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1

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

International Nuclear Information System (INIS)

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 deviighted gradient-echo imaging. Maximum deviations were 1.72 mm and 3.06 mm, respectively

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Important anatomical landmarks in the lateral nasal wall.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

OBJECTIVES The study aimed to investigate the anatomy of the lateral nasal wall to provide a set of measurements among some important anatomical landmarks and to reveal the relationship between them. METHODS Fifty half heads were dissected to determine the distances between important landmarks in the lateral nasal wall for endoscopic sinus surgery. Landmarks were measured with an electronic caliper. This study was carried out between De...

Donmez, Baris O.; Agirdir, Bulent V.; Sindel, Muzaffer M.

2005-01-01

3

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

Energy Technology Data Exchange (ETDEWEB)

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

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

International Nuclear Information System (INIS)

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

5

Development of a New Software for Automatic Anatomical landmark Detection in Cephalometric X-ray Images  

Directory of Open Access Journals (Sweden)

Full Text Available Background & Objectives: As a routine clinical procedure in orthodontics, there are many geometrical calcula-tions usually taken place on the lateral x-ray images of the head in order to develop an appropriate treatment plan. This is currently done manually by the expert radiologists and/or orthodontists. It can take an experi-enced orthodontist up to thirty minutes to analyze one x-ray image and the results are still influenced by both subjective and objective errors. Here a new software for automatic anatomical landmark detection in cepha-lometric x-ray images is presented. The software extracts ten commonly used main landmarks. Methods and Materials: In this research, a combination of various image processing techniques including Template Matching, Edge Walking, and Shape Registration is employed to develop an automatic cephalomet-ric landmark detection algorithm within the x-ray images of the head. Ten essential and commonly used landmarks were selected as the target points. Results: The accuracy of the automatic landmark detection algorithm was evaluated with comparing the re-sults obtained by the automatic algorithm to those manually identified by an expert orthodontist on a data base of 10 x-ray images. The statistical analysis showed that 92% of the landmarks were determined accurately within an acceptable region of 4 millimeters from the points an expert had defined.. Conclusions: A MATLAB-based software was developed accordingly to help an orthodontist automatically identify the most commonly used 10 main cephalometric landmarks. The method can be extended for more landmarks in the future.

S. Nooranian

2005-08-01

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The use of anatomical landmarks for percutaneous nephrolithotomy  

Directory of Open Access Journals (Sweden)

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

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Value of anatomical landmarks in single-nostril endonasal transnasal-sphenoidal surgery.  

Science.gov (United States)

The sphenoid sinus occupies a central location in transsphenoidal surgery (TSS). It is important to identify relevant anatomical landmarks to enter the sphenoid sinus and sellar region properly. The aim of this study was to identify anatomical landmarks and their value in single-nostril endonasal TSS. A retrospective study was performed to review 148 cases of single-nostril endonasal TSS for pituitary lesions. The structure of the nasal cavities and sphenoid sinus, the position of apertures of the sphenoid sinus and relevant arteries and the morphological characteristics of the anterior wall of the sphenoid sinus and sellar floor were observed and recorded. The important anatomical landmarks included the mucosal aperture of the sphenoid sinus, a blunt longitudinal prominence on the posterior nasal septum, the osseocartilaginous junction of the nasal septum, the 'bow sign' of the anterior wall of the sphenoid sinus, the osseous aperture and its relationship with the nutrient arteries, the bulge of the sellar floor and the carotid protuberance. These landmarks outlined a clear route to the sella turcica with an optimal view and lesser tissue damage. Although morphological variation may exist, the position of these landmarks was generally consistent. Locating the sphenoid sinus aperture is the gold standard to direct the surgical route of TSS. The 'bow sign' and the sellar bulge are critical landmarks for accurate entry into the sphenoid sinus and sella fossa, respectively. PMID:23596471

Wei, Liang-Feng; Zhang, Jinchao; Chen, Hong-Jie; Wang, Rumi

2013-04-01

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Reproducibility of imaging skull anatomic landmarks utilizing three-dimensional computed tomography  

International Nuclear Information System (INIS)

