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Sample records for relevant anatomical landmarks

  1. Anatomical landmarks of radical prostatecomy.

    Science.gov (United States)

    Stolzenburg, Jens-Uwe; Schwalenberg, Thilo; Horn, Lars-Christian; Neuhaus, Jochen; Constantinides, Costantinos; Liatsikos, Evangelos N

    2007-03-01

    In the present study, we review current literature and based on our experience, we present the anatomical landmarks of open and laparoscopic/endoscopic radical prostatectomy. A thorough literature search was performed with the Medline database on the anatomy and the nomenclature of the structures surrounding the prostate gland. The correct handling of puboprostatic ligaments, external urethral sphincter, prostatic fascias and neurovascular bundle is necessary for avoiding malfunction of the urogenital system after radical prostatectomy. When evaluating new prostatectomy techniques, we should always take into account both clinical and final oncological outcomes. The present review adds further knowledge to the existing "postprostatectomy anatomical hazard" debate. It emphasizes upon the role of the puboprostatic ligaments and the course of the external urethral sphincter for urinary continence. When performing an intrafascial nerve sparing prostatectomy most urologists tend to approach as close to the prostatic capsula as possible, even though there is no concurrence regarding the nomenclature of the surrounding fascias and the course of the actual neurovascular bundles. After completion of an intrafascial technique the specimen does not contain any periprostatic tissue and thus the detection of pT3a disease is not feasible. This especially becomes problematic if the tumour reaches the resection margin. Nerve sparing open and laparoscopic radical prostatectomy should aim in maintaining sexual function, recuperating early continence after surgery, without hindering the final oncological outcome to the procedure. Despite the different approaches for radical prostatectomy the key for better results is the understanding of the anatomy of the bladder neck and the urethra.

  2. Collaborative regression-based anatomical landmark detection

    International Nuclear Information System (INIS)

    Gao, Yaozong; Shen, Dinggang

    2015-01-01

    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 and 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. (paper)

  3. TIBIAL LANDMARKS IN ACL ANATOMIC REPAIR

    Directory of Open Access Journals (Sweden)

    M. V. Demesсhenko

    2016-01-01

    Full Text Available Purpose: to identify anatomical landmarks on tibial articular surface to serve as reference in preparing tibial canal with respect to the center of ACL footprint during single bundle arthroscopic repair.Materials and methods. Twelve frozen knee joint specimens and 68 unpaired macerated human tibia were studied using anatomical, morphometric, statistical methods as well as graphic simulation.Results. Center of the tibial ACL footprint was located 13,1±1,7 mm anteriorly from posterior border of intercondylar eminence, at 1/3 of the distance along the line connecting apexes of internal and external tubercles and 6,1±0,5 mm anteriorly along the perpendicular raised to this point.Conclusion. Internal and external tubercles, as well as posterior border of intercondylar eminence can be considered as anatomical references to determine the center of the tibial ACL footprint and to prepare bone canals for anatomic ligament repair.

  4. [Lymphoscintigrams with anatomical landmarks obtained with vector graphics].

    Science.gov (United States)

    Rubini, Giuseppe; Antonica, Filippo; Renna, Maria Antonia; Ferrari, Cristina; Iuele, Francesca; Stabile Ianora, Antonio Amato; Losco, Matteo; Niccoli Asabella, Artor

    2012-11-01

    Nuclear medicine images are difficult to interpret because they do not include anatomical details. The aim of this study was to obtain lymphoscintigrams with anatomical landmarks that could be easily interpreted by General Physicians. Traditional lymphoscintigrams were processed with Adobe© Photoshop® CS6 and converted into vector images created by Illustrator®. The combination with a silhouette vector improved image interpretation, without resulting in longer radiation exposure or acquisition times.

  5. Cardiac Conduction System: Delineation of Anatomic Landmarks With Multidetector CT

    Directory of Open Access Journals (Sweden)

    Farhood Saremi

    2009-11-01

    Full Text Available Major components of the cardiac conduction system including the sinoatrial node (SAN, atrioventricular node (AVN, the His Bundle, and the right and left bundle branches are too small to be directly visualized by multidetector CT (MDCT given the limited spatial resolution of current scanners. However, the related anatomic landmarks and variants of this system a well as the areas with special interest to electrophysiologists can be reliably demonstrated by MDCT. Some of these structures and landmarks include the right SAN artery, right atrial cavotricuspid isthmus, Koch triangle, AVN artery, interatrial muscle bundles, and pulmonary veins. In addition, MDCT has an imperative role in demarcating potential arrhythmogenic structures. The aim of this review will be to assess the extent at which MDCT can outline the described anatomic landmarks and therefore provide crucial information used in clinical practice.

  6. Comparison of ultrasound-guided versus anatomical landmark ...

    African Journals Online (AJOL)

    Background Femoral vein cannulation may be required during major surgery in infants and children and may prove to be life saving under certain conditions. This study compared ultrasound (US)-guided cannulation of the femoral vein in infants with the traditional anatomical landmark-guided technique. Methods Eighty ...

  7. Cloud-Based Evaluation of Anatomical Structure Segmentation and Landmark Detection Algorithms : VISCERAL Anatomy Benchmarks

    OpenAIRE

    Jimenez-del-Toro, Oscar; Muller, Henning; Krenn, Markus; Gruenberg, Katharina; Taha, Abdel Aziz; Winterstein, Marianne; Eggel, Ivan; Foncubierta-Rodriguez, Antonio; Goksel, Orcun; Jakab, Andres; Kontokotsios, Georgios; Langs, Georg; Menze, Bjoern H.; Fernandez, Tomas Salas; Schaer, Roger

    2016-01-01

    Variations in the shape and appearance of anatomical structures in medical images are often relevant radiological signs of disease. Automatic tools can help automate parts of this manual process. A cloud-based evaluation framework is presented in this paper including results of benchmarking current state-of-the-art medical imaging algorithms for anatomical structure segmentation and landmark detection: the VISCERAL Anatomy benchmarks. The algorithms are implemented in virtual machines in the ...

  8. Progressive data transmission for anatomical landmark detection in a cloud.

    Science.gov (United States)

    Sofka, M; Ralovich, K; Zhang, J; Zhou, S K; Comaniciu, D

    2012-01-01

    In the concept of cloud-computing-based systems, various authorized users have secure access to patient records from a number of care delivery organizations from any location. This creates a growing need for remote visualization, advanced image processing, state-of-the-art image analysis, and computer aided diagnosis. This paper proposes a system of algorithms for automatic detection of anatomical landmarks in 3D volumes in the cloud computing environment. The system addresses the inherent problem of limited bandwidth between a (thin) client, data center, and data analysis server. The problem of limited bandwidth is solved by a hierarchical sequential detection algorithm that obtains data by progressively transmitting only image regions required for processing. The client sends a request to detect a set of landmarks for region visualization or further analysis. The algorithm running on the data analysis server obtains a coarse level image from the data center and generates landmark location candidates. The candidates are then used to obtain image neighborhood regions at a finer resolution level for further detection. This way, the landmark locations are hierarchically and sequentially detected and refined. Only image regions surrounding landmark location candidates need to be trans- mitted during detection. Furthermore, the image regions are lossy compressed with JPEG 2000. Together, these properties amount to at least 30 times bandwidth reduction while achieving similar accuracy when compared to an algorithm using the original data. The hierarchical sequential algorithm with progressive data transmission considerably reduces bandwidth requirements in cloud-based detection systems.

  9. Human movement analysis using stereophotogrammetry. Part 4: assessment of anatomical landmark misplacement and its effects on joint kinematics.

    Science.gov (United States)

    Della Croce, Ugo; Leardini, Alberto; Chiari, Lorenzo; Cappozzo, Aurelio

    2005-02-01

    Estimating the effects of different sources of error on joint kinematics is crucial for assessing the reliability of human movement analysis. The goal of the present paper is to review the different approaches dealing with joint kinematics sensitivity to rotation axes and the precision of anatomical landmark determination. Consistent with the previous papers in this series, the review is limited to studies performed with video-based stereophotogrammetric systems. Initially, studies dealing with estimates of precision in determining the location of both palpable and internal anatomical landmarks are reviewed. Next, the effects of anatomical landmark position uncertainty on anatomical frames are shown. Then, methods reported in the literature for estimating error propagation from anatomical axes location to joint kinematics are described. Interestingly, studies carried out using different approaches reported a common conclusion: when joint rotations occur mainly in a single plane, minor rotations out of this plane are strongly affected by errors introduced at the anatomical landmark identification level and are prone to misinterpretation. Finally, attempts at reducing joint kinematics errors due to anatomical landmark position uncertainty are reported. Given the relevance of this source of errors in the determination of joint kinematics, it is the authors' opinion that further efforts should be made in improving the reliability of the joint axes determination.

  10. Ultrasound guidance versus anatomical landmarks for internal jugular vein catheterization.

    Science.gov (United States)

    Brass, Patrick; Hellmich, Martin; Kolodziej, Laurentius; Schick, Guido; Smith, Andrew F

    2015-01-09

    Central venous catheters (CVCs) can help with diagnosis and treatment of the critically ill. The catheter may be placed in a large vein in the neck (internal jugular vein), upper chest (subclavian vein) or groin (femoral vein). Whilst this is beneficial overall, inserting the catheter risks arterial puncture and other complications and should be performed with as few attempts as possible. Traditionally, anatomical 'landmarks' on the body surface were used to find the correct place in which to insert catheters, but ultrasound imaging is now available. A Doppler mode is sometimes used to supplement plain 'two-dimensional' ultrasound. The primary objective of this review was to evaluate the effectiveness and safety of two-dimensional (imaging ultrasound (US) or ultrasound Doppler (USD)) guided puncture techniques for insertion of central venous catheters via the internal jugular vein in adults and children. We assessed whether there was a difference in complication rates between traditional landmark-guided and any ultrasound-guided central vein puncture.Our secondary objectives were to assess whether the effect differs between US and USD; whether the effect differs between ultrasound used throughout the puncture ('direct') and ultrasound used only to identify and mark the vein before the start of the puncture procedure (indirect'); and whether the effect differs between different groups of patients or between different levels of experience among those inserting the catheters. We searched the Central Register of Controlled Trials (CENTRAL) (2013, Issue 1), MEDLINE (1966 to 15 January 2013), EMBASE (1966 to 15 January 2013), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to 15 January 2013 ), reference lists of articles, 'grey literature' and dissertations. An additional handsearch focused on intensive care and anaesthesia journals and abstracts and proceedings of scientific meetings. We attempted to identify unpublished or ongoing studies

  11. Technical note: Quantification of neurocranial shape variation using the shortest paths connecting pairs of anatomical landmarks.

    Science.gov (United States)

    Morita, Yusuke; Ogihara, Naomichi; Kanai, Takashi; Suzuki, Hiromasa

    2013-08-01

    Three-dimensional geometric morphometric techniques have been widely used in quantitative comparisons of craniofacial morphology in humans and nonhuman primates. However, few anatomical landmarks can actually be defined on the neurocranium. In this study, an alternative method is proposed for defining semi-landmarks on neurocranial surfaces for use in detailed analysis of cranial shape. Specifically, midsagittal, nuchal, and temporal lines were approximated using Bezier curves and equally spaced points along each of the curves were defined as semi-landmarks. The shortest paths connecting pairs of anatomical landmarks as well as semi-landmarks were then calculated in order to represent the surface morphology between landmarks using equally spaced points along the paths. To evaluate the efficacy of this method, the previously outlined technique was used in morphological analysis of sexual dimorphism in modern Japanese crania. The study sample comprised 22 specimens that were used to generate 110 anatomical semi-landmarks, which were used in geometric morphometric analysis. Although variations due to sexual dimorphism in human crania are very small, differences could be identified using the proposed landmark placement, which demonstrated the efficacy of the proposed method. Copyright © 2013 Wiley Periodicals, Inc.

  12. MRI-based anatomical landmarks for the identification of thoracic vertebral levels

    International Nuclear Information System (INIS)

    Connor, S.E.J.; Shah, A.; Latifoltojar, H.; Lung, P.

    2013-01-01

    Aim: To identify soft-tissue and bony anatomical landmarks on dedicated thoracic spine magnetic resonance imaging (MRI), and to assess their detectability, reproducibility, and accuracy in predicting specific thoracic vertebral levels. Materials and methods: One hundred dedicated thoracic MRI studies were retrospectively analysed by two radiologists independently. Ten bone and soft-tissue landmarks were localized to the adjacent vertebral level. The true numerical thoracic vertebral level was subsequently determined and recorded by cross referencing with a sagittal cervico-thoracic “counting scan”. Results: Six landmarks were defined in ≥98% cases; however, there was a low interobserver percentage agreement for the defined vertebral levels (>70% for only one landmark). The most useful landmark for defining a specific vertebral level was the most superior rib (98% detection, 95% interobserver agreement, 98% at a single vertebral level, 0.07 SD). Eight landmarks localized to a specific thoracic segment in only 16–44% of cases, with a standard deviation of >0.5 vertebral levels and with a range which was greater than four vertebral levels. Conclusion: The C2 vertebra must be identified and cross referenced to the dedicated thoracic spine MRI, as other MRI-based anatomical landmarks are unreliable in determining the correct thoracic vertebral level

  13. Comparison of digital surface displacements of maxillary dentures based on noninvasive anatomic landmarks.

    Science.gov (United States)

    Norvell, Nicholas G; Korioth, Tom V; Cagna, David R; Versluis, Antheunis

    2018-02-08

    Artificial markers called fiducials are commonly used to orient digitized surfaces for analysis. However, when these markers are tangible and placed in the region of interest, they may alter surface topography and influence data analysis. The purpose of this in vitro study was to apply a modified digital surface fitting method based on anatomic landmarks to evaluate denture accuracy and to use 2 different denture processing techniques to evaluate the method. The goal was to noninvasively measure and describe any surface differences in denture processing techniques at the intaglio and denture tooth levels. Twenty standardized maxillary complete dentures were waxed on standardized edentulous casts and processed by using acrylic resin compression (COM, n=10) and injection molding (INJ, n=10) methods. Digital scans were recorded of the anatomic surface of the cast, the intaglio and cameo surfaces of the acrylic resin dentures, and the cameo surface of the wax dentures. Three anatomic fiducials were identified on denture intaglio and cast scans and 4 on the cameo surfaces of waxed and acrylic resin denture scans. These fiducials were then used to digitally align the anatomic with the processed intaglio surfaces and the waxed with the processed cameo surfaces. Surface displacements were compared among processed dentures expressed at specific points (9 tissue landmarks and 8 tooth landmarks). The accuracy of surface displacements was assessed by changes in the number and location of anatomic fiducials. The scanning precision and the intraobserver repeatability in the selection of dental landmarks were also determined. For each landmark, the spatial (x, y, and z) mean differences between the 2 processing techniques were calculated for the intaglio and the cameo surfaces and presented on each orthogonal plane. Statistical nonparametric comparison of these means was analyzed with the Mann-Whitney U test (α=.05). Benjamini-Hochberg corrections for multiple comparisons were

  14. Technical note: Correlation of respiratory motion between external patient surface and internal anatomical landmarks

    Science.gov (United States)

    Fayad, Hadi; Pan, Tinsu; Clément, Jean-François; Visvikis, Dimitris

    2011-01-01

    Purpose Current respiratory motion monitoring devices used for motion synchronization in medical imaging and radiotherapy provide either 1D respiratory signals over a specific region or 3D information based on few external or internal markers. On the other hand, newer technology may offer the potential to monitor the entire patient external surface in real time. The main objective of this study was to assess the motion correlation between such an external patient surface and internal anatomical landmarks motion. Methods Four dimensional Computed Tomography (4D CT) volumes for ten patients were used in this study. Anatomical landmarks were manually selected in the thoracic region across the 4D CT datasets by two experts. The landmarks included normal structures as well as the tumour location. In addition, a distance map representing the entire external patient surface, which corresponds to surfaces acquired by a Time of Flight (ToF) camera or similar devices, was created by segmenting the skin of all 4D CT volumes using a thresholding algorithm. Finally, the correlation between the internal landmarks and external surface motion was evaluated for different regions (placement and size) throughout a patient’s surface. Results Significant variability was observed in the motion of the different parts of the external patient surface. The larger motion magnitude was consistently measured in the central regions of the abdominal and the thoracic areas for the different patient datasets considered. The highest correlation coefficients were observed between the motion of these external surface areas and internal landmarks such as the diaphragm and mediastinum structures as well as the tumour location landmarks (0.8 ± 0.18 and 0.72 ± 0.12 for the abdominal and the thoracic regions respectively). Worse correlation was observed when one considered landmarks not significantly influenced by respiratory motion such as the apex and the sternum. Discussion and conclusions There

  15. A multi-subject evaluation of uncertainty in anatomical landmark location on shoulder kinematic description.

    Science.gov (United States)

    Langenderfer, Joseph E; Rullkoetter, Paul J; Mell, Amy G; Laz, Peter J

    2009-04-01

    An accurate assessment of shoulder kinematics is useful for understanding healthy normal and pathological mechanics. Small variability in identifying and locating anatomical landmarks (ALs) has potential to affect reported shoulder kinematics. The objectives of this study were to quantify the effect of landmark location variability on scapular and humeral kinematic descriptions for multiple subjects using probabilistic analysis methods, and to evaluate the consistency in results across multiple subjects. Data from 11 healthy subjects performing humeral elevation in the scapular plane were used to calculate Euler angles describing humeral and scapular kinematics. Probabilistic analyses were performed for each subject to simulate uncertainty in the locations of 13 upper-extremity ALs. For standard deviations of 4 mm in landmark location, the analysis predicted Euler angle envelopes between the 1 and 99 percentile bounds of up to 16.6 degrees . While absolute kinematics varied with the subject, the average 1-99% kinematic ranges for the motion were consistent across subjects and sensitivity factors showed no statistically significant differences between subjects. The description of humeral kinematics was most sensitive to the location of landmarks on the thorax, while landmarks on the scapula had the greatest effect on the description of scapular elevation. The findings of this study can provide a better understanding of kinematic variability, which can aid in making accurate clinical diagnoses and refining kinematic measurement techniques.

  16. Fully automatic detection of corresponding anatomical landmarks in volume scans of different respiratory state

    International Nuclear Information System (INIS)

    Berlinger, Kajetan; Roth, Michael; Sauer, Otto; Vences, Lucia; Schweikard, Achim

    2006-01-01

    A method is described which provides fully automatic detection of corresponding anatomical landmarks in volume scans taken at different respiratory states. The resulting control points are needed for creating a volumetric deformation model for motion compensation in radiotherapy. Prior to treatment two CT volumes are taken, one scan during inhalation, one during exhalation. These scans and the detected control point pairs are taken as input for creating the four-dimensional model by using thin-plate splines

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

    International Nuclear Information System (INIS)

    Schmook, Maria T.; Weber, Michael; Kasprian, Gregor; Nemec, Stefan; Prayer, Daniela; Brugger, Peter C.; Krampl-Bettelheim, Elisabeth

    2010-01-01

    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.)

  18. 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.)

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

    OpenAIRE

    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 laparoscopic procedures, >5 advanced laparoscopic procedures) and 23 novices (no laparoscopy experience) performed the Camera Navigation task in an abstract virtual environment (CN-box) and in a virtu...

  20. MR-guided stereotactic neurosurgery-comparison of fiducial-based and anatomical landmark transformation approaches

    International Nuclear Information System (INIS)

    Hunsche, S; Sauner, D; Maarouf, M; Hoevels, M; Luyken, K; Schulte, O; Lackner, K; Sturm, V; Treuer, H

    2004-01-01

    For application in magnetic resonance (MR) guided stereotactic neurosurgery, two methods for transformation of MR-image coordinates in stereotactic, frame-based coordinates exist: the direct stereotactic fiducial-based transformation method and the indirect anatomical landmark method. In contrast to direct stereotactic MR transformation, indirect transformation is based on anatomical landmark coregistration of stereotactic computerized tomography and non-stereotactic MR images. In a patient study, both transformation methods have been investigated with visual inspection and mutual information analysis. Comparison was done for our standard imaging protocol, including t2-weighted spin-echo as well as contrast enhanced t1-weighted gradient-echo imaging. For t2-weighted spin-echo imaging, both methods showed almost similar and satisfying performance with a small, but significant advantage for fiducial-based transformation. In contrast, for t1-weighted gradient-echo imaging with more geometric distortions due to field inhomogenities and gradient nonlinearity than t2-weighted spin-echo imaging, mainly caused by a reduced bandwidth per pixel, anatomical landmark transformation delivered markedly better results. Here, fiducial-based transformation yielded results which are intolerable for stereotactic neurosurgery. Mean Euclidian distances between both transformation methods were 0.96 mm for t2-weighted spin-echo and 1.67 mm for t1-weighted gradient-echo imaging. Maximum deviations were 1.72 mm and 3.06 mm, respectively

  1. MR-guided stereotactic neurosurgery-comparison of fiducial-based and anatomical landmark transformation approaches

    Energy Technology Data Exchange (ETDEWEB)

    Hunsche, S [Department of Stereotaxy and Functional Neurosurgery, University of Cologne, Cologne (Germany); Sauner, D [Institute for Diagnostic and Interventional Radiology, Friedrich-Schiller-University of Jena, Jena (Germany); Maarouf, M [Department of Stereotaxy and Functional Neurosurgery, University of Cologne, Cologne (Germany); Hoevels, M [Department of Stereotaxy and Functional Neurosurgery, University of Cologne, Cologne (Germany); Luyken, K [Department of Stereotaxy and Functional Neurosurgery, University of Cologne, Cologne (Germany); Schulte, O [Department of Radiology, University of Cologne, Cologne (Germany); Lackner, K [Department of Radiology, University of Cologne, Cologne (Germany); Sturm, V [Department of Stereotaxy and Functional Neurosurgery, University of Cologne, Cologne (Germany); Treuer, H [Department of Stereotaxy and Functional Neurosurgery, University of Cologne, Cologne (Germany)

    2004-06-21

    For application in magnetic resonance (MR) guided stereotactic neurosurgery, two methods for transformation of MR-image coordinates in stereotactic, frame-based coordinates exist: the direct stereotactic fiducial-based transformation method and the indirect anatomical landmark method. In contrast to direct stereotactic MR transformation, indirect transformation is based on anatomical landmark coregistration of stereotactic computerized tomography and non-stereotactic MR images. In a patient study, both transformation methods have been investigated with visual inspection and mutual information analysis. Comparison was done for our standard imaging protocol, including t2-weighted spin-echo as well as contrast enhanced t1-weighted gradient-echo imaging. For t2-weighted spin-echo imaging, both methods showed almost similar and satisfying performance with a small, but significant advantage for fiducial-based transformation. In contrast, for t1-weighted gradient-echo imaging with more geometric distortions due to field inhomogenities and gradient nonlinearity than t2-weighted spin-echo imaging, mainly caused by a reduced bandwidth per pixel, anatomical landmark transformation delivered markedly better results. Here, fiducial-based transformation yielded results which are intolerable for stereotactic neurosurgery. Mean Euclidian distances between both transformation methods were 0.96 mm for t2-weighted spin-echo and 1.67 mm for t1-weighted gradient-echo imaging. Maximum deviations were 1.72 mm and 3.06 mm, respectively.

  2. 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.

  3. [Anatomical key points and operative principle of "two planes and four landmarks" in extralevator abdominoperineal excision].

    Science.gov (United States)

    Ye, Yingjiang; Shen, Zhanlong; Wang, Shan

    2014-11-01

    Abominoperineal resection (APR) is the main approach of lower rectal cancer treatment. Recently, it was found that conventional APR had higher incidence rate of positive circumferential resection margin(CRM) and intraoperative perforation (IOP), which was the crucial reason of local recurrence and worse prognosis. Extralevator abdominoperineal excision(ELAPE) procedure was proposed by European panels including surgeons, radiologist and pathologists, and considered to lower the positive rates of CRM and IOP. Definitive surgical planes and anatomic landmarks are the cores of this procedure, which are the prerequisite for the guarantee of safety and smoothness of surgery. To realize the anatomy of muscles, fascias, blood vessels and nervous of perineal region is the base of carrying out ELAPE procedure. In this paper, we introduce the key anatomy related to ELAPE procedure and summarize the principle of ELAPE procedure as "two planes and four landmarks", which will be beneficial to the popularization and application.

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

    Science.gov (United States)

    Christie, Lorna S.; Goossens, Richard H. M.; de Ridder, Huib; Jakimowicz, Jack 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 30° angled laparoscope, >100 basic laparoscopic procedures, >5 advanced laparoscopic procedures) and 23 novices (no laparoscopy experience) performed the Camera Navigation task in an abstract virtual environment (CN-box) and in a virtual representation of the lower abdomen (CN-abdomen). They also rated the realism and added value of the virtual environments on seven-point scales. Results Within both groups, the CN-box task was accomplished in less time and with shorter tip trajectory than the CN-abdomen task (Wilcoxon test, p  0.05). In both groups, the CN tasks were perceived as hard work and more challenging than anticipated. Conclusions Performance of the angled laparoscope navigation task is influenced by the virtual environment surrounding the exercise. The task was performed better in an abstract environment than in a virtual environment with anatomic landmarks. More insight is required into the influence and function of different types of intrinsic and extrinsic feedback on the effectiveness of preclinical simulator training. PMID:20419318

  5. 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.

  6. Medial arcuate ligament: a new anatomic landmark facilitates the location of the renal artery in retroperitoneal laparoscopic renal surgery.

    Science.gov (United States)

    Cai, Wei; Li, Hong Zhao; Zhang, Xu; Song, Yong; Ma, Xin; Dong, Jun; Chen, Wenzheng; Chen, Guang-Fu; Xu, Yong; Lu, Jin Shan; Wang, Bao-Jun; Shi, Tao-Ping

    2013-01-01

    The purpose of this study was to introduce a new method for locating the renal artery during retroperitoneal laparoscopic renal surgery. The medial arcuate ligament (MAL) is a tendinous arch in the fascia under the diaphragm that arches across the psoas major muscle and is attached medially to the side of the first or the second lumbar vertebra. The renal artery arises at the level of the intervertebral disc between the L1 and L2 vertebrae. We evaluate the role of the MAL that serves as an anatomic landmark for locating the renal artery during retroperitoneal laparoscopic renal surgery. There is a reproducible consistent anatomic relationship between MAL and the renal artery in 210 cases of retroperitoneal laparoscopic renal surgery. Two main types of the MAL, the "narrow arch" and the "fascial band" types, can be observed. MAL can serve as an accurate and reproducible anatomic landmark for the identification of the renal artery during retroperitoneal laparoscopic renal surgery.

  7. Determination of anatomic landmarks for optimal placement in captive-bolt euthanasia of goats.

    Science.gov (United States)

    Plummer, Paul J; Shearer, Jan K; Kleinhenz, Katie E; Shearer, Leslie C

    2018-03-01

    OBJECTIVE To determine the optimal anatomic site and directional aim of a penetrating captive bolt (PCB) for euthanasia of goats. SAMPLE 8 skulls from horned and polled goat cadavers and 10 anesthetized horned and polled goats scheduled to be euthanized at the end of a teaching laboratory. PROCEDURES Sagittal sections of cadaver skulls from 8 horned and polled goats were used to determine the ideal anatomic site and aiming of a PCB to maximize damage to the midbrain region of the brainstem for euthanasia. Anatomic sites for ideal placement and directional aiming were confirmed by use of 10 anesthetized horned and polled goats. RESULTS Clinical observation and postmortem examination of the sagittal sections of skulls from the 10 anesthetized goats that were euthanized confirmed that perpendicular placement and firing of a PCB at the intersection of 2 lines, each drawn from the lateral canthus of 1 eye to the middle of the base of the opposite ear, resulted in consistent disruption of the midbrain and thalamus in all goats. Immediate cessation of breathing, followed by a loss of heartbeat in all 10 of the anesthetized goats, confirmed that use of this site consistently resulted in effective euthanasia. CONCLUSIONS AND CLINICAL RELEVANCE Damage to the brainstem and key adjacent structures may be accomplished by firing a PCB perpendicular to the skull over the anatomic site identified at the intersection of 2 lines, each drawn from the lateral canthus of 1 eye to the middle of the base of the opposite ear.

  8. Anatomical landmarks and skin markers are not reliable for accurate labeling of thoracic vertebrae on MRI

    International Nuclear Information System (INIS)

    Shabshin, Nogah; Schweitzer, Mark E.; Carrino, John A.

    2010-01-01

    Background: Numbering of the thoracic spine on MRI can be tedious if C2 and L5-S1 are not included and may lead to errors in lesion level. Purpose: To determine whether anatomic landmarks or external markers are reliable as an aid for accurate numbering of thoracic vertebrae on MRI. Material and Methods: Sixty-seven thoracic spine MR studies of 67 patients (30 males, 37 females, age range 18-83 years) were studied, composed of 52 consecutive MR studies and an additional 15 MRI in which vitamin E markers were placed over the skin. In the 52 thoracic MR examinations potential numbering aids such as the level of the sternal apex, pulmonary artery, aortic arch, and osseous or disc abnormalities were numbered on both cervical localizer (standard of reference) and thoracic sagittal images. The additional 15 examinations in which vitamin E markers were placed over the skin were evaluated for consistency in the level of the markers on different sequences in the same exam. Results: The sternal apex level ranged from T2 to T5 [T3 in 28/51 patients (55%), T2 in 10/51 (20%)]. The aortic arch level ranged from T2 to T4 [T4 in 18/48 (38%) and T3 in 17 (35%)]. Pulmonary artery level ranged from T4 to T6-7 disc [T5 in 20/52 patients (38%) and T6 in 14/52 (27%)]. In 3 of 12 patients who had abnormalities in a vertebral body or disc as definite point reference, the non-localizer image mislabelled the level. In 11/15 (73%) patients with vitamin E markers that were placed over the upper thoracic spine, the results showed consistency in the level of the markers in relation to the reference points or consistent inter-marker gap between the sequences. Conclusion: There are only two reliable ways to accurately define the levels if no landmarking feature is available on the magnet. The first is by including C2 in the thoracic sequence of a diagnostic quality, and the second is by using an abnormality in the discs or vertebral bodies as a point of reference

  9. Anatomical landmarks and skin markers are not reliable for accurate labeling of thoracic vertebrae on MRI

    Energy Technology Data Exchange (ETDEWEB)

    Shabshin, Nogah (Dept. of Diagnostic Imaging, Chaim Sheba Medical Center, Tel-HaShomer (Israel)), e-mail: shabshin@gmail.com; Schweitzer, Mark E. (Dept. of Diagnostic Imaging, Ottawa Hospital and Univ. of Ottawa, Ottawa (Canada)); Carrino, John A. (Dept. of Radiology, Johns Hopkins Univ. School of Medicine, Baltimore, MD (United States))

    2010-11-15

    Background: Numbering of the thoracic spine on MRI can be tedious if C2 and L5-S1 are not included and may lead to errors in lesion level. Purpose: To determine whether anatomic landmarks or external markers are reliable as an aid for accurate numbering of thoracic vertebrae on MRI. Material and Methods: Sixty-seven thoracic spine MR studies of 67 patients (30 males, 37 females, age range 18-83 years) were studied, composed of 52 consecutive MR studies and an additional 15 MRI in which vitamin E markers were placed over the skin. In the 52 thoracic MR examinations potential numbering aids such as the level of the sternal apex, pulmonary artery, aortic arch, and osseous or disc abnormalities were numbered on both cervical localizer (standard of reference) and thoracic sagittal images. The additional 15 examinations in which vitamin E markers were placed over the skin were evaluated for consistency in the level of the markers on different sequences in the same exam. Results: The sternal apex level ranged from T2 to T5 [T3 in 28/51 patients (55%), T2 in 10/51 (20%)]. The aortic arch level ranged from T2 to T4 [T4 in 18/48 (38%) and T3 in 17 (35%)]. Pulmonary artery level ranged from T4 to T6-7 disc [T5 in 20/52 patients (38%) and T6 in 14/52 (27%)]. In 3 of 12 patients who had abnormalities in a vertebral body or disc as definite point reference, the non-localizer image mislabelled the level. In 11/15 (73%) patients with vitamin E markers that were placed over the upper thoracic spine, the results showed consistency in the level of the markers in relation to the reference points or consistent inter-marker gap between the sequences. Conclusion: There are only two reliable ways to accurately define the levels if no landmarking feature is available on the magnet. The first is by including C2 in the thoracic sequence of a diagnostic quality, and the second is by using an abnormality in the discs or vertebral bodies as a point of reference

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

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Hun; Jeong, Ho Gul; Hwang, Jae Joon; Lee, Jung Hee; Han, Sang Sun [Dept. of Oral and Maxillofacial Radiology, Yonsei University, College of Dentistry, Seoul (Korea, Republic of)

    2016-06-15

    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. 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. 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. 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.

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

    International Nuclear Information System (INIS)

    Jeon, Min Hee; Han, Gi Seok; Kim, Sung Jin; Park, Kil Sun; Cha, Sang Hoon; Bae, Il Hun; Lee, Seung Young

    2006-01-01

    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

  12. Infraorbital nerve block within the Pterygopalatine fossa of the horse: anatomical landmarks defined by computed tomography

    International Nuclear Information System (INIS)

    Carsten, S.; Hagen, G.

    2008-01-01

    In order to provide anaesthesia of the equine maxillary cheek teeth, a local nerve block of the infraorbital nerve in the pterygopalatine fossa had been proposed, which is referred to as the 'Palatine Bone Insertion' (PBI). As several complications with this method were reported, our study was designed to recommend a modified injection technique which avoids the risk of puncturing of relevant anatomical structures. Five cadaver heads and two living horses were examined by contrast medium injections and subsequent computed tomography (CT). Spinal needles were inserted using two different insertion techniques: The above mentioned (PBI), and a modification called 'Extraperiorbital Fat Body Insertion' (EFBI). Both techniques (PBI and EFBI) provide a consistent distribution of contrast medium around the infraorbital nerve. However, only the EFBI technique is appropriate to minimize the risk of complications. This study is an example for the permanent challenge of anatomists to supply a basis for clinical and surgical procedures

  13. An analysis of anatomic landmark mobility and setup errors in radiotherapy for lung cancer

    International Nuclear Information System (INIS)

    Samson, M.J.; Soernsen de Koste, J.R. van; Boer, J.C.J. de; Tankink, J.J.; Verstraate, M.B.J.; Essers, M.; Visser, A.G.; Senan, S.

    1997-01-01

    case for the SD of the translations in the cranial direction of the clavicle, aortic arch and upper thoracic wall. The carina was found to be relatively mobile (up to 6 mm) in both directions. The SD for in-plane rotations was negligible (<0.5 deg.) for all structures. The interpatient variation was very small (SD < 0.5 mm). In a preliminary analysis of patient setup, the random errors for translations are 2.0 mm in the lateral direction and 2.4 mm in the cranial direction (1 SD). The standard deviations of systematic errors are about 3 mm in both directions. In plane rotations were found to be negligible. Conclusions: We have identified a number of structures which exhibit little internal motion in the frontal plane, and recommend that a combination of these structures be used as anatomic landmarks for setup verification during radiotherapy of thoracic tumors. Preliminary results indicate that setup errors of patients with lung cancer in our center appear to be acceptable, even though no specific immobilization devices were used

  14. 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

  15. [Anatomical planes and landmarks of transanal total mesorectal excision for rectal cancer and prophylaxis of intraoperative complications].

    Science.gov (United States)

    Shen, Zhanlong; Ye, Yingjiang; Wang, Shan

    2017-07-25

    Total mesorectal excision (TME) is a mile-stone procedure in the history of rectal cancer surgery, but the exposure of surgical field of distal rectum is usually poor in patients with male, obese and narrow pelvis, which may lead to tumor residue and relative complications. Recently, a new technique called transanal TME (taTME) is considered to solve the above problems, but most medical centers are still in the learning curve of this procedure. Therefore, anatomical planes and landmarks of taTME for rectal cancer and prophylaxis of intraoperative complications are induced in this paper, which includes posterior plane: angle of anus and distal mesorectum and bleeding of mesorectum; rectosacral fascia and presacral bleeding; lateral and posterior-lateral plane: posterior branches of pelvic plexus and damage of anal function; anterior plane: vessel branches of neurovascular bundle and bleeding. Familiarity with the specific anatomical planes and landmarks plays an important role in shortening the learning curve, decreasing the complications, increasing the success rate of operation and standardization of taTME.

  16. Evaluation of the Location of Mandibular Foramen as an Anatomic Landmark Using CBCT Images: A Pioneering Study in an Iranian Population

    OpenAIRE

    Shokri, Abbas; Department of Oral & Maxillofacial Radiology – School of Dentistry – Hamadan University of Medical Sciences – Hamadan – Iran.; Falah-Kooshki, Sepideh; Department of Oral & Maxillofacial Radiology – School of Dentistry – Hamadan University of Medical Sciences – Hamadan – Iran.; Poorolajal, Jalal; Research Center for Modeling of Noncommunicable Diseases – Department of Epidemiology & Biostatistics – School of Public Health – Hamadan University of Medical Sciences – Hamadan – Iran.; Karimi, Atena; Department of Oral & Maxillofacial Radiology – School of Dentistry – Hamadan University of Medical Sciences – Hamadan – Iran.; Ostovarrad, Farzaneh; Department of Oral & Maxillofacial Radiology – School of Dentistry – Hamadan University of Medical Sciences – Hamadan – Iran.

    2014-01-01

    Objective: Mandibular foramen (MF) is located on the internal surface of the ramus through which blood vessels and nerves pass. Determination of the anatomic position of the MF is very important in inferior alveolar nerve block anesthesia (IANBA), ramus osteotomy and surgical procedures of the posterior angle of mandibular ramus. The aim of this study was to determine anatomic position of the MF using anatomic landmarks on the three dimensional CBCT images. Material and Methods: A total of 10...

  17. Arterial tree tracking from anatomical landmarks in magnetic resonance angiography scans

    Science.gov (United States)

    O'Neil, Alison; Beveridge, Erin; Houston, Graeme; McCormick, Lynne; Poole, Ian

    2014-03-01

    This paper reports on arterial tree tracking in fourteen Contrast Enhanced MRA volumetric scans, given the positions of a predefined set of vascular landmarks, by using the A* algorithm to find the optimal path for each vessel based on voxel intensity and a learnt vascular probability atlas. The algorithm is intended for use in conjunction with an automatic landmark detection step, to enable fully automatic arterial tree tracking. The scan is filtered to give two further images using the top-hat transform with 4mm and 8mm cubic structuring elements. Vessels are then tracked independently on the scan in which the vessel of interest is best enhanced, as determined from knowledge of typical vessel diameter and surrounding structures. A vascular probability atlas modelling expected vessel location and orientation is constructed by non-rigidly registering the training scans to the test scan using a 3D thin plate spline to match landmark correspondences, and employing kernel density estimation with the ground truth center line points to form a probability density distribution. Threshold estimation by histogram analysis is used to segment background from vessel intensities. The A* algorithm is run using a linear cost function constructed from the threshold and the vascular atlas prior. Tracking results are presented for all major arteries excluding those in the upper limbs. An improvement was observed when tracking was informed by contextual information, with particular benefit for peripheral vessels.

  18. Automated detection of retinal landmarks for the identification of clinically relevant regions in fundus photography

    Science.gov (United States)

    Ometto, Giovanni; Calivá, Francesco; Al-Diri, Bashir; Bek, Toke; Hunter, Andrew

    2016-03-01

    Automatic, quick and reliable identification of retinal landmarks from fundus photography is key for measurements used in research, diagnosis, screening and treating of common diseases affecting the eyes. This study presents a fast method for the detection of the centre of mass of the vascular arcades, optic nerve head (ONH) and fovea, used in the definition of five clinically relevant areas in use for screening programmes for diabetic retinopathy (DR). Thirty-eight fundus photographs showing 7203 DR lesions were analysed to find the landmarks manually by two retina-experts and automatically by the proposed method. The automatic identification of the ONH and fovea were performed using template matching based on normalised cross correlation. The centre of mass of the arcades was obtained by fitting an ellipse on sample coordinates of the main vessels. The coordinates were obtained by processing the image with hessian filtering followed by shape analyses and finally sampling the results. The regions obtained manually and automatically were used to count the retinal lesions falling within, and to evaluate the method. 92.7% of the lesions were falling within the same regions based on the landmarks selected by the two experts. 91.7% and 89.0% were counted in the same areas identified by the method and the first and second expert respectively. The inter-repeatability of the proposed method and the experts is comparable, while the 100% intra-repeatability makes the algorithm a valuable tool in tasks like analyses in real-time, of large datasets and of intra-patient variability.

  19. 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.

  20. Magnetic resonance imaging of the femoral trochlea: evaluation of anatomical landmarks and grading articular cartilage in cadaveric knees

    Energy Technology Data Exchange (ETDEWEB)

    Muhle, Claus [Marienhospital Vechta, Department of Radiology, Vechta (Germany); Veterans Affairs Medical Center, Department of Radiology, San Diego, CA (United States); Mo Ahn, Joong [University of Iowa, Department of Radiology, Iowa, IA (United States); Trudell, Debra; Resnick, Donald [Veterans Affairs Medical Center, Department of Radiology, San Diego, CA (United States)

    2008-06-15

    The purpose of the study was to define magnetic resonance imaging (MRI) findings before and after contrast medium opacification of the knee joint in cadaveric specimens to demonstrate anatomical landmarks of the trochlear surface in relation to the neighboring structures, and to evaluate different MRI sequences in the detection of cartilage defects of the trochlear and patellar surface of the knee. The morphology and relationship of the proximal trochlear surface to the prefemoral fat of the distal femur were investigated by use of different MR sequences before and after intra-articular gadolinium administration into the knee joint in ten cadaveric knees. Anatomic sections were subsequently obtained. In addition, evaluation of the articular surface of the trochlea was performed by two independent observers. The cartilage surfaces were graded using a 2-point system, and results were compared with macroscopic findings. Of 40 cartilage surfaces evaluated, histopathologic findings showed 9 normal surfaces, 20 containing partial-thickness defects, and 11 containing full-thickness defects. Compared with macroscopic data, sensitivity of MR sequences for the two reviewers was between 17 and 90%; specificity, 75 and 100%; positive predictive value, 75 and 100%; negative predictive value, 20 and 100%, depending on patellar or trochlea lesions. Interobserver variability for the presence of disease, which was measured using the kappa statistic, was dependent on the MR sequence used between 0.243 and 0.851. Magnetic resonance imaging sequences can be used to evaluate the cartilage of the trochlear surface with less accuracy when compared with the results of grading the articular cartilage of the patella. (orig.)

  1. 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.

  2. Anatomical masking of pressure footprints based on the Oxford Foot Model: validation and clinical relevance.

    Science.gov (United States)

    Giacomozzi, Claudia; Stebbins, Julie A

    2017-03-01

    Plantar pressure analysis is widely used in the assessment of foot function. In order to assess regional loading, a mask is applied to the footprint to sub-divide it into regions of interest (ROIs). The most common masking method is based on geometric features of the footprint (GM). Footprint masking based on anatomical landmarks of the foot has been implemented more recently, and involves the integration of a 3D motion capture system, plantar pressure measurement device, and a multi-segment foot model. However, thorough validation of anatomical masking (AM) using pathological footprints has not yet been presented. In the present study, an AM method based on the Oxford Foot Model (OFM) was compared to an equivalent GM. Pressure footprints from 20 young healthy subjects (HG) and 20 patients with clubfoot (CF) were anatomically divided into 5 ROIs using a subset of the OFM markers. The same foot regions were also identified by using a standard GM method. Comparisons of intra-subject coefficient of variation (CV) showed that the OFM-based AM was at least as reliable as the GM for all investigated pressure parameters in all foot regions. Clinical relevance of AM was investigated by comparing footprints from HG and CF groups. Contact time, maximum force, force-time integral and contact area proved to be sensitive parameters that were able to distinguish HG and CF groups, using both AM and GM methods However, the AM method revealed statistically significant differences between groups in 75% of measured variables, compared to 62% using a standard GM method, indicating that the AM method is more sensitive for revealing differences between groups. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. 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.

  4. Surface anatomy of major anatomical landmarks of the neck in an adult population: A Ct Evaluation of Vertebral Level.

    Science.gov (United States)

    Badshah, Masroor; Soames, Roger; Ibrahim, Muhammad; Khan, Muhammad Jaffar; Khan, Adnan

    2017-09-01

    To compare the projectional surface anatomy of healthy individuals in an adult population with those with a thyroid mass, using computed tomography (CT). Sixteen slice CT images of 101 individuals were analyzed using a 32-bit Radiant DICOM viewer to establish the relationships among major anatomical landmarks in the neck and their vertebral levels. The structures investigated included: hard palate (HP), hyoid bone (HB) including body and lesser horns, soft palate (SP), thyroid gland (TG) (both superior and inferior poles), thyroid gland anteroposterior (APD) and superoinferior (SID) diameters, thyroid isthmus (TI) superoinferior dimension, epiglottis, vertebral arteries (right and left), and both right and left parotid glands (superior and inferior extents). The vertebral levels noted most frequently were: body of hyoid bone (C4, 42.71%); lesser horns of hyoid bone (C3, 36.46%); thyroid gland superior pole (C6, 31.25%); and thyroid gland inferior pole (T2, 30.2%). TG-ID, TG-APD, and TG-SID were not significantly different between males and females in the healthy group; however, there was a significant gender difference in thyroid gland inferior diameter in the pathology group [males 2.16(±1.16) vs. females 3.37(±1.30), P = 0.01, paired sample t-test]. Further studies are needed to determine whether neck pathology in those with a thyroid mass affects the dimensions of the thyroid gland. Moreover, the surface anatomy of the neck should be revisited using modern imaging techniques to address inconsistencies in anatomy and clinical reference texts. Clin. Anat. 30:781-787, 2017. © 2017Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  5. Using anatomical landmark to avoid phrenic nerve injury during balloon-based procedures in atrial fibrillation patients.

    Science.gov (United States)

    Smith, Nicolina M; Segars, Larry; Kauffman, Travis; Olinger, Anthony B

    2017-12-01

    Atrial fibrillation (AF) is an arrhythmia which affects as many as 2.7 million Americans. AF should be treated, because it can lead to a four-to-fivefold increased risk of experiencing a stroke. The American College of Cardiology/American Heart Association guidelines for the treatment of drug refractory and symptomatic paroxysmal AF denote catheter ablation as the standard of care. The newest ablation treatment, cryoballoon, uses a cold balloon tip. The biggest risk factor associated with the cryoballoon ablation is phrenic nerve injury (PNI). The purpose of this study is to measure relevant distances from specific landmarks to the right phrenic nerve (RPN) to create a safe zone for physicians. Using 30 cadaveric specimens, we measured laterally from the right superior pulmonary vein orifice (RSPV) to the RPN at the level of the sixth thoracic vertebra and laterally from the lateral border of the sixth thoracic vertebral body (T6) to the RPN. The depth and width of the left atrium (LA) were also measured to establish a cross-sectional area of the LA. The cross-sectional area of the LA was then correlated with the averaged measurements to see if the area of the LA could be a predictor of the location of the RPN. The average distance from the RPN-RSPV was 9.6 mm (range 4.3-18.8 mm). The average RPN-T6 distance was 30.6 mm (range 13.7-49.9 mm). There was a non-significant trend that suggests as the size of the LA increases, the measured distances also increased. Using the lateral border of the sixth thoracic vertebra as a landmark, which can be viewed under fluoroscopy during the procedure, physicians can triangulate the distance to the RSPV and determine the approximate position of the RPN. Furthermore, physicians can perform a preoperative echocardiogram to determine the size of the LA to assist in determining the position of the RPN with the hopes of avoiding injury to the RPN.

  6. Iliohypogastric/ilioinguinal nerve block in inguinal hernia repair for postoperative pain management: comparison of the anatomical landmark and ultrasound guided techniques

    Directory of Open Access Journals (Sweden)

    Abdurrahman Demirci

    2014-10-01

    Full Text Available Objectives:The purpose of this study is to compare the efficacy of iliohypogastric/ilioinguinal nerve blocks performed with the ultrasound guided and the anatomical landmark techniques for postoperative pain management in cases of adult inguinal herniorrhaphy.Methods:40 patients, ASA I-II status were randomized into two groups equally: in Group AN (anatomical landmark technique and in Group ultrasound (ultrasound guided technique, iliohypogastric/ilioinguinal nerve block was performed with 20 ml of 0.5% levobupivacaine prior to surgery with the specified techniques. Pain score in postoperative assessment, first mobilization time, duration of hospital stay, score of postoperative analgesia satisfaction, opioid induced side effects and complications related to block were assessed for 24 h postoperatively.Results:VAS scores at rest in the recovery room and all the clinical follow-up points were found significantly less in Group ultrasound (p < 0.01 or p < 0.001. VAS scores at movement in the recovery room and all the clinical follow-up points were found significantly less in Group ultrasound (p < 0.001 in all time points. While duration of hospital stay and the first mobilization time were being found significantly shorter, analgesia satisfaction scores were found significantly higher in ultrasound Group (p < 0.05, p < 0.001, p < 0.001 respectively.Conclusion:According to our study, US guided iliohypogastric/ilioinguinal nerve block in adult inguinal herniorrhaphies provides a more effective analgesia and higher satisfaction of analgesia than iliohypogastric/ilioinguinal nerve block with the anatomical landmark technique. Moreover, it may be suggested that the observation of anatomical structures with the US may increase the success of the block, and minimize the block-related complications.

  7. Corona mortis: an anatomical variation with clinical relevance. Case report.

    Directory of Open Access Journals (Sweden)

    Guillermo Adrián Rivera-Cardona

    2010-12-01

    Full Text Available The obturator artery is one of the parietal branches arising from the internal iliac artery, the anatomical variation from which this artery originates is called “The corona mortis”, generally from the external iliac artery or the inferior epigastric artery. This finding was observed bilaterally in a male cadaver during a pelvis dissection. Clinical consideration of the anatomical variation in the obturator artery, during surgical procedures, is of great importance due to the risk of pelvic hemorrhage.

  8. When do objects become landmarks? A VR study of the effect of task relevance on spatial memory.

    Directory of Open Access Journals (Sweden)

    Xue Han

    Full Text Available We investigated how objects come to serve as landmarks in spatial memory, and more specifically how they form part of an allocentric cognitive map. Participants performing a virtual driving task incidentally learned the layout of a virtual town and locations of objects in that town. They were subsequently tested on their spatial and recognition memory for the objects. To assess whether the objects were encoded allocentrically we examined pointing consistency across tested viewpoints. In three experiments, we found that spatial memory for objects at navigationally relevant locations was more consistent across tested viewpoints, particularly when participants had more limited experience of the environment. When participants' attention was focused on the appearance of objects, the navigational relevance effect was eliminated, whereas when their attention was focused on objects' locations, this effect was enhanced, supporting the hypothesis that when objects are processed in the service of navigation, rather than merely being viewed as objects, they engage qualitatively distinct attentional systems and are incorporated into an allocentric spatial representation. The results are consistent with evidence from the neuroimaging literature that when objects are relevant to navigation, they not only engage the ventral "object processing stream", but also the dorsal stream and medial temporal lobe memory system classically associated with allocentric spatial memory.

  9. Variation in Location of the Mandibular Foramen/Inferior Alveolar Nerve Complex Given Anatomic Landmarks Using Cone-beam Computed Tomographic Scans.

    Science.gov (United States)

    Blacher, Jonathan; Van DaHuvel, Scott; Parashar, Vijay; Mitchell, John C

    2016-03-01

    The inferior alveolar nerve (IAN) injection is 1 of the most commonly administered and useful injections in the field of dentistry. Practitioners use intraoral anatomic landmarks, which vary greatly among patients. The objective of this study was to assist practitioners by identifying a range of normal variability within certain landmarks used in delivering IAN anesthesia. A total of 203 randomly selected retrospective cone-beam computed tomographic scans were obtained from the Midwestern University Dental Institute cone-beam computed tomographic database. InVivoDental5.0 volumetric imaging software (Anatomage, San Jose, CA) was used to measure 2 important parameters used in locating the mandibular foramen (MF)/IAN complex: (1) the angle from the contralateral premolar contact area to the MF and (2) the distance above the mandibular occlusal plane to the center of the MF. The variation of these measurements was compared with established reference values and statistically analyzed using a 1-sample t test. The angle from the contralateral premolar contact area to the MF for the right and left sides was 42.99° and 42.57°, respectively. The angulations varied significantly from the reference value of 45° (P < .001). The minimum height above the mandibular occlusal plane for the right and left sides was 9.85 mm and 9.81 mm, respectively. The heights varied significantly from the minimum reference value of 6 mm but not the maximum reference value of 10 mm (P < .001). Orienting the syringe barrel at an angulation slightly less than 45° and significantly higher than 6 mm above the mandibular occlusal plane can aid in successfully administering anesthesia to the MF/IAN complex. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  10. 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.

  11. Iliohypogastric/ilioinguinal nerve block in inguinal hernia repair for postoperative pain management: comparison of the anatomical landmark and ultrasound guided techniques

    Directory of Open Access Journals (Sweden)

    Abdurrahman Demirci

    2014-09-01

    Full Text Available Objectives: The purpose of this study is to compare the efficacy of iliohypogastric/ilioinguinal nerve blocks performed with the ultrasound guided and the anatomical landmark techniques for postoperative pain management in cases of adult inguinal herniorrhaphy. Methods: 40 patients, ASA I–II status were randomized into two groups equally: in Group AN (anatomical landmark technique and in Group ultrasound (ultrasound guided technique, iliohypogastric/ilioinguinal nerve block was performed with 20 ml of 0.5% levobupivacaine prior to surgery with the specified techniques. Pain score in postoperative assessment, first mobilization time, duration of hospital stay, score of postoperative analgesia satisfaction, opioid induced side effects and complications related to block were assessed for 24 h postoperatively. Results: VAS scores at rest in the recovery room and all the clinical follow-up points were found significantly less in Group ultrasound (p < 0.01 or p < 0.001. VAS scores at movement in the recovery room and all the clinical follow-up points were found significantly less in Group ultrasound (p < 0.001 in all time points. While duration of hospital stay and the first mobilization time were being found significantly shorter, analgesia satisfaction scores were found significantly higher in ultrasound Group (p < 0.05, p < 0.001, p < 0.001 respectively. Conclusion: According to our study, US guided iliohypogastric/ilioinguinal nerve block in adult inguinal herniorrhaphies provides a more effective analgesia and higher satisfaction of analgesia than iliohypogastric/ilioinguinal nerve block with the anatomical landmark technique. Moreover, it may be suggested that the observation of anatomical structures with the US may increase the success of the block, and minimize the block-related complications. Resumo: Objetivo: Comparar a eficácia de bloqueios dos nervos ílio-hipogástrico/ilioinguinal feitos com a técnica guiada por

  12. Comparison of Paravertebral Block by Anatomic Landmark Technique to Ultrasound-Guided Paravertebral Block for Breast Surgery Anesthesia: A Randomized Controlled Trial.

    Science.gov (United States)

    Patnaik, Rupali; Chhabra, Anjolie; Subramaniam, Rajeshwari; Arora, Mahesh K; Goswami, Devalina; Srivastava, Anurag; Seenu, Vuthaluru; Dhar, Anita

    2018-05-01

    Paravertebral block (PVB) is an established technique for providing anesthesia for breast surgery. The primary objective was to compare anatomical landmark technique (ALT) to the ultrasound-guided (USG) PVB block for providing surgical anesthesia. Secondary objectives included comparison of perioperative analgesia and complications. This randomized, controlled, observer-blinded study included 72 females, aged 18 to 65 years, American Society of Anesthesiologists physical status I or II, undergoing elective unilateral breast surgery. Study participants were randomized to the ALT group or USG group. Ipsilateral PVB was performed with the respective technique from T1 to T6. Five milliliters of local anesthetic mixture (0.5% ropivacaine, 5 μg/mL adrenaline, 1 μg/kg clonidine) was administered at each level. Paravertebral catheter was inserted at T4/T3 level. After confirming sensory loss, patients were taken up for surgery with propofol sedation (20-50 μg/kg per minute). More patients in the USG group (34/36 [94.44%]) had a successful block as compared with the ALT group (26/36 [72.22%]) (P = 0.024). Difference in proportion was 18.1 (95% confidence interval, 0.15-36.0) (P = 0.024) after adjustment for age. More dermatomes were blocked in the USG group (P = 0.0018) with less sparing of upper T2 and T3 dermatomes (P = 0.003, P = 0.006, respectively). Median time to first postoperative analgesic requirement was 502.5 minutes (range, 195-1440 minutes) in the USG group versus 377.5 minutes (range, 215-1440 minutes) in the ALT group. Pain at rest and movement 2 and 4 hours postoperatively and number of catheter top-ups in 24 hours postoperatively were lesser in the USG group (P = 0.012). Complications were comparable. Ultrasound-guided PVB provided better anesthesia and perioperative analgesia than the landmark technique for breast surgery. The trial was registered retrospectively at the Clinical Trial Registry of India, CTRI/2015/05/005774.

  13. Virtual landmarks

    Science.gov (United States)

    Tong, Yubing; Udupa, Jayaram K.; Odhner, Dewey; Bai, Peirui; Torigian, Drew A.

