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Sample records for anatomic landmarks based

  1. Collaborative regression-based anatomical landmark detection

    Science.gov (United States)

    Gao, Yaozong; Shen, Dinggang

    2015-12-01

    Anatomical landmark detection plays an important role in medical image analysis, e.g. for registration, segmentation and quantitative analysis. Among the various existing methods for landmark detection, regression-based methods have recently attracted much attention due to their robustness and efficiency. In these methods, landmarks are localised through voting from all image voxels, which is completely different from the classification-based methods that use voxel-wise classification to detect landmarks. Despite their robustness, the accuracy of regression-based landmark detection methods is often limited due to (1) the inclusion of uninformative image voxels in the voting procedure, and (2) the lack of effective ways to incorporate inter-landmark spatial dependency into the detection step. In this paper, we propose a collaborative landmark detection framework to address these limitations. The concept of collaboration is reflected in two aspects. (1) Multi-resolution collaboration. A multi-resolution strategy is proposed to hierarchically localise landmarks by gradually excluding uninformative votes from faraway voxels. Moreover, for informative voxels near the landmark, a spherical sampling strategy is also designed at the training stage to improve their prediction accuracy. (2) Inter-landmark collaboration. A confidence-based landmark detection strategy is proposed to improve the detection accuracy of ‘difficult-to-detect’ landmarks by using spatial guidance from ‘easy-to-detect’ landmarks. To evaluate our method, we conducted experiments extensively on three datasets for detecting prostate landmarks and head & neck landmarks in computed tomography images, and also dental landmarks in cone beam computed tomography images. The results show the effectiveness of our collaborative landmark detection framework in improving landmark detection accuracy, compared to other state-of-the-art methods.

  2. Semi-Automatic Anatomical Tree Matching for Landmark-Based Elastic Registration of Liver Volumes

    Directory of Open Access Journals (Sweden)

    Klaus Drechsler

    2010-01-01

    Full Text Available One promising approach to register liver volume acquisitions is based on the branching points of the vessel trees as anatomical landmarks inherently available in the liver. Automated tree matching algorithms were proposed to automatically find pair-wise correspondences between two vessel trees. However, to the best of our knowledge, none of the existing automatic methods are completely error free. After a review of current literature and methodologies on the topic, we propose an efficient interaction method that can be employed to support tree matching algorithms with important pre-selected correspondences or after an automatic matching to manually correct wrongly matched nodes. We used this method in combination with a promising automatic tree matching algorithm also presented in this work. The proposed method was evaluated by 4 participants and a CT dataset that we used to derive multiple artificial datasets.

  3. Pterion: An anatomical variation and surgical landmark

    Directory of Open Access Journals (Sweden)

    Prashant E Natekar

    2011-01-01

    Full Text Available Introduction : The frontal and the parietal bones superiorly and the greater wing of the sphenoid and the squamous temporal inferiorly of one side meet at an H-shaped sutural junction termed the pterion. This is an important anatomical and anthropological landmark as it overlies both the anterior branch of middle meningeal artery and the lateral fissure of the cerebral hemisphere. The knowledge of sutural joints between frontal, parietal, sphenoid and temporal bones at pterion is clinically, radiologically and surgically important during surgical interventions involving burr hole surgeries. Materials and Methods : Study performed on 150 dry temporal bones. The pterion, and its sutural articulations with frontal, parietal, sphenoid and temporal bones and also anatomical variations, if any, were studied. Results : Four types of pterion, i.e. sphenoparietal, frontotemporal, stellate and epipteric, were observed. Conclusions : The knowledge of the variations of pterion and its surgical anatomy, in Indian population are important for surgeons operating in the fieldThe present study will also contribute additional information of skull bone fractures in infancy and early childhood, which may be associated with large intersutural bones giving false appearance of fracture radiologically and also during surgical interventions involving burr hole surgeries, as their extensions may lead to continuation of fracture lines.

  4. Interventional guidance for cardiac resynchronization therapies: merging anatomic X-ray imaging with functional ultrasound imaging based on mutually-shared landmarks

    Energy Technology Data Exchange (ETDEWEB)

    Manzke, R.; Shechter, G.; Gutierrez, L.; Chan, R.C. [Philips Research North America, Briarcliff Manor, NY (United States); Tournoux, F.; Singh, J.; Picard, M. [Dept. of Cardiology, Massachusetts General Hospital, Harvard Medical School (United States); Brink, B. v.d.; Boomen, R. v.d. [Philips Medical System, Best (Netherlands); Gerard, O. [Philips Medical Systems, Paris (France)

    2007-06-15

    Detailed knowledge of cardiac anatomy and function is required for complex cardiac electrophysiology interventions. Cardiac resynchronization therapies (CRT), for example, requires information about coronary venous anatomy for left ventricular lead placement. In CRT, heart failure patients are equipped with dual-chamber pacemakers in order to improve cardiac output and heart failure symptoms. Cardiac function is mainly assessed with Ultrasound imaging. Fusion of complementary information from X-ray and ultrasound is an essential step towards fully utilizing all available information for CRT guidance. We present an approach for fusion of anatomical information (coronary vein structure) from X-ray with functional information (left ventricular deformation and dynamics) from ultrasound. We propose an image-based fusion approach based on mutually-shared landmarks which enable registration of both imaging spaces without the need for external tracking. (orig.)

  5. ANATOMICAL LANDMARKS FOR ROBOTIC NERVE SPARING RADICAL PROSTATECTOMY

    Directory of Open Access Journals (Sweden)

    T. N. Moiseenko

    2013-01-01

    Full Text Available A detailed anatomical study of the prostate and pelvic organs has been recently relevant. Their anatomical knowledge is directly associated with the improved procedure of nerve-sparing robot-assisted radical prostatectomy, which contributes to the preservation of the anatomical structures responsible for postsurgical erection and urinary continence. The main tasks of radical prostatectomy are effective cancer control, early recovery of urinary continence, and recovery of erectile function.The literature on the anatomy of the prostate and its adjacent structures is analyzed in the context of nerve-sparing robot-assisted radical prostatectomy.

  6. Influence of anatomic landmarks in the virtual environment on simulated angled laparoscope navigation

    NARCIS (Netherlands)

    Buzink, S.N.; Christie, L.S.; Goossens, R.H.M.; De Ridder, H.; Jakimowicz, J.J.

    2010-01-01

    Background - The aim of this study is to investigate the influence of the presence of anatomic landmarks on the performance of angled laparoscope navigation on the SimSurgery SEP simulator. Methods - Twenty-eight experienced laparoscopic surgeons (familiar with 30º angled laparoscope, >100 basic lap

  7. Automatic detection of anatomical landmarks in uterine cervix images.

    Science.gov (United States)

    Greenspan, Hayit; Gordon, Shiri; Zimmerman, Gali; Lotenberg, Shelly; Jeronimo, Jose; Antani, Sameer; Long, Rodney

    2009-03-01

    The work focuses on a unique medical repository of digital cervicographic images ("Cervigrams") collected by the National Cancer Institute (NCI) in longitudinal multiyear studies. NCI, together with the National Library of Medicine (NLM), is developing a unique web-accessible database of the digitized cervix images to study the evolution of lesions related to cervical cancer. Tools are needed for automated analysis of the cervigram content to support cancer research. We present a multistage scheme for segmenting and labeling regions of anatomical interest within the cervigrams. In particular, we focus on the extraction of the cervix region and fine detection of the cervix boundary; specular reflection is eliminated as an important preprocessing step; in addition, the entrance to the endocervical canal (the "os"), is detected. Segmentation results are evaluated on three image sets of cervigrams that were manually labeled by NCI experts.

  8. Landmark Optimization Using Local Curvature for Point-Based Nonlinear Rodent Brain Image Registration

    Directory of Open Access Journals (Sweden)

    Yutong Liu

    2012-01-01

    Full Text Available Purpose. To develop a technique to automate landmark selection for point-based interpolating transformations for nonlinear medical image registration. Materials and Methods. Interpolating transformations were calculated from homologous point landmarks on the source (image to be transformed and target (reference image. Point landmarks are placed at regular intervals on contours of anatomical features, and their positions are optimized along the contour surface by a function composed of curvature similarity and displacements of the homologous landmarks. The method was evaluated in two cases (=5 each. In one, MRI was registered to histological sections; in the second, geometric distortions in EPI MRI were corrected. Normalized mutual information and target registration error were calculated to compare the registration accuracy of the automatically and manually generated landmarks. Results. Statistical analyses demonstrated significant improvement (<0.05 in registration accuracy by landmark optimization in most data sets and trends towards improvement (<0.1 in others as compared to manual landmark selection.

  9. Autonomous Robot Navigation based on Visual Landmarks

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    autonomous navigation and self-localization using automatically selected landmarks. The thesis investigates autonomous robot navigation and proposes a new method which benefits from the potential of the visual sensor to provide accuracy and reliability to the navigation process while relying on naturally......The use of landmarks for robot navigation is a popular alternative to having a geometrical model of the environment through which to navigate and monitor self-localization. If the landmarks are defined as special visual structures already in the environment then we have the possibility of fully...... available environment features (natural landmarks). The goal is also to integrate techniques and algorithms (also related to other research field) in the same navigation system, in order to improve localization performance and system autonomy. The proposed localization strategy is based on a continuous...

  10. Forebrain development in fetal MRI: evaluation of anatomical landmarks before gestational week 27

    Energy Technology Data Exchange (ETDEWEB)

    Schmook, Maria T.; Weber, Michael; Kasprian, Gregor; Nemec, Stefan; Prayer, Daniela [Medical University of Vienna, Department of Radiology/Division of Neuro- and Musculoskeletal Radiology, Vienna (Austria); Brugger, Peter C. [Medical University of Vienna, Integrative Morphology Group, Center for Anatomy and Cell Biology, Vienna (Austria); Krampl-Bettelheim, Elisabeth [Department of Obstetrics and Gynecology / Division of Obstetrics and Feto-maternal Medicine, Vienna (Austria)

    2010-06-15

    Forebrain malformations include some of the most severe developmental anomalies and require early diagnosis. The proof of normal or abnormal prosencephalic development may have an influence on further management in the event of a suspected fetal malformation. The purpose of this retrospective study was to evaluate the detectability of anatomical landmarks of forebrain development using in vivo fetal magnetic resonance imaging (MRI) before gestational week (gw) 27. MRI studies of 83 singleton fetuses (gw 16-26, average {+-}sd: gw 22 {+-} 2) performed at 1.5 Tesla were assessed. T2-weighted (w) fast spin echo, T1w gradient-echo and diffusion-weighted sequences were screened for the detectability of anatomical landmarks as listed below. The interhemispheric fissure, ocular bulbs, corpus callosum, infundibulum, chiasm, septum pellucidum (SP), profile, and palate were detectable in 95%, 95%, 89%, 87%, 82%, 81%, 78%, 78% of cases. Olfactory tracts were more easily delineated than bulbs and sulci (37% versus 18% and 8%), with significantly higher detection rates in the coronal plane. The pituitary gland could be detected on T1w images in 60% with an increasing diameter with gestational age (p=0.041). The delineation of olfactory tracts (coronal plane), chiasm, SP and pituitary gland were significantly increased after week 21 (p<0.05). Pathologies were found in 28% of cases. This study provides detection rates for anatomical landmarks of forebrain development with fetal MRI before gw 27. Several anatomical structures are readily detectable with routine fetal MRI sequences; thus, if these landmarks are not delineable, it should raise the suspicion of a pathology. Recommendations regarding favorable sequences/planes are provided. (orig.)

  11. The secondary lobe as anatomic landmark for different pulmonary diseases

    International Nuclear Information System (INIS)

    The objective of this paper is to present the spectrum of pathological findings in the pulmonary parenchyma, based on the knowledge of the secondary lobe and its components. The evaluation was made using high-resolution computed tomography (HRCT) and compared with the histopathological findings. By definition, the secondary lobe is the small portion of pulmonary tissue separated by septa of connective tissue and supplied by 2-5 or more terminal bronchioles according to their central or peripheral location. Different disorders may become evident as a consequence of : 1) Bronchiolar obstruction (transient or definitive); 2) Intra-alveolar or wall involvement; 3) Involvement of the support tissue; 4) Involvement of the vascular or lymphatic structures. The etiology may be idiopathic, infectious, due to inhalation, neoplastic, allergic, due to collagen diseases, secondary to drug administration and/or post-transplantation. The evaluation of the secondary lobe components, with fine section HRCT, is the dynamic method of choice for the characterisation of pulmonary diseases, and allows to perform earlier and more precise differential diagnoses, when correlated with the clinical findings. The addition of sections during expiration to the routine study is paramount to underscore perfusion disturbances, which may remain undiagnosed during deep inspiration. The goal of this study is to review some of these disorders in which HRCT may be very useful and to correlate our observations with the histopathological findings. (author)

  12. Software Designation to Assess the Proximity of Different Facial Anatomic Landmarks to Midlines of the Mouth and Face

    OpenAIRE

    Moshkelgosha V.; Zare R; Safari A

    2014-01-01

    Statement of Problem: Recognition and determination of facial and dental midline is important in dentistry. Currently, there are no verifiable guidelines that direct the choice of specific anatomic landmarks to determine the midline of the face or mouth. Objectives: The purpose of this study was to determine which of facial anatomic landmarks is closest to the midline of the face as well as that of the mouth. Materials and Methods: Frontal full-face digital images of 92 subject...

  13. Software Designation to Assess the Proximity of Different Facial Anatomic Landmarks to Midlines of the Mouth and Face

    Directory of Open Access Journals (Sweden)

    Moshkelgosha V

    2014-12-01

    Full Text Available Statement of Problem: Recognition and determination of facial and dental midline is important in dentistry. Currently, there are no verifiable guidelines that direct the choice of specific anatomic landmarks to determine the midline of the face or mouth. Objectives: The purpose of this study was to determine which of facial anatomic landmarks is closest to the midline of the face as well as that of the mouth. Materials and Methods: Frontal full-face digital images of 92 subjects (men and women age range: 20-30 years in smile were taken under standardized conditions; commonly used anatomic landmarks, nasion, tip of the nose, and tip of the philtrum were digitized on the images of subjects and aesthetic analyzer software used for midline analysis using Esthetic Frame. Deviations from the midlines of the face and mouth were measured for the 3 clinical landmarks; the existing dental midline was considered as the fourth landmark. The entire process of midline analysis was done by a single observer and repeated twice. Reliability analysis and 1-sample t- tests were conducted. Results: The Intra-class correlation coefficients (ICCs for reliability analysis of RFV and RCV measures made two times revealed that the reliabilities were all acceptable. The results indicated that each of the 4 landmarks deviated uniquely and significantly (P<.001 from the midlines of the face as well as mouth in both males and females. Conclusions: There was a significant difference between the mean ratios of the chosen anatomic landmarks and the midlines of the face and mouth. The hierarchy of anatomic landmarks closest to the midline of the face is: (1 midline of the commissures, (2 nasion , (3 tip of philtrum,(4 dental midline, and (5 tip ofthe nose. The closest anatomic landmarks to the mouth midline are: (1 tip of philtrum, (2 dental midline, (3 tip of nose, and (4 nasion.

  14. Radiographic and anatomic landmarks to approach the anterior capsule in hip arthroscopy.

    Science.gov (United States)

    Salas, Antonio Porthos

    2015-12-01

    Hip arthroscopy (HA) is considered to be a very difficult and demanding surgical procedure, special instruments, an image intensifier and a fracture table or hip distractor are required to access the hip joint, the most common and worldwide used HA technique is entering blindly to the central compartment with the use of fluoroscopy and continuous distraction; with the potential danger if performed in unskillful hands of labral penetrations, labral resections and scuffing of the femoral head cartilage. Our technique describes the arthroscopic management of femoroacetabular impingement (FAI), performing a preoperative planning using radiographic and anatomic landmarks to approach the anterior capsule without the use of fluoroscopy. Access to the hip joint is made extra-articularly from the peritrochanteric compartment palpating the greater trochanter and posteriorly penetrating the iliotibial band sliding the arthroscopic sheath and obturator from the trochanteric border to the anterior femoral neck to visualize the anterior capsule bursa and anterior capsule fibers and posteriorly following our previous landmarks perform an anterior oblique Inverted 'T' or 'H' capsulotomy with a radiofrequency wand to access the cam-type impingement and distraction is made under direct controlled arthroscopic vision. Our technique in HA aiming the anterior capsule using radiographic and anatomic landmarks is safe, reliable and reproducible in FAI with big cams, deep sockets and cases with mild arthritis where the capsule is thick, stiff and calcified. PMID:27011869

  15. An investigation on the facial midline distance to some anatomic landmarks of the jaws among people with natural dentition

    Directory of Open Access Journals (Sweden)

    Mosharraf R

    2004-02-01

    Full Text Available The determination of the dental midline is necessary in most dental procedures."nOne of the methods to fulfill this goal is to determine the facial midline based on the midpoints of the"nforehead, nose, upper lip and chin. However, for various reasons, this method has not always been"nproved successful. In such cases, different techniques, based on the investigations in the edentulous"npatients, have been suggested."nPurpose: The aim of this study was to investigate the conformity of some landmarks such as labial"nfrenum, incisive papilla and mid palatal suture with dental and facial midlines among people with natural"ndentition in order to obtain accurate anatomic landmarks for denture replacement."nMaterials and Methods: In this descriptive study, 96 dental students, having all their permanent teeth"nand without any orthognathic problem, were chosen. For each subject, Alginate impressions and dental"ncasts were prepared. Then, centric occlusion was recorded with a biting wax and the facial mid line was"ndetermined on the anterior part of it. The distances from the facial midline to the upper teeth midline,"nincisive papilla, labial frenum and mid palatal suture were determined with a special tool and were"nmeasured by a VERNIEH two times. In order to analyze the results, Chi- Square and t-student tests were"nused."nResults: The average of facial midline distance to the upper teeth midline, the labial frenum, the incisive"npapilla and the mid palatal suture were 0.83±0.60, 0.67±G.54, 0.83±00.63 and 0.81±0.62 mm,"nrespectively. There was no significant difference between males and females. Labial frenum showed the"nminimum distance to the facial midline, while the incisive papilla had the maximum. There was no"nsignificant difference between these anatomic landmarks, in conformity or unconformity with the facial"nmidline"nConclusion: Considering the low percentage of the subjects with complete conformity and the lack of

  16. Verification of selected anatomic landmarks used as reference points for universal goniometer positioning during knee joint mobility range measurements.

    Science.gov (United States)

    Szulc, P; Lewandowski, J; Marecki, B

    2001-01-01

    The study was concerned with verification of the selection of reference points used for knee joint mobility range goniometry. The verification was based on photometric and electrogoniometric methods of femorotibial angle measurements. The material for measurements were three knee joint preparations. The obtained data were subjected to descriptive analysis; photographic documentation of geometric relations between the reference points was also prepared. Considerable divergence of measurement results was observed with respect to the actual knee joint flexion angle, amounting even to 16 degrees. The differences are due to the selection of anatomic landmarks, and depend in particular on the distance of the point to which the goniometer axis is applied from the approximate location of the mechanical joint axis. The corrections of knee joint flexion angle measurements were also estimated on the basis of data obtained from the photographs and the derived mathematical formula.

  17. Enhancing SAT Based Planning with Landmark Knowledge

    NARCIS (Netherlands)

    Elffers, J.; Konijnenberg, D.; Walraven, E.M.P.; Spaan, M.T.J.

    2013-01-01

    Several approaches exist to solve Artificial Intelligence planning problems, but little attention has been given to the combination of using landmark knowledge and satisfiability (SAT). Landmark knowledge has been exploited successfully in the heuristics of classical planning. Recently it was also s

  18. Anatomic landmarks of fluoroscopy guided puncture of the pulseless femoral artery

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Min Hee; Han, Gi Seok; Kim, Sung Jin; Park, Kil Sun; Cha, Sang Hoon; Bae, Il Hun; Lee, Seung Young [College of Medicine and Medical Research Institute, Chungbuk National University, Cheongju (Korea, Republic of)

    2006-07-15

    We wanted to improve puncturing the pulseless femoral artery by evaluating the anatomic landmarks that suggest the course of the femoral artery on fluoroscopy. We analyzed 37 hemipelvis spot images that were centered on the arterial sheath after puncture of the femoral artery. The inguinal angles were measured between the inguinal line connecting the anterior superior iliac spine and the symphysis pubis, and the line of the arterial sheath. Inguinal ligament ratios were measured as the distance from the symphysis pubis to the arterial sheath to the length of the inguinal ligament on the inguinal line. The femoral head ratios were measured as the distance from the medial margin of the femur head to the arterial sheath to the transverse length of the femur head. The mean inguinal angle was 66.5 and the mean inguinal ligament ratio was 0.42 ({+-} 0.03). The mean femoral head ratio was 0.08 ({+-} 0.18). In comparing the men and women, there was no significant difference in the inguinal angle and the femoral head ratio, but the inguinal distance ratio was larger in women (men: 0.41 {+-} 0.033, women: 0.44 {+-} 0.031, {rho} < 0.05). The femoral artery generally courses just lateral to the medial margin of the femur head (femoral head ratio: 0.08) and the medial 40% of the inguinal ligament (inguinal ligament ratio: 0.42). So, consideration of these relations may be helpful for puncturing the pulseless femoral artery.

  19. Dimensional ultrasonographic relationship of the right lobe of pancreas with associated anatomic landmarks in clinically normal dogs.

    Science.gov (United States)

    Wickramasekara Rajapakshage, Bandula Kumara; Ellearaewe Garuhamilage, Janaka Pradeep Kumara; De Silva, Dona Daphney Niranjala; Dangolla, Ashoka

    2016-01-01

    The purpose of this prospective study was to establish the ultrasonographic characteristics of the dimension of the right pancreatic lobe with that of the associated anatomic landmarks in healthy dogs. Ultrasonographic examinations were performed on 25 dogs. The thickness of the right pancreatic lobe was compared with that of mural thickness of duodenum, diameter of duodenum, pancreatic duct, abdominal aorta, portal vein, caudal vena cava, and length and width of the right kidney and right adrenal gland. The correlation between each pancreatic parameter and the dimensions of the anatomical landmarks were assessed using linear regression analysis and Pearson's correlation coefficient (r) test. Significant, but weak linear correlations were observed between thickness of right pancreatic lobe with that of duodenum mural thickness (r=0.605, R(2)=0.339, P=0.001); duodenum diameter (r=0.573, R(2)=0.299, P=0.003); and right adrenal gland length (r=0.508, R(2)=0.052, P=0.01). There was no significant dimensional relationship with other selected anatomic landmarks. The ratio between the thickness of right pancreatic lobe and the mural thickness of duodenum, diameter of duodenum and length of right adrenal gland were 2.88 ± 0.53, 1.27 ± 0.27 and 0.81 ± 0.15, respectively. Calculating the ratio of thickness of the right pancreatic lobe with the dimension of significantly correlated anatomic landmarks is a useful and simple method for evaluating the size of the right pancreatic lobe in dogs in clinical practice. PMID:26234888

  20. The impact of reorienting cone-beam computed tomographic images in varied head positions on the coordinates of anatomical landmarks

    Science.gov (United States)

    Kim, Jae Hun; Hwang, Jae Joon; Lee, Jung-Hee

    2016-01-01

    Purpose The aim of this study was to compare the coordinates of anatomical landmarks on cone-beam computed tomographic (CBCT) images in varied head positions before and after reorientation using image analysis software. Materials and Methods CBCT images were taken in a normal position and four varied head positions using a dry skull marked with 3 points where gutta percha was fixed. In each of the five radiographic images, reference points were set, 20 anatomical landmarks were identified, and each set of coordinates was calculated. Coordinates in the images from the normally positioned head were compared with those in the images obtained from varied head positions using statistical methods. Post-reorientation coordinates calculated using a three-dimensional image analysis program were also compared to the reference coordinates. Results In the original images, statistically significant differences were found between coordinates in the normal-position and varied-position images. However, post-reorientation, no statistically significant differences were found between coordinates in the normal-position and varied-position images. Conclusion The changes in head position impacted the coordinates of the anatomical landmarks in three-dimensional images. However, reorientation using image analysis software allowed accurate superimposition onto the reference positions. PMID:27358821

  1. Anatomic landmarks of fluoroscopy guided puncture of the pulseless femoral artery

    International Nuclear Information System (INIS)

    We wanted to improve puncturing the pulseless femoral artery by evaluating the anatomic landmarks that suggest the course of the femoral artery on fluoroscopy. We analyzed 37 hemipelvis spot images that were centered on the arterial sheath after puncture of the femoral artery. The inguinal angles were measured between the inguinal line connecting the anterior superior iliac spine and the symphysis pubis, and the line of the arterial sheath. Inguinal ligament ratios were measured as the distance from the symphysis pubis to the arterial sheath to the length of the inguinal ligament on the inguinal line. The femoral head ratios were measured as the distance from the medial margin of the femur head to the arterial sheath to the transverse length of the femur head. The mean inguinal angle was 66.5 and the mean inguinal ligament ratio was 0.42 (± 0.03). The mean femoral head ratio was 0.08 (± 0.18). In comparing the men and women, there was no significant difference in the inguinal angle and the femoral head ratio, but the inguinal distance ratio was larger in women (men: 0.41 ± 0.033, women: 0.44 ± 0.031, ρ < 0.05). The femoral artery generally courses just lateral to the medial margin of the femur head (femoral head ratio: 0.08) and the medial 40% of the inguinal ligament (inguinal ligament ratio: 0.42). So, consideration of these relations may be helpful for puncturing the pulseless femoral artery

  2. Interrater Reproducibility of Knee Movement Analyses during the Stance Phase: Use of Anatomical Landmark Calibration with a Rigid Marker Set

    Directory of Open Access Journals (Sweden)

    Takashi Fukaya

    2013-01-01

    Full Text Available Objective. Measurements of knee joint movement in gait analysis may result in large errors caused by misplacement of reflective markers by the testers. To properly understand the measurement results, it is important to guarantee the reliability of the measurement method used for the purpose. The aim of this study was to confirm the interrater reproducibility of a measurement method with a rigid marker set (RMS. Methods. The study subjects were four healthy adults, and the testers were three physical therapists. The interrater reproducibility of the measurements was verified by using the coefficient of multiple correlations (CMCs and the standard error of measurement (SEM. Results. The average CMCs values of 4 subjects in knee joint movement at the stance phase were greater than 0.8, and the average SEM values of 4 subjects in knee joint movement at the stance phase were also relatively good (maximum error: 2.42°. Conclusion. Based on these results, the measurement method with estimation of anatomical landmarks using the RMS can prevent misplacement during attachment of the reflective markers, as long as the testers have sufficient experience in attaching reflective markers.

  3. Indoor monocular mobile robot navigation based on color landmarks

    Institute of Scientific and Technical Information of China (English)

    LUO Yuan; ZHANG Bai-sheng; ZHANG Yi; LI Ling

    2009-01-01

    A robot landmark navigation system based on monocular camera was researched theoretically and experimentally. First the landmark setting and its data structure in programming was given; then the coordinates of them getting by robot and global localization of the robot was described; finally experiments based on Pioneer III mobile robot show that this system can work well at different topographic situation without lose of signposts.

  4. Nasolacrimal Duct Orifice: A Cadaveric Study in Relation to Important Anatomical Landmarks

    OpenAIRE

    Ankolekar, Vrinda Hari; Hosapatna, Mamatha; Das M, Aswin; Supriya, Supriya; Anne D Souza; Antony Sylvan D Souza

    2014-01-01

    AbstractThe nasolacrimal apparatus is intimately associated with the lateral nasal wall and may be approached using an endoscopic technique. This study was undertaken to describe in detail the gross anatomy of the nasolacrimal duct orifice in relation to various landmarks of the lateral nasal wall to improve the safety and efficiency of endoscopic surgical procedures. The study was conducted on 25 sagittal sections of adult cadavers in the Department of Anatomy, Kasturba Medical College, Mani...

  5. Adaptive Landmark-Based Navigation System Using Learning Techniques

    DEFF Research Database (Denmark)

    Zeidan, Bassel; Dasgupta, Sakyasingha; Wörgötter, Florentin;

    2014-01-01

    The goal-directed navigational ability of animals is an essential prerequisite for them to survive. They can learn to navigate to a distal goal in a complex environment. During this long-distance navigation, they exploit environmental features, like landmarks, to guide them towards their goal. In...... hexapod robots. As a result, it allows the robots to successfully learn to navigate to distal goals in complex environments.......The goal-directed navigational ability of animals is an essential prerequisite for them to survive. They can learn to navigate to a distal goal in a complex environment. During this long-distance navigation, they exploit environmental features, like landmarks, to guide them towards their goal....... Inspired by this, we develop an adaptive landmark-based navigation system based on sequential reinforcement learning. In addition, correlation-based learning is also integrated into the system to improve learning performance. The proposed system has been applied to simulated simple wheeled and more complex...

  6. The relationship of maxillary canines to the facial anatomical landmarks in a group of Thai people

    OpenAIRE

    Sinavarat, Potchaman; Anunmana, Chuchai; Hossain, Sharafat

    2013-01-01

    PURPOSE The objective was to evaluate canine positions, intercanine tip width (ICTW) and width of distal surface of canine (WDC), related to facial landmarks including interalar width (IAW), intercommissural width (ICoW), and distance between left and right projection lines drawn from inner canthus of eyes to alae of the nose (DPICa) in a group of Thai. MATERIALS AND METHODS One hundred Thai subjects aged 18-35 years were selected. IAW and ICoW were measured on subject's face using digital ve...

  7. Multirobot FastSLAM Algorithm Based on Landmark Consistency Correction

    Directory of Open Access Journals (Sweden)

    Shi-Ming Chen

    2014-01-01

    Full Text Available Considering the influence of uncertain map information on multirobot SLAM problem, a multirobot FastSLAM algorithm based on landmark consistency correction is proposed. Firstly, electromagnetism-like mechanism is introduced to the resampling procedure in single-robot FastSLAM, where we assume that each sampling particle is looked at as a charged electron and attraction-repulsion mechanism in electromagnetism field is used to simulate interactive force between the particles to improve the distribution of particles. Secondly, when multiple robots observe the same landmarks, every robot is regarded as one node and Kalman-Consensus Filter is proposed to update landmark information, which further improves the accuracy of localization and mapping. Finally, the simulation results show that the algorithm is suitable and effective.

  8. Is the omega sign a reliable landmark for the neurosurgical team? An anatomical study about the central sulcus region.

    Science.gov (United States)

    Rodrigues, Thiago; Rodrigues, Mariana; Paz, Daniel; Costa, Marcos Devanir; Santos, Bruno; Braga, Vinicius; Paiva Neto, Manoel de; Centeno, Ricardo; Cavalheiro, Sergio; Chaddad-Neto, Feres

    2015-11-01

    The central sulcus region is an eloquent area situated between the frontal and parietal lobes. During neurosurgical procedures, it is sometimes difficult to understand the cortical anatomy of this region.Objective Find alternative ways to anatomically navigate in this region during neurosurgical procedures.Method We analyzed eighty two human hemispheres using a surgical microscope and completed a review of the literature about central sulcus region.Results In 68/82 hemispheres, the central sulcus did not reach the posterior ramus of the lateral sulcus. A knob on the second curve of the precentral gyrus was reliably identified in only 64/82 hemispheres.Conclusion The morphometric data presented in this article can be useful as supplementary method to identify the central sulcus region landmarks.

  9. Is the omega sign a reliable landmark for the neurosurgical team? An anatomical study about the central sulcus region

    Directory of Open Access Journals (Sweden)

    Thiago Rodrigues

    2015-11-01

    Full Text Available ABSTRACTThe central sulcus region is an eloquent area situated between the frontal and parietal lobes. During neurosurgical procedures, it is sometimes difficult to understand the cortical anatomy of this region.Objective Find alternative ways to anatomically navigate in this region during neurosurgical procedures.Method We analyzed eighty two human hemispheres using a surgical microscope and completed a review of the literature about central sulcus region.Results In 68/82 hemispheres, the central sulcus did not reach the posterior ramus of the lateral sulcus. A knob on the second curve of the precentral gyrus was reliably identified in only 64/82 hemispheres.Conclusion The morphometric data presented in this article can be useful as supplementary method to identify the central sulcus region landmarks.

  10. An analysis of anatomic landmark mobility and setup deviations in radiotherapy for lung cancer

    International Nuclear Information System (INIS)

    Purpose: To identify thoracic structures that exhibit little internal motion during irradiation and to determine setup variations in patients with lung cancer. Methods and Materials: Intrafractional images were generated with an electronic portal-imaging device from the AP fields of 10 patients, during several fractions. To determine the intrafractional mobility of thoracic structures, visible structures were contoured in every image and matched with a reference image by means of a cross-correlation algorithm. Setup variations were determined by comparing portal images with the digitized simulator films using the stable structures as landmarks. Results: Mobility was limited in the lateral direction for the trachea, thoracic wall, paraspinal line, and aortic notch, and in the craniocaudal direction for the clavicle, aortic notch, and thoracic wall. Analysis of patient setup revealed random deviations of 2.0 mm (1 SD) in the lateral direction and 2.8 mm in the craniocaudal direction, while the systematic deviations were 2.5 and 2.0 mm (1 SD) respectively. Conclusions: We have identified thoracic structures that exhibit little internal motion in the frontal plane, and recommend that these structures be used for verifying patient setup during radiotherapy. The daily variation in the setup of lung cancer patients at our center appears to be acceptable

  11. Interfraction Displacement of Primary Tumor and Involved Lymph Nodes Relative to Anatomical Landmarks in Image–guided Radiotherapy of Locally Advanced Lung Cancer

    Science.gov (United States)

    Jan, Nuzhat; Balik, Salim; Hugo, Geoffrey D.; Mukhopadhyay, Nitai; Weiss, Elisabeth

    2014-01-01

    Purpose Image-guided radiotherapy for patients with locally advanced lung cancer relies on bony landmarks and carina or - if visible - the primary tumor (PT) for daily patient alignment, neglecting potential variations in the relative position of PT and involved lymph nodes (LN). This study analyzes PT and LN position changes relative to each other and relative to anatomical landmarks during conventionally fractionated radiotherapy. Methods and Materials In 12 patients with locally advanced non-small cell lung cancer PT, LN, carina and one thoracic vertebra were manually contoured on weekly 4D fan beam CTs. Systematic and random interfraction displacements of all contoured structures were identified in the three cardinal directions, resulting setup margins were calculated. Time trends and the effect of volume changes on displacements were analyzed. Results Three-dimensional displacement vectors and systematic/random interfraction displacements were smaller for carina than vertebra both for PT and LN. For PT, mean 3D displacement vectors with carina-based alignment were 7 mm/SD 4 mm versus 9 mm/SD 5 mm with bony anatomy (p0.05). Displacements between PT and bone (p=0.04), and between PT and LN (p=0.01) were significantly correlated with PT volume regression. Displacements between LN and carina were correlated with LN volume change (p=0.03). Conclusions Carina-based setup results in a more reproducible PT and LN alignment than bony anatomy setup. Considering the independence of PT and LN displacement and the impact of volume regression on displacements over time, repeated CT imaging even with primary tumorbased alignment is recommended in locally advanced disease. PMID:24239387

  12. Evaluation of polynomial image deformation for matching of 3D- abdominal MR-images using anatomical landmarks and for atlas construction

    CERN Document Server

    Kimiaei, S; Jonsson, E; Crafoord, J; Maguire, G Q

    1999-01-01

    The aim of this study is to compare and evaluate the potential usability of linear and non-linear (polynomial) 3D-warping for constructing an atlas by matching abdominal MR-images from a number of different individuals using manually picked anatomical landmarks. The significance of this study lies in the fact that it illustrates the potential to use polynomial matching at a local or organ level. This is a necessary requirement for constructing an atlas and for fine intra-patient image matching and fusion. Finally 3D-image warping using anatomical landmark for inter-patient intra-modality image co-registration and fusion was found to be a very powerful and robust method. Additionally it can be used for intra-patient inter- modality image matching.

  13. ANATOMIC STUDY OF LOCALIZATION OF FORAMEN OVALE, CAROTID CANAL, JUGULAR FORAMEN USING HENLE’S SPINE AS SURFACE LANDMARK IN SOUTH INDIAN ADULT SKULLS

    Directory of Open Access Journals (Sweden)

    Yogitha Ravindranath

    2016-07-01

    Full Text Available BACKGROUND Henle’s Spine (HS is a small bony prominence, anterior to the supramastoid pit, at the postero-superior margin of the external acoustic meatus. Localization of cranial structures using this anatomical landmark is of immense surgical importance to identify and avoid surgical morbidities. AIMS Considering the limited number of research articles describing its anatomy in South Indian skulls, present study was conducted to estimate the location and the difference between the right and left sides of the skull base foramen by using HS as surface landmark, which can act as a guide to various approaches of the skull base surgeries. SETTING AND DESIGN Cross-sectional observational study. MATERIALS AND METHODS Twenty nine (58 sides adult South Indian skulls with prominent HS were studied. Following distances on both right and left sides of the skulls were measured from tip of HS to anterior margin and posterior margin of foramen ovale (HS–AMFO, HS-PMFO; posterolateral and medial jugular foramen (HS-PLJF, HS-PMJF; lateral and medial margin of carotid canal (HS-LMCC, HS-MMCC using digital calliper of 0.01 mm accuracy. STATISTICAL ANALYSIS Data was analysed using SPSS version 16. Mean, Standard deviation was calculated. Side differences were estimated using paired ‘t’ test. RESULTS The mean distance from HS-AMFO was 35.96±2.05 mm, HS-PMFO was 42.57±2.38 mm; HS-PLJF 22.82±2.12 mm, HS-PMJF was 34.08±2.48 mm; HS-LMCC was 26.68±1.95 mm, HS-MMCC was 32.27±2.22 mm. There was a significant difference noted between right and left sides (p<0.05 of Henle’s spine to posterolateral margin of jugular foramen. CONCLUSION Henle’s spine can be used as a reliable landmark to locate the deeper structures of skull base. However, the possibility of side difference among the population should be kept in mind prior to surgery

  14. Radiological diagnostics of abdomen and thorax. Image interpretation considering anatomical landmarks and clinical symptoms; Radiologische Diagnostik Abdomen und Thorax. Bildinterpretation unter Beruecksichtigung anatomischer Landmarken und klinischer Symptome

    Energy Technology Data Exchange (ETDEWEB)

    Krombach, Gabriele A. [Universitaetsklinikum Giessen (Germany). Klinik fuer Diagnostische und Interventionelle Radiologie; Mahnken, Andreas H. (ed.) [Universitaetsklinikum Marburg (Germany). Diagnostische und Interventionelle Radiologie

    2015-07-01

    The book on radiological diagnostics of abdomen and thorax - image interpretation considering anatomical landmarks and clinical symptoms - includes three chapters: (1) imaging of different parts of the body: thorax and abdomen. (II) Thorax: head and neck; mediastinum; heard and pericardium; large vessels; lungs and pleura; mamma. (III) Abdomen: liver; gall bladder and biliary tract; pancreas; gastrointestinal tract; spleen and lymphatic system; adrenal glands; kidneys and urinary tract; female pelvis; male pelvis.

  15. Automatic facial expression recognition based on features extracted from tracking of facial landmarks

    Science.gov (United States)

    Ghimire, Deepak; Lee, Joonwhoan

    2014-01-01

    In this paper, we present a fully automatic facial expression recognition system using support vector machines, with geometric features extracted from the tracking of facial landmarks. Facial landmark initialization and tracking is performed by using an elastic bunch graph matching algorithm. The facial expression recognition is performed based on the features extracted from the tracking of not only individual landmarks, but also pair of landmarks. The recognition accuracy on the Extended Kohn-Kanade (CK+) database shows that our proposed set of features produces better results, because it utilizes time-varying graph information, as well as the motion of individual facial landmarks.

  16. Haptic Landmark Positioning and Automatic Landmark Transfer in 4D Lung CT Data

    Science.gov (United States)

    Färber, Matthias; Gawenda, Björn; Bohn, Christian-Arved; Handels, Heinz

    Manual landmark positioning in volumetric image data is a complex task and often results in erroneous landmark positions. The landmark positioning tool presented uses image curvature features to precompute suitable candidates for landmark positions on surface data of anatomical structures. A force-feedback I/O device is then used to haptically guide the user during the definition of the correct landmarks in the 3D data volume. Furthermore, existing landmarks in a time-point of a sequence of 3D volumes (4D data set) can iteratively be transferred to other time-points using a surface based registration technique. First results show significant time savings and small interobserver variability (IROV) compared to the IROV of manually defined landmark positions using orthogonal slices of the image data.

  17. The Comparison of Learning Radiographic Extraoral Anatomic Landmarks through Lecture and blended method(Computer-Assisted teaching and Lecture:An interventional Study

    Directory of Open Access Journals (Sweden)

    T ahmine Razi

    2013-05-01

    Full Text Available Introduction: One of the main problems in learning extraoral radiographic anatomic indexes is the long interval between presentation of radiology and human anatomy courses, resulting in forgetting anatomic regions. Therefore, radiographic indexes are formed as complete abstract and transient images in students’ minds; as a result, their learning and retention decrease. The aim of this study was to compare lecture with combination of computer-assisted learning and lecture of extra-oral radiographic landmarks among dental students. Methods: This interventional study was carried out in 2009 on 51 dental students of Tabriz University of Medical Sciences. Students were randomly allocated into two groups. The first group was taught through a teaching method which involved lectures in the classroom. In the second group, a CD was given to the students. The teaching was accomplished through presentation using skull. Six months after finishing the teaching, both groups took a similar test for evaluation of long term learning. The data was analyzed by SPSS 16 using U Mann-Whitney test. Results: There was no significant differences in the mean scores between the two groups in the first exam after teaching (P=0.13, yet it was significant in the second exam (regarding retention (P=0.006, and average of non-traditional teaching method group (20.89±10.23 was higher than that of lecture group (13.48±6.39. Conclusion: Based on the results, non-traditional technique of teaching was not more effective than the lecture in short-term learning but in longterm learning, non-traditional technique was more effective than the lecture.

  18. Automated Extraction of Cranial Landmarks from Computed Tomography Data using a Combined Method of Knowledge and Pattern Based Approaches

    Directory of Open Access Journals (Sweden)

    Roshan N. RAJAPAKSE

    2016-03-01

    Full Text Available Accurate identification of anatomical structures from medical imaging data is a significant and critical function in the medical domain. Past studies in this context have mainly utilized two main approaches, the knowledge and learning methodologies based methods. Further, most of previous reported studies have focused on identification of landmarks from lateral X-ray Computed Tomography (CT data, particularly in the field of orthodontics. However, this study focused on extracting cranial landmarks from large sets of cross sectional CT slices using a combined method of the two aforementioned approaches. The proposed method of this study is centered mainly on template data sets, which were created using the actual contour patterns extracted from CT cases for each of the landmarks in consideration. Firstly, these templates were used to devise rules which are a characteristic of the knowledge based method. Secondly, the same template sets were employed to perform template matching related to the learning methodologies approach. The proposed method was tested on two landmarks, the Dorsum sellae and the Pterygoid plate, using CT cases of 5 subjects. The results indicate that, out of the 10 tests, the output images were within the expected range (desired accuracy in 7 instances and acceptable range (near accuracy for 2 instances, thus verifying the effectiveness of the combined template sets centric approach proposed in this study.

  19. Interfraction Displacement of Primary Tumor and Involved Lymph Nodes Relative to Anatomic Landmarks in Image Guided Radiation Therapy of Locally Advanced Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jan, Nuzhat; Balik, Salim; Hugo, Geoffrey D. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia (United States); Mukhopadhyay, Nitai [Department of Biostatistics, Virginia Commonwealth University, Richmond, Virginia (United States); Weiss, Elisabeth, E-mail: eweiss@mcvh-vcu.edu [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia (United States)

    2014-01-01

    Purpose: To analyze primary tumor (PT) and lymph node (LN) position changes relative to each other and relative to anatomic landmarks during conventionally fractionated radiation therapy for patients with locally advanced lung cancer. Methods and Materials: In 12 patients with locally advanced non-small cell lung cancer PT, LN, carina, and 1 thoracic vertebra were manually contoured on weekly 4-dimensional fan-beam CT scans. Systematic and random interfraction displacements of all contoured structures were identified in the 3 cardinal directions, and resulting setup margins were calculated. Time trends and the effect of volume changes on displacements were analyzed. Results: Three-dimensional displacement vectors and systematic/random interfraction displacements were smaller for carina than for vertebra both for PT and LN. For PT, mean (SD) 3-dimensional displacement vectors with carina-based alignment were 7 (4) mm versus 9 (5) mm with bony anatomy (P<.0001). For LN, smaller displacements were found with carina- (5 [3] mm, P<.0001) and vertebra-based (6 [3] mm, P=.002) alignment compared with using PT for setup (8 [5] mm). Primary tumor and LN displacements relative to bone and carina were independent (P>.05). Displacements between PT and bone (P=.04) and between PT and LN (P=.01) were significantly correlated with PT volume regression. Displacements between LN and carina were correlated with LN volume change (P=.03). Conclusions: Carina-based setup results in a more reproducible PT and LN alignment than bony anatomy setup. Considering the independence of PT and LN displacement and the impact of volume regression on displacements over time, repeated CT imaging even with PT-based alignment is recommended in locally advanced disease.

  20. Learning-based landmarks detection for osteoporosis analysis

    Science.gov (United States)

    Cheng, Erkang; Zhu, Ling; Yang, Jie; Azhari, Azhari; Sitam, Suhardjo; Liang, Xin; Megalooikonomou, Vasileios; Ling, Haibin

    2016-03-01

    Osteoporosis is the common cause for a broken bone among senior citizens. Early diagnosis of osteoporosis requires routine examination which may be costly for patients. A potential low cost diagnosis is to identify a senior citizen at high risk of osteoporosis by pre-screening during routine dental examination. Therefore, osteoporosis analysis using dental radiographs severs as a key step in routine dental examination. The aim of this study is to localize landmarks in dental radiographs which are helpful to assess the evidence of osteoporosis. We collect eight landmarks which are critical in osteoporosis analysis. Our goal is to localize these landmarks automatically for a given dental radiographic image. To address the challenges such as large variations of appearances in subjects, in this paper, we formulate the task into a multi-class classification problem. A hybrid feature pool is used to represent these landmarks. For the discriminative classification problem, we use a random forest to fuse the hybrid feature representation. In the experiments, we also evaluate the performances of individual feature component and the hybrid fused feature. Our proposed method achieves average detection error of 2:9mm.

  1. Indirect building localization based on a prominent solid landmark from a forward-looking infrared imagery

    Institute of Scientific and Technical Information of China (English)

    Xiaoping Wang; Tianxu Zhang; Xiaoyu Yang

    2011-01-01

    A novel indirect building localization technique based on a prominent solid landmark from a forwardlooking infrared imagery is proposed to localize low, deeply buried, or carefully camouflaged buildings in dense urban areas.First, the widely used effective methods are applied to detect and localize the solid landmark.The building target is then precisely indirectly localized by perspective transformation according to the imaging parameters and the space constraint relations between the building target and the solid landmark.Experimental results demonstrate this technique can indirectly localize buildings in dense urban areas effectively.%@@ A novel indirect building localization technique based on a prominent solid landmark from a forward-looking infrared imagery is proposed to localize low, deeply buried, or carefully camouflaged buildings in dense urban areas.First, the widely used effective methods are applied to detect and localize the solid landmark.The building target is then precisely indirectly localized by perspective transformation according to the imaging parameters and the space constraint relations between the building target and the solid landmark.Experimental results demonstrate this technique can indirectly localize buildings in dense urban areas effectively.

  2. Localization of skeletal and aortic landmarks in trauma CT data based on the discriminative generalized Hough transform

    Science.gov (United States)

    Lorenz, Cristian; Hansis, Eberhard; Weese, Jürgen; Carolus, Heike

    2016-03-01

    Computed tomography is the modality of choice for poly-trauma patients to assess rapidly skeletal and vascular integrity of the whole body. Often several scans with and without contrast medium or with different spatial resolution are acquired. Efficient reading of the resulting extensive set of image data is vital, since it is often time critical to initiate the necessary therapeutic actions. A set of automatically found landmarks can facilitate navigation in the data and enables anatomy oriented viewing. Following this intention, we selected a comprehensive set of 17 skeletal and 5 aortic landmarks. Landmark localization models for the Discriminative Generalized Hough Transform (DGHT) were automatically created based on a set of about 20 training images with ground truth landmark positions. A hierarchical setup with 4 resolution levels was used. Localization results were evaluated on a separate test set, consisting of 50 to 128 images (depending on the landmark) with available ground truth landmark locations. The image data covers a large amount of variability caused by differences of field-of-view, resolution, contrast agent, patient gender and pathologies. The median localization error for the set of aortic landmarks was 14.4 mm and for the set of skeleton landmarks 5.5 mm. Median localization errors for individual landmarks ranged from 3.0 mm to 31.0 mm. The runtime performance for the whole landmark set is about 5s on a typical PC.

  3. Visual homing in the absence of feature-based landmark information.

    Science.gov (United States)

    Gillner, Sabine; Weiss, Anja M; Mallot, Hanspeter A

    2008-10-01

    Despite that fact that landmarks play a prominent role in human navigation, experimental evidence on how landmarks are selected and defined by human navigators remains elusive. Indeed, the concept of a 'landmark' is itself not entirely clear. In everyday language, the term landmark refers to salient, distinguishable, and usually nameable objects, rendering the problem of landmark recognition a special case of the general object recognition problem. In contrast, in the insect and robot literature, this notion of landmarks is often replaced by the "local position information" [e.g., Trullier, O., Wiener, S., Berthoz, A., & Meyer, J.-A. (1997). Biologically based artificial navigation systems: Review and prospects. Progress in Neurobiology, 51, 483-544], referring to the entire set of sensor readings obtained at one location. This set may then serve as a characteristic of the particular location. Honey bees have been shown to base place recognition and homing on a snapshot-like memory of the place's visual environment, not on the distances to recognized objects [Cartwright, B., & Collett, T. (1983). Landmark learning in bees. Experiments and models. Journal of Comparative Physiology A, 151, 521-543]. A number of theoretical models of snapshot-based homing [e.g., Franz, M., Schölkopf, B., Mallot, H. A., Bülthoff, H. H. (1998). Where did I take that snapshot? Scene-based homing by image matching. Biological Cybernetics, 79, 191-202; Vardy, A., & Möller, R. (2005). Biologically plausible visual homing methods based on optical flow techniques. Connection Science, 17, 47-89] predict that the accuracy of snapshot-based homing should depend on image contrast. For rodent hippocampal place fields, models have been developed using additional image information such as three-dimensional depth and allocentric orientations (e.g., room axes) and are thus less sensitive to image contrast and noise [e.g. Barry, C., Lever, C., Hayman, R., Hartley, T., Burton, S., O'Keefe, J., et al

  4. Robust 3D face landmark localization based on local coordinate coding.

    Science.gov (United States)

    Song, Mingli; Tao, Dacheng; Sun, Shengpeng; Chen, Chun; Maybank, Stephen J

    2014-12-01

    In the 3D facial animation and synthesis community, input faces are usually required to be labeled by a set of landmarks for parameterization. Because of the variations in pose, expression and resolution, automatic 3D face landmark localization remains a challenge. In this paper, a novel landmark localization approach is presented. The approach is based on local coordinate coding (LCC) and consists of two stages. In the first stage, we perform nose detection, relying on the fact that the nose shape is usually invariant under the variations in the pose, expression, and resolution. Then, we use the iterative closest points algorithm to find a 3D affine transformation that aligns the input face to a reference face. In the second stage, we perform resampling to build correspondences between the input 3D face and the training faces. Then, an LCC-based localization algorithm is proposed to obtain the positions of the landmarks in the input face. Experimental results show that the proposed method is comparable to state of the art methods in terms of its robustness, flexibility, and accuracy. PMID:25296404

  5. Referências anatômicas na cirurgia do implante auditivo de tronco cerebral Anatomical landmarks in auditory brainstem implant surgery

    Directory of Open Access Journals (Sweden)

    Rubens Vuono Brito Neto

    2005-06-01

    location of the insertion of the ABI electrode was studied through translabyrinthine access. RESULTS: The surgical technique used for implanting the brainstem electrode is similar to that used in the removal of vestibular schwannoma. The cochlear nucleus complex, comprising ventral and dorsal cochlear nuclei, is the optimal electrode site. The ventral cochlear nucleus is the principal nucleus for transmission of neural impulses from the 8th pair and form the main ascending route of the cochlear nerve. Neither the ventral nor the dorsal nuclei are visible during surgery and their location depends on the identification of adjacent anatomical structures. CONCLUSION: The region for the implantation of the electrode in the auditory brainstem implant presents anatomical landmarks that allow its easy identification during surgery.

  6. Can osseous landmarks in the distal medial humerus be used to identify the attachment sites of ligaments and tendons: paleopathologic-anatomic imaging study in cadavers

    Energy Technology Data Exchange (ETDEWEB)

    Buck, Florian M. [Veterans Administration Medical Center, Department of Radiology, San Diego, CA (United States); Institut fuer Diagnostische Radiologie, Uniklinik Balgrist, Zurich (Switzerland); Zoner, Cristiane S.; Cardoso, Fabiano; Gheno, Ramon; Nico, Marcelo A.C.; Trudell, Debra J.; Resnick, Donald [Veterans Administration Medical Center, Department of Radiology, San Diego, CA (United States); Randall, Tori D. [San Diego Museum of Man, Physical Anthropology, San Diego, CA (United States)

    2010-09-15

    To describe osseous landmarks that allow identification of the attachments of the ligaments and tendons in the distal medial aspect of the humerus. Reliable osseous landmarks in the distal medial aspect of the humerus were identified in 34 well-preserved specimens from a paleopathologic collection. These osseous landmarks were then sought in magnetic resonance (MR) images of ten cadaveric elbow specimens so that the ease of their visualization and optimal imaging plane could be assessed. To assign these osseous landmarks to specific attachments of the tendons and ligaments in the distal medial humerus, we cut the specimens in slices and photographed and examined them. Subsequently, the prevalence of these osseous landmarks as well as the attachment sites of the tendons and ligaments in this location was determined. We determined ten reliable osseous landmarks in the distal medial aspect of the humerus, their prevalence and ease of identification, and their relationship to the attachments of the tendons and ligaments at the medial distal humerus. It is possible to use osseous landmarks at the distal medial humerus to facilitate identification of the different attachments of tendons and ligaments when MR images of the elbow are assessed. (orig.)

  7. Within-compound associations explain potentiation and failure to overshadow learning based on geometry by discrete landmarks.

    Science.gov (United States)

    Austen, Joe M; Kosaki, Yutaka; McGregor, Anthony

    2013-07-01

    In three experiments, rats were trained to locate a submerged platform in one of the base corners of a triangular arena above each of which was suspended one of two distinctive landmarks. In Experiment 1, it was established that these landmarks differed in their salience by the differential control they gained over behavior after training in compound with geometric cues. In Experiment 2, it was shown that locating the platform beneath the less salient landmark potentiated learning based on geometry compared with control rats for which landmarks provided ambiguous information about the location of the platform. The presence of the more salient landmark above the platform for another group of animals appeared to have no effect on learning based on geometry. Experiment 3 established that these landmark and geometry cues entered into within-compound associations during compound training. We argue that these within-compound associations can account for the potentiation seen in Experiment 2, as well as previous failures to demonstrate overshadowing of geometric cues. We also suggest that these within-compound associations need not be of different magnitudes, despite the different effects of each of the landmarks on learning based on geometry seen in Experiment 2. Instead, within-compound associations appear to mitigate the overshadowing effects that traditional theories of associative learning would predict.

  8. Monocular vision for intelligent wheelchair indoor navigation based on natural landmark matching

    Science.gov (United States)

    Xu, Xiaodong; Luo, Yuan; Kong, Weixi

    2010-08-01

    This paper presents a real-time navigation system in a behavior-based manner. We show that autonomous navigation is possible in different rooms with the use of a single camera and natural landmarks. Firstly the intelligent wheelchair is manually guided on a path passing through different rooms and a video sequence is recorded with a front-facing camera. A 3D structure map is then gotten from this learning sequence by calculating the natural landmarks. Finally, the intelligent wheelchair uses this map to compute its localization and it follows the learning path or a slightly different path to achieve the real-time navigation. Experimental results indicate that this method is effective even when the viewpoint and scale is changed.

  9. Knee joint secondary motion accuracy improved by quaternion-based optimizer with bony landmark constraints.

    Science.gov (United States)

    Wang, Hongsheng; Zheng, Naiqaun Nigel

    2010-12-01

    Skin marker-based motion analysis has been widely used in biomechanical studies and clinical applications. Unfortunately, the accuracy of knee joint secondary motions is largely limited by the nonrigidity nature of human body segments. Numerous studies have investigated the characteristics of soft tissue movement. Utilizing these characteristics, we may improve the accuracy of knee joint motion measurement. An optimizer was developed by incorporating the soft tissue movement patterns at special bony landmarks into constraint functions. Bony landmark constraints were assigned to the skin markers at femur epicondyles, tibial plateau edges, and tibial tuberosity in a motion analysis algorithm by limiting their allowed position space relative to the underlying bone. The rotation matrix was represented by quaternion, and the constrained optimization problem was solved by Fletcher's version of the Levenberg-Marquardt optimization technique. The algorithm was validated by using motion data from both skin-based markers and bone-mounted markers attached to fresh cadavers. By comparing the results with the ground truth bone motion generated from the bone-mounted markers, the new algorithm had a significantly higher accuracy (root-mean-square (RMS) error: 0.7 ± 0.1 deg in axial rotation and 0.4 ± 0.1 deg in varus-valgus) in estimating the knee joint secondary rotations than algorithms without bony landmark constraints (RMS error: 1.7 ± 0.4 deg in axial rotation and 0.7 ± 0.1 deg in varus-valgus). Also, it predicts a more accurate medial-lateral translation (RMS error: 0.4 ± 0.1 mm) than the conventional techniques (RMS error: 1.2 ± 0.2 mm). The new algorithm, using bony landmark constrains, estimates more accurate secondary rotations and medial-lateral translation of the underlying bone.

  10. Percutaneous Placement of Central Venous Catheters: Comparing the Anatomical Landmark Method with the Radiologically Guided Technique for Central Venous Catheterization Through the Internal Jugular Vein in Emergent Hemodialysis Patients

    Energy Technology Data Exchange (ETDEWEB)

    Koroglu, M.; Demir, M.; Koroglu, B.K.; Sezer, M.T.; Akhan, O.; Yildiz, H.; Yavuz, L.; Baykal, B.; Oyar, O. [Suleyman Demirel Univ., Isparta (Turkey). Depts. of Radiology, Internal Medicine and Anesthesiology

    2006-02-15

    Purpose: To compare the success and immediate complication rates of the anatomical landmark method (group 1) and the radiologically (combined real-time ultrasound and fluoroscopy) guided technique (group 2) in the placement of central venous catheters in emergent hemodialysis patients. Material and Methods: The study was performed prospectively in a randomized manner. The success and immediate complication rates of radiologically guided placement of central venous access catheters through the internal jugular vein (n = 40) were compared with those of the anatomical landmark method (n 40). The success of placement, the complications, the number of passes required, and whether a single or double-wall puncture occurred were also noted and compared. Results: The groups were comparable in age and sex. The indication for catheter placement was hemodialysis access in all patients. Catheter placement was successful in all patients in group 2 and unsuccessful in 1 (2.5%) patient in group 1. All catheters functioned adequately and immediately after the placement (0% initial failure rate) in group 2, but 3 catheters (7.5% initial failure rate) were non-functional just after placement in group 1. The total number of needle passes, double venous wall puncture, and complication rate were significantly lower in group 2. Conclusion: Percutaneous central venous catheterization via the internal jugular vein can be performed by interventional radiologists with better technical success rates and lower immediate complications. In conclusion, central venous catheterization for emergent dialysis should be performed under both real-time ultrasound and fluoroscopic guidance.

  11. Landmark based shape analysis for cerebellar ataxia classification and cerebellar atrophy pattern visualization

    Science.gov (United States)

    Yang, Zhen; Abulnaga, S. Mazdak; Carass, Aaron; Kansal, Kalyani; Jedynak, Bruno M.; Onyike, Chiadi; Ying, Sarah H.; Prince, Jerry L.

    2016-03-01

    Cerebellar dysfunction can lead to a wide range of movement disorders. Studying the cerebellar atrophy pattern associated with different cerebellar disease types can potentially help in diagnosis, prognosis, and treatment planning. In this paper, we present a landmark based shape analysis pipeline to classify healthy control and different ataxia types and to visualize the characteristic cerebellar atrophy patterns associated with different types. A highly informative feature representation of the cerebellar structure is constructed by extracting dense homologous landmarks on the boundary surfaces of cerebellar sub-structures. A diagnosis group classifier based on this representation is built using partial least square dimension reduction and regularized linear discriminant analysis. The characteristic atrophy pattern for an ataxia type is visualized by sampling along the discriminant direction between healthy controls and the ataxia type. Experimental results show that the proposed method can successfully classify healthy controls and different ataxia types. The visualized cerebellar atrophy patterns were consistent with the regional volume decreases observed in previous studies, but the proposed method provides intuitive and detailed understanding about changes of overall size and shape of the cerebellum, as well as that of individual lobules.

  12. Landmark detection and coupled patch registration for cardiac motion tracking

    Science.gov (United States)

    Wang, Haiyan; Shi, Wenzhe; Zhuang, Xiahai; Wu, Xianliang; Tung, Kai-Pin; Ourselin, Sebastien; Edwards, Philip; Rueckert, Daniel

    2013-03-01

    Increasing attention has been focused on the estimation of the deformation of the endocardium to aid the diagnosis of cardiac malfunction. Landmark tracking can provide sparse, anatomically relevant constraints to help establish correspondences between images being tracked or registered. However, landmarks on the endocardium are often characterized by ambiguous appearance in cardiac MR images which makes the extraction and tracking of these landmarks problematic. In this paper we propose an automatic framework to select and track a sparse set of distinctive landmarks in the presence of relatively large deformations in order to capture the endocardial motion in cardiac MR sequences. To achieve this a sparse set of the landmarks is identified using an entropy-based approach. In particular we use singular value decomposition (SVD) to reduce the search space and localize the landmarks with relatively large deformation across the cardiac cycle. The tracking of the sparse set of landmarks is performed simultaneously by optimizing a two-stage Markov Random Field (MRF) model. The tracking result is further used to initialize registration based dense motion tracking. We have applied this framework to extract a set of landmarks at the endocardial border of the left ventricle in MR image sequences from 51 subjects. Although the left ventricle undergoes a number of different deformations, we show how the radial, longitudinal motion and twisting of the endocardial surface can be captured by the proposed approach. Our experiments demonstrate that motion tracking using sparse landmarks can outperform conventional motion tracking by a substantial amount, with improvements in terms of tracking accuracy of 20:8% and 19:4% respectively.

  13. Dissimilarity-based classification of anatomical tree structures

    DEFF Research Database (Denmark)

    Sørensen, Lauge Emil Borch Laurs; Lo, Pechin Chien Pau; Dirksen, Asger;

    2011-01-01

    A novel method for classification of abnormality in anatomical tree structures is presented. A tree is classified based on direct comparisons with other trees in a dissimilarity-based classification scheme. The pair-wise dissimilarity measure between two trees is based on a linear assignment betw...

  14. A landmark-based method for the geometrical 3D calibration of scanning microscopes

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, M.

    2007-04-27

    This thesis presents a new strategy and a spatial method for the geometric calibration of 3D measurement devices at the micro-range, based on spatial reference structures with nanometersized landmarks (nanomarkers). The new method was successfully applied for the 3D calibration of scanning probe microscopes (SPM) and confocal laser scanning microscopes (CLSM). Moreover, the spatial method was also used for the photogrammetric self-calibration of scanning electron microscopes (SEM). In order to implement the calibration strategy to all scanning microscopes used, the landmark-based principle of reference points often applied at land survey or at close-range applications has been transferred to the nano- and micro-range in the form of nanomarker. In order to function as a support to the nanomarkers, slope-shaped step pyramids have been developed and fabricated by focused ion beam (FIB) induced metal deposition. These FIB produced 3D microstructures have been sized to embrace most of the measurement volume of the scanning microscopes. Additionally, their special design allows the homogenous distribution of the nanomarkers. The nanomarkers were applied onto the support and the plateaus of the slope-step pyramids by FIB etching (milling) as landmarks with as little as several hundreds of nanometers in diameter. The nanomarkers are either of point-, or ring-shaped design. They are optimized so that they can be spatially measured by SPM and CLSM, and, imaged and photogrammetrically analyzed on the basis of SEM data. The centre of the each nanomarker serves as reference point in the measurement data or images. By applying image processing routines, the image (2D) or object (3D) coordinates of each nanomarker has been determined with subpixel accuracy. The correlative analysis of the SPM, CLSM and photogrammetric SEM measurement data after 3D calibration resulted in mean residues in the measured coordinates of as little as 13 nm. Without the coupling factors the mean

  15. Landmark-based shape analysis of the archaic Homo calvarium from Ceprano (Italy).

    Science.gov (United States)

    Bruner, Emiliano; Manzi, Giorgio

    2007-03-01

    The Ceprano calvarium represents one of the most important sources of information about both the dynamics of the earliest hominid dispersal toward Europe and the evolution of the genus Homo in the early-to-middle Pleistocene. In this paper, the midsagittal vault profile and the 3D frontal bone morphology of Ceprano are investigated comparatively, using landmark coordinates and Procrustes superimposition. In fact, despite the fact that the skull appears partially distorted by diagenetic pressures (thus precluding a comprehensive landmark-based analysis), some aspects of the overall morphology are suitable for consideration in terms of geometric morphometrics. The midsagittal profile shows an archaic shape, comparable with the H. ergaster/erectus range of variation because of the fronto-parietal flattening, the development of the supraorbital and nuchal structures, and the occurrence of a slightly larger occipital bone. By contrast, the frontal bone displays a derived 3D shape that, mostly because of the widening of the frontal squama, appears comparable with the Afro-European variation of the Middle Pleistocene (i.e., H. heidelbergensis/rhodesiensis). Taking into account the unique morphological pattern displayed by Ceprano, its role as a link between early Homo and the Middle Pleistocene populations of Europe and Africa is not falsified. Thus, when aspects of the Ceprano's morphology are described within the analytical framework provided by geometric morphometrics, the relationships between Ceprano and the subsequent Afro-European fossil record are emphasized, suggesting the occurrence of an ancestral stock of H. heidelbergensis/rhodesiensis that is properly represented by the Italian specimen. PMID:17177181

  16. Flexible learning and use of multiple-landmark information by pigeons (Columba livia) in a touch screen-based goal searching task.

    Science.gov (United States)

    Ushitani, Tomokazu; Jitsumori, Masako

    2011-08-01

    Three touch screen-based experiments were conducted to investigate whether pigeons would learn to use configural information about a goal's location in relation to a multiple-landmark array. In Experiment 1, 4 pigeons (Columba livia) were trained to peck a computer monitor at a location that constituted the third vertex of a hypothetical triangle defined by 2 different landmarks. The landmarks appeared in 3 orientations during the training, and the pigeons' goal-searching ability easily transferred to the landmarks presented in 3 novel orientations. Each landmark was asymmetric, so we next examined whether the pigeons used (a) the small-scale, local orientation information that could be inferred from each landmark individually, or (b) the large-scale, configural information that could be inferred from the spatial arrangement of multiple landmarks taken as a whole. Even when each single landmark appeared by itself, the pigeons were able to locate the goal accurately, suggesting that the large-scale, configural information was not essential. However, when 1 landmark locally pointed to a location that was consistent with the triangular configuration and the other landmark locally pointed to a different location, the pigeons predominantly pecked at the configurally array-consistent location. These results suggest that the pigeons redundantly learned both the large-scale, configural strategy and the local, single-landmark strategy, but they mainly used the latter information, and used the former information solely to disambiguate conflicts when the 2 landmarks pointed toward different targets. Such flexible learning and use of redundant information may reflect the pigeons' adaptation to unstable wild environments during their evolutionary history. PMID:21574692

  17. The study of set-up errors for patients with thoracic tumors by different anatomical landmarks%胸部肿瘤不同参考标记的摆位误差研究

    Institute of Scientific and Technical Information of China (English)

    李丹明; 王黎; 孙新臣; 姜楠; 杨焱; 李彩虹

    2014-01-01

    Objective: Based on different anatomical landmarks for patients with thoracic tumors, the interfractional set-up errors and intrafractional organ motions were analyzed to define appropriate planning target volume(PTV)- and planning or-gans at risk volume(PRV)-margins in intensity-modulated radiotherapy(IMRT). Methods: Eleven patients with thoracic tumors who were treated with IMRT were Enrolled. Digital reconstruction radiographs(DRRs) were generated as the reference image by electronic portal imaging device(EPID). Based on the different anatomical landmarks as follows: vertebral column , pul-monary apices, the trachea, the interfractional set-up errors and intrafractional organ motions were calculated to find the de-fine appropriate PTV-and PRV-margins. Results: The standard deviations(SDs) of the systematic set-up errors(Σ-INTER) a-long left-right(L-R), anterior-posterior(A-P) and cranial-caudal(C-C) direction ranged from 0.45-0.72, 0.58-0.85 and 0.68-1.13 mm respectively. The SDs of organ motions(Σ-intra) ranged from 0.27-0.42, 0.39-0.48 and 0.37-0.58 mm re-spectively. The SDs of the random set-up errors(δ-INTER) along left-right(L-R), anterior-posterior(A-P) and cranial-caudal (C-C) direction ranged from 2.24-2.29, 2.09-2.22 and 2.53-2.87 mm respectively. The standard deviations (SDs) of organ motions(δ-intra) ranged from 2.08-2.26, 1.97-2.10 and 2.27-2.48 mm. Based on these data as above, appropriate PTV-margins and PRV-margins for vertebral column along left-right(L-R), anterior-posterior(A-P) and cranial-caudal(C-C) were 3.68/2.53, 3.60/2.48 and 4.93/3.38 mm;3.47/2.40, 3.72/2.55, 5.00/3.42 mm;3.65/2.52, 3.73/2.56 and 4.45/3.05 mm for pulmonary apices;3.34/2.31, 3.98/2.72 and 4.03/2.78 mm for the trachea respectively. Conclusion: The set-up errors were corrected based on the different landmarks, a PTV-margin of 5 mm and a PRV-margin of 3.5 mm for thoracic IMRT were adopted at our department.%目的:采用不同的解剖标记,定量的分析胸部肿

  18. Measurement and clinical significance on anatomic landmark of anterior cervical decompression%颈椎前路减压手术解剖标志定位测量及其临床意义

    Institute of Scientific and Technical Information of China (English)

    林永绥; 王万明; 张发惠; 郑和平; 王春

    2014-01-01

    Objective The primary purpose of the current study is to provide more scientific landmarks for safe and efficient decompression within limited operating field in cervical anterior decompression. Methods Relative data were observed and measured at C3~7 of 15 adult cadaveric specimens and some data were calculated basing on above data:the ratio of anterior crus of uncinate process-medial border of longus colli muscle distance and medial border of longus colli muscle-median sagittal plane distance(AULD/MLPD), the ratio of anterior crus of uncinate process- medial border of foramen transversarium distance and anterior crus of uncinate process-medial border of longus colli muscle distance (AUTD/AULD), the ratio of anterior crus of uncinate process-lateral border of dural sac perpendicular distance and posterior crus of uncinate process-lateral border of dural sac distance(AUDD/PUDD), and the ratio of the nearest point of uncinate process and nerve root-anterior crus of uncinate process perpendicular distance and anteroposterior crus of uncinate process perpendicular distance(UNAD/APUD). Results AULD/MLPD averaged 0.83 at C3, 0.55 at C4, 0.20 at C5, 0.34 at C6, and 0.27 at C7. AUTD/AULD averaged 2.71, AUDD/PUDD averaged 0.28, and UNAD/APUD averaged 0.34. Conclusion Anterior crus of uncinate process is a consistent anatomic landmark at anterior border of cervical vertebrae, which could serve as a stationary and reliable landmark in cervical anterior decompression, and facilitate the location of dural sac, cervical nerve root and vertebral artery during operation according to the ratios of AUDD/PUDD, UNAD/APUD and AUTD/AULD.%目的:为颈椎前路减压手术在有限显露术野中达到安全、有效减压提供更科学的减压标志。方法在15具成人尸体标本上,解剖观测C3~7节段相关解剖数据,以所测量的数据为基础,计算:(1)椎体钩前脚至颈长肌内侧缘的距离/颈长肌内侧缘至正中矢状面的距离(AULD/MLPD);(2

  19. The Use of Quick Response (QR Codes in Landmark-Based Pedestrian Navigation

    Directory of Open Access Journals (Sweden)

    Anahid Basiri

    2014-01-01

    Full Text Available Vehicle navigation systems usually simply function by calculating the shortest fastest route over a road network. In contrast, pedestrian navigation can have more diverse concerns. Pedestrians are not constrained to road/path networks; their route may involve going into buildings (where accurate satellite locational signals are not available and they have different priorities, for example, preferring routes that are quieter or more sheltered from the weather. In addition, there are differences in how people are best directed: pedestrians noticing landmarks such as buildings, doors, and steps rather than junctions and sign posts. Landmarks exist both indoors and outdoors. A system has been developed that uses quick response (QR codes affixed to registered landmarks allowing users to localise themselves with respect to their route and with navigational instructions given in terms of these landmarks. In addition, the system includes images of each landmark helping users to navigate visually in addition to through textual instructions and route maps. The system runs on a mobile device; the users use the device’s camera to register each landmark’s QR code and so update their position (particularly indoors and progress through the route itinerary.

