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1

Detecting corpus callosum abnormalities in autism based on anatomical landmarks  

Science.gov (United States)

Autism is a severe developmental disorder whose neurological basis is largely unknown. Autism is a subtype of autism that displays more homogeneous features within group. The aim of this study was to identify the shape differences of the corpus callosum between patients with autism and the controls. Anatomical landmarks were collected from mid-sagittal MRI of 25 patients and 18 controls. Euclidean distance matrix analysis and thin-plate spline were used to analyze the landmark forms. Point-by-point shape comparison was performed both globally and locally. A new local shape comparison scheme was proposed which compared each part of the shape in its local coordinate system. Point correspondence was established among individual shapes based on the inherent landmark correspondence. No significant difference was found in the landmark form between patients and controls, but the distance between interior genu and posterior most was found significantly shorter in patients. Thin-plate spline analysis showed significant group difference between the landmark configurations in terms of the deformation from the overall mean configuration. Significant global shape differences were found in the anterior lower body and posterior bottom, and local shape difference existed in the anterior bottom. This study can serve as both clinical reference and a detailed procedure guideline for similar studies in the future.

He, Qing; Duan, Ye; Karsch, Kevin; Miles, Judith

2010-01-01

2

Detecting corpus callosum abnormalities in autism based on anatomical landmarks  

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Autism is a severe developmental disorder whose neurological basis is largely unknown. Autism is a subtype of autism that displays more homogeneous features within group. The aim of this study was to identify the shape differences of the corpus callosum between patients with autism and the controls. Anatomical landmarks were collected from mid-sagittal MRI of 25 patients and 18 controls. Euclidean distance matrix analysis and thin-plate spline were used to analyze the landmark forms. Point-by...

He, Qing; Duan, Ye; Karsch, Kevin; Miles, Judith

2010-01-01

3

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

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

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

2004-06-21

4

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

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

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

2007-06-15

5

[Lymphoscintigrams with anatomical landmarks obtained with vector graphics].  

Science.gov (United States)

Nuclear medicine images are difficult to interpret because they do not include anatomical details. The aim of this study was to obtain lymphoscintigrams with anatomical landmarks that could be easily interpreted by General Physicians. Traditional lymphoscintigrams were processed with Adobe© Photoshop® CS6 and converted into vector images created by Illustrator®. The combination with a silhouette vector improved image interpretation, without resulting in longer radiation exposure or acquisition times. PMID:23096740

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

2012-11-01

6

Cardiac Conduction System: Delineation of Anatomic Landmarks With Multidetector CT  

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

Farhood Saremi

2009-11-01

7

Estimation of the central position of the prostate-gland based on anatomical landmarks in X-ray CT images  

International Nuclear Information System (INIS)

Robust segmentation of pelvic organ in non-contrast CT image has been required for developing computer-aided diagnosis systems. We proposed a method to normalize the position of the pelvis based on anatomical point (LM) of pelvic bones and use those LMs to estimate central position of prostate-gland in CT images in preview works. However, the evaluation of LM placement and procedure was insufficient. In this study, we aim to investigate the effective LM location and the apply different methods for identifying the prostate center positions. In the experiment, we applied three methods to 75 cases of CT images using the different number of LMs. The distances between the estimated central positions of the prostate to the human input was regarded as estimation error. The result showed that the average estimation-error of the prostate central positions was about 5 [mm] when using 12 LMs. Furthermore, we confirmed that the estimated center coordinates of the prostate exist within the prostate-gland regions in all CT cases. (author)

2010-07-30

8

Cardiac Conduction System: Delineation of Anatomic Landmarks With Multidetector CT  

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Major components of the cardiac conduction system including the sinoatrial node (SAN), atrioventricular node (AVN), the His Bundle, and the right and left bundle branches are too small to be directly visualized by multidetector CT (MDCT) given the limited spatial resolution of current scanners. However, the related anatomic landmarks and variants of this system a well as the areas with special interest to electrophysiologists can be reliably demonstrated by MDCT. Some of these structures and ...

2009-01-01

9

Safe Treatment of Trigger Thumb With Longitudinal Anatomic Landmarks  

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Objective: Stenosing tenosynovitis of the thumb flexor tendon sheath is also known as trigger thumb. It is an inflammatory process that involves the flexor tendon sheath at the A1 pulley. Successful percutaneous or open treatment of trigger thumb depends on the ability of the clinician to properly predict the location of the A1 pulley. Longitudinal anatomic landmarks can facilitate safe treatment for the trigger thumb while circumventing injury to the neurovascular bundles. Methods: Fourteen ...

Hazani, Ron; Elston, Josh; Whitney, Ryan D.; Redstone, Jeremiah; Chowdhry, Saeed; Wilhelmi, Bradon J.

2010-01-01

10

The use of anatomical landmarks for percutaneous nephrolithotomy  

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Full Text Available Objective: The aim of our study was to describe the external anatomical landmarks and angles as a training guide for urologists in the performance of percutaneous nephrolithotomy (PCNL in the prone position. Materials and Methods: Between 2006 and 2008, 50 patients (including 10 resident cases undergoing PCNL met the study criteria. The inclusion criteria consisted of patients with renal stones scheduled for a lower calyceal puncture PCNL where the number of attempts to access the calyx ? 3, and clear urine was seen draining from the needle. The exclusion criteria consisted of previous ipsilateral kidney surgery, severe hydronephrosis, anomalies of the renal or skeletal systems, BMI>30 kg/m2, upper/middle calyceal puncture and age ?18. Several anatomical landmarks and angles were measured, recorded and analyzed. Results: The mean length of (Pi was 10.1±1.7 cm (range 7-14, (Pe was 9.9±1.7 cm (range 6-13, (a was 11.2±2.8 cm (range 5.5-17, (b was 5.3±2.3 cm (range 1.5-11 cm, (x was 5.1±1.9 cm (range 1-8, (x1 was 3.3±1.7 cm (range 1.5-8.2, (y was 7.1±1.7 cm (range 3.3-11.6, (y1 was 3.8±1.6 cm (range 1-9 and (t was 4.9±1.7 cm (range 3-9. The mean angle for (a was 49±13º (range 30-70º, (b was 41±13º (range 20-70º and (g was 61±13º (range 28-80º. In resident cases, the median number of attempts was 1 (range 1-3, the median overall time for successful access was 7.25 minutes (range 2-12 and the median fl uoroscopy time was 62.5 seconds (range 30-150. Conclusion: A knowledge of these anatomical landmarks and angles may increase the capacity of urologists to repetitively perform the precise task of percutaneous access of the lower calyceal during PCNL.

Esat Kaan Akbay

2012-06-01

11

Landmarks.  

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This theme issue on landmarks includes annotated listings of Web sites, CDROMs and computer software, videos, books, and additional resources that deal with landmarksnatural and manmade, ancient and modern, architectural and politicaland why they are important. Sidebars discuss fallen landmarks, landmark speeches, and linking landmarks. (AEF)

Online-Offline, 1999

1999-01-01

12

Detection and location of 127 anatomical landmarks in diverse CT datasets  

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The automatic detection and localization of anatomical landmarks has wide application, including intra and interpatient registration, study location and navigation, and the targeting of specialized algorithms. In this paper, we demonstrate the automatic detection and localization of 127 anatomically defined landmarks distributed throughout the body, excluding arms. Landmarks are defined on the skeleton, vasculature and major organs. Our approach builds on the classification forests method,1 using this classifier with simple image features which can be efficiently computed. For the training and validation of the method we have used 369 CT volumes on which radiographers and anatomists have marked ground truth (GT) - that is the locations of all defined landmarks occurring in that volume. A particular challenge is to deal with the wide diversity of datasets encountered in radiology practice. These include data from all major scanner manufacturers, different extents covering single and multiple body compartments, truncated cardiac acquisitions, with and without contrast. Cases with stents and catheters are also represented. Validation is by a leave-one-out method, which we show can be efficiently implemented in the context of decision forest methods. Mean location accuracy of detected landmarks is 13.45mm overall; execution time averages 7s per volume on a modern server machine. We also present localization ROC analysis to characterize detection accuracy - that is to decide if a landmark is or is not present in a given dataset.

Dabbah, Mohammad A.; Murphy, Sean; Pello, Hippolyte; Courbon, Romain; Beveridge, Erin; Wiseman, Stewart; Wyeth, Daniel; Poole, Ian

2014-03-01

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Are anatomical landmark measurements accurate for predicting endotracheal tube depth?  

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Full Text Available Background: A traditional method for depth of intubation in adult patients is taping the endotracheal tube (ETT at the upper incisors a distance of 21 or 23 cm for women and men respectively (21/23 method. A novel “topographical” measurement for estimating proper intubation depth has been suggested as a better depth predictor compared to the 21/23 method.   Objectives: To compare the 21/23 method to topographical measurements. Methods: 100 ASA physical status I-II patients scheduled for elective surgery were enrolled. The 21/23 method was initially utilized for intubation and the ETT tip to carina distance was then fiberoptically measured. Anatomical (topographical measurements were then obtained from each patient by adding the distance from the corner of the mouth to the mandibular angle to the distance from the mandibular angle to the center of the sternal notch and were recorded as the topographical intubation depth. Both measurements were assessed for percentage of ETTs that fell outside of our desired tip to carina range of 2-4 cm. Results: After the 21/23 method, 29% of ETTs fell outside our desired tip to carina range compared to 47% of ETTs with the topographical method (p=0.010. No correlation was found between the topographical measurements and airway length (upper incisors to vocal cords (r=0.248. Conclusions: Topographical measurements were not re-confirmed as an accurate intubation method and were found to be less reliable than the 21/23 method. We maintain that regardless of ETT insertion method utilized, the gold standard to ensure accurate ETT placement is fiberoptic inspection.

Devanand Mangar

2013-03-01

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Simplifying subclavian vein cannulation using innovative landmarks: a radiologic, anatomic, and clinical study.  

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The objective of this study was to investigate novel and optimal landmarks for subclavian vein (SV) cannulation. We conducted the study in three phases: (a) Various possible markers for SV cannulation were evaluated by anatomic measurements in patients from intensive care unit and the course of SV was evaluated by radiologic means; (b) Results acquired by the two means were compared and adjusted, then innovative landmarks and a new approach for SV cannulation was proposed; (c) The efficacy of new approach for SV cannulation was compared with that of a traditional one by a prospective, randomized, controlled study. Point A (the junction of the lateral border of sternocleidomastoideus clavicular head and inferior border of clavicle), point B (a point on the lower border of clavicle just above the middle of the line joining the coracoid process and midline of the body), and point D (where SV crosses the inferior border of clavicle) were close in proximity. Points A and B could be considered as innovative landmarks for SV cannulation. Beginners using the new method had significantly higher success rate (86.9% vs. 70.2%, p = 0.008); the time consumed by new method was significant shorter than that by traditional one (5.9 vs. 10.4 min, p = 0.001). Points A and B could be considered as landmarks for identifying puncture site for SV cannulation. Beginners using innovative landmarks for SV cannulation could significantly reduce operation time and increase success rate. PMID:22561227

Hu, Bin; Hu, Mei; Wang, Yan; Wang, Dao Wen

2012-01-01

15

Impact of different anatomical landmarks on registration in imaging-guided radiation for lung cancer  

International Nuclear Information System (INIS)

Objective: To evaluate the impact of different anatomical landmarks on registration in imaging-guided radiation (IGRT) for lung cancer. Methods: For 20 patients with non-small cell lung cancer receiving stereotactic body radiotherapy (SBRT) in Fudan University Cancer Hospital, 100 frames of kilo-voltage cone-beam computed tomography scanning were evaluated in this study. The spine, carina and tumor were selected as landmarks for registration, respectively. Results of registration using different landmarks were documented and compared. Results: The average set-up errors in the left-right, superior inferior and anterior-posterior directions were -0.08 cm ±0.32 cm, -0.16 cm ±0.45 cm and 0.06 cm ±0.23 cm with the spine for registration; 0.06 cm ±0.34 cm, -0.13 cm ±0.45 cm and -0.02 cm±0.23 cm with the carina; and -0.17 cm ±0.25 cm, 0.03 cm ±0.47 cm and 0.15 cm ±0.38 cm with tumor. The registration results between using the carina and tumor as landmarks were statistically significant different (q=4.61, P=0.002; q = 2.23 , P=0.118; q=3.44, P=0.017). The registration results were equal when using the spine and tumor as landmarks (q =1.85, P = 0.195; q = 2.54, P = 0.075; q = 1.89, P=0.185), as well as using the carina and tumor as landmarks (q=2.76, P=0.054; q=0.31, P=0.826; q=1.55, P=0.276). Conclusions: For early stage lung cancer, the spine and tumor can be used equally as registration landmarks in imaging-guided SBRT. The carina is not suggested for its poor reproducible position. (authors)

2010-11-01

16

Reliability of Bony Anatomic Landmark Asymmetry Assessment in the Lumbopelvic Region: Application to Osteopathic Medical Education  

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The objective of this review is to establish the current state of knowledge on the reliability of clinical assessment of asymmetry in the lumbar spine and pelvis. To search the literature, the authors consulted the databases of MEDLINE, CINAHL, AMED, MANTIS, Academic Search Complete, and Web of Knowledge using different combinations of the following keywords: palpation, asymmetry, inter- or intraex-aminer reliability, tissue texture, assessment, and anatomic landmark. Of the 23 studies identi...

2010-01-01

17

Anatomical Landmarks for Safe Elevation of the Deep Inferior Epigastric Perforator Flap: A Cadaveric Study  

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Background: Breast reconstruction techniques have focused increasingly on using autologous tissue, with emphasis being placed on employing muscle sparing adipocutaneous flaps to reduce abdominal wall complications such as hernias, bulges, weakness, and length of hospital stay. The result has been the emergence of the deep inferior epigastric perforator (DIEP) flap for breast reconstruction. Isolating perforator vessels challenges most surgeons. We describe surface anatomical landmarks to pred...

Chowdhry, Saeed; Hazani, Ron; Collis, Philip; Wilhelmi, Bradon J.

2010-01-01

18

Automatic recognition of surface landmarks of anatomical structures of back and posture  

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Faulty postures, scoliosis and sagittal plane deformities should be detected as early as possible to apply preventive and treatment measures against major clinical consequences. To support documentation of the severity of deformity and diminish x-ray exposures, several solutions utilizing analysis of back surface topography data were introduced. A novel approach to automatic recognition and localization of anatomical landmarks of the human back is presented that may provide more repeatable results and speed up the whole procedure. The algorithm was designed as a two-step process involving a statistical model built upon expert knowledge and analysis of three-dimensional back surface shape data. Voronoi diagram is used to connect mean geometric relations, which provide a first approximation of the positions, with surface curvature distribution, which further guides the recognition process and gives final locations of landmarks. Positions obtained using the developed algorithms are validated with respect to accuracy of manual landmark indication by experts. Preliminary validation proved that the landmarks were localized correctly, with accuracy depending mostly on the characteristics of a given structure. It was concluded that recognition should mainly take into account the shape of the back surface, putting as little emphasis on the statistical approximation as possible.

Micho?ski, Jakub; Glinkowski, Wojciech; Witkowski, Marcin; Sitnik, Robert

2012-05-01

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Anatomical landmarks for safe elevation of the deep inferior epigastric perforator flap: a cadaveric study.  

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Background: Breast reconstruction techniques have focused increasingly on using autologous tissue, with emphasis being placed on employing muscle sparing adipocutaneous flaps to reduce abdominal wall complications such as hernias, bulges, weakness, and length of hospital stay. The result has been the emergence of the deep inferior epigastric perforator (DIEP) flap for breast reconstruction. Isolating perforator vessels challenges most surgeons. We describe surface anatomical landmarks to predict the location of the deep inferior epigastric artery (DIEA) and its perforators to aid in the efficient elevation of this flap. Methods: Ten fresh hemi-abdomens were dissected with loupe magnification. The DIEA and its perforators were identified, and measurements in relation to the rectus muscle, xiphoid, umbilicus, and pubis were taken. Statistical analysis was undertaken to determine distance ratios to account for variance in patient size. Results: Average distance from the xiphoid to umbilicus was 18.2 +/- 1.27 cm. The distance from the umbilicus to pubis was 14.9 +/- 2.3 cm. The vertical distance from the umbilicus to the DRJ (DIEA rtctus junction) was 10.45 +/- 1.58 cm, and the vertical distance from the level of the umbilicus to where the first DIEA perforator traverses the RAM was 7.4 +/- 1.64 cm. The distance between the umbilicus and the DRJ is approximately 0.7 times the distance between the umbilicus and the pubic symphysis. The distance between the umbilicus and the first perforator is approximately 0.5 times the distance between the umbilicus and the pubic symphysis. Conclusions: Knowledge of anatomical landmarks can aid the surgeon in more efficiently harvesting the DIEP flap. Surface landmarks along the abdominal midline coupled with normalizing ratios can aid surgeons in predicting the location of the DIEA and its first perforator. The DIEA crosses the rectus at approximately two thirds of the distance between the umbilicus and pubis, and the first perforator can reliably be located at one half of this distance. PMID:20523907

Chowdhry, Saeed; Hazani, Ron; Collis, Philip; Wilhelmi, Bradon J

2010-01-01

20

Reappraisal of the anatomical landmarks of motor and premotor cortical regions for image-guided brain navigation in TMS practice.  

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Image-guided navigation systems dedicated to transcranial magnetic stimulation (TMS) have been recently developed and offer the possibility to visualize directly the anatomical structure to be stimulated. Performing navigated TMS requires a perfect knowledge of cortical anatomy, which is very variable between subjects. This study aimed at providing a detailed description of sulcal and gyral anatomy of motor cortical regions with special interest to the inter-individual variability of sulci. We attempted to identify the most stable structures, which can serve as anatomical landmarks for motor cortex mapping in navigated TMS practice. We analyzed the 3D reconstruction of 50 consecutive healthy adult brains (100 hemispheres). Different variants were identified regarding sulcal morphology, but several anatomical structures were found to be remarkably stable (four on dorsoventral axis and five on rostrocaudal axis). These landmarks were used to define a grid of 12 squares, which covered motor cortical regions. This grid was used to perform motor cortical mapping with navigated TMS in 12 healthy subjects from our cohort. The stereotactic coordinates (x-y-z) of the center of each of the 12 squares of the mapping grid were expressed into the standard Talairach space to determine the corresponding functional areas. We found that the regions whose stimulation produced almost constantly motor evoked potentials mainly correspond to the primary motor cortex, with rostral extension to premotor cortex and caudal extension to posterior parietal cortex. Our anatomy-based approach should facilitate the expression and the comparison of the results obtained in motor mapping studies using navigated TMS. PMID:24038518

Ahdab, Rechdi; Ayache, Samar S; Farhat, Wassim H; Mylius, Veit; Schmidt, Sein; Brugières, Pierre; Lefaucheur, Jean-Pascal

2014-05-01

 
 
 
 
21

Anatomy-guided discovery of large-scale consistent connectivity-based cortical landmarks.  

Science.gov (United States)

Establishment of structural and functional correspondences across different brains is one of the most fundamental issues in the human brain mapping field. Recently, several multimodal DTI/fMRI studies have demonstrated that consistent white matter fiber connection patterns can predict brain function and represent common brain architectures across individuals and populations, and along this direction, several approaches have been proposed to discover large-scale cortical landmarks with common structural connection profiles. However, an important limitation of previous approaches is that the rich anatomical information such as gyral/sulcal folding patterns has not been incorporated into the landmark discovery procedure yet. In this paper, we present a novel anatomy-guided discovery framework that defines and optimizes a dense map of cortical landmarks that possess group-wise consistent anatomical and fiber connectional profiles. This framework effectively integrates reliable and rich anatomical, morphological, and fiber connectional information for landmark initialization, optimization and prediction, which are formulated and solved as an energy minimization problem. Validation results based on fMRI data demonstrate that the identified 555 cortical landmarks are producible, predictable and exhibit accurate structural and functional correspondences across individuals and populations, offering a universal and individualized brain reference system for neuroimaging research. PMID:24505813

Jiang, Xi; Zhang, Tuo; Zhu, Dajiang; Li, Kaiming; Lv, Jinglei; Guo, Lei; Liu, Tianming

2013-01-01

22

Bony landmarks of the medial orbital wall: an anatomical study of ethmoidal foramina.  

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The study determines the distribution patterns of ethmoidal foramina (EF) evaluate how they are affected by gender or bilateral asymmetry, and highlights the surgical implications on the anatomical landmarks of the orbit. Two hundred and forty-nine dry orbits were assessed. The number and pattern of EF were determined and distances between the anterior lacrimal crest (ALC), anterior (AEF) middle (MEF), posterior (PEF) ethmoidal foramina and between PEF and the optic canal (OC) were measured. The patterns of EF were classified as type I (single foramen) in 4 orbits (1.6%), type II (double foramina) in 152 (61%), type III (triple foramina) in 71 (28.5%), and type IV (multiple foramina) in 22 orbits (16.4%). Two orbits were found with five EF and a single orbit with six EF. A significant gender difference was observed for ALC-AEF distance (P???0.03), in males 23.53?±?2.86 (20.67-26.39) versus females 22.51?±?3.72 (18.79-26.23) mm. Bilateral asymmetry was observed for ALC-AEF distance (P???0.01). The distances ALC-AEF and ALC-PEF varied significantly according to EF classification (P???0.03 and P???0.02). The navigation ratio from ALC-AEF, AEF-PEF, and PEF-OC, in Greek population was "23-10-4 mm". A variation in the number of EF was found, ranging from 1 to 6, with the first report of sextuple EF. Although measures were generally consistent across genders and side, there are significant differences across ethnicities. These findings suggest that surgeons must consider population differences in determining the anatomical landmarks and navigation points of the orbit. PMID:24000039

Piagkou, Maria; Skotsimara, Georgia; Dalaka, Aspasia; Kanioura, Eftychia; Korentzelou, Vasiliki; Skotsimara, Antonia; Piagkos, Giannoulis; Johnson, Elizabeth O

2014-05-01

23

Anatomical landmarks for safer carpal tunnel decompression: an experimental cadaveric study  

Science.gov (United States)

Background Carpal tunnel syndrome is a common presentation to surgical outpatient clinics. Treatment of carpal tunnel syndrome involves surgical division of the flexor retinaculum. Palmar and recurrent branches of the median nerve as well as the superficial palmar arch are at risk of damage. Methodology Thirteen cadavers of Sri Lankan nationality were selected. Cadavers with deformed or damaged hands were excluded. All selected cadavers were preserved with the conventional arterial method using formalin as the main preservative. Both hands of the cadavers were placed in the anatomical position and dissected carefully. We took pre- determined measurements using a vernier caliper. We hypothesized that the structures at risk during carpal tunnel decompression such as recurrent branch of the median nerve and superficial palmar arch can be protected if simple anatomical landmarks are identified. We also hypothesized that an avascular area exists in the flexor retinaculum, identification of which facilitates safe dissection with minimal intra operative bleeding. Therefore we attempted to characterize the anatomical extent of such an avascular area as well as anatomical landmarks for a safer carpal tunnel decompression. Ethical clearance was obtained for the study. Results In a majority of specimens the recurrent branch was a single trunk (n =20, 76.9%). Similarly 84.6% (n = 22) were extra ligamentous in location. Mean distance from the distal border of the TCL to the recurrent branch was 7.75 mm. Mean distance from the distal border of TCL to the superficial palmar arch was 11.48 mm. Mean length of the flexor retinaculum, as measured along the incision, was 27.00 mm. Mean proximal and distal width of the avascular area on TCL was 11.10 mm and 7.09 mm respectively. Conclusion We recommend incision along the radial border of the extended ring finger for carpal tunnel decompression. Extending the incision more than 8.16 mm proximally and 7.75 mm distally from the corresponding borders of the TCL should be avoided. Incision should be kept to a mean length of 27.0 mm, which corresponds to the length of TCL along the above axis. We also propose an avascular area along the TCL, identification of which minimizes blood loss.

2014-01-01

24

Arterial tree tracking from anatomical landmarks in magnetic resonance angiography scans  

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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.

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

2014-03-01

25

Automatic Evaluation of Landmarks for Image-Based Navigation Update  

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The successful mission of an autonomous airborne system like an unmanned aerial vehicle (UAV) strongly depends on its accurate navigation. While GPS is not always available and pose estimation based solely on Inertial Measurement Unit (IMU) drifts, image-based navigation may become a cheap and robust additional pose measurement device. For the actual navigation update a landmark-based approach is used. It is essential that the used landmarks are well chosen. Therefore we introduce an approach...

2009-01-01

26

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

Energy Technology Data Exchange (ETDEWEB)

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

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

27

Endoscopic Orientation of the Parasellar Region in Sphenoid Sinus with Ill-Defined Bony Landmarks: An Anatomic Study  

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The sphenoid bony landmarks are important for endoscopic orientation in skull base surgery but show a wide range of variations. We aimed to describe an instructional model for the endoscopic parasellar anatomy in sphenoid sinuses with ill-defined bony landmarks. Five preserved injected cadaveric heads and four sides of dry skulls were studied endoscopically via transethmoid, transsphenoidal approach. The parasellar region was exposed by drilling along the maxillary nerve (V2) canal [the lengt...

2010-01-01

28

A Landmark Based Position Estimation for Pinpoint Landing on Mars  

Science.gov (United States)

Real-time position estimation for a descent lander is a critical technological need for many of NASA's planned in situ missions including landing on a number of bodies at locations of greatest scientific interest and sample return. In particular, it enables the capability to land precisely and safely in a scientifically promising but hazardous site and is a key technology to be demonstrated by NASA in the next decade. The key challenge of pinpoint landing (PPL) is how to localize the lander by recognizing the landmarks (craters) in the landing area and match them positively to a preexisting landmark database while the spacecraft is descending. In this paper, a real-time landmark based position estimation technique for pinpoint landing is suggested. This system includes three crucial components: (1) real time landmark detection, (2) real-time landmark matching and (3) state (both position and velocity) estimation. We discuss the performance analysis of this system. Finally, we show that the suggested technology is able to deliver a spacecraft to less than 100 m from a pre-selected landing site on Mars.

Cheng, Yang; Ansar, Adnan

2005-01-01

29

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

International Nuclear Information System (INIS)

Purpose: To identify visible structures in the thorax which exhibit little internal motion during irradiation and, to determine random and systematic setup deviations in lung cancer patients with the use of these structures. Methods: Ten patients with lung cancer were set up in the supine position, and aligned using lasers. No immobilization devices were used. With an electronic portal imaging device (Siemens Beam ViewPLUS), 12 sequential images (exposure 0.54 sec.; processing time 1.5 sec.) were obtained during a single fraction of radiotherapy. These 'movie loops' were generated for the A-P fields during each of 3-5 fractions. In order to determine the mobility of internal structures during each fraction, visible structures such as the trachea, carina, the upper chest wall, aortic arch, clavicle and paraspinal line were contoured manually in each image and matched with the first image of the corresponding movie loop by means of a cross-correlation algorithm. Translations in the cranial and lateral directions and in-plane rotations were determined for each structure separately. As the reference image represents a random position, relative movements were determined by comparing the translations and rotation for every image to the calculated means per movie-loop. Standard deviations of the relative movements were determined for each structure and each patient. Patient setup was evaluated for 15 patients with lung cancer. Setup was not corrected at any time during the treatment. The electronic portal images of each fraction were matched with the digitized simulator films by using a combination of the structures which had been determined to be relatively stable in the infra-fractional analysis. Results: In the infra-fractional analysis 120 to 380 matches were made per structure (a total of 1400). The standard deviation (SD) of translations in the lateral direction was small (?1 mm) for the trachea, thoracic wall, paraspinal line and aortic arch. This was also the 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

1997-01-01

30

Evolving a Multiagent System for Landmark-based Robot Navigation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this article, we build upon a multiagent architecture for landmark-based navigation in unknown environments. In this architecture, each of the agents in the navigation system has a bidding function that is controlled by a set of parameters. We show here the good results obtained by an evolutionary approach that tunes the parameter set values for two navigation tasks.

Ambastha, Madhur; Busquets, Didac; Lopez Mantaras, Ramon; Sierra, Carles

2005-01-01

31

Reliability of Determination of Bony Landmarks of the Distal Femur on MR Images and MRI-Based 3D Models  

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Background/Objective: Consistent determination of the anatomical landmarks on image or image-based three dimensional (3D) models is a basic requirement for reliable analysis of the human joint kinematics using imaging techniques. We examined the intra- and inter-observer reliability of determination of the medial and lateral epicondyle landmarks on 2D MR images and 3D MRI-based models of the knee. "n"n Materials and Methods: Sixteen coronal plane MRI recordings were taken from 18 he...

2009-01-01

32

Opacification of tympanic membrane: As an anatomic landmark of oto-radiology  

Energy Technology Data Exchange (ETDEWEB)

Opacification of tympanic membrane was done by attachment of a cotton patch soaked with contrast media through external meatus. Detailed evaluation of fine structures in middle ear of normal adult is easily done after opacification of tympanic membrane. It was believed that opacified tympanic membrane would be an useful landmark for early detection of cholesteatoma and a good marker also in tomography of temporal bone.

Park, Jae Hyung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

1985-12-15

33

Opacification of tympanic membrane: As an anatomic landmark of oto-radiology  

International Nuclear Information System (INIS)

Opacification of tympanic membrane was done by attachment of a cotton patch soaked with contrast media through external meatus. Detailed evaluation of fine structures in middle ear of normal adult is easily done after opacification of tympanic membrane. It was believed that opacified tympanic membrane would be an useful landmark for early detection of cholesteatoma and a good marker also in tomography of temporal bone.

1985-12-01

34

Describing Wing Geometry of Aedes Aegypti Using Landmark-Based Geometric Morphometrics  

Directory of Open Access Journals (Sweden)

Full Text Available Insect wing morphology has been used in many studies to describe variations among species and populations using traditional morphometrics and more recently, geometric morphometrics. This study was conducted to determine intraspecific divergence in wing shape and venation in Aedes aegypti using landmark-based geometric morphometrics. In the Philippines, Ae. aegypti has been identified as a common dengue vector species. With the increasing cases of dengue, mosquito control programs are faced with problems on vector species diversification and proper identification. Variation in wing geometry may provide relevant information on proper identification of species and in describing population diversity. In this study, the geometry of 30 wings of female Ae. Aegypti was described using 18 anatomical landmarks and subjected to Procrustes superimposition and relative warp analysis. Results of the relative warp analysis showed some intraspecific variation in the wing outline of Ae. aegypti. The observed morphological disparity in wing shape suggest a possible morphological divergence among populations of Ae. aegypti. Based from the results of the study, landmark-based geometric morphometrics is a good tool in describing quantitatively variations in wing shape of the mosquitoes.

udy P. Sendaydiego

2013-07-01

35

Neural Network Based Sensory Fusion for Landmark Detection  

Science.gov (United States)

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.

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

1997-01-01

36

Three-dimensional analysis of maxillary anatomic landmarks for greater palatine nerve block anesthesia.  

Science.gov (United States)

Greater palatine nerve block anesthesia (GPNBA) is a local anesthetic procedure used for maxillary and nasal treatment. Investigation of the three-dimensional anatomic location of the greater palatine foramen (GPF) is important for successful local anesthesia. The study aim was to provide standards for anatomic structures in the oral cavity that can be easily referred to in GPNBA. Maxillary computed tomography data were obtained from patients between 8 and 16 years of age whose maxillary incisors and first molars had already erupted (the growth group, n = 103); changes in the maxilla were observed over time in this group. Reference values for GPNBA in adults were measured in 107 patients older than 18 years. Maxillary computed tomography images were reconstructed three-dimensionally. Regression analysis demonstrates that all maxillary measurements in the growth group except for the distance from the posterior nasal spine to the GPF in the coronal plane correlated significantly with age. In adults, the mean perpendicular distance from the interdental alveolar bone between the left and right central incisors (1alvB) to the GPF in the coronal plane was 46.16 mm, and the mean distance from 1alvB to the GPF was 51.05 mm. The mean distance from the maxillary central incisor to the GPF was 57.58 mm. The mean angle between the line from the maxillary central incisor to each GPF and the sagittal plane was 16.49 degrees. The mean perpendicular distance from the anterior nasal spine to the GPF in the coronal plane was 43.49 mm, whereas the mean perpendicular distance from the GPF to the bone plane was 12.67 mm, and the mean perpendicular distance from the GPF to the occlusal plane was 22.13 mm. These measurements can be used to find the height of the GPF. In adults, the measured perpendicular distance from the incisive foramen to the GPF in the coronal plane was 32.04 mm, and the perpendicular distance from the median of the line that connects both of the contact points between the maxillary tuberosity and the pterygoid plate to the GPF in the coronal plane was 5.23 mm. Three-dimensional reference values relative to the anatomic structures in the oral cavity may increase the success rate of GPNBA and reduce complications. Although the maxillary growth pattern was analyzed, a limitation of this study is that maxillary anatomic measurements were not analyzed with regard to race or ethnicity. PMID:22627432

Kang, Sang-Hoon; Byun, In-Young; Kim, Jin-Hong; Park, Hee-Keun; Kim, Moon-Key

2012-05-01

37

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

Science.gov (United States)

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

Ghimire, Deepak; Lee, Joonwhoan

2014-01-01

38

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

International Nuclear Information System (INIS)

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.)

2008-06-01

39

Active shape models incorporating isolated landmarks for medical image annotation  

Science.gov (United States)

Apart from their robustness in anatomic surface segmentation, purely surface based 3D Active Shape Models lack the ability to automatically detect and annotate non-surface key points of interest. However, annotation of anatomic landmarks is desirable, as it yields additional anatomic and functional information. Moreover, landmark detection might help to further improve accuracy during ASM segmentation. We present an extension of surface-based 3D Active Shape Models incorporating isolated non-surface landmarks. Positions of isolated and surface landmarks are modeled conjoint within a point distribution model (PDM). Isolated landmark appearance is described by a set of haar-like features, supporting local landmark detection on the PDM estimates using a kNN-Classi er. Landmark detection was evaluated in a leave-one-out cross validation on a reference dataset comprising 45 CT volumes of the human liver after shape space projection. Depending on the anatomical landmark to be detected, our experiments have shown in about 1/4 up to more than 1/2 of all test cases a signi cant improvement in detection accuracy compared to the position estimates delivered by the PDM. Our results encourage further research with regard to the combination of shape priors and machine learning for landmark detection within the Active Shape Model Framework.

Norajitra, Tobias; Meinzer, Hans-Peter; Stieltjes, Bram; Maier-Hein, Klaus H.

2014-03-01

40

Common Carotid Artery Bifurcation Levels Related to Clinical Relevant Anatomical Landmarks Niveles de Bifurcación de la Arteria Carótida Común en Relación a Puntos de Referencia Anatómicos Relevantes en Clínica  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In head and neck surgery, the common carotid arteries are important landmarks, defining dissection plane during radical neck surgeries. The objectives of the present study were to add information on the diameter of the carotid arteries and to correlate the common carotid artery (CCA) bifurcation level with important anatomical landmarks used regularly in clinical practice. Forty-six necks from male embalmed human cadavers were evaluated. The CCA as the external (ECA) and internal (ICA) caroti...

Rogério Alves Ribeiro; João Alberto de Souza Ribeiro; Omar Andrade Rodrigues Filho; Abadio Gonçalves Caetano; Valéria Paula Sassoli Fazan

2006-01-01

 
 
 
 
41

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

Science.gov (United States)

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. PMID:24238743

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

42

Landmark Detection via Ann for a Web Based Autonomous Mobile Robot: Sunar  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, a landmark detection method was developed for finding or position correction of a web based mobile robot designed and implemented for long term and regular scientific purposes. Colored numeric and alphanumeric character sticker in place of other artificial landmarks appropriate for robot is selected to be landmark for understanding of both human and robot. Statistical analysis of captured and segmented image part is used for feature vector extraction. Statistical properties of histogram, projections and image raw data are selectable components of feature vector. The feature vector is tested by previously trained multilayer perceptron feed forward neural network (ANN. For this aim, online programs required for robotic activities, image processing and neural network processes have been developed on web interface of web-robot. In this program, improved software libraries for SUNAR system are employed. Real time results and robot scenes are monitored online on web portal.

Nihat Y?lmaz

2006-06-01

43

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)

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. PMID:21732321

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

2011-08-01

44

Comparison of landmark-based and automatic methods for cortical surface registration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Group analysis of structure or function in cerebral cortex typically involves as a first step the alignment of the cortices. A surface based approach to this problem treats the cortex as a convoluted surface and coregisters across subjects so that cortical landmarks or features are aligned. This registration can be performed using curves representing sulcal fundi and gyral crowns to constrain the mapping. Alternatively, registration can be based on the alignment of curvature metrics computed ...

Pantazis, Dimitrios; Joshi, Anand; Jiang, Jintao; Shattuck, David; Bernstein, Lynne E.; Damasio, Hanna; Leahy, Richard M.

2010-01-01

45

Visual Homing in the Absence of Feature-Based Landmark Information  

Science.gov (United States)

Despite that fact that landmarks play a prominent role in human navigation, experimental evidence on how landmarks are selected and defined by human navigators remains elusive. Indeed, the concept of a "landmark" is itself not entirely clear. In everyday language, the term landmark refers to salient, distinguishable, and usually nameable objects,…

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

2008-01-01

46

AttentiRobot: A Visual Attention-based Landmark Selection Approach for Mobile Robot Navigation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Visual attention refers to the ability of a vision system to rapidly detect visually salient locations in a given scene. On the other hand, the selection of robust visual landmarks of an environment represents a cornerstone of reliable vision-based robot navigation systems. Indeed, can salient scene locations provided by visual attention be useful for robot navigation ? This work investigates the potential and effectiveness of the visual attention mechanism to provide pre-attentive scene info...

Ouerhani, Nabil; Hu?gli, Heinz; Gruener, G.; Codourey, A.

2009-01-01

47

A Visual Attention-Based Approach for Automatic Landmark Selection and Recognition  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Visual attention refers to the ability of a vision system to rapidly detect visually salient locations in a given scene. On the other hand, the selection of robust visual landmarks of an environment represents a cornerstone of reliable vision-based robot navigation systems. Indeed, can salient scene locations provided by visual attention be useful for robot navigation? This work investigates the potential and effectiveness of the visual attention mechanism to provide pre-attentive scene infor...

Ouerhani, Nabil; Hu?gli, Heinz; Gruener, G.; Codourey, A.

2008-01-01

48

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

Science.gov (United States)

Skin marker-based motion analysis has been widely used in biomechanical studies and clinical applications. Unfortunately, the accuracy of knee joint secondary motions is largely limited by the nonrigidity nature of human body segments. Numerous studies have investigated the characteristics of soft tissue movement. Utilizing these characteristics, we may improve the accuracy of knee joint motion measurement. An optimizer was developed by incorporating the soft tissue movement patterns at special bony landmarks into constraint functions. Bony landmark constraints were assigned to the skin markers at femur epicondyles, tibial plateau edges, and tibial tuberosity in a motion analysis algorithm by limiting their allowed position space relative to the underlying bone. The rotation matrix was represented by quaternion, and the constrained optimization problem was solved by Fletcher's version of the Levenberg-Marquardt optimization technique. The algorithm was validated by using motion data from both skin-based markers and bone-mounted markers attached to fresh cadavers. By comparing the results with the ground truth bone motion generated from the bone-mounted markers, the new algorithm had a significantly higher accuracy (root-mean-square (RMS) error: 0.7 ± 0.1 deg in axial rotation and 0.4 ± 0.1 deg in varus-valgus) in estimating the knee joint secondary rotations than algorithms without bony landmark constraints (RMS error: 1.7 ± 0.4 deg in axial rotation and 0.7 ± 0.1 deg in varus-valgus). Also, it predicts a more accurate medial-lateral translation (RMS error: 0.4 ± 0.1 mm) than the conventional techniques (RMS error: 1.2 ± 0.2 mm). The new algorithm, using bony landmark constrains, estimates more accurate secondary rotations and medial-lateral translation of the underlying bone. PMID:21142329

Wang, Hongsheng; Zheng, Naiqaun Nigel

2010-12-01

49

In vitro evaluation of anatomic landmarks for the placement of suture to achieve effective arytenoid cartilage abduction by means of unilateral cricoarytenoid lateralization in dogs.  

Science.gov (United States)

Objective-To evaluate anatomic landmarks to define the ideal suture placement location to achieve appropriate and consistent arytenoid cartilage abduction via unilateral cricoarytenoid lateralization (UCL) in dogs. Sample-6 cadaveric canine larynges. Procedures-Laryngeal airway resistance (LAR) was determined for each specimen before (baseline) and after suture placements with the epiglottis open and closed. To achieve UCL, suture was placed through the cricoid cartilage just caudal to the cricoarytenoid articulation (suture placement position [SPP] 1), one-fourth of the distance caudally between the cricoarytenoid and cricothyroid articulations (SPP 2), and three-fourths of the distance caudally between the cricoarytenoid and cricothyroid articulations (SPP 3). The LAR was again calculated after tensioning of each suture separately. Results-With a closed epiglottis, median LAR was 30.0, 20.4, 11.4, and 3.3 cm H2O/L/s at baseline and SPPs 1, 2, and 3, respectively. After UCL at SPP 1, LAR with the epiglottis closed was not significantly different from that at baseline. With an open epiglottis, median LAR was 2.0, 0.4, 0.2, and 0.0 cm H2O/L/s at baseline and SPPs 1, 2, and 3, respectively. After UCL at SPPs 1, 2, or 3, LAR with an open epiglottis was significantly lower than that at baseline. Conclusions and Clinical Relevance-Results indicated that placement of suture through the cricoid cartilage at the caudal border of the cricoarytenoid articulation was appropriate to sufficiently reduce LAR without increasing the risk of aspiration pneumonia through overabduction of the arytenoid cartilage. PMID:24866518

Gauthier, Christopher M; Monnet, Eric

2014-06-01

50

A Robot Indoor Position and Orientation Method based on 2D Barcode Landmark  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A method for robot indoor automatic positioning and orientating based on two-dimensional (2D) barcode landmark is proposed.

