is, every 3 to 4 d). Sprague-Dawley rats were housed under one of 4 conditions: no airflow occlusion, occluded air-supply inlet, occluded air-exhaust outlet, and occlusion of both inlet and outlet. Cages were changed when daily ammonia concentration exceeded 20 ppm or after 14 d had elapsed. Most cages with unoccluded or partial airflow occlusion remained below the 20 ppm limit until day 12 or 13. Cages with occlusion of both inlet and outlet exceeded 20 ppm ammonia by as early as day 5. Airflow was significantly lower in cages with occlusion of both inlet and outlet airflow. Weekly inspection revealed that occlusion of ventilation ports was detectable by 3 mo after semiannual sanitation. This study demonstrates that silicone nozzles should be removed prior to rack sanitation to improve the effectiveness of cleaning ventilation ports and nozzles. While the rack is in use, silicone nozzles and ventilation ports should be inspected regularly to identify occlusion that is likely to diminish environmental quality in the cage. Intracage ammonia levels are significantly higher when both inlet and outlet airflow are occluded.
An approach to localize the retinal blood vessels using bit planes and centerline detection.
Fraz, M M; Barman, S A; Remagnino, P; Hoppe, A; Basit, A; Uyyanonvara, B; Rudnicka, A R; Owen, C G
2012-11-01
The change in morphology, diameter, branching pattern or tortuosity of retinal blood vessels is an important indicator of various clinical disorders of the eye and the body. This paper reports an automated method for segmentation of blood vessels in retinal images. A unique combination of techniques for vessel centerlines detection and morphological bit plane slicing is presented to extract the blood vessel tree from the retinal images. The centerlines are extracted by using the first order derivative of a Gaussian filter in four orientations and then evaluation of derivative signs and average derivative values is performed. Mathematical morphology has emerged as a proficient technique for quantifying the blood vessels in the retina. The shape and orientation map of blood vessels is obtained by applying a multidirectional morphological top-hat operator with a linear structuring element followed by bit plane slicing of the vessel enhanced grayscale image. The centerlines are combined with these maps to obtain the segmented vessel tree. The methodology is tested on three publicly available databases DRIVE, STARE and MESSIDOR. The results demonstrate that the performance of the proposed algorithm is comparable with state of the art techniques in terms of accuracy, sensitivity and specificity. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
A Conceptual Design and Structural Analysis for ITER Mid-plane Brace Tools
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Nam, Kyoung O; Park, Hyun Ki; Kim, Dong Jin [National Fusion Research Institute, Daejeon (Korea, Republic of); Lee, Jae Hyuk; Kim, Kyung kyu [SFA Engineering Corp., Changwon (Korea, Republic of); Im, Kihak; Robert, Shaw [ITER Organization, St Paul lez Durance Cedex (France)
2010-10-15
The ITER, International Thermonuclear Experimental Reactor, Tokamak machine is mainly composed of 9 vacuum vessel (VV)/toroidal field coils (TFCs)/vacuum vessel thermal shields (VVTS) 40 .deg. sectors. Each VV/TFCs/VVTS 40 .deg. sector is made up of one 40 .deg. VV, two 20 .deg. TFCs and associated VVTS segments. The ITER Tokamak assembly tools are purpose-built tools to assemble the ITER Tokamak machine which includes the cryostat and the components contained therein. Based on the design description document prepared by the IO (ITER international organization), Korea has carried out the conceptual design of assembly tools with IO cooperation. The 40 .deg. sector assemblies attached mid-plane brace tools sub-assembled at assembly hall are transferred to Tokamak hall using the lifting tool operated by Tokamak main cranes. The sector sub-assembly tools are composed of the upending tool, the sector sub-assembly tool, the sector lifting tool and the vacuum vessel support and mid-plane brace tools. The mid-plane brace tool is assembled to inner surface of VV and TFCs in phase of sector sub-assembly after completion of all sector components. VV, TFC and VVTS are separated fully before completion of 9 sectors at Tokamak in-pit. In this paper the mid-plane brace tools is introduced about function, structure and status of research and development are also described
Maalek, Reza; Lichti, Derek D; Ruwanpura, Janaka Y
2018-01-01