The study investigated the reproducibility of locating specific anatomic landmarks, utilizing computed tomography (CT), for the purpose of assigning accurate coordinates on the skull. Three-dimensional (3-D) CT data, obtained by scanning a dry adult skull, were processed using a multi-planar reconstruction (MPR) system. Each landmark was identified five times by the same technician, and the average distances between points identifying the same landmark were calculated. The 15 landmarks studied were the infra-orbital foramina, the external auditory meatus, the foramina rotundum, the foramina ovale, the optic canals, anterior crinoid processes, anterior nasal spine, crista galli, and the sella turcica. Three additional artificial markers placed in occlusal dental splints were also examined. The crinoid processes were identified with the highest degree of accuracy. The crista galli and optic canals were also located with reproducible results. The standard deviation calculated from the fine attempts to locate the artificial markers was smaller than that calculated from attempts to identify any of the landmarks. This implies that coordinates on the craniofacial bones should be defined using artificial markers rather than bony landmarks. Artificial markers placed in occlusal dental splints easily can be applied clinically. Complicated facial bone contours should be analyzed mathematically. In clinical setting, these points were found to be reproducible in 15 bony landmarks d to be reproducible in 15 bony landmarks on the skull. (N.K.)

9

Autonomous Robot Navigation based on Visual Landmarks  

DEFF Research Database (Denmark)

The use of landmarks for robot navigation is a popular alternative to having a geometrical model of the environment through which to navigate and monitor self-localization. If the landmarks are defined as special visual structures already in the environment then we have the possibility of fully autonomous navigation and self-localization using automatically selected landmarks. The thesis investigates autonomous robot navigation and proposes a new method which benefits from the potential of the visual sensor to provide accuracy and reliability to the navigation process while relying on naturally available environment features (natural landmarks). The goal is also to integrate techniques and algorithms (also related to other research field) in the same navigation system, in order to improve localization performance and system autonomy. The proposed localization strategy is based on a continuous update of the estimated robot position while the robot is moving. In order to make the system autonomous, both acquisition and observation of landmarks have to be carried out automatically. The thesis consequently proposes a method for learning and navigation of a working environment and it explores automatic acquisition and recognition of visual landmarks. In particular, a two-phase procedure is proposed: first phase is for an automatic acquisition of visual-landmarks, second phase is for estimating robot position during navigation (based on the acquired landmarks). The feasibility and applicability of the proposed method is based on a system with a simple setup. The novelty and potentiality, are in combining algorithms for panoramic view-synthesis, attention selection, stereo reconstruction, triangulation, optimal triplet selection, and image-based rendering. Experiments demonstrate that the system can automatically learn and store visual landmarks, and later recognize these landmarks from arbitrary positions and thus estimate robot position and heading.

Livatino, Salvatore

10

Comparison of adhesive markers, anatomical landmarks, and surface matching in patient-to-image registration for frameless stereotaxy  

Science.gov (United States)

The application accuracy of frameless stereotaxy depends partly on the accuracy of the patient-to-image registration procedure. We compared the application accuracy of registration procedures based on anatomical landmarks, surface matching, and adhesive markers. After acquisition of a 3D-MRI volume, 30 patients were subjected to all three registration procedures. Frameless stereotaxy was performed with the STN system (Carl Zeiss, Germany). Following each registration procedure, the root-mean-squared-error (RMSE) and the target registration error (TRE) of an extra adhesive marker (target) were recorded. The first represents the goodness-of-fit of the registration procedure (not available in surface matching) while the second represents the application accuracy. The mean TRE+/- SD for each type of registration was 5.3+/- 2.1mm, 9.4+/- 6.6mm, and 3.6+/- 1.6mm (paired t-tests: pt-test: p<0.01). There was no significant correlation between the RMSE and the TRE (anatomical landmarks: R2=0.071, adhesive markers: R2=0.004). A more detailed evaluation of surface matching, using a plastic skull phantom, also could not demonstrate an improvement in application accuracy due to surface matching. In conclusion, our results indicate that adhesive markers offer the most accurate alternative to bonescrews. However, we believe anatomical landmarks to provide sufficient accuracy for many neurosurgical procedures concerning frontally located targets, reducing the need for extra preoperative imaging.

Willems, Peter W. A.; Berkelbach van der Sprenkel, Jan W.; Tulleken, Cees A. F.