  20. Landmark-based geometric morphometric analysis of wing shape among certain species of Aedes mosquitoes in District Dehradun (Uttarakhand), India

    OpenAIRE

    Ritwik Mondal; Pemola Devi, N.; R.K. Jauhari

    2015-01-01

    Background & objectives: Insect wing morphology has been used in many studies to describe variations among species and populations using traditional morphometrics, and more recently geometric morphometrics. A landmark-based geometric morphometric analysis of the wings of three species of Aedes (Diptera: Culicidae), viz. Ae. aegypti, Ae. albopictus and Ae. pseudotaeniatus, at District Dehradun was conducted belling on the fact that it can provide insight into the population structure, ecology ...

  1. 不同标记点对肺癌图像引导放疗图像配准结果的影响%Impact of different anatomical landmarks on registration in imaging-guided radiation for lung cancer

    Institute of Scientific and Technical Information of China (English)

    王艳阳; 傅小龙; 夏冰

    2010-01-01

    Objective To evaluate the impact of different anatomical landmarks on registration in imaging-guided radiation (IGRT) for lung cancer. Methods For 20 patients with non-small cell lung cancer receiving stereotactic body radiotherapy (SBRT) in Fudan University Cancer Hospital, 100 frames of kilo-voltage cone-beam computed tomography scanning were evaluated in this study. The spine, carina and tumor were selected as landmarks for registration, respectively. Results of registration using different landmarks were documented and compared. Results The average set-up errors in the left-right, superiorinferior and anterior-posterior directions were -0. 08 cm ±0. 32 cm, -0. 16 cm ±0. 45 cm and 0. 06 cm ±0. 23 cm with the spine for registration;0. 06 cm ±0. 34 cm, -0. 13 cm ±0. 45 cm and -0. 02 cm±0.23 cm with the carina;and -0. 17 cm ±0.25 cm, 0.03 cm ±0.47 cm and 0. 15 cm ±0.38 cm with tumor. The registration results between using the carina and tumor as landmarks were statistically significant different (q=4.61, P=0. 002 ;q = 2. 23 , P=0. 118;q=3.44, P=0. 017). The registration results were equal when using the spine and tumor as landmarks ( q = 1.85, P = 0. 195; q = 2. 54, P = 0. 075; q = 1.89,P=0. 185), as well as using the carina and tumor as landmarks (q=2.76, P=0. 054;q=0.31, P=0. 826 ;q = 1.55, P = 0. 276). Conclusions For early stage lung cancer, the spine and tumor can be used equally as registration landmarks in imaging-guided SBRT. The carina is not suggested for its poor reproducible position.%目的 分析不同标记点对千伏锥形束CT(KVCBCT)图像与计划设计参考图像配准的影响,为选择适合于肺癌图像引导放疗的标记点提供依据.方法 共20例(男18例,女2例)行立体定向放疗的非小细胞肺癌患者进入研究.每位患者每次治疗均行KVCBCT在线引导放疗技术分析.选择每例患者每次治疗时获得的第1幅KVCBCT图像用于研究,20例患者100幅KVCBCT图像进入分析.将胸椎、隆突

  2. Landmark-based morphometrics of the normal adult brain using MRI.

    Science.gov (United States)

    Free, S L; O'Higgins, P; Maudgil, D D; Dryden, I L; Lemieux, L; Fish, D R; Shorvon, S D

    2001-05-01

    We describe the application of statistical shape analysis to homologous landmarks on the cortical surface of the adult human brain. Statistical shape analysis has a sound theoretical basis. Landmarks are identified on the surface of a 3-D reconstruction of the segmented cortical surface from magnetic resonance image (MRI) data. Using publicly available software (morphologika) the location and size dependence of the landmarks are removed and the differences in landmark distribution across subjects are analysed using principal component analysis. These differences, representing shape differences between subjects, can be visually assessed using wireframe models and transformation grids. The MRI data of 58 adult brains (27 female and 15 left handed) were examined. Shape differences in the whole brain are described which concern the relative orientation of frontal lobe sulci. Analysis of all 116 hemispheres revealed a statistically significant difference (P < 0.001) between left and right hemispheres. This finding was significant for right- but not left-handed subjects alone. No other significant age, gender, handedness, or brain-size correlations with shape differences were found.

  3. Landmark-based robust navigation for tactical UGV control in GPS-denied communication-degraded environments

    Science.gov (United States)

    Endo, Yoichiro; Balloch, Jonathan C.; Grushin, Alexander; Lee, Mun Wai; Handelman, David

    2016-05-01

    Control of current tactical unmanned ground vehicles (UGVs) is typically accomplished through two alternative modes of operation, namely, low-level manual control using joysticks and high-level planning-based autonomous control. Each mode has its own merits as well as inherent mission-critical disadvantages. Low-level joystick control is vulnerable to communication delay and degradation, and high-level navigation often depends on uninterrupted GPS signals and/or energy-emissive (non-stealth) range sensors such as LIDAR for localization and mapping. To address these problems, we have developed a mid-level control technique where the operator semi-autonomously drives the robot relative to visible landmarks that are commonly recognizable by both humans and machines such as closed contours and structured lines. Our novel solution relies solely on optical and non-optical passive sensors and can be operated under GPS-denied, communication-degraded environments. To control the robot using these landmarks, we developed an interactive graphical user interface (GUI) that allows the operator to select landmarks in the robot's view and direct the robot relative to one or more of the landmarks. The integrated UGV control system was evaluated based on its ability to robustly navigate through indoor environments. The system was successfully field tested with QinetiQ North America's TALON UGV and Tactical Robot Controller (TRC), a ruggedized operator control unit (OCU). We found that the proposed system is indeed robust against communication delay and degradation, and provides the operator with steady and reliable control of the UGV in realistic tactical scenarios.

  4. Dorsolateral Striatal Lesions Impair Navigation Based on Landmark-Goal Vectors but Facilitate Spatial Learning Based on a "Cognitive Map"

    Science.gov (United States)

    Kosaki, Yutaka; Poulter, Steven L.; Austen, Joe M.; McGregor, Anthony

    2015-01-01

    In three experiments, the nature of the interaction between multiple memory systems in rats solving a variation of a spatial task in the water maze was investigated. Throughout training rats were able to find a submerged platform at a fixed distance and direction from an intramaze landmark by learning a landmark-goal vector. Extramaze cues were…

  5. High-precision Detection of Facial Landmarks to Estimate Head Motions Based on Vision Models

    Directory of Open Access Journals (Sweden)

    Xiaohong W. Gao

    2007-01-01

    Full Text Available A new approach of determination of head movement is presented from the pictures recorded via digital cameras monitoring the scanning processing of PET. Two human vision models of CIECAMs and BMV are applied to segment the face region via skin colour and to detect local facial landmarks respectively. The developed algorithms are evaluated on the pictures (n=12 monitoring a subject’s head while simulating PET scanning captured by two calibrated cameras (located in the front and left side from a subject. It is shown that centers of chosen facial landmarks of eye corners and middle point of nose basement have been detected with very high precision (1 0.64 pixels. Three landmarks on pictures received by the front camera and two by the side camera have been identified. Preliminary results on 2D images with known moving parameters show that movement parameters of rotations and translations along X, Y, and Z directions can be obtained very accurately via the described methods.

  6. Kinematic and dynamic analysis of an anatomically based knee joint.

    Science.gov (United States)

    Lee, Kok-Meng; Guo, Jiajie

    2010-05-01

    This paper presents a knee-joint model to provide a better understanding on the interaction between natural joints and artificial mechanisms for design and control of rehabilitation exoskeletons. The anatomically based knee model relaxes several commonly made assumptions that approximate a human knee as engineering pin-joint in exoskeleton design. Based on published MRI data, we formulate the kinematics of a knee-joint and compare three mathematical approximations; one model bases on two sequential circles rolling a flat plane; and the other two are mathematically differentiable ellipses-based models with and without sliding at the contact. The ellipses-based model taking sliding contact into accounts shows that the rolling-sliding ratio of a knee-joint is not a constant but has an average value consistent with published measurements. This knee-joint kinematics leads to a physically more accurate contact-point trajectory than methods based on multiple circles or lines, and provides a basis to derive a knee-joint kinetic model upon which the effects of a planar exoskeleton mechanism on the internal joint forces and torque during flexion can be numerically investigated. Two different knee-joint kinetic models (pin-joint approximation and anatomically based model) are compared against a condition with no exoskeleton. The leg and exoskeleton form a closed kinematic chain that has a significant effect on the joint forces in the knee. Human knee is more tolerant than pin-joint in negotiating around a singularity but its internal forces increase with the exoskeleton mass-to-length ratio. An oversimplifying pin-joint approximation cannot capture the finite change in the knee forces due to the singularity effect.

  7. Neural dynamics for landmark orientation and angular path integration.

    Science.gov (United States)

    Seelig, Johannes D; Jayaraman, Vivek

    2015-05-14

    Many animals navigate using a combination of visual landmarks and path integration. In mammalian brains, head direction cells integrate these two streams of information by representing an animal's heading relative to landmarks, yet maintaining their directional tuning in darkness based on self-motion cues. Here we use two-photon calcium imaging in head-fixed Drosophila melanogaster walking on a ball in a virtual reality arena to demonstrate that landmark-based orientation and angular path integration are combined in the population responses of neurons whose dendrites tile the ellipsoid body, a toroidal structure in the centre of the fly brain. The neural population encodes the fly's azimuth relative to its environment, tracking visual landmarks when available and relying on self-motion cues in darkness. When both visual and self-motion cues are absent, a representation of the animal's orientation is maintained in this network through persistent activity, a potential substrate for short-term memory. Several features of the population dynamics of these neurons and their circular anatomical arrangement are suggestive of ring attractors, network structures that have been proposed to support the function of navigational brain circuits. PMID:25971509

  8. Anatomically based lower limb nerve model for electrical stimulation

    Directory of Open Access Journals (Sweden)

    Soboleva Tanya K

    2007-12-01

    Full Text Available Abstract Background Functional Electrical Stimulation (FES is a technique that aims to rehabilitate or restore functionality of skeletal muscles using external electrical stimulation. Despite the success achieved within the field of FES, there are still a number of questions that remain unanswered. One way of providing input to the answers is through the use of computational models. Methods This paper describes the development of an anatomically based computer model of the motor neurons in the lower limb of the human leg and shows how it can be used to simulate electrical signal propagation from the beginning of the sciatic nerve to a skeletal muscle. One-dimensional cubic Hermite finite elements were used to represent the major portions of the lower limb nerves. These elements were fit to data that had been digitised using images from the Visible Man project. Nerves smaller than approximately 1 mm could not be seen in the images, and thus a tree-branching algorithm was used to connect the ends of the fitted nerve model to the respective skeletal muscle. To simulate electrical propagation, a previously published mammalian nerve model was implemented and solved on the anatomically based nerve mesh using a finite difference method. The grid points for the finite difference method were derived from the fitted finite element mesh. By adjusting the tree-branching algorithm, it is possible to represent different levels of motor-unit recruitment. Results To illustrate the process of a propagating nerve stimulus to a muscle in detail, the above method was applied to the nerve tree that connects to the human semitendinosus muscle. A conduction velocity of 89.8 m/s was obtained for a 15 μm diameter nerve fibre. This signal was successfully propagated down the motor neurons to a selected group of motor units in the muscle. Conclusion An anatomically and physiologically based model of the posterior motor neurons in the human lower limb was developed. This

  9. The definitions of three-dimensional landmarks on the human face: an interdisciplinary view.

    Science.gov (United States)

    Katina, Stanislav; McNeil, Kathryn; Ayoub, Ashraf; Guilfoyle, Brendan; Khambay, Balvinder; Siebert, Paul; Sukno, Federico; Rojas, Mario; Vittert, Liberty; Waddington, John; Whelan, Paul F; Bowman, Adrian W

    2016-03-01

    The analysis of shape is a key part of anatomical research and in the large majority of cases landmarks provide a standard starting point. However, while the technology of image capture has developed rapidly and in particular three-dimensional imaging is widely available, the definitions of anatomical landmarks remain rooted in their two-dimensional origins. In the important case of the human face, standard definitions often require careful orientation of the subject. This paper considers the definitions of facial landmarks from an interdisciplinary perspective, including biological and clinical motivations, issues associated with imaging and subsequent analysis, and the mathematical definition of surface shape using differential geometry. This last perspective provides a route to definitions of landmarks based on surface curvature, often making use of ridge and valley curves, which is genuinely three-dimensional and is independent of orientation. Specific definitions based on curvature are proposed. These are evaluated, along with traditional definitions, in a study that uses a hierarchical (random effects) model to estimate the error variation that is present at several different levels within the image capture process. The estimates of variation at these different levels are of interest in their own right but, in addition, evidence is provided that variation is reduced at the observer level when the new landmark definitions are used. PMID:26659272

  10. Reproducibility of the sella turcica landmark in three dimensions using a sella turcica-specific reference system

    Energy Technology Data Exchange (ETDEWEB)

    Pittayapat, Pisha; Jacobs, Reinhilde [University Hospitals Leuven, University of Leuven, Leuven (Belgium); Odri, Guillaume A. [Service de Chirurgie Orthopedique et Traumatologique, Centre Hospitalier Regional d' Orleans, Orleans Cedex2 (France); De Faria Vasconcelos, Karla [Dept. of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Sao Paulo (Brazil); Willems, Guy [Dept. of Oral Health Sciences, Orthodontics, KU Leuven and Dentistry, University Hospitals Leuven, University of Leuven, Leuven (Belgium); Olszewski, Raphael [Dept. of Oral and Maxillofacial Surgery, Cliniques Universitaires Saint Luc, Universite Catholique de Louvain, Brussels (Belgium)

    2015-03-15

    This study was performed to assess the reproducibility of identifying the sella turcica landmark in a three-dimensional (3D) model by using a new sella-specific landmark reference system. Thirty-two cone-beam computed tomographic scans (3D Accuitomo 170, J. Morita, Kyoto, Japan) were retrospectively collected. The 3D data were exported into the Digital Imaging and Communications in Medicine standard and then imported into the Maxilim software (Medicim NV, Sint-Niklaas, Belgium) to create 3D surface models. Five observers identified four osseous landmarks in order to create the reference frame and then identified two sella landmarks. The x, y, and z coordinates of each landmark were exported. The observations were repeated after four weeks. Statistical analysis was performed using the multiple paired t-test with Bonferroni correction (intraobserver precision: p<0.005, interobserver precision: p<0.0011). The intraobserver mean precision of all landmarks was <1 mm. Significant differences were found when comparing the intraobserver precision of each observer (p<0.005). For the sella landmarks, the intraobserver mean precision ranged from 0.43±0.34 mm to 0.51±0.46 mm. The intraobserver reproducibility was generally good. The overall interobserver mean precision was <1 mm. Significant differences between each pair of observers for all anatomical landmarks were found (p<0.0011). The interobserver reproducibility of sella landmarks was good, with >50% precision in locating the landmark within 1 mm. A newly developed reference system offers high precision and reproducibility for sella turcica identification in a 3D model without being based on two-dimensional images derived from 3D data.

  11. [Therapy for systemic metabolic disorders based on the detection of basic corneal landmarks in childhood].

    Science.gov (United States)

    Lisch, W; Pitz, S; Geerling, G

    2013-06-01

    Many systemic lysosomal storage disorders show basic corneal opacities already in childhood. The lysosome is a cell organelle, produced by Golgi's apparatus, that is surrounded by a membrane and contains hydrolytic enzymes that break down food molecules, especially proteins and other complex molecules. The ophthalmologist's precise diagnosis of corneal clouding at the slit-lamp may reveal the correct interpretation of the specific lysosomal storage disorder. It is very important to diagnose such diseases as soon as possible because today the development of systemic enzymatic therapies has broadened the therapeutic armamentarium for the current standard of care. The following corneal landmarks of systemic storage diseases and of the modern systemic therapy are presented: cornea verticillata in Fabry's disease, periodic infusion of alpha-galactosidase a; Kayser-Fleischer's ring in Wilson's disease, zinc, trienetin, low copper diet; multiple, punctiform crystals in cystinosis, cysteamine, Raptor RP 103(DR cysteamine) that reduces the cytotoxity in form of continous dissolving of cystine from lysosome, renal transplantation, haematopoietic stem cell transplantation; peripheral ring, but not true lipid arc, and moderate stromal haze in LCAT-deficiency, injection of recombinant enzyme or of encapsulated LCAT-secreting cells; diffuse stromal haze in mucopolysaccharidoses (MPS). Enzyme replacement therapy is currently indicated for MPS I, MPS II, and MPS VI, haematopoietic stem cell transplantation; painful, bilateral pseudo-dendritic opacities in tyrosinemia type II (eponym: Richner-Hanhart syndrome), low phenylalanine and tyrosine diet result in complete disappearance of corneal alterations with a consecutive painfree period. Strict diet during the whole life is necessary to prevent corneal recurrences and the occurrence of palmo-plantar keratoses. Such therapies can enable the patient to lead an otherwise normal life for decades.

  12. Anterolateral Ligament Reconstruction Technique: An Anatomic-Based Approach.

    Science.gov (United States)

    Chahla, Jorge; Menge, Travis J; Mitchell, Justin J; Dean, Chase S; LaPrade, Robert F

    2016-06-01

    Restoration of anteroposterior laxity after an anterior cruciate ligament reconstruction has been predictable with traditional open and endoscopic techniques. However, anterolateral rotational stability has been difficult to achieve in a subset of patients, even with appropriate anatomic techniques. Therefore, differing techniques have attempted to address this rotational laxity by augmenting or reconstructing lateral-sided structures about the knee. In recent years, there has been a renewed interest in the anterolateral ligament as a potential contributor to residual anterolateral rotatory instability in anterior cruciate ligament-deficient patients. Numerous anatomic and biomechanical studies have been performed to further define the functional importance of the anterolateral ligament, highlighting the need for surgical techniques to address these injuries in the unstable knee. This article details our technique for an anatomic anterolateral ligament reconstruction using a semitendinosus tendon allograft. PMID:27656361

  13. Automatic landmark extraction from image data using modified growing neural gas network.

    Science.gov (United States)

    Fatemizadeh, Emad; Lucas, Caro; Soltanian-Zadeh, Hamid

    2003-06-01

    A new method for automatic landmark extraction from MR brain images is presented. In this method, landmark extraction is accomplished by modifying growing neural gas (GNG), which is a neural-network-based cluster-seeking algorithm. Using modified GNG (MGNG) corresponding dominant points of contours extracted from two corresponding images are found. These contours are borders of segmented anatomical regions from brain images. The presented method is compared to: 1) the node splitting-merging Kohonen model and 2) the Teh-Chin algorithm (a well-known approach for dominant points extraction of ordered curves). It is shown that the proposed algorithm has lower distortion error, ability of extracting landmarks from two corresponding curves simultaneously, and also generates the best match according to five medical experts. PMID:12834162

  14. Neural Network-Based Landmark Recognition and Navigation with IAMRs. Understanding the Principles of Thought and Behavior.

    Science.gov (United States)

    Doty, Keith L.

    1999-01-01

    Research on neural networks and hippocampal function demonstrating how mammals construct mental maps and develop navigation strategies is being used to create Intelligent Autonomous Mobile Robots (IAMRs). Such robots are able to recognize landmarks and navigate without "vision." (SK)

  15. Establishing Cephalometric Landmarks for the Translational Study of Le Fort-based Facial Transplantation in Swine: Enhanced applications using computer-assisted surgery and custom cutting guides

    Science.gov (United States)

    Santiago, Gabriel F.; Susarla, Srinivas M.; Al Rakan, Mohammed; Coon, Devin; Rada, Erin M.; Sarhane, Karim; Shores, Jamie T.; Bonawitz, Steven C.; Cooney, Damon; Sacks, Justin; Murphy, Ryan J.; Fishman, Elliot K.; Brandacher, Gerald; Lee, WP Andrew; Liacouras, Peter; Grant, Gerald; Armand, Mehran; Gordon, Chad R.

    2014-01-01

    Background Le Fort-based, maxillofacial allotransplantation is a reconstructive alternative gaining clinical acceptance. However, the vast majority of single-jaw transplant recipients demonstrate less-than-ideal skeletal and dental relationships with suboptimal aesthetic harmony. The purpose of this study was to investigate reproducible cephalometric landmarks in a large animal model, where refinement of computer-assisted planning, intra-operative navigational guidance, translational bone osteotomies, and comparative surgical techniques could be performed. Methods Cephalometric landmarks that could be translated into the human craniomaxillofacial skeleton, and would remain reliable following maxillofacial osteotomies with mid-facial alloflap inset, were sought on six miniature swine. Le Fort I-and Le Fort III-based alloflaps were harvested in swine with osteotomies, and all alloflaps were either auto-replanted or transplanted. Cephalometric analyses were performed on lateral cephalograms pre- and post-operatively. Critical cephalometric data sets were identified with the assistance of surgical planning and virtual prediction software, and evaluated for reliability and translational predictability. Results Several pertinent landmarks and human analogues were identified including pronasale (PRN), zygion (Zy), parietale (PA), gonion (GO), gnathion (GN), lower incisior base (LIB), and alveolare (ALV). PA-PRN-ALV and PA-PRN-LIB were found to be reliable correlates of SNA and SNB measurements in humans, respectively. Conclusions There is a set of reliable cephalometric landmarks and measurement angles pertinent for utilization within a translational large animal model. These craniomaxillofacial landmarks will allow us to develop novel navigational software technology, improve our cutting guide designs, and explore new avenues for investigation and collaboration. Level of Evidence N/A (Large Animal Study) PMID:24445879

  16. Realization of Artificial Landmark Recognition Algorithm Based on DSP%基于DSP的人工路标识别算法的实现

    Institute of Scientific and Technical Information of China (English)

    刘纪红; 张璐; 赵东升

    2014-01-01

    针对以人工路标作为引导标识的视觉导航技术,提出了一种基于导引灯的人工路标识别算法。首先利用基于灰度信息的识别算法对路标上导引灯进行识别与定位;然后,利用交比不变性进行数字的初步定位;最后用投影法进行数字分割,主成分分析法( PCA)和最小距离分类器的模式识别方法对数字进行识别。算法在ICETEK-DM6437-B评估板上实现。实验表明,该算法具有很高的稳定性并能较好地满足实时性的要求。%In view of the vision navigation technology of using artificial landmark as the guiding identification,one recognition algorithm of artificial landmark based on the guiding light was proposed. Firstly,the algorithm based on gray information is used to recognize and locate the guiding light in the landmark. Then,the algorithm based on in-variance of cross-ratio realizes the localization to characters in the artificial landmark. At last,projection method is used to segment characters, meanwhile, both principal component analysis ( PCA ) method and minimum distance classifier are used to recognize the character. The algorithm is realized on the ICETEK-DM6437-B system board. The experiment shows the algorithm has high stability and meets the requirements of real-time well.

  17. Visual EKF-SLAM from Heterogeneous Landmarks.

    Science.gov (United States)

    Esparza-Jiménez, Jorge Othón; Devy, Michel; Gordillo, José L

    2016-01-01

    Many applications require the localization of a moving object, e.g., a robot, using sensory data acquired from embedded devices. Simultaneous localization and mapping from vision performs both the spatial and temporal fusion of these data on a map when a camera moves in an unknown environment. Such a SLAM process executes two interleaved functions: the front-end detects and tracks features from images, while the back-end interprets features as landmark observations and estimates both the landmarks and the robot positions with respect to a selected reference frame. This paper describes a complete visual SLAM solution, combining both point and line landmarks on a single map. The proposed method has an impact on both the back-end and the front-end. The contributions comprehend the use of heterogeneous landmark-based EKF-SLAM (the management of a map composed of both point and line landmarks); from this perspective, the comparison between landmark parametrizations and the evaluation of how the heterogeneity improves the accuracy on the camera localization, the development of a front-end active-search process for linear landmarks integrated into SLAM and the experimentation methodology. PMID:27070602

  18. Visual EKF-SLAM from Heterogeneous Landmarks

    Directory of Open Access Journals (Sweden)

    Jorge Othón Esparza-Jiménez

    2016-04-01

    Full Text Available Many applications require the localization of a moving object, e.g., a robot, using sensory data acquired from embedded devices. Simultaneous localization and mapping from vision performs both the spatial and temporal fusion of these data on a map when a camera moves in an unknown environment. Such a SLAM process executes two interleaved functions: the front-end detects and tracks features from images, while the back-end interprets features as landmark observations and estimates both the landmarks and the robot positions with respect to a selected reference frame. This paper describes a complete visual SLAM solution, combining both point and line landmarks on a single map. The proposed method has an impact on both the back-end and the front-end. The contributions comprehend the use of heterogeneous landmark-based EKF-SLAM (the management of a map composed of both point and line landmarks; from this perspective, the comparison between landmark parametrizations and the evaluation of how the heterogeneity improves the accuracy on the camera localization, the development of a front-end active-search process for linear landmarks integrated into SLAM and the experimentation methodology.

  19. Visual EKF-SLAM from Heterogeneous Landmarks.

    Science.gov (United States)

    Esparza-Jiménez, Jorge Othón; Devy, Michel; Gordillo, José L

    2016-04-07

    Many applications require the localization of a moving object, e.g., a robot, using sensory data acquired from embedded devices. Simultaneous localization and mapping from vision performs both the spatial and temporal fusion of these data on a map when a camera moves in an unknown environment. Such a SLAM process executes two interleaved functions: the front-end detects and tracks features from images, while the back-end interprets features as landmark observations and estimates both the landmarks and the robot positions with respect to a selected reference frame. This paper describes a complete visual SLAM solution, combining both point and line landmarks on a single map. The proposed method has an impact on both the back-end and the front-end. The contributions comprehend the use of heterogeneous landmark-based EKF-SLAM (the management of a map composed of both point and line landmarks); from this perspective, the comparison between landmark parametrizations and the evaluation of how the heterogeneity improves the accuracy on the camera localization, the development of a front-end active-search process for linear landmarks integrated into SLAM and the experimentation methodology.

  20. Distally Based Iliotibial Band Flap: Anatomic Study with Surgical Considerations.

    Science.gov (United States)

    Wong, Victor W; Higgins, James P

    2016-09-01

    Background Reconstruction of high-risk fascia, tendon, or ligament defects may benefit from vascularized tissue. The iliotibial band (ITB), a thick fibrous tract of connective tissue, serves as a potential donor site for free tissue transfer but its blood supply has not been thoroughly investigated. The aim of this anatomical study was to investigate the vascular supply to the distal ITB and its role as a free fascial flap. Methods We dissected 16 fresh-frozen cadaveric legs and injected latex into the superolateral geniculate artery (SLGA). A distal ITB fascial flap was designed and measurements were taken for flap dimensions, pedicle length and size, and SLGA perfusion territory. Results The SLGA perfused 11.5 ± 2.3 cm of distal ITB (proximal to the lateral femoral epicondyle) and provided 6.4 ± 0.7cm of pedicle length to the ITB flap. Conclusions Chimeric options to include bone (from the lateral femoral condyle), cartilage (from the lateral femoral trochlea), muscle (from vastus lateralis or biceps femoris), and skin are possible. Surgical harvest techniques are proposed, including preservation of ITB insertions to minimize lateral knee instability. Clinical validation is needed to determine the role of the distal ITB free fascial flap in reconstructive microsurgery.

  1. Distally Based Iliotibial Band Flap: Anatomic Study with Surgical Considerations.

    Science.gov (United States)

    Wong, Victor W; Higgins, James P

    2016-09-01

    Background Reconstruction of high-risk fascia, tendon, or ligament defects may benefit from vascularized tissue. The iliotibial band (ITB), a thick fibrous tract of connective tissue, serves as a potential donor site for free tissue transfer but its blood supply has not been thoroughly investigated. The aim of this anatomical study was to investigate the vascular supply to the distal ITB and its role as a free fascial flap. Methods We dissected 16 fresh-frozen cadaveric legs and injected latex into the superolateral geniculate artery (SLGA). A distal ITB fascial flap was designed and measurements were taken for flap dimensions, pedicle length and size, and SLGA perfusion territory. Results The SLGA perfused 11.5 ± 2.3 cm of distal ITB (proximal to the lateral femoral epicondyle) and provided 6.4 ± 0.7cm of pedicle length to the ITB flap. Conclusions Chimeric options to include bone (from the lateral femoral condyle), cartilage (from the lateral femoral trochlea), muscle (from vastus lateralis or biceps femoris), and skin are possible. Surgical harvest techniques are proposed, including preservation of ITB insertions to minimize lateral knee instability. Clinical validation is needed to determine the role of the distal ITB free fascial flap in reconstructive microsurgery. PMID:27135145

  2. Automatic anatomical structures location based on dynamic shape measurement

    Science.gov (United States)

    Witkowski, Marcin; Rapp, Walter; Sitnik, Robert; Kujawinska, Malgorzata; Vander Sloten, Jos; Haex, Bart; Bogaert, Nico; Heitmann, Kjell

    2005-09-01

    New image processing methods and active photonics apparatus have made possible the development of relatively inexpensive optical systems for complex shape and object measurements. We present dynamic 360° scanning method for analysis of human lower body biomechanics, with an emphasis on the analysis of the knee joint. The anatomical structure (of high medical interest) that is possible to scan and analyze, is patella. Tracking of patella position and orientation under dynamic conditions may lead to detect pathological patella movements and help in knee joint disease diagnosis. The processed data is obtained from a dynamic laser triangulation surface measurement system, able to capture slow to normal movements with a scan frequency between 15 and 30 Hz. These frequency rates are enough to capture controlled movements used e.g. for medical examination purposes. The purpose of the work presented is to develop surface analysis methods that may be used as support of diagnosis of motoric abilities of lower limbs. The paper presents algorithms used to process acquired lower limbs surface data in order to find the position and orientation of patella. The algorithms implemented include input data preparation, curvature description methods, knee region discrimination and patella assumed position/orientation calculation. Additionally, a method of 4D (3D + time) medical data visualization is proposed. Also some exemplary results are presented.

  3. Near Real-Time Assessment of Anatomic and Dosimetric Variations for Head and Neck Radiation Therapy via Graphics Processing Unit–based Dose Deformation Framework

    Energy Technology Data Exchange (ETDEWEB)

    Qi, X. Sharon, E-mail: xqi@mednet.ucla.edu [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States); Santhanam, Anand; Neylon, John; Min, Yugang; Armstrong, Tess; Sheng, Ke [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States); Staton, Robert J.; Pukala, Jason [Department of Radiation Oncology, UF Health Cancer Center - Orlando Health, Orlando, Florida (United States); Pham, Andrew; Low, Daniel A.; Lee, Steve P. [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States); Steinberg, Michael; Manon, Rafael [Department of Radiation Oncology, UF Health Cancer Center - Orlando Health, Orlando, Florida (United States); Chen, Allen M.; Kupelian, Patrick [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States)

    2015-06-01

    Purpose: The purpose of this study was to systematically monitor anatomic variations and their dosimetric consequences during intensity modulated radiation therapy (IMRT) for head and neck (H&N) cancer by using a graphics processing unit (GPU)-based deformable image registration (DIR) framework. Methods and Materials: Eleven IMRT H&N patients undergoing IMRT with daily megavoltage computed tomography (CT) and weekly kilovoltage CT (kVCT) scans were included in this analysis. Pretreatment kVCTs were automatically registered with their corresponding planning CTs through a GPU-based DIR framework. The deformation of each contoured structure in the H&N region was computed to account for nonrigid change in the patient setup. The Jacobian determinant of the planning target volumes and the surrounding critical structures were used to quantify anatomical volume changes. The actual delivered dose was calculated accounting for the organ deformation. The dose distribution uncertainties due to registration errors were estimated using a landmark-based gamma evaluation. Results: Dramatic interfractional anatomic changes were observed. During the treatment course of 6 to 7 weeks, the parotid gland volumes changed up to 34.7%, and the center-of-mass displacement of the 2 parotid glands varied in the range of 0.9 to 8.8 mm. For the primary treatment volume, the cumulative minimum and mean and equivalent uniform doses assessed by the weekly kVCTs were lower than the planned doses by up to 14.9% (P=.14), 2% (P=.39), and 7.3% (P=.05), respectively. The cumulative mean doses were significantly higher than the planned dose for the left parotid (P=.03) and right parotid glands (P=.006). The computation including DIR and dose accumulation was ultrafast (∼45 seconds) with registration accuracy at the subvoxel level. Conclusions: A systematic analysis of anatomic variations in the H&N region and their dosimetric consequences is critical in improving treatment efficacy. Nearly real

  4. The reliability of tablet computers in depicting maxillofacial radiographic landmarks

    Energy Technology Data Exchange (ETDEWEB)

    Tadinada, Aditya; Mahdian, Mina; Sheth, Sonam; Chandhoke, Taranpreet K.; Gopalakrishna, Aadarsh; Potluri, Anitha; Yadav, Sumit [University of Connecticut School of Dental Medicine, Farmington (United States)

    2015-09-15

    This study was performed to evaluate the reliability of the identification of anatomical landmarks in panoramic and lateral cephalometric radiographs on a standard medical grade picture archiving communication system (PACS) monitor and a tablet computer (iPad 5). A total of 1000 radiographs, including 500 panoramic and 500 lateral cephalometric radiographs, were retrieved from the de-identified dataset of the archive of the Section of Oral and Maxillofacial Radiology of the University Of Connecticut School Of Dental Medicine. Major radiographic anatomical landmarks were independently reviewed by two examiners on both displays. The examiners initially reviewed ten panoramic and ten lateral cephalometric radiographs using each imaging system, in order to verify interoperator agreement in landmark identification. The images were scored on a four-point scale reflecting the diagnostic image quality and exposure level of the images. Statistical analysis showed no significant difference between the two displays regarding the visibility and clarity of the landmarks in either the panoramic or cephalometric radiographs. Tablet computers can reliably show anatomical landmarks in panoramic and lateral cephalometric radiographs.

  5. 3D ultrasound-CT registration of the liver using combined landmark-intensity information

    International Nuclear Information System (INIS)

    An important issue in computer-assisted surgery of the liver is a fast and reliable transfer of preoperative resection plans to the intraoperative situation. One problem is to match the planning data, derived from preoperative CT or MR images, with 3D ultrasound images of the liver, acquired during surgery. As the liver deforms significantly in the intraoperative situation non-rigid registration is necessary. This is a particularly challenging task because pre- and intraoperative image data stem from different modalities and ultrasound images are generally very noisy. One way to overcome these problems is to incorporate prior knowledge into the registration process. We propose a method of combining anatomical landmark information with a fast non-parametric intensity registration approach. Mathematically, this leads to a constrained optimization problem. As distance measure we use the normalized gradient field which allows for multimodal image registration. A qualitative and quantitative validation on clinical liver data sets of three different patients has been performed. We used the distance of dense corresponding points on vessel center lines for quantitative validation. The combined landmark and intensity approach improves the mean and percentage of point distances above 3 mm compared to rigid and thin-plate spline registration based only on landmarks. The proposed algorithm offers the possibility to incorporate additional a priori knowledge - in terms of few landmarks - provided by a human expert into a non-rigid registration process. (orig.)

  6. 3D facial landmarks: Inter-operator variability of manual annotation

    DEFF Research Database (Denmark)

    Fagertun, Jens; Harder, Stine; Rosengren, Anders;

    2014-01-01

    was randomly chosen. Six operators twice manually annotated 73 anatomical and pseudo-landmarks, using a three-step scheme producing a dense point correspondence map. We analyzed both the intra- and inter-operator variability, using mixed-model ANOVA. We then compared four sparse sets of landmarks in order...

  7. Validation of Setaria (L. P. Beauv Species based on Palyonological and Anatomical Techniques.

    Directory of Open Access Journals (Sweden)

    Abdul nazir

    2014-05-01

    Full Text Available In present study external morphology, leaf epidermal anatomy and pollen structureof three species of genus Setaria(Poaceaeviz., S. glauca, S. verticillata and S. viridiswere studied. The major emphasis was on the importance of palyno-anatomical characters used as an aid in plant systematics. Light microscopy (LM and scanning electron microscopy (SEMwere used to study leaf epidermal anatomy and pollen structure.Palyno-anatomical analysis of genus Setaria shows variations within the species. It is stated that the study based on classical and modern approaches is very useful for systematic delimitation of problematic taxa like Setaria.

  8. Prostatome: A combined anatomical and disease based MRI atlas of the prostate

    Energy Technology Data Exchange (ETDEWEB)

    Rusu, Mirabela; Madabhushi, Anant, E-mail: anant.madabhushi@case.edu [Case Western Reserve University, Cleveland, Ohio 44106 (United States); Bloch, B. Nicolas; Jaffe, Carl C. [Boston University School of Medicine, Boston, Massachusetts 02118 (United States); Genega, Elizabeth M. [Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215 (United States); Lenkinski, Robert E.; Rofsky, Neil M. [UT Southwestern Medical Center, Dallas, Texas 75235 (United States); Feleppa, Ernest [Riverside Research Institute, New York, New York 10038 (United States)

    2014-07-15

    Purpose: In this work, the authors introduce a novel framework, the anatomically constrained registration (AnCoR) scheme and apply it to create a fused anatomic-disease atlas of the prostate which the authors refer to as the prostatome. The prostatome combines a MRI based anatomic and a histology based disease atlas. Statistical imaging atlases allow for the integration of information across multiple scales and imaging modalities into a single canonical representation, in turn enabling a fused anatomical-disease representation which may facilitate the characterization of disease appearance relative to anatomic structures. While statistical atlases have been extensively developed and studied for the brain, approaches that have attempted to combine pathology and imaging data for study of prostate pathology are not extant. This works seeks to address this gap. Methods: The AnCoR framework optimizes a scoring function composed of two surface (prostate and central gland) misalignment measures and one intensity-based similarity term. This ensures the correct mapping of anatomic regions into the atlas, even when regional MRI intensities are inconsistent or highly variable between subjects. The framework allows for creation of an anatomic imaging and a disease atlas, while enabling their fusion into the anatomic imaging-disease atlas. The atlas presented here was constructed using 83 subjects with biopsy confirmed cancer who had pre-operative MRI (collected at two institutions) followed by radical prostatectomy. The imaging atlas results from mapping thein vivo MRI into the canonical space, while the anatomic regions serve as domain constraints. Elastic co-registration MRI and corresponding ex vivo histology provides “ground truth” mapping of cancer extent on in vivo imaging for 23 subjects. Results: AnCoR was evaluated relative to alternative construction strategies that use either MRI intensities or the prostate surface alone for registration. The AnCoR framework

  9. Efficient and Accurate Indoor Localization Using Landmark Graphs

    Science.gov (United States)

    Gu, F.; Kealy, A.; Khoshelham, K.; Shang, J.

    2016-06-01

    Indoor localization is important for a variety of applications such as location-based services, mobile social networks, and emergency response. Fusing spatial information is an effective way to achieve accurate indoor localization with little or with no need for extra hardware. However, existing indoor localization methods that make use of spatial information are either too computationally expensive or too sensitive to the completeness of landmark detection. In this paper, we solve this problem by using the proposed landmark graph. The landmark graph is a directed graph where nodes are landmarks (e.g., doors, staircases, and turns) and edges are accessible paths with heading information. We compared the proposed method with two common Dead Reckoning (DR)-based methods (namely, Compass + Accelerometer + Landmarks and Gyroscope + Accelerometer + Landmarks) by a series of experiments. Experimental results show that the proposed method can achieve 73% accuracy with a positioning error less than 2.5 meters, which outperforms the other two DR-based methods.

  10. Quantitative assessment of regional left ventricular motion using endocardial landmarks

    NARCIS (Netherlands)

    C.J. Slager (Cornelis); T.E.H. Hooghoudt (Ton); P.W.J.C. Serruys (Patrick); J.C.H. Schuurbiers (Johan); J.H.C. Reiber (Johan); G.T. Meester (Geert); P.D. Verdouw (Pieter); P.G. Hugenholtz (Paul)

    1986-01-01

    textabstractIn this study the hypothesis is tested that the motion pattern of small anatomic landmarks, recognizable at the left ventricular endocardial border in the contrast angiocardiogram, reflects the motion of the endocardial wall. To verify this, minute metal markers were inserted in the endo

  11. Optimal landmarks selection and fiducial marker placement for minimal target registration error in image-guided neurosurgery

    Science.gov (United States)

    Shamir, Reuben R.; Joskowicz, Leo; Shoshan, Yigal

    2009-02-01

    We describe a new framework and method for the optimal selection of anatomical landmarks and optimal placement of fiducial markers in image-guided neurosurgery. The method allows the surgeon to optimally plan the markers locations on routine diagnostic images before preoperative imaging and to intraoperatively select the fiducial markers and the anatomical landmarks that minimize the Target Registration Error (TRE). The optimal fiducial marker configuration selection is performed by the surgeon on the diagnostic image following the target selection based on a visual Estimated TRE (E-TRE) map. The E-TRE map is automatically updated when the surgeon interactively adds and deletes candidate markers and targets. The method takes the guesswork out of the registration process, provides a reliable localization uncertainty error for navigation, and can reduce the localization error without additional imaging and hardware. Our clinical experiments on five patients who underwent brain surgery with a navigation system show that optimizing one marker location and the anatomical landmarks configuration reduces the average TRE from 4.7mm to 3.2mm, with a maximum improvement of 4mm. The reduction of the target registration error has the potential to support safer and more accurate minimally invasive neurosurgical procedures.

  12. Rouviere 沟定位在腹腔镜胆囊切除术中的应用--附750例报告%Role of Rouviere′s sulcus as anatomical landmark in laparoscopic cholecystectomy:a report of 750 cases

    Institute of Scientific and Technical Information of China (English)

    王守军; 王跃; 王庆文; 李洪旭; 宋金智; 侯俊丞; 唐雪梅

    2014-01-01

    目的:探讨以Rouviere 沟作为胆囊管解剖定位标志,以指导腹腔镜胆囊切除术。方法同一初学腹腔镜胆囊切除术手术者自2012年10月至2014年3月于川北医学院附属三台医院连续实施腹腔镜胆囊切除术750例,术中记录Rouviere 沟的出现率,并采用Rouviere 沟为胆囊管解剖定位标志。结果750例中,705例有 Rouviere 沟。全组未发生手术死亡,胆管损伤1例(0.13%),其术中未见 Rouviere 沟。前300例使用三孔法35例,中转30例(10%);后450例使用三孔法387例,中转15例(3.3%)。结论 Rouviere 沟是重要的胆囊管解剖定位标志,以Rouviere 沟为胆囊管解剖定位标志可以帮助胆囊三角解剖,对于初学腹腔镜胆囊切除术者预防术中胆管损伤有重要临床意义,值得推广应用。%Objective To explore the role of Rouviere′s sulcus as the anatomical landmark for the cystic duct in laparoscopic cholecystecto-my.Methods The clinical data of 750 patients who underwent laparoscopic cholecystectomy operated by one beginner from October 2012 to March 2014 in the Affiliated Santai Hospital of North Sichuan Medical College were analyzed.The frequency of appearance of Rouviere′s sul-cus was recorded during operation,and the Rouviere′s sulcus was used as the anatomical landmark for the cystic duct in laparoscopic chole-cystectomy.Results Of the 750 patients,705 had Rouviere′s sulcus.There was no mortality during operation.Bile duct injury occurred in one case (0.13%),whose Rouviere′s sulcus was not seen during operation.Among the first 300 cases,the three-hole method was used in 35 cases,and 30 cases (10%)were converted to open surgery.Among the succeeding 450 cases,the three-hole method was used in 387 cases,and 15 cases (3.3%)were converted to open surgery.Conclusion Rouviere′s sulcus is an important anatomical landmark for the cystic duct.Its identification before Calot′s triangle dissection may

  13. Landmarks in Insulin Research

    OpenAIRE

    Ward, Colin W.; Lawrence, Michael C.

    2011-01-01

    Ever since the discovery of insulin and its role in the regulation of glucose uptake and utilization, there has been great interest in insulin, its structure and the way in which it interacts with its receptor and effects signal transduction. As the 90th anniversary of the discovery of insulin approaches, it is timely to provide an overview of the landmark discoveries relating to the structure and function of this remarkable molecule and its receptor.

  14. 腹腔镜胆囊切除术中Rouviere沟解剖定位及其应用价值研究%Role of Rouviere's sulcus as anatomic landmark in laparoscopic cholecystectomy

    Institute of Scientific and Technical Information of China (English)

    蔡华杰; 叶百亮; 韩宇; 暨玲; 屠金夫; 郑晓风; 蒋飞照

    2012-01-01

    Objective To explore the role of Rouviere's sulcus as extrabiliary reference point in laparoscopic cholecystectomy. Methods The clinical data of 584 patients performed laparoscopic cholecystectomy from March 2010 to April 2011 in the Department of Endoscopic Surgery, the First Affiliated Hospital of Wenzhou Medical College were analyzed. Frequency and type of Rouviere's sulcus were documented and Rouviere's sulcus was used to guide the commencement of dissection in hepatobiliary triangle in laparoscopic cholecystectomy. Results A total of 584 patients who underwent laparoscopic cholecystectomy were included in the study. Open type of Rouviere's sulcus was visualized in 346 patients and fused type of Rouviere's sulcus was visualized in 102 patients. Hence in a total of 448 (76.7%) patients had Rouviere's sulcus. There was no bile duct injury or mortality. Three patients were converted to open operation (0.5%) and all patients recovered well. Conclusion Rouviere's sulcus is an important extrabiliary landmark and identifiable in majority of patients. Its identification before commencement of Calot' s triangle dissection may help in preventing the bile duct injury in laparoscopic cholecystectomy and should be applied widely.%目的 探讨Rouviere沟作为肝外胆管参照点在腹腔镜胆囊切除术中的作用.方法 自2010年3月至2011年4月温州医学院附属第一医院腔镜外科连续实施腹腔镜胆囊切除术584例,术中记录Rouviere沟的出现率及分型,并采用以Rouviere沟为导向的胆囊三角区解剖方法.结果 584例中,开放型Rouviere沟346例,融合型Rouviere沟102例,共448例(76.7%)存在Rouviere沟.全组未发生胆管损伤及手术死亡,3例(0.5%)中转开腹,所有病例恢复良好.结论 Rouviere沟是重要的肝外胆管解剖标志,出现于大多数人中.以Rouviere沟为导向的胆囊三角区解剖方法可以预防腹腔镜胆囊切除术中胆管损伤,值得推广应用.

  15. Exploring the human body space: A geographical information system based anatomical atlas

    Directory of Open Access Journals (Sweden)

    Antonio Barbeito

    2016-06-01

    Full Text Available Anatomical atlases allow mapping the anatomical structures of the human body. Early versions of these systems consisted of analogical representations with informative text and labeled images of the human body. With computer systems, digital versions emerged and the third and fourth dimensions were introduced. Consequently, these systems increased their efficiency, allowing more realistic visualizations with improved interactivity and functionality. The 4D atlases allow modeling changes over time on the structures represented. The anatomical atlases based on geographic information system (GIS environments allow the creation of platforms with a high degree of interactivity and new tools to explore and analyze the human body. In this study we expand the functions of a human body representation system by creating new vector data, topology, functions, and an improved user interface. The new prototype emulates a 3D GIS with a topological model of the human body, replicates the information provided by anatomical atlases, and provides a higher level of functionality and interactivity. At this stage, the developed system is intended to be used as an educational tool and integrates into the same interface the typical representations of surface and sectional atlases.

  16. Disruption of brain anatomical networks in schizophrenia: A longitudinal, diffusion tensor imaging based study.

    Science.gov (United States)

    Sun, Yu; Chen, Yu; Lee, Renick; Bezerianos, Anastasios; Collinson, Simon L; Sim, Kang

    2016-03-01

    Despite convergent neuroimaging evidence indicating a wide range of brain abnormalities in schizophrenia, our understanding of alterations in the topological architecture of brain anatomical networks and how they are modulated over time, is still rudimentary. Here, we employed graph theoretical analysis of longitudinal diffusion tensor imaging data (DTI) over a 5-year period to investigate brain network topology in schizophrenia and its relationship with clinical manifestations of the illness. Using deterministic tractography, weighted brain anatomical networks were constructed from 31 patients experiencing schizophrenia and 28 age- and gender-matched healthy control subjects. Although the overall small-world characteristics were observed at both baseline and follow-up, a scan-point independent significant deficit of global integration was found in patients compared to controls, suggesting dysfunctional integration of the brain and supporting the notion of schizophrenia as a disconnection syndrome. Specifically, several brain regions (e.g., the inferior frontal gyrus and the bilateral insula) that are crucial for cognitive and emotional integration were aberrant. Furthermore, a significant group-by-longitudinal scan interaction was revealed in the characteristic path length and global efficiency, attributing to a progressive aberration of global integration in patients compared to healthy controls. Moreover, the progressive disruptions of the brain anatomical network topology were associated with the clinical symptoms of the patients. Together, our findings provide insights into the substrates of anatomical dysconnectivity patterns for schizophrenia and highlight the potential for connectome-based metrics as neural markers of illness progression and clinical change with treatment.

  17. Probabilistic MRI brain anatomical atlases based on 1,000 Chinese subjects.

    Directory of Open Access Journals (Sweden)

    Xing Wang

    Full Text Available Brain atlases are designed to provide a standard reference coordinate system of the brain for neuroscience research. Existing human brain atlases are widely used to provide anatomical references and information regarding structural characteristics of the brain. The majority of them, however, are derived from one paticipant or small samples of the Western population. This poses a limitation for scientific studies on Eastern subjects. In this study, 10 new Chinese brain atlases for different ages and genders were constructed using MR anatomical images based on HAMMER (Hierarchical Attribute Matching Mechanism for Elastic Registration. A total of 1,000 Chinese volunteers ranging from 18 to 70 years old participated in this study. These population-specific brain atlases represent the basic structural characteristics of the Chinese population. They may be utilized for basic neuroscience studies and clinical diagnosis, including evaluation of neurological and neuropsychiatric disorders, in Chinese patients and those from other Eastern countries.

  18. Anatomic Mesenchymal Stem Cell-Based Engineered Cartilage Constructs for Biologic Total Joint Replacement.

    Science.gov (United States)

    Saxena, Vishal; Kim, Minwook; Keah, Niobra M; Neuwirth, Alexander L; Stoeckl, Brendan D; Bickard, Kevin; Restle, David J; Salowe, Rebecca; Wang, Margaret Ye; Steinberg, David R; Mauck, Robert L

    2016-02-01

    constructs. Immunohistochemistry showed abundant collagen type II staining and little collagen type I staining. APS/TEMED crosslinking can be used to produce MSC-seeded HA-based neocartilage and can be used in combination with rapid prototyping techniques to generate anatomic MSC-seeded HA constructs for use in filling large and anatomically complex chondral defects or for biologic joint replacement. PMID:26871863

  19. 膝关节置换术髓外定位系统中三种胫骨远端解剖标志物的对比研究%Comparison of three anatomical structures as a distal landmark for extramedullary tibial alignment in total knee arthroplasty

    Institute of Scientific and Technical Information of China (English)

    王新光; 史占军; 郭汉明; 肖军; 黄玉良; 陈秋兰

    2015-01-01

    flexion with 30° external rotation and 90° dorsal flexion with 30° internal rotation).The distances between the ankle centre and 3 landmarks at 3 positions were measured and compared by analysis of variance with repeated measurements and one way analysis of variance.Results Analyses of variance with repeated measurements showed significant differences between the distances to the ankle center of the 3 landmarks at tbe 3 positions (P < 0.05).The dorsal pedis artery lay the closest to the ankle center (0.20 ± 0.21 cm lateral),followed by the extensor hallucis longus tendon (0.46 ± 0.36 cm medial) and the extensor digitorum longus tendon (0.63 ± 0.30 cm lateral).One way analysis of variance showed significant differences in distance from each landmark to the ankle center at different ankle positions (P < 0.05).There were significant differences between 3 anatomical landmarks in distance to the ankle center at the same ankle position (P < 0.05).The dorsal pedis artery was the closest to the ankle center at all ankle positions.Conclusion Since the dorsal pedis artery lies closer to the ankle center than the extensor hallucis longus tendon and the extensor digitorum longus tendon at different ankle positions,it can be a reliable distal landmark for extramedullary tibial alignment in total knee arthroplasty.

  20. Early fetal anatomical sonography.

    LENUS (Irish Health Repository)

    Donnelly, Jennifer C

    2012-10-01

    Over the past decade, prenatal screening and diagnosis has moved from the second into the first trimester, with aneuploidy screening becoming both feasible and effective. With vast improvements in ultrasound technology, sonologists can now image the fetus in greater detail at all gestational ages. In the hands of experienced sonographers, anatomic surveys between 11 and 14 weeks can be carried out with good visualisation rates of many structures. It is important to be familiar with the normal development of the embryo and fetus, and to be aware of the major anatomical landmarks whose absence or presence may be deemed normal or abnormal depending on the gestational age. Some structural abnormalities will nearly always be detected, some will never be and some are potentially detectable depending on a number of factors.

  1. Accurate alignment of functional EPI data to anatomical MRI using a physics-based distortion model.

    Science.gov (United States)

    Studholme, C; Constable, R T; Duncan, J S

    2000-11-01

    Mapping of functional magnetic resonance imaging (fMRI) to conventional anatomical MRI is a valuable step in the interpretation of fMRI activations. One of the main limits on the accuracy of this alignment arises from differences in the geometric distortion induced by magnetic field inhomogeneity. This paper describes an approach to the registration of echo planar image (EPI) data to conventional anatomical images which takes into account this difference in geometric distortion. We make use of an additional spin echo EPI image and use the known signal conservation in spin echo distortion to derive a specialized multimodality nonrigid registration algorithm. We also examine a plausible modification using log-intensity evaluation of the criterion to provide increased sensitivity in areas of low EPI signal. A phantom-based imaging experiment is used to evaluate the behavior of the different criteria, comparing nonrigid displacement estimates to those provided by a imagnetic field mapping acquisition. The algorithm is then applied to a range of nine brain imaging studies illustrating global and local improvement in the anatomical alignment and localization of fMRI activations.

  2. Cryptic Species or Inadequate Taxonomy? Implementation of 2D Geometric Morphometrics Based on Integumental Organs as Landmarks for Delimitation and Description of Copepod Taxa.

    Science.gov (United States)

    Karanovic, Tomislav; Djurakic, Marko; Eberhard, Stefan M

    2016-03-01

    Discovery of cryptic species using molecular tools has become common in many animal groups but it is rarely accompanied by morphological revision, creating ongoing problems in taxonomy and conservation. In copepods, cryptic species have been discovered in most groups where fast-evolving molecular markers were employed. In this study at Yeelirrie in Western Australia we investigate a subterranean species complex belonging to the harpacticoid genus Schizopera Sars, 1905, using both the barcoding mitochondrial COI gene and landmark-based two-dimensional geometric morphometrics. Integumental organs (sensilla and pores) are used as landmarks for the first time in any crustacean group. Complete congruence between DNA-based species delimitation and relative position of integumental organs in two independent morphological structures suggests the existence of three distinct evolutionary units. We describe two of them as new species, employing a condensed taxonomic format appropriate for cryptic species. We argue that many supposedly cryptic species might not be cryptic if researchers focus on analyzing morphological structures with multivariate tools that explicitly take into account geometry of the phenotype. A perceived supremacy of molecular methods in detecting cryptic species is in our view a consequence of disparity of investment and unexploited recent advancements in morphometrics among taxonomists. Our study shows that morphometric data alone could be used to find diagnostic morphological traits and gives hope to anyone studying small animals with a hard integument or shell, especially opening the door to assessing fossil diversity and rich museum collections. We expect that simultaneous use of molecular tools with geometry-oriented morphometrics may yield faster formal description of species. Decrypted species in this study are a good example for urgency of formal descriptions, as they display short-range endemism in small groundwater calcrete aquifers in a

  3. Cryptic Species or Inadequate Taxonomy? Implementation of 2D Geometric Morphometrics Based on Integumental Organs as Landmarks for Delimitation and Description of Copepod Taxa.

    Science.gov (United States)

    Karanovic, Tomislav; Djurakic, Marko; Eberhard, Stefan M

    2016-03-01

    Discovery of cryptic species using molecular tools has become common in many animal groups but it is rarely accompanied by morphological revision, creating ongoing problems in taxonomy and conservation. In copepods, cryptic species have been discovered in most groups where fast-evolving molecular markers were employed. In this study at Yeelirrie in Western Australia we investigate a subterranean species complex belonging to the harpacticoid genus Schizopera Sars, 1905, using both the barcoding mitochondrial COI gene and landmark-based two-dimensional geometric morphometrics. Integumental organs (sensilla and pores) are used as landmarks for the first time in any crustacean group. Complete congruence between DNA-based species delimitation and relative position of integumental organs in two independent morphological structures suggests the existence of three distinct evolutionary units. We describe two of them as new species, employing a condensed taxonomic format appropriate for cryptic species. We argue that many supposedly cryptic species might not be cryptic if researchers focus on analyzing morphological structures with multivariate tools that explicitly take into account geometry of the phenotype. A perceived supremacy of molecular methods in detecting cryptic species is in our view a consequence of disparity of investment and unexploited recent advancements in morphometrics among taxonomists. Our study shows that morphometric data alone could be used to find diagnostic morphological traits and gives hope to anyone studying small animals with a hard integument or shell, especially opening the door to assessing fossil diversity and rich museum collections. We expect that simultaneous use of molecular tools with geometry-oriented morphometrics may yield faster formal description of species. Decrypted species in this study are a good example for urgency of formal descriptions, as they display short-range endemism in small groundwater calcrete aquifers in a

  4. Anatomical references for tibial sagittal alignment in total knee arthroplasty: A comparison of three anatomical axes based on 3D reconstructed CT images

    Institute of Scientific and Technical Information of China (English)

    SHAO Jun-jie; Thomas Parker Vail; WANG Qiao-jie; SHEN Hao; CHEN Yun-su; WANG Qi; JIANG Yao

    2013-01-01

    Background This study was designed to analyze three tibial axis reference lines including the anterior tibial cortex (ATC) line,the fibular line (FL),and the anatomical axis of tibia (AAT) line,to determine which line most closely parallels the mechanical axis (MA) of the tibia in the sagittal plane.The clinical relevance of the study is that through finding a reliable landmark on the leg,a surgeon may minimize posterior tibial slope measurement errors thereby and improving the technique for assuring proper alignment of total knee arthroplasty.Methods The material for this study included CT scans of the tibia from 85 consecutive patients and 168 knees (78 without osteoarthritis (OA) and 90 knees with OA).Measurements of the angles between the tibial mechanical axis and each of three reference lines in the sagittal plane were carried out using 3D imaging software.Results Mean angles of 168 knees were as follows:aMT (3.96±0.85)°,aMF (0.70±0.58)°,and aMA (1.40±0.66)°,(aMT:an angle between MA and ATC,aMF:an angle between MA and FL,aMA:an angle between MA and AAT.All abovementioned angles were measured in the sagittal plane of tibia) and the aMF was significantly smaller than the others (P <0.0001).The mean value of the medial tibial slope angle vs.the MA was (9.19±3.97)°,and this was significantly larger than the mean lateral slope angle of (6.62±4.23)° (P <0.0001).The difference between aMF without OA and with OA was not statistically significant (P=0.5015) and the association between the aMT and aMA was strong (r=0.82,P <0.01).Conclusions FL was more closely parallel to the MA of tibia,and more showed less variation between OA and nonOA controls than ATC and AAT lines.Furthermore,the amount of posterior slope in medial plateau was greater than that in lateral plateau.The findings of this analysis suggest that when using the anterior tibial cortex line as is commonly done with extramedullary tibial resection guides,the tibial resection should be sloped

  5. MICROSURGICAL LANDMARKS IN MINIMALLY INVASIVE TRANSFORAMINAL LUMBAR INTERBODY FUSION

    Directory of Open Access Journals (Sweden)

    Javier Quillo-Olvera

    2015-12-01

    Full Text Available Microsurgical landmarks of the facet joint complex were defined to provide guidance and security within the tubular retractor during transforaminal surgery. A retrospective observational study was performed in segments L4-L5 by the left side approach. Microsurgical relevant photos, anatomical models and drawing were used to expose the suggested landmarks. The MI-TLIF technique has advantages compared with conventional open TLIF technique, however minimally invasive technique implies lack of security for the surgeon due to the lack of defined microanatomical landmarks compared to open spine surgery, and disorientation within the tubular retractor, the reason why to have precise microsurgical references and its recognition within the surgical field provide speed and safety when performing minimally invasive technique.

  6. Anatomical specificity of vascular endothelial growth factor expression in glioblastomas: a voxel-based mapping analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Xing [Capital Medical University, Department of Neurosurgery, Beijing Tiantan Hospital, Beijing (China); Wang, Yinyan [Capital Medical University, Department of Neurosurgery, Beijing Tiantan Hospital, Beijing (China); Capital Medical University, Department of Neuropathology, Beijing Neurosurgical Institute, Beijing (China); Wang, Kai; Ma, Jun; Li, Shaowu [Capital Medical University, Department of Neuroradiology, Beijing Tiantan Hospital, Beijing (China); Liu, Shuai [Chinese Academy of Medical Sciences and Peking Union Medical College, Departments of Neurosurgery, Peking Union Medical College Hospital, Beijing (China); Liu, Yong [Chinese Academy of Sciences, Brainnetome Center, Institute of Automation, Beijing (China); Jiang, Tao [Capital Medical University, Department of Neurosurgery, Beijing Tiantan Hospital, Beijing (China); Beijing Academy of Critical Illness in Brain, Department of Clinical Oncology, Beijing (China)

    2016-01-15

    The expression of vascular endothelial growth factor (VEGF) is a common genetic alteration in malignant gliomas and contributes to the angiogenesis of tumors. This study aimed to investigate the anatomical specificity of VEGF expression levels in glioblastomas using voxel-based neuroimaging analysis. Clinical information, MR scans, and immunohistochemistry stains of 209 patients with glioblastomas were reviewed. All tumor lesions were segmented manually and subsequently registered to standard brain space. Voxel-based regression analysis was performed to correlate the brain regions of tumor involvement with the level of VEGF expression. Brain regions identified as significantly associated with high or low VEGF expression were preserved following permutation correction. High VEGF expression was detected in 123 (58.9 %) of the 209 patients. Voxel-based statistical analysis demonstrated that high VEGF expression was more likely in tumors located in the left frontal lobe and the right caudate and low VEGF expression was more likely in tumors that occurred in the posterior region of the right lateral ventricle. Voxel-based neuroimaging analysis revealed the anatomic specificity of VEGF expression in glioblastoma, which may further our understanding of genetic heterogeneity during tumor origination. This finding provides primary theoretical support for potential future application of customized antiangiogenic therapy. (orig.)

  7. Anatomical specificity of vascular endothelial growth factor expression in glioblastomas: a voxel-based mapping analysis

    International Nuclear Information System (INIS)

    The expression of vascular endothelial growth factor (VEGF) is a common genetic alteration in malignant gliomas and contributes to the angiogenesis of tumors. This study aimed to investigate the anatomical specificity of VEGF expression levels in glioblastomas using voxel-based neuroimaging analysis. Clinical information, MR scans, and immunohistochemistry stains of 209 patients with glioblastomas were reviewed. All tumor lesions were segmented manually and subsequently registered to standard brain space. Voxel-based regression analysis was performed to correlate the brain regions of tumor involvement with the level of VEGF expression. Brain regions identified as significantly associated with high or low VEGF expression were preserved following permutation correction. High VEGF expression was detected in 123 (58.9 %) of the 209 patients. Voxel-based statistical analysis demonstrated that high VEGF expression was more likely in tumors located in the left frontal lobe and the right caudate and low VEGF expression was more likely in tumors that occurred in the posterior region of the right lateral ventricle. Voxel-based neuroimaging analysis revealed the anatomic specificity of VEGF expression in glioblastoma, which may further our understanding of genetic heterogeneity during tumor origination. This finding provides primary theoretical support for potential future application of customized antiangiogenic therapy. (orig.)

  8. Visual SLAM for underwater vehicles using video velocity log and natural landmarks

    OpenAIRE

    Salvi, Joaquim; Petillot, Yvan R.; Thomas, Stephen; Aulinas Masó, Josep M.

    2008-01-01

    A visual SLAM system has been implemented and optimised for real-time deployment on an AUV equipped with calibrated stereo cameras. The system incorporates a novel approach to landmark description in which landmarks are local sub maps that consist of a cloud of 3D points and their associated SIFT/SURF descriptors. Landmarks are also sparsely distributed which simplifies and accelerates data association and map updates. In addition to landmark-based localisation the system utilises visual odom...

  9. Sparse decomposition and modeling of anatomical shape variation

    DEFF Research Database (Denmark)

    Sjöstrand, Karl; Rostrup, Egill; Ryberg, Charlotte;

    2007-01-01

    counterparts if constructed carefully. In most medical applications, models are required to have both good statistical performance and a relevant clinical interpretation to be of value. Morphometry of the corpus callosum is one illustrative example. This paper presents a method for relating spatial features to...... anatomical variation related to clinical outcome. In the present application, landmark-based shape data of the corpus callosum is analyzed in relation to age, gender, and clinical tests of walking speed and verbal fluency. To put the data-driven sparse principal component method into perspective, we consider...

  10. Sparse Decomposition and Modeling of Anatomical Shape Variation

    DEFF Research Database (Denmark)

    Sjöstrand, Karl; Rostrup, Egill; Ryberg, Charlotte;

    2007-01-01

    counterparts if constructed carefully. In most medical applications, models are required to have both good statistical performance and a relevant clinical interpretation to be of value. Morphometry of the corpus callosum is one illustrative example. This paper presents a method for relating spatial features to...... anatomical variation related to clinical outcome. In the present application, landmark-based shape data of the corpus callosum is analyzed in relation to age, gender, and clinical tests of walking speed and verbal fluency. To put the data-driven sparse principal component method into perspective, we consider...

  11. Evaluation and calibration of functional network modeling methods based on known anatomical connections.

    Science.gov (United States)

    Dawson, Debra Ann; Cha, Kuwook; Lewis, Lindsay B; Mendola, Janine D; Shmuel, Amir

    2013-02-15

    Recent studies have identified large scale brain networks based on the spatio-temporal structure of spontaneous fluctuations in resting-state fMRI data. It is expected that functional connectivity based on resting-state data is reflective of - but not identical to - the underlying anatomical connectivity. However, which functional connectivity analysis methods reliably predict the network structure remains unclear. Here we tested and compared network connectivity analysis methods by applying them to fMRI resting-state time-series obtained from the human visual cortex. The methods evaluated here are those previously tested against simulated data in Smith et al. (Neuroimage, 2011). To this end, we defined regions within retinotopic visual areas V1, V2, and V3 according to their eccentricity in the visual field, delineating central, intermediate, and peripheral eccentricity regions of interest (ROIs). These ROIs served as nodes in the models we study. We based our evaluation on the "ground-truth", thoroughly studied retinotopically-organized anatomical connectivity in the monkey visual cortex. For each evaluated method, we computed the fractional rate of detecting connections known to exist ("c-sensitivity"), while using a threshold of the 95th percentile of the distribution of interaction magnitudes of those connections not expected to exist. Under optimal conditions - including session duration of 68min, a relatively small network consisting of 9 nodes and artifact-free regression of the global effect - each of the top methods predicted the expected connections with 67-85% c-sensitivity. Correlation methods, including Correlation (Corr; 85%), Regularized Inverse Covariance (ICOV; 84%) and Partial Correlation (PCorr; 81%) performed best, followed by Patel's Kappa (80%), Bayesian Network method PC (BayesNet; 77%), General Synchronization measures (67-77%), and Coherence (CohB; 74%). With decreased session duration, these top methods saw decreases in c

  12. FEM-based simulation of a fluorescence tomography experiment using anatomical MR images

    Science.gov (United States)

    Ren, Wuwei; Elmer, Andreas; Augath, Mark-Aurel; Rudin, Markus

    2016-03-01

    A hybrid system combining fluorescence molecular tomography (FMT) and magnetic resonance imaging (MRI) is attractive for preclinical imaging as it allows fusion of molecular information derived from FMT and anatomical reference data derived from MRI. We have previously developed such a system and demonstrated its performance in biological applications. For reconstruction slab geometry with homogeneous optical parameters was assumed, which led to undesirable artifacts. In order to exploit the power of the hybrid system, the use of MRI derived anatomical information, as a constraint for FMT reconstruction, appears logical. Heterogeneity of tissues and irregular surface derived from MRI can be accounted for by generating a mesh using the finite element method (FEM), and attributing optical parameters to individual mesh points. We have established a forward simulation tool based on TOAST++ to mimic an FMT experiment. MRI images were recorded on a 9.4T MR scanner using a T1-weighted pulse sequence. The voxelized dataset was processed by iso2mesh to yield a 3D-mesh. Four steps of FMT simulation were included: 1) Assignment of optical properties, 2) Specification of boundary conditions and generation of 3) excitation and 4) emission maps. FEM-derived results were compared with those obtained using the analytical solution of Green's function and with experimental data with a single fluorescent inclusion in a silicon phantom. Once, the forward modeling method is properly validated it will be used as a central element of a reconstruction algorithm for analyzing data derived from a hybrid FMT/MRI setup.

  13. DETEKSI LANDMARK CITRA WAJAH DENGAN EXTRAKSI FITUR GABOR ANALISA FUZZY

    Directory of Open Access Journals (Sweden)

    Resmana Lim

    2003-01-01

    Full Text Available This paper proposes a method that automatically finds human faces as well as its landmark points in color images based on a fuzzy analysis. The proposed approach first uses color information to detect face candidate regions and then uses a fuzzy analysis of the color, shape, symmetry and interior facial features. A deformable Gabor wavelet graph matching is used to locate the facial landmark points describing the face. The latter allows for size and orientation variation since the search for landmark points allows for affine transformations as well as local deformations of the Gabor wavelet graph. The search is performed using a genetic algorithm that is essential because it effectively searches the solution space. Results based on the proposed method are included to verify the effectiveness of the proposed approach. Abstract in Bahasa Indonesia : Paper ini mengusulkan sebuah metode deteksi wajah beserta dengan titik landmarknya pada citra berwarna menggunakan analisa fuzzy. Proses awal menggunakan informasi warna kulit untuk menseleksi calon-calon obyek lantas dilanjukan dengan analisa fuzzy terhadap warna, bentuk, simetri dan fitur/landmark wajah. Proses lokalisasi landmark wajah menggunakan Gabor wavelet graph matching dengan memaksimalkan kemiripan antara landmark wajah model dengan obyek inputan. Proses maksimalisasi kemiripan ini menggunakan algoritma genetika. Hasil-hasil percobaan ditampilkan untuk memberikan gambaran keberhasilan dari metode yang diusulkan. Kata kunci: lokalisasi landmark wajah, analisa fuzzy, graph matching, algoritma genetika, Gabor wavelet.

  14. A New Anatomically Based Nomenclature for the Roots and Root Canals—Part 1: Maxillary Molars

    Directory of Open Access Journals (Sweden)

    Jojo Kottoor

    2012-01-01

    Full Text Available Numerous terminologies have been employed in the dental literature to describe the roots and root canal systems of maxillary molars. This multiplicity in naming of roots and canals makes the reader susceptible to misinterpretation and confusion. No consensus thus far has been arrived at for defining the names of roots and root canals in maxillary molars, including their various morphological aberrations. The anatomical relation of roots and their root canals were identified and were subsequently named based on definite sets of criteria. A new method for identification and naming of roots and root canal anatomy in maxillary molars, based on their root and canal relationship, was formulated and is presented in this paper. The nomenclature makes certain essential modifications to the traditional approach to accommodate naming of the various aberrations presented in the maxillary molars. A simple, yet extensive, nomenclature system has been proposed that appropriately names the internal and external morphology of maxillary molars.

