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

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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

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...

Ultrasound guidance versus anatomical landmarks for internal jugular vein catheterization.

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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

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

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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.

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

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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.

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

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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

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

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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.

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...

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

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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.

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

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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.

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

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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.

Colon flattening by landmark-driven optimal quasiconformal mapping.

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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.

The reliability of tablet computers in depicting maxillofacial radiographic landmarks

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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.

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

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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.

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

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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

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

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.

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.

Anatomical Basis for the Cardiac Interventional Electrophysiologist

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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.

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

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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

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.

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.

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

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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.

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

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.

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.

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

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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.

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.

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

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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.

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.

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

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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.

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.

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

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

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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.)

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

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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

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

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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.

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.

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.

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.

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

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

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,…

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

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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.

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.

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.

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.

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

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.

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.

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.

WIKIPEDIA ENTRIES AS A SOURCE OF CAR NAVIGATION LANDMARKS

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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.

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.

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.

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.

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.

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.

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.

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.

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.

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.)

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.

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.

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.)

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.

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

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

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

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

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.

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.

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.

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.

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...

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.

The Role of Emotional Landmarks on Topographical Memory.

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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.

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.

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.

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.

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

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.

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.

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

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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.

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

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

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.

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.

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)

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.

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.

Extra Facial Landmark Localization via Global Shape Reconstruction

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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.

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

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

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.

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.

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.

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.)

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

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)

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.

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

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.

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)

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.

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.

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."

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'.

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.

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.

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.

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.

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

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

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...

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.

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

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.

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.

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.

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

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.

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.

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

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

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.

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.

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.

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.

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.

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

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.

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

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...

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...

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.

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.

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.

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.

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.

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.

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.

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

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.

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 ...

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.

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.

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

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…

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.

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.

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...

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.

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

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

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

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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.

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.

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.

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

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.

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-...

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....

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,

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.

Neuroanatomy-based matrix-guided trimming protocol for the rat brain.

Science.gov (United States)

Defazio, Rossella; Criado, Ana; Zantedeschi, Valentina; Scanziani, Eugenio

2015-02-01

Brain trimming through defined neuroanatomical landmarks is recommended to obtain consistent sections in rat toxicity studies. In this article, we describe a matrix-guided trimming protocol that uses channels to reproduce coronal levels of anatomical landmarks. Both setup phase and validation study were performed on Han Wistar male rats (Crl:WI(Han)), 10-week-old, with bodyweight of 298 ± 29 (SD) g, using a matrix (ASI-Instruments(®), Houston, TX) fitted for brains of rats with 200 to 400 g bodyweight. In the setup phase, we identified eight channels, that is, 6, 8, 10, 12, 14, 16, 19, and 21, matching the recommended landmarks midway to the optic chiasm, frontal pole, optic chiasm, infundibulum, mamillary bodies, midbrain, middle cerebellum, and posterior cerebellum, respectively. In the validation study, we trimmed the immersion-fixed brains of 60 rats using the selected channels to determine how consistently the channels reproduced anatomical landmarks. Percentage of success (i.e., presence of expected targets for each level) ranged from 89 to 100%. Where 100% success was not achieved, it was noted that the shift in brain trimming was toward the caudal pole. In conclusion, we developed and validated a trimming protocol for the rat brain that allow comparable extensiveness, homology, and relevance of coronal sections as the landmark-guided trimming with the advantage of being quickly learned by technicians. © 2014 by The Author(s).

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

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.

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.

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.

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.

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.

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.

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

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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.

An Efficient Ceiling-view SLAM Using Relational Constraints Between Landmarks

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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.

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 ...

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

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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.

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

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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

Exploring brain function from anatomical connectivity

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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.

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

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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.

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

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

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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.

AUTOMATIC DETECTION AND CLASSIFICATION OF RETINAL VASCULAR LANDMARKS

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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.

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.

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

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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

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...

[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.

UAV VISUAL AUTOLOCALIZATON BASED ON AUTOMATIC LANDMARK RECOGNITION

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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.

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

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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.

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

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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

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.

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…

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.

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

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

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.

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

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

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.

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.

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

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.

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.

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...

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.

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.

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.

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.

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.

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

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.

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 ...

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.

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.

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.)

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

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.

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).

Physical examination of the female internal and external genitalia with and without pelvic organ prolapse: A review.

Science.gov (United States)

Pahwa, Avita K; Siegelman, Evan S; Arya, Lily A

2015-04-01

Pelvic organ prolapse, a herniation of pelvic organs through the vagina, is a common condition in older women. Pelvic organ prolapse distorts vaginal anatomy making pelvic examination difficult. A clinician must accurately identify anatomic landmarks both in women presenting with symptoms of prolapse and in women noted to have coincidental prolapse during routine gynecologic examination. We present a systematic approach to the female pelvic examination including anatomic landmarks of the external genitalia, vagina, and uterus in women with normal support as well as changes that occur with pelvic organ prolapse. Knowledge and awareness of normal anatomic landmarks will improve a clinician's ability to identify defects in pelvic support and allow for better diagnosis and treatment of pelvic organ prolapse. © 2014 Wiley Periodicals, Inc.

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.

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.

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

Ultrasound-guided approach for axillary brachial plexus, femoral nerve, and sciatic nerve blocks in dogs.

Science.gov (United States)

Campoy, Luis; Bezuidenhout, Abraham J; Gleed, Robin D; Martin-Flores, Manuel; Raw, Robert M; Santare, Carrie L; Jay, Ariane R; Wang, Annie L

2010-03-01

To describe an ultrasound-guided technique and the anatomical basis for three clinically useful nerve blocks in dogs. Prospective experimental trial. Four hound-cross dogs aged 2 +/- 0 years (mean +/- SD) weighing 30 +/- 5 kg and four Beagles aged 2 +/- 0 years and weighing 8.5 +/- 0.5 kg. Axillary brachial plexus, femoral, and sciatic combined ultrasound/electrolocation-guided nerve blocks were performed sequentially and bilaterally using a lidocaine solution mixed with methylene blue. Sciatic nerve blocks were not performed in the hounds. After the blocks, the dogs were euthanatized and each relevant site dissected. Axillary brachial plexus block Landmark blood vessels and the roots of the brachial plexus were identified by ultrasound in all eight dogs. Anatomical examination confirmed the relationship between the four ventral nerve roots (C6, C7, C8, and T1) and the axillary vessels. Three roots (C7, C8, and T1) were adequately stained bilaterally in all dogs. Femoral nerve block Landmark blood vessels (femoral artery and femoral vein), the femoral and saphenous nerves and the medial portion of the rectus femoris muscle were identified by ultrasound in all dogs. Anatomical examination confirmed the relationship between the femoral vessels, femoral nerve, and the rectus femoris muscle. The femoral nerves were adequately stained bilaterally in all dogs. Sciatic nerve block. Ultrasound landmarks (semimembranosus muscle, the fascia of the biceps femoris muscle and the sciatic nerve) could be identified in all of the dogs. In the four Beagles, anatomical examination confirmed the relationship between the biceps femoris muscle, the semimembranosus muscle, and the sciatic nerve. In the Beagles, all but one of the sciatic nerves were stained adequately. Ultrasound-guided needle insertion is an accurate method for depositing local anesthetic for axillary brachial plexus, femoral, and sciatic nerve blocks.

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.

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.

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.

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

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.

Determination of optimal ultrasound planes for the initialisation of image registration during endoscopic ultrasound-guided procedures.

Science.gov (United States)

Bonmati, Ester; Hu, Yipeng; Gibson, Eli; Uribarri, Laura; Keane, Geri; Gurusami, Kurinchi; Davidson, Brian; Pereira, Stephen P; Clarkson, Matthew J; Barratt, Dean C

2018-06-01

Navigation of endoscopic ultrasound (EUS)-guided procedures of the upper gastrointestinal (GI) system can be technically challenging due to the small fields-of-view of ultrasound and optical devices, as well as the anatomical variability and limited number of orienting landmarks during navigation. Co-registration of an EUS device and a pre-procedure 3D image can enhance the ability to navigate. However, the fidelity of this contextual information depends on the accuracy of registration. The purpose of this study was to develop and test the feasibility of a simulation-based planning method for pre-selecting patient-specific EUS-visible anatomical landmark locations to maximise the accuracy and robustness of a feature-based multimodality registration method. A registration approach was adopted in which landmarks are registered to anatomical structures segmented from the pre-procedure volume. The predicted target registration errors (TREs) of EUS-CT registration were estimated using simulated visible anatomical landmarks and a Monte Carlo simulation of landmark localisation error. The optimal planes were selected based on the 90th percentile of TREs, which provide a robust and more accurate EUS-CT registration initialisation. The method was evaluated by comparing the accuracy and robustness of registrations initialised using optimised planes versus non-optimised planes using manually segmented CT images and simulated ([Formula: see text]) or retrospective clinical ([Formula: see text]) EUS landmarks. The results show a lower 90th percentile TRE when registration is initialised using the optimised planes compared with a non-optimised initialisation approach (p value [Formula: see text]). The proposed simulation-based method to find optimised EUS planes and landmarks for EUS-guided procedures may have the potential to improve registration accuracy. Further work will investigate applying the technique in a clinical setting.

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.

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.

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…

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.

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.

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.

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.

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...

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...

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.

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...

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.

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.

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

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.

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

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.

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.

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, ...

Ultrasonography as an ancillary method for the positioning of markers in equine motion analysis

Directory of Open Access Journals (Sweden)

Luanna Ferreira Fasanelo Gomes

2014-08-01

Full Text Available Kinematic motion analysis is based on the reconstruction of selected bony anatomical landmarks identified by surface markers. Anatomical landmarks generally do not correspond to points but rather to relatively large and curved areas and their identification by palpation is not easy. Precise placement of surface markers is even more difficult and there is great variability between operators. In this study 16 examiners were asked to identify the lateral border of the left ischial tuberosity in a horse using palpation and ultrasonography for placement of a corresponding skin surface marker. Images of each marking procedure were captured using two video cameras and processed using the DVideow videogrammetry. A custom-written Matlab code was used to determine the position of the respective vectors. The positions of the markers were then compared to assess inter-examiner variability and the precision of the methods employed using the Bartletttest and the paired t-test respectively. Ultrasonography significantly improved the location of the anatomical landmark by each examiner (p = 0.04 and reduced the variability in the position of the surface marker when compared to palpation (p = 0.0028. The variability of the calculated distances (mean ± SD was 2.89 ± 2.24 cm and 1.63 ± 0.98 cm using palpation and ultrasonography respectively. Ultrasound guidance reduced inter-examiner variability and allowed visualization of the corresponding bony anatomical landmark.

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).

Modeling and segmentation of intra-cochlear anatomy in conventional CT

Science.gov (United States)

Noble, Jack H.; Rutherford, Robert B.; Labadie, Robert F.; Majdani, Omid; Dawant, Benoit M.

2010-03-01

Cochlear implant surgery is a procedure performed to treat profound hearing loss. Since the cochlea is not visible in surgery, the physician uses anatomical landmarks to estimate the pose of the cochlea. Research has indicated that implanting the electrode in a particular cavity of the cochlea, the scala tympani, results in better hearing restoration. The success of the scala tympani implantation is largely dependent on the point of entry and angle of electrode insertion. Errors can occur due to the imprecise nature of landmark-based, manual navigation as well as inter-patient variations between scala tympani and the anatomical landmarks. In this work, we use point distribution models of the intra-cochlear anatomy to study the inter-patient variations between the cochlea and the typical anatomic landmarks, and we implement an active shape model technique to automatically localize intra-cochlear anatomy in conventional CT images, where intra-cochlear structures are not visible. This fully automatic segmentation could aid the surgeon to choose the point of entry and angle of approach to maximize the likelihood of scala tympani insertion, resulting in more substantial hearing restoration.

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…

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.)

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.

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.)

Tree-based indexing for real-time ConvNet landmark-based visual place recognition

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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.

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

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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.

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...

From medical imaging data to 3D printed anatomical models.

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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.

Analgesic efficacy of ultrasound guided versus landmark-based bilateral superficial cervical plexus block for thyroid surgery

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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

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

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

2015-06-01

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

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

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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.

Registration of T2-weighted and diffusion-weighted MR images of the prostate: comparison between manual and landmark-based methods

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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.

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.

[Establishment of anatomical terminology in Japan].

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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.

Global Polity in Adult Education and UNESCO: Landmarking, Brokering and Framing Policy

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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…

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...

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

Alignment of CT images of skull dysmorphology using anatomy-based perpendicular axes

International Nuclear Information System (INIS)

Yoo, Sun K; Kim, Yong O; Kim, Hee-Joung; Kim, Nam H; Jang, Young Beom; Kim, Kee-Deog; Lee, Hye-Yeon

2003-01-01

Rigid body registration of 3D CT scans, based on manual identification of homologous landmarks, is useful for the visual analysis of skull dysmorphology. In this paper, a robust and simple alignment method was proposed to allow for the comparison of skull morphologies, within and between individuals with craniofacial anomalies, based on 3D CT scans, and the minimum number of anatomical landmarks, under rigidity and uniqueness constraints. Three perpendicular axes, extracted from anatomical landmarks, define the absolute coordinate system, through a rigid body transformation, to align multiple CT images for different patients and acquisition times. The accuracy of the alignment method depends on the accuracy of the localized landmarks and target points. The numerical simulation generalizes the accuracy requirements of the alignment method. Experiments using a human dried skull specimen, and ten sets of skull CT images (the pre- and post-operative CT scans of four plagiocephaly, and one fibrous dysplasia patients), demonstrated the feasibility of the technique in clinical practice

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.

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.

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

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

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

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.

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.

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.

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

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

[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.

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

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

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

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

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.

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.

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

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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.

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)

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.

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).

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.

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....

Movement of the external ear in human embryo.

Science.gov (United States)

Kagurasho, Miho; Yamada, Shigehito; Uwabe, Chigako; Kose, Katsumi; Takakuwa, Tetsuya

2012-02-01

External ears, one of the major face components, show an interesting movement during craniofacial morphogenesis in human embryo. The present study was performed to see if movement of the external ears in a human embryo could be explained by differential growth. In all, 171 samples between Carnegie stage (CS) 17 and CS 23 were selected from MR image datasets of human embryos obtained from the Kyoto Collection of Human Embryos. The three-dimensional absolute position of 13 representative anatomical landmarks, including external and internal ears, from MRI data was traced to evaluate the movement between the different stages with identical magnification. Two different sets of reference axes were selected for evaluation and comparison of the movements. When the pituitary gland and the first cervical vertebra were selected as a reference axis, the 13 anatomical landmarks of the face spread out within the same region as the embryo enlarged and changed shape. The external ear did move mainly laterally, but not cranially. The distance between the external and internal ear stayed approximately constant. Three-dimensionally, the external ear located in the caudal ventral parts of the internal ear in CS 17, moved mainly laterally until CS 23. When surface landmarks eyes and mouth were selected as a reference axis, external ears moved from the caudal lateral ventral region to the position between eyes and mouth during development. The results indicate that movement of all anatomical landmarks, including external and internal ears, can be explained by differential growth. Also, when the external ear is recognized as one of the facial landmarks and having a relative position to other landmarks such as the eyes and mouth, the external ears seem to move cranially. © 2012 Kagurasho et al; licensee BioMed Central Ltd.