2001-01-01

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Anatomic Landmarks Versus Fiducials for Volume-Staged Gamma Knife Radiosurgery for Large Arteriovenous Malformations  

International Nuclear Information System (INIS)

Purpose: The purpose of this investigation was to compare the accuracy of using internal anatomic landmarks instead of surgically implanted fiducials in the image registration process for volume-staged gamma knife (GK) radiosurgery for large arteriovenous malformations. Methods and Materials: We studied 9 patients who had undergone 10 staged GK sessions for large arteriovenous malformations. Each patient had fiducials surgically implanted in the outer table of the skull at the first GK treatment. These markers were imaged on orthogonal radiographs, which were scanned into the GK planning system. For the same patients, 8-10 pairs of internal landmarks were retrospectively identified on the three-dimensional time-of-flight magnetic resonance imaging studies that had been obtained for treatment. The coordinate transformation between the stereotactic frame space for subsequent treatment sessions was then determined by point matching, using four surgically embedded fiducials and then using four pairs of internal anatomic landmarks. In both cases, the transformation was ascertained by minimizing the chi-square difference between the actual and the transformed coordinates. Both transformations were then evaluated using the remaining four to six pairs of internal landmarks as the test points. Results: Averaged over all treatment sessions, the root mean square discrepancy between the coordinates of the transformed and actual test points was 1.2 ± 0.2 mm using internal landmars was 1.2 ± 0.2 mm using internal landmarks and 1.7 ± 0.4 mm using the surgically implanted fiducials. Conclusion: The results of this study have shown that using internal landmarks to determine the coordinate transformation between subsequent magnetic resonance imaging scans for volume-staged GK arteriovenous malformation treatment sessions is as accurate as using surgically implanted fiducials and avoids an invasive procedure

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

International Nuclear Information System (INIS)

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

13

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-06-15

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Stovall, Bradley A.; Kumar, Shrawan

2010-01-01

15

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

Science.gov (United States)

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

16

Are anatomical landmark measurements accurate for predicting endotracheal tube depth?  

Directory of Open Access Journals (Sweden)

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

17

Landmark-Based 3D Elastic Registration of Pre- and Postoperative Liver CT Data  

Science.gov (United States)

The qualitative and quantitative comparison of pre- and postoperative image data is an important possibility to validate computer assisted surgical procedures. Due to deformations after surgery a non-rigid registration scheme is a prerequisite for a precise comparison. Interactive landmark-based schemes are a suitable approach. Incorporation of a priori knowledge about the anatomical structures to be registered may help to reduce interaction time and improve accuracy. Concerning pre- and postoperative CT data of oncological liver resections the intrahepatic vessels are suitable anatomical structures. In addition to using landmarks at vessel branchings, we here introduce quasi landmarks at vessel segments with anisotropic localization precision. An experimental comparison of interpolating thin-plate splines (TPS) and Gaussian elastic body splines (GEBS) as well as approximating GEBS on both types of landmarks is performed.

Lange, Thomas; Wörz, Stefan; Rohr, Karl; Schlag, Peter M.

18

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

Directory of Open Access Journals (Sweden)

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

Mosharraf R

2004-02-01

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Experimental comparison of landmark-based methods for 3D elastic registration of pre- and postoperative liver CT data  

Science.gov (United States)

The qualitative and quantitative comparison of pre- and postoperative image data is an important possibility to validate surgical procedures, in particular, if computer assisted planning and/or navigation is performed. Due to deformations after surgery, partially caused by the removal of tissue, a non-rigid registration scheme is a prerequisite for a precise comparison. Interactive landmark-based schemes are a suitable approach, if high accuracy and reliability is difficult to achieve by automatic registration approaches. Incorporation of a priori knowledge about the anatomical structures to be registered may help to reduce interaction time and improve accuracy. Concerning pre- and postoperative CT data of oncological liver resections the intrahepatic vessels are suitable anatomical structures. In addition to using branching landmarks for registration, we here introduce quasi landmarks at vessel segments with high localization precision perpendicular to the vessels and low precision along the vessels. A comparison of interpolating thin-plate splines (TPS), interpolating Gaussian elastic body splines (GEBS) and approximating GEBS on landmarks at vessel branchings as well as approximating GEBS on the introduced vessel segment landmarks is performed. It turns out that the segment landmarks provide registration accuracies as good as branching landmarks and can improve accuracy if combined with branching landmarks. For a low number of landmarks segment landmarks are even superior.

Lange, Thomas; Wörz, Stefan; Rohr, Karl; Schlag, Peter M.

2009-02-01

20

Methods for determining hip and lumbosacral joint centers in a seated position from external anatomical landmarks.  