  15. Identification keys on rattans (Calamus spp.) from Central Sulawesi based on anatomical structure of stems

    OpenAIRE

    ANDI TANRA TELLU

    2005-01-01

    This study was conducted to obtain information the anatomical characteristics of 20 rattan species from Central Sulawesi and to use it for anatomical identification of rattan species. The rattan comprised 16 Calamus species, three Daemonorops species and one Korthalsia species. For anatomical observation 10-15 mm pieces of the mature stem from shares of tip do not have frond were processed with polyethilene glycol 2000, cut at 18-32 µm and stained with a combination of acridin-cryzoidin red a...

  16. Visual EKF-SLAM from Heterogeneous Landmarks

    Science.gov (United States)

    Esparza-Jiménez, Jorge Othón; Devy, Michel; Gordillo, José L.

    2016-01-01

    Many applications require the localization of a moving object, e.g., a robot, using sensory data acquired from embedded devices. Simultaneous localization and mapping from vision performs both the spatial and temporal fusion of these data on a map when a camera moves in an unknown environment. Such a SLAM process executes two interleaved functions: the front-end detects and tracks features from images, while the back-end interprets features as landmark observations and estimates both the landmarks and the robot positions with respect to a selected reference frame. This paper describes a complete visual SLAM solution, combining both point and line landmarks on a single map. The proposed method has an impact on both the back-end and the front-end. The contributions comprehend the use of heterogeneous landmark-based EKF-SLAM (the management of a map composed of both point and line landmarks); from this perspective, the comparison between landmark parametrizations and the evaluation of how the heterogeneity improves the accuracy on the camera localization, the development of a front-end active-search process for linear landmarks integrated into SLAM and the experimentation methodology. PMID:27070602

  17. Describing head shapes of white stem borers (Schirpophaga innotata Walker that are able to survive on different rice types using Landmark based geometric morphometrics

    Directory of Open Access Journals (Sweden)

    Queenilyn B. Albutra

    2012-06-01

    Full Text Available Rice stem borers are considered as the most serious insect pest of rice in Asia. It infects itsplant host by burrowing into the stem using its mandible. However, apart from the mandible, the head ofrice stem borers is also associated in the incursion process since it facilitates the entry of larvae to the riceplant. Differences in the head capsules have a direct effect on the ability of the insects to ingest hardfoods rapidly. Different rice varieties in the Philippines serve as plant host for this pest and infestationoccurred in different geographical location. Variations in habitat and plant host were thought to generateenvironmental variation in morphometric traits and host adapted herbivore phenotype respectively.Landmark based geometric morphometric analysis was used to assess the hypothesis that the head shapeof white stem borer differ between populations with respect to different rice varieties and geographicallocation where it was obtained. Relative warp analysis showed variation in the head shape betweendifferent white stem borer (Schirpophaga innotata Walker populations infesting different varieties of rice.Non-significant head shape variations were obtained between geographically separated populations. Theseresults indicate that the rice host varieties play an important role in the selection of individuals that areable to counteract the resistance factors in plants.

  18. A multi-segment foot model based on anatomically registered technical coordinate systems: method repeatability in pediatric feet.

    Science.gov (United States)

    Saraswat, Prabhav; MacWilliams, Bruce A; Davis, Roy B

    2012-04-01

    Several multi-segment foot models to measure the motion of intrinsic joints of the foot have been reported. Use of these models in clinical decision making is limited due to lack of rigorous validation including inter-clinician, and inter-lab variability measures. A model with thoroughly quantified variability may significantly improve the confidence in the results of such foot models. This study proposes a new clinical foot model with the underlying strategy of using separate anatomic and technical marker configurations and coordinate systems. Anatomical landmark and coordinate system identification is determined during a static subject calibration. Technical markers are located at optimal sites for dynamic motion tracking. The model is comprised of the tibia and three foot segments (hindfoot, forefoot and hallux) and inter-segmental joint angles are computed in three planes. Data collection was carried out on pediatric subjects at two sites (Site 1: n=10 subjects by two clinicians and Site 2: five subjects by one clinician). A plaster mold method was used to quantify static intra-clinician and inter-clinician marker placement variability by allowing direct comparisons of marker data between sessions for each subject. Intra-clinician and inter-clinician joint angle variability were less than 4°. For dynamic walking kinematics, intra-clinician, inter-clinician and inter-laboratory variability were less than 6° for the ankle and forefoot, but slightly higher for the hallux. Inter-trial variability accounted for 2-4° of the total dynamic variability. Results indicate the proposed foot model reduces the effects of marker placement variability on computed foot kinematics during walking compared to similar measures in previous models.

  19. Endoscopic expand transnasal approach to the suprasellar region :anatomical study and clinical considerations

    Institute of Scientific and Technical Information of China (English)

    LU Xiao-jie; CHEN Kai-lai; WANG Qin; JI Wei-yang; LI Bing; SUN Ji-yong; LI Jiang-an

    2009-01-01

    Backgroud The expanded endonasal approach (EEA) is used sparingly by surgeons for resection of lesions in the ventrocranial base. Herein, we examined the anatomy of the ventrocranial base by endoscopy and comment on the use of EEA in clinical practice.Methods Twenty artery-injected adult cadaveric heads were studied under surgical conditions using the endoscopic EEA. The extent of the surgical exposure, the endoscopic anatomic view and the maneuverability of surgical instruments about the suprasellar region were studied by the endoscopic EEA.Results The EEA by endoscope can reach the suprasellar region. In this approach, the optocarotid recess, supra and infra-optic chiasm interspace, the ophthalmic artery and others were important anatomical landmarks for identification of the suprasellar region.Conclusions The endoscopic EEA can be used to remove many types of lesions in the ventrocranial base. The microanatorny observed using the endoscope provides important anatomical information on the suprasellar region for neurosurgeons.

  20. The variability in the external rotation axis of the distal femur: an MRI-based anatomical study.

    Science.gov (United States)

    Jones, Carl; Nawaz, Zuhair; Hassan, Abdel; White, Simon; Khaleel, Arshad

    2016-02-01

    Commonly used total knee arthroplasty (TKA) systems utilising measured resection techniques default to 5°-7° valgus for the distal cut relative to the anatomical axis and 3° external rotation of the femoral component relative to posterior condylar axis (PCA). Rotational errors of the femoral component are associated with pain, patella maltracking and a poorer outcome. We analysed MRI scans from patients undergoing TKA using patient-specific instrumentation to assess coronal and rotational alignment from landmarks identified on the scans. One hundred and eight scans in 59 males and 49 females were studied with age range 35-93 years (mean 67.9 years). We found 91 % of patients had a femoral valgus angle between 5° and 7° (mean angles 5.9°), while only 24 % had an external rotation angle between 2.5° and 3.5° relative to PCA. There was no statistical significance in rotation between males and females although outliers tended to be female. Mean Whiteside's angle was 92.9° (87.8-98). This study highlights the variations in external rotation between patients undergoing TKA using the PCA as a reference for rotation. This may be a contributing factor in implant malalignment and patient dissatisfaction. PMID:26530410

  1. Methods of Evidence-Based Anatomy: a guide to conducting systematic reviews and meta-analysis of anatomical studies.

    Science.gov (United States)

    Henry, Brandon Michael; Tomaszewski, Krzysztof A; Walocha, Jerzy A

    2016-05-01

    Evidence-Based Anatomy (EBA) is the concept of applying evidence-based principles and research methods to the anatomical sciences. While narrative reviews are common in the anatomical sciences, true systematic reviews (SR) and meta-analysis (MA) are only beginning to grow in popularity. In order to enhance the quality of future EBA studies, and ensure the clinical reliability of their results, a uniform methodology is needed. In this paper, we present a step-by-step methodological guide for performing SRs and MAs of anatomical studies. We address the EBA-specific challenges in each step of the SR and MA process, and discuss methods and strategies to overcome these difficulties. Furthermore, we discuss in detail the statistical methods used in MA of anatomical data, including multi-categorical and single-categorical pooled prevalence estimates, as well as pooled means of one group. Lastly, we discuss the major limitations of EBA, including the lack of a proper quality assessment tool for anatomical studies. The methods described in this paper present a uniform road map for future EBA studies. PMID:26844627

  2. Global and local spatial landmarks: their role during foraging by Columbian ground squirrels (Spermophilus columbianus).

    Science.gov (United States)

    Vlasak, Anna N

    2006-01-01

    Locating food and refuge is essential for an animal's survival. However, little is known how mammals navigate under natural conditions and cope with given environmental constraints. In a series of six experiments, I investigated landmark-based navigation in free-ranging Columbian ground squirrels (Spermophilus columbianus). Squirrels were trained individually to find a baited platform within an array of nine identical platforms and artificial landmarks set up on their territories. After animals learned the location of the food platform in the array, the position of the latter with respect to local artificial, local natural, and global landmarks was manipulated, and the animal's ability to find the food platform was tested. When only positions of local artificial landmarks were changed, squirrels located food with high accuracy. When the location of the array relative to global landmarks was altered, food-finding accuracy decreased but remained significant. In the absence of known global landmarks, the presence of a familiar route and natural local landmarks resulted in significant but not highly accurate performance. Squirrels likely relied on multiple types of cues when orienting towards a food platform. Local landmarks were used only as a secondary mechanism of navigation, and were not attended to when a familiar route and known global landmarks were present. This study provided insights into landmark use by a wild mammal in a natural situation, and it demonstrated that an array of platforms can be employed to investigate landmark-based navigation under such conditions. PMID:16163480

  3. Free-form image registration of human cochlear μCT data using skeleton similarity as anatomical prior

    DEFF Research Database (Denmark)

    Kjer, Hans Martin; Fagertun, Jens; Vera, Sergio;

    2016-01-01

    Better understanding of the anatomical variability of the human cochlear is important for the design and function of Cochlear Implants. Proper non-rigid alignment of high-resolution cochlear μCT data is a challenge for the typical cubic B-spline registration model. In this paper we study one way...... of incorporating skeleton-based similarity as an anatomical registration prior. We extract a centerline skeleton of the cochlear spiral, and generate corresponding parametric pseudo-landmarks between samples. These correspondences are included in the cost function of a typical cubic B-spline registration model...

  4. Selecting landmarks in novel environments.

    Science.gov (United States)

    Miller, Jared; Carlson, Laura

    2011-02-01

    People use salient landmarks when learning a route through a novel environment. However, it is not clear what makes a given landmark salient. In two experiments, subjects learned a route through a virtual museum, performed a recognition memory test for objects in the museum, and provided spatial descriptions and drew maps of the learned route. Objects with strong perceptual features occurred at decision points or at non-decision points along the route. Objects with both of these features were recognized faster and were included more often in the maps and written directions. When these features were separated, perceptual features maintained a strong influence on the recognition task, but had no influence on the spatial tasks, which were influenced only by spatial features. These findings challenge the idea that either a recognition task or descriptive task alone provides a complete account of landmark representation. PMID:21327344

  5. Quantitative modeling of the accuracy in registering preoperative patient-specific anatomic models into left atrial cardiac ablation procedures

    Energy Technology Data Exchange (ETDEWEB)

    Rettmann, Maryam E., E-mail: rettmann.maryam@mayo.edu; Holmes, David R.; Camp, Jon J.; Cameron, Bruce M.; Robb, Richard A. [Biomedical Imaging Resource, Mayo Clinic College of Medicine, Rochester, Minnesota 55905 (United States); Kwartowitz, David M. [Department of Bioengineering, Clemson University, Clemson, South Carolina 29634 (United States); Gunawan, Mia [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington D.C. 20057 (United States); Johnson, Susan B.; Packer, Douglas L. [Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota 55905 (United States); Dalegrave, Charles [Clinical Cardiac Electrophysiology, Cardiology Division Hospital Sao Paulo, Federal University of Sao Paulo, 04024-002 Brazil (Brazil); Kolasa, Mark W. [David Grant Medical Center, Fairfield, California 94535 (United States)

    2014-02-15

    Purpose: In cardiac ablation therapy, accurate anatomic guidance is necessary to create effective tissue lesions for elimination of left atrial fibrillation. While fluoroscopy, ultrasound, and electroanatomic maps are important guidance tools, they lack information regarding detailed patient anatomy which can be obtained from high resolution imaging techniques. For this reason, there has been significant effort in incorporating detailed, patient-specific models generated from preoperative imaging datasets into the procedure. Both clinical and animal studies have investigated registration and targeting accuracy when using preoperative models; however, the effect of various error sources on registration accuracy has not been quantitatively evaluated. Methods: Data from phantom, canine, and patient studies are used to model and evaluate registration accuracy. In the phantom studies, data are collected using a magnetically tracked catheter on a static phantom model. Monte Carlo simulation studies were run to evaluate both baseline errors as well as the effect of different sources of error that would be present in a dynamicin vivo setting. Error is simulated by varying the variance parameters on the landmark fiducial, physical target, and surface point locations in the phantom simulation studies. In vivo validation studies were undertaken in six canines in which metal clips were placed in the left atrium to serve as ground truth points. A small clinical evaluation was completed in three patients. Landmark-based and combined landmark and surface-based registration algorithms were evaluated in all studies. In the phantom and canine studies, both target registration error and point-to-surface error are used to assess accuracy. In the patient studies, no ground truth is available and registration accuracy is quantified using point-to-surface error only. Results: The phantom simulation studies demonstrated that combined landmark and surface-based registration improved

  6. Quantitative modeling of the accuracy in registering preoperative patient-specific anatomic models into left atrial cardiac ablation procedures

    International Nuclear Information System (INIS)

    Purpose: In cardiac ablation therapy, accurate anatomic guidance is necessary to create effective tissue lesions for elimination of left atrial fibrillation. While fluoroscopy, ultrasound, and electroanatomic maps are important guidance tools, they lack information regarding detailed patient anatomy which can be obtained from high resolution imaging techniques. For this reason, there has been significant effort in incorporating detailed, patient-specific models generated from preoperative imaging datasets into the procedure. Both clinical and animal studies have investigated registration and targeting accuracy when using preoperative models; however, the effect of various error sources on registration accuracy has not been quantitatively evaluated. Methods: Data from phantom, canine, and patient studies are used to model and evaluate registration accuracy. In the phantom studies, data are collected using a magnetically tracked catheter on a static phantom model. Monte Carlo simulation studies were run to evaluate both baseline errors as well as the effect of different sources of error that would be present in a dynamicin vivo setting. Error is simulated by varying the variance parameters on the landmark fiducial, physical target, and surface point locations in the phantom simulation studies. In vivo validation studies were undertaken in six canines in which metal clips were placed in the left atrium to serve as ground truth points. A small clinical evaluation was completed in three patients. Landmark-based and combined landmark and surface-based registration algorithms were evaluated in all studies. In the phantom and canine studies, both target registration error and point-to-surface error are used to assess accuracy. In the patient studies, no ground truth is available and registration accuracy is quantified using point-to-surface error only. Results: The phantom simulation studies demonstrated that combined landmark and surface-based registration improved

  7. The Yale Pharyngeal Residue Severity Rating Scale: An Anatomically Defined and Image-Based Tool.

    Science.gov (United States)

    Neubauer, Paul D; Rademaker, Alfred W; Leder, Steven B

    2015-10-01

    The Yale Pharyngeal Residue Severity Rating Scale was developed, standardized, and validated to provide reliable, anatomically defined, and image-based assessment of post-swallow pharyngeal residue severity as observed during fiberoptic endoscopic evaluation of swallowing (FEES). It is a five-point ordinal rating scale based on residue location (vallecula and pyriform sinus) and amount (none, trace, mild, moderate, and severe). Two expert judges reviewed a total of 261 FEES evaluations and selected a no residue exemplar and three exemplars each of trace, mild, moderate, and severe vallecula and pyriform sinus residue. Hard-copy color images of the no residue, 12 vallecula, and 12 pyriform sinus exemplars were randomized by residue location for hierarchical categorization by 20 raters with a mean of 8.3 years of experience (range 2-27 years) performing and interpreting FEES. Severity ratings for all images were performed by the same 20 raters, 2 weeks apart, and with the order of image presentations randomized. Intra-rater test-retest reliability, inter-rater reliability, and construct validity were determined by pooled multi-category multi-rater kappa statistics. Residue ratings were excellent for intra-rater reliability for vallecula (kappa = 0.957 ± 0.014) and pyriform sinus (kappa = 0.854 ± 0.021); very good to excellent for inter-rater reliability for vallecula (kappa = 0.868 ± 0.011) and pyriform sinus (kappa = 0.751 ± 0.011); and excellent for validity for vallecula (kappa = 0.951 ± 0.014) and pyriform sinus (kappa = 0.908 ± 0.017). Clinical uses include accurate classification of vallecula and pyriform sinus residue severity patterns as none, trace, mild, moderate, or severe for diagnostic purposes, determination of functional therapeutic change, and precise dissemination of shared information. Scientific uses include tracking outcome measures, demonstrating efficacy of interventions to reduce pharyngeal residue, investigating morbidity and mortality

  8. Landmarks or panoramas: what do navigating ants attend to for guidance?

    Directory of Open Access Journals (Sweden)

    Beugnon Guy

    2011-08-01

    Full Text Available Abstract Background Insects are known to rely on terrestrial landmarks for navigation. Landmarks are used to chart a route or pinpoint a goal. The distant panorama, however, is often thought not to guide navigation directly during a familiar journey, but to act as a contextual cue that primes the correct memory of the landmarks. Results We provided Melophorus bagoti ants with a huge artificial landmark located right near the nest entrance to find out whether navigating ants focus on such a prominent visual landmark for homing guidance. When the landmark was displaced by small or large distances, ant routes were affected differently. Certain behaviours appeared inconsistent with the hypothesis that guidance was based on the landmark only. Instead, comparisons of panoramic images recorded on the field, encompassing both landmark and distal panorama, could explain most aspects of the ant behaviours. Conclusion Ants navigating along a familiar route do not focus on obvious landmarks or filter out distal panoramic cues, but appear to be guided by cues covering a large area of their panoramic visual field, including both landmarks and distal panorama. Using panoramic views seems an appropriate strategy to cope with the complexity of natural scenes and the poor resolution of insects' eyes. The ability to isolate landmarks from the rest of a scene may be beyond the capacity of animals that do not possess a dedicated object-perception visual stream like primates.

  9. Support vector machine-based classification of Alzheimer's disease from whole-brain anatomical MRI

    International Nuclear Information System (INIS)

    We present and evaluate a new automated method based on support vector machine (SVM) classification of whole-brain anatomical magnetic resonance imaging to discriminate between patients with Alzheimer's disease (AD) and elderly control subjects. We studied 16 patients with AD [mean age ± standard deviation (SD)=74.1 ±5.2 years, mini-mental score examination (MMSE) = 23.1 ± 2.9] and 22 elderly controls (72.3±5.0 years, MMSE=28.5± 1.3). Three-dimensional T1-weighted MR images of each subject were automatically parcellated into regions of interest (ROIs). Based upon the characteristics of gray matter extracted from each ROI, we used an SVM algorithm to classify the subjects and statistical procedures based on bootstrap resampling to ensure the robustness of the results. We obtained 94.5% mean correct classification for AD and control subjects (mean specificity, 96.6%; mean sensitivity, 91.5%). Our method has the potential in distinguishing patients with AD from elderly controls and therefore may help in the early diagnosis of AD. (orig.)

  10. CFD simulation of aerosol deposition in an anatomically based human large-medium airway model.

    Science.gov (United States)

    Ma, Baoshun; Lutchen, Kenneth R

    2009-02-01

    Quantitative data on aerosol deposition in the human respiratory tract are useful for understanding the causes of certain lung diseases and for designing efficient drug delivery systems via inhalation. In this study, aerosol deposition in a 3D anatomically based human large-medium airway model was simulated using computational fluid dynamics (CFD). The model extended from mouth to generation 10 and included two-thirds of the airways obtained by multi-detector row computed tomography (MDCT) imaging on normal healthy human subjects. Steady oral inhalation (15, 30, and 60 L/min) and aerosol (1-30 micrometer) deposition were computed by CFD using the realizable k-epsilon turbulence model. Based on the mean turbulence flow field, the computed extrathoracic deposition, ratio of left to right lung deposition, and deposition efficiency at each generation compared favorably with existing in vivo and in vitro experiments. The significant deposition in the large-medium airway model showed that the total tracheobronchial deposition is dominated by the large-medium airways for micrometer-sized aerosol particles. These quantitative data and the methods developed in this study provided valuable means toward subject-specific modeling of aerosol deposition in the human lung based on realistic lung geometry. PMID:19082892

  11. Segmentation of anatomical branching structures based on texture features and conditional random field

    Science.gov (United States)

    Nuzhnaya, Tatyana; Bakic, Predrag; Kontos, Despina; Megalooikonomou, Vasileios; Ling, Haibin

    2012-02-01

    This work is a part of our ongoing study aimed at understanding a relation between the topology of anatomical branching structures with the underlying image texture. Morphological variability of the breast ductal network is associated with subsequent development of abnormalities in patients with nipple discharge such as papilloma, breast cancer and atypia. In this work, we investigate complex dependence among ductal components to perform segmentation, the first step for analyzing topology of ductal lobes. Our automated framework is based on incorporating a conditional random field with texture descriptors of skewness, coarseness, contrast, energy and fractal dimension. These features are selected to capture the architectural variability of the enhanced ducts by encoding spatial variations between pixel patches in galactographic image. The segmentation algorithm was applied to a dataset of 20 x-ray galactograms obtained at the Hospital of the University of Pennsylvania. We compared the performance of the proposed approach with fully and semi automated segmentation algorithms based on neural network classification, fuzzy-connectedness, vesselness filter and graph cuts. Global consistency error and confusion matrix analysis were used as accuracy measurements. For the proposed approach, the true positive rate was higher and the false negative rate was significantly lower compared to other fully automated methods. This indicates that segmentation based on CRF incorporated with texture descriptors has potential to efficiently support the analysis of complex topology of the ducts and aid in development of realistic breast anatomy phantoms.

  12. Mapped Landmark Algorithm for Precision Landing

    Science.gov (United States)

    Johnson, Andrew; Ansar, Adnan; Matthies, Larry

    2007-01-01

    A report discusses a computer vision algorithm for position estimation to enable precision landing during planetary descent. The Descent Image Motion Estimation System for the Mars Exploration Rovers has been used as a starting point for creating code for precision, terrain-relative navigation during planetary landing. The algorithm is designed to be general because it handles images taken at different scales and resolutions relative to the map, and can produce mapped landmark matches for any planetary terrain of sufficient texture. These matches provide a measurement of horizontal position relative to a known landing site specified on the surface map. Multiple mapped landmarks generated per image allow for automatic detection and elimination of bad matches. Attitude and position can be generated from each image; this image-based attitude measurement can be used by the onboard navigation filter to improve the attitude estimate, which will improve the position estimates. The algorithm uses normalized correlation of grayscale images, producing precise, sub-pixel images. The algorithm has been broken into two sub-algorithms: (1) FFT Map Matching (see figure), which matches a single large template by correlation in the frequency domain, and (2) Mapped Landmark Refinement, which matches many small templates by correlation in the spatial domain. Each relies on feature selection, the homography transform, and 3D image correlation. The algorithm is implemented in C++ and is rated at Technology Readiness Level (TRL) 4.

  13. 基于人工路标的机器人视觉定位研究%Study on Vision Localization of Robot Based on Artificial Landmark

    Institute of Scientific and Technical Information of China (English)

    韩笑; 廖粤峰

    2015-01-01

    Self‐localization and position estimation are ones of the most important skills of autono‐mous mobile robot .According to the camera perspective mapping principle ,the parameters of inside and outside are determined to reckon the position of mobile robot .Accomplish past location by artificial landmarks .Based on experimental analysis ,bring forward a new design of artificial goal .Through es‐tablished split points at the range of RGB ,achieve detach between the objectives and background ,thus completing the image mark recognition .The experiments illustrate that the proposed method can effec‐tively identity the robot ,and can feedback the current position of the robot .%自定位和位置估计是自主移动机器人最重要的能力之一。根据摄像机透视映射原理,确定内外参数来推算机器人位置。基于实验分析,提出了一种人工路标方案。通过建立以RGB的值域范围为分割点,分层实现彩色图像的目标与背景分离,从而完成了图像标志的识别。试验表明基于人工路标信息的视觉定位系统能够有效识别出机器人,实现反馈机器人的当前位置。

  14. Phylogenetic and phytogeographical relationships in Maloideae (Rosaceae) based on morphological and anatomical characters

    NARCIS (Netherlands)

    Aldasoro, J.J.; Aedo, C.; Navarro, C.

    2005-01-01

    Phylogenetic relationships among 24 genera of Rosaceae subfam. Maloideae and Spiraeoideae are explored by means of a cladistic analysis; 16 morphological and anatomical characters were included in the analysis. Published suprageneric classifications and characters used in these classifications are b

  15. The Great American Landmarks Adventure.

    Science.gov (United States)

    Weeks, Kay

    This profusely illustrated booklet, written primarly for school children, includes drawings and descriptions of 43 of the National Historic Landmarks located in the United States. The accounts move chronologically from prehistoric cave paintings through the moon rocks collected by the Apollo astronauts in 1969. Most of the drawings represent the…

  16. ANATOMICAL PRINCIPLES BEHIND PRESERVATION OF LARYNGEAL NERVES DURING THYROIDECTOMY

    Directory of Open Access Journals (Sweden)

    O. Fabian

    2011-08-01

    Full Text Available This paper presents the anatomical principles behind preservation of inferior laryngeal nerve and of the external branch of superior laryngeal nerve during thyroidectomy. The embryological development of thyroid and recurrent laryngeal nerves explains the constant relationship between Zuckerkandl’s tuberculum and the recurrent laryngeal nerve, while anomalies in development of the aortic arches explain the presence of rare anatomical variants, with a high risk of nerve injury, of non-recurrent course of the inferior laryngeal nerve. Good knowledge of the relationship between the external branch of superior laryngeal nerve and the superior thyroid artery makes possible to avoid transection of this branch during ligature around superior thyroid artery and vein. Anatomical landmarks used to identify the recurrent laryngeal nerve (tracheo-oesophageal sulcus, the cross-over with the inferior thyroid artery, Berry’s ligament, Zuckerkandl’s tuberculum and variations in the extra-laryngeal branching of the nerve are discussed based on data from the literature. The anatomical variants when the inferior laryngeal nerve doesn’t have a recurrent course are also discussed

  17. A review of terminology for equine juvenile osteochondral conditions (JOCC) based on anatomical and functional considerations.

    Science.gov (United States)

    Denoix, J-M; Jeffcott, L B; McIlwraith, C W; van Weeren, P R

    2013-07-01

    This manuscript describes a new classification of the various joint-related lesions that can be seen in the young, growing horse based on their anatomical and functional aetiopathogenesis. Juvenile osteochondral conditions (JOCC) is a term that brings together specific disorders according to their location in the joint and their biomechanical origin. When a biomechanical insult affects the process of endochondral ossification different types of osteochondrosis (OC) lesions may occur, including osteochondral fragmentation of the articular surface or of the periarticular margins, or the formation of juvenile subchondral bone cysts. In severe cases, osteochondral collapse of the articular surface or the epiphysis or even an entire small bone may occur. Tension on ligament attachments may cause avulsion fractures of epiphyseal (or metaphyseal) ossifying bone, which are classified as JOCC, but do not result from a disturbance of the process of endochondral ossification and are not therefore classified as a form of OC. The same applies to 'physitis' which can result from damage to the physeal growth plate. PMID:23683533

  18. Grasping actions and social interaction: neural bases and anatomical circuitry in the monkey.

    Directory of Open Access Journals (Sweden)

    Stefano eRozzi

    2015-07-01

    Full Text Available The study of the neural mechanisms underlying grasping actions showed that cognitive functions are deeply embedded in motor organization. In the first part of this review, we describe the anatomical structure of the motor cortex in the monkey and the cortical and sub-cortical connections of the different motor areas. In the second part, we review the neurophysiological literature showing that motor neurons are not only involved in movement execution, but also in the transformation of object physical features into motor programs appropriate to grasp them (through visuo-motor transformations. We also discuss evidence indicating that motor neurons can encode the goal of motor acts and the intention behind action execution. Then, we describe one of the mechanisms – the mirror mechanism – considered to be at the basis of action understanding and intention reading, and describe the anatomo-functional pathways through which information about the social context can reach the areas containing mirror neurons. Finally, we briefly show that a clear similarity exists between monkey and human in the organization of the motor and mirror systems. Based on monkey and human literature, we conclude that the mirror mechanism relies on a more extended network than previously thought, and possibly subserves basic social functions. We propose that this mechanism is also involved in preparing appropriate complementary response to observed actions, allowing two individuals to become attuned and cooperate in joint actions.

  19. 胫骨前肌肌腱在膝关节置换术胫骨髓外定位系统中的作用分析%The tibialis anterior tendon as anatomical landmark in the extramedullary alignment system of the total knee arthroplasty

    Institute of Scientific and Technical Information of China (English)

    王新光; 郭汉明; 肖军; 郑少伟; 史占军

    2015-01-01

    Objective To explore the effect of the tibialis anterior tendon in the total knee arthroplasty of the extramedullary alignment. Methods The ankle center and the tibial coronal alignment in 59 lower limbs of the 59 osteoarthritis were confirmed with X-ray and was marked in the skin, the medial border of tibialis anterior tendon was also marked in the skin. The distance of the tibialis anterior tendon to the ankle center was measured at the ankle line, the distance of junction of tibialis anterior tendon and tibial coronal alignment to the ankle line also was measured. The independent t test was performed for both distances. Results The distance of the tibialis anterior tendon to the ankle center was (13.32±2.75) mm (P<0.001), and the distance of the junction of the tibialis anterior tendon and the tibial alignment to the ankle line was (71.23 ± 6.45) mm (P<0.001). Conclusion The tibialis anterior tendon has 2 points that could serve as the distal tibial anatomical landmark in extramedullary alignment of total knee arthroplasty, it could be applied in the total knee arthroplasty clinically.%目的:探讨胫骨前肌肌腱在膝关节置换术胫骨髓外定位系统的作用。方法59例行膝关节置换术中患者的59个下肢,用X线定位胫骨冠状位力线以及踝关节中点,并在皮肤上标志,标志胫骨前肌肌腱内侧缘纵轴,在内、外踝连线上测量胫骨前肌肌腱内侧缘距离踝关节中点的距离,测量胫骨力线与胫骨前肌肌腱交点到内、外踝连线距离,并用独立t检验做统计学分析。结果胫骨前肌肌腱内侧缘在内、外踝连线上与踝关节中点距离为(13.32±2.75) mm,胫骨前肌与胫骨力线交点与内外踝连线距离(71.23±6.45) mm,均有统计学意义(P<0.001)。结论胫骨前肌肌腱在胫骨远端有2个可以作为膝关节置换术中髓外定位系统中胫骨远端解剖标记,具有实际应用价值。

  20. Evaluation of a μCT-based electro-anatomical cochlear implant model

    Science.gov (United States)

    Cakir, Ahmet; Dawant, Benoit M.; Noble, Jack H.

    2016-03-01

    Cochlear implants (CIs) are considered standard treatment for patients who experience sensory-based hearing loss. Although these devices have been remarkably successful at restoring hearing, it is rare to achieve natural fidelity, and many patients experience poor outcomes. Previous studies have shown that outcomes can be improved when optimizing CI processor settings using an estimation of the CI's neural activation patterns found by detecting the distance between the CI electrodes and the nerves they stimulate in pre- and post-implantation CT images. We call this method Image-Guided CI Programming (IGCIP). More comprehensive electro-anatomical models (EAMs) might better estimate neural activation patterns than using a distance-based estimate, potentially leading to selecting further optimized CI settings. Our goal in this study is to investigate whether μCT-based EAMs can accurately estimate neural stimulation patterns. For this purpose, we have constructed EAMs of N=9 specimens. We analyzed the sensitivity of our model to design parameters such as field-of-view, resolution, and tissue resistivity. Our results show that our model is stable to parameter changes. To evaluate the utility of patient-specific modeling, we quantify the difference in estimated neural activation patterns across specimens for identically located electrodes. The average computed coefficient of variation (COV) across specimens is 0.186, suggesting patient-specific models are necessary and that the accuracy of a generic model would be insufficient. Our results suggest that development of in vivo patient-specific EAMs could lead to better methods for selecting CI settings, which would ultimately lead to better hearing outcomes with CIs.

  1. Identification keys on rattans (Calamus spp. from Central Sulawesi based on anatomical structure of stems

    Directory of Open Access Journals (Sweden)

    ANDI TANRA TELLU

    2005-04-01

    Full Text Available This study was conducted to obtain information the anatomical characteristics of 20 rattan species from Central Sulawesi and to use it for anatomical identification of rattan species. The rattan comprised 16 Calamus species, three Daemonorops species and one Korthalsia species. For anatomical observation 10-15 mm pieces of the mature stem from shares of tip do not have frond were processed with polyethilene glycol 2000, cut at 18-32 µm and stained with a combination of acridin-cryzoidin red and astrablue. Cleared preparation were used to observe stegmata, and macerated material was used to measure the length of fibers and vessel elements. Anilin sulfate was used to confirm the existence of lignin. Anatomical characteristics used in identification were shape and will thickening of epidermal cells and the position stomata at epidermal; the arrangement of sub epidermal parenchyma; composition of vascular bundles and their distribution; the shape and arrangement of central ground parenchyma and the occurrence of fiber bundles. The research result indicated that the anatomical character can be compiled to a key identify the rattan at genus and species level.

  2. Principal component analysis-based anatomical motion models for use in adaptive radiation therapy of head and neck cancer patients

    Science.gov (United States)

    Chetvertkov, Mikhail A.

    the higher dose volumes during the radiotherapy course. Modeled DVHs still underestimated the effect of parotid shrinkage due to the large compression factor (CF) used to acquire DVFs. Conclusion: Leading EDVFs from both PCA approaches have the potential to capture systematic anatomical changes during H&N radiotherapy when systematic changes are large enough with respect to random fraction-to-fraction changes. In all cases the RPCA approach appears to be more reliable than SPCA at capturing systematic changes, enabling dosimetric consequences to be projected to the future treatment fractions based on trends established early in a treatment course, or, potentially, based on population models. This work showed that PCA has a potential in identifying the major mode of anatomical changes during the radiotherapy course and subsequent use of this information in future dose predictions is feasible. Use of smaller CF values for DVFs is preferred, otherwise anatomical motion will be underestimated.

  3. Anatomically guided voxel-based partial volume effect correction in brain PET : Impact of MRI segmentation

    NARCIS (Netherlands)

    Gutierrez, Daniel; Montandon, Marie-Louise; Assal, Frederic; Allaoua, Mohamed; Ratib, Osman; Loevblad, Karl-Olof; Zaidi, Habib

    2012-01-01

    Partial volume effect is still considered one of the main limitations in brain PET imaging given the limited spatial resolution of current generation PET scanners. The accuracy of anatomically guided partial volume effect correction (PVC) algorithms in brain PET is largely dependent on the performan

  4. Memory consolidation of landmarks in good navigators.

    Science.gov (United States)

    Janzen, Gabriele; Jansen, Clemens; van Turennout, Miranda

    2008-01-01

    Landmarks play an important role in successful navigation. To successfully find your way around an environment, navigationally relevant information needs to be stored and become available at later moments in time. Evidence from functional magnetic resonance imaging (fMRI) studies shows that the human parahippocampal gyrus encodes the navigational relevance of landmarks. In the present event-related fMRI experiment, we investigated memory consolidation of navigationally relevant landmarks in the medial temporal lobe after route learning. Sixteen right-handed volunteers viewed two film sequences through a virtual museum with objects placed at locations relevant (decision points) or irrelevant (nondecision points) for navigation. To investigate consolidation effects, one film sequence was seen in the evening before scanning, the other one was seen the following morning, directly before scanning. Event-related fMRI data were acquired during an object recognition task. Participants decided whether they had seen the objects in the previously shown films. After scanning, participants answered standardized questions about their navigational skills, and were divided into groups of good and bad navigators, based on their scores. An effect of memory consolidation was obtained in the hippocampus: Objects that were seen the evening before scanning (remote objects) elicited more activity than objects seen directly before scanning (recent objects). This increase in activity in bilateral hippocampus for remote objects was observed in good navigators only. In addition, a spatial-specific effect of memory consolidation for navigationally relevant objects was observed in the parahippocampal gyrus. Remote decision point objects induced increased activity as compared with recent decision point objects, again in good navigators only. The results provide initial evidence for a connection between memory consolidation and navigational ability that can provide a basis for successful

  5. Classification of error in anatomic pathology: a proposal for an evidence-based standard.

    Science.gov (United States)

    Foucar, Elliott

    2005-05-01

    Error in anatomic pathology (EAP) is an appropriate problem to consider using the disease model with which all pathologists are familiar. In analogy to medical diseases, diagnostic errors represent a complex constellation of often-baffling deviations from the "normal" condition. Ideally, one would wish to approach such "diseases of diagnosis" with effective treatments or preventative measures, but interventions in the absence of a clear understanding of pathogenesis are often ineffective or even harmful. Medical therapy has its history of "bleeding and purging," and error-prevention has a history of "blaming and shaming." The urge to take action in dealing with either medical illnesses or diagnostic failings is, of course, admirable. However, the principle of primum non nocere should guide one's action in both circumstances. The first step in using the disease model to address EAP is the development of a valid taxonomy to allow for grouping together of abnormalities that have a similar pathogenesis. It is apparent that disease categories such as "tumor" are not valuable until they are further refined by precise and accurate classification. Likewise, "error" is an impossibly broad concept that must be parsed into meaningful subcategories before it can be understood with sufficient clarity to be prevented. One important EAP subtype that has been particularly difficult to understand and classify is knowledge-based interpretative (KBI) error. Not only is the latter sometimes confused with distinctly different error types such as human lapses, but there is danger of mistaking system-wide problems (eg, imprecise or inaccurate diagnostic criteria) for the KBI errors of individual pathologists. This paper presents a theoretically-sound taxonomic system for classification of error that can be used for evidence-based categorization of individual cases. Any taxonomy of error in medicine must distinguish between the various factors that may produce mistakes, and importantly

  6. Anatomical-based partial volume correction for low-dose dedicated cardiac SPECT/CT

    Science.gov (United States)

    Liu, Hui; Chan, Chung; Grobshtein, Yariv; Ma, Tianyu; Liu, Yaqiang; Wang, Shi; Stacy, Mitchel R.; Sinusas, Albert J.; Liu, Chi

    2015-09-01

    Due to the limited spatial resolution, partial volume effect has been a major degrading factor on quantitative accuracy in emission tomography systems. This study aims to investigate the performance of several anatomical-based partial volume correction (PVC) methods for a dedicated cardiac SPECT/CT system (GE Discovery NM/CT 570c) with focused field-of-view over a clinically relevant range of high and low count levels for two different radiotracer distributions. These PVC methods include perturbation geometry transfer matrix (pGTM), pGTM followed by multi-target correction (MTC), pGTM with known concentration in blood pool, the former followed by MTC and our newly proposed methods, which perform the MTC method iteratively, where the mean values in all regions are estimated and updated by the MTC-corrected images each time in the iterative process. The NCAT phantom was simulated for cardiovascular imaging with 99mTc-tetrofosmin, a myocardial perfusion agent, and 99mTc-red blood cell (RBC), a pure intravascular imaging agent. Images were acquired at six different count levels to investigate the performance of PVC methods in both high and low count levels for low-dose applications. We performed two large animal in vivo cardiac imaging experiments following injection of 99mTc-RBC for evaluation of intramyocardial blood volume (IMBV). The simulation results showed our proposed iterative methods provide superior performance than other existing PVC methods in terms of image quality, quantitative accuracy, and reproducibility (standard deviation), particularly for low-count data. The iterative approaches are robust for both 99mTc-tetrofosmin perfusion imaging and 99mTc-RBC imaging of IMBV and blood pool activity even at low count levels. The animal study results indicated the effectiveness of PVC to correct the overestimation of IMBV due to blood pool contamination. In conclusion, the iterative PVC methods can achieve more accurate quantification, particularly for low

  7. WIKIPEDIA ENTRIES AS A SOURCE OF CAR NAVIGATION LANDMARKS

    Directory of Open Access Journals (Sweden)

    N. Binski

    2016-06-01

    Full Text Available Car navigation system devices provide today with an easy and simple solution to the basic concept of reaching a destination. Although these systems usually achieve this goal, they still deliver a limited and poor sequence of instructions that do not consider the human nature of using landmarks during wayfinding. This research paper addresses the concept of enriching navigation route instructions by adding supplementary route information in the form of landmarks. We aim at using a contributed source of landmarks information, which is easy to access, available, show high update rate, and have a large scale of information. For this, Wikipedia was chosen, since it represents the world’s largest free encyclopaedia that includes information about many spatial entities. A survey and classification of available landmarks is implemented, coupled with ranking algorithms based on the entries’ categories and attributes. These are aimed at retrieving the most relevant landmark information required that are valuable for the enrichment of a specific navigation route. The paper will present this methodology, together with examples and results, showing the feasibility of using this concept and its potential of enriching navigation processes.

  8. Wikipedia Entries as a Source of CAR Navigation Landmarks

    Science.gov (United States)

    Binski, N.; Zhang, L.; Dalyot, S.

    2016-06-01

    Car navigation system devices provide today with an easy and simple solution to the basic concept of reaching a destination. Although these systems usually achieve this goal, they still deliver a limited and poor sequence of instructions that do not consider the human nature of using landmarks during wayfinding. This research paper addresses the concept of enriching navigation route instructions by adding supplementary route information in the form of landmarks. We aim at using a contributed source of landmarks information, which is easy to access, available, show high update rate, and have a large scale of information. For this, Wikipedia was chosen, since it represents the world's largest free encyclopaedia that includes information about many spatial entities. A survey and classification of available landmarks is implemented, coupled with ranking algorithms based on the entries' categories and attributes. These are aimed at retrieving the most relevant landmark information required that are valuable for the enrichment of a specific navigation route. The paper will present this methodology, together with examples and results, showing the feasibility of using this concept and its potential of enriching navigation processes.

  9. Diversity analysis of mangosteen (Garcinia mangostana irradiated by gamma-ray based on morphological and anatomical characteristics

    Directory of Open Access Journals (Sweden)

    MUH RAHMAD SUHARTANTO

    2010-01-01

    Full Text Available Widiastuti A, Sobir, Suhartanto MR. 2010. Diversity analysis of mangosteen (Garcinia mangostana L. irradiated by gamma-ray based on morphological and anatomical characteristics. Nusantara Bioscience 2: 23-33. The aim of this research was to increase genetic variability of mangosteen (Garcinia mangostana L. irradiated by gamma rays dosage of 0 Gy, 20 Gy, 25 Gy, 30 Gy,35 Gy and 40 Gy. Plant materials used were seeds collected from Cegal Sub-village, Karacak Village, Leuwiliang Sub-district, Bogor District, West Java. Data was generated from morphological and anatomical characteristics. The result indicated that increasing of gamma ray dosage had inhibited ability of seed to growth, which needed longer time and decreased seed viability. Morphologically, it also decreased plant heigh, stem diameter, leaf seizure, and amount of leaf. Anatomically, stomatal density had positive correlation with plant height by correlation was 90% and 74%. Gamma rays irradiation successfully increase morphological variability until 30%. Seed creavage after irradiation increased variability and survival rate of mangosteen.

  10. Quality-Aware Estimation of Facial Landmarks in Video Sequences

    DEFF Research Database (Denmark)

    Haque, Mohammad Ahsanul; Nasrollahi, Kamal; Moeslund, Thomas B.

    2015-01-01

    for facial landmark detection. If the face quality is low the proposed system corrects the facial landmarks that are detected by SDM. Depending upon the face velocity in consecutive video frames and face quality measure, two algorithms are proposed for correction of landmarks in low quality faces by using......Face alignment in video is a primitive step for facial image analysis. The accuracy of the alignment greatly depends on the quality of the face image in the video frames and low quality faces are proven to cause erroneous alignment. Thus, this paper proposes a system for quality aware face...... alignment by using a Supervised Decent Method (SDM) along with a motion based forward extrapolation method. The proposed system first extracts faces from video frames. Then, it employs a face quality assessment technique to measure the face quality. If the face quality is high, the proposed system uses SDM...

  11. Automated localization of vertebra landmarks in MRI images

    Science.gov (United States)

    Pai, Akshay; Narasimhamurthy, Anand; Rao, V. S. Veeravasarapu; Vaidya, Vivek

    2011-03-01

    The identification of key landmark points in an MR spine image is an important step for tasks such as vertebra counting. In this paper, we propose a template matching based approach for automatic detection of two key landmark points, namely the second cervical vertebra (C2) and the sacrum from sagittal MR images. The approach is comprised of an approximate localization of vertebral column followed by matching with appropriate templates in order to detect/localize the landmarks. A straightforward extension of the work described here is an automated classification of spine section(s). It also serves as a useful building block for further automatic processing such as extraction of regions of interest for subsequent image processing and also in aiding the counting of vertebra.

  12. Model-based dose calculations for COMS eye plaque brachytherapy using an anatomically realistic eye phantom

    Energy Technology Data Exchange (ETDEWEB)

    Lesperance, Marielle; Inglis-Whalen, M.; Thomson, R. M., E-mail: rthomson@physics.carleton.ca [Carleton Laboratory for Radiotherapy Physics, Department of Physics, Carleton University, Ottawa K1S 5B6 (Canada)

    2014-02-15

    Purpose : To investigate the effects of the composition and geometry of ocular media and tissues surrounding the eye on dose distributions for COMS eye plaque brachytherapy with{sup 125}I, {sup 103}Pd, or {sup 131}Cs seeds, and to investigate doses to ocular structures. Methods : An anatomically and compositionally realistic voxelized eye model with a medial tumor is developed based on a literature review. Mass energy absorption and attenuation coefficients for ocular media are calculated. Radiation transport and dose deposition are simulated using the EGSnrc Monte Carlo user-code BrachyDose for a fully loaded COMS eye plaque within a water phantom and our full eye model for the three radionuclides. A TG-43 simulation with the same seed configuration in a water phantom neglecting the plaque and interseed effects is also performed. The impact on dose distributions of varying tumor position, as well as tumor and surrounding tissue media is investigated. Each simulation and radionuclide is compared using isodose contours, dose volume histograms for the lens and tumor, maximum, minimum, and average doses to structures of interest, and doses to voxels of interest within the eye. Results : Mass energy absorption and attenuation coefficients of the ocular media differ from those of water by as much as 12% within the 20–30 keV photon energy range. For all radionuclides studied, average doses to the tumor and lens regions in the full eye model differ from those for the plaque in water by 8%–10% and 13%–14%, respectively; the average doses to the tumor and lens regions differ between the full eye model and the TG-43 simulation by 2%–17% and 29%–34%, respectively. Replacing the surrounding tissues in the eye model with water increases the maximum and average doses to the lens by 2% and 3%, respectively. Substituting the tumor medium in the eye model for water, soft tissue, or an alternate melanoma composition affects tumor dose compared to the default eye model

  13. Model-based dose calculations for COMS eye plaque brachytherapy using an anatomically realistic eye phantom

    International Nuclear Information System (INIS)

    Purpose : To investigate the effects of the composition and geometry of ocular media and tissues surrounding the eye on dose distributions for COMS eye plaque brachytherapy with125I, 103Pd, or 131Cs seeds, and to investigate doses to ocular structures. Methods : An anatomically and compositionally realistic voxelized eye model with a medial tumor is developed based on a literature review. Mass energy absorption and attenuation coefficients for ocular media are calculated. Radiation transport and dose deposition are simulated using the EGSnrc Monte Carlo user-code BrachyDose for a fully loaded COMS eye plaque within a water phantom and our full eye model for the three radionuclides. A TG-43 simulation with the same seed configuration in a water phantom neglecting the plaque and interseed effects is also performed. The impact on dose distributions of varying tumor position, as well as tumor and surrounding tissue media is investigated. Each simulation and radionuclide is compared using isodose contours, dose volume histograms for the lens and tumor, maximum, minimum, and average doses to structures of interest, and doses to voxels of interest within the eye. Results : Mass energy absorption and attenuation coefficients of the ocular media differ from those of water by as much as 12% within the 20–30 keV photon energy range. For all radionuclides studied, average doses to the tumor and lens regions in the full eye model differ from those for the plaque in water by 8%–10% and 13%–14%, respectively; the average doses to the tumor and lens regions differ between the full eye model and the TG-43 simulation by 2%–17% and 29%–34%, respectively. Replacing the surrounding tissues in the eye model with water increases the maximum and average doses to the lens by 2% and 3%, respectively. Substituting the tumor medium in the eye model for water, soft tissue, or an alternate melanoma composition affects tumor dose compared to the default eye model simulation by up to 16

  14. A New Anatomically Based Nomenclature for the Roots and Root Canals—Part 2: Mandibular Molars

    Directory of Open Access Journals (Sweden)

    Denzil Valerian Albuquerque

    2012-01-01

    Full Text Available Several terminologies have been employed in the dental literature to describe the roots and root canal systems of mandibular molars with no consensus being arrived at, thus far. The anatomical relation of roots and their root canals were identified and a naming system was formulated. The proposed nomenclature attempts to make certain essential modifications to the traditional approach to accommodate the naming of various aberrations presented in mandibular molars. A simple, yet extensive nomenclature system has been proposed that appropriately names the internal and external morphology of mandibular molars.

  15. STUDY ON COMPARISON BETWEEN LANDMARK GUIDED (BRINKMAN'S TECHNIQUE ) AND ULTRASOUND GUIDED INTERNAL JUGULAR VEIN CANNULATION

    OpenAIRE

    Vinod; Sashi Walling

    2015-01-01

    Technique of cannulating the central veins , until recently has been based on landmark guided technique . Recently ultrasound machines with high frequency probes are being used to increase success rate and reducing complications. OBJECTIVE: In our study we compare landmark guided technique ( Brinkman's technique ) ( 1 ) with ultrasound guided technique. STUDY DESIGN: outcome was evaluated in terms of 1 ) Number of attempts 2 ) ...

  16. Microstereolithography-Based Fabrication of Anatomically Shaped Beta-Tricalcium Phosphate Scaffolds for Bone Tissue Engineering.

    Science.gov (United States)

    Du, Dajiang; Asaoka, Teruo; Shinohara, Makoto; Kageyama, Tomonori; Ushida, Takashi; Furukawa, Katsuko Sakai

    2015-01-01

    Porous ceramic scaffolds with shapes matching the bone defects may result in more efficient grafting and healing than the ones with simple geometries. Using computer-assisted microstereolithography (MSTL), we have developed a novel gelcasting indirect MSTL technology and successfully fabricated two scaffolds according to CT images of rabbit femur. Negative resin molds with outer 3D dimensions conforming to the femur and an internal structure consisting of stacked meshes with uniform interconnecting struts, 0.5 mm in diameter, were fabricated by MSTL. The second mold type was designed for cortical bone formation. A ceramic slurry of beta-tricalcium phosphate (β-TCP) with room temperature vulcanization (RTV) silicone as binder was cast into the molds. After the RTV silicone was completely cured, the composite was sintered at 1500°C for 5 h. Both gross anatomical shape and the interpenetrating internal network were preserved after sintering. Even cortical structure could be introduced into the customized scaffolds, which resulted in enhanced strength. Biocompatibility was confirmed by vital staining of rabbit bone marrow mesenchymal stromal cells cultured on the customized scaffolds for 5 days. This fabrication method could be useful for constructing bone substitutes specifically designed according to local anatomical defects.

  17. Microstereolithography-Based Fabrication of Anatomically Shaped Beta-Tricalcium Phosphate Scaffolds for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Dajiang Du

    2015-01-01

    Full Text Available Porous ceramic scaffolds with shapes matching the bone defects may result in more efficient grafting and healing than the ones with simple geometries. Using computer-assisted microstereolithography (MSTL, we have developed a novel gelcasting indirect MSTL technology and successfully fabricated two scaffolds according to CT images of rabbit femur. Negative resin molds with outer 3D dimensions conforming to the femur and an internal structure consisting of stacked meshes with uniform interconnecting struts, 0.5 mm in diameter, were fabricated by MSTL. The second mold type was designed for cortical bone formation. A ceramic slurry of beta-tricalcium phosphate (β-TCP with room temperature vulcanization (RTV silicone as binder was cast into the molds. After the RTV silicone was completely cured, the composite was sintered at 1500°C for 5 h. Both gross anatomical shape and the interpenetrating internal network were preserved after sintering. Even cortical structure could be introduced into the customized scaffolds, which resulted in enhanced strength. Biocompatibility was confirmed by vital staining of rabbit bone marrow mesenchymal stromal cells cultured on the customized scaffolds for 5 days. This fabrication method could be useful for constructing bone substitutes specifically designed according to local anatomical defects.

  18. Cleft lip and palate: recommendations for dental anesthetic procedure based on anatomic evidences

    Directory of Open Access Journals (Sweden)

    Ivy Kiemle Trindade-Suedam

    2012-02-01

    Full Text Available Patients with cleft lip and palate usually present dental anomalies of number, shape, structure and position in the cleft area and the general dentist is frequently asked to restore or extract those teeth. Considering that several anatomic variations are expected in teeth adjacent to cleft areas and that knowledge of these variations by general dentists is required for optimal treatment, the objectives of this paper are: 1 to describe changes in the innervation pattern of anterior teeth and soft tissue caused by the presence of a cleft, 2 to describe a local anesthetic procedure in unilateral and bilateral clefts, and 3 to provide recommendations to improve anesthetic procedures in patients with cleft lip and palate. The cases of 2 patients are presented: one with complete unilateral cleft lip and palate, and the other with complete bilateral cleft lip and palate. The patients underwent local anesthesia in the cleft area in order to extract teeth with poor bone support. The modified anesthetic procedure, respecting the altered course of nerves in the cleft maxilla and soft tissue alterations at the cleft site, was accomplished successfully and the tooth extraction was performed with no pain to the patients. General dentists should be aware of the anatomic variations in nerve courses in the cleft area to offer high quality treatment to patients with cleft lip and palate.

  19. Prognostic classification of Hodgkin disease in pathologic stage III, based on anatomic considerations

    Energy Technology Data Exchange (ETDEWEB)

    Desser, R.K.; Golomb, H.M.; Ultmann, J.E.; Ferguson, D.J.; Moran, E.M.; Griem, M.L.; Vardiman, J.; Miller, B.; Oetzel, N.; Sweet, D.

    1977-06-01

    Fifty-two patients with pathologic stage III Hodgkin's disease were studied in an effort to determine whether location of involved abdominal nodes influenced survival. Treatment consisted of total nodal radiotherapy with or without subsequent combination chemotherapy. The initial radiation field was the ''extended mantle,'' which included supradiaphragmatic nodes, the splenic hilar area, and paraaortic nodes to the level of L2-L4. Subsequently, lower paraaortic and iliac regions were treated (''lower inverted Y''). Patients with disease limited to the spleen and/or splenic, celiac, or portal nodes (''anatomic substage'' III/sub 1/) had a more favorable 5-yr survival than did patients with involvement of paraaortic, iliac, or mesenteric nodes (''anatomic substage'' III/sub 2/) : 93% versus 57%, respectively (p < 0.05). The addition of combination chemotherapy to total nodal irradiation was associated with improved survival of patients in stage III/sub 2/, but not of those in stage III/sub 1/.

  20. Anatomical equivalence class based complete morphological descriptor for robust image analysis and abnormality detection

    Science.gov (United States)

    Baloch, Sajjad; Davatzikos, Christos

    2008-03-01

    Groupwise registration and statistical analysis of medical images are of fundamental importance in computational anatomy, where healthy and pathologic anatomies are compared relative to their differences with a common template. Accuracy of such approaches is primarily determined by the ability of finding perfectly conforming shape transformations, which is rarely achieved in practice due to algorithmic limitations arising from biological variability. Amount of the residual information not reflected by the transformation is, in fact, dictated by template selection and is lost permanently from subsequent analysis. In general, an attempt to aggressively minimize residual results in biologically incorrect correspondences, necessitating a certain level of regularity in the transformation at the cost of accuracy. In this paper, we introduce a framework for groupwise registration and statistical analysis of biomedical images that optimally fuses the information contained in a diffeomorphism and the residual to achieve completeness of representation. Since the degree of information retained in the residual depends on transformation parameters such as the level of regularization, and template selection, our approach consists of forming an equivalence class for each individual, thereby representing them via nonlinear manifolds embedded in high dimensional space. By employing a minimum variance criterion and constraining the optimization to respective anatomical manifolds, we proceed to determine their optimal morphological representation. A practical ancillary benefit of this approach is that it yields optimal choice of transformation parameters, and eliminates respective confounding variation in the data. Resultantly, the optimal signatures depend solely on anatomical variations across subjects, and may ultimately lead to more accurate diagnosis through pattern classification.

  1. Visual landmark-directed scatter-hoarding of Siberian chipmunks Tamias sibiricus.

    Science.gov (United States)

    Zhang, Dongyuan; Li, Jia; Wang, Zhenyu; Yi, Xianfeng

    2016-05-01

    Spatial memory of cached food items plays an important role in cache recovery by scatter-hoarding animals. However, whether scatter-hoarding animals intentionally select cache sites with respect to visual landmarks in the environment and then rely on them to recover their cached seeds for later use has not been extensively explored. Furthermore, there is a lack of evidence on whether there are sex differences in visual landmark-based food-hoarding behaviors in small rodents even though male and female animals exhibit different spatial abilities. In the present study, we used a scatter-hoarding animal, the Siberian chipmunk, Tamias sibiricus to explore these questions in semi-natural enclosures. Our results showed that T. sibiricus preferred to establish caches in the shallow pits labeled with visual landmarks (branches of Pinus sylvestris, leaves of Athyrium brevifrons and PVC tubes). In addition, visual landmarks of P. sylvestris facilitated cache recovery by T. sibiricus. We also found significant sex differences in visual landmark-based food-hoarding strategies in Siberian chipmunks. Males, rather than females, chipmunks tended to establish their caches with respect to the visual landmarks. Our studies show that T. sibiricus rely on visual landmarks to establish and recover their caches, and that sex differences exist in visual landmark-based food hoarding in Siberian chipmunks. PMID:27160702

  2. Elections and landmark policies in Tanzania and Uganda

    DEFF Research Database (Denmark)

    Kjær, Anne Mette; Therkildsen, Ole

    2013-01-01

    political elites to focus on policies they perceive to be able to gain votes. This is based on analyses of six landmark decisions made during the last fifteen years in the social, productive and public finance sectors in Tanzania and Uganda. Such policies share a number of key characteristics...

  3. Fat quantification and analysis of lung transplant patients on unenhanced chest CT images based on standardized anatomic space

    Science.gov (United States)

    Tong, Yubing; Udupa, Jayaram K.; Torigian, Drew A.; Wu, Caiyun; Christie, Jason; Lederer, David J.

    2016-03-01

    Chest fat estimation is important for identifying high-risk lung transplant candidates. In this paper, an approach to chest fat quantification based on a recently formulated concept of standardized anatomic space (SAS) is presented. The goal of this paper is to seek answers to the following questions related to chest fat quantification on single slice versus whole volume CT, which have not been addressed in the literature. What level of correlation exists between total chest fat volume and fat areas measured on single abdominal and thigh slices? What is the anatomic location in the chest where maximal correlation of fat area with fat volume can be expected? Do the components of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) have the same area-to-volume correlative behavior or do they differ? The SAS approach includes two steps: calibration followed by transformation which will map the patient slice locations non-linearly to SAS. The optimal slice locations found for SAT and VAT based on SAS are different and at the mid-level of the T8 vertebral body for SAT and mid-level of the T7 vertebral body for VAT. Fat volume and area on optimal slices for SAT and VAT are correlated with Pearson correlation coefficients of 0.97 and 0.86, respectively. The correlation of chest fat volume with abdominal and thigh fat areas is weak to modest.

  4. Early Esophageal Cancer Specific Survival Is Unaffected by Anatomical Location of Tumor: A Population-Based Study

    Directory of Open Access Journals (Sweden)

    Rajan N. Amin

    2016-01-01

    Full Text Available Background. Approximately one-fifth of all esophageal cancer cases are defined as early esophageal cancer (EEC. Although endoscopic therapy (ET has been shown to be equally effective as esophagectomy (EST in patients with EEC, there is little information comparing the survival outcomes of the two therapies based on anatomical location. Methods. A population-based study was conducted and the data was obtained from Surveillance, Epidemiology, and End Results program. Patients with EEC (i.e., stages Tis and T1a and treated with either ET or EST were analyzed to compare EEC-related survival for three different locations of tumor. Results. The overall EEC-specific 1-year and 5-year mean (±SE survival rates were 11.66±0.05 and 52.80±0.58 months, respectively. Tumors located in lower third had better 5-year survival compared to those located in middle third (83.50% versus 73.10%, p<0.01. However, when adjusted for age, race, gender, marital status, grade, stage of tumor, histological type, and treatment modality, there was no significant difference. Conclusion. The EEC-specific 1-year or 5-year adjusted survival did not differ by anatomic location of the tumor. Therefore, ET might serve as a minimally invasive yet effective alternative to EST to treat EEC.

  5. Early Esophageal Cancer Specific Survival Is Unaffected by Anatomical Location of Tumor: A Population-Based Study

    Science.gov (United States)

    Parikh, Samip J.; Gangireddy, Venu Gopala Reddy; Kanneganti, Praveen; Talla, Swathi; Daram, Sumanth

    2016-01-01

    Background. Approximately one-fifth of all esophageal cancer cases are defined as early esophageal cancer (EEC). Although endoscopic therapy (ET) has been shown to be equally effective as esophagectomy (EST) in patients with EEC, there is little information comparing the survival outcomes of the two therapies based on anatomical location. Methods. A population-based study was conducted and the data was obtained from Surveillance, Epidemiology, and End Results program. Patients with EEC (i.e., stages Tis and T1a) and treated with either ET or EST were analyzed to compare EEC-related survival for three different locations of tumor. Results. The overall EEC-specific 1-year and 5-year mean (±SE) survival rates were 11.66 ± 0.05 and 52.80 ± 0.58 months, respectively. Tumors located in lower third had better 5-year survival compared to those located in middle third (83.50% versus 73.10%, p < 0.01). However, when adjusted for age, race, gender, marital status, grade, stage of tumor, histological type, and treatment modality, there was no significant difference. Conclusion. The EEC-specific 1-year or 5-year adjusted survival did not differ by anatomic location of the tumor. Therefore, ET might serve as a minimally invasive yet effective alternative to EST to treat EEC. PMID:27559535

  6. The Virtual Family-development of surface-based anatomical models of two adults and two children for dosimetric simulations

    International Nuclear Information System (INIS)

    The objective of this study was to develop anatomically correct whole body human models of an adult male (34 years old), an adult female (26 years old) and two children (an 11-year-old girl and a six-year-old boy) for the optimized evaluation of electromagnetic exposure. These four models are referred to as the Virtual Family. They are based on high resolution magnetic resonance (MR) images of healthy volunteers. More than 80 different tissue types were distinguished during the segmentation. To improve the accuracy and the effectiveness of the segmentation, a novel semi-automated tool was used to analyze and segment the data. All tissues and organs were reconstructed as three-dimensional (3D) unstructured triangulated surface objects, yielding high precision images of individual features of the body. This greatly enhances the meshing flexibility and the accuracy with respect to thin tissue layers and small organs in comparison with the traditional voxel-based representation of anatomical models. Conformal computational techniques were also applied. The techniques and tools developed in this study can be used to more effectively develop future models and further improve the accuracy of the models for various applications. For research purposes, the four models are provided for free to the scientific community. (note)

  7. Dynamic Self-Organizing Landmark Extraction Method Based on 2-Dimensional Growing Dynamic Self-Organizing Feature Map%基于二维GDSOM的路标动态自组织提取方法

    Institute of Scientific and Technical Information of China (English)

    王作为; 张汝波

    2012-01-01

    A dynamic self-organizing structural feature extraction method is presented based on distance sensor. The procedure consists of three parts; design of active exploration behavior, dimensionality reduction process of spatio-temporal information and self-organizing landmark extraction method. In this paper, active exploration behavior based on follow-wall is designed to obtain high correlative spatio-temporal sequence information. Activity neurons based on variety detection and activation intensity are used to reduce the dimensionality of spatio-temporal sequence. Finally, a method of 2-Dimensional growing dynamic self-organizing feature map (2-Dimensional GDSOM) is proposed to achieve self-organizing extraction and identification of environmental landmarks. The experimental results demonstrate the effectiveness of the method.%提出一种基于距离传感器的结构化特征的动态、自组织提取方法.该方法由3个部分组成:主动感知行为的设计,时空信息的降维处理及路标的自组织提取.设计基于沿墙走的“主动感知行为”来获得高相关性的感知时空序列信息;给出基于变化检测和激活强度的活性神经元来对时空序列信息降维;最后提出一种二维动态增长自组织特征图方法,实现环境路标的自组织提取和识别.实验结果验证该方法的有效性.

  8. Landmark Finding Algorithms for Indoor Autonomous Mobile Robot Localization

    Directory of Open Access Journals (Sweden)

    L. Tóth

    2015-12-01

    Full Text Available This contribution is oriented to ways of computer vision algorithms for mobile robot localization in internal and external agricultural environment. The main aim of this work was to design, create, verify and evaluate speed and functionality of computer vision localization algorithm. An input colour camera data and depth data were captured by MS® Kinect sensor that was mounted on 6-wheel-drive mobile robot chassis. The design of the localization algorithm was focused to the most significant blobs and points (landmarks on the colour picture. Actual coordinates of autonomous mobile robot were calculated out from measured distances (depth sensor and calculated angles (RGB camera with respect to landmark points. Time measurement script was used to compare the speed of landmark finding algorithm for localization in case of one and more landmarks on picture. The main source code was written in MS Visual studio C# programming language with Microsoft.Kinect.1.7.dll on Windows based PC. Algorithms described in this article were created for a future development of an autonomous agronomical m obile robot localization and control.

  9. 基于LandMark 10 AHRS的车载动中通天线稳定系统的分析与设计%Analysis of Satelite Communication Antenna on the Move based on LandMark 10 AHRS

    Institute of Scientific and Technical Information of China (English)

    幸雪初; 王湘新; 陈绍黔

    2015-01-01

    本文首先分析了两轴陀螺稳定原理,提出了方位/俯仰控制结构,然后基于LandMark 10 AHRS,讨论了动中通天线稳定系统的原理、算法,以及算法的实现,在此基础上,提出了一种基于LandMark 10 AHRS的车载动中通天线稳定系统的稳定方案.%This article firstly analyzes the principle of two-axis gyro stabilized platform, Introduces the control Structure of azimuth/Pitch axis.Then this paper discusses the principle, control algorithm, and algorithm realization. In the Last part, this paper introduces a new method of attitude stability used by Satellite Communication Antenna On the Move Based on LandMark 10 AHRS.

  10. Landmarks selection in street map design

    International Nuclear Information System (INIS)

    In Taiwan many electrical maps present their landmarks according to the category of the feature, a designer short of knowledge about mental representation of space, can cause the map to lose its communication effects. To resolve this map design problem, in this research through long-term memory recall, navigation and observation, and short-term memory processing 111 participants were asked to select the proper landmark from study area. The results reveal that in Taiwan convenience stores are the most popular local landmark in rural and urban areas. Their commercial signs have a unique design and bright color. Contrasted to their background, this makes the convenience store a salient feature. This study also developed a rule to assess the priority of the landmarks to design them in different scale maps

  11. Population-based evaluation of a suggested anatomic and clinical classification of congenital heart defects based on the International Paediatric and Congenital Cardiac Code

    Directory of Open Access Journals (Sweden)

    Goffinet François

    2011-10-01

    Full Text Available Abstract Background Classification of the overall spectrum of congenital heart defects (CHD has always been challenging, in part because of the diversity of the cardiac phenotypes, but also because of the oft-complex associations. The purpose of our study was to establish a comprehensive and easy-to-use classification of CHD for clinical and epidemiological studies based on the long list of the International Paediatric and Congenital Cardiac Code (IPCCC. Methods We coded each individual malformation using six-digit codes from the long list of IPCCC. We then regrouped all lesions into 10 categories and 23 subcategories according to a multi-dimensional approach encompassing anatomic, diagnostic and therapeutic criteria. This anatomic and clinical classification of congenital heart disease (ACC-CHD was then applied to data acquired from a population-based cohort of patients with CHD in France, made up of 2867 cases (82% live births, 1.8% stillbirths and 16.2% pregnancy terminations. Results The majority of cases (79.5% could be identified with a single IPCCC code. The category "Heterotaxy, including isomerism and mirror-imagery" was the only one that typically required more than one code for identification of cases. The two largest categories were "ventricular septal defects" (52% and "anomalies of the outflow tracts and arterial valves" (20% of cases. Conclusion Our proposed classification is not new, but rather a regrouping of the known spectrum of CHD into a manageable number of categories based on anatomic and clinical criteria. The classification is designed to use the code numbers of the long list of IPCCC but can accommodate ICD-10 codes. Its exhaustiveness, simplicity, and anatomic basis make it useful for clinical and epidemiologic studies, including those aimed at assessment of risk factors and outcomes.

  12. Landmark perception planning for mobile robot localization

    OpenAIRE

    Armingol, José M.; Moreno, Luis; Escalera, Arturo de la; Salichs, Miguel A.

    1998-01-01

    This paper presents a fuzzy perception planner that takes into account the time cost, the suitability of every landmark detection and the different uncertainties the robot encounters along its path for mobile robot localization. The sensor used is a camera with a motorized zoom on a pan & tilt platform and the artificial landmarks are circles detected through normalized grayscale correlation. An Extended Kalman Filter is used to correct the position and orientation of the vehicle. The resulti...

  13. Cortical Terminations of the Inferior Fronto-Occipital and Uncinate Fasciculi: Anatomical Stem-Based Virtual Dissection.

    Science.gov (United States)

    Hau, Janice; Sarubbo, Silvio; Perchey, Guy; Crivello, Fabrice; Zago, Laure; Mellet, Emmanuel; Jobard, Gaël; Joliot, Marc; Mazoyer, Bernard M; Tzourio-Mazoyer, Nathalie; Petit, Laurent

    2016-01-01

    We combined the neuroanatomists' approach of defining a fascicle as all fibers passing through its compact stem with diffusion-weighted tractography to investigate the cortical terminations of two association tracts, the inferior fronto-occipital fasciculus (IFOF) and the uncinate fasciculus (UF), which have recently been implicated in the ventral language circuitry. The aim was to provide a detailed and quantitative description of their terminations in 60 healthy subjects and to do so to apply an anatomical stem-based virtual dissection, mimicking classical post-mortem dissection, to extract with minimal a priori the IFOF and UF from tractography datasets. In both tracts, we consistently observed more extensive termination territories than their conventional definitions, within the middle and superior frontal, superior parietal and angular gyri for the IFOF and the middle frontal gyrus and superior, middle and inferior temporal gyri beyond the temporal pole for the UF. We revealed new insights regarding the internal organization of these tracts by investigating for the first time the frequency, distribution and hemispheric asymmetry of their terminations. Interestingly, we observed a dissociation between the lateral right-lateralized and medial left-lateralized fronto-occipital branches of the IFOF. In the UF, we observed a rightward lateralization of the orbito-frontal and temporal branches. We revealed a more detailed map of the terminations of these fiber pathways that will enable greater specificity for correlating with diseased populations and other behavioral measures. The limitations of the diffusion tensor model in this study are also discussed. We conclude that anatomical stem-based virtual dissection with diffusion tractography is a fruitful method for studying the structural anatomy of the human white matter pathways. PMID:27252628

  14. Individual 3D region-of-interest atlas of the human brain: knowledge-based class image analysis for extraction of anatomical objects

    Science.gov (United States)

    Wagenknecht, Gudrun; Kaiser, Hans-Juergen; Sabri, Osama; Buell, Udalrich

    2000-06-01

    After neural network-based classification of tissue types, the second step of atlas extraction is knowledge-based class image analysis to get anatomically meaningful objects. Basic algorithms are region growing, mathematical morphology operations, and template matching. A special algorithm was designed for each object. The class label of each voxel and the knowledge about the relative position of anatomical objects to each other and to the sagittal midplane of the brain can be utilized for object extraction. User interaction is only necessary to define starting, mid- and end planes for most object extractions and to determine the number of iterations for erosion and dilation operations. Extraction can be done for the following anatomical brain regions: cerebrum; cerebral hemispheres; cerebellum; brain stem; white matter (e.g., centrum semiovale); gray matter [cortex, frontal, parietal, occipital, temporal lobes, cingulum, insula, basal ganglia (nuclei caudati, putamen, thalami)]. For atlas- based quantification of functional data, anatomical objects can be convoluted with the point spread function of functional data to take into account the different resolutions of morphological and functional modalities. This method allows individual atlas extraction from MRI image data of a patient without the need of warping individual data to an anatomical or statistical MRI brain atlas.