Guoyu Lin; Xu Chen

2011-01-01

51

A Sensor Network Data Compression Algorithm Based on Suboptimal Clustering and Virtual Landmark Routing Within Clusters  

Directory of Open Access Journals (Sweden)

Full Text Available A kind of data compression algorithm for sensor networks based on suboptimal clustering and virtual landmark routing within clusters is proposed in this paper. Firstly, temporal redundancy existing in data obtained by the same node in sequential instants can be eliminated. Then sensor networks nodes will be clustered. Virtual node landmarks in clusters can be established based on cluster heads. Routing in clusters can be realized by combining a greedy algorithm and a flooding algorithm. Thirdly, a global structure tree based on cluster heads will be established. During the course of data transmissions from nodes to cluster heads and from cluster heads to sink, the spatial redundancy existing in the data will be eliminated. Only part of the raw data needs to be transmitted from nodes to sink, and all raw data can be recovered in the sink based on a compression code and part of the raw data. Consequently, node energy can be saved, largely because transmission of redundant data can be avoided. As a result the overall performance of the sensor network can obviously be improved.

Shengqiang Li

2010-10-01

52

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

Energy Technology Data Exchange (ETDEWEB)

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 residues are up to 6 times higher. By taking into account the orthogonality of the measurement coordinate axes when performing a 3D calibration, a comparative and quantitative analysis of 3D scanning microscopy has been made possible. (orig.)

Ritter, M.

2007-04-27

53

Global localization of 3D anatomical structures by pre-filtered Hough forests and discrete optimization.  

Science.gov (United States)

The accurate localization of anatomical landmarks is a challenging task, often solved by domain specific approaches. We propose a method for the automatic localization of landmarks in complex, repetitive anatomical structures. The key idea is to combine three steps: (1) a classifier for pre-filtering anatomical landmark positions that (2) are refined through a Hough regression model, together with (3) a parts-based model of the global landmark topology to select the final landmark positions. During training landmarks are annotated in a set of example volumes. A classifier learns local landmark appearance, and Hough regressors are trained to aggregate neighborhood information to a precise landmark coordinate position. A non-parametric geometric model encodes the spatial relationships between the landmarks and derives a topology which connects mutually predictive landmarks. During the global search we classify all voxels in the query volume, and perform regression-based agglomeration of landmark probabilities to highly accurate and specific candidate points at potential landmark locations. We encode the candidates' weights together with the conformity of the connecting edges to the learnt geometric model in a Markov Random Field (MRF). By solving the corresponding discrete optimization problem, the most probable location for each model landmark is found in the query volume. We show that this approach is able to consistently localize the model landmarks despite the complex and repetitive character of the anatomical structures on three challenging data sets (hand radiographs, hand CTs, and whole body CTs), with a median localization error of 0.80 mm, 1.19 mm and 2.71 mm, respectively. PMID:23664450

Donner, René; Menze, Bjoern H; Bischof, Horst; Langs, Georg

2013-12-01

54

Global localization of 3D anatomical structures by pre-filtered Hough Forests and discrete optimization  

Science.gov (United States)

The accurate localization of anatomical landmarks is a challenging task, often solved by domain specific approaches. We propose a method for the automatic localization of landmarks in complex, repetitive anatomical structures. The key idea is to combine three steps: (1) a classifier for pre-filtering anatomical landmark positions that (2) are refined through a Hough regression model, together with (3) a parts-based model of the global landmark topology to select the final landmark positions. During training landmarks are annotated in a set of example volumes. A classifier learns local landmark appearance, and Hough regressors are trained to aggregate neighborhood information to a precise landmark coordinate position. A non-parametric geometric model encodes the spatial relationships between the landmarks and derives a topology which connects mutually predictive landmarks. During the global search we classify all voxels in the query volume, and perform regression-based agglomeration of landmark probabilities to highly accurate and specific candidate points at potential landmark locations. We encode the candidates’ weights together with the conformity of the connecting edges to the learnt geometric model in a Markov Random Field (MRF). By solving the corresponding discrete optimization problem, the most probable location for each model landmark is found in the query volume. We show that this approach is able to consistently localize the model landmarks despite the complex and repetitive character of the anatomical structures on three challenging data sets (hand radiographs, hand CTs, and whole body CTs), with a median localization error of 0.80 mm, 1.19 mm and 2.71 mm, respectively.

Donner, Rene; Menze, Bjoern H.; Bischof, Horst; Langs, Georg

2013-01-01

55

Expressive anatomical illustrations based on scanned patient data  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The art and profession of medical illustration depend not only on the talent and skills of an illustrator, but also on the complimentary knowledge of human anatomy. Therefore, anatomical illustrations were mostly based on comprehensive dissections and observations during surgery. Recently, illustrative visualization techniques have been utilized to illustrate features and shapes of anatomical objects. Thereby, illustrative visualization provides representations that highlight relevant feature...

Salah, Z.; Bartz, D.; Straßer, W.; Tatagiba, M.

2006-01-01

56

Automated landmarking and geometric characterization of the carotid siphon.  

Science.gov (United States)

The geometry of the carotid siphon has a large variability between subjects, which has prompted its study as a potential geometric risk factor for the onset of vascular pathologies on and off the internal carotid artery (ICA). In this work, we present a methodology for an objective and extensive geometric characterization of carotid siphon parameterized by a set of anatomical landmarks. We introduce a complete and automated characterization pipeline. Starting from the segmentation of vasculature from angiographic image and its centerline extraction, we first identify ICA by characterizing vessel tree bifurcations and training a support vector machine classifier to detect ICA terminal bifurcation. On ICA centerline curve, we detect anatomical landmarks of carotid siphon by modeling it as a sequence of four bends and selecting their centers and interfaces between them. Bends are detected from the trajectory of the curvature vector expressed in the parallel transport frame of the curve. Finally, using the detected landmarks, we characterize the geometry in two complementary ways. First, with a set of local and global geometric features, known to affect hemodynamics. Second, using large deformation diffeomorphic metric curve mapping (LDDMCM) to quantify pairwise shape similarity. We processed 96 images acquired with 3D rotational angiography. ICA identification had a cross-validation success rate of 99%. Automated landmarking was validated by computing limits of agreement with the reference taken to be the locations of the manually placed landmarks averaged across multiple observers. For all but one landmark, either the bias was not statistically significant or the variability was within 50% of the inter-observer one. The subsequently computed values of geometric features and LDDMCM were commensurate to the ones obtained with manual landmarking. The characterization based on pair-wise LDDMCM proved better in classifying the carotid siphon shape classes than the one based on geometric features. The proposed characterization provides a rich description of geometry and is ready to be applied in the search for geometric risk factors of the carotid siphon. PMID:22377655

Bogunovi?, Hrvoje; Pozo, José María; Cárdenes, Rubén; Villa-Uriol, María Cruz; Blanc, Raphaël; Piotin, Michel; Frangi, Alejandro F

2012-05-01

57

Fiber feature map based landmark initialization for highly deformable DTI registration  

Science.gov (United States)

This paper presents a novel pipeline for the registration of diffusion tensor images (DTI) with large pathological variations to normal controls based on the use of a novel feature map derived from white matter (WM) fiber tracts. The research presented aims towards an atlas based DTI analysis of subjects with considerable brain pathologies such as tumors or hydrocephalus. In this paper, we propose a novel feature map that is robust against variations in WM fiber tract integrity and use these feature maps to determine a landmark correspondence using a 3D point correspondence algorithm. This correspondence drives a deformation field computed using Gaussian radial basis functions(RBF). This field is employed as an initialization to a standard deformable registration method like demons. We present early preliminary results on the registration of a normal control dataset to a dataset with abnormally enlarged lateral ventricles affected by fatal demyelinating Krabbe disease. The results are analyzed based on a regional tensor matching criterion and a visual assessment of overlap of major WM fiber tracts. While further evaluation and improvements are necessary, the results presented in this paper highlight the potential of our method in handling registration of subjects with severe WM pathology.

Gupta, Aditya; Toews, Matthew; Janardhana, Ravikiran; Rathi, Yogesh; Gilmore, John; Escolar, Maria; Styner, Martin

2013-01-01

58

Comparing the Effectiveness of GPS-Enhanced Voice Guidance for Pedestrians with Metric- and Landmark-Based Instruction Sets  

Science.gov (United States)

This paper reports on a field experiment comparing two different kinds of verbal turn instructions in the context of GPS-based pedestrian navigation. The experiment was conducted in the city of Salzburg with 20 participants. Both instruction sets were based on qualitative turn direction concepts. The first one was enhanced with metric distance information and the second one was enhanced with landmark-anchored directions gathered from participants of a previous field experiment. The results show that in context of GPS-enhanced pedestrian navigation both kinds of instruction sets lead to similar navigation performance. Results also demonstrate that effective voice-only guidance of pedestrians in unfamiliar environments at a minimal error rate and without stopping the walk is feasible. Although both kinds of instructions lead to similar navigation performance, participants clearly preferred landmark-enhanced instructions.

Rehrl, Karl; Häusler, Elisabeth; Leitinger, Sven

59

3D CT Imaging for Craniofacial Analysis Based on Anatomical Regions.  

Science.gov (United States)

The development of a craniofacial database is a multidisciplinary initiative that will provide an important reference for community, security, social and medical applications. A method of landmark identifications and measurements in 3d on craniofacial patients is described. anatomical regions such as mandible, orbits, zygoma and maxilla are located, created and stored as templates of 3D CAD files for subsequent analysis. Data from these images were tested for accuracy and repeatability by comparing with direct measurements using caliper and CMM. The landmark points are reproducible in CAD system for further analysis. it was found that the approach provides a fast, accurate and efficient method for landmarks identification of the craniofacial areas in database development. PMID:17282309

Wan Harun, W A R; Ahmad Rajion, Zainul; Abdul Aziz, Izhar; Rani Samsudin, Abdul

2005-01-01

60

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

International Nuclear Information System (INIS)

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 cancer. These changes cannot be modeled by the conventional rigid landmark transformation method. In the current study, we found that the deformable anatomic template registration method, based on continuum-mechanics models of deformation, successfully described these large anatomic shape changes before and after ICT. These promising modeling results indicate that realistic registration of the cumulative dose distribution to the organs (or targets) of interest for radiation therapy of cervical cancers is achievable

2001-09-01

 
 
 
 
61

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

Science.gov (United States)

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. PMID:23640988

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

2013-01-01

62

Dissimilarity-Based Classification of Anatomical Tree Structures  

DEFF Research Database (Denmark)

A novel method for classification of abnormality in anatomical tree structures is presented. A tree is classified based on direct comparisons with other trees in a dissimilarity-based classification scheme. The pair-wise dissimilarity measure between two trees is based on a linear assignment between the branch feature vectors representing those trees. Hereby, localized information in the branches is collectively used in classification and variations in feature values across the tree are taken into account. An approximate anatomical correspondence between matched branches can be achieved by including anatomical features in the branch feature vectors. The proposed approach is applied to classify airway trees in computed tomography images of subjects with and without chronic obstructive pulmonary disease (COPD). Using the wall area percentage (WA%), a common measure of airway abnormality in COPD, as well as anatomical features to characterize each branch, an area under the receiver operating characteristic curve of 0.912 is achieved. This is significantly better than computing the average WA%.

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

2011-01-01

63

Dissimilarity-based classification of anatomical tree structures  

DEFF Research Database (Denmark)

A novel method for classification of abnormality in anatomical tree structures is presented. A tree is classified based on direct comparisons with other trees in a dissimilarity-based classification scheme. The pair-wise dissimilarity measure between two trees is based on a linear assignment between the branch feature vectors representing those trees. Hereby, localized information in the branches is collectively used in classification and variations in feature values across the tree are taken into account. An approximate anatomical correspondence between matched branches can be achieved by including anatomical features in the branch feature vectors. The proposed approach is applied to classify airway trees in computed tomography images of subjects with and without chronic obstructive pulmonary disease (COPD). Using the wall area percentage (WA%), a common measure of airway abnormality in COPD, as well as anatomical features to characterize each branch, an area under the receiver operating characteristic curveof 0.912 is achieved. This is significantly better than computing the average WA%.

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

2011-01-01

64

A study of quantitative comparisons of photographs and video images based on landmark derived feature vectors.  

Science.gov (United States)

An abundunce of surveillance cameras highlights the necessity of identifying individuals recorded. Images captured are often unintelligible and are unable to provide irrefutable identifications by sight, and therefore a more systematic method for identification is required to address this problem. An existing database of video and photograhic images was examined, which had previously been used in a psychological research project; material consisted of 80 video (Sample 1) and 119 photograhic (Sample 2) images, though taken with different cameras. A set of 38 anthropometric landmarks were placed by hand capturing 59 ratios of inter-landmark distances to conduct within sample and between sample comparisons using normalised correlation calculations; mean absolute value between ratios, Euclidean distance and Cosine ? distance between ratios. The statistics of the two samples were examined to determine which calculation best ascertained if there were any detectable correlation differences between faces that fall under the same conditions. A comparison of each face in Sample 1 was then compared against the database of faces in Sample 2. We present pilot results showing that the Cosine ? distance equation using Z-normalised values achieved the largest separation between True Positive and True Negative faces. Having applied the Cosine ? distance equation we were then able to determine that if a match value returned is greater than 0.7, it is likely that the best match will be a True Positive allowing a decrease of database images to be verified by a human. However, a much larger sample of images requires to be tested to verify these outcomes. PMID:22277156

Kleinberg, Krista F; Siebert, J Paul

2012-06-10

65

Optimization of Landmark Selection for Cortical Surface Registration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Manually labeled landmark sets are often required as inputs for landmark-based image registration. Identifying an optimal subset of landmarks from a training dataset may be useful in reducing the labor intensive task of manual labeling. In this paper, we present a new problem and a method to solve it: given a set of N landmarks, find the k(< N) best landmarks such that aligning these k landmarks that produce the best overall alignment of all N landmarks. The resulting procedure allows us to s...

Joshi, Anand; Pantazis, Dimitrios; Damasio, Hanna; Shattuck, David; Li, Quanzheng; Leahy, Richard

2009-01-01

66

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

Science.gov (United States)

Many systemic lysosomal storage disorders show basic corneal opacities already in childhood. The lysosome is a cell organelle, produced by Golgi's apparatus, that is surrounded by a membrane and contains hydrolytic enzymes that break down food molecules, especially proteins and other complex molecules. The ophthalmologist's precise diagnosis of corneal clouding at the slit-lamp may reveal the correct interpretation of the specific lysosomal storage disorder. It is very important to diagnose such diseases as soon as possible because today the development of systemic enzymatic therapies has broadened the therapeutic armamentarium for the current standard of care. The following corneal landmarks of systemic storage diseases and of the modern systemic therapy are presented: cornea verticillata in Fabry's disease, periodic infusion of alpha-galactosidase a; Kayser-Fleischer's ring in Wilson's disease, zinc, trienetin, low copper diet; multiple, punctiform crystals in cystinosis, cysteamine, Raptor RP 103(DR cysteamine) that reduces the cytotoxity in form of continous dissolving of cystine from lysosome, renal transplantation, haematopoietic stem cell transplantation; peripheral ring, but not true lipid arc, and moderate stromal haze in LCAT-deficiency, injection of recombinant enzyme or of encapsulated LCAT-secreting cells; diffuse stromal haze in mucopolysaccharidoses (MPS). Enzyme replacement therapy is currently indicated for MPS I, MPS II, and MPS VI, haematopoietic stem cell transplantation; painful, bilateral pseudo-dendritic opacities in tyrosinemia type II (eponym: Richner-Hanhart syndrome), low phenylalanine and tyrosine diet result in complete disappearance of corneal alterations with a consecutive painfree period. Strict diet during the whole life is necessary to prevent corneal recurrences and the occurrence of palmo-plantar keratoses. Such therapies can enable the patient to lead an otherwise normal life for decades. PMID:23794426

Lisch, W; Pitz, S; Geerling, G

2013-06-01

67

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

Science.gov (United States)

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

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

2014-01-01

68

PCR-based landmark unique gene (PLUG markers effectively assign homoeologous wheat genes to A, B and D genomes  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background EST-PCR markers normally represent specific products from target genes, and are therefore effective tools for genetic analysis. However, because wheat is an allohexaploid plant, PCR products derived from homoeologous genes are often simultaneously amplified. Such products may be easier to differentiate if they include intron sequences, which are more polymorphic than exon sequences. However, genomic sequence data for wheat are limited; therefore it is difficult to predict the location of introns. By using the similarities in gene structures between rice and wheat, we developed a system called PLUG (PCR-based Landmark Unique Gene to design primers so that PCR products include intron sequences. We then investigated whether products amplified using such primers could serve as markers able to distinguish multiple products derived from homoeologous genes. Results The PLUG system consists of the following steps: (1 Single-copy rice genes (Landmark Unique Gene loci; LUGs exhibiting high degrees of homology to wheat UniGene sequences are extracted; (2 Alignment analysis is carried out using the LUGs and wheat UniGene sequences to predict exon-exon junctions, and LUGs which can be used to design wheat primers flanking introns (TaEST-LUGs are extracted; and (3 Primers are designed in an interactive manner. From a total of 4,312 TaEST-LUGs, 24 loci were randomly selected and used to design primers. With all of these primer sets, we obtained specific, intron-containing products from the target genes. These markers were assigned to chromosomes using wheat nullisomic-tetrasomic lines. By PCR-RFLP analysis using agarose gel electrophoresis, 19 of the 24 markers were located on at least one chromosome. Conclusion In the development of wheat EST-PCR markers capable of efficiently sorting products derived from homoeologous genes, it is important to design primers able to amplify products that include intron sequences with insertion/deletion polymorphisms. Using the PLUG system, wheat EST sequences that can be used for marker development are selected based on comparative genomics with rice, and then primer sets flanking intron sequences are prepared in an interactive, semi-automatic manner. Hence, the PLUG system is an effective tool for large-scale marker development.

Saito Mika

2007-05-01

69

Sartorial Branch of Saphenous Nerve: Anatomical Relationship with Bony Landmarks and Great Saphenous Vein / Ramo Sartorial del Nervio Safeno Safeno: Relación Anatómica con Puntos de Referencia Óseos y de la vena Safena Magna  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish El ramo sartorial del nervio safeno (nervio cutáneo medial de la pierna) se origina en el lado medial de la rodilla y desciende a lo largo de la vena safena magna (VSM) para inervar la cara medial de la pierna. Su anatomía es motivo de preocupación en los procedimientos quirúrgicos y en el bloqueo a [...] nestésico. Sin embargo, los datos de medición relacionados con puntos de referencia óseos palpables y la comparación entre los lados y en ambos sexos son escasas. Se realizó la disección en 95 miembros inferiores de ambos sexos. Se encontró que el nervio perforó la fascia profunda en la mayoría de los casos (92,6%). Esta punta de perforación fue siempre distal al tubérculo del músculo aductor magno a una distancia de 5-6 cm, que representaba el 15% del largo de la pierna (la distancia entre el tubérculo del aductor magno y el maléolo medial). El nervio se localizaba 7 cm medial a la tuberosidad tibial. Al nivel del tercio medio en ambas piernas, el nervio estaba a una distancia un poco mayor a 4 cm medial al margen anterior de la tibia. El nervio se dividía 7 cm proximal al maléolo medial. Por otra parte, la relación anatómica entre el nervio y la VSM fue muy variable. El nervio era constantemente anterior, posterior o profundo a la VSM en 8,4%, 15,8% y 2,1%, respectivamente. Cruce entre las dos estructuras anatómicas se observó en el 57,9% de las muestras y la distancia hasta el maléolo medial fue de 18 cm. La simetría se encuentra en la mayoría de los parámetros y diferencias de sexo significativas se observaron en algunas distancias. Estos resultados son importantes para evitar la lesión del nervio sartorial y localizar el nervio durante los procedimientos pertinentes. Abstract in english Sartorial branch of saphenous nerve (medial crural cutaneous nerve) originates at the medial side of the knee and descends along the great saphenous vein (GSV) to innervate the medial aspect of the leg. Its anatomy is of concern in surgical procedures and anesthetic block. However, the measurement d [...] ata related to palpable bony landmarks with comparison between sexes and sides are lacking. Dissection was done in 95 lower limbs from both sexes. We found that the nerve pierced the deep fascia alone in most cases (92.6%). This piercing point was always distal to the adductor tubercle with the distance of 5-6 cm which was 15% of the leg length (the distance between the adductor tubercle and medial malleolus). The nerve was 7 cm medial to the tibial tuberosity. At the mid-level of leg length, the nerve was slightly over 4 cm medial to the anterior tibial margin. The nerve terminally divided 7 cm proximal to the medial malleolus. Furthermore, the anatomical relationship between the nerve and the GSV was highly variable. The nerve was constantly anterior, posterior or deep to the GSV in 8.4%, 15.8% and 2.1%, respectively. Crossing between the two structures was observed in 57.9% of specimens and the distance to the medial malleolus was 18 cm. Symmetry was found in most parameters and significant gender differences were observed in some distances. These results are important for avoiding the sartorial nerve injury and locating the nerve during relevant procedures.

Tothonglor, Amornrat; Agthong, Sithiporn; Huanmanop, Thanasil; Chentanez, Vilai.

70

Computerized Three-Dimmensional Craniofacial Reconstruction from Skulls Based on Landmarks.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Human identification from a skull is a critical process in legal and forensic medicine, specially when no other means are available. Traditional clay-based methods attempt to generate the human face, in order to identify the corresponding person. However, these reconstructions lack of objectivity and consistence, since they depend on the practitioner. Current computerized techniques are based on facial models, which introduce undesired facial features when the final reconstruction is built. T...

Carnero Pascual, Leticia; Lastres Redondo, Carmen; Rios Sanchez, Belen; Garrido Garrido, David; Santamaria Galdon, Maria Asuncion

2011-01-01

71

Anatomical basis of distally based anterolateral thigh flap.  

Science.gov (United States)

Abstract Soft tissue coverage around the knee has persisted as a challenge for plastic and reconstructive surgeons. The distally-based anterolateral thigh flap is often used for coverage. Nevertheless, few anatomical studies have investigated the retrograde vascular pedicle. This report clarifies the anatomy of the connection between the descending branch of the lateral circumflex femoral artery and the lateral superior genicular artery. This study examined 38 lower limbs from cadavers and recorded the numbers and locations of perforating vessels. Proximal and distal pivot points were also recorded. The proximal pivot point was 1.0-12.1 cm (average = 6.0 cm) from the inguinal ligament. The distal pivot point, found under the vastus lateralis muscle in all 38 specimens, was 4.0-13.6 cm (average = 9.8 cm) from the lateral superior edge of the patella. The most distal perforator was 8.2-28.0 cm (average = 18.9 cm) from the proximal pivot point. The most proximal perforator was 3.0-19.5 cm (average = 8.7 cm) from the distal pivot point. Details of the anastomosis of the descending branch and the superior lateral genicular artery were clarified. The distally-based anterolateral thigh flap presents one option for reconstruction around the knee. PMID:24256309

Yamada, Satoshi; Okamoto, Hideki; Sekiya, Isato; Wada, Ikuo; Kobayashi, Masaaki; Goto, Hideyuki; Mizutani, Jun; Nozaki, Masahiro; Hayashi, Katsuhiro; Murakami, Satona; Murase, Atsunori; Kawaguchi, Yohei; Inatani, Hiroyuki; Tatematsu, Naoe; Otsuka, Takanobu

2014-06-01

72

Robust Vision-based Underwater Target Identification & Homing Using Self-Similar Landmarks  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Next generation Autonomous Underwater Vehicles (AUVs) will be required to robustly identify underwater targets for tasks such as inspection, localisation and docking. Given their often unstructured operating environments, vision offers enormous potential in underwater navigation over more traditional methods, however, reliable target segmentation often plagues these systems. This paper addresses robust vision-based target recognition by presenting a novel scale and rotationally invariant targ...

Ne?gre, Amaury; Pradalier, Ce?dric; Dunbabin, Matthew

2007-01-01

73

A Multi-Agent Architecture Integrating Learning and Fuzzy Techniques for Landmark-Based Robot Navigation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper extends a navigation system implemented as a multi-agent system (MAS). The arbitration mechanism controlling the interactions between the agents was based on manually-tuned bidding functions. A difficulty with hand-tuning is that it is hard to handle situations involving complex tradeoffs. In this paper we explore the suitability of reinforcement learning for automatically tuning agents within a MAS to optimize a complex tradeoff, namely the camera use.

Busquets, Di?dac; Lopez Mantaras, Ramon; Sierra, Carles; Dietterich, Thomas G.

2002-01-01

74

Control over structure-specific flexibility improves anatomical accuracy for point-based deformable registration in bladder cancer radiotherapy  

International Nuclear Information System (INIS)

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 parameters were determined for the weighted S-TPS-RPM. Results: The weighted S-TPS-RPM registration algorithm with optimal parameters significantly improved the anatomical accuracy as compared to S-TPS-RPM registration of the bladder alone and reduced the range of the anatomical errors by half as compared with the simultaneous nonweighted S-TPS-RPM registration of the bladder and tumor structures. The weighted algorithm reduced the RDE range of lipiodol markers from 0.9–14 mm after rigid bone match to 0.9–4.0 mm, compared to a range of 1.1–9.1 mm with S-TPS-RPM of bladder alone and 0.9–9.4 mm for simultaneous nonweighted registration. All registration methods resulted in good geometric accuracy on the bladder; average error values were all below 1.2 mm. Conclusions: The weighted S-TPS-RPM registration algorithm with additional weight parameter allowed indirect control over structure-specific flexibility in multistructure registrations of bladder and bladder tumor, enabling anatomically coherent registrations. The availability of an anatomically validated deformable registration method opens up the horizon for improvements in IGART for bladder cancer.

2013-02-01

75

Control over structure-specific flexibility improves anatomical accuracy for point-based deformable registration in bladder cancer radiotherapy  

Energy Technology Data Exchange (ETDEWEB)

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 parameters were determined for the weighted S-TPS-RPM. Results: The weighted S-TPS-RPM registration algorithm with optimal parameters significantly improved the anatomical accuracy as compared to S-TPS-RPM registration of the bladder alone and reduced the range of the anatomical errors by half as compared with the simultaneous nonweighted S-TPS-RPM registration of the bladder and tumor structures. The weighted algorithm reduced the RDE range of lipiodol markers from 0.9-14 mm after rigid bone match to 0.9-4.0 mm, compared to a range of 1.1-9.1 mm with S-TPS-RPM of bladder alone and 0.9-9.4 mm for simultaneous nonweighted registration. All registration methods resulted in good geometric accuracy on the bladder; average error values were all below 1.2 mm. Conclusions: The weighted S-TPS-RPM registration algorithm with additional weight parameter allowed indirect control over structure-specific flexibility in multistructure registrations of bladder and bladder tumor, enabling anatomically coherent registrations. The availability of an anatomically validated deformable registration method opens up the horizon for improvements in IGART for bladder cancer.

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

76

Parsing radiographs by integrating landmark set detection and multi-object active appearance models  

Science.gov (United States)

This work addresses the challenging problem of parsing 2D radiographs into salient anatomical regions such as the left and right lungs and the heart. We propose the integration of an automatic detection of a constellation of landmarks via rejection cascade classifiers and a learned geometric constellation subset detector model with a multi-object active appearance model (MO-AAM) initialized by the detected landmark constellation subset. Our main contribution is twofold. First, we propose a recovery method for false positive and negative landmarks which allows to handle extreme ranges of anatomical and pathological variability. Specifically we (1) recover false negative (missing) landmarks through the consensus of inferences from subsets of the detected landmarks, and (2) choose one from multiple false positives for the same landmark by learning Gaussian distributions for the relative location of each landmark. Second, we train a MO-AAM using the true landmarks for the detectors and during test, initialize the model using the detected landmarks. Our model fitting allows simultaneous localization of multiple regions by encoding the shape and appearance information of multiple objects in a single model. The integration of landmark detection method and MO-AAM reduces mean distance error of the detected landmarks from 20.0mm to 12.6mm. We assess our method using a database of scout CT scans from 80 subjects with widely varying pathology.

Montillo, Albert; Song, Qi; Liu, Xiaoming; Miller, James V.

2014-01-01

77

A VRML-based anatomical visualization tool for medical education.  

Science.gov (United States)

The advent of the Virtual Reality Modeling Language (VRML) as a portable file format for describing three-dimensional (3-D) scenes has enabled researchers, educators, and students to share anatomical models on the World Wide Web (WWW). The implication for medical teaching is that students can interactively examine anatomical structures and their 3-D spatial relationships by using current personal computer (PC) technology. This paper describes the creation of 3-D anatomical models that are accessible on the WWW, using high-resolution middle-ear data as an example. The 3-D models are created by interactive segmentation of the source images (histological and MRI sections) and 3-D surface reconstruction. The resulting models are translated into VRML format. Section images can be superimposed on the model, allowing students to view a section in its 3-D context. To enhance the viewing of these scenes, a VRML browser was modified to support transparent rendering of surfaces. Finally, a WWW interface was designed to allow users to choose the model structures, section images, and associated viewing parameters to build their own 3-D scenes. PMID:10719514

Warrick, P A; Funnell, W R

1998-06-01

78

A new automatic landmark extraction framework on ultrasound images of femoral condyles  

Science.gov (United States)

In Computer Assisted Orthopaedic Surgery (CAOS), surgeons have to acquire some anatomical landmarks as inputs to the system. To do so, they use manual pointers that are localized in the Operating Room (OR) space using an infrared camera. When the needed landmark is not reachable through an opening, it is palpated directly on skin and there is a loss of precision that can vary from several millimeters to centimeters depending on the thickness of soft tissues. In this paper, we propose a new framework based on three main steps to register the bone surface and extract automatically anatomical landmarks with an ultrasound probe. This framework is based on an oriented gradient calculation, a simulated-compound and a contour closure using a graph representation. The oriented gradient allows extracting a set of pixels that probably belong to the bone surface. The simulatedcompound step allows using ultrasound images properties to define a set of small segments which may belong to the bone surface, and the graph representation allows eliminating false positive detection among remaining segments. The proposed method has been validated on a database of 230 ultrasound images of anterior femoral condyles (on the knee). The average computation time is 0.11 sec per image, and average errors are: 0.54 mm for the bone surface extraction, 0.31 mm for the condylar line, and 1.4 mm for the trochlea middle.

Masson-Sibut, Agnès; Nakib, Amir; Petit, Eric; Leitner, François

2012-02-01

79

Relative warps meet cladistics: A contribution to the phylogenetic relationships ofbaleen whales based on landmark analyses of mysticete crania  

Directory of Open Access Journals (Sweden)

Full Text Available During the last few years research on fossil baleen whales experienced a renaissance. Several important fossils weredescribed, and new and extended cladistic analyses were performed, partly including molecular data from living species.Despite the progress in our knowledge of their phylogeny, many questions have still not been resolved. A different attemptto illustrate mysticete relationships is presented here using landmark analyses. For the present analysis, 38 dorsalviews of mysticete skulls and skull reconstructions were scanned and thirteen landmarks were defined. The method usedis the relative warp analysis. This method allows a clustering of elements according to their similarity in shape. The calculatedrelative warps explain main shape variations in the sample. As in parsimony analyses the toothed mysticetes areclearly distinguishable. Representatives of the Aetocetoidea are grouped very closely together and therefore their classificationin this family is strongly supported. The performed analysis shows that the crania of the Balaenidae have developedsimilarities to the cranium of Janjucetus hunderi. The restriction of the Cetotheriidae to a small group of taxa isconfirmed here and includes in this analysis Cetotherium, Mixocetus, Piscobalaena, and Titanocetus with a close relationshipto the living gray whale. The stem-balaenopterids do not show any clear signals in the present analysis. There isno support for a subdivision into further families. The structure of the dorsal cranium of Protororqualus andPraemegaptera is very similar to that of Balaenoptera

Hampe O Baszio S

2010-06-01

80

Magnetic Resonance–Based Anatomical Analysis of Scar-Related Ventricular Tachycardia: Implications for Catheter Ablation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In catheter ablation of scar-related monomorphic ventricular tachycardia (VT), substrate voltage mapping is used to electrically define the scar during sinus rhythm. However, the electrically defined scar may not accurately reflect the anatomical scar. Magnetic resonance–based visualization of the scar may elucidate the 3D anatomical correlation between the fine structural details of the scar and scar-related VT circuits. We registered VT activation sequence with the 3D scar anatomy derived...

Ashikaga, Hiroshi; Sasano, Tetsuo; Dong, Jun; Zviman, M. Muz; Evers, Robert; Hopenfeld, Bruce; Castro, Valeria; Helm, Robert H.; Dickfeld, Timm; Nazarian, Saman; Donahue, J. Kevin; Berger, Ronald D.; Calkins, Hugh; Abraham, M. Roselle; Marba?n, Eduardo

2007-01-01

 
 
 
 
81

Landmarks in insulin research  

Directory of Open Access Journals (Sweden)

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

MichaelLawrence

2011-11-01

82

Evaluation of lesion detectability for anatomical-based MAP image reconstruction methods using computer observer study  

International Nuclear Information System (INIS)

In this study, we evaluate lesion detection performance of the anatomical-based maximum a posteriori (MAP) image reconstruction methods in emission computed tomography using the computer observer model. In lesion detection tasks, the conventional anatomical-MAP reconstruction methods cannot preserve lesions not present in the anatomical image with high contrast and, at the same time, suppress noise in the background regions. We previously proposed a new anatomical-MAP reconstruction method, called the SOS-MAP method, based on the spots-on-smooth image model by which the image is modeled by the sum of the smooth background image and the sparse spot image, and showed that the SOS-MAP method can overcome the above-mentioned drawback of the conventional anatomical-MAP methods. However, lesion detection performance of the SOS-MAP method is not still clear. This paper investigates, through the computer observer study, the lesion detection performance of the SOS-MAP method, and shows that the lesion detectability of the SOS-MAP method is superior to that of the conventional anatomical-MAP methods. (author)

2010-07-30

83

Knowledge-based extraction of cerebral vasculature from anatomical MRI  

Science.gov (United States)

A vessel extraction approach is presented that permits visualization of the cerebral vasculature in 3D from anatomical proton density (PD) weighted magnetic resonance imaging (MRI) volumes. The approach presented utilizes general knowledge about the shape and size of the cerebral vasculature and is divided into multi-scale vessel enhancement filtering, centre-line extraction, and surface modeling. To improve the discrimination between blood vessels and other tissue a multi-scale filtering method that enhances tubular structures is used as a pre-processing step. Centre-line extraction is applied to roughly estimate the centre-line of the vasculature involving both segmentation and skeletonization. The centre-line is used to initialize an active contour modeling process where cylinders are used to model the 3D surface of the blood vessels. The accuracy and robustness of the vessel extraction approach have been demonstrated on both simulated and real data (1mm3 voxels). On simulated data, the mean error of the estimated radii was found to be less than 0.4mm. On real data, the vasculature was successfully extracted from 20 MRI data sets using the same input parameters. An expert found the extracted vessel surfaces to coincide with the vessel walls in the data. Results from CTA data indicate that the approach will work successfully with other imaging modalities as well.

Oestergaard, Lasse R.; Larsen, Ole V.; Haase, Jens; Van Meer, Frederick; Evans, Alan C.; Collins, D. Louis

2001-07-01

84

Piriformis fossa - an anatomical and orthopedics consideration.  

Science.gov (United States)

Introduction: Piriformis fossa is an important anatomical landmark having significant clinical value in orthopedic surgery; but its location and anatomical relationship with surrounding structures are not clearly defined. Hence it is necessary to clearly describe it in respect to anatomical and orthopedic aspect. Materials and Methods: Fifty Cadaveric dry femoral bones and Dissection of the four hip specimens were used to study the Piriformis fossa in respect to location and its relationship with surrounding structures. Clinical importance of piriformis fossa was determined in reference to antegrade femoral nail insertion. Observations: Piriformis muscle and so called piriformis fossa are unrelated entities. Piriformis fossa is anatomical site of insertion of obturator externus. In dry cadaveric femora; fossa was not always located in the direction of femoral shaft. It was located in the direction of femoral shaft in 24% cases only. In 68% cases femoral canal was aligned lateral and in 8% cases, it lies medial to the fossa. Conclusion: Piriformis fossa should be named as Trorchanteric fossa or Obturator fossa for better anatomical description. So called Piriformis fossa does not found to be universally corresponding to femoral shaft hence selection of entry site should be based on variable proximal femur and area on femur which corresponds to femoral shaft. PMID:24783092

Lakhwani, O P; Mittal, P S; Naik, D C

2014-03-01

85

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

Directory of Open Access Journals (Sweden)

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

Abdul nazir

2014-05-01

86

Preparation of the Human Skull for Skull Base Anatomic Study  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Human skulls are unsurpassed in the ability to provide three-dimensional instruction in osteology as well as understanding the sites of soft tissue insertion and the intricate course of neurovascular structures in the skull base. Recent geopolitical developments in Asia have led to extreme difficulty in obtaining human skull specimens. The purpose of this article is to present a method for the preparation of dried human skulls from fresh and frozen cadavers using commonly available chemicals....

Ator, Gregory A.; Andrews, James C.; Maxwell, David S.

1993-01-01

87

Galeal flap based on superficial temporal vessels for oral cavity and pharynx reconstruction: an anatomical study  

Digital Repository Infrastructure Vision for European Research (DRIVER)

PURPOSE: Despite the advances in microvascular free tissue transfer for intraoral reconstruction, this surgery is not recommended for all patients. In specific cases, the pedicled temporoparietal galeal flap may be an option for reconstructive procedures in the head and neck regions. The objective of this paper is to present the anatomical aspects of a galeal flap based on the superficial temporal vessels and to test its potential for reconstructing diverse sites of the oral cavity and pharyn...

Fabio Pinto; Roberto Magalhães; Marcelo Durazzo; Lenine Brandão; Aldo Junqueira Rodrigues Jr.

2008-01-01

88

DETEKSI LANDMARK CITRA WAJAH DENGAN EXTRAKSI FITUR GABOR ANALISA FUZZY  

Directory of Open Access Journals (Sweden)

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.

Resmana Lim

2003-01-01

89

Color Atlas of Skeletal landmark definitions. Guidelines for reproducible manual and virtual palpations.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This book defines the location of anatomic landmarks by means of two palpation protocols: manual palpation, which allows spatial location of landmarks using hands combined or not with threedimensional (3D) digitizing, and virtual palpation on 3D computer models obtained, for example, from medical imaging. These protocols can be used independently or in combination. Manual palpation is used clinically for variouspurposes:• Identification of painful areas• Positioning of particular pieces o...

Sint Jan, Serge

2007-01-01

90

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

Directory of Open Access Journals (Sweden)

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

Queenilyn B. Albutra

2012-06-01

91

Early fetal anatomical sonography.  

LENUS (Irish Health Repository)

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.

Donnelly, Jennifer C

2012-10-01

92

DETEKSI LANDMARK CITRA WAJAH DENGAN EXTRAKSI FITUR GABOR ANALISA FUZZY  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Resmana Lim

2003-01-01

93

Evaluation of lesion detection capabilities of anatomically based MAP image reconstruction methods using the computer observer model  

International Nuclear Information System (INIS)

This study was conducted to evaluate the lesion detection capabilities of anatomically based maximum a posteriori (MAP) image reconstruction methods in emission computed tomography using the computer observer model. In lesion detection tasks, conventional anatomically based MAP reconstruction methods cannot preserve lesions not present in the anatomical image with high contrast and at the same time suppress noise in the background regions. We previously proposed a new anatomically based MAP reconstruction method called the SOS-MAP method, which is based on the spots-on-smooth image model in which the image is modeled by the sum of the smooth background image and the sparse spot image, and showed that the SOS-MAP method can overcome the above-mentioned drawback of conventional anatomically based MAP methods. However, the lesion detection capabilities of the SOS-MAP method remained to be clarified. In the present study, the computer observer model was used to evaluate the lesion detection capabilities of the SOS-MAP method, and it was found that the SOS-MAP method is superior to conventional anatomically based MAP methods for the detection of lesions. (author)

2010-09-01

94

Mapped Landmark Algorithm for Precision Landing  

Science.gov (United States)

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

Johnson, Andrew; Ansar, Adnan; Matthies, Larry

2007-01-01

95

Galeal flap based on superficial temporal vessels for oral cavity and pharynx reconstruction: an anatomical study  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english PURPOSE: Despite the advances in microvascular free tissue transfer for intraoral reconstruction, this surgery is not recommended for all patients. In specific cases, the pedicled temporoparietal galeal flap may be an option for reconstructive procedures in the head and neck regions. The objective o [...] f this paper is to present the anatomical aspects of a galeal flap based on the superficial temporal vessels and to test its potential for reconstructing diverse sites of the oral cavity and pharynx. METHODS: We performed 40 dissections on 34 fresh adult cadavers. The flap vascular anatomy was studied by injecting latex into the superficial temporal vessels. A standardized square-shape flap measuring 10 x 10 cm², pedicled on the superficial temporal vessels, was raised. Oral cavity and oropharynx reconstruction simulations were performed after flap transposition into the mouth by passing it under the zygomatic arch. Hypopharyngeal reconstruction was tested by transposing the flap to the neck under the facial nerve. RESULTS: After latex injection, a rich vascular network over the temporoparietal galea was observed directly from the superficial temporal artery, and a well-vascularized flap based on this vessel was raised. In the reconstruction simulations, the flap was shown to be suitable for the coverage of hypothetical defects in most oral cavity and pharyngeal sites, mainly the retromolar trigone, tonsil area, and buccal mucosa. CONCLUSIONS: A galeal flap based on the superficial temporal vessels presents favorable anatomical characteristics for oral cavity and pharyngeal reconstruction.

Pinto, Fabio; Magalhães, Roberto; Durazzo, Marcelo; Brandão, Lenine; Rodrigues Jr., Aldo Junqueira.