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.

An eFTD-VP framework for efficiently generating patient-specific anatomically detailed facial soft tissue FE mesh for craniomaxillofacial surgery simulation.

Science.gov (United States)

Zhang, Xiaoyan; Kim, Daeseung; Shen, Shunyao; Yuan, Peng; Liu, Siting; Tang, Zhen; Zhang, Guangming; Zhou, Xiaobo; Gateno, Jaime; Liebschner, Michael A K; Xia, James J

2018-04-01

Accurate surgical planning and prediction of craniomaxillofacial surgery outcome requires simulation of soft tissue changes following osteotomy. This can only be achieved by using an anatomically detailed facial soft tissue model. The current state-of-the-art of model generation is not appropriate to clinical applications due to the time-intensive nature of manual segmentation and volumetric mesh generation. The conventional patient-specific finite element (FE) mesh generation methods are to deform a template FE mesh to match the shape of a patient based on registration. However, these methods commonly produce element distortion. Additionally, the mesh density for patients depends on that of the template model. It could not be adjusted to conduct mesh density sensitivity analysis. In this study, we propose a new framework of patient-specific facial soft tissue FE mesh generation. The goal of the developed method is to efficiently generate a high-quality patient-specific hexahedral FE mesh with adjustable mesh density while preserving the accuracy in anatomical structure correspondence. Our FE mesh is generated by eFace template deformation followed by volumetric parametrization. First, the patient-specific anatomically detailed facial soft tissue model (including skin, mucosa, and muscles) is generated by deforming an eFace template model. The adaptation of the eFace template model is achieved by using a hybrid landmark-based morphing and dense surface fitting approach followed by a thin-plate spline interpolation. Then, high-quality hexahedral mesh is constructed by using volumetric parameterization. The user can control the resolution of hexahedron mesh to best reflect clinicians' need. Our approach was validated using 30 patient models and 4 visible human datasets. The generated patient-specific FE mesh showed high surface matching accuracy, element quality, and internal structure matching accuracy. They can be directly and effectively used for clinical

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.

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.

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...

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.

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

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

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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.

SU-D-BRA-04: Computerized Framework for Marker-Less Localization of Anatomical Feature Points in Range Images Based On Differential Geometry Features for Image-Guided Radiation Therapy

International Nuclear Information System (INIS)

Soufi, M; Arimura, H; Toyofuku, F; Nakamura, K; Hirose, T; Umezu, Y; Shioyama, Y

2016-01-01

Purpose: To propose a computerized framework for localization of anatomical feature points on the patient surface in infrared-ray based range images by using differential geometry (curvature) features. Methods: The general concept was to reconstruct the patient surface by using a mathematical modeling technique for the computation of differential geometry features that characterize the local shapes of the patient surfaces. A region of interest (ROI) was firstly extracted based on a template matching technique applied on amplitude (grayscale) images. The extracted ROI was preprocessed for reducing temporal and spatial noises by using Kalman and bilateral filters, respectively. Next, a smooth patient surface was reconstructed by using a non-uniform rational basis spline (NURBS) model. Finally, differential geometry features, i.e. the shape index and curvedness features were computed for localizing the anatomical feature points. The proposed framework was trained for optimizing shape index and curvedness thresholds and tested on range images of an anthropomorphic head phantom. The range images were acquired by an infrared ray-based time-of-flight (TOF) camera. The localization accuracy was evaluated by measuring the mean of minimum Euclidean distances (MMED) between reference (ground truth) points and the feature points localized by the proposed framework. The evaluation was performed for points localized on convex regions (e.g. apex of nose) and concave regions (e.g. nasofacial sulcus). Results: The proposed framework has localized anatomical feature points on convex and concave anatomical landmarks with MMEDs of 1.91±0.50 mm and 3.70±0.92 mm, respectively. A statistically significant difference was obtained between the feature points on the convex and concave regions (P<0.001). Conclusion: Our study has shown the feasibility of differential geometry features for localization of anatomical feature points on the patient surface in range images. The proposed

SU-D-BRA-04: Computerized Framework for Marker-Less Localization of Anatomical Feature Points in Range Images Based On Differential Geometry Features for Image-Guided Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Soufi, M; Arimura, H; Toyofuku, F [Kyushu University, Fukuoka, Fukuoka (Japan); Nakamura, K [Hamamatsu University School of Medicine, Hamamatsu, Shizuoka (Japan); Hirose, T; Umezu, Y [Kyushu University Hospital, Fukuoka, Fukuoka (Japan); Shioyama, Y [Saga Heavy Ion Medical Accelerator in Tosu, Tosu, Saga (Japan)

2016-06-15

Purpose: To propose a computerized framework for localization of anatomical feature points on the patient surface in infrared-ray based range images by using differential geometry (curvature) features. Methods: The general concept was to reconstruct the patient surface by using a mathematical modeling technique for the computation of differential geometry features that characterize the local shapes of the patient surfaces. A region of interest (ROI) was firstly extracted based on a template matching technique applied on amplitude (grayscale) images. The extracted ROI was preprocessed for reducing temporal and spatial noises by using Kalman and bilateral filters, respectively. Next, a smooth patient surface was reconstructed by using a non-uniform rational basis spline (NURBS) model. Finally, differential geometry features, i.e. the shape index and curvedness features were computed for localizing the anatomical feature points. The proposed framework was trained for optimizing shape index and curvedness thresholds and tested on range images of an anthropomorphic head phantom. The range images were acquired by an infrared ray-based time-of-flight (TOF) camera. The localization accuracy was evaluated by measuring the mean of minimum Euclidean distances (MMED) between reference (ground truth) points and the feature points localized by the proposed framework. The evaluation was performed for points localized on convex regions (e.g. apex of nose) and concave regions (e.g. nasofacial sulcus). Results: The proposed framework has localized anatomical feature points on convex and concave anatomical landmarks with MMEDs of 1.91±0.50 mm and 3.70±0.92 mm, respectively. A statistically significant difference was obtained between the feature points on the convex and concave regions (P<0.001). Conclusion: Our study has shown the feasibility of differential geometry features for localization of anatomical feature points on the patient surface in range images. The proposed

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

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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.

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

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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.

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

A Comprehensive Reanalysis of the Distal Iliotibial Band: Quantitative Anatomy, Radiographic Markers, and Biomechanical Properties.

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Godin, Jonathan A; Chahla, Jorge; Moatshe, Gilbert; Kruckeberg, Bradley M; Muckenhirn, Kyle J; Vap, Alexander R; Geeslin, Andrew G; LaPrade, Robert F

2017-09-01

The qualitative anatomy of the distal iliotibial band (ITB) has previously been described. However, a comprehensive characterization of the quantitative anatomic, radiographic, and biomechanical properties of the Kaplan fibers of the deep distal ITB has not yet been established. It is paramount to delineate these characteristics to fully understand the distal ITB's contribution to rotational knee stability. Purpose/Hypothesis: There were 2 distinct purposes for this study: (1) to perform a quantitative anatomic and radiographic evaluation of the distal ITB's attachment sites and their relationships to pertinent osseous and soft tissue landmarks, and (2) to quantify the biomechanical properties of the deep (Kaplan) fibers of the distal ITB. It was hypothesized that the distal ITB has definable parameters concerning its anatomic attachments and consistent relationships to surgically pertinent landmarks with correlating plain radiographic findings. In addition, it was hypothesized that the biomechanical properties of the Kaplan fibers would support their role as important restraints against internal rotation. Descriptive laboratory study. Ten nonpaired, fresh-frozen human cadaveric knees (mean age, 61.1 years; range, 54-65 years) were dissected for anatomic and radiographic purposes. A coordinate measuring device quantified the attachment areas of the distal ITB to the distal femur, patella, and proximal tibia and their relationships to pertinent bony landmarks. A radiographic analysis was performed by inserting pins into the attachment sites of relevant anatomic structures to assess their location relative to pertinent bony landmarks with fluoroscopic guidance. A further biomechanical assessment of 10 cadaveric knees quantified the load to failure and stiffness of the Kaplan fibers' insertion on the distal femur after a preconditioning protocol. Two separate deep (Kaplan) fiber bundles were identified with attachments to 2 newly identified femoral bony prominences

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

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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.

Extended Endoscopic Endonasal Approaches for Cerebral Aneurysms: Anatomical, Virtual Reality and Morphometric Study

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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.

ANATOMICAL PROPERTIES AND FIBER QUALITY OF FIVE POTENTIAL COMMERCIAL WOOD SPECIES FROM CIANJUR, WEST JAVA

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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.

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

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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.

Anatomical Basis for Safe and Effective Volumization of the Temple.

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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.

The anteroposterior axis of the tibia in Korean patients undergoing total knee replacement.

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Kim, C W; Seo, S S; Kim, J H; Roh, S M; Lee, C R

2014-11-01

The aim of this study was to find anatomical landmarks for rotational alignment of the tibial component in total knee replacement (TKR) in a CT-based study. Pre-operative CT scanning was performed on 94 South Korean patients (nine men, 85 women, 188 knees) with osteoarthritis of the knee joint prior to TKR. The tibial anteroposterior (AP) axis was defined as a line perpendicular to the femoral surgical transepicondylar axis and passing through the centre of the posterior cruciate ligament (PCL). The angles between the defined tibial AP axis and anatomical landmarks at various levels of the tibia were measured. The mean values of the angles between the defined tibial AP axis and the line connecting the anterior border of the proximal third of the tibia to the centre of the PCL was -0.2° (-17 to 14.1, sd 4.1). This was very close to the defined tibial axis, and remained so regardless of lower limb alignment and the degree of tibial bowing. Therefore, AP axis defined as described, is a reliable anatomical landmark for rotational alignment of tibial components. ©2014 The British Editorial Society of Bone & Joint Surgery.

Outline-based morphometrics, an overlooked method in arthropod studies?

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Dujardin, Jean-Pierre; Kaba, D; Solano, P; Dupraz, M; McCoy, K D; Jaramillo-O, N

2014-12-01

Modern methods allow a geometric representation of forms, separating size and shape. In entomology, as well as in many other fields involving arthropod studies, shape variation has proved useful for species identification and population characterization. In medical entomology, it has been applied to very specific questions such as population structure, reinfestation of insecticide-treated areas and cryptic species recognition. For shape comparisons, great importance is given to the quality of landmarks in terms of comparability. Two conceptually and statistically separate approaches are: (i) landmark-based morphometrics, based on the relative position of a few anatomical "true" or "traditional" landmarks, and (ii) outline-based morphometrics, which captures the contour of forms through a sequence of close "pseudo-landmarks". Most of the studies on insects of medical, veterinary or economic importance make use of the landmark approach. The present survey makes a case for the outline method, here based on elliptic Fourier analysis. The collection of pseudo-landmarks may require the manual digitization of many points and, for this reason, might appear less attractive. It, however, has the ability to compare homologous organs or structures having no landmarks at all. This strength offers the possibility to study a wider range of anatomical structures and thus, a larger range of arthropods. We present a few examples highlighting its interest for separating close or cryptic species, or characterizing conspecific geographic populations, in a series of different vector organisms. In this simple application, i.e. the recognition of close or cryptic forms, the outline approach provided similar scores as those obtained by the landmark-based approach. Copyright © 2014 Elsevier B.V. All rights reserved.

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

The study of radiographic technique with low exposure using computed panoramic tomography

International Nuclear Information System (INIS)

Saito, Yasuhiro

1987-01-01

A new imaging system for the dental field that combines recent advances in both the electronics and computer technologies was developed. This new imaging system is a computed panoramic tomography process based on the newly developed laser-scan system. In this study a quantitative image evaluation was performed comparing anatomical landmark in computed panoramic tomography at a low exposure (LPT) and in conventional panoramic tomography at a routin (CPT), and the following results were obtained: 1. The diagnostic value of the CPT decreased with decreasing exposure, paticularly with regard to the normal anatomical landmarks of such microstructural parts as the periodontal space, lamina dura and the enamel-dentin border. 2. The LPT was highly diagnostic value for all normal anatomical landmark, averaging about twice as valuable diagnostically as CPT. 3. The visually diagnostic value of the periodontal space, lamina dura, enamel-dentin border and the anatomical morphology of the teeth on the LPT beeing slightly dependent on the spatial frequency enhancement rank. 4. The LPT formed images with almost the same range of density as the CPT. 5. Computed panoramic tomographs taken at a low exposure revealed more information of the trabecular bone pattern on the image than conventional panoramic tomographs taken under routine condition in the visual spatial frequency range (0.1 - 5.0 cycle/mm). (author) 67 refs

Influence of Head Motion on the Accuracy of 3D Reconstruction with Cone-Beam CT: Landmark Identification Errors in Maxillofacial Surface Model.

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Kyung-Min Lee

Full Text Available The purpose of this study was to investigate the influence of head motion on the accuracy of three-dimensional (3D reconstruction with cone-beam computed tomography (CBCT scan.Fifteen dry skulls were incorporated into a motion controller which simulated four types of head motion during CBCT scan: 2 horizontal rotations (to the right/to the left and 2 vertical rotations (upward/downward. Each movement was triggered to occur at the start of the scan for 1 second by remote control. Four maxillofacial surface models with head motion and one control surface model without motion were obtained for each skull. Nine landmarks were identified on the five maxillofacial surface models for each skull, and landmark identification errors were compared between the control model and each of the models with head motion.Rendered surface models with head motion were similar to the control model in appearance; however, the landmark identification errors showed larger values in models with head motion than in the control. In particular, the Porion in the horizontal rotation models presented statistically significant differences (P < .05. Statistically significant difference in the errors between the right and left side landmark was present in the left side rotation which was opposite direction to the scanner rotation (P < .05.Patient movement during CBCT scan might cause landmark identification errors on the 3D surface model in relation to the direction of the scanner rotation. Clinicians should take this into consideration to prevent patient movement during CBCT scan, particularly horizontal movement.

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

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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.

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

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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.

Introducing 3-Dimensional Printing of a Human Anatomic Pathology Specimen: Potential Benefits for Undergraduate and Postgraduate Education and Anatomic Pathology Practice.