  15. Cortical projection of the inferior choroidal point as a reliable landmark to place the corticectomy and reach the temporal horn through a middle temporal gyrus approach

    Directory of Open Access Journals (Sweden)

    Thomas Frigeri

    2014-10-01

    Full Text Available Objective To establish preoperatively the localization of the cortical projection of the inferior choroidal point (ICP and use it as a reliable landmark when approaching the temporal horn through a middle temporal gyrus access. To review relevant anatomical features regarding selective amigdalohippocampectomy (AH for treatment of mesial temporal lobe epilepsy (MTLE. Method The cortical projection of the inferior choroidal point was used in more than 300 surgeries by one authors as a reliable landmark to reach the temporal horn. In the laboratory, forty cerebral hemispheres were examined. Conclusion The cortical projection of the ICP is a reliable landmark for reaching the temporal horn.

  16. Encoding and retrieval of landmark-related spatial cues during navigation: an fMRI study.

    Science.gov (United States)

    Wegman, Joost; Tyborowska, Anna; Janzen, Gabriele

    2014-07-01

    To successfully navigate, humans can use different cues from their surroundings. Learning locations in an environment can be supported by parallel subsystems in the hippocampus and the striatum. We used fMRI to look at differences in the use of object-related spatial cues while 47 participants actively navigated in an open-field virtual environment. In each trial, participants navigated toward a target object. During encoding, three positional cues (columns) with directional cues (shadows) were available. During retrieval, the removed target had to be replaced while either two objects without shadows (objects trial) or one object with a shadow (shadow trial) were available. Participants were informed in blocks about which type of retrieval trial was most likely to occur, thereby modulating expectations of having to rely on a single landmark or on a configuration of landmarks. How the spatial learning systems in the hippocampus and caudate nucleus were involved in these landmark-based encoding and retrieval processes were investigated. Landmark configurations can create a geometry similar to boundaries in an environment. It was found that the hippocampus was involved in encoding when relying on configurations of landmarks, whereas the caudate nucleus was involved in encoding when relying on single landmarks. This might suggest that the observed hippocampal activation for configurations of objects is linked to a spatial representation observed with environmental boundaries. Retrieval based on configurations of landmarks activated regions associated with the spatial updation of object locations for reorientation. When only a single landmark was available during retrieval, regions associated with updating the location of oneself were activated. There was also evidence that good between-participant performance was predicted by right hippocampal activation. This study therefore sheds light on how the brain deals with changing demands on spatial processing related purely

  17. Online updating of context-aware landmark detectors for prostate localization in daily treatment CT images

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Xiubin [College of Geographic and Biologic Information, Nanjing University of Posts and Telecommunications, Nanjing, Jiangsu 210015, China and IDEA Lab, Department of Radiology and BRIC, University of North Carolina at Chapel Hill, 130 Mason Farm Road, Chapel Hill, North Carolina 27510 (United States); Gao, Yaozong [IDEA Lab, Department of Radiology and BRIC, University of North Carolina at Chapel Hill, 130 Mason Farm Road, Chapel Hill, North Carolina 27510 (United States); Shen, Dinggang, E-mail: dgshen@med.unc.edu [IDEA Lab, Department of Radiology and BRIC, University of North Carolina at Chapel Hill, 130 Mason Farm Road, Chapel Hill, North Carolina 27510 and Department of Brain and Cognitive Engineering, Korea University, Seoul (Korea, Republic of)

    2015-05-15

    Purpose: In image guided radiation therapy, it is crucial to fast and accurately localize the prostate in the daily treatment images. To this end, the authors propose an online update scheme for landmark-guided prostate segmentation, which can fully exploit valuable patient-specific information contained in the previous treatment images and can achieve improved performance in landmark detection and prostate segmentation. Methods: To localize the prostate in the daily treatment images, the authors first automatically detect six anatomical landmarks on the prostate boundary by adopting a context-aware landmark detection method. Specifically, in this method, a two-layer regression forest is trained as a detector for each target landmark. Once all the newly detected landmarks from new treatment images are reviewed or adjusted (if necessary) by clinicians, they are further included into the training pool as new patient-specific information to update all the two-layer regression forests for the next treatment day. As more and more treatment images of the current patient are acquired, the two-layer regression forests can be continually updated by incorporating the patient-specific information into the training procedure. After all target landmarks are detected, a multiatlas random sample consensus (multiatlas RANSAC) method is used to segment the entire prostate by fusing multiple previously segmented prostates of the current patient after they are aligned to the current treatment image. Subsequently, the segmented prostate of the current treatment image is again reviewed (or even adjusted if needed) by clinicians before including it as a new shape example into the prostate shape dataset for helping localize the entire prostate in the next treatment image. Results: The experimental results on 330 images of 24 patients show the effectiveness of the authors’ proposed online update scheme in improving the accuracies of both landmark detection and prostate segmentation

  18. Evaluation of web-based instruction for anatomical interpretation in maxillofacial cone beam computed tomography

    NARCIS (Netherlands)

    W.T. Al-Rawi; R. Jacobs; B.A. Hassan; G. Sanderink; W.C. Scarfe

    2007-01-01

    Objectives: To evaluate the effectiveness of a web-based instruction in the interpretation of anatomy in images acquired with maxillofacial cone beam CT (CBCT). Methods: An interactive web-based education course for the interpretation of craniofacial CBCT images was recently developed at our institu

  19. Support vector machine-based classification of Alzheimer's disease from whole-brain anatomical MRI

    Energy Technology Data Exchange (ETDEWEB)

    Magnin, Benoit [UMR-S 678, Inserm, Paris (France)]|[UMR-S 610, Inserm, Paris (France)]|[UMPC Univ Paris 06, Faculte de Medecine Pitie-Salpetriere, Paris (France)]|[IFR 49, Gif-sur-Yvette (France); Mesrob, Lilia [UMR-S 610, Inserm, Paris (France)]|[UMPC Univ Paris 06, Faculte de Medecine Pitie-Salpetriere, Paris (France)]|[IFR 49, Gif-sur-Yvette (France); Kinkingnehun, Serge [UMR-S 610, Inserm, Paris (France)]|[UMPC Univ Paris 06, Faculte de Medecine Pitie-Salpetriere, Paris (France)]|[IFR 49, Gif-sur-Yvette (France)]|[BRAIN, Vitry-sur-Seine (France); Pelegrini-Issac, Melanie [UMR-S 678, Inserm, Paris (France)]|[UMPC Univ Paris 06, Faculte de Medecine Pitie-Salpetriere, Paris (France)]|[IFR 49, Gif-sur-Yvette (France); Colliot, Olivier [IFR 49, Gif-sur-Yvette (France)]|[UPR 640 LENA, CNRS, Paris (France); Sarazin, Marie; Dubois, Bruno [UMR-S 610, Inserm, Paris (France)]|[UMPC Univ Paris 06, Faculte de Medecine Pitie-Salpetriere, Paris (France)]|[IFR 49, Gif-sur-Yvette (France)]|[Pitie-Salpetriere Hospital, Department of Neurology, Paris (France); Lehericy, Stephane [UMR-S 610, Inserm, Paris (France)]|[UMPC Univ Paris 06, Faculte de Medecine Pitie-Salpetriere, Paris (France)]|[IFR 49, Gif-sur-Yvette (France)]|[UMPC Univ. Paris 06, Center for NeuroImaging Research-CENIR, Paris (France)]|[Pitie-Salpetriere Hospital, Department of Neuroradiology, Paris (France); Benali, Habib [UMR-S 678, Inserm, Paris (France)]|[UMPC Univ Paris 06, Faculte de Medecine Pitie-Salpetriere, Paris (France)]|[IFR 49, Gif-sur-Yvette (France)]|[UNF/CRIUGM, Universite de Montreal, Montreal, QC (Canada)

    2009-02-15

    We present and evaluate a new automated method based on support vector machine (SVM) classification of whole-brain anatomical magnetic resonance imaging to discriminate between patients with Alzheimer's disease (AD) and elderly control subjects. We studied 16 patients with AD [mean age {+-} standard deviation (SD)=74.1 {+-}5.2 years, mini-mental score examination (MMSE) = 23.1 {+-} 2.9] and 22 elderly controls (72.3{+-}5.0 years, MMSE=28.5{+-} 1.3). Three-dimensional T1-weighted MR images of each subject were automatically parcellated into regions of interest (ROIs). Based upon the characteristics of gray matter extracted from each ROI, we used an SVM algorithm to classify the subjects and statistical procedures based on bootstrap resampling to ensure the robustness of the results. We obtained 94.5% mean correct classification for AD and control subjects (mean specificity, 96.6%; mean sensitivity, 91.5%). Our method has the potential in distinguishing patients with AD from elderly controls and therefore may help in the early diagnosis of AD. (orig.)

  20. Landmark Analysis Of Leaf Shape Using Polygonal Approximation

    Science.gov (United States)

    Firmansyah, Zakhi; Herdiyeni, Yeni; Paruhum Silalahi, Bib; Douady, Stephane

    2016-01-01

    This research proposes a method to extract landmark of leaf shape using static threshold of polygonal approximation. Leaf shape analysis has played a central role in many problems in vision and perception. Landmark-based shape analysis is the core of geometric morphometric and has been used as a quantitative tool in evolutionary and developmental biology. In this research, the polygonal approximation is used to select the best points that can represent the leaf shape variability. We used a static threshold as the control parameter of fitting a series of line segment over a digital curve of leaf shape. This research focuses on seven leaf shape, i.e., eliptic, obovate, ovate, oblong and special. Experimental results show static polygonal approximation shows can be used to find the important points of leaf shape.

  1. An Efficient Ceiling-view SLAM Using Relational Constraints Between Landmarks

    OpenAIRE

    Hyukdoo Choi; Ryunseok Kim; Euntai Kim

    2014-01-01

    In this paper, we present a new indoor ‘simultaneous localization and mapping’ (SLAM) technique based on an upward-looking ceiling camera. Adapted from our previous work [17], the proposed method employs sparsely-distributed line and point landmarks in an indoor environment to aid with data association and reduce extended Kalman filter computation as compared with earlier techniques. Further, the proposed method exploits geometric relationships between the two types of landmarks to provide ad...

  2. EXPLOITING 3D ULTRASOUND FOR FETAL DIAGNOSTIC PURPOSE THROUGH FACIAL LANDMARKING

    OpenAIRE

    Enrico Vezzetti; Domenico Speranza; Federica Marcolin; Giulia Fracastoro; Giorgia Buscicchio

    2014-01-01

    In the last decade, three-dimensional landmarking has gained attention for different applications, such as face recognition for both identification of suspects and authentication, facial expression recognition, corrective and aesthetic surgery, syndrome study and diagnosis. This work focuses on the last one by proposing a geometrically-based landmark extraction algorithm aimed at diagnosing syndromes on babies before their birth. Pivotal role in this activity is the support provided by physic...

  3. Desert ants learn vibration and magnetic landmarks.

    Directory of Open Access Journals (Sweden)

    Cornelia Buehlmann

    Full Text Available The desert ants Cataglyphis navigate not only by path integration but also by using visual and olfactory landmarks to pinpoint the nest entrance. Here we show that Cataglyphis noda can additionally use magnetic and vibrational landmarks as nest-defining cues. The magnetic field may typically provide directional rather than positional information, and vibrational signals so far have been shown to be involved in social behavior. Thus it remains questionable if magnetic and vibration landmarks are usually provided by the ants' habitat as nest-defining cues. However, our results point to the flexibility of the ants' navigational system, which even makes use of cues that are probably most often sensed in a different context.

  4. Electronic and film portal images: a comparison of landmark visibility and review accuracy

    International Nuclear Information System (INIS)

    Purpose: To quantitatively compare a scanning liquid ion chamber electronic portal imaging device (SLIC-EPID) and an amorphous silicon flat panel (aSi) EPID with portal film in clinical applications using measures of landmark visibility and treatment review accuracy. Methods and Materials: Six radiation oncologists viewed 39 electronic portal images (EPIs) from the SLIC-EPID, 36 EPIs from the aSi-EPID, and portal films of each of these treatment fields. The physicians rated the clarity of anatomic landmarks in the portal images, and the scores were compared between EPID and film. Nine hundred portal image reviews were performed. EPID and film portal images were acquired with known setup errors in either phantom or cadaver treatments. Physicians identified the errors visually in portal films and with computerized analysis for EPID. Results: There were no statistically significant (p<0.05) differences between film and SLIC-EPID in ratings of landmark clarity. Eleven of 12 landmarks were more visible in aSi-EPID than in film. Translational setup errors were identified with an average accuracy of 2.5 mm in film, compared to 1.5 mm with SLIC-EPID and 1.3 mm with aSi-EPID. Conclusions: Both EPIDs are clinically viable replacements for film, but aSi-EPID represents a significant advancement in image quality over film

  5. Surface-Based Analyses of Anatomical Properties of the Visual Cortex in Macular Degeneration.

    Directory of Open Access Journals (Sweden)

    Doety Prins

    Full Text Available Macular degeneration (MD can cause a central visual field defect. In a previous study, we found volumetric reductions along the entire visual pathways of MD patients, possibly indicating degeneration of inactive neuronal tissue. This may have important implications. In particular, new therapeutic strategies to restore retinal function rely on intact visual pathways and cortex to reestablish visual function. Here we reanalyze the data of our previous study using surface-based morphometry (SBM rather than voxel-based morphometry (VBM. This can help determine the robustness of the findings and will lead to a better understanding of the nature of neuroanatomical changes associated with MD.The metrics of interest were acquired by performing SBM analysis on T1-weighted MRI data acquired from 113 subjects: patients with juvenile MD (JMD; n = 34, patients with age-related MD (AMD; n = 24 and healthy age-matched controls (HC; n = 55.Relative to age-matched controls, JMD patients showed a thinner cortex, a smaller cortical surface area and a lower grey matter volume in V1 and V2, while AMD patients showed thinning of the cortex in V2. Neither patient group showed a significant difference in mean curvature of the visual cortex.The thinner cortex, smaller surface area and lower grey matter volume in the visual cortex of JMD patients are consistent with our previous results showing a volumetric reduction in their visual cortex. Finding comparable results using two rather different analysis techniques suggests the presence of marked cortical degeneration in the JMD patients. In the AMD patients, we found a thinner cortex in V2 but not in V1. In contrast to our previous VBM analysis, SBM revealed no volumetric reductions of the visual cortex. This suggests that the cortical changes in AMD patients are relatively subtle, as they apparently can be missed by one of the methods.

  6. Dosimetric intercomparison for multicenter clinical trials using a patient-based anatomic pelvic phantom

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, M. A.; Harrison, K. M.; Howlett, S. J.; Cornes, D.; Bulsara, M.; Hamilton, C. S.; Kron, T.; Joseph, D. J.; Denham, J. W. [Department of Radiation Oncology, Sir Charles Gairdner Hospital, Western Australia 6009, Australia and School of Physics, University of Western Australia, 6009 Australia (Australia); Department of Radiation Oncology, Calvary Mater Newcastle, Waratah, New South Wales 2298 (Australia); Australasian College of Physical Scientists and Engineers in Medicine, Mascot, New South Wales 2020 (Australia); Trans-Tasman Radiation Oncology Group, Calvary Mater Newcastle, New South Wales 2298 (Australia); Institute of Health and Rehabilitation Research, University of Notre Dame, Fremantle, Western Australia 6160 (Australia); Heidelberg Repatriation Hospital, Victoria 3084 (Australia); Department of Physical Sciences, Peter MacCallum Cancer Centre, Victoria 3002 (Australia); Department of Radiation Oncology, Sir Charles Gairdner Hospital, Western Australia 6009, Australia and School of Surgery, University of Western Australia, Western Australia 6009 (Australia); Department of Radiation Oncology, Calvary Mater Newcastle, Waratah, New South Wales 2298, Australia and School of Medicine and Population Health, University of Newcastle, New South Wales 2308 (Australia)

    2011-09-15

    Purpose: To assess dose delivery accuracy to clinically significant points in a realistic patient geometry for two separate pelvic radiotherapy scenarios. Methods: An inhomogeneous pelvic phantom was transported to 36 radiotherapy centers in Australia and New Zealand. The phantom was treated according to Phase III rectal and prostate trial protocols. Point dose measurements were made with thermoluminescent dosimeters (TLDs) and an ionisation chamber. Comprehensive site-demographic, treatment planning, and physical data were collected for correlation with measurement outcomes. Results: Dose delivery to the prescription point for the rectal treatment was consistent with planned dose (mean difference between planned and measured dose - 0.1 {+-} 0.3% std err). Dose delivery in the region of the sacral hollow was consistently higher than planned (+1.2 {+-} 0.2%). For the prostate treatment, dose delivery to the prostate volume was consistent with planned doses (-0.49 {+-} 0.2%) and planned dose uniformity, though with a tendency to underdose the PTV at the prostate-rectal border. Measured out-of-field doses were significantly higher than planned. Conclusions: A phantom based on realistic anatomy and heterogeneity can be used to comprehensively assess the influence of multiple aspects of the radiotherapy treatment process on dose delivery. The ability to verify dose delivery for two trials with a single phantom was advantageous.

  7. Voxel-based morphometric analysis in hypothyroidism using diffeomorphic anatomic registration via an exponentiated lie algebra algorithm approach.

    Science.gov (United States)

    Singh, S; Modi, S; Bagga, D; Kaur, P; Shankar, L R; Khushu, S

    2013-03-01

    The present study aimed to investigate whether brain morphological differences exist between adult hypothyroid subjects and age-matched controls using voxel-based morphometry (VBM) with diffeomorphic anatomic registration via an exponentiated lie algebra algorithm (DARTEL) approach. High-resolution structural magnetic resonance images were taken in ten healthy controls and ten hypothyroid subjects. The analysis was conducted using statistical parametric mapping. The VBM study revealed a reduction in grey matter volume in the left postcentral gyrus and cerebellum of hypothyroid subjects compared to controls. A significant reduction in white matter volume was also found in the cerebellum, right inferior and middle frontal gyrus, right precentral gyrus, right inferior occipital gyrus and right temporal gyrus of hypothyroid patients compared to healthy controls. Moreover, no meaningful cluster for greater grey or white matter volume was obtained in hypothyroid subjects compared to controls. Our study is the first VBM study of hypothyroidism in an adult population and suggests that, compared to controls, this disorder is associated with differences in brain morphology in areas corresponding to known functional deficits in attention, language, motor speed, visuospatial processing and memory in hypothyroidism.

  8. TINA manual landmarking tool: software for the precise digitization of 3D landmarks

    Directory of Open Access Journals (Sweden)

    Schunke Anja C

    2012-04-01

    Full Text Available Abstract Background Interest in the placing of landmarks and subsequent morphometric analyses of shape for 3D data has increased with the increasing accessibility of computed tomography (CT scanners. However, current computer programs for this task suffer from various practical drawbacks. We present here a free software tool that overcomes many of these problems. Results The TINA Manual Landmarking Tool was developed for the digitization of 3D data sets. It enables the generation of a modifiable 3D volume rendering display plus matching orthogonal 2D cross-sections from DICOM files. The object can be rotated and axes defined and fixed. Predefined lists of landmarks can be loaded and the landmarks identified within any of the representations. Output files are stored in various established formats, depending on the preferred evaluation software. Conclusions The software tool presented here provides several options facilitating the placing of landmarks on 3D objects, including volume rendering from DICOM files, definition and fixation of meaningful axes, easy import, placement, control, and export of landmarks, and handling of large datasets. The TINA Manual Landmark Tool runs under Linux and can be obtained for free from http://www.tina-vision.net/tarballs/.

  9. Locally Linear Diffeomorphic Metric Embedding (LLDME) for surface-based anatomical shape modeling.

    Science.gov (United States)

    Yang, Xianfeng; Goh, Alvina; Qiu, Anqi

    2011-05-01

    This paper presents the algorithm, Locally Linear Diffeomorphic Metric Embedding (LLDME), for constructing efficient and compact representations of surface-based brain shapes whose variations are characterized using Large Deformation Diffeomorphic Metric Mapping (LDDMM). Our hypothesis is that the shape variations in the infinite-dimensional diffeomorphic metric space can be captured by a low-dimensional space. To do so, traditional Locally Linear Embedding (LLE) that reconstructs a data point from its neighbors in Euclidean space is extended to LLDME that requires interpolating a shape from its neighbors in the infinite-dimensional diffeomorphic metric space. This is made possible through the conservation law of momentum derived from LDDMM. It indicates that initial momentum, a linear transformation of the initial velocity of diffeomorphic flows, at a fixed template shape determines the geodesic connecting the template to a subject's shape in the diffeomorphic metric space and becomes the shape signature of an individual subject. This leads to the compact linear representation of the nonlinear diffeomorphisms in terms of the initial momentum. Since the initial momentum is in a linear space, a shape can be approximated by a linear combination of its neighbors in the diffeomorphic metric space. In addition, we provide efficient computations for the metric distance between two shapes through the first order approximation of the geodesic using the initial momentum as well as for the reconstruction of a shape given its low-dimensional Euclidean coordinates using the geodesic shooting with the initial momentum as the initial condition. Experiments are performed on the hippocampal shapes of 302 normal subjects across the whole life span (18-94years). Compared with Principal Component Analysis and ISOMAP, LLDME provides the most compact and efficient representation of the age-related hippocampal shapes. Even though the hippocampal volumes among young adults are as

  10. Anatomic Total Shoulder System

    Medline Plus

    Full Text Available GLOBAL AP ANATOMIC TOTAL SHOULDER SYSTEM METHODIST HOSPITAL PHILADELPHIA, PA April 17, 2008 00:00:10 ANNOUNCER: ... you'll be able to watch a live global AP anatomic total shoulder surgery from Methodist Hospital ...

  11. The accuracy of a designed software for automated localization of craniofacial landmarks on CBCT images

    International Nuclear Information System (INIS)

    Two-dimensional projection radiographs have been traditionally considered the modality of choice for cephalometric analysis. To overcome the shortcomings of two-dimensional images, three-dimensional computed tomography (CT) has been used to evaluate craniofacial structures. However, manual landmark detection depends on medical expertise, and the process is time-consuming. The present study was designed to produce software capable of automated localization of craniofacial landmarks on cone beam (CB) CT images based on image registration and to evaluate its accuracy. The software was designed using MATLAB programming language. The technique was a combination of feature-based (principal axes registration) and voxel similarity-based methods for image registration. A total of 8 CBCT images were selected as our reference images for creating a head atlas. Then, 20 CBCT images were randomly selected as the test images for evaluating the method. Three experts twice located 14 landmarks in all 28 CBCT images during two examinations set 6 weeks apart. The differences in the distances of coordinates of each landmark on each image between manual and automated detection methods were calculated and reported as mean errors. The combined intraclass correlation coefficient for intraobserver reliability was 0.89 and for interobserver reliability 0.87 (95% confidence interval, 0.82 to 0.93). The mean errors of all 14 landmarks were <4 mm. Additionally, 63.57% of landmarks had a mean error of <3 mm compared with manual detection (gold standard method). The accuracy of our approach for automated localization of craniofacial landmarks, which was based on combining feature-based and voxel similarity-based methods for image registration, was acceptable. Nevertheless we recommend repetition of this study using other techniques, such as intensity-based methods

  12. Using Local Symmetry for Landmark Selection

    NARCIS (Netherlands)

    Kootstra, Gert; de Jong, Sjoerd; Schomaker, Lambert R. B.; Fritz, M; Schiele, B; Piater, JH

    2009-01-01

    Most visual Simultaneous Localization And Mapping (SLAM) methods use interest points as landmarks in their maps of the environment. Often the interest points are detected using contrast features, for instance those of the Scale Invariant Feature Transform (SIFT). The SIFT interest points, however, h

  13. Automated landmark-guided deformable image registration

    Science.gov (United States)

    Kearney, Vasant; Chen, Susie; Gu, Xuejun; Chiu, Tsuicheng; Liu, Honghuan; Jiang, Lan; Wang, Jing; Yordy, John; Nedzi, Lucien; Mao, Weihua

    2015-01-01

    The purpose of this work is to develop an automated landmark-guided deformable image registration (LDIR) algorithm between the planning CT and daily cone-beam CT (CBCT) with low image quality. This method uses an automated landmark generation algorithm in conjunction with a local small volume gradient matching search engine to map corresponding landmarks between the CBCT and the planning CT. The landmarks act as stabilizing control points in the following Demons deformable image registration. LDIR is implemented on graphics processing units (GPUs) for parallel computation to achieve ultra fast calculation. The accuracy of the LDIR algorithm has been evaluated on a synthetic case in the presence of different noise levels and data of six head and neck cancer patients. The results indicate that LDIR performed better than rigid registration, Demons, and intensity corrected Demons for all similarity metrics used. In conclusion, LDIR achieves high accuracy in the presence of multimodality intensity mismatch and CBCT noise contamination, while simultaneously preserving high computational efficiency.

  14. The Effect of Electrode Designs Based on the Anatomical Heart Location for the Non-Contact Heart Activity Measurement.

    Science.gov (United States)

    Gi, Sun Ok; Lee, Young-Jae; Koo, Hye Ran; Lee, Seung Pyo; Lee, Kang-Hwi; Kim, Kyeng-Nam; Kang, Seung-Jin; Lee, Joo Hyeon; Lee, Jeong-Whan

    2015-12-01

    This research is an extension of a previous research [1] on the different effects of sensor location that is relatively suitable for heart rate sensing. This research aimed to elucidate the causes of wide variations in heart rate measurements from the same sensor position among subjects, as observed in previous research [1], and to enhance designs of the inductive textile electrode to overcome these variations. To achieve this, this study comprised two parts: In part 1, X-ray examinations were performed to determine the cause of the wide variations noted in the findings from previous research [1], and we found that at the same sensor position, the heart activity signal differed with slight differences in the positions of the heart of each subject owing to individual differences in the anatomical heart location. In part 2, three types of dual-loop-type textile electrodes were devised to overcome variations in heart location that were confirmed in part 1 of the study. The variations with three types of sensor designs were compared with that with a single-round type of electrode design, by using computer simulation and by performing a t-test on the data obtained from the experiments. We found that the oval-oval shaped, dual-loop-type textile electrode was more suitable than the single round type for determining morphological characteristics as well as for measuring appropriate heart activity signals. Based on these results, the oval-oval, dual-loop-type was a better inductive textile electrode that more effectively overcomes individual differences in heart location during heart activity sensing based on the magnetic-induced conductivity principle. PMID:26490149

  15. The Effect of Electrode Designs Based on the Anatomical Heart Location for the Non-Contact Heart Activity Measurement.

    Science.gov (United States)

    Gi, Sun Ok; Lee, Young-Jae; Koo, Hye Ran; Lee, Seung Pyo; Lee, Kang-Hwi; Kim, Kyeng-Nam; Kang, Seung-Jin; Lee, Joo Hyeon; Lee, Jeong-Whan

    2015-12-01

    This research is an extension of a previous research [1] on the different effects of sensor location that is relatively suitable for heart rate sensing. This research aimed to elucidate the causes of wide variations in heart rate measurements from the same sensor position among subjects, as observed in previous research [1], and to enhance designs of the inductive textile electrode to overcome these variations. To achieve this, this study comprised two parts: In part 1, X-ray examinations were performed to determine the cause of the wide variations noted in the findings from previous research [1], and we found that at the same sensor position, the heart activity signal differed with slight differences in the positions of the heart of each subject owing to individual differences in the anatomical heart location. In part 2, three types of dual-loop-type textile electrodes were devised to overcome variations in heart location that were confirmed in part 1 of the study. The variations with three types of sensor designs were compared with that with a single-round type of electrode design, by using computer simulation and by performing a t-test on the data obtained from the experiments. We found that the oval-oval shaped, dual-loop-type textile electrode was more suitable than the single round type for determining morphological characteristics as well as for measuring appropriate heart activity signals. Based on these results, the oval-oval, dual-loop-type was a better inductive textile electrode that more effectively overcomes individual differences in heart location during heart activity sensing based on the magnetic-induced conductivity principle.

  16. Evaluation of sexual history-based screening of anatomic sites for chlamydia trachomatis and neisseria gonorrhoeae infection in men having sex with men in routine practice

    Directory of Open Access Journals (Sweden)

    Jansen Casper L

    2011-07-01

    Full Text Available Abstract Background Sexually transmitted infection (STI screening programmes are implemented in many countries to decrease burden of STI and to improve sexual health. Screening for Chlamydia trachomatis and Neisseria gonorrhoeae has a prominent role in these protocols. Most of the screening programmes concerning men having sex with men (MSM are based on opportunistic urethral testing. In The Netherlands, a history-based approach is used. The aim of this study is to evaluate the protocol of screening anatomic sites for C. trachomatis and N. gonorrhoeae infection based on sexual history in MSM in routine practice in The Netherlands. Methods All MSM visiting the clinic for STI in The Hague are routinely asked about their sexual practice during consulting. As per protocol, tests for urogenital, oropharyngeal and anorectal infection are obtained based on reported site(s of sexual contact. All consultations are entered into a database as part of the national STI monitoring system. Data of an 18 months period were retrieved from this database and analysed. Results A total of 1455 consultations in MSM were registered during the study period. The prevalence of C. trachomatis and N. gonorrhoeae per anatomic site was: urethral infection 4.0% respectively and 2.8%, oropharynx 1.5% and 4.2%, and anorectum 8.2% and 6.0%. The majority of chlamydia cases (72% involved a single anatomic site, which was especially manifest for anorectal infections (79%, while 42% of gonorrhoea cases were single site. Twenty-six percent of MSM with anorectal chlamydia and 17% with anorectal gonorrhoea reported symptoms of proctitis; none of the oropharyngeal infections were symptomatic. Most cases of anorectal infection (83% and oropharyngeal infection (100% would have remained undiagnosed with a symptom-based protocol. Conclusions The current strategy of sexual-history based screening of multiple anatomic sites for chlamydia and gonorrhoea in MSM is a useful and valid guideline

  17. Efficacy of an Intra-Operative Imaging Software System for Anatomic Anterior Cruciate Ligament Reconstruction Surgery

    Directory of Open Access Journals (Sweden)

    Xudong Zhang

    2012-01-01

    Full Text Available An imaging software system was studied for improving the performance of anatomic anterior cruciate ligament (ACL reconstruction which requires identifying ACL insertion sites for bone tunnel placement. This software predicts and displays the insertion sites based on the literature data and patient-specific bony landmarks. Twenty orthopaedic surgeons performed simulated arthroscopic ACL surgeries on 20 knee specimens, first without and then with the visual guidance by fluoroscopic imaging, and their tunnel entry positions were recorded. The native ACL insertion morphologies of individual specimens were quantified in relation to CT-based bone models and then used to evaluate the software-generated insertion locations. Results suggested that the system was effective in leading surgeons to predetermined locations while the application of averaged insertion morphological information in individual surgeries can be susceptible to inaccuracy and uncertainty. Implications on challenges associated with developing engineering solutions to aid in re-creating or recognizing anatomy in surgical care delivery are discussed.

  18. TINA manual landmarking tool: software for the precise digitization of 3D landmarks

    OpenAIRE

    Schunke Anja C; Bromiley Paul A; Tautz Diethard; Thacker Neil A

    2012-01-01

    Abstract Background Interest in the placing of landmarks and subsequent morphometric analyses of shape for 3D data has increased with the increasing accessibility of computed tomography (CT) scanners. However, current computer programs for this task suffer from various practical drawbacks. We present here a free software tool that overcomes many of these problems. Results The TINA Manual Landmarking Tool was developed for the digitization of 3D data sets. It enables the generation of a modifi...

  19. Anatomical imaging for radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Philip M [Joint Physics Department, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey SM2 5PT (United Kingdom)], E-mail: phil.evans@icr.ac.uk

    2008-06-21

    scans is taken on different days. Both allow planning to account for variability intrinsic to the patient. Treatment verification has been carried out using a variety of technologies including: MV portal imaging, kV portal/fluoroscopy, MVCT, conebeam kVCT, ultrasound and optical surface imaging. The various methods have their pros and cons. The four x-ray methods involve an extra radiation dose to normal tissue. The portal methods may not generally be used to visualize soft tissue, consequently they are often used in conjunction with implanted fiducial markers. The two CT-based methods allow measurement of inter-fraction variation only. Ultrasound allows soft-tissue measurement with zero dose but requires skilled interpretation, and there is evidence of systematic differences between ultrasound and other data sources, perhaps due to the effects of the probe pressure. Optical imaging also involves zero dose but requires good correlation between the target and the external measurement and thus is often used in conjunction with an x-ray method. The use of anatomical imaging in radiotherapy allows treatment uncertainties to be determined. These include errors between the mean position at treatment and that at planning (the systematic error) and the day-to-day variation in treatment set-up (the random error). Positional variations may also be categorized in terms of inter- and intra-fraction errors. Various empirical treatment margin formulae and intervention approaches exist to determine the optimum strategies for treatment in the presence of these known errors. Other methods exist to try to minimize error margins drastically including the currently available breath-hold techniques and the tracking methods which are largely in development. This paper will review anatomical imaging techniques in radiotherapy and how they are used to boost the therapeutic benefit of the treatment. (topical review)

  20. Landmarks GIScience for intelligent services

    CERN Document Server

    Richter, Kai-Florian

    2014-01-01

    Summarizes the latest studies on car navigation services, mobile location-based services, museum guides, tourist guides, public transport planners and recent voice interfaces to mobile devices Broadens understanding of spatial applications for smart phones Contains numerous exercises and examples to reinforce concepts

  1. Notes on the Landmark Development of CBR in China

    Institute of Scientific and Technical Information of China (English)

    Dahong Zhuo

    2009-01-01

    Community-based rehabilitation has a history of 22 years in China.In spite of the preliminary achievement and experiences obtained by the pioneering and trial projects,it was not until the beginning of the new century that CBR in China experienced a landmark development.This iS characterized by a number of favorable pohcy by the government for CBR;the mechanism facilitating primary health care with CBR,a new work-force system of CBR reorganized with better motivation and efficiency,99 demonstration projects of CBR bringing about benchmark promotion effect and the active involvement in CBR by social resources agents.

  2. 4D measurement system for automatic location of anatomical structures

    Science.gov (United States)

    Witkowski, Marcin; Sitnik, Robert; Kujawińska, Małgorzata; Rapp, Walter; Kowalski, Marcin; Haex, Bart; Mooshake, Sven

    2006-04-01

    Orthopedics and neurosciences are fields of medicine where the analysis of objective movement parameters is extremely important for clinical diagnosis. Moreover, as there are significant differences between static and dynamic parameters, there is a strong need of analyzing the anatomical structures under functional conditions. In clinical gait analysis the benefits of kinematical methods are undoubted. In this paper we present a 4D (3D + time) measurement system capable of automatic location of selected anatomical structures by locating and tracing the structures' position and orientation in time. The presented system is designed to help a general practitioner in diagnosing selected lower limbs' dysfunctions (e.g. knee injuries) and also determine if a patient should be directed for further examination (e.g. x-ray or MRI). The measurement system components are hardware and software. For the hardware part we adapt the laser triangulation method. In this way we can evaluate functional and dynamic movements in a contact-free, non-invasive way, without the use of potentially harmful radiation. Furthermore, opposite to marker-based video-tracking systems, no preparation time is required. The software part consists of a data acquisition module, an image processing and point clouds (point cloud, set of points described by coordinates (x, y, z)) calculation module, a preliminary processing module, a feature-searching module and an external biomechanical module. The paper briefly presents the modules mentioned above with the focus on the feature-searching module. Also we present some measurement and analysis results. These include: parameters maps, landmarks trajectories in time sequence and animation of a simplified model of lower limbs.

  3. Sub-map matching algorithm based on signature vector and landmark localization%基于签名向量与路标定位的子地图匹配算法

    Institute of Scientific and Technical Information of China (English)

    姚芝凤; 叶秀芬; 戴学丰

    2013-01-01

    在移动机器人的分层同时定位和地图构建SLAM算法中,通过签名元素实现局部子地图的匹配存在计算复杂性的问题,提出了通过构建签名元素向量的方法来解决子地图匹配的问题;由于机器人在重复访问某一个区域的时候,两次的运动轨迹不可能完全重合,因此在该方法中结合了基于路标进行定位的技术,从而实现可靠的回路闭合确认计算.另外,讨论了在获得全局地图的后处理过程中存在两个或者多于两个的闭合回路共享部分路径时,实现全局优化的算法中限制条件的修改问题.最后,通过一个算例说明子地图匹配过程的具体操作.%Because of the computational complexity in the signature element based local sub-map matching for hierarchical Simultaneous Localization and Mapping (SLAM) algorithm,a signature vector based matching approach was proposed in this paper.Since there may be a difference between the two trajectories that the robot passed the same sub-region at first time and at second time,the approach was improved by combining a landmark localization technique to realize more reliable loop closing calculation.In addition,the constraints equation was discussed for the case that two or more closed loops share a common sub-path for obtaining a global optimized map of the environment.Finally,a demonstration case was given to show the application of our approach.

  4. The behavioural relevance of landmark texture for honeybee homing

    Directory of Open Access Journals (Sweden)

    Laura eDittmar

    2011-04-01

    Full Text Available Honeybees visually pinpoint the location of a food source using landmarks. Studies on the role of visual memories have suggested that bees approach the goal by finding a close match between their current view and a memorized view of the goal location. The most relevant landmark features for this matching process seem to be their retinal positions, the size as defined by their edges, and their colour. Recently, we showed that honeybees can use landmarks that are statically camouflaged, suggesting that motion cues are relevant as well. Currently it is unclear how bees weight these different landmark features when accomplishing navigational tasks, and whether this depends on their saliency. Since natural objects are often distinguished by their texture, we investigate the behavioural relevance and the interplay of the spatial configuration and the texture of landmarks. We show that landmark texture is a feature that bees memorise, and being given the opportunity to identify landmarks by their texture improves the bees’ navigational performance. Landmark texture is weighted more strongly than landmark configuration when it provides the bees with positional information and when the texture is salient. In the vicinity of the landmark honeybees changed their flight behaviour according to its texture.

  5. Landmark experiments in twentieth-century physics

    CERN Document Server

    Trigg, George L

    2011-01-01

    Physics is very much an experimental science, but too often, students at the undergraduate level are not exposed to the reality of experimental physics ― i.e., what was done in a given experiment, why it was done, the background of physics against which the experiment was carried out and the changes in theory and knowledge that resulted. In this hook, the author helps to remedy the situation by presenting a variety of ""landmark"" experiments that have brought about significant alterations in our ideas about some aspect of nature. Among these scientific milestones are discoveries about the wa

  6. Longwall automation - an ACARP Landmark Project

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, M.; Hainsworth, D.; Lever, P.; Gurgenci, H. [CSIRO Exploration and Mining, Kenmore, Qld. (Australia)

    2002-07-01

    A Landmark Longwall Automation project was commenced in July 2001. The major outcome of automation using on-face observation has been divided into ten outcome areas that have been fully scoped for a three-year initial project life. A major facilitating technology has been the implementation of inertial navigation system (INS) technology that can map the shearer position in 3D. A focus of the project is to deliver a system that is at least as productive as the current most productive manually controlled longwall face. 4 refs., 6 figs.

  7. Optimization of abdominal fat quantification on CT imaging through use of standardized anatomic space: A novel approach

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Yubing; Udupa, Jayaram K., E-mail: jay@mail.med.upenn.edu [Department of Radiology, Medical Image Processing Group, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6021 (United States); Torigian, Drew A. [Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6021 (United States)

    2014-06-15

    Purpose: The quantification of body fat plays an important role in the study of numerous diseases. It is common current practice to use the fat area at a single abdominal computed tomography (CT) slice as a marker of the body fat content in studying various disease processes. This paper sets out to answer three questions related to this issue which have not been addressed in the literature. At what single anatomic slice location do the areas of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) estimated from the slice correlate maximally with the corresponding fat volume measures? How does one ensure that the slices used for correlation calculation from different subjects are at the same anatomic location? Are there combinations of multiple slices (not necessarily contiguous) whose area sum correlates better with volume than does single slice area with volume? Methods: The authors propose a novel strategy for mapping slice locations to a standardized anatomic space so that same anatomic slice locations are identified in different subjects. The authors then study the volume-to-area correlations and determine where they become maximal. To address the third issue, the authors carry out similar correlation studies by utilizing two and three slices for calculating area sum. Results: Based on 50 abdominal CT data sets, the proposed mapping achieves significantly improved consistency of anatomic localization compared to current practice. Maximum correlations are achieved at different anatomic locations for SAT and VAT which are both different from the L4-L5 junction commonly utilized currently for single slice area estimation as a marker. Conclusions: The maximum area-to-volume correlation achieved is quite high, suggesting that it may be reasonable to estimate body fat by measuring the area of fat from a single anatomic slice at the site of maximum correlation and use this as a marker. The site of maximum correlation is not at L4-L5 as commonly assumed

  8. Basic Restriction and Reference Level in Anatomically-based Japanese Models for Low-Frequency Electric and Magnetic Field Exposures

    Science.gov (United States)

    Takano, Yukinori; Hirata, Akimasa; Fujiwara, Osamu

    Human exposed to electric and/or magnetic fields at low frequencies may cause direct effect such as nerve stimulation and excitation. Therefore, basic restriction is regulated in terms of induced current density in the ICNIRP guidelines and in-situ electric field in the IEEE standard. External electric or magnetic field which does not produce induced quantities exceeding the basic restriction is used as a reference level. The relationship between the basic restriction and reference level for low-frequency electric and magnetic fields has been investigated using European anatomic models, while limited for Japanese model, especially for electric field exposures. In addition, that relationship has not well been discussed. In the present study, we calculated the induced quantities in anatomic Japanese male and female models exposed to electric and magnetic fields at reference level. A quasi static finite-difference time-domain (FDTD) method was applied to analyze this problem. As a result, spatially averaged induced current density was found to be more sensitive to averaging algorithms than that of in-situ electric field. For electric and magnetic field exposure at the ICNIRP reference level, the maximum values of the induced current density for different averaging algorithm were smaller than the basic restriction for most cases. For exposures at the reference level in the IEEE standard, the maximum electric fields in the brain were larger than the basic restriction in the brain while smaller for the spinal cord and heart.

  9. Three-dimensional in vivo imaging of the murine liver: a micro-computed tomography-based anatomical study.

    Directory of Open Access Journals (Sweden)

    Teresa Fiebig

    Full Text Available Various murine models are currently used to study acute and chronic pathological processes of the liver, and the efficacy of novel therapeutic regimens. The increasing availability of high-resolution small animal imaging modalities presents researchers with the opportunity to precisely identify and describe pathological processes of the liver. To meet the demands, the objective of this study was to provide a three-dimensional illustration of the macroscopic anatomical location of the murine liver lobes and hepatic vessels using small animal imaging modalities. We analysed micro-CT images of the murine liver by integrating additional information from the published literature to develop comprehensive illustrations of the macroscopic anatomical features of the murine liver and hepatic vasculature. As a result, we provide updated three-dimensional illustrations of the macroscopic anatomy of the murine liver and hepatic vessels using micro-CT. The information presented here provides researchers working in the field of experimental liver disease with a comprehensive, easily accessable overview of the macroscopic anatomy of the murine liver.

  10. The use of radial symmetry to localize retinal landmarks.

    Science.gov (United States)

    Giachetti, A; Ballerini, L; Trucco, E; Wilson, P J

    2013-01-01

    Locating the optic disc center and the fovea in digital fundus images is surprisingly difficult due to the variation range in color and contrast and the possible presence of pathologies creating bright spots or changing the appearance of retinal landmarks. These reasons make it difficult to find good templates of optic disc and fovea shape and color for pattern matching. In this paper we propose radial symmetry as the principal cue to locate both optic disc and macula centers. Centers of bright and dark circularly symmetrical regions with arbitrary radii, can be found robustly against changes in brightness and contrast by using the Fast Radial Symmetry transform. Detectors based on this transform coupled with a weak hypothesis on vessel density (optic disc intersects large vessels while the fovea lies in an avascular region), can provide a fast location of both OD and macula with accuracy similar or better than state-of-the-art methods. The approach has been chosen as the default technique for fast localization of the two landmarks in the VAMPIRE software suite. PMID:23886574

  11. An Efficient Ceiling-view SLAM Using Relational Constraints Between Landmarks

    Directory of Open Access Journals (Sweden)

    Hyukdoo Choi

    2014-01-01

    Full Text Available In this paper, we present a new indoor ‘simultaneous localization and mapping’ (SLAM technique based on an upward-looking ceiling camera. Adapted from our previous work [17], the proposed method employs sparsely-distributed line and point landmarks in an indoor environment to aid with data association and reduce extended Kalman filter computation as compared with earlier techniques. Further, the proposed method exploits geometric relationships between the two types of landmarks to provide added information about the environment. This geometric information is measured with an upward-looking ceiling camera and is used as a constraint in Kalman filtering. The performance of the proposed ceiling-view (CV SLAM is demonstrated through simulations and experiments. The proposed method performs localization and mapping more accurately than those methods that use the two types of landmarks without taking into account their relative geometries.

  12. Boosting multi-features with prior knowledge for mini unmanned helicopter landmark detection

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Without sufficient real training data, the data driven classification algorithms based on boosting method cannot solely be utilized to applications such as the mini unmanned helicopter landmark image detection. In this paper, we propose an approach which uses a boosting algorithm with the prior knowledge for the mini unmanned helicopter landmark image detection. The stage forward stagewise additive model of boosting is analyzed, and the approach how to combine it with the prior knowledge model is presented. The approach is then applied to landmark image detection, where the multi-features are boosted to solve a series of problems, such as rotation, noises affected, etc. Results of real flight experiments demonstrate that for small training examples the boosted learning system using prior knowledge is dramatically better than the one driven by data only.

  13. Geodesic distances to landmarks for dense correspondence on ensembles of complex shapes.

    Science.gov (United States)

    Datar, Manasi; Lyu, Ilwoo; Kim, SunHyung; Cates, Joshua; Styner, Martin A; Whitaker, Ross

    2013-01-01

    Establishing correspondence points across a set of biomedical shapes is an important technology for a variety of applications that rely on statistical analysis of individual subjects and populations. The inherent complexity (e.g. cortical surface shapes) and variability (e.g. cardiac chambers) evident in many biomedical shapes introduce significant challenges in finding a useful set of dense correspondences. Application specific strategies, such as registration of simplified (e.g. inflated or smoothed) surfaces or relying on manually placed landmarks, provide some improvement but suffer from limitations including increased computational complexity and ambiguity in landmark placement. This paper proposes a method for dense point correspondence on shape ensembles using geodesic distances to a priori landmarks as features. A novel set of numerical techniques for fast computation of geodesic distances to point sets is used to extract these features. The proposed method minimizes the ensemble entropy based on these features, resulting in isometry invariant correspondences in a very general, flexible framework. PMID:24579119

  14. The Behavioral Relevance of Landmark Texture for Honeybee Homing

    OpenAIRE

    Laura eDittmar; Martin eEgelhaaf; Wolfgang eStürzl; Norbert eBoeddeker

    2011-01-01

    Honeybees visually pinpoint the location of a food source using landmarks. Studies on the role of visual memories have suggested that bees approach the goal by finding a close match between their current view and a memorized view of the goal location. The most relevant landmark features for this matching process seem to be their retinal positions, the size as defined by their edges, and their colour. Recently, we showed that honeybees can use landmarks that are statically camouflaged, suggest...

  15. Tridimensional Regression for Comparing and Mapping 3D Anatomical Structures

    Directory of Open Access Journals (Sweden)

    Kendra K. Schmid

    2012-01-01

    Full Text Available Shape analysis is useful for a wide variety of disciplines and has many applications. There are many approaches to shape analysis, one of which focuses on the analysis of shapes that are represented by the coordinates of predefined landmarks on the object. This paper discusses Tridimensional Regression, a technique that can be used for mapping images and shapes that are represented by sets of three-dimensional landmark coordinates, for comparing and mapping 3D anatomical structures. The degree of similarity between shapes can be quantified using the tridimensional coefficient of determination (2. An experiment was conducted to evaluate the effectiveness of this technique to correctly match the image of a face with another image of the same face. These results were compared to the 2 values obtained when only two dimensions are used and show that using three dimensions increases the ability to correctly match and discriminate between faces.

  16. Algorithms to automatically quantify the geometric similarity of anatomical surfaces

    CERN Document Server

    Boyer, D; Clair, E St; Puente, J; Funkhouser, T; Patel, B; Jernvall, J; Daubechies, I

    2011-01-01

    We describe new approaches for distances between pairs of 2-dimensional surfaces (embedded in 3-dimensional space) that use local structures and global information contained in inter-structure geometric relationships. We present algorithms to automatically determine these distances as well as geometric correspondences. This is motivated by the aspiration of students of natural science to understand the continuity of form that unites the diversity of life. At present, scientists using physical traits to study evolutionary relationships among living and extinct animals analyze data extracted from carefully defined anatomical correspondence points (landmarks). Identifying and recording these landmarks is time consuming and can be done accurately only by trained morphologists. This renders these studies inaccessible to non-morphologists, and causes phenomics to lag behind genomics in elucidating evolutionary patterns. Unlike other algorithms presented for morphological correspondences our approach does not requir...

  17. UAV Control on the Basis of 3D Landmark Bearing-Only Observations.

    Science.gov (United States)

    Karpenko, Simon; Konovalenko, Ivan; Miller, Alexander; Miller, Boris; Nikolaev, Dmitry

    2015-11-27

    The article presents an approach to the control of a UAV on the basis of 3D landmark observations. The novelty of the work is the usage of the 3D RANSAC algorithm developed on the basis of the landmarks' position prediction with the aid of a modified Kalman-type filter. Modification of the filter based on the pseudo-measurements approach permits obtaining unbiased UAV position estimation with quadratic error characteristics. Modeling of UAV flight on the basis of the suggested algorithm shows good performance, even under significant external perturbations.

  18. Application of a Fast Connected Components Labeling Algorithm in Processing Landmark Images

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Extracting geometric data of landmarks from fluoroscopic images plays an important role in camera calibration process of a fluoroscopic-image-based surgical navigation system. Connected components labeling is the essential technique for the extraction. A new fast connected components labeling algorithm was presented. The definition of upward concave set was introduced to explain the algorithm. Feasibility and efficiency of the algorithm were verified with experiments. This algorithm performs well in labeling non-upward concave set connected components and applies to landmarks labeling well. Moreover, the proposed algorithm possesses a desirable characteristic that will facilitate the subsequent processing of fluoroscopic images.

  19. UAV Control on the Basis of 3D Landmark Bearing-Only Observations.

    Science.gov (United States)

    Karpenko, Simon; Konovalenko, Ivan; Miller, Alexander; Miller, Boris; Nikolaev, Dmitry

    2015-01-01

    The article presents an approach to the control of a UAV on the basis of 3D landmark observations. The novelty of the work is the usage of the 3D RANSAC algorithm developed on the basis of the landmarks' position prediction with the aid of a modified Kalman-type filter. Modification of the filter based on the pseudo-measurements approach permits obtaining unbiased UAV position estimation with quadratic error characteristics. Modeling of UAV flight on the basis of the suggested algorithm shows good performance, even under significant external perturbations. PMID:26633394

  20. Cochlear implant electrode insertion: Jacobson’s nerve, a useful anatomical landmark

    OpenAIRE

    Goravalingappa, Ravi

    2002-01-01

    The classical technique in approaching the scala tympani through the round window niche by way of facial recess has not always been successful. There have been recent reports on false insertion of the electrode array into the hypotympanic cells tracts or infralabrynithine cells tracts. In these cases the round window niche are situated posterior, or obliterated due to bony growth, or sclerosed at the basal turn of the cochlea. Therefore, successful intubation of the scala tympani much depends...

  1. 36 CFR 62.7 - Natural landmark modifications.

    Science.gov (United States)

    2010-07-01

    ... nationally significant features, professional error in the original designation, or additional landowners... landmark: Loss of integrity of the natural features or professional error in the original designation....

  2. Absence of Flexor Carpi Radialis during an Elective Carpometacarpal Arthroplasty of the Thumb: A Rare Anatomical Variation

    Directory of Open Access Journals (Sweden)

    Stratos S. Sofos

    2016-01-01

    Full Text Available Purpose. We present an extremely rare anatomical variation of unilateral flexor carpi radialis (FCR absence. This rare anatomical variation posed a clinical dilemma to us and we highlight the importance of the surgeon being aware of this anatomical variation of an important structure both as a reconstruction tool and as an anatomical landmark. Methods. This anatomical variation of the unilaterally absent FCR was found upon dissection during a carpometacarpal arthroplasty of the thumb. Results. Upon the discovery of an absent FCR tendon, we proceeded with a simple trapeziectomy. Conclusions. We present an extremely rare anatomical variation of unilateral FCR absence. This rare anatomical variation may pose clinical dilemmas to the operating surgeon who aims to utilise the FCR either for tendon transfer, for tendon graft, or, as seen in our case, in the reconstruction of a carpometacarpal excision at the thumb. We highlight this diagnosis of suspicion, which may influence the clinical procedure.

  3. Post-trial anatomical frame alignment procedure for comparison of 3D joint angle measurement from magnetic/inertial measurement units and camera-based systems.

    Science.gov (United States)

    Li, Qingguo; Zhang, Jun-Tian

    2014-11-01

    Magnetic and inertial measurement units (MIMUs) have been widely used as an alternative to traditional camera-based motion capture systems for 3D joint kinematics measurement. Since these sensors do not directly measure position, a pre-trial anatomical calibration, either with the assistance of a special protocol/apparatus or with another motion capture system is required to establish the transformation matrices between the local sensor frame and the anatomical frame (AF) of each body segment on which the sensors are attached. Because the axes of AFs are often used as the rotational axes in the joint angle calculation, any difference in the AF determination will cause discrepancies in the calculated joint angles. Therefore, a direct comparison of joint angles between MIMU systems and camera-based systems is less meaningful because the calculated joint angles contain a systemic error due to the differences in the AF determination. To solve this problem a new post-trial AF alignment procedure is proposed. By correcting the AF misalignments, the joint angle differences caused by the difference in AF determination are eliminated and the remaining discrepancies are mainly from the measurement accuracy of the systems themselves. Lower limb joint angles from 30 walking trials were used to validate the effectiveness of the proposed AF alignment procedure. This technique could serve as a new means for calibrating magnetic/inertial sensor-based motion capture systems and correcting for AF misalignment in scenarios where joint angles are compared directly.

  4. Anatomic Total Shoulder System

    Medline Plus

    Full Text Available GLOBAL AP ANATOMIC TOTAL SHOULDER SYSTEM METHODIST HOSPITAL PHILADELPHIA, PA April 17, 2008 00:00:10 ANNOUNCER: DePuy Orthopedics is continually advancing the standard of orthopedic patient care. In a few ...

  5. Anatomic Total Shoulder System

    Medline Plus

    Full Text Available ... to a patient's unique anatomical makeup. Dr. Gerald R. Williams, Jr., a shoulder specialist from the Rothman ... That might help. Could you raise the O.R. table, please? 00:28:35 WOMAN: Can you ...

  6. Anatomic Total Shoulder System

    Medline Plus

    Full Text Available GLOBAL AP ANATOMIC TOTAL SHOULDER SYSTEM METHODIST HOSPITAL PHILADELPHIA, PA April 17, 2008 00:00:10 ANNOUNCER: DePuy Orthopedics is continually advancing the standard of orthopedic patient ...

  7. EXPLOITING 3D ULTRASOUND FOR FETAL DIAGNOSTIC PURPOSE THROUGH FACIAL LANDMARKING

    Directory of Open Access Journals (Sweden)

    Enrico Vezzetti

    2014-06-01

    Full Text Available In the last decade, three-dimensional landmarking has gained attention for different applications, such as face recognition for both identification of suspects and authentication, facial expression recognition, corrective and aesthetic surgery, syndrome study and diagnosis. This work focuses on the last one by proposing a geometrically-based landmark extraction algorithm aimed at diagnosing syndromes on babies before their birth. Pivotal role in this activity is the support provided by physicians and 3D ultrasound tools for working on real faces. In particular, the landmarking algorithm here proposed only relies on descriptors coming from Differential Geometry (Gaussian, mean, and principal curvatures, derivatives, coefficients of first and second fundamental forms, Shape and Curvedness indexes and is tested on nine facial point clouds referred to nine babies taken by a three-dimensional ultrasound tool at different weeks' gestation. The results obtained, validated with the support of four practitioners, show that the localization is quite accurate. All errors lie in the range between 0 and 3.5 mm and the mean distance for each shell is in the range between 0.6 and 1.6 mm. The landmarks showing the highest errors are the ones belonging to the mouth region. Instead, the most precise landmark is the pronasal, on the nose tip, with a mean distance of 0.55 mm. Relying on current literature, this study is something missing in the state-of-the-art of the field, as present facial studies on 3D ultrasound do not work on automatic landmarking yet.

  8. FACIAL LANDMARKING LOCALIZATION FOR EMOTION RECOGNITION USING BAYESIAN SHAPE MODELS

    Directory of Open Access Journals (Sweden)

    Hernan F. Garcia

    2013-02-01

    Full Text Available This work presents a framework for emotion recognition, based in facial expression analysis using Bayesian Shape Models (BSM for facial landmarking localization. The Facial Action Coding System (FACS compliant facial feature tracking based on Bayesian Shape Model. The BSM estimate the parameters of the model with an implementation of the EM algorithm. We describe the characterization methodology from parametric model and evaluated the accuracy for feature detection and estimation of the parameters associated with facial expressions, analyzing its robustness in pose and local variations. Then, a methodology for emotion characterization is introduced to perform the recognition. The experimental results show that the proposed model can effectively detect the different facial expressions. Outperforming conventional approaches for emotion recognition obtaining high performance results in the estimation of emotion present in a determined subject. The model used and characterization methodology showed efficient to detect the emotion type in 95.6% of the cases.

  9. Quantitation of maxillary remodeling. 2. Masking of remodeling effects when an "anatomical" method of superimposition is used in the absence of metallic implants.

    Science.gov (United States)

    Baumrind, S; Korn, E L; Ben-Bassat, Y; West, E E

    1987-06-01

    We report the results of a study aimed at quantifying the differences in the perceived pattern of maxillary remodeling that are observed when different methods are used to superimpose maxillary images in roentgenographic cephalometrics. In a previous article, we reported cumulative changes in the positions of anterior nasal spine (ANS), posterior nasal spine (PNS), and Point A for a sample of 31 subjects with maxillary metallic implants. Measurements had been made on lateral cephalograms taken at annual intervals relative to superimposition on the implants. In the present article, we quantify the differences in the perceived displacement of the same landmarks in the same sample when a standard "anatomical best bit" rule was used in lieu of superimposition on the implants. The anatomical best fit superimposition as herein defined was found in this sample to lose important information on the downward remodeling of the superior surface of the maxilla that had been detected when the implant superimposition was used. In fact, we observed a small artifactual upward displacement of the ANS-PNS line. In the anteroposterior direction, the tendency toward backward displacement of skeletal landmarks through time that had been detected with the implant superimposition was replaced by a small forward displacement of ANS and Point A together with reduced backward displacement of PNS. To the extent that the implant superimposition is to be considered the true and correct one, the anatomical best fit superimposition appears to understate the true downward remodeling of the palate by an average of about 0.3 and 0.4 mm per year, although this value differs at different ages and timepoints. The anatomical best fit superimposition also misses entirely the small mean tendency toward backward remodeling that was observed when the implant superimposition was used. In situations in which there are no implants, clinicians and research workers must necessarily continue to use anatomically

  10. Precision landmark location for machine vision and photogrammetry finding and achieving the maximum possible accuracy

    CERN Document Server

    Gutierrez, José A

    2007-01-01

    Shows the reader how to derive theoretical limits to the precision of landmark identification in electronic imagesMATLAB® package assists the reader with applying theoretical results in real engineering systemsSteps outside the usual earth-sciences and civil-engineering base of photogrammetry to improve animation, medical imaging and robotic vision applications

  11. 基于CPR和CLM的多视角人脸特征点定位方法%A Multi-view Facial Landmark Localization Method Based on CPR and CLM

    Institute of Scientific and Technical Information of China (English)

    石正权; 赵启军; 陈虎

    2015-01-01

    准确定位人脸特征点在人脸识别、三维人脸模型重建等领域都有重要作用.目前,针对正面人脸的特征点定位已经相当成熟;但是,当姿态偏转角较大时,准确定位人脸特征点依然是一个有待解决的难题.文中针对姿态偏转比较大的特征点定位,提出了一种多视角人脸特征点定位方法.在训练阶段,针对不同姿态角度,分别定义其特征点模板,并通过训练得到用于特征点搜索的CPR(级联姿态回归)模型和用于特征点模板选择的CLM (约束局部模型)模型.在测试阶段,利用每个模型分别对测试样本进行特征点搜索,然后,利用CLM模型计算各特征点模板的拟合度,选择拟合度最高的模型作为最终结果.在FERET公开库上,与当前比较先进的算法进行的对比实验表明,文中方法有效提高了较大偏转姿态下人脸特征点定位的准确性.%Facial landmark localization plays an important role in many face-related applications such as face recognition and 3D face re-construction. Although existing methods already achieve promising results on frontal and near-frontal face images,their performance on face images with large pose angles is still far from being satisfactory. A multi-view facial landmark localization method is proposed in this paper. It divides head pose angles into a number of non-overlapping ranges. During training,for each range of head pose angles,a facial landmark template is constructed by using the CPR (Cascaded Pose Regression) method,and a corresponding texture model is established by using the CLM (Constrained Local Model) method. During testing,given a new face image,all the templates are applied to it,each resulting in a set of facial landmarks. The associated texture models are then used to compute the fitness values of them,from which the one with the maximum fitness is chosen as the final result. Experiments on the FERET database with comparison to a state-of-the-art method

  12. Visual motion-sensitive neurons in the bumblebee brain convey information about landmarks during a navigational task

    Directory of Open Access Journals (Sweden)

    Marcel eMertes

    2014-09-01

    Full Text Available Bees use visual memories to find the spatial location of previously learnt food sites. Characteristic learning flights help acquiring these memories at newly discovered foraging locations where landmarks - salient objects in the vicinity of the goal location - can play an important role in guiding the animal’s homing behavior. Although behavioral experiments have shown that bees can use a variety of visual cues to distinguish objects as landmarks, the question of how landmark features are encoded by the visual system is still open. Recently, it could be shown that motion cues are sufficient to allow bees localizing their goal using landmarks that can hardly be discriminated from the background texture. Here, we tested the hypothesis that motion sensitive neurons in the bee’s visual pathway provide information about such landmarks during a learning flight and might, thus, play a role for goal localization. We tracked learning flights of free-flying bumblebees (Bombus terrestris in an arena with distinct visual landmarks, reconstructed the visual input during these flights, and replayed ego-perspective movies to tethered bumblebees while recording the activity of direction-selective wide-field neurons in their optic lobe. By comparing neuronal responses during a typical learning flight and targeted modifications of landmark properties in this movie we demonstrate that these objects are indeed represented in the bee’s visual motion pathway. We find that object-induced responses vary little with object texture, which is in agreement with behavioral evidence. These neurons thus convey information about landmark properties that are useful for view-based homing.

  13. Chronic Pancreatitis: Landmark Papers, Management Decisions, and Future.

    Science.gov (United States)

    DiMagno, Eugene P; DiMagno, Matthew J

    2016-01-01

    On May 16, 2015 at the invitation of the American Gastroenterological Association Institute Council E.P.D. presented a state-of-the-art lecture at Digestive Disease Week 2015. The aims were to discuss a selection of landmark papers in chronic pancreatitis (CP) that influence modern management and to conclude by suggesting some future directions. This is based on that presentation. We will specifically review the following: duct anatomy and pancreas divisum, description of chronic relapsing pancreatitis and its differentiation from recurrent acute pancreatitis and established CP (ECP), natural histories and gene discoveries of alcoholic, idiopathic and hereditary pancreatitis, development of pancreatic cancer in CP, exocrine pancreatic insufficiency and calculation of dose and delivery of enzymes, endoscopic ultrasonography, and autoimmune pancreatitis. With some exceptions, we exclude basic science and surgery.

  14. Assessing the anatomical variations of lingual foramen and its bony canals with CBCT taken from 102 patients in Isfahan

    Directory of Open Access Journals (Sweden)

    Mahnaz Sheikhi

    2012-01-01

    Conclusion: These anatomical landmarks in Isfahan population vary from previous studies. All of the images had at least one lingual foramen which demonstrates high prevalence of this anatomy among Isfehanian population. Therefore, it is recommended to use CBCT imaging for preoperative evaluation prior to installing dental implants.

  15. Automatic 2.5-D Facial Landmarking and Emotion Annotation for Social Interaction Assistance.

    Science.gov (United States)

    Zhao, Xi; Zou, Jianhua; Li, Huibin; Dellandrea, Emmanuel; Kakadiaris, Ioannis A; Chen, Liming

    2016-09-01

    People with low vision, Alzheimer's disease, and autism spectrum disorder experience difficulties in perceiving or interpreting facial expression of emotion in their social lives. Though automatic facial expression recognition (FER) methods on 2-D videos have been extensively investigated, their performance was constrained by challenges in head pose and lighting conditions. The shape information in 3-D facial data can reduce or even overcome these challenges. However, high expenses of 3-D cameras prevent their widespread use. Fortunately, 2.5-D facial data from emerging portable RGB-D cameras provide a good balance for this dilemma. In this paper, we propose an automatic emotion annotation solution on 2.5-D facial data collected from RGB-D cameras. The solution consists of a facial landmarking method and a FER method. Specifically, we propose building a deformable partial face model and fit the model to a 2.5-D face for localizing facial landmarks automatically. In FER, a novel action unit (AU) space-based FER method has been proposed. Facial features are extracted using landmarks and further represented as coordinates in the AU space, which are classified into facial expressions. Evaluated on three publicly accessible facial databases, namely EURECOM, FRGC, and Bosphorus databases, the proposed facial landmarking and expression recognition methods have achieved satisfactory results. Possible real-world applications using our algorithms have also been discussed. PMID:26316289

  16. White matter abnormalities in young males with antisocial personality disorder Evidence from voxel-based morphometry-diffeomorphic anatomical registration using exponentiated lie algebra analysis

    Institute of Scientific and Technical Information of China (English)

    Daxing Wu; Ying Zhao; Jian Liao; Huifang Yin; Wei Wang

    2011-01-01

    Voxel-based morphometry-diffeomorphic anatomical registration using exponentiated lie algebra analysis was used to investigate the structural characteristics of white matter in young males with antisocial personality disorder (APD) and healthy controls without APD. The results revealed that APD subjects, relative to healthy subjects, exhibited increased white matter volume in the bilateral prefrontal lobe, right insula, precentral gyrus, bilateral superior temporal gyrus, right postcentral gyrus, right inferior parietal lobule, right precuneus, right middle occipital lobe, right parahippocampal gyrus and bilateral cingulate, and decreased volume in the middle temporal cortex and right cerebellum. The white matter volume in the medial frontal gyrus was significantly correlated with antisocial type scores on the Personality Diagnostic Questionnaire in APD subjects. These experimental findings indicate that white matter abnormalities in several brain areas may contribute to antisocial behaviors in APD subjects.

  17. The location of midfacial landmarks according to the method of establishing the midsagittal reference plane in three-dimensional computed tomography analysis of facial asymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Sun; Lee, Eun Joo; Lee, Jae Seo; Kang, Byung Cheock; Yoon, Suk Ja [Dental Science Research Institute, Chonnam National University, Gwangju (Korea, Republic of); Song, In Ja [Dept. of Nursing, Kwangju Women' s University, Gwangju (Korea, Republic of)

    2015-12-15

    The purpose of this study was to evaluate the influence of methods of establishing the midsagittal reference plane (MRP) on the locations of midfacial landmarks in the three-dimensional computed tomography (CT) analysis of facial asymmetry. A total of 24 patients (12 male and 12 female; mean age, 22.5 years; age range, 18.2-29.7 years) with facial asymmetry were included in this study. The MRP was established using two different methods on each patient's CT image. The x-coordinates of four midfacial landmarks (the menton, nasion, upper incisor, and lower incisor) were obtained by measuring the distance and direction of the landmarks from the MRP, and the two methods were compared statistically. The direction of deviation and the severity of asymmetry found using each method were also compared. The x-coordinates of the four anatomic landmarks all showed a statistically significant difference between the two methods of establishing the MRP. For the nasion and lower incisor, six patients (25.0%) showed a change in the direction of deviation. The severity of asymmetry also changed in 16 patients (66.7%). The results of this study suggest that the locations of midfacial landmarks change significantly according to the method used to establish the MRP.

  18. Plantar calcaneal enthesophytes: new observations regarding sites of origin based on radiographic, MR imaging, anatomic, and paleopathologic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, M.R.; Chung, C.B.; Mendes, L.; Mohana-Borges, A.; Trudell, D.; Resnick, D. [Department of Radiology, Musculoskeletal Section, VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161 (United States)

    2003-01-01

    To determine the relationship between sites of calcaneal plantar enthesophytes and surrounding fascial and soft tissue structures using routine radiography, MR imaging, and data derived from cadaveric and paleopathologic specimens.Design and patients. Two observers analyzed the MR imaging studies of 40 ankles in 38 patients (35 males, 3 females; mean age 48.3 years) with plantar calcaneal enthesophytes that were selected from all the ankle MR examinations performed during the past year. Data derived from these MR examinations were the following: the size of the enthesophyte; its location in relation to the plantar fascia (PF) and flexor muscles; and the thickness and signal of the PF. The corresponding radiographs of the ankles were evaluated at a different time by the same observers for the presence or absence of plantar enthesophytes and, when present, their measurements. A third observer reviewed all the discordant observations of MR imaging and radiographic examinations. Two observers analyzed 22 calcaneal specimens with plantar enthesophytes at an anthropology museum to determine the orientation of each plantar enthesophyte. MR imaging of a cadaveric foot with a plantar enthesophyte with subsequent sagittal sectioning was performed to provide further anatomic understanding.Results. With regard to MR imaging, the mean size of the plantar enthesophytes was 4.41 mm (SD 2.4). Twenty (50%) enthesophytes were located above the PF, 16 (40%) between the fascia and abductor digiti minimi, flexor digitorum brevis and abductor hallucis muscles, and only one (3%) was located within the PF. In three (8%) cases the location was not determined. The size of enthesophytes seen with MR imaging and radiographs was highly correlated (P<0.01). The interobserver agreement for all measurements was good (Pearson >0.8, kappa >0.9). Eleven of the 22 bone specimens had plantar enthesophytes oriented in the direction of the abductor digiti minimi and 11 oriented in the direction of the

  19. Factors influencing superimposition error of 3D cephalometric landmarks by plane orientation method using 4 reference points: 4 point superimposition error regression model.

    Science.gov (United States)

    Hwang, Jae Joon; Kim, Kee-Deog; Park, Hyok; Park, Chang Seo; Jeong, Ho-Gul

    2014-01-01

    Superimposition has been used as a method to evaluate the changes of orthodontic or orthopedic treatment in the dental field. With the introduction of cone beam CT (CBCT), evaluating 3 dimensional changes after treatment became possible by superimposition. 4 point plane orientation is one of the simplest ways to achieve superimposition of 3 dimensional images. To find factors influencing superimposition error of cephalometric landmarks by 4 point plane orientation method and to evaluate the reproducibility of cephalometric landmarks for analyzing superimposition error, 20 patients were analyzed who had normal skeletal and occlusal relationship and took CBCT for diagnosis of temporomandibular disorder. The nasion, sella turcica, basion and midpoint between the left and the right most posterior point of the lesser wing of sphenoidal bone were used to define a three-dimensional (3D) anatomical reference co-ordinate system. Another 15 reference cephalometric points were also determined three times in the same image. Reorientation error of each landmark could be explained substantially (23%) by linear regression model, which consists of 3 factors describing position of each landmark towards reference axes and locating error. 4 point plane orientation system may produce an amount of reorientation error that may vary according to the perpendicular distance between the landmark and the x-axis; the reorientation error also increases as the locating error and shift of reference axes viewed from each landmark increases. Therefore, in order to reduce the reorientation error, accuracy of all landmarks including the reference points is important. Construction of the regression model using reference points of greater precision is required for the clinical application of this model. PMID:25372707

  20. An anatomically oriented breast model for MRI

    Science.gov (United States)

    Kutra, Dominik; Bergtholdt, Martin; Sabczynski, Jörg; Dössel, Olaf; Buelow, Thomas

    2015-03-01

    Breast cancer is the most common cancer in women in the western world. In the breast cancer care-cycle, MRIis e.g. employed in lesion characterization and therapy assessment. Reading of a single three dimensional image or comparing a multitude of such images in a time series is a time consuming task. Radiological reporting is done manually by translating the spatial position of a finding in an image to a generic representation in the form of a breast diagram, outlining quadrants or clock positions. Currently, registration algorithms are employed to aid with the reading and interpretation of longitudinal studies by providing positional correspondence. To aid with the reporting of findings, knowledge about the breast anatomy has to be introduced to translate from patient specific positions to a generic representation. In our approach we fit a geometric primitive, the semi-super-ellipsoid to patient data. Anatomical knowledge is incorporated by fixing the tip of the super-ellipsoid to the mammilla position and constraining its center-point to a reference plane defined by landmarks on the sternum. A coordinate system is then constructed by linearly scaling the fitted super-ellipsoid, defining a unique set of parameters to each point in the image volume. By fitting such a coordinate system to a different image of the same patient, positional correspondence can be generated. We have validated our method on eight pairs of baseline and follow-up scans (16 breasts) that were acquired for the assessment of neo-adjuvant chemotherapy. On average, the location predicted and the actual location of manually set landmarks are within a distance of 5.6 mm. Our proposed method allows for automatic reporting simply by uniformly dividing the super-ellipsoid around its main axis.