Automated segmentation of planar and linear features of point clouds acquired from construction sites is essential for the automatic extraction of building construction elements such as columns, beams and slabs. However, many planar and linear segmentation methods use scene-dependent similarity thresholds that may not provide generalizable solutions for all environments. In addition, outliers exist in construction site point clouds due to data artefacts caused by moving objects, occlusions and dust. To address these concerns, a novel method for robust classification and segmentation of planar and linear features is proposed. First, coplanar and collinear points are classified through a robust principal components analysis procedure. The classified points are then grouped using a new robust clustering method, the robust complete linkage method. A robust method is also proposed to extract the points of flat-slab floors and/or ceilings independent of the aforementioned stages to improve computational efficiency. The applicability of the proposed method is evaluated in eight datasets acquired from a complex laboratory environment and two construction sites at the University of Calgary. The precision, recall, and accuracy of the segmentation at both construction sites were 96.8%, 97.7% and 95%, respectively. These results demonstrate the suitability of the proposed method for robust segmentation of planar and linear features of contaminated datasets, such as those collected from construction sites. PMID:29518062
Laser photocoagulation for retinal vein occlusion
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K. A. Mirzabekova
2015-03-01
Full Text Available Retinal vein occlusion (RVO is one of the leading causes of permanent vision loss. In adults, central retinal vein occlusion (CRVO occurs in 1.8% while branch retinal vein occlusion (BRVO occurs in 0.2%. Treatment strategy and disease prognosis are determined by RVO type (ischemic/non-ischemic. Despite numerous studies and many current CRVO and BRVO treatment approaches, the management of these patients is still being debated. Intravitreal injections of steroids (triamcinolone acetate, dexamethasone and vascular endothelial growth factor (VEGF inhibitors (bevacizumab, ranibizumab were shown to be fairly effective. However, it is unclear whether anti-VEGF agents are reasonable in ischemic RVOs. Laser photocoagulation remains the only effective treatment of optic nerve head and/or retinal neovascularization. Laser photocoagulation is also indicated for the treatment of macular edema. Both threshold and sub-threshold photocoagulation may be performed. Photocoagulation performed with argon (514 nm, krypton (647 nm, or diode (810 nm laser for macular edema provides similar results (no significant differences. The treatment may be complex and include medication therapy and/or surgery. Medication therapy includes anti-aggregant agents and antioxidants, i.e., emoxypine which may be used in acute RVO as well as in post-thrombotic retinopathy.
Laser photocoagulation for retinal vein occlusion
Directory of Open Access Journals (Sweden)
K. A. Mirzabekova
2015-01-01
Full Text Available Retinal vein occlusion (RVO is one of the leading causes of permanent vision loss. In adults, central retinal vein occlusion (CRVO occurs in 1.8% while branch retinal vein occlusion (BRVO occurs in 0.2%. Treatment strategy and disease prognosis are determined by RVO type (ischemic/non-ischemic. Despite numerous studies and many current CRVO and BRVO treatment approaches, the management of these patients is still being debated. Intravitreal injections of steroids (triamcinolone acetate, dexamethasone and vascular endothelial growth factor (VEGF inhibitors (bevacizumab, ranibizumab were shown to be fairly effective. However, it is unclear whether anti-VEGF agents are reasonable in ischemic RVOs. Laser photocoagulation remains the only effective treatment of optic nerve head and/or retinal neovascularization. Laser photocoagulation is also indicated for the treatment of macular edema. Both threshold and sub-threshold photocoagulation may be performed. Photocoagulation performed with argon (514 nm, krypton (647 nm, or diode (810 nm laser for macular edema provides similar results (no significant differences. The treatment may be complex and include medication therapy and/or surgery. Medication therapy includes anti-aggregant agents and antioxidants, i.e., emoxypine which may be used in acute RVO as well as in post-thrombotic retinopathy.
Occlus-o-Guide® versus Andresen activator appliance: neuromuscular evaluation.