96

Galeal flap based on superficial temporal vessels for oral cavity and pharynx reconstruction: an anatomical study  

Directory of Open Access Journals (Sweden)

Full Text Available PURPOSE: Despite the advances in microvascular free tissue transfer for intraoral reconstruction, this surgery is not recommended for all patients. In specific cases, the pedicled temporoparietal galeal flap may be an option for reconstructive procedures in the head and neck regions. The objective of this paper is to present the anatomical aspects of a galeal flap based on the superficial temporal vessels and to test its potential for reconstructing diverse sites of the oral cavity and pharynx. METHODS: We performed 40 dissections on 34 fresh adult cadavers. The flap vascular anatomy was studied by injecting latex into the superficial temporal vessels. A standardized square-shape flap measuring 10 x 10 cm², pedicled on the superficial temporal vessels, was raised. Oral cavity and oropharynx reconstruction simulations were performed after flap transposition into the mouth by passing it under the zygomatic arch. Hypopharyngeal reconstruction was tested by transposing the flap to the neck under the facial nerve. RESULTS: After latex injection, a rich vascular network over the temporoparietal galea was observed directly from the superficial temporal artery, and a well-vascularized flap based on this vessel was raised. In the reconstruction simulations, the flap was shown to be suitable for the coverage of hypothetical defects in most oral cavity and pharyngeal sites, mainly the retromolar trigone, tonsil area, and buccal mucosa. CONCLUSIONS: A galeal flap based on the superficial temporal vessels presents favorable anatomical characteristics for oral cavity and pharyngeal reconstruction.

Fabio Pinto

2008-01-01

97

Anatomic considerations for central venous cannulation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Central venous cannulation is a commonly performed procedure which facilitates resuscitation, nutritional support, and long-term vascular access. Mechanical complications most often occur during insertion and are intimately related to the anatomic relationship of the central veins. Working knowledge of surface and deep anatomy minimizes complications. Use of surface anatomic landmarks to orient the deep course of cannulating needle tracts appropriately comprises the crux of complication avoid...

2011-01-01

98

Landmark Discrimination Learning in the Dog  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Allocentric spatial memory was studied in dogs of varying ages and sources using a landmark discrimination task. The primary goal of this study was to develop a protocol to test landmark discrimination learning in the dog. Using a modified version of a landmark test developed for use in monkeys, we successfully trained dogs to make a spatial discrimination on the basis of the position of a visual landmark relative to two identical discriminanda. Task performance decreased, however, as the dis...

Milgram, Norton W.; Adams, Beth; Callahan, Heather; Head, Elizabeth; Mackay, Bill; Thirlwell, Celeste; Cotman, Carl W.

1999-01-01

99

Anatomical parameterization for volumetric meshing of the liver  

Science.gov (United States)

A coordinate system describing the interior of organs is a powerful tool for a systematic localization of injured tissue. If the same coordinate values are assigned to specific anatomical landmarks, the coordinate system allows integration of data across different medical image modalities. Harmonic mappings have been used to produce parametric coordinate systems over the surface of anatomical shapes, given their flexibility to set values at specific locations through boundary conditions. However, most of the existing implementations in medical imaging restrict to either anatomical surfaces, or the depth coordinate with boundary conditions is given at sites of limited geometric diversity. In this paper we present a method for anatomical volumetric parameterization that extends current harmonic parameterizations to the interior anatomy using information provided by the volume medial surface. We have applied the methodology to define a common reference system for the liver shape and functional anatomy. This reference system sets a solid base for creating anatomical models of the patient's liver, and allows comparing livers from several patients in a common framework of reference.

Vera, Sergio; González Ballester, Miguel A.; Gil, Debora

2014-03-01

100

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

Energy Technology Data Exchange (ETDEWEB)

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 landmark-only registration provided the noise in the surface points is not excessively high. Increased variability on the landmark fiducials resulted in increased registration errors; however, refinement of the initial landmark registration by the surface-based algorithm can compensate for small initial misalignments. The surface-based registration algorithm is quite robust to noise on the surface points and continues to improve landmark registration even at high levels of noise on the surface points. Both the canine and patient studies also demonstrate that combined landmark and surface registration has lower errors than landmark registration alone. Conclusions: In this work, we describe a model for evaluating the impact of noise variability on the input parameters of a registration algorithm in the context of cardiac ablation therapy. The model can be used to predict both registration error as well as assess which inputs have the largest effect on registration accuracy.

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

 
 
 
 
101

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

International Nuclear Information System (INIS)

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

2014-02-01

102

Glucose sensing using the Brewster reflection: polarimetric ray-tracing based upon an anatomical eye model  

Science.gov (United States)

In this paper we present theoretical analysis to support the polarimetric approach for glucose detection in the human eye applying Brewster reflection off the ocular lens. The theoretical eye model of Navarro, which is based upon anatomical data, was used to perform ray-tracing, whereas the electromagnetic and polarization parameters of light propagation through the eye-media were calculated. The errors in glucose concentration determination due to refraction and deviation from the ideal optical path were calculated under different conditions. Effects of using incident linearly and circularly polarized light and variation of intersection condition of the incoming light beam with the anterior corneal surface were taken into consideration. Calculations were performed for a wide spectral range by applying dispersion curves for the eye-media. These simulations show the potential and the limits of the proposed optical approach.

Bockle, Stefan; Rovati, Luigi; Ansari, Rafat R.

2003-07-01

103

Knowledge-based, interactive, custom anatomical scene creation for medical education: the Biolucida system.  

Science.gov (United States)

Few biomedical subjects of study are as resource-intensive to teach as gross anatomy. Medical education stands to benefit greatly from applications which deliver virtual representations of human anatomical structures. While many applications have been created to achieve this goal, their utility to the student is limited because of a lack of interactivity or customizability by expert authors. Here we describe the first version of the Biolucida system, which allows an expert anatomist author to create knowledge-based, customized, and fully interactive scenes and lessons for students of human macroscopic anatomy. Implemented in Java and VRML, Biolucida allows the sharing of these instructional 3D environments over the internet. The system simplifies the process of authoring immersive content while preserving its flexibility and expressivity. PMID:16779148

Warren, Wayne; Brinkley, James F

2005-01-01

104

Unsupervised Connectivity-Based Thresholding Segmentation of Midsagittal Brain MR Images  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, we propose an algorithm for automated segmentation of midsagittal brain MR images. First, we apply thresholding to obtain binary images. From the binary images, we locate some landmarks. Based on the landmarks and anatomical information, we preprocess the binary images, which substantially simplifies the subsequent operations. To separate regions that are incorrectly merged after this initial segmentation, a new connectivity-based threshold algorithm is proposed. Assuming that ...

1998-01-01

105

Pontos referenciais nos acessos cranianos Landmarks to the cranial approaches  

Directory of Open Access Journals (Sweden)

Full Text Available O conhecimento da topografia cranioencefálica permite delimitar os acessos cranianos. Sistematiza-se os pontos referenciais, definidos em relação aos pontos craniométricos, usados nos diferentes acessos cranianos. Dos 22 pontos referenciais descritos, os doze primeiros estão em relação com a base do crânio e os demais com a convexidade.The knowledge of the craniotopography allows the delimitation of the cranial approaches. In this study the landmarks, defined in relation to the craniometric points and used in the different cranial approaches, were systematized. Twenty two landmarks are described: the first twelve are in relation to the skull base and the remainder are in relation to the skull vertex.

Sebastião Gusmão

2003-06-01

106

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

International Nuclear Information System (INIS)

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

2003-08-21

107

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

Energy Technology Data Exchange (ETDEWEB)

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.

Yoo, Sun K [Department of Medical Engineering, Yonsei University College of Medicine, Seoul (Korea, Republic of); Kim, Yong O [Department of Plastic and Reconstructive Surgery, Yonsei University College of Medicine, Institute of Human Tissue Restoration, Seoul (Korea, Republic of); Kim, Hee-Joung [Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul (Korea, Republic of); Kim, Nam H [Department of Medical Engineering, Yonsei University College of Medicine, Seoul (Korea, Republic of); Jang, Young Beom [Department of Information and Telecommunication Engineering, Sangmyung University, Cheoan (Korea, Republic of); Kim, Kee-Deog [Department of Oral and Maxillofacial Radiology, Yonsei University College of Dentistry, Seoul (Korea, Republic of); Lee, Hye-Yeon [Department of Anatomy, Yonsei University College of Medicine, Seoul (Korea, Republic of)

2003-08-21

108

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

Science.gov (United States)

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.

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

2003-08-01

109

A statistical method for 2-D facial landmarking.  

Science.gov (United States)

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 coarse-to-fine fashion and complemented with a shape prior. We assess the accuracy and the robustness of the proposed approach in extensive cross-database conditions conducted on four face data sets (Face Recognition Grand Challenge, Cohn-Kanade, Bosphorus, and BioID). Our method has 99.33% accuracy on the Bosphorus database and 97.62% accuracy on the BioID database on the average, which improves the state of the art. We show that the method is not significantly affected by low-resolution images, small rotations, facial expressions, and natural occlusions such as beard and mustache. We further test the goodness of the landmarks in a facial expression recognition application and report landmarking-induced improvement over baseline on two separate databases for video-based expression recognition (Cohn-Kanade and BU-4DFE). PMID:21803691

Dibeklio?lu, Hamdi; Salah, Albert Ali; Gevers, Theo

2012-02-01

110

Discriminative BoW framework for mobile landmark recognition.  

Science.gov (United States)

This paper proposes a new soft bag-of-words (BoW) method for mobile landmark recognition based on discriminative learning of image patches. Conventional BoW methods often consider the patches/regions in the images as equally important for learning. Amongst the few existing works that consider the discriminative information of the patches, they mainly focus on selecting the representative patches for training, and discard the others. This binary hard selection approach results in underutilization of the information available, as some discarded patches may still contain useful discriminative information. Further, not all the selected patches will contribute equally to the learning process. In view of this, this paper presents a new discriminative soft BoW approach for mobile landmark recognition. The main contribution of the method is that the representative and discriminative information of the landmark is learned at three levels: patches, images, and codewords. The patch discriminative information for each landmark is first learned and incorporated through vector quantization to generate soft BoW histograms. Coupled with the learned representative information of the images and codewords, these histograms are used to train an ensemble of classifiers using fuzzy support vector machine. Experimental results on two different datasets show that the proposed method is effective in mobile landmark recognition. PMID:23846513

Chen, Tao; Yap, Kim-Hui

2014-05-01

111

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

Science.gov (United States)

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

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

2012-02-01

112

Retrosplenial Cortex Codes for Permanent Landmarks  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Landmarks are critical components of our internal representation of the environment, yet their specific properties are rarely studied, and little is known about how they are processed in the brain. Here we characterised a large set of landmarks along a range of features that included size, visual salience, navigational utility, and permanence. When human participants viewed images of these single landmarks during functional magnetic resonance imaging (fMRI), parahippocampal cortex (PHC) and r...

Auger, Stephen D.; Mullally, Sine?ad L.; Maguire, Eleanor A.

2012-01-01

113

Retrosplenial cortex codes for permanent landmarks.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Landmarks are critical components of our internal representation of the environment, yet their specific properties are rarely studied, and little is known about how they are processed in the brain. Here we characterised a large set of landmarks along a range of features that included size, visual salience, navigational utility, and permanence. When human participants viewed images of these single landmarks during functional magnetic resonance imaging (fMRI), parahippocampal cortex (PHC) and r...

2012-01-01

114

Desert Ants Learn Vibration and Magnetic Landmarks  

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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 a...

Buehlmann, Cornelia; Hansson, Bill S.; Knaden, Markus

2012-01-01

115

New optimization algorithm for the anatomical-based MAP image reconstruction using joint entropy  

International Nuclear Information System (INIS)

Recently, a maximum a posteriori image reconstruction method (MAP-JE), which uses sparsity of the joint histogram of an emission CT image and its corresponding anatomical image as a priori knowledge, was proposed for emission CT. The conventional MAP-JE methods use gradient-based methods to minimize the cost function including the non-convex joint entropy so that the image quality of the conventional MAP-JE methods depends highly on the free parameters that affect non-convexity of the cost function, such as the bin width of the joint histogram and the width of the Parzen window function. In this paper, we propose a new optimization algorithm with less number of free parameters for the MAP-JE reconstruction, which is developed based on the optimization technique called the surrogate function method. We show through computer simulation studies that the proposed algorithm is less sensitive to the free parameters than the conventional method and generates stably the reconstructed image reflecting the a priori knowledge. (author)

2010-07-30

116

ANATOMICAL PRINCIPLES BEHIND PRESERVATION OF LARYNGEAL NERVES DURING THYROIDECTOMY  

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

O. Fabian

2011-08-01

117

Adaptive bioinspired landmark identification for navigation control  

Science.gov (United States)

In this paper a new methodology for landmark navigation will be introduced. Either for animals or for artificial agents, the whole problem of landmark navigation can be divided into two parts: first, the agent has to recognize, from the dynamic environment, space invariant objects which can be considered as suitable landmarks for driving the motion towards a goal position; second, it has to use the information on the landmarks to effectively navigate within the environment. Here, the problem of determining landmarks has been addressed by processing the external information through a spiking network with dynamic synapses plastically tuned by an STDP algorithm. The learning processes establish correlations between the incoming stimuli, allowing the system to extract from the scenario important features which can play the role of landmarks. Once established the landmarks, the agent acquires geometric relationships between them and the goal position. This process defines the parameters of a recurrent neural network (RNN). This in turn drives the agent navigation, filtering the information about landmarks given within an absolute reference system (e.g the North). When the absolute reference is not available, a safety mechanism acts to control the motion maintaining a correct heading. Simulation results showed the potentiality of the proposed architecture: this is able to drive an agent towards the desired position in presence of stimuli subject to noise and also in the case of partially obscured landmarks.

Arena, Paolo; Cruse, Holk; Fortuna, Luigi; Lombardo, Davide; Patané, Luca; Rapisarda, Rosa

2007-06-01

118

Anatomical bases for the radiological delineation of lymph node areas. Upper limbs, chest and abdomen  

International Nuclear Information System (INIS)

Cancer spreads locally through direct infiltration into soft tissues, or at distance by invading vascular structures, then migrating through the lymphatic or blood flow. Although cancer cells carried in the blood can end in virtually any corner of the body, lymphatic migration is usually stepwise, through successive nodal stops, which can temporarily delay further progression. In radiotherapy, irradiation of lymphatic paths relevant to the localisation of the primary has been common practice for decades. Similarly, excision of cancer is often completed by lymphatic dissection. Both in radiotherapy and in surgery, advanced knowledge of the lymphatic pathways relevant to any tumour location is an important information for treatment preparation and execution. This second part describes the lymphatics of the upper limb, of the thorax and of the upper abdomen. Providing anatomical bases for the radiological delineation of lymph nodes areas in the axilla, in the chest and in the abdomen, it also offers a simplified classification for labeling the mediastinal and intra-abdominal nodal levels, grouped in each location inside three major functional areas (called I, II and III) which are all divided into three sublevels (named a, b or c)

2007-09-01

119

Proposal of a new disease concept "biliary diseases with pancreatic counterparts". Anatomical and pathological bases.  

Science.gov (United States)

The biliary tract and pancreas are located closely anatomically, and both develop from the endoderm foregut almost at the same time. Interestingly, the lining epithelia of the bile duct and main pancreatic duct show similar morphologies and phenotypes, and both are accompanied by periductal glands. Furthermore, the exocrine pancreatic acini are remnantly found in the peribiliary glands. Based on these findings, it seems plausible that the biliary tract has features of pancreatic elements in addition to the duct system, which is specialized for the drainage of bile secreted by hepatic parenchyma, particularly, hepatocytes. Interestingly, some pancreatic and biliary diseases show similar pathological features and even biological behaviors. For example, extrahepatic cholangiocarcinoma and ductal adenocarcinoma of the pancreas share many clinicopathological features. Both of them are hypothesized to arise from similar preneoplastic and early neoplastic intraepithelial lesions. Intraductal papillary tumors, with frequent mucin hyperproduction, develop in the pancreas (intraductal papillary mucinous neoplasm) and also in the biliary tract (intraductal papillary neoplasm of the bile duct). IgG4-related disease affects the biliary tract (IgG4-related sclerosing cholangitis) and the pancreas (autoimmune pancreatitis) in the same patients, with both showing similar morphologies. Herein, we propose that these non-neoplastic and neoplastic biliary diseases showing similarities to corresponding pancreatic diseases could be included in a new disease concept "biliary diseases with pancreatic counterparts". Based on this new concept, information obtained in biliary tract diseases could be applied to the analysis of pancreatic disease and vice versa, and also novel therapeutical strategies and molecular and genetic studies on pancreatic and biliary diseases may be developed with a unified approach. PMID:24108502

Nakanuma, Yasuni; Harada, Kenichi; Sasaki, Motoko; Sato, Yasunori

2014-01-01

120

Minimum cross-entropy reconstruction of PET images with anatomically based anisotropic median-diffusion filtering.  

Science.gov (United States)

We propose a spatially-variant anisotropic median-diffusion filter prior aided by anatomical knowledge for PET reconstruction. The anisotropic median-diffusion filter is applied locally to an anatomical region which is defined from a co-registered CT image. The individually smoothed regions are then combined to form a prior term in the minimum cross-entropy reconstruction algorithm. A simulated PET thorax phantom with lesions was investigated in terms of bias and contrast versus noise tradeoffs. Compared with MLEM and three other maximum a posteriori (MAP)-like reconstruction algorithms, the proposed algorithm demonstrated better bias-noise tradeoff except when the lesion was close to an anatomical boundary and better contrast-noise tradeoff in all cases. PMID:18003521

Chan, Chung; Fulton, Roger; Cai, Weidong; Feng, David Dagan; Meikle, Steven

2007-01-01

 
 
 
 
121

Motivation and Organizational Principles for Anatomical Knowledge Representation: The Digital Anatomist Symbolic Knowledge Base  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Objective: Conceptualization of the physical objects and spaces that constitute the human body at the macroscopic level of organization, specified as a machine-parseable ontology that, in its human-readable form, is comprehensible to both expert and novice users of anatomical information.

Rosse, Cornelius; Mejino, Jose? L.; Modayur, Bharath R.; Jakobovits, Rex; Hinshaw, Kevin P.; Brinkley, James F.

1998-01-01

122

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

Directory of Open Access Journals (Sweden)

Full Text Available En las ultimas dos décadas, el uso de colgajos perforantes musculocutaneos se ha incrementado a medida que los microcirujanos se han familiarizado con la técnica y estos colgajos se han convertido en una parte de la evolución de la Microcirugía. Como se basan en perforantes musculocutaneas o septocutaneas individuales, el microcirujano reconstructivodebe tener la información anatómica detallada para planificar la transferencia de colgajos perforantes. El fin de este trabajo es la revisión de las diversas técnicas angiográficas disponibles para estudiar la anatomía vascular del cuerpo humano y presentar nuestra técnica habitual de inyección vascular. Exhibiremos ejemplos ilustrativos utilizando la técnica de la inyección de gelatina de oxido de plomo para visualizar la anatomía relevante de los sitios donantes de colgajos perforantes. La técnica de la inyección de gelatina de óxido descrita por Salmon y Rees y Taylor, puede ser utilizada para inyecciones arteriales o venosas, pero la hemos utilizado primariamente para inyección arterial. Los pasos para la inyección se describen detalladamente en el trabajo. En los pasados 5 años hemos disecado un total de 21 cadáveres frescos tras estudios de inyección arterial de gelatina de oxido de plomo. Se han revisado un total de 7000 radiografías. Presentamos los resultados de la búsqueda anatómica en las áreas de cabeza, cuello, miembros superiores, torso y miembros inferiores. La técnica de la inyección de gelatina de oxido de plomo es simple y económica a su vez; la técnica de análisis computarizado es barata y las técnicas de análisis informático son directas y proveen excelente visualización de la arquitectura de la piel humana. Los delicados detalles identificados utilizando esta técnica de inyección proveen información útil a los cirujanos para planificar transferencias de piel, músculo, hueso y nervio, y por tanto favorecen nuestra comprensión de la anatomía vascular clínicamente relacionada de los colgajos perforantes.Over the past 2 decades the use of musculocutaneous perforator flaps has increased worldwide as microsurgeons have become more comfortable with the technique. Perforator flaps have now become well established as a part of the evolution of microsurgery. Since perforator flaps are based on individual musculocutaneous or septocutaneous perforators, it is imperative that the reconstructive microsurgeon has the detailed anatomical information necessary to plan perforator flap transfers. The goal of this paper is to review the various angiographic techniques which are available to study the vascular anatomy of the human body and to present our current vascular injection technique. We will show illustrative examples using the lead oxide gelatin injection technique to elucidate the relevant anatomy of perforator flap donor sites. The lead oxide gelatin injection technique has been previously reported by Salmon and Rees and Taylor. The injection technique may be used for arterial or venous injections but we have primarily used it for arterial injections. The injection steps are detailed in the paper. Over the past five years we have dissected a total of 21 human fresh cadavers after lead oxide gelatin arterial injection studies. A total of over 7000 radiographs have been reviewed and summarized. We present summarized results of the anatomical research in the areas of head and neck, upper limb, torso and lower limb regions. The lead oxide gelatin injection technique is simple and inexpensive and the computer analysis technique is straight forward and provides excellent visualization of the architecture of the human skin. The fine details identified using this injection technique provides useful information to surgeons planning transfers of skin, muscle, bone and nerve and therefore our understandingly of clinically related vascular anatomy of perforator flaps can be improved.

S. Morris

2006-12-01

123

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish En las ultimas dos décadas, el uso de colgajos perforantes musculocutaneos se ha incrementado a medida que los microcirujanos se han familiarizado con la técnica y estos colgajos se han convertido en una parte de la evolución de la Microcirugía. Como se basan en perforantes musculocutaneas o septocu [...] taneas individuales, el microcirujano reconstructivodebe tener la información anatómica detallada para planificar la transferencia de colgajos perforantes. El fin de este trabajo es la revisión de las diversas técnicas angiográficas disponibles para estudiar la anatomía vascular del cuerpo humano y presentar nuestra técnica habitual de inyección vascular. Exhibiremos ejemplos ilustrativos utilizando la técnica de la inyección de gelatina de oxido de plomo para visualizar la anatomía relevante de los sitios donantes de colgajos perforantes. La técnica de la inyección de gelatina de óxido descrita por Salmon y Rees y Taylor, puede ser utilizada para inyecciones arteriales o venosas, pero la hemos utilizado primariamente para inyección arterial. Los pasos para la inyección se describen detalladamente en el trabajo. En los pasados 5 años hemos disecado un total de 21 cadáveres frescos tras estudios de inyección arterial de gelatina de oxido de plomo. Se han revisado un total de 7000 radiografías. Presentamos los resultados de la búsqueda anatómica en las áreas de cabeza, cuello, miembros superiores, torso y miembros inferiores. La técnica de la inyección de gelatina de oxido de plomo es simple y económica a su vez; la técnica de análisis computarizado es barata y las técnicas de análisis informático son directas y proveen excelente visualización de la arquitectura de la piel humana. Los delicados detalles identificados utilizando esta técnica de inyección proveen información útil a los cirujanos para planificar transferencias de piel, músculo, hueso y nervio, y por tanto favorecen nuestra comprensión de la anatomía vascular clínicamente relacionada de los colgajos perforantes. Abstract in english Over the past 2 decades the use of musculocutaneous perforator flaps has increased worldwide as microsurgeons have become more comfortable with the technique. Perforator flaps have now become well established as a part of the evolution of microsurgery. Since perforator flaps are based on individual [...] musculocutaneous or septocutaneous perforators, it is imperative that the reconstructive microsurgeon has the detailed anatomical information necessary to plan perforator flap transfers. The goal of this paper is to review the various angiographic techniques which are available to study the vascular anatomy of the human body and to present our current vascular injection technique. We will show illustrative examples using the lead oxide gelatin injection technique to elucidate the relevant anatomy of perforator flap donor sites. The lead oxide gelatin injection technique has been previously reported by Salmon and Rees and Taylor. The injection technique may be used for arterial or venous injections but we have primarily used it for arterial injections. The injection steps are detailed in the paper. Over the past five years we have dissected a total of 21 human fresh cadavers after lead oxide gelatin arterial injection studies. A total of over 7000 radiographs have been reviewed and summarized. We present summarized results of the anatomical research in the areas of head and neck, upper limb, torso and lower limb regions. The lead oxide gelatin injection technique is simple and inexpensive and the computer analysis technique is straight forward and provides excellent visualization of the architecture of the human skin. The fine details identified using this injection technique provides useful information to surgeons planning transfers of skin, muscle, bone and nerve and therefore our understandingly of clinically related vascular anatomy of perforator flaps can be improved.

S., Morris; M., Tang; C.R., Geddes.

124

LARGE AREA LANDMARKS - DYNAMAP V.12.2  

Science.gov (United States)

GDT Large Area Landmarks represents common landmark areas within United States including military areas, prisons, educational institutions, amusement centers, government centers, sport centers, golf courses, and cemeteries....

125

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Patients with cleft lip and palate usually present dental anomalies of number, shape, structure and position in the cleft area and the general dentist is frequently asked to restore or extract those teeth. Considering that several anatomic variations are expected in teeth adjacent to cleft areas and that knowledge of these variations by general dentists is required for optimal treatment, the objectives of this paper are: 1) to describe changes in the innervation pattern of anterior teeth and ...

Ivy Kiemle Trindade-Suedam; Bruno Felipe Gaia; Cheong Kuo Cheng; Paulo Alceu Kiemle Trindade; José Carlos da Cunha Bastos; Beatriz Silva Câmara Mattos

2012-01-01

126

Landmarks selection in street map design  

Science.gov (United States)

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.

Kao, C. J.

2014-02-01

127

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

Directory of Open Access Journals (Sweden)

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

MUH RAHMAD SUHARTANTO

2010-01-01

128

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

Energy Technology Data Exchange (ETDEWEB)

Purpose : To investigate the effects of the composition and geometry of ocular media and tissues surrounding the eye on dose distributions for COMS eye plaque brachytherapy with{sup 125}I, {sup 103}Pd, or {sup 131}Cs seeds, and to investigate doses to ocular structures. Methods : An anatomically and compositionally realistic voxelized eye model with a medial tumor is developed based on a literature review. Mass energy absorption and attenuation coefficients for ocular media are calculated. Radiation transport and dose deposition are simulated using the EGSnrc Monte Carlo user-code BrachyDose for a fully loaded COMS eye plaque within a water phantom and our full eye model for the three radionuclides. A TG-43 simulation with the same seed configuration in a water phantom neglecting the plaque and interseed effects is also performed. The impact on dose distributions of varying tumor position, as well as tumor and surrounding tissue media is investigated. Each simulation and radionuclide is compared using isodose contours, dose volume histograms for the lens and tumor, maximum, minimum, and average doses to structures of interest, and doses to voxels of interest within the eye. Results : Mass energy absorption and attenuation coefficients of the ocular media differ from those of water by as much as 12% within the 20–30 keV photon energy range. For all radionuclides studied, average doses to the tumor and lens regions in the full eye model differ from those for the plaque in water by 8%–10% and 13%–14%, respectively; the average doses to the tumor and lens regions differ between the full eye model and the TG-43 simulation by 2%–17% and 29%–34%, respectively. Replacing the surrounding tissues in the eye model with water increases the maximum and average doses to the lens by 2% and 3%, respectively. Substituting the tumor medium in the eye model for water, soft tissue, or an alternate melanoma composition affects tumor dose compared to the default eye model simulation by up to 16%. In the full eye model simulations, the average dose to the lens is larger by 7%–9% than the dose to the center of the lens, and the maximum dose to the optic nerve is 17%–22% higher than the dose to the optic disk for all radionuclides. In general, when normalized to the same prescription dose at the tumor apex, doses delivered to all structures of interest in the full eye model are lowest for{sup 103}Pd and highest for {sup 131}Cs, except for the tumor where the average dose is highest for {sup 103}Pd and lowest for {sup 131}Cs. Conclusions : The eye is not radiologically water-equivalent, as doses from simulations of the plaque in the full eye model differ considerably from doses for the plaque in a water phantom and from simulated TG-43 calculated doses. This demonstrates the importance of model-based dose calculations for eye plaque brachytherapy, for which accurate elemental compositions of ocular media are necessary.

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

2014-02-15

129

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

International Nuclear Information System (INIS)

Purpose : To investigate the effects of the composition and geometry of ocular media and tissues surrounding the eye on dose distributions for COMS eye plaque brachytherapy with125I, 103Pd, or 131Cs seeds, and to investigate doses to ocular structures. Methods : An anatomically and compositionally realistic voxelized eye model with a medial tumor is developed based on a literature review. Mass energy absorption and attenuation coefficients for ocular media are calculated. Radiation transport and dose deposition are simulated using the EGSnrc Monte Carlo user-code BrachyDose for a fully loaded COMS eye plaque within a water phantom and our full eye model for the three radionuclides. A TG-43 simulation with the same seed configuration in a water phantom neglecting the plaque and interseed effects is also performed. The impact on dose distributions of varying tumor position, as well as tumor and surrounding tissue media is investigated. Each simulation and radionuclide is compared using isodose contours, dose volume histograms for the lens and tumor, maximum, minimum, and average doses to structures of interest, and doses to voxels of interest within the eye. Results : Mass energy absorption and attenuation coefficients of the ocular media differ from those of water by as much as 12% within the 20–30 keV photon energy range. For all radionuclides studied, average doses to the tumor and lens regions in the full eye model differ from those for the plaque in water by 8%–10% and 13%–14%, respectively; the average doses to the tumor and lens regions differ between the full eye model and the TG-43 simulation by 2%–17% and 29%–34%, respectively. Replacing the surrounding tissues in the eye model with water increases the maximum and average doses to the lens by 2% and 3%, respectively. Substituting the tumor medium in the eye model for water, soft tissue, or an alternate melanoma composition affects tumor dose compared to the default eye model simulation by up to 16%. In the full eye model simulations, the average dose to the lens is larger by 7%–9% than the dose to the center of the lens, and the maximum dose to the optic nerve is 17%–22% higher than the dose to the optic disk for all radionuclides. In general, when normalized to the same prescription dose at the tumor apex, doses delivered to all structures of interest in the full eye model are lowest for103Pd and highest for 131Cs, except for the tumor where the average dose is highest for 103Pd and lowest for 131Cs. Conclusions : The eye is not radiologically water-equivalent, as doses from simulations of the plaque in the full eye model differ considerably from doses for the plaque in a water phantom and from simulated TG-43 calculated doses. This demonstrates the importance of model-based dose calculations for eye plaque brachytherapy, for which accurate elemental compositions of ocular media are necessary

2014-02-01

130

Pontos referenciais nos acessos cranianos / Landmarks to the cranial approaches  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O conhecimento da topografia cranioencefálica permite delimitar os acessos cranianos. Sistematiza-se os pontos referenciais, definidos em relação aos pontos craniométricos, usados nos diferentes acessos cranianos. Dos 22 pontos referenciais descritos, os doze primeiros estão em relação com a base do [...] crânio e os demais com a convexidade. Abstract in english The knowledge of the craniotopography allows the delimitation of the cranial approaches. In this study the landmarks, defined in relation to the craniometric points and used in the different cranial approaches, were systematized. Twenty two landmarks are described: the first twelve are in relation t [...] o the skull base and the remainder are in relation to the skull vertex.

Gusmão, Sebastião; Silveira, Roberto Leal; Arantes, Aluízio.

131

Associative Basis of Landmark Learning and Integration in Vertebrates  

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Early work on spatial navigation evaluated what stimuli (kinesthetic or extra-maze) support small-scale navigation and the nature of the underlying learning (place versus response) process. Contemporary research has focused primarily on how cues interact to determine spatial search. This review covers three general findings from research on landmark-based spatial search in vertebrates. First, pigeons and rats encode simple spatial maps in both open-field and touchscreen environments. Second, ...

Leising, Kenneth J.; Blaisdell, Aaron P.

2009-01-01

132

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

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

Schunke Anja C

2012-04-01

133

Anatomical Bases of the Mechanical Complications during the Positioning of Subclavian Catheters  

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Full Text Available The subclavian vein is located at the edge of scalenecosto-clavicular triangle, surrounded by the medial aspect of the clavicle in its anterior side, the first rib on its underside and the anterior scalene muscle in his back side. Subclavian catheterization by puncture is not a harmless procedure, in fact, is the path that shows more of major mechanical complications. The main mechanical complications observed with the subclavian approach are the development of uncomplicated supraclavicular hematoma (5% and pneumothorax (1.5 - 3%. The fact of not having in mind the concept of proximity of the subclavian vein with the subclavian artery and the lung, favors the occurrence of such complications. The aim of this work is to show the structures involved in more frequent mechanical complications of percutaneous subclavian venous catheters.We used human cadaveric material, preserved in formaldehyde 10%, in which conventional and special dissected supra-and infraclavicular regions showing subclavian vein and adjacent structures.Through dissection of supraclavicular and infraclavicular regions was achieved by a proper display of the morphology of the subclavian vein and surrounding structures to be taken into account while performing the puncture of the vein and the development of complications.Considering that the puncture of the subclavian vein is a blind procedure where the vein can not be seen through the skin or palpated, it is essential to accurate knowledge of the anatomical relations of the region to successfully channel the vein and lower the risk of mechanical complications.

Giannelli, Alberto

2011-12-01

134

VISITO Tuscany: landmark recognition for cultural heritage  

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VISITO Tuscany (VIsual Support to Interactive TOurism in Tuscany) is a research project which investigates techniques for producing an interactive guide, accessible via smartphone, for tourists visiting cities of art. The system applies image analysis and content recognition techniques to recognize photographed monuments. The user just has to take a picture of a tourist landmark to obtain pertinent information on his or her smartphone.

Amato, Giuseppe; Falchi, Fabrizio; Bolettieri, Paolo

2011-01-01

135

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

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

Goffinet François

2011-10-01

136

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

Science.gov (United States)

Partial volume effect is still considered one of the main limitations in brain PET imaging given the limited spatial resolution of current generation PET scanners. The accuracy of anatomically guided partial volume effect correction (PVC) algorithms in brain PET is largely dependent on the performance of MRI segmentation algorithms partitioning the brain into its main classes, namely gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF). A comparative evaluation of four brain MRI segmentation algorithms bundled in the successive releases of Statistical Parametric Mapping (SPM) package (SPM99, SPM2, SPM5, SPM8) using clinical neurological examinations was performed. Subsequently, their impact on PVC in (18)F-FDG brain PET imaging was assessed. The principle of the different variants of the image segmentation algorithm is to spatially normalize the subject's MR images to a corresponding template. PET images were corrected for partial volume effect using GM volume segmented from coregistered MR images. The PVC approach aims to compensate for signal dilution in non-active tissues such as CSF, which becomes an important issue in the case of tissue atrophy to prevent a misinterpretation of decrease of metabolism owing to PVE. The study population consisted of 19 patients suffering from neurodegenerative dementia. Image segmentation performed using SPM5 was used as reference. The comparison showed that previous releases of SPM (SPM99 and SPM2) result in larger gray matter regions (~20%) and smaller white matter regions (between -17% and -6%), thus introducing non-negligible bias in PVC PET activity estimates (between 30% and 90%). In contrary, the more recent release (SPM8) results in similar results (<1%). It was concluded that the choice of the segmentation algorithm for MRI-guided PVC in PET plays a crucial role for the accurate estimation of PET activity concentration. The segmentation algorithm embedded within the latest release of SPM satisfies the requirement of robust and accurate segmentation for MRI-guided PVC in brain PET imaging. PMID:23046730

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

2012-12-01

137

A landmark analysis-based approach to age and sex classification of the skull of the Mediterranean monk seal (Monachus monachus) (Hermann, 1779).  

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This work aimed at applying geometric morphometric analysis techniques to the skull of the Mediterranean monk seal (Monachus monachus, Hermann, 1779). Inferential analyses were performed using a non-parameteric permutation framework based on a series of skulls of different age classes belonging to individuals of both sexes. Our goal was to establish whether a statistical approach based on osteometric measurements and surface analysis of photographs of the left lateral plane of the skull may lead to a different and scientifically sound method of age and sex classification in this critically endangered marine mammal. Our data indicate that non-parametric combination methodology enables the researcher to give local assessment using a combination with domains. Developing geometric morphometric techniques in a non-parametric permutation framework could be useful in solving high dimensional and small sample size problems as well as classification problems, including zoological classification of specimens within a specific population. The Mediterranean monk seal is believed to be the world's rarest pinniped and one of the most endangered mammals of the world, with fewer than 600 individuals currently surviving. The use of shape analysis would allow new insights into the biological characteristics of the monk seal by simply extracting potentially new information on age and size from museal specimens. PMID:19694647

Brombin, C; Mo, G; Zotti, A; Giurisato, M; Salmaso, L; Cozzi, B

2009-10-01

138

Power deposition in the head and neck of an anatomically based human body model for plane wave exposures  

International Nuclear Information System (INIS)

At certain frequencies, when the human head becomes a resonant structure, the power absorbed by the head and neck, when the body is exposed to a vertically polarized plane wave propagating from front to back, becomes significantly larger than would ordinarily be expected from its shadow cross section. This has possible implications in the study of the biological effects of electromagnetic fields. Additionally the frequencies at which these resonances occur are not readily predicted by simple approximations of the head in isolation. In order to determine these resonant conditions an anatomically based model of the whole human body has been used, with the finite-difference time-domain (FDTD) algorithm to accurately determine field propagation, specific absorption rate (SAR) distributions and power absorption in both the whole body and the head region (head and neck). This paper shows that resonant frequencies can be determined using two methods. The first is by use of the accurate anatomically based model (with heterogeneous tissue properties) and secondly using a model built from parallelepiped sections (for the torso and legs), an ellipsoid for the head and a cylinder for the neck. This approximation to the human body is built from homogeneous tissue the equivalent of two-thirds the conductivity and dielectric constant of that of muscle. An IBM SP-2 supercomputer together with a parallel FDTD code has been used to accommodate the large problem size. We find resonant frequencies for the head and neck at 207 MHz and 193 MHz for the isolated and grounded conditions, with absorption cross sections that are respectively 3.27 and 2.62 times the shadow cross section. (author)

1998-08-01

139

Ultrasound of the elbow: A systematic approach using bony landmarks  

International Nuclear Information System (INIS)

The use of bony landmarks can be helpful in performing an ultrasound study of the elbow. We discuss bony landmarks that can be used for evaluation of the common extensor tendon, ulnar collateral ligament and common flexor tendon, coronoid and olecranon fossa, ulnar nerve, and biceps tendon. We discuss bony landmarks for each of these structures.

2012-05-01

140

Strategies in Landmark Use by Children, Adults, and Marmoset Monkeys  

Science.gov (United States)

Common marmosets ("Callithrix jacchus jacchus"), human children, and human adults learned to find a goal that was located in the center of a square array of four identical landmarks. The location of the landmark array and corresponding goal varied across trials, so the task could not be solved without using the landmark array. In Experiment 1, a…

MacDonald, Suzanne E.; Spetch, Marcia L.; Kelly, Debbie M.; Cheng, Ken

2004-01-01

 
 
 
 
141

Bases Anatómicas de la Gluteoplastía Dinámica / Anatomical Basis of the Dinamic Gluteoplaty  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish La disrupción anatómica del esfínter es el mecanismo más común de incontinencia fecal. La creación de un mecanismo esfinteriano con control voluntario permite mantener la contracción en el reposo o durante los movimientos y es uno de los principios fisiológicos y quirúrgicos para la continencia. Est [...] a corrección puede realizarse mediante la transposición de músculo glúteo mayor alrededor del ano y recrear así un esfínter voluntario. La gluteoplastía dinámica consiste en la colocación de un marcapasos que permite la estimulación eléctrica crónica intermitente del músculo esquelético, resultando en la adaptación de la contractilidad basal. El objetivo del trabajo consiste en el estudio anatómico de la longitud in situ y esqueletizado del fascículo inferior del músculo glúteo máximo, de su principal pedículo nervioso, la altura en la cual penetra al músculo desde el cóccix, y la longitud de su rama más distal para finalmente, proponer variantes técnicas para este procedimiento. Se disecaron 21 regiones glúteas de ambos lados de cadáveres frescos y formolizados al 10% de ambos sexos. La longitud del fascículo muscular sin esqueletizar osciló entre 17,8 y 19,65 cm, y esqueletizado entre 23,9 y 20.7 cm. La distancia de penetración del nervio principal fue entre 11,25 10,2 cm y la del nervio más medial se situó promedialmente entre 8,72 y 5,97 cm. La máxima longitud adquirida por el nervio principal hasta su rama más distal, osciló entre 10,4 y 9,2 cm. El fascículo inferior posee una longitud final que permite rodear completamente al ano e incluso, llegar al isquion contralateral hechos que apoyan el uso de este músculo en las transposiciones para la corrección de las incontinencias anales, sin la necesidad de realizar abordajes desmedidos y lejanos, permitiendo a su vez, el uso de un músculo de la región, evitando tracciones del pedículo neurovascular y la consiguiente isquemia luego del procedimiento quirúrgico. Se proponen tres técnicas para la rotación del colgajo Abstract in english The anatomical disruption of the sphincter is the most common mechanism of fecal incontinence. The creation of an sphincter mechanism with voluntary control allows to maintain the contraction during rest or movements and is one of the physiological and surgical principles of continence. This correct [...] ion can be made by the gluteus maximus muscle transposition around the anus recreating a voluntary sphincter. The dynamic gluteoplasty consists in the positioning of a nerve stimulator that allows the intermittent chronic electrical stimulation of the skeletal muscle resulting in the adaptation of the basal contractility. The objective of the work is the anatomic study of the inferior fascicle of the gluteus maximus muscle (its length in situ and squeletized) and of its main nervous pedicle (the height in which penetrates the muscle from coccyx, and the length of its distal branch) so as to propose technical changes for the procedure. Twenty and one gluteus regions of both sides from fresh and formalized cadavers of both sexes were dissected. The length of muscular fascicle without squeletized oscillated between 17.8 and 19.65 cm, and squeletized between 23.9 and 20.7 cm. The distance of penetration of the main nerve was between 11.25 and 10.2 cm and the one of the most internal nerve was located promedially between 8.72 and 5.97 cm. The maximun length acquired by the main nerve until its distal branch oscillated between 10.4 and 9.2 cm. The inferior fascicle has a final length that allows to surround completely the anus or even to reach the contralateral isquion, facts which support the use of this muscle in the transpositions for the correction of the anal incontinence, without making excessive or distant boardings, allowing as well the use of a muscle from the region, avoiding tractions of neurovascular pedicle and the consequent isquemia after the surgical procedure. Three technical changes for the rotation of

Borgno, Laura; Scanniello, Varinia; Rompani, Omar; Laxague, Alejandra; Páez, Sofía.