  1. Anatomic Total Shoulder System

    Medline Plus

    Full Text Available ... advancing the standard of orthopedic patient care. In a few moments, you'll be able to watch a live global AP anatomic total shoulder surgery from Methodist Hospital in Philadelphia. A revolution in shoulder orthopedics, the Global AP gives ...

  2. Evaluation of deformation accuracy of a virtual pneumoperitoneum method based on clinical trials for patient-specific laparoscopic surgery simulator

    Science.gov (United States)

    Oda, Masahiro; Qu, Jia Di; Nimura, Yukitaka; Kitasaka, Takayuki; Misawa, Kazunari; Mori, Kensaku

    2012-02-01

    This paper evaluates deformation accuracy of a virtual pneumoperitoneum method by utilizing measurement data of real deformations of patient bodies. Laparoscopic surgery is an option of surgical operations that is less invasive technique as compared with traditional surgical operations. In laparoscopic surgery, the pneumoperitoneum process is performed to create a viewing and working space. Although a virtual pneumoperitoneum method based on 3D CT image deformation has been proposed for patient-specific laparoscopy simulators, quantitative evaluation based on measurements obtained in real surgery has not been performed. In this paper, we evaluate deformation accuracy of the virtual pneumoperitoneum method based on real deformation data of the abdominal wall measured in operating rooms (ORs.) The evaluation results are used to find optimal deformation parameters of the virtual pneumoperitoneum method. We measure landmark positions on the abdominal wall on a 3D CT image taken before performing a pneumoperitoneum process. The landmark positions are defined based on anatomical structure of a patient body. We also measure the landmark positions on a 3D CT image deformed by the virtual pneumoperitoneum method. To measure real deformations of the abdominal wall, we measure the landmark positions on the abdominal wall of a patient before and after the pneumoperitoneum process in the OR. We transform the landmark positions measured in the OR from the tracker coordinate system to the CT coordinate system. A positional error of the virtual pneumoperitoneum method is calculated based on positional differences between the landmark positions on the 3D CT image and the transformed landmark positions. Experimental results based on eight cases of surgeries showed that the minimal positional error was 13.8 mm. The positional error can be decreased from the previous method by calculating optimal deformation parameters of the virtual pneumoperitoneum method from the experimental

  3. Single Robot Localisation Approach for Indoor Robotic Systems through Integration of Odometry and Artificial Landmarks

    OpenAIRE

    Ņikitenko, A; Liekna, A; Ekmanis, M.; Kuļikovskis, G; Andersone, I

    2013-01-01

    we present an integrated approach for robot localization that allows to integrate for the artificial landmark localization data with odometric sensors and signal transfer function data to provide means for different practical application scenarios. The sensor data fusion deals with asynchronous sensor data using inverse Laplace transform. We demonstrate a simulation software system that ensures smooth integration of the odometry-based and signal transfer – based localization into one approach.

  4. Anatomical mapping of the nasal muscles and application to cosmetic surgery.

    Science.gov (United States)

    Konschake, Marko; Fritsch, Helga

    2014-11-01

    We present an anatomical mapping of the most important muscles influencing the nose, incorporating constant anatomical structures, and their spatial correlations. At our disposal were the midfaces of 18 bodies of both sexes, obtained by informed consent from body donors aged between 60 and 80 years. Macroscopically, we dissected the nasal regions of eight corpses, six midfaces were prepared according to plastination histology, four by creating plastinated slices. On their way from their periosteal origin to the edge of the skin, the muscles of the nose cross the subcutaneous adipose tissue, dividing it into superficial and deep layers. The individual muscle fibers insert into the skin directly at the reticular corium. Sometimes, they reach the border of the epidermis which represents a special arrangement of corial muscle attachments. The course of the anatomical fibers of individual nasal muscles presented macroscopically and microscopically in this study offers surgeons a detailed overview of the anatomically important muscular landmarks of the midface. PMID:24863980

  5. Landmarks of History of Soil Science in Sri Lanka

    Science.gov (United States)

    Mapa, R.

    2012-04-01

    Sri Lanka is a tropical Island in the Southern tip of Indian subcontinent positioned at 50 55' to 90 50' N latitude and 790 42' to 810 53' E longitude surrounded by the Indian Ocean. It is an island 435 km in length and 224 km width consisting of a land are of 6.56 million ha with a population of 20 million. In area wise it is ranked as 118th in the world, where at present ranked as 47 in population wise and ranked 19th in population density. The country was under colonial rule under Portuguese, Dutch and British from 1505 to 1948. The majority of the people in the past and present earn their living from activities based on land, which indicates the important of the soil resource. The objective of this paper is to describe the landmarks of the history of Soil Science to highlight the achievements and failures, which is useful to enrich our present understanding of Sri Lankan soils. The landmarks of the history of Soil Science in Sri Lanka can be divided to three phases namely, the early period (prior to 1956), the middle period (1956 to 1972) and the present period (from 1972 onwards). During the early period, detailed analytical studies of coffee and tea soils were compiled, and these gave mainly information on up-country soils which led to fertilizer recommendations based on field trials. In addition, rice and forest soils were also studied in less detail. The first classification of Sri Lankan soils and a provisional soil map based on parent material was published by Joachim in 1945 which is a major landmark of history of Soil Science in Sri Lanka. In 1959 Ponnamperuma proposed a soil classification system for wetland rice soils. From 1963 to 1968 valuable information on the land resource was collected and documented by aerial resource surveys funded by Canada-Ceylon Colombo plan aid project. This covered 18 major river basins and about 1/4th of Sri Lanka, which resulted in producing excellent soil maps and information of the areas called the Kelani Aruvi Ara

  6. Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra provides reduced effect of scanner for cortex volumetry with atlas-based method in healthy subjects

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Masami; Ino, Kenji; Yano, Keiichi [University of Tokyo Hospital, Department of Radiological Technology, Bunkyo-ku, Tokyo (Japan); Abe, Osamu [Nihon University School of Medicine, Department of Radiology, Itabashi-ku, Tokyo (Japan); Aoki, Shigeki [Juntendo University, Department of Radiology, Bunkyo-ku, Tokyo (Japan); Hayashi, Naoto [University of Tokyo Hospital, Department of Computational Diagnostic Radiology and Preventive Medicine, Bunkyo-ku, Tokyo (Japan); Miyati, Tosiaki [Kanazawa University, Graduate School of Medical Science, Kanazawa (Japan); Takao, Hidemasa; Mori, Harushi; Kunimatsu, Akira; Ohtomo, Kuni [University of Tokyo Hospital, Department of Radiology and Department of Computational Diagnostic Radiology and Preventive Medicine, Bunkyo-ku, Tokyo (Japan); Iwatsubo, Takeshi [University of Tokyo, Department of Neuropathology, Bunkyo-ku, Tokyo (Japan); Yamashita, Fumio [Iwate Medical University, Department of Radiology, Yahaba, Iwate (Japan); Matsuda, Hiroshi [Integrative Brain Imaging Center National Center of Neurology and Psychiatry, Department of Nuclear Medicine, Kodaira, Tokyo (Japan); Collaboration: Japanese Alzheimer' s Disease Neuroimaging Initiative

    2013-07-15

    This study aimed to investigate whether the effect of scanner for cortex volumetry with atlas-based method is reduced using Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) normalization compared with standard normalization. Three-dimensional T1-weighted magnetic resonance images (3D-T1WIs) of 21 healthy subjects were obtained and evaluated for effect of scanner in cortex volumetry. 3D-T1WIs of the 21 subjects were obtained with five MRI systems. Imaging of each subject was performed on each of five different MRI scanners. We used the Voxel-Based Morphometry 8 tool implemented in Statistical Parametric Mapping 8 and WFU PickAtlas software (Talairach brain atlas theory). The following software default settings were used as bilateral region-of-interest labels: ''Frontal Lobe,'' ''Hippocampus,'' ''Occipital Lobe,'' ''Orbital Gyrus,'' ''Parietal Lobe,'' ''Putamen,'' and ''Temporal Lobe.'' Effect of scanner for cortex volumetry using the atlas-based method was reduced with DARTEL normalization compared with standard normalization in Frontal Lobe, Occipital Lobe, Orbital Gyrus, Putamen, and Temporal Lobe; was the same in Hippocampus and Parietal Lobe; and showed no increase with DARTEL normalization for any region of interest (ROI). DARTEL normalization reduces the effect of scanner, which is a major problem in multicenter studies. (orig.)

  7. Reference Man anatomical model

    Energy Technology Data Exchange (ETDEWEB)

    Cristy, M.

    1994-10-01

    The 70-kg Standard Man or Reference Man has been used in physiological models since at least the 1920s to represent adult males. It came into use in radiation protection in the late 1940s and was developed extensively during the 1950s and used by the International Commission on Radiological Protection (ICRP) in its Publication 2 in 1959. The current Reference Man for Purposes of Radiation Protection is a monumental book published in 1975 by the ICRP as ICRP Publication 23. It has a wealth of information useful for radiation dosimetry, including anatomical and physiological data, gross and elemental composition of the body and organs and tissues of the body. The anatomical data includes specified reference values for an adult male and an adult female. Other reference values are primarily for the adult male. The anatomical data include much data on fetuses and children, although reference values are not established. There is an ICRP task group currently working on revising selected parts of the Reference Man document.

  8. Smart grid initialization reduces the computational complexity of multi-objective image registration based on a dual-dynamic transformation model to account for large anatomical differences

    Science.gov (United States)

    Bosman, Peter A. N.; Alderliesten, Tanja

    2016-03-01

    We recently demonstrated the strong potential of using dual-dynamic transformation models when tackling deformable image registration problems involving large anatomical differences. Dual-dynamic transformation models employ two moving grids instead of the common single moving grid for the target image (and single fixed grid for the source image). We previously employed powerful optimization algorithms to make use of the additional flexibility offered by a dual-dynamic transformation model with good results, directly obtaining insight into the trade-off between important registration objectives as a result of taking a multi-objective approach to optimization. However, optimization has so far been initialized using two regular grids, which still leaves a great potential of dual-dynamic transformation models untapped: a-priori grid alignment with image structures/areas that are expected to deform more. This allows (far) less grid points to be used, compared to using a sufficiently refined regular grid, leading to (far) more efficient optimization, or, equivalently, more accurate results using the same number of grid points. We study the implications of exploiting this potential by experimenting with two new smart grid initialization procedures: one manual expert-based and one automated image-feature-based. We consider a CT test case with large differences in bladder volume with and without a multi-resolution scheme and find a substantial benefit of using smart grid initialization.

  9. Modeling and matching of landmarks for automation of Mars Rover localization

    Science.gov (United States)

    Wang, Jue

    The Mars Exploration Rover (MER) mission, begun in January 2004, has been extremely successful. However, decision-making for many operation tasks of the current MER mission and the 1997 Mars Pathfinder mission is performed on Earth through a predominantly manual, time-consuming process. Unmanned planetary rover navigation is ideally expected to reduce rover idle time, diminish the need for entering safe-mode, and dynamically handle opportunistic science events without required communication to Earth. Successful automation of rover navigation and localization during the extraterrestrial exploration requires that accurate position and attitude information can be received by a rover and that the rover has the support of simultaneous localization and mapping. An integrated approach with Bundle Adjustment (BA) and Visual Odometry (VO) can efficiently refine the rover position. However, during the MER mission, BA is done manually because of the difficulty in the automation of the cross-sitetie points selection. This dissertation proposes an automatic approach to select cross-site tie points from multiple rover sites based on the methods of landmark extraction, landmark modeling, and landmark matching. The first step in this approach is that important landmarks such as craters and rocks are defined. Methods of automatic feature extraction and landmark modeling are then introduced. Complex models with orientation angles and simple models without those angles are compared. The results have shown that simple models can provide reasonably good results. Next, the sensitivity of different modeling parameters is analyzed. Based on this analysis, cross-site rocks are matched through two complementary stages: rock distribution pattern matching and rock model matching. In addition, a preliminary experiment on orbital and ground landmark matching is also briefly introduced. Finally, the reliability of the cross-site tie points selection is validated by fault detection, which

  10. Pilot study: Computer-based virtual anatomical interactivity for rehabilitation of individuals with chronic acquired brain injury

    OpenAIRE

    C. Douglas Simmons, PhD, OTR/L, FAOTA; Sajay Arthanat, PhD, OTR/L, ATP; Vincent J. Macri, BA, MA

    2014-01-01

    Deficiencies in upper-limb motor function and executive functioning can compromise an affected individual’s ability to complete everyday activities. Impaired motor and executive functioning therefore pose a risk to increasing numbers of veterans who have been diagnosed with acquired brain injury. This article reports on changes in upper-limb motor function and executive functioning of 12 adult participants with chronic acquired brain injury using a novel, computer-based, motor and cognitive r...

  11. Genomic differentiation of Neanderthals and anatomically modern man allows a fossil-DNA-based classification of morphologically indistinguishable hominid bones.

    OpenAIRE

    Scholz, M.; Bachmann, L; Nicholson, G J; Bachmann, J.; Giddings, I; Rüschoff-Thale, B; Czarnetzki, A; Pusch, C. M.

    2000-01-01

    Southern blot hybridizations of genomic DNA were introduced as a relatively simple fossil-DNA-based approach to classify remains of Neanderthals. When hybridized with genomic DNA of either human or Neanderthal origin, DNA extracted from two Neanderthal finds-the Os parietale, from Warendorf-Neuwarendorf, Germany, and a clavicula, from Krapina, Croatia-was shown to yield hybridization signals that differ by at least a factor of two compared to the signals obtained with the use of fossil DNA of...

  12. Design, construction and mechanical testing of digital 3D anatomical data-based PCL-HA bone tissue engineering scaffold.

    Science.gov (United States)

    Yao, Qingqiang; Wei, Bo; Guo, Yang; Jin, Chengzhe; Du, Xiaotao; Yan, Chao; Yan, Junwei; Hu, Wenhao; Xu, Yan; Zhou, Zhi; Wang, Yijin; Wang, Liming

    2015-01-01

    The study aims to investigate the techniques of design and construction of CT 3D reconstructional data-based polycaprolactone (PCL)-hydroxyapatite (HA) scaffold. Femoral and lumbar spinal specimens of eight male New Zealand white rabbits were performed CT and laser scanning data-based 3D printing scaffold processing using PCL-HA powder. Each group was performed eight scaffolds. The CAD-based 3D printed porous cylindrical stents were 16 piece × 3 groups, including the orthogonal scaffold, the Pozi-hole scaffold and the triangular hole scaffold. The gross forms, fiber scaffold diameters and porosities of the scaffolds were measured, and the mechanical testing was performed towards eight pieces of the three kinds of cylindrical scaffolds, respectively. The loading force, deformation, maximum-affordable pressure and deformation value were recorded. The pore-connection rate of each scaffold was 100 % within each group, there was no significant difference in the gross parameters and micro-structural parameters of each scaffold when compared with the design values (P > 0.05). There was no significant difference in the loading force, deformation and deformation value under the maximum-affordable pressure of the three different cylinder scaffolds when the load was above 320 N. The combination of CT and CAD reverse technology could accomplish the design and manufacturing of complex bone tissue engineering scaffolds, with no significant difference in the impacts of the microstructures towards the physical properties of different porous scaffolds under large load.

  13. Lateral femoral cutaneous neuralgia: an anatomical insight.

    Science.gov (United States)

    Dias Filho, L C; Valença, M M; Guimarães Filho, F A V; Medeiros, R C; Silva, R A M; Morais, M G V; Valente, F P; França, S M L

    2003-07-01

    A detailed anatomic study was carried out on the lateral femoral cutaneous nerve to better understand the etiology and treatment of lateral femoral cutaneous neuralgia. As it passed from the pelvis into the thigh, the lateral femoral cutaneous nerve ran through an "aponeuroticofascial tunnel," beginning at the iliopubic tract and ending at the inguinal ligament; as it passed through the tunnel, an enlargement in its side-to-side diameter was observed, suggesting that the fascial structures proximal to the inguinal ligament may be implicated in the genesis of lateral femoral cutaneous neuralgia. The finding of pseudoneuromas at this location, distant from the inguinal ligament, supports this hypothesis. The anterior superior iliac spine is located approximately 0.7 cm from the lateral femoral cutaneous nerve and serves as the bony landmark for nerve localization. Within the first 3 cm of leaving the pelvis, the lateral femoral cutaneous nerve was observed deep to the fascia lata; therefore, surgical dissection within the subcutaneous fascia may be conducted with relative impunity near the anterior superior iliac spine just inferior to the inguinal ligament. In 36% of cases there was no posterior branch of the nerve, which is correlated to lateral femoral cutaneous neuralgia symptoms often being limited to the anterior branch region. An accessory nerve was found in 30% of cases. PMID:12794914

  14. Bases anatómicas vasculares de los colgajos perforantes cutáneos Vascular anatomical basis of perforator skin flaps

    Directory of Open Access Journals (Sweden)

    S. Morris

    2006-12-01

    ía vascular clínicamente relacionada de los colgajos perforantes.Over the past 2 decades the use of musculocutaneous perforator flaps has increased worldwide as microsurgeons have become more comfortable with the technique. Perforator flaps have now become well established as a part of the evolution of microsurgery. Since perforator flaps are based on individual musculocutaneous or septocutaneous perforators, it is imperative that the reconstructive microsurgeon has the detailed anatomical information necessary to plan perforator flap transfers. The goal of this paper is to review the various angiographic techniques which are available to study the vascular anatomy of the human body and to present our current vascular injection technique. We will show illustrative examples using the lead oxide gelatin injection technique to elucidate the relevant anatomy of perforator flap donor sites. The lead oxide gelatin injection technique has been previously reported by Salmon and Rees and Taylor. The injection technique may be used for arterial or venous injections but we have primarily used it for arterial injections. The injection steps are detailed in the paper. Over the past five years we have dissected a total of 21 human fresh cadavers after lead oxide gelatin arterial injection studies. A total of over 7000 radiographs have been reviewed and summarized. We present summarized results of the anatomical research in the areas of head and neck, upper limb, torso and lower limb regions. The lead oxide gelatin injection technique is simple and inexpensive and the computer analysis technique is straight forward and provides excellent visualization of the architecture of the human skin. The fine details identified using this injection technique provides useful information to surgeons planning transfers of skin, muscle, bone and nerve and therefore our understandingly of clinically related vascular anatomy of perforator flaps can be improved.

  15. Development and application of stent-based image guided navigation system for oral and maxillofacial surgery

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Woo Jin; Kim, Dae Seung [Interdisciplinary Program in Radiation Applied Life Science, Dental Research Institute and BK21, College of Medicine, Seoul National University, Seoul (Korea, Republic of); Yi, Won Jin; Lee, Sam Sun; Choi, Soon Chul; Heo, Min Suk; Huh, Kyung Hoe; Kim, Myung Jin; Lee, Jee Ho [Department of Oral and Maxillofacial Surgery, Dental Research Institute, School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    2009-09-15

    The purpose of this study was to develop a stent-based image guided surgery system and to apply it to oral and maxillofacial surgeries for anatomically complex sites. We devised a patient-specific stent for patient-to-image registration and navigation. Three dimensional positions of the reference probe and the tool probe were tracked by an optical camera system and the relative position of the handpiece drill tip to the reference probe was monitored continuously on the monitor of a PC. Using 8 landmarks for measuring accuracy, the spatial discrepancy between CT image coordinate and physical coordinate was calculated for testing the normality. The accuracy over 8 anatomical landmarks showed an overall mean of 0.56 {+-} 0.16 mm. The developed system was applied to a surgery for a vertical alveolar bone augmentation in right mandibular posterior area and possible interior alveolar nerve injury case of an impacted third molar. The developed system provided continuous monitoring of invisible anatomical structures during operation and 3D information for operation sites. The clinical challenge showed sufficient accuracy and availability of anatomically complex operation sites. The developed system showed sufficient accuracy and availability in oral and maxillofacial surgeries for anatomically complex sites.

  16. Pilot study: Computer-based virtual anatomical interactivity for rehabilitation of individuals with chronic acquired brain injury

    Directory of Open Access Journals (Sweden)

    C. Douglas Simmons, PhD, OTR/L, FAOTA

    2014-06-01

    Full Text Available Deficiencies in upper-limb motor function and executive functioning can compromise an affected individual’s ability to complete everyday activities. Impaired motor and executive functioning therefore pose a risk to increasing numbers of veterans who have been diagnosed with acquired brain injury. This article reports on changes in upper-limb motor function and executive functioning of 12 adult participants with chronic acquired brain injury using a novel, computer-based, motor and cognitive rehabilitation program called PreMotor Exercise Games (PEGs. Manual muscle, goniometric range of motion, and dynamometer assessments were used to determine motor functioning while the Executive Function Performance Test measured cognitive functioning. A three-level repeated measures design was conducted to determine changes pre- and postintervention. Participants demonstrated significant improvement in shoulder (p = 0.01 and wrist (p = 0.01 range of motion and clinically relevant improvement for elbow range of motion. Participants demonstrated clinically relevant improvement in shoulder, elbow, and wrist strength. Finally, participants demonstrated significant improvement in executive functioning (p < 0.05. Using PEGs as a modality for both motor and cognitive intervention is a potentially beneficial adjunct to rehabilitation and warrants further study.

  17. Reconstruction of the postauricular defects using retroauricular artery perforator-based island flaps: Anatomical study and clinical report.

    Science.gov (United States)

    Zhang, Yuan Zheng; Li, Ying Li; Yang, Chao; Fang, Shuo; Fan, Hao; Xing, Xin

    2016-09-01

    The objectives of the study were to introduce and investigate the reliability of a new flap for postauricular defects using the retroauricular artery perforator.Twenty auricles from 10 Asian human cadavers were dissected to examine the retroauricular perforator distribution and diameter. Fourteen patients with postauricular defects underwent reconstruction using the retroauricular artery perforator from 2013 to 2015. After locating the position of the perforator by ultrasound Doppler blood flow detection, a suitable flap was designed according to the defect's size, condition, and distance from the pedicle. The flap was meticulously elevated, rotated appropriately, and sutured to the defect. The donor site was then closed.Cadaver dissection showed that the posterior auricular artery produces at least 2 constant branches with an external diameter of 0.84 ± 0.25 mm at the origin. These branches proceed toward the mastoid process at the height of the auriculocephalic angle to nourish the skin and fascia. A total of 14 clinical cases were available for 3 to 12 months postoperative follow-up. All flaps survived completely, maintaining good skin color, perfect outer contour, and complete patient satisfaction with the aesthetic results after initial treatment.Retroauricular artery perforator-based island flaps appear to be ideal for 1-stage reconstruction of postauricular skin defects. PMID:27631246

  18. An Anatomical Study of the Nutrient Foramina of the Human Humeral Diaphysis.

    Science.gov (United States)

    Xue, Zichao; Ding, Haoliang; Hu, Chuanzhen; Xu, Haitao; An, Zhiquan

    2016-05-16

    BACKGROUND Understanding the nutrient foramina is critical to clinical practice. An insult to the nutrient foramina can be caused by trauma and/or surgical dissection and lead to devascularization and bad outcomes. Few studies have looked at the humerus, and no studies have described relative information of humeral nutrient foramen related to anatomical structures that might be located by palpable landmarks. In this study, we analyzed the anatomical features of the nutrient foramina of the diaphyseal humerus and provide a discussion of clinical relevance. MATERIAL AND METHODS We dissected 19 cadavers and analyzed the relative positions of the foramina and surrounding muscles, and the number, direction, diameter, and location of the nutrient foramina. Foramina index and a new landmark index were used to calculate the location. We compared the data from both sides and the relationships between transverse and longitudinal locations, diameter and total length, and foramina index and landmark index were also analyzed. RESULTS The humeri had one or two main nutrient foramina located in a small area between the coracobrachialis and brachial muscles and oriented toward the elbow. The mean diameter was 1.11±0.32 mm. The mean index and landmark index were 43.76±4.94% and 42.26±5.35%, respectively. There were no differences between sides in terms of diameter, length, or nutrient foramina index. There were no significant correlations between transverse and longitudinal locations or diameter and total length. The foramina index and landmark index showed strong positive correlation (r=0.994, p<0.0001). CONCLUSIONS Our study provides details about the nutrient foramina that will benefit clinicians who treat injuries and diseases of the humerus. Surgeons should be mindful of soft tissue in the foraminal area during surgical procedures.

  19. Landmark learning by the Ozark zigzag salamander Plethodon angusticlavius

    Directory of Open Access Journals (Sweden)

    Adam L. CRANE, Alicia MATHIS

    2011-08-01

    Full Text Available Although salamanders have been shown to respond to classical conditioning, spatial learning has been largely unstudied. We tested whether salamanders could learn to locate foraging areas by using landmarks. We trained 10 salamanders Plethodon angusticlavius to use landmarks (small rocks to locate patches within the arena containing food (blackworms Lumbriculus variegatus. At the corners of each square testing arena were four plastic dishes, one containing blackworms and the other three empty. A rock was placed in front of the dish containing blackworms, and the location of the food-dish was randomly chosen for each training trial. A control group was also trained to feed on blackworms in the presence of a rock, but the rock was positioned randomly among the four dish locations so that the rock was not a reliable landmark for the worms. Although the length of the training period for individual salamanders varied (22–38 trainings per individual, the mean number of trainings for salamanders in the control and experimental groups was equal (30 training trials. During testing, no blackworms were present to eliminate any visual or chemical cues emanating directly from the prey. Individuals trained with the rock landmarks spent significantly more time in the area of the landmark than did control salamanders [Current Zoology 57 (4: 485–490, 2011].

  20. Digital imaging in anatomic pathology.

    Science.gov (United States)

    O'Brien, M J; Sotnikov, A V

    1996-10-01

    Advances in computer technology continue to bring new innovations to departments of anatomic pathology. This article briefly reviews the present status of digital optical imaging, and explores the directions that this technology may lead over the next several years. Technical requirements for digital microscopic and gross imaging, and the available options for image archival and retrieval are summarized. The advantages of digital images over conventional photography in the conference room, and the usefulness of digital imaging in the frozen section suite and gross room, as an adjunct to surgical signout and as a resource for training and education, are discussed. An approach to the future construction of digital histologic sections and the computer as microscope is described. The digital technologic applications that are now available as components of the surgical pathologist's workstation are enumerated. These include laboratory information systems, computerized voice recognition, and on-line or CD-based literature searching, texts and atlases and, in some departments, on-line image databases. The authors suggest that, in addition to these resources that are already available, tomorrow's surgical pathology workstation will include network-linked digital histologic databases, on-line software for image analysis and 3-D image enhancement, expert systems, and ultimately, advanced pattern recognition capabilities. In conclusion, the authors submit that digital optical imaging is likely to have a significant and positive impact on the future development of anatomic pathology. PMID:8853053

  1. PC Assisted Anatomical Measurements in 3D Using CT Data

    DEFF Research Database (Denmark)

    Hvidtfeldt, Mogens; Pedersen, Steen

    1999-01-01

    To assess facilities and applications of a programme for a PC based CT measurements in 3D of anatomical angelse in the skeleton.......To assess facilities and applications of a programme for a PC based CT measurements in 3D of anatomical angelse in the skeleton....

  2. Spatial Language and Children’s Spatial Landmark Use

    Directory of Open Access Journals (Sweden)

    Amber A. Ankowski

    2012-01-01

    Full Text Available We examined how spatial language affected search behavior in a landmark spatial search task. In Experiment 1, two- to six-year-old children were trained to find a toy in the center of a square array of four identical landmarks. Children heard one of three spatial language cues once during the initial training trial (“here,” “in the middle,” “next to this one”. After search performance reached criterion, children received a probe test trial in which the landmark array was expanded. In Experiment 2, two- to four-year-old children participated in the search task and also completed a language comprehension task. Results revealed that children’s spatial language comprehension scores and spatial language cues heard during training trials were related to children’s performance in the search task.

  3. Validation of simple quantification methods for 18F FP CIT PET Using Automatic Delineation of volumes of interest based on statistical probabilistic anatomical mapping and isocontour margin setting

    International Nuclear Information System (INIS)

    18F FP CIT positron emission tomography (PET) is an effective imaging for dopamine transporters. In usual clinical practice, 18F FP CIT PET is analyzed visually or quantified using manual delineation of a volume of interest (VOI) fir the stratum. in this study, we suggested and validated two simple quantitative methods based on automatic VOI delineation using statistical probabilistic anatomical mapping (SPAM) and isocontour margin setting. Seventy five 18F FP CIT images acquired in routine clinical practice were used for this study. A study-specific image template was made and the subject images were normalized to the template. afterwards, uptakes in the striatal regions and cerebellum were quantified using probabilistic VOI based on SPAM. A quantitative parameter, QSPAM, was calculated to simulate binding potential. additionally, the functional volume of each striatal region and its uptake were measured in automatically delineated VOI using isocontour margin setting. Uptake volume product(QUVP) was calculated for each striatal region. QSPAMand QUVPwas calculated for each visual grading and the influence of cerebral atrophy on the measurements was tested. Image analyses were successful in all the cases. Both the QSPAMand QUVPwere significantly different according to visual grading (0.001). The agreements of QUVPand QSPAMwith visual grading were slight to fair for the caudate nucleus (K= 0.421 and 0.291, respectively) and good to prefect to the putamen (K=0.663 and 0.607, respectively). Also, QSPAMand QUVPhad a significant correlation with each other (0.001). Cerebral atrophy made a significant difference in QSPAMand QUVPof the caudate nuclei regions with decreased 18F FP CIT uptake. Simple quantitative measurements of QSPAMand QUVPshowed acceptable agreement with visual grad-ing. although QSPAMin some group may be influenced by cerebral atrophy, these simple methods are expected to be effective in the quantitative analysis of F FP CIT PET in usual clinical

  4. A Landmark-Free Method for Three-Dimensional Shape Analysis.

    Directory of Open Access Journals (Sweden)

    Benjamin J Pomidor

    Full Text Available The tools and techniques used in morphometrics have always aimed to transform the physical shape of an object into a concise set of numerical data for mathematical analysis. The advent of landmark-based morphometrics opened new avenues of research, but these methods are not without drawbacks. The time investment required of trained individuals to accurately landmark a data set is significant, and the reliance on readily-identifiable physical features can hamper research efforts. This is especially true of those investigating smooth or featureless surfaces.In this paper, we present a new method to perform this transformation for data obtained from high-resolution scanning technology. This method uses surface scans, instead of landmarks, to calculate a shape difference metric analogous to Procrustes distance and perform superimposition. This is accomplished by building upon and extending the Iterative Closest Point algorithm. We also explore some new ways this data can be used; for example, we can calculate an averaged surface directly and visualize point-wise shape information over this surface. Finally, we briefly demonstrate this method on a set of primate skulls and compare the results of the new methodology with traditional geometric morphometric analysis.

  5. Anatomically Plausible Surface Alignment and Reconstruction

    DEFF Research Database (Denmark)

    Paulsen, Rasmus R.; Larsen, Rasmus

    2010-01-01

    With the increasing clinical use of 3D surface scanners, there is a need for accurate and reliable algorithms that can produce anatomically plausible surfaces. In this paper, a combined method for surface alignment and reconstruction is proposed. It is based on an implicit surface representation...

  6. Delivering high-resolution landmarks using inkjet micropatterning for spatial monitoring of leaf expansion

    Directory of Open Access Journals (Sweden)

    Cronk Quentin CB

    2011-01-01

    Full Text Available Abstract Background Inkjet micropatterning is a versatile deposition technique with broad applications in numerous fields. However, its application in plant science is largely unexplored. Leaf expansion is one of the most important parameters in the field of plant science and many methods have been developed to examine differential expansion rates of different parts of the leaf lamina. Among them, methods based on the tracking of natural landmarks through digital imaging require a complicated setup in which the leaf must remain fixed and under tension. Furthermore, the resolution is limited to that of the natural landmarks, which are often difficult to find, particularly in young leaves. To study the fine scale expansion dynamics of the leaf lamina using artificial landmarks it is necessary to place small, noninvasive marks on a leaf surface and then recover the location of those marks after a period of time. Results To monitor leaf expansion in two dimensions, at very fine scales, we used a custom designed inkjet micropatterning system to print a grid composed of c. 0.19 mm2 cells on small developing leaves of ivy (Hedera helix using 40 μm dots at a spacing of c. 91 μm. The leaves in different growing stages were imaged under magnification to extract the coordinates of the marks which were then used in subsequent computer-assisted leaf expansion analyses. As an example we obtained quantified global and local expansion information and created expansion maps over the entire leaf surface. The results reveal a striking pattern of fine-scale expansion differences over short periods of time. In these experiments, the base of the leaf is a "cold spot" for expansion, while the leaf sinuses are "hot spots" for expansion. We have also measured a strong shading effect on leaf expansion. We discuss the features required to build an inkjet printing apparatus optimized for use in plant science, which will further maximize the range of tissues that can be

  7. The anatomical basis and prevention of neurogenic voiding dysfunction following radical hysterectomy.

    Science.gov (United States)

    Tong, X K; Huo, R J

    1991-01-01

    The disorder of neurogenic dysfunction is one of the most important complications of radical hysterectomy. In order to prevent this potential complication, the authors have studied the composition and layers of the pelvic paravisceral structures. The nerve branching and distribution of the pelvic plexus of 12 adult female cadavers were analyzed. From lateral to medial the pelvic paravisceral structure is made up of three layers. The lateral layer is the pelvic visceral fascia, the middle, a vascular layer, and the medial one, a nervous one which consists of the pelvic plexus and subsidiary plexuses. The pelvic plexus and subsidiary plexuses are laid closely to the lateral walls of pelvic organs. The ischial spine was taken as the central point and two perpendicular lines penetrating through the ischial spine were used as the longitudinal axis and transverse axis. According to these landmarks, the pelvic plexus could be divided into three parts: behind the longitudinal axis are the roots of the pelvic plexus, near the longitudinal axis is the uterovaginal plexus, and in front of the longitudinal axis are the branches distributed to bladder and urethra. The pelvic plexus and the uterosacral and cardinal ligaments are closely related. The pelvic and subsidiary plexuses can be damaged in radical hysterectomy and voiding dysfunction may then develop. Some anatomic bases are provided to explain and hopefully prevent this from happening. PMID:1925917

  8. Standardized anatomic space for abdominal fat quantification

    Science.gov (United States)

    Tong, Yubing; Udupa, Jayaram K.; Torigian, Drew A.

    2014-03-01

    The ability to accurately measure subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) from images is important for improved assessment and management of patients with various conditions such as obesity, diabetes mellitus, obstructive sleep apnea, cardiovascular disease, kidney disease, and degenerative disease. Although imaging and analysis methods to measure the volume of these tissue components have been developed [1, 2], in clinical practice, an estimate of the amount of fat is obtained from just one transverse abdominal CT slice typically acquired at the level of the L4-L5 vertebrae for various reasons including decreased radiation exposure and cost [3-5]. It is generally assumed that such an estimate reliably depicts the burden of fat in the body. This paper sets out to answer two questions related to this issue which have not been addressed in the literature. How does one ensure that the slices used for correlation calculation from different subjects are at the same anatomic location? At what anatomic location do the volumes of SAT and VAT correlate maximally with the corresponding single-slice area measures? To answer these questions, we propose two approaches for slice localization: linear mapping and non-linear mapping which is a novel learning based strategy for mapping slice locations to a standardized anatomic space so that same anatomic slice locations are identified in different subjects. We then study the volume-to-area correlations and determine where they become maximal. We demonstrate on 50 abdominal CT data sets that this mapping achieves significantly improved consistency of anatomic localization compared to current practice. Our results also indicate that maximum correlations are achieved at different anatomic locations for SAT and VAT which are both different from the L4-L5 junction commonly utilized.

  9. An Adaptive Algorithm for Finding Frequent Sets in Landmark Windows

    DEFF Research Database (Denmark)

    Dang, Xuan-Hong; Ong, Kok-Leong; Lee, Vincent

    2012-01-01

    We consider a CPU constrained environment for finding approximation of frequent sets in data streams using the landmark window. Our algorithm can detect overload situations, i.e., breaching the CPU capacity, and sheds data in the stream to “keep up”. This is done within a controlled error threshold...

  10. Audiovisual navigation in virtual mazes : The benefits of audiovisual landmarks

    NARCIS (Netherlands)

    Werkhoven, Peter; Philippi, Tom; van Erp, J.B.F.

    2014-01-01

    It has been shown that multisensory presentation can improve perception, attention, and object memory compared with unisensory presentation. Consequently, we expect that multisensory presentation of landmarks can improve spatial memory and navigation. In this study we tested the effect of visual, au

  11. Navigating virtual mazes : The benefits of audiovisual landmarks

    NARCIS (Netherlands)

    Werkhoven, P.; Erp, J.B.F. van; Philippi, T.G.

    2014-01-01

    It has been shown that multisensory presentation can improve perception, attention, and object memory compared with unisensory presentation. Consequently, we expect that multisensory presentation of landmarks can improve spatial memory and navigation. In this study we tested the effect of visual, au

  12. 36 CFR 62.8 - Natural landmark designation removal.

    Science.gov (United States)

    2010-07-01

    ... the site did not meet the criteria for national significance at the time of designation; (ii) When the... whether the NPS considers the documentation sufficient to consider removal of the natural landmark... submits a recommendation for removal to the National Park System Advisory Board. The Advisory...

  13. Improving anatomical mapping of complexly deformed anatomy for external beam radiotherapy and brachytherapy dose accumulation in cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Vásquez Osorio, Eliana M., E-mail: e.vasquezosorio@erasmusmc.nl; Kolkman-Deurloo, Inger-Karine K.; Schuring-Pereira, Monica; Zolnay, András; Heijmen, Ben J. M.; Hoogeman, Mischa S. [Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam 3075 (Netherlands)

    2015-01-15

    Purpose: In the treatment of cervical cancer, large anatomical deformations, caused by, e.g., tumor shrinkage, bladder and rectum filling changes, organ sliding, and the presence of the brachytherapy (BT) applicator, prohibit the accumulation of external beam radiotherapy (EBRT) and BT dose distributions. This work proposes a structure-wise registration with vector field integration (SW+VF) to map the largely deformed anatomies between EBRT and BT, paving the way for 3D dose accumulation between EBRT and BT. Methods: T2w-MRIs acquired before EBRT and as a part of the MRI-guided BT procedure for 12 cervical cancer patients, along with the manual delineations of the bladder, cervix-uterus, and rectum-sigmoid, were used for this study. A rigid transformation was used to align the bony anatomy in the MRIs. The proposed SW+VF method starts by automatically segmenting features in the area surrounding the delineated organs. Then, each organ and feature pair is registered independently using a feature-based nonrigid registration algorithm developed in-house. Additionally, a background transformation is calculated to account for areas far from all organs and features. In order to obtain one transformation that can be used for dose accumulation, the organ-based, feature-based, and the background transformations are combined into one vector field using a weighted sum, where the contribution of each transformation can be directly controlled by its extent of influence (scope size). The optimal scope sizes for organ-based and feature-based transformations were found by an exhaustive analysis. The anatomical correctness of the mapping was independently validated by measuring the residual distances after transformation for delineated structures inside the cervix-uterus (inner anatomical correctness), and for anatomical landmarks outside the organs in the surrounding region (outer anatomical correctness). The results of the proposed method were compared with the results of the

  14. Improving anatomical mapping of complexly deformed anatomy for external beam radiotherapy and brachytherapy dose accumulation in cervical cancer

    International Nuclear Information System (INIS)

    Purpose: In the treatment of cervical cancer, large anatomical deformations, caused by, e.g., tumor shrinkage, bladder and rectum filling changes, organ sliding, and the presence of the brachytherapy (BT) applicator, prohibit the accumulation of external beam radiotherapy (EBRT) and BT dose distributions. This work proposes a structure-wise registration with vector field integration (SW+VF) to map the largely deformed anatomies between EBRT and BT, paving the way for 3D dose accumulation between EBRT and BT. Methods: T2w-MRIs acquired before EBRT and as a part of the MRI-guided BT procedure for 12 cervical cancer patients, along with the manual delineations of the bladder, cervix-uterus, and rectum-sigmoid, were used for this study. A rigid transformation was used to align the bony anatomy in the MRIs. The proposed SW+VF method starts by automatically segmenting features in the area surrounding the delineated organs. Then, each organ and feature pair is registered independently using a feature-based nonrigid registration algorithm developed in-house. Additionally, a background transformation is calculated to account for areas far from all organs and features. In order to obtain one transformation that can be used for dose accumulation, the organ-based, feature-based, and the background transformations are combined into one vector field using a weighted sum, where the contribution of each transformation can be directly controlled by its extent of influence (scope size). The optimal scope sizes for organ-based and feature-based transformations were found by an exhaustive analysis. The anatomical correctness of the mapping was independently validated by measuring the residual distances after transformation for delineated structures inside the cervix-uterus (inner anatomical correctness), and for anatomical landmarks outside the organs in the surrounding region (outer anatomical correctness). The results of the proposed method were compared with the results of the

  15. Virtual skeletal complex model- and landmark-guided orthognathic surgery system.

    Science.gov (United States)

    Lee, Sang-Jeong; Woo, Sang-Yoon; Huh, Kyung-Hoe; Lee, Sam-Sun; Heo, Min-Suk; Choi, Soon-Chul; Han, Jeong Joon; Yang, Hoon Joo; Hwang, Soon Jung; Yi, Won-Jin

    2016-05-01

    In this study, correction of the maxillofacial deformities was performed by repositioning bone segments to an appropriate location according to the preoperative planning in orthognathic surgery. The surgery was planned using the patient's virtual skeletal models fused with optically scanned three-dimensional dentition. The virtual maxillomandibular complex (MMC) model of the patient's final occlusal relationship was generated by fusion of the maxillary and mandibular models with scanned occlusion. The final position of the MMC was simulated preoperatively by planning and was used as a goal model for guidance. During surgery, the intraoperative registration was finished immediately using only software processing. For accurate repositioning, the intraoperative MMC model was visualized on the monitor with respect to the simulated MMC model, and the intraoperative positions of multiple landmarks were also visualized on the MMC surface model. The deviation errors between the intraoperative and the final positions of each landmark were visualized quantitatively. As a result, the surgeon could easily recognize the three-dimensional deviation of the intraoperative MMC state from the final goal model without manually applying a pointing tool, and could also quickly determine the amount and direction of further MMC movements needed to reach the goal position. The surgeon could also perform various osteotomies and remove bone interference conveniently, as the maxillary tracking tool could be separated from the MMC. The root mean square (RMS) difference between the preoperative planning and the intraoperative guidance was 1.16 ± 0.34 mm immediately after repositioning. After surgery, the RMS differences between the planning and the postoperative computed tomographic model were 1.31 ± 0.28 mm and 1.74 ± 0.73 mm for the maxillary and mandibular landmarks, respectively. Our method provides accurate and flexible guidance for bimaxillary orthognathic surgery based on

  16. A New 2D Corner Detector for Extracting Landmarks from Brain MR Images

    OpenAIRE

    Mohammadi, Gelareh; Fatemizadeh, Emad

    2007-01-01

    Point-based registration of images strongly depends on the extraction of suitable landmarks. Recently, various 2D operators have been proposed for the detection of corner points but most of them are not effective for medical images that need a high accuracy. In this paper we have proposed a new automatic corner detector based on the covariance between the small region of support around a central pixel and its rotated one. The main goal of this paper is medical images so we especially focus on...

  17. Audible Signage as a Wayfinding Aid: Verbal Landmark versus Talking Signs.

    Science.gov (United States)

    Bentzen, B. L.; Mitchell, P. A.

    1995-01-01

    Comparison by 40 users of 2 technologies--Verbal Landmark and Talking Signs--that provide speech messages to hand-held receivers for blind travelers found that, on all measures, the Talking Signs system proved superior to the Verbal Landmark system. This was attributed to Verbal Landmark's more cognitively demanding technology. (DB)

  18. Cephalometric landmark variability among orthodontists and dentomaxillofacial radiologists: a comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Durao, Ana Paula Reis; Ferreira, Afonso P. [Dept.of Faculty of Dental Medicine, University of Porto, Porto (Portugal); Morosolli, Aline [Dept.of Surgery, Dentistry School, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul (Brazil); Pittayapat, Pisha [Dept.of Radiology, Faculty of Dentistry, Chulalongkorn University, Bangkok (Thailand); Bolstad, Napat [Dept.of Clinical Dentistry, Faculty of Health Science, UiT The Arctic University of Norway, Tromso (Norway); Jacobs, Reinhilde [Dept.of Oral Imaging Center, OMFS-IMPATH Research Group, Dept. of Imaging and Pathology, Faculty of Medicine, University of Leuven, Leuven (Belgium)

    2015-12-15

    The aim this study was to compare the accuracy of orthodontists and dentomaxillofacial radiologists in identifying 17 commonly used cephalometric landmarks, and to determine the extent of variability associated with each of those landmarks. Twenty digital lateral cephalometric radiographs were evaluated by two groups of dental specialists, and 17 cephalometric landmarks were identified. The x and y coordinates of each landmark were recorded. The mean value for each landmark was considered the best estimate and used as the standard. Variation in measurements of the distance between landmarks and measurements of the angles associated with certain landmarks was also assessed by a subset of two observers, and intraobserver and interobserver agreement were evaluated. Intraclass correlation coefficients were excellent for intraobserver agreement, but only good for interobserver agreement. The least reliable landmark for orthodontists was the gnathion (Gn) point (standard deviation [SD], 5.92 mm), while the orbitale (Or) was the least reliable landmark (SD, 4.41 mm) for dentomaxillofacial radiologists. Furthermore, the condylion (Co)-Gn plane was the least consistent (SD, 4.43 mm). We established that some landmarks were not as reproducible as others, both horizontally and vertically. The most consistently identified landmark in both groups was the lower incisor border, while the least reliable points were Co, Gn, Or, and the anterior nasal spine. Overall, a lower level of reproducibility in the identification of cephalometric landmarks was observed among orthodontists.

  19. 78 FR 13377 - Landmarks Committee of the National Park System Advisory Board Meeting

    Science.gov (United States)

    2013-02-27

    ... National Park Service Landmarks Committee of the National Park System Advisory Board Meeting AGENCY... INFORMATION: The purpose of the meeting of the Landmarks Committee of the National Park System Advisory Board... Historic Landmarks to the National Park System Advisory Board at a subsequent meeting at a place and...

  20. Towards anatomic scale agent-based modeling with a massively parallel spatially explicit general-purpose model of enteric tissue (SEGMEnT_HPC.

    Directory of Open Access Journals (Sweden)

    Robert Chase Cockrell

    Full Text Available Perhaps the greatest challenge currently facing the biomedical research community is the ability to integrate highly detailed cellular and molecular mechanisms to represent clinical disease states as a pathway to engineer effective therapeutics. This is particularly evident in the representation of organ-level pathophysiology in terms of abnormal tissue structure, which, through histology, remains a mainstay in disease diagnosis and staging. As such, being able to generate anatomic scale simulations is a highly desirable goal. While computational limitations have previously constrained the size and scope of multi-scale computational models, advances in the capacity and availability of high-performance computing (HPC resources have greatly expanded the ability of computational models of biological systems to achieve anatomic, clinically relevant scale. Diseases of the intestinal tract are exemplary examples of pathophysiological processes that manifest at multiple scales of spatial resolution, with structural abnormalities present at the microscopic, macroscopic and organ-levels. In this paper, we describe a novel, massively parallel computational model of the gut, the Spatially Explicitly General-purpose Model of Enteric Tissue_HPC (SEGMEnT_HPC, which extends an existing model of the gut epithelium, SEGMEnT, in order to create cell-for-cell anatomic scale simulations. We present an example implementation of SEGMEnT_HPC that simulates the pathogenesis of ileal pouchitis, and important clinical entity that affects patients following remedial surgery for ulcerative colitis.

  1. MR neurography with multiplanar reconstruction of 3D MRI datasets: an anatomical study and clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Freund, Wolfgang; Aschoff, Andrik J.; Stuber, Gregor; Schmitz, Bernd [University Hospitals Ulm, Clinic for Diagnostic and Interventional Radiology, Ulm (Germany); Brinkmann, Alexander; Wagner, Florian; Dinse, Alexander [University Hospitals Ulm, Department of Anesthesiology, Ulm (Germany)

    2007-04-15

    Extracranial MR neurography has so far mainly been used with 2D datasets. We investigated the use of 3D datasets for peripheral neurography of the sciatic nerve. A total of 40 thighs (20 healthy volunteers) were examined with a coronally oriented magnetization-prepared rapid acquisition gradient echo sequence with isotropic voxels of 1 x 1 x 1 mm and a field of view of 500 mm. Anatomical landmarks were palpated and marked with MRI markers. After MR scanning, the sciatic nerve was identified by two readers independently in the resulting 3D dataset. In every volunteer, the sciatic nerve could be identified bilaterally over the whole length of the thigh, even in areas of close contact to isointense muscles. The landmark of the greater trochanter was falsely palpated by 2.2 cm, and the knee joint by 1 cm. The mean distance between the bifurcation of the sciatic nerve and the knee-joint gap was 6 cm ({+-}1.8 cm). The mean results of the two readers differed by 1-6%. With the described method of MR neurography, the sciatic nerve was depicted reliably and objectively in great anatomical detail over the whole length of the thigh. Important anatomical information can be obtained. The clinical applications of MR neurography for the brachial plexus and lumbosacral plexus/sciatic nerve are discussed. (orig.)

  2. Registration now open for landmark CERN conference

    CERN Multimedia

    2003-01-01

    Journalist registration is now available for the Role of Science in the Information Society (RSIS) conference, to be held at CERN on 8-9 December....RSIS will explore future contributions of science to the information society based on past and present practice (1 page).

  3. Landmark Image Retrieval Using Visual Synonyms

    NARCIS (Netherlands)

    E. Gavves; C.G.M. Snoek

    2010-01-01

    In this paper, we consider the incoherence problem of the visual words in bag-of-words vocabularies. Different from existing work, which performs assignment of words based solely on closeness in descriptor space, we focus on identifying pairs of independent, distant words - the visual synonyms - tha

  4. A Stochastic Approach to Diffeomorphic Point Set Registration with Landmark Constraints.

    Science.gov (United States)

    Kolesov, Ivan; Lee, Jehoon; Sharp, Gregory; Vela, Patricio; Tannenbaum, Allen

    2016-02-01

    This work presents a deformable point set registration algorithm that seeks an optimal set of radial basis functions to describe the registration. A novel, global optimization approach is introduced composed of simulated annealing with a particle filter based generator function to perform the registration. It is shown how constraints can be incorporated into this framework. A constraint on the deformation is enforced whose role is to ensure physically meaningful fields (i.e., invertible). Further, examples in which landmark constraints serve to guide the registration are shown. Results on 2D and 3D data demonstrate the algorithm's robustness to noise and missing information. PMID:26761731

  5. Undecidability and temporal logic: some landmarks from Turing to the present

    DEFF Research Database (Denmark)

    Goranko, Valentin

    2012-01-01

    This is a selective survey and discussion of some of the landmark undecidability results in temporal logic, beginning with Turing's undecidability of the Halting problem which, in retrospect, can be regarded as the historically first undecidability result for a suitable temporal logic over...... configuration graphs of Turing machines. I will discuss some of the natural habitats of undecidable temporal logics, such as first-order, interval-based and real time temporal logics, as well as some extensions that often lead to undecidability, such as two-dimensional temporal logics and temporal...

  6. ANATOMICAL PROPERTIES OF PLANTAGO ARENARIA

    OpenAIRE

    Nicoleta IANOVICI; SINITEAN, Adrian; Aurel FAUR

    2011-01-01

    Psammophytes are marked by a number of adaptations that enable them to exist in the hard environmental conditions of the sand habitats. In this study, the anatomical characteristics of Plantago arenaria were examined. Studies were conducted to assess the diversity of anatomical adaptations of vegetative organs in this taxa. Results are presented with original photographs. The analysis of leaf anatomy in P. arenaria showed that the leaves contained a contained xeromorphic traits. Arbuscular my...

  7. Visual EKF-SLAM from Heterogeneous Landmarks

    OpenAIRE

    Jorge Othón Esparza-Jiménez; Michel Devy; Gordillo, José L.

    2016-01-01

    Many applications require the localization of a moving object, e.g., a robot, using sensory data acquired from embedded devices. Simultaneous localization and mapping from vision performs both the spatial and temporal fusion of these data on a map when a camera moves in an unknown environment. Such a SLAM process executes two interleaved functions: the front-end detects and tracks features from images, while the back-end interprets features as landmark observations and estimates both the land...

  8. The influence of off-screen landmarks on user orientation

    OpenAIRE

    Korda, Amichai

    2014-01-01

    Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies. Maps displayed on hand held devices, such as smartphones; provide limited visibility due to their small screen display. In order to overcome display limitations, researchers have developed new techniques that point users to objects and landmarks located off-screen, which is known as an “off-screen interface”. Since this is a new type of map interface, there is l...

  9. Visual landmarks facilitate rodent spatial navigation in virtual reality environments

    OpenAIRE

    Youngstrom, Isaac A.; Strowbridge, Ben W.

    2012-01-01

    Because many different sensory modalities contribute to spatial learning in rodents, it has been difficult to determine whether spatial navigation can be guided solely by visual cues. Rodents moving within physical environments with visual cues engage a variety of nonvisual sensory systems that cannot be easily inhibited without lesioning brain areas. Virtual reality offers a unique approach to ask whether visual landmark cues alone are sufficient to improve performance in a spatial task. We ...

  10. Insite: Canada's landmark safe injecting program at risk

    OpenAIRE

    Drucker Ernest

    2006-01-01

    Abstract InSite is North Americas first supervised injection site and a landmark public heath initiative operating in Vancouver since 2003. The program is a vital component of that cities internationally recognized harm reduction approach to its serious problems with drugs, crime, homelessness and AIDS. InSite currently operates under a waiver of Federal rules that allow it to provide services as a research project. An extensive evaluation has produced very positive results for thousands of u...

  11. AUTOMATIC DETECTION AND CLASSIFICATION OF RETINAL VASCULAR LANDMARKS

    Directory of Open Access Journals (Sweden)

    Hadi Hamad

    2014-06-01

    Full Text Available The main contribution of this paper is introducing a method to distinguish between different landmarks of the retina: bifurcations and crossings. The methodology may help in differentiating between arteries and veins and is useful in identifying diseases and other special pathologies, too. The method does not need any special skills, thus it can be assimilated to an automatic way for pinpointing landmarks; moreover it gives good responses for very small vessels. A skeletonized representation, taken out from the segmented binary image (obtained through a preprocessing step, is used to identify pixels with three or more neighbors. Then, the junction points are classified into bifurcations or crossovers depending on their geometrical and topological properties such as width, direction and connectivity of the surrounding segments. The proposed approach is applied to the public-domain DRIVE and STARE datasets and compared with the state-of-the-art methods using proper validation parameters. The method was successful in identifying the majority of the landmarks; the average correctly identified bifurcations in both DRIVE and STARE datasets for the recall and precision values are: 95.4% and 87.1% respectively; also for the crossovers, the recall and precision values are: 87.6% and 90.5% respectively; thus outperforming other studies.

  12. Integrating anatomical pathology to the healthcare enterprise.

    Science.gov (United States)

    Daniel-Le Bozec, Christel; Henin, Dominique; Fabiani, Bettina; Bourquard, Karima; Ouagne, David; Degoulet, Patrice; Jaulent, Marie-Christine

    2006-01-01

    For medical decisions, healthcare professionals need that all required information is both correct and easily available. We address the issue of integrating anatomical pathology department to the healthcare enterprise. The pathology workflow from order to report, including specimen process and image acquisition was modeled. Corresponding integration profiles were addressed by expansion of the IHE (Integrating the Healthcare Enterprise) initiative. Implementation using respectively DICOM Structured Report (SR) and DICOM Slide-Coordinate Microscopy (SM) was tested. The two main integration profiles--pathology general workflow and pathology image workflow--rely on 13 transactions based on HL7 or DICOM standard. We propose a model of the case in anatomical pathology and of other information entities (orders, image folders and reports) and real-world objects (specimen, tissue samples, slides, etc). Cases representation in XML schemas, based on DICOM specification, allows producing DICOM image files and reports to be stored into a PACS (Picture Archiving and Communication System. PMID:17108550

  13. Review of the Historical Evolution of Anatomical Terms

    Directory of Open Access Journals (Sweden)

    Algieri, Rubén D.

    2011-12-01

    Full Text Available Most of the medical terms of Greek origin are traditionally attributed to Hippocrates (460-370 BC. Claudius Galen of Pergamum (130-200 BC developed a classification of bones and joints and described different brain areas. His teachings have remained unchanged for over a thousand years. Andreas Vesalius of Brussels (1514-1564, through the systematic study of human body structure, changed many concepts. He published his work in his production "De humani corporis fabrica libri septem", where a special attention is evident to the discovery and description of new anatomical facts. From here there is a revolution in the morphological sciences, where the same anatomical structure passed to receive different names. In the nineteenth century, the different anatomists in the world decide to meet in order to unify criteria regarding the anatomical structures and determine a only one universal language in the anatomical sciences. In 1895, in Basel (Switzerland it’s approved a list of 5.573 terms, called Basle Nomina Anatomica (BNA and was written in Latin. Eponyms were deleted. In 1903, he founded the International Federation of Associations of anatomists (IFAA. In 1935, in Jena (Germany, approving the Jena Nomina Anatomica (JNA. In 1950, in Oxford, formed the Committee of the International Anatomical Nomenclature (IANC. In 1955, in Paris (France it is agreed to adopt a Latin nomenclature based on the BNA, the Paris Nomina Anatomica (PNA. In 1980, for the first time in Latin America, takes place on the 11th International Congress of Anatomists, Mexico. In 1989, the International Committee of Anatomical Nomenclature, published the sixth edition of the Nomina Anatomica, without review by the IFAA. The same year, the latter established a Federative International Committee of Anatomical Terminology (FICAT. In 1998, he published a new list FICAT: International Anatomical Terminology (TAI, with the structures named in Latin language and their equivalence in

  14. Digital 3D anatomical modeling of the mandible with full teeth%数字化全牙列下颌骨三维解剖建模

    Institute of Scientific and Technical Information of China (English)

    朱赴东; 石珏; 宋恩; 葛巍立; 廖胜辉

    2014-01-01

    Objective To study and establish a high quality digital 3D anatomical modeling of the mandible with full teeth.Methods A set of accurate digital models of standard anatomical specimens of mandibular teeth were obtained by laser scanning, and the 3D mandible model was reconstructed by CT scan data;then, a registration deformation method based on the geometry and image anatomical landmark was employed to do the registration of each tooth to the mandible model, and finally the tooth enamel , dentin, periodontal ligament were generated .Results A high quality digital 3D anatomical modeling of the mandible with full teeth was built , each tooth had detail crown and whole root , the distinction between the enamel , dentin, periodontal ligament , and any anatomical regions can be zoomed and rotately displayed . Conclusion The digital 3D anatomical modeling of the mandible with full teeth has realistic 3D imaging view and convenient teaching-learning function , and has tremendous apllication futures in the stomatology , maxillofacial and other medical departments .%目的:探讨建立具有高质量牙列的下颌骨三维数字化解剖模型。方法用激光扫描获取1套标准下颌牙列解剖标本的精确三维模型,用CT扫描数据重建下颌骨三维模型,使用基于几何和图像解剖标志的配准变形方法将每颗牙齿模型对齐融合到下颌骨模型,进一步生成牙齿的牙釉质、牙本质、牙周膜。结果成功建立了具有高质量牙列的下颌骨三维数字化解剖模型,每颗牙齿具有牙冠细节和完整的牙根,区分牙釉质、牙本质、牙周膜,可以对任意解剖区域放大和旋转观察,显示解剖标志。结论高质量牙列的下颌骨三维数字化解剖模型具有逼真的三维显象和方便的教学学习功能,可用于口腔、颌面、解剖等多个学科。

  15. 基于地标点几何形态测量法识别北部湾4种白姑鱼矢耳石形态%Using landmark-based geometric morphometrics analysis to identify sagittal otolith of four Pennahia fish species

    Institute of Scientific and Technical Information of China (English)

    侯刚; 刘丹丹; 冯波; 卢伙胜

    2013-01-01

    We investigated the identification in sagittal otoliths using landmark-based geometric morphometrics method among four sympatric species of the genus Pennahia: truncatetail white croaker P.anea (n=49), bighead white croaker P.macrocephalus (n=50), pawak croaker P. pawak (n=49) and white croaker P.argentata (n=29).The specimens were collected off Beibu Gulf from April 2010 to October 2010. Landmark coordinate values were extracted after otolith digitized by image processing and processed by relative warp principal component (RW), thin plate spline analysis and grad distortion. The 12 RW were then identified using discrimination analysis to differentiate the otoliths of four Pennahia species. The result indicated that, the 1st, 2nd and 3rd RW accounted for 46.57%, 25.39% and 10.02% of the total variation respectively, of which TypeⅠlandmarks 6 and 7, TypeⅡlandmarks 5 and 8 had important contributions, and could explain the most variation. The most morphological variation were displayed in neck, head width pole, and tail of tadpole-shaped sulcus. The gradual discrimination analysis and cross validation indicated that P.anea, P.macrocephalus and P. pawak got average exactitude distinguish ratios of 81.6%~100%, while P.argentata 58.6%, indicating that it contained a potential risk by using the morphology of tadpole-shaped impression owned by Sciaenidae to discriminate the four congeneric Pennahia species. It is necessary to notice this problem in the related otolith morphology research and application in feeding ecology.%利用2010年4月至2010年10月采自北部湾海域的49尾截尾白姑鱼(Pennahia anea)、50尾大头白姑鱼(P. macrocephalus)、49尾斑鳍白姑鱼(P. pawak )和29尾白姑鱼(P.argentata)矢耳石样本,运用基于地标点法的几何形态测量学方法研究了4种鱼类矢耳石形态识别问题。耳石经图像处理后提取地标点坐标值,进行相对扭曲主成分分析,通过判别分析来区分4种白姑鱼的耳石,

  16. Fusion of WiFi, smartphone sensors and landmarks using the Kalman filter for indoor localization.

    Science.gov (United States)

    Chen, Zhenghua; Zou, Han; Jiang, Hao; Zhu, Qingchang; Soh, Yeng Chai; Xie, Lihua

    2015-01-01

    Location-based services (LBS) have attracted a great deal of attention recently. Outdoor localization can be solved by the GPS technique, but how to accurately and efficiently localize pedestrians in indoor environments is still a challenging problem. Recent techniques based on WiFi or pedestrian dead reckoning (PDR) have several limiting problems, such as the variation of WiFi signals and the drift of PDR. An auxiliary tool for indoor localization is landmarks, which can be easily identified based on specific sensor patterns in the environment, and this will be exploited in our proposed approach. In this work, we propose a sensor fusion framework for combining WiFi, PDR and landmarks. Since the whole system is running on a smartphone, which is resource limited, we formulate the sensor fusion problem in a linear perspective, then a Kalman filter is applied instead of a particle filter, which is widely used in the literature. Furthermore, novel techniques to enhance the accuracy of individual approaches are adopted. In the experiments, an Android app is developed for real-time indoor localization and navigation. A comparison has been made between our proposed approach and individual approaches. The results show significant improvement using our proposed framework. Our proposed system can provide an average localization accuracy of 1 m. PMID:25569750

  17. Continuous Indoor Positioning Fusing WiFi, Smartphone Sensors and Landmarks.

    Science.gov (United States)

    Deng, Zhi-An; Wang, Guofeng; Qin, Danyang; Na, Zhenyu; Cui, Yang; Chen, Juan

    2016-01-01

    To exploit the complementary strengths of WiFi positioning, pedestrian dead reckoning (PDR), and landmarks, we propose a novel fusion approach based on an extended Kalman filter (EKF). For WiFi positioning, unlike previous fusion approaches setting measurement noise parameters empirically, we deploy a kernel density estimation-based model to adaptively measure the related measurement noise statistics. Furthermore, a trusted area of WiFi positioning defined by fusion results of previous step and WiFi signal outlier detection are exploited to reduce computational cost and improve WiFi positioning accuracy. For PDR, we integrate a gyroscope, an accelerometer, and a magnetometer to determine the user heading based on another EKF model. To reduce accumulation error of PDR and enable continuous indoor positioning, not only the positioning results but also the heading estimations are recalibrated by indoor landmarks. Experimental results in a realistic indoor environment show that the proposed fusion approach achieves substantial positioning accuracy improvement than individual positioning approaches including PDR and WiFi positioning. PMID:27608019

  18. Continuous Indoor Positioning Fusing WiFi, Smartphone Sensors and Landmarks

    Directory of Open Access Journals (Sweden)

    Zhi-An Deng

    2016-09-01

    Full Text Available To exploit the complementary strengths of WiFi positioning, pedestrian dead reckoning (PDR, and landmarks, we propose a novel fusion approach based on an extended Kalman filter (EKF. For WiFi positioning, unlike previous fusion approaches setting measurement noise parameters empirically, we deploy a kernel density estimation-based model to adaptively measure the related measurement noise statistics. Furthermore, a trusted area of WiFi positioning defined by fusion results of previous step and WiFi signal outlier detection are exploited to reduce computational cost and improve WiFi positioning accuracy. For PDR, we integrate a gyroscope, an accelerometer, and a magnetometer to determine the user heading based on another EKF model. To reduce accumulation error of PDR and enable continuous indoor positioning, not only the positioning results but also the heading estimations are recalibrated by indoor landmarks. Experimental results in a realistic indoor environment show that the proposed fusion approach achieves substantial positioning accuracy improvement than individual positioning approaches including PDR and WiFi positioning.

  19. Continuous Indoor Positioning Fusing WiFi, Smartphone Sensors and Landmarks

    Science.gov (United States)

    Deng, Zhi-An; Wang, Guofeng; Qin, Danyang; Na, Zhenyu; Cui, Yang; Chen, Juan

    2016-01-01

    To exploit the complementary strengths of WiFi positioning, pedestrian dead reckoning (PDR), and landmarks, we propose a novel fusion approach based on an extended Kalman filter (EKF). For WiFi positioning, unlike previous fusion approaches setting measurement noise parameters empirically, we deploy a kernel density estimation-based model to adaptively measure the related measurement noise statistics. Furthermore, a trusted area of WiFi positioning defined by fusion results of previous step and WiFi signal outlier detection are exploited to reduce computational cost and improve WiFi positioning accuracy. For PDR, we integrate a gyroscope, an accelerometer, and a magnetometer to determine the user heading based on another EKF model. To reduce accumulation error of PDR and enable continuous indoor positioning, not only the positioning results but also the heading estimations are recalibrated by indoor landmarks. Experimental results in a realistic indoor environment show that the proposed fusion approach achieves substantial positioning accuracy improvement than individual positioning approaches including PDR and WiFi positioning. PMID:27608019

  20. Fusion of WiFi, Smartphone Sensors and Landmarks Using the Kalman Filter for Indoor Localization

    Directory of Open Access Journals (Sweden)

    Zhenghua Chen

    2015-01-01

    Full Text Available Location-based services (LBS have attracted a great deal of attention recently. Outdoor localization can be solved by the GPS technique, but how to accurately and efficiently localize pedestrians in indoor environments is still a challenging problem. Recent techniques based on WiFi or pedestrian dead reckoning (PDR have several limiting problems, such as the variation of WiFi signals and the drift of PDR. An auxiliary tool for indoor localization is landmarks, which can be easily identified based on specific sensor patterns in the environment, and this will be exploited in our proposed approach. In this work, we propose a sensor fusion framework for combining WiFi, PDR and landmarks. Since the whole system is running on a smartphone, which is resource limited, we formulate the sensor fusion problem in a linear perspective, then a Kalman filter is applied instead of a particle filter, which is widely used in the literature. Furthermore, novel techniques to enhance the accuracy of individual approaches are adopted. In the experiments, an Android app is developed for real-time indoor localization and navigation. A comparison has been made between our proposed approach and individual approaches. The results show significant improvement using our proposed framework. Our proposed system can provide an average localization accuracy of 1 m.

  1. Femoroacetabular impingement and the cam-effect. A MRI-based quantitative anatomical study of the femoral head-neck offset.

    Science.gov (United States)

    Ito, K; Minka, M A; Leunig, M; Werlen, S; Ganz, R

    2001-03-01

    We have observed damage to the labrum as a result of repetitive acetabular impingement in non-dysplastic hips, in which the femoral neck appears to abut against the acetabular labrum and a non-spherical femoral head to press against the labrum and adjacent cartilage. In both mechanisms anatomical variations of the proximal femur may be a factor. We have measured the orientation of the femoral neck and the offset of the head at various circumferential positions, using MRI data from volunteers with no osteoarthritic changes on standard radiographs. Compared with the control subjects, paired for gender and age, patients showed a significant reduction in mean femoral anteversion and mean head-neck offset on the anterior aspect of the neck. This was consistent with the site of symptomatic impingement in flexion and internal rotation, and with lesions of the adjacent rim. Furthermore, when stratified for gender and age, and compared with the control group, the mean femoral head-neck offset was significantly reduced in the lateral-to-anterior aspect of the neck for young men, and in the anterolateral-to-anterior aspect of the neck for older women. For patients suspected of having impingement of the rim, anatomical variations in the proximal femur should be considered as a possible cause.

  2. Hoffa's fat pad injuries and their relationship with anterior cruciate ligament tears: new observations based on MR imaging in patients and MR imaging and anatomic correlation in cadavers

    International Nuclear Information System (INIS)

    To determine the normal anatomic relationships of Hoffa's fat pad with the anterior cruciate ligament (ACL) and with the frequency of Hoffa's fat pad abnormalities in ACL-deficient knees. Retrospective clinical study on patients and observational anatomic study on cadavers. The study was approved by the Institutional Review Board. MR imaging studies of the knees of 100 patients (21-48 years old) with or without arthroscopically proven tears of the ACL, performed at a single institution, were reviewed by two readers for abnormalities of Hoffa's fat pad. Ten cadaveric knee specimens were studied with MR imaging and Faxitron radiographs, and by inspection of sections and histology. Alterations in Hoffa's fat pad on MR imaging were present in 64% (32/50) of patients with torn ACLs, and in 24% (12/50) of patients without a tear of the ACL (P < 0.05). Hoffa's fat pad inserted into the intercondylar notch in 50% (5/10) of cadaveric specimens, four in conjunction with the ligamentum mucosum and in one in an isolated fashion. Histological study demonstrated the composition of the ligamentum mucosum and Hoffa's fat pad and their course and insertion sites in the intercondylar notch. Abnormalities of Hoffa's fat pad, such as focal and diffuse edema, tears, scars and synovial proliferation, are more common in knees with torn ACLs than in knees with intact ACLs. (orig.)

  3. Probabilistic anatomical labeling of brain structures using statistical probabilistic anatomical maps

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Su; Lee, Dong Soo; Lee, Byung Il; Lee, Jae Sung; Shin, Hee Won; Chung, June Key; Lee, Myung Chul [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2002-12-01

    The use of statistical parametric mapping (SPM) program has increased for the analysis of brain PET and SPECT images. Montreal neurological institute (MNI) coordinate is used in SPM program as a standard anatomical framework. While the most researchers look up Talairach atlas to report the localization of the activations detected in SPM program, there is significant disparity between MNI templates and Talairach atlas. That disparity between Talairach and MNI coordinates makes the interpretation of SPM result time consuming, subjective and inaccurate. The purpose of this study was to develop a program to provide objective anatomical information of each x-y-z position in ICBM coordinate. Program was designed to provide the anatomical information for the given x-y-z position in MNI coordinate based on the statistical probabilistic anatomical map (SPAM) images of ICBM. When x-y-z position was given to the program, names of the anatomical structures with non-zero probability and the probabilities that the given position belongs to the structures were tabulated. The program was coded using IDL and JAVA language for the easy transplantation to any operating system or platform. Utility of this program was shown by comparing the results of this program to those of SPM program. Preliminary validation study was performed by applying this program to the analysis of PET brain activation study of human memory in which the anatomical information on the activated areas are previously known. Real time retrieval of probabilistic information with 1 mm spatial resolution was archived using the programs. Validation study showed the relevance of this program: probability that the activated area for memory belonged to hippocampal formation was more than 80%. These programs will be useful for the result interpretation of the image analysis performed on MNI coordinate, as done in SPM program.