Science.gov (United States)

Mahmoud, Amr; Bennett, Michael

2015-08-01

Three-dimensional (3D) printing, a rapidly advancing technology, is widely applied in fields such as mechanical engineering and architecture. Three-dimensional printing has been introduced recently into medical practice in areas such as reconstructive surgery, as well as in clinical research. Three-dimensionally printed models of anatomic and autopsy pathology specimens can be used for demonstrating pathology entities to undergraduate medical, dental, and biomedical students, as well as for postgraduate training in examination of gross specimens for anatomic pathology residents and pathology assistants, aiding clinicopathological correlation at multidisciplinary team meetings, and guiding reconstructive surgical procedures. To apply 3D printing in anatomic pathology for teaching, training, and clinical correlation purposes. Multicolored 3D printing of human anatomic pathology specimens was achieved using a ZCorp 510 3D printer (3D Systems, Rock Hill, South Carolina) following creation of a 3D model using Autodesk 123D Catch software (Autodesk, Inc, San Francisco, California). Three-dimensionally printed models of anatomic pathology specimens created included pancreatoduodenectomy (Whipple operation) and radical nephrectomy specimens. The models accurately depicted the topographic anatomy of selected specimens and illustrated the anatomic relation of excised lesions to adjacent normal tissues. Three-dimensional printing of human anatomic pathology specimens is achievable. Advances in 3D printing technology may further improve the quality of 3D printable anatomic pathology specimens.

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.

Consensus guidelines for the uniform reporting of study ethics in anatomical research within the framework of the anatomical quality assurance (AQUA) checklist.

Science.gov (United States)

Henry, Brandon Michael; Vikse, Jens; Pekala, Przemyslaw; Loukas, Marios; Tubbs, R Shane; Walocha, Jerzy A; Jones, D Gareth; Tomaszewski, Krzysztof A

2018-05-01

Unambiguous reporting of a study's compliance with ethical guidelines in anatomical research is imperative. As such, clear, universal, and uniform reporting guidelines for study ethics are essential. In 2016, the International Evidence-Based Anatomy Working group in collaboration with international partners established reporting guidelines for anatomical studies, the Anatomical Quality Assurance (AQUA) Checklist. In this elaboration of the AQUA Checklist, consensus guidelines for reporting study ethics in anatomical studies are provided with in the framework of the AQUA Checklist. The new guidelines are aimed to be applicable to research across the spectrum of the anatomical sciences, including studies on both living and deceased donors. The authors hope the established guidelines will improve ethical compliance and reporting in anatomical research. Clin. Anat. 31:521-524, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

The role of Long-Range Connectivity for the Characterization of the Functional-Anatomical Organization of the Cortex

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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.

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.

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

Radial force distribution changes associated with tangential force production in cylindrical grasping, and the importance of anatomical registration.

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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.

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.

New Statistical Method to Analyze Three-Dimensional Landmark Configurations Obtained with Cone-Beam CT: Basic Features and Clinical Application for Rapid Maxillary Expansion

Energy Technology Data Exchange (ETDEWEB)

Gamble, Jennifer; Lagravere, Manuel O.; Major, Paul W.; Heo, Giseon [University of Alberta, Edmonton (Canada)

2012-03-15

To describe a statistical method of three-dimensional landmark configuration data and apply it to an orthodontic data set comparing two types of rapid maxillary expansion (RME) treatments. Landmark configurations obtained from cone beam CT scans were used to represent patients in two types (please describe what were two types) of RME groups and a control group over four time points. A method using tools from persistent homology and dimensionality reduction is presented and used to identify variability between the subjects. The analysis was in agreement with previous results using conventional methods, which found significant differences between treatment groups and the control, but no distinction between the types of treatment. Additionally, it was found that second molar eruption varied considerably between the subjects, and this has not been evaluated in previous analyses. This method of analysis allows entire configurations to be considered as a whole, and does not require specific inter-landmark distances or angles to be selected. Sources of variability present themselves, without having to be individually sought after. This method is suggested as an additional tool for the analysis of landmark configuration data.

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…

Can Achilles tendon be used as a new distal landmark for coronal tibial component alignment in total knee replacement surgery? An observational MRI study

Directory of Open Access Journals (Sweden)

Tiftikçi U

2017-01-01

Full Text Available Uğur Tiftikçi,1 Sancar Serbest,1 Veysel Burulday2 1Department of Orthopaedics and Traumatology, 2Department of Radiology, Faculty of Medicine, Kırıkkale University, Kırıkkale, Turkey Background: In total knee arthroplasty, it is better to use more than one reference point for correct alignment of the components. By measuring the distances of Achilles tendon (AT and other conventional landmarks from the mechanical axis in magnetic resonance imaging (MRI of the ankle, we aimed to demonstrate that, as a novel landmark which can help for correct alignment in the coronal plane, AT is a better option than other landmarks. Materials and methods: This retrospective study was done on 53 ankle MRIs that met the criteria for inclusion to the study among 158 ankle MRIs. After identification of the mechanical axis, the distances of distal landmarks, which were extensor hallucis longus tendon (EHLT, tibialis anterior tendon (TAT, dorsalis pedis artery (DPA, AT, extensor digitorum longus tendon (EDLT, and malleoli, were measured from the mechanical axis and were statistically evaluated. Results: In proximal measurements, the distances of the landmarks to the mechanical axis (on average were AT, 2.64±1.62 mm lateral; EHLT, 3.89±2.45 mm medial; DPA, 4.69±2.39 mm medial; TAT, 8.24±3.60 mm medial; and EDLT, 14.2±4.14 mm lateral (P<0.001. In distal measurements, the distances of the landmarks to the mechanical axis (on average were AT, 1.99±1.24 mm medial; EHLT, 4.27±2.49 mm medial; DPA, 4.79±2.10 mm medial; TAT, 12.9±4.07 mm medial; and EDLT, 12.18±4.17 mm lateral (P<0.001. Conclusion: In this study, the mechanical axis line, which is the center of talus, passes through the AT. Our MRI investigations showed that the AT, EHLT, DPA, and malleolar center (3–5 mm medial may help in correct alignment. Keywords: total knee arthroplasty, tibial component, alignment, distal references, landmark, MRI, Achilles tendon

Clinical anatomy of the elbow and shoulder.

Science.gov (United States)

Villaseñor-Ovies, Pablo; Vargas, Angélica; Chiapas-Gasca, Karla; Canoso, Juan J; Hernández-Díaz, Cristina; Saavedra, Miguel Ángel; Navarro-Zarza, José Eduardo; Kalish, Robert A

The elbow patients herein discussed feature common soft tissue conditions such as tennis elbow, golfers' elbow and olecranon bursitis. Relevant anatomical structures for these conditions can easily be identified and demonstrated by cross examination by instructors and participants. Patients usually present rotator cuff tendinopathy, frozen shoulder, axillary neuropathy and suprascapular neuropathy. The structures involved in tendinopathy and frozen shoulder can be easily identified and demonstrated under normal conditions. The axillary and the suprascapular nerves have surface landmarks but cannot be palpated. In neuropathy however, physical findings in both neuropathies are pathognomonic and will be discussed. Copyright © 2012 Elsevier España, S.L. All rights reserved.

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

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.

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...

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)

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

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

2009-09-15

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

Computed Tomographic Analysis of Ventral Atlantoaxial Optimal Safe Implantation Corridors in 27 Dogs.

Science.gov (United States)

Leblond, Guillaume; Gaitero, Luis; Moens, Noel M M; Zur Linden, Alex; James, Fiona M K; Monteith, Gabrielle J; Runciman, John

2017-11-01

Objectives  Ventral atlantoaxial stabilization techniques are challenging surgical procedures in dogs. Available surgical guidelines are based upon subjective anatomical landmarks, and limited radiographic and computed tomographic data. The aims of this study were (1) to provide detailed anatomical descriptions of atlantoaxial optimal safe implantation corridors to generate objective recommendations for optimal implant placements and (2) to compare anatomical data obtained in non-affected Toy breed dogs, affected Toy breed dogs suffering from atlantoaxial instability and non-affected Beagle dogs. Methods  Anatomical data were collected from a prospectively recruited population of 27 dogs using a previously validated method of optimal safe implantation corridor analysis using computed tomographic images. Results  Optimal implant positions and three-dimensional numerical data were generated successfully in all cases. Anatomical landmarks could be used to generate objective definitions of optimal insertion points which were applicable across all three groups. Overall the geometrical distribution of all implant sites was similar in all three groups with a few exceptions. Clinical Significance  This study provides extensive anatomical data available to facilitate surgical planning of implant placement for atlantoaxial stabilization. Our data suggest that non-affected Toy breed dogs and non-affected Beagle dogs constitute reasonable research models to study atlantoaxial stabilization constructs. Schattauer GmbH Stuttgart.

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.

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)

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)

"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.

"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.

Anatomical knowledge retention in third-year medical students prior to obstetrics and gynecology and surgery rotations.

Science.gov (United States)

Jurjus, Rosalyn A; Lee, Juliet; Ahle, Samantha; Brown, Kirsten M; Butera, Gisela; Goldman, Ellen F; Krapf, Jill M

2014-01-01

Surgical anatomy is taught early in medical school training. The literature shows that many physicians, especially surgical specialists, think that anatomical knowledge of medical students is inadequate and nesting of anatomical sciences later in the clinical curriculum may be necessary. Quantitative data concerning this perception of an anatomical knowledge deficit are lacking, as are specifics as to what content should be reinforced. This study identifies baseline areas of strength and weakness in the surgical anatomy knowledge of medical students entering surgical rotations. Third-year medical students completed a 20-25-question test at the beginning of the General Surgery and Obstetrics and Gynecology rotations. Knowledge of inguinal anatomy (45.3%), orientation in abdominal cavity (38.8%), colon (27.7%), and esophageal varices (12.8%) was poor. The numbers in parentheses are the percentage of questions answered correctly per topic. In comparing those scores to matched test items from this cohort as first-year students in the anatomy course, the drop in retention overall was very significant (P = 0.009) from 86.9 to 51.5%. Students also scored lower in questions relating to pelvic organs (46.7%), urogenital development (54.0%), pulmonary development (17.8%), and pregnancy (17.8%). These data showed that indeed, knowledge of surgical anatomy is poor for medical students entering surgical clerkships. These data collected will be utilized to create interactive learning modules, aimed at improving clinically relevant anatomical knowledge retention. These modules, which will be available to students during their inpatient surgical rotations, connect basic anatomy principles to clinical cases, with the ultimate goal of closing the anatomical knowledge gap. © 2014 American Association of Anatomists.

Size and asymmetry of the planum temporale. A new three-dimensional method for analysis of the supratemporal plane using MR imaging and computer-aided graphics

International Nuclear Information System (INIS)

Utsunomiya, H.; Nawata, M.; Ogasawara, T.; Okazaki, M.; Miyoshi, M.

1996-01-01

The planum temporale of the supratemporal plane is important for language function and shows left-right asymmetry in most brains. To estimate the size and allow side comparison of the planum temporale, we developed a new technique for 3-D MR analysis of the supratemporal plane using a personal computer and computer-aided graphics. The temporal lobes of 5 human cadavers were imaged by MR in the sagittal plane, at a slice thickness of 3 mm. The images of the supratemporal plane were entered into a personal computer using the original software to determine the positions of anatomic landmarks and the size of the planum temporale. The data were then transferred to a supercomputer to reconstruct the 3-D surface image of the supratemporal plane. Computer images of the spuratemporal plane agreed with macroscopic observations. The positions of anatomic landmarks and the size of the planum temporale also agreed with macroscopic measurements. Thus, the persent technique provides valuable anatomic data on the spuratemporal plane which should be useful for further clarification of the anatomic basis of language function. (orig.)

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.

Use of anatomic measurement to guide injection of botulinum toxin for the management of chronic lateral epicondylitis: a randomized controlled trial

Science.gov (United States)

Espandar, Ramin; Heidari, Pedram; Rasouli, Mohammad Reza; Saadat, Soheil; Farzan, Mahmood; Rostami, Mohsen; Yazdanian, Shideh; Mortazavi, S.M. Javad

2010-01-01

Background When using botulinum toxin for the management of lateral epicondylitis, injection at a fixed distance from an anatomic landmark could result in inadequate paralysis of the intended muscle. We assessed the effectiveness of injection of botulinum toxin using precise anatomic measurement in individual patients. Methods In this randomized placebo-controlled trial, 48 patients with chronic refractory lateral epicondylitis were randomly assigned to receive a single injection of either botulinum toxin (60 units) or placebo (normal saline). The site of injection was chosen as a distance one-third the length of the forearm from the tip of the lateral epicondyle on the course of the posterior interosseus nerve. The primary outcome measure was intensity of pain at rest, measured with the use of a 100-mm visual analogue scale, at baseline and at 4, 8 and 16 weeks after injection. Results Compared with the placebo group, the group given botulinum toxin had significant reductions in pain at rest during follow-up (decrease at 4 weeks 14.1 mm, 95% confidence interval [CI] 5.8–22.3; at 8 weeks 11.5 mm, 95% CI 2.0–21.0; at 16 weeks 12.6 mm, 95% CI 7.7–17.8; p = 0.01). As for the secondary outcomes, the intensity of pain during maximum pinch decreased in the botulinum toxin group; there was no difference in pain during maximum grip or in grip strength between the two groups. All but one of the patients in the intervention group experienced weakness in the extension of the third and fourth fingers at week 4 that resolved by week 16. No serious adverse events were reported. Interpretation The use of precise anatomic measurement to guide injection of botulinum toxin significantly reduced pain at rest in patients with chronic refractory lateral epicondylitis. However, the transient extensor lag makes this method inappropriate for patients whose job requires finger extension. (ClinicalTrials.gov trial register no. NCT00497913.) PMID:20421357

Anatomical Studies on Several Species of Heliotropium L. in Iran

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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.

The error analysis of Lobular and segmental division of right liver by volume measurement.

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Zhang, Jianfei; Lin, Weigang; Chi, Yanyan; Zheng, Nan; Xu, Qiang; Zhang, Guowei; Yu, Shengbo; Li, Chan; Wang, Bin; Sui, Hongjin

2017-07-01

The aim of this study is to explore the inconsistencies between right liver volume as measured by imaging and the actual anatomical appearance of the right lobe. Five healthy donated livers were studied. The liver slices were obtained with hepatic segments multicolor-infused through the portal vein. In the slices, the lobes were divided by two methods: radiological landmarks and real anatomical boundaries. The areas of the right anterior lobe (RAL) and right posterior lobe (RPL) on each slice were measured using Photoshop CS5 and AutoCAD, and the volumes of the two lobes were calculated. There was no statistically significant difference between the volumes of the RAL or RPL as measured by the radiological landmarks (RL) and anatomical boundaries (AB) methods. However, the curves of the square error value of the RAL and RPL measured using CT showed that the three lowest points were at the cranial, intermediate, and caudal levels. The U- or V-shaped curves of the square error rate of the RAL and RPL revealed that the lowest value is at the intermediate level and the highest at the cranial and caudal levels. On CT images, less accurate landmarks were used to divide the RAL and RPL at the cranial and caudal layers. The measured volumes of hepatic segments VIII and VI would be less than their true values, and the measured volumes of hepatic segments VII and V would be greater than their true values, according to radiological landmarks. Clin. Anat. 30:585-590, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Determining customer satisfaction in anatomic pathology.