    2017-03-01

    Much has been published on finding landmarks on object surfaces in the context of shape modeling. While this is still an open problem, many of the challenges of past approaches can be overcome by removing the restriction that landmarks must be on the object surface. The virtual landmarks we propose may reside inside, on the boundary of, or outside the object and are tethered to the object. Our solution is straightforward, simple, and recursive in nature, proceeding from global features initially to local features in later levels to detect landmarks. Principal component analysis (PCA) is used as an engine to recursively subdivide the object region. The object itself may be represented in binary or fuzzy form or with gray values. The method is illustrated in 3D space (although it generalizes readily to spaces of any dimensionality) on four objects (liver, trachea and bronchi, and outer boundaries of left and right lungs along pleura) derived from 5 patient computed tomography (CT) image data sets of the thorax and abdomen. The virtual landmark identification approach seems to work well on different structures in different subjects and seems to detect landmarks that are homologously located in different samples of the same object. The approach guarantees that virtual landmarks are invariant to translation, scaling, and rotation of the object/image. Landmarking techniques are fundamental for many computer vision and image processing applications, and we are currently exploring the use virtual landmarks in automatic anatomy recognition and object analytics.

  14. 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.)

  15. Reliability of a coordinate system based on anatomical landmarks of the maxillofacial skeleton. An evaluation method for three-dimensional images obtained by cone-beam computed tomography

    International Nuclear Information System (INIS)

    Kimura, Momoko; Nawa, Hiroyuki; Yoshida, Kazuhito; Muramatsu, Atsushi; Fuyamada, Mariko; Goto, Shigemi; Ariji, Eiichiro; Tokumori, Kenji; Katsumata, Akitoshi

    2009-01-01

    We propose a method for evaluating the reliability of a coordinate system based on maxillofacial skeletal landmarks and use it to assess two coordinate systems. Scatter plots and 95% confidence ellipses of an objective landmark were defined as an index for demonstrating the stability of the coordinate system. A head phantom was positioned horizontally in reference to the Frankfurt horizontal and occlusal planes and subsequently scanned once in each position using cone-beam computed tomography. On the three-dimensional images created with a volume-rendering procedure, six dentists twice set two different coordinate systems: coordinate system 1 was defined by the nasion, sella, and basion, and coordinate system 2 was based on the left orbitale, bilateral porions, and basion. The menton was assigned as an objective landmark. The scatter plot and 95% ellipse of the menton indicated the high-level reliability of coordinate system 2. The patterns with the two coordinate systems were similar between data obtained in different head positions. The method presented here may be effective for evaluating the reliability (reproducibility) of coordinate systems based on skeletal landmarks. (author)

  16. 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.

  17. Canine intrahepatic vasculature: is a functional anatomic model relevant to the dog?

    Science.gov (United States)

    Hall, Jon L; Mannion, Paddy; Ladlow, Jane F

    2015-01-01

    To clarify canine intrahepatic portal and hepatic venous system anatomy using corrosion casting and advanced imaging and to devise a novel functional anatomic model of the canine liver to investigate whether this could help guide the planning and surgical procedure of partial hepatic lobectomy and interventional radiological procedures. Prospective experimental study. Adult Greyhound cadavers (n = 8). Portal and hepatic vein corrosion casts of healthy livers were assessed using computed tomography (CT). The hepatic lobes have a consistent hilar hepatic and portal vein supply with some variation in the number of intrahepatic branches. For all specimens, 3 surgically resectable areas were identified in the left lateral lobe and 2 surgically resectable areas were identified in the right medial lobe as defined by a functional anatomic model. CT of detailed acrylic casts allowed complex intrahepatic vascular relationships to be investigated and compared with previous studies. Improving understanding of the intrahepatic vascular supply facilitates interpretation of advanced images in clinical patients, the planning and performance of surgical procedures, and may facilitate interventional vascular procedures, such as intravenous embolization of portosystemic shunts. Functional division of the canine liver similar to human models is possible. The left lateral and right medial lobes can be consistently divided into surgically resectable functional areas and partial lobectomies can be performed following a functional model; further study in clinically affected animals would be required to investigate the relevance of this functional model in the dog. © Copyright 2014 by The American College of Veterinary Surgeons.

  18. State Landmarks.

    Science.gov (United States)

    Pappas, Marjorie L.

    2003-01-01

    Explains how to develop lesson plans to help students become effective researchers using electronic searching tools. Uses a unit developed for Kansas landmarks to discuss information skills, competency standards, inquiry, technology use, information literacy and process skills, finding information, and an example of a research log. (LRW)

  19. Anatomical curve identification

    Science.gov (United States)

    Bowman, Adrian W.; Katina, Stanislav; Smith, Joanna; Brown, Denise

    2015-01-01

    Methods for capturing images in three dimensions are now widely available, with stereo-photogrammetry and laser scanning being two common approaches. In anatomical studies, a number of landmarks are usually identified manually from each of these images and these form the basis of subsequent statistical analysis. However, landmarks express only a very small proportion of the information available from the images. Anatomically defined curves have the advantage of providing a much richer expression of shape. This is explored in the context of identifying the boundary of breasts from an image of the female torso and the boundary of the lips from a facial image. The curves of interest are characterised by ridges or valleys. Key issues in estimation are the ability to navigate across the anatomical surface in three-dimensions, the ability to recognise the relevant boundary and the need to assess the evidence for the presence of the surface feature of interest. The first issue is addressed by the use of principal curves, as an extension of principal components, the second by suitable assessment of curvature and the third by change-point detection. P-spline smoothing is used as an integral part of the methods but adaptations are made to the specific anatomical features of interest. After estimation of the boundary curves, the intermediate surfaces of the anatomical feature of interest can be characterised by surface interpolation. This allows shape variation to be explored using standard methods such as principal components. These tools are applied to a collection of images of women where one breast has been reconstructed after mastectomy and where interest lies in shape differences between the reconstructed and unreconstructed breasts. They are also applied to a collection of lip images where possible differences in shape between males and females are of interest. PMID:26041943

  20. Tibialis Anterior Tendon: A Reliable Anatomical Landmark Indicating the Ankle Centre. Potential Utility in Extra-Medullary Alignment During Total Knee Replacement

    Directory of Open Access Journals (Sweden)

    Avadhoot P. Kantak

    2017-07-01

    Full Text Available Background Extramedullary alignment is a well established surgical technique during total knee replacement. There are different methods to achieve accuracy but variability is quite extensive. To attain uniformity in the surgical technique we have been using the tibialis tendon to align our resection guide. This may prove to be a useful aid for surgeons during knee replacement surgery. Objectives The purpose of our study was to establish if tibialis anterior tendon represents the centre of ankle joint and if it could be used as an anatomical reference for alignment during knee replacement. Methods We designed a retrospective radiological cohort study. We studied sixty MRI scans of normal ankles. The centre of ankle joint was marked as a bisection point of the intermalleolar line at the level of superior surface of the talus. A line was drawn connecting the centre of Achilles tendon to the ankle centre and this was extended anteriorly. This line was found to have a constant relation to the ankle centre and it would simulate the positioning of the standard alignment device used. Results The tibialis anterior tendon lies less than 3mm medial to the ankle centre in the frontal plane. Conclusions We conclude that the tibialis anterior tendon can be used during knee replacement surgery as an accurate alignment guide.

  1. 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.

  2. 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.

    Science.gov (United States)

    Frigeri, Thomas; Rhoton, Albert; Paglioli, Eliseu; Azambuja, Ney

    2014-10-01

    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). 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. The cortical projection of the ICP is a reliable landmark for reaching the temporal horn.

  3. A survey of anatomical items relevant to the practice of rheumatology: upper extremity, head, neck, spine, and general concepts.

    Science.gov (United States)

    Villaseñor-Ovies, Pablo; Navarro-Zarza, José Eduardo; Saavedra, Miguel Ángel; Hernández-Díaz, Cristina; Canoso, Juan J; Biundo, Joseph J; Kalish, Robert A; de Toro Santos, Francisco Javier; McGonagle, Dennis; Carette, Simon; Alvarez-Nemegyei, José

    2016-12-01

    This study aimed to identify the anatomical items of the upper extremity and spine that are potentially relevant to the practice of rheumatology. Ten rheumatologists interested in clinical anatomy who published, taught, and/or participated as active members of Clinical Anatomy Interest groups (six seniors, four juniors), participated in a one-round relevance Delphi exercise. An initial, 560-item list that included 45 (8.0 %) general concepts items; 138 (24.8 %) hand items; 100 (17.8 %) forearm and elbow items; 147 (26.2 %) shoulder items; and 130 (23.2 %) head, neck, and spine items was compiled by 5 of the participants. Each item was graded for importance with a Likert scale from 1 (not important) to 5 (very important). Thus, scores could range from 10 (1 × 10) to 50 (5 × 10). An item score of ≥40 was considered most relevant to competent practice as a rheumatologist. Mean item Likert scores ranged from 2.2 ± 0.5 to 4.6 ± 0.7. A total of 115 (20.5 %) of the 560 initial items reached relevance. Broken down by categories, this final relevant item list was composed by 7 (6.1 %) general concepts items; 32 (27.8 %) hand items; 20 (17.4 %) forearm and elbow items; 33 (28.7 %) shoulder items; and 23 (17.6 %) head, neck, and spine items. In this Delphi exercise, a group of practicing academic rheumatologists with an interest in clinical anatomy compiled a list of anatomical items that were deemed important to the practice of rheumatology. We suggest these items be considered curricular priorities when training rheumatology fellows in clinical anatomy skills and in programs of continuing rheumatology education.

  4. Landmark Mixed-Media Collage

    Science.gov (United States)

    Hubbert, Beth

    2009-01-01

    For the author, it all began with a summer trip to London and Paris. Inspired by the art and architecture of London and Paris, she was determined to bring her experience back home to her students. To do this, she organized a lesson in world landmarks focusing on structures of importance that fit into three categories: relevance to the world,…

  5. Anatomical variations of the right hepatic veins and their relevance to surgery.

    Science.gov (United States)

    Hribernik, Marija; de Cecchis, Lucio; Trotovsek, Blaz; Gadzijev, Eldar M; Ravnik, Dean

    2003-01-01

    In a morphological study of the right hepatic veins anatomical characteristics of surgical importance were looked for. 110 cadaveric human livers were prepared by the corrosion casts method. The confluence patterns of the superior right hepatic vein, the hepatocaval confluence, the accessory right hepatic veins and the anastomoses between hepatic veins in the right hemiliver were examined. Four types of the superior right hepatic vein, based on the length of its trunk and the confluence pattern of its main tributaries were determined and their frequency was calculated. Type I was found in 20%, type II in 40%, type III in 25% and type IV in 15%. Accessory right hepatic veins with a minimal caliber of 0.4 cm, which were always present in type IV, were also found in other types, all together in 27% of the casts. The tributary-free part of the superior right hepatic vein at hepatocaval confluence was longer than 1 cm in 77%. In the right hemiliver 109 anastomoses were found in 29/110 liver casts. Knowing the characteristics of different superior right hepatic vein types and of the accessory right hepatic veins may be useful in segment-oriented liver resections and in right side living donor resections.

  6. Investigation of anatomical landmarks for paravertebral anaesthesia ...

    African Journals Online (AJOL)

    The result of this study showed that the spinal nerve emerges from the intervertebral foramina and bifurcates into dorsal and ventral branches with the dorsal nerve branch passing cranially to the body of the succeeding lumbar transverse process in a caudolateral manner. While the ventral branches of the lumbar nerves ...

  7. Anatomical Basis for the Cardiac Interventional Electrophysiologist

    Directory of Open Access Journals (Sweden)

    Damián Sánchez-Quintana

    2015-01-01

    Full Text Available The establishment of radiofrequency catheter ablation techniques as the mainstay in the treatment of tachycardia has renewed new interest in cardiac anatomy. The interventional arrhythmologist has drawn attention not only to the gross anatomic details of the heart but also to architectural and histological characteristics of various cardiac regions that are relevant to the development or recurrence of tachyarrhythmias and procedural related complications of catheter ablation. In this review, therefore, we discuss some anatomic landmarks commonly used in catheter ablations including the terminal crest, sinus node region, Koch’s triangle, cavotricuspid isthmus, Eustachian ridge and valve, pulmonary venous orifices, venoatrial junctions, and ventricular outflow tracts. We also discuss the anatomical features of important structures in the vicinity of the atria and pulmonary veins, such as the esophagus and phrenic nerves. This paper provides basic anatomic information to improve understanding of the mapping and ablative procedures for cardiac interventional electrophysiologists.

  8. Landmarks in Linoleum

    Science.gov (United States)

    Skophammer, Karen

    2010-01-01

    This printmaking unit will get students excited about geography and history. In this article, the author describes how her eighth-grade students created a report and a linoleum print of a famous "landmark."

  9. Automated human skull landmarking with 2D Gabor wavelets

    Science.gov (United States)

    de Jong, Markus A.; Gül, Atilla; de Gijt, Jan Pieter; Koudstaal, Maarten J.; Kayser, Manfred; Wolvius, Eppo B.; Böhringer, Stefan

    2018-05-01

    Landmarking of CT scans is an important step in the alignment of skulls that is key in surgery planning, pre-/post-surgery comparisons, and morphometric studies. We present a novel method for automatically locating anatomical landmarks on the surface of cone beam CT-based image models of human skulls using 2D Gabor wavelets and ensemble learning. The algorithm is validated via human inter- and intra-rater comparisons on a set of 39 scans and a skull superimposition experiment with an established surgery planning software (Maxilim). Automatic landmarking results in an accuracy of 1–2 mm for a subset of landmarks around the nose area as compared to a gold standard derived from human raters. These landmarks are located in eye sockets and lower jaw, which is competitive with or surpasses inter-rater variability. The well-performing landmark subsets allow for the automation of skull superimposition in clinical applications. Our approach delivers accurate results, has modest training requirements (training set size of 30–40 items) and is generic, so that landmark sets can be easily expanded or modified to accommodate shifting landmark interests, which are important requirements for the landmarking of larger cohorts.

  10. Proximal Femoral Morphology and the Relevance to Design of Anatomically Precontoured Plates: A Study of the Chinese Population

    Directory of Open Access Journals (Sweden)

    Kun-Jhih Lin

    2014-01-01

    Full Text Available Adequately shaped femoral plate is critical for the fixation of fracture in the pertrochanteric regions. Lateral aspect of greater trochanter is an important region where the proximal femoral plate anchored. However, little is known regarding the morphology of greater trochanter. The objective of this study was to measure main dimensions of greater trochanter and other regions in the proximal end of the femur to provide an anatomical basis for the design of the proximal femoral plate. Anthropometric data on the proximal femur were performed utilizing three-dimensional computational modeling. Computed tomography images of healthy femurs in 53 women and 47 men were contributed to three-dimensional femur modeling. All data were compared between male and female femora. The results showed that mean values for male group were found to be greater in most of measured femoral dimensions. Oppositely, females demonstrated higher neck-shaft angle on anteroposterior view and femoral anteversion angle. The anthropometric data can be used for the anatomical shape design of femoral plates for osteosynthesis of fractures in the trochanteric regions. A distinct plate design may be necessary to accommodate differences between the genders.

  11. 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.

  12. Colon flattening by landmark-driven optimal quasiconformal mapping.

    Science.gov (United States)

    Zeng, Wei; Yang, Yi-Jun

    2014-01-01

    In virtual colonoscopy, colon conformal flattening plays an important role, which unfolds the colon wall surface to a rectangle planar image and preserves local shapes by conformal mapping, so that the cancerous polyps and other abnormalities can be easily and thoroughly recognized and visualized without missing hidden areas. In such maps, the anatomical landmarks (taeniae coli, flexures, and haustral folds) are naturally mapped to convoluted curves on 2D domain, which poses difficulty for comparing shapes from geometric feature details. Understanding the nature of landmark curves to the whole surface structure is meaningful but it remains challenging and open. In this work, we present a novel and effective colon flattening method based on quasiconformal mapping, which straightens the main anatomical landmark curves with least conformality (angle) distortion. It provides a canonical and straightforward view of the long, convoluted and folded tubular colon surface. The computation is based on the holomorphic 1-form method with landmark straightening constraints and quasiconformal optimization, and has linear time complexity due to the linearity of 1-forms in each iteration. Experiments on various colon data demonstrate the efficiency and efficacy of our algorithm and its practicability for polyp detection and findings visualization; furthermore, the result reveals the geometric characteristics of anatomical landmarks on colon surfaces.

  13. Anatomic study of the vascular perfusion of the sternum and its clinical relevance in deep sternal wound infection

    Directory of Open Access Journals (Sweden)

    Spindler, Nick

    2017-06-01

    Full Text Available Introduction: Deep sternal wound infections (DSWI are a rare but devastating complication after median sternotomy. Minor perfusion in bone and soft tissue, especially after recruiting the internal mammary artery for bypass supports the development of wound infection and nonunion of the sternal bone. The aim of the study was the macroscopic and radiological presentation of the vascular system supplying the sternum, in particular the compensating blood supply routes in the event that the internal mammary artery is no longer available after use as a bypass vessel.Method: This anatomic study was carried out on the anterior chest wall of 7 specimens. The thorax plates of 7 specimens were analyzed macroscopically after microsurgical preparation. Different anatomic preparations were produced using different contrast or form-giving substances. Radiological analysis and three-dimensional reconstructions were performed to show alternative, collateral sternal vessel perfusion under estimation of the loss of the internal thoracic artery due to a bypass.Results: The length of the ITA (internal thoracic artery, measured from the beginning of the first rib to the division into the superior epigastric artery and musculophrenic artery, was an average of 16.3 cm. On average, 18.5 branches were delivered from each artery, 10 medially to the sternum supply, and the intercostal muscle. Conclusion: Our analysis gives an overview of the macroanatomic vessel system supplying the sternal bone, describing especially a common trunk deriving from the ITA and supplying multiple branches and playing an important role in building a collateral circulation of the sternum.For better evaluation, in vivo CT analysis with contrast media should be performed in patients prior to the operation and directly after the use of the double ITA to demonstrate the change in perfusion of the sternum.In the future, preconditioning of the sternum by coiling the deriving branches could become an

  14. 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.

  15. 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

  16. Neurovascular Content of the Mandibular Canal and Its Clinical Relevance: A Literature Review of the Related Anatomical and Radiological Studies

    Directory of Open Access Journals (Sweden)

    Eliades Apostolos N.

    2014-11-01

    Full Text Available In literature, anatomical variations of the inferior alveolar nerve branches (infratemporal, extraosseous and intraosseous are reported and their importance in clinical practice is discussed too. The spatial vessels’ position in relationship with the nerve in the mandibular canal was explored, which is of clinical significance in impacted third molar and implant surgery. It is believed that the neurovascular content of the main mandibular canal follows any variations of the mandibular canal i.e. bifid mandibular, retromolar and accessory mental canals. Retrospective studies and case reports reported the presence of multiple foramina on the medial surface of the ramus, near the main mandibular foramen. In some cases, one supplementary mandibular foramen was found to be connected with the lower third molar, which is called “temporal crest canal”. Others found an accessory mandibular foramen that led into a second mandibular canal which joined the main mandibular canal (double anteriorly. The bony canals contained a terminal branch of the anterior trunk of the mandibular nerve or a branch of inferior alveolar nerve before it entered the mandibular foramen.

  17. The frontal-anatomic specificity of design fluency repetitions and their diagnostic relevance for behavioral variant frontotemporal dementia.

    Science.gov (United States)

    Possin, Katherine L; Chester, Serana K; Laluz, Victor; Bostrom, Alan; Rosen, Howard J; Miller, Bruce L; Kramer, Joel H

    2012-09-01

    On tests of design fluency, an examinee draws as many different designs as possible in a specified time limit while avoiding repetition. The neuroanatomical substrates and diagnostic group differences of design fluency repetition errors and total correct scores were examined in 110 individuals diagnosed with dementia, 53 with mild cognitive impairment (MCI), and 37 neurologically healthy controls. The errors correlated significantly with volumes in the right and left orbitofrontal cortex (OFC), the right and left superior frontal gyrus, the right inferior frontal gyrus, and the right striatum, but did not correlate with volumes in any parietal or temporal lobe regions. Regression analyses indicated that the lateral OFC may be particularly crucial for preventing these errors, even after excluding patients with behavioral variant frontotemporal dementia (bvFTD) from the analysis. Total correct correlated more diffusely with volumes in the right and left frontal and parietal cortex, the right temporal cortex, and the right striatum and thalamus. Patients diagnosed with bvFTD made significantly more repetition errors than patients diagnosed with MCI, Alzheimer's disease, semantic dementia, progressive supranuclear palsy, or corticobasal syndrome. In contrast, total correct design scores did not differentiate the dementia patients. These results highlight the frontal-anatomic specificity of design fluency repetitions. In addition, the results indicate that the propensity to make these errors supports the diagnosis of bvFTD. (JINS, 2012, 18, 1-11).

  18. A Tissue Relevance and Meshing Method for Computing Patient-Specific Anatomical Models in Endoscopic Sinus Surgery Simulation

    Science.gov (United States)

    Audette, M. A.; Hertel, I.; Burgert, O.; Strauss, G.

    This paper presents on-going work on a method for determining which subvolumes of a patient-specific tissue map, extracted from CT data of the head, are relevant to simulating endoscopic sinus surgery of that individual, and for decomposing these relevant tissues into triangles and tetrahedra whose mesh size is well controlled. The overall goal is to limit the complexity of the real-time biomechanical interaction while ensuring the clinical relevance of the simulation. Relevant tissues are determined as the union of the pathology present in the patient, of critical tissues deemed to be near the intended surgical path or pathology, and of bone and soft tissue near the intended path, pathology or critical tissues. The processing of tissues, prior to meshing, is based on the Fast Marching method applied under various guises, in a conditional manner that is related to tissue classes. The meshing is based on an adaptation of a meshing method of ours, which combines the Marching Tetrahedra method and the discrete Simplex mesh surface model to produce a topologically faithful surface mesh with well controlled edge and face size as a first stage, and Almost-regular Tetrahedralization of the same prescribed mesh size as a last stage.

  19. Digital analysis of facial landmarks in determining facial midline among Punjabi population

    Directory of Open Access Journals (Sweden)

    Nirmal Kurian

    2018-01-01

    Full Text Available Introduction: Prosthodontic rehabilitation aims to achieve the best possible facial esthetic appearance for a patient. Attaining facial symmetry forms the basic element for esthetics, and knowledge of the midline of face will result in a better understanding of dentofacial esthetics. Currently, there are no guidelines that direct the choice of specific anatomic landmarks to determine the midline of the face or mouth. Most clinicians choose one specific anatomic landmark and an imaginary line passing through it. Thus, the clinician is left with no established guidelines to determine facial midline. Objective: The purpose of the study is to digitally determine the relationship of facial landmarks with midline of face and formulate a guideline for choosing anatomic landmark among Punjabi population. Materials and Methods: Three commonly used anatomic landmarks, namely nasion, tip of the nose, and tip of the philtrum, were marked clinically on 100 participants (age range: 21–45 years. Frontal full-face digital images of the participants in smile were then made under standardized conditions. Midline analysis was carried out digitally using an image analyzing software. The entire process of midline analysis was done by a single observer and repeated twice. Reliability analysis and one-sample t-tests were conducted. Results: The results indicated that each of the four landmarks deviated uniquely and significantly (P < 0.001 from the midlines of the face as well as the mouth. Conclusions: Within the limitations of the study, the hierarchy of anatomic landmarks closest to the midline of the face in smile was as follows: (1 Intercommissural midlines, (2 Tip of philtrum, (3 Nasion, (4 Tip of the nose, and (5 Dental midlines. The hierarchy of anatomical landmarks closest to the intercommissural/mouth midline was: (1 Tip of philtrum, (2 Tip of the nose, (3 Nasion, and (4 dental midline.

  20. Left septal atrial tachycardia after open-heart surgery: relevance to surgical approach, anatomical and electrophysiological characteristics associated with catheter ablation, and procedural outcomes.

    Science.gov (United States)

    Adachi, Toru; Yoshida, Kentaro; Takeyasu, Noriyuki; Masuda, Keita; Sekiguchi, Yukio; Sato, Akira; Tada, Hiroshi; Nogami, Akihiko; Aonuma, Kazutaka

    2015-02-01

    Septal atrial tachycardia (AT) can occur in patients without structural heart disease and in patients with previous catheter ablation of atrial fibrillation. We aimed to assess septal AT that occurs after open-heart surgery. This study comprised 20 consecutive patients undergoing catheter ablation of macroreentrant AT after open-heart surgery. Relevance to surgical approach, mechanisms, anatomic and electrophysiological characteristics, and outcomes were assessed. Septal AT was identified in 7 patients who had all undergone mitral valve surgery. All septal ATs were localized in the left atrial septum, whereas 10 of 13 nonseptal ATs originated from the right atrium. Patients with left septal AT had a thicker fossa ovalis (median, 4.0; 25th-75th percentile, 3.6-4.2 versus 2.3; 1.6-2.6 mm; P=0.006) and broader area of low voltage (open-heart surgery was characterized by a thicker septum, more scar burden in the septum, and repeated prolongations of the tachycardia cycle length during ablation. Such an arrhythmogenic substrate may interfere with transmural lesion formation by ablation and may account for higher likelihood of recurrence of left septal AT. © 2014 American Heart Association, Inc.

  1. Assessment and feasibility of the four landmarks of the aortic root in a cohort of very preterm infants

    Directory of Open Access Journals (Sweden)

    Sam Phillips

    2015-01-01

    Conclusion : We present reliability and reference values for all four anatomic landmarks of the aortic root in very preterm infants and demonstrated the importance of standardizing and reporting cardiac output measurements in preterm infants.

  2. 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.

  3. CBCT images of anatomic landmarks in maxillofacial region

    OpenAIRE

    Mayil, Meltem; Keser, Gaye; Namdar Pekiner, Filiz

    2014-01-01

    Conventional radiographic techniques in dental radiology allows only 2D images of 3D structures of head and neck region. CBCT is a recent technology, is also named as dental volumetric tomography, which was developed as an alternative to conventional CT using cone beam-shaped X-ray to provide more rapid acquisition of a data set of entire maxillofacial region. CBCT has remarkable advantages such as shorter exposure time, reduced image distortion due to patient movements, dec...

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

    International Nuclear Information System (INIS)

    Spina, Juan C.; Spina, Juan C. h; Rolnik, Maria C.; Lema, Carlos; Venditi, Julio; Magarinos, Gabriel

    2002-01-01

    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)

  5. 4D Flow Analysis of BAV-Related Fluid-Dynamic Alterations: Evidences of Wall Shear Stress Alterations in Absence of Clinically-Relevant Aortic Anatomical Remodeling

    Directory of Open Access Journals (Sweden)

    Filippo Piatti

    2017-06-01

    -dynamic alterations, no clinically relevant anatomical remodeling was observed in the BAV patients at 3-year follow-up. In light of previous evidence from the literature, our results suggest that WSS alterations may precede the onset of aortopathy and may contribute to its triggering, but WSS-driven anatomical remodeling, if any, is a very slow process.

  6. Study of the anatomical position of the femoral nerve by magnetic resonance imaging in patients with fractured neck of femur: relevance to femoral nerve block.

    LENUS (Irish Health Repository)

    Mehmood, Shehzad

    2012-01-31

    STUDY OBJECTIVE: To determine the anatomical location of the femoral nerve in patients who have sustained fracture of the neck of femur, and its relevance to femoral nerve block technique. DESIGN: Prospective, observational clinical study. SETTING: Orthopedic and Radiology departments of a regional hospital. SUBJECTS: 10 consecutive adult ASA physical status II and III patients (mean age, 78.5 yrs) and 4 adult healthy volunteers. INTERVENTIONS: A T1 magnetic resonance imaging scan was performed of both upper thighs in patients and healthy volunteers successfully. MEASUREMENTS: The distance (mm) between the midpoint of the femoral artery and the midpoint of the femoral nerve, and the distance of the femoral nerve from the skin was measured at the mid-inguinal ligament, the pubic tubercle, and at the mid-inguinal crease. Data are shown as means (SD). Differences between both sides were compared using paired Student\\'s t-tests. P < 0.05 was significant. MAIN RESULTS: In patients the mean distance (mm) between the midpoint of the femoral nerve from the midpoint of femoral artery at the mid-inguinal crease on the fractured and non-fractured sides was 10.7 and 11.0, respectively (P = 0.87). The mean distance (mm) between the midpoint of the femoral nerve from the midpoint of the femoral artery at the mid-inguinal ligament on the fractured and non-fractured sides was 9.64 and 12.5, respectively (P = 0.03). The mean distance (mm) between the midpoint of the femoral nerve from the midpoint of the femoral artery at the pubic tubercle on the fractured and non-fractured sides was 8.74 and 10.49, respectively (P = 0.18). CONCLUSIONS: Blockade of the femoral nerve may be easier to perform at the mid-inguinal crease in patients with fractured neck of femur.

  7. Salton and Buckley’s Landmark Research in Experimental Text Information Retrieval. A Review of: Salton, G., & Buckley, C. (1990. Improving retrieval performance by relevance feedback. Journal of the American Society for Information Science, 41(4, 288–297.

    Directory of Open Access Journals (Sweden)

    Christine F. Marton

    2011-01-01

    Full Text Available Objectives – To compare the performance of the vector space model and the probabilistic weighting model of relevance feedback for the overall purpose of determining the most useful relevance feedback procedures. The amount of improvement that can be obtained from searching several test document collections with only one feedback iteration of each relevance feedback model was measured.Design – The experimental design consisted of 72 different tests: 2 different relevance feedback methods, each with 6 permutations, on 6 test document collections of various sizes. A residual collection method was utilized to ascertain the “true advantage provided by the relevance feedback process.” (Salton & Buckley, 1990, p. 293Setting – Department of Computer Science at Cornell University.Subjects – Six test document collections.Methods – Relevance feedback is an effective technique for query modification that provides significant improvement in search performance. Relevance feedback entails both “term reweighting,” the modification of term weights based on term use in retrieved relevant and non-relevant documents, and “query expansion,” which is the addition of new terms from relevant documents retrieved (Harman, 1992. Salton and Buckley (1990 evaluated two established relevance feedback models based on the vector space model (a spatial model and the probabilistic model, respectively. Harman (1992 describes the two key differences between these competing models of relevance feedback.[The vector space model merges] document vectors and original query vectors. This automatically reweights query terms by adding the weights from the actual occurrence of those query terms in the relevant documents, and subtracting the weights of those terms occurring in the non-relevant documents. Queries are automatically expanded by adding all the terms not in the original query that are in the relevant documents and non-relevant documents. They are expanded

  8. 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.

  9. Multiobjective optimization framework for landmark measurement error correction in three-dimensional cephalometric tomography.

    Science.gov (United States)

    DeCesare, A; Secanell, M; Lagravère, M O; Carey, J

    2013-01-01

    The purpose of this study is to minimize errors that occur when using a four vs six landmark superimpositioning method in the cranial base to define the co-ordinate system. Cone beam CT volumetric data from ten patients were used for this study. Co-ordinate system transformations were performed. A co-ordinate system was constructed using two planes defined by four anatomical landmarks located by an orthodontist. A second co-ordinate system was constructed using four anatomical landmarks that are corrected using a numerical optimization algorithm for any landmark location operator error using information from six landmarks. The optimization algorithm minimizes the relative distance and angle between the known fixed points in the two images to find the correction. Measurement errors and co-ordinates in all axes were obtained for each co-ordinate system. Significant improvement is observed after using the landmark correction algorithm to position the final co-ordinate system. The errors found in a previous study are significantly reduced. Errors found were between 1 mm and 2 mm. When analysing real patient data, it was found that the 6-point correction algorithm reduced errors between images and increased intrapoint reliability. A novel method of optimizing the overlay of three-dimensional images using a 6-point correction algorithm was introduced and examined. This method demonstrated greater reliability and reproducibility than the previous 4-point correction algorithm.

  10. Landmark-based elastic registration using approximating thin-plate splines.

    Science.gov (United States)

    Rohr, K; Stiehl, H S; Sprengel, R; Buzug, T M; Weese, J; Kuhn, M H

    2001-06-01

    We consider elastic image registration based on a set of corresponding anatomical point landmarks and approximating thin-plate splines. This approach is an extension of the original interpolating thin-plate spline approach and allows to take into account landmark localization errors. The extension is important for clinical applications since landmark extraction is always prone to error. Our approach is based on a minimizing functional and can cope with isotropic as well as anisotropic landmark errors. In particular, in the latter case it is possible to include different types of landmarks, e.g., unique point landmarks as well as arbitrary edge points. Also, the scheme is general with respect to the image dimension and the order of smoothness of the underlying functional. Optimal affine transformations as well as interpolating thin-plate splines are special cases of this scheme. To localize landmarks we use a semi-automatic approach which is based on three-dimensional (3-D) differential operators. Experimental results are presented for two-dimensional as well as 3-D tomographic images of the human brain.

  11. Autonomous Robot Navigation based on Visual Landmarks

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    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 a...... automatically learn and store visual landmarks, and later recognize these landmarks from arbitrary positions and thus estimate robot position and heading.......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...... 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...

  12. Macroanatomical Landmarks Featuring Junctions of Major Sulci and Fissures and Scalp Landmarks Based on the International 10–10 System for Analyzing Lateral Cortical Development of Infants

    Directory of Open Access Journals (Sweden)

    Daisuke Tsuzuki

    2017-07-01

    Full Text Available The topographic relationships between the macroanatomical structure of the lateral cortex, including sulci and fissures, and anatomical landmarks on the external surface of the head are known to be consistent. This allows the coregistration of EEG electrodes or functional near-infrared spectroscopy over the scalp with underlying cortical regions. However, limited information is available as to whether the topographic relationships are maintained in rapidly developing infants, whose brains and heads exhibit drastic growth. We used MRIs of infants ranging in age from 3 to 22 months old, and identified 20 macroanatomical landmarks, featuring the junctions of major sulci and fissures, as well as cranial landmarks and virtually determined positions of the international 10-20 and 10-10 systems. A Procrustes analysis revealed developmental trends in changes of shape in both the cortex and head. An analysis of Euclidian distances between selected pairs of cortical landmarks at standard stereotactic coordinates showed anterior shifts of the relative positions of the premotor and parietal cortices with age. Finally, cortical landmark positions and their spatial variability were compared with 10-10 landmark positions. The results indicate that variability in the distribution of each macroanatomical landmark was much smaller than the pitch of the 10-10 landmarks. This study demonstrates that the scalp-based 10-10 system serves as a good frame of reference in infants not only for assessing the development of the macroanatomy of the lateral cortical structure, but also for functional studies of cortical development using transcranial modalities such as EEG and fNIRS.

  13. Finding Home: Landmark Ambiguity in Human Navigation

    Directory of Open Access Journals (Sweden)

    Simon Jetzschke

    2017-07-01

    Full Text Available Memories of places often include landmark cues, i.e., information provided by the spatial arrangement of distinct objects with respect to the target location. To study how humans combine landmark information for navigation, we conducted two experiments: To this end, participants were either provided with auditory landmarks while walking in a large sports hall or with visual landmarks while walking on a virtual-reality treadmill setup. We found that participants cannot reliably locate their home position due to ambiguities in the spatial arrangement when only one or two uniform landmarks provide cues with respect to the target. With three visual landmarks that look alike, the task is solved without ambiguity, while audio landmarks need to play three unique sounds for a similar performance. This reduction in ambiguity through integration of landmark information from 1, 2, and 3 landmarks is well modeled using a probabilistic approach based on maximum likelihood estimation. Unlike any deterministic model of human navigation (based e.g., on distance or angle information, this probabilistic model predicted both the precision and accuracy of the human homing performance. To further examine how landmark cues are integrated we introduced systematic conflicts in the visual landmark configuration between training of the home position and tests of the homing performance. The participants integrated the spatial information from each landmark near-optimally to reduce spatial variability. When the conflict becomes big, this integration breaks down and precision is sacrificed for accuracy. That is, participants return again closer to the home position, because they start ignoring the deviant third landmark. Relying on two instead of three landmarks, however, goes along with responses that are scattered over a larger area, thus leading to higher variability. To model the breakdown of integration with increasing conflict, the probabilistic model based on a

  14. A median sacral artery anterior to the iliocaval junction: a case report-anatomical considerations and clinical relevance for spine surgery.

    Science.gov (United States)

    Chenin, Louis; Tandabany, Sharmila; Foulon, Pascal; Havet, Eric; Peltier, Johann

    2018-01-01

    The median sacral artery (MSA) is a relatively small vessel that always arises from the posterior, terminal part of the infrarenal aorta. In most cases, the MSA runs behind the iliocaval junction. Here, we describe a very rare case of an MSA running in front of this junction. During a human cadaveric dissection of the retroperitoneal area, we unexpectedly observed that the MSA passed in front of the left common iliac vein. The anatomy of the MSA has been extensively described and variations are quite rare. On the basis of this specific case, knowledge of the anatomic interactions between the MSA and other lumbar retroperitoneal vessels may help to avoid potential complications during surgery.

  15. Correlations of External Landmarks With Internal Structures of the Temporal Bone.

    Science.gov (United States)

    Piromchai, Patorn; Wijewickrema, Sudanthi; Smeds, Henrik; Kennedy, Gregor; O'Leary, Stephen

    2015-09-01

    The internal anatomy of a temporal bone could be inferred from external landmarks. Mastoid surgery is an important skill that ENT surgeons need to acquire. Surgeons commonly use CT scans as a guide to understanding anatomical variations before surgery. Conversely, in cases where CT scans are not available, or in the temporal bone laboratory where residents are usually not provided with CT scans, it would be beneficial if the internal anatomy of a temporal bone could be inferred from external landmarks. We explored correlations between internal anatomical variations and metrics established to quantify the position of external landmarks that are commonly exposed in the operating room, or the temporal bone laboratory, before commencement of drilling. Mathematical models were developed to predict internal anatomy based on external structures. From an operating room view, the distances between the following external landmarks were observed to have statistically significant correlations with the internal anatomy of a temporal bone: temporal line, external auditory canal, mastoid tip, occipitomastoid suture, and Henle's spine. These structures can be used to infer a low lying dura mater (p = 0.002), an anteriorly located sigmoid sinus (p = 0.006), and a more lateral course of the facial nerve (p external landmarks. The distances between these two landmarks and the operating view external structures were able to further infer the laterality of the facial nerve (p internal structures with a high level of accuracy: the distance from the sigmoid sinus to the posterior external auditory canal (p external landmarks found on the temporal bone. These relationships could be used as a guideline to predict challenges during drilling and choosing appropriate temporal bones for dissection.

  16. Landmark Agnosia: Evaluating the Definition of Landmark-based Navigation Impairment.

    Science.gov (United States)

    van der Ham, Ineke J M; Martens, Marieke A G; Claessen, Michiel H G; van den Berg, Esther

    2017-06-01

    Landmark agnosia is a rare type of navigation impairment, for which various definitions have been presented. From a clinical as well as theoretical perspective, consensus on the characteristics of landmark agnosia would be valuable. In the current study we review the literature concerning landmark agnosia and present a new case study. Existing literature highlights the importance of examining familiar as well as novel landmark processing and substantial variation in performance patterns of individual patients. We performed a case study with patient KS, a 53-year-old male, suffering from landmark agnosia, making use of elaborate neuropsychological screening and virtual reality-based tests of navigation ability. Our extensive examination of his impairment shows that landmark agnosia can be very narrow; in KS it is restricted to recognition of newly learned landmarks only. Also, he has no trouble recognizing familiar landmarks that are not part of a navigated route. The literature review shows that the right temporal lobe, and the right hippocampus in particular are the main lesion sites for landmark agnosia. Furthermore, our case study substantiates that this disorder can occur for both familiar and novel landmarks, and can affect novel landmarks in isolation from familiar landmarks. Moreover, it can occur in isolation from problems with processing route information. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Anatomic and Radiologic Study of Renal Avascular Plane (Brödel's Line) and Its Potential Relevance on Percutaneous and Surgical Approaches to the Kidney.

    Science.gov (United States)

    Macchi, Veronica; Picardi, Edgardo; Inferrera, Antonino; Porzionato, Andrea; Crestani, Alessandro; Novara, Giacomo; De Caro, Raffaele; Ficarra, Vincenzo

    2018-02-01

    The aim of the present anatomic and radiologic study was to evaluate the location, extension, and characteristics of the Brödel's plane and eventually define its different patterns. We evaluated 15 human normal kidneys sampled from unembalmed cadavers without clinical history or anatomical evidence of renal diseases. Kidneys with the surrounding perirenal fat tissue were removed en bloc with the abdominal segment of the aorta. The renal artery was injected with acrylic and radiopaque resins. A CT examination of the injected kidneys was performed. After the imaging acquisition, the specimens were treated with sodium hydroxide for removal of the parenchyma to obtain the vascular casts. All the CT images were elaborated using dedicated three-dimensional (3D) software with the aim to improve the possibility to identify the Brödel's plane. The avascular plane was identified directly on the vascular casts and confirmed on the corresponding 3D images. The avascular plane was located in all cases medially to the lateral convex border of the kidneys. The recorded mean distance was 2.04 cm (range 1.8-2.4 cm). Three patterns of distribution of the Brödel's line were identified. In five (33.3%) cases the avascular plane was extended from the apical to the inferior segment of the kidneys (type 1); in six (40%) from the superior to the inferior segment (type 2); and in four (26.7%) from the apical to the middle segment (type 3). Fourth and fifth order vessels crossing the Brödel's line were detected in all the analyzed cases. The renal avascular plane showed a different extension allowing us to cluster three different patterns. Preoperative identification of the Brödel's line patterns could help surgeons to minimize hemorrhagic complications during percutaneous and surgical procedures requiring an incision of the renal parenchyma such as traditional or robot-assisted nephrolithotomy or partial nephrectomy for endophytic renal tumors. Radiologic studies validated that

  18. 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

  19. Anatomical Variations of the Vertebral Artery in the Upper Cervical Spine: Clinical Relevance for Procedures Targeting the C1/C2 and C2/C3 Joints.

    Science.gov (United States)

    Elgueta, Maria Francisca; Ortiz Jimenez, Johanna; Wang, Nina Nan; Pérez Lara, Almudena; Chankowsky, Jeffrey; Charghi, Roshanak; Tran, De Q; Finlayson, Roderick J

    2018-05-01

    Accidental breach of the vertebral artery (VA) during the performance of cervical pain blocks can result in significant morbidity. Whereas anatomical variations have been described for the foraminal (V2) segment of the VA, those involving its V3 portion (between the C2 transverse process and dura) have not been investigated and may be of importance for procedures targeting the third occipital nerve or the lateral atlantoaxial joint. Five hundred computed tomography angiograms of the neck performed in patients older than 50 years for the management of cerebrovascular accident or cervical trauma (between January 2010 and May 2016) were retrospectively and independently reviewed by 2 neuroradiologists. Courses of the VA in relation to the lateral aspect of the C2/C3 joint and the posterior surface of the C1/C2 joint were examined. For the latter, any medial encroachment of the VA (or one of its branches) was noted. The presence of a VA loop between C1 and C2 and its distance from the upper border of the superior articular process (SAP) of C3 were also recorded. If the VA loop coursed posteriorly, its position in relation to 6 fields found on the lateral aspects of the articular pillars of C2 and C3 was tabulated. At the C1/C2 level, the VA coursed medially over the lateral quarter of the dorsal joint surface in 1% of subjects (0.6% and 0.4% on the left and right sides, respectively; P = 0.998). A VA loop originating between C1 and C2 was found to travel posteroinferiorly over the anterolateral aspect of the inferior articular pillar of C2 in 55.5% of patients on the left and 41.9% on the right side (P < 0.001), as well as over the SAP of C3 in 0.4% of subjects. When present in the quadrant immediately cephalad to the C3 SAP, VA loops coursed within 2.0 ± 1.5 and 3.3 ± 2.5 mm on the left and right sides, respectively, of its superior aspect (P < 0.001). The VA commonly travels adjacent to areas targeted by third occipital nerve procedures and more rarely over the

  20. 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.

  1. Effect of Ultrasonography on Student Learning of Shoulder Anatomy and Landmarks.

    Science.gov (United States)

    de Vries, Kristen D; Brown, Rebecca; Mazzie, Joseph; Jung, Min-Kyung; Yao, Sheldon C; Terzella, Michael J

    2018-01-01

    Ultrasonography is becoming more common in clinical use, and it has been shown to have promising results when introduced into medical school curricula. To determine whether the use of ultrasonography as an educational supplement can improve osteopathic medical students' confidence and ability to locate 4 specific shoulder anatomical landmarks: the coracoid process, the transverse process of T1, the long head of the biceps within the bicipital groove, and the supraspinatus tendon. In this randomized controlled study, first-year osteopathic medical students aged 18 years or older were recruited and randomly assigned to a group with exposure (ultrasonography group) or without exposure (control group) to an ultrasonography machine. First, a survey was administered to measure students' baseline knowledge of shoulder anatomy, confidence in palpation skills, and opinion on anatomical landmark identification teaching methods. Next, students were shown presentations on shoulder anatomy and allowed to practice locating and palpating the specified landmarks. Students in the ultrasonography group were also given instruction on the use of ultrasonography. All students were asked to locate each of the 4 specified anatomical landmarks and then given a follow-up survey. A Mann Whitney U test was used to compare the confidence of the students before and after the intervention. A secondary analysis was performed to compare the degree of deviance from the correct position of the specified anatomical landmark between the ultrasonography and control groups. P values less than .05 were considered statistically significant. Sixty-four students participated. Compared with the control group, students in the ultrasonography group had a greater increase in confidence after the session in their ability to locate the coracoid process, bicipital tendon, and supraspinatus tendon (P=.022, P=.029, P=.44, respectively). Students in the ultrasonography group were also able to more accurately palpate

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

    International Nuclear Information System (INIS)

    Pittayapat, Pisha; Jacobs, Reinhilde; Odri, Guillaume A.; De Faria Vasconcelos, Karla; Willems, Guy; Olszewski, Raphael

    2015-01-01

    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.

  3. 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.

  4. Landmarks selection in street map design

    International Nuclear Information System (INIS)

    Kao, C J

    2014-01-01

    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

  5. Landmarks selection in street map design

    Science.gov (United States)

    Kao, C. J.

    2014-02-01

    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.

  6. Evaluating Users' Satisfaction With Landmark University's Online ...

    African Journals Online (AJOL)

    OPAC) of Landmark University, Nigeria. The study adopted the descriptive survey design. The target population were 200 students, which were purposively selected to participate in the study. Questionnaire were distributed to all the purposively ...

  7. Landmark based localization in urban environment

    Science.gov (United States)

    Qu, Xiaozhi; Soheilian, Bahman; Paparoditis, Nicolas

    2018-06-01

    A landmark based localization with uncertainty analysis based on cameras and geo-referenced landmarks is presented in this paper. The system is developed to adapt different camera configurations for six degree-of-freedom pose estimation. Local bundle adjustment is applied for optimization and the geo-referenced landmarks are integrated to reduce the drift. In particular, the uncertainty analysis is taken into account. On the one hand, we estimate the uncertainties of poses to predict the precision of localization. On the other hand, uncertainty propagation is considered for matching, tracking and landmark registering. The proposed method is evaluated on both KITTI benchmark and the data acquired by a mobile mapping system. In our experiments, decimeter level accuracy can be reached.

  8. Accuracy of intraoral digital impressions using an artificial landmark.

    Science.gov (United States)

    Kim, Jong-Eun; Amelya, Ami; Shin, Yooseok; Shim, June-Sung

    2017-06-01

    Intraoral scanners have been reported to have limited accuracy in edentulous areas. Large amounts of mobile tissue and the lack of obvious anatomic landmarks make it difficult to acquire a precise digital impression of an edentulous area with an intraoral scanner. The purpose of this in vitro study was to determine the effect of an artificial landmark on a long edentulous space on the accuracy outcomes of intraoral digital impressions. A mandibular model containing 4 prepared teeth and an edentulous space of 26 mm in length was used. A blue-light light-emitting diode tabletop scanner was used as a control scanner, and 3 intraoral scanners were used as experimental groups. Five scans were made using each intraoral scanner without an artificial landmark, and another 5 scans were performed after application of an artificial landmark (a 4×3 mm alumina material) on the edentulous area. The obtained datasets were used to evaluate trueness and precision. Without an artificial landmark on the edentulous area, the mean trueness for the intraoral scanner ranged from 36.1 to 38.8 μm and the mean precision ranged from 13.0 to 43.6 μm. With an artificial landmark on the edentulous area, accuracy was improved significantly: the mean trueness was 26.7 to 31.8 μm, and the mean precision was 9.2 to 12.4 μm. The use of an alumina artificial landmark in an edentulous space improved the trueness and precision of the intraoral scanners tested. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  9. Comparison of the spatial landmark scatter of various 3D digitalization methods.

    Science.gov (United States)

    Boldt, Florian; Weinzierl, Christian; Hertrich, Klaus; Hirschfelder, Ursula

    2009-05-01

    The aim of this study was to compare four different three-dimensional digitalization methods on the basis of the complex anatomical surface of a cleft lip and palate plaster cast, and to ascertain their accuracy when positioning 3D landmarks. A cleft lip and palate plaster cast was digitalized with the SCAN3D photo-optical scanner, the OPTIX 400S laser-optical scanner, the Somatom Sensation 64 computed tomography system and the MicroScribe MLX 3-axis articulated-arm digitizer. First, four examiners appraised by individual visual inspection the surface detail reproduction of the three non-tactile digitalization methods in comparison to the reference plaster cast. The four examiners then localized the landmarks five times at intervals of 2 weeks. This involved simply copying, or spatially tracing, the landmarks from a reference plaster cast to each model digitally reproduced by each digitalization method. Statistical analysis of the landmark distribution specific to each method was performed based on the 3D coordinates of the positioned landmarks. Visual evaluation of surface detail conformity assigned the photo-optical digitalization method an average score of 1.5, the highest subjectively-determined conformity (surpassing computer tomographic and laser-optical methods). The tactile scanning method revealed the lowest degree of 3D landmark scatter, 0.12 mm, and at 1.01 mm the lowest maximum 3D landmark scatter; this was followed by the computer tomographic, photo-optical and laser-optical methods (in that order). This study demonstrates that the landmarks' precision and reproducibility are determined by the complexity of the reference-model surface as well as the digital surface quality and individual ability of each evaluator to capture 3D spatial relationships. The differences in the 3D-landmark scatter values and lowest maximum 3D-landmark scatter between the best and the worst methods showed minor differences. The measurement results in this study reveal that it

  10. Simultaneous detection of landmarks and key-frame in cardiac perfusion MRI using a joint spatial-temporal context model

    Science.gov (United States)

    Lu, Xiaoguang; Xue, Hui; Jolly, Marie-Pierre; Guetter, Christoph; Kellman, Peter; Hsu, Li-Yueh; Arai, Andrew; Zuehlsdorff, Sven; Littmann, Arne; Georgescu, Bogdan; Guehring, Jens

    2011-03-01

    Cardiac perfusion magnetic resonance imaging (MRI) has proven clinical significance in diagnosis of heart diseases. However, analysis of perfusion data is time-consuming, where automatic detection of anatomic landmarks and key-frames from perfusion MR sequences is helpful for anchoring structures and functional analysis of the heart, leading toward fully automated perfusion analysis. Learning-based object detection methods have demonstrated their capabilities to handle large variations of the object by exploring a local region, i.e., context. Conventional 2D approaches take into account spatial context only. Temporal signals in perfusion data present a strong cue for anchoring. We propose a joint context model to encode both spatial and temporal evidence. In addition, our spatial context is constructed not only based on the landmark of interest, but also the landmarks that are correlated in the neighboring anatomies. A discriminative model is learned through a probabilistic boosting tree. A marginal space learning strategy is applied to efficiently learn and search in a high dimensional parameter space. A fully automatic system is developed to simultaneously detect anatomic landmarks and key frames in both RV and LV from perfusion sequences. The proposed approach was evaluated on a database of 373 cardiac perfusion MRI sequences from 77 patients. Experimental results of a 4-fold cross validation show superior landmark detection accuracies of the proposed joint spatial-temporal approach to the 2D approach that is based on spatial context only. The key-frame identification results are promising.

  11. 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

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

    International Nuclear Information System (INIS)

    Dai, Xiubin; Gao, Yaozong; Shen, Dinggang

    2015-01-01

    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

  13. 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.

  14. Tension-free vaginal tape versus lata fascia sling: The importance of transvulvar ultrasound in the assessment of relevant anatomical parameters in treatment of women with stress urinary incontinence

    Directory of Open Access Journals (Sweden)

    Frederico Teixeira Brandt

    2009-01-01

    Full Text Available Objective: To describe the relevance of transvulvar ultrasound in the assessment of anatomical differences induced by the lata fascia sling (LFS and tension-free vaginal tape (TVT procedures. Materials and Methods: Forty women with stress urinary incontinence (SUI, aged 30 to 60 years, have been treated with either LFS (20 patients or TVT (20 patients. The transvulvar ultrasound of the urethrovesical junction (UVJ and proximal urethra (PU has been used as the main investigational tool both pre- and post-operatively. The studied parameters were the vertical (VUVJD and horizontal (HUVJD UVJ distances, the pubourethral distance (PUD and the PU length. Results: The VUVJD did not vary significantly after the LFS surgery (P=0.10. The PUD became shorter (P=0.001 and the HUVJD became shorter only at rest (P=0.03 after the correction by LFS. The TVT procedure has led to shortening of the VUVJ displacement (P=0.0005 and of the PU length (P=0.02. Conclusions: The transvulvar ultrasound was of utmost importance in the demonstration that both the LFS and TVT surgical procedures elongate the PU, even though the LFS technique does it more efficiently. The LFS technique focus more on shortening the PUD and the TVT procedure focus more on the correction of the vertical UVJ displacement.

  15. 3D ultrasound-CT registration of the liver using combined landmark-intensity information

    International Nuclear Information System (INIS)

    Lange, Thomas; Schlag, Peter M.; Papenberg, Nils; Heldmann, Stefan; Modersitzki, Jan; Fischer, Bernd; Lamecker, Hans

    2009-01-01

    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.)

  16. Landmark-based deep multi-instance learning for brain disease diagnosis.

    Science.gov (United States)

    Liu, Mingxia; Zhang, Jun; Adeli, Ehsan; Shen, Dinggang

    2018-01-01

    In conventional Magnetic Resonance (MR) image based methods, two stages are often involved to capture brain structural information for disease diagnosis, i.e., 1) manually partitioning each MR image into a number of regions-of-interest (ROIs), and 2) extracting pre-defined features from each ROI for diagnosis with a certain classifier. However, these pre-defined features often limit the performance of the diagnosis, due to challenges in 1) defining the ROIs and 2) extracting effective disease-related features. In this paper, we propose a landmark-based deep multi-instance learning (LDMIL) framework for brain disease diagnosis. Specifically, we first adopt a data-driven learning approach to discover disease-related anatomical landmarks in the brain MR images, along with their nearby image patches. Then, our LDMIL framework learns an end-to-end MR image classifier for capturing both the local structural information conveyed by image patches located by landmarks and the global structural information derived from all detected landmarks. We have evaluated our proposed framework on 1526 subjects from three public datasets (i.e., ADNI-1, ADNI-2, and MIRIAD), and the experimental results show that our framework can achieve superior performance over state-of-the-art approaches. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. 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

    2015-01-07

    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.

  18. Automated landmark-guided deformable image registration

    International Nuclear Information System (INIS)

    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. (paper)

  19. 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,

  20. On-Skin Interaction Using Body Landmarks

    DEFF Research Database (Denmark)

    Steimle, Juergen; Bergstrom-Lehtovirta, Joanna; Weigel, Martin

    2017-01-01

    The human skin is a promising surface for input to computing devices but differs fundamentally from existing touch-sensitive devices. The authors propose the use of skin landmarks, which offer unique tactile and visual cues, to enhance body-based user interfaces....

  1. Remembered landmarks enhance the precision of path integration

    Directory of Open Access Journals (Sweden)

    Shannon O´Leary

    2005-01-01

    Full Text Available When navigating by path integration, knowledge of one’s position becomes increasingly uncertain as one walks from a known location. This uncertainty decreases if one perceives a known landmark location nearby. We hypothesized that remembering landmarks might serve a similar purpose for path integration as directly perceiving them. If this is true, walking near a remembered landmark location should enhance response consistency in path integration tasks. To test this, we asked participants to view a target and then attempt to walk to it without vision. Some participants saw the target plus a landmark during the preview. Compared with no-landmark trials, response consistency nearly doubled when participants passed near the remembered landmark location. Similar results were obtained when participants could audibly perceive the landmark while walking. A control experiment ruled out perceptual context effects during the preview. We conclude that remembered landmarks can enhance path integration even though they are not directly perceived.

  2. A cadaveric study of surgical landmarks for retrograde parotidectomy

    Directory of Open Access Journals (Sweden)

    Wenjie Zhong

    2016-08-01

    Conclusion: The findings indicate that all three landmarks are useful for surgeons to locate the facial nerve branches during retrograde parotidectomy. Since all three landmarks were consistent indicators for the corresponding facial nerve branches, the surgeon has more than one option should one landmark be obscured by tumors. The optimal landmark is the distance from A to MM because it is shortest and most reliable, followed by RMV to MM, and Z to B.

  3. A statistical method for 2D facial landmarking

    NARCIS (Netherlands)

    Dibeklioğlu, H.; Salah, A.A.; Gevers, T.

    2012-01-01

    Many facial-analysis approaches rely on robust and accurate automatic facial landmarking to correctly function. In this paper, we describe a statistical method for automatic facial-landmark localization. Our landmarking relies on a parsimonious mixture model of Gabor wavelet features, computed in

  4. Using local symmetry for landmark selection

    OpenAIRE

    Kootstra, Geert; de Jong, Sjoerd; Schomaker, Lambert R. B.

    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, have problems with stability, and noise robustness. Taking our inspiration from human vision, we therefore propose the use of local symmetry to select interest points. Our method, the MUlti-scale Sy...