142

Bases Anatómicas de la Gluteoplastía Dinámica Anatomical Basis of the Dinamic Gluteoplaty  

Directory of Open Access Journals (Sweden)

Full Text Available La disrupción anatómica del esfínter es el mecanismo más común de incontinencia fecal. La creación de un mecanismo esfinteriano con control voluntario permite mantener la contracción en el reposo o durante los movimientos y es uno de los principios fisiológicos y quirúrgicos para la continencia. Esta corrección puede realizarse mediante la transposición de músculo glúteo mayor alrededor del ano y recrear así un esfínter voluntario. La gluteoplastía dinámica consiste en la colocación de un marcapasos que permite la estimulación eléctrica crónica intermitente del músculo esquelético, resultando en la adaptación de la contractilidad basal. El objetivo del trabajo consiste en el estudio anatómico de la longitud in situ y esqueletizado del fascículo inferior del músculo glúteo máximo, de su principal pedículo nervioso, la altura en la cual penetra al músculo desde el cóccix, y la longitud de su rama más distal para finalmente, proponer variantes técnicas para este procedimiento. Se disecaron 21 regiones glúteas de ambos lados de cadáveres frescos y formolizados al 10% de ambos sexos. La longitud del fascículo muscular sin esqueletizar osciló entre 17,8 y 19,65 cm, y esqueletizado entre 23,9 y 20.7 cm. La distancia de penetración del nervio principal fue entre 11,25 10,2 cm y la del nervio más medial se situó promedialmente entre 8,72 y 5,97 cm. La máxima longitud adquirida por el nervio principal hasta su rama más distal, osciló entre 10,4 y 9,2 cm. El fascículo inferior posee una longitud final que permite rodear completamente al ano e incluso, llegar al isquion contralateral hechos que apoyan el uso de este músculo en las transposiciones para la corrección de las incontinencias anales, sin la necesidad de realizar abordajes desmedidos y lejanos, permitiendo a su vez, el uso de un músculo de la región, evitando tracciones del pedículo neurovascular y la consiguiente isquemia luego del procedimiento quirúrgico. Se proponen tres técnicas para la rotación del colgajoThe anatomical disruption of the sphincter is the most common mechanism of fecal incontinence. The creation of an sphincter mechanism with voluntary control allows to maintain the contraction during rest or movements and is one of the physiological and surgical principles of continence. This correction can be made by the gluteus maximus muscle transposition around the anus recreating a voluntary sphincter. The dynamic gluteoplasty consists in the positioning of a nerve stimulator that allows the intermittent chronic electrical stimulation of the skeletal muscle resulting in the adaptation of the basal contractility. The objective of the work is the anatomic study of the inferior fascicle of the gluteus maximus muscle (its length in situ and squeletized and of its main nervous pedicle (the height in which penetrates the muscle from coccyx, and the length of its distal branch so as to propose technical changes for the procedure. Twenty and one gluteus regions of both sides from fresh and formalized cadavers of both sexes were dissected. The length of muscular fascicle without squeletized oscillated between 17.8 and 19.65 cm, and squeletized between 23.9 and 20.7 cm. The distance of penetration of the main nerve was between 11.25 and 10.2 cm and the one of the most internal nerve was located promedially between 8.72 and 5.97 cm. The maximun length acquired by the main nerve until its distal branch oscillated between 10.4 and 9.2 cm. The inferior fascicle has a final length that allows to surround completely the anus or even to reach the contralateral isquion, facts which support the use of this muscle in the transpositions for the correction of the anal incontinence, without making excessive or distant boardings, allowing as well the use of a muscle from the region, avoiding tractions of neurovascular pedicle and the consequent isquemia after the surgical procedure. Three technical changes for the rotation of flap are proposed

Laura Borgno

2007-09-01

143

Wavelet-based resolution recovery using an anatomical prior provides quantitative recovery for human population phantom PET [11C]raclopride data  

Science.gov (United States)

The objective of this study was to evaluate a resolution recovery (RR) method using a variety of simulated human brain [11C]raclopride positron emission tomography (PET) images. Simulated datasets of 15 numerical human phantoms were processed by a wavelet-based RR method using an anatomical prior. The anatomical prior was in the form of a hybrid segmented atlas, which combined an atlas for anatomical labelling and a PET image for functional labelling of each anatomical structure. We applied RR to both 60 min static and dynamic PET images. Recovery was quantified in 84 regions, comparing the typical ‘true’ value for the simulation, as obtained in normal subjects, simulated and RR PET images. The radioactivity concentration in the white matter, striatum and other cortical regions was successfully recovered for the 60 min static image of all 15 human phantoms; the dependence of the solution on accurate anatomical information was demonstrated by the difficulty of the technique to retrieve the subthalamic nuclei due to mismatch between the two atlases used for data simulation and recovery. Structural and functional synergy for resolution recovery (SFS-RR) improved quantification in the caudate and putamen, the main regions of interest, from?-30.1% and?-26.2% to?-17.6% and?-15.1%, respectively, for the 60 min static image and from?-51.4% and?-38.3% to?-27.6% and?-20.3% for the binding potential (BPND) image, respectively. The proposed methodology proved effective in the RR of small structures from brain [11C]raclopride PET images. The improvement is consistent across the anatomical variability of a simulated population as long as accurate anatomical segmentations are provided.

Shidahara, M.; Tsoumpas, C.; McGinnity, C. J.; Kato, T.; Tamura, H.; Hammers, A.; Watabe, H.; Turkheimer, F. E.

2012-05-01

144

Wavelet-based resolution recovery using an anatomical prior provides quantitative recovery for human population phantom PET [11C]raclopride data  

International Nuclear Information System (INIS)

The objective of this study was to evaluate a resolution recovery (RR) method using a variety of simulated human brain [11C]raclopride positron emission tomography (PET) images. Simulated datasets of 15 numerical human phantoms were processed by a wavelet-based RR method using an anatomical prior. The anatomical prior was in the form of a hybrid segmented atlas, which combined an atlas for anatomical labelling and a PET image for functional labelling of each anatomical structure. We applied RR to both 60 min static and dynamic PET images. Recovery was quantified in 84 regions, comparing the typical ‘true’ value for the simulation, as obtained in normal subjects, simulated and RR PET images. The radioactivity concentration in the white matter, striatum and other cortical regions was successfully recovered for the 60 min static image of all 15 human phantoms; the dependence of the solution on accurate anatomical information was demonstrated by the difficulty of the technique to retrieve the subthalamic nuclei due to mismatch between the two atlases used for data simulation and recovery. Structural and functional synergy for resolution recovery (SFS-RR) improved quantification in the caudate and putamen, the main regions of interest, from??30.1% and??26.2% to??17.6% and??15.1%, respectively, for the 60 min static image and from??51.4% and??38.3% to??27.6% and??20.3% for the binding potential (BPND) image, respectively. The proposed methodology proved effective in the RR of small structures from brain [11C]raclopride PET images. The improvement is consistent across the anatomical variability of a simulated population as long as accurate anatomical segmentations are provided. (paper)

2012-05-21

145

An ethanol-based fixation method for anatomical and micro-morphological characterization of leaves of various tree species.  

Science.gov (United States)

The use of formalin constitutes serious health hazards for laboratory workers. We investigated the suitability and performance of the ethanol-based fixative, FineFIX, as a substitute for formalin for anatomical and cellular structure investigations of leaves by light microscopy and for leaf surface and ultrastructural analysis by scanning electron microscopy (SEM). We compared the anatomical features of leaf materials prepared using conventional formalin fixation with the FineFIX. Leaves were collected from ornamental tree species commonly used in urban areas. FineFIX was also compared with glutaraldehyde fixation and air drying normally used for scanning electron microscopy to develop a new method for evaluating leaf morphology and microstructure in three ornamental tree species. The cytological features of the samples processed for histological analysis were well preserved by both fixatives as demonstrated by the absence of nuclear swelling or shrinkage, cell wall detachment or tissue flaking, and good presentation of cytoplasmic vacuolization. In addition, good preservation of surface details and the absence of shrinkage artefacts confirmed the efficacy of FineFIX fixation for SEM analysis. Cuticular wax was preserved only in air dried samples. Samples treated with chemical substances during the fixation and dehydration phases showed various alterations of the wax structures. In some air dried samples a loss of turgidity of the cells was observed that caused general wrinkling of the epidermal surfaces. Commercial FineFIX is an adequate substitute for formalin in histology and it can be applied successfully also for SEM investigation, while reducing the health risks of glutaraldehyde or other toxic fixatives. To investigate the potential for plants to absorb and capture particulates in air, which requires preservation of the natural morphology of trichomes and epicuticular waxes, a combination of FineFIX fixation and air drying is recommended. PMID:23244233

Chieco, C; Rotondi, A; Morrone, L; Rapparini, F; Baraldi, R

2013-02-01

146

Automatic X-ray landmark detection and shape segmentation via data-driven joint estimation of image displacements.  

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In this paper, we propose a new method for fully-automatic landmark detection and shape segmentation in X-ray images. To detect landmarks, we estimate the displacements from some randomly sampled image patches to the (unknown) landmark positions, and then we integrate these predictions via a voting scheme. Our key contribution is a new algorithm for estimating these displacements. Different from other methods where each image patch independently predicts its displacement, we jointly estimate the displacements from all patches together in a data driven way, by considering not only the training data but also geometric constraints on the test image. The displacements estimation is formulated as a convex optimization problem that can be solved efficiently. Finally, we use the sparse shape composition model as the a priori information to regularize the landmark positions and thus generate the segmented shape contour. We validate our method on X-ray image datasets of three different anatomical structures: complete femur, proximal femur and pelvis. Experiments show that our method is accurate and robust in landmark detection, and, combined with the shape model, gives a better or comparable performance in shape segmentation compared to state-of-the art methods. Finally, a preliminary study using CT data shows the extensibility of our method to 3D data. PMID:24561486

Chen, C; Xie, W; Franke, J; Grutzner, P A; Nolte, L-P; Zheng, G

2014-04-01

147

A Bony Landmark ‘RAI Triangle’ to Prevent ‘Misplaced and Misdirected’ Medial Cut in SSRO  

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‘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 ...

2011-01-01

148

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2009-02-15

149

Not enough skeletons in the closet: collections-based anatomical research in an age of conservation conscience.  

Science.gov (United States)

The emergence of new technologies and improved computing power helped to introduce a renewed vitality in morphological research in recent decades. This is especially apparent in the new advances made in understanding the evolutionary morphology of the skeletal system in extinct and extant squamate reptiles. The new data generated as a result of the recent increase in attention are relevant not only for systematic analyses but also are valuable in their own right for contributing to holistic perspectives on organismal evolution, mosaic evolution in the rates of change in different anatomical systems, and broader patterns of macroevolution. A global community of morphological researchers now can share data through online digital collections, but opportunities for continued advance are hindered because we lack even basic data on patterns of variation of the skeletal system for virtually all squamate lineages. Most work on skeletal morphology of squamates is based on a sample size of n?=?1; this is an especially noticeable phenomenon for studies relying on X-ray computed tomography technology. We need new collections of skeletal specimens, both material and digital, and new approaches to the study of skeletal morphology. Promising areas for continued research include the recent focus on skeletal elements not traditionally included in morphological studies (especially systematic analyses based upon morphological data) and efforts to elucidate patterns of variation and phylogenetically informative features of disarticulated skeletal elements. PMID:24482266

Bell, Christopher J; Mead, Jim I

2014-03-01

150

The heart of the newborn child: an anatomical study based upon transverse serial sections.  

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This study of the newborn child heart is based mainly on observations made on thin (0.2 mm) serial transverse sections of an entire thorax. Several features of the cardiovascular system associated with the fetal circulation are discussed. Despite considerable differences between the cardiac form in the newborn child and that in later postnatal life, the orientation of the heart in the newborn child has already attained many of its postnatal features. For example, it lies more nearly in the ho...

Walmsley, R.; Monkhouse, W. S.

1988-01-01

151

The behavioural relevance of landmark texture for honeybee homing  

Directory of Open Access Journals (Sweden)

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

LauraDittmar

2011-04-01

152

Anatomical correlates of quality of life: Evidence from voxel-based morphometry.  

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Quality of life (QOL) has been defined in many ways, and these definitions usually emphasize happiness and satisfaction with life. Health-related problems are known to cause lower QOL. However, the neural mechanisms underlying individual differences in QOL measured by questionnaire (QOLMQ) in young healthy subjects are unknown. QOL is essential to our well-being, and investigation of the neural mechanisms underlying QOL in uncompromised subjects is obviously of great scientific and social interest. We used voxel-based morphometry to investigate the association between regional gray matter volume (rGMV) and QOLMQ across the brain in healthy young adults (age, 21.4 ± 1.8 years) men (n = 88) and women (n = 68) in humans. We found significant negative relationships between QOLMQ and rGMV in a region in the left rostrolateral prefrontal cortex and regions in the dorsal part of the anterior cingulate gyrus and contingent cingulate regions. These findings show that structural variations in regions associated with processing of negative emotions such as fear and anger as well as those associated with evaluation of internally generated information are associated with QOLMQ. These findings suggest that these processes might be related to QOLMQ in healthy young adults. Hum Brain Mapp 35:1834-1846, 2014. © 2013 Wiley Periodicals, Inc. PMID:23671021

Takeuchi, Hikaru; Taki, Yasuyuki; Nouchi, Rui; Hashizume, Hiroshi; Sassa, Yuko; Sekiguchi, Atsushi; Kotozaki, Yuka; Nakagawa, Seishu; Nagase, Tomomi; Miyauchi, Carlos Makoto; Kawashima, Ryuta

2014-05-01

153

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

International Nuclear Information System (INIS)

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

2011-09-01

154

[Surgical landmarks of course of atrioventricular conduction system].  

Science.gov (United States)

There is a certain tendency in the relationship between the distribution of the conduction system and the type of VSD as classified by Soto and coworkers. The course of the conduction system and its surgical landmarks were investigated histologically in various cardiac anomalies. In perimembranous inlet VSD, the His bundle ran superficially on the crest of the ventricular septum. It ran on the left ventricular aspect and somewhat deeply in trabecular VSD and far deeply in infundibular VSD. In perimembranous inlet or trabecular VSD, the RBB laid beneath or just anterior to a series of upper-uppermost accessory papillary muscle when these were present and descended posteroinferior to the MPM, basically as in the normal heart. The upper-uppermost AcPM are reliable landmarks for the RBB. The RBB descended just anterior to the so called MPM (embryologically the uppermost AcPM--Van Mierop) in infundibular VSD and TOF. These findings have provided us useful bases for suture placement to avoid conduction disturbance. PMID:9301911

Yamashiro, T; Matsumoto, T; Kiyoku, H; Tamiya, T

1989-04-01

155

Landmark vs. Geometry Learning: Explaining Female Rats' Selective Preference for a Landmark  

Science.gov (United States)

Rats were trained in a triangular-shaped pool to find a hidden platform, whose location was defined in terms of two sources of information, a landmark outside the pool and a particular corner of the pool. Subsequent test trials without the platform pitted these two sources of information against one another. In Experiment 1 this test revealed a…

Torres, Marta N.; Rodríguez, Clara A.; Chamizo, V. D.; Mackintosh, N. J.

2014-01-01

156

The behavioural relevance of landmark texture for honeybee homing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

2011-01-01

157

The Behavioral Relevance of Landmark Texture for Honeybee Homing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

2011-01-01

158

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

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

Jansen Casper L

2011-07-01

159

Role of Dentate Gyrus in Aligning Internal Spatial Map to External Landmark  

Science.gov (United States)

Humans and animals form internal representations of external space based on their own body movement (dead reckoning) as well as external landmarks. It is poorly understood, however, how different types of information are integrated to form a unified representation of external space. To examine the role of dentate gyrus (DG) in this process, we…

Lee, Jong Won; Kim, Woon Ryoung; Sun, Woong; Jung, Min Whan

2009-01-01

160

Load-transfer analysis after insertion of cementless anatomical femoral stem using pre- and post-operative CT images based patient-specific finite element analysis.  

Science.gov (United States)

Periprosthetic bone remodeling is commonly seen after total hip arthroplasty, but the remodeling pattern differs among patients even in those implanted with the same stem. Remodeling occurs mainly because of the difference in load transmitted from the stem to the femur. In this study, we evaluated the load-transfer pattern in eight female patients implanted with an anatomical stem on an individual basis by patient-specific finite element analysis that is based on pre- and postoperative computed tomography images. Load transfer was evaluated using interface stress between the stem and bone. One of eight patients demonstrated proximal dominant load transfer, while the other patients demonstrated a distal dominant pattern. The results of our biomechanical simulations reveal the differences in load-transfer pattern after surgery among patients with the same anatomical stem. PMID:24629623

Yamako, Go; Chosa, Etsuo; Zhao, Xin; Totoribe, Koji; Watanabe, Shinji; Sakamoto, Takero; Nakane, Nobutake

2014-06-01

 
 
 
 
161

An Image-Based Model of the Whole Human Heart with Detailed Anatomical Structure and Fiber Orientation  

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Many heart anatomy models have been developed to study the electrophysiological properties of the human heart. However, none of them includes the geometry of the whole human heart. In this study, an anatomically detailed mathematical model of the human heart was firstly reconstructed from the computed tomography images. In the reconstructed model, the atria consisted of atrial muscles, sinoatrial node, crista terminalis, pectinate muscles, Bachmann's bundle, intercaval bundles, and limbus of ...

Deng, Dongdong; Jiao, Peifeng; Ye, Xuesong; Xia, Ling

2012-01-01

162

Anatomical imaging for radiotherapy  

International Nuclear Information System (INIS)

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

2008-06-21

163

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

Science.gov (United States)

...Activities: National Historic Landmarks (NHL) Condition Survey AGENCY: National Park...1024-NEW, National Historic Landmarks (NHL) Condition Survey in the subject line...Abstract National Historic Landmarks (NHL) are nationally significant historic...

2012-07-30

164

Midline Incisional Hernia. Anatomical Repairs for the Treatment with Prothesis  

Directory of Open Access Journals (Sweden)

Full Text Available 77% of the incisional hernias are located in the midline of the anterior abdominal wall. As a reinforcement of this surgical intervention, the use of a prothesis has been proposed. It’s of main concern the proper knowledge of the anatomical landmarks to perform the colocation of a prothesis in an intermuscular region. The objective of this work is to describe the anatomical landmarks for the colocation of the prothesis in the “retro-rectal intravainal space” during the treatment of midline incisional hernias. A bibliographic and retrospective analysis of the patients treated by the Ponka technique was made, emphasizing on the description of the anatomical landmarks and the technical complications recorded along the period of January 2002 – January 2012. The anatomical and surgical findings are analyzed in this work. On the therapeutic point of view, 431 surgical interventions where effectuated by the use of the Ponka technique, 253 of this group where women with an average age of 41 years old. In 194 cases, transaction of aponeurosis of external oblique muscle was made. The medial edge of the aponeurosis of the rectal muscle was dissected and the posterior space of the muscle was also dissected. In all cases, the superior and inferior epigastric vessels where identified. The polypropylene mesh was located with stitches in a “U” pattern; reabsorbable string was used, in the anterior region of the lateral sector. The medial edge of the aponeurosis of the rectal muscle was sutured. The Ponka technique is an easy and reproductible technique, with a short learning curve. The dissection of the aponeurosis of the rectal muscle, the placement of the mesh and the posterior suture are easy surgical interventions. By this technique, the objectives established by Shell and other authors are accomplished in the treatment of midline medial incisional hernia.

Madeo, Sergio Damián

2012-09-01

165

Application of landmark morphometrics to skulls representing the orders of living mammals  

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Full Text Available Abstract Statistical analyses of geometric morphometric data have been generally restricted to the Euclidean space tangent to curved shape space. This approach is based on the knowledge that such an approximation does not affect statistical and biological conclusions, when differences among specimens' shapes are not too large. We examined the wide variation of shapes within the vertebrate class Mammalia to determine the tangent space approximation by comparing Procrustes distances in Kendall shape space to tangent space distances among 53 mammal skulls and articulated jaws belonging to almost all of the living orders. Previous studies have been restricted to relatively low taxonomic levels, implying a narrower range of shapes. Thirty-five three-dimensional (3D landmarks on the sagittal plane and right side of each specimen were digitized using a MicroScribe 3DX. Procrustes and tangent space distances between all specimens were compared using the program TPSSMALL (Rohlf, 1998b. The correlations between these distances were always greater than 0.99. Lower jaw and brain subsets of the landmarks gave similar results, while the face subset had more scatter, but nearly the same correlation. The 3D shapes, as summarized by the landmarks, were clustered and the dendrogram was compared to a currently hypothesized phylogeny. We also point out that data from landmark morphometrics are as appropriate as morphological and molecular data for cladistic analysis.

Leslie Marcus

2000-06-01

166

Landmarks and ant search strategies after interrupted tandem runs.  

Science.gov (United States)

During a tandem run, a single leading ant recruits a single follower to an important resource such as a new nest. To examine this process, we used a motorized gantry, which has not previously been used in ant studies, to track tandem running ants accurately in a large arena and we compared their performance in the presence of different types of landmark. We interrupted tandem runs by taking away the leader and moved a large distant landmark behind the new nest just at the time of this separation. Our aim was to determine what information followers might have obtained from the incomplete tandem run they had followed, and how they behaved after the tandem run had been interrupted. Our results show that former followers search by using composite random strategies with elements of sub-diffusive and diffusive movements. Furthermore, when we provided more landmarks former followers searched for longer. However, when all landmarks were removed completely from the arena, the ants' search duration lasted up to four times longer. Hence, their search strategy changes in the presence or absence of landmarks. Even after extensive search of this kind, former followers headed back to their old nest but did not return along the path of the tandem run they had followed. The combination of the position to which the large distant landmark behind the new nest was moved and the presence or absence of additional landmarks influenced the orientation of the former followers' paths back to the old nest. We also found that these ants exhibit behavioural lateralization in which they possibly use their right eye more than their left eye to recognize landmarks for navigation. Our results suggest that former follower ants learn landmarks during tandem running and use this information to make strategic decisions. PMID:24198259

Basari, Norasmah; Bruendl, Aisha C; Hemingway, Charlotte E; Roberts, Nicholas W; Sendova-Franks, Ana B; Franks, Nigel R

2014-03-15

167

Pigeons combine compass and landmark guidance in familiar route navigation  

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How do birds orient over familiar terrain? In the best studied avian species, the homing pigeon (Columba livia), two apparently independent primary mechanisms are currently debated: either memorized visual landmarks provide homeward guidance directly, or birds rely on a compass to home from familiar locations. Using miniature Global Positioning System tracking technology and clock-shift procedures, we set sun-compass and landmark information in conflict, showing that experienced birds can acc...

Biro, Dora; Freeman, Robin; Meade, Jessica; Roberts, Stephen; Guilford, Tim

2007-01-01

168

3D face analysis : landmarking, expression recognition and beyond  

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This Ph.D thesis work is dedicated to automatic facial analysis in 3D, including facial landmarking and facial expression recognition. Indeed, facial expression plays an important role both in verbal and non verbal communication, and in expressing emotions. Thus, automatic facial expression recognition has various purposes and applications and particularly is at the heart of "intelligent" human-centered human/computer(robot) interfaces. Meanwhile, automatic landmarking provides aprior knowled...

Zhao, Xi

2010-01-01

169

Landmarks of History of Soil Science in Sri Lanka  

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Sri Lanka is a tropical Island in the Southern tip of Indian subcontinent positioned at 50 55' to 90 50' N latitude and 790 42' to 810 53' E longitude surrounded by the Indian Ocean. It is an island 435 km in length and 224 km width consisting of a land are of 6.56 million ha with a population of 20 million. In area wise it is ranked as 118th in the world, where at present ranked as 47 in population wise and ranked 19th in population density. The country was under colonial rule under Portuguese, Dutch and British from 1505 to 1948. The majority of the people in the past and present earn their living from activities based on land, which indicates the important of the soil resource. The objective of this paper is to describe the landmarks of the history of Soil Science to highlight the achievements and failures, which is useful to enrich our present understanding of Sri Lankan soils. The landmarks of the history of Soil Science in Sri Lanka can be divided to three phases namely, the early period (prior to 1956), the middle period (1956 to 1972) and the present period (from 1972 onwards). During the early period, detailed analytical studies of coffee and tea soils were compiled, and these gave mainly information on up-country soils which led to fertilizer recommendations based on field trials. In addition, rice and forest soils were also studied in less detail. The first classification of Sri Lankan soils and a provisional soil map based on parent material was published by Joachim in 1945 which is a major landmark of history of Soil Science in Sri Lanka. In 1959 Ponnamperuma proposed a soil classification system for wetland rice soils. From 1963 to 1968 valuable information on the land resource was collected and documented by aerial resource surveys funded by Canada-Ceylon Colombo plan aid project. This covered 18 major river basins and about 1/4th of Sri Lanka, which resulted in producing excellent soil maps and information of the areas called the Kelani Aruvi Ara and Walawe basins. The provisional soil map was updated by many other workers as Moorman and Panabokke in 1961 and 1972 using this information. The soil map produced by De Alwis and Panabokke in 1972 at a scale of 1:500,000 was the soil maps mostly used during the past years During the present era, the need for classification of Soils of Sri Lanka according to international methods was felt. A major leap forward in Soil Survey, Classification leading to development of a soil data base was initiated in 1995 with the commencement of the "SRICANSOL" project which was a twining project between the Soil Science Societies of Sri Lanka and Canada. This project is now completed with detail soil maps at a scale of 1:250,000 and soil classified according to international methods for the Wet, Intermediate and Dry zones of Sri Lanka. A digital database consisting of soil profile description and physical and chemical data is under preparation for 28, 40 and 51 benchmark sites of the Wet, Intermediate and Dry zones respectively. The emphases on studies on Soil Science in the country at present is more towards environmental conservation related to soil erosion control, reducing of pollution of soil and water bodies from nitrates, pesticide residues and heavy metal accumulation. Key words: Sri Lanka, Provisional soil map

Mapa, R.

2012-04-01

170

Comparison of radiographic measurements of the patellar tendon-tibial plateau angle with anatomical measurements in dogs. Validity of the common tangent and tibial plateau methods.  

Science.gov (United States)

Objective: To evaluate the validity of the common tangent and conventional tibial plateau angle methods for measuring the patellar tendon angle (PTA) in dogs. Methods: Radiographs of cadaveric stifles (n = 20) placed at 135° in true lateral position were obtained to measure the PTA with both methods. A Kirschner wire was inserted perpendicularly to the patellar tendon at its insertion on the tibia and the stifle was dissected. Two Kirschner wires were then used to identify the anatomical landmarks of the tibial plateau. A digital image was obtained of the proximal tibia in true lateral position. Six blinded observers measured each PTA digitally while the anatomical PTA was determined by an independent blinded observer from the angle between the line representing the tibial plateau and the Kirschner wire representing the perpendicular to the patellar tendon. The agreement between the methods was determined statistically from an intraclass correlation coefficient (ICC). Results: The global ICC for the common tangent method (0.44) and for the conventional method (0.4) indicated that their overall validity is poor. The measurements obtained by common tangentmethod and conventional method were respectively below and above the anatomical measurements. The reproducibility of the PTA measurements based on images of the dissected stifles was very good. Clinical significance: Both the common tangent and conventional methods show poor concordance with the anatomical measurement of PTA. Further studies are needed to determine if errors in measurements affect the clinical outcome. PMID:24763422

Bismuth, C; Ferrand, F X; Millet, M; Labrunie, A; Marin, B; Pillard, P; Deroy, C; Fau, D; Carozzo, C; Cachon, T; Viguier, E

2014-05-19

171

Anatomic aspects of inguinal lymph nodes applied to lymphadenectomy in penile cancer.  

Science.gov (United States)

Objectives. To provide a better understanding of the distribution of inguinal nodes in order to prevent the complications of unnecessary and extended dissections in penile cancer. Methods. The bilateral inguinal regions of 19 male cadavers were dissected. Nodal distribution was noted and quantified based on anatomical location. The superficial nodes were subdivided into quarters as follows: superomedial, superolateral, inferomedial, and inferolateral. Statistical analysis was performed comparing node distribution between quarters using one-way analysis of variance (ANOVA), and the unpaired T-test was used between superficial and deep nodes. Results. Superficial nodes were found in all inguinal regions studied (mean = 13.60), and their distribution was more prominent in the superomedial quarter (mean = 3.94) and less in the inferolateral quarter (mean = 2.73). There was statistical significance between quarters when comparing the upper group with the lower one (P = 0.02). Nodes were widely distributed in the superficial region compared with deep lymph nodes (mean = 13.60 versus 1.71, P < 0.001). Conclusions. A great number of inguinal lymph nodes are distributed near the classical anatomical landmarks for inguinal lymphadenectomy, more prominent in upper quadrants. PMID:22110493

de Carvalho, João Paulo Martins; Patrício, Bruno F; Medeiros, Jorge; Sampaio, Francisco J B; Favorito, Luciano A

2011-01-01

172

NOTE: The Virtual Family—development of surface-based anatomical models of two adults and two children for dosimetric simulations  

Science.gov (United States)

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

Christ, Andreas; Kainz, Wolfgang; Hahn, Eckhart G.; Honegger, Katharina; Zefferer, Marcel; Neufeld, Esra; Rascher, Wolfgang; Janka, Rolf; Bautz, Werner; Chen, Ji; Kiefer, Berthold; Schmitt, Peter; Hollenbach, Hans-Peter; Shen, Jianxiang; Oberle, Michael; Szczerba, Dominik; Kam, Anthony; Guag, Joshua W.; Kuster, Niels

2010-01-01

173

A framework for automated landmark recognition in community contributed image corpora  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Any large library of information requires efficient ways to organise it and methods that allow people to access information efficiently and collections of digital images are no exception. Automatically creating high-level semantic tags based on image content is difficult, if not impossible to achieve accurately. In this thesis a framework is presented that allows for the automatic creation of rich and accurate tags for images with landmarks as the main object. This framework uses state of the...

Hughes, Mark

2011-01-01

174

Information Geometry for Landmark Shape Analysis: Unifying Shape Representation and Deformation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Shape matching plays a prominent role in the comparison of similar structures. We present a unifying framework for shape matching that uses mixture models to couple both the shape representation and deformation. The theoretical foundation is drawn from information geometry wherein information matrices are used to establish intrinsic distances between parametric densities. When a parameterized probability density function is used to represent a landmark-based shape, the modes of deformation ar...

Peter, Adrian M.; Rangarajan, Anand

2009-01-01

175

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

Science.gov (United States)

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. PMID:23181631

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

2014-01-01

176

Learning model of eye movement system based on anatomical structure; Kaibogakuteki kozo ni motozuita gakushu kino wo motsu gankyu undo system to sono tokusei  

Energy Technology Data Exchange (ETDEWEB)

A learning system is proposed to explain the adaptive function of an eye movement consisting of compensatory and optokinetic reflex, and pursuit movements based on the brain anatomy and physiology. Thereby, the learning system is synthesized as an artificial neural network based on the structure and function of the biological neural network of flocculus. The role of neural paths into flocculus from stretch receptors of ocular muscles are discussed in detail from the viewpoint of system control engineering. The mathematical learning process is also shown taking into account the adaptive mechanism and the anatomical structure of vestibular nuclei. The experimental results through simulation confirm the validity of the hypothesis and the appropriateness of the inference process in connection with the proposed mathematical model. 18 refs., 11 figs.

Zhang, X.; Wakamatsu, H. [Tokyo Medical and Dental University, Tokyo (Japan)

1998-07-01

177

Anatomic Total Shoulder System  

Medline Plus

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

178

Anatomic Total Shoulder System  

Medline Plus

Full Text Available ... osteotomy on his anatomic neck posteriorly. Now in terms of positioning of the arm for glenoid exposure, ... BOARDMAN III, MD: Jerry, could you comment in terms of what type of a guide you use ...

179

Anatomic Total Shoulder System  

Medline Plus

Full Text Available ... wide array of options with an arrange of neck, angle, and version variability which allows adaptability to ... out of the osteotomy surface at the anatomic neck. Hit me. 00:05:29 Suck in there, ...

180

Anatomic Total Shoulder System  

Medline Plus

Full Text Available ... surface at the anatomic neck. Hit me. 00:05:29 Suck in there, Brent. Hit me. good. ... retroverted to the picture right now. 00:29:05 GERALD WILLIAMS, MD: Let's turn the table away ...

 
 
 
 
181

Anatomic Total Shoulder System  

Medline Plus

Full Text Available ... a patient's unique anatomical makeup. Dr. Gerald R. Williams, Jr., a shoulder specialist from the Rothman Institute ... at Methodist Hospital in Philadelphia, where Dr. Jerry Williams will be performing a total shoulder arthroplasty. Before ...

182

Anatomic Total Shoulder System  

Medline Plus

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

183

Proper name retrieval in temporal lobe epilepsy: naming of famous faces and landmarks.  

Science.gov (United States)

The objective of this study was to further explore proper name (PN) retrieval and conceptual knowledge in patients with left and right temporal lobe epilepsy (69 patients with LTLE and 62 patients with RTLE) using a refined assessment procedure. Based on the performance of a large group of age- and education-matched normals, a new test of famous faces and famous landmarks was designed. Recognition, naming, and semantic knowledge were assessed consecutively, allowing for a better characterization of deficient levels in the naming system. Impairment in PN retrieval was common in the cohort with TLE. Furthermore, side of seizure onset impaired stages of name retrieval differently: LTLE impaired the lexico-phonological processing, whereas RTLE mainly impaired the perceptual-semantic stage of object recognition. In addition to deficient PN retrieval, patients with TLE had reduced conceptual knowledge regarding famous persons and landmarks. PMID:23542541

Benke, Thomas; Kuen, Eva; Schwarz, Michael; Walser, Gerald

2013-05-01

184

Landmark learning by the Ozark zigzag salamander Plethodon angusticlavius  

Directory of Open Access Journals (Sweden)

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

Adam L. CRANE, Alicia MATHIS

2011-08-01

185

Pathology accessioning and retrieval system with encoding by computer (PARSEC). A microcomputer-based system for anatomic pathology featuring automated SNOP coding and multiple administrative functions.  

Science.gov (United States)

A pathology accessioning and retrieval system with encoding by computer (PARSEC) has been developed, employing a relatively inexpensive microcomputer. PARSEC performs a variety of administrative functions for anatomic pathology, including accessioning of surgical specimens, storage of patient demographic information, editing, retrieval, and archiving of patient data, as well as CAP (college of American Pathologists) workload units, billing, and inventory functions for histopathology. In addition, appropriate gross and microscopic descriptions and pathologic diagnoses can be entered into the system by a text editor. Automatic assignment of SNOP (Systematized Nomenclature of Pathology) codes, is accomplished via an online SNOP lexicon, allowing the ultimate generation of completed surgical pathology reports. The data base management system employed makes optimum use of disk storage space, while permitting rapid data retrieval. Data file maintenance is automatically accomplished by the system, requiring no user intervention. PMID:7395803

Foulis, P R; Norbut, A M; Mendelow, H; Kessler, G F

1980-06-01

186

The Landmark on Film: Representations of Place and Identity  

Directory of Open Access Journals (Sweden)

Full Text Available This paper examines two documentary essays focusing on landmark architecture in the transnational Øresund region comprising Copenhagen and Malmö. I argue that the motif of construction and deconstruction is congruous to our understanding of the ways identities are negotiated vis-à-vis spatial experience. In the films, the multiple trajectories of characters of diverse nationalities and cultures are woven into the (deconstruction of the landmark structures, producing a visual space that interrogates what ‘identity’ means in an increasingly networked and global world.

Pei-Sze Chow

2012-12-01

187

Precise visual navigation using multi-stereo vision and landmark matching  

Science.gov (United States)

Traditional vision-based navigation system often drifts over time during navigation. In this paper, we propose a set of techniques which greatly reduce the long term drift and also improve its robustness to many failure conditions. In our approach, two pairs of stereo cameras are integrated to form a forward/backward multi-stereo camera system. As a result, the Field-Of-View of the system is extended significantly to capture more natural landmarks from the scene. This helps to increase the pose estimation accuracy as well as reduce the failure situations. Secondly, a global landmark matching technique is used to recognize the previously visited locations during navigation. Using the matched landmarks, a pose correction technique is used to eliminate the accumulated navigation drift. Finally, in order to further improve the robustness of the system, measurements from low-cost Inertial Measurement Unit (IMU) and Global Positioning System (GPS) sensors are integrated with the visual odometry in an extended Kalman Filtering framework. Our system is significantly more accurate and robust than previously published techniques (1˜5% localization error) over long-distance navigation both indoors and outdoors. Real world experiments on a human worn system show that the location can be estimated within 1 meter over 500 meters (around 0.1% localization error averagely) without the use of GPS information.

Zhu, Zhiwei; Oskiper, Taragay; Samarasekera, Supun; Kumar, Rakesh

2007-05-01

188

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

189

Anatomic Motor Point Localization of the Biceps Brachii and Brachialis Muscles  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Injection of the neurolytic agents into motor points of the biceps brachii or brachialis muscles is an effective treatment of spasticity of the elbow flexors in many stroke survivors. Accurate localization of the motor points of each muscle is necessary for enhancing the efficacy of motor point blocks. To identify the precise locations of the motor points (terminal nerve endings) of the biceps brachii and brachialis muscles in relation to anatomic surface landmarks for motor point blocks, we ...

Park, Byung Kyu; Shin, Yong Beom; Ko, Hyun-yoon; Park, Jae Heung; Baek, Sun-yong

2007-01-01

190

A field study investigating effects of landmarks on territory size and shape.  

Science.gov (United States)

Few studies have examined how landmarks affect territories' fundamental characteristics. In this field study, we investigated effects of landmarks on territory size, shape and location in a cichlid fish (Amatitlania siquia). We provided cans as breeding sites and used plastic plants as landmarks. During 10 min trials, we recorded locations where residents chased intruders and used those locations to outline and measure the territory. In two experiments, we observed pairs without landmarks and with either a point landmark (one plant) or linear landmark (four plants) placed near the nest can. We alternated which trial occurred first and performed the second trial 24 h after the first. Territories were approximately round without landmarks or with a point landmark but were significantly more elongated when we added a linear landmark. Without landmarks, nests were centrally located; however, with any landmark, pairs set territory boundaries closer to the landmark and thus the nest. Territory size was significantly reduced in the presence of any landmark. This reduction suggests that a smaller territory with well-defined boundaries has greater benefits than a larger territory with less well-defined borders. PMID:24759367

Suriyampola, Piyumika S; Eason, Perri K

2014-01-01

191

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

Directory of Open Access Journals (Sweden)

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

Cronk Quentin CB

2011-01-01

192

Dose reduction in computed tomography by attenuation-based on-line modulation of tube current: evaluation of six anatomical regions  

International Nuclear Information System (INIS)

This study investigated the potential of attenuation-based on-line modulation of tube current to reduce the dose of computed tomography (in milliamperes) without loss in image quality. The dose can be reduced for non-circular patient cross-sections by reducing the tube current at the angular positions at which the diameter through the patient diameter is smallest. We investigated a new technical approach with attenuation-based on-line modulation of tube current. Computed tomographic projection data were analyzed to determine the optimal milliampere values for each projection angle in real time, instead of performing prior measurements with localizer radiographs. We compared image quality, noise pattern, and dose for standard scans and for scans with attenuation-based on-line modulation of tube current in a group of 30 radiation therapy patients. Six different anatomical regions were examined: head, shoulder, thorax, abdomen, pelvis, and extremities (knee). Image quality was evaluated by four radiologists in a blinded fashion. We found the dose to be reduced typically by 15-50 %. In general, no deterioration in image quality was observed. Thus the dose in computed tomography be reduced substantially by technical measures without sacrificing image quality. Attenuation-based on-line modulation of tube current is an efficient and practical means for this. (orig.)

2000-02-01

193

On-line SLAM using clustered landmarks with omnidirectional vision  

Directory of Open Access Journals (Sweden)

Full Text Available The problem of SLAM (simultaneous localization and mapping is a fundamental problem in autonomous robotics. It arises when a robot must create a map of the regions it has navigated while localizing itself on it, using results from one step to increase precision in another by eliminating errors inherent to the sensors. One common solution consists of establishing landmarks in the environment which are used as reference points for absolute localization estimates and form a sparse map that is iteratively refined as more information is obtained. This paper introduces a method of landmark selection and clustering in omnidirectional images for on-line SLAM, using the SIFT algorithm for initial feature extraction and assuming no prior knowledge of the environment. Visual sensors are an attractive way of collecting information from the environment, but tend to create an excessive amount of landmarks that are individually prone to false matches due to image noise and object similarities. By clustering several features in single objects, our approach eliminates landmarks that do not consistently represent the environment, decreasing computational cost and increasing the reliability of information incorporated. Tests conducted in real navigational situations show a significant improvement in performance without loss of quality.

Jun Okamoto Jr.

2010-12-01

194

On-line SLAM using clustered landmarks with omnidirectional vision  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The problem of SLAM (simultaneous localization and mapping) is a fundamental problem in autonomous robotics. It arises when a robot must create a map of the regions it has navigated while localizing itself on it, using results from one step to increase precision in another by eliminating errors inhe [...] rent to the sensors. One common solution consists of establishing landmarks in the environment which are used as reference points for absolute localization estimates and form a sparse map that is iteratively refined as more information is obtained. This paper introduces a method of landmark selection and clustering in omnidirectional images for on-line SLAM, using the SIFT algorithm for initial feature extraction and assuming no prior knowledge of the environment. Visual sensors are an attractive way of collecting information from the environment, but tend to create an excessive amount of landmarks that are individually prone to false matches due to image noise and object similarities. By clustering several features in single objects, our approach eliminates landmarks that do not consistently represent the environment, decreasing computational cost and increasing the reliability of information incorporated. Tests conducted in real navigational situations show a significant improvement in performance without loss of quality.

Okamoto Jr., Jun; Guizilini, Vitor Campanholo.

195

IAEA Director General welcomes landmark convention to combat nuclear terrorism  

International Nuclear Information System (INIS)

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

2005-04-18

196

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-07-15

197

Anatomic Total Shoulder System  

Medline Plus

Full Text Available ... of the osteotomy surface at the anatomic neck. Hit me. 00:05:29 Suck in there, Brent. Hit me. good. Once more. Good. So there we ... Tamp. Mallet. Good. Drill. De-rotation peg. Tamp. Hit me. Good, suction. Let's see if we have ...