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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.

A prospective longitudinal study of postnatal dentoalveolar and palatal growth: The anatomical basis for CAD/CAM-assisted production of cleft-lip-palate feeding plates.

Science.gov (United States)

Bauer, Franz X; Güll, Florian D; Roth, Maximilian; Ritschl, Lucas M; Rau, Andrea; Gau, Dominik; Gruber, Maximilian; Eblenkamp, Markus; Hilmer, Bettina; Wolff, Klaus-Dietrich; Loeffelbein, Denys J

2017-10-01

This study describes the dentoalveolar and palatal growth during the first months of life. Knowledge concerning this development is essential to avoid unwanted events such as mucosal ulcerations or restriction of growth when cleft-lip and palate (CLP) patients are treated. The results involve the generation of CAD/CAM CLP-feeding plates. Intraoral impressions from 32 healthy newborns were taken monthly for 5 months, supplemented by measurements of body weight, length, and occipital-frontal head circumference. The casts were digitalized, and two observers manually selected defined anatomical landmarks on virtual 3-D models. The distances between these landmarks were evaluted. Statistical analysis included an inter-rater agreement analysis and the determination of growth. In total, 213 casts were analyzed, with 65 models excluded because of inaccuracies in impression-taking or cast production. Overall longitudinal growth was 20.3%, whereas transversal growth reached a maximum of 21.1%. Vertical growth was 32.4% at the tuberal level. On the basis of these results, a semiautomated series of feeding plates allowing for monthly expansion could be generated. The acquired data serve as a useful reference for other pediatric and orthofacial investigations and treatments. One such application is the automated, fully virtual manufacture of CLP-feeding plates based on only one impression-taking. Our data reveal when caution is needed to prevent ulceration. The series of plates generated can minimize the time-consuming impression-taking and the production of further plaster models. The method of measurement is suitable for documentary purposes. Clin. Anat. 30:846-854, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

LANDMARKS REGARDING THE EXTERNAL PUBLIC AUDIT IN ROMANIA

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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.

Establishing cephalometric landmarks for the translational study of Le Fort-based facial transplantation in Swine: enhanced applications using computer-assisted surgery and custom cutting guides.

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

2014-05-01

Le Fort-based, maxillofacial allotransplantation is a reconstructive alternative gaining clinical acceptance. However, the vast majority of single-jaw transplant recipients demonstrate less-than-ideal skeletal and dental relationships, with suboptimal aesthetic harmony. The purpose of this study was to investigate reproducible cephalometric landmarks in a large-animal model, where refinement of computer-assisted planning, intraoperative navigational guidance, translational bone osteotomies, and comparative surgical techniques could be performed. Cephalometric landmarks that could be translated into the human craniomaxillofacial skeleton, and that would remain reliable following maxillofacial osteotomies with midfacial alloflap inset, were sought on six miniature swine. Le Fort I- and Le Fort III-based alloflaps were harvested in swine with osteotomies, and all alloflaps were either autoreplanted or transplanted. Cephalometric analyses were performed on lateral cephalograms preoperatively and postoperatively. Critical cephalometric data sets were identified with the assistance of surgical planning and virtual prediction software and evaluated for reliability and translational predictability. Several pertinent landmarks and human analogues were identified, including pronasale, zygion, parietale, gonion, gnathion, lower incisor base, and alveolare. Parietale-pronasale-alveolare and parietale-pronasale-lower incisor base were found to be reliable correlates of sellion-nasion-A point angle and sellion-nasion-B point angle measurements in humans, respectively. There is a set of reliable cephalometric landmarks and measurement angles pertinent for use within a translational large-animal model. These craniomaxillofacial landmarks will enable development of novel navigational software technology, improve cutting guide designs, and facilitate exploration of new avenues for investigation and collaboration.

Interpreting and Integrating Clinical and Anatomic Pathology Results.

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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.

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 ...

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).

Generating a normalized geometric liver model with warping

International Nuclear Information System (INIS)

Boes, J.L.; Weymouth, T.E.; Meyer, C.R.; Quint, L.E.; Bland, P.H.; Bookstein, F.L.

1990-01-01

This paper reports on the automated determination of the liver surface in abdominal CT scans for radiation treatment, surgery planning, and anatomic visualization. The normalized geometric model of the liver is generated by averaging registered outlines from a set of 15 studies of normal liver. The outlines have been registered with the use of thin-plate spline warping based on a set of five homologous landmarks. Thus, the model consists of an average of the surface and a set of five anatomic landmarks. The accuracy of the model is measured against both the set of studies used in model generation and an alternate set of 15 normal studies with use of, as an error measure, the ratio of nonoverlapping model and study volume to total model volume

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

Benchmarking Academic Anatomic Pathologists

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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

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

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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.

Standardized anatomic space for abdominal fat quantification

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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.

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

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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.

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

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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

Success Rate and Complications of Internal Jugular Vein Catheterization With and Without Ultrasonography Guide

OpenAIRE

Karimi-Sari, Hamidreza; Faraji, Mehrdad; Mohazzab Torabi, Saman; Asjodi, Gholamreza

2014-01-01

Background: Central venous catheterization (CVC) is an important procedure in emergency departments (EDs). Despite existence of ultrasonography (US) devices in every ED, CVC is done using anatomical landmarks in many EDs in Iran. Objectives: This study aimed to compare the traditional landmark method vs. US-guided method of CVC placement in terms of complications and success rate. Patients and Methods: In this randomized controlled trial, patients who were candidate for internal jugular vein ...

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

International Nuclear Information System (INIS)

Lee, Woo Jin; Kim, Dae Seung; Yi, Won Jin; Lee, Sam Sun; Choi, Soon Chul; Heo, Min Suk; Huh, Kyung Hoe; Kim, Myung Jin; Lee, Jee Ho

2009-01-01

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

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.

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.

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).

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.

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.

Mistakes in the usage of anatomical terminology in clinical practice.

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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.

3D Reconstruction and Standardization of the Rat Vibrissal Cortex for Precise Registration of Single Neuron Morphology

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Egger, Robert; Narayanan, Rajeevan T.; Helmstaedter, Moritz; de Kock, Christiaan P. J.; Oberlaender, Marcel

2012-01-01

The three-dimensional (3D) structure of neural circuits is commonly studied by reconstructing individual or small groups of neurons in separate preparations. Investigation of structural organization principles or quantification of dendritic and axonal innervation thus requires integration of many reconstructed morphologies into a common reference frame. Here we present a standardized 3D model of the rat vibrissal cortex and introduce an automated registration tool that allows for precise placement of single neuron reconstructions. We (1) developed an automated image processing pipeline to reconstruct 3D anatomical landmarks, i.e., the barrels in Layer 4, the pia and white matter surfaces and the blood vessel pattern from high-resolution images, (2) quantified these landmarks in 12 different rats, (3) generated an average 3D model of the vibrissal cortex and (4) used rigid transformations and stepwise linear scaling to register 94 neuron morphologies, reconstructed from in vivo stainings, to the standardized cortex model. We find that anatomical landmarks vary substantially across the vibrissal cortex within an individual rat. In contrast, the 3D layout of the entire vibrissal cortex remains remarkably preserved across animals. This allows for precise registration of individual neuron reconstructions with approximately 30 µm accuracy. Our approach could be used to reconstruct and standardize other anatomically defined brain areas and may ultimately lead to a precise digital reference atlas of the rat brain. PMID:23284282

Network of anatomical texts (NAnaTex), an open-source project for visualizing the interaction between anatomical terms.

Science.gov (United States)

Momota, Ryusuke; Ohtsuka, Aiji

2018-01-01

Anatomy is the science and art of understanding the structure of the body and its components in relation to the functions of the whole-body system. Medicine is based on a deep understanding of anatomy, but quite a few introductory-level learners are overwhelmed by the sheer amount of anatomical terminology that must be understood, so they regard anatomy as a dull and dense subject. To help them learn anatomical terms in a more contextual way, we started a new open-source project, the Network of Anatomical Texts (NAnaTex), which visualizes relationships of body components by integrating text-based anatomical information using Cytoscape, a network visualization software platform. Here, we present a network of bones and muscles produced from literature descriptions. As this network is primarily text-based and does not require any programming knowledge, it is easy to implement new functions or provide extra information by making changes to the original text files. To facilitate collaborations, we deposited the source code files for the network into the GitHub repository ( https://github.com/ryusukemomota/nanatex ) so that anybody can participate in the evolution of the network and use it for their own non-profit purposes. This project should help not only introductory-level learners but also professional medical practitioners, who could use it as a quick reference.

TU-AB-202-02: Deformable Image Registration Accuracy Between External Beam Radiotherapy and HDR Brachytherapy CT Images for Cervical Cancer Using a 3D-Printed Deformable Pelvis Phantom

International Nuclear Information System (INIS)

Miyasaka, Y; Kadoya, N; Ito, K; Chiba, M; Nakajima, Y; Dobashi, S; Takeda, K; Jingu, K; Kuroda, Y; Sato, K

2016-01-01

Purpose: Accurate deformable image registration (DIR) between external beam radiotherapy (EBRT) and HDR brachytherapy (BT) CT images in cervical cancer is challenging. DSC has been evaluated only on the basis of the consistency of the structure, and its use does not guarantee an anatomically reasonable deformation. We evaluate the DIR accuracy for cervical cancer with DSC and anatomical landmarks using a 3D-printed pelvis phantom. Methods: A 3D-printed, deformable female pelvis phantom was created on the basis of the patient’s CT image. Urethane and silicon were used as materials for creating the uterus and bladder, respectively, in the phantom. We performed DIR in two cases: case-A with a full bladder (170 ml) in both the EBRT and BT images and case-B with a full bladder in the BT image and a half bladder (100 ml) in the EBRT image. DIR was evaluated using DSCs and 70 uterus and bladder landmarks. A Hybrid intensity and structure DIR algorithm with two settings (RayStation) was used. Results: In the case-A, DSCs of the intensity-based DIR were 0.93 and 0.85 for the bladder and uterus, respectively, whereas those of hybrid-DIR were 0.98 and 0.96, respectively. The mean landmark error values of intensity-based DIR were 0.73±0.29 and 1.70±0.19 cm for the bladder and uterus, respectively, whereas those of Hybrid-DIR were 0.43±0.33 and 1.23±0.25 cm, respectively. In both cases, the Hybrid-DIR accuracy was better than the intensity-based DIR accuracy for both evaluation methods. However, for several bladder landmarks, the Hybrid-DIR landmark errors were larger than the corresponding intensity-based DIR errors (e.g., 2.26 vs 1.25 cm). Conclusion: Our results demonstrate that Hybrid-DIR can perform with a better accuracy than the intensity-based DIR for both DSC and landmark errors; however, Hybrid-DIR shows a larger landmark error for some landmarks because the technique focuses on both the structure and intensity.

TU-AB-202-02: Deformable Image Registration Accuracy Between External Beam Radiotherapy and HDR Brachytherapy CT Images for Cervical Cancer Using a 3D-Printed Deformable Pelvis Phantom

Energy Technology Data Exchange (ETDEWEB)

Miyasaka, Y; Kadoya, N; Ito, K; Chiba, M; Nakajima, Y; Dobashi, S; Takeda, K; Jingu, K [Tohoku University Graduate School of Medicine, Sendai, Miyagi (Japan); Kuroda, Y [Cybermedia Center, Osaka University, Toyonaka, Osaka (Japan); Sato, K [Tohoku University Hospital, Sendai, Miyagi (Japan)

2016-06-15

Purpose: Accurate deformable image registration (DIR) between external beam radiotherapy (EBRT) and HDR brachytherapy (BT) CT images in cervical cancer is challenging. DSC has been evaluated only on the basis of the consistency of the structure, and its use does not guarantee an anatomically reasonable deformation. We evaluate the DIR accuracy for cervical cancer with DSC and anatomical landmarks using a 3D-printed pelvis phantom. Methods: A 3D-printed, deformable female pelvis phantom was created on the basis of the patient’s CT image. Urethane and silicon were used as materials for creating the uterus and bladder, respectively, in the phantom. We performed DIR in two cases: case-A with a full bladder (170 ml) in both the EBRT and BT images and case-B with a full bladder in the BT image and a half bladder (100 ml) in the EBRT image. DIR was evaluated using DSCs and 70 uterus and bladder landmarks. A Hybrid intensity and structure DIR algorithm with two settings (RayStation) was used. Results: In the case-A, DSCs of the intensity-based DIR were 0.93 and 0.85 for the bladder and uterus, respectively, whereas those of hybrid-DIR were 0.98 and 0.96, respectively. The mean landmark error values of intensity-based DIR were 0.73±0.29 and 1.70±0.19 cm for the bladder and uterus, respectively, whereas those of Hybrid-DIR were 0.43±0.33 and 1.23±0.25 cm, respectively. In both cases, the Hybrid-DIR accuracy was better than the intensity-based DIR accuracy for both evaluation methods. However, for several bladder landmarks, the Hybrid-DIR landmark errors were larger than the corresponding intensity-based DIR errors (e.g., 2.26 vs 1.25 cm). Conclusion: Our results demonstrate that Hybrid-DIR can perform with a better accuracy than the intensity-based DIR for both DSC and landmark errors; however, Hybrid-DIR shows a larger landmark error for some landmarks because the technique focuses on both the structure and intensity.

Anatomic features involved in technical complexity of partial nephrectomy.

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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.

Anatomically-aided PET reconstruction using the kernel method.

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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.

Anatomic and functional leg-length inequality: A review and recommendation for clinical decision-making. Part I, anatomic leg-length inequality: prevalence, magnitude, effects and clinical significance

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Knutson Gary A

2005-07-01

Full Text Available Abstract Background Leg-length inequality is most often divided into two groups: anatomic and functional. Part I of this review analyses data collected on anatomic leg-length inequality relative to prevalence, magnitude, effects and clinical significance. Part II examines the functional "short leg" including anatomic-functional relationships, and provides an outline for clinical decision-making. Methods Online database – Medline, CINAHL and MANTIS – and library searches for the time frame of 1970–2005 were done using the term "leg-length inequality". Results and Discussion Using data on leg-length inequality obtained by accurate and reliable x-ray methods, the prevalence of anatomic inequality was found to be 90%, the mean magnitude of anatomic inequality was 5.2 mm (SD 4.1. The evidence suggests that, for most people, anatomic leg-length inequality does not appear to be clinically significant until the magnitude reaches ~ 20 mm (~3/4". Conclusion Anatomic leg-length inequality is near universal, but the average magnitude is small and not likely to be clinically significant.