  5. The auriculotemporal nerve in etiology of migraine headaches: compression points and anatomical variations.

    Science.gov (United States)

    Chim, Harvey; Okada, Haruko C; Brown, Matthew S; Alleyne, Brendan; Liu, Mengyuan T; Zwiebel, Samantha; Guyuron, Bahman

    2012-08-01

    The auriculotemporal nerve has been identified as one of the peripheral trigger sites for migraine headaches. However, its distal course is poorly mapped following emergence from the parotid gland. In addition, a reliable anatomical landmark for locating the potential compression points along the course of the nerve during surgery has not been sufficiently described. Twenty hemifaces on 10 fresh cadavers were dissected to trace the course of the auriculotemporal nerve from the inferior border of the zygomatic arch to its termination in the temporal scalp. The compression points were mapped and the distances were measured from the most anterosuperior point of the external auditory meatus, which was used as a fixed anatomical landmark. Three potential compression points along the course of the auriculotemporal nerve were identified. Compression points 1 and 2 corresponded to preauricular fascial bands. Compression point 1 was centered 13.1±5.9 mm anterior and 5.0±7.0 mm superior to the most anterosuperior point of the external auditory meatus, whereas compression point 2 was centered at 11.9±6.0 mm anterior and 17.2±10.4 mm superior to the most anterosuperior point of the external auditory meatus. A significant relationship was found between the auriculotemporal nerve and superficial temporal artery (compression point 3) in 80 percent of hemifaces, with three patterns of interaction: a single site of artery crossing over the nerve (62.5 percent), a helical intertwining relationship (18.8 percent), and nerve crossing over the artery (18.8 percent). Findings from this cadaver study provide information relevant to the operative localization of potential compression points along the auriculotemporal nerve.

  6. Elections and landmark policies in Tanzania and Uganda

    DEFF Research Database (Denmark)

    Kjær, Anne Mette; Therkildsen, Ole

    2013-01-01

    Much of the relevant literature on Africa downplays the salience of elections for policy-making and implementation. Instead, the importance of factors such as clientelism, ethnicity, organized interest group and donor influence, is emphasized. We argue that, in addition, elections now motivate...... 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......: they are clearly identifiable with the party in power; citizens country-wide are targeted; and policy implementation aim at immediate, visible results. The influence of elections on policy making and implementation could therefore be more significant in countries where elections are more competitive than...

  7. A Bony Landmark 'RAI Triangle' to Prevent 'Misplaced and Misdirected' Medial Cut in SSRO.

    Science.gov (United States)

    Rai, Kirthi Kumar; Arakeri, Gururaj; Khaji, Shahanavaj I

    2011-03-01

    'Rai triangle', a new anatomic landmark on the medial surface of the ramus of the mandible which when identified and taken into consideration, may have a definite advantage. This is especially in terms of performing the medial horizontal cut which is an important and integral part of the sagittal split ramus osteotomy so as to avoid a bad split. The objective of this article is to propose an easily identifiable bony land mark, which is closely related to lingula of mandible that may ease the procedure of osteotomy and avoid bad splits.

  8. Anatomically shaped cranial collimation (ACC) for lateral cephalometric radiography: a technical report.

    Science.gov (United States)

    Hoogeveen, R C; van der Stelt, P F; Berkhout, W E R

    2014-01-01

    Lateral cephalograms in orthodontic practice display an area cranial of the base of the skull that is not required for diagnostic evaluation. Attempts have been made to reduce the radiation dose to the patient using collimators combining the shielding of the areas above the base of the skull and below the mandible. These so-called "wedge-shaped" collimators have not become standard equipment in orthodontic offices, possibly because these collimators were not designed for today's combination panoramic-cephalometric imaging systems. It also may be that the anatomical variability of the area below the mandible makes this area unsuitable for standardized collimation. In addition, a wedge-shaped collimator shields the cervical vertebrae; therefore, assessment of skeletal maturation, which is based on the stage of development of the cervical vertebrae, cannot be performed. In this report, we describe our investigations into constructing a collimator to be attached to the cephalostat and shield the cranial area of the skull, while allowing the visualization of diagnostically relevant structures and markedly reducing the size of the irradiated area. The shape of the area shielded by this "anatomically shaped cranial collimator" (ACC) was based on mean measurements of cephalometric landmarks of 100 orthodontic patients. It appeared that this collimator reduced the area of irradiation by almost one-third without interfering with the imaging system or affecting the quality of the image. Further research is needed to validate the clinical efficacy of the collimator.

  9. Reorienting with terrain slope and landmarks.

    Science.gov (United States)

    Nardi, Daniele; Newcombe, Nora S; Shipley, Thomas F

    2013-02-01

    Orientation (or reorientation) is the first step in navigation, because establishing a spatial frame of reference is essential for a sense of location and heading direction. Recent research on nonhuman animals has revealed that the vertical component of an environment provides an important source of spatial information, in both terrestrial and aquatic settings. Nonetheless, humans show large individual and sex differences in the ability to use terrain slope for reorientation. To understand why some participants--mainly women--exhibit a difficulty with slope, we tested reorientation in a richer environment than had been used previously, including both a tilted floor and a set of distinct objects that could be used as landmarks. This environment allowed for the use of two different strategies for solving the task, one based on directional cues (slope gradient) and one based on positional cues (landmarks). Overall, rather than using both cues, participants tended to focus on just one. Although men and women did not differ significantly in their encoding of or reliance on the two strategies, men showed greater confidence in solving the reorientation task. These facts suggest that one possible cause of the female difficulty with slope might be a generally lower spatial confidence during reorientation.

  10. The Role of Emotional Landmarks on Topographical Memory

    Directory of Open Access Journals (Sweden)

    Massimiliano Palmiero

    2017-05-01

    Full Text Available The investigation of the role of emotional landmarks on human navigation has been almost totally neglected in psychological research. Therefore, the extent to which positive and negative emotional landmarks affect topographical memory as compared to neutral emotional landmark was explored. Positive, negative and neutral affect-laden images were selected as landmarks from the International Affective Picture System (IAPS Inventory. The Walking Corsi test (WalCT was used in order to test the landmark-based topographical memory. Participants were instructed to learn and retain an eight-square path encompassing positive, negative or neutral emotional landmarks. Both egocentric and allocentric frames of references were considered. Egocentric representation encompasses the object’s relation to the self and it is generated from sensory data. Allocentric representation expresses a location with respect to an external frame regardless of the self and it is the basis for long-term storage of complex layouts. In particular, three measures of egocentric and allocentric topographical memory were taken into account: (1 the ability to learn the path; (2 the ability to recall by walking the path five minutes later; (3 the ability to reproduce the path on the outline of the WalCT. Results showed that both positive and negative emotional landmarks equally enhanced the learning of the path as compared to neutral emotional landmarks. In addition, positive emotional landmarks improved the reproduction of the path on the map as compared to negative and neutral emotional landmarks. These results generally show that emotional landmarks enhance egocentric-based topographical memory, whereas positive emotional landmarks seem to be more effective for allocentric-based topographical memory.

  11. The Role of Emotional Landmarks on Topographical Memory.

    Science.gov (United States)

    Palmiero, Massimiliano; Piccardi, Laura

    2017-01-01

    The investigation of the role of emotional landmarks on human navigation has been almost totally neglected in psychological research. Therefore, the extent to which positive and negative emotional landmarks affect topographical memory as compared to neutral emotional landmark was explored. Positive, negative and neutral affect-laden images were selected as landmarks from the International Affective Picture System (IAPS) Inventory. The Walking Corsi test (WalCT) was used in order to test the landmark-based topographical memory. Participants were instructed to learn and retain an eight-square path encompassing positive, negative or neutral emotional landmarks. Both egocentric and allocentric frames of references were considered. Egocentric representation encompasses the object's relation to the self and it is generated from sensory data. Allocentric representation expresses a location with respect to an external frame regardless of the self and it is the basis for long-term storage of complex layouts. In particular, three measures of egocentric and allocentric topographical memory were taken into account: (1) the ability to learn the path; (2) the ability to recall by walking the path five minutes later; (3) the ability to reproduce the path on the outline of the WalCT. Results showed that both positive and negative emotional landmarks equally enhanced the learning of the path as compared to neutral emotional landmarks. In addition, positive emotional landmarks improved the reproduction of the path on the map as compared to negative and neutral emotional landmarks. These results generally show that emotional landmarks enhance egocentric-based topographical memory, whereas positive emotional landmarks seem to be more effective for allocentric-based topographical memory.

  12. Wild hummingbirds rely on landmarks not geometry when learning an array of flowers.

    Science.gov (United States)

    Hurly, T Andrew; Fox, Thomas A O; Zwueste, Danielle M; Healy, Susan D

    2014-09-01

    Rats, birds or fish trained to find a reward in one corner of a small enclosure tend to learn the location of the reward using both nearby visual features and the geometric relationships of corners and walls. Because these studies are conducted under laboratory and thereby unnatural conditions, we sought to determine whether wild, free-living rufous hummingbirds (Selasphorus rufus) learning a single reward location within a rectangular array of flowers would similarly employ both nearby visual landmarks and the geometric relationships of the array. Once subjects had learned the location of the reward, we used test probes in which one or two experimental landmarks were moved or removed in order to reveal how the birds remembered the reward location. The hummingbirds showed no evidence that they used the geometry of the rectangular array of flowers to remember the reward. Rather, they used our experimental landmarks, and possibly nearby, natural landmarks, to orient and navigate to the reward. We believe this to be the first test of the use of rectangular geometry by wild animals, and we recommend further studies be conducted in ecologically relevant conditions in order to help determine how and when animals form complex geometric representations of their local environments.

  13. Cadaver study of anatomic landmark identification for placing ankle arthroscopy portals.

    Science.gov (United States)

    Scheibling, B; Koch, G; Clavert, P

    2017-05-01

    Arthroscopy-assisted surgery is now widely used at the ankle for osteochondral lesions of the talus, anterior and posterior impingement syndromes, talocrural or subtalar fusion, foreign body removal, and ankle instability. Injuries to the vessels and nerves may occur during these procedures. To determine whether ultrasound topographic identification of vulnerable structures decreased the risk of iatrogenic injuries to vessels, nerves, and tendons and influenced the distance separating vulnerable structures from the arthroscope introduced through four different portals. Ultrasonography to identify vulnerable structures before or during arthroscopic surgery on the ankle may be useful. Twenty fresh cadaver ankles from body donations to the anatomy institute in Strasbourg, France, were divided into two equal groups. Preoperative ultrasonography to mark the trajectories of vessels, nerves, and tendons was performed in one group but not in the other. The portals were created using a 4-mm trocar. Each portal was then dissected. The primary evaluation criterion was the presence or absence of injuries to vessels, nerves, and tendons. The secondary evaluation criterion was the distance between these structures and the arthroscope. No tendon injuries occurred with ultrasonography. Without ultrasonography, there were two full-thickness tendon lesions, one to the extensor hallucis longus and the other to the Achilles tendon. Furthermore, with the anterolateral, anteromedial, and posteromedial portals, the distance separating the vessels and nerves from the arthroscope was greater with than without ultrasonography (P=0.041, P=0.005, and P=0.002), respectively; no significant difference was found with the anterior portal. Preoperative ultrasound topographic identification decreases the risk of iatrogenic injury to the vessels, nerves, and tendons during ankle arthroscopy and places these structures at a safer distance from the arthroscope. Our hypothesis was confirmed. IV, cadaver study. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  14. 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.

  15. Accuracy of Automatic Cephalometric Software on Landmark Identification

    Science.gov (United States)

    Anuwongnukroh, N.; Dechkunakorn, S.; Damrongsri, S.; Nilwarat, C.; Pudpong, N.; Radomsutthisarn, W.; Kangern, S.

    2017-11-01

    This study was to assess the accuracy of an automatic cephalometric analysis software in the identification of cephalometric landmarks. Thirty randomly selected digital lateral cephalograms of patients undergoing orthodontic treatment were used in this study. Thirteen landmarks (S, N, Or, A-point, U1T, U1A, B-point, Gn, Pog, Me, Go, L1T, and L1A) were identified on the digital image by an automatic cephalometric software and on cephalometric tracing by manual method. Superimposition of printed image and manual tracing was done by registration at the soft tissue profiles. The accuracy of landmarks located by the automatic method was compared with that of the manually identified landmarks by measuring the mean differences of distances of each landmark on the Cartesian plane where X and Y coordination axes passed through the center of ear rod. One-Sample T test was used to evaluate the mean differences. Statistically significant mean differences (pmean differences in both horizontal and vertical directions. Small mean differences (mean differences were found for A-point (3.0 4mm) in vertical direction. Only 5 of 13 landmarks (38.46%; S, N, Gn, Pog, and Go) showed no significant mean difference between the automatic and manual landmarking methods. It is concluded that if this automatic cephalometric analysis software is used for orthodontic diagnosis, the orthodontist must correct or modify the position of landmarks in order to increase the accuracy of cephalometric analysis.

  16. 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.

  17. 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.

  18. Extra Facial Landmark Localization via Global Shape Reconstruction

    Directory of Open Access Journals (Sweden)

    Shuqiu Tan

    2017-01-01

    Full Text Available Localizing facial landmarks is a popular topic in the field of face analysis. However, problems arose in practical applications such as handling pose variations and partial occlusions while maintaining moderate training model size and computational efficiency still challenges current solutions. In this paper, we present a global shape reconstruction method for locating extra facial landmarks comparing to facial landmarks used in the training phase. In the proposed method, the reduced configuration of facial landmarks is first decomposed into corresponding sparse coefficients. Then explicit face shape correlations are exploited to regress between sparse coefficients of different facial landmark configurations. Finally extra facial landmarks are reconstructed by combining the pretrained shape dictionary and the approximation of sparse coefficients. By applying the proposed method, both the training time and the model size of a class of methods which stack local evidences as an appearance descriptor can be scaled down with only a minor compromise in detection accuracy. Extensive experiments prove that the proposed method is feasible and is able to reconstruct extra facial landmarks even under very asymmetrical face poses.

  19. 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

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...... 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...

  1. Topographic anatomy of the great auricular point: landmarks for its localization and classification.

    Science.gov (United States)

    Raikos, Athanasios; English, Thomas; Yousif, Omar Khalid; Sandhu, Mandeep; Stirling, Allan

    2017-05-01

    The great auricular point (GAP) marks the exit of the great auricular nerve at the posterior border of the sternocleidomastoid muscle (SCM). It is a key landmark for the identification of the spinal accessory nerve, and its intraoperative localization is vital to avoid neurological sequelae. This study delineates the topography and surface anatomy landmarks that used to localize the GAP. Thirty cadaveric heminecks were dissected on a layer-by-layer approach. The topography of the GAP was examined relative to the insertion point of the SCM at the clavicle, tip of the mastoid process, and angle of the mandible. The GAP and its relation to the SCM were determined as a ratio of the total length of the SCM. The GAP was demonstrated to be in a predictable location. The mean length of the SCM was 131.4 ± 22 mm, and the mean distance between the GAP and the mastoid process was found to be 60.4 ± 13.76 mm. The ratio of the GAP location to the total SCM length ranged between 0.33-0.57. The mean distance between the angle of the mandible and the GAP was determined to be 57 ± 22.2 mm. Based on the midpoint of the SCM, the GAP was above it in 66.7 % of subjects and classified to Type A, and below it in 33.3 % of subjects appointed to Type B. The anatomical landmarks utilized in this study are helpful in predicting the location of the GAP relative to the midpoint of the SCM and can reduce neural injuries within the posterior triangle of the neck.

  2. Landmark survey tracks decade of changes in India's rural schools ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2011-12-21

    Dec 21, 2011 ... These are just a few comments from parents of school-aged children in rural ... Landmark survey tracks decade of changes in India's rural schools ... funded by Canada's International Development Research Centre (IDRC).

  3. Route and landmark selection tool (RULST) : user's manual.; TOPICAL

    International Nuclear Information System (INIS)

    Widing, M. A.

    2002-01-01

    The Route and Landmark Selection Tool (RULST) is a software program designed to assist military planners in defining geographical objects, such as routes, landmarks, spurs, and yards, at a given facility. Argonne National Laboratory is currently developing a prototype of this tool for use by the Military Traffic Management Command Transportation Engineering Agency (MTMCTEA). The primary objective of RULST is to populate database tables of facility objects for use in MTMCTEA models. RULST defines facility data for use in models such as Port Simulation (PORTSIM) and Transportation System Capability (TRANSCAP), which simulate the transportation of equipment through ports and military installations. The main purpose of RULST is to allow you to specify the relationships between landmarks and routes. The nodes, links, and landmarks that describe a facility are often predefined on the basis of the layout of the physical site

  4. 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.

  5. Procrustes-based geometric morphometrics on MRI images: An example of inter-operator bias in 3D landmarks and its impact on big datasets.

    Science.gov (United States)

    Daboul, Amro; Ivanovska, Tatyana; Bülow, Robin; Biffar, Reiner; Cardini, Andrea

    2018-01-01

    Using 3D anatomical landmarks from adult human head MRIs, we assessed the magnitude of inter-operator differences in Procrustes-based geometric morphometric analyses. An in depth analysis of both absolute and relative error was performed in a subsample of individuals with replicated digitization by three different operators. The effect of inter-operator differences was also explored in a large sample of more than 900 individuals. Although absolute error was not unusual for MRI measurements, including bone landmarks, shape was particularly affected by differences among operators, with up to more than 30% of sample variation accounted for by this type of error. The magnitude of the bias was such that it dominated the main pattern of bone and total (all landmarks included) shape variation, largely surpassing the effect of sex differences between hundreds of men and women. In contrast, however, we found higher reproducibility in soft-tissue nasal landmarks, despite relatively larger errors in estimates of nasal size. Our study exemplifies the assessment of measurement error using geometric morphometrics on landmarks from MRIs and stresses the importance of relating it to total sample variance within the specific methodological framework being used. In summary, precise landmarks may not necessarily imply negligible errors, especially in shape data; indeed, size and shape may be differentially impacted by measurement error and different types of landmarks may have relatively larger or smaller errors. Importantly, and consistently with other recent studies using geometric morphometrics on digital images (which, however, were not specific to MRI data), this study showed that inter-operator biases can be a major source of error in the analysis of large samples, as those that are becoming increasingly common in the 'era of big data'.

  6. 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.

  7. Dispersion assessment in the location of facial landmarks on photographs.

    Science.gov (United States)

    Campomanes-Álvarez, B R; Ibáñez, O; Navarro, F; Alemán, I; Cordón, O; Damas, S

    2015-01-01

    The morphological assessment of facial features using photographs has played an important role in forensic anthropology. The analysis of anthropometric landmarks for determining facial dimensions and angles has been considered in diverse forensic areas. Hence, the quantification of the error associated to the location of facial landmarks seems to be necessary when photographs become a key element of the forensic procedure. In this work, we statistically evaluate the inter- and intra-observer dispersions related to the facial landmark identification on photographs. In the inter-observer experiment, a set of 18 facial landmarks was provided to 39 operators. They were requested to mark only those that they could precisely place on 10 photographs with different poses (frontal, oblique, and lateral views). The frequency of landmark location was studied together with their dispersion. Regarding the intra-observer evaluation, three participants identified 13 facial points on five photographs classified in the frontal and oblique views. Each landmark location was repeated five times at intervals of at least 24 h. The frequency results reveal that glabella, nasion, subnasale, labiale superius, and pogonion obtained the highest location frequency in the three image categories. On the contrary, the lowest rate corresponds to labiale inferius and menton. Meanwhile, zygia, gonia, and gnathion were significantly more difficult to locate than other facial landmarks. They produced a significant effect on the dispersion depending on the pose of the image where they were placed, regardless of the type of observer that positioned them. In particular, zygia and gonia presented a statistically greater variation in the three image poses, while the location of gnathion is less precise in oblique view photographs. Hence, our findings suggest that the latter landmarks tend to be highly variable when determining their exact position.

  8. Surgical anatomy of the sternoclavicular joint: a qualitative and quantitative anatomical study.

    Science.gov (United States)

    Lee, Jared T; Campbell, Kevin J; Michalski, Max P; Wilson, Katharine J; Spiegl, Ulrich J A; Wijdicks, Coen A; Millett, Peter J

    2014-10-01

    The quantitative anatomical relationships of the main ligamentous, tendinous, and osseous structures of the sternoclavicular joint have not been widely investigated. The purpose of this study was to provide a quantitative description of the sternoclavicular joint in relation to relevant surgical landmarks. We dissected eleven nonpaired, fresh-frozen cadaveric sternoclavicular joints from four men and seven women (mean age at death, fifty-three years; range, thirty-three to sixty-four years) and measured the ligaments, musculature, and osseous landmarks with use of a three-dimensional coordinate-measuring device. The clavicular pectoralis ridge, located at the 9:30 clock-face position on a right clavicle, served as a reliable osseous landmark for reference to the soft-tissue attachments around the sternoclavicular joint. The costoclavicular ligament was the largest ligament of the sternoclavicular joint, with 80% greater footprint area than that of the posterior sternoclavicular ligament. Articular cartilage covered 67% of the medial end of the clavicle and was located anteroinferiorly. The sternohyoid muscle inserted directly over the posterior sternoclavicular joint and the medial end of the clavicle, whereas the sternothyroid muscle inserted 9.5 mm inferior to the posterior-superior articular margin of the manubrium and coursed 19.8 mm laterally along the first rib. An avascular plane that can serve as a "safe zone" for posterior dissection was observed in each specimen, posterior to the sternoclavicular joint and anterior to the sternohyoid and sternothyroid muscles. The clavicular pectoralis ridge can be used as an intraoperative guide for clavicle orientation and tunnel placement in sternoclavicular ligament reconstruction. Sternoclavicular joint resection arthroplasty should avoid injuring the costoclavicular ligament, which is the largest sternoclavicular joint ligament. Resection of only the anteroinferior aspect of the medial end of the clavicle may

  9. Study of robot landmark recognition with complex background

    Science.gov (United States)

    Huang, Yuqing; Yang, Jia

    2007-12-01

    It's of great importance for assisting robot in path planning, position navigating and task performing by perceiving and recognising environment characteristic. To solve the problem of monocular-vision-oriented landmark recognition for mobile intelligent robot marching with complex background, a kind of nested region growing algorithm which fused with transcendental color information and based on current maximum convergence center is proposed, allowing invariance localization to changes in position, scale, rotation, jitters and weather conditions. Firstly, a novel experiment threshold based on RGB vision model is used for the first image segmentation, which allowing some objects and partial scenes with similar color to landmarks also are detected with landmarks together. Secondly, with current maximum convergence center on segmented image as each growing seed point, the above region growing algorithm accordingly starts to establish several Regions of Interest (ROI) orderly. According to shape characteristics, a quick and effectual contour analysis based on primitive element is applied in deciding whether current ROI could be reserved or deleted after each region growing, then each ROI is judged initially and positioned. When the position information as feedback is conveyed to the gray image, the whole landmarks are extracted accurately with the second segmentation on the local image that exclusive to landmark area. Finally, landmarks are recognised by Hopfield neural network. Results issued from experiments on a great number of images with both campus and urban district as background show the effectiveness of the proposed algorithm.

  10. Landmark Detection in Orbital Images Using Salience Histograms

    Science.gov (United States)

    Wagstaff, Kiri L.; Panetta, Julian; Schorghofer, Norbert; Greeley, Ronald; PendletonHoffer, Mary; bunte, Melissa

    2010-01-01

    NASA's planetary missions have collected, and continue to collect, massive volumes of orbital imagery. The volume is such that it is difficult to manually review all of the data and determine its significance. As a result, images are indexed and searchable by location and date but generally not by their content. A new automated method analyzes images and identifies "landmarks," or visually salient features such as gullies, craters, dust devil tracks, and the like. This technique uses a statistical measure of salience derived from information theory, so it is not associated with any specific landmark type. It identifies regions that are unusual or that stand out from their surroundings, so the resulting landmarks are context-sensitive areas that can be used to recognize the same area when it is encountered again. A machine learning classifier is used to identify the type of each discovered landmark. Using a specified window size, an intensity histogram is computed for each such window within the larger image (sliding the window across the image). Next, a salience map is computed that specifies, for each pixel, the salience of the window centered at that pixel. The salience map is thresholded to identify landmark contours (polygons) using the upper quartile of salience values. Descriptive attributes are extracted for each landmark polygon: size, perimeter, mean intensity, standard deviation of intensity, and shape features derived from an ellipse fit.

  11. Landmarks for Identifying the Suprascapular Foramen Anteriorly: Application to Anterior Neurotization and Decompressive Procedures.

    Science.gov (United States)

    Manouvakhova, Olga V; Macchi, Veronica; Fries, Fabian N; Loukas, Marios; De Caro, Raffaele; Oskouian, Rod J; Spinner, Robert J; Tubbs, R Shane

    2018-02-01

    Additional landmarks for identifying the suprascapular nerve at its entrance into the suprascapular foramen from an anterior approach would be useful to the surgeon. To identify landmarks for the identification of this hidden site within an anterior approach. In 8 adult cadavers (16 sides), lines were used to connect the superior angle of the scapula, the acromion, and the coracoid process tip thus creating an anatomic triangle. The suprascapular nerve's entrance into the suprascapular foramen was documented regarding its position within this anatomical triangle. Depths from the skin surface and specifically from the medial-most point of the clavicular attachment of the trapezius to the suprascapular nerve's entrance into the suprascapular foramen were measured using calipers and a ruler. The clavicle was then fractured and retracted superiorly to verify the position of the nerve's entrance into the suprascapular foramen. From the trapezius, the nerve's entrance into the foramen was 3 to 4.2 cm deep (mean, 3.5 cm). The mean distance from the tip of the corocoid process to the suprascapular foramen was 3.8 cm. The angle best used to approach the suprascapular foramen from the surface was 15° to 20°. Based on our study, an anterior suprascapular approach to the suprascapular nerve as it enters the suprascapular foramen can identify the most medial fibers of the trapezius attachment onto the clavicle and insert a finger at an angle of 15° to 20° laterally and advanced to an average depth of 3.5 cm. Copyright © 2017 by the Congress of Neurological Surgeons

  12. Colocación transpectoral superior de implantes mamarios: Relevancia técnica y anatómica Superior transpectoral insertion of breast implants: Anatomical and technical relevance

    Directory of Open Access Journals (Sweden)

    G. Peña Cabús

    2008-12-01

    Full Text Available Los tres planos de colocación de implantes para aumento mamario tienen particularidades claramente identificables. Cada modificación anatómica y los elementos tisulares acompañantes establecen beneficios y efectos adversos que influyen sobre el resultado final. El presente estudio tiene como objetivo la comunicación temprana de los hallazgos clínicos obtenidos con la creación de una cavidad de implantación en diferentes condiciones, utilizando una combinación de planos y haciendo énfasis en un fundamento anatómico y funcional de gran relevancia. El mejor manejo de los implantes mamarios y de otros biomateriales es el mantenimiento de su integridad y el control de su comportamiento a largo plazo. De manera prospectiva valoramos la colocación de implantes mamarios en una cavidad que es subfascial en la porción caudal de la mama y retropectoral en la porción cefálica. El aislamiento de las rutas linfáticas suprafasciales proporciona un menor riesgo de contaminación del implante. La facilidad técnica se produce al no tener que desinsertar inferior y medialmente el músculo pectoral. En los 15 casos estudiados, no se produjo ningún desplazamiento cefálico de los implantes con la contracción pectoral. Hacemos también una revisión de la sustentación anatómica y funcional del nuevo plano de implantación utilizado. El resultado es una suma de beneficios y la prevención de un frecuente efecto adverso, con lo que cumplimos el objetivo final de reducir la morbilidad e incrementar la seguridad del procedimiento.The particular benefits and adverse effects of the three different planes for breast implant placement are widely known. The search for a safer implantation cavity led to a combination of two dissection planes with different anatomical components placed in continuity. Instead of supporting its value with statistics of good outcomes, emphasis is stressed in the functional and anatomical consequences of the proposed plane of

  13. Development of a patient-specific anatomical foot model from structured light scan data.

    Science.gov (United States)

    Lochner, Samuel J; Huissoon, Jan P; Bedi, Sanjeev S

    2014-01-01

    The use of anatomically accurate finite element (FE) models of the human foot in research studies has increased rapidly in recent years. Uses for FE foot models include advancing knowledge of orthotic design, shoe design, ankle-foot orthoses, pathomechanics, locomotion, plantar pressure, tissue mechanics, plantar fasciitis, joint stress and surgical interventions. Similar applications but for clinical use on a per-patient basis would also be on the rise if it were not for the high costs associated with developing patient-specific anatomical foot models. High costs arise primarily from the expense and challenges of acquiring anatomical data via magnetic resonance imaging (MRI) or computed tomography (CT) and reconstructing the three-dimensional models. The proposed solution morphs detailed anatomy from skin surface geometry and anatomical landmarks of a generic foot model (developed from CT or MRI) to surface geometry and anatomical landmarks acquired from an inexpensive structured light scan of a foot. The method yields a patient-specific anatomical foot model at a fraction of the cost of standard methods. Average error for bone surfaces was 2.53 mm for the six experiments completed. Highest accuracy occurred in the mid-foot and lowest in the forefoot due to the small, irregular bones of the toes. The method must be validated in the intended application to determine if the resulting errors are acceptable.

  14. 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.

  15. The ligament of Parks as a key anatomical structure for safer hemorrhoidectomy: Anatomic study and a simple surgical note

    Directory of Open Access Journals (Sweden)

    Menelaos Zoulamoglou

    2017-12-01

    Full Text Available Hemorrhoids are a common anal disorder which affects both men and women of all ages. One out of ten patients with hemorrhoidal disease, requires surgical treatment. Unfortunately though, hemorrhoidectomy is closely related to complications that can be present early or late postoperatively. In the present manuscript, the safe surgical technique which emphasizes to the identification of the key anatomical structure of the ligament of Parks (Trietz's muscle is adequately described. A total of 200 patients with grades III and IV hemorrhoids, underwent Milligan-Morgan or Ferguson's hemorrhoidectomy. The mucosal ligament of Parks was identified to all patients and was used as a key anatomical structure through the excision of the hemorrhoids. Its identification guides surgeons during the operation and reduces the major problem of postoperative complications. Finally, since the mucosal ligament of Parks represents a constantly identifiable landmark, it allows simple and reliable identification of the internal sphincter muscle and minimizes the probability of postoperative complications.

  16. Evidence for discrete landmark use by pigeons during homing.

    Science.gov (United States)

    Mora, Cordula V; Ross, Jeremy D; Gorsevski, Peter V; Chowdhury, Budhaditya; Bingman, Verner P

    2012-10-01

    Considerable efforts have been made to investigate how homing pigeons (Columba livia f. domestica) are able to return to their loft from distant, unfamiliar sites while the mechanisms underlying navigation in familiar territory have received less attention. With the recent advent of global positioning system (GPS) data loggers small enough to be carried by pigeons, the role of visual environmental features in guiding navigation over familiar areas is beginning to be understood, yet, surprisingly, we still know very little about whether homing pigeons can rely on discrete, visual landmarks to guide navigation. To assess a possible role of discrete, visual landmarks in navigation, homing pigeons were first trained to home from a site with four wind turbines as salient landmarks as well as from a control site without any distinctive, discrete landmark features. The GPS-recorded flight paths of the pigeons on the last training release were straighter and more similar among birds from the turbine site compared with those from the control site. The pigeons were then released from both sites following a clock-shift manipulation. Vanishing bearings from the turbine site continued to be homeward oriented as 13 of 14 pigeons returned home. By contrast, at the control site the vanishing bearings were deflected in the expected clock-shift direction and only 5 of 13 pigeons returned home. Taken together, our results offer the first strong evidence that discrete, visual landmarks are one source of spatial information homing pigeons can utilize to navigate when flying over a familiar area.

  17. Is radiographic measurement of bony landmarks reliable for lateral meniscal sizing?

    Science.gov (United States)

    Yoon, Jung-Ro; Kim, Taik-Seon; Lim, Hong-Chul; Lim, Hyung-Tae; Yang, Jae-Hyuk

    2011-03-01

    The accuracy of meniscal measurement methods is still in debate. The authors' protocol for radiologic measurements will provide reproducible bony landmarks, and this measurement method of the lateral tibial plateau will correlate with the actual anatomic value. Controlled laboratory study. Twenty-five samples of fresh lateral meniscus with attached proximal tibia were obtained during total knee arthroplasty. Each sample was obtained without damage to the meniscus and bony attachment sites. The inclusion criterion was mild to moderate osteoarthritis in patients with mechanical axis deviation of less than 15°. Knees with lateral compartment osteoarthritic change or injured or degenerated menisci were excluded. For the lateral tibial plateau length measurements, the radiographic beam was angled 10° caudally at neutral rotation, which allowed differentiation of the lateral plateau cortical margins from the medial plateau. The transition points were identified and used for length measurement. The values of length were then compared with the conventional Pollard method and the anatomic values. The width measurement was done according to Pollard's protocol. For each knee, the percentage deviation from the anatomic dimension was recorded. Intraobserver error and interobserver error were calculated. The deviation of the authors' radiographic length measurements from anatomic dimensions was 1.4 ± 1.1 mm. The deviation of Pollard's radiographic length measurements was 4.1 ± 2.0 mm. With respect to accuracy-which represents the frequency of measurements that fall within 10% of measurements-the accuracy of authors' length was 98%, whereas for Pollard's method it was 40%. There was a good correlation between anatomic meniscal dimensions and each radiologic plateau dimensions for lateral meniscal width (R(2) = .790) and the authors' lateral meniscal length (R(2) = .823) and fair correlation for Pollard's lateral meniscal length (R(2) = .660). The reliability of each

  18. Quantifying agreement between anatomical and functional interhemispheric correspondences in the resting brain.

    Directory of Open Access Journals (Sweden)

    Hang Joon Jo

    Full Text Available The human brain is composed of two broadly symmetric cerebral hemispheres, with an abundance of reciprocal anatomical connections between homotopic locations. However, to date, studies of hemispheric symmetries have not identified correspondency precisely due to variable cortical folding patterns. Here we present a method to establish accurate correspondency using position on the unfolded cortical surface relative to gyral and sulcal landmarks. The landmark method is shown to outperform the method of reversing standard volume coordinates, and it is used to quantify the functional symmetry in resting fMRI data throughout the cortex. Resting brain activity was found to be maximally correlated with locations less than 1 cm away on the cortical surface from the corresponding anatomical location in nearly half of the cortex. While select locations exhibited asymmetric patterns, precise symmetric relationships were found to be the norm, with fine-grained symmetric functional maps demonstrated in motor, occipital, and inferior frontal cortex.

  19. Relevancia de la anatomía humana en el ejercicio de la medicina de asistencia primaria y en el estudio de las asignaturas de segundo ciclo de la licenciatura en medicina Relevance of Gross Human Anatomy in health primary care and in clinical disciplines of medical studies

    Directory of Open Access Journals (Sweden)

    Blanca Mompeó

    2003-03-01

    Full Text Available El objetivo de este trabajo fue conocer la relevancia y la necesidad que de conocimientos en Anatomía macroscópica tenían los médicos de asistencia primaria y los alumnos del segundo ciclo de la licenciatura en Medicina. También nos interesó saber cual era su opinión sobre esta disciplina del curriculum médico. Para ello, médicos de asistencia primaria de los Centros de Salud de la provincia de las Palmas y alumnos de 6º curso de la Licenciatura en Medicina de la U.L.P.G.C., cumplimentaron un cuestionario en el que se valoraron los aspectos referidos. Ambos grupos consideraron que la Anatomía era fundamental para la exploración física y para la interpretación de técnicas de imagen. Los conocimientos más necesarios a la hora de su aplicación a la práctica y al estudio de las asignaturas clínicas fueron los de sistema nervioso y aparato locomotor. Modificarían la docencia que recibieron, incrementando el número de clases prácticas y dándole un mayor enfoque clínico. Los tres objetivos fundamentales de aprendizaje propuestos por los profesionales en ejercicio fueron: 1. Conocer las estructuras anatómicas y relaciones entre ellas 2. Reconocer estructuras anatómicas mediante técnicas de imagen y 3. Ser capaz de describir las bases anatómicas de la patología.The aim of this work was to highlight the relevance and necessity about gross anatomy knowledge had on family physicians and clinical-courses medical students. We also wanted to know their suggestions about the discipline Human Anatomy in Medical studies. To obtain our objective, physicians of Health Centres in Las Palmas and last-year medical students of U.L.P.G.C. were asked to fill a questionnaire. In this questionnaire the referred items were considered. The data obtained showed that both groups thought that Gross Anatomy was fundamental in the physical exploration and the image techniques interpretation. They considered that anatomical knowledge more necessary for

  20. Robust facial landmark detection based on initializing multiple poses

    Directory of Open Access Journals (Sweden)

    Xin Chai

    2016-10-01

    Full Text Available For robot systems, robust facial landmark detection is the first and critical step for face-based human identification and facial expression recognition. In recent years, the cascaded-regression-based method has achieved excellent performance in facial landmark detection. Nevertheless, it still has certain weakness, such as high sensitivity to the initialization. To address this problem, regression based on multiple initializations is established in a unified model; face shapes are then estimated independently according to these initializations. With a ranking strategy, the best estimate is selected as the final output. Moreover, a face shape model based on restricted Boltzmann machines is built as a constraint to improve the robustness of ranking. Experiments on three challenging datasets demonstrate the effectiveness of the proposed facial landmark detection method against state-of-the-art methods.

  1. 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...

  2. 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.

  3. Robust surface registration using salient anatomical features for image-guided liver surgery: Algorithm and validation

    OpenAIRE

    Clements, Logan W.; Chapman, William C.; Dawant, Benoit M.; Galloway, Robert L.; Miga, Michael I.

    2008-01-01

    A successful surface-based image-to-physical space registration in image-guided liver surgery (IGLS) is critical to provide reliable guidance information to surgeons and pertinent surface displacement data for use in deformation correction algorithms. The current protocol used to perform the image-to-physical space registration involves an initial pose estimation provided by a point based registration of anatomical landmarks identifiable in both the preoperative tomograms and the intraoperati...

  4. Face landmark point tracking using LK pyramid optical flow

    Science.gov (United States)

    Zhang, Gang; Tang, Sikan; Li, Jiaquan

    2018-04-01

    LK pyramid optical flow is an effective method to implement object tracking in a video. It is used for face landmark point tracking in a video in the paper. The landmark points, i.e. outer corner of left eye, inner corner of left eye, inner corner of right eye, outer corner of right eye, tip of a nose, left corner of mouth, right corner of mouth, are considered. It is in the first frame that the landmark points are marked by hand. For subsequent frames, performance of tracking is analyzed. Two kinds of conditions are considered, i.e. single factors such as normalized case, pose variation and slowly moving, expression variation, illumination variation, occlusion, front face and rapidly moving, pose face and rapidly moving, and combination of the factors such as pose and illumination variation, pose and expression variation, pose variation and occlusion, illumination and expression variation, expression variation and occlusion. Global measures and local ones are introduced to evaluate performance of tracking under different factors or combination of the factors. The global measures contain the number of images aligned successfully, average alignment error, the number of images aligned before failure, and the local ones contain the number of images aligned successfully for components of a face, average alignment error for the components. To testify performance of tracking for face landmark points under different cases, tests are carried out for image sequences gathered by us. Results show that the LK pyramid optical flow method can implement face landmark point tracking under normalized case, expression variation, illumination variation which does not affect facial details, pose variation, and that different factors or combination of the factors have different effect on performance of alignment for different landmark points.

  5. 36 CFR 62.5 - Natural landmark criteria.

    Science.gov (United States)

    2010-07-01

    ... be characteristic of a given natural region. Such features include terrestrial and aquatic ecosystems... feature is so large as to be impracticable for natural landmark consideration (e.g., a mountain range...: Criterion Description Example Diversity In addition to its primary natural feature, area contains high...

  6. 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...

  7. Anatomical imaging for radiotherapy

    International Nuclear Information System (INIS)

    Evans, Philip M

    2008-01-01

    The goal of radiation therapy is to achieve maximal therapeutic benefit expressed in terms of a high probability of local control of disease with minimal side effects. Physically this often equates to the delivery of a high dose of radiation to the tumour or target region whilst maintaining an acceptably low dose to other tissues, particularly those adjacent to the target. Techniques such as intensity modulated radiotherapy (IMRT), stereotactic radiosurgery and computer planned brachytherapy provide the means to calculate the radiation dose delivery to achieve the desired dose distribution. Imaging is an essential tool in all state of the art planning and delivery techniques: (i) to enable planning of the desired treatment, (ii) to verify the treatment is delivered as planned and (iii) to follow-up treatment outcome to monitor that the treatment has had the desired effect. Clinical imaging techniques can be loosely classified into anatomic methods which measure the basic physical characteristics of tissue such as their density and biological imaging techniques which measure functional characteristics such as metabolism. In this review we consider anatomical imaging techniques. Biological imaging is considered in another article. Anatomical imaging is generally used for goals (i) and (ii) above. Computed tomography (CT) has been the mainstay of anatomical treatment planning for many years, enabling some delineation of soft tissue as well as radiation attenuation estimation for dose prediction. Magnetic resonance imaging is fast becoming widespread alongside CT, enabling superior soft-tissue visualization. Traditionally scanning for treatment planning has relied on the use of a single snapshot scan. Recent years have seen the development of techniques such as 4D CT and adaptive radiotherapy (ART). In 4D CT raw data are encoded with phase information and reconstructed to yield a set of scans detailing motion through the breathing, or cardiac, cycle. In ART a set of

  8. Benchmarking Academic Anatomic Pathologists

    Directory of Open Access Journals (Sweden)

    Barbara S. Ducatman MD

    2016-10-01

    Full Text Available The most common benchmarks for faculty productivity are derived from Medical Group Management Association (MGMA or Vizient-AAMC Faculty Practice Solutions Center ® (FPSC databases. The Association of Pathology Chairs has also collected similar survey data for several years. We examined the Association of Pathology Chairs annual faculty productivity data and compared it with MGMA and FPSC data to understand the value, inherent flaws, and limitations of benchmarking data. We hypothesized that the variability in calculated faculty productivity is due to the type of practice model and clinical effort allocation. Data from the Association of Pathology Chairs survey on 629 surgical pathologists and/or anatomic pathologists from 51 programs were analyzed. From review of service assignments, we were able to assign each pathologist to a specific practice model: general anatomic pathologists/surgical pathologists, 1 or more subspecialties, or a hybrid of the 2 models. There were statistically significant differences among academic ranks and practice types. When we analyzed our data using each organization’s methods, the median results for the anatomic pathologists/surgical pathologists general practice model compared to MGMA and FPSC results for anatomic and/or surgical pathology were quite close. Both MGMA and FPSC data exclude a significant proportion of academic pathologists with clinical duties. We used the more inclusive FPSC definition of clinical “full-time faculty” (0.60 clinical full-time equivalent and above. The correlation between clinical full-time equivalent effort allocation, annual days on service, and annual work relative value unit productivity was poor. This study demonstrates that effort allocations are variable across academic departments of pathology and do not correlate well with either work relative value unit effort or reported days on service. Although the Association of Pathology Chairs–reported median work relative

  9. The Anterolateral Limit of the Occipital Lobe: An Anatomical and Imaging Study.

    Science.gov (United States)

    Reis, Cassius Vinicius C; Yagmurlu, Kaan; Elhadi, Ali M; Dru, Alexander; Lei, Ting; Gusmão, Sebastião N S; Tazinaffo, Uédson; Zabramski, Joseph M; Spetzler, Robert F; Preul, Mark C

    2016-12-01

    Objectives  The boundaries of the temporal lobe, the parietal lobe, and the anterior portion of the occipital lobe (OL) are poorly defined. Lesions in these areas can be difficult to localize. Therefore, we studied the anterolateral limit of the OL to identify reliable anatomical landmarks. Design  In 10 formalin-fixed cadaveric heads, the boundaries of the OL and relative anatomical landmarks were studied. Main Outcome Measures  Distances between the following structures were measured: (1) preoccipital tentorial plica (POTP) to the junction between lambdoid suture and superior border of the transverse sinus (POTP-SL), (2) POTP to the sinodural angle of Citelli (POTP-PP), (3) lambda to parietooccipital sulcus (L-POS), and (4) preoccipital notch to termination of the vein of Labbé (PON-VL). Landmarks in 559 computed tomography and magnetic resonance images were also studied. Results  The POTP was found on the tentorium of all anatomical specimens, located at the same coronal level as the PON and its attachment to the bony protuberance (BP) at the lateral cranial wall. The mean distances were POTP-SL, 6.5 ± 6.4 mm; POTP-PP, 18.1 ± 7.8 mm; L-POS, 10.8 ± 5.0 mm; and PON-VL, 8.8 ± 10.1 mm. Conclusion  Osseous (asterion, lambda, and BP), dural (POTP), and vascular (VL) landmarks can be used as reference structures to identify the anterolateral limit of the OL.

  10. 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.

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

    International Nuclear Information System (INIS)

    Durao, Ana Paula Reis; Ferreira, Afonso P.; Morosolli, Aline; Pittayapat, Pisha; Bolstad, Napat; Jacobs, Reinhilde

    2015-01-01

    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

  12. Navigating Deep Time: Landmarks for Time from the Big Bang to the Present

    Science.gov (United States)

    Delgado, Cesar

    2013-01-01

    People make sense of the world by comparing and relating new information to their existing landmarks. Each individual may have different landmarks, developed through idiosyncratic experiences. Identifying specific events that constitute landmarks for a group of learners may help instructors in gauging students' prior knowledge and in planning…

  13. Technical note: a landmark-based approach to the study of the ear ossicles using ultra-high-resolution X-ray computed tomography data.

    Science.gov (United States)

    Schmidt, Jodi L; Cole, Theodore M; Silcox, Mary T

    2011-08-01

    Previous study of the ear ossicles in Primates has demonstrated that they vary on both functional and phylogenetic bases. Such studies have generally employed two-dimensional linear measurements rather than three-dimensional data. The availability of Ultra- high-resolution X-ray computed tomography (UhrCT) has made it possible to accurately image the ossicles so that broadly accepted methodologies for acquiring and studying morphometric data can be applied. Using UhrCT data also allows for the ossicular chain to be studied in anatomical position, so that it is possible to consider the spatial and size relationships of all three bones. One issue impeding the morphometric study of the ear ossicles is a lack of broadly recognized landmarks. Distinguishing landmarks on the ossicles is difficult in part because there are only two areas of articulation in the ossicular chain, one of which (the malleus/incus articulation) has a complex three-dimensional form. A measurement error study is presented demonstrating that a suite of 16 landmarks can be precisely located on reconstructions of the ossicles from UhrCT data. Estimates of measurement error showed that most landmarks were highly replicable, with an average CV for associated interlandmark distances of less than 3%. The positions of these landmarks are chosen to reflect not only the overall shape of the bones in the chain and their relative positions, but also functional parameters. This study should provide a basis for further examination of the smallest bones in the body in three dimensions. Copyright © 2011 Wiley-Liss, Inc.

  14. [Inferring landmark displacements from changes in cephalometric angles].

    Science.gov (United States)

    Xu, T; Baumrind, S

    2001-07-01

    To investigate the appropriateness of using changes in angular measurements to reflect the actually profile changes. The sample consists of 48 growing malocclusion patients, contained 24 Class I and 24 Class II subjects, treated by an experienced orthodontist using Edgewise technique. Landmark and superimpositional data were extracted from the previously prepared numerical database. Three pairs of angular and linear measures were computed by the Craniofacial Software Package. Although the associations between all three angular measures and their corresponding linear measures are statistically significant at the 0.001 level, the disagreement between these three pairs of measures are 10.4%, 22.9% and 37.5% respectively in this sample. The direction of displacement of anterior facial landmarks during growth and treatment cannot reliably be inferred merely from changes in cephalometric Angles.

  15. Uav Visual Autolocalizaton Based on Automatic Landmark Recognition

    Science.gov (United States)

    Silva Filho, P.; Shiguemori, E. H.; Saotome, O.

    2017-08-01

    Deploying an autonomous unmanned aerial vehicle in GPS-denied areas is a highly discussed problem in the scientific community. There are several approaches being developed, but the main strategies yet considered are computer vision based navigation systems. This work presents a new real-time computer-vision position estimator for UAV navigation. The estimator uses images captured during flight to recognize specific, well-known, landmarks in order to estimate the latitude and longitude of the aircraft. The method was tested in a simulated environment, using a dataset of real aerial images obtained in previous flights, with synchronized images, GPS and IMU data. The estimated position in each landmark recognition was compatible with the GPS data, stating that the developed method can be used as an alternative navigation system.

  16. UAV VISUAL AUTOLOCALIZATON BASED ON AUTOMATIC LANDMARK RECOGNITION

    Directory of Open Access Journals (Sweden)

    P. Silva Filho

    2017-08-01

    Full Text Available Deploying an autonomous unmanned aerial vehicle in GPS-denied areas is a highly discussed problem in the scientific community. There are several approaches being developed, but the main strategies yet considered are computer vision based navigation systems. This work presents a new real-time computer-vision position estimator for UAV navigation. The estimator uses images captured during flight to recognize specific, well-known, landmarks in order to estimate the latitude and longitude of the aircraft. The method was tested in a simulated environment, using a dataset of real aerial images obtained in previous flights, with synchronized images, GPS and IMU data. The estimated position in each landmark recognition was compatible with the GPS data, stating that the developed method can be used as an alternative navigation system.

  17. Occipital neuralgia: anatomic considerations.

    Science.gov (United States)

    Cesmebasi, Alper; Muhleman, Mitchel A; Hulsberg, Paul; Gielecki, Jerzy; Matusz, Petru; Tubbs, R Shane; Loukas, Marios

    2015-01-01

    Occipital neuralgia is a debilitating disorder first described in 1821 as recurrent headaches localized in the occipital region. Other symptoms that have been associated with this condition include paroxysmal burning and aching pain in the distribution of the greater, lesser, or third occipital nerves. Several etiologies have been identified in the cause of occipital neuralgia and include, but are not limited to, trauma, fibrositis, myositis, fracture of the atlas, and compression of the C-2 nerve root, C1-2 arthrosis syndrome, atlantoaxial lateral mass osteoarthritis, hypertrophic cervical pachymeningitis, cervical cord tumor, Chiari malformation, and neurosyphilis. The management of occipital neuralgia can include conservative approaches and/or surgical interventions. Occipital neuralgia is a multifactorial problem where multiple anatomic areas/structures may be involved with this pathology. A review of these etiologies may provide guidance in better understanding occipital neuralgia. © 2014 Wiley Periodicals, Inc.

  18. Neural Network Based Sensory Fusion for Landmark Detection

    Science.gov (United States)

    Kumbla, Kishan -K.; Akbarzadeh, Mohammad R.

    1997-01-01

    NASA is planning to send numerous unmanned planetary missions to explore the space. This requires autonomous robotic vehicles which can navigate in an unstructured, unknown, and uncertain environment. Landmark based navigation is a new area of research which differs from the traditional goal-oriented navigation, where a mobile robot starts from an initial point and reaches a destination in accordance with a pre-planned path. The landmark based navigation has the advantage of allowing the robot to find its way without communication with the mission control station and without exact knowledge of its coordinates. Current algorithms based on landmark navigation however pose several constraints. First, they require large memories to store the images. Second, the task of comparing the images using traditional methods is computationally intensive and consequently real-time implementation is difficult. The method proposed here consists of three stages, First stage utilizes a heuristic-based algorithm to identify significant objects. The second stage utilizes a neural network (NN) to efficiently classify images of the identified objects. The third stage combines distance information with the classification results of neural networks for efficient and intelligent navigation.

  19. 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.

  20. Spinal cord localization in the treatment of lung cancer: use of radiographic landmarks

    International Nuclear Information System (INIS)

    Miller, Robert C.; Bonner, James A.; Wenger, Doris E.; Foote, Robert L.; Kisrow, Kevin L.; Shaw, Edward G.

    1998-01-01

    Purpose: In the treatment of thoracic malignancies with radiotherapy, the critical dose-limiting structure is the spinal cord. Oblique fields typically are designed to exclude the spinal cord, and by convention, the field edge that shields the spinal cord is placed at the anterior border of the vertebral pedicles. Thus, the purpose of our study was to estimate the distance between the field edge and spinal cord in oblique fields that were designed by using the vertebral pedicle as a radiographic landmark. Methods and Materials: The spinal cord of a cadaver was wrapped in wire, and oblique fields were simulated at 15 deg. intervals. The distance from the spinal cord to a field edge placed at the anterior border of the pedicle was measured. In the second investigation, a three-dimensional treatment planning system was used to simulate hypothetical fields using actual patient data from computed tomography (n = 10), and measurements identical to those in the anatomical model were made (n = 1,100). Results: The results of the anatomical and computed tomographic models were in close agreement (mean difference, 0.6 mm). The computed tomographic model predicted a mean field edge to spinal cord distance of 8.7 mm (95% confidence interval, 5.6-11.8 mm) for (30 deg. (150 deg.)) oblique fields and 8.0 mm (95% confidence interval, 4.7-11.7 mm) for (45 deg. (135 deg.)) oblique fields. This distance was greatest at levels T-1, T-2, and T-11 (8 to 20% greater). Conclusions: The mean distance from a field edge placed at the anterior border of a vertebral pedicle to the spinal cord for commonly used oblique angles constitutes a sufficient margin to account for expected differences in daily positional variations and mechanical uncertainties

  1. 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.

  2. Wild rufous hummingbirds use local landmarks to return to rewarded locations.

    Science.gov (United States)

    Pritchard, David J; Scott, Renee D; Healy, Susan D; Hurly, Andrew T

    2016-01-01

    Animals may remember an important location with reference to one or more visual landmarks. In the laboratory, birds and mammals often preferentially use landmarks near a goal ("local landmarks") to return to that location at a later date. Although we know very little about how animals in the wild use landmarks to remember locations, mammals in the wild appear to prefer to use distant landmarks to return to rewarded locations. To examine what cues wild birds use when returning to a goal, we trained free-living hummingbirds to search for a reward at a location that was specified by three nearby visual landmarks. Following training we expanded the landmark array to test the extent that the birds relied on the local landmarks to return to the reward. During the test the hummingbirds' search was best explained by the birds having used the experimental landmarks to remember the reward location. How the birds used the landmarks was not clear and seemed to change over the course of each test. These wild hummingbirds, then, can learn locations in reference to nearby visual landmarks. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. The anatomic basis of lingual nerve trauma associated with inferior alveolar block injections.

    Science.gov (United States)

    Morris, Christopher D; Rasmussen, Jared; Throckmorton, Gaylord S; Finn, Richard

    2010-11-01

    This study describes the anatomic variability in the position of the lingual nerve in the pterygomandibular space, the location of the inferior alveolar nerve block injection. Simulated standard landmark-based inferior alveolar nerve blocks were administered to 44 fixed sagitally bisected cadaver heads. Measurements were made of the diameter of the nerves and distances between the needle and selected anatomic landmarks and the nerves. Of 44 simulated injections, 42 (95.5%) passed lateral to the lingual nerve, 7 (16%) passed within 0.1 mm of the nerve, and 2 (4.5%) penetrated the nerve. The position of the lingual nerve relative to bony landmarks within the interpterygoid fascia was highly variable. Variation in the position of the lingual nerve is an important contributor to lingual nerve trauma during inferior alveolar block injections. This factor should be an important part of preoperative informed consent. Copyright © 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  4. Femoral rotational asymmetry is a common anatomical variant.

    Science.gov (United States)

    Newman, Christopher R; Walter, William L; Talbot, Simon

    2018-05-01

    The sulcus line (SL) is a three-dimensional landmark that corrects for individual variation in the coronal alignment of the trochlear groove in contrast to the traditional Whiteside's line (WL). Femoral rotational asymmetry (FRA) is an anatomical variation in which the posterior condyles and trochlear groove are not perpendicular to each other. This study aims to measure the SL and assess its reliability relative to WL, in addition to measuring and classifying the FRA. A retrospective analysis of a series of 191 CT scans of nonarthritic knees was performed. Measurements were taken of rotational landmarks in three-dimensional reconstructions. The variability and outlier rate of SL was less than WL (P  0.05), however it decreased the rate of change of the rotational alignment of the trochlear groove between the native knee and the prosthetic knee from 31% to 5% (P 5° in 56/191 (29%) of cases. The SL technique is more accurate than WL for determining the rotational alignment of the trochlear groove. Nonarthritic femora have a high rate of rotational asymmetry. Identifying and classifying FRA in individual cases allows the femoral component to be inserted in a position which gives the best possible match to both the native posterior condyles and trochlear groove. Clin. Anat. 31:551-559, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

  5. Anatomic study of the pterion in Nigerian dry human skulls.

    Science.gov (United States)

    Ukoha, U; Oranusi, C K; Okafor, J I; Udemezue, O O; Anyabolu, A E; Nwamarachi, T C

    2013-01-01

    The pterion is a point of sutural confluence seen in the norma lateralis of the skull. The site is an important landmark in surgical approaches to the anterior and middle cranial fossa. This study was designed to determine the frequency of pterion types and anatomic positions of the pterion in dry human skulls of Nigerians in the South Eastern Zone. Specific measurements were taken on both sides of 56 Nigerian human skulls of unknown sex, obtained from the Department of Anatomy, Nnamdi Azikiwe University, Nnewi Campus, Nnewi, Nigeria. All the four types of the pterion were present, i.e. sphenoparietal, frontotemporal, stellate, and epipteric. The study showed that the sphenoparietal type was 75% on the right side, 76% on the left side, the frontotemporal type was 19.6% on both sides, the stellate type was 1.8% on the right side and absent on the left side. The epipteric type was 3.6% on both sides. The distances from the centre of pterion to the frontozygomatic suture were 2.74 ± 0.07 cm on the right side and 2.74 ± 0.06 cm on the left side. The pterion was 4.02 ± 0.05 and 4.01 ± 0.03 cm above the midpoint of the zygomatic arch on the right and left sides, respectively. These findings are important for the surgeon as the pterion junction is a common extracranial landmark in neurosurgical and surgical approaches.