  4. ANATOMICAL PROPERTIES OF PLANTAGO ARENARIA

    Directory of Open Access Journals (Sweden)

    Nicoleta IANOVICI

    2011-01-01

    Full Text Available Psammophytes are marked by a number of adaptations that enable them to exist in the hard environmental conditions of the sand habitats. In this study, the anatomical characteristics of Plantago arenaria were examined. Studies were conducted to assess the diversity of anatomical adaptations of vegetative organs in this taxa. Results are presented with original photographs. The analysis of leaf anatomy in P. arenaria showed that the leaves contained a contained xeromorphic traits. Arbuscular mycorrhizal symbiosis seems to be critical for their survival.

  5. MUC1 positive, Kras and Pten driven mouse gynecologic tumors replicate human tumors and vary in survival and nuclear grade based on anatomical location.

    Directory of Open Access Journals (Sweden)

    Tejas S Tirodkar

    Full Text Available Activating mutations of Kras oncogene and deletions of Pten tumor suppressor gene play important roles in cancers of the female genital tract. We developed here new preclinical models for gynecologic cancers, using conditional (Cre-loxP mice with floxed genetic alterations in Kras and Pten. The triple transgenic mice, briefly called MUC1KrasPten, express human MUC1 antigen as self and carry a silent oncogenic KrasG12D and Pten deletion mutation. Injection of Cre-encoding adenovirus (AdCre in the ovarian bursa, oviduct or uterus activates the floxed mutations and initiates ovarian, oviductal, and endometrial cancer, respectively. Anatomical site-specific Cre-loxP recombination throughout the genital tract of MUC1KrasPten mice leads to MUC1 positive genital tract tumors, and the development of these tumors is influenced by the anatomical environment. Endometrioid histology was consistently displayed in all tumors of the murine genital tract (ovaries, oviducts, and uterus. Tumors showed increased expression of MUC1 glycoprotein and triggered de novo antibodies in tumor bearing hosts, mimicking the immunobiology seen in patients. In contrast to the ovarian and endometrial tumors, oviductal tumors showed higher nuclear grade. Survival for oviduct tumors was significantly lower than for endometrial tumors (p = 0.0015, yet similar to survival for ovarian cancer. Oviducts seem to favor the development of high grade tumors, providing preclinical evidence in support of the postulated role of fallopian tubes as the originating site for high grade human ovarian tumors.

  6. Detection and Analysis of Statistical Differences in Anatomical Shape

    OpenAIRE

    Golland, Polina; Grimson, W. Eric L.; Martha E. Shenton; Kikinis, Ron

    2005-01-01

    We present a computational framework for image-based analysis and interpretation of statistical differences in anatomical shape between populations. Applications of such analysis include understanding developmental and anatomical aspects of disorders when comparing patients vs. normal controls, studying morphological changes caused by aging, or even differences in normal anatomy, for example, differences between genders. Once a quantitative description of organ shape is extracted from input i...

  7. Exploring brain function from anatomical connectivity

    Directory of Open Access Journals (Sweden)

    Gorka eZamora-López

    2011-06-01

    Full Text Available The intrinsic relationship between the architecture of the brain and the range of sensory and behavioral phenomena it produces is a relevant question in neuroscience. Here, we review recent knowledge gained on the architecture of the anatomical connectivity by means of complex network analysis. It has been found that corticocortical networks display a few prominent characteristics: (i modular organization, (ii abundant alternative processing paths and (iii the presence of highly connected hubs. Additionally, we present a novel classification of cortical areas of the cat according to the role they play in multisensory connectivity. All these properties represent an ideal anatomical substrate supporting rich dynamical behaviors, as-well-as facilitating the capacity of the brain to process sensory information of different modalities segregated and to integrate them towards a comprehensive perception of the real world. The result here exposed are mainly based in anatomical data of cats’ brain, but we show how further observations suggest that, from worms to humans, the nervous system of all animals might share fundamental principles of organization.

  8. Shape analysis of simulated breast anatomical structures

    Science.gov (United States)

    Contijoch, Francisco; Lynch, Jennifer M.; Pokrajac, David D.; Maidment, Andrew D. A.; Bakic, Predrag R.

    2012-03-01

    Recent advances in high-resolution 3D breast imaging, namely, digital breast tomosynthesis and dedicated breast CT, have enabled detailed analysis of the shape and distribution of anatomical structures in the breast. Such analysis is critically important, since the projections of breast anatomical structures make up the parenchymal pattern in clinical images which can mask the existing abnormalities or introduce false alarms; the parenchymal pattern is also correlated with the risk of cancer. As a first step towards the shape analysis of anatomical structures in the breast, we have analyzed an anthropomorphic software breast phantom. The phantom generation is based upon the recursive splitting of the phantom volume using octrees, which produces irregularly shaped tissue compartments, qualitatively mimicking the breast anatomy. The shape analysis was performed by fitting ellipsoids to the simulated tissue compartments. The ellipsoidal semi-axes were calculated by matching the moments of inertia of each individual compartment and of an ellipsoid. The distribution of Dice coefficients, measuring volumetric overlap between the compartment and the corresponding ellipsoid, as well as the distribution of aspect ratios, measuring relative orientations of the ellipsoids, were used to characterize various classes of phantoms with qualitatively distinctive appearance. A comparison between input parameters for phantom generation and the properties of fitted ellipsoids indicated the high level of user control in the design of software breast phantoms. The proposed shape analysis could be extended to clinical breast images, and used to inform the selection of simulation parameters for improved realism.

  9. Quantifying anatomical shape variations in neurological disorders.

    Science.gov (United States)

    Singh, Nikhil; Fletcher, P Thomas; Preston, J Samuel; King, Richard D; Marron, J S; Weiner, Michael W; Joshi, Sarang

    2014-04-01

    We develop a multivariate analysis of brain anatomy to identify the relevant shape deformation patterns and quantify the shape changes that explain corresponding variations in clinical neuropsychological measures. We use kernel Partial Least Squares (PLS) and formulate a regression model in the tangent space of the manifold of diffeomorphisms characterized by deformation momenta. The scalar deformation momenta completely encode the diffeomorphic changes in anatomical shape. In this model, the clinical measures are the response variables, while the anatomical variability is treated as the independent variable. To better understand the "shape-clinical response" relationship, we also control for demographic confounders, such as age, gender, and years of education in our regression model. We evaluate the proposed methodology on the Alzheimer's Disease Neuroimaging Initiative (ADNI) database using baseline structural MR imaging data and neuropsychological evaluation test scores. We demonstrate the ability of our model to quantify the anatomical deformations in units of clinical response. Our results also demonstrate that the proposed method is generic and generates reliable shape deformations both in terms of the extracted patterns and the amount of shape changes. We found that while the hippocampus and amygdala emerge as mainly responsible for changes in test scores for global measures of dementia and memory function, they are not a determinant factor for executive function. Another critical finding was the appearance of thalamus and putamen as most important regions that relate to executive function. These resulting anatomical regions were consistent with very high confidence irrespective of the size of the population used in the study. This data-driven global analysis of brain anatomy was able to reach similar conclusions as other studies in Alzheimer's disease based on predefined ROIs, together with the identification of other new patterns of deformation. The

  10. Anatomically Correct Surface Recovery

    DEFF Research Database (Denmark)

    Jensen, Rasmus Ramsbøl; Nielsen, Jannik Boll; Larsen, Rasmus;

    2015-01-01

    We present a method for 3D surface recovery in partial surface scans. The method is based on an Active Shape Model, which is used to predict missing data. The model is constructed using a bootstrap framework, where an initially small collection of hand-annotated samples is used to fit......-of-the-art surface reconstruction algorithm, the presented method gives matching prediction results for the synthetic evaluation samples and superior results for the direct scanner data....

  11. A cubic B-spline-based hybrid registration of lung CT images for a dynamic airway geometric model with large deformation

    International Nuclear Information System (INIS)

    The goal of this study is to develop a matching algorithm that can handle large geometric changes in x-ray computed tomography (CT)-derived lung geometry occurring during deep breath maneuvers. These geometric relationships are further utilized to build a dynamic lung airway model for computational fluid dynamics (CFD) studies of pulmonary air flow. The proposed algorithm is based on a cubic B-spline-based hybrid registration framework that incorporates anatomic landmark information with intensity patterns. A sequence of invertible B-splines is composed in a multiresolution framework to ensure local invertibility of the large deformation transformation and a physiologically meaningful similarity measure is adopted to compensate for changes in voxel intensity due to inflation. Registrations are performed using the proposed approach to match six pairs of 3D CT human lung datasets. Results show that the proposed approach has the ability to match the intensity pattern and the anatomical landmarks, and ensure local invertibility for large deformation transformations. Statistical results also show that the proposed hybrid approach yields significantly improved results as compared with approaches using either landmarks or intensity alone.

  12. A cubic B-spline-based hybrid registration of lung CT images for a dynamic airway geometric model with large deformation

    Energy Technology Data Exchange (ETDEWEB)

    Yin Youbing; Lin, Ching-Long [Department of Mechanical and Industrial Engineering, University of Iowa, Iowa City, IA 52242 (United States); Hoffman, Eric A [Department of Radiology, University of Iowa, Iowa City, IA 52242 (United States); Ding Kai; Reinhardt, Joseph M, E-mail: ching-long-lin@uiowa.edu [Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242 (United States)

    2011-01-07

    The goal of this study is to develop a matching algorithm that can handle large geometric changes in x-ray computed tomography (CT)-derived lung geometry occurring during deep breath maneuvers. These geometric relationships are further utilized to build a dynamic lung airway model for computational fluid dynamics (CFD) studies of pulmonary air flow. The proposed algorithm is based on a cubic B-spline-based hybrid registration framework that incorporates anatomic landmark information with intensity patterns. A sequence of invertible B-splines is composed in a multiresolution framework to ensure local invertibility of the large deformation transformation and a physiologically meaningful similarity measure is adopted to compensate for changes in voxel intensity due to inflation. Registrations are performed using the proposed approach to match six pairs of 3D CT human lung datasets. Results show that the proposed approach has the ability to match the intensity pattern and the anatomical landmarks, and ensure local invertibility for large deformation transformations. Statistical results also show that the proposed hybrid approach yields significantly improved results as compared with approaches using either landmarks or intensity alone.

  13. APFiLoc: An Infrastructure-Free Indoor Localization Method Fusing Smartphone Inertial Sensors, Landmarks and Map Information

    Directory of Open Access Journals (Sweden)

    Jianga Shang

    2015-10-01

    Full Text Available The utility and adoption of indoor localization applications have been limited due to the complex nature of the physical environment combined with an increasing requirement for more robust localization performance. Existing solutions to this problem are either too expensive or too dependent on infrastructure such as Wi-Fi access points. To address this problem, we propose APFiLoc—a low cost, smartphone-based framework for indoor localization. The key idea behind this framework is to obtain landmarks within the environment and to use the augmented particle filter to fuse them with measurements from smartphone sensors and map information. A clustering method based on distance constraints is developed to detect organic landmarks in an unsupervised way, and the least square support vector machine is used to classify seed landmarks. A series of real-world experiments were conducted in complex environments including multiple floors and the results show APFiLoc can achieve 80% accuracy (phone in the hand and around 70% accuracy (phone in the pocket of the error less than 2 m error without the assistance of infrastructure like Wi-Fi access points.

  14. Corner Feature Extraction: Techniques for Landmark Based Navigation Systems

    OpenAIRE

    Namoshe, Molaletsa; Matsebe, Oudetse; Tlale, Nkgatho

    2010-01-01

    In this paper we discussed the results of an EKF SLAM using real data logged and computed offline. One of the most important parts of the SLAM process is to accurately map the environment the robot is exploring and localize in it. To achieve this however, is depended on the precise acquirement of features extracted from the external sensor. We looked at corner detection methods and we proposed an improved version of the method discussed in section 2.1.1. It transpired that methods found in th...

  15. Disorientation inhibits landmark use in 12-18-month-old infants.

    Science.gov (United States)

    Lew, Adina R; Foster, Kirsty A; Bremner, J Gavin

    2006-07-01

    Recent research has indicated that, particularly under conditions of inertial disorientation, mammals may be sensitive to landmark configuration geometry at the expense of individual featural information when locating hidden goals. The current study sought to establish whether landmark use could be demonstrated in 12-18-month-old infants with and without a disorientation procedure, and with geometrically ambiguous landmark configurations. A peekaboo paradigm was employed in which infants learned to anticipate a peekaboo event after a cue from two locations within a circular arena, followed by a test trial from a novel position in which no peekaboo occurred after the cue. In all conditions, an isosceles triangle arrangement of landmarks was used, with peekaboo occurring between the landmarks of one of the two equal "sides", thus being geometrically ambiguous. In two conditions, the landmarks were distinctive, and in two further conditions, they were identical. In one of the distinctive conditions and one of the identical landmark conditions, infants underwent a disorientation procedure in between training and test trials. Only oriented infants with distinctive landmarks were successful in test trials, thus suggesting that infants are able to use the individual features of landmarks to locate a goal, but can only do so if oriented. PMID:17138289

  16. Evaluation of association between mandibular crowding and some of anatomical indexes in skeletal Cl II 8-12 years old patient with mandibular deficiency

    OpenAIRE

    Shirazi Mohsen; Darvishpour Hojat; Nateghi Reza; Mirhashemi Amir Hosein; Salari Behzad

    2015-01-01

    Tehran University of Medical Sciences, Tehran, Iran ( )   Background and Aims: Nowadays patients refer to orthodontist for issue such as dental crowding and other aesthetic problems. The aims of this study were to evaluate the relationship between some of mandibular anatomical landmarks and dental crowding in the patient with skeletal Cl II due to mandibular deficiency.   Materials and Methods: 108 cases have been randomly selected out of patients with mandibular relate...

  17. Application of the Restriction Landmark Genome Scanning (RLGS Method for Analysis of Genetic Diversity between Asian and African Sorghum

    Directory of Open Access Journals (Sweden)

    Hisato Okuizumi*, Tomotsugu Noguchi, Tatsuya Saguchi,Takuma Fujita, Eri Nonaka, Shinsuke Yamanaka, Koffi Kombate, Subbarayan Sivakumar , Kulandaivelu Ganesamurthy, Yasufumi Murakami

    2010-07-01

    Full Text Available Restriction Landmark Genome Scanning (RLGS used to detect large numbers of restriction landmarks in a single experiment andapplied to analyze the genetic diversity of Asian and African sorghum accessions. This method is one of the genome analysistools based on the concept that restriction enzyme sites can serve as landmarks throughout a genome. RLGS uses direct endlabelingof the genomic DNA digested with a rare-cutting restriction enzyme and high-resolution two-dimensionalelectrophoresis. It has an advantage of providing precise information on a spot intensity that reflects the copy number ofrestriction landmarks and to visualize differences in methylation levels across the genome. RLGS becomes very useful for doingwhole genome scans that equals the work of thousands of polymerase chain reactions. A study was carried out using Sorghumaccessions collected from countries viz., Morocco, Nigeria, Sudan, South Africa, Japan, South Korea, and China. Onerepresentative sample was chosen from a country for analysis carried out at National Institute of Agrobiological Sciences(NIAS. Two dimensional spot images for seven accessions obtained and spot intensities were scanned. Totally, 119 spots weredetected of which 95 spots observed as polymorphic and 24 as non polymorphic. Unique presence and null spots werespecifically detected in all accessions taken for study. A total of 37 unique spots and 12 null spots, detected in this experiment.Principal Coordinate Analysis indicated, four African accessions scattered in the diagram were diverse and three Asianaccessions closely distributed with narrow diversity. The phylogenetic tree showed that Sudan and Nigerian accessions weredistant while Chinna, Japan and Korea accessions had close proximity

  18. Maximized Posteriori Attributes Selection from Facial Salient Landmarks for Face Recognition

    CERN Document Server

    Gupta, Phalguni; Sing, Jamuna Kanta; Tistarelli, Massimo

    2010-01-01

    This paper presents a robust and dynamic face recognition technique based on the extraction and matching of devised probabilistic graphs drawn on SIFT features related to independent face areas. The face matching strategy is based on matching individual salient facial graph characterized by SIFT features as connected to facial landmarks such as the eyes and the mouth. In order to reduce the face matching errors, the Dempster-Shafer decision theory is applied to fuse the individual matching scores obtained from each pair of salient facial features. The proposed algorithm is evaluated with the ORL and the IITK face databases. The experimental results demonstrate the effectiveness and potential of the proposed face recognition technique also in case of partially occluded faces.

  19. Landmarks in nature to support wayfinding: the effects of seasons and experimental methods.

    Science.gov (United States)

    Kettunen, Pyry; Irvankoski, Katja; Krause, Christina M; Sarjakoski, L Tiina

    2013-08-01

    Landmarks constitute an essential basis for a structural understanding of the spatial environment. Therefore, they are crucial factors in external spatial representations such as maps and verbal route descriptions, which are used to support wayfinding. However, selecting landmarks for these representations is a difficult task, for which an understanding of how people perceive and remember landmarks in the environment is needed. We investigated the ways in which people perceive and remember landmarks in nature using the thinking aloud and sketch map methods during both the summer and the winter seasons. We examined the differences between methods to identify those landmarks that should be selected for external spatial representations, such as maps or route descriptions, in varying conditions. We found differences in the use of landmarks both in terms of the methods and also between the different seasons. In particular, the participants used passage and tree-related landmarks at significantly different frequencies with the thinking aloud and sketch map methods. The results are likely to reflect the different roles of the landmark groups when using the two methods, but also the differences in counting landmarks when using both methods. Seasonal differences in the use of landmarks occurred only with the thinking aloud method. Sketch maps were drawn similarly in summertime and wintertime; the participants remembered and selected landmarks similarly independent of the differences in their perceptions of the environment due to the season. The achieved results may guide the planning of external spatial representations within the context of wayfinding as well as when planning further experimental studies.

  20. Anatomical structure of Polystichum Roth ferns rachises

    Directory of Open Access Journals (Sweden)

    Oksana V. Tyshchenko

    2012-03-01

    Full Text Available The morpho-anatomical characteristics of rachis cross sections of five Polystichum species is presented. The main and auxiliary anatomical features which help to distinguish investigated species are revealed.

  1. Anatomic study of infrapopliteal vessels.

    Science.gov (United States)

    Lappas, D; Stavropoulos, N A; Noussios, G; Sakellariou, V; Skandalakis, P

    2012-08-01

    The purpose of this project is to study and analyse the anatomical variations of the infrapopliteal vessels concerning their branching pattern. A reliable sample of one hundred formalin-fixed adult cadavers was dissected by the Anatomical Laboratory of Athens University. The variations can be classified in the following way: the normal branching of the popliteal artery was present in 90%. The remainder revealed variant branching patterns: hypoplastic or aplastic posterior tibial artery and the pedis arteries arising from the peroneal (3%); hypoplastic or aplastic anterior tibial artery (1.5%); and the dorsalis pedis formed by two equal branches, arising from the peroneal and the anterior tibial artery (2%). The variations were more frequent in females and in short-height individuals. Knowledge of these variations is rather important for any invasive technic concerning lower extremities.

  2. Reorienting strategies in a rectangular array of landmarks by domestic chicks (Gallus gallus).

    Science.gov (United States)

    Pecchia, Tommaso; Vallortigara, Giorgio

    2010-05-01

    Spatial reorientation in a rectangular array of four landmarks located in the center of a circular enclosure was investigated in domestic chicks (Gallus gallus). One of the landmark possessed unique visual features, indicating the location of a food reward. After training, chicks were tested (a) with the same array as during the training; (b) with four identical landmarks of the type previously nonrewarded, of the type previously rewarded, or of a new type; (c) after having transformed one of the landmarks located at the geometric incorrect location into the type of landmark previously rewarded; or (d) with a fifth landmark of the rewarded type at a new location. Chicks encoded information provided by local featural cues but not the geometric information provided by the shape of the array. Moreover, when trained in a rectangular array of identical landmarks chicks failed to reorient. In a second series of experiments, the array was located in correspondence to the corners of a rectangular enclosure. This time chicks successfully learned to locate the reward using geometric information. However, when the rectangular array was located in the center of a larger rectangular enclosure, chicks failed to reorient, indicating that the geometric information given by the macroscopic layout of arena surfaces was not used to specify different locations. These results suggest that chicks reorient on the basis of a local representation of single landmarks and that encoding of the global aspects of geometry only occurs with respect to the large, extended surfaces of an enclosure. PMID:20476814

  3. An Evaluation of Cellular Neural Networks for the Automatic Identification of Cephalometric Landmarks on Digital Images

    Directory of Open Access Journals (Sweden)

    Rosalia Leonardi

    2009-01-01

    Full Text Available Several efforts have been made to completely automate cephalometric analysis by automatic landmark search. However, accuracy obtained was worse than manual identification in every study. The analogue-to-digital conversion of X-ray has been claimed to be the main problem. Therefore the aim of this investigation was to evaluate the accuracy of the Cellular Neural Networks approach for automatic location of cephalometric landmarks on softcopy of direct digital cephalometric X-rays. Forty-one, direct-digital lateral cephalometric radiographs were obtained by a Siemens Orthophos DS Ceph and were used in this study and 10 landmarks (N, A Point, Ba, Po, Pt, B Point, Pg, PM, UIE, LIE were the object of automatic landmark identification. The mean errors and standard deviations from the best estimate of cephalometric points were calculated for each landmark. Differences in the mean errors of automatic and manual landmarking were compared with a 1-way analysis of variance. The analyses indicated that the differences were very small, and they were found at most within 0.59 mm. Furthermore, only few of these differences were statistically significant, but differences were so small to be in most instances clinically meaningless. Therefore the use of X-ray files with respect to scanned X-ray improved landmark accuracy of automatic detection. Investigations on softcopy of digital cephalometric X-rays, to search more landmarks in order to enable a complete automatic cephalometric analysis, are strongly encouraged.

  4. Interactions of visual odometry and landmark guidance during food search in honeybees

    NARCIS (Netherlands)

    Vladusich, T; Hemmi, JM; Srinivasan, MV; Zeil, J

    2005-01-01

    How do honeybees use visual odometry and goal-defining landmarks to guide food search? In one experiment, bees were trained to forage in an optic-flow-rich tunnel with a landmark positioned directly above the feeder. Subsequent food-search tests indicated that bees searched much more accurately when

  5. The Development of Landmark and Beacon Use in Young Children: Evidence from a Touchscreen Search Task

    Science.gov (United States)

    Sutton, Jennifer E.

    2006-01-01

    Children ages 2, 3 and 4 years participated in a novel hide-and-seek search task presented on a touchscreen monitor. On beacon trials, the target hiding place could be located using a beacon cue, but on landmark trials, searching required the use of a nearby landmark cue. In Experiment 1, 2-year-olds performed less accurately than older children…

  6. Fully Automatic System for Accurate Localisation and Analysis of Cephalometric Landmarks in Lateral Cephalograms.

    Science.gov (United States)

    Lindner, Claudia; Wang, Ching-Wei; Huang, Cheng-Ta; Li, Chung-Hsing; Chang, Sheng-Wei; Cootes, Tim F

    2016-01-01

    Cephalometric tracing is a standard analysis tool for orthodontic diagnosis and treatment planning. The aim of this study was to develop and validate a fully automatic landmark annotation (FALA) system for finding cephalometric landmarks in lateral cephalograms and its application to the classification of skeletal malformations. Digital cephalograms of 400 subjects (age range: 7-76 years) were available. All cephalograms had been manually traced by two experienced orthodontists with 19 cephalometric landmarks, and eight clinical parameters had been calculated for each subject. A FALA system to locate the 19 landmarks in lateral cephalograms was developed. The system was evaluated via comparison to the manual tracings, and the automatically located landmarks were used for classification of the clinical parameters. The system achieved an average point-to-point error of 1.2 mm, and 84.7% of landmarks were located within the clinically accepted precision range of 2.0 mm. The automatic landmark localisation performance was within the inter-observer variability between two clinical experts. The automatic classification achieved an average classification accuracy of 83.4% which was comparable to an experienced orthodontist. The FALA system rapidly and accurately locates and analyses cephalometric landmarks in lateral cephalograms, and has the potential to significantly improve the clinical work flow in orthodontic treatment. PMID:27645567

  7. 78 FR 69437 - Landmarks Committee of the National Park System Advisory Board Meeting

    Science.gov (United States)

    2013-11-19

    ... National Park Service Landmarks Committee of the National Park System Advisory Board Meeting AGENCY... Federal Regulations, that a meeting of the Landmarks Committee of the National Park System Advisory Board... National Park System Advisory Board at a subsequent meeting at a place and time to be determined....

  8. Bringing history to life: simulating landmark experiments in psychology.

    Science.gov (United States)

    Boynton, David M; Smith, Laurence D

    2006-05-01

    The course in history of psychology can be challenging for students, many of whom enter it with little background in history and faced with unfamiliar names and concepts. The sheer volume of material can encourage passive memorization unless efforts are made to increase student involvement. As part of a trend toward experiential history, historians of science have begun to supplement their lectures with demonstrations of classic physics experiments as a way to bring the history of science to life. Here, the authors report on computer simulations of five landmark experiments from early experimental psychology in the areas of reaction time, span of attention, and apparent motion. The simulations are designed not only to permit hands-on replication of historically important results but also to reproduce the experimental procedures closely enough that students can gain a feel for the nature of early research and the psychological processes being studied. PMID:17152604

  9. Landmark and route knowledge in children’s spatial representation of a virtual environment

    Directory of Open Access Journals (Sweden)

    Marion eNys

    2015-01-01

    Full Text Available This study investigates the development of landmark and route knowledge in complex wayfinding situations. Our study focuses on how children (aged 6, 8 and 10 years and young adults (n=79 indicate, recognize, and bind landmarks and directions in both verbal and visuo-spatial tasks after learning a virtual route. Performance in these tasks is also related to general verbal and visuo-spatial abilities as assessed by independent standardized tests (attention, working memory, perception of direction, production and comprehension of spatial terms, sentences and stories. The results first show that the quantity and quality of landmarks and directions produced and recognized by participants in both verbal and visuo-spatial tasks increased with age. In addition, an increase with age was observed in participants’ selection of decisional landmarks (i.e. landmarks associated with a change of direction, as well as in their capacity to bind landmarks and directions. Our results confirm the view that children first acquire landmark knowledge, then route knowledge, as shown by their late developing ability to bind knowledge of directions and landmarks. Overall, the quality of verbal and visuo-spatial information in participants’ spatial representations was found to vary mostly with their visuo-spatial abilities (attention and perception of directions and not with their verbal abilities. Interestingly, however, when asked to recognize landmarks encountered during the route, participants show an increasing bias with age toward choosing a related landmark of the same category, regardless of its visual characteristics, i.e. they incorrectly choose the picture of another fountain. The discussion highlights the need for further studies to determine more precisely the role of verbal and visuo-spatial knowledge and the nature of how children learn to represent and memorize routes.

  10. [Sigismund Laskowski and his anatomical preparations technique].

    Science.gov (United States)

    Gryglewski, Ryszard W

    2015-01-01

    Fixation of the entire bodies or individual organs, and later as well tissues and cellular structures, was and still is often a challenge for anatomists and histologists. Technique that combines extensive knowledge of natural sciences, as well as technical skills, was by those best researchers as Frederik Ruysch, brought to perfection. Preparations, if done with care and talent, are really propelling progress in anatomical studies and determining the quality of education for medical students and young physicians. And as it is true for many of today's medical disciplines and natural sciences, the nineteenth century was in many ways a breaking point for preparatory techniques in the realm of anatomy and histology. Among those who have achieved success, earning notoriety during their lifetime and often going into the annals of European most distinguished scholars were some Polish names: Louis Maurice Hirschfeld, whose preparations of the nervous system earned him well-deserved, international fame, Louis Charles Teichmann, who was the very first so precisely describing the lymphatic system and a creator of unique injection mass, Henry Kadyi, known for his outstanding preparations, especially of vascular system. Henry Frederick Hoyer sen., who was one of the first to use formalin regularly for accurate microscopic preparations, is seen by many as the founder of the Polish histology. In this group of innovators and precursors of modern preparation techniques place should be reserved for Zygmunt (Sigismund) Laskowski, Polish patriot, fighting in January Uprising, later an immigrant, a professor at the university sequentially Paris and Geneva. Acclaimed author of anatomical tables and certainly creator of one of the groundbreaking techniques in anatomical preparations. Based after many years of research on the simple glycerine-phenol mixture achieved excellent results both in fixation of entire bodies and organs or tissues. Quality of those preparations was as high and

  11. Parametric Anatomical Modeling: A method for modeling the anatomical layout of neurons and their projections

    Directory of Open Access Journals (Sweden)

    Martin ePyka

    2014-09-01

    Full Text Available Computational models of neural networks can be based on a variety of different parameters. These parameters include, for example, the 3d shape of neuron layers, the neurons' spatial projection patterns, spiking dynamics and neurotransmitter systems. While many well-developed approaches are available to model, for example, the spiking dynamics, there is a lack of approaches for modeling the anatomical layout of neurons and their projections. We present a new method, called Parametric Anatomical Modeling (PAM, to fill this gap. PAM can be used to derive network connectivities and conduction delays from anatomical data, such as the position and shape of the neuronal layers and the dendritic and axonal projection patterns. Within the PAM framework, several mapping techniques between layers can account for a large variety of connection properties between pre- and post-synaptic neuron layers. PAM is implemented as a Python tool and integrated in the 3d modeling software Blender. We demonstrate on a 3d model of the hippocampal formation how PAM can help reveal complex properties of the synaptic connectivity and conduction delays, properties that might be relevant to uncover the function of the hippocampus. Based on these analyses, two experimentally testable predictions arose: i the number of neurons and the spread of connections is heterogeneously distributed across the main anatomical axes, ii the distribution of connection lengths in CA3-CA1 differ qualitatively from those between DG-CA3 and CA3-CA3. Models created by PAM can also serve as an educational tool to visualize the 3d connectivity of brain regions. The low-dimensional, but yet biologically plausible, parameter space renders PAM suitable to analyse allometric and evolutionary factors in networks and to model the complexity of real networks with comparatively little effort.

  12. Parametric Anatomical Modeling: a method for modeling the anatomical layout of neurons and their projections.

    Science.gov (United States)

    Pyka, Martin; Klatt, Sebastian; Cheng, Sen

    2014-01-01

    Computational models of neural networks can be based on a variety of different parameters. These parameters include, for example, the 3d shape of neuron layers, the neurons' spatial projection patterns, spiking dynamics and neurotransmitter systems. While many well-developed approaches are available to model, for example, the spiking dynamics, there is a lack of approaches for modeling the anatomical layout of neurons and their projections. We present a new method, called Parametric Anatomical Modeling (PAM), to fill this gap. PAM can be used to derive network connectivities and conduction delays from anatomical data, such as the position and shape of the neuronal layers and the dendritic and axonal projection patterns. Within the PAM framework, several mapping techniques between layers can account for a large variety of connection properties between pre- and post-synaptic neuron layers. PAM is implemented as a Python tool and integrated in the 3d modeling software Blender. We demonstrate on a 3d model of the hippocampal formation how PAM can help reveal complex properties of the synaptic connectivity and conduction delays, properties that might be relevant to uncover the function of the hippocampus. Based on these analyses, two experimentally testable predictions arose: (i) the number of neurons and the spread of connections is heterogeneously distributed across the main anatomical axes, (ii) the distribution of connection lengths in CA3-CA1 differ qualitatively from those between DG-CA3 and CA3-CA3. Models created by PAM can also serve as an educational tool to visualize the 3d connectivity of brain regions. The low-dimensional, but yet biologically plausible, parameter space renders PAM suitable to analyse allometric and evolutionary factors in networks and to model the complexity of real networks with comparatively little effort.

  13. TOPICAL REVIEW: Anatomical imaging for radiotherapy

    Science.gov (United States)

    Evans, Philip M.

    2008-06-01

    scans is taken on different days. Both allow planning to account for variability intrinsic to the patient. Treatment verification has been carried out using a variety of technologies including: MV portal imaging, kV portal/fluoroscopy, MVCT, conebeam kVCT, ultrasound and optical surface imaging. The various methods have their pros and cons. The four x-ray methods involve an extra radiation dose to normal tissue. The portal methods may not generally be used to visualize soft tissue, consequently they are often used in conjunction with implanted fiducial markers. The two CT-based methods allow measurement of inter-fraction variation only. Ultrasound allows soft-tissue measurement with zero dose but requires skilled interpretation, and there is evidence of systematic differences between ultrasound and other data sources, perhaps due to the effects of the probe pressure. Optical imaging also involves zero dose but requires good correlation between the target and the external measurement and thus is often used in conjunction with an x-ray method. The use of anatomical imaging in radiotherapy allows treatment uncertainties to be determined. These include errors between the mean position at treatment and that at planning (the systematic error) and the day-to-day variation in treatment set-up (the random error). Positional variations may also be categorized in terms of inter- and intra-fraction errors. Various empirical treatment margin formulae and intervention approaches exist to determine the optimum strategies for treatment in the presence of these known errors. Other methods exist to try to minimize error margins drastically including the currently available breath-hold techniques and the tracking methods which are largely in development. This paper will review anatomical imaging techniques in radiotherapy and how they are used to boost the therapeutic benefit of the treatment.

  14. A hierarchical scheme for geodesic anatomical labeling of airway trees

    DEFF Research Database (Denmark)

    Feragen, Aasa; Petersen, Jens; Owen, Megan;

    2012-01-01

    We present a fast and robust supervised algorithm for label- ing anatomical airway trees, based on geodesic distances in a geometric tree-space. Possible branch label configurations for a given unlabeled air- way tree are evaluated based on the distances to a training set of labeled airway trees....

  15. Germ band retraction as a landmark in glucose metabolism during Aedes aegypti embryogenesis

    Directory of Open Access Journals (Sweden)

    Logullo Carlos

    2010-02-01

    Full Text Available Abstract Background The mosquito A. aegypti is vector of dengue and other viruses. New methods of vector control are needed and can be achieved by a better understanding of the life cycle of this insect. Embryogenesis is a part of A. aegypty life cycle that is poorly understood. In insects in general and in mosquitoes in particular energetic metabolism is well studied during oogenesis, when the oocyte exhibits fast growth, accumulating carbohydrates, lipids and proteins that will meet the regulatory and metabolic needs of the developing embryo. On the other hand, events related with energetic metabolism during A. aegypti embryogenesis are unknown. Results Glucose metabolism was investigated throughout Aedes aegypti (Diptera embryonic development. Both cellular blastoderm formation (CBf, 5 h after egg laying - HAE and germ band retraction (GBr, 24 HAE may be considered landmarks regarding glucose 6-phosphate (G6P destination. We observed high levels of glucose 6-phosphate dehydrogenase (G6PDH activity at the very beginning of embryogenesis, which nevertheless decreased up to 5 HAE. This activity is correlated with the need for nucleotide precursors generated by the pentose phosphate pathway (PPP, of which G6PDH is the key enzyme. We suggest the synchronism of egg metabolism with carbohydrate distribution based on the decreasing levels of phosphoenolpyruvate carboxykinase (PEPCK activity and on the elevation observed in protein content up to 24 HAE. Concomitantly, increasing levels of hexokinase (HK and pyruvate kinase (PK activity were observed, and PEPCK reached a peak around 48 HAE. Glycogen synthase kinase (GSK3 activity was also monitored and shown to be inversely correlated with glycogen distribution during embryogenesis. Conclusions The results herein support the hypothesis that glucose metabolic fate changes according to developmental embryonic stages. Germ band retraction is a moment that was characterized as a landmark in glucose

  16. Gastric Anatomic Type Is Associated with Obesity and Gender

    Directory of Open Access Journals (Sweden)

    Yu Jen Wang

    2016-06-01

    Full Text Available Objective: To enhance our understanding of the associations among gastric anatomy, obesity, and gender. Methods: 777 randomly selected participants received health checkups, including a series of radiographs of the upper gastrointestinal tract (UGI; the findings were linked with each corresponding subject's gender and BMI. We measured the length, angle, and different portions of the stomach with the subjects in the standing position using radiographs to classify all individuals into anatomic types 1 through 6 based on gastric morphology. The gastric morphology was identified based on the initial UGI examination: 166 follow-up UGI radiographs at 12 ± 1.5 months to evaluate whether the stability of gastric anatomy persisted over time. Results: There was a significant difference in anatomic types between females and males (p Conclusion: Gastric anatomic types were associated with obesity and gender.

  17. Comparison of difference registration landmarks for image - guided radiotherapy for lung cancer%肺癌图像引导IMRT配准标志的比较研究

    Institute of Scientific and Technical Information of China (English)

    张彦新; 惠周光; 李明辉; 章众; 符贵山; 戴建荣

    2015-01-01

    Objective To investigate the impact of anatomical landmarks on registration in image⁃guided radiotherapy (IGRT) for central and peripheral lung cancer. Methods Twenty⁃five patients with central or peripheral lung cancer for IGRT were enrolled in this study. Kilo⁃voltage cone⁃beam CT ( kV⁃CBCT) scanning was acquired before irradiotion. Tumor coverage on CBCT was assessed using gross tumor volume (GTV), clinical target volume (CTV), and planning target volume (PTV) contours according to tumor alignment, carina registration, and spine registration, respectively. The grading analysiswas based on visual tumor assessment as follows:grade 0, tumor within GTV;grade 1, tumor outside GTV but inside CTV;grade 2, tumor outside CTV but inside PTV;and grade 3, tumor outside PTV. Results Totally 177 sets of kV⁃CBCT of 25 patients was collected. According to the registration landmarks of the tumor, carina and spine for central lung cancer, the percentages were 57�55%, 53�77% and 16�04% in grade 0, 39�62%, 45�28%and 58�49% in grade 1, and 1�89%, 0�94% and 25�47% in grade 2, respectively. For peripheral lung cancer, the percentages were 47�89%, 14�08% and 2�82% in grade 0, 43�66%, 29�58% and 45�07% in grade 1, and 8�45%, 40�85% and 35�21% in grade 2, respectively. Conclusions For central lung cancer,the tumor was recommended as the best registration landmark, and the carina was recommended as well, while the spine was not recommended. For peripheral lung cancer, the tumor was recommended as the best registration landmark, while the spine and the carina were not recommended.%目的:研究肺癌患者图像引导IMRT中采用不同配准标志的靶区符合度差异,确定合理的图像配准方法。方法回顾性收集和分析25例肺癌患者CBCT影像,按原发肿瘤位置分为中央型和周围型两组,每组分别采用肿瘤、隆突、脊柱为标志的配准方法。根据肿瘤组织靶区符合度分为4

  18. Faithful Completion of Images of Scenic Landmarks Using Internet Images.

    Science.gov (United States)

    Zhu, Zhe; Huang, Hao-Zhi; Tan, Zhi-Peng; Xu, Kun; Hu, Shi-Min

    2016-08-01

    Previous works on image completion typically aim to produce visually plausible results rather than factually correct ones. In this paper, we propose an approach to faithfully complete the missing regions of an image. We assume that the input image is taken at a well-known landmark, so similar images taken at the same location can be easily found on the Internet. We first download thousands of images from the Internet using a text label provided by the user. Next, we apply two-step filtering to reduce them to a small set of candidate images for use as source images for completion. For each candidate image, a co-matching algorithm is used to find correspondences of both points and lines between the candidate image and the input image. These are used to find an optimal warp relating the two images. A completion result is obtained by blending the warped candidate image into the missing region of the input image. The completion results are ranked according to combination score, which considers both warping and blending energy, and the highest ranked ones are shown to the user. Experiments and results demonstrate that our method can faithfully complete images. PMID:26394429

  19. [The landmarks of the measurement of cerebral blood flow].

    Science.gov (United States)

    István, Nyáry

    2008-01-30

    History of the measurement of local cerebral blood flow may cover a period of one and a half centuries. Parallel forthcoming of both theoretical and technical development were the key elements of ensuing progress resulting in the present state, when by the aid of in vivo blood flow and metabolic maps, we can visualize locales of brain functioning and their interconnections. Two theoretical landmarks should be mentioned in this historic process. First, the work of Adolf Fick, as the starter of quantitative measurements in this field, and Seymour Kety's model of a single, homogenously perfused tissue element. The solution of this model, in the form of Kety's equation is still fundamental to present day blood flow mapping techniques. Among the numerous investigators over the past years, two Hungarian scientist can be named as major contributors. Kálmán Sántha made substantial studies with continuous registration of local cerebral blood flow by the aid of thermocouples, while Emil P6sztor invented the hydrogen clearance method for the measurement of local cerebral blood flow both in human and in animal studies.

  20. Printed Three-dimensional Anatomic Templates for Virtual Preoperative Planning Before Reconstruction of Old Pelvic Injuries: Initial Results

    Directory of Open Access Journals (Sweden)

    Xin-Bao Wu

    2015-01-01

    Full Text Available Background: Old pelvis fractures are among the most challenging fractures to treat because of their complex anatomy, difficult-to-access surgical sites, and the relatively low incidence of such cases. Proper evaluation and surgical planning are necessary to achieve the pelvic ring symmetry and stable fixation of the fracture. The goal of this study was to assess the use of three-dimensional (3D printing techniques for surgical management of old pelvic fractures. Methods: First, 16 dried human cadaveric pelvises were used to confirm the anatomical accuracy of the 3D models printed based on radiographic data. Next, nine clinical cases between January 2009 and April 2013 were used to evaluate the surgical reconstruction based on the 3D printed models. The pelvic injuries were all type C, and the average time from injury to reconstruction was 11 weeks (range: 8-17 weeks. The workflow consisted of: (1 Printing patient-specific bone models based on preoperative computed tomography (CT scans, (2 virtual fracture reduction using the printed 3D anatomic template, (3 virtual fracture fixation using Kirschner wires, and (4 preoperatively measuring the osteotomy and implant position relative to landmarks using the virtually defined deformation. These models aided communication between surgical team members during the procedure. This technique was validated by comparing the preoperative planning to the intraoperative procedure. Results: The accuracy of the 3D printed models was within specification. Production of a model from standard CT DICOM data took 7 hours (range: 6-9 hours. Preoperative planning using the 3D printed models was feasible in all cases. Good correlation was found between the preoperative planning and postoperative follow-up X-ray in all nine cases. The patients were followed for 3-29 months (median: 5 months. The fracture healing time was 9-17 weeks (mean: 10 weeks. No delayed incision healing, wound infection, or nonunions occurred. The

  1. Printed Three-dimensional Anatomic Templates for Virtual Preoperative Planning Before Reconstruction of Old Pelvic Injuries: Initial Results

    Institute of Scientific and Technical Information of China (English)

    Xin-Bao Wu; Jun-Qiang Wang; Chun-Peng Zhao; Xu Sun; Yin Shi; Zi-An Zhang; Yu-Neng Li

    2015-01-01

    Background:Old pelvis fractures are among the most challenging fractures to treat because of their complex anatomy,difficult-to-access surgical sites,and the relatively low incidence of such cases.Proper evaluation and surgical planning are necessary to achieve the pelvic ring symmetry and stable fixation of the fracture.The goal of this study was to assess the use of three-dimensional (3D) printing techniques for surgical management of old pelvic fractures.Methods:First,16 dried human cadaveric pelvises were used to confirm the anatomical accuracy of the 3D models printed based on radiographic data.Next,nine clinical cases between January 2009 and April 2013 were used to evaluate the surgical reconstruction based on the 3D printed models.The pelvic injuries were all type C,and the average time from injury to reconstruction was 11 weeks (range:8-17 weeks).The workflow consisted of.:(1) Printing patient-specific bone models based on preoperative computed tomography (CT) scans,(2) virtual fracture reduction using the printed 3D anatomic template,(3) virtual fracture fixation using Kirschner wires,and (4) preoperatively measuring the osteotomy and implant position relative to landmarks using the virtually defined deformation.These models aided communication between surgical team members during the procedure.This technique was validated by comparing the preoperative planning to the intraoperative procedure.Results:The accuracy of the 3D printed models was within specification.Production of a model from standard CT DICOM data took 7 hours (range:6-9 hours).Preoperative planning using the 3D printed models was feasible in all cases.Good correlation was found between the preoperative planning and postoperative follow-up X-ray in all nine cases.The patients were followed for 3-29 months (median:5 months).The fracture healing time was 9-17 weeks (mean:l0 weeks).No delayed incision healing,wound infection,or nonunions occurred.The results were excellent in two cases,good in

  2. Three-Dimensional Anatomic Evaluation of the Anterior Cruciate Ligament for Planning Reconstruction

    Directory of Open Access Journals (Sweden)

    Yuichi Hoshino

    2012-01-01

    Full Text Available Anatomic study related to the anterior cruciate ligament (ACL reconstruction surgery has been developed in accordance with the progress of imaging technology. Advances in imaging techniques, especially the move from two-dimensional (2D to three-dimensional (3D image analysis, substantially contribute to anatomic understanding and its application to advanced ACL reconstruction surgery. This paper introduces previous research about image analysis of the ACL anatomy and its application to ACL reconstruction surgery. Crucial bony landmarks for the accurate placement of the ACL graft can be identified by 3D imaging technique. Additionally, 3D-CT analysis of the ACL insertion site anatomy provides better and more consistent evaluation than conventional “clock-face” reference and roentgenologic quadrant method. Since the human anatomy has a complex three-dimensional structure, further anatomic research using three-dimensional imaging analysis and its clinical application by navigation system or other technologies is warranted for the improvement of the ACL reconstruction.

  3. Internal Occipital Crest Misalignment with Internal Occipital Protuberance: A Case Report of Posterior Cranial Fossa Anatomic Variations

    Directory of Open Access Journals (Sweden)

    Jae Ha Kim

    2016-01-01

    Full Text Available During gross anatomy head and neck laboratory session, one dissection group observed an abnormal anatomic variation in the posterior cranial fossa of a 94-year-old male cadaver. The internal occipital crest was not aligned with internal occipital protuberance and groove for superior sagittal sinus. It seemed that the internal occipital protuberance was shifted significantly to the right side. As a result the skull was overly stretched in order to connect with the internal occipital ridge. These internal skull variations of occipital bone landmarks can influence the location of adjacent dural venous sinuses and possibly influence cerebrospinal fluid flow. Similar anatomical anomalies have been attributed to presence of hydrocephalus and abnormalities in cisterna magna.

  4. Optimizing conditions for computer-assisted anatomical learning

    NARCIS (Netherlands)

    Luursema, Jan-Maarten; Verwey, Willem B.; Kommers, Piet A.M.; Geelkerken, Robert H.; Vos, Hans J.

    2006-01-01

    An experiment evaluated the impact of two typical features of virtual learning environments on anatomical learning for users of differing visuo-spatial ability. The two features studied are computer-implemented stereopsis (the spatial information that is based on differences in visual patterns proje

  5. A global solution for the gravity field, rotation, landmarks and ephemeris of Eros

    Science.gov (United States)

    Konopliv, A. S.; Miller, J. K.; Owen, W. M.; Yeomans, D. K.; Giorgini, J. D.; Garmier, R.; Barriot, J. P.

    2001-01-01

    This solution uses the entire one-year in orbit collection of X-band radiometric tracking (Doppler and range) from the Deep Space Network and landmark tracking observations generated from the NEAR spacecraft images of Eros.

  6. Links Between Surgical Landmarks of the Temporal Bone and Cochlear Implant Approaches

    Directory of Open Access Journals (Sweden)

    Gabriel Lostun

    2015-12-01

    Full Text Available Objective: We aimed to underline the surgical importance of the distances between the landmarks of the temporal bone, important for quantifying the benefits and disadvantages of two different cochlear implant techniques.

  7. Cálculo distribuido de landmarks para sistemas de planificación multiagente

    OpenAIRE

    Oropesa Física, Ana

    2013-01-01

    En este Proyecto Final de Carrera se verá la motivación por la que hacer una heurística multiagente utilizando landmarks, la construcción de ésta y unos posteriores resultados y comparativas con la heurística monoagente entre otras. Oropesa Física, A. (2013). Cálculo distribuido de landmarks para sistemas de planificación multiagente. http://hdl.handle.net/10251/32520. Archivo delegado

  8. Effects of image enhancement on reliability of landmark identification in digital cephalometry

    Directory of Open Access Journals (Sweden)

    M Oshagh

    2013-01-01

    Full Text Available Introduction: Although digital cephalometric radiography is gaining popularity in orthodontic practice, the most important source of error in its tracing is uncertainty in landmark identification. Therefore, efforts to improve accuracy in landmark identification were directed primarily toward the improvement in image quality. One of the more useful techniques of this process involves digital image enhancement which can increase overall visual quality of image, but this does not necessarily mean a better identification of landmarks. The purpose of this study was to evaluate the effectiveness of digital image enhancements on reliability of landmark identification. Materials and Methods: Fifteen common landmarks including 10 skeletal and 5 soft tissues were selected on the cephalograms of 20 randomly selected patients, prepared in Natural Head Position (NHP. Two observers (orthodontists identified landmarks on the 20 original photostimulable phosphor (PSP digital cephalogram images and 20 enhanced digital images twice with an intervening time interval of at least 4 weeks. The x and y coordinates were further analyzed to evaluate the pattern of recording differences in horizontal and vertical directions. Reliability of landmarks identification was analyzed by paired t test. Results: There was a significant difference between original and enhanced digital images in terms of reliability of points Ar and N in vertical and horizontal dimensions, and enhanced images were significantly more reliable than original images. Identification of A point, Pogonion and Pronasal points, in vertical dimension of enhanced images was significantly more reliable than original ones. Reliability of Menton point identification in horizontal dimension was significantly more in enhanced images than original ones. Conclusion: Direct digital image enhancement by altering brightness and contrast can increase reliability of some landmark identification and this may lead to more

  9. Sequential egocentric navigation and reliance on landmarks in Williams syndrome and typical development

    Directory of Open Access Journals (Sweden)

    Hannah eBroadbent

    2015-02-01

    Full Text Available Visuospatial difficulties in Williams syndrome (WS are well documented. Recently, research has shown that spatial difficulties in WS extend to large-scale space, particularly in coding space using an allocentric frame of reference. Typically developing (TD children and adults predominantly rely on the use of a sequential egocentric strategy to navigate a large-scale route (retracing a sequence of left-right body turns. The aim of this study was to examine whether individuals with WS are able to employ a sequential egocentric strategy to guide learning and the retracing of a route. Forty-eight TD children, aged 5, 7 and 9 years and 18 participants with WS were examined on their ability to learn and retrace routes in two (6-turn virtual environment mazes (with and without landmarks. The ability to successfully retrace a route following the removal of landmarks (use of sequential egocentric coding was also examined.Although in line with TD 5 year-olds when learning a route with landmarks, individuals with WS showed significantly greater detriment when these landmarks were removed, relative to all TD groups. Moreover, the WS group made significantly more errors than all TD groups when learning a route that never contained landmarks. On a perceptual view-matching task, results revealed a high level of performance across groups, indicative of an ability to use this visual information to potentially aid navigation. These findings suggest that individuals with WS rely on landmarks to a greater extent than TD children, both for learning a route and for retracing a recently learned route. TD children, but not individuals with WS, were able to fall back on the use of a sequential egocentric strategy to navigate when landmarks were not present. Only TD children therefore coded sequential route information simultaneously with landmark information. The results are discussed in relation to known atypical cortical development and perceptual-matching abilities

  10. Ultrasound Guided Internal Jugular Venous Cannulation: Comparison with Land-Mark Technique

    International Nuclear Information System (INIS)

    Objective: To compare real-time ultrasonography-guided technique versus the traditional land-mark technique for internal Jugular venous cannulation. Study Design: Randomized controlled trial. Place and Duration of Study: Department of Anaesthesia, Combined Military Hospital, Rawalpindi, from September 2013 to July 2014. Methodology:Atotal of 200 patients who required internal jugular vein cannulation were randomly assigned using either real-time ultrasound-guided technique or land-mark technique. Access time, number of attempts until successful cannulation, complications and the demographics of each patient were recorded. Results:Access time was significantly less in real-time ultrasound group (34.95 ± 11.47 vs. 146.59 ± 40.20 seconds, p < 0.001). Cannulation was performed in first attempt in 99 percentage of patients in ultrasound group as compared to 89 percentage of landmark group. Complication rate was significantly higher in the land-mark group than in the ultrasound-guided group. Carotid artery puncture rate (9 percentage vs. 1 percentage) and haematoma formation (7 percentage vs. 0 percentage) were more frequent in the land-mark group than in the ultrasound-guided group. Brachial plexus irritation was also more in land-mark group (6 percentage vs. 0 percentage). Conclusion:Access time, failure rate and procedure related complications are reduced when real-time ultrasonography is used to cannulate internal Jugular vein. (author)

  11. Insite: Canada's landmark safe injecting program at risk

    Directory of Open Access Journals (Sweden)

    Drucker Ernest

    2006-08-01

    Full Text Available Abstract InSite is North Americas first supervised injection site and a landmark public heath initiative operating in Vancouver since 2003. The program is a vital component of that cities internationally recognized harm reduction approach to its serious problems with drugs, crime, homelessness and AIDS. InSite currently operates under a waiver of Federal rules that allow it to provide services as a research project. An extensive evaluation has produced very positive results for thousands of users. Normally such strong evidence documenting the successes of such a program, and the medical and public health significance of these positive outcomes, would be the basis for celebration and moves to expand the model and provide similar services elsewhere in Canada. Instead, there is a distinct possibility that InSite will be closed by the newly elected Canadian Prime Minister Paul Harper – a conservative who has traveled to the US to visit George WQ Bush and come back antagonistic to harm reduction in all its forms. Because InSites federal waiver is expiring and up for renewal in September, the fear is that Mr. Harpers will not renew the approval and that the program will be forced to close down. The risks associated with the potential closure of InSite need to be fully understood. This editorial lays out these public health risks and the associated economic impact if InSite were to be closed. In addition to preventable deaths and disease, InSites closure will cost Vancouver and British Columbia between $3.8 and $ 8.8 million in preventable health care expenses over the next two years.

  12. Brain Morphometry Using Anatomical Magnetic Resonance Imaging

    Science.gov (United States)

    Bansal, Ravi; Gerber, Andrew J.; Peterson, Bradley S.

    2008-01-01

    The efficacy of anatomical magnetic resonance imaging (MRI) in studying the morphological features of various regions of the brain is described, also providing the steps used in the processing and studying of the images. The ability to correlate these features with several clinical and psychological measures can help in using anatomical MRI to…

  13. Are the Genitalia of Anatomical Dolls Distorted?

    Science.gov (United States)

    Bays, Jan

    1990-01-01

    To determine whether the genitalia of anatomical dolls are disproportionately large and may suggest sexual activity to children who have not been abused, the genitalia and breasts of 17 sets of anatomical dolls were measured. When the measurements were extrapolated to adult human proportions, the sizes were not found to be exaggerated. (Author/JDD)

  14. Evaluation of contrast reproduction method based on the anatomical guidance of the cerebral images reconstruction in positron emission tomography; Evaluation d'une methode de restitution de contraste basee sur le guidage anatomique de la reconstruction des images cerebrales en tomographie par emission de positons

    Energy Technology Data Exchange (ETDEWEB)

    Bataille, F

    2007-04-15

    Positron emission tomography is a medical imaging modality providing in-vivo volumetric images of functional processes of the human body, which is used for the diagnosis and the following of neuro degenerative diseases. PET efficiency is however limited by its poor spatial resolution, which generates a decrease of the image local contrast and leads to an under-estimation of small cerebral structures involved in the degenerative mechanism of those diseases. This so-called partial volume effect degradation is usually corrected in a post-reconstruction processing framework through the use of anatomical information, whose spatial resolution allows a better discrimination between functional tissues. However, this kind of method has the major drawback of being very sensitive to the residual mismatches on the anatomical information processing. We developed in this thesis an alternative methodology to compensate for the degradation, by incorporating in the reconstruction process both a model of the system impulse response and an anatomically-based image prior constraint. This methodology was validated by comparison with a post-reconstruction correction strategy, using data from an anthropomorphic phantom acquisition and then we evaluated its robustness to the residual mismatches through a realistic Monte Carlo simulation corresponding to a cerebral exam. The proposed algorithm was finally applied to clinical data reconstruction. (author)

  15. Electric field and current density distributions induced in an anatomically-based model of the human head by magnetic fields from a hair dryer.

    Science.gov (United States)

    Tofani, S; Ossola, P; d'Amore, G; Gandhi, O P

    1995-01-01

    We have used the impedance method to calculate the induced electric (E) fields and current densities (J) for the spatially varying vector magnetic fields due to a hair dryer. In this method, applicable for low-frequency exposures where the quasi-static approximation may be made, the biological body or the exposed parts thereof are represented by a three-dimensional (3-D) network of impedances whose individual values are obtained from the electrical properties sigma, epsilon r for the various tissues. We have measured the 3-D variations of the 50-Hz magnetic fields from a typical hair dryer and found that the various components correlate well with those for a helical coil. The non-uniform magnetic fields thus obtained are used to calculate the induced E and J with a resolution of 1.31 cm for the model of the head and neck. The induced E values are compared with the fields endogenous to the body and the minimum detectable E-field limits based on the cellular thermal noise model proposed by Weaver and Astumian (1990, 1992).

  16. An anatomical and functional topography of human auditory cortical areas

    Directory of Open Access Journals (Sweden)

    Michelle eMoerel

    2014-07-01

    Full Text Available While advances in magnetic resonance imaging (MRI throughout the last decades have enabled the detailed anatomical and functional inspection of the human brain non-invasively, to date there is no consensus regarding the precise subdivision and topography of the areas forming the human auditory cortex. Here, we propose a topography of the human auditory areas based on insights on the anatomical and functional properties of human auditory areas as revealed by studies of cyto- and myelo-architecture and fMRI investigations at ultra-high magnetic field (7 Tesla. Importantly, we illustrate that - whereas a group-based approach to analyze functional (tonotopic maps is appropriate to highlight the main tonotopic axis - the examination of tonotopic maps at single subject level is required to detail the topography of primary and non-primary areas that may be more variable across subjects. Furthermore, we show that considering multiple maps indicative of anatomical (i.e. myelination as well as of functional properties (e.g. broadness of frequency tuning is helpful in identifying auditory cortical areas in individual human brains. We propose and discuss a topography of areas that is consistent with old and recent anatomical post mortem characterizations of the human auditory cortex and that may serve as a working model for neuroscience studies of auditory functions.

  17. Digital inlaid design based on anatomical characteristics and preliminary implementation of its program%基于解剖特征的数字化嵌体设计及程序的初步实现

    Institute of Scientific and Technical Information of China (English)

    宋杨; 孙玉春; 王勇; 韩景芸; 吕培军

    2011-01-01

    Objective : To explore the technical guideline of inlays computer aided design ( CAD) for further development, to test the feasibility of processing for the design results of the technical guideline, and to assist co-operation with automatic inlay CAD software development. Methods: On the basis of point cloud data of right mandibular first molar of standard crown, we established the coordinate system, the landmarks and lines and the characteristic curves. A dental cast of right mandibular first molar MODinlay of an individual normal occlusion was scanned. The following objects were digitized: prepared tooth、neighbor teeth and intercuspal bite record. On the basis of parametric standard crown established in the research, using Surfacer 11. 0, we achieved the reconstruction of MOD-inlay by extracting margin line, constructing tissue surface, constructing outer surface and occlusal grinding, then the design result was processed and try-in on the cast. We also developed automatic inlay CAD software based on the guideline of inlay CAD. Results : The guideline of inlay CAD was established, the design results were processed and an automatic inlay CAD software was developed on basis of Surfacer 11. 0. Conclusion: It is a feasible method to establish technical guideline of inlay based on reverse engineering technology and process its design result, and a automatic inlay CAD software could be developed based on the technical guideline.%目的:应用逆向工程软件,探索一条开发嵌体CAD软件的技术路线,验证其加工可行性,并尝试应用二次开发软件平台进行具有较高自动化设计能力的嵌体CAD软件程序的研发.方挂:首先在标准冠点云数据上创建坐标系、标志点/线以及特征曲线,建立参数化标准冠数据集,然后使用线激光扫描仪进行嵌体预备体、邻牙及咬合记录的数据采集并进行三维数据建模,再应用Surfacer 11.0软件,基于建立的参数化标准冠数据集,通过提取

  18. Personal Landmarks from the Legacy of Arthur Phelps

    Science.gov (United States)

    Lowke, John

    2013-09-01

    I have been influenced for my whole life by Art Phelps, more than by anyone else - other than my wife! I first heard of Art Phelps in 1960 when, in the middle of doing my PhD in Adelaide, South Australia, Frost and Phelps published their land-mark paper, not only on drift velocities, the subject of my PhD, but on Boltzmann analyses, which were to deliver detailed cross sections for all common gases. Later I dared to suggest to my university that one of my two external PhD examiners be Phelps, a move that led to me being accepted for a position at Westinghouse Research Laboratories in Pittsburgh for 6 years, with Phelps as my direct supervisor. Throughout this period, Phelps refused to be a co-author of any of my papers, leaving me with severe doubts as to what he thought of their quality! I list areas where insights from Phelps inspired the growth of new fruit. (1) That transverse and longitudinal electron diffusion coefficients differ, typically by a factor of two. (2) That averaging radiation absorption coefficients in electric arcs, using common weightings involving Black Body radiation, can and usually do lead to errors of orders of magnitude. (3) That CO2 laser discharges are largely controlled by electron attachment rather than by diffusion or recombination. (4) That boundary conditions for electrons at metal electrodes in arc welding, are not zero, but from an astrophysical analogy, are zero when extrapolated to one mean free path beyond the surface. (5) That the metastable vibrational states of nitrogen become an energy gain rather than a loss process for low energy electrons as occur in electrical breakdown in air, resulting in increases of the ionisation coefficient by orders of magnitude. Coupled with the detachment of electrons from negative ions by singlet delta states of metastable oxygen molecules, sustaining discharge electric fields are reduced a factor of five. Phelps worked on this problem with me until a few months before he died.

  19. Anatomical entity recognition with a hierarchical framework augmented by external resources.

    Directory of Open Access Journals (Sweden)

    Yan Xu

    Full Text Available References to anatomical entities in medical records consist not only of explicit references to anatomical locations, but also other diverse types of expressions, such as specific diseases, clinical tests, clinical treatments, which constitute implicit references to anatomical entities. In order to identify these implicit anatomical entities, we propose a hierarchical framework, in which two layers of named entity recognizers (NERs work in a cooperative manner. Each of the NERs is implemented using the Conditional Random Fields (CRF model, which use a range of external resources to generate features. We constructed a dictionary of anatomical entity expressions by exploiting four existing resources, i.e., UMLS, MeSH, RadLex and BodyPart3D, and supplemented information from two external knowledge bases, i.e., Wikipedia and WordNet, to improve inference of anatomical entities from implicit expressions. Experiments conducted on 300 discharge summaries showed a micro-averaged performance of 0.8509 Precision, 0.7796 Recall and 0.8137 F1 for explicit anatomical entity recognition, and 0.8695 Precision, 0.6893 Recall and 0.7690 F1 for implicit anatomical entity recognition. The use of the hierarchical framework, which combines the recognition of named entities of various types (diseases, clinical tests, treatments with information embedded in external knowledge bases, resulted in a 5.08% increment in F1. The resources constructed for this research will be made publicly available.

  20. Multiple landmarks, the encoding of environmental geometry and the spatial logics of a dual brain.

    Science.gov (United States)

    Chiesa, A Della; Pecchia, T; Tommasi, L; Vallortigara, G

    2006-10-01

    A series of place learning experiments was carried out in young chicks (Gallus gallus) in order to investigate how the geometry of a landmark array and that of a walled enclosure compete when disoriented animals could rely on both of them to re-orient towards the centre of the enclosure. A square-shaped array (four wooden sticks) was placed in the middle of a square-shaped enclosure, the two structures being concentric. Chicks were trained to ground-scratch to search for food hidden in the centre of the enclosure (and the array). To check for effects of array degradation, one, two, three or all landmarks were removed during test trials. Chicks concentrated their searching activity in the central area of the enclosure, but their accuracy was inversely contingent on the number of landmarks removed; moreover, the landmarks still present within the enclosure appeared to influence the shape of the searching patterns. The reduction in the number of landmarks affected the searching strategy of chicks, suggesting that they had focussed mainly on local cues when landmarks were present within the enclosure. When all the landmarks were removed, chicks searched over a larger area, suggesting an absolute encoding of distances from the local cues and less reliance on the relationships provided by the geometry of the enclosure. Under conditions of monocular vision, chicks tended to rely on different strategies to localize the centre on the basis of the eye (and thus the hemisphere) in use, the left hemisphere attending to details of the environment and the right hemisphere attending to the global shape. PMID:16941155

  1. Three-dimensional modeling of human hands based on hand anatomical structures%基于解剖结构可视化手模型的构建

    Institute of Scientific and Technical Information of China (English)

    白桂有; 张正治; 杨博贵; 孙华; 贾卫斗

    2007-01-01

    确显示手掌部主要解剖结构.%BACKGROUND:The anatomic structures and kinetic characteristics are the bases to establish hand model, and the kinetic characteristics of hand are determined by the anatomic structure. So, numerous scholars have paid close attention to virtual hand models based on the anatomic structures of hand.OBJECTIVE: To construct visible hand model based on anatomic structure.DESIGN: Single sample trial.SETTING: Center Laboratory, Third Military Medical University of Chinese PLA.MATERIALS: This trial was carried out in the Center Laboratory, Third Military Medical University of Chinese PLA in October 2003. Two fresh adult hands, which involved wrist joint, provided by the Department of Anatomy, Third Military Medical University of Chinese PLA, were employed. The two hands had no organic damage by naked observation.METHODS: The specimens were embedded and mill-cut (mill-cut layer thinness 0.2 mm). Cannon (ESO 1OD) digital camera (6.3 million pixel) was used for image collection. Each image was 31.5 MB, Data of 1 200 images were obtained.Adobe Photoshop 7.0 software was used for image treatment and then two-dimensional cross-section images were collected. The bone, flexor tendon and the outline of hand was three-dimensionally reconstructed by using the software,which was developed by the Department of Computer Science and Technology,Tsinghua University and Institute of Computer Medicine, Department of Anatomy, Third Military Medical University of Chinese PLA.MATN OUTCOME MEASURES: Three-dimensional reconstruction of the bone, flexor tendon and outline of hand.RESULTS: ①The outline of hand: After being reconstructed, the outline, which consisted of all fingers and nails, was well displayed, and observed from many directions.② Three-dimensional reconstruction of the bone of hand: The reconstructed bones of hands involved digital bones, metacarpal bones, carpal bones and all joints, and they could be displayed solely or in groups with other

  2. An anatomic gene expression atlas of the adult mouse brain

    OpenAIRE

    Ng, Lydia; Bernard, Amy; Lau, Chris; Overly, Caroline C.; Dong, Hong-Wei; Kuan, Chihchau; Pathak, Sayan; Sunkin, Susan M.; Dang, Chinh; Bohland, Jason W.; Bokil, Hemant; Mitra, Partha P.; Puelles, Luis; Hohmann, John; Anderson, David J.

    2009-01-01

    Studying gene expression provides a powerful means of understanding structure-function relationships in the nervous system. The availability of genome-scale in situ hybridization datasets enables new possibilities for understanding brain organization based on gene expression patterns. The Anatomic Gene Expression Atlas (AGEA) is a new relational atlas revealing the genetic architecture of the adult C57Bl/6J mouse brain based on spatial correlations across expression data for thousands of gene...

  3. Anatomic Eponyms in Neuroradiology: Head and Neck.

    Science.gov (United States)

    Bunch, Paul M

    2016-10-01

    In medicine, an eponym is a word-typically referring to an anatomic structure, disease, or syndrome-that is derived from a person's name. Medical eponyms are ubiquitous and numerous. They are also at times controversial. Eponyms reflect medicine's rich and colorful history and can be useful for concisely conveying complex concepts. Familiarity with eponyms facilitates correct usage and accurate communication. In this article, 22 eponyms used to describe anatomic structures of the head and neck are discussed. For each structure, the author first provides a biographical account of the individual for whom the structure is named. An anatomic description and brief discussion of the structure's clinical relevance follow. PMID:27283070

  4. This place looks familiar – how navigators distinguish places with ambiguous landmark objects when learning novel routes

    OpenAIRE

    Marianne eStrickrodt; Mary eO'Malley; Wiener, Jan M.

    2015-01-01

    We present two experiments investigating how navigators deal with ambiguous landmark information when learning unfamiliar routes. In the experiments we presented landmark objects repeatedly along a route, which allowed us to manipulate how informative single landmarks were (1) about the navigators’ location along the route and (2) about the action navigators had to take at that location. Experiment 1 demonstrated that reducing location informativeness alone did not affect route learning perfo...

  5. This Place Looks Familiar—How Navigators Distinguish Places with Ambiguous Landmark Objects When Learning Novel Routes

    OpenAIRE

    Strickrodt, Marianne; O'Malley, Mary; Wiener, Jan M.

    2015-01-01

    We present two experiments investigating how navigators deal with ambiguous landmark information when learning unfamiliar routes. In the experiments we presented landmark objects repeatedly along a route, which allowed us to manipulate how informative single landmarks were (1) about the navigators' location along the route and (2) about the action navigators had to take at that location. Experiment 1 demonstrated that reducing location informativeness alone did not affect route learning perfo...

  6. Characterizing brain anatomical connections using diffusion weighted MRI and graph theory.

    Science.gov (United States)

    Iturria-Medina, Y; Canales-Rodríguez, E J; Melie-García, L; Valdés-Hernández, P A; Martínez-Montes, E; Alemán-Gómez, Y; Sánchez-Bornot, J M

    2007-07-01

    A new methodology based on Diffusion Weighted Magnetic Resonance Imaging (DW-MRI) and Graph Theory is presented for characterizing the anatomical connections between brain gray matter areas. In a first step, brain voxels are modeled as nodes of a non-directed graph in which the weight of an arc linking two neighbor nodes is assumed to be proportional to the probability of being connected by nervous fibers. This probability is estimated by means of probabilistic tissue segmentation and intravoxel white matter orientational distribution function, obtained from anatomical MRI and DW-MRI, respectively. A new tractography algorithm for finding white matter routes is also introduced. This algorithm solves the most probable path problem between any two nodes, leading to the assessment of probabilistic brain anatomical connection maps. In a second step, for assessing anatomical connectivity between K gray matter structures, the previous graph is redefined as a K+1 partite graph by partitioning the initial nodes set in K non-overlapped gray matter subsets and one subset clustering the remaining nodes. Three different measures are proposed for quantifying anatomical connections between any pair of gray matter subsets: Anatomical Connection Strength (ACS), Anatomical Connection Density (ACD) and Anatomical Connection Probability (ACP). This methodology was applied to both artificial and actual human data. Results show that nervous fiber pathways between some regions of interest were reconstructed correctly. Additionally, mean connectivity maps of ACS, ACD and ACP between 71 gray matter structures for five healthy subjects are presented.

  7. Altered anatomical network in early blindness revealed by diffusion tensor tractography.

    Directory of Open Access Journals (Sweden)

    Ni Shu

    Full Text Available The topological architecture of the cerebral anatomical network reflects the structural organization of the human brain. Recently, topological measures based on graph theory have provided new approaches for quantifying large-scale anatomical networks. Diffusion MRI studies have revealed the efficient small-world properties and modular structure of the anatomical network in normal subjects. However, no previous study has used diffusion MRI to reveal changes in the brain anatomical network in early blindness. Here, we utilized diffusion tensor imaging to construct binary anatomical networks for 17 early blind subjects and 17 age- and gender-matched sighted controls. We established the existence of structural connections between any pair of the 90 cortical and sub-cortical regions using deterministic tractography. Compared with controls, early blind subjects showed a decreased degree of connectivity, a reduced global efficiency, and an increased characteristic path length in their brain anatomical network, especially in the visual cortex. Moreover, we revealed some regions with motor or somatosensory function have increased connections with other brain regions in the early blind, which suggested experience-dependent compensatory plasticity. This study is the first to show alterations in the topological properties of the anatomical network in early blindness. From the results, we suggest that analyzing the brain's anatomical network obtained using diffusion MRI data provides new insights into the understanding of the brain's re-organization in the specific population with early visual deprivation.

  8. An Anatomically Oriented Breast Coordinate System for Mammogram Analysis

    DEFF Research Database (Denmark)

    Brandt, Sami; Karemore, Gopal Raghunath; Karssemeijer, Nico;

    2011-01-01

    We have developed a breast coordinate system that is based on breast anatomy to register female breasts into a common coordinate frame in 2D mediolateral (ML) or mediolateral oblique (MLO) view mammograms. The breasts are registered according to the location of the pectoral muscle and the nipple...... and the shape of the breast boundary because these are the most robust features independent of the breast size and shape. On the basis of these landmarks, we have constructed a nonlinear mapping between the parameter frame and the breast region in the mammogram. This mapping makes it possible to identify...... and orientations are registered and extracted without non-linearly deforming the images. We use the proposed breast coordinate transform in a cross-sectional breast cancer risk assessment study of 490 women, in which we attempt to learn breast cancer risk factors from mammograms that were taken prior to when...