Farronato, Giampietro; Giannini, Lucia; Galbiati, Guido; Grillo, Elena; Maspero, Cinzia
2013-05-20
The aim of the present study was to assess the muscular variations at the electromyography (EMG) level for the anterior temporalis muscles and masseter muscles during treatment with Occlus-o-Guide® and Andresen activator appliances. Eighty-two patients (35 males and 47 females) aged between 8 and 12 years (mean age, 10.5±0.8 years) participated in the study. Fifty patients underwent treatment with an Occlus-o-Guide® and 32 patients with an Andresen activator. All patients underwent EMG examination using a Freely EMG (De Gotzen, Legnano, Italy) and surface bipolar electrodes when the appliances were worn for the first time (T0), and after 6 months (T1) and after 12 months (T2) of appliance use. Statistical analysis showed that both at T0 and T2, the percent overlapping coefficient (POC) of the anterior temporalis muscles was not statistically different between the appliance groups. At T0, the POC of the masseter muscles was significantly lower for the Andresen appliance as compared to the Occlus-o-Guide® (p=0.02), while at T2 this significance was lost. At insertion of an appliance, all patients show neuromuscular balance that does not correspond to orthognathic occlusion. Both appliances work by creating muscular imbalance. With the appliances in situ, EMG responses were generally analogous for the Occlus-o-Guide® and the Andresen activator; however, the imbalance was greater and the recovery of the orthological muscular balance was slower in patients under treatment with the Andresen activator as compared to those with the Occlus-o-Guide®.
Autofluorescence and high-definition optical coherence tomography of retinal artery occlusions
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Raeba Mathew
2010-10-01
Full Text Available Raeba Mathew, Evangelia Papavasileiou, Sobha SivaprasadLaser and Retinal Research Unit, Department of Ophthalmology, King’s College Hospital, Denmark Hill, London, UKBackground: The purpose of this study is to illustrate the fundus autofluorescence and high-definition optical coherence tomography (HD-OCT features of acute and long-standing retinal artery occlusions.Design: Retrospective case series.Participants: Patients with acute and chronic retinal and cilioretinal artery occlusions are included in this series.Methods: A detailed clinical examination, color fundus photographs, autofluorescence, and HD-OCT of the subjects were performed.Results: HD-OCT demonstrates the localized and well-demarcated thickening of the inner retina in the acute phase of arterial occlusions that correlates with the areas of blocked autofluorescence caused by the cloudy swelling of the retina. The areas of blocked autofluorescence disappear with chronicity of the disease and this corresponds to the thinning of the inner retinal layers on HD-OCT.Conclusion: Heidelberg OCT and autofluorescence are useful tools to assess retinal arterial occlusions especially in subjects with unexplained visual field loss.Keywords: autofluorescence, high definition OCT, retinal artery occlusion
Instability of in-plane vortices in two-dimensional easy-plane ferromagnets
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Wysin, G.M.
1994-01-01
An analysis of the core region of an in-plane vortex in the two-dimensional Heisenberg model with easy-plane anisotropy λ=J z /J xy leads to a clear understanding of the instability towards transformation into an out-of-plane vortex as a function of anisotropy. The anisotropy parameter λ c at which the in-plane vortex becomes unstable and develops into an out-of-plane vortex is determined with an accuracy comparable to computer simulations for square, hexagonal, and triangular lattices. For λ c , the in-plane vortex is stable but exhibits a normal mode whose frequency goes to zero as ω∝(λ c -λ) 1/2 as λ approaches λ c . For λ>λ c , the static nonzero out-of-plane spin components grow as (λ-λ c ) 1/2 . The lattice dependence of λ c is determined strongly by the number of spins in the core plaquette, is fundamentally a discreteness effect, and cannot be obtained in a continuum theory
Creugers, N. H. J.; Witter, D. J.; Van 't Spijker, A.; Gerritsen, A. E.; Kreulen, C. M.