  6. Muscle Insertion Line as a Simple Landmark To Identify the Transverse Sinus When Neuronavigation Is Unavailable.

    Science.gov (United States)

    Kivelev, Juri; Kivisaari, Riku; Niemelä, Mika; Hernesniemi, Juha

    2016-10-01

    Skull opening in occipital and suboccipital regions might be associated with risk of damage to the transverse venous sinus and the confluence of sinuses. We analyze the value of magnetic resonance (MR) imaging in localizing the venous sinuses in relation to the superior muscle insertion line (MIL) on the occipital bone. We retrospectively analyzed head MR images of 100 consecutive patients imaged for any reason from 1 January 2013. All MR images were interpreted by a radiologist (R.K.). The superior MIL was identified at the midline and on both midpupillar lines, which represent the most frequent sites of skin incision and craniotomy (median and lateral suboccipital craniotomy, respectively). Patients comprised 56 women (56%) and 44 men (44%). Their mean age was 54 (range 18-84) years. The muscles of the posterior skull were readily visible and clearly identified in both T1 and T2 images of all patients. Identification of the insertion zone and its relation to the venous structures was most readily made in the sagittal plane. We found that the upper muscle insertion line on occipital bone corresponds to the underlying venous sinus and can be used as a reliable anatomic landmark. We identified it in 100% of preoperative MR images of heads with an intact occiput. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. The transverse ligament as a landmark for tibial sagittal insertions of the anterior cruciate ligament: a cadaveric study.

    Science.gov (United States)

    Kongcharoensombat, Wirat; Ochi, Mitsuo; Abouheif, Mohamed; Adachi, Nobuo; Ohkawa, Shingo; Kamei, Goki; Okuhara, Atushi; Shibuya, Hoyatoshi; Niimoto, Takuya; Nakasa, Tomoyuki; Nakamae, Atsuo; Deie, Masataka

    2011-10-01

    The purpose of this study was to determine the relation between the position of the transverse ligament, the anterior edge of the anterior cruciate ligament (ACL) tibial footprint, and the center of the ACL tibial insertion. We used arthroscopy for localization of the anatomic landmarks, followed by insertions of guide pins under direct visualization, and then the position of these guide pins was checked on plain lateral radiographs. The transverse ligament and the anterior aspect of the ACL tibial footprint were identified by arthroscopy in 20 unpaired cadaveric knees (10 left and 10 right). Guide pins were inserted with tibial ACL adapter drill guides under direct observation at the transverse ligament, the anterior aspect of the tibial footprint, and the center of tibial insertion of the ACL. Then, plain lateral radiographs of specimens were taken. The Amis and Jakob line was used to define the attachment of the ACL tibial insertion and the transverse ligament. A sagittal percentage of the location of the insertion point was determined and calculated from the anterior margin of the tibia in the anteroposterior direction. The transverse ligament averaged 21.20% ± 4.1%, the anterior edge of the ACL tibial insertion averaged 21.60% ± 4.0%, and the center of the ACL tibial insertion averaged 40.30% ± 4.8%. There were similar percent variations between the transverse ligament and the anterior edge of the ACL tibial insertion, with no significant difference between them (P = .38). Intraobserver and interobserver reliability was high, with small standard errors of measurement. This study shows that the transverse ligament coincides with the anterior edge of the ACL tibial footprint in the sagittal plane. The transverse ligament can be considered as a new landmark for tibial tunnel positioning during anatomic ACL reconstruction. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

    Kim, Jin Su; Lee, Dong Soo; Lee, Byung Il; Lee, Jae Sung; Shin, Hee Won; Chung, June Key; Lee, Myung Chul

    2002-01-01

    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

  9. 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

  10. Gender differences in landmark learning for virtual navigation: the role of distance to a goal.

    Science.gov (United States)

    Chamizo, V D; Artigas, A A; Sansa, J; Banterla, F

    2011-09-01

    We used a new virtual program in two experiments to prepare subjects to perform the Morris water task (www.nesplora.com). The subjects were Psychology students; they were trained to locate a safe platform amidst the presence of four pinpoint landmarks spaced around the edge of the pool (i.e., two landmarks relatively near the platform and two landmarks relatively distant away from it). At the end of the training phase, we administered one test trial without the platform and recorded the amount of time that the students had spent in the platform quadrant. In Experiment 1, we conducted the test trial in the presence of one or two of the distant landmarks. When only one landmark was present during testing, performance fell to chance. However, the men outperformed the women when the two distant landmarks were both present. Experiment 2 replicated the previous results and extended it by showing that no sex differences exist when the searching process is based on the near landmarks. Both the men and the women had similarly good performances when the landmarks were present both individually and together. When present together, an addition effect was found. Far landmark tests favor configural learning processes, whereas near landmark tests favor elemental learning. Our findings suggest that other factors in addition to the use of directional cues can underlie the sex differences in the spatial learning process. Thus, we expand upon previous research in the field. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. The post-birthday world: consequences of temporal landmarks for temporal self-appraisal and motivation.

    Science.gov (United States)

    Peetz, Johanna; Wilson, Anne E

    2013-02-01

    Much as physical landmarks help structure our representation of space, temporal landmarks such as birthdays and significant calendar dates structure our perception of time, such that people may organize or categorize their lives into "chunks" separated by these markers. Categories on the temporal landscape may vary depending on what landmarks are salient at a given time. We suggest these landmarks have implications for identity and motivation. The present research examined consequences of salient temporal landmarks for perceptions of the self across time and motivation to pursue successful future selves. Studies 1 and 2 show that temporally extended selves are perceived as less connected to, and more dissimilar from, the current self when an intervening landmark event has been made salient. Study 3 addresses the proposed mechanism, demonstrating that intervening landmarks lead people to categorize pre- and postlandmark selves into separate categories more often than when the same time period contains no salient landmarks. Finally, we examined whether landmark-induced mental contrasting of present state and future desired state could increase goal-pursuit motivation (in an effort to bridge the gap between inferior present and better future states). Studies 4-6 demonstrate that landmark-induced discrepancies between current health and hoped-for future health increased participants' motivation to exercise and increased the likelihood that they acted in line with their future-oriented goals. (c) 2013 APA, all rights reserved.

  12. Generalization decrement and not overshadowing by associative competition among pairs of landmarks in a navigation task.

    Science.gov (United States)

    Chamizo, Victoria D; Rodríguez, Clara A; Espinet, Alfredo; Mackintosh, N J

    2012-07-01

    When they are trained in a Morris water maze to find a hidden platform, whose location is defined by a number of equally spaced visual landmarks round the circumference of the pool, rats are equally able to find the platform when tested with any two of the landmarks (Prados, & Trobalon, 1998; Rodrigo, Chamizo, McLaren, & Mackintosh, 1997). This suggests that none of the landmarks was completely overshadowed by any of the others. In Experiment 1 one pair of groups was trained with four equally salient visual landmarks spaced at equal intervals around the edge of the pool, while a second pair was trained with two landmarks only, either relatively close to or far from the hidden platform. After extensive training, both male and female rats showed a reciprocal overshadowing effect: on a test with two landmarks only (either close to or far from the platform), rats trained with four landmarks spent less time in the platform quadrant than those trained with only two. Experiment 2 showed that animals trained with two landmarks and then tested with four also performed worse on test than those trained and tested with two landmarks only. This suggests that generalization decrement, rather than associative competition, provides a sufficient explanation for the overshadowing observed in Experiment 1. Experiment 3 provided a within-experiment replication of the results of Experiments 1 and 2. Finally, Experiment 4 showed that rats trained with a configuration of two landmarks learn their identity.

  13. 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.

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

    International Nuclear Information System (INIS)

    Freund, Wolfgang; Aschoff, Andrik J.; Stuber, Gregor; Schmitz, Bernd; Brinkmann, Alexander; Wagner, Florian; Dinse, Alexander

    2007-01-01

    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.)

  15. [New international classification of corneal dystrophies and clinical landmarks].

    Science.gov (United States)

    Lisch, W; Seitz, B

    2008-07-01

    The International Committee on Classification of Corneal Dystrophies, briefly IC (3)D, was founded with the sponsorship of the American Cornea Society and the American Academy of Ophthalmology in July 2005. This committee consists of 17 corneal experts (1) from USA, Asia and Europe. The goal of this group was to develop a new, internationally accepted classification of corneal dystrophies (CD) based on modern clinical, histological and genetical knowledge. The aim of the new classification should be to avoid wrong interpretations and misnomers of the different forms of CD. The IC (3)D extensive manuscript is in press as Supplement publication in the journal "Cornea". The 25 different CD are divided in four categories by clinical and genetical knowledge. Additionally, templates for each type of CD are included. Finally, many typical color slit-lamp photos are presented in the publication together with essential references and current genetical results in tabular form. As members of IC (3)D the authors present a clinical landmark survey of the different corneal dystrophies. The ophthalmologist is the first to examine and to diagnose a new patient with a probable CD at the slit-lamp. Our elaborated table of landmarks is supposed to be a "bridge" for the ophthalmologist to precisely define the corneal opacities of a presumed CD. This "bridge" makes it easier for them to study the IC (3)D Supplement publication and to get more information including adequate differential diagnosis.

  16. Landmarks for Sacral Debridement in Sacral Pressure Sores.

    Science.gov (United States)

    Choo, Joshua H; Wilhelmi, Bradon J

    2016-03-01

    Most cases of sacral osteomyelitis arising in the setting of sacral pressure ulcers require minimal cortical debridement. When faced with advanced bony involvement, the surgeon is often unclear about how much can safely be resected. Unfamiliarity with sacral anatomy can lead to concerns of inadvertent entry into the dural space and compromise of future flap options. A cadaveric study (n = 6), in which a wide posterior dissection of the sacrum, was performed. Relationships of the dural sac to bony landmarks of the posterior pelvis were noted. The termination of the dural sac was found in our study to occur at the junction of S2/S3 vertebral bodies, which was located at a mean distance of 0.38 ± 0.16 cm distal to the inferior-most extent of the posterior superior iliac spine (PSIS). The mean thickness of the posterior table of sacrum at this level was 1.7 cm at the midline and 0.5 cm at the sacral foramina. The PSIS is a reliable landmark for localizing the S2/S3 junction and the termination of the dural sac. Sacral debridement medial to the sacral foramina above the level of PSIS must be conservative whenever possible. If aggressive debridement is necessary above this level, the surgeon must be alert to the possibility of dural involvement.

  17. Putting emotions in routes: the influence of emotionally laden landmarks on spatial memory.

    Science.gov (United States)

    Ruotolo, F; Claessen, M H G; van der Ham, I J M

    2018-04-16

    The aim of this study was to assess how people memorize spatial information of emotionally laden landmarks along a route and if the emotional value of the landmarks affects the way metric and configurational properties of the route itself are represented. Three groups of participants were asked to watch a movie of a virtual walk along a route. The route could contain positive, negative, or neutral landmarks. Afterwards, participants were asked to: (a) recognize the landmarks; (b) imagine to walk distances between landmarks; (c) indicate the position of the landmarks along the route; (d) judge the length of the route; (e) draw the route. Results showed that participants who watched the route with positive landmarks were more accurate in locating the landmarks along the route and drawing the route. On the other hand, participants in the negative condition judged the route as longer than participants in the other two conditions and were less accurate in mentally reproducing distances between landmarks. The data will be interpreted in the light of the "feelings-as-information theory" by Schwarz (2010) and the most recent evidence about the effect of emotions on spatial memory. In brief, the evidence collected in this study supports the idea that spatial cognition emerges from the interaction between an organism and contextual characteristics.

  18. The problem of assessing landmark error in geometric morphometrics: theory, methods, and modifications.

    Science.gov (United States)

    von Cramon-Taubadel, Noreen; Frazier, Brenda C; Lahr, Marta Mirazón

    2007-09-01

    Geometric morphometric methods rely on the accurate identification and quantification of landmarks on biological specimens. As in any empirical analysis, the assessment of inter- and intra-observer error is desirable. A review of methods currently being employed to assess measurement error in geometric morphometrics was conducted and three general approaches to the problem were identified. One such approach employs Generalized Procrustes Analysis to superimpose repeatedly digitized landmark configurations, thereby establishing whether repeat measures fall within an acceptable range of variation. The potential problem of this error assessment method (the "Pinocchio effect") is demonstrated and its effect on error studies discussed. An alternative approach involves employing Euclidean distances between the configuration centroid and repeat measures of a landmark to assess the relative repeatability of individual landmarks. This method is also potentially problematic as the inherent geometric properties of the specimen can result in misleading estimates of measurement error. A third approach involved the repeated digitization of landmarks with the specimen held in a constant orientation to assess individual landmark precision. This latter approach is an ideal method for assessing individual landmark precision, but is restrictive in that it does not allow for the incorporation of instrumentally defined or Type III landmarks. Hence, a revised method for assessing landmark error is proposed and described with the aid of worked empirical examples. (c) 2007 Wiley-Liss, Inc.

  19. The concept of individualized anatomic anterior cruciate ligament (ACL) reconstruction

    NARCIS (Netherlands)

    Hofbauer, M.; Muller, B. [=Bart; Murawski, C. D.; van Eck, C. F.; Fu, F. H.

    2014-01-01

    To describe the concept of individualized anatomic anterior cruciate ligament (ACL) reconstruction. The PubMed/Medline database was searched using keywords pertaining to ACL reconstruction. Relevant articles were reviewed in order to summarize important concepts of individualized surgery in ACL

  20. Automatic detection of anatomical regions in frontal x-ray images: comparing convolutional neural networks to random forest

    Science.gov (United States)

    Olory Agomma, R.; Vázquez, C.; Cresson, T.; De Guise, J.

    2018-02-01

    Most algorithms to detect and identify anatomical structures in medical images require either to be initialized close to the target structure, or to know that the structure is present in the image, or to be trained on a homogeneous database (e.g. all full body or all lower limbs). Detecting these structures when there is no guarantee that the structure is present in the image, or when the image database is heterogeneous (mixed configurations), is a challenge for automatic algorithms. In this work we compared two state-of-the-art machine learning techniques in order to determine which one is the most appropriate for predicting targets locations based on image patches. By knowing the position of thirteen landmarks points, labelled by an expert in EOS frontal radiography, we learn the displacement between salient points detected in the image and these thirteen landmarks. The learning step is carried out with a machine learning approach by exploring two methods: Convolutional Neural Network (CNN) and Random Forest (RF). The automatic detection of the thirteen landmarks points in a new image is then obtained by averaging the positions of each one of these thirteen landmarks estimated from all the salient points in the new image. We respectively obtain for CNN and RF, an average prediction error (both mean and standard deviation in mm) of 29 +/-18 and 30 +/- 21 for the thirteen landmarks points, indicating the approximate location of anatomical regions. On the other hand, the learning time is 9 days for CNN versus 80 minutes for RF. We provide a comparison of the results between the two machine learning approaches.

  1. Conservation landmarks: bureau of biological survey and national biological service

    Science.gov (United States)

    Friend, M.

    1995-01-01

    A century separates the recent development of the National Biological Service (NBS) and an early predecessor, the Bureau of Biological Survey (BBS). Both organizations were established at critical crossroads for the conservation of the nation's living biological resources and are conservation landmarks of their times. The BBS of the 192()'s was described as 'a government Bureau of the first rank, handling affairs of great scientific, educational, social, and above all, economic importance throughout the United States and its outlying possessions'' (Cameron 1929:144-145). This stature was achieved at a time of great social, economic, and ecological change. BBS had the vision to pioneer new approaches that led to enhanced understanding of the relation between people, other living things, and the environment. The NBS faces similar challenges to address the issues of the 1990's and beyond.

  2. 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.

  3. Media Portrayal of a Landmark Neuroscience Experiment on Free Will.

    Science.gov (United States)

    Racine, Eric; Nguyen, Valentin; Saigle, Victoria; Dubljevic, Veljko

    2017-08-01

    The concept of free will has been heavily debated in philosophy and the social sciences. Its alleged importance lies in its association with phenomena fundamental to our understandings of self, such as autonomy, freedom, self-control, agency, and moral responsibility. Consequently, when neuroscience research is interpreted as challenging or even invalidating this concept, a number of heated social and ethical debates surface. We undertook a content analysis of media coverage of Libet's et al.'s (Brain 106(Pt 3):623-642, 1983) landmark study, which is frequently interpreted as posing a serious challenge to the existence of free will. Media descriptions of Libet et al.'s experiment provided limited details about the original study. Overall, many media articles reported that Libet et al.'s experiments undermined the existence of free will, despite acknowledging that several methodological limitations had been identified in the literature. A propensity to attribute greater credibility than warranted to neurobiological explanations could be at stake.

  4. LANDMARKS REGARDING THE EXTERNAL PUBLIC AUDIT IN ROMANIA

    Directory of Open Access Journals (Sweden)

    TRINCU-DRĂGUŞIN CRISTINA-PETRINA

    2018-02-01

    Full Text Available This paper falls within the category of those about the external public audit in Romania and is intended to be an investigative approach through which we propose to bring in the light of the scientific reflectors certain significant landmarks in the field, starting from the premise that it is a subject of considerable interest from multiple directions. In the described context, the coordinates of the article focus on the topical elements of the approached field and include conceptual delimitations regarding the external public audit, normative approaches in our country, aspects regarding the organization, functioning and management of the supreme audit institution, the presentation of competencies, the field of application for the activities of the Romanian Court of Accounts, as well as its specific attributions related to the external public audit. At the end of the paper, the conclusions on the debated topic are outlined.

  5. Nocturnal vision and landmark orientation in a tropical halictid bee.

    Science.gov (United States)

    Warrant, Eric J; Kelber, Almut; Gislén, Anna; Greiner, Birgit; Ribi, Willi; Wcislo, William T

    2004-08-10

    Some bees and wasps have evolved nocturnal behavior, presumably to exploit night-flowering plants or avoid predators. Like their day-active relatives, they have apposition compound eyes, a design usually found in diurnal insects. The insensitive optics of apposition eyes are not well suited for nocturnal vision. How well then do nocturnal bees and wasps see? What optical and neural adaptations have they evolved for nocturnal vision? We studied female tropical nocturnal sweat bees (Megalopta genalis) and discovered that they are able to learn landmarks around their nest entrance prior to nocturnal foraging trips and to use them to locate the nest upon return. The morphology and optics of the eye, and the physiological properties of the photoreceptors, have evolved to give Megalopta's eyes almost 30 times greater sensitivity to light than the eyes of diurnal worker honeybees, but this alone does not explain their nocturnal visual behavior. This implies that sensitivity is improved by a strategy of photon summation in time and in space, the latter of which requires the presence of specialized cells that laterally connect ommatidia into groups. First-order interneurons, with significantly wider lateral branching than those found in diurnal bees, have been identified in the first optic ganglion (the lamina ganglionaris) of Megalopta's optic lobe. We believe that these cells have the potential to mediate spatial summation. Despite the scarcity of photons, Megalopta is able to visually orient to landmarks at night in a dark forest understory, an ability permitted by unusually sensitive apposition eyes and neural photon summation.

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

    NARCIS (Netherlands)

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

    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

  7. Automatic generation of 3D statistical shape models with optimal landmark distributions.

    Science.gov (United States)

    Heimann, T; Wolf, I; Meinzer, H-P

    2007-01-01

    To point out the problem of non-uniform landmark placement in statistical shape modeling, to present an improved method for generating landmarks in the 3D case and to propose an unbiased evaluation metric to determine model quality. Our approach minimizes a cost function based on the minimum description length (MDL) of the shape model to optimize landmark correspondences over the training set. In addition to the standard technique, we employ an extended remeshing method to change the landmark distribution without losing correspondences, thus ensuring a uniform distribution over all training samples. To break the dependency of the established evaluation measures generalization and specificity from the landmark distribution, we change the internal metric from landmark distance to volumetric overlap. Redistributing landmarks to an equally spaced distribution during the model construction phase improves the quality of the resulting models significantly if the shapes feature prominent bulges or other complex geometry. The distribution of landmarks on the training shapes is -- beyond the correspondence issue -- a crucial point in model construction.

  8. Design and recognition of artificial landmarks for reliable indoor self-localization of mobile robots

    Directory of Open Access Journals (Sweden)

    Xu Zhong

    2017-02-01

    Full Text Available This article presents a self-localization scheme for indoor mobile robot navigation based on reliable design and recognition of artificial visual landmarks. Each landmark is patterned with a set of concentric circular rings in black and white, which reliably encodes the landmark’s identity under environmental illumination. A mobile robot in navigation uses an onboard camera to capture landmarks in the environment. The landmarks in an image are detected and identified using a bilayer recognition algorithm: A global recognition process initially extracts candidate landmark regions across the whole image and tries to identify enough landmarks; if necessary, a local recognition process locally enhances those unidentified regions of interest influenced by illumination and incompleteness and reidentifies them. The recognized landmarks are used to estimate the position and orientation of the onboard camera in the environment, based on the geometric relationship between the image and environmental frames. The experiments carried out in a real indoor environment show high robustness of the proposed landmark design and recognition scheme to the illumination condition, which leads to reliable and accurate mobile robot localization.

  9. 3D facial landmarks: Inter-operator variability of manual annotation

    DEFF Research Database (Denmark)

    Fagertun, Jens; Harder, Stine; Rosengren, Anders

    2014-01-01

    Background Manual annotation of landmarks is a known source of variance, which exist in all fields of medical imaging, influencing the accuracy and interpretation of the results. However, the variability of human facial landmarks is only sparsely addressed in the current literature as opposed to ...

  10. Looking beyond the Boundaries: Time to Put Landmarks Back on the Cognitive Map?

    Science.gov (United States)

    Lew, Adina R.

    2011-01-01

    Since the proposal of Tolman (1948) that mammals form maplike representations of familiar environments, cognitive map theory has been at the core of debates on the fundamental mechanisms of animal learning and memory. Traditional formulations of cognitive map theory emphasize relations between landmarks and between landmarks and goal locations as…

  11. Uniportal anatomic combined unusual segmentectomies.

    Science.gov (United States)

    González-Rivas, Diego; Lirio, Francisco; Sesma, Julio

    2017-01-01

    Nowadays, sublobar anatomic resections are gaining momentum as a valid alternative for early stage lung cancer. Despite being technically demanding, anatomic segmentectomies can be performed by uniportal video-assisted thoracic surgery (VATS) approach to combine the benefits of minimally invasiveness with the maximum lung sparing. This procedure can be even more complex if a combined resection of multiple segments from different lobes has to be done. Here we report five cases of combined and unusual segmentectomies done by the same experienced surgeon in high volume institutions to show uniportal VATS is a feasible approach for these complex resections and to share an excellent educational resource.

  12. Competition between landmarks in spatial learning: the role of proximity to the goal.

    Science.gov (United States)

    Chamizo, V D; Manteiga, R D; Rodrigo, T; Mackintosh, N J

    2006-01-10

    In two experiments, rats were trained to find a hidden platform in a Morris pool in the presence of two landmarks. Landmark B was present on all training trials, on half the trials accompanied by landmark A, on the remainder by landmark C. For rats in Group Bn, B was near the location of the platform; for those in Group Bf, B was far from the platform. Group Bn performed better than Group Bf on test trials to B alone, but significantly worse on test trials to a new configuration formed by A and C. Thus, the spatial proximity of B to the platform affected not only how well it could be used to locate the platform, but also its ability to prevent learning about other landmarks.

  13. The Fate of Anatomical Collections

    NARCIS (Netherlands)

    Knoeff, Rina; Zwijnenberg, Robert

    Almost every medical faculty possesses anatomical and/or pathological collections: human and animal preparations, wax- and other models, as well as drawings, photographs, documents and archives relating to them. In many institutions these collections are well-preserved, but in others they are poorly

  14. Normal anatomical measurements in cervical computerized tomography

    International Nuclear Information System (INIS)

    Zaunbauer, W.; Daepp, S.; Haertel, M.

    1985-01-01

    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. (orig.) [de

  15. Landmark-based augmented reality system for paranasal and transnasal endoscopic surgeries.

    Science.gov (United States)

    Thoranaghatte, Ramesh; Garcia, Jaime; Caversaccio, Marco; Widmer, Daniel; Gonzalez Ballester, Miguel A; Nolte, Lutz-P; Zheng, Guoyan

    2009-12-01

    In this paper we present a landmark-based augmented reality (AR) endoscope system for endoscopic paranasal and transnasal surgeries along with fast and automatic calibration and registration procedures for the endoscope. Preoperatively the surgeon selects natural landmarks or can define new landmarks in CT volume. These landmarks are overlaid, after proper registration of preoperative CT to the patient, on the endoscopic video stream. The specified name of the landmark, along with selected colour and its distance from the endoscope tip, is also augmented. The endoscope optics are calibrated and registered by fast and automatic methods. Accuracy of the system is evaluated in a metallic grid and cadaver set-up. Root mean square (RMS) error of the system is 0.8 mm in a controlled laboratory set-up (metallic grid) and was 2.25 mm during cadaver studies. A novel landmark-based AR endoscope system is implemented and its accuracy is evaluated. Augmented landmarks will help the surgeon to orientate and navigate the surgical field. Studies prove the capability of the system for the proposed application. Further clinical studies are planned in near future. Copyright (c) 2009 John Wiley & Sons, Ltd.

  16. a Landmark Extraction Method Associated with Geometric Features and Location Distribution

    Science.gov (United States)

    Zhang, W.; Li, J.; Wang, Y.; Xiao, Y.; Liu, P.; Zhang, S.

    2018-04-01

    Landmark plays an important role in spatial cognition and spatial knowledge organization. Significance measuring model is the main method of landmark extraction. It is difficult to take account of the spatial distribution pattern of landmarks because that the significance of landmark is built in one-dimensional space. In this paper, we start with the geometric features of the ground object, an extraction method based on the target height, target gap and field of view is proposed. According to the influence region of Voronoi Diagram, the description of target gap is established to the geometric representation of the distribution of adjacent targets. Then, segmentation process of the visual domain of Voronoi K order adjacent is given to set up target view under the multi view; finally, through three kinds of weighted geometric features, the landmarks are identified. Comparative experiments show that this method has a certain coincidence degree with the results of traditional significance measuring model, which verifies the effectiveness and reliability of the method and reduces the complexity of landmark extraction process without losing the reference value of landmark.

  17. Visual cues for the retrieval of landmark memories by navigating wood ants.

    Science.gov (United States)

    Harris, Robert A; Graham, Paul; Collett, Thomas S

    2007-01-23

    Even on short routes, ants can be guided by multiple visual memories. We investigate here the cues controlling memory retrieval as wood ants approach a one- or two-edged landmark to collect sucrose at a point along its base. In such tasks, ants store the desired retinal position of landmark edges at several points along their route. They guide subsequent trips by retrieving the appropriate memory and moving to bring the edges in the scene toward the stored positions. The apparent width of the landmark turns out to be a powerful cue for retrieving the desired retinal position of a landmark edge. Two other potential cues, the landmark's apparent height and the distance that the ant walks, have little effect on memory retrieval. A simple model encapsulates these conclusions and reproduces the ants' routes in several conditions. According to this model, the ant stores a look-up table. Each entry contains the apparent width of the landmark and the desired retinal position of vertical edges. The currently perceived width provides an index for retrieving the associated stored edge positions. The model accounts for the population behavior of ants and the idiosyncratic training routes of individual ants. Our results imply binding between the edge of a shape and its width and, further, imply that assessing the width of a shape does not depend on the presence of any particular local feature, such as a landmark edge. This property makes the ant's retrieval and guidance system relatively robust to edge occlusions.

  18. Landmark navigation and autonomous landing approach with obstacle detection for aircraft

    Science.gov (United States)

    Fuerst, Simon; Werner, Stefan; Dickmanns, Dirk; Dickmanns, Ernst D.

    1997-06-01

    A machine perception system for aircraft and helicopters using multiple sensor data for state estimation is presented. By combining conventional aircraft sensor like gyros, accelerometers, artificial horizon, aerodynamic measuring devices and GPS with vision data taken by conventional CCD-cameras mounted on a pan and tilt platform, the position of the craft can be determined as well as the relative position to runways and natural landmarks. The vision data of natural landmarks are used to improve position estimates during autonomous missions. A built-in landmark management module decides which landmark should be focused on by the vision system, depending on the distance to the landmark and the aspect conditions. More complex landmarks like runways are modeled with different levels of detail that are activated dependent on range. A supervisor process compares vision data and GPS data to detect mistracking of the vision system e.g. due to poor visibility and tries to reinitialize the vision system or to set focus on another landmark available. During landing approach obstacles like trucks and airplanes can be detected on the runway. The system has been tested in real-time within a hardware-in-the-loop simulation. Simulated aircraft measurements corrupted by noise and other characteristic sensor errors have been fed into the machine perception system; the image processing module for relative state estimation was driven by computer generated imagery. Results from real-time simulation runs are given.

  19. 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

  20. Practical landmarks for visual field disability in glaucoma.

    Science.gov (United States)

    Saunders, Luke J; Russell, Richard A; Crabb, David P

    2012-09-01

    To assess whether mean deviation (MD) from automated perimetry is related to the visual field (VF) component for legal fitness to drive (LFTD) in glaucoma patients. Monocular 24-2 VFs of 2604 patients with bilateral VF damage were retrospectively investigated. Integrated visual fields were calculated and used as a surrogate to assess LFTD according to current UK driving licence criteria. The better eye MD (BEMD), worse eye MD (WEMD) and a measure utilising MD of both eyes were compared, to assess respective diagnostic capabilities to predict LFTD (using the integrated visual field surrogate test as the gold standard) and a 'Probability of Failure' (PoF) for various defect levels was calculated. BEMD appears to be a good predictor of the VF component for a patient's LFTD (receiver operating characteristic area under the curve: 96.2%); MDs from both eyes offered no significant extra diagnostic power (area under the curve: 96.4%). PoF for BEMD thresholds of ≤-10 dB and ≤-14 dB were 70 (95% CI 66% to 74%) and 92% (87% to 95%), respectively. There is a strong relationship between BEMD and a patient's LFTD. PoF values for LFTD associated with readily available MD values provide practical landmarks for VF disability in glaucoma.

  1. Unification of Sinonasal Anatomical Terminology

    Directory of Open Access Journals (Sweden)

    Voegels, Richard Louis

    2015-07-01

    Full Text Available The advent of endoscopy and computed tomography at the beginning of the 1980s brought to rhinology a revival of anatomy and physiology study. In 1994, the International Conference of Sinus Disease was conceived because the official “Terminologia Anatomica”[1] had little information on the detailed sinonasal anatomy. In addition, there was a lack of uniformity of terminology and definitions. After 20 years, a new conference has been held. The need to use the same terminology led to the publication by the European Society of Rhinology of the “European Position Paper on the Anatomical Terminology of the Internal Nose and Paranasal Sinuses,” that can be accessed freely at www.rhinologyjournal.com. Professor Valerie Lund et al[2] wrote this document reviewing the anatomical terms, comparing to the “Terminology Anatomica” official order to define the structures without eponyms, while respecting the embryological development and especially universalizing and simplifying the terms. A must-read! The text's purpose lies beyond the review of anatomical terminology to universalize the language used to refer to structures of the nasal and paranasal cavities. Information about the anatomy, based on extensive review of the current literature, is arranged in just over 50 pages, which are direct and to the point. The publication may be pleasant reading for learners and teachers of rhinology. This text can be a starting point and enables searching the universal terminology used in Brazil, seeking to converge with this new European proposal for a nomenclature to help us communicate with our peers in Brazil and the rest of the world. The original text of the European Society of Rhinology provides English terms that avoided the use of Latin, and thus fall beyond several national personal translations. It would be admirable if we created our own cross-cultural adaptation of this new suggested anatomical terminology.

  2. [Cellular subcutaneous tissue. Anatomic observations].

    Science.gov (United States)

    Marquart-Elbaz, C; Varnaison, E; Sick, H; Grosshans, E; Cribier, B

    2001-11-01

    We showed in a companion paper that the definition of the French "subcutaneous cellular tissue" considerably varied from the 18th to the end of the 20th centuries and has not yet reached a consensus. To address the anatomic reality of this "subcutaneous cellular tissue", we investigated the anatomic structures underlying the fat tissue in normal human skin. Sixty specimens were excised from the surface to the deep structures (bone, muscle, cartilage) on different body sites of 3 cadavers from the Institut d'Anatomie Normale de Strasbourg. Samples were paraffin-embedded, stained and analysed with a binocular microscope taking x 1 photographs. Specimens were also excised and fixed after subcutaneous injection of Indian ink, after mechanic tissue splitting and after performing artificial skin folds. The aspects of the deep parts of the skin greatly varied according to their anatomic localisation. Below the adipose tissue, we often found a lamellar fibrous layer which extended from the interlobular septa and contained horizontally distributed fat cells. No specific tissue below the hypodermis was observed. Artificial skin folds concerned either exclusively the dermis, when they were superficial or included the hypodermis, but no specific structure was apparent in the center of the fold. India ink diffused to the adipose tissue, mainly along the septa, but did not localise in a specific subcutaneous compartment. This study shows that the histologic aspects of the deep part of the skin depend mainly on the anatomic localisation. Skin is composed of epidermis, dermis and hypodermis and thus the hypodermis can not be considered as being "subcutaneous". A difficult to individualise, fibrous lamellar structure in continuity with the interlobular septa is often found under the fat lobules. This structure is a cleavage line, as is always the case with loose connective tissues, but belongs to the hypodermis (i.e. fat tissue). No specific tissue nor any virtual space was

  3. Inexpensive anatomical trainer for bronchoscopy.

    Science.gov (United States)

    Di Domenico, Stefano; Simonassi, Claudio; Chessa, Leonardo

    2007-08-01

    Flexible fiberoptic bronchoscopy is an indispensable tool for optimal management of intensive care unit patients. However, the acquisition of sufficient training in bronchoscopy is not straightforward during residency, because of technical and ethical problems. Moreover, the use of commercial simulators is limited by their high cost. In order to overcome these limitations, we realized a low-cost anatomical simulator to acquire and maintain the basic skill to perform bronchoscopy in ventilated patients. We used 1.5 mm diameter iron wire to construct the bronchial tree scaffold; glazier-putty was applied to create the anatomical model. The model was covered by several layers of newspaper strips previously immersed in water and vinilic glue. When the model completely dried up, it was detached from the scaffold by cutting it into six pieces, it was reassembled, painted and fitted with an endotracheal tube. We used very cheap material and the final cost was euro16. The trainer resulted in real-scale and anatomically accurate, with appropriate correspondence on endoscopic view between model and patients. All bronchial segments can be explored and easily identified by endoscopic and external vision. This cheap simulator is a valuable tool for practicing, particularly in a hospital with limited resources for medical training.

  4. Cluster-based upper body marker models for three-dimensional kinematic analysis: Comparison with an anatomical model and reliability analysis.

    Science.gov (United States)

    Boser, Quinn A; Valevicius, Aïda M; Lavoie, Ewen B; Chapman, Craig S; Pilarski, Patrick M; Hebert, Jacqueline S; Vette, Albert H

    2018-04-27

    Quantifying angular joint kinematics of the upper body is a useful method for assessing upper limb function. Joint angles are commonly obtained via motion capture, tracking markers placed on anatomical landmarks. This method is associated with limitations including administrative burden, soft tissue artifacts, and intra- and inter-tester variability. An alternative method involves the tracking of rigid marker clusters affixed to body segments, calibrated relative to anatomical landmarks or known joint angles. The accuracy and reliability of applying this cluster method to the upper body has, however, not been comprehensively explored. Our objective was to compare three different upper body cluster models with an anatomical model, with respect to joint angles and reliability. Non-disabled participants performed two standardized functional upper limb tasks with anatomical and cluster markers applied concurrently. Joint angle curves obtained via the marker clusters with three different calibration methods were compared to those from an anatomical model, and between-session reliability was assessed for all models. The cluster models produced joint angle curves which were comparable to and highly correlated with those from the anatomical model, but exhibited notable offsets and differences in sensitivity for some degrees of freedom. Between-session reliability was comparable between all models, and good for most degrees of freedom. Overall, the cluster models produced reliable joint angles that, however, cannot be used interchangeably with anatomical model outputs to calculate kinematic metrics. Cluster models appear to be an adequate, and possibly advantageous alternative to anatomical models when the objective is to assess trends in movement behavior. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. 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.

  6. IAEA Director General welcomes landmark convention to combat nuclear terrorism

    International Nuclear Information System (INIS)

    2005-01-01

    Full text: IAEA Director General Mohamed ElBaradei welcomed the adoption of an International convention against nuclear terrorism. 'This is a landmark achievement which will bolster global efforts to combat nuclear terrorism,' Dr. ElBaradei said. 'It will be a key part of international efforts to prevent terrorists from gaining access to nuclear weapons'. The United Nations General Assembly adopted the convention, The International Convention for the Suppression of Acts of Nuclear Terrorism, on 13 April 2005. The Convention strengthens the global legal framework to counter terrorist threats. Based on a proposal by the Russian Federation in 1998, the Convention focuses on criminal offences related to nuclear terrorism and covers a broad range of possible targets, including nuclear reactors as well as nuclear material and radioactive substances. Under its provisions, alleged offenders - for example any individual or group that unlawfully and intentionally possesses or uses radioactive material with the intent to cause harm - must be either extradited or prosecuted. States are also encouraged to cooperate with each other in connection with criminal investigations and extradition proceedings. The Convention further requires that any seized nuclear or radiological material be held in accordance with IAEA safeguards, and handled in keeping with the IAEA's health, safety and physical protection standards. Dr. ElBaradei also recalled that the Agency is in the process of amending the Convention on the Physical Protection of Nuclear Material, in order to broaden its scope, and in so doing, strengthen the current legal framework for securing nuclear material against illicit uses. A conference will be held from 4 to 8 July in Vienna to consider and adopt the amendments. The Convention opens for signature in September this year. Dr ElBaradei urged all States to 'sign and ratify the Convention without delay so nuclear terrorism will have no chance'. (IAEA)

  7. Influence of Landmarks on Wayfinding and Brain Connectivity in Immersive Virtual Reality Environment

    Directory of Open Access Journals (Sweden)

    Greeshma Sharma

    2017-07-01

    Full Text Available Spatial navigation is influenced by landmarks, which are prominent visual features in the environment. Although previous research has focused on finding advantages of landmarks on wayfinding via experimentation; however, less attention has been given to identifying the key attributes of landmarks that facilitate wayfinding, including the study of neural correlates (involving electroencephalogram, EEG analyses. In this paper, we combine behavioral measures, virtual environment, and EEG signal-processing to provide a holistic investigation about the influence of landmarks on performance during navigation in a maze-like environment. In an experiment, participants were randomly divided into two conditions, Landmark-enriched (LM+; N = 17 and Landmark-devoid (LM-; N = 18, and asked to navigate from an initial location to a goal location in a maze. In the LM+ condition, there were landmarks placed at certain locations, which participants could use for wayfinding in the maze. However, in the LM- condition, such landmarks were not present. Beyond behavioral analyses of data, analyses were carried out of the EEG data collected using a 64-channel device. Results revealed that participants took less time and committed fewer errors in navigating the maze in the LM+ condition compared to the LM- condition. EEG analyses of the data revealed that the left-hemispheric activation was more prominent in the LM+ condition compared to the LM- condition. The event-related desynchronization/synchronization (ERD/ERS of the theta frequency band, revealed activation in the left posterior inferior and superior regions in the LM+ condition compared to the LM- condition, suggesting an occurrence of an object-location binding in the LM+ condition along with spatial transformation between representations. Moreover, directed transfer function method, which measures information flow between two regions, showed a higher number of active channels in the LM- condition compared to

  8. Corrective surgery for canine patellar luxation in 75 cases (107 limbs): landmark for block recession

    OpenAIRE

    Mitsuhiro Isaka; Masahiko Befu; Nami Matsubara; Mayuko Ishikawa; Yurie Arase; Toshiyuki Tsuyama; Akiko Doi; Shinichi Namba

    2014-01-01

    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, bod...

  9. 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

  10. Efficacy of navigation may be influenced by retrosplenial cortex-mediated learning of landmark stability.

    Science.gov (United States)

    Auger, Stephen D; Zeidman, Peter; Maguire, Eleanor A

    2017-09-01

    Human beings differ considerably in their ability to orient and navigate within the environment, but it has been difficult to determine specific causes of these individual differences. Permanent, stable landmarks are thought to be crucial for building a mental representation of an environment. Poor, compared to good, navigators have been shown to have difficulty identifying permanent landmarks, with a concomitant reduction in functional MRI (fMRI) activity in the retrosplenial cortex. However, a clear association between navigation ability and the learning of permanent landmarks has not been established. Here we tested for such a link. We had participants learn a virtual reality environment by repeatedly moving through it during fMRI scanning. The environment contained landmarks of which participants had no prior experience, some of which remained fixed in their locations while others changed position each time they were seen. After the fMRI learning phase, we divided participants into good and poor navigators based on their ability to find their way in the environment. The groups were closely matched on a range of cognitive and structural brain measures. Examination of the learning phase during scanning revealed that, while good and poor navigators learned to recognise the environment's landmarks at a similar rate, poor navigators were impaired at registering whether landmarks were stable or transient, and this was associated with reduced engagement of the retrosplenial cortex. Moreover, a mediation analysis showed that there was a significant effect of landmark permanence learning on navigation performance mediated through retrosplenial cortex activity. We conclude that a diminished ability to process landmark permanence may be a contributory factor to sub-optimal navigation, and could be related to the level of retrosplenial cortex engagement. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  11. 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

  12. 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

  13. ExpNet: Landmark-Free, Deep, 3D Facial Expressions

    OpenAIRE

    Chang, Feng-Ju; Tran, Anh Tuan; Hassner, Tal; Masi, Iacopo; Nevatia, Ram; Medioni, Gerard

    2018-01-01

    We describe a deep learning based method for estimating 3D facial expression coefficients. Unlike previous work, our process does not relay on facial landmark detection methods as a proxy step. Recent methods have shown that a CNN can be trained to regress accurate and discriminative 3D morphable model (3DMM) representations, directly from image intensities. By foregoing facial landmark detection, these methods were able to estimate shapes for occluded faces appearing in unprecedented in-the-...

  14. Anatomical study of the pigs temporal bone by microdissection.

    Science.gov (United States)

    Garcia, Leandro de Borborema; Andrade, José Santos Cruz de; Testa, José Ricardo Gurgel

    2014-01-01

    Initial study of the pig`s temporal bone anatomy in order to enable a new experimental model in ear surgery. Dissection of five temporal bones of Sus scrofa pigs obtained from UNIFESP - Surgical Skills Laboratory, removed with hole saw to avoid any injury and stored in formaldehyde 10% for better conservation. The microdissection in all five temporal bone had the following steps: inspection of the outer part, external canal and tympanic membrane microscopy, mastoidectomy, removal of external ear canal and tympanic membrane, inspection of ossicular chain and middle ear. Anatomically it is located at the same position than in humans. Some landmarks usually found in humans are missing. The tympanic membrane of the pig showed to be very similar to the human, separating the external and the middle ear. The middle ear`s appearance is very similar than in humans. The ossicular chain is almost exactly the same, as well as the facial nerve, showing the same relationship with the lateral semicircular canal. The temporal bone of the pigs can be used as an alternative for training in ear surgery, especially due the facility to find it and its similarity with temporal bone of the humans.

  15. Influence of Landmarks on Spatial Memory in Short-nosed Fruit Bat, Cynopterus sphinx.

    Science.gov (United States)

    Zeng, Yu; Zhang, Xin-Wen; Zhu, Guang-Jian; Gong, Yan-Yan; Yang, Jian; Zhang, Li-Biao

    2010-04-01

    In order to study the relationship between landmarks and spatial memory in short-nosed fruit bat, Cynopterus sphinx (Megachiroptera, Pteropodidae), we simulated a foraging environment in the laboratory. Different landmarks were placed to gauge the spatial memory of C. sphinx. We changed the number of landmarks every day with 0 landmarks again on the fifth day (from 0, 2, 4, 8 to 0). Individuals from the control group were exposed to the identical artificial foraging environment, but without landmarks. The results indicated that there was significant correlation between the time of the first foraging and the experimental days in both groups (Pearson Correlation: experimental group: r=-0.593, P0.05), but there was significant correlation between the success rates of foraging and the experimental days in the control groups (Pearson Correlation: r=0.445, P0.05); also, there was no significant difference in success rates of foraging between these two groups (GLM: F(0.05,1 )=0.849, P>0.05). The results of our experiment suggest that spatial memory in C. sphinx was formed gradually and that the placed landmarks appeared to have no discernable effects on the memory of the foraging space.

  16. Cephalometric landmark detection in dental x-ray images using convolutional neural networks

    Science.gov (United States)

    Lee, Hansang; Park, Minseok; Kim, Junmo

    2017-03-01

    In dental X-ray images, an accurate detection of cephalometric landmarks plays an important role in clinical diagnosis, treatment and surgical decisions for dental problems. In this work, we propose an end-to-end deep learning system for cephalometric landmark detection in dental X-ray images, using convolutional neural networks (CNN). For detecting 19 cephalometric landmarks in dental X-ray images, we develop a detection system using CNN-based coordinate-wise regression systems. By viewing x- and y-coordinates of all landmarks as 38 independent variables, multiple CNN-based regression systems are constructed to predict the coordinate variables from input X-ray images. First, each coordinate variable is normalized by the length of either height or width of an image. For each normalized coordinate variable, a CNN-based regression system is trained on training images and corresponding coordinate variable, which is a variable to be regressed. We train 38 regression systems with the same CNN structure on coordinate variables, respectively. Finally, we compute 38 coordinate variables with these trained systems from unseen images and extract 19 landmarks by pairing the regressed coordinates. In experiments, the public database from the Grand Challenges in Dental X-ray Image Analysis in ISBI 2015 was used and the proposed system showed promising performance by successfully locating the cephalometric landmarks within considerable margins from the ground truths.

  17. The test-retest reliability of anatomical co-ordinate axes definition for the quantification of lower extremity kinematics during running.

    Science.gov (United States)

    Sinclair, Jonathan; Taylor, Paul John; Greenhalgh, Andrew; Edmundson, Christopher James; Brooks, Darrell; Hobbs, Sarah Jane

    2012-12-01

    Three-dimensional (3-D) kinematic analyses are used widely in both sport and clinical examinations. However, this procedure depends on reliable palpation of anatomical landmarks and mal-positioning of markers between sessions may result in improperly defined segment co-ordinate system axes which will produce in-consistent joint rotations. This had led some to question the efficacy of this technique. The aim of the current investigation was to assess the reliability of the anatomical frame definition when quantifying 3-D kinematics of the lower extremities during running. Ten participants completed five successful running trials at 4.0 m·s(-1) ± 5%. 3-D angular joint kinematics parameters from the hip, knee and ankle were collected using an eight camera motion analysis system. Two static calibration trials were captured. The first (test) was conducted prior to the running trials following which anatomical landmarks were removed. The second was obtained following completion of the running trials where anatomical landmarks were re-positioned (retest). Paired samples t-tests were used to compare 3-D kinematic parameters quantified using the two static trials, and intraclass correlations were employed to examine the similarities between the sagittal, coronal and transverse plane waveforms. The results indicate that no significant (p>0.05) differences were found between test and retest 3-D kinematic parameters and strong (R(2)≥0.87) correlations were observed between test and retest waveforms. Based on the results obtained from this investigation, it appears that the anatomical co-ordinate axes of the lower extremities can be defined reliably thus confirming the efficacy of studies using this technique.

  18. Utilization management in anatomic pathology.

    Science.gov (United States)

    Lewandrowski, Kent; Black-Schaffer, Steven

    2014-01-01

    There is relatively little published literature concerning utilization management in anatomic pathology. Nonetheless there are many utilization management opportunities that currently exist and are well recognized. Some of these impact only the cost structure within the pathology department itself whereas others reduce charges for third party payers. Utilization management may result in medical legal liabilities for breaching the standard of care. For this reason it will be important for pathology professional societies to develop national utilization guidelines to assist individual practices in implementing a medically sound approach to utilization management. © 2013.

  19. ArthroBroström Lateral Ankle Stabilization Technique: An Anatomic Study.

    Science.gov (United States)

    Acevedo, Jorge I; Ortiz, Cristian; Golano, Pau; Nery, Caio

    2015-10-01

    Arthroscopic ankle lateral ligament repair techniques have recently been developed and biomechanically as well as clinically validated. Although there has been 1 anatomic study relating suture and anchor proximity to anatomic structures, none has evaluated the ArthroBroström procedure. To evaluate the proximity of anatomic structures for the ArthroBroström lateral ankle ligament stabilization technique and to define ideal landmarks and "safe zones" for this repair. Descriptive laboratory study. Ten human cadaveric ankle specimens (5 matched pairs) were screened for the study. All specimens underwent arthroscopic lateral ligament repair according to the previously described ArthroBroström technique with 2 suture anchors in the fibula. Three cadaveric specimens were used to test the protocol, and 7 were dissected to determine the proximity of anatomic structures. Several distances were measured, including those of different anatomic structures to the suture knots, to determine the "safe zones." Measurements were obtained by 2 separate observers, and statistical analysis was performed. None of the specimens revealed entrapment by either of the suture knots of the critical anatomic structures, including the superficial peroneal nerve (SPN), sural nerve, peroneus tertius tendon, peroneus brevis tendon, or peroneus longus tendon. The internervous safe zone between the intermediate branch of the SPN and sural nerve was a mean of 51 mm (range, 39-64 mm). The intertendinous safe zone between the peroneus tertius and peroneus brevis was a mean of 43 mm (range, 37-49 mm). On average, a 20-mm (range, 8-36 mm) safe distance was maintained from the most medial suture to the intermediate branch of the SPN. The amount of inferior extensor retinaculum (IER) grasped by either suture knot varied from 0 to 12 mm, with 86% of repairs including the retinaculum. The results indicate that there is a relatively wide internervous and intertendinous safe zone when performing the Arthro

  20. 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.

  1. Brain anatomical network and intelligence.

    Directory of Open Access Journals (Sweden)

    Yonghui Li

    2009-05-01

    Full Text Available Intuitively, higher intelligence might be assumed to correspond to more efficient information transfer in the brain, but no direct evidence has been reported from the perspective of brain networks. In this study, we performed extensive analyses to test the hypothesis that individual differences in intelligence are associated with brain structural organization, and in particular that higher scores on intelligence tests are related to greater global efficiency of the brain anatomical network. We constructed binary and weighted brain anatomical networks in each of 79 healthy young adults utilizing diffusion tensor tractography and calculated topological properties of the networks using a graph theoretical method. Based on their IQ test scores, all subjects were divided into general and high intelligence groups and significantly higher global efficiencies were found in the networks of the latter group. Moreover, we showed significant correlations between IQ scores and network properties across all subjects while controlling for age and gender. Specifically, higher intelligence scores corresponded to a shorter characteristic path length and a higher global efficiency of the networks, indicating a more efficient parallel information transfer in the brain. The results were consistently observed not only in the binary but also in the weighted networks, which together provide convergent evidence for our hypothesis. Our findings suggest that the efficiency of brain structural organization may be an important biological basis for intelligence.

  2. Anatomic partial nephrectomy: technique evolution.

    Science.gov (United States)

    Azhar, Raed A; Metcalfe, Charles; Gill, Inderbir S

    2015-03-01

    Partial nephrectomy provides equivalent long-term oncologic and superior functional outcomes as radical nephrectomy for T1a renal masses. Herein, we review the various vascular clamping techniques employed during minimally invasive partial nephrectomy, describe the evolution of our partial nephrectomy technique and provide an update on contemporary thinking about the impact of ischemia on renal function. Recently, partial nephrectomy surgical technique has shifted away from main artery clamping and towards minimizing/eliminating global renal ischemia during partial nephrectomy. Supported by high-fidelity three-dimensional imaging, novel anatomic-based partial nephrectomy techniques have recently been developed, wherein partial nephrectomy can now be performed with segmental, minimal or zero global ischemia to the renal remnant. Sequential innovations have included early unclamping, segmental clamping, super-selective clamping and now culminating in anatomic zero-ischemia surgery. By eliminating 'under-the-gun' time pressure of ischemia for the surgeon, these techniques allow an unhurried, tightly contoured tumour excision with point-specific sutured haemostasis. Recent data indicate that zero-ischemia partial nephrectomy may provide better functional outcomes by minimizing/eliminating global ischemia and preserving greater vascularized kidney volume. Contemporary partial nephrectomy includes a spectrum of surgical techniques ranging from conventional-clamped to novel zero-ischemia approaches. Technique selection should be tailored to each individual case on the basis of tumour characteristics, surgical feasibility, surgeon experience, patient demographics and baseline renal function.

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

    International Nuclear Information System (INIS)

    Shahidi, Shoaleh; Bahrampour, Ehsan; Soltanimehr, Elham; Zamani, Ali; Oshagh, Morteza; Moattari, Marzieh; Mehdizadeh, Alireza

    2014-01-01

    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

  4. Landmark memories are more robust when acquired at the nest site than en route: experiments in desert ants.

    Science.gov (United States)

    Bisch-Knaden, Sonja; Wehner, Rüdiger

    2003-03-01

    Foraging desert ants, Cataglyphis fortis, encounter different sequences of visual landmarks while navigating by path integration. This paper explores the question whether the storage of landmark information depends on the context in which the landmarks are learned during an ant's foraging journey. Two experimental set-ups were designed in which the ants experienced an artificial landmark panorama that was placed either around the nest entrance (nest marks) or along the vector route leading straight towards the feeder (route marks). The two training paradigms resulted in pronounced differences in the storage characteristics of the acquired landmark information: memory traces of nest marks were much more robust against extinction and/or suppression than those of route marks. In functional terms, this result is in accord with the observation that desert ants encounter new route marks during every foraging run but always pass the same landmarks when approaching the nest entrance.

  5. An anatomic study of nipple position and areola size in Asian men.

    Science.gov (United States)

    Kasai, Shogo; Shimizu, Yusuke; Nagasao, Tomohisa; Ohnishi, Fumio; Minabe, Toshiharu; Momosawa, Akira; Kishi, Kazuo

    2015-02-01

    In planning gender-reassignment surgery for biological women and treating men with gynecomastia, surgeons must have a thorough understanding of anatomically correct nipple positions and appropriate areola sizes in men. The authors sought to determine whether body height or body mass index (BMI) affects nipple position or areola size in men. Anatomic measurements of the nipples and areolae of 50 Japanese men were obtained. A relative coordinate system was defined, where the medial-lateral and superior-inferior positions of the nipple were quantitatively indicated by distance ratios between anatomic landmarks. Nipple positions were evaluated for each patient by referring to this coordinate system, and the positions were compared between groups categorized by body height or BMI. Nipple position was not significantly affected by body height. However, the nipple tended to be located more laterally in participants with higher BMI. The vertical nipple position differed between standing and supine positions. Tall men had larger areolae than short men; however, areola size did not differ with respect to BMI. Nipple position and areola size vary by body shape. Consideration of the differences is recommended when performing procedures such as female-to-male gender-reassignment surgery or correction of gynecomastia. © 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

  6. 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.

  7. Gender differences in the use of external landmarks versus spatial representations updated by self-motion.

    Science.gov (United States)

    Lambrey, Simon; Berthoz, Alain

    2007-09-01

    Numerous data in the literature provide evidence for gender differences in spatial orientation. In particular, it has been suggested that spatial representations of large-scale environments are more accurate in terms of metric information in men than in women but are richer in landmark information in women than in men. One explanatory hypothesis is that men and women differ in terms of navigational processes they used in daily life. The present study investigated this hypothesis by distinguishing two navigational processes: spatial updating by self-motion and landmark-based orientation. Subjects were asked to perform a pointing task in three experimental conditions, which differed in terms of reliability of the external landmarks that could be used. Two groups of subjects were distinguished, a mobile group and an immobile group, in which spatial updating of environmental locations did not have the same degree of importance for the correct performance of the pointing task. We found that men readily relied on an internal egocentric representation of where landmarks were expected to be in order to perform the pointing task, a representation that could be updated during self-motion (spatial updating). In contrast, women seemed to take their bearings more readily on the basis of the stable landmarks of the external world. We suggest that this gender difference in spatial orientation is not due to differences in information processing abilities but rather due to the differences in higher level strategies.

  8. Automated landmark extraction for orthodontic measurement of faces using the 3-camera photogrammetry methodology.

    Science.gov (United States)

    Deli, Roberto; Di Gioia, Eliana; Galantucci, Luigi Maria; Percoco, Gianluca

    2010-01-01

    To set up a three-dimensional photogrammetric scanning system for precise landmark measurements, without any physical contact, using a low-cost and noninvasive digital photogrammetric solution, for supporting several necessity in clinical orthodontics and/or surgery diagnosis. Thirty coded targets were directly applied onto the subject's face on the soft tissue landmarks, and then, 3 simultaneous photos were acquired using photogrammetry, at room light conditions. For comparison, a dummy head was digitized both with a photogrammetric technique and with the laser scanner Minolta Vivid 910i (Konica Minolta, Tokyo, Japan). The precise measurement of the landmarks is ranged between 0.017 and 0.029 mm. The system automatically measures spatial position of face landmarks, from which distances and angles can be obtained. The facial measurements were compared with those done using laser scanning and manual caliper. The adopted method gives higher precision than the others (0.022-mm mean value on points and 0.038-mm mean value on linear distances on a dummy head), is simple, and can be used easily as a standard routine. The study demonstrated the validity of photogrammetry for accurate digitization of human face landmarks. This research points out the potential of this low-cost photogrammetry approach for medical digitization.