Science.gov (United States)

A global coordinate system (GCS) method is proposed to estimate hip and lumbosacral joint centers (HJC and LSJC) from at least three distances between joint center of interest and target anatomic landmarks (ALs). The distances from HJC and LSJC to relevant pelvis and femur ALs were analyzed with respect to usual pelvis and femur scaling dimensions. Forty six pelves and related pairs of femurs from a same sample of adult specimens were examined. The corresponding regression equations were obtained. These equations can be used to estimate HJC and LSJC in conditions where a very limited number of ALs are available: for example, during seated posture analysis as performed in the automotive industry. Compared to currently existing HJC and LSJC methods from ALs, the proposed method showed better results with an average error less than 11mm. PMID:25497377

Peng, Junfeng; Panda, Jules; Van Sint Jan, Serge; Wang, Xuguang

2015-01-21

 
 
 
 
21

Arterial tree tracking from anatomical landmarks in magnetic resonance angiography scans  

Science.gov (United States)

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

22

Loss of anatomical landmarks with eutectic mixture of local anesthetic cream for neonatal male circumcision.  

Science.gov (United States)

We report two cases of newborns who developed marked local edema after application of a eutectic mixture of local anesthetic (EMLA) topical anesthetic cream for neonatal male circumcision (NMC). Although local edema and erythema are known potential side effects of EMLA cream, a common anesthetic used for NMC, the loss of landmarks precluding safe NMC has not previously been reported, and is described here. Although we cannot recommend an alternate local anesthetic for neonates with this reaction to EMLA, based on a review of the published data we think that serious systemic adverse events related to EMLA are extremely rare. PMID:23102766

Plank, Rebeca M; Kubiak, David W; Abdullahi, Rasak Bamidele; Ndubuka, Nnamdi; Nkgau, Maggie M; Dapaah-Siakwan, Fredrick; Powis, Kathleen M; Lockman, Shahin

2013-02-01

23

Analysis of anatomical landmarks of the mandibular interforaminal region using CBCT in a Brazilian population  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Aim: To evaluate the position, presence, appearance and extent of various anatomical landmarks in the mandibular interforaminal region of Brazilian patients using cone-beam computed tomography (CBCT). Methods: A total of 142 CBCT examinations were analyzed to determine the most common location of th [...] e mental foramen (MF), the presence and extent of the anterior loop (AL) of the inferior alveolar nerve, and the appearance and length of the incisive canal (IC). The presence of sexual dimorphism and differences with relation to the left and right sides were also evaluated. Results: Most of the MF (45.5%) was located below the second premolar. The AL and the IC were observed in 18.9 and 96.5% of the images respectively. The average length of AL and IC was 3.14±1.25 mm and 13.68±5.94 mm respectively. No significant differences (p>0.05) between genders or left and right sides were observed for all evaluated parameters. Conclusions: The most common location of the MF, the high rate of visualization of the IC and the occasional presence of AL in the studied Brazilian population demonstrate the importance of using three-dimensional images of the mandibular anterior region, allowing proper surgical planning and preventing injury to the neurovascular bundle.

Paloma Rodrigues, Genú; Ricardo José de Holanda, Vasconcellos; Bruna Paloma de, Oliveira; Bruna Caroline Gonçalves de, Vasconcelos; Nádia Cristina da Cruz, Delgado.

2014-12-01

24

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

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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

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

International Nuclear Information System (INIS)

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 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

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Automatic Evaluation of Landmarks for Image-Based Navigation Update  

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Full Text Available 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 for evaluating landmarks in terms of the matching distance, which is the maximum misplacement in the position of the landmark that can be corrected. We validate the evaluations with our 3D reconstruction system working on data captured from a helicopter.

Stefan Lang

2009-01-01

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The effect of anatomic landmark selection of the distal humerus on registration accuracy in computer-assisted elbow surgery.  