  9. Complex anatomic variation in the brachial region.

    Science.gov (United States)

    Troupis, Th; Michalinos, A; Protogerou, V; Mazarakis, A; Skandalakis, P

    2015-01-01

    Authors describe a case of a complex anatomic variation discovered during dissection of the humeral region. On the right side, brachial artery followed a superficial course. Musculocutaneous nerve did not pierce coracobrachialis muscle but instead passed below the muscle before continuing in the forearm. On the left side, a communication between musculocutaneous and median nerve was dissected. Those variations are analytically presented with a brief review on their anatomic and clinical implications. Considerations on their embryological origin are attempted.

  10. [The anatomical revolution and the transition of anatomical conception in late imperial china].

    Science.gov (United States)

    Sihn, Kyu Hwan

    2012-04-30

    This paper aimed to examine the anatomical revolution from Yilingaicuo (Correcting the Errors of Medicine) and Quantixinlun(Outline of Anatomy and Physiology) in late imperial China. As the cephalocentrism which the brain superintend human operation of the mind was diffused in China since 16th century, the cephalocentrism and the cardiocentrism had competed for the hegemony of anatomical conception. Because of the advent of Yilingaicuo and Quantixinlun, the cephalocentrism became the main stream in the anatomical conception. The supporters of the Wang Yangming's Xinxue(the Learning of Heart and Mind) argued that the heart was the central organ of perception, sensitivity, and morality of the human body in medicine since 16th century. Even reformist and revolutionary intellectuals like Tan sitong and Mao zedong who had supported the Wang Yangming's Xinxue embraced the cephalocentrism in the late 19th century and the early 20th century. May Fourth intellectuals had not obsessed metaphysical interpretation of human body any more in the New Culture Movement in 1910s. They regarded human body as the object of research and writing. The anatomy was transformed into the instrumental knowledge for mutilation of the body. Yilingaicuo challenged the traditional conception of body, and Chinese intellectuals drew interest in the anatomy knowledge based on real mutilation. Quantixinlun based on Western medicine fueled a controversy about anatomy. Though new knowledge of anatomy was criticized by traditional Chinese medical doctors from the usefulness and morality of anatomy, nobody disavowed new knowledge of anatomy from the institutionalization of Western medicine in medical school. The internal development of cephalocentrism and positivism had influence on anatomy in China since 16th century. The advent of Yilingaicuo and Quantixinlun provided the milestone of new anatomy, though both sides represented traditional Chinese medicine and Western medicine respectively. They

  11. The Architectural Features and Prevalence of Contemporary Landmarks in Kaunas City

    Directory of Open Access Journals (Sweden)

    Almantas Bružas

    2011-03-01

    Full Text Available The article focuses on contemporary architectural accents and their architectural features in Kaunas city. The paper also analyses the prevalence of contemporary architectural accents in the city. Some tendencies towards creating Kaunas landmarks, relationship between them and the built environment and aesthetic measures are discussed on the basis of analyzing the most important and characteristic sacral, commercial, industrial and residential architecture patterns. It can be concluded that contemporary materials as well as a lightweight construction and the courage of architects helped with producing the image of modern architectural landmark, though the spread of Kaunas contemporary landmarks has a chaotic character and the cityscape has not been enriched by the powerful dominants of space structure.Article in Lithuanian

  12. The language of landmarks: the role of background knowledge in indoor wayfinding.

    Science.gov (United States)

    Frankenstein, Julia; Brüssow, Sven; Ruzzoli, Felix; Hölscher, Christoph

    2012-08-01

    To effectively wayfind through unfamiliar buildings, humans infer their relative position to target locations not only by interpreting geometric layouts, especially length of line of sight, but also by using background knowledge to evaluate landmarks with respect to their probable spatial relation to a target. Questionnaire results revealed that participants have consistent background knowledge about the relative position of target locations. Landmarks were rated significantly differently with respect to their spatial relation to targets. In addition, results from a forced-choice task comparing snapshots of a virtual environment revealed that background knowledge influenced wayfinding decisions. We suggest that landmarks are interpreted semantically with respect to their function and spatial relation to the target location and thereby influence wayfinding decisions. This indicates that background knowledge plays a role in wayfinding.

  13. Analysis of anatomic variability in children with low mathematical skills

    Science.gov (United States)

    Han, Zhaoying; Fuchs, Lynn; Davis, Nikki; Cannistraci, Christopher J.; Anderson, Adam W.; Gore, John C.; Dawant, Benoit M.

    2008-03-01

    Mathematical difficulty affects approximately 5-9% of the population. Studies on individuals with dyscalculia, a neurologically based math disorder, provide important insight into the neural correlates of mathematical ability. For example, cognitive theories, neuropsychological studies, and functional neuroimaging studies in individuals with dyscalculia suggest that the bilateral parietal lobes and intraparietal sulcus are central to mathematical performance. The purpose of the present study was to investigate morphological differences in a group of third grade children with poor math skills. We compare population averages of children with low math skill (MD) to gender and age matched controls with average math ability. Anatomical data were gathered with high resolution MRI and four different population averaging methods were used to study the effect of the normalization technique on the results. Statistical results based on the deformation fields between the two groups show anatomical differences in the bilateral parietal lobes, right frontal lobe, and left occipital/parietal lobe.

  14. Surgeon's view of the skull base from the lateral approach.

    Science.gov (United States)

    Goldenberg, R A

    1984-12-01

    This paper presents the surgical anatomy of the skull base and infratemporal fossa. The information has been derived from the author's own experience in surgical and cadaver dissection, standard anatomical references, and selected experience of other skull base surgeons. Because the lateral approach has become the utilitarian method of exposure, the intricate detailed anatomy is demonstrated from this view at five levels of dissection, so the surgeon may gain a practical understanding of the surgical relationship of critical structures. Consistent anatomical landmarks can be used by the surgeon in the location of these critical structures. The styloid process, sphenoidal spine, and middle meningeal artery identify the internal carotid artery as it enters the carotid canal. The bony or fibrous septum that divides the jugular foramen into neural and vascular compartments may be used to better identify nerves IX, X, and XI. The zygomatic root is useful for location of the middle fossa dura. The lateral pterygoid plate leads directly to the foramen ovale. The increased precision of dissection permitted by use of the microscope requires an increased level of knowledge of anatomical structures in this area. It is hoped that the information presented in this paper will assist surgeons in the meticulous and thorough removal of skull base tumors and in the preservation of neural and vascular structures that are presently being sacrificed.

  15. Anatomical Localization of Lister’s Tubercle and its Clinical and Surgical Importance

    Science.gov (United States)

    Ağır, İsmail; Aytekin, Mahmut Nedim; Küçükdurmaz, Fatih; Gökhan, Servan; Çavuş, Umut Yücel

    2014-01-01

    The dorsal tubercle of the radius, once called Lister’s tubercle, is used as a landmark in wrist arthroscopy, wrist joint injections, and similar surgical and clinical procedures. However, there is no useful information in the reference anatomy books and literature. The aim of this study was to identify the anatomical localization of Lister’s tubercle on the dorsum of radius in relation to the radial styloid process and the ulnar notch of radius and to demonstrate the clinical and surgical importance of these relationships. We studied 20 dried cadaver radius specimens. The distances from Lister’s tubercle to the radial styloid process and to the ulnar notch were measured by using a digital micrometer caliber and the ratio of the two measures was calculated. The dorsal tubercle of the radius is variable in position and can be either closer to the radial styloid process or to the ulnar notch. The present study showed that in 11 of the radii the dorsal tubercle of the radius was nearer to the radial styloid process than the ulnar notch, while in 9 subjects it was nearer to the ulnar notch. This anatomical variation may be relevant for wrist injections, wrist artroscopy or wrist surgery. PMID:24843388

  16. Comparative validity and reproducibility study of various landmark-oriented reference planes in 3-dimensional computed tomographic analysis for patients receiving orthognathic surgery.

    Directory of Open Access Journals (Sweden)

    Hsiu-Hsia Lin

    Full Text Available Three-dimensional computed tomographic imaging has become popular in clinical evaluation, treatment planning, surgical simulation, and outcome assessment for maxillofacial intervention. The purposes of this study were to investigate whether there is any correlation among landmark-based horizontal reference planes and to validate the reproducibility and reliability of landmark identification.Preoperative and postoperative cone-beam computed tomographic images of patients who had undergone orthognathic surgery were collected. Landmark-oriented reference planes including the Frankfort horizontal plane (FHP and the lateral semicircular canal plane (LSP were established. Four FHPs were defined by selecting 3 points from the orbitale, porion, or midpoint of paired points. The LSP passed through both the lateral semicircular canal points and nasion. The distances between the maxillary or mandibular teeth and the reference planes were measured, and the differences between the 2 sides were calculated and compared. The precision in locating the landmarks was evaluated by performing repeated tests, and the intraobserver reproducibility and interobserver reliability were assessed.A total of 30 patients with facial deformity and malocclusion--10 patients with facial symmetry, 10 patients with facial asymmetry, and 10 patients with cleft lip and palate--were recruited. Comparing the differences among the 5 reference planes showed no statistically significant difference among all patient groups. Regarding intraobserver reproducibility, the mean differences in the 3 coordinates varied from 0 to 0.35 mm, with correlation coefficients between 0.96 and 1.0, showing high correlation between repeated tests. Regarding interobserver reliability, the mean differences among the 3 coordinates varied from 0 to 0.47 mm, with correlation coefficients between 0.88 and 1.0, exhibiting high correlation between the different examiners.The 5 horizontal reference planes were

  17. MORPHOLOGICAL ANATOMICAL AND PHITOCHEMICAL CHARACTERISTICS OF SOME ALGAE

    OpenAIRE

    N. S. Kaysheva; M. N. Arkhipova; A. S. Kayshev

    2014-01-01

    Morphological and anatomical features of thalluses of brown (Laminaria saccharina, Fucus vesiculosus) and red (Ahnfeltia plicata) algae, procured at a coastal strip of the Northern basin in gulfs of Ura-Guba and Palkina-Guba at different depths. Compliance of Fucus and Ahnfeltia with pharmacopoeial norms and merchandising indices for Laminaria was established, except for high concentration of sand in Ahnfeltia thalluses. The identity of algae between each other was shown based on the results ...

  18. A Catalytic Role for Mod5 in the Formation of the Tea1 Cell Polarity Landmark

    OpenAIRE

    Bicho, Claudia C.; Kelly, David A.; Snaith, Hilary A.; Goryachev, Andrew B.; Sawin, Kenneth E.

    2010-01-01

    Summary Many systems regulating cell polarity involve stable landmarks defined by internal cues [1–5]. In the rod-shaped fission yeast Schizosaccharomyces pombe, microtubules regulate polarized vegetative growth via a landmark involving the protein Tea1 [6–9]. Tea1 is delivered to cell tips as packets of molecules associated with growing microtubule ends [10] and anchored at the plasma membrane via a mechanism involving interaction with the membrane protein Mod5 [11, 12]. Tea1 and Mod5 are hi...

  19. Localization and navigation using a novel artificial landmark for indoor mobile robots

    Institute of Scientific and Technical Information of China (English)

    Wen Feng; Yuan Kui; Zheng Rui

    2009-01-01

    This paper presents a practical topological navigation system for indoor mobile robots, making use of a novel artificial landmark which is called MR code. This new kind of paper-made landmarks can be easily attached on the ceilings or on the walls. Localization algorithms for the two cases are given respectively. A docking control algorithm is also described, which a robot employs to approach its current goal. A simple topological navigation algorithm is proposed. Experiment results show the effectiveness of the method in real environment.

  20. Employing anatomical knowledge in vertebral column labeling

    Science.gov (United States)

    Yao, Jianhua; Summers, Ronald M.

    2009-02-01

    The spinal column constitutes the central axis of human torso and is often used by radiologists to reference the location of organs in the chest and abdomen. However, visually identifying and labeling vertebrae is not trivial and can be timeconsuming. This paper presents an approach to automatically label vertebrae based on two pieces of anatomical knowledge: one vertebra has at most two attached ribs, and ribs are attached only to thoracic vertebrae. The spinal column is first extracted by a hybrid method using the watershed algorithm, directed acyclic graph search and a four-part vertebra model. Then curved reformations in sagittal and coronal directions are computed and aggregated intensity profiles along the spinal cord are analyzed to partition the spinal column into vertebrae. After that, candidates for rib bones are detected using features such as location, orientation, shape, size and density. Then a correspondence matrix is established to match ribs and vertebrae. The last vertebra (from thoracic to lumbar) with attached ribs is identified and labeled as T12. The rest of vertebrae are labeled accordingly. The method was tested on 50 CT scans and successfully labeled 48 of them. The two failed cases were mainly due to rudimentary ribs.

  1. Is the cervical fascia an anatomical proteus?

    Science.gov (United States)

    Natale, Gianfranco; Condino, Sara; Stecco, Antonio; Soldani, Paola; Belmonte, Monica Mattioli; Gesi, Marco

    2015-11-01

    The cervical fasciae have always represented a matter of debate. Indeed, in the literature, it is quite impossible to find two authors reporting the same description of the neck fascia. In the present review, a historical background was outlined, confirming that the Malgaigne's definition of the cervical fascia as an anatomical Proteus is widely justified. In an attempt to provide an essential and a more comprehensive classification, a fixed pattern of description of cervical fasciae is proposed. Based on the morphogenetic criteria, two fascial groups have been recognized: (1) fasciae which derive from primitive fibro-muscular laminae (muscular fasciae or myofasciae); (2) fasciae which derive from connective thickening (visceral fasciae). Topographic and comparative approaches allowed to distinguish three different types of fasciae in the neck: the superficial, the deep and the visceral fasciae. The first is most connected to the skin, the second to the muscles and the third to the viscera. The muscular fascia could be further divided into three layers according to the relationship with the different muscles.

  2. Testing anatomically specified hypotheses in functional imaging using cytoarchitectonic maps.

    Science.gov (United States)

    Eickhoff, Simon B; Heim, Stefan; Zilles, Karl; Amunts, Katrin

    2006-08-15

    The statistical inference on functional imaging data is severely complicated by the embedded multiple testing problem. Defining a region of interest (ROI) where the activation is hypothesized a priori helps to circumvent this problem, since in this case the inference is restricted to fewer simultaneous tests, rendering it more sensitive. Cytoarchitectonic maps obtained from postmortem brains provide objective, a priori ROIs that can be used to test anatomically specified hypotheses about the localization of functional activations. We here analyzed three methods for the definition of ROIs based on probabilistic cytoarchitectonic maps. (1) ROIs defined by the volume assigned to a cytoarchitectonic area in the summary map of all areas (maximum probability map, MPM), (2) ROIs based on thresholding the individual probabilistic maps and (3) spherical ROIs build around the cytoarchitectonic center of gravity. The quality with which the thus defined ROIs represented the respective cytoarchitectonic areas as well as their sensitivity for detecting functional activations was subsequently statistically evaluated. Our data showed that the MPM method yields ROIs, which reflect most adequately the underlying anatomical hypotheses. These maps also show a high degree of sensitivity in the statistical analysis. We thus propose the use of MPMs for the definition of ROIs. In combination with thresholding based on the Gaussian random field theory, these ROIs can then be applied to test anatomically specified hypotheses in functional neuroimaging studies. PMID:16781166

  3. Animals' Use of Landmarks and Metric Information to Reorient: Effects of the Size of the Experimental Space

    Science.gov (United States)

    Sovrano, Valeria Anna; Bisazza, Angelo; Vallortigara, Giorgio

    2005-01-01

    Disoriented children could use geometric information in combination with landmark information to reorient themselves in large but not in small experimental spaces. We tested fish in the same task and found that they were able to conjoin geometric and non-geometric (landmark) information to reorient themselves in both the large and the small space…

  4. Navigating in small-scale space: the role of landmarks and resource monitoring in understanding saddleback tamarin travel.

    Science.gov (United States)

    Garber, Paul A; Porter, Leila M

    2014-05-01

    Recent studies of spatial memory in wild nonhuman primates indicate that foragers may rely on a combination of navigational strategies to locate nearby and distant feeding sites. When traveling in large-scale space, tamarins are reported to encode spatial information in the form of a route-based map. However, little is known concerning how wild tamarins navigate in small-scale space (between feeding sites located at a distance of ≤60 m). Therefore, we collected data on range use, diet, and the angle and distance traveled to visit sequential feeding sites in the same group of habituated Bolivian saddleback tamarins (Saguinus fuscicollis weddelli) in 2009 and 2011. For 7-8 hr a day for 54 observation days, we recorded the location of the study group at 10 min intervals using a GPS unit. We then used GIS software to map and analyze the monkeys' movements and travel paths taken between feeding sites. Our results indicate that in small-scale space the tamarins relied on multiple spatial strategies. In 31% of cases travel was route-based. In the remaining 69% of cases, however, the tamarins appeared to attend to the spatial positions of one or more near-to-site landmarks to relocate feeding sites. In doing so they approached the same feeding site from a mean of 4.5 different directions, frequently utilized different arboreal pathways, and traveled approximately 30% longer than then the straight-line distance. In addition, the monkeys' use of non-direct travel paths allowed them to monitor insect and fruit availability in areas within close proximity of currently used food patches. We conclude that the use of an integrated spatial strategy (route-based travel and attention to near-to-goal landmarks) provides tamarins with the opportunity to relocate productive feeding sites as well as monitor the availability of nearby resources in small-scale space.

  5. Lateral laryngopharyngeal diverticulum: anatomical and videofluoroscopic study

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Milton Melciades Barbosa [Universidade Federal do Rio de Janeiro ICB/CCS/UFRJ, Laboratorio de Motilidade Digestiva e Imagem, S. F1-008, Departamento de Anatomia, Rio de Janeiro (Brazil); Koch, Hilton Augusto [Universidade Federal do Rio de Janeiro ICB/CCS/UFRJ, Departamento de Radiologia, Rio de Janeiro (Brazil)

    2005-07-01

    The aims were to characterize the anatomical region where the lateral laryngopharyngeal protrusion occurs and to define if this protrusion is a normal or a pathological entity. This protrusion was observed on frontal contrasted radiographs as an addition image on the upper portion of the laryngopharynx. We carried out a plane-by-plane qualitative anatomical study through macroscopic and mesoscopic surgical dissection on 12 pieces and analyzed through a videofluoroscopic method on frontal incidence the pharyngeal phase of the swallowing process of 33 patients who had a lateral laryngopharyngeal protrusion. The anatomical study allowed us to identify the morphological characteristics that configure the high portion of the piriform recess as a weak anatomical point. The videofluoroscopic study allowed us to observe the laryngopharyngeal protrusion and its relation to pharyngeal repletion of the contrast medium. All kinds of the observed protrusions could be classified as ''lateral laryngopharyngeal diverticula.'' The lateral diverticula were more frequent in older people. These lateral protrusions can be found on one or both sides, usually with a small volume, without sex or side prevalence. This formation is probably a sign of a pharyngeal transference difficulty associated with a deficient tissue resistance in the weak anatomical point of the high portion of the piriform recess. (orig.)

  6. Anatomic research on distally based compound flap pedicled with the nutrient vessels of cephalic vein%头静脉营养血管远端蒂复合瓣的解剖学研究

    Institute of Scientific and Technical Information of China (English)

    张发惠; 林松庆; 郑和平; 张国栋

    2006-01-01

    BACKGROUND: Distally based flap pedicled with the distal nutritional vessels in forearm is especially suitable for reconstructing the tissue defects in the distal end of hands, while high rotation point cannot satisfy the requirements of reconstructing the distal injuries or defects in hands, and severer lesion may even be caused in the donor site.OBJECTIVE: To study the anatomic proceeding of artery perforators in distal radial margin of forearms, so as to provide anatomic basis for the design of distally based compound flap pedicled with the nutrient vessel of cephalic vein in distal radial margin of forearms.DESIGN: Single sample experiment.SETTING: Center for Clinical Anatomy of the Department of Orthopedics,Fuzhou General Hospital of Chinese PLA of Nanjing Military Area Command.MATERIALS: The experiment was conducted in the Laboratory of Center for Clinical Anatomy of Department of Orthopedics, Fuzhou General Hospital of Chinese PLA of Nanjing Military Area Command between August and December 2004. The upper extremities of 30 cadavers injected with a mixture of red gelatin into the artery (provided by the Center for Clinical Anatomy of Department of Orthopedics, Fuzhou General Hospital of Chinese PLA of Nanjing Military Area Command) were adopted.METHODS: The vascular external diameter and distance were measured with sliding caliper and ruler with radial styloid process as the marker.MAIN OUTCOME MEASURES: ① The perforator artery in distal radial margin of forearms. ② The nutrient vessels of cephalic vein. ③ The relationship of blood supply between the nutrient vessels and vicinal bone and skin as well as the lateral antebrachial cutaneous nerve. ④ The superficial and deep communicating branches of cephalic vein.RESULTS: The perforator artery in distal radial margin of forearms derived from: 6-11 cutaneous branches of radial artery with external diameter of (0.7±0.3) mm; 2-6 cutaneous branches of superficial palma with the external diameter of (0.5±0

  7. Detection and analysis of statistical differences in anatomical shape.

    Science.gov (United States)

    Golland, Polina; Grimson, W Eric L; Shenton, Martha E; Kikinis, Ron

    2005-02-01

    We present a computational framework for image-based analysis and interpretation of statistical differences in anatomical shape between populations. Applications of such analysis include understanding developmental and anatomical aspects of disorders when comparing patients versus normal controls, studying morphological changes caused by aging, or even differences in normal anatomy, for example, differences between genders. Once a quantitative description of organ shape is extracted from input images, the problem of identifying differences between the two groups can be reduced to one of the classical questions in machine learning of constructing a classifier function for assigning new examples to one of the two groups while making as few misclassifications as possible. The resulting classifier must be interpreted in terms of shape differences between the two groups back in the image domain. We demonstrate a novel approach to such interpretation that allows us to argue about the identified shape differences in anatomically meaningful terms of organ deformation. Given a classifier function in the feature space, we derive a deformation that corresponds to the differences between the two classes while ignoring shape variability within each class. Based on this approach, we present a system for statistical shape analysis using distance transforms for shape representation and the support vector machines learning algorithm for the optimal classifier estimation and demonstrate it on artificially generated data sets, as well as real medical studies. PMID:15581813

  8. Bicycle Chain Shape Models

    DEFF Research Database (Denmark)

    Sommer, Stefan Horst; Tatu, Aditya Jayant; Chen, Chen;

    2009-01-01

    In this paper we introduce landmark-based preshapes which allow mixing of anatomical landmarks and pseudo-landmarks, constraining consecutive pseudo-landmarks to satisfy planar equidistance relations. This defines naturally a structure of Riemannian manifold on these preshapes, with a natural act...

  9. Illusionary Inclusion--What Went Wrong with New Labour's Landmark Educational Policy?

    Science.gov (United States)

    Hodkinson, Alan

    2012-01-01

    This article examines the emergence and evolution of New Labour's landmark educational policy; namely that of inclusion. The author, Alan Hodkinson, associate professor at the Centre for Cultural and Disability Studies at Liverpool Hope University, illuminates his conceptual difficulties in attempting to define what inclusion was and what…

  10. Obstacles Facing Promoting Tourism for Islamic Landmarks from the Perspective of Tour Operators in Egypt

    Directory of Open Access Journals (Sweden)

    Suzan Bakri Hassan

    2015-05-01

    Full Text Available The UNESCO launched a campaign #unite4heritage in Egypt to defeat extremism and intolerance. The message of such campaigne is peace, dialogue and unity embedded in cultural heritage. As culture and tourism are linked together, such message could be delivered through improving culture heritage tourism in Egypt. Islamic landmarks  are considered as a part of human heritage. Therefore, the purpose of this study is to identify how much tour operators in Egypt include Islamic landmarks in their programs to determine the obstacles facing promoting cultural tourism in Islamic landmarks' areas. Additionally, the study would identify positive results in the case of developing heritage tourism in Egypt. To achieve a high result, a survey approach was employed to collect data from 100 tour operators, using a completed questionnaire technique as well as a Likert Scale and statistical models in order to test and interpret the research outcomes. The research findings indicated that although tour operators in Egypt are convinced of the significance of the Islamic landmarks, there is no contradiction between creating global understanding and at the same time achieving benefit to the local community. However, there is a range of obstacles facing promoting such type of tourism in Egypt. Keywords: Culture heritage tourism, community, Egypt, Islamic civilization.

  11. Global Polity in Adult Education and UNESCO: Landmarking, Brokering and Framing Policy

    Science.gov (United States)

    Milana, Marcella

    2016-01-01

    Aknowledging the complexity of local-global interconnections, the author argues for the adoption of a global polity perspective in adult education, here applied to study mobilisation processes that occur through UNESCO. The findings point to three processes that cross geopolitical borders and professional interests: "landmarking," by…

  12. Landmark Recognition in Alzheimer's Dementia: Spared Implicit Memory for Objects Relevant for Navigation

    NARCIS (Netherlands)

    Kessels, R.P.C.; Doormaal, A.A.M. van; Janzen, G.

    2011-01-01

    Background: In spatial navigation, landmark recognition is crucial. Specifically, memory for objects placed at decision points on a route is relevant. Previous fMRI research in healthy adults showed higher medial-temporal lobe (MTL) activation for objects placed at decision points compared to non-de

  13. Landmark recognition in Alzheimer's dementia: spared implicit memory for objects relevant for navigation

    NARCIS (Netherlands)

    Kessels, R.P.C.; Doormaal, A. van; Janzen, G.

    2011-01-01

    BACKGROUND: In spatial navigation, landmark recognition is crucial. Specifically, memory for objects placed at decision points on a route is relevant. Previous fMRI research in healthy adults showed higher medial-temporal lobe (MTL) activation for objects placed at decision points compared to non-de

  14. Smells like home: Desert ants, Cataglyphis fortis, use olfactory landmarks to pinpoint the nest

    Directory of Open Access Journals (Sweden)

    Knaden Markus

    2009-02-01

    Full Text Available Abstract Background Cataglyphis fortis ants forage individually for dead arthropods in the inhospitable salt-pans of Tunisia. Locating the inconspicuous nest after a foraging run of more than 100 meters demands a remarkable orientation capability. As a result of high temperatures and the unpredictable distribution of food, Cataglyphis ants do not lay pheromone trails. Instead, path integration is the fundamental system of long-distance navigation. This system constantly informs a foraging ant about its position relative to the nest. In addition, the ants rely on visual landmarks as geocentric navigational cues to finally pinpoint the nest entrance. Results Apart from the visual cues within the ants' habitat, we found potential olfactory landmark information with different odour blends coupled to various ground structures. Here we show that Cataglyphis ants can use olfactory information in order to locate their nest entrance. Ants were trained to associate their nest entrance with a single odour. In a test situation, they focused their nest search on the position of the training odour but not on the positions of non-training odours. When trained to a single odour, the ants were able to recognise this odour within a mixture of four odours. Conclusion The uniform salt-pans become less homogenous if one takes olfactory landmarks into account. As Cataglyphis ants associate environmental odours with the nest entrance they can be said to use olfactory landmarks in the vicinity of the nest for homing.

  15. An intelligent gradient detector with minimization of visual landmarks distortion for monitoring of passenger flows

    OpenAIRE

    Gorbenko, A.; Popov, V.

    2013-01-01

    In this paper, we study the problem of monitoring of passenger flows. We consider an intelligent gradient algorithm to solve the problem. We use a method of minimization of visual landmarks distortion to improve the quality of recognition. © 2013 Anna Gorbenko and Vladimir Popov.

  16. Parallel striatal and hippocampal systems for landmarks and boundaries in spatial memory.

    Science.gov (United States)

    Doeller, Christian F; King, John A; Burgess, Neil

    2008-04-15

    How the memory systems centered on the hippocampus and dorsal striatum interact to support behavior remains controversial. We used functional MRI while people learned the locations of objects by collecting and replacing them over multiple trials within a virtual environment comprising a landmark, a circular boundary, and distant cues for orientation. The relative location of landmark and boundary was occasionally changed, with specific objects paired with one or other cue, allowing dissociation of learning and performance relative to either cue. Right posterior hippocampal activation reflected learning and remembering of boundary-related locations, whereas right dorsal striatal activation reflected learning and remembering of landmark-related locations. Within the right hippocampus, anterior processing of environmental change (spatial novelty) was dissociated from posterior processing of location. Behavioral studies show that landmark-related learning obeys associative reinforcement, whereas boundary-related learning is incidental [Doeller CF, Burgess N (2008) Proc Natl Acad Sci USA 105:5909-5914]. The distinct incidental hippocampal processing of boundaries is suggestive of a "geometric module" or "cognitive map" and may explain the hippocampal support of incidental/observational learning in "declarative" or "episodic" memory versus the striatal support of trial-and-error learning in "procedural" memory. Finally, the hippocampal and striatal systems appear to combine "bottom-up," simply influencing behavior proportional to their activations, without direct interaction, with "top-down" ventromedial prefrontal involvement when both are similarly active. PMID:18408152

  17. The developmental trajectory of intramaze and extramaze landmark biases in spatial navigation: An unexpected journey.

    Science.gov (United States)

    Buckley, Matthew G; Haselgrove, Mark; Smith, Alastair D

    2015-06-01

    Adults learning to navigate to a hidden goal within an enclosed space have been found to prefer information provided by the distal cues of an environment, as opposed to proximal landmarks within the environment. Studies with children, however, have shown that 5- or 7-year-olds do not display any preference toward distal or proximal cues during navigation. This suggests that a bias toward learning about distal cues occurs somewhere between the age of 7 years and adulthood. We recruited 5- to 11-year-old children and an adult sample to explore the developmental profile of this putative change. Across a series of 3 experiments, participants were required to navigate to a hidden goal in a virtual environment, the location of which was signaled by both extramaze and intramaze landmark cues. During testing, these cues were placed into conflict to assess the search preferences of participants. Consistent with previously reported findings, adults were biased toward using extramaze information. However, analysis of the data from children, which incorporated age as a continuous variable, suggested that older children in our sample were, in fact, biased toward using the intramaze landmark in our task. These findings suggest the bias toward using distal cues in spatial navigation, frequently displayed by adults, may be a comparatively late developing trait, and one that could supersede an initial developmental preference for proximal landmarks. PMID:25844850

  18. 76 FR 60079 - Landmarks Committee of the National Park System Advisory Board Meeting

    Science.gov (United States)

    2011-09-28

    ... National Park Service Landmarks Committee of the National Park System Advisory Board Meeting AGENCY... Advisory Board will be held beginning at 1 p.m. on November 8, 2011, at the following location. The meeting... System Advisory Board at a subsequent meeting at a place and time to be determined. The Committee...

  19. 76 FR 55701 - Landmarks Committee of the National Park System Advisory Board Meeting

    Science.gov (United States)

    2011-09-08

    ... National Park Service Landmarks Committee of the National Park System Advisory Board Meeting AGENCY... Advisory Board will be held beginning at 1 p.m. on November 8, 2011, at the following location. The meeting... System Advisory Board at a subsequent meeting at a place and time to be determined. The Committee...

  20. 77 FR 14420 - Landmarks Committee of the National Park System Advisory Board Meeting

    Science.gov (United States)

    2012-03-09

    ... National Park Service Landmarks Committee of the National Park System Advisory Board Meeting AGENCY... Advisory Board will be held beginning at 10 a.m. on May 15, 2012, at the following location. The meeting... National Park System Advisory Board at a subsequent meeting at a place and time to be determined....

  1. 36 CFR 62.4 - Natural landmark designation and recognition process.

    Science.gov (United States)

    2010-07-01

    ... sufficient representation of the significant natural features. (g) National Park System Advisory Board. (1... qualifies for national natural landmark designation. (2) Notice of Advisory Board meetings to review... also attend the board meeting and upon request may address the board concerning an area's...

  2. Landmarks in the Professional and Academic Development of Mid-Career Teacher Educators

    Science.gov (United States)

    Griffiths, Vivienne; Thompson, Simon; Hryniewicz, Liz

    2014-01-01

    This paper focuses on the professional and academic development of mid-career teacher educators from two universities in England. The objectives of the study were to analyse and compare the career experiences of teacher educators; in particular, to identify stages of development, landmark events and contextual factors affecting professional…

  3. Observer Reliability of Three-Dimensional Cephalometric Landmark Identification on Cone-Beam CT

    Science.gov (United States)

    de Oliveira, Ana Emilia F.; Cevidanes, Lucia Helena S.; Phillips, Ceib; Motta, Alexandre; Burke, Brandon; Tyndall, Donald

    2009-01-01

    Objective To evaluate reliability in 3D landmark identification using Cone-Beam CT. Study Design Twelve pre-surgery CBCTs were randomly selected from 159 orthognathic surgery patients. Three observers independently repeated three times the identification of 30 landmarks in the sagittal, coronal, and axial slices. A mixed effects ANOVA model estimated the Intraclass Correlations (ICC) and assessed systematic bias. Results The ICC was >0.9 for 86% of intra-observer assessments and 66% of inter-observer assessments. Only 1% of intra-observer and 3% of inter-observer coefficients were <0.45. The systematic difference among observers was greater in X and Z than in Y dimensions, but the maximum mean difference was quite small. Conclusion Overall, the intra- and inter-observer reliability was excellent. 3D landmark identification using CBCT can offer consistent and reproducible data, if a protocol for operator training and calibration is followed. This is particularly important for landmarks not easily specified in all three planes of space. PMID:18718796

  4. Anatomic Breast Coordinate System for Mammogram Analysis

    DEFF Research Database (Denmark)

    Karemore, Gopal Raghunath; Brandt, S; Karssemeijer, N;

    2011-01-01

    inside the breast. Most of the risk assessment and CAD modules use a breast region in a image centered Cartesian x,y coordinate system. Nevertheless, anatomical structure follows curve-linear trajectories. We examined an anatomical breast coordinate system that preserves the anatomical correspondence...... between the mammograms and allows extracting not only the aligned position but also the orientation aligned with the anatomy of the breast tissue structure. Materials and Methods The coordinate system used the nipple location as the point A and the border of the pectoral muscle as a line BC. The skin air...... was represented by geodesic distance (s) from nipple and parametric angle (¿) as shown in figure 1. The scoring technique called MTR (mammographic texture resemblance marker) used this breast coordinate system to extract Gaussian derivative features. The features extracted using the (x,y) and the curve...

  5. Sensitivity of predicted muscle forces during gait to anatomical variability in musculotendon geometry.

    Science.gov (United States)

    Bosmans, Lode; Valente, Giordano; Wesseling, Mariska; Van Campen, Anke; De Groote, Friedl; De Schutter, Joris; Jonkers, Ilse

    2015-07-16

    Scaled generic musculoskeletal models are commonly used to drive dynamic simulations of motions. It is however, acknowledged that not accounting for variability in musculoskeletal geometry and musculotendon parameters may confound the simulation results, even when analysing control subjects. This study documents the three-dimensional anatomical variability of musculotendon origins and insertions of 33 lower limb muscles determined based on magnetic resonance imaging in six subjects. This anatomical variability was compared to the musculotendon point location in a generic musculoskeletal model. Furthermore, the sensitivity of muscle forces during gait, calculated using static optimization, to perturbations of the musculotendon point location was analyzed with a generic model. More specific, a probabilistic approach was used: for each analyzed musculotendon point, the three-dimensional location was re-sampled with a uniform Latin hypercube method within the anatomical variability and the static optimization problem was then re-solved for all perturbations. We found that musculotendon point locations in the generic model showed only variable correspondences with the anatomical variability. The anatomical variability of musculotendon point location did affect the calculated muscle forces: muscles most sensitive to perturbations within the anatomical variability are iliacus and psoas. Perturbation of the gluteus medius anterior, iliacus and psoas induces the largest concomitant changes in muscle forces of the unperturbed muscles. Therefore, when creating subject-specific musculoskeletal models, these attachment points should be defined accurately. In addition, the size of the anatomical variability of the musculotendon point location was not related to the sensitivity of the calculated muscle forces. PMID:25979383

  6. Congenital neck masses: embryological and anatomical perspectives

    Directory of Open Access Journals (Sweden)

    Zahida Rasool

    2013-08-01

    Full Text Available Neck masses are a common problem in paediatric age group. They tend to occur frequently and pose a diagnostic dilemma to the ENT surgeons. Although the midline and lateral neck masses differ considerably in their texture and presentation but the embryological perspective of these masses is not mostly understood along with the fundamental anatomical knowledge. The article tries to correlate the embryological, anatomical and clinical perspectives for the same. [Int J Res Med Sci 2013; 1(4.000: 329-332

  7. Anatomical basis for Wilms tumor surgery

    Directory of Open Access Journals (Sweden)

    Trobs R

    2009-01-01

    Full Text Available Wilms tumor surgery requires meticulous planning and sophisticated surgical technique. Detailed anatomical knowledge can facilitate the uneventful performance of tumor nephrectomy and cannot be replaced by advanced and sophisticated imaging techniques. We can define two main goals for surgery: (1 exact staging as well as (2 safe and complete resection of tumor without spillage. This review aims to review the anatomical basis for Wilms tumor surgery. It focuses on the surgical anatomy of retroperitoneal space, aorta, vena cava and their large branches with lymphatics. Types and management of vascular injuries are discussed.

  8. Shape-based diagnosis of the aortic valve

    Science.gov (United States)

    Ionasec, Razvan Ioan; Tsymbal, Alexey; Vitanovski, Dime; Georgescu, Bogdan; Zhou, S. Kevin; Navab, Nassir; Comaniciu, Dorin

    2009-02-01

    Disorders of the aortic valve represent a common cardiovascular disease and an important public-health problem worldwide. Pathological valves are currently determined from 2D images through elaborate qualitative evalu- ations and complex measurements, potentially inaccurate and tedious to acquire. This paper presents a novel diagnostic method, which identies diseased valves based on 3D geometrical models constructed from volumetric data. A parametric model, which includes relevant anatomic landmarks as well as the aortic root and lea ets, represents the morphology of the aortic valve. Recently developed robust segmentation methods are applied to estimate the patient specic model parameters from end-diastolic cardiac CT volumes. A discriminative distance function, learned from equivalence constraints in the product space of shape coordinates, determines the corresponding pathology class based on the shape information encoded by the model. Experiments on a heterogeneous set of 63 patients aected by various diseases demonstrated the performance of our method with 94% correctly classied valves.

  9. Indexing Anatomical Phrases in Neuro-Radiology Reports to the UMLS 2005AA

    OpenAIRE

    Bashyam, Vijayaraghavan; Taira, Ricky K.

    2005-01-01

    This work describes a methodology to index anatomical phrases to the 2005AA release of the Unified Medical Language System (UMLS). A phrase chunking tool based on Natural Language Processing (NLP) was developed to identify semantically coherent phrases within medical reports. Using this phrase chunker, a set of 2,551 unique anatomical phrases was extracted from brain radiology reports. These phrases were mapped to the 2005AA release of the UMLS using a vector space model. Pr...

  10. Marginal space learning for medical image analysis efficient detection and segmentation of anatomical structures

    CERN Document Server

    Zheng, Yefeng

    2014-01-01

    Presents an award winning image analysis technology (Thomas Edison Patent Award, MICCAI Young Investigator Award) that achieves object detection and segmentation with state-of-the-art accuracy and efficiency Flexible, machine learning-based framework, applicable across multiple anatomical structures and imaging modalities Thirty five clinical applications on detecting and segmenting anatomical structures such as heart chambers and valves, blood vessels, liver, kidney, prostate, lymph nodes, and sub-cortical brain structures, in CT, MRI, X-Ray and Ultrasound.

  11. Anatomical and psychometric relationships of behavioral neglect in daily living.

    Science.gov (United States)

    Rousseaux, Marc; Allart, Etienne; Bernati, Thérèse; Saj, Arnaud

    2015-04-01

    Spatial neglect has been related to both cortical (predominantly at the temporal-parietal junction) and subcortical (predominantly of the superior longitudinal fasciculus) lesions. The objectives of this observational study were to specify the anatomical relationships of behavioral neglect in activities of daily living (N-ADLs), and the anatomical and psychometric relationships of N-ADLs on one hand and components of neglect (peripersonal neglect and personal neglect) and anosognosia on the other. Forty five patients were analyzed for behavioral difficulties in daily living (on the Catherine Bergego scale) and the main components of neglect (using conventional clinical assessments) during the first months post right hemisphere stroke. Voxel-based lesion-symptom mapping was used to identify brain areas within which lesions explained the severity of bias in each assessment (non-parametric permutation test; p<0.01, one tailed). N-ADLs was associated with lesions centered on the posterior part of the superior temporal gyrus and extending to the temporo-parietal junction, temporo-occipital junction and subcortical white matter (including the superior longitudinal fasciculus). Peripersonal neglect resulted from extended cortical lesions centered on the superior temporal gyrus and the inferior parietal gyrus, with subcortical extension. Personal neglect resulted predominantly from lesions centered on the somatosensory cortex and at a lesser degree on the superior temporal sulcus. Anosognosia resulted from lesions of the posterior inferior temporal gyrus and superior temporal gyrus. In anatomic terms, N-ADLs was strongly related to peripersonal neglect, and those relationships were also shown by the psychometric analysis. In conclusions, superior temporal gyrus and superior longitudinal fasciculus lesions have a pivotal role in N-ADLs. N-ADLs is principally related (anatomically and psychometrically) to peripersonal neglect, and at a lesser degree to anosognosia and

  12. Evaluation of association between mandibular crowding and some of anatomical indexes in skeletal Cl II 8-12 years old patient with mandibular deficiency

    Directory of Open Access Journals (Sweden)

    Shirazi Mohsen

    2015-05-01

    Full Text Available Tehran University of Medical Sciences, Tehran, Iran ( mirahashemi@tums.ac.ir   Background and Aims: Nowadays patients refer to orthodontist for issue such as dental crowding and other aesthetic problems. The aims of this study were to evaluate the relationship between some of mandibular anatomical landmarks and dental crowding in the patient with skeletal Cl II due to mandibular deficiency.   Materials and Methods: 108 cases have been randomly selected out of patients with mandibular related Cl II problem associated with lower incisor crowding, out of orthodontic patient department of Tehran university of medical sciences. ANB, SNB, mandibular discrepancy, gonial angle, Sn-Go-Gn and IMPA was evaluated out of the data. Lateral cephalograms were used for this matter. The correlation between variables was evaluated by correlation test and after reviewing the data was analyzed using Normality test, the Pearson correlation coefficient was used for normally distributed variables.   Results: Corpus-ramus length ratio had a significant relationship with dental crowding (P≤0.05 but there was no meaningful and significant relationship between other facial landmarks ( P = 0.26 .   Conclusion: there seems to be a slight relationship between facial landmarks and dental crowding in lower incisors. But further case control and clinical studies may be helpful in achieving more reliable data.

  13. Identifying characteristic back shapes from anatomical scans of wheelchair users to improve seating design.

    Science.gov (United States)

    Crytzer, Theresa M; Hong, Eun-Kyoung; Dicianno, Brad E; Pearlman, Jon; Schmeler, Mark; Cooper, Rory A

    2016-09-01

    Spinal deformities are common in people who require the use of a wheelchair for mobility as a result of spinal cord injuries and other disabilities. Sitting positions vary between individuals with disabilities who use wheelchairs and individuals without disabilities. In individuals with spinal cord injury, spinal deformities can result in the development of back contours that deviate from the shape of standard rigid back support shells. The purpose of this study was to distinguish and classify various back contours of wheelchair users by utilizing digital anatomic scanning technology in order to inform the future development of back supports that would enhance postural support for those with spinal deformities. The three dimensional (3D) locations of bony landmarks were digitized when participants were in position, using a mechanical wand linked to the FastScan(tm) system commonly used to measure surface contours. Raw FastScan(tm) data were transformed according to bony landmarks. A total of 129 individuals participated in this study. A wide range of back contours were identified and categorized. Although participant characteristics (e.g., gender, diagnosis) were similar amongst the contour groups; no one characteristic explained the contours. Participants who were seated in a forward lean position had a higher amount of pelvic obliquity compared to those seated in an upright position; however, participants' back contour was not correlated with pelvic obliquity. In conclusion, an array of different back shapes were classified in our cohort through 3D laser scanning technology. The methods and technology applied in this study could be replicated in future studies to categorize ranges of back shapes in larger populations of people with spinal cord injuries. Preliminary evidence indicates that customized postural support may be warranted to optimize positioning and posture when a standard rigid shell does not align with contours of a person's back. To optimize

  14. Handbook of anatomical models for radiation dosimetry

    CERN Document Server

    Eckerman, Keith F

    2010-01-01

    Covering the history of human model development, this title presents the major anatomical and physical models that have been developed for human body radiation protection, diagnostic imaging, and nuclear medicine therapy. It explores how these models have evolved and the role that modern technologies have played in this development.

  15. HPV Vaccine Effective at Multiple Anatomic Sites

    Science.gov (United States)

    A new study from NCI researchers finds that the HPV vaccine protects young women from infection with high-risk HPV types at the three primary anatomic sites where persistent HPV infections can cause cancer. The multi-site protection also was observed at l

  16. Influences on anatomical knowledge: The complete arguments

    NARCIS (Netherlands)

    Bergman, E.M.; Verheijen, I.W.; Scherpbier, A.J.J.A.; Vleuten, C.P.M. van der; Bruin, A.B. De

    2014-01-01

    Eight factors are claimed to have a negative influence on anatomical knowledge of medical students: (1) teaching by nonmedically qualified teachers, (2) the absence of a core anatomy curriculum, (3) decreased use of dissection as a teaching tool, (4) lack of teaching anatomy in context, (5) integrat

  17. Report of a rare anatomic variant

    DEFF Research Database (Denmark)

    De Brucker, Y; Ilsen, B; Muylaert, C;

    2015-01-01

    We report the CT findings in a case of partial anomalous pulmonary venous return (PAPVR) from the left upper lobe in an adult. PAPVR is an anatomic variant in which one to three pulmonary veins drain into the right atrium or its tributaries, rather than into the left atrium. This results in a lef...

  18. Anatomical characteristics of lingual artery in physiological condition and its relationship with tongue base%生理状态下舌动脉的解剖特点及其与舌根的关系

    Institute of Scientific and Technical Information of China (English)

    龚明杰; 邹嘉平; 王均干

    2012-01-01

    Objective:To provide the clinical anatomic data of the lingual artery with 3D CT reconstruction. Method:Ten healthy subjects were recruited. Spiral CT scan ranged from the sternoclavicular joint to the lower edge of the orbit and the data was subjected to three-dimensional reconstruction. The distance from the origin of the lingual artery to the bifurcation of the common carotid artery and tip of the greater horn of hyoid bone were measured respectively and the distance between the midline of the lingual artery and the midline of tongue were also measured. Result: The horizontal distance between starting level of lingual artery to the level of the hyoid horn tip was(l. 51±0. 35)cm. The horizontal distance between the level of the lingual artery to the carotid bifurcation was(0.95±0.31)cm. The comparison of the distance from lingual artery 1 cm anterior or posterior to foramen ce-cum to midline of tongue showed (t = 45. 27,P<0. 01)a statistically significant difference.Conclusion:The lingual artery could be demonstrated clearly in 3D reconstruction. To ensure the operative safety, the depth of radiofre-quency for OSAHS at the tongue base should be limited within 2 centimeters.%目的:通过CT三维重建技术,对舌动脉的起源、分段和走行进行研究,探讨其位置关系在临床中的作用.方法:选取10例健康人,CT扫描范围从胸锁关节至眼眶下缘,数据传送到工作站进行三维重建.同时测量舌动脉起始点水平到舌骨大角尖端水平及到颈动脉分叉水平的垂直距离,以及舌动脉与舌表面和舌中线的距离.结果:舌动脉起始点水平到舌骨大角尖端水平的垂直距离为(1.51±0.35)cm,舌动脉起始点水平到颈动脉分叉水平的垂直距离为(0.95±0.31)cm;在舌盲孔前1 cm与舌盲孔后1 cm的舌动脉与舌中线距离比较,差异有统计学意义(t=45.27,P<0.01).结论:舌动脉以舌骨大角为标志的分段法更符合舌动脉走行变异大的特点.在进行舌

  19. Age-Related Differences in Associative Learning of Landmarks and Heading Directions in a Virtual Navigation Task.

    Science.gov (United States)

    Zhong, Jimmy Y; Moffat, Scott D

    2016-01-01

    Previous studies have showed that spatial memory declines with age but have not clarified the relevance of different landmark cues for specifying heading directions among different age groups. This study examined differences between younger, middle-aged and older adults in route learning and memory tasks after they navigated a virtual maze that contained: (a) critical landmarks that were located at decision points (i.e., intersections) and (b) non-critical landmarks that were located at non-decision points (i.e., the sides of the route). Participants were given a recognition memory test for critical and non-critical landmarks and also given a landmark-direction associative learning task. Compared to younger adults, older adults committed more navigation errors during route learning and were poorer at associating the correct heading directions with both critical and non-critical landmarks. Notably, older adults exhibited a landmark-direction associative memory deficit at decision points; this was the first finding to show that an associative memory deficit exist among older adults in a navigational context for landmarks that are pertinent for reaching a goal, and suggest that older adults may expend more cognitive resources on the encoding of landmark/object features than on the binding of landmark and directional information. This study is also the first to show that older adults did not have a tendency to process non-critical landmarks, which were regarded as distractors/irrelevant cues for specifying the directions to reach the goal, to an equivalent or larger extent than younger adults. We explain this finding in view of the low number of non-critical cues in our virtual maze (relative to a real-world urban environment) that might not have evoked older adults' usual tendency toward processing or encoding distractors. We explain the age differences in navigational and cognitive performance with regards to functional and structural changes in the hippocampus and

  20. Rhizosphere of Avicennia marina (Forsk.) Vierh. as a landmark for polythene degrading bacteria.

    Science.gov (United States)

    Shahnawaz, Mohd; Sangale, Manisha K; Ade, Avinash B

    2016-07-01

    Due to high durability, cheap cost, and ease of manufacture, 311 million tons of plastic-based products are manufactured around the globe per annum. The slow/least rate of plastic degradation leads to generation of million tons of plastic waste per annum, which is of great environmental concern. Of the total plastic waste generated, polythene shared about 64 %. Various methods are available in the literature to tackle with the plastic waste, and biodegradation is considered as the most accepted, eco-friendly, and cost-effective method of polythene waste disposal. In the present study, an attempt has been made to isolate, screen, and characterize the most efficient polythene degrading bacteria by using rhizosphere soil of Avicennia marina as a landmark. From 12 localities along the west coast of India, a total of 123 bacterial isolates were recorded. Maximum percent weight loss (% WL; 21.87 ± 6.37 %) was recorded with VASB14 at pH 3.5 after 2 months of shaking at room temperature. Maximum percent weight gain (13.87 ± 3.6 %) was reported with MANGB5 at pH 7. Maximum percent loss in tensile strength (% loss in TS; 87.50 ± 4.8 %) was documented with VASB1 at pH 9.5. The results based on the % loss in TS were only reproducible. Further, the level of degradation was confirmed by scanning electron microscopic (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis. In SEM analysis, scions/crakes were found on the surface of the degraded polythene, and mass of bacterial cell was also recorded on the weight-gained polythene strips. Maximum reduction in carbonyl index (4.14 %) was recorded in untreated polythene strip with Lysinibacillus fusiformis strain VASB14/WL. Based on 16S ribosomal RNA (rRNA) gene sequence homology, the most efficient polythene degrading bacteria were identified as L. fusiformis strainVASB14/WL and Bacillus cereus strain VASB1/TS. PMID:27072028

  1. Hoffa's fat pad injuries and their relationship with anterior cruciate ligament tears: new observations based on MR imaging in patients and MR imaging and anatomic correlation in cadavers

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, Marcelo R. [University of California San Diego, VA Health Care System, San Diego, CA (United States); Chung, Christine B.; Trudell, Debra; Resnick, Donald [University of California San Diego, VA Health Care System, San Diego, CA (United States); Hospital Mae de Deus, Porto Alegre, RS (Brazil)

    2008-04-15

    To determine the normal anatomic relationships of Hoffa's fat pad with the anterior cruciate ligament (ACL) and with the frequency of Hoffa's fat pad abnormalities in ACL-deficient knees. Retrospective clinical study on patients and observational anatomic study on cadavers. The study was approved by the Institutional Review Board. MR imaging studies of the knees of 100 patients (21-48 years old) with or without arthroscopically proven tears of the ACL, performed at a single institution, were reviewed by two readers for abnormalities of Hoffa's fat pad. Ten cadaveric knee specimens were studied with MR imaging and Faxitron radiographs, and by inspection of sections and histology. Alterations in Hoffa's fat pad on MR imaging were present in 64% (32/50) of patients with torn ACLs, and in 24% (12/50) of patients without a tear of the ACL (P < 0.05). Hoffa's fat pad inserted into the intercondylar notch in 50% (5/10) of cadaveric specimens, four in conjunction with the ligamentum mucosum and in one in an isolated fashion. Histological study demonstrated the composition of the ligamentum mucosum and Hoffa's fat pad and their course and insertion sites in the intercondylar notch. Abnormalities of Hoffa's fat pad, such as focal and diffuse edema, tears, scars and synovial proliferation, are more common in knees with torn ACLs than in knees with intact ACLs. (orig.)

  2. Landmarks of Contemporary Fiscal Policy in The European Union

    OpenAIRE

    Ionuţ-Cătălin CROITORU

    2011-01-01

    Fiscal policy is one of the key concerns of each state and one of the direct ways to influence economic development. Therefore, a well-based fiscal policy that takes into account the specific conditions of economic and social imperatives of the present and future requirements, it may prove beneficial for progress. This paper aims to trace the main features of modern tax policy and make an analysis of the evolution of direct and indirect taxes in Europe. The analysis includes the role attribut...

  3. Design of an enhanced visual odometry by building and matching compressive panoramic landmarks online

    Institute of Scientific and Technical Information of China (English)

    Wei LU; Zhi-yu XIANG; Ji-lin LIU

    2015-01-01

    Efficient and precise localization is a prerequisite for the intelligent navigation of mobile robots. Traditional visual localization systems, such as visual odometry (VO) and simultaneous localization and mapping (SLAM), suffer from two short-comings: a drift problem caused by accumulated localization error, and erroneous motion estimation due to illumination varia-tion and moving objects. In this paper, we propose an enhanced VO by introducing a panoramic camera into the traditional stereo-only VO system. Benefiting from the 360° field of view, the panoramic camera is responsible for three tasks: (1) detect-ing road junctions and building a landmark library online; (2) correcting the robot’s position when the landmarks are revisited with any orientation; (3) working as a panoramic compass when the stereo VO cannot provide reliable positioning results. To use the large-sized panoramic images efficiently, the concept of compressed sensing is introduced into the solution and an adap-tive compressive feature is presented. Combined with our previous two-stage local binocular bundle adjustment (TLBBA) stereo VO, the new system can obtain reliable positioning results in quasi-real time. Experimental results of challenging long-range tests show that our enhanced VO is much more accurate and robust than the traditional VO, thanks to the compressive panoramic landmarks built online.

  4. A low-cost test-bed for real-time landmark tracking

    Science.gov (United States)

    Csaszar, Ambrus; Hanan, Jay C.; Moreels, Pierre; Assad, Christopher

    2007-04-01

    A low-cost vehicle test-bed system was developed to iteratively test, refine and demonstrate navigation algorithms before attempting to transfer the algorithms to more advanced rover prototypes. The platform used here was a modified radio controlled (RC) car. A microcontroller board and onboard laptop computer allow for either autonomous or remote operation via a computer workstation. The sensors onboard the vehicle represent the types currently used on NASA-JPL rover prototypes. For dead-reckoning navigation, optical wheel encoders, a single axis gyroscope, and 2-axis accelerometer were used. An ultrasound ranger is available to calculate distance as a substitute for the stereo vision systems presently used on rovers. The prototype also carries a small laptop computer with a USB camera and wireless transmitter to send real time video to an off-board computer. A real-time user interface was implemented that combines an automatic image feature selector, tracking parameter controls, streaming video viewer, and user generated or autonomous driving commands. Using the test-bed, real-time landmark tracking was demonstrated by autonomously driving the vehicle through the JPL Mars yard. The algorithms tracked rocks as waypoints. This generated coordinates calculating relative motion and visually servoing to science targets. A limitation for the current system is serial computing-each additional landmark is tracked in order-but since each landmark is tracked independently, if transferred to appropriate parallel hardware, adding targets would not significantly diminish system speed.

  5. ANATOMIC RESEARCH OF SUPERIOR CLUNIAL NERVE TRAUMA

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    In order to find the mechanism of superior clunial nerve (SCN) trauma, we dissected and revealed SCN from 12 corpses (24 sides). Combining 100 sides of SCN trauma, we inspected the course of SCN, the relation between SCN and it's neighbour tissues with the situation of SCN when being subjected to force. We found that the following special anatomic characteristics and mechanical elements such as the course of SCN, it's turning angles, the bony fibrous tube at the iliac crest, the posterior layer of the lumbodorsal fascia and SCN neighbour adipose tissue, are the causes of external force inducing SCN trauma. The anatomic revealment is the guidance of SCN trauma treatment with edged needle.

  6. Strong links between genomic and anatomical diversity in both mammalian olfactory chemosensory systems.

    Science.gov (United States)

    Garrett, Eva C; Steiper, Michael E

    2014-05-22

    Mammalian olfaction comprises two chemosensory systems: the odorant-detecting main olfactory system (MOS) and the pheromone-detecting vomeronasal system (VNS). Mammals are diverse in their anatomical and genomic emphases on olfactory chemosensation, including the loss or reduction of these systems in some orders. Despite qualitative evidence linking the genomic evolution of the olfactory systems to specific functions and phenotypes, little work has quantitatively tested whether the genomic aspects of the mammalian olfactory chemosensory systems are correlated to anatomical diversity. We show that the genomic and anatomical variation in these systems is tightly linked in both the VNS and the MOS, though the signature of selection is different in each system. Specifically, the MOS appears to vary based on absolute organ and gene family size while the VNS appears to vary according to the relative proportion of functional genes and relative anatomical size and complexity. Furthermore, there is little evidence that these two systems are evolving in a linked fashion. The relationships between genomic and anatomical diversity strongly support a role for natural selection in shaping both the anatomical and genomic evolution of the olfactory chemosensory systems in mammals. PMID:24718758

  7. Increased cortical-limbic anatomical network connectivity in major depression revealed by diffusion tensor imaging.

    Directory of Open Access Journals (Sweden)

    Peng Fang

    Full Text Available Magnetic resonance imaging studies have reported significant functional and structural differences between depressed patients and controls. Little attention has been given, however, to the abnormalities in anatomical connectivity in depressed patients. In the present study, we aim to investigate the alterations in connectivity of whole-brain anatomical networks in those suffering from major depression by using machine learning approaches. Brain anatomical networks were extracted from diffusion magnetic resonance images obtained from both 22 first-episode, treatment-naive adults with major depressive disorder and 26 matched healthy controls. Using machine learning approaches, we differentiated depressed patients from healthy controls based on their whole-brain anatomical connectivity patterns and identified the most discriminating features that represent between-group differences. Classification results showed that 91.7% (patients=86.4%, controls=96.2%; permutation test, p<0.0001 of subjects were correctly classified via leave-one-out cross-validation. Moreover, the strengths of all the most discriminating connections were increased in depressed patients relative to the controls, and these connections were primarily located within the cortical-limbic network, especially the frontal-limbic network. These results not only provide initial steps toward the development of neurobiological diagnostic markers for major depressive disorder, but also suggest that abnormal cortical-limbic anatomical networks may contribute to the anatomical basis of emotional dysregulation and cognitive impairments associated with this disease.

  8. Some scientific landmarks of the MIT radium toxicity studies

    Energy Technology Data Exchange (ETDEWEB)

    Maletskos, C.J. [Constantine Maletskos, Gloucester, MA (United States)

    1996-12-31

    Until the recent forced termination of the studies on radium toxicity, more than six decades of investigation and research have been devoted to them. These studies involve {approximately}2400 subjects who were exposed to long-term internally deposited radium [high linear energy transfer (LET)], whose health status was evaluated in great detail and whose radiation dosimetry was based on measurements of their actual radium body burdens. The quality and usefulness of these studies are, therefore, in sharp contrast to other human radiation-exposure studies that involve instantaneous or somewhat protracted external low-LET exposures and inferred radiation dose, as in the atomic-bomb survivor studies. As a consequence of national news in 1932 concerning the gruesome death of a prominent Pittsburgh businessman and sportsman, Robley D. Evans became involved with radium toxicity, and its study became an important project when he joined the faculty of the Massachusetts Institute of Technology physics department and set up the interdisciplinary Radioactivity Center.

  9. ACCESSORY SPLEEN: A CLINICALLY RELEVANT ANATOMIC ANOMALY

    OpenAIRE

    Prachi Saffar; Amit Kumar; Ankur

    2016-01-01

    The purpose of our study is to emphasize on the clinical relevance of the presence of accessory spleen. It is not only a well-documented anatomic anomaly, it holds special significance in the differential diagnosis of intra-abdominal tumours and lymphadenopathy. MATERIALS AND METHODS Thirty male cadavers from North Indian population above the age of 60 yrs. were dissected in the Anatomy Department of FMHS, SGT University, Gurgaon, over a period of 5 yrs. (Sep 2010-Aug 2015) and presence...

  10. Microstructure and Anatomical Characteristics of Daemonorops margaritae

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Daemonorops margaritae is among the most important commercial rattan in South China. Its microstructure and basic anatomical characteristics as well as variation were investigated. Results show that: 1)The variation along the height is small, while the variation along the radial direction is significant; 2) The fibre length, fibre ratio and distribution density of the vascular bundles in the cross section decrease from cortex to core, while the fibre width, vessel element length and width, parenchyma ratio,...

  11. Pure endoscopic endonasal odontoidectomy: anatomical study

    OpenAIRE

    Messina, Andrea; Bruno, Maria Carmela; Decq, Philippe; Coste, Andre; Cavallo, Luigi Maria; de Divittis, Enrico; Cappabianca, Paolo; Tschabitscher, Manfred

    2007-01-01

    Different disorders may produce irreducible atlanto-axial dislocation with compression of the ventral spinal cord. Among the surgical approaches available for a such condition, the transoral resection of the odontoid process is the most often used. The aim of this anatomical study is to demonstrate the possibility of an anterior cervico-medullary decompression through an endoscopic endonasal approach. Three fresh cadaver heads were used. A modified endonasal endoscopic approach was made in al...

  12. Anatomical MRI with an atomic magnetometer

    CERN Document Server

    Savukov, I

    2012-01-01

    Ultra-low field (ULF) MRI is a promising method for inexpensive medical imaging with various additional advantages over conventional instruments such as low weight, low power, portability, absence of artifacts from metals, and high contrast. Anatomical ULF MRI has been successfully implemented with SQUIDs, but SQUIDs have the drawback of cryogen requirement. Atomic magnetometers have sensitivity comparable to SQUIDs and can be in principle used for ULF MRI to replace SQUIDs. Unfortunately some problems exist due to the sensitivity of atomic magnetometers to magnetic field and gradients. At low frequency, noise is also substantial and a shielded room is needed for improving sensitivity. In this paper, we show that at 85 kHz, the atomic magnetometer can be used to obtain anatomical images. This is the first demonstration of any use of atomic magnetometers for anatomical MRI. The demonstrated resolution is 1.1x1.4 mm2 in about six minutes of acquisition with SNR of 10. Some applications of the method are discuss...

  13. Computer tomographic imaging and anatomic correlation of the human brain: A comparative atlas of thin CT-scan sections and correlated neuro-anatomic preparations

    International Nuclear Information System (INIS)

    It is of the greatest importance to the radiologist, the neurologist and the neurosurgeon to be able to localize topographically a pathological brain process on the CT scan as precisely as possible. For that purpose, the identification of as many anatomical structures as possible on the CT scan image are necessary and indispensable. In this atlas a great number of detailed anatomical data on frontal horizontal CT scan sections, each being only 2 mm thick, are indicated, e.g. the cortical gyri, the basal ganglia, details of the white matter, extracranial muscles and blood vessels, parts of the base and the vault of the skull, etc. The very precise topographical description of the numerous CT scan images was realized by the author by confrontation of these images with the corresponding anatomical sections of the same brain specimen, performed by an original technique

  14. Deviation of landmarks in accordance with methods of establishing reference planes in three-dimensional facial CT evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Kaeng Won; Yoon, Suk Ja; Kang, Byung Cheol; Kook, Min Suk; Lee, Jae Seo [School of Dentistry, Dental Science Research Institute, Chonnam National University, Gwangju (Korea, Republic of); Kim, Young Hee [Dept. of Oral and Maxillofacial Radiology, Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of); Palomo, Juan Martin [Dept. of Orthodontics, School of Dental Medicine, Case Western Reserve University, Cleveland (Korea, Republic of)

    2014-09-15

    This study aimed to investigate the deviation of landmarks from horizontal or midsagittal reference planes according to the methods of establishing reference planes. Computed tomography (CT) scans of 18 patients who received orthodontic and orthognathic surgical treatment were reviewed. Each CT scan was reconstructed by three methods for establishing three orthogonal reference planes (namely, the horizontal, midsagittal, and coronal reference planes). The horizontal (bilateral porions and bilateral orbitales) and midsagittal (crista galli, nasion, prechiasmatic point, opisthion, and anterior nasal spine) landmarks were identified on each CT scan. Vertical deviation of the horizontal landmarks and horizontal deviation of the midsagittal landmarks were measured. The porion and orbitale, which were not involved in establishing the horizontal reference plane, were found to deviate vertically from the horizontal reference plane in the three methods. The midsagittal landmarks, which were not used for the midsagittal reference plane, deviated horizontally from the midsagittal reference plane in the three methods. In a three-dimensional facial analysis, the vertical and horizontal deviations of the landmarks from the horizontal and midsagittal reference planes could vary depending on the methods of establishing reference planes.

  15. Anatomical description and clinical significance of unilateral triheaded sternocleidomastoid muscle

    Directory of Open Access Journals (Sweden)

    Preeti Goswami

    2014-06-01

    Full Text Available Objective of this report is to observe and report unusual pattern of origin of sternal and clavicular heads of Sternocleidomastoid (SCM. An embryological insight into the possible causes for present anomaly is elucidated. The neck region of an adult male cadaver during gross anatomy teaching program. An abnormal Sternocleidomastoid (SCM was observed while dissecting the neck region of an adult. Additional clavicular head of SCM muscle were found on the right side. The accessory clavicular head coursed deep to the sternal head whereas the some fibres of main clavicular head joined the accessory belly and together they fused with the main sternal head of SCM. There was another slip arising from sternal head and merge with deep cervical fascia near base of mandible. The topographical anatomy of SCM is extremely important, particularly because it serves as a useful surgical landmark and its relation to crucial neuro-vascular structures of the neck. The usage of SCM in reconstruction operations for covering defects is discussed. A detailed knowledge of the anatomy of SCM proves vital for radiological studies of the neck. [Int J Res Med Sci 2014; 2(3.000: 1161-1164

  16. Introducing International Journal of Anatomical Variations

    Directory of Open Access Journals (Sweden)

    Tunali S

    2008-06-01

    Full Text Available Welcome to International Journal of Anatomical Variations (IJAV - an annual journal of anatomical variations and clinical anatomy case reports. After having a notable experience for eight years in NEUROANATOMY, we are pleased to introduce you IJAV. We are eventually announcing our new journal after three years of feasibility and background study period. We hope that IJAV will fill in the gap in anatomy journals’ bunch. IJAV is an annual, open access journal having electronic version only. Despite of unavailability of a budget for publishing IJAV, the evaluation of submissions and access to the full text articles is totally free of charge.Our vision for IJAV is to constitute an online compendium for anatomical variations in gross, radiological and surgical anatomy, neuroanatomy and case reports in clinical anatomy. We believe that cases have an important role in clinical anatomy education. In this aspect, we aim to serve as an open source of case reports. We hope that IJAV will be cited in most of the case reports related to clinical anatomy and anatomical variations in near future.In NEUROANATOMY, we encouraged the submission of case reports in the area of neuroanatomy. Whereas in IJAV, besides neuroanatomy, we will consider case reports in any area related to human anatomy. The scope of IJAV will encompass any anatomical variations in gross, radiological and surgical anatomy. Case reports in clinical anatomy are also welcome.All submitted articles will be peer-reviewed. No processing fee will be charged from authors. One of the most important features of IJAV will be speedy review and rapid publication. We strive to publish an accepted manuscript within three weeks of initial submission. Our young and dynamic Scientific Advisory Board will achieve this objective.A few remarks about our logo and page design: Prof. Dr. M. Mustafa ALDUR designed our logo, being inspired by a quadricuspid aortic valve case, reported by Francesco FORMICA et al

  17. Integration, Disintegration, and Self-Similarity: Characterizing the Scales of Shape Variation in Landmark Data

    OpenAIRE

    Bookstein, Fred L.

    2015-01-01

    The biologist examining samples of multicellular organisms in anatomical detail must already have an intuitive concept of morphological integration. But quantifying that intuition has always been fraught with difficulties and paradoxes, especially for the anatomically labelled Cartesian coordinate data that drive today’s toolkits of geometric morphometrics. Covariance analyses of interpoint distances, such as the Olson–Miller factor approach of the 1950’s, cannot validly be extended to handle...

  18. An anatomical study of the parasacral block using magnetic resonance imaging of healthy volunteers.

    LENUS (Irish Health Repository)

    O'Connor, Maeve

    2012-01-31

    BACKGROUND: The parasacral approach to sciatic blockade is reported to be easy to learn and perform, with a high success rate and few complications. METHODS: Using magnetic resonance imaging, we evaluated the accuracy of a simulated needle (perpendicular to skin) in contacting the sacral plexus with this approach in 10 volunteers. Intrapelvic structures encountered during the simulated parasacral blocks were also recorded. RESULTS: The sacral plexus was contacted by the simulated needle in 4 of the 10 volunteers, and the sciatic nerve itself in one volunteer. The plexus was accurately located adjacent to a variety of visceral structures, including small bowel, blood vessels, and ovary. In the remaining five volunteers (in whom the plexus was not contacted on first needle pass), small bowel, rectum, blood vessels, seminal vesicles, and bony structures were encountered. Historically, when plexus is not encountered, readjustment of the needle insertion point more caudally has been recommended. We found that such an adjustment resulted in simulated perforation of intrapelvic organs or the perianal fossa. CONCLUSIONS: These findings question the reliability of the anatomical landmarks of the parasacral block and raise the possibility of frequent visceral puncture using this technique.

  19. [Dyspraxia: landmarks].

    Science.gov (United States)

    Mazeau, M

    2010-03-01

    Despite its frequency, little is known about dyspraxia. Dyspraxia, which represents disorders in development and learning movements, within the context of a deficiency in the management of spatial information (in children whose verbal intelligence is spared), is often a severe handicap at school and in social life. Dyspraxia must be distinguished from "common" difficulties of unmotivated children at school, with which it is often confused. Hence, the diagnosis must correspond to rigorous methodology. And one should avoid proposing endless training for the deficient action (writing, getting dressed...); indeed such strategies only lead to short-term 'pseudo' progress, without any long term efficacy on the educational success of these intelligent children. To the contrary, the child should be rapidly oriented in two therapeutic directions: (1) a battle between the "double-task" effect stemming from the graphical and spatial difficulties; (2) the use of palliatives (including computing). In conditions of early diagnosis (at 4-8/9 years of age) and well-coordinated management with the school, the prognosis would be excellent in terms of schooling, choice of a profession and social insertion. If not, or if (as is the case in almost a third of cases) dyspraxia is not isolated (associated with dyslexia, hyperactivity, attentional deficit and psychotic traits), the child should be oriented towards a specialised classroom and care. PMID:19942418

  20. PAVA: Physiological and Anatomical Visual Analytics for Mapping of Tissue-Specific Concentration and Time-Course Data

    Science.gov (United States)

    We describe the development and implementation of a Physiological and Anatomical Visual Analytics tool (PAVA), a web browser-based application, used to visualize experimental/simulated chemical time-course data (dosimetry), epidemiological data and Physiologically-Annotated Data ...