198

Improving Detection Rate in Intrusion Detection Systems Using FCM Clustering to Select Meaningful Landmarks in Incremental Landmark Isomap Algorithm  

Directory of Open Access Journals (Sweden)

Full Text Available Dimension reduction is crucial when it is applied on intrusion detection systems. Many data mining algorithms have been used for this purpose. For example, manifold learning algorithms, especially Isometric feature mapping (Isomap have been investigated. Researchers successfully applied Isomap on intrusion detection system as a nonlinear dimension reduction method. But it had some problems such as operation on batch mode and being disabled to handle new data points, additionally, it had computational cost and could not be properly applied on huge datasets. Losing time and reducing speed of detection is another problem of Isomap in intrusion detection systems. Incremental Landmark Isomap which selects landmarks among whole data points has been invented for solving these problems. In this paper, we use FCM as a data reduction method to select meaningful landmarks for Incremental L-Isomap instead of choosing them randomly. This method is implemented and applied on some UCI datasets and also NSLKDD dataset. The results demonstrate higher detection rate for the proposed method, comparing to classical Incremental L-Isomap which chooses landmarks randomly.

Babak Nassersharif

2012-09-01

199

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Mohammadi, Gelareh; Fatemizadeh, Emad

2007-01-01

200

Manejo actual de la microtia: redefinición anátomo-quirúrgica / Management of microtia based on a redefinition of its anatomical-surgical classification  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish Objetivos: Reportar y evaluar la efectividad de una técnica quirúrgica, previamente descrita para el tratamiento de microtias, basado en un nuevo concepto de clasificación anátomo-quirúrgica. Material y Método: Estudio retrospectivo de pacientes tratados en el Hospital Militar y Clínica Alemana de S [...] antiago en el Servicio de Cirugía Plástica desde enero de 2008 hasta diciembre de 2010. Se reclutaron a un total de 15 pacientes, 13 (87%) de los cuales eran unilaterales y 2 (13%) bilaterales. A todos los pacientes se les realizó la reconstrucción mediante técnica quirúrgica de Firmin. Resultados: Se operó a 15 pacientes de rango de edad entre 9 y 25 años, con una mediana de 11 años. De los casos unilaterales; 7 correspondían a tipo I de Firmin, 5 casos a tipo II Firmin y un caso tipo IIIa. De los casos bilaterales, ambos tenían microtia tipo IIIb. Se logró en la totalidad de los casos unilaterales una buena proyección inicial del marco cartilaginoso durante el primer tiempo quirúrgico. Seis casos fueron sometidos a un segundo tiempo quirúrgico. Durante el seguimiento mínimo de 18 meses, se observaron complicaciones en 4 (16%) pacientes. Conclusiones: Se comprueba que mediante una técnica basada en la clasificación anátomo-quirúrgica, los resultados a corto plazo fueron favorables y satisfactorios. Abstract in english Background: Incomplete development and growth of the pinna can lead to a small or deformed pinna, called microtia. Aim: To report and evaluate the effectiveness of a surgical technique previously described for the treatment of microtia, based on a new anatomical-surgical classification. Materials an [...] d Methods: Retrospective study of patients treated at two plastic surgery departments from January 2008 to December 2010. We recruited a total of 15 patients aged 9 to 25 years. Thirteen (87%) had unilateral and 2 (13%) bilateral microtia. All patients underwent the surgical reconstructive technique described by Firmin. Results: Among patients with unilateral microtia, seven belonged to Firmin type I, five to type II and one to type IIIa. Both patients with bilateral microtia, were classified as type IIIb. In all cases with unilateral microtia, a good initial projection of the cartilage frame was achieved during the first surgical procedure. Six patients were subjected to a second operation. During 18 months follow up, four patients (16%) had complications. Conclusions: This surgical technique that is based on an anatomical surgical classification, achieves favorable and satisfactory results.

Sorolla P, Juan Pablo; Arbulo L, Douglas; Obaid G, Miguel; Ibarra M, Carla; Fontbona, Montserrat; Cabello P, Rodrigo; Wisnia C, Pamela; Bautista S, Ángela.

 
 
 
 
201

Development of IDL-based software for multimodal image registration  

International Nuclear Information System (INIS)

Image registration with anatomical modalities such as CT and MRI, facilitates the anatomical localization in the interpretation of nuclear medicine images, which are relatively lacking in anatomical information. User-friendly program for image registration and fusion of registered images was developed. In consideration of easy transplantation to various operating systems (OS), the program was developed using IDL language. For the registration without operator's interaction, several automatic algorithms were implemented, which include principal axes matching and maximization of mutual information methods. User interface was designed to support the manual registration using point landmarks and the correction for unwanted mis-registration. Fused images were composed by overlaying one image with the other one transparently, in which the opacity of overlaid image was interactively controlled. OS and platform independent program for image registration was developed based on IDL language. It will be useful for the clinical application of image registration techniques

2001-11-16

202

Anatomy of the Clitoris: Revision and Clarifications about the Anatomical Terms for the Clitoris Proposed (without Scientific Bases) by Helen O'Connell, Emmanuele Jannini, and Odile Buisson  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The anatomy of the clitoris is described in human anatomy textbooks. Some researchers have proposal and divulged a new anatomical terminology for the clitoris. This paper is a revision of the anatomical terms proposed by Helen O'Connell, Emmanuele Jannini, and Odile Buisson. Gynecologists, sexual medicine experts, and sexologists should spread certainties for all women, not hypotheses or personal opinions, they should use scientific terminology: clitoral/vaginal/uterine orgasm, G/A/C/U spot o...

Puppo, Vincenzo

2011-01-01

203

AIDS-Related Cancers - SEER Landmark Studies  

Science.gov (United States)

SEER is an authoratitive source of information on cancer incidence and survival in the United States. SEER currently collects and publishes cancer incidence and survival data from population-based cancer registries covering approximately 28 percent of the U.S. population.

204

Physical Activity and Cancer - SEER Landmark Studies  

Science.gov (United States)

SEER is an authoritative source of information on cancer incidence and survival in the United States. SEER currently collects and publishes cancer incidence and survival data from population-based cancer registries covering approximately 28 percent of the U.S. population.

205

National Bladder Cancer Study - SEER Landmark Studies  

Science.gov (United States)

SEER is an authoratitive source of information on cancer incidence and survival in the United States. SEER currently collects and publishes cancer incidence and survival data from population-based cancer registries covering approximately 28 percent of the U.S. population.

206

Correction of dental artifacts within the anatomical surface in PET/MRI using active shape models and k-nearest-neighbors  

Science.gov (United States)

In combined PET/MR, attenuation correction (AC) is performed indirectly based on the available MR image information. Metal implant-induced susceptibility artifacts and subsequent signal voids challenge MR-based AC. Several papers acknowledge the problem in PET attenuation correction when dental artifacts are ignored, but none of them attempts to solve the problem. We propose a clinically feasible correction method which combines Active Shape Models (ASM) and k- Nearest-Neighbors (kNN) into a simple approach which finds and corrects the dental artifacts within the surface boundaries of the patient anatomy. ASM is used to locate a number of landmarks in the T1-weighted MR-image of a new patient. We calculate a vector of offsets from each voxel within a signal void to each of the landmarks. We then use kNN to classify each voxel as belonging to an artifact or an actual signal void using this offset vector, and fill the artifact voxels with a value representing soft tissue. We tested the method using fourteen patients without artifacts, and eighteen patients with dental artifacts of varying sizes within the anatomical surface of the head/neck region. Though the method wrongly filled a small volume in the bottom part of a maxillary sinus in two patients without any artifacts, due to their abnormal location, it succeeded in filling all dental artifact regions in all patients. In conclusion, we propose a method, which combines ASM and kNN into a simple approach which, as the results show, succeeds to find and correct the dental artifacts within the anatomical surface.

Ladefoged, Claes N.; Andersen, Flemming L.; Keller, Sune H.; Beyer, Thomas; Højgaard, Liselotte; Lauze, François

2014-03-01

207

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

DEFF Research Database (Denmark)

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

Goranko, Valentin

2012-01-01

208

Reference Man anatomical model  

Energy Technology Data Exchange (ETDEWEB)

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

Cristy, M.

1994-10-01

209

Discovering landmark preferences and movement patterns from photo postings  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This article presents a geovisual analytics approach to discovering people's preferences for landmarks and movement patterns from photos posted on the Flickr website. The approach combines an exploratory spatio-temporal analysis of geographic coordinates and dates representing locations and time of taking photos with basic thematic information available through the Google Maps Web mapping service, and interpretation of the analyzed area. The article describes data aggregation and filtering te...

2010-01-01

210

Comparative genome mapping with mobile physical map landmarks.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We describe a method for comparative macrorestriction mapping of the chromosomes of Escherichia coli strains. In this method, a series of physically tagged E. coli K-12 alleles serve as mobile landmarks for mapping DNAs from other strains. This technique revealed evidence of strain-specific chromosomal additions or deletions in a pathogenic isolate and can be applied to most strains, yielding information on genealogy as well as virulence. In theory, the same strategy can be used to map and co...

Bloch, C. A.; Rode, C. K.; Obreque, V.; Russell, K. Y.

1994-01-01

211

Visual landmarks facilitate rodent spatial navigation in virtual reality environments  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Youngstrom, Isaac A.; Strowbridge, Ben W.

2012-01-01

212

Probing navigation strategies of honeybees – landmark experiments and simulations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this study we probed the content of the spatial memory of honeybees in two landmark manipulation experiments accompanied by computer modelling. While the results of the first experiments are in line with an image-like representation of places, the findings of the second experiment suggest that bees also memorize the depth structure of a scene, most probably inferred from optic flow. This is supported by the fact that bees actively control their visual input.

2008-01-01

213

Multifeature landmark-free active appearance models: application to prostate MRI segmentation.  

Science.gov (United States)

Active shape models (ASMs) and active appearance models (AAMs) are popular approaches for medical image segmentation that use shape information to drive the segmentation process. Both approaches rely on image derived landmarks (specified either manually or automatically) to define the object's shape, which require accurate triangulation and alignment. An alternative approach to modeling shape is the levelset representation, defined as a set of signed distances to the object's surface. In addition, using multiple image derived attributes (IDAs) such as gradient information has previously shown to offer improved segmentation results when applied to ASMs, yet little work has been done exploring IDAs in the context of AAMs. In this work, we present a novel AAM methodology that utilizes the levelset implementation to overcome the issues relating to specifying landmarks, and locates the object of interest in a new image using a registration based scheme. Additionally, the framework allows for incorporation of multiple IDAs. Our multifeature landmark-free AAM (MFLAAM) utilizes an efficient, intuitive, and accurate algorithm for identifying those IDAs that will offer the most accurate segmentations. In this paper, we evaluate our MFLAAM scheme for the problem of prostate segmentation from T2-w MRI volumes. On a cohort of 108 studies, the levelset MFLAAM yielded a mean Dice accuracy of 88% ± 5%, and a mean surface error of 1.5 mm ±.8 mm with a segmentation time of 150/s per volume. In comparison, a state of the art AAM yielded mean Dice and surface error values of 86% ± 9% and 1.6 mm ± 1.0 mm, respectively. The differences with respect to our levelset-based MFLAAM model are statistically significant . In addition, our results were in most cases superior to several recent state of the art prostate MRI segmentation methods. PMID:22665505

Toth, Robert; Madabhushi, Anant

2012-08-01

214

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

International Nuclear Information System (INIS)

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

2012-12-01

215

A clinical test and application research of IMRT dose verification system based on patient's anatomical structure and on-line dosimetry  

International Nuclear Information System (INIS)

Objective: To test a three-dimensional dose verification system, which reconstructing dose to anatomy based on modeling and online measurements (RDBMOM), and to evaluate the accuracy and feasibility of its application in clinical intensity-modulated radiotherapy (IMRT) quality assurance. Methods: Phantom plans of regular and irregular fields were selected for the testing. All test plans were implemented and the dose distributions were measured using the thimble ion-chamber and two-dimensional ion-chamber array, the accuracy of RDBMOM were then evaluated by comparing the corresponding results.Two practical treated nasopharyngeal carcinoma IMRT plans were verified with RDBMOM and the clinic significance were valued. Results: Compared with measurements of the thimble ion-chamber, deviations of RDBMOM were within 1% in all tested cases except small field of 3 cm x 3 cm. The largest deviation of reconstructed dose in IMRT cases was 2.12%. The dose profile reconstructed by RDBMOM coincided with the measurement using two-dimensional ion-chamber array. The ? rates (3%/3 mm) were 94.56% - 100%. The RDBMOM verification of IMRT cases shown that the ? rate > 99% in total and > 98% in planning target volume,deviation in D95 <0.4%, but the largest deviations in mean dose of the parotids and lens were 2.97% and 59.58% respectively. Conclusions: Accuracy of the tested system satisfies the demand of IMRT dose verification. RDBMOM is able to provide information of volumetric dosimetry and anatomical location of dose error, which is benefit for evaluating the clinical value of verification results. (authors)

2012-05-01

216

Skull base tumors  

International Nuclear Information System (INIS)

Modern imaging techniques have great importance in the diagnosis and therapy of skull-base pathologies. Many of these lesions, especially in relation to their specific location, can be evaluated using CT and MR imaging. Tumors commonly found in the anterior skull base include carcinoma, rhabdomyosarcoma, esthesioneuroblastoma and meningioma. In the central cranial fossa, nasopharyngeal carcinoma, metastases, meningioma, pituitary adenoma and neurinoma have to be considered. The most common neoplasms of the posterior skull base, including the CP angle, are neurinoma, meningioma, nasopharyngeal carcinoma, chordoma and paraganglioma. One major task of imaging is the evaluation of the exact tumor extent as well as its relationship to the neighboring neurovascular structures. The purpose of this review is to recapitulate the most important anatomical landmarks of the skull base. The typical imaging findings of the most common tumors involving the skull base are also presented. (orig.)

2005-09-01

217

Comparative genome mapping with mobile physical map landmarks.  

Science.gov (United States)

We describe a method for comparative macrorestriction mapping of the chromosomes of Escherichia coli strains. In this method, a series of physically tagged E. coli K-12 alleles serve as mobile landmarks for mapping DNAs from other strains. This technique revealed evidence of strain-specific chromosomal additions or deletions in a pathogenic isolate and can be applied to most strains, yielding information on genealogy as well as virulence. In theory, the same strategy can be used to map and compare genomic DNAs from a wide variety of species. PMID:7961483

Bloch, C A; Rode, C K; Obreque, V; Russell, K Y

1994-11-01

218

Extracción de puntos característicos del rostro para medidas antropométricas Face landmarks extraction for anthropometric measures  

Directory of Open Access Journals (Sweden)

Full Text Available En este documento se propone una técnica para la extracción de 22 puntos característicos del rostro, orientada a aplicaciones de antropometría. La técnica se fundamenta en la transformada wavelets-Gabor y el uso del algoritmo EBGM (del término en inglés: Elastic Bunch Graph Matching. Este último algoritmo fue modificado para que los puntos extraídos correspondan a puntos característicos del rostro, los cuales se utilizan comúnmente en medidas antropométricas faciales. Las modificaciones consisten en un conjunto de restricciones geométricas para ajustar inicialmente la ubicación de los centros de búsqueda, y posteriormente para la definición de la región de esta búsqueda. Los resultados mostraron que los puntos centrales del rostro presentan errores de ubicación inferiores al milímetro, lo cual es consistente con las medidas en antropometría facial directa.In this research, a technique for the extraction of a 22 face landmarks set oriented to anthropometry applications has been proposed. The technique is based on wavelets Gabor transformation and the Elastic Bunch Graph Matching (EBGM algorithm. The EBGM algorithm was modified so that the extracted points correspond to face landmarks which are commonly used in face anthropometric measures. Modifications were: some geometric restrictions to initially fit the centers location of the region search, and later for the definition of the region. Results show that the face central points present location errors smaller than a millimeter, which is consistent with the measures in direct face anthropometry.

Alejandro González

2010-07-01

219

Extracción de puntos característicos del rostro para medidas antropométricas / Face landmarks extraction for anthropometric measures  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish En este documento se propone una técnica para la extracción de 22 puntos característicos del rostro, orientada a aplicaciones de antropometría. La técnica se fundamenta en la transformada wavelets-Gabor y el uso del algoritmo EBGM (del término en inglés: Elastic Bunch Graph Matching). Este último al [...] goritmo fue modificado para que los puntos extraídos correspondan a puntos característicos del rostro, los cuales se utilizan comúnmente en medidas antropométricas faciales. Las modificaciones consisten en un conjunto de restricciones geométricas para ajustar inicialmente la ubicación de los centros de búsqueda, y posteriormente para la definición de la región de esta búsqueda. Los resultados mostraron que los puntos centrales del rostro presentan errores de ubicación inferiores al milímetro, lo cual es consistente con las medidas en antropometría facial directa. Abstract in english In this research, a technique for the extraction of a 22 face landmarks set oriented to anthropometry applications has been proposed. The technique is based on wavelets Gabor transformation and the Elastic Bunch Graph Matching (EBGM) algorithm. The EBGM algorithm was modified so that the extracted p [...] oints correspond to face landmarks which are commonly used in face anthropometric measures. Modifications were: some geometric restrictions to initially fit the centers location of the region search, and later for the definition of the region. Results show that the face central points present location errors smaller than a millimeter, which is consistent with the measures in direct face anthropometry.

Alejandro, González; Flavio, Prieto.

220

Based On Edge Extraction of ASM Automatic Landmark Placement  

Directory of Open Access Journals (Sweden)

Full Text Available In the Active Shape Model, the most time consuming and scientifically unsatisfactory part of building shape models is the labeling of the training images. Manually placing hundreds (in 2D of points on every image is both tedious and error prone. To reduce the burden, the combination of the image edge information and the traditional manual calibration methods have been developed. This method improves the calibration accuracy, and obtains more accurate statistical shape model and local texture model. Aiming at the characteristics of ASM modeling, this paper adopts a multiscale wavelet transform modulus maximum method of edge extraction, using the maximum variance method to obtain a threshold, after the use of connectivity judgment for each scale edge fusion. The simulation results show that, this algorithm can effectively reduce the burden, improve the modeling accuracy.

Zhang Liguo

2012-11-01

 
 
 
 
221

Statistical analysis of shape through triangulation of landmarks: A study of sexual dimorphism in hominids  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Two objects with homologous landmarks are said to be of the same shape if the configuration of landmarks of one object can be exactly matched with that of the other by translation, rotation/reflection, and scaling. In an earlier paper, the authors proposed statistical analysis of shape by considering logarithmic differences of all possible Euclidean distances between landmarks. Tests of significance for differences in the shape of objects and methods of discrimination between populations were...

1998-01-01

222

Standardized anatomic space for abdominal fat quantification  

Science.gov (United States)

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.

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

2014-03-01

223

Necessity Of Anatomical Knowledge In Thoracic Surgery.  

Directory of Open Access Journals (Sweden)

Full Text Available The necessity of anatomical knowledge was fundamental issue for medical practice since prehistoric times and with the passing of centuries, that knowledge was improved very slowly. So in mid-1535 Vesalius began to study the human body by dissecting cadavers and warned that the dissection was the most important means by direct observation as the only reliable source. Through his work set aside age-old classic mistakes to discover that Galen's investigations were based on the dissection of animals, not of humans. His contemporary highlighted the anatomical knowledge as essential to the practice of surgery, shared this view with Vesalius. He was the initiator of the regional anatomy describing topographic anatomical areas and regional levels. Through the centuries, the anatomical knowledge was updated to facilitate the incorporation of techniques and technologies that emerged every day. Alejandro Posadas in Argentina who opened the thoracic surgery endocavitary insisted on a clear notion of the thoracic anatomy to aid in surgical practice. Later Avelino Gutierrez and Eugenio A. Galli highlighted a reasoned interpretation and a new nomenclature for the cardiac chambers according to their topographic reality. Jose Luis Martinez finally gave a distinctive character to Argentinian thoracic surgery by highlighting a detailed anatomical knowledge and begin to dissect the pulmonary hilum neglecting mass ligation of the pedicle. The acquisition of new Biostructural knowledge allows therapeutic approaches by new routes such as video-assisted surgical procedures and new diagnostic imaging such as magnetic resonance angiography. There is talk of a new disease for lack of anatomical basics notions. Its integration with the semiologic knowledges allows the combination of the basic notions that provide adequate medical care.

Arribalzaga, Eduardo B.

2011-09-01

224

MR arthrography of the shoulder and hip after fluoroscopic landmarking  

International Nuclear Information System (INIS)

Purpose. To describe a technique for intra-articular injection in the MR suite after conventional fluoroscopic landmarking in order to streamline MR arthrography.Design and patients. This technique was performed on 33 consecutive patients referred for MR arthrography of the shoulder to evaluate the glenoid labrum and on 15 consecutive patients referred for MR arthrography of the hip to evaluate the acetabular labrum. The patients were landmarked in the fluoroscopy suite, followed by a conventional MR examination. The intra-articular injection was then performed on the MR table and the MR arthrographic sequences obtained.Results. One of the 48 injections was extra-articular, requiring a second injection. The other injections were performed without incident, and the average total procedure time for all injections was 10 min.Conclusions. This technique is a reliable method of streamlining intra-articular injections when performing conventional MR imaging prior to the MR arthrographic portion of the examination. It shortens the total MR examination time by eliminating a visit to the fluoroscopy suite in the middle of the MR study, and its use of a straight anterior approach for both the shoulder and hip joints should be familiar to most people who perform conventional arthrography. (orig.)

2000-02-01

225

Dominance of the odometer over serial landmark learning in honeybee navigation  

Science.gov (United States)

Honeybees use their visual flow field to measure flight distance. It has been suggested that the experience of serial landmarks encountered on the flight toward a feeding place contributes to distance estimation. Here, we address this question by tracing the flight paths of individual bees with a harmonic radar system. Bees were trained along an array of three landmarks (tents), and the distance between these landmarks was either increased or decreased under two test conditions. We find that absolute distance estimation dominates the search for the feeding place, but serial position effects are also found. In the latter case, bees search only or additionally at locations determined by serial experience of the landmarks.

Menzel, Randolf; Fuchs, Jacqueline; Nadler, Leonard; Weiss, Benjamin; Kumbischinski, Nicole; Adebiyi, Daniel; Hartfil, Sergej; Greggers, Uwe

2010-08-01

226

Lateral Antebrachial Cutaneous Nerve at the Elbow Crease. Anatomical Research with Clinical and Surgical Applications.  

Directory of Open Access Journals (Sweden)

Full Text Available The anatomy of the lateral antebrachial cutaneous nerve is relevant in the clinical and surgical medical knowledge. Its lesion may be doing by nerve entrapment, needle procedures, trauma, among others. The objectives of this study are to establish the anatomical elements that may participate in the nerve entrapment and to establish anatomical landmarks to localize the nerve at the elbow. We have dissected 20 upper limbs (12 left, 8 right exploring the lateral bicipital canal, focusing in the anatomical relations of the musculocutaneous nerve and the lateral antebrachial cutaneous nerve. The tendon of the biceps has an extensive and sharp lateral edge. The lateral antebrachial cutaneous nerve passes beneath the tendon. A muscle-aponeurotic tunnel was observed at the lateral bicipital region. This tunnel may support the contact between the nerve and the biceps tendon. The results of the measurements show the nerve has a extensive contact between the lateral antebrachial cutaneous nerve and biceps tendon. The results of this research support the use of the biceps tendon as landmark to localize the lateral antebrachial cutaneous nerve at the elbow.

Postan, Daniel

2012-03-01

227

Anatomical entity mention recognition at literature scale  

Science.gov (United States)

Motivation: Anatomical entities ranging from subcellular structures to organ systems are central to biomedical science, and mentions of these entities are essential to understanding the scientific literature. Despite extensive efforts to automatically analyze various aspects of biomedical text, there have been only few studies focusing on anatomical entities, and no dedicated methods for learning to automatically recognize anatomical entity mentions in free-form text have been introduced. Results: We present AnatomyTagger, a machine learning-based system for anatomical entity mention recognition. The system incorporates a broad array of approaches proposed to benefit tagging, including the use of Unified Medical Language System (UMLS)- and Open Biomedical Ontologies (OBO)-based lexical resources, word representations induced from unlabeled text, statistical truecasing and non-local features. We train and evaluate the system on a newly introduced corpus that substantially extends on previously available resources, and apply the resulting tagger to automatically annotate the entire open access scientific domain literature. The resulting analyses have been applied to extend services provided by the Europe PubMed Central literature database. Availability and implementation: All tools and resources introduced in this work are available from http://nactem.ac.uk/anatomytagger. Contact: sophia.ananiadou@manchester.ac.uk Supplementary Information: Supplementary data are available at Bioinformatics online.

Pyysalo, Sampo; Ananiadou, Sophia

2014-01-01

228

Maximized Posteriori Attributes Selection from Facial Salient Landmarks for Face Recognition  

Science.gov (United States)

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

Gupta, Phalguni; Kisku, Dakshina Ranjan; Sing, Jamuna Kanta; Tistarelli, Massimo

229

Maximized Posteriori Attributes Selection from Facial Salient Landmarks for Face Recognition  

CERN Multimedia

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

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

2010-01-01

230

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

Directory of Open Access Journals (Sweden)

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

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

2010-07-01

231

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

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Landmarks constitute an essential basis for a structural understanding of the spatial environment. Therefore, they are crucial factors in external spatial representations such as maps and verbal route descriptions, which are used to support wayfinding. However, selecting landmarks for these representations is a difficult task, for which an understanding of how people perceive and remember landmarks in the environment is needed. We investigated the ways in which people perceive and remember landmarks in nature using the thinking aloud and sketch map methods during both the summer and the winter seasons. We examined the differences between methods to identify those landmarks that should be selected for external spatial representations, such as maps or route descriptions, in varying conditions. We found differences in the use of landmarks both in terms of the methods and also between the different seasons. In particular, the participants used passage and tree-related landmarks at significantly different frequencies with the thinking aloud and sketch map methods. The results are likely to reflect the different roles of the landmark groups when using the two methods, but also the differences in counting landmarks when using both methods. Seasonal differences in the use of landmarks occurred only with the thinking aloud method. Sketch maps were drawn similarly in summertime and wintertime; the participants remembered and selected landmarks similarly independent of the differences in their perceptions of the environment due to the season. The achieved results may guide the planning of external spatial representations within the context of wayfinding as well as when planning further experimental studies. PMID:23392783

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

2013-08-01

232

PET image reconstruction with anatomical edge guided level set prior  

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Acquiring both anatomical and functional images during one scan, PET/CT systems improve the ability to detect and localize abnormal uptakes. In addition, CT images provide anatomical boundary information that can be used to regularize positron emission tomography (PET) images. Here we propose a new approach to maximum a posteriori reconstruction of PET images with a level set prior guided by anatomical edges. The image prior models both the smoothness of PET images and the similarity between functional boundaries in PET and anatomical boundaries in CT. Level set functions (LSFs) are used to represent smooth and closed functional boundaries. The proposed method does not assume an exact match between PET and CT boundaries. Instead, it encourages similarity between the two boundaries, while allowing different region definition in PET images to accommodate possible signal and position mismatch between functional and anatomical images. While the functional boundaries are guaranteed to be closed by the LSFs, the proposed method does not require closed anatomical boundaries and can utilize incomplete edges obtained from an automatic edge detection algorithm. We conducted computer simulations to evaluate the performance of the proposed method. Two digital phantoms were constructed based on the Digimouse data and a human CT image, respectively. Anatomical edges were extracted automatically from the CT images. Tumors were simulated in the PET phantoms with different mismatched anatomical boundaries. Compared with existing methods, the new method achieved better bias-variance performance. The proposed method was also applied to real mouse data and achieved higher contrast than other methods.

Cheng-Liao, Jinxiu; Qi Jinyi, E-mail: qi@ucdavis.edu [Department of Biomedical Engineering, University of California, Davis, CA 95616 (United States)

2011-11-07

233

Die Reproduzierbarkeit von radiologisch-anatomischen Landmarks zur Determination der Gelenkspaltgrenzen des Articulatio temporomandibularis  

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Zur dreidimensionalen Evaluation des Kiefergelenkspaltes ist eine exakte Ausrichtung des Gelenkes an eine Referenzebene notwendig. Um diese Ebene zu determinieren wurden an Computer-Tomogrammen des menschlichen Schädels radiologisch-anatomische landmarks definiert und auf ihre interindividuelle Reproduzierbarkeit hin überprüft. Fünf Untersucher haben an achtzehn CT-Datensätzen jeweils neunzehn landmarks identifiziert. Aus der Euklidischen Distanz zwischen gleichen Punkten verschiedener U...

2006-01-01

234

A comparative study of anatomic structures on the panoramic radiograph and some extraoral radiographs  

International Nuclear Information System (INIS)

The author has studied each landmark for successful interpretation in the radiograph of the head that have the complex anatomic structures, using panoramic radiograph, postero-anterior cephalometric radiograph, lateral cephalometric radiograph, Waters' radiograph of the skull. The anatomic structures of the human dry skull attached by radiopaque materials were taken radiographs and analysed comparatively. The results were as follows: 1. The overall anatomic structures of the mandible showed sharp images in the panoramic radiograph than other radiographs with relatively less distortion, superimposition, blurring of the image. 2. The anatomic structures were situated on sagittal plane of the skull showed blurred images in panoramic radiograph than other radiographs. 3. The anatomic structures which were situated on the basal portion of the skull showed blurred and secondary images in the panoramic radiograph than other radiographs. 4. In the panoramic radiograph, the lower 3rd portion of the orbit appeared to be superimposed with the superior portion of the maxillary sinus and the medial and lateral surface of the nasal cavity showed extensively superimposition of the orbit and the maxillary sinus, which images showed blurring. 5. The inferior surface and posterior surface of maxillary sinus showed to be good image in the panoramic radiograph than other radiographs. 6. In the panoramic radiograph, line of maxillary bone between lateral pterygoid plate, line of maxillary bone between zygomatic bone showed distinct image with another structures.

1984-11-01

235

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

International Nuclear Information System (INIS)

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

2008-04-01

236

High resolution, quantitative reconstruction of erosion rates based on anatomical changes in exposed roots at Draix, Alpes de Haute-Provence — critical review of existing approaches and independent quality control of results  

Science.gov (United States)

Extensive areas of the French Alps are underlain by Jurassic black marls. Wherever these "terres noires" crop out they become subject to intense erosion, causing major sedimentation in regional reservoirs and river systems. In the badlands near Draix (Alpes de Haute-Provence, France), measured sediment rates were obtained at the plot scale by surface elevation change-based methods and at the catchment scale by monitoring sedimentation in dams. In this study, we use a dendrogeomorphic approach based on anatomical changes in exposed roots of Pinus sylvestris L. to accurately quantify continuous denudation rates. A total of 123 cross sections (75 from buried and 48 from exposed roots of 23 trees) were sampled in the Moulin basin. The size and position of roots at the time of exposure was determined via anatomical variations in the annual growth rings of roots. In cross sections of buried roots, a sharp reduction of earlywood tracheid lumen area — a growth signature which has traditionally been used to determine the moment of root denudation — was observed as soon as erosion reduced soil cover to ? 3 cm. As a consequence, estimates of eroded soil thickness had to be adjusted to take account of this bias. Bias-adjusted, averaged, medium-term erosion rates derived from exposed roots vary between 6 and 7 mm y -1 at Moulin basin depending on the importance accorded to the uplift of roots after exposure. Values are significantly correlated to slope angle and match with erosion rates derived from monitored iron stakes (5.7 mm y -1) or measurements of sediment yield in retention dams (4.7 mm y -1) at the outlet of the Moulin basin. Besides demonstrating that the interpretation of anatomical signatures in tree roots to erosion have to be revised, this paper also shows that dendrogeomorphic analyses of roots are indeed a powerful tool for the quantification of minimal rates of soil erosion in environments where measurements of past activity are not available.

Corona, Christophe; Lopez Saez, Jérôme; Rovéra, Georges; Stoffel, Markus; Astrade, Laurent; Berger, Frédéric

2011-02-01

237

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

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

Logullo Carlos

2010-02-01

238

ROLE OF ANATOMICAL OBSTRUCTION IN THE PATHOGENESIS OF CHRONIC SINUSITIS  

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Full Text Available Sinusitis is a commonly diagnosed condition in the general population.This article is a study to asses the role of anatomical obstruction in the pathogenesis of chronic sinusitis,based on symptomatology and radiological findings of the patients.The frequency of major anatomical variants like deviated nasal septum,concha bullosa and paradoxical middle turbinate leading to chronic sinusitis have been analyzed.Most of the time the obstruction at osteomeatal complex leading to chronic sinusitis is caused by more than one anatomical factor.

Balasubramanian Thiagarajan

2012-08-01

239

Is there consistency in cephalometric landmark identification amongst oral and maxillofacial surgeons?  

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There may be significant variation amongst oral and maxillofacial surgeons (OMFS) in the identification and placement of cephalometric landmarks for orthognathic surgery, and this could impact upon the surgical plan and final treatment outcome. In an effort to assess this variability, 10 lateral cephalometric radiographs were selected for evaluation by 16 OMFS with different levels of surgical knowledge and experience, and the position of 21 commonly used cephalometric landmarks were identified on radiographs displayed on a computer screen using a computer mouse on a pen tablet. The database consisted of real position measurements (x, y) to determine the consistency of landmark identification between surgeons and within individual surgeons. Inter-examiner analysis demonstrated that most landmark points had excellent reliability (intra-class correlation coefficient >0.90). Regardless of the level of surgeon experience, certain landmarks presented consistently poor reliability, and intra-examiner reliability analysis demonstrated that some locations had a higher average difference for both x and y axes. In particular, porion, condylion, and gonion showed poor agreement and reliability between examiners. The identification of most landmarks showed some inconsistencies within different parameters of evaluation. Such variability among surgeons may be addressed by the consistent use of high-quality images, and also by periodic surgeon education of the definition of the specific landmarks. PMID:24055177

Miloro, M; Borba, A M; Ribeiro-Junior, O; Naclério-Homem, M G; Jungner, M

2014-04-01

240

Distal landmarks and hippocampal place cells: effects of relative translation versus rotation.  

Science.gov (United States)

Hippocampal neurons are selectively active when a rat occupies restricted locations in an environment. These place cells derive their specificity from a multitude of sources, including idiothetic cues and sensory input derived from both distal and local landmarks. Most experiments have attempted to dissociate the relative strengths and roles played by these sources by rotating one set against the other. Few studies have addressed the effects of relative translation of the local cue set versus salient distal landmarks. To address this question, ensembles of place cells were recorded as a rectangular or circular track was moved to different locations in a room with controlled visual landmarks. Place cells primarily maintained their firing fields relative to the track (i.e., occupying new locations relative to the distal landmarks), even though the track could occupy completely nonoverlapping regions of the room. When the distal landmarks were rotated around the circular track, however, the place fields rotated with the landmarks, demonstrating that the cues were perceptible to the rat. These results suggest that, under these conditions, the spatial tuning of place cells may derive from an interaction between local and idiothetic cues, which define the precise firing locations of the cells and the relationships between them, and distal landmarks, which set the orientation of the ensemble representation relative to the external environment. PMID:12921350

Knierim, James J; Rao, Geeta

2003-01-01

 
 
 
 
241

Quantification of organ motion based on an adaptive image-based scale invariant feature method  

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Purpose: The availability of corresponding landmarks in IGRT image series allows quantifying the inter and intrafractional motion of internal organs. In this study, an approach for the automatic localization of anatomical landmarks is presented, with the aim of describing the nonrigid motion of anatomo-pathological structures in radiotherapy treatments according to local image contrast.Methods: An adaptive scale invariant feature transform (SIFT) was developed from the integration of a standard 3D SIFT approach with a local image-based contrast definition. The robustness and invariance of the proposed method to shape-preserving and deformable transforms were analyzed in a CT phantom study. The application of contrast transforms to the phantom images was also tested, in order to verify the variation of the local adaptive measure in relation to the modification of image contrast. The method was also applied to a lung 4D CT dataset, relying on manual feature identification by an expert user as ground truth. The 3D residual distance between matches obtained in adaptive-SIFT was then computed to verify the internal motion quantification with respect to the expert user. Extracted corresponding features in the lungs were used as regularization landmarks in a multistage deformable image registration (DIR) mapping the inhale vs exhale phase. The residual distances between the warped manual landmarks and their reference position in the inhale phase were evaluated, in order to provide a quantitative indication of the registration performed with the three different point sets.Results: The phantom study confirmed the method invariance and robustness properties to shape-preserving and deformable transforms, showing residual matching errors below the voxel dimension. The adapted SIFT algorithm on the 4D CT dataset provided automated and accurate motion detection of peak to peak breathing motion. The proposed method resulted in reduced residual errors with respect to standard SIFT, providing a motion description comparable to expert manual identification, as confirmed by DIR.Conclusions: The application of the method to a 4D lung CT patient dataset demonstrated adaptive-SIFT potential as an automatic tool to detect landmarks for DIR regularization and internal motion quantification. Future works should include the optimization of the computational cost and the application of the method to other anatomical sites and image modalities.

Paganelli, Chiara [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, piazza L. Da Vinci 32, Milano 20133 (Italy); Peroni, Marta [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, piazza L. Da Vinci 32, Milano 20133, Italy and Paul Scherrer Institut, Zentrum für Protonentherapie, WMSA/C15, CH-5232 Villigen PSI (Italy); Baroni, Guido; Riboldi, Marco [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, piazza L. Da Vinci 32, Milano 20133, Italy and Bioengineering Unit, Centro Nazionale di Adroterapia Oncologica, strada Campeggi 53, Pavia 27100 (Italy)

2013-11-15

242

Regularized emission tomography reconstruction using adaptive filtering and anatomical prior  

International Nuclear Information System (INIS)

Full text: In emission tomography, a substantial amount of smoothing is often required for suppression of noise in the reconstructed images. A technique based on minimum cross-entropy (MXE) has been developed that utilizes both functional and anatomical data for edge-preserving regularization of SPET reconstruction. MXE provides a natural scheme for using an edge-preserving smoothing filter for coding edge information obtained from CT or MR images. A limitation is that smoothing that is constrained to within anatomical boundaries may reduce edge resolution in areas where variation in functional data does not align with anatomical boundaries. To overcome this problem, we have introduced a filter that is both adaptive to the anatomical edges and the functional edges defined in previous iterations. A brain phantom with lesions has been constructed to represent emission and anatomical data. The phantom was forward-projected with Poisson noise, depth-dependent detector resolution, uniform linear attenuation coefficient and fan-beam geometry. Projections were generated for clinically realistic counts. The phantom was designed for quantifying resolution, contrast and reconstructed noise of MXE with and without corresponding anatomical prior. Our findings confirm that MXE reconstruction provides significant improvement in the signal-to-noise ratio; smaller variance for lesions; and better recovery coefficients compared to maximum likelihood reconstructions. The algorithm therefore appears to provide a regularized solution that incorporates anatomical prior information without loss of emission edge definition

1999-04-01

243

Clinically Significant Anatomical Variants of the Paranasal Sinuses  

Science.gov (United States)

Objective Anatomic structural variations of the paranasal sinuses have a practical significance during surgical procedures conducted on the sinuses by otolaryngologists. This study aims to evaluate the prevalence of clinically significant anatomical variations of the paranasal sinuses. Methods A prospective analysis of 435 computed tomography (CT) examinations of adult Omani patients was conducted to determine the prevalence of clinically significant anatomical variations of the paranasal sinuses. A total of 360 CT scans were included from January 2009 to January 2010. Results The findings showed abnormal Agger nasi cells in 49% of cases (95% CI: 44-54%), concha bullosa in 49% (95% CI: 44-54%), Haller cells in 24% (95% CI: 18-31%), asymmetry in anterior ethmoidal roof 32% (CI: 29-37%), Onodi cells in 8% (CI: 5%-10%). The type of skull base were as follows; Type 1 was 30% (n=107; 95% CI: 25-35%), Type 2 was 34% (n=123; 95% CI: 29-39), and Type 3 was 36% (n=130; 95% CI: 31-41%). Many other surgically significant anatomical variations in small numbers (1-3) were incidentally identified. Conclusion Knowledge of the presence of anatomical variations of the sinuses has a clinical significance as it minimizes the potential for surgical complications. There is an ethnical difference in the prevalence of anatomical variations. Further studies of anatomical variations with clinical disease correlations are needed.

Al-Abri, Rashid; Bhargava, Deepa; Al-Bassam, Wameedh; Al-Badaai, Yahya; Sawhney, Sukhpal

2014-01-01

244

Learning of landmark stability and instability by hippocampal place cells.  

Science.gov (United States)

Place cells in the rat hippocampus fire whenever the animal is in a particular location. In a symmetrical environment, their receptive fields (place fields) are oriented by visual cues, and if these are unavailable they are oriented by movement-generated (idiothetic) cues. The present study tested the hypothesis that the cells would learn not to 'trust' a visual cue if the rat experienced it to be unstable (Knierim et al., 1995. Place cells, head direction cells and the learning of landmark stability. J. Neurosci. 15, 1648-1659). In an otherwise symmetrical environment, a visual cue was moved with respect to the idiothetic cues, either in sight or out-of-sight of the rat. When the visual cue was moved out-of-sight of the rat, place fields were initially oriented by this cue in preference to the idiothetic cues. However, if the cue was seen by the rat to be mobile, place fields ceased following the visual cue and became oriented by the idiothetic cues instead. If the cue was not seen to be mobile until the rat had had several days of experience in the environment, then the fields continued to be oriented by the (now visibly mobile) visual cue. It thus appears that the orienting influence of a visual cue on place fields can be either strengthened or weakened relative to the idiothetic cues, depending on the experience of the rat. PMID:9705005

Jeffery, K J

1998-01-01

245

PET Image Reconstruction Using Information Theoretic Anatomical Priors  

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We describe a nonparametric framework for incorporating information from co-registered anatomical images into positron emission tomographic (PET) image reconstruction through priors based on information theoretic similarity measures. We compare and evaluate the use of mutual information (MI) and joint entropy (JE) between feature vectors extracted from the anatomical and PET images as priors in PET reconstruction. Scale-space theory provides a framework for the analysis of images at different...