2010-01-01
Objective. To quantify effects on occlusion and temporomandibular function of mandibular distal extension removable partial dentures in shortened dental arches. Methods. Subjects wearing mandibular extension removable partial dentures (n = 25) were compared with subjects with shortened dental arches without extension (n = 74) and with subjects who had worn a mandibular extension removable partial denture in the past (n = 19). Subjects with complete dentitions (n = 72) were controls. Data were collected at baseline and at 3-, 6-, and 9-year observations. Results. Occlusal activity in terms of reported awareness of bruxism and occlusal tooth wear of lower anterior teeth did not differ significantly between the groups. In contrast, occlusal tooth wear of premolars in shortened dental arches with or without extension dentures was significantly higher than in the controls. Differences amongst groups with respect to signs and symptoms related to temporomandibular disorders were not found. Occlusal support of the dentures did not influence anterior spatial relationship. Occlusal contacts of the denture teeth decreased from 70% for second premolars via 50% for first molars, to 30% for second molars. Conclusions. Mandibular distal extension removable partial dentures in moderate shortened dental arches had no effects on occlusion and temporomandibular function. PMID:20671961
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Nicholas A Famoso
Full Text Available Four groups of equids, "Anchitheriinae," Merychippine-grade Equinae, Hipparionini, and Equini, coexisted in the middle Miocene, but only the Equini remains after 16 Myr of evolution and extinction. Each group is distinct in its occlusal enamel pattern. These patterns have been compared qualitatively but rarely quantitatively. The processes influencing the evolution of these occlusal patterns have not been thoroughly investigated with respect to phylogeny, tooth position, and climate through geologic time. We investigated Occlusal Enamel Index, a quantitative method for the analysis of the complexity of occlusal patterns. We used analyses of variance and an analysis of co-variance to test whether equid teeth increase resistive cutting area for food processing during mastication, as expressed in occlusal enamel complexity, in response to increased abrasion in their diet. Results suggest that occlusal enamel complexity was influenced by climate, phylogeny, and tooth position through time. Occlusal enamel complexity in middle Miocene to Modern horses increased as the animals experienced increased tooth abrasion and a cooling climate.
Famoso, Nicholas A; Davis, Edward Byrd
2014-01-01
Four groups of equids, "Anchitheriinae," Merychippine-grade Equinae, Hipparionini, and Equini, coexisted in the middle Miocene, but only the Equini remains after 16 Myr of evolution and extinction. Each group is distinct in its occlusal enamel pattern. These patterns have been compared qualitatively but rarely quantitatively. The processes influencing the evolution of these occlusal patterns have not been thoroughly investigated with respect to phylogeny, tooth position, and climate through geologic time. We investigated Occlusal Enamel Index, a quantitative method for the analysis of the complexity of occlusal patterns. We used analyses of variance and an analysis of co-variance to test whether equid teeth increase resistive cutting area for food processing during mastication, as expressed in occlusal enamel complexity, in response to increased abrasion in their diet. Results suggest that occlusal enamel complexity was influenced by climate, phylogeny, and tooth position through time. Occlusal enamel complexity in middle Miocene to Modern horses increased as the animals experienced increased tooth abrasion and a cooling climate.
Chun, Bo Young; Kwon, Soon Jae; Chae, Sun Hwa; Kwon, Jung Yoon
2007-09-01
To evaluate changes in ocular alignment in partially accommodative esotropic children age ranged from 3 to 8 years during occlusion therapy for amblyopia. Angle measurements of twenty-two partially accommodative esotropic patients with moderate amblyopia were evaluated before and at 2 years after occlusion therapy. Mean deviation angle with glasses at the start of occlusion treatment was 19.45+/-5.97 PD and decreased to 12.14+/-12.96 PD at 2 years after occlusion therapy (pocclusion therapy, 9 (41%) cases were indications of surgery for residual deviation but if we had planned surgery before occlusion treatment, 18 (82%) of patients would have had surgery. There was a statistical relationship between increase of visual acuity ratio and decrease of deviation angle (r=-0.479, p=0.024). There was a significant reduction of deviation angle of partially accommodative esotropic patients at 2 years after occlusion therapy. Our results suggest that occlusion therapy has an influence on ocular alignment in partially accommodative esotropic patients with amblyopia.
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Liang, GangZhu; Zhang, FuXian, E-mail: gangzhuliang@126.com; Luo, XiaoYun; Zhang, ChangMing; Feng, YaPing; Niu, LuYuan; Zhang, Huan; Hu, Lu; Zhao, Hui; Cheng, Long; Zhang, MingYi [Capital Medical University, Department of Vascular Surgery, Beijing Shijitan Hospital (China)
2016-12-15
PurposeOur aim was to describe the technical aspects and clinical outcomes of an open surgical approach to retrograde transtibial endovascular therapy for recanalization of chronic total occlusions (CTOs) of peripheral arteries because of inability to acquire antegrade intravascular access across the occlusion.Materials and MethodsBetween January 2011 and May 2014, conventional antegrade revascularization failed in 15 limbs of 15 patients (11 males, 4 females) with complex CTOs. The mean age of the patients was 74 years (range 48–83 years). Five patients had severe claudication (Rutherford Category 3), and 10 patients had critical limb-threatening ischemia (Rutherford Categories 4–5). For each of these cases of antegrade failure, an open surgical exposure of the tibial or dorsalis pedis artery was used to allow a safe retrograde transtibial endovascular approach to recanalize the CTO.ResultsSurgical retrograde access from the tibial artery was achieved successfully in 14 of the 15 patients. In the 14 successful retrograde endovascular approaches, surgical retrograde transtibial access was achieved from the dorsalis pedis artery in 8 patients and from the posterior tibial artery in 6. The average time to obtain retrograde access was 5 min (range 2–11 min). No stenosis or occlusion occurred in the tibial or dorsalis pedis arteries used for the retrograde access sites during follow-up.ConclusionsRoutine surgical exposure can be a safe and an effective method for retrograde transtibial access to the more proximal occluded arterial segments in selected patients with CTO.