  1. Tennis elbow. Anatomical, epidemiological and therapeutic aspects.

    Science.gov (United States)

    Verhaar, J A

    1994-10-01

    Five studies of tennis elbow are presented. Epidemiological studies showed an incidence of tennis elbow between 1 and 2%. The prevalence of tennis elbow in women between 40 and 50 years of age was 10%. Half of the patients with tennis elbow seek medical attention. Local corticosteroid injections were superior to the physiotherapy regime of Cyriax. Release of the common forearm extensor origin resulted in 70% excellent or good results one year after operation and 89% at five years. Anatomical investigations and nerve conduction studies of the Radial Tunnel Syndrome supported the hypothesis that the Lateral Cubital Force Transmission System is involved in the pathogenesis of tennis elbow.

  2. Constitutional and Anatomical Characteristics of Mature Women

    Institute of Scientific and Technical Information of China (English)

    Vladimir NNikolenko; DmitryBNikityuk; SvetlanaVKlochkova; AnastasiaABahmet

    2015-01-01

    Objective To identify the constitutional and anatomical peculiarities of constitution of women of mature age.Methods There was completed comprehensive anthropometric and bio-electrical survey of 651 mature women ( relative norm) living in the Moscow region .Results The quantitative distribution of women by somatotypological affiliation was revealed;anthropometric and body component composition in representatives of different somatotypes were defined .Conclusion Thus, the performed study revealed and quantiely character-ised the distribution of women according to their constitutional types in the studied population of mature age women living in Moscow region under the relative norm conditions .

  3. "Direct DICOM Slice Landmarking" A Novel Research Technique to Quantify Skeletal Changes in Orthognathic Surgery.

    Directory of Open Access Journals (Sweden)

    Anas Almukhtar

    Full Text Available The limitations of the current methods of quantifying the surgical movements of facial bones inspired this study. The aim of this study was the assessment of the accuracy and reproducibility of directly landmarking of 3D DICOM images (Digital Imaging and Communications in Medicine to quantify the changes in the jaw bones following surgery. The study was carried out on plastic skull to simulate the surgical movements of the jaw bones. Cone beam CT scans were taken at 3mm, 6mm, and 9mm maxillary advancement; together with a 2mm, 4mm, 6mm and 8mm "down graft" which in total generated 12 different positions of the maxilla for the analysis. The movements of the maxilla were calculated using two methods, the standard approach where distances between surface landmarks on the jaw bones were measured and the novel approach where measurements were taken directly from the internal structures of the corresponding 3D DICOME slices. A one sample t-test showed that there was no statistically significant difference between the two methods of measurements for the y and z directions, however, the x direction showed a significant difference. The mean difference between the two absolute measurements were 0.34±0.20mm, 0.22±0.16mm, 0.18±0.13mm in the y, z and x directions respectively. In conclusion, the direct landmarking of 3D DICOM image slices is a reliable, reproducible and informative method for assessment of the 3D skeletal changes. The method has a clear clinical application which includes the analysis of the jaw movements "orthognathic surgery" for the correction of facial deformities.

  4. Isolated Male Epispadias: Anatomic Functional Restoration Is the Primary Goal

    Science.gov (United States)

    Bruneel, Elke; Ploumidis, Achilles; Van Laecke, Erik; Hoebeke, Piet

    2016-01-01

    Background. Isolated male epispadias (IME) is a rare congenital penile malformation, as often part of bladder-exstrophy-epispadias complex (BEEC). In its isolated presentation, it consists in a defect of the dorsal aspect of the penis, leaving the urethral plate open. Occurrence of urinary incontinence is related to the degree of dorsal displacement of the meatus and the underlying underdevelopment of the urethral sphincter. The technique for primary IME reconstruction, based on anatomic restoration of the urethra and bladder neck, is here illustrated. Patients and Methods. A retrospective database was created with patients who underwent primary IME repair between June 1998 and February 2014. Intraoperative variables, postoperative complications, and outcomes were assessed. A descriptive statistical analysis was performed. Results and Limitations. Eight patients underwent primary repair, with penopubic epispadias (PPE) in 3, penile epispadias (PE) in 2, and glandular epispadias (GE) in 3. Median age at surgery was 13.0 months [7–47]; median follow-up was 52 months [9–120]. Complications requiring further surgery were reported in two patients, while further esthetic surgeries were required in 4 patients. Conclusion. Anatomical restoration in primary IME is safe and effective, with acceptable results given the initial pathology. PMID:27722172

  5. DESIGN OF 3D MODEL OF CUSTOMIZED ANATOMICALLY ADJUSTED IMPLANTS

    Directory of Open Access Journals (Sweden)

    Miodrag Manić

    2015-12-01

    Full Text Available Design and manufacturing of customized implants is a field that has been rapidly developing in recent years. This paper presents an originally developed method for designing a 3D model of customized anatomically adjusted implants. The method is based upon a CT scan of a bone fracture. A CT scan is used to generate a 3D bone model and a fracture model. Using these scans, an indicated location for placing the implant is recognized and the design of a 3D model of customized implants is made. With this method it is possible to design volumetric implants used for replacing a part of the bone or a plate type for fixation of a bone part. The sides of the implants, this one lying on the bone, are fully aligned with the anatomical shape of the bone surface which neighbors the fracture. The given model is designed for implants production utilizing any method, and it is ideal for 3D printing of implants.

  6. Performance Characterization of a Landmark Measurement System for ARRM Terrain Relative Navigation

    Science.gov (United States)

    Shoemaker, Michael; Wright, Cinnamon; Liounis, Andrew; Getzandanner, Kenneth; Van Eepoel, John; Deweese, Keith

    2016-01-01

    This paper describes the landmark measurement system being developed for terrain relative navigation on NASAs Asteroid Redirect Robotic Mission (ARRM),and the results of a performance characterization study given realistic navigational and model errors. The system is called Retina, and is derived from the stereophotoclinometry methods widely used on other small-body missions. The system is simulated using synthetic imagery of the asteroid surface and discussion is given on various algorithmic design choices. Unlike other missions, ARRMs Retina is the first planned autonomous use of these methods during the close-proximity and descent phase of the mission.

  7. 膝关节有限元解剖模型的构建及其力学分析%The construction of the anatomical finite element model of knee joint and its mechanical anal-ysis

    Institute of Scientific and Technical Information of China (English)

    董跃福; 牟志芳; 蒋胜波; 刘建; 刘旭东

    2015-01-01

    Objective To develop an anatomically accurate finite element model of knee joint through the method of multimodality CT and MRI image data fusion and to further analyze and verify it for offering a useful tool for the study of knee biomechanics. Methods CT and MRI image data of an intact knee joint were imported into Mimics soft-ware. 3D models of bones,articular cartilages and ligaments were respectively constructed from image data. Following the fusion of the constructed 3D models based on external landmarks, the complete knee model was constructed. Then the knee finite element model was developed in Hypermesh software. Based on anatomical observation and manual measurement, the finite element model was assessed in its fidelity level. Finally the finite element model was analyzed and verified after the definition of its material behavior, boundary conditions and loading. Results The complete knee finite element mode composed of bone,meniscus, articular cartilage,and ligament was developed from CT and MRI images, and it maintained its important anatomical features of knee joint. The obtained finite element analysis results corresponded to that reported in the literature, which meaned the model′s reliability. Conclusions Through the method of multimodality CT and MRI image data fusion, the anatomically accurate finite element model of knee joint can be developed, and it maintains its important anatomical features. This model is a useful tool for the study of knee biomechanics.%目的 通过多模态CT和MRI影像数据融合构建膝关节有限元解剖模型,并进行有限元分析和验证,为膝关节力学仿真研究提供可靠的有限元模型. 方法 采集正常膝关节CT和MRI影像数据,导入到 Mimics软件中,构建膝关节骨骼、半月板、关节软骨、韧带等结构的三维模型. 以外部标记为参照点进行模型配准,融合成膝关节整体模型. 在Hypermesh软件中进行网格划分,构建膝关节有限元模型. 通

  8. Modification of the right subclavian vein catheterization and its anatomic basis and techniques

    Institute of Scientific and Technical Information of China (English)

    LUO Guang-hui; LI Wen-jian; ZHONG Shi-zhen; LI Zhong-hua; FANG Ji

    2005-01-01

    Background Several million subclavian-vein catheters are placed in patients each year to enable caregivers to administer chemotherapy, total parenteral nutrition, or long-term antibiotics or to manage preoperative fluids. Subclavian venipuncture requires the position of a deep vein to be identified with only surface landmarks. But the traditional right subclavian vein (RSV) catheterization (primitive procedures) is not the answer for all patients. The precise location of the vein is not known, and it is important to select the most appropriate method to achieve central venous access safely in any given patient. To modify the primitive procedures of the RSV catheterization for greater success and reduce the complications, anatomic studies and ultrasonography were conducted and clinical applications were validated.Methods Anatomical observation and measurement of the RSV and its adjacent structures were performed on 20 adult cadavers according to modified procedures. The RSV catheterization of 2900 cases was carried out by the modified procedure, 500 of these cases were observed by ultrasonography after the operation.Results The anatomical studies and clinical application showed that the insertion point differs from the bodily form of fatness or leptosome. The clinical data revealed that in the 2900 cases which were performed with the modified approach, the success rate was 98.90% (2868 cases), the failure rate was 1.10% (32 cases), and the complication rate is 0.79% (23 cases), and the catheterization time is (31.2±10.5) minutes. Five hundred and sixty cases of the RSV catheterization were carried out by the recommended insertion procedure; the results were compared with the modified approach and the traditional approach. The successful rate of the traditional approach was 73.0%, of which the complication rate was 6.1%; the two approaches were significantly different (successful rate: χ2=626.642, P<0.01; complication rate: χ2=80.708, P<0.01).Conclusions The

  9. Integration of tomato reproductive developmental landmarks and expression profiles, and the effect of SUN on fruit shape

    Directory of Open Access Journals (Sweden)

    Li Dongmei

    2009-05-01

    Full Text Available Abstract Background Universally accepted landmark stages are necessary to highlight key events in plant reproductive development and to facilitate comparisons among species. Domestication and selection of tomato resulted in many varieties that differ in fruit shape and size. This diversity is useful to unravel underlying molecular and developmental mechanisms that control organ morphology and patterning. The tomato fruit shape gene SUN controls fruit elongation. The most dramatic effect of SUN on fruit shape occurs after pollination and fertilization although a detailed investigation into the timing of the fruit shape change as well as gene expression profiles during critical developmental stages has not been conducted. Results We provide a description of floral and fruit development in a red-fruited closely related wild relative of tomato, Solanum pimpinellifolium accession LA1589. We use established and propose new floral and fruit landmarks to present a framework for tomato developmental studies. In addition, gene expression profiles of three key stages in floral and fruit development are presented, namely floral buds 10 days before anthesis (floral landmark 7, anthesis-stage flowers (floral landmark 10 and fruit landmark 1, and 5 days post anthesis fruit (fruit landmark 3. To demonstrate the utility of the landmarks, we characterize the tomato shape gene SUN in fruit development. SUN controls fruit shape predominantly after fertilization and its effect reaches a maximum at 8 days post-anthesis coinciding with fruit landmark 4 representing the globular embryo stage of seed development. The expression profiles of the NILs that differ at sun show that only 34 genes were differentially expressed and most of them at a less than 2-fold difference. Conclusion The landmarks for flower and fruit development in tomato were outlined and integrated with the effect of SUN on fruit shape. Although we did not identify many genes differentially expressed in

  10. THE POSSIBILITIES OF SPREADING OF THE DOWNSHIFTING IN MODERN SOCIETY: THE VALUE LANDMARKS ANALYSIS OF MOSCOW AND ST. PETERSBURG SPECIALISTS

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    Yana Vadimovna Ovechkina

    2015-12-01

    Full Text Available This article provides an analysis of the «downshifting» phenomena, which is voluntary downward vertical mobility, as an alternative path to success. The author defines downshif-ters as a social group, analyzes the motives of this voluntary downward mobility. Basing on the own hypothesis, author takes an attempt to outline those social groups, which are subject to this so-called downward motion on the «social ladder». Author also tries to predict the possible spread of the «downshifting» phenomena in Russian Federation. The value landmarks of two groups of specialists were researched, one being the «young adults» group (ages 25-30, the other – «adults» (ages 31-36. Both their emotional tension and the quality of life satisfaction being closely examined. The attention to these problems and further examination of practices and standards of downshifters and followers of adjacent movements will help the researchers to determine zones of increased tension in society, professional staff and family. In addition, it will help to predict possible changes in the labour relations system.

  11. The anatomical study of transoral atlantoaxial reduction plate internal fixation

    Institute of Scientific and Technical Information of China (English)

    AI Fu-zhi; YIN Qing-shui; WANG Zhi-yun; XIA Hong; CHANG Yun-bing; WU Zeng-hui; LIU Jing-fa

    2006-01-01

    ). The vertical distance (b) between the line connecting the two C1 screw entry points and that connecting the two C2 screw entry points (at the central part of the vertebrae, namely 3-4 mm lateral to the midline of C2 vertebrae) was ( 21.3 ± 2.7 ) mm ( ranging 19.4-24.3 mm), with an a/b ratio of 1.3-1.5. The screws of TARP had a lateral tilt of 12.2°± 0.4°(ranging10.2° -14.6°) at C1 and a medial tilt of7.3°±0.3°(ranging5.1°-9.4°) at C2 relative to the coronal plane.Conclusions: An atlanto-axial surgery through transoral approach is safe and feasible. This approach is suitable for an anterior TARP internal fixation, and the design of the internal fixation system should be based on the above anatomical data.

  12. Anatomic correlations in radiogallium imaging of the peritoneum and retroperitoneum

    International Nuclear Information System (INIS)

    Radiogallium (67Ga) imaging of the abdomen and pelvis has been useful not only in detecting inflammations in these regions, but in pointing out their precise anatomic localization. Once the anatomic site is determined, it is often possible to infer the source of origin of the problem (such as ruptured viscus or pancreatitis). Interpretation of the images depends on recognition of patterns that define known anatomic boundaries such as the transverse mesocolon, root of the small mesentery, perirenal space, and pararenal space, or else show diffuse peritoneal uptake. The anatomic patterns may have continued usefulness in future studies, such as when radiolabeled leukocytes are employed to localize inflammations

  13. Do retractile testes have anatomical anomalies?

    Science.gov (United States)

    Anderson, Kleber M.; Costa, Suelen F.; Sampaio, Francisco J.B.; Favorito, Luciano A.

    2016-01-01

    ABSTRACT Objectives: To assess the incidence of anatomical anomalies in patients with retractile testis. Materials and Methods: We studied prospectively 20 patients (28 testes) with truly retractile testis and compared them with 25 human fetuses (50 testes) with testis in scrotal position. We analyzed the relations among the testis, epididymis and patency of the processus vaginalis (PV). To analyze the relations between the testis and epididymis, we used a previous classification according to epididymis attachment to the testis and the presence of epididymis atresia. To analyze the structure of the PV, we considered two situations: obliteration of the PV and patency of the PV. We used the Chi-square test for contingency analysis of the populations under study (p patent processus vaginalis and epididymal anomalies. PMID:27564294

  14. [Antique anatomical collections for contemporary museums].

    Science.gov (United States)

    Nesi, Gabriella; Santi, Raffaella

    2013-01-01

    Anatomy and Pathology Museum collections display a great biological value and offer unique samples for research purposes. Pathological specimens may be investigated by means of modern radiological and molecular biology techniques in order to provide the etiological background of disease, with relevance to present-day knowledge. Meanwhile, historical resources provide epidemiologic data regarding the socio-economic conditions of the resident populations, the more frequently encountered illnesses and dietary habits. These multidisciplinary approaches lead to more accurate diagnoses also allowing new strategies in cataloguing and musealization of anatomical specimens. Further, once these data are gathered, they may constitute the basis of riedited Museum catalogues feasible to be digitalized and displayed via the Web.

  15. Normal anatomical measurements in cervical computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Zaunbauer, W.; Daepp, S.; Haertel, M.

    1985-11-01

    Radiodiagnostically relevant normal values and variations for measurements of the cervical region, the arithmetical average and the standard deviation were determined from adequate computer tomograms on 60 healthy women and men, aged 20 to 83 years. The sagittal diameter of the prevertebral soft tissue and the lumina of the upper respiratory tract were evaluated at exactly defined levels between the hyoid bone and the incisura jugularis sterni. - The thickness of the aryepiglottic folds, the maximal sagittal and transverse diameters of the thyroid gland and the calibre of the great cervical vessels were defined. - To assess information about laryngeal function in computerized tomography, measurements of distances between the cervical spine and anatomical fixed points of the larynx and hypopharynx were made as well as of the degree of vocal cord movement during normal respiration and phonation.

  16. A "Second Life" for Gross Anatomy: Applications for Multiuser Virtual Environments in Teaching the Anatomical Sciences

    Science.gov (United States)

    Richardson, April; Hazzard, Matthew; Challman, Sandra D.; Morgenstein, Aaron M.; Brueckner, Jennifer K.

    2011-01-01

    This article describes the emerging role of educational multiuser virtual environments, specifically Second Life[TM], in anatomical sciences education. Virtual worlds promote inquiry-based learning and conceptual understanding, potentially making them applicable for teaching and learning gross anatomy. A short introduction to Second Life as an…

  17. Anatomical variation of abductor pollicis longus in Indian population A cadaveric study

    Directory of Open Access Journals (Sweden)

    Jerina Tewari

    2015-01-01

    Conclusion: Bi-tendinous APL is commonly observed on the dorsal compartment of the wrist in Indian population and these tendon-slips are commonly attached to thefirst metacarpal base and trapezium. This variation must be understood by the Indian Orthopedic surgeons as the response to treatment of DQT and reason forfirst carpo-metacarpal arthritis can be dependent on this anatomical variation.

  18. Foundations of Intonational Meaning: Anatomical and Physiological Factors.

    Science.gov (United States)

    Gussenhoven, Carlos

    2016-04-01

    Like non-verbal communication, paralinguistic communication is rooted in anatomical and physiological factors. Paralinguistic form-meaning relations arise from the way these affect speech production, with some fine-tuning by the cultural and linguistic context. The effects have been classified as "biological codes," following the terminological lead of John Ohala's Frequency Code. Intonational morphemes, though arguably non-arbitrary in principle, are in fact heavily biased toward these paralinguistic meanings. Paralinguistic and linguistic meanings for four biological codes are illustrated. In addition to the Frequency Code, the Effort Code, and the Respiratory Code, the Sirenic Code is introduced here, which is based on the use of whispery phonation, widely seen as being responsible for the signaling and perception of feminine attractiveness and sometimes used to express interrogativity in language. In the context of the evolution of language, the relations between physiological conditions and the resulting paralinguistic and linguistic meanings will need to be clarified. PMID:27016315

  19. Comparison of Image Registration Based Measures of Regional Lung Ventilation from Dynamic Spiral CT with Xe-CT

    CERN Document Server

    Ding, Kai; Fuld, Matthew K; Du, Kaifang; Christensen, Gary E; Hoffman, Eric A; Reinhardt, Joseph M

    2012-01-01

    Purpose: Regional lung volume change as a function of lung inflation serves as an index of parenchymal and airway status as well as an index of regional ventilation and can be used to detect pathologic changes over time. In this article, we propose a new regional measure of lung mechanics --- the specific air volume change by corrected Jacobian. Methods: 4DCT and Xe-CT data sets from four adult sheep are used in this study. Nonlinear, 3D image registration is applied to register an image acquired near end inspiration to an image acquired near end expiration. Approximately 200 annotated anatomical points are used as landmarks to evaluate registration accuracy. Three different registration-based measures of regional lung mechanics are derived and compared: the specific air volume change calculated from the Jacobian (SAJ); the specific air volume change calculated by the corrected Jacobian (SACJ); and the specific air volume change by intensity change (SAI). Results: After registration, the mean registration err...

  20. Landmark Sequence Data Association Method for Robot Simultaneous Localization and Map Building%特征序列数据关联机器人同步定位与地图构建

    Institute of Scientific and Technical Information of China (English)

    弋英民; 黄莹; 王智敏; 张孟志

    2014-01-01

    For the noise uncertainty increases,a landmark sequence data association( LSDA) method for robot simul-taneous localization and map building( SLAM) is proposed. As robot simultaneous localization and map building,the spatial geometry of the landmarks are considered. Then the correlation among landmarks based on graph theory is established. Between the adjacent two-step observations,the difference of innovation covariance is transformed into maximum correlation function of sequence by solving the TSP problem. Then landmark data association is performed. The experiments show that the proposed method can be to ensure the consistency of estimation in the case of uncertainty noise increasing.%针对噪声不确定性增大的数据关联问题,提出特征点序列数据关联机器人同步定位与地图构建方法。根据机器人环境特征点的空间几何信息,基于图论建立特征点间的信息相关性。利用相邻两步的特征点观测信息协方差的变化,转化成求解特征点TSP问题和特征序列最大相关函数,以此确定所观测特征点的数据关联。实验证明,提出的方法可在噪声不确定性增大的情况下,保证同步定位与地图构建算法的一致性。

  1. Internal fixation of the unstable pelvic fracture based on the anatomic features of the pelvis%骨盆的形态特点与不稳定型骨折内固定治疗评价

    Institute of Scientific and Technical Information of China (English)

    翁阳华; 吴显奎; 彭扬国; 欧耀芬

    2011-01-01

    目的 探讨根据骨盆的形态特点选择不同的内固定手术治疗不稳定型骨盆骨折的临床应用价值。方法65例不稳定型骨盆骨折,31例Tile B型骨折经前入路,将耻骨联合或耻骨支复位用重建钢板固定,其中8例合并髂骨骨折经髂窝入路将之复位用重建钢板固定;34例Tile C型骨折的前环损伤均采用与Tile B型骨盆骨折相同的方法处理,后环损伤的固定方法:17例骶骨骨折或骶髂关节脱位之中,复位后在透视引导下从后方经皮骶髂螺钉固定11例,经髂骨的螺栓固定4例,经后路在双侧髂骨后嵴之间用张力带钢板固定2例;9例骶髂关节骨折-脱位之中,经皮骶髂螺钉固定6例,钢板固定3例;8例合并髋臼骨折行重建钢板内固定。结果通过对术后骨盆X线测量骨折分离移位的最大距离,根据Matta评分标准:小于4 mm为优,占86.1%(56例);4~10mm为良,占7.7%(5例);10~20 mm为可,占6.2%(4例);大于20 mm为差(0例)。本组骨盆X线测量结果总优良率为93.8%。结论不稳定型骨盆骨折应在血流动力学稳定时尽早根据骨折的类型及骨盆的解剖形态特点选择合理的内固定手术方案。%Objective To explore clinical efficiency of different surgical internal fixations on treating the unstable pelvic fracture according to the anatomic features of the pelvis. Methods 65 cases suffering from the unstable pelvic fractures, were included in this study. Anterior approach, with the replacement and plate fixation of symphysis pubis or ramus of pubis, was performed for 31 cases of Tile B type fracture. 8 cases combined with ilium fracture among them were replaced and fixed through iliac fossa approach. As well, anterior approach also was used for fixing damaged anterior girdle of 34 cases of Tile C type fracture. However, the damaged posterior girdles were treated with the replacement and the posterior sacroiliac screw fixation

  2. Observations of the origin and insertion of the plantar aponeurosis based on anatomic and sonographic analysis%跖腱膜起点的解剖及超声影像学研究

    Institute of Scientific and Technical Information of China (English)

    程迅生; 章仁品; 罗福成; 张勇

    2009-01-01

    Objective To identify the exact origin and insertion of plantar aponeurosis and the anatomic relationship of calcaneal spur to plantar aponeurosis. Methods Fourteen specimen of feet were dissected and radiographed. Three fetus feet were observed histologically. Sonographic evaluation was carried out on 20 normal adults and 52 patients with plantar fasciitis. Results (1) Anatomic observation found that plantar aponeurosis was located under the medial process of caleaneus but not attached to it, and proximally attached to the plantar aspect of calcaneal tuborosity. The insertion (origin) of plantar aponeurosis was not a point but a face. Posteriorly the plantar aponeurosis and fascia of Archlles heel were fused or transmigrated together,entirely covered and attached very coherently to the plantar and posterior aspect of calcaneal tuborosity. (2) Histological observation of heel of fetuses found plantar aponeurosis and fascia of Arehlles heel were eosinophil band-like structure. Both continued at the plantar and posterior aspect of calcaneus and attached closely to bone at this area. There were no significant demarcation between them. (3) Sonographic evaluation:normal plantar aponeurosis showed a thin band-like echo, its orgin attached to entire plantar aspect of calcaneal tuberosity and continued with fascia coming posteriorly from Archlles heel. No distinct boundary existed between these two fascias. When plantar fasciitis occurred, the orgin of plantar aponeurosis thickened significantly,this phenomenon could be detected in wholly plantar aspect of calcaneal tuberrosity. The heel spur didn't located within plantar aponeurosis. Conclusions Plantar aponeurosis orginates from entire plantar aspect of cancaneal tuberosity. Heel spur oeeures in the orgin of the intrinsic musculature, such as flexor digitorum brevis,and doesn't locate within plantar aponeurosis.%目的 研究跖腱膜起点的确切部位及其与跟骨骨刺的关系.方法 对14只足标

  3. Curricular response to increase recall and transfer of anatomical knowledge into the obstetrics/gynecology clerkship.

    Science.gov (United States)

    Jurjus, Rosalyn A; Brown, Kirsten; Goldman, Ellen; Galoosian, Artin; Butera, Gisela; Krapf, Jill M

    2016-07-01

    Deficits in retention of anatomy knowledge from the preclinical years to clinical application on the wards have been well documented in the medical education literature. We developed and evaluated a web and laboratory-based curriculum to address deficits in anatomy knowledge retention and to increase anatomy knowledge recall through repetition and application of clinical concepts during the obstetrics and gynecology (Ob/Gyn) core clinical clerkship. Using principles of adult learning and instructional design, a curriculum was designed consisting of (1) interactive, case-based e-modules reviewing clinically relevant anatomical topics and (2) a hands-on laboratory session reinforcing the content of the e-modules, with the practice of clinical techniques using anatomical cadaveric dissections. The curriculum's effectiveness was evaluated by using multiple choice testing and comparing baseline and final test scores. For questions testing content directly covered in this curriculum, mean final scores increased by 14.3% (P improvement, P = 0.002). A curriculum with web-based preparatory material and a hands-on gross anatomy laboratory session effectively addresses deficits in anatomy retention and improves anatomical knowledge recall for medical students on a clinical clerkship. In the future, the authors plan to conduct a multicenter study to further evaluate the ability of this curriculum to improve clinically relevant anatomical knowledge. Anat Sci Educ 9: 337-343. © 2015 American Association of Anatomists. PMID:26588426

  4. Applied Endoscopic Anatomical Evaluation of the Lacrimal Sac

    Directory of Open Access Journals (Sweden)

    Seyyed Mostafa Hashemi

    2015-05-01

    Full Text Available Introduction: Dacryocystorhinostomy (DCR, a popular surgical procedure, has been performed using an endoscopic approach over recent years. Excellent anatomical knowledge is required for this endoscopic surgical approach. This study was performed in order to better evaluate the anatomical features of the lacrimal apparatus from cadavers in the Isfahan forensic center as a sample of the Iranian population.   Materials and Methods: DCR was performed using a standard method on 26 cadaver eyes from the forensic center of Isfahan. The lacrimal sac was exposed completely, then the anatomical features of the lacrimal sac and canaliculus were measured using a specified ruler.   Results: A total of 26 male cadaveric eyes were used, of which four (16.7% were probably non-Caucasian. Two (8% of the eyes needed septoplasty, one (4% needed uncinectomy, and none needed turbinoplasty. Four (16% lacrimal sacs were anterior to axilla, one (4% was posterior and 20 (80% were at the level of the axilla of the middle turbinate. The distance  from the nasal sill to the anterior edge of the lacrimal sac (from its mid-height was 39.04 (±4.92 mm. The distance from the nasal sill to the posterior edge of the lacrimal sac (from its mid-height was 45.50 (±4.47 mm. The width and length of the lacrimal sac was 7.54 (±1.44 mm and 13.16 (±5.37 mm, respectively. The distance from the anterior edge of the lacrimal sac to the posterior edge of the uncinate process was 14.06 (±3.00 mm, while the distance from the anterior nasal spine to the anterior edge of the lacrimal sac (from its mid-height was 37.20 (±5.37 mm.The height of the fundus was 3.26 (±1.09 mm. The distance from the superior punctum to the fundus was 12.70 (±1.45 mm, and the distance from the inferior punctum to the fundus was 11.10 (±2.02 mm.   Conclusion:  Given the differences between the various studies conducted in order to evaluate the position of the lacrimal sac, studies such as this can help to

  5. Corrective surgery for canine patellar luxation in 75 cases (107 limbs: landmark for block recession

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Isaka

    2014-05-01

    Full Text Available Canine medial patellar luxation (MPL is a very common orthopedic disease in small animals. Because the pathophysiology of this disease involves various pathways, the surgical techniques and results vary according to the veterinarian. Further, the landmark for block recession is not completely clear. We retrospectively evaluated 75 dogs (107 limbs with MPL in whom our landmark for block recession was used from July 2008 to May 2013. Information regarding the breed, age, sex, body weight, body condition score (BCS, lateral vs bilateral, pre-operative grading, surgical techniques, removal of implants, concomitance with anterior cruciate ligament (ACL rupture, re-luxation, re-operation, and rehabilitation was obtained from the medical records. The breeds were as follows: Chihuahua (n=23, Pomeranian (n=12, Yorkshire Terrier (n=9, and so on. The study group consisted of 33 males (castrated n=13 and 42 females (spayed n=21. The median age was 53.3±35.9 months (32-146 months; 13 cases were less than 12 months of age (17.3%. The pre-surgical BCSs were as follows: 1 (n=0, 2 (n=20, 3 (n=24, 4 (n=24 and 5 (n=7. The body weight was 4.51±3.48 kg (1.34-23.0 kg; 71 cases (94.7% were less than 10 kg. The MPL grades (each limb were G1 (n=1, G2 (n=18, G3 (n=78, and G4 (n=10; 32 cases were bilateral and 43 cases were unilateral (right n=27; left n=16. The specific surgical procedure (distal femoral osteotomy was 3 stifles in Chihuahuas. Concurrent with ACL rupture was 16/107 stifles (15.0% corrected with the over-the-top method or the extracapsular method in Papillons (5/6, Chihuahuas (5/23, and so on. The occurrences of re-luxation and re-operation were 3 out of 107 stifles (2.8% and 0%, respectively. In this retrospective study, we present a potentially good surgical landmark for block recession of MPL in dogs.

  6. 16 CFR Figure 1 to Part 1203 - Anatomical Planes

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Anatomical Planes 1 Figure 1 to Part 1203 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS SAFETY STANDARD FOR BICYCLE HELMETS Pt. 1203, Fig. 1 Figure 1 to Part 1203—Anatomical Planes ER10MR98.001...

  7. An Investigation of Anatomical Competence in Junior Medical Doctors

    Science.gov (United States)

    Vorstenbosch, Marc A. T. M.; Kooloos, Jan G. M.; Bolhuis, Sanneke M.; Laan, Roland F. J. M.

    2016-01-01

    Because of a decrease of the time available for anatomy education, decisions need to be made to reduce the relevant content of the anatomy curriculum. Several expert consensus initiatives resulted in lists of structures, lacking analysis of anatomical competence. This study aims to explore the use of anatomical knowledge by medical doctors in an…

  8. Effects of Spatial Ability, Gender Differences, and Pictorial Training on Children Using 2-D and 3-D Environments to Recall Landmark Locations from Memory

    Science.gov (United States)

    Kopcha, Theodore J.; Otumfuor, Beryl A.; Wang, Lu

    2015-01-01

    This study examines the effects of spatial ability, gender differences, and pictorial training on fourth grade students' ability to recall landmark locations from memory. Ninety-six students used Google Earth over a 3-week period to locate landmarks (3-D) and mark their location on a 2-D topographical map. Analysis of covariance on posttest scores…

  9. Landmarks in particle physics at Brookhaven National Laboratory: Brookhaven Lecture Series, Number 238

    International Nuclear Information System (INIS)

    Robert Adair's lecture on Landmarks in Particle Physics at Brookhaven National Laboratory (BNL) is a commemoration of the 40th Anniversary of Brookhaven National Laboratory. Adair describes ten researches in elementary particle physics at Brookhaven that had a revolutionary impact on the understanding of elementary particles. Two of the discoveries were made in 1952 and 1956 at the Cosmotron, BNL's first proton accelerator. Four were made in 1962 and 1964 at the Alternating Gradient Synchrotron, the Cosmotron's replacement. Two other discoveries in 1954 and 1956 were theoretical, and strong focusing (1952) is the only technical discovery. One discovery (1958) happened in an old barrack. Four of the discoveries were awarded the Nobel prize in Physics. Adair believes that all of the discoveries are worthy of the Nobel prize. 14 figs

  10. Design and use of numerical anatomical atlases for radiotherapy

    International Nuclear Information System (INIS)

    The main objective of this thesis is to provide radio-oncology specialists with automatic tools for delineating organs at risk of a patient undergoing a radiotherapy treatment of cerebral or head and neck tumors. To achieve this goal, we use an anatomical atlas, i.e. a representative anatomy associated to a clinical image representing it. The registration of this atlas allows us to segment automatically the patient structures and to accelerate this process. Contributions in this method are presented on three axes. First, we want to obtain a registration method which is as independent as possible from the setting of its parameters. This setting, done by the clinician, indeed needs to be minimal while guaranteeing a robust result. We therefore propose registration methods allowing a better control of the obtained transformation, using rejection techniques of inadequate matching or locally affine transformations. The second axis is dedicated to the consideration of structures associated with the presence of the tumor. These structures, not present in the atlas, indeed lead to local errors in the atlas-based segmentation. We therefore propose methods to delineate these structures and take them into account in the registration. Finally, we present the construction of an anatomical atlas of the head and neck region and its evaluation on a database of patients. We show in this part the feasibility of the use of an atlas for this region, as well as a simple method to evaluate the registration methods used to build an atlas. All this research work has been implemented in a commercial software (Imago from DOSIsoft), allowing us to validate our results in clinical conditions. (author)

  11. Anatomical Correlates of Non-Verbal Perception in Dementia Patients

    Science.gov (United States)

    Lin, Pin-Hsuan; Chen, Hsiu-Hui; Chen, Nai-Ching; Chang, Wen-Neng; Huang, Chi-Wei; Chang, Ya-Ting; Hsu, Shih-Wei; Hsu, Che-Wei; Chang, Chiung-Chih

    2016-01-01

    Purpose: Patients with dementia who have dissociations in verbal and non-verbal sound processing may offer insights into the anatomic basis for highly related auditory modes. Methods: To determine the neuronal networks on non-verbal perception, 16 patients with Alzheimer’s dementia (AD), 15 with behavior variant fronto-temporal dementia (bv-FTD), 14 with semantic dementia (SD) were evaluated and compared with 15 age-matched controls. Neuropsychological and auditory perceptive tasks were included to test the ability to compare pitch changes, scale-violated melody and for naming and associating with environmental sound. The brain 3D T1 images were acquired and voxel-based morphometry (VBM) was used to compare and correlated the volumetric measures with task scores. Results: The SD group scored the lowest among 3 groups in pitch or scale-violated melody tasks. In the environmental sound test, the SD group also showed impairment in naming and also in associating sound with pictures. The AD and bv-FTD groups, compared with the controls, showed no differences in all tests. VBM with task score correlation showed that atrophy in the right supra-marginal and superior temporal gyri was strongly related to deficits in detecting violated scales, while atrophy in the bilateral anterior temporal poles and left medial temporal structures was related to deficits in environmental sound recognition. Conclusions: Auditory perception of pitch, scale-violated melody or environmental sound reflects anatomical degeneration in dementia patients and the processing of non-verbal sounds are mediated by distinct neural circuits.

  12. Auxiliary anatomical labels for joint segmentation and atlas registration

    Science.gov (United States)

    Gass, Tobias; Szekely, Gabor; Goksel, Orcun

    2014-03-01

    This paper studies improving joint segmentation and registration by introducing auxiliary labels for anatomy that has similar appearance to the target anatomy while not being part of that target. Such auxiliary labels help avoid false positive labelling of non-target anatomy by resolving ambiguity. A known registration of a segmented atlas can help identify where a target segmentation should lie. Conversely, segmentations of anatomy in two images can help them be better registered. Joint segmentation and registration is then a method that can leverage information from both registration and segmentation to help one another. It has received increasing attention recently in the literature. Often, merely a single organ of interest is labelled in the atlas. In the presense of other anatomical structures with similar appearance, this leads to ambiguity in intensity based segmentation; for example, when segmenting individual bones in CT images where other bones share the same intensity profile. To alleviate this problem, we introduce automatic generation of additional labels in atlas segmentations, by marking similar-appearance non-target anatomy with an auxiliary label. Information from the auxiliary-labeled atlas segmentation is then incorporated by using a novel coherence potential, which penalizes differences between the deformed atlas segmentation and the target segmentation estimate. We validated this on a joint segmentation-registration approach that iteratively alternates between registering an atlas and segmenting the target image to find a final anatomical segmentation. The results show that automatic auxiliary labelling outperforms the same approach using a single label atlasses, for both mandibular bone segmentation in 3D-CT and corpus callosum segmentation in 2D-MRI.

  13. Anatomical Correlates of Non-Verbal Perception in Dementia Patients

    Science.gov (United States)

    Lin, Pin-Hsuan; Chen, Hsiu-Hui; Chen, Nai-Ching; Chang, Wen-Neng; Huang, Chi-Wei; Chang, Ya-Ting; Hsu, Shih-Wei; Hsu, Che-Wei; Chang, Chiung-Chih

    2016-01-01

    Purpose: Patients with dementia who have dissociations in verbal and non-verbal sound processing may offer insights into the anatomic basis for highly related auditory modes. Methods: To determine the neuronal networks on non-verbal perception, 16 patients with Alzheimer’s dementia (AD), 15 with behavior variant fronto-temporal dementia (bv-FTD), 14 with semantic dementia (SD) were evaluated and compared with 15 age-matched controls. Neuropsychological and auditory perceptive tasks were included to test the ability to compare pitch changes, scale-violated melody and for naming and associating with environmental sound. The brain 3D T1 images were acquired and voxel-based morphometry (VBM) was used to compare and correlated the volumetric measures with task scores. Results: The SD group scored the lowest among 3 groups in pitch or scale-violated melody tasks. In the environmental sound test, the SD group also showed impairment in naming and also in associating sound with pictures. The AD and bv-FTD groups, compared with the controls, showed no differences in all tests. VBM with task score correlation showed that atrophy in the right supra-marginal and superior temporal gyri was strongly related to deficits in detecting violated scales, while atrophy in the bilateral anterior temporal poles and left medial temporal structures was related to deficits in environmental sound recognition. Conclusions: Auditory perception of pitch, scale-violated melody or environmental sound reflects anatomical degeneration in dementia patients and the processing of non-verbal sounds are mediated by distinct neural circuits. PMID:27630558

  14. Anatomical Correlates of Non-Verbal Perception in Dementia Patients

    Directory of Open Access Journals (Sweden)

    Pin-Hsuan Lin

    2016-08-01

    Full Text Available Purpose: Patients with dementia who have dissociations in verbal and non-verbal sound processing may offer insights into the anatomic basis for highly related auditory modes. Methods: To determine the neuronal networks on non-verbal perception, 16 patients with Alzheimer’s dementia (AD, 15 with behavior variant fronto-temporal dementia (bv-FTD, 14 with semantic dementia (SD were evaluated and compared with 15 age-matched controls. Neuropsychological and auditory perceptive tasks were included to test the ability to compare pitch changes, scale-violated melody and for naming and associating with environmental sound. The brain 3D T1 images were acquired and voxel-based morphometry (VBM was used to compare and correlated the volumetric measures with task scores. Results: The SD group scored the lowest among 3 groups in pitch or scale-violated melody tasks. In the environmental sound test, the SD group also showed impairment in naming and also in associating sound with pictures. The AD and bv-FTD groups, compared with the controls, showed no differences in all tests. VBM with task score correlation showed that atrophy in the right supra-marginal and superior temporal gyri was strongly related to deficits in detecting violated scales, while atrophy in the bilateral anterior temporal poles and left medial temporal structures was related to deficits in environmental sound recognition. Conclusions: Auditory perception of pitch, scale-violated melody or environmental sound reflects anatomical degeneration in dementia patients and the processing of non-verbal sounds is mediated by distinct neural circuits.

  15. Volumetric Image Guidance Using Carina vs Spine as Registration Landmarks for Conventionally Fractionated Lung Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Lavoie, Caroline; Higgins, Jane; Bissonnette, Jean-Pierre [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario, M5G 2M9 (Canada); Le, Lisa W. [Department of Biostatistics, Princess Margaret Hospital, Toronto, Ontario, M5G 2M9 (Canada); Sun, Alexander; Brade, Anthony; Hope, Andrew; Cho, John [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario, M5G 2M9 (Canada); Bezjak, Andrea, E-mail: andrea.bezjak@rmp.uhn.on.ca [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario, M5G 2M9 (Canada)

    2012-12-01

    Purpose: To compare the relative accuracy of 2 image guided radiation therapy methods using carina vs spine as landmarks and then to identify which landmark is superior relative to tumor coverage. Methods and Materials: For 98 lung patients, 2596 daily image-guidance cone-beam computed tomography scans were analyzed. Tattoos were used for initial patient alignment; then, spine and carina registrations were performed independently. A separate analysis assessed the adequacy of gross tumor volume, internal target volume, and planning target volume coverage on cone-beam computed tomography using the initial, middle, and final fractions of radiation therapy. Coverage was recorded for primary tumor (T), nodes (N), and combined target (T+N). Three scenarios were compared: tattoos alignment, spine registration, and carina registration. Results: Spine and carina registrations identified setup errors {>=}5 mm in 35% and 46% of fractions, respectively. The mean vector difference between spine and carina matching had a magnitude of 3.3 mm. Spine and carina improved combined target coverage, compared with tattoos, in 50% and 34% (spine) to 54% and 46% (carina) of the first and final fractions, respectively. Carina matching showed greater combined target coverage in 17% and 23% of fractions for the first and final fractions, respectively; with spine matching, this was only observed in 4% (first) and 6% (final) of fractions. Carina matching provided superior nodes coverage at the end of radiation compared with spine matching (P=.0006), without compromising primary tumor coverage. Conclusion: Frequent patient setup errors occur in locally advanced lung cancer patients. Spine and carina registrations improved combined target coverage throughout the treatment course, but carina matching provided superior combined target coverage.

  16. Anatomical imbalance between cortical networks in autism

    Science.gov (United States)

    Watanabe, Takamitsu; Rees, Geraint

    2016-01-01

    Influential psychological models of autism spectrum disorder (ASD) have proposed that this prevalent developmental disorder results from impairment of global (integrative) information processing and overload of local (sensory) information. However, little neuroanatomical evidence consistent with this account has been reported. Here, we examined relative grey matter volumes (rGMVs) between three cortical networks, how they changed with age, and their relationship with core symptomatology. Using public neuroimaging data of high-functioning ASD males and age-/sex-/IQ-matched controls, we first identified age-associated atypical increases in rGMVs of the regions of two sensory systems (auditory and visual networks), and an age-related aberrant decrease in rGMV of a task-control system (fronto-parietal network, FPN) in ASD children. While the enlarged rGMV of the auditory network in ASD adults was associated with the severity of autistic socio-communicational core symptom, that of the visual network was instead correlated with the severity of restricted and repetitive behaviours in ASD. Notably, the atypically decreased rGMV of FPN predicted both of the two core symptoms. These findings suggest that disproportionate undergrowth of a task-control system (FPN) may be a common anatomical basis for the two ASD core symptoms, and relative overgrowth of the two different sensory systems selectively compounds the distinct symptoms. PMID:27484308

  17. Anatomical imbalance between cortical networks in autism.

    Science.gov (United States)

    Watanabe, Takamitsu; Rees, Geraint

    2016-01-01

    Influential psychological models of autism spectrum disorder (ASD) have proposed that this prevalent developmental disorder results from impairment of global (integrative) information processing and overload of local (sensory) information. However, little neuroanatomical evidence consistent with this account has been reported. Here, we examined relative grey matter volumes (rGMVs) between three cortical networks, how they changed with age, and their relationship with core symptomatology. Using public neuroimaging data of high-functioning ASD males and age-/sex-/IQ-matched controls, we first identified age-associated atypical increases in rGMVs of the regions of two sensory systems (auditory and visual networks), and an age-related aberrant decrease in rGMV of a task-control system (fronto-parietal network, FPN) in ASD children. While the enlarged rGMV of the auditory network in ASD adults was associated with the severity of autistic socio-communicational core symptom, that of the visual network was instead correlated with the severity of restricted and repetitive behaviours in ASD. Notably, the atypically decreased rGMV of FPN predicted both of the two core symptoms. These findings suggest that disproportionate undergrowth of a task-control system (FPN) may be a common anatomical basis for the two ASD core symptoms, and relative overgrowth of the two different sensory systems selectively compounds the distinct symptoms. PMID:27484308

  18. Hamstring tendons insertion - an anatomical study

    Directory of Open Access Journals (Sweden)

    Cristiano Antonio Grassi

    2013-09-01

    Full Text Available OBJECTIVE: To study the anatomy of the hamstring tendons insertion and anatomical rela-tionships. METHODS: Ten cadaver knees with medial and anterior intact structures were selected. The dissection was performed from anteromedial access to exposure of the insertion of the flexor tendons (FT, tibial plateau (TP and tibial tuberosity (TT. A needle of 40 × 12 and a caliper were used to measure the distance of the tibial plateau of the knee flexor tendons insertion at 15 mm from the medial border of the patellar tendon and tibial tuberosity to the insertion of the flexor tendons of the knee. The angle between tibial plateau and the insertion of the flexor tendons of the knee (A-TP-FT was calculated using Image Pro Plus software. RESULTS: The mean distance TP-FT was 41 ± 4.6 mm. The distance between the TT-FT was 6.88 ± 1 mm. The (A-TP-FT was 20.3 ± 4.9°. CONCLUSION: In the anterior tibial flexor tendons are about 40 mm from the plateau with an average of 20°.

  19. Anatomic Reconstruction of the Proximal Tibiofibular Joint.

    Science.gov (United States)

    Warner, Brent T; Moulton, Samuel G; Cram, Tyler R; LaPrade, Robert F

    2016-02-01

    Proximal tibiofibular joint (PTFJ) instability can be easily missed or confused for other, more common lateral knee pathologies such as meniscal tears, fibular collateral ligament injury, biceps femoris pathology, or iliotibial band syndrome. Because of this confusion, some authors believe that PTFJ instability is more common than initially appreciated. Patients with PTFJ subluxation may have no history of inciting trauma or injury, and it is not uncommon for these patients to have bilateral symptoms and generalized ligamentous laxity. Currently, the optimal surgical treatment for patients with chronic PTFJ instability is unknown. Historically, a variety of surgical treatments have been reported. Initially, joint arthrodesis and fibular head resection were recommended. More recently, temporary screw fixation, nonanatomic reconstruction with strips of the biceps femoris tendon or iliotibial band, and reconstruction with free hamstring autograft have been described. The purpose of this report is to present our surgical technique for treatment of chronic PTFJ instability using an anatomic reconstruction of the posterior ligamentous structures of the PTFJ with a semitendinosus autograft. PMID:27274455

  20. Framework for quantitative evaluation of 3D vessel segmentation approaches using vascular phantoms in conjunction with 3D landmark localization and registration

    Science.gov (United States)

    Wörz, Stefan; Hoegen, Philipp; Liao, Wei; Müller-Eschner, Matthias; Kauczor, Hans-Ulrich; von Tengg-Kobligk, Hendrik; Rohr, Karl

    2016-03-01

    We introduce a framework for quantitative evaluation of 3D vessel segmentation approaches using vascular phantoms. Phantoms are designed using a CAD system and created with a 3D printer, and comprise realistic shapes including branches and pathologies such as abdominal aortic aneurysms (AAA). To transfer ground truth information to the 3D image coordinate system, we use a landmark-based registration scheme utilizing fiducial markers integrated in the phantom design. For accurate 3D localization of the markers we developed a novel 3D parametric intensity model that is directly fitted to the markers in the images. We also performed a quantitative evaluation of different vessel segmentation approaches for a phantom of an AAA.

  1. Learning Your Way around Town: How Virtual Taxicab Drivers Learn to Use Both Layout and Landmark Information

    Science.gov (United States)

    Newman, Ehren L.; Caplan, Jeremy B.; Kirschen, Matthew P.; Korolev, Igor O.; Sekuler, Robert; Kahana, Michael J.

    2007-01-01

    By having subjects drive a virtual taxicab through a computer-rendered town, we examined how landmark and layout information interact during spatial navigation. Subject-drivers searched for passengers, and then attempted to take the most efficient route to the requested destinations (one of several target stores). Experiment 1 demonstrated that…

  2. An anatomic gene expression atlas of the adult mouse brain.

    Science.gov (United States)

    Ng, Lydia; Bernard, Amy; Lau, Chris; Overly, Caroline C; Dong, Hong-Wei; Kuan, Chihchau; Pathak, Sayan; Sunkin, Susan M; Dang, Chinh; Bohland, Jason W; Bokil, Hemant; Mitra, Partha P; Puelles, Luis; Hohmann, John; Anderson, David J; Lein, Ed S; Jones, Allan R; Hawrylycz, Michael

    2009-03-01

    Studying gene expression provides a powerful means of understanding structure-function relationships in the nervous system. The availability of genome-scale in situ hybridization datasets enables new possibilities for understanding brain organization based on gene expression patterns. The Anatomic Gene Expression Atlas (AGEA) is a new relational atlas revealing the genetic architecture of the adult C57Bl/6J mouse brain based on spatial correlations across expression data for thousands of genes in the Allen Brain Atlas (ABA). The AGEA includes three discovery tools for examining neuroanatomical relationships and boundaries: (1) three-dimensional expression-based correlation maps, (2) a hierarchical transcriptome-based parcellation of the brain and (3) a facility to retrieve from the ABA specific genes showing enriched expression in local correlated domains. The utility of this atlas is illustrated by analysis of genetic organization in the thalamus, striatum and cerebral cortex. The AGEA is a publicly accessible online computational tool integrated with the ABA (http://mouse.brain-map.org/agea). PMID:19219037

  3. Assessment and Evaluation of Anatomic Variations of Retromolar Pad: A Cross Sectional Study

    Science.gov (United States)

    Deep, Anchal; Siwach, Amit; Singh, Manas; Bhargava, Akshay; Siwach, Reenu

    2016-01-01

    Introduction The retromolar pad also called piriformis papilla is a mucosal elevation located in the retromolar area covering the retromolar triangle. After molar loss, the bony alveolar process and surrounding soft periodontal tissue remodel, mainly resorb and blend with retromolar pad. It is a key intraoral landmark in prosthodontics. Aim The aim of this in-vitro study was to analyze the various anatomical shapes and sizes of retromolar pad in 150 completely edentulous patients between 55 to 70 years of age group. Materials and Methods The study was conducted on 150 completely edentulous patients. The shapes of retromolar pad on the left and right side were seen and divided into pear, triangular and round shape. The comparison of the mean longitudinal diameter and transverse diameter on the right and left sides was done. The data was evaluated statistically. The chi-square test was used for the comparison between the proportions with the help of standard deviation, t-test was used for comparison between the left and the right side and ANOVA test was used for comparison between the various shapes of the retromolar pads. Results The result showed that there was statistically significant difference among different shapes of retromolar pad and there was significant difference in mean transverse and longitudinal diameter on right and left side, the mean value of the longitudinal diameter on left and right side was 8.81 and 8.69 whereas the mean value of the transverse diameter on left and right side was 6.79 and 6.82 respectively and p-value obtained for both was 0.550 and 0.814 respectively. Conclusion The study conclude that there are three different shapes of retromolar pad among which pear and triangular shaped retomolar pad provides more stability in lower denture because of increase surface area. PMID:27437350

  4. Neuroanatomy-based matrix-guided trimming protocol for the rat brain.

    Science.gov (United States)

    Defazio, Rossella; Criado, Ana; Zantedeschi, Valentina; Scanziani, Eugenio

    2015-02-01

    Brain trimming through defined neuroanatomical landmarks is recommended to obtain consistent sections in rat toxicity studies. In this article, we describe a matrix-guided trimming protocol that uses channels to reproduce coronal levels of anatomical landmarks. Both setup phase and validation study were performed on Han Wistar male rats (Crl:WI(Han)), 10-week-old, with bodyweight of 298 ± 29 (SD) g, using a matrix (ASI-Instruments(®), Houston, TX) fitted for brains of rats with 200 to 400 g bodyweight. In the setup phase, we identified eight channels, that is, 6, 8, 10, 12, 14, 16, 19, and 21, matching the recommended landmarks midway to the optic chiasm, frontal pole, optic chiasm, infundibulum, mamillary bodies, midbrain, middle cerebellum, and posterior cerebellum, respectively. In the validation study, we trimmed the immersion-fixed brains of 60 rats using the selected channels to determine how consistently the channels reproduced anatomical landmarks. Percentage of success (i.e., presence of expected targets for each level) ranged from 89 to 100%. Where 100% success was not achieved, it was noted that the shift in brain trimming was toward the caudal pole. In conclusion, we developed and validated a trimming protocol for the rat brain that allow comparable extensiveness, homology, and relevance of coronal sections as the landmark-guided trimming with the advantage of being quickly learned by technicians. PMID:24947989

  5. Choroid plexus of the fourth ventricle: Review and anatomic study highlighting anatomical variations.

    Science.gov (United States)

    Tubbs, R Shane; Shoja, Mohammadali M; Aggarwal, Anjali; Gupta, Tulika; Loukas, Marios; Sahni, Daisy; Ansari, Shaheryar F; Cohen-Gadol, Aaron A

    2016-04-01

    Relatively few studies have been performed that analyze the morphology of the choroid plexus of the fourth ventricle. Due to the importance of this tissue as a landmark on imaging and during surgical intervention of the fourth ventricle, the authors performed a cadaveric study to better characterize this important structure. The choroid plexus of the fourth ventricle of 60 formalin fixed adult human brains was examined and measured. The horizontal distance from the midline to the lateral most point of the protruding tip of the horizontal limbs was measured. In the majority of the 60 brain specimens, right and left horizontal limbs of the choroid plexus were seen extending from the midline and protruding out of their respective lateral apertures of the fourth ventricle and into the subarachnoid space. However, on 3.3% of sides, there was absence of an extension into the foramen of Luschka and in one specimen, this lack of extension into the foramen of Luschka was bilateral. On two sides, there was discontinuity between the midline choroid plexus and the tuft of choroid just outside the foramen of Luschka. For specimens in which the choroid plexus did protrude through the foramen of Luschka (96.7%), these tufts were located anterior to the flocculus and inferolateral to the facial/vestibulocochlear nerve complex and posterosuperior to the glossopharyngeal/vagal/accessory complex. A thorough understanding of the normal and variant anatomy of the fourth ventricular choroid plexus is necessary for those who operate in, or interpret imaging of, this region.

  6. An unusual intraventricular interthalamic vein: two anatomical case reports.

    Science.gov (United States)

    Capel, Cyrille; Peltier, Johann; Foulon, Pascal; Page, Cyril; Havet, Eric; Le Gars, Daniel

    2012-12-01

    Neurosurgeons use ventricular veins during an endoscopic third ventriculocisternostomy as landmark to progress in ventricles. In the current literature, there is lack of detailed intraventricular venous anatomy. Majority of those papers treats Monro's foramen venous variations. There are no data of third ventricle venous anatomy and variations in the literature. We reported two cases of unusual interthalamic vein that we need to spare during endoscopy. PMID:22543760

  7. Sacro-Iliac Joint Sensory Block and Radiofrequency Ablation: Assessment of Bony Landmarks Relevant for Image-Guided Procedures

    Science.gov (United States)

    Roberts, Shannon L.; Burnham, Robert S.; Loh, Eldon; Agur, Anne M.

    2016-01-01

    Image-guided sensory block and radiofrequency ablation of the nerves innervating the sacro-iliac joint require readily identifiable bony landmarks for accurate needle/electrode placement. Understanding the relative locations of the transverse sacral tubercles along the lateral sacral crest is important for ultrasound guidance, as they demarcate the position of the posterior sacral network (S1–S3 ± L5/S4) innervating the posterior sacro-iliac joint. No studies were found that investigated the spatial relationships of these bony landmarks. The purpose of this study was to visualize and quantify the interrelationships of the transverse sacral tubercles and posterior sacral foramina to inform image-guided block and radiofrequency ablation of the sacro-iliac joint. The posterior and lateral surfaces of 30 dry sacra (15 M/15 F) were digitized and modeled in 3D and the distances between bony landmarks quantified. The relationships of bony landmarks (S1–S4) were not uniform. The mean intertubercular and interforaminal distances decreased from S1 to S4, whereas the distance from the lateral margin of the posterior sacral foramina to the transverse sacral tubercles increased from S1 to S3. The mean intertubercular distance from S1 to S3 was significantly (p < 0.05) larger in males. The interrelationships of the sacral bony landmarks should be taken into consideration when estimating the site and length of an image-guided strip lesion targeting the posterior sacral network. PMID:27747222

  8. Embryologic and anatomic basis of duodenal surgery.

    Science.gov (United States)

    Androulakis, J; Colborn, G L; Skandalakis, P N; Skandalakis, L J; Skandalakis, J E

    2000-02-01

    The following points should be remembered by surgeons (Table 1). In writing about the head of the pancreas, the common bile duct, and the duodenum in 1979, the authors stated that Embryologically, anatomically and surgically these three entities form an inseparable unit. Their relations and blood supply make it impossible for the surgeon to remove completely the head of the pancreas without removing the duodenum and the distal part of the common bile duct. Here embryology and anatomy conspire to produce some of the most difficult surgery of the abdominal cavity. The only alternative procedure, the so-called 95% pancreatectomy, leaves a rim of pancreas along the medial border of the duodenum to preserve the duodenal blood supply. The authors had several conversations with Child, one of the pioneers of this procedure, whose constant message was to always be careful with the blood supply of the duodenum (personal communication, 1970). Beger et al popularized duodenum-preserving resection of the pancreatic head, emphasizing preservation of endocrine pancreatic function. They reported that ampullectomy (removal of the papilla and ampulla of Vater) carries a mortality rate of less than 0.4% and a morbidity rate of less than 10.0%. Surgeons should not ligate the superior and inferior pancreaticoduodenal arteries because such ligation may cause necrosis of the head of the pancreas and of much of the duodenum. The accessory pancreatic duct of Santorini passes under the gastrointestinal artery. For safety, surgeons should ligate the artery away from the anterior medial duodenal wall, where the papilla is located, thereby avoiding injury to or ligation of the duct. "Water under the bridge" applies not only to the relationship of the uterine artery and ureter but also to the gastroduodenal artery and the accessory pancreatic duct. In 10% of cases, the duct of Santorini is the only duct draining the pancreas, so ligation of the gastroduodenal artery with accidental inclusion of

  9. Landmark-based model-free 3D face shape reconstruction from video sequences

    NARCIS (Netherlands)

    Dam, van Chris; Veldhuis, Raymond; Spreeuwers, Luuk; Broemme, A.; Busch, C.

    2013-01-01

    In forensic comparison of facial video data, often only the best quality frontal face frames are selected, and hence potentially useful video data is ignored. To improve 2D facial comparison for law enforcement and forensic investigation, we introduce a model-free 3D shape reconstruction algorithm b

  10. Landmark based morphometric variation in Common dolphin (Delphinus delphis L.,1758)

    OpenAIRE

    Nicolosi, Paola; Loy, Anna

    2010-01-01

    In this study we compare Mediterranean stocks of Delphinus delphis (L., 1758) with other populations of the same species coming from different seas using a geometric morphometrics method. The aim is to define the patterns of geographical variation of Delphinus delphis through a geometric morphometrics analysis of the skulls of 124 individuals from seven marine areas (West and East Pacific Ocean; North-east and South-East Atlantic Ocean, West and East Indian Ocean, Mediterran...

  11. ACCESSORY SPLEEN: A CLINICALLY RELEVANT ANATOMIC ANOMALY

    Directory of Open Access Journals (Sweden)

    Prachi Saffar

    2016-02-01

    Full Text Available The purpose of our study is to emphasize on the clinical relevance of the presence of accessory spleen. It is not only a well-documented anatomic anomaly, it holds special significance in the differential diagnosis of intra-abdominal tumours and lymphadenopathy. MATERIALS AND METHODS Thirty male cadavers from North Indian population above the age of 60 yrs. were dissected in the Anatomy Department of FMHS, SGT University, Gurgaon, over a period of 5 yrs. (Sep 2010-Aug 2015 and presence of accessory spleen recorded. Tissue from the accessory spleen was also subjected to routine histological processing and slide prepared by haematoxylin and eosin staining. RESULTS Accessory spleen was present in two cadavers near the splenic hilum. One was 3.9 cm in the long axis and weighed about 48.4 grams, while the other was 1.2 cm in long axis and weighed about 12.5 grams. One had a separate arterial branch from the main splenic artery; that it was splenic tissue was confirmed histologically. DISCUSSION The presence of accessory spleen is considered to be due to embryonic non-fusion of the splenic aggregate with the main mass. CONCLUSION Though accessory spleen in itself pose no clinical problems, its significance cannot be undermined. Surgeons and radiologists are advised to look for and rule out the presence of accessory spleen, especially while evaluating a case of abdominal and perineal pathology, else it may be wrongly diagnosed as malignant tumour or enlarged lymph node leading to grave consequences.

  12. An Improved Medical Image Fusion Algorithm for Anatomical and Functional Medical Images

    Institute of Scientific and Technical Information of China (English)

    CHEN Mei-ling; TAO Ling; QIAN Zhi-yu

    2009-01-01

    In recent years,many medical image fusion methods had been exploited to derive useful information from multimodality medical image data,but,not an appropriate fusion algorithm for anatomical and functional medical images.In this paper,the traditional method of wavelet fusion is improved and a new fusion algorithm of anatomical and functional medical images,in which high-frequency and low-frequency coefficients are studied respectively.When choosing high-frequency coefficients,the global gradient of each sub-image is calculated to realize adaptive fusion,so that the fused image can reserve the functional information;while choosing the low coefficients is based on the analysis of the neighborbood region energy,so that the fused image can reserve the anatomical image's edge and texture feature.Experimental results and the quality evaluation parameters show that the improved fusion algorithm can enhance the edge and texture feature and retain the function information and anatomical information effectively.

  13. An anatomically driven anisotropic diffusion filtering method for 3D SPECT reconstruction

    International Nuclear Information System (INIS)

    In this study, we aim to reconstruct single-photon emission computed tomography images using anatomical information from magnetic resonance imaging as a priori knowledge about the activity distribution. The trade-off between anatomical and emission data is one of the main concerns for such studies. In this work, we propose an anatomically driven anisotropic diffusion filter (ADADF) as a penalized maximum likelihood expectation maximization optimization framework. The ADADF method has improved edge-preserving denoising characteristics compared to other smoothing penalty terms based on quadratic and non-quadratic functions. The proposed method has an important ability to retain information which is absent in the anatomy. To make our approach more stable to the noise-edge classification problem, robust statistics have been employed. Comparison of the ADADF method is performed with a successful anatomically driven technique, namely, the Bowsher prior (BP). Quantitative assessment using simulated and clinical neuroreceptor volumetric data show the advantage of the ADADF over the BP. For the modelled data, the overall image resolution, the contrast, the signal-to-noise ratio and the ability to preserve important features in the data are all improved by using the proposed method. For clinical data, the contrast in the region of interest is significantly improved using the ADADF compared to the BP, while successfully eliminating noise. (paper)

  14. Anatomical Variations of Anterior Osteomeatal Complex in Patients With Chronic Sinusitis

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    Sarafraz

    2016-06-01

    Full Text Available Background Identifying predisposing factors for chronic sinusitis is very important. Objectives Anatomical variation of the lateral nasal wall has been investigated in several studies and it has been suggested as a predisposing factor for sinusitis. Patients and Methods In this case-control study, 74 patients who were diagnosed with chronic sinusitis (the case group based on clinical criteria and CT scan were entered into the study and 74 patients without chronic sinusitis were considered as the control group. CT scans of all patients were reviewed by a radiologist to interpret and evaluate anatomic variations of anterior osteomeatal complex including nasal deviation, concha bullosa, agger nasi, lateralized uncinate, Haller’s cells, paradoxical middle turbinate, and maxillary hypoplasia. Data were analyzed using the chi-squared test and Fisher’s exact test with SPSS software version 18. P < 0.05 was considered statistically significant. Results Results showed that the most common sinus involved was maxillary sinus. Among anatomic variations, septal deviation and concha bullosa were associated with chronic sinusitis (P < 0.01 and P < 0.032, respectively. Conclusions Among anatomic variations, septal deviation and concha bullosa are predisposing factors for chronic sinusitis and we recommend that patients with chronic sinusitis be treated by surgical procedures.

  15. ANATOMICAL PROPERTIES AND FIBER QUALITY OF FIVE POTENTIAL COMMERCIAL WOOD SPECIES FROM CIANJUR, WEST JAVA

    Directory of Open Access Journals (Sweden)

    Ratih Damayanti

    2010-06-01

    Full Text Available A detailed description of wood anatomy is essential for assessing the use of a wood species for processing , and also beneficial for the identification of wood samples. Computerized keys are available that allow the identification of wood samples until the genus level; however, it is not easy to use these keys to identif y unknown species. Therefore, a database of anatomical characteristics and the computerized keys need to be completed up to species level. As the relevance, this study has examined the wood anatomical properties of the five corresponding tree species originated from Cianjur, West Java, which are commercially potential for their exploitation, i.e Castanopsis acuminatissima ADC. (Fagaceae; Castanopsistungurrut ADC. (Fagaceae; Cinnamomum inners Reinw. ex Blume (Lauraceae; Ficus nervosa Heyne (Moraceae and Horsfieldia glabra Warb. (Myristicaceae. Expectedly the results would be beneficial for wood identification purposes and evaluation for other possible uses. Obser vations on anatomical structures covered macroscopic and microscopic characteristics were carried out through the sectioned and macerated wood samples. The obser ved characteristics of the anatomical features were defined conforming to the IAWA List of Microscopic Features for Hardwood  Identification.  Based on the scrutiny on those obser ved characteristics and linked to the fiber quality, it was judged that the fiber in all the five wood species could be classified as class I for pulp and paper processing.

  16. Hemispheric Asymmetry of Human Brain Anatomical Network Revealed by Diffusion Tensor Tractography

    Directory of Open Access Journals (Sweden)

    Ni Shu

    2015-01-01

    Full Text Available The topological architecture of the cerebral anatomical network reflects the structural organization of the human brain. Recently, topological measures based on graph theory have provided new approaches for quantifying large-scale anatomical networks. However, few studies have investigated the hemispheric asymmetries of the human brain from the perspective of the network model, and little is known about the asymmetries of the connection patterns of brain regions, which may reflect the functional integration and interaction between different regions. Here, we utilized diffusion tensor imaging to construct binary anatomical networks for 72 right-handed healthy adult subjects. We established the existence of structural connections between any pair of the 90 cortical and subcortical regions using deterministic tractography. To investigate the hemispheric asymmetries of the brain, statistical analyses were performed to reveal the brain regions with significant differences between bilateral topological properties, such as degree of connectivity, characteristic path length, and betweenness centrality. Furthermore, local structural connections were also investigated to examine the local asymmetries of some specific white matter tracts. From the perspective of both the global and local connection patterns, we identified the brain regions with hemispheric asymmetries. Combined with the previous studies, we suggested that the topological asymmetries in the anatomical network may reflect the functional lateralization of the human brain.

  17. Hemispheric Asymmetry of Human Brain Anatomical Network Revealed by Diffusion Tensor Tractography.

    Science.gov (United States)

    Shu, Ni; Liu, Yaou; Duan, Yunyun; Li, Kuncheng

    2015-01-01

    The topological architecture of the cerebral anatomical network reflects the structural organization of the human brain. Recently, topological measures based on graph theory have provided new approaches for quantifying large-scale anatomical networks. However, few studies have investigated the hemispheric asymmetries of the human brain from the perspective of the network model, and little is known about the asymmetries of the connection patterns of brain regions, which may reflect the functional integration and interaction between different regions. Here, we utilized diffusion tensor imaging to construct binary anatomical networks for 72 right-handed healthy adult subjects. We established the existence of structural connections between any pair of the 90 cortical and subcortical regions using deterministic tractography. To investigate the hemispheric asymmetries of the brain, statistical analyses were performed to reveal the brain regions with significant differences between bilateral topological properties, such as degree of connectivity, characteristic path length, and betweenness centrality. Furthermore, local structural connections were also investigated to examine the local asymmetries of some specific white matter tracts. From the perspective of both the global and local connection patterns, we identified the brain regions with hemispheric asymmetries. Combined with the previous studies, we suggested that the topological asymmetries in the anatomical network may reflect the functional lateralization of the human brain.

  18. Reprint of "Quantitative evaluation of brain development using anatomical MRI and diffusion tensor imaging".

    Science.gov (United States)

    Oishi, Kenichi; Faria, Andreia V; Yoshida, Shoko; Chang, Linda; Mori, Susumu

    2014-02-01

    The development of the brain is structure-specific, and the growth rate of each structure differs depending on the age of the subject. Magnetic resonance imaging (MRI) is often used to evaluate brain development because of the high spatial resolution and contrast that enable the observation of structure-specific developmental status. Currently, most clinical MRIs are evaluated qualitatively to assist in the clinical decision-making and diagnosis. The clinical MRI report usually does not provide quantitative values that can be used to monitor developmental status. Recently, the importance of image quantification to detect and evaluate mild-to-moderate anatomical abnormalities has been emphasized because these alterations are possibly related to several psychiatric disorders and learning disabilities. In the research arena, structural MRI and diffusion tensor imaging (DTI) have been widely applied to quantify brain development of the pediatric population. To interpret the values from these MR modalities, a "growth percentile chart," which describes the mean and standard deviation of the normal developmental curve for each anatomical structure, is required. Although efforts have been made to create such a growth percentile chart based on MRI and DTI, one of the greatest challenges is to standardize the anatomical boundaries of the measured anatomical structures. To avoid inter- and intra-reader variability about the anatomical boundary definition, and hence, to increase the precision of quantitative measurements, an automated structure parcellation method, customized for the neonatal and pediatric population, has been developed. This method enables quantification of multiple MR modalities using a common analytic framework. In this paper, the attempt to create an MRI- and a DTI-based growth percentile chart, followed by an application to investigate developmental abnormalities related to cerebral palsy, Williams syndrome, and Rett syndrome, have been introduced. Future

  19. Quantitative evaluation of brain development using anatomical MRI and diffusion tensor imaging.

    Science.gov (United States)

    Oishi, Kenichi; Faria, Andreia V; Yoshida, Shoko; Chang, Linda; Mori, Susumu

    2013-11-01

    The development of the brain is structure-specific, and the growth rate of each structure differs depending on the age of the subject. Magnetic resonance imaging (MRI) is often used to evaluate brain development because of the high spatial resolution and contrast that enable the observation of structure-specific developmental status. Currently, most clinical MRIs are evaluated qualitatively to assist in the clinical decision-making and diagnosis. The clinical MRI report usually does not provide quantitative values that can be used to monitor developmental status. Recently, the importance of image quantification to detect and evaluate mild-to-moderate anatomical abnormalities has been emphasized because these alterations are possibly related to several psychiatric disorders and learning disabilities. In the research arena, structural MRI and diffusion tensor imaging (DTI) have been widely applied to quantify brain development of the pediatric population. To interpret the values from these MR modalities, a "growth percentile chart," which describes the mean and standard deviation of the normal developmental curve for each anatomical structure, is required. Although efforts have been made to create such a growth percentile chart based on MRI and DTI, one of the greatest challenges is to standardize the anatomical boundaries of the measured anatomical structures. To avoid inter- and intra-reader variability about the anatomical boundary definition, and hence, to increase the precision of quantitative measurements, an automated structure parcellation method, customized for the neonatal and pediatric population, has been developed. This method enables quantification of multiple MR modalities using a common analytic framework. In this paper, the attempt to create an MRI- and a DTI-based growth percentile chart, followed by an application to investigate developmental abnormalities related to cerebral palsy, Williams syndrome, and Rett syndrome, have been introduced. Future

  20. A reusable anatomically segmented digital mannequin for public health communication.

    Science.gov (United States)

    Fujieda, Kaori; Okubo, Kosaku

    2016-01-01

    The ongoing development of world wide web technologies has facilitated a change in health communication, which has now become bi-directional and encompasses people with diverse backgrounds. To enable an even greater role for medical illustrations, a data set, BodyParts3D, has been generated and its data set can be used by anyone to create and exchange customised three-dimensional (3D) anatomical images. BP3D comprises more than 3000 3D object files created by segmenting a digital mannequin in accordance with anatomical naming conventions. This paper describes the methodologies and features used to generate an anatomically correct male mannequin.