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

    Science.gov (United States)

    Kim, Jae Ha

    2016-01-01

    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. PMID:27648322

  10. Comparison of three methods for registration of abdominal/pelvic volume data sets from functional-anatomic scans

    Science.gov (United States)

    Mahmoud, Faaiza; Ton, Anthony; Crafoord, Joakim; Kramer, Elissa L.; Maguire, Gerald Q., Jr.; Noz, Marilyn E.; Zeleznik, Michael P.

    2000-06-01

    The purpose of this work was to evaluate three volumetric registration methods in terms of technique, user-friendliness and time requirements. CT and SPECT data from 11 patients were interactively registered using: a 3D method involving only affine transformation; a mixed 3D - 2D non-affine (warping) method; and a 3D non-affine (warping) method. In the first method representative isosurfaces are generated from the anatomical images. Registration proceeds through translation, rotation, and scaling in all three space variables. Resulting isosurfaces are fused and quantitative measurements are possible. In the second method, the 3D volumes are rendered co-planar by performing an oblique projection. Corresponding landmark pairs are chosen on matching axial slice sets. A polynomial warp is then applied. This method has undergone extensive validation and was used to evaluate the results. The third method employs visualization tools. The data model allows images to be localized within two separate volumes. Landmarks are chosen on separate slices. Polynomial warping coefficients are generated and data points from one volume are moved to the corresponding new positions. The two landmark methods were the least time consuming (10 to 30 minutes from start to finish), but did demand a good knowledge of anatomy. The affine method was tedious and required a fair understanding of 3D geometry.

  11. Automatic Craniomaxillofacial Landmark Digitization via Segmentation-guided Partially-joint Regression Forest Model and Multi-scale Statistical Features

    Science.gov (United States)

    Zhang, Jun; Gao, Yaozong; Wang, Li; Tang, Zhen; Xia, James J.; Shen, Dinggang

    2016-01-01

    Objective The goal of this paper is to automatically digitize craniomaxillofacial (CMF) landmarks efficiently and accurately from cone-beam computed tomography (CBCT) images, by addressing the challenge caused by large morphological variations across patients and image artifacts of CBCT images. Methods We propose a Segmentation-guided Partially-joint Regression Forest (S-PRF) model to automatically digitize CMF landmarks. In this model, a regression voting strategy is first adopted to localize each landmark by aggregating evidences from context locations, thus potentially relieving the problem caused by image artifacts near the landmark. Second, CBCT image segmentation is utilized to remove uninformative voxels caused by morphological variations across patients. Third, a partially-joint model is further proposed to separately localize landmarks based on the coherence of landmark positions to improve the digitization reliability. In addition, we propose a fast vector quantization (VQ) method to extract high-level multi-scale statistical features to describe a voxel's appearance, which has low dimensionality, high efficiency, and is also invariant to the local inhomogeneity caused by artifacts. Results Mean digitization errors for 15 landmarks, in comparison to the ground truth, are all less than 2mm. Conclusion Our model has addressed challenges of both inter-patient morphological variations and imaging artifacts. Experiments on a CBCT dataset show that our approach achieves clinically acceptable accuracy for landmark digitalization. Significance Our automatic landmark digitization method can be used clinically to reduce the labor cost and also improve digitalization consistency. PMID:26625402

  12. Landmark matching based retinal image alignment by enforcing sparsity in correspondence matrix.

    Science.gov (United States)

    Zheng, Yuanjie; Daniel, Ebenezer; Hunter, Allan A; Xiao, Rui; Gao, Jianbin; Li, Hongsheng; Maguire, Maureen G; Brainard, David H; Gee, James C

    2014-08-01

    Retinal image alignment is fundamental to many applications in diagnosis of eye diseases. In this paper, we address the problem of landmark matching based retinal image alignment. We propose a novel landmark matching formulation by enforcing sparsity in the correspondence matrix and offer its solutions based on linear programming. The proposed formulation not only enables a joint estimation of the landmark correspondences and a predefined transformation model but also combines the benefits of the softassign strategy (Chui and Rangarajan, 2003) and the combinatorial optimization of linear programming. We also introduced a set of reinforced self-similarities descriptors which can better characterize local photometric and geometric properties of the retinal image. Theoretical analysis and experimental results with both fundus color images and angiogram images show the superior performances of our algorithms to several state-of-the-art techniques. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. 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.

  14. Connecting imaging mass spectrometry and magnetic resonance imaging-based anatomical atlases for automated anatomical interpretation and differential analysis.

    Science.gov (United States)

    Verbeeck, Nico; Spraggins, Jeffrey M; Murphy, Monika J M; Wang, Hui-Dong; Deutch, Ariel Y; Caprioli, Richard M; Van de Plas, Raf

    2017-07-01

    Imaging mass spectrometry (IMS) is a molecular imaging technology that can measure thousands of biomolecules concurrently without prior tagging, making it particularly suitable for exploratory research. However, the data size and dimensionality often makes thorough extraction of relevant information impractical. To help guide and accelerate IMS data analysis, we recently developed a framework that integrates IMS measurements with anatomical atlases, opening up opportunities for anatomy-driven exploration of IMS data. One example is the automated anatomical interpretation of ion images, where empirically measured ion distributions are automatically decomposed into their underlying anatomical structures. While offering significant potential, IMS-atlas integration has thus far been restricted to the Allen Mouse Brain Atlas (AMBA) and mouse brain samples. Here, we expand the applicability of this framework by extending towards new animal species and a new set of anatomical atlases retrieved from the Scalable Brain Atlas (SBA). Furthermore, as many SBA atlases are based on magnetic resonance imaging (MRI) data, a new registration pipeline was developed that enables direct non-rigid IMS-to-MRI registration. These developments are demonstrated on protein-focused FTICR IMS measurements from coronal brain sections of a Parkinson's disease (PD) rat model. The measurements are integrated with an MRI-based rat brain atlas from the SBA. The new rat-focused IMS-atlas integration is used to perform automated anatomical interpretation and to find differential ions between healthy and diseased tissue. IMS-atlas integration can serve as an important accelerator in IMS data exploration, and with these new developments it can now be applied to a wider variety of animal species and modalities. This article is part of a Special Issue entitled: MALDI Imaging, edited by Dr. Corinna Henkel and Prof. Peter Hoffmann. Copyright © 2017. Published by Elsevier B.V.

  15. Comparison of joint modeling and landmarking for dynamic prediction under an illness-death model.

    Science.gov (United States)

    Suresh, Krithika; Taylor, Jeremy M G; Spratt, Daniel E; Daignault, Stephanie; Tsodikov, Alexander

    2017-11-01

    Dynamic prediction incorporates time-dependent marker information accrued during follow-up to improve personalized survival prediction probabilities. At any follow-up, or "landmark", time, the residual time distribution for an individual, conditional on their updated marker values, can be used to produce a dynamic prediction. To satisfy a consistency condition that links dynamic predictions at different time points, the residual time distribution must follow from a prediction function that models the joint distribution of the marker process and time to failure, such as a joint model. To circumvent the assumptions and computational burden associated with a joint model, approximate methods for dynamic prediction have been proposed. One such method is landmarking, which fits a Cox model at a sequence of landmark times, and thus is not a comprehensive probability model of the marker process and the event time. Considering an illness-death model, we derive the residual time distribution and demonstrate that the structure of the Cox model baseline hazard and covariate effects under the landmarking approach do not have simple form. We suggest some extensions of the landmark Cox model that should provide a better approximation. We compare the performance of the landmark models with joint models using simulation studies and cognitive aging data from the PAQUID study. We examine the predicted probabilities produced under both methods using data from a prostate cancer study, where metastatic clinical failure is a time-dependent covariate for predicting death following radiation therapy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Towards Real-Time Facial Landmark Detection in Depth Data Using Auxiliary Information

    Directory of Open Access Journals (Sweden)

    Connah Kendrick

    2018-06-01

    Full Text Available Modern facial motion capture systems employ a two-pronged approach for capturing and rendering facial motion. Visual data (2D is used for tracking the facial features and predicting facial expression, whereas Depth (3D data is used to build a series of expressions on 3D face models. An issue with modern research approaches is the use of a single data stream that provides little indication of the 3D facial structure. We compare and analyse the performance of Convolutional Neural Networks (CNN using visual, Depth and merged data to identify facial features in real-time using a Depth sensor. First, we review the facial landmarking algorithms and its datasets for Depth data. We address the limitation of the current datasets by introducing the Kinect One Expression Dataset (KOED. Then, we propose the use of CNNs for the single data stream and merged data streams for facial landmark detection. We contribute to existing work by performing a full evaluation on which streams are the most effective for the field of facial landmarking. Furthermore, we improve upon the existing work by extending neural networks to predict into 3D landmarks in real-time with additional observations on the impact of using 2D landmarks as auxiliary information. We evaluate the performance by using Mean Square Error (MSE and Mean Average Error (MAE. We observe that the single data stream predicts accurate facial landmarks on Depth data when auxiliary information is used to train the network. The codes and dataset used in this paper will be made available.

  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. Anatomic study of cranial nerve emergence and associated skull foramina in cats using CT and MRI.

    Science.gov (United States)

    Gomes, Eymeric; Degueurce, Christophe; Ruel, Yannick; Dennis, Ruth; Begon, Dominique

    2009-01-01

    Magnetic resonance (MR) images of the brain of four normal cats were reviewed retrospectively to assess the emergence and course of the cranial nerves (CNs). Two-millimeter-thick images were obtained in transverse, sagittal, and dorsal planes using a 1.5 T unit. CN skull foramina, as anatomic landmarks for MR imaging, were identified by computed tomography performed on an isolated cat skull using thin wire within each skull foramen. Thin slice (1 mm slice thickness) images were obtained with a high-resolution bone filter scan protocol. The origins of CNs II, V, VII, and VIII and the group of IX, X, XI, and XII could be identified. The pathway and proximal divisions of CNs V were described. CNs III, IV, and VI were not distinguished from each other but could be seen together in the orbital fissure. CN V was characterized by slight contrast enhancement.

  19. Image-based dose planning of intracavitary brachytherapy: registration of serial-imaging studies using deformable anatomic templates

    International Nuclear Information System (INIS)

    Christensen, Gary E.; Carlson, Blake; Chao, K.S. Clifford; Yin Pen; Grigsby, Perry W.; Nguyen, Kim; Dempsey, James F; Lerma, Fritz A.; Bae, Kyongtae T.; Vannier, Michael W.; Williamson, Jeffrey F.

    2001-01-01

    Purpose: To demonstrate that high-dimensional voxel-to-voxel transformations, derived from continuum mechanics models of the underlying pelvic tissues, can be used to register computed tomography (CT) serial examinations into a single anatomic frame of reference for cumulative dose calculations. Methods and Materials: Three patients with locally advanced cervix cancer were treated with CT-compatible intracavitary (ICT) applicators. Each patient underwent five volumetric CT examinations: before initiating treatment, and immediately before and after the first and second ICT insertions, respectively. Each serial examination was rigidly registered to the patient's first ICT examination by aligning the bony anatomy. Detailed nonrigid alignment for organs (or targets) of interest was subsequently achieved by deforming the CT exams as a viscous-fluid, described by the Navier-Stokes equation, until the coincidence with the corresponding targets on CT image was maximized. In cases where ICT insertion induced very large and topologically complex rearrangements of pelvic organs, e.g., extreme uterine canal reorientation following tandem insertion, a viscous-fluid-landmark transformation was used to produce an initial registration. Results: For all three patients, reasonable registrations for organs (or targets) of interest were achieved. Fluid-landmark initialization was required in 4 of the 11 registrations. Relative to the best rigid bony landmark alignment, the viscous-fluid registration resulted in average soft-tissue displacements from 2.8 to 28.1 mm, and improved organ coincidence from the range of 5.2% to 72.2% to the range of 90.6% to 100%. Compared to the viscous-fluid transformation, global registration of bony anatomy mismatched 5% or more of the contoured organ volumes by 15-25 mm. Conclusion: Pelvic soft-tissue structures undergo large deformations and displacements during the external-beam and multiple-ICT course of radiation therapy for locally advanced cervix

  20. 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.

  1. Anatomical and palynological characteristics of Salvia willeana ...

    African Journals Online (AJOL)

    In this study, anatomical and palynological features of the roots, stems, petiole and leaves of Salvia willeana (Holmboe) Hedge and Salvia veneris Hedge, Salvia species endemic to Cyprus, were investigated. In the anatomical characteristics of stem structures, it was found that the chlorenchyma composed of 6 or 7 rows of ...

  2. Development and preliminary evaluation of a new anatomically based prosthetic alignment method for below-knee prosthesis.

    Science.gov (United States)

    Tafti, Nahid; Karimlou, Masoud; Mardani, Mohammad Ali; Jafarpisheh, Amir Salar; Aminian, Gholam Reza; Safari, Reza

    2018-04-20

    The objectives of current study were to a) assess similarities and relationships between anatomical landmark-based angles and distances of lower limbs in unilateral transtibial amputees and b) develop and evaluate a new anatomically based static prosthetic alignment method. First sub-study assessed the anthropometrical differences and relationships between the lower limbs in the photographs taken from amputees. Data were analysed via paired t-test and regression analysis. Results show no significant differences in frontal and transverse planes. In the sagittal plane, the anthropometric parameters of the amputated limb were significantly correlated to the corresponding variables of the sound limb. The results served as bases for the development of a new prosthetic alignment method. The method was evaluated on a single subject study. Prosthetic alignment carried out by an experienced prosthetist was compared with such alignment adjusted by an inexperienced prosthetist but with the use of the developed method. In sagittal and frontal planes, the socket angle was tuned with respect to the shin angle, and the position of the prosthetic foot was tuned in relation to the pelvic landmarks. Further study is needed to assess the proposed method on a larger sample of amputees and prosthetists.

  3. Cortical Activation during Landmark-Centered vs. Gaze-Centered Memory of Saccade Targets in the Human: An FMRI Study

    Directory of Open Access Journals (Sweden)

    Ying Chen

    2017-06-01

    Full Text Available A remembered saccade target could be encoded in egocentric coordinates such as gaze-centered, or relative to some external allocentric landmark that is independent of the target or gaze (landmark-centered. In comparison to egocentric mechanisms, very little is known about such a landmark-centered representation. Here, we used an event-related fMRI design to identify brain areas supporting these two types of spatial coding (i.e., landmark-centered vs. gaze-centered for target memory during the Delay phase where only target location, not saccade direction, was specified. The paradigm included three tasks with identical display of visual stimuli but different auditory instructions: Landmark Saccade (remember target location relative to a visual landmark, independent of gaze, Control Saccade (remember original target location relative to gaze fixation, independent of the landmark, and a non-spatial control, Color Report (report target color. During the Delay phase, the Control and Landmark Saccade tasks activated overlapping areas in posterior parietal cortex (PPC and frontal cortex as compared to the color control, but with higher activation in PPC for target coding in the Control Saccade task and higher activation in temporal and occipital cortex for target coding in Landmark Saccade task. Gaze-centered directional selectivity was observed in superior occipital gyrus and inferior occipital gyrus, whereas landmark-centered directional selectivity was observed in precuneus and midposterior intraparietal sulcus. During the Response phase after saccade direction was specified, the parietofrontal network in the left hemisphere showed higher activation for rightward than leftward saccades. Our results suggest that cortical activation for coding saccade target direction relative to a visual landmark differs from gaze-centered directional selectivity for target memory, from the mechanisms for other types of allocentric tasks, and from the directionally

  4. Anatomic variables affecting interdental papilla

    Directory of Open Access Journals (Sweden)

    Swapna A. Mahale

    2013-01-01

    Full Text Available Aim: The aim of this study is to evaluate the anatomic variables affecting the interdental papilla. Materials and Methods: Thirty adult patients were evaluated. Papilla score (PS, tooth form/shape, gingival thickness, crest bone height and keratinized gingiva/attached gingiva were recorded for 150 inter proximal sites. Data were analyzed using SPSS software package (version 7.0 and the significance level was set at 95% confidence interval. Pearson′s correlation was applied to correlate the relationship between the factors and the appearance of the papilla. Results: Competent papillae (complete fill interdentally were associated with: (1 Crown width (CW: length ≥0.87; (2 bone crest-contact point ≤5 mm; and (3 inter proximal gingival tissue thickness ≥1.5 mm. Gingival thickness correlated negatively with PS (r = −0.37 to −0.54 and positively with tissue height (r = 0.23-0.43. Tooth form (i.e., CW to length ratio correlated negatively with PS (r = −0.37 to −0.61. Conclusion: Gingival papilla appearance was associated significantly with tooth form/shape, crestal bone height and interproximal gingival thickness.

  5. The Anatomic Midpoint of the Attachment of the Medial Patellofemoral Complex.

    Science.gov (United States)

    Tanaka, Miho J; Voss, Andreas; Fulkerson, John P

    2016-07-20

    The medial patellofemoral ligament varies in attachment of its fibers to the patella and vastus intermedius tendon. Our aim was to identify and describe its anatomic midpoint. To account for the variability of the attachment site, we refer to it as the medial patellofemoral complex. Using AutoCAD software, we identified the midpoint of the medial patellofemoral complex attachment on photographs of 31 cadaveric knee dissections. The midpoint was referenced relative to the superior articular surface of the patella (P1) and was described in terms of the percentage of the patellar articular length distal to this point. A second point, at the junction of the medial border of the vastus intermedius tendon with the superior articular border of the patella, was identified (P2). The distances of the midpoint to P1 and P2 were calculated and were compared using paired t tests. Twenty-five images had appropriate quality and landmarks for digital analysis. The midpoint of the medial patellofemoral complex was located a mean (and standard deviation) of 2.3% ± 15.8% of the patellar articular length distal to the superior pole and was at or proximal to P1 in 12 knees. In all knees, the midpoint was at or proximal to P2. After exclusion of 2 knees with vastus intermedius tendon attachments only, the medial patellofemoral complex midpoint was closer to P2 (5.3% ± 8.6% of the patellar articular length) than to P1 (9.3% ± 8.5% of the patellar articular length) (p = 0.06). The midpoint of the medial patellofemoral complex was 2.3% of the articular length distal to the superior pole of the patella. Additionally, we describe an anatomic landmark at the junction of the medial border of the vastus intermedius tendon and the articular border of the patella that approximates the midpoint of this complex. Our study shows that the anatomic midpoint of the attachment of the medial patellofemoral complex is proximal to the junction of the medial vastus intermedius tendon and the articular

  6. A Methodology for Anatomic Ultrasound Image Diagnostic Quality Assessment

    DEFF Research Database (Denmark)

    Hemmsen, Martin Christian; Lange, Theis; Brandt, Andreas Hjelm

    2017-01-01

    are presented. Earlier uses of the methodology has shown that it ensures validity of the assessment, as it separates the influences between developer, investigator, and assessor once a research protocol has been established. This separation reduces confounding influences on the result from the developer......This paper discusses methods for assessment of ultrasound image quality based on our experiences with evaluating new methods for anatomic imaging. It presents a methodology to ensure a fair assessment between competing imaging methods using clinically relevant evaluations. The methodology...... to properly reveal the clinical value. The paper exemplifies the methodology using recent studies of Synthetic Aperture Sequential Beamforming tissue harmonic imaging....

  7. Route-external and route-internal landmarks in route descriptions : Effects of route length and map design

    NARCIS (Netherlands)

    Westerbeek, Hans; Maes, Alfons

    2013-01-01

    Landmarks are basic ingredients in route descriptions. They often mark choice points: locations where travellers choose from different options how to continue the route. This study focuses on one of the loose ends in the taxonomy of landmarks. In a memory-based production experiment in which

  8. Route-Learning Strategies in Typical and Atypical Development; Eye Tracking Reveals Atypical Landmark Selection in Williams Syndrome

    Science.gov (United States)

    Farran, E. K.; Formby, S.; Daniyal, F.; Holmes, T.; Van Herwegen, J.

    2016-01-01

    Background: Successful navigation is crucial to everyday life. Individuals with Williams syndrome (WS) have impaired spatial abilities. This includes a deficit in spatial navigation abilities such as learning the route from A to B. To-date, to determine whether participants attend to landmarks when learning a route, landmark recall tasks have been…

  9. 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…

  10. Landmark-based morphometric analysis of two sibling species of the genus Asida (Coleoptera, Tenebrionidae)

    NARCIS (Netherlands)

    Palmer, Miquel

    2002-01-01

    The case described here analyses morphological change at the boundary between ecological and evolutionary scales. The size and shape of 8 populations of two sibling species of tenebrionid beetles (Asida planipennis and A. moraguesi) are analysed using landmark-based methods. The two species differ

  11. Student acceptance of e-books: A case study of landmark university ...

    African Journals Online (AJOL)

    Student acceptance of e-books was tested using UTAUT model. Performance expectancy Effort expectancy and Facilitating conditions were seen to significantly influence the acceptance of e-books by students in Landmark University, while Social Influence did not influence acceptance of e-books. Key Words: E-books, ...

  12. 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.

  13. 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.

  14. 77 FR 44670 - Information Collection Activities: National Historic Landmarks (NHL) Condition Survey

    Science.gov (United States)

    2012-07-30

    ... information regarding the condition of designated landmarks. A questionnaire will be designed and used to... the design of the questionnaire that is the subject of this request. II. Data OMB Control Number: 1024... address, phone number, email address, or other personal identifying information in your comment, you...

  15. Benchmarking recent national practice in rectal cancer treatment with landmark randomized controlled trials

    NARCIS (Netherlands)

    Borstlap, Waa; Deijen, C. L.; den Dulk, M.; Bonjer, H. J.; van de Velde, C. J.; Bemelman, W. A.; Tanis, P. J.; Aalbers, A.; Acherman, Y.; Algie, G. D.; Alting von Geusau, B.; Amelung, F.; Aukema, T. S.; Bakker, I. S.; Basha, S.; Bastiaansen, A. J. N. M.; Belgers, E.; Bleeker, W.; Blok, J.; Bosker, R. J. I.; Bosmans, J. W.; Boute, M. C.; Bouvy, N. D.; Bouwman, H.; Brandt-Kerkhof, A.; Brinkman, D. J.; Bruin, S.; Bruns, E. R. J.; Burbach, J. P. M.; Burger, J. W. A.; Buskens, C. J.; Clermonts, S.; Coenen, P. P. L. O.; Compaan, C.; Consten, E. C. J.; Darbyshire, T.; de Mik, S. M. L.; de Graaf, E. J. R.; de Groot, I.; de Vos Tot Nederveen Cappel, R. J. L.; de Wilt, J. H. W.; van der Wolde, J.; den Boer, F. C.; Dekker, J. W. T.; Demirkiran, A.; van Duijvendijk, P.; Musters, G. D.; van Rossem, C. C.; Schreuder, A. M.; Swank, H. A.

    2017-01-01

    Aim A Snapshot study design eliminates changes in treatment and outcome over time. This population based Snapshot study aimed to determine current practice and outcome of rectal cancer treatment with published landmark randomized controlled trials as a benchmark. Method In this collaborative

  16. Benchmarking recent national practice in rectal cancer treatment with landmark randomized controlled trials

    NARCIS (Netherlands)

    Borstlap, W. A. A.; Deijen, C. L.; den Dulk, M.; Bonjer, H. J.; van de Velde, C. J.; Bemelman, W. A.; Tanis, P. J.; Aalbers, A.; Acherman, Y.; Algie, G. D.; von Geu-sau, B. Alting; Amelung, F.; Aukema, T. S.; Bakker, I. S.; Bartels, S. A.; Basha, S.; Bastiaansen, A. J. N. M.; Belgers, E.; Bleeker, W.; Blok, J.; Bosker, R. J. I.; Bosmans, J. W.; Boute, M. C.; Bouvy, N. D.; Bouwman, H.; Brandt-Kerkhof, A.; Brinkman, D. J.; Bruin, S.; Bruns, E. R. J.; Burbach, J. P. M.; Burger, J. W. A.; Buskens, C. J.; Clermonts, S.; Coene, P. P. L. O.; Compaan, C.; Consten, E. C. J.; Darbyshire, T.; de Mik, S. M. L.; de Graaf, E. J. R.; de Groot, I.; Cappel, R. J. L. de Vos Tot Nederveen; de Wilt, J. H. W.; van der Wolde, J.; den Boer, F. C.; Furnee, E. J. B.; Havenga, K.; Klaase, J.; Holzik, M. F. Lutke; Meerdink, M.; Wevers, K.

    Aim A Snapshot study design eliminates changes in treatment and outcome over time. This population based Snapshot study aimed to determine current practice and outcome of rectal cancer treatment with published landmark randomized controlled trials as a benchmark. Method In this collaborative

  17. 78 FR 79643 - Energy Conservation Program for Consumer Products: Landmark Legal Foundation; Petition for...

    Science.gov (United States)

    2013-12-31

    ... consumer behavior; and questions about why comments on the Draft National Climate Assessment were not... Program for Consumer Products: Landmark Legal Foundation; Petition for Reconsideration AGENCY: Office of... Energy Consumers of America (IECA), American Gas Association (AGA), Cato Institute Center for Study of...

  18. 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…

  19. Toward a model for lexical access based on acoustic landmarks and distinctive features

    Science.gov (United States)

    Stevens, Kenneth N.

    2002-04-01

    This article describes a model in which the acoustic speech signal is processed to yield a discrete representation of the speech stream in terms of a sequence of segments, each of which is described by a set (or bundle) of binary distinctive features. These distinctive features specify the phonemic contrasts that are used in the language, such that a change in the value of a feature can potentially generate a new word. This model is a part of a more general model that derives a word sequence from this feature representation, the words being represented in a lexicon by sequences of feature bundles. The processing of the signal proceeds in three steps: (1) Detection of peaks, valleys, and discontinuities in particular frequency ranges of the signal leads to identification of acoustic landmarks. The type of landmark provides evidence for a subset of distinctive features called articulator-free features (e.g., [vowel], [consonant], [continuant]). (2) Acoustic parameters are derived from the signal near the landmarks to provide evidence for the actions of particular articulators, and acoustic cues are extracted by sampling selected attributes of these parameters in these regions. The selection of cues that are extracted depends on the type of landmark and on the environment in which it occurs. (3) The cues obtained in step (2) are combined, taking context into account, to provide estimates of ``articulator-bound'' features associated with each landmark (e.g., [lips], [high], [nasal]). These articulator-bound features, combined with the articulator-free features in (1), constitute the sequence of feature bundles that forms the output of the model. Examples of cues that are used, and justification for this selection, are given, as well as examples of the process of inferring the underlying features for a segment when there is variability in the signal due to enhancement gestures (recruited by a speaker to make a contrast more salient) or due to overlap of gestures from

  20. Anatomical basis of the lateral superior gluteal artery perforator (LSGAP) flap and role in bilateral breast reconstruction.

    Science.gov (United States)

    Fade, Geraldine; Gobel, Fabienne; Pele, Eric; Chaput, Benoit; Garrido, Ignacio; Pinsolle, Vincent; Pelissier, Philippe; Sinna, Raphael

    2013-06-01

    Deep inferior epigastric perforator (DIEP) flap is one of the gold standards in autologous breast reconstruction. When the abdominal tissue is not available, the superior gluteal artery perforator (SGAP) is often a second option with its drawback, especially the donor-site deformity. Reports have highlighted that a higher and more lateral SGAP flap can be harvested to overcome several drawbacks of the classical SGAP, allowing in the same procedure a body-contouring procedure. In order to set the anatomical basis of this flap, we proposed to study the characteristics of a reliable and easily identifiable superior and lateral perforator of the superior gluteal artery (lateral SGAP (LSGAP)) situated in the region of the lower body-lift resection allowing to perform bilateral breast reconstruction at the same time. The anatomical study of 50 scans (or 100 buttocks) allows us to set forth a diagnostic assumption on the localisation of the perforator with respect to osseous landmarks (coccyx, iliac crest and great trochanter) which will be verified during the dissection of 10 cadavers (or 20 buttocks) and during the 20 colour Doppler examination (or 40 buttocks). In our computed tomography (CT) scan study, in 96% of cases, the perforator was situated in a circle with a radius≤3 cm with a 95% confidence interval and located at the junction of the proximal third-middle third of the distance summit of the posterior iliac crest (point B), most lateral point of the greater trochanter (point C). This assumption was verified by the cadaveric dissection and in vivo studies. Our study sets the anatomical landmarks of the LSGAP flap. This option allows the raising of an SGAP flap avoiding the main drawbacks of this flap and allows harvesting a flap with the tissue that is often discarded during the body-lift procedure. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  1. [Establishment of anatomical terminology in Japan].

    Science.gov (United States)

    Shimada, Kazuyuki

    2008-12-01

    The history of anatomical terminology in Japan began with the publication of Waran Naikei Ihan-teimŏ in 1805 and Chŏtei Kaitai Shinsho in 1826. Although the establishment of Japanese anatomical terminology became necessary during the Meiji era when many western anatomy books imported into Janan were translated, such terminology was not unified during this period and varied among translators. In 1871, Tsukumo Ono's Kaibŏgaku Gosen was published by the Ministry of Education. Although this book is considered to be the first anatomical glossary terms in Japan, its contents were incomplete. Overseas, the German Anatomical Society established a unified anatomical terminology in 1895 called the Basle Nomina Anatomica (B.N.A.). Based on this development, Kaibŏgaku Meishŭ which follows the BNA, by Buntarŏ Suzuki was published in 1905. With the subsequent establishment in 1935 of Jena Nomina Anatomica (J.N.A.), the unification of anatomical terminology was also accelerated in Japan, leading to the further development of terminology.

  2. The importance of accurate anatomic assessment for the volumetric analysis of the amygdala

    Directory of Open Access Journals (Sweden)

    L. Bonilha

    2005-03-01

    Full Text Available There is a wide range of values reported in volumetric studies of the amygdala. The use of single plane thick magnetic resonance imaging (MRI may prevent the correct visualization of anatomic landmarks and yield imprecise results. To assess whether there is a difference between volumetric analysis of the amygdala performed with single plane MRI 3-mm slices and with multiplanar analysis of MRI 1-mm slices, we studied healthy subjects and patients with temporal lobe epilepsy. We performed manual delineation of the amygdala on T1-weighted inversion recovery, 3-mm coronal slices and manual delineation of the amygdala on three-dimensional volumetric T1-weighted images with 1-mm slice thickness. The data were compared using a dependent t-test. There was a significant difference between the volumes obtained by the coronal plane-based measurements and the volumes obtained by three-dimensional analysis (P < 0.001. An incorrect estimate of the amygdala volume may preclude a correct analysis of the biological effects of alterations in amygdala volume. Three-dimensional analysis is preferred because it is based on more extensive anatomical assessment and the results are similar to those obtained in post-mortem studies.

  3. Why relevance theory is relevant for lexicography

    DEFF Research Database (Denmark)

    Bothma, Theo; Tarp, Sven

    2014-01-01

    This article starts by providing a brief summary of relevance theory in information science in relation to the function theory of lexicography, explaining the different types of relevance, viz. objective system relevance and the subjective types of relevance, i.e. topical, cognitive, situational...... that is very important for lexicography as well as for information science, viz. functional relevance. Since all lexicographic work is ultimately aimed at satisfying users’ information needs, the article then discusses why the lexicographer should take note of all these types of relevance when planning a new...... dictionary project, identifying new tasks and responsibilities of the modern lexicographer. The article furthermore discusses how relevance theory impacts on teaching dictionary culture and reference skills. By integrating insights from lexicography and information science, the article contributes to new...

  4. Sex differences on the judgment of line orientation task: a function of landmark presence and hormonal status.

    Science.gov (United States)

    Goyette, Sharon Ramos; McCoy, John G; Kennedy, Ashley; Sullivan, Meghan

    2012-02-28

    It has been well-established that men outperform women on some spatial tasks. The tools commonly used to demonstrate this difference (e.g. The Mental Rotations Task) typically involve problems and solutions that are presented in a context devoid of referents. The study presented here assessed whether the addition of referents (or "landmarks") would attenuate the well-established sex difference on the judgment of line orientation task (JLOT). Three versions of the JLOT were presented in a within design. The first iteration contained the original JLOT (JLOT 1). JLOT 2 contained three "landmarks" or referents and JLOT 3 contained only one landmark. The sex difference on JLOT 1 was completely negated by the addition of three landmarks on JLOT 2 or the addition of one landmark on JLOT3. In addition, salivary testosterone was measured. In men, gains in performance on the JLOT due to the addition of landmarks were positively correlated with testosterone levels. This suggests that men with the highest testosterone levels benefited the most from the addition of landmarks. These data help to highlight different strategies used by men and women to solve spatial tasks. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. A new method for automatic tracking of facial landmarks in 3D motion captured images (4D).

    Science.gov (United States)

    Al-Anezi, T; Khambay, B; Peng, M J; O'Leary, E; Ju, X; Ayoub, A

    2013-01-01

    The aim of this study was to validate the automatic tracking of facial landmarks in 3D image sequences. 32 subjects (16 males and 16 females) aged 18-35 years were recruited. 23 anthropometric landmarks were marked on the face of each subject with non-permanent ink using a 0.5mm pen. The subjects were asked to perform three facial animations (maximal smile, lip purse and cheek puff) from rest position. Each animation was captured by the 3D imaging system. A single operator manually digitised the landmarks on the 3D facial models and their locations were compared with those of the automatically tracked ones. To investigate the accuracy of manual digitisation, the operator re-digitised the same set of 3D images of 10 subjects (5 male and 5 female) at 1 month interval. The discrepancies in x, y and z coordinates between the 3D position of the manual digitised landmarks and that of the automatic tracked facial landmarks were within 0.17mm. The mean distance between the manually digitised and the automatically tracked landmarks using the tracking software was within 0.55 mm. The automatic tracking of facial landmarks demonstrated satisfactory accuracy which would facilitate the analysis of the dynamic motion during facial animations. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  6. 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

    , but is more superiorly located at T12-L1 for SAT and at L3-L4 for VAT. Furthermore, the optimal anatomic locations for SAT and VAT estimation are not the same, contrary to common assumption. The proposed standardized space mapping achieves high consistency of anatomic localization by accurately managing nonlinearities in the relationships among landmarks. Multiple slices achieve greater improvement in correlation for VAT than for SAT. The optimal locations in the case of multiple slices are not contiguous.

  7. Critical concepts and important anatomic landmarks encountered during transanal total mesorectal excision (taTME): toward the mastery of a new operation for rectal cancer surgery.

    Science.gov (United States)

    Atallah, S; Albert, M; Monson, J R T

    2016-07-01

    Over the past 3 years, colorectal surgeons have begun to adapt the technique of transanal total mesorectal excision. As international experience has been quickly forged, an improved recognition of the pitfalls and the practical details of this disruptive technique have been realized. The purpose of this technical note was to express the various nuances of transanal total mesorectal excision as learned during the course of its clinical application and international teaching, so as to rapidly communicate and share important insights with other surgeons who are in the early adoption phase of this approach. The technical points specific to transanal total mesorectal excision are addressed herein. When correctly applied, these will likely improve the quality of surgery and decrease morbidity attributable to inexperience with the transanal approach to total mesorectal excision.

  8. Sex differences in a landmark environmental re-orientation task only during the learning phase.

    Science.gov (United States)

    Piccardi, Laura; Bianchini, Filippo; Iasevoli, Luigi; Giannone, Gianluca; Guariglia, Cecilia

    2011-10-10

    Sex differences are consistently reported in human navigation. Indeed, to orient themselves during navigation women are more likely to use landmark-based strategies and men Euclidean-based strategies. The difference could be due to selective social pressure, which fosters greater spatial ability in men, or biological factors. And the great variability of the results reported in the literature could be due to the experimental setting more than real differences in ability. In this study, navigational behaviour was assessed by means of a place-learning task in which a modified version of the Morris water maze for humans was used to evaluate sex differences. In using landmarks, sex differences emerged only during the learning phase. Although the men were faster than the women in locating the target position, the differences between the sexes disappeared in delayed recall. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  9. Anatomical eponyms - unloved names in medical terminology.

    Science.gov (United States)

    Burdan, F; Dworzański, W; Cendrowska-Pinkosz, M; Burdan, M; Dworzańska, A

    2016-01-01

    Uniform international terminology is a fundamental issue of medicine. Names of various organs or structures have developed since early human history. The first proper anatomical books were written by Hippocrates, Aristotle and Galen. For this reason the modern terms originated from Latin or Greek. In a modern time the terminology was improved in particular by Vasalius, Fabricius and Harvey. Presently each known structure has internationally approved term that is explained in anatomical or histological terminology. However, some elements received eponyms, terms that incorporate the surname of the people that usually describe them for the first time or studied them (e.g., circle of Willis, follicle of Graff, fossa of Sylvious, foramen of Monro, Adamkiewicz artery). Literature and historical hero also influenced medical vocabulary (e.g. Achilles tendon and Atlas). According to various scientists, all the eponyms bring colour to medicine, embed medical traditions and culture to our history but lack accuracy, lead of confusion, and hamper scientific discussion. The current article presents a wide list of the anatomical eponyms with their proper anatomical term or description according to international anatomical terminology. However, since different eponyms are used in various countries, the list could be expanded.

  10. Determining customer satisfaction in anatomic pathology.

    Science.gov (United States)

    Zarbo, Richard J

    2006-05-01

    Measurement of physicians' and patients' satisfaction with laboratory services has become a standard practice in the United States, prompted by national accreditation requirements. Unlike other surveys of hospital-, outpatient care-, or physician-related activities, no ongoing, comprehensive customer satisfaction survey of anatomic pathology services is available for subscription that would allow continual benchmarking against peer laboratories. Pathologists, therefore, must often design their own local assessment tools to determine physician satisfaction in anatomic pathology. To describe satisfaction survey design that would elicit specific information from physician customers about key elements of anatomic pathology services. The author shares his experience in biannually assessing customer satisfaction in anatomic pathology with survey tools designed at the Henry Ford Hospital, Detroit, Mich. Benchmarks for physician satisfaction, opportunities for improvement, and characteristics that correlated with a high level of physician satisfaction were identified nationally from a standardized survey tool used by 94 laboratories in the 2001 College of American Pathologists Q-Probes quality improvement program. In general, physicians are most satisfied with professional diagnostic services and least satisfied with pathology services related to poor communication. A well-designed and conducted customer satisfaction survey is an opportunity for pathologists to periodically educate physician customers about services offered, manage unrealistic expectations, and understand the evolving needs of the physician customer. Armed with current information from physician customers, the pathologist is better able to strategically plan for resources that facilitate performance improvements in anatomic pathology laboratory services that align with evolving clinical needs in health care delivery.

  11. Reproducibility of lateral cephalometric landmarks on conventional radiographs and spatial frequency-processed digital images

    International Nuclear Information System (INIS)

    Shin, Jeong Won; Heo, Min Suk; Lee, Sam Sun; Choi, Hyun Bae; Choi, Soon Chul; Choi, Hang Moon

    2002-01-01

    Computed radiography (CR) has been used in cephalometric radiography and many studies have been carried out to improve image quality using various digital enhancement and filtering techniques. During CR image acquisition, the frequency rank and type affect to the image quality. The aim of this study was to compare the diagnostic quality of conventional cephalometric radiographs to those of computed radiography. The diagnostic quality of conventional cephalometric radiographs (M0) and their digital image counterparts were compared, and at the same time, six modalities (M1-M6) of spatial frequency-processed digital images were compared by evaluating the reproducibility of 23 cephalometric landmark locations. Reproducibility was defined as an observer's deviation (in mm) from the mean between all observers. In comparison with the conventional cephalometric radiograph (M0), M1 showed statistically significant differences in 8 locations, M2 in 9, M3 12, M4 in 7, M5 in 12, and M6 showed significant differences in 14 of 23 landmark locations (p<0.05). The number of reproducible landmarks that each modality possesses were 7 in M6, 6 in M5, 5 in M3, 4 in M4, 3 in M2, 2 in M1, and 1 location in M0. The image modality that observers selected as having the best image quality was M5.

  12. 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.

  13. Deep learning relevance

    DEFF Research Database (Denmark)

    Lioma, Christina; Larsen, Birger; Petersen, Casper

    2016-01-01

    train a Recurrent Neural Network (RNN) on existing relevant information to that query. We then use the RNN to "deep learn" a single, synthetic, and we assume, relevant document for that query. We design a crowdsourcing experiment to assess how relevant the "deep learned" document is, compared...... to existing relevant documents. Users are shown a query and four wordclouds (of three existing relevant documents and our deep learned synthetic document). The synthetic document is ranked on average most relevant of all....

  14. Anatomical variants of lister's tubercle; A new morphological classification based on magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Wan Ying; Chong, Le Roy [Dept. of Radiology, Changi General Hospital, Singapore (Singapore)

    2017-11-15

    Lister's tubercle is used as a standard anatomical landmark in hand surgery and arthroscopy procedures. In this study, we aimed to evaluate and propose a classification for anatomical variants of Lister's tubercle. Between September 2011 and July 2014, 360 MRI examinations for wrists performed using 1.5T scanners in a single institution were retrospectively evaluated. The prevalence of anatomical variants of Lister's tubercle based on the heights and morphology of its radial and ulnar peaks was assessed. These were classified into three distinct types: radial peak larger than ulnar peak (Type 1), similar radial and ulnar peaks (Type 2) and ulnar peak larger than radial peak (Type 3). Each type was further divided into 2 subtypes (A and B) based on the morphology of the peaks. The proportions of Type 1, Type 2, and Type 3 variants in the study population were 69.2, 21.4, and 9.5%, respectively. For the subtypes, the Type 1A variant was the most common (41.4%) and conformed to the classical appearance of Lister's tubercle; whereas, Type 3A and 3B variants were rare configurations (6.4% and 3.1%, respectively) wherein the extensor pollicis longus tendon coursed along the radial aspect of Lister's tubercle. Anatomical variations of Lister's tubercle have potential clinical implications for certain pathological conditions and pre-procedural planning. The proposed classification system facilitates a better understanding of these anatomical variations and easier identification of at-risk and rare variants.

  15. Posterolateral supporting structures of the knee: findings on anatomic dissection, anatomic slices and MR images

    Energy Technology Data Exchange (ETDEWEB)

    Maeseneer, M. de; Shahabpour, M.; Vanderdood, K.; Ridder, F. de; Osteaux, M. [Dept. of Radiology, Free Univ. Brussels (Belgium); Roy, F. van [Dept. of Experimental Anatomy, Free Univ. Brussels (Belgium)

    2001-11-01

    In this article we study the ligaments and tendons of the posterolateral corner of the knee by anatomic dissection, MR-anatomic correlation, and MR imaging. The posterolateral aspect of two fresh cadaveric knee specimens was dissected. The MR-anatomic correlation was performed in three other specimens. The MR images of 122 patients were reviewed and assessed for the visualization of different posterolateral structures. Anatomic dissection and MR-anatomic correlation demonstrated the lateral collateral, fabellofibular, and arcuate ligaments, as well as the biceps and popliteus tendons. On MR images of patients the lateral collateral ligament was depicted in all cases. The fabellofibular, arcuate, and popliteofibular ligaments were visualized in 33, 25, and 38% of patients, respectively. Magnetic resonance imaging allows a detailed appreciation of the posterolateral corner of the knee. (orig.)

  16. Intensity modulated radiation therapy (IMRT: differences in target volumes and improvement in clinically relevant doses to small bowel in rectal carcinoma

    Directory of Open Access Journals (Sweden)

    Delclos Marc E

    2011-06-01

    Full Text Available Abstract Background A strong dose-volume relationship exists between the amount of small bowel receiving low- to intermediate-doses of radiation and the rates of acute, severe gastrointestinal toxicity, principally diarrhea. There is considerable interest in the application of highly conformal treatment approaches, such as intensity-modulated radiation therapy (IMRT, to reduce dose to adjacent organs-at-risk in the treatment of carcinoma of the rectum. Therefore, we performed a comprehensive dosimetric evaluation of IMRT compared to 3-dimensional conformal radiation therapy (3DCRT in standard, preoperative treatment for rectal cancer. Methods Using RTOG consensus anorectal contouring guidelines, treatment volumes were generated for ten patients treated preoperatively at our institution for rectal carcinoma, with IMRT plans compared to plans derived from classic anatomic landmarks, as well as 3DCRT plans treating the RTOG consensus volume. The patients were all T3, were node-negative (N = 1 or node-positive (N = 9, and were planned to a total dose of 45-Gy. Pairwise comparisons were made between IMRT and 3DCRT plans with respect to dose-volume histogram parameters. Results IMRT plans had superior PTV coverage, dose homogeneity, and conformality in treatment of the gross disease and at-risk nodal volume, in comparison to 3DCRT. Additionally, in comparison to the 3DCRT plans, IMRT achieved a concomitant reduction in doses to the bowel (small bowel mean dose: 18.6-Gy IMRT versus 25.2-Gy 3DCRT; p = 0.005, bladder (V40Gy: 56.8% IMRT versus 75.4% 3DCRT; p = 0.005, pelvic bones (V40Gy: 47.0% IMRT versus 56.9% 3DCRT; p = 0.005, and femoral heads (V40Gy: 3.4% IMRT versus 9.1% 3DCRT; p = 0.005, with an improvement in absolute volumes of small bowel receiving dose levels known to induce clinically-relevant acute toxicity (small bowel V15Gy: 138-cc IMRT versus 157-cc 3DCRT; p = 0.005. We found that the IMRT treatment volumes were typically larger than that

  17. 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

  18. 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.

  19. The 360 photography: a new anatomical insight of the sphenoid bone. Interest for anatomy teaching and skull base surgery.

    Science.gov (United States)

    Jacquesson, Timothée; Mertens, Patrick; Berhouma, Moncef; Jouanneau, Emmanuel; Simon, Emile

    2017-01-01

    Skull base architecture is tough to understand because of its 3D complex shape and its numerous foramen, reliefs or joints. It is especially true for the sphenoid bone whom central location hinged with most of skull base components is unique. Recently, technological progress has led to develop new pedagogical tools. This way, we bought a new real-time three-dimensional insight of the sphenoid bone that could be useful for the teacher, the student and the surgeon. High-definition photography was taken all around an isolated dry skull base bone prepared with Beauchêne's technique. Pictures were then computed to provide an overview with rotation and magnification on demand. From anterior, posterior, lateral or oblique views and from in out looks, anatomical landmarks and subtleties were described step by step. Thus, the sella turcica, the optic canal, the superior orbital fissure, the sphenoid sinus, the vidian canal, pterygoid plates and all foramen were clearly placed relative to the others at each face of the sphenoid bone. In addition to be the first report of the 360 Photography tool, perspectives are promising as the development of a real-time interactive tridimensional space featuring the sphenoid bone. It allows to turn around the sphenoid bone and to better understand its own special shape, numerous foramen, neurovascular contents and anatomical relationships. This new technological tool may further apply for surgical planning and mostly for strengthening a basic anatomical knowledge firstly introduced.

  20. 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.

  1. Lacrimal Gland Pathologies from an Anatomical Perspective

    Directory of Open Access Journals (Sweden)

    Mahmut Sinan Abit

    2015-06-01

    Full Text Available Most of the patients in our daily practice have one or more ocular surface disorders including conjucntivitis, keratitis, dry eye disease, meibomian gland dysfunction, contact lens related symptoms, refractive errors,computer vision syndrome. Lacrimal gland has an important role in all above mentioned pathologies due to its major secretory product. An anatomical and physiological knowledge about lacrimal gland is a must in understanding basic and common ophthalmological cases. İn this paper it is aimed to explain the lacrimal gland diseases from an anatomical perspective.

  2. Anatomical Studies on Several Species of Heliotropium L. in Iran

    Directory of Open Access Journals (Sweden)

    Maryam ABBASI

    2011-11-01

    Full Text Available Heliotropium spp. is distributed worldwide mainly in tropical and subtropical regions, with dry and warm temperate to semi-arid regions so that Southwest and center of Asia have considered as the main centre of origin and diversity of Heliotropium genus. Iran, with 32 species and 14 (sub endemic species, has the highest diversity in the world followed by Pakistan and Turkey with 15 species and only one endemic species and the Arabian Peninsula with 15 species and three endemic species are in the next ranks. In order to anatomical studies on Heliotropium, twelve species of this genus were selected from different regions of Iran. The selected species included: H. bacciferum Forssk., H. ramossisimum BGE., H. brevilimb Boiss., H. transoxanum BGE., H. dasycarpum Ledeb, H. dyginum Forssk., H. aucheri Dc., H. carmanicum BGE. As perennial group and H. ellipticum Ledeb., H. lasiocarpum Fisch., H. suaveolens M.B. as annual group. In order to add more data to leaf anatomy characters, evaluating of systematic relevance and/or adaptive value of the morphological and anatomical diversity we have studied 24 anatomical characters in theses 12 species. For example shape and vascular bundles of main midrib, type of parenchyma cells located under lower epidermis of midrib, distance between vascular bundles and lower or upper epidermis, angle of between two parts of blade, number of cellular layers in lower or upper mesophylla, length of upper and lower mesophylla, type of cell wall in lower and upper mesophylla and thickness of lamina were investigated in this study. In order to this present obtained H. aucheri can be separated from H. carmanicum in H. aucheri subsp. carmanicum. It can be conclude that two species H. aucheri and H. carmanicum are independent species and can accept H. transoxanum as a sub group of H. dasycarpum.

  3. Deviation of landmarks in accordance with methods of establishing reference planes in three-dimensional facial CT evaluation.

    Science.gov (United States)

    Yoon, Kaeng Won; Yoon, Suk-Ja; Kang, Byung-Cheol; Kim, Young-Hee; Kook, Min Suk; Lee, Jae-Seo; Palomo, Juan Martin

    2014-09-01

    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.

  4. Deviation of landmarks in accordance with methods of establishing reference planes in three-dimensional facial CT evaluation

    International Nuclear Information System (INIS)

    Yoon, Kaeng Won; Yoon, Suk Ja; Kang, Byung Cheol; Kook, Min Suk; Lee, Jae Seo; Kim, Young Hee; Palomo, Juan Martin

    2014-01-01

    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.

  5. 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.

  6. A study on the anatomical morphology of the minor fissure

    International Nuclear Information System (INIS)

    Lee, Hyeong Gon; Kim, Hyung Jin; You, Jin Jong; Ahn, In Oak; Chung, Sung Hoon

    1993-01-01

    The minor fissure is an important anatomical landmark in the localization of the pulmonary disease. For the evaluation of the normal feature of the minor fissure, we analyzed the high-resolution computed tomography (CT) scans in 51 normal patients. The purpose of this study are to evaluate the normal appearance of the minor fissure on high-resolution CT scans and to compare it with that on the conventional CT and radiographys. We analyzed the morphologic feature of the minor fissure on the high-resolution CT scans in 51 normal patients, and compared it with that on the conventional CT scans. On the high-resolution CT scans, we particularly paid attention to the completeness and types according to Berkmen classification. And finally, we compared the types determined by the high-resolution CT scans with those by the plain radiographys. In most patients (n=47), the minor fissure was seen as a hyperattenuating line or band on the high resolution CT scans. In contrast, it was mostly seen as a lucent zone on the conventional CT scans (n=44). Of 47 patient having a hyperattenuating line or band on the high-resolution CT scans, the minor fissure was considered to be complete in 17 patients (36%), and incomplete in 30 patients (64%), who had a defeat at medial portion of the minor fissure. The most common type of the minor fissure seen on the high-resolution CT scans was type I variety (n=23), followed by tape IIa (n=8). We could not determined the type in six patients. The type determined by the high-resolution CT scans was highly well correlated with that determined by the plain radiographys (p<0.05). In conclusion, the minor fissure was seen CT studies as variable appearances and high-resolution CT scans were superior to the conventional CT scans in the evaluation of the minor fissure. The types of the minor fissure determined by the high-resolution CT scans were well correlated with those seen on the radiographys

  7. From medical imaging data to 3D printed anatomical models.

    Directory of Open Access Journals (Sweden)

    Thore M Bücking

    Full Text Available Anatomical models are important training and teaching tools in the clinical environment and are routinely used in medical imaging research. Advances in segmentation algorithms and increased availability of three-dimensional (3D printers have made it possible to create cost-efficient patient-specific models without expert knowledge. We introduce a general workflow that can be used to convert volumetric medical imaging data (as generated by Computer Tomography (CT to 3D printed physical models. This process is broken up into three steps: image segmentation, mesh refinement and 3D printing. To lower the barrier to entry and provide the best options when aiming to 3D print an anatomical model from medical images, we provide an overview of relevant free and open-source image segmentation tools as well as 3D printing technologies. We demonstrate the utility of this streamlined workflow by creating models of ribs, liver, and lung using a Fused Deposition Modelling 3D printer.

  8. Anatomical Basis for Safe and Effective Volumization of the Temple.

    Science.gov (United States)

    Breithaupt, Andrew D; Jones, Derek H; Braz, Andre; Narins, Rhoda; Weinkle, Susan

    2015-12-01

    One of the earliest but often unaddressed signs of facial aging is volume loss in the temple. Treatment of the area can produce satisfying results for both patient and practitioner. Safe injection requires explicit knowledge of the anatomy to avoid complications related to the multitude of vessels that course throughout the region at various depths. The authors aim to detail the anatomy of the area and provide a safe and easy-to-follow method for injection. The authors review the relevant anatomy of the temporal region and its application to cosmetic filler injections. The authors describe an easy-to-follow approach for a safe and effective injection window based on numerous anatomical studies. Injection in this area is not without risk, including potential blindness. The authors review the potential complications and their treatments. Hollowing of the temple is an early sign of aging that, when corrected, can lead to significant patient and practitioner satisfaction. Proper anatomically knowledge is required to avoid potentially severe complications. In this study, the authors present a reliable technique to safely and effectively augment this often undertreated area of the aging face.

  9. Magnetic resonance angiography: infrequent anatomic variants

    International Nuclear Information System (INIS)

    Trejo, Mariano; Meli, Francisco; Lambre, Hector; Blessing, Ricardo; Gigy Traynor, Ignacio; Miguez, Victor

    2002-01-01

    We studied through RM angiography (3D TOF) with high magnetic field equipment (1.5 T) different infrequent intracerebral vascular anatomic variants. For their detection we emphasise the value of post-processed images obtained after conventional angiographic sequences. These post-processed images should be included in routine protocols for evaluation of the intracerebral vascular structures. (author)

  10. 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 left...

  11. 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

  12. 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)

  13. Evolution of the Anatomical Theatre in Padova

    Science.gov (United States)

    Macchi, Veronica; Porzionato, Andrea; Stecco, Carla; Caro, Raffaele

    2014-01-01

    The anatomical theatre played a pivotal role in the evolution of medical education, allowing students to directly observe and participate in the process of dissection. Due to the increase of training programs in clinical anatomy, the Institute of Human Anatomy at the University of Padova has renovated its dissecting room. The main guidelines in…

  14. MR urography: Anatomical and quantitative information on ...

    African Journals Online (AJOL)

    Background and Aim: Magnetic resonance urography (MRU) is considered to be the next step in uroradiology. This technique combines superb anatomical images and functional information in a single test. In this article, we aim to present the topic of MRU in children and how it has been implemented in Northern Greece so ...

  15. 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...

  16. 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.

  17. Anatomical characteristics of southern pine stemwood

    Science.gov (United States)

    Elaine T. Howard; Floyd G. Manwiller

    1968-01-01

    To obtain a definitive description of the wood and anatomy of all 10 species of southern pine, juvenile, intermediate, and mature wood was sampled at three heights in one tree of each species and examined under a light microscope. Photographs and three-dimensional drawings were made to illustrate the morphology. No significant anatomical differences were found...