International Nuclear Information System (INIS)
Liang, GangZhu; Zhang, FuXian; Luo, XiaoYun; Zhang, ChangMing; Feng, YaPing; Niu, LuYuan; Zhang, Huan; Hu, Lu; Zhao, Hui; Cheng, Long; Zhang, MingYi
2016-01-01
PurposeOur aim was to describe the technical aspects and clinical outcomes of an open surgical approach to retrograde transtibial endovascular therapy for recanalization of chronic total occlusions (CTOs) of peripheral arteries because of inability to acquire antegrade intravascular access across the occlusion.Materials and MethodsBetween January 2011 and May 2014, conventional antegrade revascularization failed in 15 limbs of 15 patients (11 males, 4 females) with complex CTOs. The mean age of the patients was 74 years (range 48–83 years). Five patients had severe claudication (Rutherford Category 3), and 10 patients had critical limb-threatening ischemia (Rutherford Categories 4–5). For each of these cases of antegrade failure, an open surgical exposure of the tibial or dorsalis pedis artery was used to allow a safe retrograde transtibial endovascular approach to recanalize the CTO.ResultsSurgical retrograde access from the tibial artery was achieved successfully in 14 of the 15 patients. In the 14 successful retrograde endovascular approaches, surgical retrograde transtibial access was achieved from the dorsalis pedis artery in 8 patients and from the posterior tibial artery in 6. The average time to obtain retrograde access was 5 min (range 2–11 min). No stenosis or occlusion occurred in the tibial or dorsalis pedis arteries used for the retrograde access sites during follow-up.ConclusionsRoutine surgical exposure can be a safe and an effective method for retrograde transtibial access to the more proximal occluded arterial segments in selected patients with CTO.
The dental literature on occlusion and myogenous orofacial pain: application of critical thinking.
Solow, Roger Alan
2016-09-01
To enhance the reader's critical thinking when reading the dental literature on the relationship of occlusion and myogenous orofacial pain (MOP). Representative journal articles and systematic reviews from the dental literature confirming and denying a relationship of occlusion to MOP were analyzed and reviewed. Studies using computerized occlusal analysis (COA) consistently find a relationship of the occlusion to MOP. Studies that do not confirm this relationship have problems with invalid primary source conclusions, unstated assumptions, bias, and errors in logic that disqualify their conclusion. This review explains four categories of problems with the dental literature that denies occlusion has a relationship with MOP. When the reader understands these examples of flaws in this literature, they can apply this critical thinking to future studies. Correct interpretation of the literature on occlusion and MOP requires a foundation of basic and clinical scientific knowledge as well as an understanding of the details of the primary source articles.
Islet neogenesis is stimulated by brief occlusion of the main ...
African Journals Online (AJOL)
Islet neogenesis is stimulated by brief occlusion of the main pancreatic duct. ... South African Medical Journal ... where the initial events that culminate in increased pancreatic endocrine mass caube studied. ... The animals were killed 56 days post .occlusion, and the pancreata excised and fiXed tor histological analysis.
Vascular endoprostheses for femoro-popliteal occlusive disease
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Triller, J; Mahler, F; Do, D; Thalmann, R
1989-03-01
A self-expanding vascular endoprothesis (wall stent) was implanted in 26 patients with femoro-popliteal occlusive disease following recurrent stenosis or occlusion after percutaneous angioplasty. Implantation was successful in all cases and there were no complications. Five of the 26 patients developped a thrombosis in the first nine days; in four of these, thrombolysis was successful. Patency rate after one month was 96%, after three months 95%, after six months 85% and after nine months 87%. In order to prevent thrombosis after implantation, anticoagulant therapy is indicated. Poor distal flow encourages intimal hyperplasia and therefore recurrences.