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

Broad Anatomical Variation within a Narrow Wood Density Range—A Study of Twig Wood across 69 Australian Angiosperms

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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

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.

Unification of Sinonasal Anatomical Terminology

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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.

Anatomical terminology and nomenclature: past, present and highlights.

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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.

Extra-Anatomic Revascularization of Extensive Coral Reef Aorta.

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Gaggiano, Andrea; Kasemi, Holta; Monti, Andrea; Laurito, Antonella; Maselli, Mauro; Manzo, Paola; Quaglino, Simone; Tavolini, Valeria

2017-10-01

Coral reef aorta (CRA) is a rare, potential lethal disease of the visceral aorta as it can cause visceral and renal infarction. Various surgical approaches have been proposed for the CRA treatment. The purpose of this article is to report different extensive extra-anatomic CRA treatment modalities tailored on the patients' clinical and anatomic presentation. From April 2006 to October 2012, 4 symptomatic patients with extensive CRA were treated at our department. Extra-anatomic aortic revascularization with selective visceral vessels clamping was performed in all cases. Technical success was 100%. No perioperative death was registered. All patients remained asymptomatic during the follow-up period (62, 49, 25, and 94 months, respectively), with bypasses and target vessels patency. The extra-anatomic bypass with selective visceral vessels clamping reduces the aortic occlusion time and the risk of organ ischemia. All approaches available should be considered on a case-by-case basis and in high-volume centers. Copyright © 2017 Elsevier Inc. All rights reserved.

Reappraising the functional implications of the primate visual anatomical hierarchy.

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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.

Concentric Tube Robot Design and Optimization Based on Task and Anatomical Constraints

Science.gov (United States)

Bergeles, Christos; Gosline, Andrew H.; Vasilyev, Nikolay V.; Codd, Patrick J.; del Nido, Pedro J.; Dupont, Pierre E.

2015-01-01

Concentric tube robots are catheter-sized continuum robots that are well suited for minimally invasive surgery inside confined body cavities. These robots are constructed from sets of pre-curved superelastic tubes and are capable of assuming complex 3D curves. The family of 3D curves that the robot can assume depends on the number, curvatures, lengths and stiffnesses of the tubes in its tube set. The robot design problem involves solving for a tube set that will produce the family of curves necessary to perform a surgical procedure. At a minimum, these curves must enable the robot to smoothly extend into the body and to manipulate tools over the desired surgical workspace while respecting anatomical constraints. This paper introduces an optimization framework that utilizes procedureor patient-specific image-based anatomical models along with surgical workspace requirements to generate robot tube set designs. The algorithm searches for designs that minimize robot length and curvature and for which all paths required for the procedure consist of stable robot configurations. Two mechanics-based kinematic models are used. Initial designs are sought using a model assuming torsional rigidity. These designs are then refined using a torsionally-compliant model. The approach is illustrated with clinically relevant examples from neurosurgery and intracardiac surgery. PMID:26380575

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.

Inexpensive anatomical trainer for bronchoscopy.

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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.

Anatomically contoured plates for fixation of rib fractures.

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Bottlang, Michael; Helzel, Inga; Long, William B; Madey, Steven

2010-03-01

: Intraoperative contouring of long bridging plates for stabilization of flail chest injuries is difficult and time consuming. This study implemented for the first time biometric parameters to derive anatomically contoured rib plates. These plates were tested on a range of cadaveric ribs to quantify plate fit and to extract a best-fit plating configuration. : Three left and three right rib plates were designed, which accounted for anatomic parameters required when conforming a plate to the rib surface. The length lP over which each plate could trace the rib surface was evaluated on 109 cadaveric ribs. For each rib level 3-9, the plate design with the highest lP value was extracted to determine a best-fit plating configuration. Furthermore, the characteristic twist of rib surfaces was measured on 49 ribs to determine the surface congruency of anatomic plates with a constant twist. : The tracing length lP of the best-fit plating configuration ranged from 12.5 cm to 14.7 cm for ribs 3-9. The corresponding range for standard plates was 7.1-13.7 cm. The average twist of ribs over 8-cm, 12-cm, and 16-cm segments was 8.3 degrees, 20.6 degrees, and 32.7 degrees, respectively. The constant twist of anatomic rib plates was not significantly different from the average rib twist. : A small set of anatomic rib plates can minimize the need for intraoperative plate contouring for fixation of ribs 3-9. Anatomic rib plates can therefore reduce the time and complexity of flail chest stabilization and facilitate spanning of flail segments with long plates.

Anatomic mapping of molecular subtypes in diffuse glioma.

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Tang, Qisheng; Lian, Yuxi; Yu, Jinhua; Wang, Yuanyuan; Shi, Zhifeng; Chen, Liang

2017-09-15

Tumor location served as an important prognostic factor in glioma patients was considered to postulate molecular features according to cell origin theory. However, anatomic distribution of unique molecular subtypes was not widely investigated. The relationship between molecular phenotype and histological subgroup were also vague based on tumor location. Our group focuses on the study of glioma anatomic location of distinctive molecular subgroups and histology subtypes, and explores the possibility of their consistency based on clinical background. We retrospectively reviewed 143 cases with both molecular information (IDH1/TERT/1p19q) and MRI images diagnosed as cerebral diffuse gliomas. The anatomic distribution was analyzed between distinctive molecular subgroups and its relationship with histological subtypes. The influence of tumor location, molecular stratification and histology diagnosis on survival outcome was investigated as well. Anatomic locations of cerebral diffuse glioma indicate varied clinical outcome. Based on that, it can be stratified into five principal molecular subgroups according to IDH1/TERT/1p19q status. Triple-positive (IDH1 and TERT mutation with 1p19q codeletion) glioma tended to be oligodendroglioma present with much better clinical outcome compared to TERT mutation only group who is glioblastoma inclined (median overall survival 39 months VS 18 months). Five molecular subgroups were demonstrated with distinctive locational distribution. This kind of anatomic feature is consistent with its corresponding histological subtypes. Each molecular subgroup in glioma has unique anatomic location which indicates distinctive clinical outcome. Molecular diagnosis can be served as perfect complementary tool for the precise diagnosis. Integration of histomolecular diagnosis will be much more helpful in routine clinical practice in the future.

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

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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.

Bringing history to life: simulating landmark experiments in psychology.

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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.

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

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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

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

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.)

CT following US for possible appendicitis: anatomic coverage

International Nuclear Information System (INIS)

O'Malley, Martin E.; Alharbi, Fawaz; Chawla, Tanya P.; Moshonov, Hadas

2016-01-01

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.)

How far are we from solving the 2D & 3D Face Alignment problem? (and a dataset of 230,000 3D facial landmarks)

OpenAIRE

Bulat, Adrian; Tzimiropoulos, Georgios

2017-01-01

This paper investigates how far a very deep neural network is from attaining close to saturating performance on existing 2D and 3D face alignment datasets. To this end, we make the following 5 contributions: (a) we construct, for the first time, a very strong baseline by combining a state-of-the-art architecture for landmark localization with a state-of-the-art residual block, train it on a very large yet synthetically expanded 2D facial landmark dataset and finally evaluate it on all other 2...

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.

[Project HRANAFINA--Croatian anatomical and physiological terminology].

Science.gov (United States)

Vodanović, Marin

2012-01-01

HRANAFINA--Croatian Anatomical and Physiological Terminology is a project of the University of Zagreb School of Dental Medicine funded by the Croatian Science Foundation. It is performed in cooperation with other Croatian universities with medical schools. This project has a two-pronged aim: firstly, building of Croatian anatomical and physiological terminology and secondly, Croatian anatomical and physiological terminology usage popularization between health professionals, medical students, scientists and translators. Internationally recognized experts from Croatian universities with medical faculties and linguistics experts are involved in the project. All project activities are coordinated in agreement with the National Coordinator for Development of Croatian Professional Terminology. The project enhances Croatian professional terminology and Croatian language in general, increases competitiveness of Croatian scientists on international level and facilitates the involvement of Croatian scientists, health care providers and medical students in European projects.

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

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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.

Magnetic Resonance Imaging of the Normal Stifle Joint in Buffaloes (Bos Bubalis: An Anatomic Study

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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.

Sinus Surgery

Science.gov (United States)

... sinus computed tomography (CT) scan (without contrast), nasal physiology (rhinomanometry and nasal cytology), smell testing, and selected ... altered anatomical landmarks, or where a patient’s sinus anatomy is very unusual, making typical surgery difficult. Image ...

Ultrasound comparison of external and internal neck anatomy with the LMA Unique.

Science.gov (United States)

Lee, Steven M; Wojtczak, Jacek A; Cattano, Davide

2017-12-01

Internal neck anatomy landmarks and their relation after placement of an extraglottic airway devices have not been studied extensively by the use of ultrasound. Based on our group experience with external landmarks as well as internal landmarks evaluation with other techniques, we aimed use ultrasound to analyze the internal neck anatomy landmarks and the related changes due to the placement of the Laryngeal Mask Airway Unique. Observational pilot investigation. Non-obese adult patients with no evidence of airway anomalies, were recruited. External neck landmarks were measured based on a validated and standardized method by tape. Eight internal anatomical landmarks, reciprocal by the investigational hypothesis to the external landmarks, were also measured by ultrasound guidance. The internal landmarks were re-measured after optimal placement and inflation of the extraglottic airway devices cuff Laryngeal Mask Airway Unique. Six subjects were recruited. Ultrasound measurements of hyoid-mental distance, thyroid-cricoid distance, thyroid height, and thyroid width were found to be significantly ( p internal neck anatomy. The induced changes and respective specific internal neck anatomy landmarks could help to design devices that would modify their shape accordingly to areas of greatest displacement. Also, while external neck landmark measurements overestimate their respective internal neck landmarks, as we previously reported, the concordance of each measurement and their respective conversion factor could continue to be of help in sizing extraglottic airway devices. Due to the pilot nature of the study, more investigations are warranted.

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

Directory of Open Access Journals (Sweden)

Yan Xu

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

2D or Not 2D? Testing the Utility of 2D Vs. 3D Landmark Data in Geometric Morphometrics of the Sculpin Subfamily Oligocottinae (Pisces; Cottoidea).

Science.gov (United States)

Buser, Thaddaeus J; Sidlauskas, Brian L; Summers, Adam P

2018-05-01

We contrast 2D vs. 3D landmark-based geometric morphometrics in the fish subfamily Oligocottinae by using 3D landmarks from CT-generated models and comparing the morphospace of the 3D landmarks to one based on 2D landmarks from images. The 2D and 3D shape variables capture common patterns across taxa, such that the pairwise Procrustes distances among taxa correspond and the trends captured by principal component analysis are similar in the xy plane. We use the two sets of landmarks to test several ecomorphological hypotheses from the literature. Both 2D and 3D data reject the hypothesis that head shape correlates significantly with the depth at which a species is commonly found. However, in taxa where shape variation in the z-axis is high, the 2D shape variables show sufficiently strong distortion to influence the outcome of the hypothesis tests regarding the relationship between mouth size and feeding ecology. Only the 3D data support previous studies which showed that large mouth sizes correlate positively with high percentages of elusive prey in the diet. When used to test for morphological divergence, 3D data show no evidence of divergence, while 2D data show that one clade of oligocottines has diverged from all others. This clade shows the greatest degree of z-axis body depth within Oligocottinae, and we conclude that the inability of the 2D approach to capture this lateral body depth causes the incongruence between 2D and 3D analyses. Anat Rec, 301:806-818, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Morpho-anatomical investigations on Momordica charantia L. (Cucurbitaceae

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İlham Eröz Poyraz

2016-05-01

Full Text Available Momordica charantia L. (Cucurbitaceae used for some medicinal purposes like antidiabetic, anticancer, antiviral and treat to gastritis was investigated. Morphological studies were supported by morphometric measurements and drawings of male and female flowers, fruit and seeds of the species. In anatomical studies, cross sections of stem and leaf, upper and lower surface sections of leaves were evaluated. It was detected that the stem with typical anatomical properties of a climbing dicotyl plant. The leaves were amphistotamic and with lots of cyctoliths on the lower surface of leaves. Stomata are anomocytic and situated much more at the lower surface of leaves. Morpho-anatomical investigations on Momordica charantia L. (Cucurbitaceae*

Influence of the sagittal anatomy of the pelvis on the intercrestal line position.

Science.gov (United States)

Horduna, M; Legaye, J

2008-03-01

The line joining the two iliac crests is classically regarded as the anatomical landmark determining the inter-vertebral space L4-L5 for the spinal punctures. Its variability has been reported but never related to predictive clinical anatomic factors identifying patients groups in which there is increased risk of miscalculation of the spinal level. Two sagittal pelvic anatomical angles, called 'pelvic incidence' and 'pelvic lordosis' were measured on lateral X-rays of the pelvis of 132 normal individuals and 49 spondylolysis patients. The values were compared with the sagittal projection of the intercrestal line on the disco-vertebral lumbar structures. A strict relation was observed between this projection of the intercrestal line and the sagittal pelvic anatomical angles. The greater the pelvic incidence, the higher the intercrestal line was projected, all the more in patients with spondylolysis with a listhesis or a disc narrowing. The relation between the pelvic sagittal angles and the intercrestal line projection explains the variability described for this anatomical landmark. It implies precautions minimizing neurological risk in the case of a puncture carried out more cranially than expected, particularly for high values of pelvic incidence occurring in spinal pathologies such as spondylolysis, in the elderly or in the obese patients. In these cases, we recommend the use of spinal imaging during the procedure to assist selection of the desired insertion level.

Creating vascular models by postprocessing computed tomography angiography images: a guide for anatomical education.

Science.gov (United States)

Govsa, Figen; Ozer, Mehmet Asim; Sirinturk, Suzan; Eraslan, Cenk; Alagoz, Ahmet Kemal

2017-08-01

A new application of teaching anatomy includes the use of computed tomography angiography (CTA) images to create clinically relevant three-dimensional (3D) printed models. The purpose of this article is to review recent innovations on the process and the application of 3D printed models as a tool for using under and post-graduate medical education. Images of aortic arch pattern received by CTA were converted into 3D images using the Google SketchUp free software and were saved in stereolithography format. Using a 3D printer (Makerbot), a model mode polylactic acid material was printed. A two-vessel left aortic arch was identified consisting of the brachiocephalic trunk and left subclavian artery. The life-like 3D models were rotated 360° in all axes in hand. The early adopters in education and clinical practices have embraced the medical imaging-guided 3D printed anatomical models for their ability to provide tactile feedback and a superior appreciation of visuospatial relationship between the anatomical structures. Printed vascular models are used to assist in preoperative planning, develop intraoperative guidance tools, and to teach patients surgical trainees in surgical practice.