  18. ANATOMIC STRUCTURE OF CAMPANULA ROTUNDIFOLIA L. GRASS

    Directory of Open Access Journals (Sweden)

    V. N. Bubenchikova

    2017-01-01

    Full Text Available The article present results of the study for a anatomic structure of Campanula rotundifolia grass from Campanulaceae family. Despite its dispersion and application in folk medicine, there are no data about its anatomic structure, therefore to estimate the indices of authenticity and quality of raw materials it is necessary to develop microdiagnostical features in the first place, which could help introducing of thisplant in a medical practice. The purpose of this work is to study anatomical structureof Campanula rotundifolia grass to determine its diagnostic features. Methods. Thestudy for anatomic structure was carried out in accordance with the requirements of State Pharmacopoeia, edition XIII. Micromed laboratory microscope with digital adjutage was used to create microphotoes, Photoshop CC was used for their processing. Result. We have established that stalk epidermis is prosenchymal, slightly winding with straight of splayed end cells. After study for the epidermis cells we established that upper epidermis cells had straight walls and are slightly winding. The cells of lower epidermishave more winding walls with prolong wrinkled cuticule. Presence of simple one-cell, thin wall, rough papillose hair on leaf and stalk epidermis. Cells of epidermis in fauces of corolla are prosenchymal, with winding walls, straight or winding walls in a cup. Papillary excrescences can be found along the cup edges. Stomatal apparatus is anomocytic. Conclusion. As the result of the study we have carried out the research for Campanula rotundifolia grass anatomic structure, and determined microdiagnostic features for determination of raw materials authenticity, which included presence of simple, one-cell, thin-walled, rough papillose hair on both epidermises of a leaf, along the veins, leaf edge, and stalk epidermis, as well as the presence of epidermis cells with papillary excrescences along the edges of leaves and cups. Intercellular canals are situatedalong the

  19. Relevance of Whitnall's tubercle and auditory meatus in diagnosing exclusions during skull-photo superimposition.

    Science.gov (United States)

    Jayaprakash, Paul T; Hashim, Natassha; Yusop, Ridzuan Abd Aziz Mohd

    2015-08-01

    Video vision mixer based skull-photo superimposition is a popular method for identifying skulls retrieved from unidentified human remains. A report on the reliability of the superimposition method suggested increased failure rates of 17.3 to 32% to exclude and 15 to 20% to include skulls while using related and unrelated face photographs. Such raise in failures prompted an analysis of the methods employed for the research. The protocols adopted for assessing the reliability are seen to vary from those suggested by the practitioners in the field. The former include overlaying the skull- and face-images on the basis of morphology by relying on anthropometric landmarks on the front plane of the face-images and evaluating the goodness of match depending on mix-mode images; the latter consist of orienting the skull considering landmarks on both the eye and ear planes of the face- and skull-images and evaluating the match utilizing images seen in wipe-mode in addition to those in mix-mode. Superimposition of a skull with face-images of five living individuals in two sets of experiments, one following the procedure described for the research on reliability and the other applying the methods suggested by the practitioners has shown that overlaying the images on the basis of morphology depending on the landmarks on the front plane alone and assessing the match in mix-mode fails to exclude the skull. However, orienting the skull relying on the relationship between the anatomical landmarks on the skull- and face-images such as Whitnall's tubercle and exocanthus in the front (eye) plane and the porion and tragus in the rear (ear) plane as well as assessing the match using wipe-mode images enables excluding that skull while superimposing with the same set of face-images. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. 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

  1. MRI anatomical mapping and direct stereotactic targeting in the subthalamic region: functional and anatomical correspondence in Parkinson's disease

    International Nuclear Information System (INIS)

    Lemaire, Jean-Jacques; Coste, Jerome; Ouchchane, Lemlih; Hemm, Simone; Derost, Philippe; Ulla, Miguel; Durif, Franck; Siadoux, Severine; Gabrillargues, Jean; Chazal, Jean

    2007-01-01

    Object Relationships between clinical effects, anatomy, and electrophysiology are not fully understood in DBS of the subthalamic region in Parkinson's disease. We proposed an anatomic study based on direct image-guided stereotactic surgery with a multiple source data analysis. Materials and Methods A manual anatomic mapping was realized on coronal 1.5-Tesla MRI of 15 patients. Biological data were collected under local anesthesia: the spontaneous neuron activities and the clinical efficiency and the appearance of adverse effects. They were related to relevant current values (mA), the benefit threshold (bt, minimal current leading an clear efficiency), the adverse effect threshold (at, minimal current leading an adverse effect) and the stimulation margin (sm = at - bt); they were matched with anatomy. Results We found consistent relationships between anatomy and biological data. The optimal stimulation parameters (low bt + high sm) were noted in the dorsolateral STN. The highest spontaneous neuron activity was found in the ventromedial STN. Dorsolateral (sensorimotor) STN seems the main DBS effector. The highest spontaneous neuron activity seems related to the anterior (rostral) ventromedial (limbic) STN. Conclusion 1.5 Tesla images provide sufficiently detailed subthalamic anatomy for image-guided stereotactic surgery and may aid in understanding DBS mechanisms. (orig.)

  2. Renal mass anatomic characteristics and perioperative outcomes of laparoscopic partial nephrectomy: a critical analysis.

    Science.gov (United States)

    Tsivian, Matvey; Ulusoy, Said; Abern, Michael; Wandel, Ayelet; Sidi, A Ami; Tsivian, Alexander

    2012-10-01

    Anatomic parameters determining renal mass complexity have been used in a number of proposed scoring systems despite lack of a critical analysis of their independent contributions. We sought to assess the independent contribution of anatomic parameters on perioperative outcomes of laparoscopic partial nephrectomy (LPN). Preoperative imaging studies were reviewed for 147 consecutive patients undergoing LPN for a single renal mass. Renal mass anatomy was recorded: Size, growth pattern (endo-/meso-/exophytic), centrality (central/hilar/peripheral), anterior/posterior, lateral/medial, polar location. Multivariable models were used to determine associations of anatomic parameters with warm ischemia time (WIT), operative time (OT), estimated blood loss (EBL), intra- and postoperative complications, as well as renal function. All models were adjusted for the learning curve and relevant confounders. Median (range) tumor size was 3.3 cm (1.5-11 cm); 52% were central and 14% hilar. While 44% were exophytic, 23% and 33% were mesophytic and endophytic, respectively. Anatomic parameters did not uniformly predict perioperative outcomes. WIT was associated with tumor size (P=0.068), centrality (central, P=0.016; hilar, P=0.073), and endophytic growth pattern (P=0.017). OT was only associated with tumor size (Panatomic parameter predicted EBL. Tumor centrality increased the odds of overall and intraoperative complications, without reaching statistical significance. Postoperative renal function was not associated with any of the anatomic parameters considered after adjustment for baseline function and WIT. Learning curve, considered as a confounder, was independently associated with reduced WIT and OT as well as reduced odds of intraoperative complications. This study provides a detailed analysis of the independent impact of renal mass anatomic parameters on perioperative outcomes. Our findings suggest diverse independent contributions of the anatomic parameters to the

  3. "Direct DICOM Slice Landmarking" A Novel Research Technique to Quantify Skeletal Changes in Orthognathic Surgery.

    Science.gov (United States)

    Almukhtar, Anas; Khambay, Balvinder; Ayoub, Ashraf; Ju, Xiangyang; Al-Hiyali, Ali; Macdonald, James; Jabar, Norhayati; Goto, Tazuko

    2015-01-01

    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. "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.

  5. Landmark reading alterations in patients with gastro-oesophageal reflux symptoms undergoing diagnostic gastroscopy.

    Science.gov (United States)

    Kaplan, Mustafa; Tanoglu, Alpaslan; Sakin, Yusuf Serdar; Akyol, Taner; Oncu, Kemal; Kara, Muammer; Yazgan, Yusuf

    2016-12-01

    There is still a debate about the exact measurement of the oesophagogastric junction and the diaphragmatic hiatus among clinicians. The aim of this study was to investigate the differences between landmark readings of gastroscopy on intubation and extubation, and to correlate these readings with a gastro-oesophageal reflux questionnaire. 116 cases who underwent diagnostic gastroscopy between January 2013 and June 2013 were included in this study. Landmark measurements were noted while withdrawing the endoscope and were also evaluated after the gastric air was fully emptied. We first used a frequency scale for the gastro-oesophageal reflux disease symptoms (FSSG) questionnaire in order to investigate dysmotility and acid reflux symptoms in the study population and correlated the FSSG questionnaire with intubation and extubation measurements at endoscopic examination. Mean age of included subjects was 49.41±17.7 (19-82) years. Males and females were equally represented. On FSSG scores, the total dysmotility score was 7.99±5.06 and the total score was 15.18±10.11. The difference between intubation and extubation measurements ranged from -3cm to +2cm (mean: -0.4). When an FSSG score of 30 was accepted as a cut-off value, we detected a significant difference between the measurements (p<0.05; t: 0.048). Accuracy of landmark measurements during gastroscopy is clearly affected from insertion or withdrawal of the endoscope. When differences in measurements between insertion and withdrawal were evident, comparable with the FSSG scores, the results became significantly different. In conclusion, according to FSSG scores, these measurements should be performed at the end of the endoscopy. Copyright © 2016 Pan-Arab Association of Gastroenterology. Published by Elsevier B.V. All rights reserved.

  6. Anatomical sciences: A foundation for a solid learning experience in dental technology and dental prosthetics.

    Science.gov (United States)

    Bakr, Mahmoud M; Thompson, C Mark; Massadiq, Magdalena

    2017-07-01

    Basic science courses are extremely important as a foundation for scaffolding knowledge and then applying it in future courses, clinical situations as well as in a professional career. Anatomical sciences, which include tooth morphology, oral histology, oral embryology, and head and neck anatomy form a core part of the preclinical courses in dental technology programs. In this article, the importance and relevance of anatomical sciences to dental personnel with no direct contact with patients (dental technicians) and limited discipline related contact with patients (dental prosthetists) is highlighted. Some light is shed on the role of anatomical sciences in the pedagogical framework and its significance in the educational process and interprofessional learning of dental technicians and prosthetists using oral biology as an example in the dental curriculum. To conclude, anatomical sciences allow dental technicians and prosthetists to a gain a better insight of how tissues function, leading to a better understanding of diagnosis, comprehensive treatment planning and referrals if needed. Patient communication and satisfaction also increases as a result of this deep understanding of oral tissues. Anatomical sciences bridge the gap between basic science, preclinical, and clinical courses, which leads to a holistic approach in patient management. Finally, treatment outcomes are positively affected due to the appreciation of the macro and micro structure of oral tissues. Anat Sci Educ 10: 395-404. © 2016 American Association of Anatomists. © 2016 American Association of Anatomists.

  7. 100 years of Epilepsia: landmark papers and their influence in neuropsychology and neuropsychiatry.

    Science.gov (United States)

    Hermann, Bruce

    2010-07-01

    As part of the 2009 International League Against Epilepsy (ILAE) Centenary Celebration, a special symposium was dedicated to Epilepsia (100 Years of Epilepsia: Landmark Papers and Their Influence). The Associate Editors were asked to identify a particularly salient and meaningful paper in their areas of expertise. From the content areas of neuropsychology and neuropsychiatry two very interesting papers were identified using quite different ascertainment techniques. One paper addressed the problem of psychosis in temporal lobe epilepsy, whereas the other represents the first paper to appear in Epilepsia presenting quantitative assessment of cognitive status in epilepsy. These two papers are reviewed in detail and placed in historical context.

  8. Registration of cortical surfaces using sulcal landmarks for group analysis of MEG data☆

    Science.gov (United States)

    Joshi, Anand A.; Shattuck, David W.; Thompson, Paul M.; Leahy, Richard M.

    2010-01-01

    We present a method to register individual cortical surfaces to a surface-based brain atlas or canonical template using labeled sulcal curves as landmark constraints. To map one cortex smoothly onto another, we minimize a thin-plate spline energy defined on the surface by solving the associated partial differential equations (PDEs). By using covariant derivatives in solving these PDEs, we compute the bending energy with respect to the intrinsic geometry of the 3D surface rather than evaluating it in the flattened metric of the 2D parameter space. This covariant approach greatly reduces the confounding effects of the surface parameterization on the resulting registration. PMID:20824115

  9. Method of mobile robot indoor navigation by artificial landmarks with use of computer vision

    Science.gov (United States)

    Glibin, E. S.; Shevtsov, A. A.; Enik, O. A.

    2018-05-01

    The article describes an algorithm of the mobile robot indoor navigation based on the use of visual odometry. The results of the experiment identifying calculation errors in the distance traveled on a slip are presented. It is shown that the use of computer vision allows one to correct erroneous coordinates of the robot with the help of artificial landmarks. The control system utilizing the proposed method has been realized on the basis of Arduino Mego 2560 controller and a single-board computer Raspberry Pi 3. The results of the experiment on the mobile robot navigation with the use of this control system are presented.

  10. The atypical subthalamic nucleus--an anatomical variant relevant for stereotactic targeting.

    Science.gov (United States)

    Reese, René; Pinsker, Markus O; Herzog, Jan; Wodarg, Fritz; Steigerwald, Frank; Pötter-Nerger, Monika; Falk, Daniela; Deuschl, Günther; Mehdorn, H Maximilian; Volkmann, Jens

    2012-04-01

    The improvement of PD motor symptoms by DBS of the STN depends on exact targeting. A combination of MRI and multitrajectory microrecordings was used for localization of the STN in a group of 228 consecutive PD patients. In 1% of our cases, the STN was consistently shifted in the anterior (3.3 ± 0.8mm) and medial (3.0 ± 0.9 mm) direction within the target plane, compared to controls. Adjustment of the original target coordinates after intraoperative reevaluation of the MRI and confirmation by typical subthalamic neuronal recordings along the deviant trajectory allowed the implantation of clinically effective electrodes in all cases. The relative improvement of the motor UPDRS at 6-months follow-up in patients with an atypical and typical STN was comparable. An atypical position of the STN does not need to complicate DBS surgery, if detected by a combination of MRI-based targeting and electrophysiological guidance. Copyright © 2012 Movement Disorder Society.

  11. The fibular head projection is of limited use as a radiographic landmark in preoperative planning of total knee arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Matziolis, Doerte; Meiser, Marius; Matziolis, Georg [University Hospital Jena, Orthopedic Department, Eisenberg (Germany); Sieber, Norbert [Radiology Practice Eisenberg, Eisenberg (Germany); Teichgraeber, Ulf [University Hospital Jena, Institute of Diagnostic and Interventional Radiology, Eisenberg (Germany)

    2017-10-15

    The projection of the fibular head is recommended as a quality indicator of a correct radiographic projection. However, this landmark has yet to be sufficiently validated. The MRIs of 334 knee joints were included. On the MRIs, the distance between the FH and lateral tibial cortical bone was simulated in projections parallel to surgically relevant axes. Then, the Pearson correlation coefficient between the distance of the FH to the lateral tibial cortical bone and the projection plane causing this was determined. A projection of the knee joint perpendicular to Akagi's line projected the center of the fibular head on average 4.8 ± 2.9 mm laterally of the tibial cortical bone, parallel to the maximum mediolateral axis of the tibia 7.5 ± 3.4 mm, parallel to the posterior condylar axis 5.6 ± 3.6 mm and parallel to the surgical epicondylar axis 6.1 ± 3.5 mm laterally of the tibial cortical bone. An almost linear correlation was seen, with 1.9 tilting of the projection plane per mm change in distance between the fibular head and tibial cortical bone. At the same time, the interindividual scatter was over 60 . The rule of thumb for a partial overlap of the fibular head by the tibia in the case of a correct antero-posterior projection plane was also confirmed. However, a considerable interindividual variability of the position of the FH was found, which limits a conclusion regarding the quality of the radiographic projection on the basis of the position of the fibular head. (orig.)

  12. Double uterus with obstructed hemivagina and ipsilateral renal agenesis: pelvic anatomic variants in 87 cases.

    Science.gov (United States)

    Fedele, L; Motta, F; Frontino, G; Restelli, E; Bianchi, S

    2013-06-01

    What are the anatomic variants (and their frequencies) of double uterus, obstructed hemivagina and ipsilateral renal agenesis? Most cases examined (72.4%) were of the classic anatomic variant of the Herlyn-Werner-Wunderlich syndrome (with didelphys uterus, obstructed hemivagina and ipsilateral renal agenesis) but the 27.6% of cases are of a rare variant of the syndrome (with uterus septum or cervical agenesis), showing relevant clinical and surgical implications. The extreme variability of anatomic structures involved in this syndrome (both uterus, cervico-vaginal and renal anomalies) is well known, even if a complete and uniform analysis of all its heterogeneous presentations in a large series is lacking. This is a retrospective study with 87 patients referred to our third level referral center between 1981 and 2011. We analyzed the laparoscopic and chart records of 87 women, who referred to our institute with double uterus, unilateral cervico-vaginal obstruction and ipsilateral renal anomalies. Sixty-three of 87 patients had the more classic variant of didelphys uterus with obstructed hemivagina; 10/87 patients had septate bicollis uterus with obstructed hemivagina; 9/87 patients had bicornuate bicollis uterus with obstructed hemivagina; 4/87 patients had didelphys uterus with unilateral cervical atresia; 1/87 patients had bicornuate uterus with one septate cervix and unilateral obstructed hemivagina. This is a retrospective study with a long enrolling period (30 years). New insights in the anatomic variants of this rare syndrome with their relevant surgical implications.

  13. Accurate landmarking of three-dimensional facial data in the presence of facial expressions and occlusions using a three-dimensional statistical facial feature model.

    Science.gov (United States)

    Zhao, Xi; Dellandréa, Emmanuel; Chen, Liming; Kakadiaris, Ioannis A

    2011-10-01

    Three-dimensional face landmarking aims at automatically localizing facial landmarks and has a wide range of applications (e.g., face recognition, face tracking, and facial expression analysis). Existing methods assume neutral facial expressions and unoccluded faces. In this paper, we propose a general learning-based framework for reliable landmark localization on 3-D facial data under challenging conditions (i.e., facial expressions and occlusions). Our approach relies on a statistical model, called 3-D statistical facial feature model, which learns both the global variations in configurational relationships between landmarks and the local variations of texture and geometry around each landmark. Based on this model, we further propose an occlusion classifier and a fitting algorithm. Results from experiments on three publicly available 3-D face databases (FRGC, BU-3-DFE, and Bosphorus) demonstrate the effectiveness of our approach, in terms of landmarking accuracy and robustness, in the presence of expressions and occlusions.

  14. 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

  15. Anatomically corrected transposition of great vessels

    International Nuclear Information System (INIS)

    Ivanitskij, A.V.; Sarkisova, T.N.

    1989-01-01

    The paper is concerned with the description of rare congenital heart disease: anatomically corrected malposition of major vessels in a 9-mos 24 day old girl. The diagnosis of this disease was shown on the results of angiocardiography, concomitant congenital heart diseases were descibed. This abnormality is characterized by common atrioventricular and ventriculovascular joints and inversion position of the major vessels, it is always attended by congenital heart diseases. Surgical intervention is aimed at the elimination of concomitant heart dieseases

  16. Comparing the accuracy and precision of three techniques used for estimating missing landmarks when reconstructing fossil hominin crania.

    Science.gov (United States)

    Neeser, Rudolph; Ackermann, Rebecca Rogers; Gain, James

    2009-09-01

    Various methodological approaches have been used for reconstructing fossil hominin remains in order to increase sample sizes and to better understand morphological variation. Among these, morphometric quantitative techniques for reconstruction are increasingly common. Here we compare the accuracy of three approaches--mean substitution, thin plate splines, and multiple linear regression--for estimating missing landmarks of damaged fossil specimens. Comparisons are made varying the number of missing landmarks, sample sizes, and the reference species of the population used to perform the estimation. The testing is performed on landmark data from individuals of Homo sapiens, Pan troglodytes and Gorilla gorilla, and nine hominin fossil specimens. Results suggest that when a small, same-species fossil reference sample is available to guide reconstructions, thin plate spline approaches perform best. However, if no such sample is available (or if the species of the damaged individual is uncertain), estimates of missing morphology based on a single individual (or even a small sample) of close taxonomic affinity are less accurate than those based on a large sample of individuals drawn from more distantly related extant populations using a technique (such as a regression method) able to leverage the information (e.g., variation/covariation patterning) contained in this large sample. Thin plate splines also show an unexpectedly large amount of error in estimating landmarks, especially over large areas. Recommendations are made for estimating missing landmarks under various scenarios. Copyright 2009 Wiley-Liss, Inc.

  17. Prospective analysis of in vivo landmark point-based MRI geometric distortion in head and neck cancer patients scanned in immobilized radiation treatment position: Results of a prospective quality assurance protocol

    Directory of Open Access Journals (Sweden)

    Abdallah S.R. Mohamed

    2017-12-01

    Full Text Available Purpose: Uncertainties related to geometric distortion are a major obstacle for effectively utilizing MRI in radiation oncology. We aim to quantify the geometric distortion in patient images by comparing their in-treatment position MRIs with the corresponding planning CTs, using CT as the non-distorted gold standard. Methods: Twenty-one head and neck cancer patients were imaged with MRI as part of a prospective Institutional Review Board approved study. MR images were acquired with a T2 SE sequence (0.5 × 0.5 × 2.5 mm voxel size in the same immobilization position as in the CTs. MRI to CT rigid registration was then done and geometric distortion comparison was assessed by measuring the corresponding anatomical landmarks on both the MRI and the CT images. Several landmark measurements were obtained including; skin to skin (STS, bone to bone, and soft tissue to soft tissue at specific levels in horizontal and vertical planes of both scans. Inter-observer variability was assessed and interclass correlation (ICC was calculated. Results: A total of 430 landmark measurements were obtained. The median distortion for all landmarks in all scans was 1.06 mm (IQR 0.6–1.98. For each patient 48% of the measurements were done in the right-left direction and 52% were done in the anteroposterior direction. The measured geometric distortion was not statistically different in the right-left direction compared to the anteroposterior direction (1.5 ± 1.6 vs. 1.6 ± 1.7 mm, respectively, p = 0.4. The magnitude of distortion was higher in the STS peripheral landmarks compared to the more central landmarks (2.0 ± 1.9 vs. 1.2 ± 1.3 mm, p < 0.0001. The mean distortion measured by observer one was not significantly different compared to observer 2, 3, and 4 (1.05, 1.23, 1.06 and 1.05 mm, respectively, p = 0.4 with ICC = 0.84. Conclusion: MRI geometric distortions were

  18. Anatomic variation of cranial parasympathetic ganglia

    Directory of Open Access Journals (Sweden)

    Selma Siéssere

    2008-06-01

    Full Text Available Having broad knowledge of anatomy is essential for practicing dentistry. Certain anatomical structures call for detailed studies due to their anatomical and functional importance. Nevertheless, some structures are difficult to visualize and identify due to their small volume and complicated access. Such is the case of the parasympathetic ganglia located in the cranial part of the autonomic nervous system, which include: the ciliary ganglion (located deeply in the orbit, laterally to the optic nerve, the pterygopalatine ganglion (located in the pterygopalatine fossa, the submandibular ganglion (located laterally to the hyoglossus muscle, below the lingual nerve, and the otic ganglion (located medially to the mandibular nerve, right beneath the oval foramen. The aim of this study was to present these structures in dissected anatomic specimens and perform a comparative analysis regarding location and morphology. The proximity of the ganglia and associated nerves were also analyzed, as well as the number and volume of fibers connected to them. Human heads were dissected by planes, partially removing the adjacent structures to the point we could reach the parasympathetic ganglia. With this study, we concluded that there was no significant variation regarding the location of the studied ganglia. Morphologically, our observations concur with previous classical descriptions of the parasympathetic ganglia, but we observed variations regarding the proximity of the otic ganglion to the mandibular nerve. We also observed that there were variations regarding the number and volume of fiber bundles connected to the submandibular, otic, and pterygopalatine ganglia.

  19. Laryngeal spaces and lymphatics: current anatomic concepts

    International Nuclear Information System (INIS)

    Welsh, L.W.; Welsh, J.J.; Rizzo, T.A. Jr.

    1983-01-01

    This investigation evaluates the anatomic concepts of individual spaces or compartments within the larynx by isotope and dye diffusion. The authors identified continuity of spaces particularly within the submucosal planes and a relative isolation within the fixed structures resulting from the longitudinal pattern of fibroelastic tissues, muscle bands, and perichondrium. The historical data of anatomic resistance are refuted by the radioisotope patterns of dispersion and the histologic evidence of tissue permeability to the carbon particles. There is little clinical application of the compartment concept to the perimeter of growth and the configuration of extensive endolaryngeal cancers. The internal and extralaryngeal lymphatic network is presented and the regional associations are identified. The normal ipsilateral relationship is distorted by dispersion within the endolarynx supervening the anatomic midline. The effects of lymphatic obstruction caused by regional lymphadenectomy, tumor fixation, and irradiation-infection sequelae are illustrated; these result in widespread bilateral lymphatic nodal terminals. Finally, the evidence suggests that the internal network is modified by external interruption to accommodate an outflow system in continuity with the residual patent lymphatic channels

  20. A Customizable Multimodality Imaging Compound That Relates External Landmarks to Internal Structures.

    Science.gov (United States)

    Semework, Mulugeta

    2015-12-01

    Numerous research and clinical interventions, such as targeting drug deliveries or surgeries and finding blood clots, abscesses, or lesions, require accurate localization of various body parts. Individual differences in anatomy make it hard to use typical stereotactic procedures that rely on external landmarks and standardized atlases. For instance, it is not unusual to incorrectly place a craniotomy in brain surgery. This project was thus performed to find a new and easy method to correctly establish the relationship between external landmarks and medical scans of internal organs, such as specific regions of the brain. This paper introduces an MRI, CT, and radiographically visible compound that can be applied to any surface and therefore provide an external reference point to an internal (eye-invisible) structure. Tested on nonhuman primates and isolated brain scans, this compound showed up with the same color in different scan types, making practical work possible. Conventional, and mostly of specific utility, products such as contrast agents were differentially colored or completely failed to show up and were not flexible. This compound can be customized to have different viscosities, colors, odors, and other characteristics. It can also be mixed with hardening materials such as acrylic for industrial or engineering uses, for example. Laparoscopy wands, electroencephalogram leads, and other equipment could also be embedded with or surrounded by the compound for ease in 3-dimensional visualizations. A pending U.S. patent endorses this invention. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  1. One-shot 3D scanning by combining sparse landmarks with dense gradient information

    Science.gov (United States)

    Di Martino, Matías; Flores, Jorge; Ferrari, José A.

    2018-06-01

    Scene understanding is one of the most challenging and popular problems in the field of robotics and computer vision and the estimation of 3D information is at the core of most of these applications. In order to retrieve the 3D structure of a test surface we propose a single shot approach that combines dense gradient information with sparse absolute measurements. To that end, we designed a colored pattern that codes fine horizontal and vertical fringes, with sparse corners landmarks. By measuring the deformation (bending) of horizontal and vertical fringes, we are able to estimate surface local variations (i.e. its gradient field). Then corner sparse landmarks are detected and matched to infer spare absolute information about the test surface height. Local gradient information is combined with the sparse absolute values which work as anchors to guide the integration process. We show that this can be mathematically done in a very compact and intuitive way by properly defining a Poisson-like partial differential equation. Then we address in detail how the problem can be formulated in a discrete domain and how it can be practically solved by straight forward linear numerical solvers. Finally, validation experiment are presented.

  2. 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.

  3. Probability-Based Recognition Framework for Underwater Landmarks Using Sonar Images †.

    Science.gov (United States)

    Lee, Yeongjun; Choi, Jinwoo; Ko, Nak Yong; Choi, Hyun-Taek

    2017-08-24

    This paper proposes a probability-based framework for recognizing underwater landmarks using sonar images. Current recognition methods use a single image, which does not provide reliable results because of weaknesses of the sonar image such as unstable acoustic source, many speckle noises, low resolution images, single channel image, and so on. However, using consecutive sonar images, if the status-i.e., the existence and identity (or name)-of an object is continuously evaluated by a stochastic method, the result of the recognition method is available for calculating the uncertainty, and it is more suitable for various applications. Our proposed framework consists of three steps: (1) candidate selection, (2) continuity evaluation, and (3) Bayesian feature estimation. Two probability methods-particle filtering and Bayesian feature estimation-are used to repeatedly estimate the continuity and feature of objects in consecutive images. Thus, the status of the object is repeatedly predicted and updated by a stochastic method. Furthermore, we develop an artificial landmark to increase detectability by an imaging sonar, which we apply to the characteristics of acoustic waves, such as instability and reflection depending on the roughness of the reflector surface. The proposed method is verified by conducting basin experiments, and the results are presented.

  4. Visual navigation of the UAVs on the basis of 3D natural landmarks

    Science.gov (United States)

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

    2015-12-01

    This work considers the tracking of the UAV (unmanned aviation vehicle) on the basis of onboard observations of natural landmarks including azimuth and elevation angles. It is assumed that UAV's cameras are able to capture the angular position of reference points and to measure the angles of the sight line. Such measurements involve the real position of UAV in implicit form, and therefore some of nonlinear filters such as Extended Kalman filter (EKF) or others must be used in order to implement these measurements for UAV control. Recently it was shown that modified pseudomeasurement method may be used to control UAV on the basis of the observation of reference points assigned along the UAV path in advance. However, the use of such set of points needs the cumbersome recognition procedure with the huge volume of on-board memory. The natural landmarks serving as such reference points which may be determined on-line can significantly reduce the on-board memory and the computational difficulties. The principal difference of this work is the usage of the 3D reference points coordinates which permits to determine the position of the UAV more precisely and thereby to guide along the path with higher accuracy which is extremely important for successful performance of the autonomous missions. The article suggests the new RANSAC for ISOMETRY algorithm and the use of recently developed estimation and control algorithms for tracking of given reference path under external perturbation and noised angular measurements.

  5. Superior cognitive mapping through single landmark-related learning than through boundary-related learning.

    Science.gov (United States)

    Zhou, Ruojing; Mou, Weimin

    2016-08-01

    Cognitive mapping is assumed to be through hippocampus-dependent place learning rather than striatum-dependent response learning. However, we proposed that either type of spatial learning, as long as it involves encoding metric relations between locations and reference points, could lead to a cognitive map. Furthermore, the fewer reference points to specify individual locations, the more accurate a cognitive map of these locations will be. We demonstrated that participants have more accurate representations of vectors between 2 locations and of configurations among 3 locations when locations are individually encoded in terms of a single landmark than when locations are encoded in terms of a boundary. Previous findings have shown that learning locations relative to a boundary involve stronger place learning and higher hippocampal activation whereas learning relative to a single landmark involves stronger response learning and higher striatal activation. Recognizing this, we have provided evidence challenging the cognitive map theory but favoring our proposal. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  6. 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

    2016-09-05

    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.

  7. PEOPLE'S EVALUATION TOWARDS MEDIA FAÇADE AS NEW URBAN LANDMARKS AT NIGHT

    Directory of Open Access Journals (Sweden)

    Elyas Vahedi Moghaddam

    2016-04-01

    Full Text Available This paper attempts to help designers to turn a building into media facade as an attractive landmark for people’s urban night life. The literature survey points towards being dynamic and interactive with observers as the two quality dimensions for implementing this emerging lighting technology. Based on a survey of eleven selected media facades using video films to 250 students and staff at a public university, results identified twelve attributes for these two qualities. However, item analysis and exploratory factor analysis of the results determined only ten attributes actually support people’s attention towards media facade. The attributes of unique landmark, different nocturnal appearance, dynamic colour, informative lighting, artistic lighting performance, on going process, and dynamic advertisement could be categorized under the visual quality dimension. On the other hand, attributes of covert interaction, overt interaction, and predesigned interaction could be categorized under the interactive quality dimension. This study contributes in prioritizing visual qualities for guiding the attractiveness of buildings’ appearances at night, hence enabling the creation of new dynamic urban spaces when designing buildings.

  8. Anatomical relations of anterior and posterior ankle arthroscopy portals: a cadaveric study.

    Science.gov (United States)

    Oliva, Xavier Martin; Méndez López, José Manuel; Monzo Planella, Mariano; Bravo, Alex; Rodrigues-Pinto, Ricardo

    2015-04-01

    Ankle arthroscopy is an increasingly used technique. Knowledge of the anatomical structures in relation to its portals is paramount to avoid complications. Twenty cadaveric ankles were analysed to assess the distance between relevant neurovascular structures to the anteromedial, anterolateral, posteromedial, and posterolateral arthroscopy portals. The intermediate dorsal branch of the superficial peroneal nerve was the closest structure to any of the portals (4.8 mm from the anterolateral portal), followed by the posterior tibial nerve (7.3 mm from the posteromedial portal). All structures analysed but one (posterior tibial artery) were, at least in one specimen, portals. This study provides information on the anatomical relations of ankle arthroscopy portals and relevant neurovascular structures, confirming previous studies identifying the superficial peroneal nerve as the structure at highest risk of injury, but also highlighting some important variations. Techniques to minimise the injury to these structures are discussed.

  9. Vertebral artery injury in cervical spine surgery: anatomical considerations, management, and preventive measures.

    Science.gov (United States)

    Peng, Chan W; Chou, Benedict T; Bendo, John A; Spivak, Jeffrey M

    2009-01-01

    Vertebral artery (VA) injury can be a catastrophic iatrogenic complication of cervical spine surgery. Although the incidence is rare, it has serious consequences including fistulas, pseudoaneurysm, cerebral ischemia, and death. It is therefore imperative to be familiar with the anatomy and the instrumentation techniques when performing anterior or posterior cervical spine surgeries. To provide a review of VA injury during common anterior and posterior cervical spine procedures with an evaluation of the surgical anatomy, management, and prevention of this injury. Comprehensive literature review. A systematic review of Medline for articles related to VA injury in cervical spine surgery was conducted up to and including journal articles published in 2007. The literature was then reviewed and summarized. Overall, the risk of VA injury during cervical spine surgery is low. In anterior cervical procedures, lateral dissection puts the VA at the most risk, so sound anatomical knowledge and constant reference to the midline are mandatory during dissection. With the development and rise in popularity of posterior cervical stabilization and instrumentation, recognition of the dangers of posterior drilling and insertion of transarticular screws and pedicle screws is important. Anomalous vertebral anatomy increases the risk of injury and preoperative magnetic resonance imaging and/or computed tomography (CT) scans should be carefully reviewed. When the VA is injured, steps should be taken to control local bleeding. Permanent occlusion or ligation should only be attempted if it is known that the contralateral VA is capable of providing adequate collateral circulation. With the advent of endovascular repair, this treatment option can be considered when a VA injury is encountered. VA injury during cervical spine surgery is a rare but serious complication. It can be prevented by careful review of preoperative imaging studies, having a sound anatomical knowledge and paying attention

  10. Tomographic diagnosis and relevant aspects of otosclerosis

    International Nuclear Information System (INIS)

    Gaiotti, Juliana Oggioni; Gomes, Natalia Delage; Costa, Ana Maria Doffemond; Villela, Caroline Laurita Batista Couto; Moreira, Wanderval; Diniz, Renata Lopes Furletti Caldeira

    2013-01-01

    A literature review and pictorial essay were developed to discuss the importance of knowing the main findings and locations of otosclerosis at multidetector computed tomography (MDCT). The authors performed a retrospective review of cases of otosclerosis diagnosed in their institution by means of high resolution multidetector computed tomography. Otosclerosis corresponds to otic capsule dysplasia characterized by metabolic derangement of its endochondral layer. Such condition constitutes a relevant cause of sensorineural hearing loss, affecting about 7% to 10% of the general population. The diagnosis is usually clinical, but imaging methods play a significant role in the anatomical detailing, differential diagnosis, surgical planning and evaluation of postoperative complications. Among such methods, the relevance of MDCT is highlighted. Radiologists should be familiar with the MDCT findings of otosclerosis, as well as with the temporal bone anatomy to assist in the appropriate clinical management of this disease. (author)

  11. Tomographic diagnosis and relevant aspects of otosclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Gaiotti, Juliana Oggioni; Gomes, Natalia Delage; Costa, Ana Maria Doffemond; Villela, Caroline Laurita Batista Couto; Moreira, Wanderval; Diniz, Renata Lopes Furletti Caldeira, E-mail: jugaiotti@gmail.com [Hospital Mater Dei-Mater Imagem, Belo Horizonte, MG (Brazil)

    2013-09-15

    A literature review and pictorial essay were developed to discuss the importance of knowing the main findings and locations of otosclerosis at multidetector computed tomography (MDCT). The authors performed a retrospective review of cases of otosclerosis diagnosed in their institution by means of high resolution multidetector computed tomography. Otosclerosis corresponds to otic capsule dysplasia characterized by metabolic derangement of its endochondral layer. Such condition constitutes a relevant cause of sensorineural hearing loss, affecting about 7% to 10% of the general population. The diagnosis is usually clinical, but imaging methods play a significant role in the anatomical detailing, differential diagnosis, surgical planning and evaluation of postoperative complications. Among such methods, the relevance of MDCT is highlighted. Radiologists should be familiar with the MDCT findings of otosclerosis, as well as with the temporal bone anatomy to assist in the appropriate clinical management of this disease. (author)

  12. Not only … but also: REM sleep creates and NREM Stage 2 instantiates landmark junctions in cortical memory networks.

    Science.gov (United States)

    Llewellyn, Sue; Hobson, J Allan

    2015-07-01

    This article argues both rapid eye movement (REM) and non-rapid eye movement (NREM) sleep contribute to overnight episodic memory processes but their roles differ. Episodic memory may have evolved from memory for spatial navigation in animals and humans. Equally, mnemonic navigation in world and mental space may rely on fundamentally equivalent processes. Consequently, the basic spatial network characteristics of pathways which meet at omnidirectional nodes or junctions may be conserved in episodic brain networks. A pathway is formally identified with the unidirectional, sequential phases of an episodic memory. In contrast, the function of omnidirectional junctions is not well understood. In evolutionary terms, both animals and early humans undertook tours to a series of landmark junctions, to take advantage of resources (food, water and shelter), whilst trying to avoid predators. Such tours required memory for emotionally significant landmark resource-place-danger associations and the spatial relationships amongst these landmarks. In consequence, these tours may have driven the evolution of both spatial and episodic memory. The environment is dynamic. Resource-place associations are liable to shift and new resource-rich landmarks may be discovered, these changes may require re-wiring in neural networks. To realise these changes, REM may perform an associative, emotional encoding function between memory networks, engendering an omnidirectional landmark junction which is instantiated in the cortex during NREM Stage 2. In sum, REM may preplay associated elements of past episodes (rather than replay individual episodes), to engender an unconscious representation which can be used by the animal on approach to a landmark junction in wake. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. 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.

  14. Anatomical study of phrenic nerve course in relation to neck dissection.

    Science.gov (United States)

    Hamada, Tomohiro; Usami, Akinobu; Kishi, Asuka; Kon, Hideki; Takada, Satoshi

    2015-04-01

    The present study sought to clarify the course of the phrenic nerve and its correlation with anatomical landmarks in the neck region. We examined 17 cadavers (30 sides). In each, the phrenic nerves was dissected from the lateral side of the neck, and its position within the triangle formed by the mastoid process and sternal and acromial ends of the clavicle was determined. The point where the phrenic nerve arises in the posterior triangle was found to be similar to the point where the cutaneous blanches of the cervical plexus emerge at the middle of the posterior border of the sternocleidomastoid muscle. In the supraclavian triangle, the phrenic nerve crosses the anterior border of the anterior scalene muscle near Erb's point where the superficial point is 2-3 cm superior from the clavicle and posterior border of the sternocleidomastoid muscle. The phrenic nerve arises in the posterior triangle near the nerve point, then descends to the anterior surface of the anterior scalene muscle in the supraclavian triangle. It is necessary to be aware of the supraclavian triangle below Erb's point during neck dissection procedures.

  15. 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

  16. 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.

  17. Radiographic landmarks for locating the femoral origin of the superficial medial collateral ligament.

    Science.gov (United States)

    Hartshorn, Timothy; Otarodifard, Karimdad; White, Eric A; Hatch, George F Rick

    2013-11-01

    Little has been written about the use of radiographic landmarks for locating the origin of the superficial medial collateral ligament (sMCL). A standardized radiographic landmark for the sMCL origin using intraoperative fluoroscopic imaging may be of value in aiding the surgeon in accurate femoral tunnel placement in the setting of extensive soft tissue disruption and bony attrition. To determine a reproducible radiographic landmark that will assist in correct femoral tunnel placement in sMCL repair and reconstruction. Descriptive laboratory study. Ten fresh-frozen unmatched human cadaveric knees were dissected, and the origin of the sMCL was exposed. A 2-mm metallic marker was then placed at the center of the femoral origin of the sMCL. True lateral fluoroscopically assisted digital radiographs were obtained of the knee with the posterior and distal femoral condyles overlapping in a standardized fashion. With the use of computer software, reference lines were drawn on the images, creating 4 quadrants. Two independent examiners performed quantitative measurements of the sMCL origin in relation to this axis and to the Blumensaat line. Mean measurements showed the sMCL origin to be closely related to the intersection point of the Blumensaat line and a line drawn distally from the posterior femoral cortex on a true lateral radiograph. The sMCL origin was found at a mean point 1.6 ± 4.3 mm posterior and 4.9 ± 2.1 mm proximal to the intersection of a line paralleling the posterior femoral cortex and a line drawn perpendicular to the posterior femoral cortical line, where it intersects the Blumensaat line. In 5 of 10 specimens, the center of the sMCL origin fell precisely on the Blumensaat line. The remaining specimens had sMCL origins anterior to the Blumensaat line. The femoral origin of the sMCL was found in the proximal and posterior quadrants in 8 of 10 specimens. With a relatively small amount of deviation, the sMCL origin can be consistently identified on a true

  18. Familial intracranial aneurysms: is anatomic vulnerability heritable?

    Science.gov (United States)

    Mackey, Jason; Brown, Robert D; Moomaw, Charles J; Hornung, Richard; Sauerbeck, Laura; Woo, Daniel; Foroud, Tatiana; Gandhi, Dheeraj; Kleindorfer, Dawn; Flaherty, Matthew L; Meissner, Irene; Anderson, Craig; Rouleau, Guy; Connolly, E Sander; Deka, Ranjan; Koller, Daniel L; Abruzzo, Todd; Huston, John; Broderick, Joseph P

    2013-01-01

    Previous studies have suggested that family members with intracranial aneurysms (IAs) often harbor IAs in similar anatomic locations. IA location is important because of its association with rupture. We tested the hypothesis that anatomic susceptibility to IA location exists using a family-based IA study. We identified all affected probands and first-degree relatives (FDRs) with a definite or probable phenotype in each family. We stratified each IA of the probands by major arterial territory and calculated each family's proband-FDR territory concordance and overall contribution to the concordance analysis. We then matched each family unit to an unrelated family unit selected randomly with replacement and performed 1001 simulations. The median concordance proportions, odds ratios (ORs), and P values from the 1001 logistic regression analyses were used to represent the final results of the analysis. There were 323 family units available for analysis, including 323 probands and 448 FDRs, with a total of 1176 IAs. IA territorial concordance was higher in the internal carotid artery (55.4% versus 45.6%; OR, 1.54 [1.04-2.27]; P=0.032), middle cerebral artery (45.8% versus 30.5%; OR, 1.99 [1.22-3.22]; P=0.006), and vertebrobasilar system (26.6% versus 11.3%; OR, 2.90 [1.05-8.24], P=0.04) distributions in the true family compared with the comparison family. Concordance was also higher when any location was considered (53.0% versus 40.7%; OR, 1.82 [1.34-2.46]; PIA development, we found that IA territorial concordance was higher when probands were compared with their own affected FDRs than with comparison FDRs, which suggests that anatomic vulnerability to IA formation exists. Future studies of IA genetics should consider stratifying cases by IA location.

  19. Chronic ankle instability: Arthroscopic anatomical repair.

    Science.gov (United States)

    Arroyo-Hernández, M; Mellado-Romero, M; Páramo-Díaz, P; García-Lamas, L; Vilà-Rico, J

    Ankle sprains are one of the most common injuries. Despite appropriate conservative treatment, approximately 20-40% of patients continue to have chronic ankle instability and pain. In 75-80% of cases there is an isolated rupture of the anterior talofibular ligament. A retrospective observational study was conducted on 21 patients surgically treated for chronic ankle instability by means of an arthroscopic anatomical repair, between May 2012 and January 2013. There were 15 men and 6 women, with a mean age of 30.43 years (range 18-48). The mean follow-up was 29 months (range 25-33). All patients were treated by arthroscopic anatomical repair of anterior talofibular ligament. Four (19%) patients were found to have varus hindfoot deformity. Associated injuries were present in 13 (62%) patients. There were 6 cases of osteochondral lesions, 3 cases of posterior ankle impingement syndrome, and 6 cases of peroneal pathology. All these injuries were surgically treated in the same surgical time. A clinical-functional study was performed using the American Orthopaedic Foot and Ankle Society (AOFAS) score. The mean score before surgery was 66.12 (range 60-71), and after surgery it increased up to a mean of 96.95 (range 90-100). All patients were able to return to their previous sport activity within a mean of 21.5 weeks (range 17-28). Complications were found in 3 (14%) patients. Arthroscopic anatomical ligament repair technique has excellent clinical-functional results with a low percentage of complications, and enables patients to return to their previous sport activity within a short period of time. Copyright © 2016 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. An anatomical study of the proximal aspect of the medial femoral condyle to define the proximal-distal condylar length

    Directory of Open Access Journals (Sweden)

    Chia-Ming Chang

    2017-01-01

    Full Text Available Objective: Despite its possible role in knee arthroplasty, the proximal-distal condylar length (PDCL of the femur has never been reported in the literature. We conducted an anatomic study of the proximal aspect of the medial femoral condyle to propose a method for measuring the PDCL. Materials and Methods: Inspection of dried bone specimens was carried out to assure the most proximal condylar margin (MPCM as the eligible starting point to measure the PDCL. Simulation surgery was performed on seven pairs of cadaveric knees to verify the clinical application of measuring the PDCL after locating the MPCM. Interobserver reliability of this procedure was also analyzed. Results: Observation of the bone specimens showed that the MPCM is a concavity formed by the junction of the distal end of the supracondylar ridge and the proximal margin of the medial condyle. This anatomically distinctive structure made the MPCM an unambiguous landmark. The cadaveric simulation surgical dissection demonstrated that the MPCM is easily accessed in a surgical setting, making the measurement of the PDCL plausible. The intraclass correlation coefficient was 0.78, indicating good interobserver reliability for this technique. Conclusion: This study has suggested that the PDCL can be measured based on the MPCM in a surgical setting. PDCL measurement might be useful in joint line position management, selection of femoral component sizes, and other applications related to the proximal-distal dimension of the knee. Further investigation is required.

  1. Direct visualization of anatomic subfields within the superior aspect of the human lateral thalamus by MRI at 7T.

    Science.gov (United States)

    Kanowski, M; Voges, J; Buentjen, L; Stadler, J; Heinze, H-J; Tempelmann, C

    2014-09-01

    The morphology of the human thalamus shows high interindividual variability. Therefore, direct visualization of landmarks within the thalamus is essential for an improved definition of electrode positions for deep brain stimulation. The aim of this study was to provide anatomic detail in the thalamus by using inversion recovery TSE imaging at 7T. The MR imaging protocol was optimized on 1 healthy subject to segment thalamic nuclei from one another. Final images, acquired with 0.5(2)-mm2 in-plane resolution and 3-mm section thickness, were compared with stereotactic brain atlases to assign visualized details to known anatomy. The robustness of the visualization of thalamic nuclei was assessed with 4 healthy subjects at lower image resolution. Thalamic subfields were successfully delineated in the dorsal aspect of the lateral thalamus. T1-weighting was essential. MR images had an appearance very similar to that of myelin-stained sections seen in brain atlases. Visualized intrathalamic structures were, among others, the lamella medialis, the external medullary lamina, the reticulatum thalami, the nucleus centre médian, the boundary between the nuclei dorso-oralis internus and externus, and the boundary between the nuclei dorso-oralis internus and zentrolateralis intermedius internus. Inversion recovery-prepared TSE imaging at 7T has a high potential to reveal fine anatomic detail in the thalamus, which may be helpful in enhancing the planning of stereotactic neurosurgery in the future. © 2014 by American Journal of Neuroradiology.

  2. Making Deferred Taxes Relevant

    NARCIS (Netherlands)

    Brouwer, Arjan; Naarding, Ewout

    2018-01-01

    We analyse the conceptual problems in current accounting for deferred taxes and provide solutions derived from the literature in order to make International Financial Reporting Standards (IFRS) deferred tax numbers value-relevant. In our view, the empirical results concerning the value relevance of

  3. Parsimonious relevance models

    NARCIS (Netherlands)

    Meij, E.; Weerkamp, W.; Balog, K.; de Rijke, M.; Myang, S.-H.; Oard, D.W.; Sebastiani, F.; Chua, T.-S.; Leong, M.-K.

    2008-01-01

    We describe a method for applying parsimonious language models to re-estimate the term probabilities assigned by relevance models. We apply our method to six topic sets from test collections in five different genres. Our parsimonious relevance models (i) improve retrieval effectiveness in terms of

  4. Talocalcaneal luxation: an anatomic and clinical study

    International Nuclear Information System (INIS)

    Gorse, M.J.; Purinton, P.T.; Penwick, R.C.; Aron, D.N.; Roberts, R.E.

    1990-01-01

    Talocalcaneal luxation in dogs was studied by anatomic dissection of the talocalcaneal joint in cadavers and review of five clinical cases. The integrity of the talocalcaneal joint was maintained by two strong ligaments traversing the tarsal sinus between the two bones. The joint was found to be a low motion joint. Luxation in clinical cases was not always apparent on standard radiographic views. Three dogs were treated surgically with a screw inserted in lag fashion from talus to calcaneus. One luxation was treated surgically with figure-of-eight orthopedic wires and one was treated with external coaptation. Four dogs returned to their previous levels of function without clinically detectable lameness

  5. Embryologic and anatomic basis of inguinal herniorrhaphy.

    Science.gov (United States)

    Skandalakis, J E; Colborn, G L; Androulakis, J A; Skandalakis, L J; Pemberton, L B

    1993-08-01

    The embryology and surgical anatomy of the inguinal area is presented with emphasis on embryologic and anatomic entities related to surgery. We have presented the factors, such as patent processus vaginalis and defective posterior wall of the inguinal canal, that may be responsible for the genesis of congenital inguinofemoral herniation. These, together with impaired collagen synthesis and trauma, are responsible for the formation of the acquired inguinofemoral hernia. Still, we do not have all the answers for an ideal repair. Despite the latest successes in repair, we, to paraphrase Ritsos, are awaiting the triumphant return of Theseus.

  6. On-board landmark navigation and attitude reference parallel processor system

    Science.gov (United States)

    Gilbert, L. E.; Mahajan, D. T.

    1978-01-01

    An approach to autonomous navigation and attitude reference for earth observing spacecraft is described along with the landmark identification technique based on a sequential similarity detection algorithm (SSDA). Laboratory experiments undertaken to determine if better than one pixel accuracy in registration can be achieved consistent with onboard processor timing and capacity constraints are included. The SSDA is implemented using a multi-microprocessor system including synchronization logic and chip library. The data is processed in parallel stages, effectively reducing the time to match the small known image within a larger image as seen by the onboard image system. Shared memory is incorporated in the system to help communicate intermediate results among microprocessors. The functions include finding mean values and summation of absolute differences over the image search area. The hardware is a low power, compact unit suitable to onboard application with the flexibility to provide for different parameters depending upon the environment.

  7. Landmarks in particle physics at Brookhaven National Laboratory: Brookhaven Lecture Series, Number 238

    International Nuclear Information System (INIS)

    Adair, R.K.

    1987-01-01

    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

  8. The Royal Philanthropic Expedition of the Vaccine: a landmark in the history of public health.

    Science.gov (United States)

    Soto-Pérez-de-Celis, E

    2008-11-01

    In 1979, smallpox officially became the first disease ever to be eradicated by mankind. The global efforts to defeat this dreadful pandemic, however, started almost two centuries before. One of the most important, and sometimes forgotten, events in the fight against smallpox was the Royal Philanthropic Expedition of the Vaccine, commissioned by Charles IV of Spain to physicians Francisco Xavier Balmis y Berenguer and Jose Salvany in 1804. The aim of this expedition was to take the smallpox vaccine, discovered by Jenner, to Spain's territories in the Americas and in the Far East. After several years of vaccination in modern day Puerto Rico, Cuba, Venezuela, Ecuador, Peru, Bolivia, Chile, Mexico and the Philippines, the expedition returned to Europe. To this day, the Balmis and Salvany expedition remains a great example of international cooperation, and a landmark in the history of public health.

  9. 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.

  10. Volumetric Image Guidance Using Carina vs Spine as Registration Landmarks for Conventionally Fractionated Lung Radiotherapy

    International Nuclear Information System (INIS)

    Lavoie, Caroline; Higgins, Jane; Bissonnette, Jean-Pierre; Le, Lisa W.; Sun, Alexander; Brade, Anthony; Hope, Andrew; Cho, John; Bezjak, Andrea

    2012-01-01

    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.

  11. [Anatomical study of men's nipple areola complex].

    Science.gov (United States)

    Vaucher, R; Dast, S; Assaf, N; Sinna, R

    2016-06-01

    The surgical approach of gynecomastia, sexual reassignment surgery in female-to-male transsexuals and the increase of number of obese wishing to turn to plastic surgery led us to deepen the anatomical knowledge of the nipple areola complex (NAC) in men, poorly retailed in the literature. By inspiring us of the methodology of a Japanese study, we studied 50 healthy volunteers male, from 18 to 55 years old, from July till August 2015. We measured various distances relative to the NAC to define its vertical and horizontal position, as well as the internipple distance according to the size, to the weight and to the body mass index (BMI). At the end of the analysis, we were able to underline a lower vertical thoracic position of the NAC in the tall category of person, a more side horizontal position to the subject presenting a high BMI and a linear relation between the BMI and the internipple (Em) defined by (Em)=8.96×BMI. The surgeon's judgment and the desires of the patient are essentials basis of therapeutics decisions that could be lean on this anatomical study, which allowed to establish an idea of the cartography of the NAC in man. It will be interesting and necessary to confront it with other studies with larger scale. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  12. Radio-guided sentinel lymph node identification by lymphoscintigraphy fused with an anatomical vector profile: clinical applications.

    Science.gov (United States)

    Niccoli Asabella, A; Antonica, F; Renna, M A; Rubini, D; Notaristefano, A; Nicoletti, A; Rubini, G

    2013-12-01

    To develop a method to fuse lymphoscintigraphic images with an adaptable anatomical vector profile and to evaluate its role in the clinical practice. We used Adobe Illustrator CS6 to create different vector profiles, we fused those profiles, using Adobe Photoshop CS6, with lymphoscintigraphic images of the patient. We processed 197 lymphoscintigraphies performed in patients with cutaneous melanomas, breast cancer or delayed lymph drainage. Our models can be adapted to every patient attitude or position and contain different levels of anatomical details ranging from external body profiles to the internal anatomical structures like bones, muscles, vessels, and lymph nodes. If needed, more new anatomical details can be added and embedded in the profile without redrawing them, saving a lot of time. Details can also be easily hidden, allowing the physician to view only relevant information and structures. Fusion times are about 85 s. The diagnostic confidence of the observers increased significantly. The validation process showed a slight shift (mean 4.9 mm). We have created a new, practical, inexpensive digital technique based on commercial software for fusing lymphoscintigraphic images with built-in anatomical reference profiles. It is easily reproducible and does not alter the original scintigraphic image. Our method allows a more meaningful interpretation of lymphoscintigraphies, an easier recognition of the anatomical site and better lymph node dissection planning.

  13. Anatomic atlas for computed tomography in the mesaticephalic dog: head and neck

    International Nuclear Information System (INIS)

    George, T.F. II; Smallwood, J.E.

    1992-01-01

    The purpose of this study was to produce a comprehensive anatomic atlas of CT anatomy of the dog for use by veterinary radiologists, clinicians, and surgeons. Whole-body CT images of two mature beagle dogs were made with the dogs supported in sternal recumbency and using a slice thickness of 13 mm. The head was scanned using high-resolution imaging with a slice thickness of 8 mm. At the end of the CT session, each dog was euthanized, and while carefully maintaining the same position, the body was placed in a walk-in freezer until completely frozen. The body was then sectioned at 13-mm (head at 8-mm) intervals, with the cuts matched as closely as possible to the CT slices. The forzen sections were cleaned, photographed, and radiographed using xeroradiography. Each CT image was studied and compared with its corresponding xeroradiograph and anatomic section to assist in the accurate identification of specific structures. Intact, sagittally sectioned, and disarticulated dog skulls were used as reference models. Clinically relevant anatomic structures were identified and labeled in the three corresponding photographs (CT image, xeroradiograph, and anatomic section). In this paper, the CT anatomy of the head and neck of the mesaticephalic dog is presented

  14. Anatomic atlas for computed tomography in the mesaticephalic dog: caudal abdomen and pelvis

    International Nuclear Information System (INIS)

    Smallwood, J.E.; George, T. II.

    1993-01-01

    The purpose of this study was to produce a comprehensive anatomic atlas of CT anatomy of the dog for use by veterinary radiologists, clinicians, and surgeons. Whole-body CT images of two mature beagle dogs were made with the dogs supported in sternal recumbency and using a slice thickness of 13 mm. At the end of the CT session, each dog was euthanized, and while carefully maintaining the same position, the body was frozen. The body was then sectioned at 13-mm intervals, with the cuts matched as closely as possible to the CT slices. The frozen sections were cleaned, photographed, and radiographed using xeroradiography. Each CT image was studied and compared with its corresponding xeroradiograph and anatomic section to assist in the accurate identification of specific structures. Clinically relevant anatomic structures were identified and labeled in the three corresponding photographs (CT image, xeroradiograph, and anatomic section). In previous papers, the head and neck, and the thorax and cranial abdomen of the mesaticephalic (beagle) dog were presented. In this paper, the caudal part of the abdomen and pelvis of the bitch and male dog are presented

  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. 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…

  17. Map generation in unknown environments by AUKF-SLAM using line segment-type and point-type landmarks

    Science.gov (United States)

    Nishihta, Sho; Maeyama, Shoichi; Watanebe, Keigo

    2018-02-01

    Recently, autonomous mobile robots that collect information at disaster sites are being developed. Since it is difficult to obtain maps in advance in disaster sites, the robots being capable of autonomous movement under unknown environments are required. For this objective, the robots have to build maps, as well as the estimation of self-location. This is called a SLAM problem. In particular, AUKF-SLAM which uses corners in the environment as point-type landmarks has been developed as a solution method so far. However, when the robots move in an environment like a corridor consisting of few point-type features, the accuracy of self-location estimated by the landmark is decreased and it causes some distortions in the map. In this research, we propose AUKF-SLAM which uses walls in the environment as a line segment-type landmark. We demonstrate that the robot can generate maps in unknown environment by AUKF-SLAM, using line segment-type and point-type landmarks.

  18. Culturally Relevant Cyberbullying Prevention

    OpenAIRE

    Phillips, Gregory John

    2017-01-01

    In this action research study, I, along with a student intervention committee of 14 members, developed a cyberbullying intervention for a large urban high school on the west coast. This high school contained a predominantly African American student population. I aimed to discover culturally relevant cyberbullying prevention strategies for African American students. The intervention committee selected video safety messages featuring African American actors as the most culturally relevant cyber...