Vascular endoprostheses for femoro-popliteal occlusive disease
International Nuclear Information System (INIS)
Triller, J.; Mahler, F.; Do, D.; Thalmann, R.
1989-01-01
A self-expanding vascular endoprothesis (wall stent) was implanted in 26 patients with femoro-popliteal occlusive disease following recurrent stenosis or occlusion after percutaneous angioplasty. Implantation was successful in all cases and there were no complications. Five of the 26 patients developped a thrombosis in the first nine days; in four of these, thrombolysis was successful. Patency rate after one month was 96%, after three months 95%, after six months 85% and after nine months 87%. In order to prevent thrombosis after implantation, anticoagulant therapy is indicated. Poor distal flow encourages intimal hyperplasia and therefore recurrences. (orig.) [de
Heteroepitaxial growth of basal plane stacking fault free a-plane GaN
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Wieneke, Matthias; Hempel, Thomas; Noltemeyer, Martin; Witte, Hartmut; Dadgar, Armin; Blaesing, Juergen; Christen, Juergen; Krost, Alois [Otto-von-Guericke Universitaet Magdeburg, FNW/IEP, Magdeburg (Germany)
2010-07-01
Growth of light emitting quantum-wells based on a-plane GaN is a possibility to reduce or even to avoid polarization correlated luminescence red shift and reduction of radiative recombination efficiency. But until now heteroepitaxially grown a-plane GaN films are characterized by a poor crystalline quality expressed by a high density of basal plane stacking faults (BSF) and partial dislocations. We present Si doped a-plane GaN films grown on r-plane sapphire substrates by metal organic vapor phase epitaxy using high temperature AlGaN nucleation layers. FE-SEM images revealed three dimensionally grown GaN crystallites sized up to tenth micrometer in the basal plane and a few tenth micrometers along the c-axes. Though, the full width at half maxima of the X-ray diffraction {omega}-scans of the in-plane GaN(1 anti 100) and GaN(0002) Bragg reflections exhibited a very high crystal quality. Furthermore, luminescence spectra were dominated by near band gap emission, while there was no separated peak of the basal plane stacking fault. In summary we present heteroepitaxially grown a-plane GaN without an evidence of basal plane stacking faults in X-ray diffraction measurements and luminescence spectra.
[The influence of occlusal interferences on pulp vitality threshold in permanent dentition].
Hejne, Arletta Julita
2003-01-01
Examination of pulp vitality is a valuable aid in diagnosis and treatment and thus has been in use for a long time. Numerous factors influencing the pain threshold have been found including occlusal interferences. The effect of EOI (Experimental Occlusal Interferences) has been described, while the effect of primary occlusal interference awaits further investigation. The aim of this work was to evaluate the influence of malocclusion (primary occlusal interference) on pulp vitality. At first, the pattern of bite forces in normal occlusion was established. For this purpose, 20 individuals were examined. The following results were found: (a) Bite forces on the right and left side are symmetrical; (b) Total bite forces are distributed as follows: (I) upper half arch: medial incisor 6.3%, lateral incisor 2.9%, canine 3.6%, first premolar 10.4%, second premolar 11.7%, first molar 29.4%, second molar 23.8%; (II) lower half arch: medial incisor 4.1%, lateral incisor 4%, canine 4.8%, first premolar 9%, second premolar 15.1%, first molar 27.3%, second molar 29.7% (Fig. 4). Next, 83 patients with unilateral malocclusion were subjected to clinical examination (orthodontic diagnosis) and measurement of bite forces (with T-Scan system). A computer program was used to establish bite forces (in %) for each tooth. 576 teeth were divided into 9 groups in accordance with the orthodontic diagnosis as follows: class II tendency (n = 126), cross-bite (n = 50), rotated (n = 30), scissors bite (n = 23), class III tendency (n = 19), class II (n = 16), open bite (n = 15), class III (n = 9), normal occlusion (n = 288). Each tooth in malocclusion was assigned a contralateral "control" tooth (Fig. 5). Bite forces acting on teeth in malocclusion were compared with control teeth using Student's t-test (Fig. 6). There is no difference between bite forces of teeth in normal occlusion and malocclusion on the opposite side of dental arches in the same patient, the only exceptions being open and
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Karna, Satya
2017-05-01
Full Text Available Objectives: To report a rare occurrence combination of central retinal artery occlusion (CRAO and Terson syndrome in a Barrow’s type A carotid cavernous fistula (CCF patient.Methods: Observational case report.Results: A twenty-year-old male patient with a history of road traffic accident presented with periorbital swelling and redness in the left eye. Examination revealed a CRAO with intraretinal and preretinal hemorrhages. On imaging, type A CCF and subarachnoid hemorrhage were detected. He underwent embolization of the fistula for cosmetic blemish. The possible mechanisms and clinical implications are discussed. Conclusion: Patients with a head injury can have serious ocular damage. Posterior segment manifestations of CCFs are varied and at times can occur in various rare combinations, making it challenging. Early recognition of these rare manifestations and a multi-disciplinary approach are needed in patients with head trauma.