Somayajula, Sangeetha; Panagiotou, Christos; Rangarajan, Anand; Li, Quanzheng; Arridge, Simon R.; Leahy, Richard M.

2011-01-01

246

Anatomic Total Shoulder System  

Medline Plus

Full Text Available ... take down his subscapularis with a lesser tuberosity osteotomy. Large curved osteotome, please. It's always a question about how deep we go with this osteotomy. I tend to go almost to the base ...

247

Anatomic Total Shoulder System  

Medline Plus

Full Text Available ... the base of the coracoid. We'll take down his subscapularis with a lesser tuberosity osteotomy. Large ... coagulated the antehumeral circumflex vessels. I'll go down here in the fleshy portion of subscap and ...

248

Study on the Construction of a High-definition Whole-body Voxel Model based on Cadaver's Color Photographic Anatomical Slice Images and Monte Carlo Dose Calculations  

International Nuclear Information System (INIS)

Ajou University School of Medicine made the serially sectioned anatomical images from the Visible Korean Human (VKH) Project in Korea. The VKH images, which are the high-resolution color photographic images, show the organs and tissues in the human body very clearly at 0.2 mm intervals. In this study, we constructed a high-quality voxel model (VKH-Man) with a total of 30 organs and tissues by manual and automatic segmentation method using the serially sectioned anatomical image data from the Visible Korean Human (VKH) project in Korea. The height and weight of VKH-Man voxel model is 164 cm and 57.6 kg, respectively, and the voxel resolution is 1.875 x 1.875 x 2 mm3. However, this voxel phantom can be used to calculate the organ and tissue doses of only one person. Therefore, in this study, we adjusted the voxel phantom to the 'Reference Korean' data to construct the voxel phantom that represents the radiation workers in Korea. The height and weight of the voxel model (HDRK-Man) that is finally developed are 171 cm and 68 kg, respectively, and the voxel resolution is 1.981 x 1.981 x 2.0854 mm3. VKH-Man and HDRK-Man voxel model were implemented in a Monte Carlo particle transport simulation code for calculation of the organ and tissue doses in various irradiation geometries. The calculated values were compared with each other to see the effect of the adjustment and also compared with other computational models (KTMAN-2, ICRP-74 and VIP-Man). According to the results, the adjustment of the voxel model was found hardly affect the dose calculations and most of the organ and tissue equivalent doses showed some differences among the models. These results shows that the difference in figure, and organ topology affects the organ doses more than the organ size. The calculated values of the effective dose from VKH-Man and HDRK-Man according to the ICRP-60 and upcoming ICRP recommendation were compared. For the other radiation geometries (AP, LLAT, RLAT) except for PA radiation geometry, the effective dose according to the upcoming ICRP recommendation was somewhat larger than that according to the ICRP-60. This seems due to change of the tissue weighting factor in the upcoming ICRP recommendation. The developed phantoms (VKH-Man and HDRK-Man) are expected to be used to estimate the radiation risk of only Korean in external and internal dosimetry. Dose conversion coefficients calculated in this study are also expected to be used in radiation protection assessment of Korean since those were distinguished from those of the western

2007-01-01

249

A FastSLAM-based algorithm for omnidirectional cameras  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Environments with a low density of landmarks are difficult for vision-based Simultaneous Localization and Mapping (SLAM) algorithms. The use of omnidirectional cameras, which have a wide field of view, is specially interesting in these environments as several landmarks are usually detected in each image. A typical example of this kind of situation happens in indoor environments when the lights placed on the ceiling are the landmarks. The use of omnivision combined with this type of landmarks ...

Cristina Gamallo; Manuel Mucientes; Regueiro, Carlos V.

2013-01-01

250

Quantifying anatomical shape variations in neurological disorders.  

Science.gov (United States)

We develop a multivariate analysis of brain anatomy to identify the relevant shape deformation patterns and quantify the shape changes that explain corresponding variations in clinical neuropsychological measures. We use kernel Partial Least Squares (PLS) and formulate a regression model in the tangent space of the manifold of diffeomorphisms characterized by deformation momenta. The scalar deformation momenta completely encode the diffeomorphic changes in anatomical shape. In this model, the clinical measures are the response variables, while the anatomical variability is treated as the independent variable. To better understand the "shape-clinical response" relationship, we also control for demographic confounders, such as age, gender, and years of education in our regression model. We evaluate the proposed methodology on the Alzheimer's Disease Neuroimaging Initiative (ADNI) database using baseline structural MR imaging data and neuropsychological evaluation test scores. We demonstrate the ability of our model to quantify the anatomical deformations in units of clinical response. Our results also demonstrate that the proposed method is generic and generates reliable shape deformations both in terms of the extracted patterns and the amount of shape changes. We found that while the hippocampus and amygdala emerge as mainly responsible for changes in test scores for global measures of dementia and memory function, they are not a determinant factor for executive function. Another critical finding was the appearance of thalamus and putamen as most important regions that relate to executive function. These resulting anatomical regions were consistent with very high confidence irrespective of the size of the population used in the study. This data-driven global analysis of brain anatomy was able to reach similar conclusions as other studies in Alzheimer's disease based on predefined ROIs, together with the identification of other new patterns of deformation. The proposed methodology thus holds promise for discovering new patterns of shape changes in the human brain that could add to our understanding of disease progression in neurological disorders. PMID:24667299

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

2014-04-01

251

ANATOMICAL PROPERTIES OF PLANTAGO ARENARIA  

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

Nicoleta IANOVICI

2011-01-01

252

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

Science.gov (United States)

...the National Park System Advisory Board of the qualifications of each property being proposed for National Historic Landmark (NHL) designation, and to make recommendations regarding the possible designation of those properties as National Historic...

2013-11-19

253

Resultados funcionales y anatómicos en la facoemulsificación coaxial estándar mediante la técnica de multichop Functional and anatomical results of standard coaxial phacoemulsification based on the multichop technique  

Directory of Open Access Journals (Sweden)

Full Text Available OBJETIVOS: Describir los resultados funcionales y anatómicos obtenidos con la facoemulsificación coaxial estándar por la técnica de multichop en la cirugía de catarata. MÉTODOS: Estudio descriptivo, longitudinal y prospectivo en el período comprendido entre septiembre de 2005 y mayo de 2007, de pacientes operados de catarata en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer". RESULTADOS: El poder del ultrasonido promedio fue de 20,7 %, el tiempo de ultrasonido medio fue de 46 segundos y el tiempo efectivo de facoemulsificación promedio fue de 10,2 s; existió relación significativa entre la dureza del núcleo y el tiempo de ultrasonido empleado (p OBJECTIVES: To describe the functional and anatomical results achieved in standard coaxial phacoemulsification using multichop technique in the cataract surgery. METHODS: Prospective longitudinal and descriptive study of patients operated on from cataract at "Ramón Pando Ferrer" Cuban Institute of Ophthalmology, conducted from September 2005 to May 2007. RESULTS: The average ultrasound power was 20,7 %, the average ultrasound time was 46 seconds and the average effective phaco time was 10,3 seconds; there was significant relation between nucleus hardness and time of ultrasound (p < 0.05. Postoperative best corrected average visual acuity was 0,8 with significant relation (p = 0.00 as well as induced astigmatism of 0,37 dioptres. Significant relation was observed between loss of endothelial cells and nucleus hardness (p < 0.05. CONCLUSIONS: The used phacodynamic parameters were low, postoperative visual acuity improved and induced astigmatism was also low.

Neisy Bernal Reyes

2009-12-01

254

Learning Compact Visual Descriptors for Low Bit Rate Mobile Landmark Search  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Coming with the ever growing computational power of mobile devices, mobile visual search have undergone an evolution in techniques and applications. A significant trend is low bit rate visual search, where compact visual descriptors are extracted directly over a mobile and delivered as queries rather than raw images to reduce the query transmission latency. In this article, we introduce our work on low bit rate mobile landmark search, in which a compact yet discriminative landmark image descr...

Duan, Ling-yu Peking University; Chen, Jie Peking University; Ji, Rongrong Peking University; Huang, Tiejun Peking University; Gao, Wen Peking University

2013-01-01

255

Coupling between place cells and head direction cells during relative translations and rotations of distal landmarks.  

Science.gov (United States)

Hippocampal place cells are selectively active when a rat occupies restricted locations in an environment, and head direction cells fire selectively when the rat's head is pointed in a particular direction in allocentric space. Both place cells and head direction cells are usually coupled, and they are controlled by a complex interaction between external landmarks and idiothetic cues. Most studies have investigated this interaction by rotating the landmarks in the environment. In contrast, a recent study translated the apparatus relative to the landmarks in an environment and found that most place cells maintained the same preferred location on the apparatus regardless of the location of the apparatus in the room. Because head direction cells are insensitive to the rat's location in an environment, the distal landmarks may influence the place field firing locations primarily by controlling the bearing of the head direction cell system. To address this question, ensembles of CA1 place cells and head direction cells of the anterior thalamus were recorded simultaneously, as a rectangular or circular track was moved to different locations in a room with distinct visual landmarks. Most place cells maintained their firing fields relative to the track when the track was translated, and head direction cells maintained the same preferred firing direction. When the distal landmarks were rotated around the track, the firing fields of place cells and the preferred directions of head direction cells rotated with the cues. These results suggest that the precise firing locations of place cells are controlled by an interaction between local and idiothetic cues, and the orientation of the CA1 ensemble representation relative to the distal landmarks may be controlled indirectly by the distal landmarks' influence over the bearing of the head direction cell system. PMID:15340767

Yoganarasimha, D; Knierim, James J

2005-01-01

256

A comparison of two methods for natural landmark classification with Biosonar  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Most current sonar systems for mobile robots only yield time of flight distance information produced by measuring the time of a single sonar pulse. However, sonar systems of animals like sonar bats are much more sophisticated, allowing to recognize not only the shape, but also the type of landmark trees that they use during their nocturnal flights. In this paper we compare two methods for natural landmark classification by a biomimetic sonar consisting of one sender (mouth) and two receivers ...

Wang, Maosen; Zell, Andreas; Mu?ller, Rolf; Wilhelm-schickard-institut Fu?r Informatik, Tu?bingen

2004-01-01

257

Insite: Canada's landmark safe injecting program at risk  

Directory of Open Access Journals (Sweden)

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

Drucker Ernest

2006-08-01

258

Clinical study of quantitative analysis of the anatomical structure after canalicular laceration  

Directory of Open Access Journals (Sweden)

Full Text Available AIM: To quantitatively analyse the anatomical structure after canalicular laceration, to provide a basis for finding nasal ends of the canalicular and to evaluate the feasibility of taking the lacrimal caruncle as anatomic landmarks for finding the nasal ends of the inferior canalicular. METHODS: In this prospective case-control study, 100 cases(72 males and 28 femalesof traumatic inferior canalicular laceration were chosen. They were completely random divided into the experimental group(n=50, finding the nasal ends of the inferior canalicular by applying the method of lacrimal caruncle anatomic landmarks; the control group(n=50, finding the nasal ends of the inferior canalicular by applying the direct vision method. The distance of the lacrimal punctum and the temporal side of the stump, the vertical distance and quadrant between nasal ends of the canalicular and lacrimal caruncle were measured. The success rate of the two groups to find the nasa lends of the canalicular were recorded. The data were compared using ?2 test. RESULTS: The nasal ends of the inferior canalicular in the semi-quadrant of the lacrimal caruncle was 94%. The canalicular nasal ends from the lacrimal caruncle of the vertical distance was 2.34±0.68 mm,in which lacrimal punctums pitch temporal side of the stump7mm was 3.05±0.97mm. The success rate of surgery looking the inferior lacrimal duct nasal stump: experimental group: 49/50(98%, control group: 40/50(80%, the difference was statistically significant(PCONCLUSION: Nasal ends of the inferior canalicular locates below the parallel lines of the lacrimal caruncle. The canalicular nasal ends locates in the deep side of the lacrimal caruncle within 2-3mm. The lacrimal punctum and the length of the temporal side can be used to clear the radius around the lacrimal caruncle. The success rate of finding the nasal ends of the experimental group is faster than the control group. The lacrimal caruncle as anatomic landmarks to find the nasal ends of the inferior canalicular is feasible, especially for patients whose inferior canalicular bitamporal side of the stump from inferior lacrimal punctum was 4-7mm.

Min Wei

2013-06-01

259

Compensation for fluctuations in crosswind drift without stationary landmarks in butterflies migrating over seas.  

Science.gov (United States)

Migrating insects may fly over large bodies of water that lack landmarks, but little is known about their ability to navigate in such a fluid environment. Using boat navigation instruments to measure compensation for fluctuations in crosswind drift, I investigated the ability of butterflies (Lepidoptera: Hesperiidae, Nymphalidae and Pieridae) to orient with and without landmarks as they migrated naturally over the Caribbean Sea. I used the presence or absence of landmarks or clouds to evaluate their use by the butterflies as guides for compensation. Forty-one per cent of the butterflies compensated for crosswind drift, whereas only 16% did not compensate. No conclusion could be drawn for the remainder. Without landmarks or clouds, butterflies were significantly less likely to compensate for drift than when these local cues were present. Butterflies were more likely to compensate fully in the presence of a landmark than when only clouds were present. Phoebis sennae butterflies drifted in the morning and overcompensated for drift in the afternoon, a pattern found both within and between individuals independent of landmarks. Although I cannot exclude the use of clouds, this would probably result in undercompensation. Hence, a ground reference in conjunction with a sun or magnetic compass is the most likely orientation cue. In the absence of clouds, one butterfly compensated, at least in part, indicating that it was using ripples on the sea surface as a ground reference in conjunction with a sun or magnetic compass. Copyright 2001 The Association for the Study of Animal Behaviour. PMID:11170709

Srygley, Robert B.

2001-01-01

260

3D reconstruction of prostate histology based on quantified tissue cutting and deformation parameters  

Science.gov (United States)

Methods for 3D histology reconstruction from sparse 2D digital histology images depend on knowledge about the positions, orientations, and deformations of tissue slices due to the histology process. This work quantitatively evaluates typical assumptions about the position and orientation of whole-mount prostate histology sections within coarsely sliced tissue blocks and about the deformation of tissue during histological processing and sectioning. 3-5 midgland tissue blocks from each of 7 radical prostatectomy specimens were imaged using magnetic resonance imaging before histology processing. After standard whole-mount paraffin processing and sectioning, the resulting sections were digitised. Homologous anatomic landmarks were identified on 22 midgland histology and MR images. Orientations and depths of sections relative to the front faces of the tissue blocks were measured based on the best-fit plane through the landmarks on the MR images. The mean+/-std section orientation was 1.7+/-1.1° and the mean+/-std depth of the sections was 1.0+/-0.5 mm. Deformation was assessed by using four transformation models (rigid, rigid+scale, affine and thin-plate-spline (TPS)) to align landmarks from histology and MR images, and evaluating each by measuring the target registration error (TRE) using a leave-one-out cross-validation. The rigid transformation model had higher mean TRE (pprostate histology reconstruction based on extrinsic strand-shaped fiducial markers which yielded a 0.7+/-0.4 mm mean+/-std TRE.

Gibson, Eli; Gómez, José A.; Moussa, Madeleine; Crukley, Cathie; Bauman, Glenn; Fenster, Aaron; Ward, Aaron D.

2012-02-01

 
 
 
 
261

Involvement of the hippocampus and associative parietal cortex in the use of proximal and distal landmarks for navigation.  

Science.gov (United States)

Rats with dorsal hippocampus or associative parietal cortex (APC) lesions and sham-operated controls were trained on variants of the Morris water maze navigation task. In the 'proximal landmark condition', the rats had to localize the hidden platform solely on the basis of three salient object landmarks placed directly in the swimming pool. In the 'distal landmark condition', rats could rely only on distal landmarks (room cues) to locate the platform. In the 'beacon condition', the platform location was signaled by a salient cue directly attached to it. Rats with hippocampal lesions were impaired in the distal and to a less extent in the proximal landmark condition whereas rats with parietal lesions were impaired only in the proximal landmark condition. None of the lesioned groups was impaired in the beacon condition. These results suggest that the processing of information related to proximal, distal landmarks or associated beacon are mediated by different neural systems. The hippocampus would contribute to both proximal and distal landmark processing whereas the APC would be involved in the processing of proximal landmarks only. Navigation relying on a cued-platform would not require participation of the hippocampus nor the APC. Assuming that the processing of proximal landmarks heavily depends on the integration of visuospatial and idiothetic information, these results are consistent with the hypothesis that the APC plays a role in the combination of multiple sensory information and contributes to the formation of an allocentric spatial representation. PMID:10762689

Save, E; Poucet, B

2000-05-01

262

Anatomical structure of Polystichum Roth ferns rachises  

Directory of Open Access Journals (Sweden)

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

Oksana V. Tyshchenko

2012-03-01

263

Femoral arterial puncture: comparison of using the inguinal crease and bony landmarks  

Energy Technology Data Exchange (ETDEWEB)

We tried to compare the accuracy of using bony landmarks and inguinal crease landmarks for performing femoral artery puncture and to determine an ideal puncture site. We studied ninety consecutive patients who underwent femoral arterial puncture for performing angiogram. For the evaluation of bony landmarks, the pelvis and inguinal areas were divided into 8 zones according to 7 lines that were drawn parallel to the line drawn between the anterior superior iliac spine and the pubic tubercle. For evaluation of the inguinal crease as a landmark, the 8 zones above and 4 zones below the inguinal crease were determined. The zones were divided by 11 lines drawn parallel to the inguinal crease, and the interval between each line was 1 cm. Locations of the inguinal ligament and femoral bifurcation were recorded for every patient according to the above zones, and an ideal zone for the femoral arterial puncture was decided upon. The ideal zone was considered if the locations of all of inguinal ligaments were above the zone and the least possibility to puncture was below the femoral bifurcation. On the bony landmark, the femoral bifurcations were located at zone 3 in 1 patient (1.1%), at zone 4 in 2 patients (2.2%), at zone 5 in 3 patients (3.3%), at zone 6 in 24 patients (26.7%), and at zone 7 in 44 patients (48.9%). Inguinal ligaments were at zone 1 in 2 patient (3.0%), at zone 2 in 34 patients (50.7%), at zone 3 in 25 patients (37.3%), and at zone 4 in 6 patients (8.9%). When the inguinal creases were used as a landmark, the femoral bifurcations were located at zone 4 in 4 patients (4.4%), at zone 3 in 19 patients (21.1%). at zone 2 in 30 patients (33.3%), at zone 1 in 19 patients (21.1%), at zone -1 in 13 patients (14.4%), at zone -2 in 3 patients (3.3%) and at zone -4 in 2 patients (2.2%). Inguinal ligaments were at zone 8 in 7 patients (10.4%), at zone 7 in 11 patients (16.4%), at zone 6 in 19 patients (28.4%), at zone 5 in 20 patients (29.9%), at zone 4 in 7 patients (10.4%), and at zone 3 in 3 patients (4.5%). Therefore, the best zone for femoral arterial puncture was zone 5 with using bony landmarks and zone 2 with using inguinal crease landmarks. In terms of zone 5 on the bony landmark, every locations of inguinal ligaments was above it and 84 patients (93.4%) had their femoral bifurcation below it, excluding the 6 patients who had their femoral bifurcations at zones 3, 4, and 5. Therefore, zone 5 with using the bony landmarks was a good indicator for femoral arterial puncture. In case of zone 2 on the inguinal crease landmark, although every location of the inguinal ligament was above it, 53 patients (58.8%) had their femoral bifurcation above it at zone 4, 3, and 2. So, it was not a good indicator for femoral arterial puncture. Bony landmarks are more accurate indicators for performing femoral arterial puncture than the inguinal crease landmark. Zone 5 on the bony landmark is an ideal location for femoral arterial puncture.

Chung, Hwan Hoon; Ha, Jong Soo; Cha, Sang Hoon; Kim, Baek Hyun; Lee, Kee Yeol; Kim, Taik Kun; Lee, Seung Hwa; Kim, Jung Hyuck; Seol, Hae Seol [Korea University College of Medicine, Seoul (Korea, Republic of)

2006-04-15

264

Anatomic study of infrapopliteal vessels.  

Science.gov (United States)

The purpose of this project is to study and analyse the anatomical variations of the infrapopliteal vessels concerning their branching pattern. A reliable sample of one hundred formalin-fixed adult cadavers was dissected by the Anatomical Laboratory of Athens University. The variations can be classified in the following way: the normal branching of the popliteal artery was present in 90%. The remainder revealed variant branching patterns: hypoplastic or aplastic posterior tibial artery and the pedis arteries arising from the peroneal (3%); hypoplastic or aplastic anterior tibial artery (1.5%); and the dorsalis pedis formed by two equal branches, arising from the peroneal and the anterior tibial artery (2%). The variations were more frequent in females and in short-height individuals. Knowledge of these variations is rather important for any invasive technic concerning lower extremities. PMID:22936551

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

2012-08-01

265

Anatomical Considerations of the Suprascapular Nerve in Rotator Cuff Repairs  

Science.gov (United States)

Introduction. When using the double interval slide technique for arthroscopic repair of chronic large or massive rotator cuff tears, the posterior interval release is directed toward the scapular spine until the fat pad that protects the suprascapular nerve is reached. Injury to the suprascapular nerve can occur due to the nerve's proximity to the operative field. This study aimed to identify safe margins for avoiding injury to the suprascapular nerve. Materials and Methods. For 20 shoulders in ten cadavers, the distance was measured from the suprascapular notch to the glenoid rim, the articular margin of the rotator cuff footprint, and the lateral border of the acromion. Results. From the suprascapular notch, the suprascapular nerve coursed an average of 3.42?cm to the glenoid rim, 5.34?cm to the articular margin of the rotator cuff footprint, and 6.09?cm to the lateral border of the acromion. Conclusions. The results of this study define a safe zone, using anatomic landmarks, to help surgeons avoid iatrogenic injury to the suprascapular nerve when employing the double interval slide technique in arthroscopic repair of the rotator cuff.

Tom, James A.; Shah, Mitesh P.; Lee, Dan J.; Cerynik, Douglas L.; Amin, Nirav H.

2014-01-01

266

Technical Note: Anatomic identification of isolated modern human molars: testing Procrustes aligned outlines as a standardization procedure for elliptic fourier analysis.  

Science.gov (United States)

The determination of the precise position of permanent first and second modern human molars, following standard tooth identification criteria, is often difficult because of their morphological similarities. Here, we proposed to evaluate the suitability of two-dimensional crown contour shape analysis in achieving this objective. The method was tested separately on 180 first and second maxillary molars (UM) and 180 first and second mandibular molars (LM) securely identified (in anatomical position in their sockets). Generalized Procrustes superimposition is used to normalize the outlines prior to applying elliptic Fourier analyses ("EFAproc" method). Reliability and effectiveness of this morphometric procedure was evaluated by comparing the results obtained for the same dataset with four other morphometric methods of contour analysis. Cross-validated ("leave one individual out") percentages of misclassification yielded by linear discriminant analyses were used for determining the anatomic position of modern human molars. The percentages of misclassifications obtained from every method of contour analysis were low (1.67% to 3.33% for the UM, 5.56% to 6.67% for the LM) indicating the high suitability of crown contour analyses in correctly identifying molars. A reliable protocol, based on predictive linear discriminant analyses, was then proposed for identification of isolated molars. In addition, our results confirmed that the EFAproc method is suitable for normalizing outlines prior to undertaking elliptic Fourier analyses, especially in the case of nearly circular outlines: it obtained better classification than the classic method of normalization of Fourier descriptors for UM and provided also some advantages over the three landmarks-based methods tested here. PMID:24242977

Corny, Julien; Détroit, Florent

2014-02-01

267

Anatomic variations on PNS CT  

Energy Technology Data Exchange (ETDEWEB)

To illustrate frequently encountered anatomic variations on PNS computed tomography(CT) and to assess their clinical significance. CT findings of 1523 patients, who underwent PNS CT with no history of sinus surgery, were reviewed, and prevalence of each anatomic variation and its relationship with mucociliary clearance pathway was evaluated. Two categories of anatomic variations were encountered. The first group included variations of the turbinates, such as concha bullosa(28.6%), paradoxical middle turbinate(31.5%), of the uncinate process, such as medially bent or folded(36.3%), laterally bent(3.7%) or uncinate bulla(0.5%), of the ethmoidal sinus, such as Haller's cell(28.2%), large agger nasi cell(9.6%) or large ethmoidal bulla(23.5%) and nasal septal deviation(24.1%), which might cause obstruction of mucociliary clearance pathway and thus give rise to secondary obstructive sinusitis. The second group included Onodi cell(1.4%) and medial depression of the lamina papyracea(3.5%), which were not related with obstructive sinusitis. 87 cases of large agger nasi cell were associated with obstruction of nasofrontal recess. Large ethmoidal bulla(452 cases), Haller's cell(245 case) and true concha bullosa(25 cases) contributed to narrowing of the infundibulum. Medially bent uncinate process(220 cases), concha bullosa(157 cases), paradoxical middle turbinate(126 cases) and nasal septal deviation(93 case) were observed in middle meatal obstruction and supreme concha(3 case) accompanied sphenoethmoidal recess obstruction. Recognition of anatomic variations on PNS CT is important to build a treatment plan in patients with obstructive sinusitis as they may represent causes of the disease, and to avoid critical complications during functional endoscopic sinus surgery.

Lee, Kuk Jin; Youn, Eun Kyung; Lee, Young Uk; Kim, Dong Hyun; Suh, Jong Dae [Koryo General Hospital, Seoul (Korea, Republic of)

1994-09-15

268

Anatomic variations on PNS CT  

International Nuclear Information System (INIS)

To illustrate frequently encountered anatomic variations on PNS computed tomography(CT) and to assess their clinical significance. CT findings of 1523 patients, who underwent PNS CT with no history of sinus surgery, were reviewed, and prevalence of each anatomic variation and its relationship with mucociliary clearance pathway was evaluated. Two categories of anatomic variations were encountered. The first group included variations of the turbinates, such as concha bullosa(28.6%), paradoxical middle turbinate(31.5%), of the uncinate process, such as medially bent or folded(36.3%), laterally bent(3.7%) or uncinate bulla(0.5%), of the ethmoidal sinus, such as Haller's cell(28.2%), large agger nasi cell(9.6%) or large ethmoidal bulla(23.5%) and nasal septal deviation(24.1%), which might cause obstruction of mucociliary clearance pathway and thus give rise to secondary obstructive sinusitis. The second group included Onodi cell(1.4%) and medial depression of the lamina papyracea(3.5%), which were not related with obstructive sinusitis. 87 cases of large agger nasi cell were associated with obstruction of nasofrontal recess. Large ethmoidal bulla(452 cases), Haller's cell(245 case) and true concha bullosa(25 cases) contributed to narrowing of the infundibulum. Medially bent uncinate process(220 cases), concha bullosa(157 cases), paradoxical middle turbinate(126 cases) and nasal septal deviation(93 case) were observed in middle meatal obstruction and supreme concha(3 case) accompanied sphenoethmoidal recess obstruction. Recognition of anatomic variations on PNS CT is important to build a treatment plan in patients with obstructive sinusitis as they may represent causes of the disease, and to avoid critical complications during functional endoscopic sinus surgery

1994-09-01

269

Brain Anatomical Network and Intelligence  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Intuitively, higher intelligence might be assumed to correspond to more efficient information transfer in the brain, but no direct evidence has been reported from the perspective of brain networks. In this study, we performed extensive analyses to test the hypothesis that individual differences in intelligence are associated with brain structural organization, and in particular that higher scores on intelligence tests are related to greater global efficiency of the brain anatomical network. W...

Li, Yonghui; Liu, Yong; Li, Jun; Qin, Wen; Li, Kuncheng; Yu, Chunshui; Jiang, Tianzi

2009-01-01

270

Anatomical Background of the Perforator Flap Based on the Deep Branch of the Superficial Circumflex Iliac Artery (SCIP Flap): A Cadaveric Study  

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Background: The groin flap, based on the superficial circumflex iliac artery, was the first successful free flap. However, its popularity was lost essentially due to variable arterial anatomy. Clinical applications of perforator flap based on superficial circumflex iliac artery suggest that a dominant perforator based on his deep branch is enough to supply a large groin flap. Methods: Fresh cadaveric dissections were performed and the perforators of Sartorius based on the deep branch of super...

Sinna, Raphael; Hajji, Hassene; Qassemyar, Quentin; Perignon, David; Benhaim, Thomas; Havet, Eric

2010-01-01

271

Anatomical brain networks on the prediction of abnormal brain states.  

Science.gov (United States)

Graph-based brain anatomical network analysis models the brain as a graph whose nodes represent structural/functional regions, whereas the links between them represent nervous fiber connections. Initial studies of brain anatomical networks using this approach were devoted to describe the key organizational principles of the normal brain, while current trends seem to be more focused on detecting network alterations associated to specific brain disorders. Anatomical networks reconstructed using diffusion-weighed magnetic resonance-imaging techniques can be particularly useful in predicting abnormal brain states in which the white matter structure and, subsequently, the interconnections between gray matter regions are altered (e.g., due to the presence of diseases such as schizophrenia, stroke, multiple sclerosis, and dementia). This article offers an overview from early gross connectional anatomy explorations until more recent advances on anatomical brain network reconstruction approaches, with a specific focus on how the latter move toward the prediction of abnormal brain states. While anatomical graph-based predictor approaches are still at an early stage, they bear promising implications for individualized clinical diagnosis of neurological and psychiatric disorders, as well as for neurodevelopmental evaluations and subsequent assisted creation of educational strategies related to specific cognitive disorders. PMID:23249224

Iturria-Medina, Yasser

2013-01-01

272

Internal jugular vein cannulation: an ultrasound-guided technique versus a landmark-guided technique  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english OBJECTIVES: To compare the landmark-guided technique versus the ultrasound-guided technique for internal jugular vein cannulation in spontaneously breathing patients. METHODS: A total of 380 patients who required internal jugular vein cannulation were randomly assigned to receive internal jugular ve [...] in cannulation using either the landmark- or ultrasound-guided technique in Bursa, Uludag University Faculty of Medicine, between April and November, 2008. Failed catheter placement, risk of complications from placement, risk of failure on first attempt at placement, number of attempts until successful catheterization, time to successful catheterization and the demographics of each patient were recorded. RESULTS: The overall complication rate was higher in the landmark group than in the ultrasound-guided group (p

Gurkan, Turker; Fatma Nur, Kaya; Alp, Gurbet; Hale, Aksu; Cuneyt, Erdogan; Ahmet, Atlas.

273

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

Science.gov (United States)

Background: Some studies have been performed on assessing the anatomical variations of lingual foramen and its bony canals, in many different countries but no study has been performed in Iran yet. The purpose of this study is to assess the anatomical variations of lingual foramen and its bony canals with cone-beam computed tomography (CBCT) imaging in Isfahan. Materials and Methods: This was a cross-sectional study in which CBCT images taken from 102 patients referred to the Radiology Department of Head and Neck in Esfahan (Iran) University between 2010 and 2011. The presence of the lingual foramen and its bony canals, the locations, sizes, and length were assessed. The distances between the terminal end of lingual canal at the buccal and lingual side from the inferior border of the mandible and alveolar crest were measured. We also evaluated the effect of patient age and gender on the dimensional measurements of the anatomical landmark mentioned above t test, analysis of variance (ANOVA), and pearson's correlation were used for statistical analysis and P value lower than 0.05 was considered significant. Result: All of the CBCT images taken showed the presence of lingual foramen. Of all the participants, 52% of them had two foramens in their images. The mean diameters of the upper and lower lingual foramen were 1.12 and 0.9 mm, respectively. Conclusion: These anatomical landmarks in Isfahan population vary from previous studies. All of the images had at least one lingual foramen which demonstrates high prevalence of this anatomy among Isfehanian population. Therefore, it is recommended to use CBCT imaging for preoperative evaluation prior to installing dental implants.

Sheikhi, Mahnaz; Mosavat, Farzaneh; Ahmadi, Ahura

2012-01-01

274

Anatomic variability of groin innervation.  

Science.gov (United States)

Inguinal hernia repairs are very common yet fairly complex surgical procedures.Variations in the anatomical course of the inguinal nerves require that diligence is taken in their proper recognition. Inadvertent surgical injury to these nerves is associated with long term postoperative pain and complications. The aim of the present study was to highlight the complexity and variation in the innervation of the inguinal region in order to increase proper nerve identification during surgical interventions. Bilateral dissection of the inguinal and posterior abdominal regions in one human male cadaver revealed an atypical anatomic topography of the groin innervation. This unusual case was observed at the Jagiellonian University Anatomy Department during routine cadaveric preparations. The left ilioinguinal nerve was absent. The left genital branch of the genitofemoral nerve arose higher than expected from the lumbar plexus and supplied the groin region, which is typically innervated by the ilioinguinal nerve. Furthermore, the left lateral cutaneous femoral nerve and the right genital branch of the genitofemoral nerve also followed uncharacteristic courses. Awareness of topographical nerve variations during inguinal hernia repair will help surgeons identify and preserve important nerves, thus decreasing the incidence of chronic postoperative pain. PMID:24068690

Bachul, P; Tomaszewski, K A; Kmiotek, E K; Kratochwil, M; Solecki, R; Walocha, J A

2013-08-01

275

Co-Segmentation of Functional and Anatomical Images  

Science.gov (United States)

This paper presents a novel method for segmenting functional and anatomical structures simultaneously. The proposed method unifies domains of anatomical and functional images (PET-CT), represents them in a product lattice, and performs simultaneous delineation of regions based on a random walk image segmentation. In addition, we propose a simple yet efficient object/background seed localization method, where background and foreground object cues are automatically obtained from PET images and propagated onto the corresponding anatomical images (CT). In our experiments, abnormal anatomies on PET-CT images from human subjects are segmented synergistically by the proposed fully automatic co-segmentation method with high precision (mean DSC of 91.44%) in seconds (avg. 40 seconds).

Bagci, Ulas; Udupa, Jayaram K.; Yao, Jianhua; Mollura, Daniel J.

2012-01-01

276

Surface-based prostate registration with biomechanical regularization  

Science.gov (United States)

Adding MR-derived information to standard transrectal ultrasound (TRUS) images for guiding prostate biopsy is of substantial clinical interest. A tumor visible on MR images can be projected on ultrasound by using MRUS registration. A common approach is to use surface-based registration. We hypothesize that biomechanical modeling will better control deformation inside the prostate than a regular surface-based registration method. We developed a novel method by extending a surface-based registration with finite element (FE) simulation to better predict internal deformation of the prostate. For each of six patients, a tetrahedral mesh was constructed from the manual prostate segmentation. Next, the internal prostate deformation was simulated using the derived radial surface displacement as boundary condition. The deformation field within the gland was calculated using the predicted FE node displacements and thin-plate spline interpolation. We tested our method on MR guided MR biopsy imaging data, as landmarks can easily be identified on MR images. For evaluation of the registration accuracy we used 45 anatomical landmarks located in all regions of the prostate. Our results show that the median target registration error of a surface-based registration with biomechanical regularization is 1.88 mm, which is significantly different from 2.61 mm without biomechanical regularization. We can conclude that biomechanical FE modeling has the potential to improve the accuracy of multimodal prostate registration when comparing it to regular surface-based registration.

van de Ven, Wendy J. M.; Hu, Yipeng; Barentsz, Jelle O.; Karssemeijer, Nico; Barratt, Dean; Huisman, Henkjan J.

2013-03-01

277

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

Energy Technology Data Exchange (ETDEWEB)

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

Bataille, F

2007-04-15

278

Navigating in small-scale space: the role of landmarks and resource monitoring in understanding saddleback tamarin travel.  

Science.gov (United States)

Recent studies of spatial memory in wild nonhuman primates indicate that foragers may rely on a combination of navigational strategies to locate nearby and distant feeding sites. When traveling in large-scale space, tamarins are reported to encode spatial information in the form of a route-based map. However, little is known concerning how wild tamarins navigate in small-scale space (between feeding sites located at a distance of ?60?m). Therefore, we collected data on range use, diet, and the angle and distance traveled to visit sequential feeding sites in the same group of habituated Bolivian saddleback tamarins (Saguinus fuscicollis weddelli) in 2009 and 2011. For 7-8?hr a day for 54 observation days, we recorded the location of the study group at 10?min intervals using a GPS unit. We then used GIS software to map and analyze the monkeys' movements and travel paths taken between feeding sites. Our results indicate that in small-scale space the tamarins relied on multiple spatial strategies. In 31% of cases travel was route-based. In the remaining 69% of cases, however, the tamarins appeared to attend to the spatial positions of one or more near-to-site landmarks to relocate feeding sites. In doing so they approached the same feeding site from a mean of 4.5 different directions, frequently utilized different arboreal pathways, and traveled approximately 30% longer than then the straight-line distance. In addition, the monkeys' use of non-direct travel paths allowed them to monitor insect and fruit availability in areas within close proximity of currently used food patches. We conclude that the use of an integrated spatial strategy (route-based travel and attention to near-to-goal landmarks) provides tamarins with the opportunity to relocate productive feeding sites as well as monitor the availability of nearby resources in small-scale space. PMID:24038234

Garber, Paul A; Porter, Leila M

2014-05-01

279

Dosimetric accuracy of a deterministic radiation transport based {sup 192}Ir brachytherapy treatment planning system. Part III. Comparison to Monte Carlo simulation in voxelized anatomical computational models  

Energy Technology Data Exchange (ETDEWEB)

Purpose: To compare TG43-based and Acuros deterministic radiation transport-based calculations of the BrachyVision treatment planning system (TPS) with corresponding Monte Carlo (MC) simulation results in heterogeneous patient geometries, in order to validate Acuros and quantify the accuracy improvement it marks relative to TG43. Methods: Dosimetric comparisons in the form of isodose lines, percentage dose difference maps, and dose volume histogram results were performed for two voxelized mathematical models resembling an esophageal and a breast brachytherapy patient, as well as an actual breast brachytherapy patient model. The mathematical models were converted to digital imaging and communications in medicine (DICOM) image series for input to the TPS. The MCNP5 v.1.40 general-purpose simulation code input files for each model were prepared using information derived from the corresponding DICOM RT exports from the TPS. Results: Comparisons of MC and TG43 results in all models showed significant differences, as reported previously in the literature and expected from the inability of the TG43 based algorithm to account for heterogeneities and model specific scatter conditions. A close agreement was observed between MC and Acuros results in all models except for a limited number of points that lay in the penumbra of perfectly shaped structures in the esophageal model, or at distances very close to the catheters in all models. Conclusions: Acuros marks a significant dosimetry improvement relative to TG43. The assessment of the clinical significance of this accuracy improvement requires further work. Mathematical patient equivalent models and models prepared from actual patient CT series are useful complementary tools in the methodology outlined in this series of works for the benchmarking of any advanced dose calculation algorithm beyond TG43.

Zourari, K.; Pantelis, E.; Moutsatsos, A.; Sakelliou, L.; Georgiou, E.; Karaiskos, P.; Papagiannis, P. [Medical Physics Laboratory, Medical School, University of Athens, 75 Mikras Asias, 115 27 Athens (Greece); Department of Physics, Nuclear and Particle Physics Section, University of Athens, Ilisia, 157 71 Athens (Greece); Medical Physics Laboratory, Medical School, University of Athens, 75 Mikras Asias, 115 27 Athens (Greece)

2013-01-15

280

Constructivist Learning of Anatomy: Gaining Knowledge by Creating Anatomical Casts  

Science.gov (United States)

Educators are encouraged to provide inquiry-based, collaborative, and problem solving activities that enhance learning and promote curiosity, skepticism, objectivity, and the use of scientific reasoning. Making anatomical casts or models by injecting solidifying substances into organs is an example of a constructivist activity for achieving these…

Hermiz, David J.; O'Sullivan, Daniel J.; Lujan, Heidi L.; DiCarlo, Stephen E.

2011-01-01

 
 
 
 
281

New insights into the role of hilar ectopic granule cells in the dentate gyrus based on quantitative anatomic analysis and three-dimensional reconstruction.  

Science.gov (United States)

The dentate gyrus is one of two main areas of the mammalian brain where neurons are born throughout adulthood, a phenomenon called postnatal neurogenesis. Most of the neurons that are generated are granule cells (GCs), the major principal cell type in the dentate gyrus. Some adult-born granule cells develop in ectopic locations, such as the dentate hilus. The generation of hilar ectopic granule cells (HEGCs) is greatly increased in several animal models of epilepsy and has also been demonstrated in surgical specimens from patients with intractable temporal lobe epilepsy (TLE). Herein we review the results of our quantitative neuroanatomic analysis of HEGCs that were filled with Neurobiotin following electrophysiologic characterization in hippocampal slices. The data suggest that two types of HEGCs exist, based on a proximal or distal location of the cell body relative to the granule cell layer, and based on the location of most of the dendrites, in the molecular layer or hilus. Three-dimensional reconstruction revealed that the dendrites of distal HEGCs can extend along the transverse and longitudinal axis of the hippocampus. Analysis of axons demonstrated that HEGCs have projections that contribute to the normal mossy fiber innervation of CA3 as well as the abnormal sprouted fibers in the inner molecular layer of epileptic rodents (mossy fiber sprouting). These data support the idea that HEGCs could function as a "hub" cell in the dentate gyrus and play a critical role in network excitability. PMID:22612815

Scharfman, Helen E; Pierce, Joseph P

2012-06-01

282

Shape shifting: Local landmarks interfere with navigation by, and recognition of, global shape.  