Comparative validity and reproducibility study of various landmark-oriented reference planes in 3-dimensional computed tomographic analysis for patients receiving orthognathic surgery.

Science.gov (United States)

Lin, Hsiu-Hsia; Chuang, Ya-Fang; Weng, Jing-Ling; Lo, Lun-Jou

2015-01-01

Three-dimensional computed tomographic imaging has become popular in clinical evaluation, treatment planning, surgical simulation, and outcome assessment for maxillofacial intervention. The purposes of this study were to investigate whether there is any correlation among landmark-based horizontal reference planes and to validate the reproducibility and reliability of landmark identification. Preoperative and postoperative cone-beam computed tomographic images of patients who had undergone orthognathic surgery were collected. Landmark-oriented reference planes including the Frankfort horizontal plane (FHP) and the lateral semicircular canal plane (LSP) were established. Four FHPs were defined by selecting 3 points from the orbitale, porion, or midpoint of paired points. The LSP passed through both the lateral semicircular canal points and nasion. The distances between the maxillary or mandibular teeth and the reference planes were measured, and the differences between the 2 sides were calculated and compared. The precision in locating the landmarks was evaluated by performing repeated tests, and the intraobserver reproducibility and interobserver reliability were assessed. A total of 30 patients with facial deformity and malocclusion--10 patients with facial symmetry, 10 patients with facial asymmetry, and 10 patients with cleft lip and palate--were recruited. Comparing the differences among the 5 reference planes showed no statistically significant difference among all patient groups. Regarding intraobserver reproducibility, the mean differences in the 3 coordinates varied from 0 to 0.35 mm, with correlation coefficients between 0.96 and 1.0, showing high correlation between repeated tests. Regarding interobserver reliability, the mean differences among the 3 coordinates varied from 0 to 0.47 mm, with correlation coefficients between 0.88 and 1.0, exhibiting high correlation between the different examiners. The 5 horizontal reference planes were reliable and

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

A reference dataset for deformable image registration spatial accuracy evaluation using the COPDgene study archive

International Nuclear Information System (INIS)

Castillo, Richard; Castillo, Edward; Wood, Abbie M; Ludwig, Michelle S; Guerrero, Thomas; Fuentes, David; Ahmad, Moiz

2013-01-01

Landmark point-pairs provide a strategy to assess deformable image registration (DIR) accuracy in terms of the spatial registration of the underlying anatomy depicted in medical images. In this study, we propose to augment a publicly available database (www.dir-lab.com) of medical images with large sets of manually identified anatomic feature pairs between breath-hold computed tomography (BH-CT) images for DIR spatial accuracy evaluation. Ten BH-CT image pairs were randomly selected from the COPDgene study cases. Each patient had received CT imaging of the entire thorax in the supine position at one-fourth dose normal expiration and maximum effort full dose inspiration. Using dedicated in-house software, an imaging expert manually identified large sets of anatomic feature pairs between images. Estimates of inter- and intra-observer spatial variation in feature localization were determined by repeat measurements of multiple observers over subsets of randomly selected features. 7298 anatomic landmark features were manually paired between the 10 sets of images. Quantity of feature pairs per case ranged from 447 to 1172. Average 3D Euclidean landmark displacements varied substantially among cases, ranging from 12.29 (SD: 6.39) to 30.90 (SD: 14.05) mm. Repeat registration of uniformly sampled subsets of 150 landmarks for each case yielded estimates of observer localization error, which ranged in average from 0.58 (SD: 0.87) to 1.06 (SD: 2.38) mm for each case. The additions to the online web database (www.dir-lab.com) described in this work will broaden the applicability of the reference data, providing a freely available common dataset for targeted critical evaluation of DIR spatial accuracy performance in multiple clinical settings. Estimates of observer variance in feature localization suggest consistent spatial accuracy for all observers across both four-dimensional CT and COPDgene patient cohorts. (paper)

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.

[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

A New Design for Airway Management Training with Mixed Reality and High Fidelity Modeling.

Science.gov (United States)

Shen, Yunhe; Hananel, David; Zhao, Zichen; Burke, Daniel; Ballas, Crist; Norfleet, Jack; Reihsen, Troy; Sweet, Robert

2016-01-01

Restoring airway function is a vital task in many medical scenarios. Although various simulation tools have been available for learning such skills, recent research indicated that fidelity in simulating airway management deserves further improvements. In this study, we designed and implemented a new prototype for practicing relevant tasks including laryngoscopy, intubation and cricothyrotomy. A large amount of anatomical details or landmarks were meticulously selected and reconstructed from medical scans, and 3D-printed or molded to the airway intervention model. This training model was augmented by virtually and physically presented interactive modules, which are interoperable with motion tracking and sensor data feedback. Implementation results showed that this design is a feasible approach to develop higher fidelity airway models that can be integrated with mixed reality interfaces.

Cadaveric dissection as an educational tool for anatomical sciences in the 21st century.

Science.gov (United States)

Ghosh, Sanjib Kumar

2017-06-01

Anatomical education has been undergoing reforms in line with the demands of medical profession. The aim of the present study is to assess the impact of a traditional method like cadaveric dissection in teaching/learning anatomy at present times when medical schools are inclining towards student-centered, integrated, clinical application models. The article undertakes a review of literature and analyzes the observations made therein reflecting on the relevance of cadaveric dissection in anatomical education of 21st century. Despite the advent of modern technology and evolved teaching methods, dissection continues to remain a cornerstone of anatomy curriculum. Medical professionals of all levels believe that dissection enables learning anatomy with relevant clinical correlates. Moreover dissection helps to build discipline independent skills which are essential requirements of modern health care setup. It has been supplemented by other teaching/learning methods due to limited availability of cadavers in some countries. However, in the developing world due to good access to cadavers, dissection based teaching is central to anatomy education till date. Its utility is also reflected in the perception of students who are of the opinion that dissection provides them with a foundation critical to development of clinical skills. Researchers have even suggested that time has come to reinstate dissection as the core method of teaching gross anatomy to ensure safe medical practice. Nevertheless, as dissection alone cannot provide uniform learning experience hence needs to be complemented with other innovative learning methods in the future education model of anatomy. Anat Sci Educ 10: 286-299. © 2016 American Association of Anatomists. © 2016 American Association of Anatomists.

Automatic, anatomically selective, artifact-free enhancement of digital chest radiographs

International Nuclear Information System (INIS)

Sezan, M.I.; Tekalp, A.M.; Schaetzing, R.

1988-01-01

The authors propose a technique for automatic, anatomically selective, artifact-free enhancement of digital chest radiographs. Anatomically selective enhancement is motivated by the different enhancement requirements of the lung field and the mediastinum. A recent peak detection algorithm is applied to the image histogram to automatically determine a gray-level threshold between the lung and mediastinum fields. The gray-level threshold facilitates anatomically selective gray-scale modification and unsharp masking. Further, in an attempt to suppress possible white-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 that varied asymmetrically with positive and negative values of the local image contrast

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

The brain's default network: anatomy, function, and relevance to disease.

Science.gov (United States)

Buckner, Randy L; Andrews-Hanna, Jessica R; Schacter, Daniel L

2008-03-01

Thirty years of brain imaging research has converged to define the brain's default network-a novel and only recently appreciated brain system that participates in internal modes of cognition. Here we synthesize past observations to provide strong evidence that the default network is a specific, anatomically defined brain system preferentially active when individuals are not focused on the external environment. Analysis of connectional anatomy in the monkey supports the presence of an interconnected brain system. Providing insight into function, the default network is active when individuals are engaged in internally focused tasks including autobiographical memory retrieval, envisioning the future, and conceiving the perspectives of others. Probing the functional anatomy of the network in detail reveals that it is best understood as multiple interacting subsystems. The medial temporal lobe subsystem provides information from prior experiences in the form of memories and associations that are the building blocks of mental simulation. The medial prefrontal subsystem facilitates the flexible use of this information during the construction of self-relevant mental simulations. These two subsystems converge on important nodes of integration including the posterior cingulate cortex. The implications of these functional and anatomical observations are discussed in relation to possible adaptive roles of the default network for using past experiences to plan for the future, navigate social interactions, and maximize the utility of moments when we are not otherwise engaged by the external world. We conclude by discussing the relevance of the default network for understanding mental disorders including autism, schizophrenia, and Alzheimer's disease.

Success rate and complications of internal jugular vein catheterization with and without ultrasonography guide.

Science.gov (United States)

Karimi-Sari, Hamidreza; Faraji, Mehrdad; Mohazzab Torabi, Saman; Asjodi, Gholamreza

2014-12-01

Central venous catheterization (CVC) is an important procedure in emergency departments (EDs). Despite existence of ultrasonography (US) devices in every ED, CVC is done using anatomical landmarks in many EDs in Iran. This study aimed to compare the traditional landmark method vs. US-guided method of CVC placement in terms of complications and success rate. In this randomized controlled trial, patients who were candidate for internal jugular vein catheterization, and referred to Baqiyatallah Hospital ED were randomly allocated into US-guided CVC and anatomical landmarks guided CVC groups. Central vein access time, number of attempts, success rate, and complications in each group were evaluated. Mann-Whitney U, chi-square and Fisher exact tests along with Pearson and Spearman correlation coefficients were used to analyze the data. Out of 100 patients, 56 were male and 44 were female. No significant differences were found between the US-guided and traditional landmark methods of CVC insertion in terms of age, gender, BMI, and site of catheter insertion. The mean access time was significantly lower in the US-guided group (37.12 ± 17.33 s vs. 63.42 ± 35.19 s, P < 0.001). The mean number of attempts was also significantly lower in the US-guided group (1.12 ± 0.3 vs. 1.58 ± 0.64 times, P < 0.001). Eighty-eight percent of patients in the US-guided group were catheterized in the first attempt, while 50% of patients in the traditional landmark group were catheterized in the second or more attempts (P < 0.001). The success rate was 100% in the US-guided group, while it was 88% in the landmark group (P = 0.013). Moreover, the rate of complications was significantly lower in the US-guided group (4% vs. 24%, P = 0.004). The US-guided method for CVC placement was superior to the traditional landmark method in terms of access time, number of attempts, success rate, and fewer complications.

Local SAR in High Pass Birdcage and TEM Body Coils for Multiple Human Body Models in Clinical Landmark Positions at 3T

Science.gov (United States)

Yeo, Desmond TB; Wang, Zhangwei; Loew, Wolfgang; Vogel, Mika W; Hancu, Ileana

2011-01-01

Purpose To use EM simulations to study the effects of body type, landmark position, and RF body coil type on peak local SAR in 3T MRI. Materials and Methods Numerically computed peak local SAR for four human body models (HBMs) in three landmark positions (head, heart, pelvic) were compared for a high-pass birdcage and a transverse electromagnetic 3T body coil. Local SAR values were normalized to the IEC whole-body average SAR limit of 2.0 W/kg for normal scan mode. Results Local SAR distributions were highly variable. Consistent with previous reports, the peak local SAR values generally occurred in the neck-shoulder area, near rungs, or between tissues of greatly differing electrical properties. The HBM type significantly influenced the peak local SAR, with stockier HBMs, extending extremities towards rungs, displaying the highest SAR. There was also a trend for higher peak SAR in the head-centric and heart-centric positions. The impact of the coil-types studied was not statistically significant. Conclusion The large variability in peak local SAR indicates the need to include more than one HBM or landmark position when evaluating safety of body coils. It is recommended that a HBM with arms near the rungs be included, to create physically realizable high-SAR scenarios. PMID:21509880

The Relevance of the Organic Tradition in Architecture in the Digital Age

DEFF Research Database (Denmark)

Jaeger, Thomas Arvid; Carter, Adrian Stanley

2017-01-01

The paper will propose that as the digital technology evolves, enabling us to increasingly emulate the forms of nature within our built environment, as we see in the parametric design, it will be ever more important to understand the origins of nature and organic growth in form and concept...... of the factors, behind and involved in, creating his version of “new organic architecture” in the fifties - in order to make it possible to compare this with later studies of “digital organic” architecture of the 21. Cent. The relevance of going back to Mumford’s criticism of the consequences...... - and what this means for our perception of architecture. The Digital Age has been introducing a new wave of sculptural, organic curved architecture – often placed as iconic landmarks in the city. These buildings represent a new kind of aesthetics in contrast to the rectangular Euclidian rationalistic...

Conservation landmarks: bureau of biological survey and national biological service

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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.

Imaging and PET - PET/CT imaging

International Nuclear Information System (INIS)

Von Schulthess, G.K.; Hany, Th.F.

2008-01-01

PET/CT has grown because the lack of anatomic landmarks in PET makes 'hardware-fusion' to anatomic cross-sectional data extremely useful. Addition of CT to PET improves specificity, but also sensitivity, and adding PET to CT adds sensitivity and specificity in tumor imaging. The synergistic advantage of adding CT is that the attenuation correction needed for PET data can also be derived from the CT data. This makes PET-CT 25-30% faster than PET alone, leading to higher patient throughput and a more comfortable examination for patients typically lasting 20 minutes or less. FDG-PET-CT appears to provide relevant information in the staging and therapy monitoring of many tumors, such as lung carcinoma, colorectal cancer, lymphoma, gynaecological cancers, melanoma and many others, with the notable exception of prostatic cancer. for this cancer, choline derivatives may possibly become useful radiopharmaceuticals. The published literature on the applications of FDG-PET-CT in oncology is still limited but several designed studies have demonstrated the benefits of PET-CT. (authors)

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 ...

Anatomical planes: are we teaching accurate surface anatomy?