Campbell, W B; Baird, R N; Cole, S E; Evans, J M; Skidmore, R; Woodcock, J P
1983-01-01
A new method is presented for assessing the femorodistal segment in multisegmental arterial disease, using the Laplace transform technique of Doppler waveform analysis. Blood velocity/time waveforms were obtained at femoral and ankle levels in three groups of limbs--50 without arterial disease, 12 with isolated aortoiliac stenoses, and 32 with femoropopliteal occlusions, with and without proximal disease. The waveforms were analysed for Laplace transform and pulsatility index values. The omega 0 coefficients of the Laplace transform analysis at femoral and ankle levels were compared in each subject, as the omega 0 gradient (femoral/ankle omega 0): and pulsatility index damping factor (femoral/ankle P1) was also calculated. The omega 0 gradient was shown to detect femoropopliteal occlusion in the presence of multisegmental arterial disease and to give some indication of its haemodynamic significance. The diagnostic accuracy of the omega 0 gradient was superior to that of pulsatility index damping factor. When combined with its existing ability to detect aortoiliac stenosis, this new application of the Laplace transform method offers the possibility both of a system for complete localisation of significant arterial lesions, and potential for follow-up of vascular surgical procedures in the lower limb, from two simple Doppler recordings.
Intraoral Digital Impressions for Virtual Occlusal Records: Section Quantity and Dimensions
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Eneko Solaberrieta
2016-01-01
Full Text Available The purpose of this study was to locate the 3D spatial position mandibular cast and determine its occlusal contacts in a novel way by using an intraoral scanner as part of the virtual occlusal record procedure. This study also analyzes the requirements in quantity and dimensions of the intraoral virtual occlusal record. The results showed that the best section combination consists of 2 lateral and frontal sections, the width of this section being that of 2 teeth (24 mm × 15 mm. This study concluded that this procedure was accurate enough to locate the mandibular cast on a virtual articulator. However, at least 2 sections of the virtual occlusal records were necessary, and the best results were obtained when the distance between these sections was maximum.
Intraoral Digital Impressions for Virtual Occlusal Records: Section Quantity and Dimensions
Solaberrieta, Eneko; Garmendia, Asier; Brizuela, Aritza; Otegi, Jose Ramon; Pradies, Guillermo; Szentpétery, Andras
2016-01-01
The purpose of this study was to locate the 3D spatial position mandibular cast and determine its occlusal contacts in a novel way by using an intraoral scanner as part of the virtual occlusal record procedure. This study also analyzes the requirements in quantity and dimensions of the intraoral virtual occlusal record. The results showed that the best section combination consists of 2 lateral and frontal sections, the width of this section being that of 2 teeth (24 mm × 15 mm). This study concluded that this procedure was accurate enough to locate the mandibular cast on a virtual articulator. However, at least 2 sections of the virtual occlusal records were necessary, and the best results were obtained when the distance between these sections was maximum. PMID:26881226
Occlusal consequence of using average condylar guidance settings: An in vitro study.