  19. Anatomical study of middle cluneal nerve entrapment

    Directory of Open Access Journals (Sweden)

    Konno T

    2017-06-01

    Full Text Available Tomoyuki Konno,1 Yoichi Aota,2 Tomoyuki Saito,1 Ning Qu,3 Shogo Hayashi,3 Shinichi Kawata,3 Masahiro Itoh3 1Department of Orthopaedic Surgery, Yokohama City University, 2Department of Spine and Spinal Cord, Yokohama Brain and Spine Center, Yokohama City, 3Department of Anatomy, Tokyo Medical University, Tokyo, Japan Object: Entrapment of the middle cluneal nerve (MCN under the long posterior sacroiliac ligament (LPSL is a possible, and underdiagnosed, cause of low-back and/or leg symptoms. To date, detailed anatomical studies of MCN entrapment are few. The purpose of this study was to ascertain, using cadavers, the relationship between the MCN and LPSL and to investigate MCN entrapment. Methods: A total of 30 hemipelves from 20 cadaveric donors (15 female, 5 male designated for education or research, were studied by gross anatomical dissection. The age range of the donors at death was 71–101 years with a mean of 88 years. Branches of the MCN were identified under or over the gluteus maximus fascia caudal to the posterior superior iliac spine (PSIS and traced laterally as far as their finest ramification. Special attention was paid to the relationship between the MCN and LPSL. The distance from the branch of the MCN to the PSIS and to the midline and the diameter of the MCN were measured. Results: A total of 64 MCN branches were identified in the 30 hemipelves. Of 64 branches, 10 (16% penetrated the LPSL. The average cephalocaudal distance from the PSIS to where the MCN penetrated the LPSL was 28.5±11.2 mm (9.1–53.7 mm. The distance from the midline was 36.0±6.4 mm (23.5–45.2 mm. The diameter of the MCN branch traversing the LPSL averaged 1.6±0.5 mm (0.5–3.1 mm. Four of the 10 branches penetrating the LPSL had obvious constriction under the ligament. Conclusion: This is the first anatomical study illustrating MCN entrapment. It is likely that MCN entrapment is not a rare clinical entity. Keywords: middle cluneal nerve, sacroiliac joint

  20. Basilar expansion of the human sphenoidal sinus: an integrated anatomical and computerized tomography study

    International Nuclear Information System (INIS)

    Haetinger, Rainer G.; Navarro, Joao A.C.; Liberti, Edson A.

    2006-01-01

    Basilar expansion of the sphenoidal sinus (BESS) was studied in order to demonstrate its critical relevance in endoscopic or microscopic endonasal surgical interventions, including access to the sphenoidal sinus itself or in transsphenoidal pituitary approaches. Direct evaluation of anatomical specimens (25 dry skulls and 25 formalin-fixed hemi heads) and the use of computerized tomography (CT) (50 dry skulls and 750 patients) showed a high BESS frequency (69%). The authors considered BESS to be critical when the posterior wall of the clivus was 2-mm thick and found a high incidence of this important anatomical variation (44%). This study also evaluated the relationship between the sinonasal septa, the clivus, and the internal carotid arteries, and a considerable regularity in the location of these structures was seen. The septa were anatomically related to the internal carotid arteries in 55% and to the clivus in 33% of the cases. In conclusion, the high frequency of critical BESS here described is relevant to endoscopic or microscopic endonasal surgical interventions, including access to the sphenoidal sinus itself or in transsphenoidal pituitary approaches. (orig.)

  1. Mistakes in the usage of anatomical terminology in clinical practice.

    Science.gov (United States)

    Kachlik, David; Bozdechova, Ivana; Cech, Pavel; Musil, Vladimir; Baca, Vaclav

    2009-06-01

    Anatomical terminology serves as a basic communication tool in all the medical fields. Therefore Latin anatomical nomenclature has been repetitively issued and revised from 1895 (Basiliensia Nomina Anatomica) until 1998, when the last version was approved and published as the Terminologia Anatomica (International Anatomical Terminology) by the Federative Committee on Anatomical Terminology. A brief history of the terminology and nomenclature development is mentioned, along with the concept and contributions of the Terminologia Anatomica including the employed abbreviations. Examples of obsolete anatomical terms and their current synonyms are listed. Clinicians entered the process of the nomenclature revision and this aspect is demonstrated with several examples of terms used in clinical fields only, some already incorporated in the Terminologia Anatomica and a few obsolete terms still alive in non-theoretical communication. Frequent mistakes in grammar and orthography are stated as well. Authors of the article strongly recommend the use of the recent revision of the Latin anatomical nomenclature both in theoretical and clinical medicine.

  2. 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

  3. An anatomic transcriptional atlas of human glioblastoma.

    Science.gov (United States)

    Puchalski, Ralph B; Shah, Nameeta; Miller, Jeremy; Dalley, Rachel; Nomura, Steve R; Yoon, Jae-Guen; Smith, Kimberly A; Lankerovich, Michael; Bertagnolli, Darren; Bickley, Kris; Boe, Andrew F; Brouner, Krissy; Butler, Stephanie; Caldejon, Shiella; Chapin, Mike; Datta, Suvro; Dee, Nick; Desta, Tsega; Dolbeare, Tim; Dotson, Nadezhda; Ebbert, Amanda; Feng, David; Feng, Xu; Fisher, Michael; Gee, Garrett; Goldy, Jeff; Gourley, Lindsey; Gregor, Benjamin W; Gu, Guangyu; Hejazinia, Nika; Hohmann, John; Hothi, Parvinder; Howard, Robert; Joines, Kevin; Kriedberg, Ali; Kuan, Leonard; Lau, Chris; Lee, Felix; Lee, Hwahyung; Lemon, Tracy; Long, Fuhui; Mastan, Naveed; Mott, Erika; Murthy, Chantal; Ngo, Kiet; Olson, Eric; Reding, Melissa; Riley, Zack; Rosen, David; Sandman, David; Shapovalova, Nadiya; Slaughterbeck, Clifford R; Sodt, Andrew; Stockdale, Graham; Szafer, Aaron; Wakeman, Wayne; Wohnoutka, Paul E; White, Steven J; Marsh, Don; Rostomily, Robert C; Ng, Lydia; Dang, Chinh; Jones, Allan; Keogh, Bart; Gittleman, Haley R; Barnholtz-Sloan, Jill S; Cimino, Patrick J; Uppin, Megha S; Keene, C Dirk; Farrokhi, Farrokh R; Lathia, Justin D; Berens, Michael E; Iavarone, Antonio; Bernard, Amy; Lein, Ed; Phillips, John W; Rostad, Steven W; Cobbs, Charles; Hawrylycz, Michael J; Foltz, Greg D

    2018-05-11

    Glioblastoma is an aggressive brain tumor that carries a poor prognosis. The tumor's molecular and cellular landscapes are complex, and their relationships to histologic features routinely used for diagnosis are unclear. We present the Ivy Glioblastoma Atlas, an anatomically based transcriptional atlas of human glioblastoma that aligns individual histologic features with genomic alterations and gene expression patterns, thus assigning molecular information to the most important morphologic hallmarks of the tumor. The atlas and its clinical and genomic database are freely accessible online data resources that will serve as a valuable platform for future investigations of glioblastoma pathogenesis, diagnosis, and treatment. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  4. Anatomic breast coordinate system for mammogram analysis

    DEFF Research Database (Denmark)

    Karemore, Gopal; Brandt, S.; Karssemeijer, N.

    2011-01-01

    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......Purpose Many researchers have investigated measures also other than density in the mammogram such as measures based on texture to improve breast cancer risk assessment. However, parenchymal texture characteristics are highly dependent on the orientation of vasculature structure and fibrous tissue...... methodologies as seen from table 2 in given temporal study. Conclusion The curve-linear anatomical breast coordinate system facilitated computerized analysis of mammograms. The proposed coordinate system slightly improved the risk segregation by Mammographic Texture Resemblance and minimized the geometrical...

  5. Internuclear ophthalmoplegia: MR imaging and anatomic correlation

    International Nuclear Information System (INIS)

    Atlas, S.W.; Grossman, R.I.; Savino, P.J.

    1986-01-01

    Internuclear ophthalmoplegia is a gaze disorder characterized by impaired adduction of the side of a lesion in the medial longitudinal fasciculus (MLF) with dissociated nystagmus of the abducting eye. Eleven patients with internuclear ophthalmoplegia (nine with multiple sclerosis, two with infarction) were examined with spin-echo MR imaging performed at 1.5 T. Nine of the 11 patients also underwent CT. MR imaging was highly sensitive (10 of 11 cases) and CT was of no value (0 of 9 cases) in detecting clinically suspected MLF lesions. These lesions must be distinguished from ''pseudo-MLF hyperintensity,'' which appears as a thin, strictly midline, linear hyperintensity just interior to the fourth ventricle and aqueduct in healthy subjects. True MLF lesions are nodular, more prominent, and slightly off the midline, corresponding to the paramedian anatomic site of the MLF

  6. Early Results of Anatomic Double Bundle Anterior Cruciate Ligament Reconstruction

    OpenAIRE

    Demet Pepele

    2014-01-01

    Aim: The goal in anterior cruciate ligament reconstruction (ACLR) is to restore the normal anatomic structure and function of the knee. In the significant proportion of patients after the traditional single-bundle ACLR, complaints of instability still continue. Anatomic double bundle ACLR may provide normal kinematics in knees, much closer to the natural anatomy. The aim of this study is to clinically assess the early outcomes of our anatomical double bundle ACLR. Material and Method: In our ...

  7. A comparison of five approaches to measurement of anatomic knee alignment from radiographs.

    Science.gov (United States)

    McDaniel, G; Mitchell, K L; Charles, C; Kraus, V B

    2010-02-01

    The recent recognition of the correlation of the hip-knee-ankle angle (HKA) with femur-tibia angle (FTA) on a standard knee radiograph has led to the increasing inclusion of FTA assessments in OA studies due to its clinical relevance, cost effectiveness and minimal radiation exposure. Our goal was to investigate the performance metrics of currently used methods of FTA measurement to determine whether a specific protocol could be recommended based on these results. Inter- and intra-rater reliability of FTA measurements were determined by intraclass correlation coefficient (ICC) of two independent analysts. Minimal detectable differences were determined and the correlation of FTA and HKA was analyzed by linear regression. Differences among methods of measuring HKA were assessed by ANOVA. All five methods of FTA measurement demonstrated high precision by inter- and intra-rater reproducibility (ICCs>or=0.93). All five methods displayed good accuracy, but after correction for the offset of FTA from HKA, the femoral notch landmark method was the least accurate. However, the methods differed according to their minimal detectable differences; the FTA methods utilizing the center of the base of the tibial spines or the center of the tibial plateau as knee center landmarks yielded the smallest minimal detectable differences (1.25 degrees and 1.72 degrees, respectively). All methods of FTA were highly reproducible, but varied in their accuracy and sensitivity to detect meaningful differences. Based on these parameters we recommend standardizing measurement angles with vertices at the base of the tibial spines or the center of the tibia and comparing single-point and two-point methods in larger studies. Copyright 2009 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  8. The Limits to Relevance

    Science.gov (United States)

    Averill, M.; Briggle, A.

    2006-12-01

    Science policy and knowledge production lately have taken a pragmatic turn. Funding agencies increasingly are requiring scientists to explain the relevance of their work to society. This stems in part from mounting critiques of the "linear model" of knowledge production in which scientists operating according to their own interests or disciplinary standards are presumed to automatically produce knowledge that is of relevance outside of their narrow communities. Many contend that funded scientific research should be linked more directly to societal goals, which implies a shift in the kind of research that will be funded. While both authors support the concept of useful science, we question the exact meaning of "relevance" and the wisdom of allowing it to control research agendas. We hope to contribute to the conversation by thinking more critically about the meaning and limits of the term "relevance" and the trade-offs implicit in a narrow utilitarian approach. The paper will consider which interests tend to be privileged by an emphasis on relevance and address issues such as whose goals ought to be pursued and why, and who gets to decide. We will consider how relevance, narrowly construed, may actually limit the ultimate utility of scientific research. The paper also will reflect on the worthiness of research goals themselves and their relationship to a broader view of what it means to be human and to live in society. Just as there is more to being human than the pragmatic demands of daily life, there is more at issue with knowledge production than finding the most efficient ways to satisfy consumer preferences or fix near-term policy problems. We will conclude by calling for a balanced approach to funding research that addresses society's most pressing needs but also supports innovative research with less immediately apparent application.

  9. Relevant Subspace Clustering

    DEFF Research Database (Denmark)

    Müller, Emmanuel; Assent, Ira; Günnemann, Stephan

    2009-01-01

    Subspace clustering aims at detecting clusters in any subspace projection of a high dimensional space. As the number of possible subspace projections is exponential in the number of dimensions, the result is often tremendously large. Recent approaches fail to reduce results to relevant subspace...... clusters. Their results are typically highly redundant, i.e. many clusters are detected multiple times in several projections. In this work, we propose a novel model for relevant subspace clustering (RESCU). We present a global optimization which detects the most interesting non-redundant subspace clusters...... achieves top clustering quality while competing approaches show greatly varying performance....

  10. Morphological approach of the sternal foramen: an anatomic study and a short review of the literature.

    Science.gov (United States)

    Gkantsinikoudis, N; Chaniotakis, C; Gkasdaris, G; Georgiou, N; Kapetanakis, S

    2017-01-01

    The sternal foramen (SF) constitutes a specific anatomic defect in sternum, indicating an impaired fusion of ossificated segments, which occurs either in an anatomical part of the sternum or in sternal joints. The aim of this article is to provide baseline statistical data about the variations of the SF, to present a short review of the relevant literature and to compare results with other studies and populations. We review relevant literature, and we present data obtai-ned from skeletal samples of known population and sex. A total of 35 well-preserved dried sterna from the prefecture of Eastern Macedonia and Thrace, Greece, were selected: 20 men and 15 women with a mean age of 55 ± 6 years old. Measurements were made with a sliding calliper and photographic documentation. The incidence of the SF in the 35 dried specimens was 14.2%, 4 men (20% of male sample) and 1 woman (6.6% of female sample) and 80% of sternal foramina were observed in male individuals. The SF was found in the sternum body (2 cases, 40% of foramina), in xiphoid process (2 cases, 40% of foramina) and in sternoxiphoidal junction (1 case, 20% of foramina). All of the sterna presented 1 single visible SF. Two anatomically unique cases were identified throughout these 5 sterna, both belonging in male subjects. The SF constitutes a relatively common variation with great radiological, clinical, and forensic significance. Presence of a SF with irregular bony margins complicates considerably radiological differential diagnosis. Awareness of this important anatomic variation is fundamental for clinicians and autopsy pathologists, in order to avoid severe fatal complications and elucidate the exact cause of death, respectively.

  11. Anatomic variability of the vascularized composite osteomyocutaneous flap from the medial femoral condyle: an anatomical study

    Directory of Open Access Journals (Sweden)

    Trung-Hau Le Thua

    2014-12-01

    Full Text Available Aim: The anatomical study and clinical application for the vascularized corticoperiosteal flap from the medial femoral condyle have been performed and described previously. Although prior studies have described the composite osteomyocutaneous flap from the medial femoral condyle, a detailed analysis of the vascularity of this region has not yet been fully evaluated. Methods: This anatomical study described the variability of the arteries from the medial femoral condyle in 40 cadaveric specimens. Results: The descending genicular artery (DGA was found in 33 of 40 cases (82.5%. The  superomedial genicular artery (SGA was present in 10 cases (25%. All 33 cases (100% of the DGA had articular branches to the periosteum of the medial femoral condyle. Muscular branches and saphenous branches of the DGA were present in 25 cases (62.5% and 26 cases (70.3%, respectively. Conclusion: The current study demonstrates that the size and length of the vessels to the medial femoral condyle are sufficient for a vascularized bone flap. A careful preoperative vascular assessment is essential prior to use of the vascularized composite osteomyocutaneous flap from the medial femoral condyle, because of the considerable anatomical variations in different branches of the DGA.

  12. The anatomical diaspora: evidence of early American anatomical traditions in North Dakota.

    Science.gov (United States)

    Stubblefield, Phoebe R

    2011-09-01

    The current focus in forensic anthropology on increasing scientific certainty in ancestry determination reinforces the need to examine the ancestry of skeletal remains used for osteology instruction. Human skeletal remains were discovered on the University of North Dakota campus in 2007. After recovery, the osteological examination resulted in a profile for a 33- to 46-year-old woman of African descent with stature ranging from 56.3 to 61.0 in. The pattern of postmortem damage indicated that the remains had been prepared for use as an anatomical teaching specimen. Review of the American history of anatomical teaching revealed a preference for Black subjects, which apparently extended to states like North Dakota despite extremely low resident populations of people of African descent. This study emphasizes the need to examine the ancestry of older teaching specimens that lack provenience, rather than assuming they are derived from typical (i.e., Indian) sources of anatomical material. © 2011 American Academy of Forensic Sciences.

  13. Recent advances in standards for collaborative Digital Anatomic Pathology

    Science.gov (United States)

    2011-01-01

    Context Collaborative Digital Anatomic Pathology refers to the use of information technology that supports the creation and sharing or exchange of information, including data and images, during the complex workflow performed in an Anatomic Pathology department from specimen reception to report transmission and exploitation. Collaborative Digital Anatomic Pathology can only be fully achieved using medical informatics standards. The goal of the international integrating the Healthcare Enterprise (IHE) initiative is precisely specifying how medical informatics standards should be implemented to meet specific health care needs and making systems integration more efficient and less expensive. Objective To define the best use of medical informatics standards in order to share and exchange machine-readable structured reports and their evidences (including whole slide images) within hospitals and across healthcare facilities. Methods Specific working groups dedicated to Anatomy Pathology within multiple standards organizations defined standard-based data structures for Anatomic Pathology reports and images as well as informatic transactions in order to integrate Anatomic Pathology information into the electronic healthcare enterprise. Results The DICOM supplements 122 and 145 provide flexible object information definitions dedicated respectively to specimen description and Whole Slide Image acquisition, storage and display. The content profile “Anatomic Pathology Structured Report” (APSR) provides standard templates for structured reports in which textual observations may be bound to digital images or regions of interest. Anatomic Pathology observations are encoded using an international controlled vocabulary defined by the IHE Anatomic Pathology domain that is currently being mapped to SNOMED CT concepts. Conclusion Recent advances in standards for Collaborative Digital Anatomic Pathology are a unique opportunity to share or exchange Anatomic Pathology structured

  14. Is Information Still Relevant?

    Science.gov (United States)

    Ma, Lia

    2013-01-01

    Introduction: The term "information" in information science does not share the characteristics of those of a nomenclature: it does not bear a generally accepted definition and it does not serve as the bases and assumptions for research studies. As the data deluge has arrived, is the concept of information still relevant for information…

  15. Use of redundant sets of landmark information by humans (Homo sapiens) in a goal-searching task in an open field and on a computer screen.

    Science.gov (United States)

    Sekiguchi, Katsuo; Ushitani, Tomokazu; Sawa, Kosuke

    2018-05-01

    Landmark-based goal-searching tasks that were similar to those for pigeons (Ushitani & Jitsumori, 2011) were provided to human participants to investigate whether they could learn and use multiple sources of spatial information that redundantly indicate the position of a hidden target in both an open field (Experiment 1) and on a computer screen (Experiments 2 and 3). During the training in each experiment, participants learned to locate a target in 1 of 25 objects arranged in a 5 × 5 grid, using two differently colored, arrow-shaped (Experiments 1 and 2) or asymmetrically shaped (Experiment 3) landmarks placed adjacent to the goal and pointing to the goal location. The absolute location and directions of the landmarks varied across trials, but the constant configuration of the goal and the landmarks enabled participants to find the goal using both global configural information and local vector information (pointing to the goal by each individual landmark). On subsequent test trials, the direction was changed for one of the landmarks to conflict with the global configural information. Results of Experiment 1 indicated that participants used vector information from a single landmark but not configural information. Further examinations revealed that the use of global (metric) information was enhanced remarkably by goal searching with nonarrow-shaped landmarks on the computer monitor (Experiment 3) but much less so with arrow-shaped landmarks (Experiment 2). The General Discussion focuses on a comparison between humans in the current study and pigeons in the previous study. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  16. Automatic localization of landmark sets in head CT images with regression forests for image registration initialization

    Science.gov (United States)

    Zhang, Dongqing; Liu, Yuan; Noble, Jack H.; Dawant, Benoit M.

    2016-03-01

    Cochlear Implants (CIs) are electrode arrays that are surgically inserted into the cochlea. Individual contacts stimulate frequency-mapped nerve endings thus replacing the natural electro-mechanical transduction mechanism. CIs are programmed post-operatively by audiologists but this is currently done using behavioral tests without imaging information that permits relating electrode position to inner ear anatomy. We have recently developed a series of image processing steps that permit the segmentation of the inner ear anatomy and the localization of individual contacts. We have proposed a new programming strategy that uses this information and we have shown in a study with 68 participants that 78% of long term recipients preferred the programming parameters determined with this new strategy. A limiting factor to the large scale evaluation and deployment of our technique is the amount of user interaction still required in some of the steps used in our sequence of image processing algorithms. One such step is the rough registration of an atlas to target volumes prior to the use of automated intensity-based algorithms when the target volumes have very different fields of view and orientations. In this paper we propose a solution to this problem. It relies on a random forest-based approach to automatically localize a series of landmarks. Our results obtained from 83 images with 132 registration tasks show that automatic initialization of an intensity-based algorithm proves to be a reliable technique to replace the manual step.

  17. Intensity and sulci landmark combined brain atlas construction for Chinese pediatric population.

    Science.gov (United States)

    Luo, Yishan; Shi, Lin; Weng, Jian; He, Hongjian; Chu, Winnie C W; Chen, Feiyan; Wang, Defeng

    2014-08-01

    Constructing an atlas from a population of brain images is of vital importance to medical image analysis. Especially in neuroscience study, creating a brain atlas is useful for intra- and inter-population comparison. Research on brain atlas construction has attracted great attention in recent years, but the research on pediatric population is still limited, mainly due to the limited availability and the relatively low quality of pediatric magnetic resonance brain images. This article is targeted at creating a high quality representative brain atlas for Chinese pediatric population. To achieve this goal, we have designed a set of preprocessing procedures to improve the image quality and developed an intensity and sulci landmark combined groupwise registration method to align the population of images for atlas construction. As demonstrated in experiments, the newly constructed atlas can better represent the size and shape of brains of Chinese pediatric population, and show better performance in Chinese pediatric brain image analysis compared with other standard atlases. Copyright © 2014 Wiley Periodicals, Inc.

  18. Big tobacco "pull out all stops" for a landmark example: The Burswood Casino case.

    Science.gov (United States)

    Laura, Bond; Julia, Stafford; Mike, Daube

    2011-01-01

    With the aid of internal tobacco industry documents, this paper provides a chronology of events documenting the role of the Philip Morris tobacco company in the 1993 litigation case against the Burswood International Resort Casino (BIRC). The paper also examines the implications of this case for the regulation of second hand smoke exposure. A systematic keyword search and analysis of internal tobacco industry documents was conducted using documents available on the World Wide Web through the Master Settlement Agreement. The industry documents provide comprehensive evidence that the Philip Morris tobacco company provided assistance to the BIRC in its defence against action by the Western Australian government. The Philip Morris tobacco company, along with others, sought to publicise and promote the outcome as a 'landmark example' to lobby against the implementation of indoor smoking bans. Philip Morris' investment in the BIRC defence demonstrated the industry's recognition of the potential significance of the case beyond Western Australia. Involvement in the BIRC case assisted the wider tobacco industry by helping to prolong smoking at casinos and other Australian hospitality venues. The findings contribute to our understanding of the history of tobacco industry strategies implemented in Western Australia and internationally to slow tobacco control progress, and the preparedness of the tobacco industry to exploit favourable developments originating anywhere in the world.

  19. Investigation of radon and thoron concentrations in a landmark skyscraper in Tokyo

    International Nuclear Information System (INIS)

    Kazumasa Inoue; Masahiro Fukushi

    2013-01-01

    The temporal variation of the radon concentration, and the radon and thoron concentrations every 3 months for a year were measured using two types of devices in a landmark skyscraper, the Tokyo Metropolitan Government Daiichi Building. In the measurement of temporal variation of the radon concentration using a pulse type ionization chamber, the average radon concentration was 21 ± 13 Bq m -3 (2-68 Bq m -3 ). The measured indoor radon concentration had a strong relationship with the operation of the mechanical ventilation system and the activities of the office workers. The radon concentration also increased together with temperature. Other environmental parameters, such as air pressure and relative humidity, were not related to the radon concentration. In the long-term measurements using a passive radon and thoron discriminative monitor, no seasonal variation was observed. The annual average concentrations of radon and thoron were 16 ± 8 and 16 ± 7 Bq m -3 , respectively. There was also no relationship between the two concentrations. The annual average effective dose for office workers in this skyscraper was estimated to be 0.08 mSv y -1 for 2000 working hours per year. When considering the indoor radon exposure received from their residential dwellings using the annual mean radon concentration indoors in Japan (15.5 Bq m -3 ), the annual average effective dose was estimated to be 0.37 mSv y -1 . This value was 31 % of the worldwide average annual effective dose. (author)

  20. Anatomical placement of the human eyeball in the orbit--validation using CT scans of living adults and prediction for facial approximation.

    Science.gov (United States)

    Guyomarc'h, Pierre; Dutailly, Bruno; Couture, Christine; Coqueugniot, Hélène

    2012-09-01

    Accuracy of forensic facial approximation and superimposition techniques relies on the knowledge of anatomical correlations between soft and hard tissues. Recent studies by Stephan and collaborators (6,8,10) reviewed traditional guidelines leading to a wrong placement of the eyeball in the orbit. As those statements are based on a small cadaver sample, we propose a validation of these findings on a large database (n = 375) of living people. Computed tomography scans of known age and sex subjects were used to collect landmarks on three-dimensional surfaces and DICOM with TIVMI. Results confirmed a more superior and lateral position of the eyeball relatively to the orbital rims. Orbital height and breadth were used to compute regression formulae and proportional placement using percentages to find the most probable position of the eyeball in the orbit. A size-related sexual dimorphism was present but did not impact on the prediction accuracy. © 2012 American Academy of Forensic Sciences.

  1. Standards to support information systems integration in anatomic pathology.

    Science.gov (United States)

    Daniel, Christel; García Rojo, Marcial; Bourquard, Karima; Henin, Dominique; Schrader, Thomas; Della Mea, Vincenzo; Gilbertson, John; Beckwith, Bruce A

    2009-11-01

    Integrating anatomic pathology information- text and images-into electronic health care records is a key challenge for enhancing clinical information exchange between anatomic pathologists and clinicians. The aim of the Integrating the Healthcare Enterprise (IHE) international initiative is precisely to ensure interoperability of clinical information systems by using existing widespread industry standards such as Digital Imaging and Communication in Medicine (DICOM) and Health Level Seven (HL7). To define standard-based informatics transactions to integrate anatomic pathology information to the Healthcare Enterprise. We used the methodology of the IHE initiative. Working groups from IHE, HL7, and DICOM, with special interest in anatomic pathology, defined consensual technical solutions to provide end-users with improved access to consistent information across multiple information systems. The IHE anatomic pathology technical framework describes a first integration profile, "Anatomic Pathology Workflow," dedicated to the diagnostic process including basic image acquisition and reporting solutions. This integration profile relies on 10 transactions based on HL7 or DICOM standards. A common specimen model was defined to consistently identify and describe specimens in both HL7 and DICOM transactions. The IHE anatomic pathology working group has defined standard-based informatics transactions to support the basic diagnostic workflow in anatomic pathology laboratories. In further stages, the technical framework will be completed to manage whole-slide images and semantically rich structured reports in the diagnostic workflow and to integrate systems used for patient care and those used for research activities (such as tissue bank databases or tissue microarrayers).

  2. 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 ...

  3. 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....

  4. Evaluation of anatomical and physical properties of Khaya nthotheca

    African Journals Online (AJOL)

    The anatomical and physical properties of Khaya anthotheca (Welw.) C. DC wood from the transition forest of middle altitude (zone 1) and the humid dense forest of low altitude (zone 2) in the East of the Democratic Republic of Congo were evaluated to ascertain the effect of growth area on the anatomical and physical ...

  5. Anatomical variability of the trunk wood and root tissues of ...

    African Journals Online (AJOL)

    The aim of this study was to investigate the anatomical structure of the trunk wood and the roots of A. nitida and R. racemosa, two mangrove trees from Gabon. The anatomical differences between the trunks and the roots were used to understand their bio-remediating differences through heavy metals. It was found that the ...

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

    International Nuclear Information System (INIS)

    Vásquez Osorio, Eliana M.; Kolkman-Deurloo, Inger-Karine K.; Schuring-Pereira, Monica; Zolnay, András; Heijmen, Ben J. M.; Hoogeman, Mischa S.

    2015-01-01

    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

  7. 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

  8. Topographical memory for newly-learned maps is differentially affected by route-based versus landmark-based learning

    DEFF Research Database (Denmark)

    Beatty, Erin L.; Muller-Gass, Alexandra; Wojtarowicz, Dorothy

    2018-01-01

    on their ability to distinguish previously studied 'old' maps from completely unfamiliar 'new' maps under conditions of high and low working memory load in the functional MRI scanner. Viewing old versus new maps was associated with relatively greater activation in a distributed set of regions including bilateral...... inferior temporal gyrus - an important region for recognizing visual objects. Critically, whereas the performance of participants who had followed a route-based strategy dropped to chance level under high working memory load, participants who had followed a landmark-based strategy performed at above chance...... levels under both high and low working memory load - reflected by relatively greater activation in the left inferior parietal lobule (i.e. rostral part of the supramarginal gyrus known as area PFt). Our findings suggest that landmark-based learning may buffer against the effects of working memory load...

  9. 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.

  10. [Corneal transparency: anatomical basis and evaluation methods].

    Science.gov (United States)

    Avetisov, S E; Narbut, M N

    Being just a relatively small part of the fibrous tunic of the eyeball, the cornea is, nevertheless, unique in terms of the variety of its functions. Because the cornea differs significantly from other protective frames in its structure, it provides the possibility of light transmission and strong refraction that largely contributes to the total refraction of the eye. The development of ophthalmology is impossible without improving methods of adequate anatomical and functional assessment of the eye not only as a whole, but also as a collection of interacting structures.In this regard, examination methods of the cornea have undergone significant advances in recent years. So far, the level of corneal transparency has been judged by biomicroscopy findings or indirect characteristics (thickness, structure, etc.). Confocal microscopy of the cornea and wave-based examinations involving one of the available laser interferometers (OCT or HRT) are also used. However, the data obtained with these methods resembles that of layer-specific reflectometry, i.e. the magnitude of directed reflection of the light beam from corneal corpuscles, which does not completely agree with the classical idea of transparency.

  11. Anatomical basis of the liver hanging maneuver.

    Science.gov (United States)

    Trotovsek, Blaz; Belghiti, Jacques; Gadzijev, Eldar M; Ravnik, Dean; Hribernik, Marija

    2005-01-01

    The anterior approach to right hepatectomy using the liver hanging maneuver without liver mobilization claims to be anatomically evaluated. During this procedure a 4 to 6-cm blind dissection between the inferior vena cava and the liver is performed. Short subhepatic veins, entering the inferior vena cava could be torn and a hemorrhage, difficult to control, could occur. On 100 corrosive casts of livers the anterior surface of the inferior vena cava was studied to evaluate the position, diameter and draining area of short subhepatic veins and inferior right hepatic vein. The width of the narrowest point on the planned route of blind dissection was determined. The average value of the narrowest point on the planned route of blind dissection was 8.7+/-2.3mm (range 2-15mm). The ideal angle of dissection being 0 degrees was found in 93% of cases. In 7% we found the angle of 5 degrees toward the right border of inferior vena cava to be the better choice. Our results show that liver hanging maneuver is a safe procedure. With the dissection in the proposed route the risk of disrupting short subhepatic veins is low (7%).

  12. Nonintubated uniportal VATS pulmonary anatomical resections.

    Science.gov (United States)

    Galvez, Carlos; Navarro-Martinez, Jose; Bolufer, Sergio; Lirio, Francisco; Sesma, Julio; Corcoles, Juan Manuel

    2017-01-01

    Nonintubated procedures have widely developed during the last years, thus nowadays major anatomical resections are performed in spontaneously breathing patients in some centers. In an attempt for combining less invasive surgical approaches with less aggressive anesthesia, nonintubated uniportal video-assisted thoracic surgery (VATS) lobectomies and segmentectomies have been proved feasible and safe, but there are no comparative trials and the evidence is still poor. A program in nonintubated uniportal major surgery should be started in highly experienced units, overcoming first a learning period performing minor procedures and a training program for the management of potential crisis situations when operating on these patients. A multidisciplinary approach including all the professionals in the operating room (OR), emergency protocols and a comprehensive knowledge of the special physiology of nonintubated surgery are mandatory. Some concerns about regional analgesia, vagal block for cough reflex control and oxygenation techniques, combined with some specific surgical tips can make safer these procedures. Specialists must remember an essential global concept: all the efforts are aimed at decreasing the invasiveness of the whole procedure in order to benefit patients' intraoperative status and postoperative recovery.

  13. [The meninges, an anatomical point of view].

    Science.gov (United States)

    Sakka, L; Chazal, J

    2005-03-01

    The meninges correspond to an anatomical concept. For the morphologist, the microscopic organization, the hypothetical presence of a subdural space, the nature of the interface between the deep meningeal layer and the nervous parenchyma in the perivascular spaces are the central issues. For the clinician, dynamic aspects of cerebrospinal fluid flow, secretion, and resorption are essential factors with practical consequences in terms of disease and patient management. Comparative anatomy, embryology, and organogenesis provide an interesting perspective for the descriptive and functional anatomy of the meninges. Usually considered as protective membranes, the meninges play a prominent role in the development and maintenance of the central nervous system. The meninges are in constant evolution, from their formation to senescence. The meninges present three layers in children and adults: the dura mater, the arachnoid and the pia mater. The cerebrospinal fluid is secreted by the choroid plexuses, flows through the ventricles and the subarachnoid space, and is absorbed by arachnoid granulations. Other sites of secretion and resorption are suggested by comparative anatomy and human embryology and organogenesis.

  14. Clinical Relevance of Adipokines

    Directory of Open Access Journals (Sweden)

    Matthias Blüher

    2012-10-01

    Full Text Available The incidence of obesity has increased dramatically during recent decades. Obesity increases the risk for metabolic and cardiovascular diseases and may therefore contribute to premature death. With increasing fat mass, secretion of adipose tissue derived bioactive molecules (adipokines changes towards a pro-inflammatory, diabetogenic and atherogenic pattern. Adipokines are involved in the regulation of appetite and satiety, energy expenditure, activity, endothelial function, hemostasis, blood pressure, insulin sensitivity, energy metabolism in insulin sensitive tissues, adipogenesis, fat distribution and insulin secretion in pancreatic β-cells. Therefore, adipokines are clinically relevant as biomarkers for fat distribution, adipose tissue function, liver fat content, insulin sensitivity, chronic inflammation and have the potential for future pharmacological treatment strategies for obesity and its related diseases. This review focuses on the clinical relevance of selected adipokines as markers or predictors of obesity related diseases and as potential therapeutic tools or targets in metabolic and cardiovascular diseases.

  15. 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.

  16. Medial calcar of proximal humeral fracture as landmark in restoration of humeral length in case of hemiarthroplasty

    Czech Academy of Sciences Publication Activity Database

    Hromádka, R.; Kuběna, Aleš Antonín; Šmíd, Martin; Popelka, S.

    2014-01-01

    Roč. 35, č. 5 (2014), s. 473-479 ISSN 0930-1038 Institutional support: RVO:67985556 Keywords : Fracture of proximal humerus * Calcar of humeral fracture * Reconstruction of proximal humerus * Reconstruction of humeral length * Shoulder arthroplasty * Shoulder hemiarthroplasty Subject RIV: FJ - Surgery incl. Transplants Impact factor: 1.047, year: 2014 http://library.utia.cas.cz/separaty/2013/E/smid-medial calcar of proximal humeral fracture as landmark in restoration of humeral length in case of hemiarthroplasty.pdf

  17. Newly defined landmarks for a three-dimensionally based cephalometric analysis: a retrospective cone-beam computed tomography scan review.

    Science.gov (United States)

    Lee, Moonyoung; Kanavakis, Georgios; Miner, R Matthew

    2015-01-01

    To identify two novel three-dimensional (3D) cephalometric landmarks and create a novel three-dimensionally based anteroposterior skeletal measurement that can be compared with traditional two-dimensional (2D) cephalometric measurements in patients with Class I and Class II skeletal patterns. Full head cone-beam computed tomography (CBCT) scans of 100 patients with all first molars in occlusion were obtained from a private practice. InvivoDental 3D (version 5.1.6, Anatomage, San Jose, Calif) was used to analyze the CBCT scans in the sagittal and axial planes to create new landmarks and a linear 3D analysis (M measurement) based on maxillary and mandibular centroids. Independent samples t-test was used to compare the mean M measurement to traditional 2D cephalometric measurements, ANB and APDI. Interexaminer and intraexaminer reliability were evaluated using 2D and 3D scatterplots. The M measurement, ANB, and APDI could statistically differentiate between patients with Class I and Class II skeletal patterns (P < .001). The M measurement exhibited a correlation coefficient (r) of -0.79 and 0.88 with APDI and ANB, respectively. The overall centroid landmarks and the M measurement combine 2D and 3D methods of imaging; the measurement itself can distinguish between patients with Class I and Class II skeletal patterns and can serve as a potential substitute for ANB and APDI. The new three-dimensionally based landmarks and measurements are reliable, and there is great potential for future use of 3D analyses for diagnosis and research.

  18. Success of ultrasound-guided versus landmark-guided arthrocentesis of hip, ankle, and wrist in a cadaver model.

    Science.gov (United States)

    Berona, Kristin; Abdi, Amin; Menchine, Michael; Mailhot, Tom; Kang, Tarina; Seif, Dina; Chilstrom, Mikaela

    2017-02-01

    The objectives of this study were to evaluate emergency medicine resident-performed ultrasound for diagnosis of effusions, compare the success of a landmark-guided (LM) approach with an ultrasound-guided (US) technique for hip, ankle and wrist arthrocentesis, and compare change in provider confidence with LM and US arthrocentesis. After a brief video on LM and US arthrocentesis, residents were asked to identify artificially created effusions in the hip, ankle and wrist in a cadaver model and to perform US and LM arthrocentesis of the effusions. Outcomes included success of joint aspiration, time to aspiration, and number of attempts. Residents were surveyed regarding their confidence in identifying effusions with ultrasound and performing LM and US arthrocentesis. Eighteen residents completed the study. Sensitivity of ultrasound for detecting joint effusion was 86% and specificity was 90%. Residents were successful with ultrasound in 96% of attempts and with landmark 89% of attempts (p=0.257). Median number of attempts was 1 with ultrasound and 2 with landmarks (p=0.12). Median time to success with ultrasound was 38s and 51s with landmarks (p=0.23). After the session, confidence in both US and LM arthrocentesis improved significantly, however the post intervention confidence in US arthrocentesis was higher than LM (4.3 vs. 3.8, p<0.001). EM residents were able to successfully identify joint effusions with ultrasound, however we were unable to detect significant differences in actual procedural success between the two modalities. Further studies are needed to define the role of ultrasound for arthrocentesis in the emergency department. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Semi-automated landmark-based 3D analysis reveals new morphometric characteristics in the trochlear dysplastic femur.

    Science.gov (United States)

    Van Haver, Annemieke; De Roo, Karel; De Beule, Matthieu; Van Cauter, Sofie; Audenaert, Emmanuel; Claessens, Tom; Verdonk, Peter

    2014-11-01

    The authors hypothesise that the trochlear dysplastic distal femur is not only characterised by morphological changes to the trochlea. The purpose of this study is to describe the morphological characteristics of the trochlear dysplastic femur in and outside the trochlear region with a landmark-based 3D analysis. Arthro-CT scans of 20 trochlear dysplastic and 20 normal knees were used to generate 3D models including the cartilage. To rule out size differences, a set of landmarks were defined on the distal femur to isotropically scale the 3D models to a standard size. A predefined series of landmark-based reference planes were applied on the distal femur. With these landmarks and reference planes, a series of previously described characteristics associated with trochlear dysplasia as well as a series of morphometric characteristics were measured. For the previously described characteristics, the analysis replicated highly significant differences between trochlear dysplastic and normal knees. Furthermore, the analysis showed that, when knee size is taken into account, the cut-off values of the trochlear bump and depth would be 1 mm larger in the largest knees compared to the smallest knees. For the morphometric characteristics, the analysis revealed that the trochlear dysplastic femur is also characterised by a 10% smaller intercondylar notch, 6-8% larger posterior condyles (lateral-medial) in the anteroposterior direction and a 6% larger medial condyle in the proximodistal direction compared to a normal femur. This study shows that knee size is important in the application of absolute metric cut-off values and that the posterior femur also shows a significantly different morphology.

  20. Extra-anatomic transplantations in autologous adult cell therapies aiding anatomical regeneration and physiological recovery – An insight and categorization

    Directory of Open Access Journals (Sweden)

    Editorial

    2015-12-01

    stimuli (voluntary and lack propagation of action potentials. However, the skeletal myoblasts in vitro, expanded as patches, have aided the in situ regeneration of the dysfunctional myocardium by secreting relevant growth factors [3]. Similarly, the buccal mucosal epithelium which is an opaque tissue has been applied to regenerate the damaged corneal epithelium, which in contrast is a transparent tissue. Here the buccal mucosal epithelium has been found to replace directly the dysfunctional corneal epithelium to assist in its regeneration and the resumption of proper function [4]. Though the source of the cells taken for repair of cartilage and corneal epithelium are extra-anatomic, they belong to the same germ layer of developmental origin; skeletal myoblasts (source and cardiomyocytes (target both from the mesoderm while buccal mucosal epithelium (source and corneal epithelium (target are both from the ectoderm. Extra-anatomic cell therapies reported in the literature such as the transplantation of olfactory ensheathing cells in spinal cord injury [5] also fit into this association, as the cell source for the replacement and the target organ exist within the same germ layer of ectoderm, developmentally but separated regionally. All these exchanges, we propose, should be termed as “Intra-germ Extra-anatomic Cell Therapies” (IECT. We have come across two extra-anatomic cell therapies that have been reported in the literature, where cells of the source and target tissue have different embryonic origins. Firstly, the transplantation of in vitro expanded buccal mucosal epithelial cells to treat urethral strictures in the “BEES-HAUS” (Buccal Epithelium Expanded & encapsulated in Scaffold - Hybrid Approach to Urethral Stricture approach reported by Vaddi et al [6] and secondly the use of gingival fibroblasts to replace the lost dermal fibroblasts in cell therapy for facial anti-aging [7] by Ebisawa et al both fall under this category. The buccal mucosal epithelial

  1. Bony landmarks are not an adequate substitute for lymphangiography in defining pelvic lymph node location for the treatment of cervical cancer with radiotherapy

    International Nuclear Information System (INIS)

    Bonin, Steven R.; Lanciano, Rachelle M.; Corn, Benjamin W.; Hogan, W. Michael; Hartz, William H.; Hanks, Gerald E.

    1996-01-01

    cm from the previously described reference line had mean values of 2.0 ± 1.0 cm (range 1.3 to 3.0 cm), 0.9 ± 3.9 cm (range -1.9 to 5.1 cm), and 1.8 ± 2.1 cm (range -0.8 to 3.5 cm), respectively. Ten of 22 (45%) patients would have had inadequate nodal irradiation if their fields had been designed according to standard GOG parameters. In all cases, these incompletely irradiated lymph nodes were from the lowest of the lateral external iliac group. Conclusions: Great variability in pelvic lymph node location is demonstrated when LAG is used to directly visualize their location. Bony structures are inaccurate landmarks for pelvic lymph node position. The GOG standard pelvic fields are not consistently adequate to cover all lateral external iliac lymph nodes, although the clinical significance of this subgroup of lymph nodes is not known. At this time, LAG remains the ideal radiographic modality to define anatomic location of regional lymph nodes for pelvic RT treatment planning. The clinical importance of the most lateral group of external iliac lymph nodes in various stages of cervical cancer represents a potential area of future research

  2. Information Needs/Relevance

    OpenAIRE

    Wildemuth, Barbara M.

    2009-01-01

    A user's interaction with a DL is often initiated as the result of the user experiencing an information need of some kind. Aspects of that experience and how it might affect the user's interactions with the DL are discussed in this module. In addition, users continuously make decisions about and evaluations of the materials retrieved from a DL, relative to their information needs. Relevance judgments, and their relationship to the user's information needs, are discussed in this module. Draft

  3. The time-course of activation in the dorsal and ventral visual streams during landmark cueing and perceptual discrimination tasks.

    Science.gov (United States)

    Lambert, Anthony J; Wootton, Adrienne

    2017-08-01

    Different patterns of high density EEG activity were elicited by the same peripheral stimuli, in the context of Landmark Cueing and Perceptual Discrimination tasks. The C1 component of the visual event-related potential (ERP) at parietal - occipital electrode sites was larger in the Landmark Cueing task, and source localisation suggested greater activation in the superior parietal lobule (SPL) in this task, compared to the Perceptual Discrimination task, indicating stronger early recruitment of the dorsal visual stream. In the Perceptual Discrimination task, source localisation suggested widespread activation of the inferior temporal gyrus (ITG) and fusiform gyrus (FFG), structures associated with the ventral visual stream, during the early phase of the P1 ERP component. Moreover, during a later epoch (171-270ms after stimulus onset) increased temporal-occipital negativity, and stronger recruitment of ITG and FFG were observed in the Perceptual Discrimination task. These findings illuminate the contrasting functions of the dorsal and ventral visual streams, to support rapid shifts of attention in response to contextual landmarks, and conscious discrimination, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    Shang, Jianga; Gu, Fuqiang; Hu, Xuke; Kealy, Allison

    2015-01-01

    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. PMID:26516858

  5. Resources or landmarks: which factors drive homing success in Tetragonula carbonaria foraging in natural and disturbed landscapes?

    Science.gov (United States)

    Leonhardt, Sara D; Kaluza, Benjamin F; Wallace, Helen; Heard, Tim A

    2016-10-01

    To date, no study has investigated how landscape structural (visual) alterations affect navigation and thus homing success in stingless bees. We addressed this question in the Australian stingless bee Tetragonula carbonaria by performing marking, release and re-capture experiments in landscapes differing in habitat homogeneity (i.e., the proportion of elongated ground features typically considered prominent visual landmarks). We investigated how landscape affected the proportion of bees and nectar foragers returning to their hives as well as the earliest time bees and foragers returned. Undisturbed landscapes with few landmarks (that are conspicuous to the human eye) and large proportions of vegetation cover (natural forests) were classified visually/structurally homogeneous, and disturbed landscapes with many landmarks and fragmented or no extensive vegetation cover (gardens and plantations) visually/structurally heterogeneous. We found that proportions of successfully returning nectar foragers and earliest times first bees and foragers returned did not differ between landscapes. However, most bees returned in the visually/structurally most (forest) and least (garden) homogeneous landscape, suggesting that they use other than elongated ground features for navigation and that return speed is primarily driven by resource availability in a landscape.

  6. [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

  7. Computed tomography of the dog's brain: normal aspects and anatomical correlation

    International Nuclear Information System (INIS)

    Lorigados, C.A.B.; Pinto, A.C.B.F.

    2013-01-01

    Normal tomographic images of dog's heads were obtained, aimed to familiarize them with the normal aspects of the brain and correlate these findings with the relevant anatomy of the region studied. Several anatomical structures, such as the parenchyma of the frontal, parietal, temporal and occipital lobes, the longitudinal fissure, the ventricular system, the cerebellum, the olfactory bulb, the corpus callosum, diencephalon, the pons, the medulla oblongata and the chiasmatic sulcus were directly identified or were related to neighboring structures which helped in their identification. (author)

  8. Ultrasound guided versus landmark guided corticosteroid injection in patients with rotator cuff syndrome: Randomised controlled trial.

    Science.gov (United States)

    Bhayana, Himanshu; Mishra, Puneet; Tandon, Anupama; Pankaj, Amite; Pandey, Rohit; Malhotra, Raskesh

    2018-03-01

    Impingement syndrome is the most common differential in a patient presenting to an orthopaedic OPD with shoulder pain. Impingement syndrome is often managed with subacromial corticosteroid injection, which can be instilled using either landmark guided (LMG) approach or with the assistance of ultrasound (US). This study was envisaged to enquire whether ultrasound assistance improves the accuracy, efficacy or safety profile of the injection. 60 patients of rotator cuff syndrome underwent diagnostic ultrasound. They were randomly assigned to receive subacromial injection of 2 ml (40 mg/ml) methylprenisolone and 2 ml of 1% lignocaine combination either by US assistance (n = 30) or using LMG assistance (n = 30). The patients were evaluated before injection and on follow up visits at day 5, week 3, week 6 and 3rd month by a single assessor. The assessor was blinded of the treatment group to which patient belonged. Clinical assessment included demographic and clinical data, accuracy of injection, VAS (0-100) for pain, Constant score with goniometer evaluation of range of motion, patient's self assessment proforma and post injection side effects if any. Initial demographic, clinical and US findings in the groups exhibited no significant differences. The accuracy of US guided injections (100%) was more when compared from LMG injection (93.3%). Both VAS and Constant score showed significant improvement following steroid injection up to 3 months of follow up. However the differences in the two groups were not significant suggesting comparable efficacy of the two approaches. (Mean VAS score decrease: 27.23 for US and 25.16 for LMG, p guided injections have a higher accuracy of drug placement in the subacromial bursa, there is no difference in terms of clinical outcomes or safety profile of either of the method. Hence US guided injections seems to be unjustified, when compared to equally efficacious and cost effective LMG steroid injection.

  9. Spike sorting using locality preserving projection with gap statistics and landmark-based spectral clustering.

    Science.gov (United States)

    Nguyen, Thanh; Khosravi, Abbas; Creighton, Douglas; Nahavandi, Saeid

    2014-12-30

    Understanding neural functions requires knowledge from analysing electrophysiological data. The process of assigning spikes of a multichannel signal into clusters, called spike sorting, is one of the important problems in such analysis. There have been various automated spike sorting techniques with both advantages and disadvantages regarding accuracy and computational costs. Therefore, developing spike sorting methods that are highly accurate and computationally inexpensive is always a challenge in the biomedical engineering practice. An automatic unsupervised spike sorting method is proposed in this paper. The method uses features extracted by the locality preserving projection (LPP) algorithm. These features afterwards serve as inputs for the landmark-based spectral clustering (LSC) method. Gap statistics (GS) is employed to evaluate the number of clusters before the LSC can be performed. The proposed LPP-LSC is highly accurate and computationally inexpensive spike sorting approach. LPP spike features are very discriminative; thereby boost the performance of clustering methods. Furthermore, the LSC method exhibits its efficiency when integrated with the cluster evaluator GS. The proposed method's accuracy is approximately 13% superior to that of the benchmark combination between wavelet transformation and superparamagnetic clustering (WT-SPC). Additionally, LPP-LSC computing time is six times less than that of the WT-SPC. LPP-LSC obviously demonstrates a win-win spike sorting solution meeting both accuracy and computational cost criteria. LPP and LSC are linear algorithms that help reduce computational burden and thus their combination can be applied into real-time spike analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Institutional landmarks in Brazilian research on soil erosion: a historical overview

    Directory of Open Access Journals (Sweden)

    Tiago Santos Telles

    2013-12-01

    Full Text Available The problem of soil erosion in Brazil has been a focus of agricultural scientific research since the 19th century. The aim of this study was to provide a historical overview of the institutional landmarks which gave rise to the first studies in soil erosion and established the foundations of agricultural research in Brazil. The 19th century and beginning of the 20th century saw the founding of a series of institutions in Brazil, such as Botanical Gardens, executive institutions, research institutes, experimental stations, educational institutions of agricultural sciences, as well as the creation and diversification of scientific journals. These entities, each in its own way, served to foster soil erosion research in Brazil. During the Imperial period (1808-1889, discussions focused on soil degradation and conserving the fertility of agricultural land. During the First Republic (1889-1930, with the founding of various educational institutions and consolidation of research on soil degradation conducted by the Agronomic Institute of Campinas in the State of São Paulo, studies focused on soil depletion, identification of the major factors causing soil erosion and the measures necessary to control it. During the New State period (1930-1945, many soil conservation practices were developed and disseminated to combat erosion and field trials were set up, mainly to measure soil and water losses induced by hydric erosion. During the Brazilian New Republic (1945-1964, experiments were conducted throughout Brazil, consolidating soil and water conservation as one of the main areas of Soil Science in Brazil. This was followed by scientific conferences on erosion and the institutionalization of post-graduate studies. During the Military Regime (1964-1985, many research and educational institutions were founded, experimental studies intensified, and coincidently, soil erosion reached alarming levels which led to the development of the no-tillage system.

  11. Anatomical Variability of the Posterior Communicating Artery.

    Science.gov (United States)

    Gunnal, Sandhya Arvind; Farooqui, Mujibuddin S; Wabale, Rajendra N

    2018-01-01

    Although posterior communicating artery (PCoA) is a smaller branch of the internal carotid artery, it gives the main contribution in the formation of circle of Willis (CW) by communicating with the internal carotid arterial system and the vertebro-basilar arterial system. The size of PCoA varies frequently. The present work aims to study the PCoA regarding its morphology, morphometry, and symmetry. This study was conducted on 170 human cadaveric brains. Brains were dissected carefully and delicately to expose all components of CW, especially PCoA. Morphological variations of PCoA were noted along with its morphometry and symmetry. Morphological variations of PCoA were aplasia (3.52%), hypoplasia (25.29%), fenestration (0.58%), and persistent fetal pattern (16.47%). In the present study, we found the five different types of terminations of PCoA. Type I termination was the most common type, seen in 92.94% of cases, Type II termination was seen in 1.17%, Type III and Type IV terminations both were seen in 0.58%, and Type V was seen in 1.17%. The mean length of PCoA was 15.9 mm and 15.3 mm on the right and left sides, respectively. The mean diameter of PCoA was 2.1 mm and 1.9 mm on the right and left sides, respectively. Symmetry of PCoA was seen in 65.29% and asymmetric PCoA was seen in 34.70% of cases. The present study provides the complete description of PCoA regarding its morphology, symmetry, and morphometry. Awareness of these anatomical variations is important in neurovascular procedures.

  12. Etiologic analysis of 100 anatomically failed dacryocystorhinostomies

    Science.gov (United States)

    Dave, Tarjani Vivek; Mohammed, Faraz Ali; Ali, Mohammad Javed; Naik, Milind N

    2016-01-01

    Background The aim of this study was to assess the etiological factors contributing to the failure of a dacryocystorhinostomy (DCR). Patients and methods Retrospective review was performed in 100 consecutive patients who were diagnosed with anatomically failed DCR at presentation to a tertiary care hospital over a 5-year period from 2010 to 2015. Patient records were reviewed for demographic data, type of past surgery, preoperative endoscopic findings, previous use of adjuvants such as intubation and mitomycin C, and intraoperative notes during the re-revision. The potential etiological factors for failure were noted. Results Of the 100 patients with failed DCRs, the primary surgery was an external DCR in 73 and endoscopic DCR in 27 patients. Six patients in each group had multiple revisions. The mean ages at presentation in the external and endoscopic groups were 39.41 years and 37.19 years, respectively. All patients presented with epiphora. The most common causes of failure were inadequate osteotomy (69.8% in the external group and 85.1% in the endoscopic group, P=0.19) followed by inadequate or inappropriate sac marsupialization (60.2% in the external group and 77.7% in the endoscopic group, P=0.16) and cicatricial closure of the ostium (50.6% in the external group and 55.5% in the endoscopic group, P=0.83). The least common causes such as ostium granulomas and paradoxical middle turbinate (1.37%, n=1) were noted in the external group only. Conclusion Inadequate osteotomy, incomplete sac marsupialization, and cicatricial closure of the ostium were the most common causes of failure and did not significantly differ in the external and endoscopic groups. Meticulous evaluation to identify causative factors for failure and addressing them are crucial for subsequent successful outcomes. PMID:27555748

  13. Noninvasive study of anatomic variations of the bile and pancreatic duct using magnetic resonance cholangiopancreatography

    International Nuclear Information System (INIS)

    Fernandez, E.; Falco, J.; Campo, R.; Martin, J.; Brullet, E.; Espinos, J.

    1999-01-01

    To identify anatomic variations of the bile duct and pancreatic duct and papillary anomalies by means of magnetic resonance cholangiopancreatography (MRCP) and determine their correlation with endoscopic retrograde cholangiopancreatography (ERCP) findings. Eighty-five patients were selected by means of a prospective study comparing MRCP and ERCP. Coronal and axial HASTE images and coronal and oblique coronal RARE images were acquired in all the patients. Four of the studies (6%) were excluded because of poor technical quality. Anatomic variations were observed in 26 cases (30.5%), including trifurcation (n=7; 27%), right hepatic duct draining into left hepatic duct (n=2, 7.7%), right hepatic duct draining into common bile duct (n=4; 15.4%), extrahepatic confluence (n=2; 7.7%), medial cystic duct (n=2; 7.7%), parallel cystic duct (n=3; 11.5%), juxtapapillary duodenal diverticulum (n=3; 11.5%) and pancreas divisum (n=3; 11.5%). A good correlation was observed between the MRCP and ERCP findings. The introduction of MRCP into the noninvasive study of biliary disease may be useful in the detection of anatomic variations relevant to laparoscopic surgery and other endoscopic and interventional techniques. (Author) 11 refs

  14. Extended Endoscopic Endonasal Approaches for Cerebral Aneurysms: Anatomical, Virtual Reality and Morphometric Study

    Directory of Open Access Journals (Sweden)

    Alberto Di Somma

    2014-01-01

    Full Text Available Introduction. The purpose of the present contribution is to perform a detailed anatomic and virtual reality three-dimensional stereoscopic study in order to test the effectiveness of the extended endoscopic endonasal approaches for selected anterior and posterior circulation aneurysms. Methods. The study was divided in two main steps: (1 simulation step, using a dedicated Virtual Reality System (Dextroscope, Volume Interactions; (2 dissection step, in which the feasibility to reach specific vascular territory via the nose was verified in the anatomical laboratory. Results. Good visualization and proximal and distal vascular control of the main midline anterior and posterior circulation territory were achieved during the simulation step as well as in the dissection step (anterior communicating complex, internal carotid, ophthalmic, superior hypophyseal, posterior cerebral and posterior communicating, basilar, superior cerebellar, anterior inferior cerebellar, vertebral, and posterior inferior cerebellar arteries. Conclusion. The present contribution is intended as strictly anatomic study in which we highlighted some specific anterior and posterior circulation aneurysms that can be reached via the nose. For clinical applications of these approaches, some relevant complications, mainly related to the endonasal route, such as proximal and distal vascular control, major arterial bleeding, postoperative cerebrospinal fluid leak, and olfactory disturbances must be considered.