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Mirjalili, S Ali; McFadden, Sarah L; Buckenham, Tim; Wilson, Ben; Stringer, Mark D

2012-10-01

Anatomical planes used in clinical practice and teaching anatomy are largely derived from cadaver studies. Numerous inconsistencies in clinically important surface markings exist between and within anatomical reference texts. The aim of this study was to reassess the accuracy of common anatomical planes in vivo using computed tomographic (CT) imaging. CT scans of the trunk in supine adults at end tidal inspiration were analyzed by dual consensus reporting to determine the anatomy of five anatomical planes: sternal angle, transpyloric, subcostal, supracristal, and the plane of the pubic crest. Patients with kyphosis, scoliosis, or abnormal lordosis, distorting space-occupying lesions, or visceromegaly were excluded. Among 153 thoracic CT scans (mean age 63 years, 53% female), the sternal angle was most common at T4 (females) or T4/5 (males) vertebral level, and the tracheal bifurcation, aortic arch, and pulmonary trunk were most often below this plane. In 108 abdominal CT scans (mean age 60 years, 59% female), the subcostal and supracristal planes were most often at L2 (58%) and L4 (69%), respectively. In 52 thoracoabdominal CT scans (mean age 61 years, 56% female), the transpyloric plane was between lower L1 and upper L2 (75%); in this plane were the superior mesenteric artery (56%), formation of the portal vein (53%), tip of the ninth rib (60%), and the left renal hilum (54%), but the right renal hilum and gallbladder fundus were more often below. The surface anatomy of anatomical planes needs revising in the light of results from living subjects using modern imaging techniques. Copyright © 2012 Wiley Periodicals, Inc.

Construction of a 3-D anatomical model for teaching temporal lobectomy.

Science.gov (United States)

de Ribaupierre, Sandrine; Wilson, Timothy D

2012-06-01

Although we live and work in 3 dimensional space, most of the anatomical teaching during medical school is done on 2-D (books, TV and computer screens, etc). 3-D spatial abilities are essential for a surgeon but teaching spatial skills in a non-threatening and safe educational environment is a much more difficult pedagogical task. Currently, initial anatomical knowledge formation or specific surgical anatomy techniques, are taught either in the OR itself, or in cadaveric labs; which means that the trainee has only limited exposure. 3-D computer models incorporated into virtual learning environments may provide an intermediate and key step in a blended learning approach for spatially challenging anatomical knowledge formation. Specific anatomical structures and their spatial orientation can be further clinically contextualized through demonstrations of surgical procedures in the 3-D digital environments. Recordings of digital models enable learner reviews, taking as much time as they want, stopping the demonstration, and/or exploring the model to understand the anatomical relation of each structure. We present here how a temporal lobectomy virtual model has been developed to aid residents and fellows conceptualization of the anatomical relationships between different cerebral structures during that procedure. We suggest in comparison to cadaveric dissection, such virtual models represent a cost effective pedagogical methodology providing excellent support for anatomical learning and surgical technique training. Copyright © 2012 Elsevier Ltd. All rights reserved.

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.

The Anatomical Institute at the University of Greifswald during National Socialism: The procurement of bodies and their use for anatomical purposes.

Science.gov (United States)

Alvermann, Dirk; Mittenzwei, Jan

2016-05-01

This is the first comprehensive account of body procurement at the Anatomical Institute at Greifswald University during National Socialism (NS). As in all other German anatomical departments, the bodies received during this period included increasing numbers of victims of the NS regime. Prior to 1939, 90% of all bodies came from hospitals, state nursing homes and mental institutions (Heil- und Pflegeanstalten), but dropped to less than 30% after 1941. While the total catchment area for body procurement decreased, the number of suppliers increased and included prisons, POW camps, Gestapo offices and military jurisdiction authorities. Among the 432 documented bodies delivered to the institute, 132 came from state nursing homes and mental institutions, mainly from Ueckermünde. These were bodies of persons, who probably were victims of "euthanasia" crimes. The Anatomical Institute also procured 46 bodies of forced laborers, of whom at least twelve had been executed. Other groups of victims included 21 bodies of executed Wehrmacht soldiers and 16 Russian prisoners of war from the camp Stalag II C in Greifswald, who had died of starvation and exhaustion. From 1941 onwards, the number of bodies delivered from prisons and penitentiaries greatly increased. In total, 60 bodies of prisoners, mainly from the penitentiary in Gollnow, were delivered to the Anatomical Institute. Greifswald Anatomical Institute was not just a passive recipient of bodies from all of these sources, but the anatomists actively lobbied with the authorities for an increased body supply for teaching and research purposes. Copyright © 2016 Elsevier GmbH. All rights reserved.

Safe Corridor to Access Clivus for Endoscopic Trans-Sphenoidal Surgery: A Radiological and Anatomical Study.

Directory of Open Access Journals (Sweden)

Ye Cheng

Full Text Available Penetration of the clivus is required for surgical access of the brain stem. The endoscopic transclivus approach is a difficult procedure with high risk of injury to important neurovascular structures. We undertook a novel anatomical and radiological investigation to understand the structure of the clivus and neurovascular structures relevant to the extended trans-nasal trans-sphenoid procedure and determine a safe corridor for the penetration of the clivus.We examined the clivus region in the computed tomographic angiography (CTA images of 220 adults, magnetic resonance (MR images of 50 adults, and dry skull specimens of 10 adults. Multiplanar reconstruction (MPR of the CT images was performed, and the anatomical features of the clivus were studied in the coronal, sagittal, and axial planes. The data from the images were used to determine the anatomical parameters of the clivus and neurovascular structures, such as the internal carotid artery and inferior petrosal sinus.The examination of the CTA and MR images of the enrolled subjects revealed that the thickness of the clivus helped determine the depth of the penetration, while the distance from the sagittal midline to the important neurovascular structures determined the width of the penetration. Further, data from the CTA and MR images were consistent with those retrieved from the examination of the cadaveric specimens.Our findings provided certain pointers that may be useful in guiding the surgery such that inadvertent injury to vital structures is avoided and also provided supportive information for the choice of the appropriate endoscopic equipment.

The anatomy and isometry of a quasi-anatomical reconstruction of the medial patellofemoral ligament.

Science.gov (United States)

Pérez-Prieto, Daniel; Capurro, Bruno; Gelber, Pablo E; Ginovart, Gerard; Reina, Francisco; Sanchis-Alfonso, Vicente; Monllau, Joan C

2017-08-01

To describe the anatomy of the medial patellofemoral ligament (MPFL) and its relationship to the Adductor Magnus (AM) tendon as well as the behaviour exhibited in length changes during knee flexion. Ten cadaveric knees were dissected. The length from the superior and inferior patellar origin of the MPFL to its femoral insertion was measured at different degrees of knee flexion (0°, 30°, 60°, 90° and 120°). The same measures were made from both patellar origins of the MPFL up to the femoral insertion of the AM. The distance between the insertion of the AM and the Hunter canal was also measured. In general, isometry up to 90° was seen in all measures of the MPFL and those of the AM. The most isometric behaviour was seen in 2 measures: the length of the AM femoral insertion up to the inferior origin of the MPFL on the patella and the length of the femoral insertion of the MPFL up to the inferior origin of the MPFL on the patella. Similar behaviour was seen regardless of the anatomical or quasi-anatomical femoral point of attachment (n.s.). The distance from the AM tendon to the Hunter canal had a mean value of 78.6 mm (SD 9.4 mm). The behaviour exhibited during the changes in the length of the anatomical femoral footprint of the MPFL and the AM is similar. Neurovascular structures were not seen at risk. This is relevant in the daily clinical practice since the AM tendon might be a suitable point of insertion for MPFL reconstruction.

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.

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.

The Science and Politics of Naming: Reforming Anatomical Nomenclature, ca. 1886-1955.

Science.gov (United States)

Buklijas, Tatjana

2017-04-01

Anatomical nomenclature is medicine's official language. Early in their medical studies, students are expected to memorize not only the bodily geography but also the names for all the structures that, by consensus, constitute the anatomical body. The making and uses of visual maps of the body have received considerable historiographical attention, yet the history of production, communication, and reception of anatomical names-a history as long as the history of anatomy itself-has been studied far less. My essay examines the reforms of anatomical naming between the first modern nomenclature, the 1895 Basel Nomina Anatomica (BNA), and the 1955 Nomina Anatomica Parisiensia (NAP, also known as PNA), which is the basis for current anatomical terminology. I focus on the controversial and ultimately failed attempt to reform anatomical nomenclature, known as Jena Nomina Anatomica (INA), of 1935. Discussions around nomenclature reveal not only how anatomical names are made and communicated, but also the relationship of anatomy with the clinic; disciplinary controversies within anatomy; national traditions in science; and the interplay between international and scientific disciplinary politics. I show how the current anatomical nomenclature, a successor to the NAP, is an outcome of both political and disciplinary tensions that reached their peak before 1945. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Deformable meshes for medical image segmentation accurate automatic segmentation of anatomical structures

CERN Document Server

Kainmueller, Dagmar

2014-01-01

? Segmentation of anatomical structures in medical image data is an essential task in clinical practice. Dagmar Kainmueller introduces methods for accurate fully automatic segmentation of anatomical structures in 3D medical image data. The author's core methodological contribution is a novel deformation model that overcomes limitations of state-of-the-art Deformable Surface approaches, hence allowing for accurate segmentation of tip- and ridge-shaped features of anatomical structures. As for practical contributions, she proposes application-specific segmentation pipelines for a range of anatom

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 ...

Feature-based morphometry: discovering group-related anatomical patterns.

Science.gov (United States)

Toews, Matthew; Wells, William; Collins, D Louis; Arbel, Tal

2010-02-01

This paper presents feature-based morphometry (FBM), a new fully data-driven technique for discovering patterns of group-related anatomical structure in volumetric imagery. In contrast to most morphometry methods which assume one-to-one correspondence between subjects, FBM explicitly aims to identify distinctive anatomical patterns that may only be present in subsets of subjects, due to disease or anatomical variability. The image is modeled as a collage of generic, localized image features that need not be present in all subjects. Scale-space theory is applied to analyze image features at the characteristic scale of underlying anatomical structures, instead of at arbitrary scales such as global or voxel-level. A probabilistic model describes features in terms of their appearance, geometry, and relationship to subject groups, and is automatically learned from a set of subject images and group labels. Features resulting from learning correspond to group-related anatomical structures that can potentially be used as image biomarkers of disease or as a basis for computer-aided diagnosis. The relationship between features and groups is quantified by the likelihood of feature occurrence within a specific group vs. the rest of the population, and feature significance is quantified in terms of the false discovery rate. Experiments validate FBM clinically in the analysis of normal (NC) and Alzheimer's (AD) brain images using the freely available OASIS database. FBM automatically identifies known structural differences between NC and AD subjects in a fully data-driven fashion, and an equal error classification rate of 0.80 is achieved for subjects aged 60-80 years exhibiting mild AD (CDR=1). Copyright (c) 2009 Elsevier Inc. All rights reserved.

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.

Intraoperative cone-beam computed tomography and multi-slice computed tomography in temporal bone imaging for surgical treatment.

Science.gov (United States)

Erovic, Boban M; Chan, Harley H L; Daly, Michael J; Pothier, David D; Yu, Eugene; Coulson, Chris; Lai, Philip; Irish, Jonathan C

2014-01-01

Conventional computed tomography (CT) imaging is the standard imaging technique for temporal bone diseases, whereas cone-beam CT (CBCT) imaging is a very fast imaging tool with a significant less radiation dose compared with conventional CT. We hypothesize that a system for intraoperative cone-beam CT provides comparable image quality to diagnostic CT for identifying temporal bone anatomical landmarks in cadaveric specimens. Cross-sectional study. University tertiary care facility. Twenty cadaveric temporal bones were affixed into a head phantom and scanned with both a prototype cone-beam CT C-arm and multislice helical CT. Imaging performance was evaluated by 3 otologic surgeons and 1 head and neck radiologist. Participants were presented images in a randomized order and completed landmark identification questionnaires covering 21 structures. CBCT and multislice CT have comparable performance in identifying temporal structures. Three otologic surgeons indicated that CBCT provided statistically equivalent performance for 19 of 21 landmarks, with CBCT superior to CT for the chorda tympani and inferior for the crura of the stapes. Subgroup analysis showed that CBCT performed superiorly for temporal bone structures compared with CT. The radiologist rated CBCT and CT as statistically equivalent for 18 of 21 landmarks, with CT superior to CBCT for the crura of stapes, chorda tympani, and sigmoid sinus. CBCT provides comparable image quality to conventional CT for temporal bone anatomical sites in cadaveric specimens. Clinical applications of low-dose CBCT imaging in surgical planning, intraoperative guidance, and postoperative assessment are promising but require further investigation.

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

Magnetic resonance cisternography for preoperative evaluation of arachnoid cysts

Energy Technology Data Exchange (ETDEWEB)

Awaji, M. [Niigata University, Department of Radiology, Faculty of Medicine, Niigata (Japan); Okamoto, K. [Niigata University, Center for Integrated Human Brain Science, Brain Research Institute, Niigata (Japan); Nishiyama, K. [Niigata University, Department of Neurosurgery, Brain Research Institute, Niigata (Japan)

2007-09-15

With a high likelihood of clinical improvement and low rates of complications, minimally invasive neuroendoscopic surgery is becoming the treatment of choice for symptomatic or growing arachnoid cysts. In neuroendoscopic surgery, visualization of anatomical landmarks is essential in achieving successful fenestration without complications. Because of the restricted visual field in neuroendoscopic surgery, preoperative anatomical assessment is very helpful. Magnetic resonance cisternography (MRC) with high spatial resolution and contrast, using for example 3-D Fourier transformation constructive interference in steady state (CISS) or fast imaging employing steady-state acquisition (FIESTA) sequences, is able to detect the arachnoid cyst wall and neighboring anatomical structures as the anatomical landmarks. We retrospectively reviewed T2-weighted (T2-W) fast spin-echo images, and the MRC and intraoperative findings. Axial and coronal T2-W images (6 and 3 mm thickness, respectively) and axial and coronal 0.8 mm thick MRC images with CISS or FIESTA were obtained from four patients with arachnoid cysts treated by neuroendoscopic surgery. Intraoperative findings were reviewed on videotape recorded during the procedures. At the brain surface, the arachnoid cyst wall could be detected clearly in any of the four patients on MRC images, and was only partly seen in the fourth patient T2-W images. Adjacent important anatomical structures including vessels and cranial nerves, and an enough space for cystocisternostomy were identified on MRC images, and the findings were consistent with the findings during neuroendoscopic surgery. Preoperative identification of the arachnoid cyst wall and surrounding anatomical structures by MRC may help avoid complications and allow safer neuroendoscopic surgery. (orig.)

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. Conclusions: Relaxing retinectomies for retinal shortening can improve the anatomical success rate in patients with complex RD. (author)

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 ...

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

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

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

The Intermingled History of Occupational Therapy and Anatomical Education: A Retrospective Exploration

Science.gov (United States)

Carroll, Melissa A.; Lawson, Katherine

2014-01-01

Few research articles have addressed the anatomical needs of entry-level occupational therapy students. Given this paucity of empirical evidence, there is a lack of knowledge regarding anatomical education in occupational therapy. This article will primarily serve as a retrospective look at the inclusion of anatomical education in the occupational…

Comparative histology of mouse, rat, and human pelvic ligaments.