Science.gov (United States)

An influential theory of spatial navigation states that the boundary shape of an environment is preferentially encoded over and above other spatial cues, such that it is impervious to interference from alternative sources of information. We explored this claim with 3 intradimensional-extradimensional shift experiments, designed to examine the interaction of landmark and geometric features of the environment in a virtual navigation task. In Experiments 1 and 2, participants were first required to find a hidden goal using information provided by the shape of the arena or landmarks integrated into the arena boundary (Experiment 1) or within the arena itself (Experiment 2). Participants were then transferred to a different-shaped arena that contained novel landmarks and were again required to find a hidden goal. In both experiments, participants who were navigating on the basis of cues that were from the same dimension that was previously relevant (intradimensional shift) learned to find the goal significantly faster than participants who were navigating on the basis of cues that were from a dimension that was previously irrelevant (extradimensional shift). This suggests that shape information does not hold special status when learning about an environment. Experiment 3 replicated Experiment 2 and also assessed participants' recognition of the global shape of the navigated arenas. Recognition was attenuated when landmarks were relevant to navigation throughout the experiment. The results of these experiments are discussed in terms of associative and non-associative theories of spatial learning. PMID:24245537

Buckley, Matthew G; Smith, Alastair D; Haselgrove, Mark

2014-03-01

283

Computed reconstruction of spatial ammonoid-shell orientation captured from digitized grinding and landmark data  

Science.gov (United States)

The internal orientation of fossil mass occurrences can be exploited as useful source of information about their primary depositional conditions. A series of studies, using different kinds of fossils, especially those with elongated shape (e.g., elongated gastropods), deal with their orientation and the subsequent reconstruction of the depositional conditions (e.g., paleocurrents and transport mechanisms). However, disk-shaped fossils like planispiral cephalopods or gastropods were used, up to now, with caution for interpreting paleocurrents. Moreover, most studies just deal with the topmost surface of such mass occurrences, due to the easier accessibility. Within this study, a new method for three-dimensional reconstruction of the internal structure of a fossil mass occurrence and the subsequent calculation of its spatial shell orientation is established. A 234 million-years-old (Carnian, Triassic) monospecific mass occurrence of the ammonoid Kasimlarceltites krystyni from the Taurus Mountains in Turkey, embedded in limestone, is used for this pilot study. Therefore, a 150×45×140 mm3 block of the ammonoid bearing limestone bed has been grinded to 70 slices, with a distance of 2 mm between each slice. By using a semi-automatic region growing algorithm of the 3D-visualization software Amira, ammonoids of a part of this mass occurrence were segmented and a 3D-model reconstructed. Landmarks, trigonometric and vector-based calculations were used to compute the diameters and the spatial orientation of each ammonoid. The spatial shell orientation was characterized by dip and dip-direction and aperture direction of the longitudinal axis, as well as by dip and azimuth of an imaginary sagittal-plane through each ammonoid. The exact spatial shell orientation was determined for a sample of 675 ammonoids, and their statistical orientation analyzed (i.e., NW/SE). The study combines classical orientation analysis with modern 3D-visualization techniques, and establishes a novel spatial orientation analyzing method, which can be adapted to any kind of abundant solid matter.

Lukeneder, Susanne; Lukeneder, Alexander; Weber, Gerhard W.

2014-03-01

284

Brain Morphometry Using Anatomical Magnetic Resonance Imaging  

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

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

2008-01-01

285

Use of deformed intensity distributions for on-line modification of image-guided IMRT to account for interfractional anatomic changes  

International Nuclear Information System (INIS)

Purpose: Recent imaging studies have demonstrated that there can be significant changes in anatomy from day to day and over the course of radiotherapy as a result of daily positioning uncertainties and physiologic and clinical factors. There are a number of strategies to minimize such changes, reduce their impact, or correct for them. Measures to date have included improved immobilization of external and internal anatomy or adjustment of positions based on portal or ultrasound images. Perhaps the most accurate way is to use CT image-guided radiotherapy, for which the possibilities range from simple correction of setup based on daily CT images to on-line near real-time intensity modulated radiotherapy (IMRT) replanning. In addition, there are numerous intermediate possibilities. In this paper, we report the development of one such intermediate method that takes into account anatomic changes by deforming the intensity distributions of each beam based on deformations of anatomy as seen in the beam's-eye-view. Methods and materials: The intensity distribution deformations are computed based on anatomy deformations discerned from the changes in the current image relative to a reference image (e.g., the pretreatment CT scan). First, a reference IMRT plan is generated based on the reference CT image. A new CT image is acquired using an in-room CT for every fraction. The anatomic structure contours are obtained for the new image. (For this article, these contours were manually drawn. When image guided IMRT methods are implemented, anatomic structure contours on subsequent images will likely be obtained with automatic or semiautomatic means. This could be achieved by, for example, first deforming the original CT image to match today's image, and then using the same deformation transformation to map original contours to today's image.) The reference intensity distributions for each beam are then deformed so that the projected geometric relationship within the beam's-eye-view between the anatomy (both target and normal tissues) extracted from the reference image and the reference intensity distribution is the same as (or as close as possible to) the corresponding relationship between anatomy derived from today's image and the newly deformed intensity distributions. To verify whether the dose distributions calculated using the deformed intensity distributions are acceptable for treatment as compared to the original intensity distributions, the deformed intensities are transformed into leaf sequences, which are then used to compute intensity and dose distributions expected to be delivered. The corresponding dose-volume histograms and dose-volume and dose-response indices are also computed. These data are compared with the corresponding data derived (a) from the original treatment plan applied to the original image, (b) from the original treatment plan applied to today's image, and (c) from a new full-fledged IMRT plan designed based on today's image. Results: Depending on the degree of anatomic changes, the use of an IMRT plan designed based on the original planning CT for the treatment of the current fraction could lead to significant differences compared to the intended dose distributions. CT-guided setup compared to the setup based on skin marks or bony landmarks may improve dose distributions somewhat. Replanning IMRT based on the current fraction's image yields the best physically deliverable plan (the 'gold standard'). For the prostate and head-and-neck examples studied as proof of principle, the results of deforming intensities within each beam based on the anatomy seen in the beam's-eye-view are a good approximation of full-fledged replanning compared with other alternatives. Conclusions: Our preliminary results encourage us to believe that deforming intensities taking into account deformation in the anatomy may be a rapid way to produce new treatment plans on-line in near real-time based on daily CT images. The methods we have developed need to be applied to a group of patients for both prostate and head-and-neck cases to co

2005-03-15

286

Comparison of technical and anatomical noise in digital thorax X-ray images  

International Nuclear Information System (INIS)

Former studies by Hoeschen and Buhr indicated a higher total noise in a thorax image than expected from technical noise, i.e. quantum and detector noise. This difference results from the overlay of many small anatomical structures along the X-ray beam, which leads to a noise-like appearance without distinguishable structures in the projected image. A method is proposed to quantitatively determine this 'anatomical noise' component, which is not to be confused with the anatomical background (e.g. ribs). This specific anatomical noise pattern in a radiograph changes completely when the imaging geometry changes because different small anatomical structures contribute to the projected image. Therefore, two images are taken using slightly different exposure geometry, and a correlation analysis based on wavelet transforms allows to determining the uncorrelated noise components. Since the technical noise also differs from image to image, which makes it difficult to separate the anatomical noise, images of a lung phantom were produced on a low-sensitive industrial X-ray film using high-exposure levels. From these results, the anatomical noise level in real clinical thorax radiographs using realistic exposure levels is predicted using the general dose dependence described in the paper text and compared with the quantum and detector noise level of an indirect flat-panel detector system. For consistency testing, the same lung phantom was imaged with the same digital flat-panel detector and the total image noise including anatomical noise is determined. The results show that the relative portion of anatomical noise may exceed the technical noise level. Anatomical noise is an important contributor to the total image noise and, therefore, impedes the recognition of anatomical structures. (authors)

2004-04-23

287

Comparison of technical and anatomical noise in digital thorax X-ray images.  

Science.gov (United States)

Former studies by Hoeschen and Buhr indicated a higher total noise in a thorax image than expected from technical noise, i.e. quantum and detector noise. This difference results from the overlay of many small anatomical structures along the X-ray beam, which leads to a noise-like appearance without distinguishable structures in the projected image. A method is proposed to quantitatively determine this 'anatomical noise' component, which is not to be confused with the anatomical background (e.g. ribs). This specific anatomical noise pattern in a radiograph changes completely when the imaging geometry changes because different small anatomical structures contribute to the projected image. Therefore, two images are taken using slightly different exposure geometry, and a correlation analysis based on wavelet transforms allows to determining the uncorrelated noise components. Since the technical noise also differs from image to image, which makes it difficult to separate the anatomical noise, images of a lung phantom were produced on a low-sensitive industrial X-ray film using high-exposure levels. From these results, the anatomical noise level in real clinical thorax radiographs using realistic exposure levels is predicted using the general dose dependence described in the paper text and compared with the quantum and detector noise level of an indirect flat-panel detector system. For consistency testing, the same lung phantom was imaged with the same digital flat-panel detector and the total image noise including anatomical noise is determined. The results show that the relative portion of anatomical noise may exceed the technical noise level. Anatomical noise is an important contributor to the total image noise and, therefore, impedes the recognition of anatomical structures. PMID:15933084

Hoeschen, Christoph; Tischenko, Oleg; Buhr, Egbert; Illers, Hartmut

2005-01-01

288

Evaluation of soft tissue thicknesses of facial midline landmarks before and after puberty  

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Full Text Available Introduction: In recent years, proportions and harmony of orofacial soft tissues have gained great importance in orthodontics. The aim of this research was to evaluate soft tissue thickness changes of facial midline landmarks during growth in both genders.Materials and methods: In this analytical-descriptive study, lateral cephalometric views of ninety-eight 6-18 year-old patients referring to the Orthodontics Department of Khorasegan Azad University were evaluated. The positions of 7 facial midline landmarks, including glabella, soft tissue nasion, soft tissue points A and B, soft tissue pogonion, and superior and inferior labrale, were determined and then the thicknesses of the landmarks were measured. Data was compared between two groups of under and above 12 years of age between males and females using independent t-test (?=0.05.Results: There were no statistically significant differences between the soft tissue thicknesses of both sexes in any of the landmarks except nasion (p value=0.026 and point B (p value=0.043 in the group under 12 years of age. Differences between the soft tissue thicknesses in both sexes over 12 years of age were statistically significant in nasion (p value = 0.043, point A (p value=0.001, and superior labrale (p value<0.001. Differences between soft tissue thicknesses of all the landmarks were statistically significant between the two age groups in males except point B (p value=0.119; however, in females only the thickness of soft tissue nasion (p value=0.105 and superior labrale (p value=0.968 were not statistically significant between the two age groups.Conclusion: Soft tissue thicknesses were almost the same in boys and girls except nasion and point B before puberty. After puberty upper face soft tissue thicknesses, including glabella and point A, were greater in boys compared to girls. However, in both sexes, soft tissue thicknesses of facial midline landmarks increased after 12 years of age. Key words: Soft tissue, Orthodontics, Radiography.

Soosan Sadeghian

2011-01-01

289

Women's Interview Study of Health - SEER Landmark Studies  

Science.gov (United States)

SEER is an authoratitive source of information on cancer incidence and survival in the United States. SEER currently collects and publishes cancer incidence and survival data from population-based cancer registries covering approximately 28 percent of the U.S. population.

290

Black/White Cancer Survival Study - SEER Landmark Studies  

Science.gov (United States)

SEER is an authoratitive source of information on cancer incidence and survival in the United States. SEER currently collects and publishes cancer incidence and survival data from population-based cancer registries covering approximately 28 percent of the U.S. population.

291

Prostate-Specific Antigen (PSA) Testing - SEER Landmark Studies  

Science.gov (United States)

SEER is an authoratitive source of information on cancer incidence and survival in the United States. SEER currently collects and publishes cancer incidence and survival data from population-based cancer registries covering approximately 28 percent of the U.S. population.

292

Anatomical barriers for antimicrobial agents.  

Science.gov (United States)

It is often suggested that there are substantial anatomic barriers to the passage of antibiotics from the circulation into tissues and fluids of the body. In fact, most capillary beds are fenestrated and allow the passage of antimicrobial agents into tissue fluids fairly readily. At equilibrium, the mean concentrations of free (unbound) antibiotic in plasma and tissue fluids over the dosing interval are equal. However, the time to achieve equilibrium may range from minutes to days, depending on the ratio of surface area to volume of the tissue fluid compartment. There are several sites in the body in which nonfenestrated capillary beds pose appreciable barriers to the diffusion of antibiotics, namely the central nervous system, the eye and the prostate gland. Only lipid-soluble drugs traverse these capillaries readily. If the nonporosity of the capillaries were the only barrier to drug diffusion in these sites, the mean concentrations would eventually be equal to those in the plasma. However, in the central nervous system and the retina of the eye, transport pumps for organic anions combine with the effect of nonporous capillaries to produce concentrations which, even at equilibrium, are lower than those in the plasma. Bulk flow may also play a role in lowering drug concentrations in the cerebrospinal fluid. In the prostate gland, pH partition may cause mean concentrations in the prostatic secretions to differ from those in the plasma at equilibrium. PMID:8477760

Barza, M

1993-01-01

293

Ethmomaxillary sinus: a particular anatomic variation of the paranasal sinuses  

Energy Technology Data Exchange (ETDEWEB)

We assessed the morphological and radiological characteristics of ethmomaxillary sinus (EMS), which is an enlarged posterior ethmoidal air cell occupying the superior portion of the maxillary sinus while draining into superior meatus. This study is based on 1450 patients submitted to CT examination of the paranasal sinuses between 1998 and 2002. Sequential CT scans were obtained in the coronal plane in all the patients with 2.5- to 5-mm section thickness and were evaluated for EMS. The diagnosis of EMS was made when there was a posterior ethmoidal cell occupying the superior part of the maxillary sinus while draining to the superior meatus. When EMS was diagnosed, the morphology of the septum between the and maxillary sinus, and width of the superior meatus, were noted. The EMS was found in 10 of 1450 (0.7%) patients. The coexisting anatomic variations were concha bullosa (50%), upper concha pneumatization (20%), maxillary sinus hypoplasia (20%), uncinate bulla (10%), hypertrophied inferior concha (10%), paradoxic middle concha (10%), and septate maxillary sinus (10%). There was no relation between EMS and sinus disease. The EMS is a rare anatomic variation and does not appear to be associated with sinusitis. The EMS is not a well-studied anatomic variation, and the literature is lacking adequate information about this anatomic variation. This study performed in a large series of patients will possibly contribute to better understanding of this particular anomaly. (orig.)

Sirikci, Akif; Bayram, Metin [Department of Radiology, Faculty of Medicine, Gaziantep University, Kolejtepe, 27310, Gaziantep (Turkey); Bayazit, Y.A.; Kanlikama, Muzaffer [Department of Otorhinolaryngology and Head and Neck Surgery, Faculty of Medicine, Gaziantep University, Kolejtepe, 27310, Gaziantep (Turkey)

2004-02-01

294

Diffusion of innovations: anatomical informatics and iPods.  

Science.gov (United States)

Over the course of many centuries, evolving scientific methods and technologies have advanced the study of anatomy. More recently, such dissemination of innovations has been formally studied in multidisciplinary psychosocial contexts, yielding useful knowledge about underlying principles and processes. We review these precepts and show how diffusion of innovations theory and principles apply to the development and dissemination of anatomical information methods and resources. We consider the factors affecting the late-20th-century dissemination of personal computers and World Wide Web hypermedia into widespread use in anatomical research and instruction. We report on the results of a small experiment in applied diffusion, the development and Internet-based distribution of learning resources for a popular, widely distributed personal media player. With these wearable microcomputer devices already in use by a variety of students, new opportunities exist for widespread dissemination of anatomical information. The continuing evolution of wearable computing devices underscores the need for maintaining anatomical information transportability via standardized data formats. PMID:16955498

Trelease, Robert B

2006-09-01

295

Spherical Demons: Fast Diffeomorphic Landmark-Free Surface Registration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present the Spherical Demons algorithm for registering two spherical images. By exploiting spherical vector spline interpolation theory, we show that a large class of regularizors for the modified Demons objective function can be efficiently approximated on the sphere using iterative smoothing. Based on one parameter subgroups of diffeomorphisms, the resulting registration is diffeomorphic and fast. The Spherical Demons algorithm can also be modified to register a given spherical image to ...

Yeo, B. T. Thomas; Sabuncu, Mert R.; Vercauteren, Tom; Ayache, Nicholas; Fischl, Bruce; Golland, Polina

2010-01-01

296

Detection of New Genomic Landmarks in the Maltese Goat Using Rapd PCR  

Directory of Open Access Journals (Sweden)

Full Text Available Since no information of the Maltese goat genome is available, RAPD technique has been used to identify a number of DNA landmarks. Genome Landmarks have been obtained from the DNA of 66 Maltese goats which were studied with Random Amplification of Polymorphic DNA (RAPD. Eleven (11 reproducible RAPD polymorphic zones were identified. For sequencing, the RAPD zones were cloned into the Puc 18 vector utilising E. coli and then sequenced using both the forward (universal and reverse primers specific for the Puc 18 vector. After sequencing a total of nine new markers (AF078170, AF078171, AF078172, AF078173, AF078174, AF078175, AF078176, AF078177, AF078178 amounting to approximately 5,500 bp of sequence from the goat genome were identified and their homologies with known nucleic acid and protein databases were described. The new sequences could provide useful anchors for more extensive mapping and sequencing and for genomics assisted breeding of the Maltese goat.

Blundell, R.

2006-01-01

297

The eminent German pathologist Siegfried Oberndorfer (1876-1944 and his landmark work on carcinoid tumors  

Directory of Open Access Journals (Sweden)

Full Text Available

Siegfried Oberndorfer has a distinct place in the Pantheon of pathology as a century ago he described a new neoplastic entity in small bowel and coined first the term “carcinoid”. His research stands as a classical landmark in the understanding of carcinoid tumors.


Keywords Siegfried Oberndorfer, carcinoid tumors, small intestine

Ann Gastroenterol 2011; 24 (2: 98-100

Gregory Tsoucalas

2011-05-01

298

The effect of providing a USB syllabus on resident reading of landmark articles  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: The acquisition of new knowledge is a primary goal of residency training. Retrieving and retaining influential primary and secondary medical literature can be challenging for house officers. We set out to investigate the effect of a Universal Serial Bus (USB) drive loaded with landmark scientific articles on housestaff education in a pilot study. Methods: We created a USB syllabus that contains 187 primary scientific research articles. The electronic syllabus had links to the full...

Mayy Chahla; Michael Eberlein; Scott Wright

2010-01-01

299

Orbitozygomatic Approach: A Neurosurgical Approach Applied to the Anatomic Study of the Orbit  

Directory of Open Access Journals (Sweden)

Full Text Available From an anatomical point of view, the orbit is usually approached by resecting its roof. In this paper, the authors introduced minor modifications to a widely used neurosurgical technique in order to study the anatomy of the orbit: that is, the orbitozygomatic approach. The orbitozygomatic approach was performed in 3 half-heads of adult formalin-fixed cadavers. Three skulls were used to identify anatomical landmarks. The approach must be performed on a half-head without calvaria. An incision to reaching the bone was made on the skin of the temporal region and a combined flap of skin and temporalis muscle was reclined. Finally, 3 osteotomies were performed with a saw: 1 at the level of the root of the zygoma and the temporal squama, 2 over the orbital rim, medial to the supraorbitalis foramen and 3 at the zygomatic-frontal junction. In this way, the superior and lateral walls of the orbit were exposed. The adaptation of the orbitozygomatic approach allowed a wide exposure of the orbit and constituted an example of cooperation between clinical and basic disciplines.

Martínez, Fernando

2013-03-01

300

A FastSLAM-based Algorithm for Omnidirectional Cameras  

Directory of Open Access Journals (Sweden)

Full Text Available Environments with a low density of landmarks are difficult for vision-based Simultaneous Localization and Mapping (SLAM algorithms. The use of omnidirectional cameras, which have a wide field of view, is specially interesting in these environments as several landmarks are usually detected in each image. A typical example of this kind of situation happens in indoor environments when the lights placed on the ceiling are the landmarks. The use of omnivision combined with this type of landmarks presents two challenges: the data association and the initialization of the landmarks with a bearing-only sensor. In this paper we present a SLAM algorithm  based on the well-known FastSLAM approach. The proposal includes a novel hierarchical data association method based on the Hungarian algorithm, and a delayed initialization of the landmarks. The approach has been tested on a real environment with a Pioneer 3-DX robot.

Cristina Gamallo

2013-01-01

 
 
 
 
301

Anatomic fitting of total artificial hearts for in vivo evaluation.  

Science.gov (United States)

Successful anatomic fitting of a total artificial heart (TAH) is vital to achieve optimal pump hemodynamics after device implantation. Although many anatomic fitting studies have been completed in humans prior to clinical trials, few reports exist that detail the experience in animals for in vivo device evaluation. Optimal hemodynamics are crucial throughout the in vivo phase to direct design iterations and ultimately validate device performance prior to pivotal human trials. In vivo evaluation in a sheep model allows a realistically sized representation of a smaller patient, for which smaller third-generation TAHs have the potential to treat. Our study aimed to assess the anatomic fit of a single device rotary TAH in sheep prior to animal trials and to use the data to develop a three-dimensional, computer-aided design (CAD)-operated anatomic fitting tool for future TAH development. Following excision of the native ventricles above the atrio-ventricular groove, a prototype TAH was inserted within the chest cavity of six sheep (28-40?kg). Adjustable rods representing inlet and outlet conduits were oriented toward the center of each atrial chamber and the great vessels, with conduit lengths and angles recorded for future analysis. A three-dimensional, CAD-operated anatomic fitting tool was then developed, based on the results of this study, and used to determine the inflow and outflow conduit orientation of the TAH. The mean diameters of the sheep left atrium, right atrium, aorta, and pulmonary artery were 39, 33, 12, and 11?mm, respectively. The center-to-center distance and outer-edge-to-outer-edge distance between the atria, found to be 39?±?9?mm and 72?±?17?mm in this study, were identified as the most critical geometries for successful TAH connection. This geometric constraint restricts the maximum separation allowable between left and right inlet ports of a TAH to ensure successful alignment within the available atrial circumference. PMID:23461712

Gregory, Shaun D; Loechel, Nicole; Pearcy, Mark J; Fraser, John; Parnis, Steven; Cohn, William E; Timms, Daniel

2013-08-01

302

Evaluation of a Glass Ionomer Restoration to Treat Hypersensitive Cervical Anatomic Deficiencies.  

Science.gov (United States)

The objective of the research will be to test the usefulness of a glass ionomer cement ot treat hypersensitive cervical anatomic deficiencies with a restorative material that required no tooth preparation for its application. Based on the findings of this...

E. B. Mandel

1983-01-01

303

Restoration of the round locomotive depot, a moscow landmark ??????????? ????????? ??????????? — ?????? ????????? ??????????? ????  

Directory of Open Access Journals (Sweden)

Full Text Available Nikolaev railway depot is one of the first locomotive depots in Russia. It is a monument of cultural heritage, and it belongs to a group of buildings of the Leningrad Railroad Station in Moscow. The depot was designed by renowned architects K.A. Ton andR.A. Zhelyazevich in 1951. The depot building is round; it consists of 22 sections. The bearing structures of the building, its columns, arches and vaults are made of masonry. The depot building was remodeled several times, following changes in its intended use. Therefore, the original look of the building has lost its initial splendour. Now its structures are badly damaged, and the bearing capacity of its masonry columns and arches has changed for the worse. Its reconstruction will be accompanied by the restoration of its original exterior. Its reconstruction must be accompanied by the comprehensive monitoring of the stress-strain state of its surviving structures. The renovation must be based on the structural analysis of changes of its properties and damages. Currently, the engineering staff of our university is monitoring the strained state of the building to give advice in the course of its further restoration.????????? ??????? ??????? ?????????? ? ???? ???????? ??????????????? ??????????????? ?????????? ?????? ????????? ???? — ?????? ?? ???????? ?????????? ???????????? ??????????? XIX ?. ??????? ???????????? ??????????? ???????????? ????? ?????? ? ?? ??????????? ??????????? ?????????. ??????????? ???????? ???????????? ?????? ??? ??????????? ??????. ?????????? ???????????? ?? ??????????? ??????? ??????????? ? ??????????? ?????????.

Perunov Aleksandr Sergeevich

2013-05-01

304

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

Energy Technology Data Exchange (ETDEWEB)

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

Kim, Yong Il; Im, Hyung Jun; Paeng, Jin Chul; Lee, Jae Sung; Eo, Jae Seon; Kim, Dong Hyun; Kim, Euishin E.; Kang, Keon Wook; Chung, June Key; Lee Dong Soo [Seoul National Univ. Hospital, Seoul (Korea, Republic of)

2012-12-15

305

Generalized metrics induced anatomical prior for MAP PET image reconstruction  

International Nuclear Information System (INIS)

Information theoretic metrics, including mutual information (MI) and joint entropy (JE), have been investigated as priors to incorporate anatomical information in ill-posed positron emission tomography (PET) image reconstruction. These metrics are generally based on the Shannon entropy. Meanwhile, in this paper, we proposed a generalized metrics induced anatomical prior for maximum a posteriori (MAP) PET reconstruction based on the generalized Shannon entropy metrics or Tsallis entropy. For the presented prior computation, a non-parametric method was used to estimate the joint probability density of the PET and MR image. Furthermore, we also developed an one-step-advance (OSA) MAP algorithm for PET image reconstruction with the presented prior regularization. Simulation results show that the presented novel prior has significantly improved the reconstructed PET image quality. (orig.)

2011-07-11

306

Generalized metrics induced anatomical prior for MAP PET image reconstruction  

Energy Technology Data Exchange (ETDEWEB)

Information theoretic metrics, including mutual information (MI) and joint entropy (JE), have been investigated as priors to incorporate anatomical information in ill-posed positron emission tomography (PET) image reconstruction. These metrics are generally based on the Shannon entropy. Meanwhile, in this paper, we proposed a generalized metrics induced anatomical prior for maximum a posteriori (MAP) PET reconstruction based on the generalized Shannon entropy metrics or Tsallis entropy. For the presented prior computation, a non-parametric method was used to estimate the joint probability density of the PET and MR image. Furthermore, we also developed an one-step-advance (OSA) MAP algorithm for PET image reconstruction with the presented prior regularization. Simulation results show that the presented novel prior has significantly improved the reconstructed PET image quality. (orig.)

Lu, Lijun; Huang, Jing; Zhang, Hua; Bian, Zhaoying; Chen, Wufan [Southern Medical Univ., Guangzhou (China). School of Biomedical Engineering; Ma, Jianhua [Southern Medical Univ., Guangzhou (China). School of Biomedical Engineering; State Univ. of New York, Stony Brook, NY (United States). Dept. of Radiology; Liang, Zhengrong [State Univ. of New York, Stony Brook, NY (United States). Dept. of Radiology

2011-07-01

307

Analysis of anatomic variability in children with low mathematical skills  

Science.gov (United States)

Mathematical difficulty affects approximately 5-9% of the population. Studies on individuals with dyscalculia, a neurologically based math disorder, provide important insight into the neural correlates of mathematical ability. For example, cognitive theories, neuropsychological studies, and functional neuroimaging studies in individuals with dyscalculia suggest that the bilateral parietal lobes and intraparietal sulcus are central to mathematical performance. The purpose of the present study was to investigate morphological differences in a group of third grade children with poor math skills. We compare population averages of children with low math skill (MD) to gender and age matched controls with average math ability. Anatomical data were gathered with high resolution MRI and four different population averaging methods were used to study the effect of the normalization technique on the results. Statistical results based on the deformation fields between the two groups show anatomical differences in the bilateral parietal lobes, right frontal lobe, and left occipital/parietal lobe.

Han, Zhaoying; Fuchs, Lynn; Davis, Nikki; Cannistraci, Christopher J.; Anderson, Adam W.; Gore, John C.; Dawant, Benoit M.

2008-04-01

308

Insect navigation en route to the goal: multiple strategies for the use of landmarks  

Science.gov (United States)

There are at least four distinct ways in which familiar landmarks aid an insect on its trips between nest and foraging site. Recognising scenes: when bees are displaced unexpectedly from their hive to one of several familiar locations, they are able to head in the direction of home as though they had previously linked an appropriate directional vector to a view of the scene at the release site. Biased detours: ants recognise familiar landmarks en route and will correct their path by steering consistently to the left or to the right around them. Aiming at beacons: bees and ants also guide their path by approaching familiar landmarks lying on or close to the direct line between start and finish. Simulations suggest that such mechanisms acting together may suffice to account for the routes taken by desert ants through a landmark-strewn environment: the stereotyped trajectories of individual ants can be modelled by a weighted combination of dead reckoning, biased detours and beacon-aiming. These mechanisms guide an insect sufficiently close to an inconspicuous goal for image matching to be successfully employed to locate it. Insects then move until their current retinal image matches a stored view of the surrounding panorama seen from a vantage point close to the goal. Bees and wasps perform learning flights on their first departure from a site to which they will return. These flights seem to be designed to pick up the information needed for several navigational strategies. Thus, a large portion of the learning flight of a bee leaving a feeder tends to be spent close to the feeder so aiding the acquisition of a view from that vantage point, as is needed for image matching. Bees and social wasps also tend to inspect their surroundings while facing along preferred directions and to adopt similar bearings before landing, thereby making it easy to employ retinotopically stored patterns in image matching. Aiming at beacons, in contrast, requires a landmark to be familiar to the frontal retina. Objects tend to be viewed frontally while the insect circles through arcs centred on the goal. This procedure may help insects to pick out those objects close to the goal that are best suited for guiding later returns. PMID:9317693

Collett

1996-01-01

309

Anatomic variation of cranial parasympathetic ganglia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Having broad knowledge of anatomy is essential for practicing dentistry. Certain anatomical structures call for detailed studies due to their anatomical and functional importance. Nevertheless, some structures are difficult to visualize and identify due to their small volume and complicated access. Such is the case of the parasympathetic ganglia located in the cranial part of the autonomic nervous system, which include: the ciliary ganglion (located deeply in the orbit, laterally to the optic...

Selma Siéssere; Mathias Vitti; Luiz Gustavo de Sousa; Marisa Semprini; Mamie Mizusaki Iyomasa; Simone Cecílio Hallak Regalo

2008-01-01

310

Individualized Anatomic Anterior Cruciate Ligament Reconstruction  

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Arthroscopic anterior cruciate ligament reconstruction (ACL-R) is a technique that continues to evolve. Good results have been established with respect to reducing anteroposterior laxity. However, these results have come into question because nonanatomic techniques have been ineffective at restoring knee kinematics and raised concerns that abnormal kinematics may impact long-term knee health. Anatomic ACL-R attempts to closely reproduce the patient's individual anatomic characteristics. Measu...

Rabuck, Stephen J.; Middleton, Kellie K.; Maeda, Shugo; Fujimaki, Yoshimasa; Muller, Bart; Araujo, Paulo H.; Fu, Freddie H.

2012-01-01

311

Lumbar pedicle: surgical anatomic evaluation and relationships  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Although several clinical applications of transpedicular screw fixation in the lumbar spine have been documented for many years, few anatomic studies concerning the lumbar pedicle and adjacent neural structures have been published. The lumbar pedicle and its relationships to adjacent neural structures were investigated through an anatomic study. Our objective is to highlight important considerations in performing transpedicular screw fixation in the lumbar spine. Twenty cadavers were used for...

Attar, Ayhan; Ugur, Hasan Caglar; Uz, Aysun; Tekdemir, Ibrahim; Egemen, Nihat; Genc, Yasemin

2001-01-01

312

ElePhant--an anatomical electronic phantom as simulation-system for otologic surgery.  

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This paper describes the ElePhant (Electronic Phantom)-an anatomical correct simulation system based on 3D rapid prototyping models for the otologic intervention "Mastoidectomy". The anatomical structures of the head are created with plaster as base material using 3D-printing as rapid prototyping technology (RPT). Structures at risk, represented by electrically conductible material and fiber optics, are realized as an electric circuit and can be detected during the simulation of the surgical ...

Grunert, Ronny; Strauss, Gero; Moeckel, Hendrick; Hofer, Mathias; Poessneck, Antje; Fickweiler, Ulrich; Thalheim, Mario; Schmiedel, Ronny; Jannin, Pierre; Schulz, Thomas; Oeken, Jens; Dietz, Andreas; Korb, Werner

2006-01-01

313

SEGMENTATION OF ANATOMICAL STRUCTURES BY CONNECTED STATISTICAL MODELS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents a framework for the segmentation of anatomical structures in medical imagery by connected statistical models. The framework is based on three types of models: first, generic models which operate directly on image intensities, second, connecting models that impose restrictions on the spatial relationship of generic models, and third, a supervising model that represents an arbitrary number of generic and connecting models. In this paper, the statistical model of appearance i...

Marko Bukovec; Boštjan Likar; Franjo Pernuš

2011-01-01

314

Integration of Word Processing with an Anatomic Pathology Information System  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A commercially available wordprocessor has been integrated with an end-user developed Anatomic Pathology information system (“APD”) that is based on Snomed coding of diagnoses. Both software packages are written in Standard MUMPS and run on DEC PDP-11 equipment. The APD software initializes and formats the word processor document, and forms the document header and trailer from patient data on file. The diagnoses from all prior Pathology reports are automatically inserted into the body of ...

Sharkey, Francis E.; Bej, Mark D.

1985-01-01

315

Characterizing anatomical variability in breast CT images.  

Science.gov (United States)

Previous work [Burgess et al., Med. Phys. 28, 419-437 (2001)] has shown that anatomical noise in projection mammography results in a power spectrum well modeled over a range of frequencies by a power law, and the exponent (beta) of this power law plays a critical role in determining the size at which a growing lesion reaches the threshold for detection. In this study, the authors evaluated the power-law model for breast computed tomography (bCT) images, which can be thought of as thin sections through a three-dimensional (3D) volume. Under the assumption of a 3D power law describing the distribution of attenuation coefficients in the breast parenchyma, the authors derived the relationship between the power-law exponents of bCT and projection images and found it to be betasection=betaproj-1. They evaluated this relationship on clinical images by comparing bCT images from a set of 43 patients to Burgess' findings in mammography. They were able to make a direct comparison for 6 of these patients who had both a bCT exam and a digitized film-screen mammogram. They also evaluated segmented bCT images to investigate the extent to which the bCT power-law exponent can be explained by a binary model of attenuation coefficients based on the different attenuation of glandular and adipose tissue. The power-law model was found to be a good fit for bCT data over frequencies from 0.07 to 0.45 cyc/mm, where anatomical variability dominates the spectrum. The average exponent for bCT images was 1.86. This value is close to the theoretical prediction using Burgess' published data for projection mammography and for the limited set of mammography data available from the authors' patient sample. Exponents from the segmented bCT images (average value: 2.06) were systematically slightly higher than bCT images, with substantial correlation between the two (r=0.84). PMID:18975714

Metheany, Kathrine G; Abbey, Craig K; Packard, Nathan; Boone, John M

2008-10-01

316

A hybrid biomechanical model-based image registration method for sliding objects  

Science.gov (United States)

The sliding motion between two anatomic structures, such as lung against chest wall, liver against surrounding tissues, produces a discontinuous displacement field between their boundaries. Capturing the sliding motion is quite challenging for intensity-based image registration methods in which a smoothness condition has commonly been applied to ensure the deformation consistency of neighborhood voxels. Such a smoothness constraint contradicts motion physiology at the boundaries of these anatomic structures. Although various regularisation schemes have been developed to handle sliding motion under the framework of non-rigid intensity-based image registration, the recovered displacement field may still not be physically plausible. In this study, a new framework that incorporates a patient-specific biomechanical model with a non-rigid image registration scheme for motion estimation of sliding objects has been developed. The patient-specific model provides the motion estimation with an explicit simulation of sliding motion, while the subsequent non-rigid image registration compensates for smaller residuals of the deformation due to the inaccuracy of the physical model. The algorithm was tested against the results of the published literature using 4D CT data from 10 lung cancer patients. The target registration error (TRE) of 3000 landmarks with the proposed method (1.37+/-0.89 mm) was significantly lower than that with the popular B-spline based free form deformation (FFD) registration (4.5+/-3.9 mm), and was smaller than that using the B-spline based FFD registration with the sliding constraint (1.66+/-1.14 mm) or using the B-spline based FFD registration on segmented lungs (1.47+/-1.1 mm). A paired t-test showed that the improvement of registration performance with the proposed method was significant (p<0.01). The propose method also achieved the best registration performance on the landmarks near lung surfaces. Since biomechanical models captured most of the lung deformation, the final estimated deformation field was more physically plausible.

Han, Lianghao; Hawkes, David; Barratt, Dean

2014-03-01

317

Characterization of Capsicum species using anatomical and molecular data.  

Science.gov (United States)

Capsicum species are frequently described in terms of genetic divergence, considering morphological, agronomic, and molecular databases. However, descriptions of genetic differences based on anatomical characters are rare. We examined the anatomy and the micromorphology of vegetative and reproductive organs of several Capsicum species. Four Capsicum accessions representing the species C. annuum var. annuum, C. baccatum var. pendulum, C. chinense, and C. frutescens were cultivated in a greenhouse; leaves, fruits and seeds were sampled and their organ structure analyzed by light and scanning electronic microscopy. Molecular accession characterization was made using ISSR markers. Polymorphism was observed among tector trichomes and also in fruit color and shape. High variability among accessions was detected by ISSR markers. Despite the species studied present a wide morphological and molecular variability that was not reflected by anatomical features. PMID:23479174

Dias, G B; Gomes, V M; Moraes, T M S; Zottich, U P; Rabelo, G R; Carvalho, A O; Moulin, M; Gonçalves, L S A; Rodrigues, R; Da Cunha, M

2013-01-01

318

The role of anatomic information in quantifying functional neuroimaging data  

International Nuclear Information System (INIS)

When using modern neuroimaging tools, such as CT, PET, SPECT, MRI and MEG, in brain research and brain diagnostics, there is a common need for including external anatomical information into the interpretation and analysis of data. This information may be used to aid the interpretation of structures in images from low resolution imaging tools. With high resolution tools it can help to identify resolved structures. It can also facilitate the merging of data from different modalities, or from different individuals. The anatomical information is often given as regions of interests (ROIs), which may be manually created from an anatomy rich image or automatically created from a standard template collection or from an atlas data base. Automatic methods will lead to a substantial reduction in bias and in size of the systematic errors. Functional ROIs can correspondingly be derived from functional images (usually PET or SPECT). Different aspects of these processes are discussed in the report. (authors)

1992-01-01

319

Gamma camera-mounted anatomical X-ray tomography: technology, system characteristics and first images  

International Nuclear Information System (INIS)

Scintigraphic diagnosis, based on functional image interpretation, becomes more accurate and meaningful when supported by corresponding anatomical data. In order to produce anatomical images that are inherently registered with images of emission computerised tomography acquired with a gamma camera, an X-ray transmission system was mounted on the slip-ring gantry of a GEMS millennium VG gamma camera. The X-ray imaging system is composed of an X-ray tube and a set of detectors located on opposite sides of the gantry rotor that moves around the patient along with the nuclear detectors. A cross-sectional anatomical transmission map is acquired as the system rotates around the patient in a manner similar to a third-generation computerised tomography (CT) system. Following transmission, single-photon emission tomography (SPET) or positron emission tomography (PET) coincidence detection images are acquired and the resultant emission images are thus inherently registered to the anatomical maps. Attenuation correction of the emission images is performed with the same anatomical maps to generate transmission maps. Phantom experiments of system performance and examples of first SPET and coincidence detection patient images are presented. Despite limitations of the system when compared with a state of the art CT scanner, the transmission anatomical maps allow for precise anatomical localisation and for attenuation correction of the emission images. (orig.)

2000-06-01

320

Anatomical aspect of the hard palate of the Cebus apella (Linnaeus, 1766 primates  

Directory of Open Access Journals (Sweden)

Full Text Available Fourteen hard palates of neotropical primates were studied (Cebus apella, fixed on formaldehyde (10% and preserved in ethylic alcohol (70%, collected according to the International Bioethics Committee. The animals were supplied by the Medicine College Veterinary Medicine and Zootecnica of the University of São Paulo in 1994. They originated from the São Paulo Zoo. They had died naturally. Measurement (in centimeters of the viscerocranium (8 adults and 6 young animals was made, including palatine length (PL, interpremolar distance (ID, intermolar distance (ID, interorbital distance (IDi, and midface height (MH. The palatine anatomy showed complete right crests (7.64 to 1.22, complete left crests (8.07 to 1.71, incomplete right crests (1.71 to 1.43, and incomplete left crests (1.64 to 1.3. The diasten between the lateral incisive teeth was the main anatomical landmark for the anterior end of the crest, and the landmark for the posterior end was the second molar teeth for all the specimens. The palate is very peculiar: mild concave, from the dental arcade to the median line, covered by the non-pigmented mucous tissue, with osseous structure composed of horizontal layers of the maxilar and palatine bones; sub mucous tissue attached to the periosteum and mucous tissue showing relatively prominent palatine crests. The crests appear as a rigid elevation of the mucous tissue, with some variations at the antimers. It may be concluded that the length of the hard palate is strongly related to the maturity of the animal, relative to the interorbital distance, and that the latter is also related to the length of the palate and the labial opening.

Andréia Luciana Martins Ramos

2008-03-01

 
 
 
 
321

Anatomic research of suboccipito-retrosigmoidal approach for minimally invasive exposure of facial-acoustic nerve complex utilizing virtual reality skill  

Directory of Open Access Journals (Sweden)

Full Text Available Objective To discuss microanatomy features of facial-acoustic nerve complex in suboccipito-retrosigmoidal minimally invasive approach based on virtual reality image model. Methods CT and MRI scans were performed to 5 adult cadaver heads, and then, image data was inputted into Vitrea virtual reality system to establish three-dimensional anatomy model of facial-acoustic nerve complex. Suboccipito-retrosigmoidal approach was simulated by selecting osseous landmark points on the calvaria and skull base. Anatomic exposures in surgical trajectory were observed and measured following minimally invasive design. Statistical comparison was launched by paired t test. Results Routes simulating suboccipito-retrosigmoidal approach for exposure of facial-acoustic nerve complex passed under the inferior edge of transverse sinus. Spacial sequence of nerves and vessels in the route was displayed clearly. Vertebral artery and posterior inferior cerebellar artery did not show in the route. Cerebella, lower cranial nerves, anterior inferior cerebellar artery, facial-acoustic nerve complex were exposed successively in route before minimally invasive design. Then, lower cranial nerves pierced the jugular foramen at the site between the jugular bulb and inferior petrosal sinus. Minimally invasive route was higher than that before minimally invasive design and involved cerebella, anterior inferior cerebellar artery and facial-acoustic nerve complex successively. Lower cranial nerves and jugular bulb were not shown in minimally invasive route. Measure and comparative analysis showed that volumes of route (t = 36.331, P = 0.000 and cerebella (t = 16.775, P = 0.000 involved before minimally invasive design were more than that after minimally invasive design with statistically significant difference. Comparison did not show significant differences for the volumes of facial-acoustic nerve complex (t = 1.680, P = 0.127 and anterior inferior cerebellar artery (t = 1.278, P = 0.233 between routes before and after minimally invasive design. Conclusions Minimally invasive routes of suboccipito-retrosigmoidal approach can reduce surgical injury without sacrifice of anatomic exposure for facial-acoustic nerve complex. doi: 10.3969/j.issn.1672-6731.2014.06.008

Ke TANG

2014-06-01

322

Reciprocal anatomical relationship between primary sensory and prefrontal cortices in the human brain  

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The human brain exhibits remarkable inter-individual variability in cortical architecture. Despite extensive evidence for the behavioral consequences of such anatomical variability in individual cortical regions, it is unclear whether and how different cortical regions covary in morphology. Using a novel approach that combined non-invasive cortical functional mapping with whole-brain voxel-based morphometric analyses, we investigated the anatomical relationship between the functionally define...