  15. Magnetic Resonance Imaging of the Normal Stifle Joint in Buffaloes (Bos Bubalis: An Anatomic Study

    Directory of Open Access Journals (Sweden)

    Moustafa Samy Sherif

    2014-12-01

    Full Text Available The aim of the present study was to describe the normal anatomy of the stifle joint in buffaloes (Bos bubalis on magnetic resonance images and related anatomical sectional slices to facilitate the interpretation of all these images, as well as to understand the basis for diseases diagnosis. The hind limbs of ten healthy adult buffaloes (Twenty stifle joints were used. After slaughtering, MR images were made in sagittal, transverse, and dorsal planes. The limbs then were frozen at -20° then correspondingly sectioned using an electric band saw. Clinically relevant anatomic structures were identified and labeled at each level in the corresponding images (MR and anatomic slices. MRI images were used to identify the bony and soft tissue structures of the stifle joint. The articular cartilage appeared with hyperintense signal and separated from the subcondral bone by gray line (moderate signal intensity. It is difficult to differentiate between the synovia, infrapatellar fat body and the articular cartilage because they appeared with hyperintense signal. The meniscial, femoropatellar and cruciate ligaments recognized as moderate signal intensity. However, the collateral and intermediate patellar ligaments, the common tendon of the Mm. extensor digitorum longus and peroneus tertius as well as the menisci and the medial patellar fibrocartilage appeared with hypointense signal. The knowledge of normal anatomy of the buffalo stifle joint would serve as initial reference to the evaluation of MR images in this species.

  16. Analgesic efficacy of ultrasound guided versus landmark-based bilateral superficial cervical plexus block for thyroid surgery

    Directory of Open Access Journals (Sweden)

    Rasha M. Hassan

    2017-10-01

    Full Text Available Background: The use of bilateral superficial cervical plexus block (BSCPB to provide analgesia for thyroid operations remains debatable. This study was done to assess the analgesic efficacy and safety of ultrasound (US guided or landmark-based BSCPB, performed under general anesthesia, compared to systemic narcotics in thyroid surgery. Patients and methods: A total of 69 patients ASA I and II scheduled for thyroid surgery were randomly assigned into three groups (23 patients each: Group (US received US guided BSCPB. Group (LM received landmark-based BSCPB. In both groups, the block was performed under general anesthesia and before surgery using 0.5% bupivacaine 12 ml on each side. Group (C who didn’t receive any block. We measured intra-operative hemodynamics and fentanyl requirements. We also measured postoperative analgesia within 24 h of surgery as regard: pethidine consumption, visual analogue scale (VAS pain scores and time to first rescue analgesic demand. Postoperative nausea and vomiting (PONV and other adverse events were noted as well. Results: There was a significant reduction in systolic blood pressure (SBP and heart rate (HR in groups US and LM compared with group C. Intra-operative fentanyl requirements were significantly increased in group C compared to groups US and LM. Time to first analgesic request was significantly longer in groups US and LM than in group C. Postoperative pethidine consumption and VAS scores, measured during the first postoperative day, were significantly higher in group C than groups US and LM. No significant difference was noted between the three groups regarding PONV. No other adverse events were recorded. No significant differences were noted between groups US and LM. Conclusion: BSCPB (US guided or landmark-based, performed under general anesthesia, effectively decreased peri-operative analgesic requirements in thyroid operations. However, there was no significant difference in analgesic efficacy or

  17. Cue reliability and a landmark stability heuristic determine relative weighting between egocentric and allocentric visual information in memory-guided reach.

    Science.gov (United States)

    Byrne, Patrick A; Crawford, J Douglas

    2010-06-01

    It is not known how egocentric visual information (location of a target relative to the self) and allocentric visual information (location of a target relative to external landmarks) are integrated to form reach plans. Based on behavioral data from rodents and humans we hypothesized that the degree of stability in visual landmarks would influence the relative weighting. Furthermore, based on numerous cue-combination studies we hypothesized that the reach system would act like a maximum-likelihood estimator (MLE), where the reliability of both cues determines their relative weighting. To predict how these factors might interact we developed an MLE model that weighs egocentric and allocentric information based on their respective reliabilities, and also on an additional stability heuristic. We tested the predictions of this model in 10 human subjects by manipulating landmark stability and reliability (via variable amplitude vibration of the landmarks and variable amplitude gaze shifts) in three reach-to-touch tasks: an egocentric control (reaching without landmarks), an allocentric control (reaching relative to landmarks), and a cue-conflict task (involving a subtle landmark "shift" during the memory interval). Variability from all three experiments was used to derive parameters for the MLE model, which was then used to simulate egocentric-allocentric weighting in the cue-conflict experiment. As predicted by the model, landmark vibration--despite its lack of influence on pointing variability (and thus allocentric reliability) in the control experiment--had a strong influence on egocentric-allocentric weighting. A reduced model without the stability heuristic was unable to reproduce this effect. These results suggest heuristics for extrinsic cue stability are at least as important as reliability for determining cue weighting in memory-guided reaching.

  18. Three-dimensional Frankfort horizontal plane for 3D cephalometry: a comparative assessment of conventional versus novel landmarks and horizontal planes.

    Science.gov (United States)

    Pittayapat, Pisha; Jacobs, Reinhilde; Bornstein, Michael M; Odri, Guillaume A; Lambrichts, Ivo; Willems, Guy; Politis, Constantinus; Olszewski, Raphael

    2018-05-25

    To assess the reproducibility of landmarks in three dimensions that determine the Frankfort horizontal plane (FH) as well as two new landmarks, and to evaluate the angular differences of newly introduced planes to the FH. Three-dimensional (3D) surface models were created from CBCT scans of 26 dry human skulls. Porion (Po), orbitale (Or), internal acoustic foramen (IAF), and zygomatico-maxillary suture (ZyMS) were indicated in the software by three observers twice with a 4-week interval. Angles between two FHs (FH 1: Or-R, Or-L, mid-Po; FH 2: Po-R, Po-L, mid-Or) and between FHs and new planes (Plane 1-6) were measured. Coordinates were exported to a spreadsheet. A statistical analysis was performed to define the landmark reproducibility and 3D angles. Intra- and inter-observer landmark reproducibility showed mean difference more than 1 mm for x-coordinates of all landmarks except IAF. IAF showed significantly better reproducibility than other landmarks (P Plane 3, connecting Or-R, Or-L and mid-IAF, and Plane 4, connecting Po-R, Po-L and mid-ZyMS, both showed an angular difference of less than 1 degree when compared to FHs. This study revealed poor reproducibility of the traditional FH landmarks on the x-axis and good reproducibility of a new landmark tested to replace Po, the IAF. Yet, Or showed superior results compared to ZyMS. The potential of using new horizontal planes was demonstrated. Future studies should focus on identification of a valid alternative for Or and ZyMS and on clinical implementation of the findings.

  19. Perceptions of science. The anatomical mission to Burma.

    Science.gov (United States)

    Sappol, Michael

    2003-10-10

    Until the 1830s, most Americans were unfamiliar with the images of anatomy. Then a small vanguard of reformers and missionaries began to preach, at home and around the world, that an identification with the images and concepts of anatomy was a crucial part of the civilizing process. In his essay, Sappol charts the changes in the perception of self that resulted from this anatomical evangelism. Today, as anatomical images abound in the arts and the media, we still believe that anatomical images show us our inner reality.

  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.

  1. [Relevant public health enteropathogens].

    Science.gov (United States)

    Riveros, Maribel; Ochoa, Theresa J

    2015-01-01

    Diarrhea remains the third leading cause of death in children under five years, despite recent advances in the management and prevention of this disease. It is caused by multiple pathogens, however, the prevalence of each varies by age group, geographical area and the scenario where cases (community vs hospital) are recorded. The most relevant pathogens in public health are those associated with the highest burden of disease, severity, complications and mortality. In our country, norovirus, Campylobacter and diarrheagenic E. coli are the most prevalent pathogens at the community level in children. In this paper we review the local epidemiology and potential areas of development in five selected pathogens: rotavirus, norovirus, Shiga toxin-producing E. coli (STEC), Shigella and Salmonella. Of these, rotavirus is the most important in the pediatric population and the main agent responsible for child mortality from diarrhea. The introduction of rotavirus vaccination in Peru will have a significant impact on disease burden and mortality from diarrhea. However, surveillance studies are needed to determine the impact of vaccination and changes in the epidemiology of diarrhea in Peru following the introduction of new vaccines, as well as antibiotic resistance surveillance of clinical relevant bacteria.

  2. Control over structure-specific flexibility improves anatomical accuracy for point-based deformable registration in bladder cancer radiotherapy.

    Science.gov (United States)

    Wognum, S; Bondar, L; Zolnay, A G; Chai, X; Hulshof, M C C M; Hoogeman, M S; Bel, A

    2013-02-01

    Future developments in image guided adaptive radiotherapy (IGART) for bladder cancer require accurate deformable image registration techniques for the precise assessment of tumor and bladder motion and deformation that occur as a result of large bladder volume changes during the course of radiotherapy treatment. The aim was to employ an extended version of a point-based deformable registration algorithm that allows control over tissue-specific flexibility in combination with the authors' unique patient dataset, in order to overcome two major challenges of bladder cancer registration, i.e., the difficulty in accounting for the difference in flexibility between the bladder wall and tumor and the lack of visible anatomical landmarks for validation. The registration algorithm used in the current study is an extension of the symmetric-thin plate splines-robust point matching (S-TPS-RPM) algorithm, a symmetric feature-based registration method. The S-TPS-RPM algorithm has been previously extended to allow control over the degree of flexibility of different structures via a weight parameter. The extended weighted S-TPS-RPM algorithm was tested and validated on CT data (planning- and four to five repeat-CTs) of five urinary bladder cancer patients who received lipiodol injections before radiotherapy. The performance of the weighted S-TPS-RPM method, applied to bladder and tumor structures simultaneously, was compared with a previous version of the S-TPS-RPM algorithm applied to bladder wall structure alone and with a simultaneous nonweighted S-TPS-RPM registration of the bladder and tumor structures. Performance was assessed in terms of anatomical and geometric accuracy. The anatomical accuracy was calculated as the residual distance error (RDE) of the lipiodol markers and the geometric accuracy was determined by the surface distance, surface coverage, and inverse consistency errors. Optimal parameter values for the flexibility and bladder weight parameters were determined

  3. Control over structure-specific flexibility improves anatomical accuracy for point-based deformable registration in bladder cancer radiotherapy

    International Nuclear Information System (INIS)

    Wognum, S.; Chai, X.; Hulshof, M. C. C. M.; Bel, A.; Bondar, L.; Zolnay, A. G.; Hoogeman, M. S.

    2013-01-01

    Purpose: Future developments in image guided adaptive radiotherapy (IGART) for bladder cancer require accurate deformable image registration techniques for the precise assessment of tumor and bladder motion and deformation that occur as a result of large bladder volume changes during the course of radiotherapy treatment. The aim was to employ an extended version of a point-based deformable registration algorithm that allows control over tissue-specific flexibility in combination with the authors’ unique patient dataset, in order to overcome two major challenges of bladder cancer registration, i.e., the difficulty in accounting for the difference in flexibility between the bladder wall and tumor and the lack of visible anatomical landmarks for validation. Methods: The registration algorithm used in the current study is an extension of the symmetric-thin plate splines-robust point matching (S-TPS-RPM) algorithm, a symmetric feature-based registration method. The S-TPS-RPM algorithm has been previously extended to allow control over the degree of flexibility of different structures via a weight parameter. The extended weighted S-TPS-RPM algorithm was tested and validated on CT data (planning- and four to five repeat-CTs) of five urinary bladder cancer patients who received lipiodol injections before radiotherapy. The performance of the weighted S-TPS-RPM method, applied to bladder and tumor structures simultaneously, was compared with a previous version of the S-TPS-RPM algorithm applied to bladder wall structure alone and with a simultaneous nonweighted S-TPS-RPM registration of the bladder and tumor structures. Performance was assessed in terms of anatomical and geometric accuracy. The anatomical accuracy was calculated as the residual distance error (RDE) of the lipiodol markers and the geometric accuracy was determined by the surface distance, surface coverage, and inverse consistency errors. Optimal parameter values for the flexibility and bladder weight

  4. Control over structure-specific flexibility improves anatomical accuracy for point-based deformable registration in bladder cancer radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Wognum, S.; Chai, X.; Hulshof, M. C. C. M.; Bel, A. [Department of Radiotherapy, Academic Medical Center, Meiberdreef 9, 1105 AZ Amsterdam (Netherlands); Bondar, L.; Zolnay, A. G.; Hoogeman, M. S. [Department of Radiation Oncology, Daniel den Hoed Cancer Center, Erasmus Medical Center, Groene Hilledijk 301, 3075 EA Rotterdam (Netherlands)

    2013-02-15

    Purpose: Future developments in image guided adaptive radiotherapy (IGART) for bladder cancer require accurate deformable image registration techniques for the precise assessment of tumor and bladder motion and deformation that occur as a result of large bladder volume changes during the course of radiotherapy treatment. The aim was to employ an extended version of a point-based deformable registration algorithm that allows control over tissue-specific flexibility in combination with the authors' unique patient dataset, in order to overcome two major challenges of bladder cancer registration, i.e., the difficulty in accounting for the difference in flexibility between the bladder wall and tumor and the lack of visible anatomical landmarks for validation. Methods: The registration algorithm used in the current study is an extension of the symmetric-thin plate splines-robust point matching (S-TPS-RPM) algorithm, a symmetric feature-based registration method. The S-TPS-RPM algorithm has been previously extended to allow control over the degree of flexibility of different structures via a weight parameter. The extended weighted S-TPS-RPM algorithm was tested and validated on CT data (planning- and four to five repeat-CTs) of five urinary bladder cancer patients who received lipiodol injections before radiotherapy. The performance of the weighted S-TPS-RPM method, applied to bladder and tumor structures simultaneously, was compared with a previous version of the S-TPS-RPM algorithm applied to bladder wall structure alone and with a simultaneous nonweighted S-TPS-RPM registration of the bladder and tumor structures. Performance was assessed in terms of anatomical and geometric accuracy. The anatomical accuracy was calculated as the residual distance error (RDE) of the lipiodol markers and the geometric accuracy was determined by the surface distance, surface coverage, and inverse consistency errors. Optimal parameter values for the flexibility and bladder weight

  5. Pilot study of dynamic cine CT angiography for the evaluation of abdominal aortic aneurysms : Implications for endograft treatment

    NARCIS (Netherlands)

    Teutelink, A; Rutten, A; Muhs, BE; Olree, M; van Herwaarden, JA; de Vos, AM; Prokop, M; Moll, FL; Verhagen, HJM

    Purpose: To utilize 40-slice electrocardiographically (ECG)-gated cine computed tomographic angiography (CTA) to characterize normal aortic motion during the cardiac cycle at relevant anatomical landmarks in preoperative abdominal aortic aneurysm (AAA) patients. Methods: In 10 consecutive

  6. 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. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Clinical applications of the superior epigastric artery perforator (SEAP) flap: anatomical studies and preoperative perforator mapping with multidetector CT.

    Science.gov (United States)

    Hamdi, Moustapha; Van Landuyt, Koenraad; Ulens, Sara; Van Hedent, Eddy; Roche, Nathalie; Monstrey, Stan

    2009-09-01

    Pedicled superior epigastric artery perforator (SEAP) flaps can be raised to cover challenging thoracic defects. We present an anatomical study based on multidetector computerized tomography (MDCT) scan findings of the SEA perforators in addition to the first reported clinical series of SEAP flaps in anterior chest wall reconstruction. (a) In the CT scan study, images of a group of 20 patients who underwent MDCT scan analysis were used to visualise bilaterally the location of musculocutaneous SEAP. X- and Y-axes were used as landmarks to localise the perforators. The X-axis is a horizontal line at the junction of sternum and xyphoid (JCX) and the Y-axis is at the midline. (b) In the clinical study, seven pedicled SEAP flaps were performed in another group of patients. MDCT images revealed totally 157 perforators with a mean of 7.85 perforators per patient. The dominant perforators (137 perforators) were mainly localised in an area between 1.5 and 6.5 cm from the X-axis on both sides and between 3 and 16 cm below the Y-axis. The calibre of these dominant perforators was judged as 'good' to 'very good' in 82.5% of the cases. The average dimension of the flap was 21.7x6.7 cm. All flaps were based on one perforator. Mean harvesting time was 110 min. There were no flap losses. Minor tip necrosis occurred in two flaps. One of them was treated with excision and primary closure. Our clinical experience indicates that the SEAP flap provides a novel and useful approach for reconstruction of anterior chest wall defects. CT-based imaging allows for anatomical assessment of the perforators of the superior epigastric artery (SEA).

  8. Anatomical Study of Healthy Aortic Arches.

    Science.gov (United States)

    Girsowicz, Elie; Georg, Yannick; Lefebvre, François; Lejay, Anne; Thaveau, Fabien; Roy, Catherine; Ohana, Mickael; Chakfe, Nabil

    2017-10-01

    With the steady increase of endovascular procedures involving the aortic arch (AA), an actual depiction of its anatomy has become mandatory. It has also become necessary to evaluate the natural evolution of the AA morphology as part of the evaluation of endovascular devices durability. The objective of this study was to perform a morphological and anatomical study of the AA and of the supra aortic trunks (SAT) in healthy patients, with an evaluation of their evolution with time, with a specific orientation applied to endovascular therapies of the AA. Sixty-one patients (31 men, mean age 50.8 [18-82]) with a normal anatomy were included in the study. Measurements included the diameters of the AA and SAT in 17 locations, their distance and angulation based on computed tomography angiography data. Statistical analysis focused on descriptive statistics, differences between genders, as well as correlations with age. Aortic diameters (mean ± SD) were 29.5 ± 3.9 mm at the ascending aorta, 28.6 ± 3.9 mm at the innominate artery (IA), 27.1 ± 3.2 mm at the left common carotid artery (LCCA), 25.3 ± 3.0 mm at the left subclavian artery (LSCA), 23.9 ± 3.3 mm at the descending aorta. Mean angulation of the AA was 82° (95% confidence interval [CI]: 78.95-85.19°), mean angulation between LSCA/LCCA was -5.7° (95% CI: -0.9 to 18.7°) and -1.8° (95% CI: 5.4-26.4°) between LCCA/IA. Mean distance between the LSCA and the LCCA was 14.3 mm (95% CI: 13-15.6 mm) and 21.8 mm (95% CI: 20.3-23.4 mm) between LCCA and IA. All diameters of the AA increased with age (P Men had diameters statistically (P women except at the LCCA ostium level. A statistically significant increase of the distances between the LSCA and the LCCA, between the LSCA and the IA and between the IA and the LCCA was found with age, P = 0.027, better understanding of the three-dimensional aspects of the AA, confirmed the variability and heterogeneity of the SAT disposition, and discussed the principles of vascular

  9. Other relevant biological papers

    International Nuclear Information System (INIS)

    Shimizu, M.

    1989-01-01

    A considerable number of CRESP-relevant papers concerning deep-sea biology and radioecology have been published. It is the purpose of this study to call attention to them. They fall into three general categories. The first is papers of general interest. They are mentioned only briefly, and include text references to the global bibliography at the end of the volume. The second are papers that are not only mentioned and referenced, but for various reasons are described in abstract form. The last is a list of papers compiled by H.S.J. Roe specifically for this volume. They are listed in bibliographic form, and are also included in the global bibliography at the end of the volume

  10. A Review of the Published Anatomical Research on the African ...

    African Journals Online (AJOL)

    A Review of the Published Anatomical Research on the African Giant Rat ... of their anatomy and morphophysiology however, the scientific bases for these ... conference proceedings and unpublished research dissertations and thesis. All data ...

  11. Anatomic features involved in technical complexity of partial nephrectomy.

    Science.gov (United States)

    Hou, Weibin; Yan, Weigang; Ji, Zhigang

    2015-01-01

    Nephrometry score systems, including RENAL nephrometry, preoperative aspects and dimensions used for an anatomical classification system, C-index, diameter-axial-polar nephrometry, contact surface area score, calculating resected and ischemized volume, renal tumor invasion index, surgical approach renal ranking score, zonal NePhRO score, and renal pelvic score, have been reviewed. Moreover, salient anatomic features like the perinephric fat and vascular variants also have been discussed. We then extract 7 anatomic characteristics, namely tumor size, spatial location, adjacency, exophytic/endophytic extension, vascular variants, pelvic anatomy, and perinephric fat as important features for partial nephrectomy. For novice surgeons, comprehensive and adequate anatomic consideration may help them in their early clinical practice. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. A theoretical ovary position in link with the global anatomical ...

    African Journals Online (AJOL)

    anatomical structure of each human female body. Hassen ... pregnancy ovaries become really slightly displaced they would keep the proposed three- ... ovarian ligament, which anchors the ovary to the uterus; and the suspensory ligament,.

  13. Anatomical terminology and nomenclature: past, present and highlights.

    Science.gov (United States)

    Kachlik, David; Baca, Vaclav; Bozdechova, Ivana; Cech, Pavel; Musil, Vladimir

    2008-08-01

    The anatomical terminology is a base for medical communication. It is elaborated into a nomenclature in Latin. Its history goes back to 1895, when the first Latin anatomical nomenclature was published as Basiliensia Nomina Anatomica. It was followed by seven revisions (Jenaiensia Nomina Anatomica 1935, Parisiensia Nomina Anatomica 1955, Nomina Anatomica 2nd to 6th edition 1960-1989). The last revision, Terminologia Anatomica, (TA) created by the Federative Committee on Anatomical Terminology and approved by the International Federation of Associations of Anatomists, was published in 1998. Apart from the official Latin anatomical terminology, it includes a list of recommended English equivalents. In this article, major changes and pitfalls of the nomenclature are discussed, as well as the clinical anatomy terms. The last revision (TA) is highly recommended to the attention of not only teachers, students and researchers, but also to clinicians, doctors, translators, editors and publishers to be followed in their activities.

  14. Anatomically-aided PET reconstruction using the kernel method.

    Science.gov (United States)

    Hutchcroft, Will; Wang, Guobao; Chen, Kevin T; Catana, Ciprian; Qi, Jinyi

    2016-09-21

    This paper extends the kernel method that was proposed previously for dynamic PET reconstruction, to incorporate anatomical side information into the PET reconstruction model. In contrast to existing methods that incorporate anatomical information using a penalized likelihood framework, the proposed method incorporates this information in the simpler maximum likelihood (ML) formulation and is amenable to ordered subsets. The new method also does not require any segmentation of the anatomical image to obtain edge information. We compare the kernel method with the Bowsher method for anatomically-aided PET image reconstruction through a simulated data set. Computer simulations demonstrate that the kernel method offers advantages over the Bowsher method in region of interest quantification. Additionally the kernel method is applied to a 3D patient data set. The kernel method results in reduced noise at a matched contrast level compared with the conventional ML expectation maximization algorithm.

  15. Anatomical influences on internally coupled ears in reptiles.

    Science.gov (United States)

    Young, Bruce A

    2016-10-01

    Many reptiles, and other vertebrates, have internally coupled ears in which a patent anatomical connection allows pressure waves generated by the displacement of one tympanic membrane to propagate (internally) through the head and, ultimately, influence the displacement of the contralateral tympanic membrane. The pattern of tympanic displacement caused by this internal coupling can give rise to novel sensory cues. The auditory mechanics of reptiles exhibit more anatomical variation than in any other vertebrate group. This variation includes structural features such as diverticula and septa, as well as coverings of the tympanic membrane. Many of these anatomical features would likely influence the functional significance of the internal coupling between the tympanic membranes. Several of the anatomical components of the reptilian internally coupled ear are under active motor control, suggesting that in some reptiles the auditory system may be more dynamic than previously recognized.

  16. Automatic anatomically selective image enhancement in digital chest radiography

    International Nuclear Information System (INIS)

    Sezan, M.I.; Minerbo, G.N.; Schaetzing, R.

    1989-01-01

    The authors develop a technique for automatic anatomically selective enhancement of digital chest radiographs. Anatomically selective enhancement is motivated by the desire to simultaneously meet the different enhancement requirements of the lung field and the mediastinum. A recent peak detection algorithm and a set of rules are applied to the image histogram to determine automatically a gray-level threshold between the lung field and mediastinum. The gray-level threshold facilitates anatomically selective gray-scale modification and/or unsharp masking. Further, in an attempt to suppress possible white-band or black-band artifacts due to unsharp masking at sharp edges, local-contrast adaptivity is incorporated into anatomically selective unsharp masking by designing an anatomy-sensitive emphasis parameter which varies asymmetrically with positive and negative values of the local image contrast

  17. Ultrasound of the rotator cuff with MRI and anatomic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Rutten, Matthieu J.C.M. [Department of Radiology, Jeroen Bosch Hospital, Nieuwstraat 34, 5211 NL ' s-Hertogenbosch (Netherlands)]. E-mail: M.Rutten@JBZ.nl; Maresch, Bas J. [Department of Radiology, Hospital Gelderse Vallei, Willy Brandtlaan 10, 6710 HN Ede (Netherlands)]. E-mail: MareschB@zgv.nl; Jager, Gerrit J. [Department of Radiology, Jeroen Bosch Hospital, Nieuwstraat 34, 5211 NL ' s-Hertogenbosch (Netherlands)]. E-mail: G.Jager@JBZ.nl; Blickman, Johan G. [Department of Radiology, University Medical Center Nijmegen, Geert Grooteplein Zuid 18, 6500 HB Nijmegen (Netherlands)]. E-mail: J.Blickman@rad.umcn.nl; Holsbeeck, Marnix T. van [Department of Radiology, Henry Ford Hospital, 2799 W Grand Boulevard, Detroit, MI 48202 (United States)]. E-mail: vanholsbeeck@comcast.net

    2007-06-15

    Magnetic resonance imaging and high-resolution ultrasound (US) are frequently used for the detection of rotator cuff tears. The diagnostic yield of US is influenced by several factors as technique, knowledge of the imaging characteristics of anatomic and pathologic findings and of pitfalls. The purpose of this article is to illustrates that the standardized high-resolution US examination of the shoulder covers the entire rotator cuff and correlates with MR imaging and anatomic sections.

  18. Spatial distribution and longitudinal development of deep cortical sulcal landmarks in infants.

    Science.gov (United States)

    Meng, Yu; Li, Gang; Lin, Weili; Gilmore, John H; Shen, Dinggang

    2014-10-15

    , which likely has close relationships with the lateralization of brain functions of these regions. This study provides detailed insights into the spatial distribution and temporal development of deep sulcal landmarks in infants. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Correlating Intravital Multi-Photon Microscopy to 3D Electron Microscopy of Invading Tumor Cells Using Anatomical Reference Points

    Science.gov (United States)

    Karreman, Matthia A.; Mercier, Luc; Schieber, Nicole L.; Shibue, Tsukasa; Schwab, Yannick; Goetz, Jacky G.

    2014-01-01

    Correlative microscopy combines the advantages of both light and electron microscopy to enable imaging of rare and transient events at high resolution. Performing correlative microscopy in complex and bulky samples such as an entire living organism is a time-consuming and error-prone task. Here, we investigate correlative methods that rely on the use of artificial and endogenous structural features of the sample as reference points for correlating intravital fluorescence microscopy and electron microscopy. To investigate tumor cell behavior in vivo with ultrastructural accuracy, a reliable approach is needed to retrieve single tumor cells imaged deep within the tissue. For this purpose, fluorescently labeled tumor cells were subcutaneously injected into a mouse ear and imaged using two-photon-excitation microscopy. Using near-infrared branding, the position of the imaged area within the sample was labeled at the skin level, allowing for its precise recollection. Following sample preparation for electron microscopy, concerted usage of the artificial branding and anatomical landmarks enables targeting and approaching the cells of interest while serial sectioning through the specimen. We describe here three procedures showing how three-dimensional (3D) mapping of structural features in the tissue can be exploited to accurately correlate between the two imaging modalities, without having to rely on the use of artificially introduced markers of the region of interest. The methods employed here facilitate the link between intravital and nanoscale imaging of invasive tumor cells, enabling correlating function to structure in the study of tumor invasion and metastasis. PMID:25479106

  20. Radial force distribution changes associated with tangential force production in cylindrical grasping, and the importance of anatomical registration.

    Science.gov (United States)

    Pataky, Todd C; Slota, Gregory P; Latash, Mark L; Zatsiorsky, Vladimir M

    2012-01-10

    Radial force (F(r)) distributions describe grip force coordination about a cylindrical object. Recent studies have employed only explicit F(r) tasks, and have not normalized for anatomical variance when considering F(r) distributions. The goals of the present study were (i) to explore F(r) during tangential force production tasks, and (ii) to examine the extent to which anatomical registration (i.e. spatial normalization of anatomically analogous structures) could improve signal detectability in F(r) data. Twelve subjects grasped a vertically oriented cylindrical handle (diameter=6 cm) and matched target upward tangential forces of 10, 20, and 30 N. F(r) data were measured using a flexible pressure mat with an angular resolution of 4.8°, and were registered using piecewise-linear interpolation between five manually identified points-of-interest. Results indicate that F(r) was primarily limited to three contact regions: the distal thumb, the distal fingers, and the fingers' metatacarpal heads, and that, while increases in tangential force caused significant increases in F(r) for these regions, they did not significantly affect the F(r) distribution across the hand. Registration was found to substantially reduce between-subject variability, as indicated by both accentuated F(r) trends, and amplification of the test statistic. These results imply that, while subjects focus F(r) primarily on three anatomical regions during cylindrical grasp, inter-subject anatomical differences introduce a variability that, if not corrected for via registration, may compromise one's ability to draw anatomically relevant conclusions from grasping force data. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. The linguistic roots of Modern English anatomical terminology.

    Science.gov (United States)

    Turmezei, Tom D

    2012-11-01

    Previous research focusing on Classical Latin and Greek roots has shown that understanding the etymology of English anatomical terms may be beneficial for students of human anatomy. However, not all anatomical terms are derived from Classical origins. This study aims to explore the linguistic roots of the Modern English terminology used in human gross anatomy. By reference to the Oxford English Dictionary, etymologies were determined for a lexicon of 798 Modern English gross anatomical terms from the 40(th) edition of Gray's Anatomy. Earliest traceable language of origin was determined for all 798 terms; language of acquisition was determined for 747 terms. Earliest traceable languages of origin were: Classical Latin (62%), Classical Greek (24%), Old English (7%), Post-Classical Latin (3%), and other (4%). Languages of acquisition were: Classical Latin (42%), Post-Classical Latin (29%), Old English (8%), Modern French (6%), Classical Greek (5%), Middle English (3%), and other (7%). While the roots of Modern English anatomical terminology mostly lie in Classical languages (accounting for the origin of 86% of terms), the anatomical lexicon of Modern English is actually much more diverse. Interesting and perhaps less familiar examples from these languages and the methods by which such terms have been created and absorbed are discussed. The author suggests that awareness of anatomical etymologies may enhance the enjoyment and understanding of human anatomy for students and teachers alike. Copyright © 2012 Wiley Periodicals, Inc.

  2. Reappraising the functional implications of the primate visual anatomical hierarchy.

    Science.gov (United States)

    Hegdé, Jay; Felleman, Daniel J

    2007-10-01

    The primate visual system has been shown to be organized into an anatomical hierarchy by the application of a few principled criteria. It has been widely assumed that cortical visual processing is also hierarchical, with the anatomical hierarchy providing a defined substrate for clear levels of hierarchical function. A large body of empirical evidence seemed to support this assumption, including the general observations that functional properties of visual neurons grow progressively more complex at progressively higher levels of the anatomical hierarchy. However, a growing body of evidence, including recent direct experimental comparisons of functional properties at two or more levels of the anatomical hierarchy, indicates that visual processing neither is hierarchical nor parallels the anatomical hierarchy. Recent results also indicate that some of the pathways of visual information flow are not hierarchical, so that the anatomical hierarchy cannot be taken as a strict flowchart of visual information either. Thus, while the sustaining strength of the notion of hierarchical processing may be that it is rather simple, its fatal flaw is that it is overly simplistic.

  3. Anatomic and radiographic evaluation of the hip

    Energy Technology Data Exchange (ETDEWEB)

    Llopis, Eva, E-mail: evallopis@gmail.com [Hospital de la Ribera, Carretera de Corbera km1, Alzira 46600, Valencia (Spain); Higueras, Victoria; Vaño, Maria [Hospital de la Ribera, Carretera de Corbera km1, Alzira 46600, Valencia (Spain); Altónaga, José R. [Leon University, 24071 Leon (Spain)

    2012-12-15

    The hip is a challenging joint to study is deeply located in the pelvis and surrounding by a large group of muscles with complex tendinous attachments. Our knowledge has recently increased together with the advent of new surgical techniques but further research is needed to better understand hip biomechanics and the relevance of some of radiological findings. Although recent techniques such as MR show anatomy exquisitely is essential to start with pelvis plain radiography for a good evaluation of bone structures and pelvis alignment. During this chapter we will be give a short overview of pelvis normal structures and some key points of MR and MR arthrography technique, because more detailed description is done on every specific chapter.

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

    Science.gov (United States)

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

    2015-06-01

    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 and taxonomic identification. Adult Aedes mosquito specimens were randomly collected using aerial nets and morphologically examined and identified. The landmarks were identified on the basis of landmark based geometric morphometric analysis thin-plate spline (mainly the software tps-Util 1.28; tps-Dig 1.40; tps-Relw 1.53; and tps-Spline 1.20) and integrated morphometrics programme (mainly twogroup win8 and PCA win8) were utilized. In relative warp (RW) analysis, the first two RW of Ae. aegypti accounted for the highest value (95.82%), followed by Ae. pseudotaeniatus (90.89%), while the lowest (90.12%) being recorded for Ae. albopictus. The bending energies of Ae. aegypti and Ae. pseudotaeniatus were quite identical being 0.1882 and 0.1858 respectively, while Ae. albopictus recorded the highest value of 0.9774. The mean difference values of the distances among Aedes species performing Hotelling's T 2 test were significantly high, predicting major differences among the taxa. In PCA analysis, the horizontal and vertical axis summarized 52.41 and 23.30% of variances respectively. The centroid size exhibited significant differences among populations (non-parametric Kruskal-Wallis test, H = 10.56, p < 0.01). It has been marked out that the geometric morphometrics utilizes powerful and comprehensive statistical procedures to analyze the shape differences of a morphological feature, assuming that the studied mosquitoes may represent different genotypes and probably come from one diverse gene pool.

  5. Reliability of lower limb alignment measures using an established landmark-based method with a customized computer software program

    Science.gov (United States)

    Sled, Elizabeth A.; Sheehy, Lisa M.; Felson, David T.; Costigan, Patrick A.; Lam, Miu; Cooke, T. Derek V.

    2010-01-01

    The objective of the study was to evaluate the reliability of frontal plane lower limb alignment measures using a landmark-based method by (1) comparing inter- and intra-reader reliability between measurements of alignment obtained manually with those using a computer program, and (2) determining inter- and intra-reader reliability of computer-assisted alignment measures from full-limb radiographs. An established method for measuring alignment was used, involving selection of 10 femoral and tibial bone landmarks. 1) To compare manual and computer methods, we used digital images and matching paper copies of five alignment patterns simulating healthy and malaligned limbs drawn using AutoCAD. Seven readers were trained in each system. Paper copies were measured manually and repeat measurements were performed daily for 3 days, followed by a similar routine with the digital images using the computer. 2) To examine the reliability of computer-assisted measures from full-limb radiographs, 100 images (200 limbs) were selected as a random sample from 1,500 full-limb digital radiographs which were part of the Multicenter Osteoarthritis (MOST) Study. Three trained readers used the software program to measure alignment twice from the batch of 100 images, with two or more weeks between batch handling. Manual and computer measures of alignment showed excellent agreement (intraclass correlations [ICCs] 0.977 – 0.999 for computer analysis; 0.820 – 0.995 for manual measures). The computer program applied to full-limb radiographs produced alignment measurements with high inter- and intra-reader reliability (ICCs 0.839 – 0.998). In conclusion, alignment measures using a bone landmark-based approach and a computer program were highly reliable between multiple readers. PMID:19882339

  6. User perspectives on relevance criteria

    DEFF Research Database (Denmark)

    Maglaughlin, Kelly L.; Sonnenwald, Diane H.

    2002-01-01

    , partially relevant, or not relevant to their information need; and explained their decisions in an interview. Analysis revealed 29 criteria, discussed positively and negatively, that were used by the participants when selecting passages that contributed or detracted from a document's relevance......This study investigates the use of criteria to assess relevant, partially relevant, and not-relevant documents. Study participants identified passages within 20 document representations that they used to make relevance judgments; judged each document representation as a whole to be relevant...... matter, thought catalyst), full text (e.g., audience, novelty, type, possible content, utility), journal/publisher (e.g., novelty, main focus, perceived quality), and personal (e.g., competition, time requirements). Results further indicate that multiple criteria are used when making relevant, partially...

  7. A comparative study of two techniques (electrocardiogram- and landmark-guided for correct depth of the central venous catheter placement in paediatric patients undergoing elective cardiovascular surgery

    Directory of Open Access Journals (Sweden)

    Neeraj Kumar Barnwal

    2016-01-01

    Full Text Available Background and Aims: The complications of central venous catheterisation can be minimized by ensuring catheter tip placement just above the superior vena cava-right atrium junction. We aimed to compare two methods, using an electrocardiogram (ECG or landmark as guides, for assessing correct depth of central venous catheter (CVC placement. Methods: In a prospective randomised study of sixty patients of <12 years of age, thirty patients each were allotted randomly to two groups (ECG and landmark. After induction, central venous catheterisation was performed by either of the two techniques and position of CVC tip was compared in post-operative chest X-ray with respect to carina. Unpaired t-test was used for quantitative data and Chi-square test was used for qualitative data. Results: In ECG group, positions of CVC tip were above carina in 12, at carina in 9 and below carina in 9 patients. In landmark group, the positions of CVC tips were above carina in 10, at carina in 4 and below carina in 16 patients. Mean distance of CVC tip in ECG group was 0.34 ± 0.23 cm and 0.66 ± 0.35 cm in landmark group (P = 0.0001. Complications occurred in one patient in ECG group and in nine patients in landmark group (P = 0.0056. Conclusion: Overall, landmark-guided technique was comparable with ECG technique. ECG-guided technique was more precise for CVC tip placement closer to carina. The incidence of complications was more in the landmark group.

  8. Tree-based indexing for real-time ConvNet landmark-based visual place recognition

    Directory of Open Access Journals (Sweden)

    Yi Hou

    2017-01-01

    Full Text Available Recent impressive studies on using ConvNet landmarks for visual place recognition take an approach that involves three steps: (a detection of landmarks, (b description of the landmarks by ConvNet features using a convolutional neural network, and (c matching of the landmarks in the current view with those in the database views. Such an approach has been shown to achieve the state-of-the-art accuracy even under significant viewpoint and environmental changes. However, the computational burden in step (c significantly prevents this approach from being applied in practice, due to the complexity of linear search in high-dimensional space of the ConvNet features. In this article, we propose two simple and efficient search methods to tackle this issue. Both methods are built upon tree-based indexing. Given a set of ConvNet features of a query image, the first method directly searches the features’ approximate nearest neighbors in a tree structure that is constructed from ConvNet features of database images. The database images are voted on by features in the query image, according to a lookup table which maps each ConvNet feature to its corresponding database image. The database image with the highest vote is considered the solution. Our second method uses a coarse-to-fine procedure: the coarse step uses the first method to coarsely find the top-N database images, and the fine step performs a linear search in Hamming space of the hash codes of the ConvNet features to determine the best match. Experimental results demonstrate that our methods achieve real-time search performance on five data sets with different sizes and various conditions. Most notably, by achieving an average search time of 0.035 seconds/query, our second method improves the matching efficiency by the three orders of magnitude over a linear search baseline on a database with 20,688 images, with negligible loss in place recognition accuracy.

  9. Human tibial torsion - Morphometric assessment and clinical relevance

    Directory of Open Access Journals (Sweden)

    Swati Gandhi

    2014-02-01

    Full Text Available Background: Tibial torsion is an important anatomical parameter in clinical practice and displays variability among individuals. These variations are extremely significant in view of alignment guides such as those related to rotational landmarks of tibia in total knee arthroplasty. Further, precise knowledge and information pertaining to angle of tibial torsion also helps in correction of traumatic malunion or congenital maltorsion of tibia. Methods: The present study was carried out to determine the angle of tibial torsion in 100 adult dry tibia bones in the Department of Anatomy, Government Medical College, Amritsar. The study group comprised 50 males and 50 females with equal number of right- and left-sided bones. The measurements were meticulously recorded and the data were subjected to statistical analysis. The results were analyzed and discussed in the light of existing literature. Results: On the right side, it was found to be 29.84° ± 4.86°° (range = 22.00° -38.00° in males and 28.92° ± 5.10°° (range = 15.00°-38.00° in females. On the left side, it was found to be 28.00° ± 4.94°° (range = 20.00°-40.00°° in males and 28.12° ± 4.28°° (range = 20.00°-37.00°° in females. Conclusion: The present study is an endeavor to provide baseline data with reference to the angle of tibial torsion in the Indian population. The results of the study assume special importance in view of the technical advancements in reconstructive surgical procedures in orthopedic practice.

  10. The role of Long-Range Connectivity for the Characterization of the Functional-Anatomical Organization of the Cortex

    Directory of Open Access Journals (Sweden)

    Thomas R Knösche

    2011-07-01

    Full Text Available This review focuses on the role of long-range connectivity as one element of brain structure that is of key importance for the functional-anatomical organization of the cortex. In this context, we discuss the putative guiding principles for mapping brain function and structure onto the cortical surface. Such mappings reveal a high-degree of functional-anatomical segregation. Given that brain regions frequently maintain characteristic connectivity profiles and the functional repertoire of a cortical area is closely related to its anatomical connections, long-range connectivity may be used to define segregated cortical areas. This methodology is called connectivity-based parcellation.Within this framework, we investigate different techniques to estimate connectivity profiles with emphasis given to non-invasive methods based on diffusion magnetic resonance imaging (dMRI and diffusion tractography. Cortical parcellation is then defined based on similarity between diffusion tractograms, and different clustering approaches are discussed.We conclude that the use of non-invasively acquired connectivity estimates to characterize the functional-anatomical organization of the brain is a valid, relevant and necessary endeavor. Current and future developments in dMRI technology, tractography algorithms and models of the similarity structure hold great potential for a substantial improvement and enrichment of the results of the technique.

  11. The role of long-range connectivity for the characterization of the functional-anatomical organization of the cortex.

    Science.gov (United States)

    Knösche, Thomas R; Tittgemeyer, Marc

    2011-01-01

    This review focuses on the role of long-range connectivity as one element of brain structure that is of key importance for the functional-anatomical organization of the cortex. In this context, we discuss the putative guiding principles for mapping brain function and structure onto the cortical surface. Such mappings reveal a high degree of functional-anatomical segregation. Given that brain regions frequently maintain characteristic connectivity profiles and the functional repertoire of a cortical area is closely related to its anatomical connections, long-range connectivity may be used to define segregated cortical areas. This methodology is called connectivity-based parcellation. Within this framework, we investigate different techniques to estimate connectivity profiles with emphasis given to non-invasive methods based on diffusion magnetic resonance imaging (dMRI) and diffusion tractography. Cortical parcellation is then defined based on similarity between diffusion tractograms, and different clustering approaches are discussed. We conclude that the use of non-invasively acquired connectivity estimates to characterize the functional-anatomical organization of the brain is a valid, relevant, and necessary endeavor. Current and future developments in dMRI technology, tractography algorithms, and models of the similarity structure hold great potential for a substantial improvement and enrichment of the results of the technique.

  12. Broad Anatomical Variation within a Narrow Wood Density Range—A Study of Twig Wood across 69 Australian Angiosperms

    Science.gov (United States)

    Ziemińska, Kasia; Westoby, Mark; Wright, Ian J.

    2015-01-01

    Objectives Just as people with the same weight can have different body builds, woods with the same wood density can have different anatomies. Here, our aim was to assess the magnitude of anatomical variation within a restricted range of wood density and explore its potential ecological implications. Methods Twig wood of 69 angiosperm tree and shrub species was analyzed. Species were selected so that wood density varied within a relatively narrow range (0.38–0.62 g cm-3). Anatomical traits quantified included wood tissue fractions (fibres, axial parenchyma, ray parenchyma, vessels, and conduits with maximum lumen diameter below 15 μm), vessel properties, and pith area. To search for potential ecological correlates of anatomical variation the species were sampled across rainfall and temperature contrasts, and several other ecologically-relevant traits were measured (plant height, leaf area to sapwood area ratio, and modulus of elasticity). Results Despite the limited range in wood density, substantial anatomical variation was observed. Total parenchyma fraction varied from 0.12 to 0.66 and fibre fraction from 0.20 to 0.74, and these two traits were strongly inversely correlated (r = -0.86, P area to sapwood area ratio, and modulus of elasticity (0.24 ≤|r|≤ 0.41, P area to sapwood area ratio (0.47 ≤|r|≤ 0.65, all P area spectrum. The fibre-parenchyma spectrum does not yet have any clear or convincing ecological interpretation. PMID:25906320

  13. Broad Anatomical Variation within a Narrow Wood Density Range--A Study of Twig Wood across 69 Australian Angiosperms.

    Science.gov (United States)

    Ziemińska, Kasia; Westoby, Mark; Wright, Ian J

    2015-01-01

    Just as people with the same weight can have different body builds, woods with the same wood density can have different anatomies. Here, our aim was to assess the magnitude of anatomical variation within a restricted range of wood density and explore its potential ecological implications. Twig wood of 69 angiosperm tree and shrub species was analyzed. Species were selected so that wood density varied within a relatively narrow range (0.38-0.62 g cm-3). Anatomical traits quantified included wood tissue fractions (fibres, axial parenchyma, ray parenchyma, vessels, and conduits with maximum lumen diameter below 15 μm), vessel properties, and pith area. To search for potential ecological correlates of anatomical variation the species were sampled across rainfall and temperature contrasts, and several other ecologically-relevant traits were measured (plant height, leaf area to sapwood area ratio, and modulus of elasticity). Despite the limited range in wood density, substantial anatomical variation was observed. Total parenchyma fraction varied from 0.12 to 0.66 and fibre fraction from 0.20 to 0.74, and these two traits were strongly inversely correlated (r = -0.86, P area to sapwood area ratio, and modulus of elasticity (0.24 ≤|r|≤ 0.41, P area to sapwood area ratio (0.47 ≤|r|≤ 0.65, all P area spectrum. The fibre-parenchyma spectrum does not yet have any clear or convincing ecological interpretation.

  14. Perceptually Relevant and Piecewise Linear Matching of Silhouettes

    DEFF Research Database (Denmark)

    Zabulis, Xenophon; Sporring, Jon; Orphanoudakis, Xenophon

    2005-01-01

    In this paper, a novel alignment method for silhouettes is proposed. This method is based on the establishment of correspondences between landmarks on their boundaries and, in turn, on the establishment of correspondences of the boundary pieces in between these landmarks. The method yields more c...

  15. Feasibility of Using the Marginal Blood Vessels as Reference Landmarks for CT Colonography

    Science.gov (United States)

    Wei, Zhuoshi; Yao, Jianhua; Wang, Shijun; Liu, Jiamin; Dwyer, Andrew J.; Pickhardt, Perry J.; Nowinski, Wieslaw L.; Summers, Ronald M.

    2015-01-01

    .6 ± 9.4 mm (5.5–13.7 mm) (p = 0.15) and expressed as a percentage of the colon circumference was 3.1% ± 2.0% (2.3–4.0%) (p = 0.83). We were able to trace the marginal blood vessels for 10 collapsed colonic segments and determine the paths of the colon in these regions. CONCLUSION The marginal blood vessels run parallel to the colon in proximity to the tenia mesocolica and enable accurate supine-prone registration of polyps and localization of the colon path in areas of collapse. Thus, the marginal blood vessels may be used as reference landmarks complementary to the colon centerline and teniae coli. PMID:24370165

  16. Registration of T2-weighted and diffusion-weighted MR images of the prostate: comparison between manual and landmark-based methods

    Science.gov (United States)

    Peng, Yahui; Jiang, Yulei; Soylu, Fatma N.; Tomek, Mark; Sensakovic, William; Oto, Aytekin

    2012-02-01

    Quantitative analysis of multi-parametric magnetic resonance (MR) images of the prostate, including T2-weighted (T2w) and diffusion-weighted (DW) images, requires accurate image registration. We compared two registration methods between T2w and DW images. We collected pre-operative MR images of 124 prostate cancer patients (68 patients scanned with a GE scanner and 56 with Philips scanners). A landmark-based rigid registration was done based on six prostate landmarks in both T2w and DW images identified by a radiologist. Independently, a researcher manually registered the same images. A radiologist visually evaluated the registration results by using a 5-point ordinal scale of 1 (worst) to 5 (best). The Wilcoxon signed-rank test was used to determine whether the radiologist's ratings of the results of the two registration methods were significantly different. Results demonstrated that both methods were accurate: the average ratings were 4.2, 3.3, and 3.8 for GE, Philips, and all images, respectively, for the landmark-based method; and 4.6, 3.7, and 4.2, respectively, for the manual method. The manual registration results were more accurate than the landmark-based registration results (p < 0.0001 for GE, Philips, and all images). Therefore, the manual method produces more accurate registration between T2w and DW images than the landmark-based method.

  17. Megaliths as land-marks. Chronicle of the territorial role of the megalithic monuments through written sources

    Directory of Open Access Journals (Sweden)

    Martinón-Torres, Marcos

    2001-06-01

    Full Text Available Megalithic monuments have played dijferent roles throughout History. One of them has a spatial function, i.e. as landmarks. The aim of this paper has been to collect and analyse every written reference concerning Galician megaliths operating as landmarks between the 6th and 19th centuries AD. On this basis, the evolution of this social-territorial function of the monuments through time is reconstructed, and an interpretative hypothesis for this phenomenon is proposed. Finally, the importance of reviewing written sources as a methodology for archaeological survey and for studies of the topographic settings of monuments is emphasised.

    A lo largo de la Historia, los monumentos megalíticos han desempeñado, entre otras, una función espacial, como marcos de territorio. Para este artículo se recogen y analizan las referencias escritas a megalitos gallegos funcionando como marcadores o identificadores espaciales, entre los siglos VI y XIX d.C. A partir de este registro de fuentes se reconstruye la evolución de este papel social-territorial de los monumentos en las distintas épocas. Se plantea un modelo interpretativo para este fenómeno, y se valora la revisión de fuentes escritas como metodología para la prospección arqueológica y para los estudios de emplazamiento de megalitos.

  18. Adiponectin is associated with cardiovascular disease in male renal transplant recipients: baseline results from the LANDMARK 2 study

    Directory of Open Access Journals (Sweden)

    Mudge David

    2009-10-01

    Full Text Available Abstract Background Adiponectin is a major adipocyte-derived protein with insulin-sensitizing, anti-inflammatory and anti-atherogenic properties. Adiponectin levels correlate inversely with renal function and higher levels are predictive of lower cardiovascular disease (CVD in patients with normal renal function and chronic kidney disease. No data exists on the association between adiponectin and CVD in renal transplant recipients (RTR. Methods Standard biochemistry, clinical data and adiponectin were collected from 137 RTR recruited to the LANDMARK 2 study at baseline. The LANDMARK 2 study is an ongoing randomized controlled study that compares the outcome of aggressive risk factor modification for cardiovascular disease versus standard post-transplant care in renal transplant recipients with impaired glucose tolerance or diabetes mellitus. Results Mean patient age was 53.4 ± 12 years and the median post-transplantation period was 5 (0.5-31.9 years. Mean serum adiponectin level was 12.3 ± 7.1 μg/mL. On univariate analysis, adiponectin was positively associated with female gender (P = 0.01 and serum high-density lipoprotein (HDL concentration (P Conclusion In conclusion, adiponectin is positively correlated with inflammation, dyslipidemia and abnormal glucose tolerance in RTR. Furthermore, hypoadiponectinemia correlated with increased baseline CVD in male RTR.

  19. Interpreting and Integrating Clinical and Anatomic Pathology Results.

    Science.gov (United States)

    Ramaiah, Lila; Hinrichs, Mary Jane; Skuba, Elizabeth V; Iverson, William O; Ennulat, Daniela

    2017-01-01

    The continuing education course on integrating clinical and anatomical pathology data was designed to communicate the importance of using a weight of evidence approach to interpret safety findings in toxicology studies. This approach is necessary, as neither clinical nor anatomic pathology data can be relied upon in isolation to fully understand the relationship between study findings and the test article. Basic principles for correlating anatomic pathology and clinical pathology findings and for integrating these with other study end points were reviewed. To highlight these relationships, a series of case examples, presented jointly by a clinical pathologist and an anatomic pathologist, were used to illustrate the collaborative effort required between clinical and anatomical pathologists. In addition, the diagnostic utility of traditional liver biomarkers was discussed using results from a meta-analysis of rat hepatobiliary marker and histopathology data. This discussion also included examples of traditional and novel liver and renal biomarker data implementation in nonclinical toxicology studies to illustrate the relationship between discrete changes in biochemistry and tissue morphology.

  20. CT following US for possible appendicitis: anatomic coverage

    Energy Technology Data Exchange (ETDEWEB)

    O' Malley, Martin E. [University of Toronto, Princess Margaret Hospital, 3-920, Joint Department of Medical Imaging, Toronto, Ontario (Canada); Alharbi, Fawaz [University of Toronto, Toronto General Hospital, NCSB 1C572, Joint Department of Medical Imaging, Toronto, Ontario (Canada); Qassim University, Department of Medical Imaging, Buraydah, Qassim (Saudi Arabia); Chawla, Tanya P. [University of Toronto, Mount Sinai Hospital, Room 567, Joint Department of Medical Imaging, Toronto, Ontario (Canada); Moshonov, Hadas [University of Toronto, Joint Department of Medical Imaging, Toronto, Ontario (Canada)

    2016-02-15

    To determine superior-inferior anatomic borders for CT following inconclusive/nondiagnostic US for possible appendicitis. Ninety-nine patients with possible appendicitis and inconclusive/nondiagnostic US followed by CT were included in this retrospective study. Two radiologists reviewed CT images and determined superior-inferior anatomic borders required to diagnose or exclude appendicitis and diagnose alternative causes. This ''targeted'' coverage was used to estimate potential reduction in anatomic coverage compared to standard abdominal/pelvic CT. The study group included 83 women and 16 men; mean age 32 (median, 29; range 18-73) years. Final diagnoses were: nonspecific abdominal pain 50/99 (51 %), appendicitis 26/99 (26 %), gynaecological 12/99 (12 %), gastrointestinal 9/99 (10 %), and musculoskeletal 2/99 (2 %). Median dose-length product for standard CT was 890.0 (range, 306.3 - 2493.9) mGy.cm. To confidently diagnose/exclude appendicitis or identify alternative diagnoses, maximum superior-inferior anatomic CT coverage was the superior border of L2-superior border of pubic symphysis, for both reviewers. Targeted CT would reduce anatomic coverage by 30-55 % (mean 39 %, median 40 %) compared to standard CT. When CT is performed for appendicitis following inconclusive/nondiagnostic US, targeted CT from the superior border of L2-superior border of pubic symphysis can be used resulting in significant reduction in exposure to ionizing radiation compared to standard CT. (orig.)

  1. Anatomical success in patients after retinectomy for complex retinal detachment

    International Nuclear Information System (INIS)

    Mukhtar, A.; Ishaq, M.; Islam, Q.U.

    2015-01-01

    To evaluate the efficacy of primary and redo retinectomy in eyes with complex retinal detachment. Study Design: Quasi-experimental study. Place and Duration of Study: Armed Forces Institute of Ophthalmology Rawalpindi from Jan 2012 to June 2013. Patients and Methods: Fifty eight eyes (patients) underwent relaxing retinectomies for complex retinal detachment with proliferative vitreoretinopathy or intrinsic retinal shortening. Operative technique included pars plana vitrectomy, proliferative vitreoretinopathy management, use of intraoperative perfluorocarbon liquid, retinectomy, endolaser and intraocular temponade. The main outcome was anatomic success, defined as complete retinal reattachment at four months follow up. Eighteen eyes out of the same primary group underwent second retinectomy because of anatomical failure. Results: Mean age of study population was 53.78 ± 15.11 years, 56.9% of patients were male(s). Anatomic success rate after 1st retinectomy was achieved in 68.96% (40 eyes out of 58). In eighteen eyes that underwent 2nd retinectomy, anatomic success rate was 72.22% (13 eyes out of 18). Overall success rate was 91.3% (53 eyes out of 58) in our study. Concl