Lee, Wonsup; Lim, Young-Jun; Kim, Myung-Joo; Kwon, Ho-Beom
2017-04-01
A simplified mounting technique that adopts an average condylar guidance has been advocated. Despite this, the experimental explanation of how average settings differ from individual condylar guidance remains unclear. The purpose of this in vitro study was to examine potential occlusal error by using average condylar guidance settings during nonworking side movement of the articulator. Three-dimensional positions of the nonworking side maxillary first molar at various condylar and incisal settings were traced using a laser displacement sensor attached to the motorized stages with biaxial freedom of movement. To examine clinically relevant occlusal consequences of condylar guidance setting errors, the vertical occlusal error was defined as the vertical-axis positional difference between the average setting trace and the other condylar guidance setting trace. In addition, the respective contribution of the condylar and incisal guidance to the position of the maxillary first molar area was analyzed by multiple regression analysis using the resultant coordinate data. Alteration from individual to average settings led to a positional difference in the maxillary first molar nonworking side movement. When the individual setting was lower than average, vertical occlusal error occurred, which might cause occlusal interference. The vertical occlusal error ranged from -2964 to 1711 μm. In addition, the occlusal effect of incisal guidance was measured as a partial regression coefficient of 0.882, which exceeded the effect of condylar guidance, 0.431. Potential occlusal error as a result of adopting an average condylar guidance setting was observed. The occlusal effect of incisal guidance doubled the effect of condylar guidance. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.
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Weimin Wang
2016-11-01
Full Text Available The segmentation of point clouds is an important aspect of automated processing tasks such as semantic extraction. However, the sparsity and non-uniformity of the point clouds gathered by the popular 3D mobile LiDAR devices pose many challenges for existing segmentation methods. To improve the segmentation results of point clouds from mobile LiDAR devices, we propose an optimized segmentation method based on Scanline Continuity Constraint (SLCC in this work. Unlike conventional scanline-based segmentation methods, SLCC clusters scanlines using the continuity constraints in terms of the distance as well as the direction of two consecutive points. In addition, scanline clusters are agglomerated not only into primitive geometrical shapes but also irregular shapes. Another downside to existing segmentation methods is that they are not capable of incremental processing. This causes unnecessary memory and time consumption for applications that require frame-wise segmentation or when new point clouds are added. In order to address this, we propose an incremental scheme—the Incremental Recursive Segmentation (IRIS, that can be easily applied to any segmentation method. IRIS is achieved by combining the segments of newly added point clouds and the previously segmented results. Furthermore, as an example application, we construct a processing pipeline consisting of plane fitting and surface reconstruction using the segmentation results. Finally, we evaluate the proposed methods on three datasets acquired from a handheld Velodyne HDL-32E LiDAR device. The experimental results verify the efficiency of IRIS for any segmentation method and the advantages of SLCC for processing mobile LiDAR data.
[Influence of the occlusal interference time on masticatory muscle mechanical hyperalgesia in rats].
Liu, Cun-rui; Xu, Xiao-xiang; Cao, Ye; Xie, Qiu-fei
2016-02-18
To investigate the relationship between the removal time of 0.2 mm occlusal interference and the recovery of masticatory muscle mechanical hyperalgesia in rats. Forty male Sprague-Dawley rats (200-220 g) were randomly assigned to eight groups, with five rats in each group: (1) naive group: these rats were anesthetized and their mouths were forced open for about 5 min (the same duration as the other groups), but restorations were not applied; (2) sham-occlusal interference control group: bands were bonded to the right maxillary first molars which did not interfere with occlusion; (3)occlusal interference group: 0.2 mm thick crowns were bonded to the right maxillary first molars; (4) 2, 3, 4, 5, and 6 d removal of occlusal interference groups: 0.2 mm thick crowns were bonded to the right maxillary first molars and removed on days 2, 3, 4, 5, and 6. The naive group and sham-occlusal interference control group were control groups. The other groups were experimental groups. Bilateral masticatory muscle mechanical withdrawal thresholds were tested on pre-application days 1, 2, and 3, and on post-application days 1, 3, 5, 7, 10, 14, 21 and 28. The rats were weighed on pre-application day 1 and on post-application days 1, 2, 3, 4, 5, 6, and 7. Between the naive group and the sham-occlusal interference control group, there was no significant difference in the masticatory muscle mechanical withdrawal threshold of bilateral temporalis and masseters at each time point. No significant difference was detected between the contralateral side and ipsilateral side in experimental groups (P>0.05). In the 2, 3, 4, and 5 d removal of occlusal interference groups, the masticatory muscle mechanical withdrawal thresholds decreased after occlusal interference and increased after removal of the crowns and recovered to the baseline on days 7, 10, 14, and 14, respectively [the masticatory muscle mechanical withdrawal thresholds of right masseter muscle were (137.46 ± 2.08) g, (139.02 ± 2