2011-01-01

323

Global relationship between anatomical connectivity and activity propagation in the cerebral cortex.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Anatomical connectivity is a prerequisite for cooperative interactions between cortical areas, but it has yet to be demonstrated that association fibre networks determine the macroscopical flow of activity in the cerebral cortex. To test this notion, we constructed a large-scale model of cortical areas whose interconnections were based on published anatomical data from tracing studies. Using this model we simulated the propagation of activity in response to activation of individual cortical a...

Ko?tter, R.; Sommer, F. T.

2000-01-01

324

A study on the anatomical morphology of the minor fissure  

International Nuclear Information System (INIS)

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

1993-07-01

325

A study on the anatomical morphology of the minor fissure  

Energy Technology Data Exchange (ETDEWEB)

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.

Lee, Hyeong Gon; Kim, Hyung Jin; You, Jin Jong; Ahn, In Oak; Chung, Sung Hoon [Gyeongsang University College of Medicine, Chinju (Korea, Republic of)

1993-07-15

326

[Anatomic preparations in the Petersburg "art chamber"].  

Science.gov (United States)

The first museums on history of nature were opened in early Enlightenment and had originated from baroque curio galleries at most of the European courts. Peter the Great, too, had his "Art Chamber" converted to a universal museum primarily designed to didactic purposes. Much of the space was devoted to anatomic and teratological exhibits. To complete these collections, Peter repeatedly ordered all malformations to be handed over ("Monster Decree"). When travelling abroad, he purchased anatomic, zoological, botanic, and mineralogical collections, such as the famous collection previously owned by Frederik Ruysch in Amsterdam, with injected anatomic specimens with period-style decorations. The Art Chamber collection was later on described by K. W. Burdach, anatomist, and K. E. v. Baer, anthropologist. Many of its exhibits are still at show. PMID:2694687

Müller-Dietz, H E

1989-01-01

327

Importance of anatomical noise in mammography  

Science.gov (United States)

Normal tissue structure in a radiological image, called anatomical noise, can prevent radiologists from seeing the pathology they are looking for. The goal of this paper is to show the importance of this noise component compared to the system one (quantum mottle, screen structure and film noises) in the particular case of mammography. Two normal mammographic images are digitized in order to provide an anatomical structure. On this background, an object simulating a microcalcification (a sphere) or a tumor (a spherical lens) is filtrated by the modulation transfer function of the imaging system representative of a mammographic unit and superimposed. A two alternative forced choice experiment is effected on these synthesized images in which the amount of object contrast and system noise is varied. The images are presented on a high resolution screen to five observers used for this kind of experiment. The experimental results are then compared to the signal to noise ratios given by the non-prewhitening matched filter model in which the human visual transfer function is taken into account. When comparing the experimental results with the model in which the anatomical noise is considered as a noise or as a signal, it is observed that the experimental results are in-between. This means that the anatomical background has a component that can be considered as a noise and another that can be recognized as signal. At the present time, there is no observer model who takes the anatomical noise effect into account. The use of a homogeneous test object without anatomical structure to qualify the system performance or to optimize the radiological procedure then appears questionable.

Bochud, Francois O.; Verdun, Francis R.; Valley, Jean-Francois; Hessler, Christian; Moeckli, Raphael

1997-04-01

328

Integration of tomato reproductive developmental landmarks and expression profiles, and the effect of SUN on fruit shape  

Directory of Open Access Journals (Sweden)

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 the NILs that differ at the sun locus, higher or lower transcript levels for many genes involved in phytohormone biosynthesis or signaling as well as organ identity and patterning of tomato fruit were found between developmental time points.

Li Dongmei

2009-05-01

329

Reduction of anatomical noise in medical X-ray images  

International Nuclear Information System (INIS)

The X-ray pattern of a mass of very fine non-distinguishable anatomical structures alters completely from radiograph to radiograph due to the unavoidable movements of the patient during the exposure. The corresponding image component shows noise-like behaviour and is therefore referred to as the anatomical noise. Reducing this component would enhance the quality of the clinical X-ray image and increase the detectability of radiological signal. We have found that by comparing two X-ray images of the same anatomy acquired under slightly different imaging geometry, it is possible to reduce the anatomical noise in one of the image pair. The proposed method, which allows this, is based on the appropriate attenuation in the wavelet domain. The values of attenuating factors for the wavelet coefficients are proportional to the correlation between the corresponding features of both images. This method was tested for different changes in the imaging geometry. In the case of no geometrical changes, only the quantum and the electronic noise are reduced. An effect of de-noising for the investigated images is obvious. (authors)

2004-04-23

330

Reduction of anatomical noise in medical X-ray images.  

Science.gov (United States)

The X-ray pattern of a mass of very fine non-distinguishable anatomical structures alters completely from radiograph to radiograph due to the unavoidable movements of the patient during the exposure. The corresponding image component shows noise-like behaviour and is therefore referred to as the anatomical noise. Reducing this component would enhance the quality of the clinical X-ray image and increase the detectability of radiological signal. We have found that by comparing two X-ray images of the same anatomy acquired under slightly different imaging geometry, it is possible to reduce the anatomical noise in one of the image pair. The proposed method, which allows this, is based on the appropriate attenuation in the wavelet domain. The values of attenuating factors for the wavelet coefficients are proportional to the correlation between the corresponding features of both images. This method was tested for different changes in the imaging geometry. In the case of no geometrical changes, only the quantum and the electronic noise are reduced. An effect of de-noising for the investigated images is obvious. PMID:15933083

Tischenko, Oleg; Hoeschen, Christoph; Buhr, Egbert

2005-01-01

331

Electrochemical degradation of electrodeposited Pt particles on mask scratched substrate using a landmark for ex situ scanning electron microscopy  

International Nuclear Information System (INIS)

Pt particles were deposited on a glassy carbon substrate using a landmark by a mask scratch-based Pt electrodeposition method to observe the same Pt particles by ex situ scanning electron microscopy before and after a potential cycling procedure. The potential cycling was conducted in a H2O2-containing 0.5 mol dm-3 H2SO4 solution. As a result, the Pt particle degradations are clearly observed in the solution containing 100 mmol dm-3 H2O2 in the potential range of 0.04-1.44 V vs. RHE; whereas, the degradations become more remarkable at 0.34-1.44 V vs. RHE. To clarify the reason for this potential cycling range-dependence of the Pt particle degradations, the weight change of a Pt electrode during potential cycling in the presence of H2O2 was measured using an electrochemical quartz crystal microbalance. The result suggests that the dissolved Pt is re-deposited on the Pt in ca. 0.01-0.40 V vs. RHE, which well explains the difference of the Pt particle degradations by the potential cyclings between 0.04-1.44 and 0.34-1.44 V vs. RHE.

2012-07-15

332

Electrochemical degradation of electrodeposited Pt particles on mask scratched substrate using a landmark for ex situ scanning electron microscopy  

Energy Technology Data Exchange (ETDEWEB)

Pt particles were deposited on a glassy carbon substrate using a landmark by a mask scratch-based Pt electrodeposition method to observe the same Pt particles by ex situ scanning electron microscopy before and after a potential cycling procedure. The potential cycling was conducted in a H{sub 2}O{sub 2}-containing 0.5 mol dm{sup -3} H{sub 2}SO{sub 4} solution. As a result, the Pt particle degradations are clearly observed in the solution containing 100 mmol dm{sup -3} H{sub 2}O{sub 2} in the potential range of 0.04-1.44 V vs. RHE; whereas, the degradations become more remarkable at 0.34-1.44 V vs. RHE. To clarify the reason for this potential cycling range-dependence of the Pt particle degradations, the weight change of a Pt electrode during potential cycling in the presence of H{sub 2}O{sub 2} was measured using an electrochemical quartz crystal microbalance. The result suggests that the dissolved Pt is re-deposited on the Pt in ca. 0.01-0.40 V vs. RHE, which well explains the difference of the Pt particle degradations by the potential cyclings between 0.04-1.44 and 0.34-1.44 V vs. RHE.

Kishi, Akira; Inoue, Mitsuhiro; Shironita, Sayoko [Department of Materials Science and Technology, Faculty of Engineering, Nagaoka University of Technology, Kamitomioka 1603-1, Nagaoka, Niigata 940-2188 (Japan); Umeda, Minoru, E-mail: mumeda@vos.nagaokaut.ac.jp [Department of Materials Science and Technology, Faculty of Engineering, Nagaoka University of Technology, Kamitomioka 1603-1, Nagaoka, Niigata 940-2188 (Japan)

2012-07-15

333

A 3-dimensional transnasal endoscopic journey through the paranasal sinuses and adjacent skull base: a practical and surgery-oriented perspective.  

Science.gov (United States)

An endoscopic approach through the transnasal corridor is currently the treatment of choice in the management of benign sinonasal tumors, cerebrospinal fluid leaks, and pituitary lesions. Moreover, this approach can be considered a valid option in the management of selected sinonasal malignancies extending to the skull base, midline meningiomas, parasellar lesions such as craniopharyngioma and Rathke cleft cyst, and clival lesions such as chordoma and ecchordosis. Over the past decade, strict cooperation between otorhinolaryngologists and neurosurgeons and acquired surgical skills, together with high-definition cameras, dedicated instrumentation, and navigation systems, have made it possible to broaden the indications of endoscopic surgery. Despite these improvements, depth perception, as provided by the use of a microscope, was still lacking with this technology. The aim of the present project is to reveal new perspectives in the endoscopic perception of the sinonasal complex and skull base thanks to 3-dimensional endoscopes, which are well suited to access and explore the endonasal corridor. In the anatomic dissection herein, this innovative device came across with sophisticated and long-established fresh cadaver preparation provided by one of the most prestigious universities of Europe. The final product is a 3-dimensional journey starting from the nasal cavity, reaching the anterior, middle, and posterior cranial fossae, passing through the ethmoidal complex, paranasal sinuses, and skull base. Anatomic landmarks, critical areas, and tips and tricks to safely dissect delicate anatomic structures are addressed through audio comments, figures, and their captions. PMID:24064484

Bolzoni Villaret, Andrea; Battaglia, Paolo; Tschabitscher, Manfred; Mattavelli, Davide; Turri-Zanoni, Mario; Castelnuovo, Paolo; Nicolai, Piero

2014-03-01

334

Anatomical Studies in Relation to Taxonomy of Persian Linum Species  

Directory of Open Access Journals (Sweden)

Full Text Available The present survey was performed on twelve Persian Linum species with the aim to illustrate species inter-relationships and to evaluate the taxonomic treatments proposed for the genus Linum in Iran. It includes comparative anatomy of the species based on leaves and stems transverse sections. The results are highly in agreement with the previous morphologic based taxonomic treatments of the genus and anatomical traits used are efficient for application at generic and sub-generic levels of the genus Linum in Iran.

Fariba Sharifnia

2002-01-01

335

Rats with lesions of the vestibular system require a visual landmark for spatial navigation.  

Science.gov (United States)

The role of the vestibular system in acquisition and performance of a spatial navigation task was examined in rats. Male Long-Evans rats received sham or bilateral sodium arsanilate-induced vestibular lesions. After postoperative recovery, under partial water-deprivation, rats were trained (16 trials/day) to find a water reward in one corner of a black square enclosure. A cue card fixed to one wall of the enclosure served as a stable landmark cue. The orientation of the rat at the start of each trial was pseudo-randomized such that the task could not be solved by an egocentric response strategy. Rats with vestibular lesions acquired the task in fewer trials than the sham treated control rats. Vestibular lesions did not influence the motivation or motor function necessary to perform the task. Performance of sham rats was maintained during probe trials in which the cue card was removed from the enclosure, while lesioned rats were markedly impaired. Rotation of the cue card (+/-90 degrees ) caused an equivalent shift in corner choice behavior of the lesioned rats. However, sham rats often disregarded the rotated cue card and made place responses. These results suggest that the vestibular lesions disrupt idiothetic navigation or path integration and render navigational behavior critically dependent upon external landmarks. These results are consistent with the navigational abilities of humans with bilateral vestibular dysfunction. PMID:11755687

Stackman, Robert W; Herbert, Aaron M

2002-01-01

336

The effect of providing a USB syllabus on resident reading of landmark articles  

Directory of Open Access Journals (Sweden)

Full Text Available Background: The acquisition of new knowledge is a primary goal of residency training. Retrieving and retaining influential primary and secondary medical literature can be challenging for house officers. We set out to investigate the effect of a Universal Serial Bus (USB drive loaded with landmark scientific articles on housestaff education in a pilot study. Methods: We created a USB syllabus that contains 187 primary scientific research articles. The electronic syllabus had links to the full-text articles and was organized using an html webpage with a table of contents according to medical subspecialties. We performed a prospective cohort study of 53 house officers in the internal medicine residency program who received the USB syllabus. We evaluated the impact of the USB syllabus on resident education with surveys at the beginning and conclusion of the nine-month study period. Results: All 50 respondents (100% reported to have used the USB syllabus. The self-reported number of original articles read each month was higher at the end of the nine-month study period compared to baseline. Housestaff rated original articles as being a more valuable educational resource after the intervention. Conclusions: An electronic syllabus with landmark scientific articles placed on a USB drive was widely utilized by housestaff, increased the self-reported reading of original scientific articles and seemed to have positively influenced residents’ attitude toward original medical literature.

Mayy Chahla

2010-01-01

337

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

Energy Technology Data Exchange (ETDEWEB)

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

Abreu, Marcelo R. [University of California San Diego, VA Health Care System, San Diego, CA (United States); Chung, Christine B.; Trudell, Debra; Resnick, Donald [University of California San Diego, VA Health Care System, San Diego, CA (United States); Hospital Mae de Deus, Porto Alegre, RS (Brazil)

2008-04-15

338

Illustrative Visualization of Anatomical Structures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Illustrative visualization is a term for visualization techniques inspired by traditional technical and medical illustration. These techniques are based on knowledge of the human perception and provide effective visual abstraction to make the visualizations more understandable. Within volume rendering these expressive visualizations can be achieved using non-photorealistic rendering that combines different levels of abstraction to convey the most important information to the viewer. In this t...

Jonsson, Erik

2011-01-01

339

Handbook of anatomical models for radiation dosimetry  

CERN Document Server

Covering the history of human model development, this title presents the major anatomical and physical models that have been developed for human body radiation protection, diagnostic imaging, and nuclear medicine therapy. It explores how these models have evolved and the role that modern technologies have played in this development.

Eckerman, Keith F

2010-01-01

340

Magnetic resonance angiography: infrequent anatomic variants  

International Nuclear Information System (INIS)

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

2002-01-01

 
 
 
 
341

Anatomical Data for Analyzing Human Motion.  

Science.gov (United States)

Anatomical data obtained from cadavers and from water displacement studies with living subjects were used to determine the weight, center of gravity, and radius of gyration for 16 body segments. A lead model was used to study movement patterns of the trunk section of the body. (Authors/PP)

Plagenhoef, Stanley; And Others

1983-01-01

342

Interactions between idiothetic cues and external landmarks in the control of place cells and head direction cells.  

Science.gov (United States)

Two types of neurons in the rat brain have been proposed to participate in spatial learning and navigation: place cells, which fire selectively in specific locations of an environment and which may constitute key elements of cognitive maps, and head direction cells, which fire selectively when the rat's head is pointed in a specific direction and which may serve as an internal compass to orient the cognitive map. The spatially and directionally selective properties of these cells arise from a complex interaction between input from external landmarks and from idiothetic cues; however, the exact nature of this interaction is poorly understood. To address this issue, directional information from visual landmarks was placed in direct conflict with directional information from idiothetic cues. When the mismatch between the two sources of information was small (45 degrees), the visual landmarks had robust control over the firing properties of place cells; when the mismatch was larger, however, the firing fields of the place cells were altered radically, and the hippocampus formed a new representation of the environment. Similarly, the visual cues had control over the firing properties of head direction cells when the mismatch was small (45 degrees), but the idiothetic input usually predominated over the visual landmarks when the mismatch was larger. Under some conditions, when the visual landmarks predominated after a large mismatch, there was always a delay before the visual cues exerted their control over head direction cells. These results support recent models proposing that prewired intrinsic connections enable idiothetic cues to serve as the primary drive on place cells and head direction cells, whereas modifiable extrinsic connections mediate a learned, secondary influence of visual landmarks. PMID:9658061

Knierim, J J; Kudrimoti, H S; McNaughton, B L

1998-07-01

343

Acetabular orientation variability and symmetry based on CT scans of adults  

Energy Technology Data Exchange (ETDEWEB)

Understanding acetabular orientation is important in many orthopaedic procedures. Acetabular orientation, usually described by anteversion and abduction angles, has uncertain measurement variability in adult patients. The goals of this study are threefold: (1) to describe a new method for computing patient-specific abduction/anteversion angles from a single CT study based on the identification of anatomical landmarks and acetabular rim points; (2) to quantify the inaccuracies associated with landmark selection in computing the acetabular angles; and (3) to quantify the variability and symmetry of acetabular orientation. A total of 25 CT studies from adult patients scanned for non-orthopaedic indications were retrospectively reviewed. The patients were randomly selected from the hospital's database. Inclusion criteria were adults 20-65 years of age. Acetabular landmark coordinates were identified by expert observers and tabulated in a spreadsheet. Two sets of calculations were done using the data: (1) computation of the abduction and anteversion for each patient, and (2) evaluation of the variability of measurements in the same individual by the same surgeon. The results were tabulated and summary statistics computed. This retrospective study showed that acetabular abduction and anteversion angles averaged 54 and 17 , respectively, in adults. A clinically significant intra-patient variability of >20 was found. We also found that the right and left side rim plane orientation were significantly correlated, but were not always symmetric. A new method of computing patient-specific abduction and anteversion angles from a CT study of the anterior pelvic plane and the left and right acetabular rim planes was reliable and accurate. We found that the acetabular rim plane can be reliably and accurately computed from identified points on the rim. The novelty of this work is that angular measurements are performed between planes on a 3-D model rather than lines on 2-D projections, as was done in the past. (orig.)

Lubovsky, Omri; Liebergall, Meir; Khoury, Amal [Hadassah-Hebrew University Medical Center, Orthopedic Surgery Complex, Jerusalem (Israel); Peleg, Eran [Hadassah-Hebrew University Medical Center, Department of Medical Engineering, Jerusalem (Israel); Joskowicz, Leo [Hebrew University of Jerusalem, School of Engineering and Computer Science, Jerusalem (Israel)

2010-09-15

344

Acetabular orientation variability and symmetry based on CT scans of adults  

International Nuclear Information System (INIS)

Understanding acetabular orientation is important in many orthopaedic procedures. Acetabular orientation, usually described by anteversion and abduction angles, has uncertain measurement variability in adult patients. The goals of this study are threefold: (1) to describe a new method for computing patient-specific abduction/anteversion angles from a single CT study based on the identification of anatomical landmarks and acetabular rim points; (2) to quantify the inaccuracies associated with landmark selection in computing the acetabular angles; and (3) to quantify the variability and symmetry of acetabular orientation. A total of 25 CT studies from adult patients scanned for non-orthopaedic indications were retrospectively reviewed. The patients were randomly selected from the hospital's database. Inclusion criteria were adults 20-65 years of age. Acetabular landmark coordinates were identified by expert observers and tabulated in a spreadsheet. Two sets of calculations were done using the data: (1) computation of the abduction and anteversion for each patient, and (2) evaluation of the variability of measurements in the same individual by the same surgeon. The results were tabulated and summary statistics computed. This retrospective study showed that acetabular abduction and anteversion angles averaged 54 and 17 , respectively, in adults. A clinically significant intra-patient variability of >20 was found. We also found that the right and left side rim plane orientation were significantly correlated, but were not always symmetric. A new method of computing patient-specific abduction and anteversion angles from a CT study of the anterior pelvic plane and the left and right acetabular rim planes was reliable and accurate. We found that the acetabular rim plane can be reliably and accurately computed from identified points on the rim. The novelty of this work is that angular measurements are performed between planes on a 3-D model rather than lines on 2-D projections, as was done in the past. (orig.)

2010-09-01

345

Influence of landmark and surgical variability on virtual assessment of total knee arthroplasty.  

Science.gov (United States)

Given advances in recent years in imaging modalities and computational hardware/software, virtual analyses are increasingly valuable and practical for evaluating total knee arthroplasty (TKA). However, the influence of variabilities at each step in computational analyses on predictions of TKA performance for a population has not yet been thoroughly investigated, nor the relationship between these variabilities and expected variations in surgical practice. Understanding these influences is nevertheless essential for ensuring the clinical relevance of theoretical predictions. Here, a morphological analysis of proximal tibial resections within TKA is proposed and investigated. The goals of this analysis are to quantify the influence of variability in landmark detection on resection parameters and to evaluate this sensitivity relative to expected clinical variability in TKA resections. Results here are directly applicable to population-level computational analyses of morphological and functional TKA performance. PMID:23216047

Dai, Y; Seebeck, J; Henderson, A D; Bischoff, J E

2014-08-01

346

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

Energy Technology Data Exchange (ETDEWEB)

Purpose: To compare the relative accuracy of 2 image guided radiation therapy methods using carina vs spine as landmarks and then to identify which landmark is superior relative to tumor coverage. Methods and Materials: For 98 lung patients, 2596 daily image-guidance cone-beam computed tomography scans were analyzed. Tattoos were used for initial patient alignment; then, spine and carina registrations were performed independently. A separate analysis assessed the adequacy of gross tumor volume, internal target volume, and planning target volume coverage on cone-beam computed tomography using the initial, middle, and final fractions of radiation therapy. Coverage was recorded for primary tumor (T), nodes (N), and combined target (T+N). Three scenarios were compared: tattoos alignment, spine registration, and carina registration. Results: Spine and carina registrations identified setup errors {>=}5 mm in 35% and 46% of fractions, respectively. The mean vector difference between spine and carina matching had a magnitude of 3.3 mm. Spine and carina improved combined target coverage, compared with tattoos, in 50% and 34% (spine) to 54% and 46% (carina) of the first and final fractions, respectively. Carina matching showed greater combined target coverage in 17% and 23% of fractions for the first and final fractions, respectively; with spine matching, this was only observed in 4% (first) and 6% (final) of fractions. Carina matching provided superior nodes coverage at the end of radiation compared with spine matching (P=.0006), without compromising primary tumor coverage. Conclusion: Frequent patient setup errors occur in locally advanced lung cancer patients. Spine and carina registrations improved combined target coverage throughout the treatment course, but carina matching provided superior combined target coverage.

Lavoie, Caroline; Higgins, Jane; Bissonnette, Jean-Pierre [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario, M5G 2M9 (Canada); Le, Lisa W. [Department of Biostatistics, Princess Margaret Hospital, Toronto, Ontario, M5G 2M9 (Canada); Sun, Alexander; Brade, Anthony; Hope, Andrew; Cho, John [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario, M5G 2M9 (Canada); Bezjak, Andrea, E-mail: andrea.bezjak@rmp.uhn.on.ca [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario, M5G 2M9 (Canada)

2012-12-01

347

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

International Nuclear Information System (INIS)

Purpose: To compare the relative accuracy of 2 image guided radiation therapy methods using carina vs spine as landmarks and then to identify which landmark is superior relative to tumor coverage. Methods and Materials: For 98 lung patients, 2596 daily image-guidance cone-beam computed tomography scans were analyzed. Tattoos were used for initial patient alignment; then, spine and carina registrations were performed independently. A separate analysis assessed the adequacy of gross tumor volume, internal target volume, and planning target volume coverage on cone-beam computed tomography using the initial, middle, and final fractions of radiation therapy. Coverage was recorded for primary tumor (T), nodes (N), and combined target (T+N). Three scenarios were compared: tattoos alignment, spine registration, and carina registration. Results: Spine and carina registrations identified setup errors ?5 mm in 35% and 46% of fractions, respectively. The mean vector difference between spine and carina matching had a magnitude of 3.3 mm. Spine and carina improved combined target coverage, compared with tattoos, in 50% and 34% (spine) to 54% and 46% (carina) of the first and final fractions, respectively. Carina matching showed greater combined target coverage in 17% and 23% of fractions for the first and final fractions, respectively; with spine matching, this was only observed in 4% (first) and 6% (final) of fractions. Carina matching provided superior nodes coverage at the end of radiation compared with spine matching (P=.0006), without compromising primary tumor coverage. Conclusion: Frequent patient setup errors occur in locally advanced lung cancer patients. Spine and carina registrations improved combined target coverage throughout the treatment course, but carina matching provided superior combined target coverage.

2012-12-01

348

Volume registration of interventional MRI data using needle paths and point landmarks  

Science.gov (United States)

We created a method for three-dimensional registration of medical scanner image volumes to images of physical tissue sections or other volumes, and evaluated its accuracy. The method is applicable for many animal experiments, and we are applying it to evaluate interventional MRI imaging of thermal ablation and to quantify in vivo drug release from a new device for localized, controlled release. The method computes an optimum set of rigid body registration parameters by iterative minimization of the Euclidean distances between automatically generated correspondence points, along manually selected fiducial needle paths, and optional point landmarks. For numerically simulated registrations, using two needle paths over a range of needle orientations, median voxel displacement errors depended only on needle localization error when the angle between needles was at least 15 degrees. For parameters typical of our in vivo experiments, the median error was landmarks. Registration error was always

Lazebnik, Roee S.; Breen, Michael S.; Lancaster, Tanya L.; Nour, Sherif G.; Lewin, Jonathan S.; Wilson, David L.

2002-05-01

349

Anatomic pathology laboratory information systems: a review.  

Science.gov (United States)

The modern anatomic pathology laboratory depends on a reliable information infrastructure to register specimens, record gross and microscopic findings, regulate laboratory workflow, formulate and sign out report(s), disseminate them to the intended recipients across the whole health system, and support quality assurance measures. This infrastructure is provided by the Anatomical Pathology Laboratory Information Systems (APLIS), which have evolved over decades and now are beginning to support evolving technologies like asset tracking and digital imaging. As digital pathology transitions from "the way of the future" to "the way of the present," the APLIS continues to be one of the key effective enablers of the scope and practice of pathology. In this review, we discuss the evolution, necessary components, architecture and functionality of the APLIS that are crucial to today's practicing pathologist and address the demands of emerging trends on the future APLIS. PMID:22313836

Park, Seung Lyung; Pantanowitz, Liron; Sharma, Gaurav; Parwani, Anil Vasdev

2012-03-01

350

Computed tomography and gross anatomical studies on the head of one-humped camel (Camelus dromedarius).  

Science.gov (United States)

The current study aimed to document by computed tomography (CT) the anatomical structures of the one-Humped camel head relative to their adaptability to living environments. Seven adult one-Humped camels' heads were used in this study. The structures of the nasal cavity, paranasal sinuses, oral cavity, orbit, and cranium were investigated using computed tomographic scans, cross, and sagittal sections of the head cadavers, and skulls. The study showed the nasal conchae had special properties where the dorsal nasal concha contained the dorsal conchal sinus, the middle nasal concha contained the middle conchal sinus, while the ventral nasal concha did not contain a sinus. The middle nasal concha was large and extended rostral between the dorsal and ventral nasal concha. The nasal meatuses were narrow spaces that suggested adaptability to a desert environment. The paranasal sinuses comprised maxillary, frontal, sphenoidal, lacrimal, and ethmoidal that were identified and labeled according to cheek teeth landmarks. The topographic description and relationship between nasal, oral, orbital, cranial cavities, pharynx, larynx, and paranasal sinuses were demonstrated. The articular disc, articular surface, and joint capsule of the temporomandibular joint were described by CT and cross sectional images. The current CT, cross, and sagittal sections images provide a reference for normal camel head anatomy. PMID:24639077

Alsafy, Mohamed A M; El-Gendy, Samir A A; Abumandour, Mohamed M A

2014-04-01

351

Description of a novel anatomic venous structure in the nasoglabellar area.  

Science.gov (United States)

Injectable dermal fillers are frequently used to reduce the appearance of various facial creases and rhytids. However, venous complications can develop while injecting dermal filler, especially in the nasoglabellar area. The aims of this study were to determine the anatomic patterns of the veins in the nasoglabellar area and to elucidate their detailed location with reference to various facial landmarks. Forty-one heads from Korean and Thai cadavers were dissected. When the anastomosing vein between the bilateral angular veins (AVs) was located in the nasoglabellar area, it was designated the intercanthal vein (ICV). The bilateral AVs continued as the facial vein without any communicating branches in 12 cases (29.3%). At the radix of the nose, the AV communicated with the ICV, connecting them bilaterally. The ICV was found above (type IIA) and below (type IIB) the intercanthal line in 26 (63.4%) and 3 (7.3%) cases, respectively. The ICV can be regarded as a candidate causative site for the frequent complications associated with dermal filler injection in the nasoglabellar area, and utmost care should be taken when injecting in this area, such as when performing radix augmentation and softening wrinkles in the glabellar area. PMID:24621711

Lee, Hyung-Jin; Kang, In-Won; Won, Sung-Yoon; Lee, Jae-Gi; Hu, Kyung-Seok; Tansatit, Tanvaa; Kim, Hee-Jin

2014-03-01

352

An anatomical study of the parasacral block using magnetic resonance imaging of healthy volunteers.  

LENUS (Irish Health Repository)

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.

O'Connor, Maeve

2012-01-31

353

Anatomical and molecular imaging of skin cancer  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Skin cancer is the most common form of cancer types. It is generally divided into two categories: melanoma (? 5%) and nonmelanoma (? 95%), which can be further categorized into basal cell carcinoma, squamous cell carcinoma, and some rare skin cancer types. Biopsy is still the gold standard for skin cancer evaluation in the clinic. Various anatomical imaging techniques have been used to evaluate different types of skin cancer lesions, including laser scanning confocal microscopy, optical c...

Hong, Hao; Sun, Jiangtao; Cai, Weibo

2008-01-01

354

Anatomic variations of the human semicircular canals  

International Nuclear Information System (INIS)

The anatomic variations of the semicircular canals were investigated in a series of 95 plastic temporal bone preparations. The results showed a wider range of variability than has been assumed previously. An intraindividual correlation was found between the sizes of the superior and lateral semicircular canals. Observations indicate why a semicircular canal is not invariably delineated on one tomographic plane despite correct positioning for its optimum reproduction. (orig.)

1986-01-01

355

Bifid Rib: Anatomical Considerations in Three Cases  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The present study involved a detailed investigation of 3 cases of bifid rib, focusing on anatomical features, and classified them into 2 types. The bifid ribs were in the right fourth rib of all 3 male cadavers. The upper intercostal spaces of the fourth bifid rib were considerably narrowed, whereas the lower intercostal spaces were widened. Although the size and shape of the bifid space between the upper and lower divisions of the bifid rib were different, the intercostal muscles were presen...

Song, Wu-chul; Kim, Sang-hyun; Park, Dae-kyoon; Koh, Ki-seok

2009-01-01

356

Clinico-anatomical correlations in uncomplicated stroke.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A method for making clinico-anatomical correlations by computer superimposition of brain maps derived from CT scan images, described in a companion paper, was tested in 19 patients with an uncomplicated left hemiparesis due to acute stroke. Eight patients with an isolated left hemiparesis had small lesions in the most rostral part of the right internal capsule. The composite lesion maps of 11 patients whose left hemiparesis was complicated only by spinothalamic sensory loss showed a larger ar...

Allen, C. M.; Hoare, R. D.; Fowler, C. J.; Harrison, M. J.

1984-01-01

357

Accessory mental foramen: a rare anatomical finding  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Accessory mental foramen (AMF) is a rare anatomical variation with a prevalence ranging from 1.4 to 10%. Even so, in order to avoid neurovascular complications, particular attention should be paid to the possible occurrence of one or more AMF during surgical procedures involving the mandible. Careful surgical dissection should be performed in the region so that the presence of AMF can be detected and the occurrence of a neurosensory disturbance or haemorrhage can be avoided. Although this ana...

Thakur, Gagan; Thomas, Shaji; Thayil, Sumeeth Cyriac; Nair, Preeti P.

2011-01-01

358

Anatomical Pathways for Auditory Memory in Primates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Episodic memory or the ability to store context-rich information about everyday events depends on the hippocampal formation (entorhinal cortex, subiculum, presubiculum, parasubiculum, hippocampus proper, and dentate gyrus). A substantial amount of behavioral-lesion and anatomical studies have contributed to our understanding of the organization of how visual stimuli are retained in episodic memory. However, whether auditory memory is organized similarly is still unclear. One hypothesis is tha...

Munoz-lopez, Monica M.; Mohedano-moriano, Alicia; Insausti, Ricardo

2010-01-01

359

Anatomic Brain Asymmetry in Vervet Monkeys  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Asymmetry is a prominent feature of human brains with important functional consequences. Many asymmetric traits show population bias, but little is known about the genetic and environmental sources contributing to inter-individual variance. Anatomic asymmetry has been observed in Old World monkeys, but the evidence for the direction and extent of asymmetry is equivocal and only one study has estimated the genetic contributions to inter-individual variance. In this study we characterize a rang...

Fears, Scott C.; Scheibel, Kevin; Abaryan, Zvart; Lee, Chris; Service, Susan K.; Jorgensen, Matthew J.; Fairbanks, Lynn A.; Cantor, Rita M.; Freimer, Nelson B.; Woods, Roger P.

2011-01-01

360

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

Czech Academy of Sciences Publication Activity Database

Shoulder hemiarthroplastyKód oboru RIV: FJ - Chirurgie v?. transplantologieImpakt faktor: 1.130, rok: 2012 http://library.utia.cas.cz/separaty/2013/E/smid-medial calcar of proximal humeral fracture as landmark in restoration of humeral length in case of hemiarthroplasty.pdf

Hromádka, R.; Kub?na, Aleš Antonín; Šmíd, Martin; Popelka, S.

 
 
 
 
361

Learning Your Way around Town: How Virtual Taxicab Drivers Learn to Use Both Layout and Landmark Information  

Science.gov (United States)

By having subjects drive a virtual taxicab through a computer-rendered town, we examined how landmark and layout information interact during spatial navigation. Subject-drivers searched for passengers, and then attempted to take the most efficient route to the requested destinations (one of several target stores). Experiment 1 demonstrated that…

Newman, Ehren L.; Caplan, Jeremy B.; Kirschen, Matthew P.; Korolev, Igor O.; Sekuler, Robert; Kahana, Michael J.

2007-01-01

362

Bases anatômicas para o bloqueio anestésico do plexo braquial por via infraclavicular Bases anatómicas para el bloqueo anestésico del plexo braquial por vía infraclavicular Anatomical basis for infraclavicular brachial plexus block  

Directory of Open Access Journals (Sweden)

Full Text Available JUSTIFICATIVA E OBJETIVOS: Procuramos demonstrar neste estudo a presença constante da fossa infraclavicular, com a finalidade de sua utilização como via de acesso para o bloqueio anestésico do plexo braquial por via infraclavicular. Visando solucionar o ponto onde os fascículos do plexo braquial podem ser localizados no interior da fossa, propusemos medidas a partir da face anterior da clavícula e do ângulo formado pelo encontro do músculo deltóide com a clavícula (ângulo deltoclavicular. A primeira medida permite localizar em profundidade o local onde passa o plexo braquial. Já a segunda, determina a projeção dos fascículos dentro da fossa, o que corresponde ao ponto de entrada da agulha na superfície cutânea. MÉTODO: Foram efetuadas medidas entre a face anterior da clavícula e os fascículos do plexo braquial, e do ângulo deltoclavicular até a projeção superficial dos fascículos. Com base nos achados anatômicos foi proposta uma técnica de abordagem do plexo braquial por via infraclavicular. RESULTADOS: Foram analisadas 100 regiões infraclaviculares de cadáveres fixados. A fossa infraclavicular foi detectada em 96 casos. Nessas os fascículos do plexo braquial localiza-se totalmente ou parcialmente em 97,9%. A medida aferida entre a face anterior da clavícula e os fascículos do plexo, foi de 2,49 cm e do ângulo deltoclavicular até a projeção superficial dos fascículos estava em 2,21 cm. CONCLUSÕES: Os dados obtidos permitem a determinação precisa do ponto de introdução da agulha, a qual, dirigida perpendicular à pele, atinge o plexo braquial sem perigo de provocar pneumotórax ou lesão vascular, possibilitando uma segurança maior aos anestesiologistas, e permitindo a volta da prática do bloqueio do plexo abaixo da clavícula.JUSTIFICATIVA Y OBJETIVOS: Buscamos demostrar en este estudio la presencia constante de la fosa infraclavicular, con la finalidad de su utilización como vía de acceso para el bloqueo anestésico del plexo braquial por via infraclavicular. Con la idea de solucionar el punto donde los fascículos del plexo braquial pueden ser localizados en el interior de la fosa, propusimos medidas a partir de la face anterior de la clavícula y del ángulo formado por el encuentro del músculo deltóide con la clavícula (ángulo deltoclavicular. La primera medida permite localizar en profundidad el local donde pasa el plexo braquial. Ya la segunda, determina la proyección de los fascículos dentro de la fosa, lo que corresponde al punto de entrada de la aguja en la superficie cutánea. MÉTODO: Fueron efectuadas medidas entre la face anterior de la clavícula y los fascículos del plexo braquial, y del ángulo deltoclavicular hasta la proyección superficial de los fascículos. Con base en los encuentros anatómicos fue propuesta una técnica de abordaje del plexo braquial por via infraclavicular. RESULTADOS: Fueron analizadas 100 regiones infraclaviculares de cadáveres fijados. La fosa infraclavicular fue detectada en 96 casos. En ésas, los fascículos del plexo braquial se localizan totalmente o parcialmente en 97,9%. La medida comparada entre la face anterior de la clavícula y los fascículos del plexo, fue de 2,49 cm y del ángulo deltoclavicular hasta la proyección superficial de los fascículos estaba en 2,21 cm. CONCLUSIONES: Los datos obtenidos permiten la determinación exacta del punto de introducción de la aguja, la cual, dirigida perpendicular a la piel, alcanza el plexo braquial sin peligro de provocar pneumotórax o lesión vascular, posibilitando una mayor seguridad a los anestesiologistas, y permitiendo la vuelta de la práctica del bloqueo del plexo abajo de la clavícula.BACKGROUND AND OBJECTIVES: This study shows the constant infraclavicular fossa presence, aiming at using it as a pathway for infraclavicular brachial plexus block. Determining the point where brachial plexus fascicles may be located within the fossa, the authors have proposed measurements from the anterior surface of the clavicle and the angle formed by the de

Luiz Carlos Buarque de Gusmão

2002-06-01

363

Anatomic variation of cranial parasympathetic ganglia  

Directory of Open Access Journals (Sweden)

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

Selma Siéssere

2008-06-01

364

Anatomic variation of cranial parasympathetic ganglia  

Scientific Electronic Library Online (English)

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

Selma, Siéssere; Mathias, Vitti; Luiz Gustavo de, Sousa; Marisa, Semprini; Mamie Mizusaki, Iyomasa; Simone Cecílio Hallak, Regalo.

365

Anatomic variation of cranial parasympathetic ganglia.  

Science.gov (United States)

Having broad knowledge of anatomy is essential for practicing dentistry. Certain anatomical structures call for detailed studies due to their anatomical and functional importance. Nevertheless, some structures are difficult to visualize and identify due to their small volume and complicated access. Such is the case of the parasympathetic ganglia located in the cranial part of the autonomic nervous system, which include: the ciliary ganglion (located deeply in the orbit, laterally to the optic nerve), the pterygopalatine ganglion (located in the pterygopalatine fossa), the submandibular ganglion (located laterally to the hyoglossus muscle, below the lingual nerve), and the otic ganglion (located medially to the mandibular nerve, right beneath the oval foramen). The aim of this study was to present these structures in dissected anatomic specimens and perform a comparative analysis regarding location and morphology. The proximity of the ganglia and associated nerves were also analyzed, as well as the number and volume of fibers connected to them. Human heads were dissected by planes, partially removing the adjacent structures to the point we could reach the parasympathetic ganglia. With this study, we concluded that there was no significant variation regarding the location of the studied ganglia. Morphologically, our observations concur with previous classical descriptions of the parasympathetic ganglia, but we observed variations regarding the proximity of the otic ganglion to the mandibular nerve. We also observed that there were variations regarding the number and volume of fiber bundles connected to the submandibular, otic, and pterygopalatine ganglia. PMID:18622477

Siéssere, Selma; Vitti, Mathias; Sousa, Luiz Gustavo de; Semprini, Marisa; Iyomasa, Mamie Mizusaki; Regalo, Simone Cecílio Hallak

2008-01-01

366

Anatomical MRI with an atomic magnetometer  

Science.gov (United States)

Ultra-low field (ULF) MRI is a promising method for inexpensive medical imaging with various additional advantages over conventional instruments such as low weight, low power, portability, absence of artifacts from metals, and high contrast. Anatomical ULF MRI has been successfully implemented with SQUIDs, but SQUIDs have the drawback of a cryogen requirement. Atomic magnetometers have sensitivity comparable to SQUIDs and can be in principle used for ULF MRI to replace SQUIDs. Unfortunately some problems exist due to t