Science.gov (United States)

Iwanaga, Ritsuko; Orlicky, David J; Arnett, Jameson; Guess, Marsha K; Hurt, K Joseph; Connell, Kathleen A

2016-11-01

The uterosacral (USL) and cardinal ligaments (CL) provide support to the uterus and pelvic organs, and the round ligaments (RL) maintain their position in the pelvis. In women with pelvic organ prolapse (POP), the connective tissue, smooth muscle, vasculature, and innervation of the pelvic support structures are altered. Rodents are commonly used animal models for POP research. However, the pelvic ligaments have not been defined in these animals. In this study, we hypothesized that the gross anatomy and histological composition of pelvic ligaments in rodents and humans are similar. We performed an extensive literature search for anatomical and histological descriptions of the pelvic support ligaments in rodents. We also performed anatomical dissections of the pelvis to define anatomical landmarks in relation to the ligaments. In addition, we identified the histological components of the pelvic ligaments and performed quantitative analysis of the smooth muscle bundles and connective tissue of the USL and RL. The anatomy of the USL, CL, and RL and their anatomical landmarks are similar in mice, rats, and humans. All species contain the same cellular components and have similar histological architecture. However, the cervical portion of the mouse USL and RL contain more smooth muscle and less connective tissue compared with rat and human ligaments. The pelvic support structures of rats and mice are anatomically and histologically similar to those of humans. We propose that both mice and rats are appropriate, cost-effective models for directed studies in POP research.

Anthropometric Renal Anatomic Alterations Between Supine and Prone Positions in Percutaneous Renal Ablation for Renal Cortical Neoplasms.

Science.gov (United States)

Lusch, Achim; Fujimoto, Scott; Findeiss, Laura K; Okhunov, Zhamshid; McDougall, Elspeth M; Landman, Jaime

2016-02-01

To establish patterns of anatomic changes relevant to the kidney and colon during positional change between the supine and prone positions as noted on CT scans performed during percutaneous cryoablation for renal cortical neoplasms (RCN). Nineteen patients undergoing percutaneous cryoablation for RCN with abdominal CT scan in both the supine and prone positions were included in the study. We documented the anterior/posterior, medial/lateral, and cranial/caudal anatomic changes of the kidney, kidney rotation, and the proportion of the kidney whose access was limited by the liver, spleen, and lung. We also calculated the length of the percutaneous access tract and the distance between the colon and kidney in hilar position as well as the anterior/posterior location of the colon relative to the kidney. In the prone position, the kidney lies significantly more anteriorly on both sides: 4.7 cm vs 4.3 cm (L) and 4.4 cm vs 4.1 cm (R) (p = 0.02 and p = 0.03, respectively). On prone CT images, both kidneys are more cranial when compared with the supine position: 80.4 mm vs 60.8 mm (L) and 87.2 mm vs 57.4 mm (R) (p = 0.002 and p anatomic alterations between supine and prone CT imaging. The changes associated with the prone position modify percutaneous access, particularly for right upper pole tumors. Prone imaging before surgery may be helpful in selected cases.

Customer satisfaction in anatomic pathology. A College of American Pathologists Q-Probes study of 3065 physician surveys from 94 laboratories.

Science.gov (United States)

Zarbo, Richard J; Nakhleh, Raouf E; Walsh, Molly

2003-01-01

relevant information, teaching conferences and courses, notification of significant abnormal results, and timeliness of reporting). The database of 3065 physician surveys was derived from 94 laboratories. An average of 32.6 surveys (median 30) was returned per institution, with a range of 5 to 50 surveys per institution. The mean response rate was 35.6% (median 32.5%). The median (50th percentile) laboratory had an overall median satisfaction score of 4.4. The lowest satisfaction scores that were obtained all related to poor communication, which included timeliness of reporting, communication of relevant information, and notification of significant abnormal results. Statistically significant associations of customer satisfaction with certain institutional characteristics and laboratory performance improvement activities were identified. The importance of this satisfaction survey lies not in its requirement as an exercise for accrediting agencies but in understanding the needs of the customer (in this case the physician) to direct performance improvement in the delivery of quality anatomic pathology laboratory services.

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.

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

Evolution of wood anatomical characters in Nepenthes and close relatives of Caryophyllales.

Science.gov (United States)

Schwallier, Rachel; Gravendeel, Barbara; de Boer, Hugo; Nylinder, Stephan; van Heuven, Bertie Joan; Sieder, Anton; Sumail, Sukaibin; van Vugt, Rogier; Lens, Frederic

2017-05-01

Nepenthes attracts wide attention with its spectacularly shaped carnivorous pitchers, cultural value and horticultural curiosity. Despite the plant's iconic fascination, surprisingly little anatomical detail is known about the genus beyond its modified leaf tip traps. Here, the wood anatomical diversity of Nepenthes is explored. This diversity is further assessed with a phylogenetic framework to investigate whether the wood characters within the genus are relevant from an evolutionary or ecological perspective, or rather depend on differences in developmental stages, growth habits, substrates or precipitation. Observations were performed using light microscopy and scanning electron microscopy. Ancestral states of selected wood and pith characters were reconstructed using an existing molecular phylogeny for Nepenthes and a broader Caryophyllales framework. Pairwise comparisons were assessed for possible relationships between wood anatomy and developmental stages, growth habits, substrates and ecology. Wood anatomy of Nepenthes is diffuse porous, with mainly solitary vessels showing simple, bordered perforation plates and alternate intervessel pits, fibres with distinctly bordered pits (occasionally septate), apotracheal axial parenchyma and co-occurring uni- and multiseriate rays often including silica bodies. Precipitation and growth habit (stem length) are linked with vessel density and multiseriate ray height, while soil type correlates with vessel diameter, vessel element length and maximum ray width. For Caryophyllales as a whole, silica grains, successive cambia and bordered perforation plates are the result of convergent evolution. Peculiar helical sculpturing patterns within various cell types occur uniquely within the insectivorous clade of non-core Caryophyllales. The wood anatomical variation in Nepenthes displays variation for some characters dependent on soil type, precipitation and stem length, but is largely conservative. The helical-banded fibre

Evaluation of 3D printed anatomically scalable transfemoral prosthetic knee.

Science.gov (United States)

Ramakrishnan, Tyagi; Schlafly, Millicent; Reed, Kyle B

2017-07-01

This case study compares a transfemoral amputee's gait while using the existing Ossur Total Knee 2000 and our novel 3D printed anatomically scalable transfemoral prosthetic knee. The anatomically scalable transfemoral prosthetic knee is 3D printed out of a carbon-fiber and nylon composite that has a gear-mesh coupling with a hard-stop weight-actuated locking mechanism aided by a cross-linked four-bar spring mechanism. This design can be scaled using anatomical dimensions of a human femur and tibia to have a unique fit for each user. The transfemoral amputee who was tested is high functioning and walked on the Computer Assisted Rehabilitation Environment (CAREN) at a self-selected pace. The motion capture and force data that was collected showed that there were distinct differences in the gait dynamics. The data was used to perform the Combined Gait Asymmetry Metric (CGAM), where the scores revealed that the overall asymmetry of the gait on the Ossur Total Knee was more asymmetric than the anatomically scalable transfemoral prosthetic knee. The anatomically scalable transfemoral prosthetic knee had higher peak knee flexion that caused a large step time asymmetry. This made walking on the anatomically scalable transfemoral prosthetic knee more strenuous due to the compensatory movements in adapting to the different dynamics. This can be overcome by tuning the cross-linked spring mechanism to emulate the dynamics of the subject better. The subject stated that the knee would be good for daily use and has the potential to be adapted as a running knee.

Incidencia del foramen retromolar en mandibulas humanas: aspectos étnicos y clínicos

OpenAIRE

Rossi, Ana Claudia; Freire, Alexandre Rodrigues; Prado, Guilherme Bevilacqua; Prado, Felippe Bevilacqua; Botacin, Paulo Roberto [UNESP; Ferreira Caria, Paulo Henrique

2012-01-01

The retromolar foramen allows the passage of the neurovascular bundles that contribute to nutrition and innervation of the pulp and periodontium of the lower teeth. Knowledge of this anatomical variation may prevent complications in the anesthesia and surgical procedures in this area and serve as an anatomical landmark for ethnic identification. The aim of this study was to evaluate the impact of the retromolar foramen in human mandibles of adult Brazilians and discuss the clinical and ethnic...

Anatomical image-guided fluorescence molecular tomography reconstruction using kernel method

Science.gov (United States)

Baikejiang, Reheman; Zhao, Yue; Fite, Brett Z.; Ferrara, Katherine W.; Li, Changqing

2017-01-01

Abstract. Fluorescence molecular tomography (FMT) is an important in vivo imaging modality to visualize physiological and pathological processes in small animals. However, FMT reconstruction is ill-posed and ill-conditioned due to strong optical scattering in deep tissues, which results in poor spatial resolution. It is well known that FMT image quality can be improved substantially by applying the structural guidance in the FMT reconstruction. An approach to introducing anatomical information into the FMT reconstruction is presented using the kernel method. In contrast to conventional methods that incorporate anatomical information with a Laplacian-type regularization matrix, the proposed method introduces the anatomical guidance into the projection model of FMT. The primary advantage of the proposed method is that it does not require segmentation of targets in the anatomical images. Numerical simulations and phantom experiments have been performed to demonstrate the proposed approach’s feasibility. Numerical simulation results indicate that the proposed kernel method can separate two FMT targets with an edge-to-edge distance of 1 mm and is robust to false-positive guidance and inhomogeneity in the anatomical image. For the phantom experiments with two FMT targets, the kernel method has reconstructed both targets successfully, which further validates the proposed kernel method. PMID:28464120

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.

Panagraphic study of maxillofacial region

International Nuclear Information System (INIS)

You, Dong Soo

1973-01-01

The author has studied maxillo-facial anatomical landmarks using Status X with two methods. The one has performed by application of contrast media on the human dry skull, the other has performed on living human skull as control group. Comparing the panagraphs taken by two methods, the author has drawn following results: 1. The panagraphs revealed the undistorted highly sharp panoramic shadows of each jaw on a film. 2. Diminishing the inserted anode tube to 4 cm (focal incisor distance 3 cm), overlapping-free representation of the in terdental spaces of the premolars and anterior teeth was taken. 3. Alternating the head position of the objects, direction of anode tube and film placing, the shadows of temporomandibular joint and zygomatic arch were taken without overlapping the other bone tissues. 4. In the panagraphs applied various shaped contrast media to each anatomical landmark, a radio-anatomical atlas which is necessary to interpret various bone tissues was taken. 5. In order to interpret panagraphic shadows easily, the author has tried this study by comparing the films of the living human skull with the films of the human dry skull applied contrast media.

Radiation fibrosis : differentiation from true hilar mass on plain chest film

International Nuclear Information System (INIS)

Baik, Jun Hyun; Ahn, Kook Jin; Park, Seog Hee; Shinn, Kyung Sub

1996-01-01

Radiation-induced fibrotic mass might masquerade as a true hilar tumor mass on a plain chest radiograph. We attempted to differentiate radiation fibrosis from a true hilar tumor using only a plain radiograph. Plain chest radiographs were obtained from seven patients who had developed radiation fibrosis simulating hilar mass after radiation therapy for lung cancer, and from 19 patients with lung cancer, a comparison group, who had not received radiation therapy. They were reviewed for the obliteration of the overlapped mediastinal and hilar anatomical silhouettes by the mass : pulmonary artery, heart or aorta border, and paraspinal line. All seven patients with radiation-induced fibrotic mass(bilateral lesion in two patients) showed obliteration of all three overlapped anatomical silhouettes of the mediastinum and hilum on chest radiographs. In the comparison group of 19 patients with a true hilar mass, there was, however, no case which demonstrated obliteration of all landmarks, Obliteration of all anatomical landmarks at the hilum and mediastinum may be a helpful clue in the differential diagnosis of radiation-induced fibrotic mass from true hilar mass on a plain radiograph, particularly when clinical information on previous radiation therapy is unavailable

Panagraphic study of maxillofacial region

Energy Technology Data Exchange (ETDEWEB)

You, Dong Soo [School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

1973-11-15

The author has studied maxillo-facial anatomical landmarks using Status X with two methods. The one has performed by application of contrast media on the human dry skull, the other has performed on living human skull as control group. Comparing the panagraphs taken by two methods, the author has drawn following results: 1. The panagraphs revealed the undistorted highly sharp panoramic shadows of each jaw on a film. 2. Diminishing the inserted anode tube to 4 cm (focal incisor distance 3 cm), overlapping-free representation of the in terdental spaces of the premolars and anterior teeth was taken. 3. Alternating the head position of the objects, direction of anode tube and film placing, the shadows of temporomandibular joint and zygomatic arch were taken without overlapping the other bone tissues. 4. In the panagraphs applied various shaped contrast media to each anatomical landmark, a radio-anatomical atlas which is necessary to interpret various bone tissues was taken. 5. In order to interpret panagraphic shadows easily, the author has tried this study by comparing the films of the living human skull with the films of the human dry skull applied contrast media.

A computed tomographic anatomical study of the upper sacrum. Application for a user guide of pelvic fixation with iliosacral screws in adult spinal deformity.

Science.gov (United States)

Dubory, Arnaud; Bouloussa, Houssam; Riouallon, Guillaume; Wolff, Stéphane

2017-12-01

Widely used in traumatic pelvic ring fractures, the iliosacral (IS) screw technique for spino-pelvic fixation remains anecdotal in adult spinal deformity. The objective of this study was to assess anatomical variability of the adult upper sacrum and to provide a user guide of spino-pelvic fixation with IS screws in adult spinal deformity. Anatomical variability of the upper sacrum according to age, gender, height and weight was sought on 30 consecutive pelvic CT-scans. Thus, a user guide of spino-pelvic fixation with IS screws was modeled and assessed on ten CT-scans as described below. Two invariable landmarks usable during the surgical procedure were defined: point A (corresponding to the connector binding the IS screw to the spinal rod), equidistant from the first posterior sacral hole and the base of the S1 articular facet and 10 mm-embedded into the sacrum; point B (corresponding to the tip of the IS screw) located at the junction of the anterior third and middle third of the sacral endplate in the sagittal plane and at the middle of the endplate in the coronal plane. Point C corresponded to the intersection between the A-B direction and the external facet of the iliac wing. Three-dimensional reconstructions modeling the IS screw optimal direction according to the A-B-C straight line were assessed. Age had no effect on the anatomy of the upper sacrum. The distance between the base of the S1 superior articular facet and the top of the first posterior sacral hole was correlated with weight (r = 0.6; 95% CI [0.6-0.9]); p guide of spinopelvic fixation with IS screws seems to be reliable and reproducible independently of age, gender and morphologic characteristics but needs clinical assessment. Level IV.