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Incorrect selection of the flexion-extension axis of the elbow may be an important cause of failure following total elbow arthroplasty. Axis selection can be improved by locating it on a pre-operative image and registering the image to the subject intra-operatively. However, registration is dependent on the availability of anatomic landmarks that may be distorted or absent because of tumors, arthritis, dislocations, or fractures. This study determined the anatomic landmarks required to register surface data accurately to a pre-operative image of the distal humerus. Registration error for landmarks unlikely to be compromised by severe bone loss was 1.1 +/- 0.2 mm in translation and 0.4 +/- 0.1 degrees in rotation. These results suggest that a close alignment of a pre-operative image with intra-operative surface data can be achieved using only a relatively small portion of the distal humerus that is readily available to the surgeon, and unlikely to be compromised, even in the setting of significant articular bone loss. PMID:18572422

McDonald, Colin P; Beaton, Brendon J B; King, Graham J W; Peters, Terry M; Johnson, James A

2008-01-01

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

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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 dcer. 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

29

Systematic review of cadaveric studies on anatomic posterior cruciate ligament reconstruction: the landmarks in anatomic posterior cruciate ligament reconstruction.  

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Recently, several new techniques for anatomic posterior cruciate ligament reconstruction (PCLR) have emerged and are believed to restore the normal anatomy of the posterior cruciate ligament more accurately. Despite the latest trend, the optimal methods for anatomic PCLR remain controversial. The purpose of this research is to review surgical techniques for PCLR in cadaver studies and suggest consistent and reproducible technical criteria. For the review of the literature, MEDLINE and EMBASE were screened for articles on anatomic PCLR. Only basic science studies on PCLR performed on human cadavers and written in English were included. Seventeen studies were included in this systematic review. Only the tunnel positions, graft types, and surgical techniques were reported in the majority of the studies. There were many variations of the reported tunnel positions, graft types, and surgical techniques among the studies. In most studies, surgical techniques for consistent and reproducible anatomic PCLR were not explained clearly. Therefore, high level medical research should be encouraged in order to establish standard surgical techniques for anatomic PCLR. PMID:25505700

Lee, Dong Yeong; Kim, Dong Hee; Park, Jin Sung; Nam, Dae Cheol; Cho, Seong Hee; Jeong, Jin Hoon; Hwang, Sun Chul

2014-12-01

30

Does Spatial Locative Comprehension Predict Landmark-Based Navigation?  

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In the present study we investigated the role of spatial locative comprehension in learning and retrieving pathways when landmarks were available and when they were absent in a sample of typically developing 6- to 11-year-old children. Our results show that the more proficient children are in understanding spatial locatives the more they are able to learn pathways, retrieve them after a delay and represent them on a map when landmarks are present in the environment. These findings suggest that spatial language is crucial when individuals rely on sequences of landmarks to drive their navigation towards a given goal but that it is not involved when navigational representations based on the geometrical shape of the environment or the coding of body movements are sufficient for memorizing and recalling short pathways. PMID:25629814

Piccardi, Laura; Palermo, Liana; Bocchi, Alessia; Guariglia, Cecilia; D’Amico, Simonetta

2015-01-01

31

Combining Speedup techniques based on Landmarks and Containers  

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Full Text Available The Dijkstra’s algorithm [1] , which is applied in many real world problems like mobile routing, road maps, railway networks, etc,. is used to find the shortest path between source and destination. There are many techniques available to speedup the algorithm while guaranteeing the optimality of the solution. The main focus of the work is to implement landmark technique and Containers separately and compare the results with random graphs and planar graphs. The combined speedup technique which is based on landmarks and containers were also experimented with random graphs and planar graphs to improvethe speedup of the shortest path queries.

R. KALPANA

2010-09-01

32

Loss of Anatomical Landmarks with Eutectic Mixture of Local Anesthetic Cream for Neonatal Male Circumcision  

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We report two cases of newborns who developed marked local edema after application of a eutectic mixture of local anesthetic (EMLA) topical anesthetic cream for neonatal male circumcision (NMC). Although local edema and erythema are known potential side effects of EMLA cream, a common anesthetic used for NMC, the loss of landmarks precluding safe NMC has not previously been reported, and is described here. Although we cannot recommend an alternate local anesthetic for neonates with this react...

Plank, Rebeca M.; Kubiak, David W.; Abdullahi, Rasak Bamidele; Ndubuka, Nnamdi; Nkgau, Maggie M.; Dapaah-siakwan, Fredrick; Powis, Kathleen M.; Lockman, Shahin

2012-01-01

33

Role of squamosal suture as a consistent landmark for middle fossa approach craniotomy: an anatomical study.  

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Objective?To establish a consistent surface bony landmark for a middle fossa approach (MFA) lateral craniotomy represented by the squamosal suture (SS). Methods?In 60 dried skulls, we assessed the relation between the SS and the external auditory canal (EAC). The lateral portion of the middle cranial fossa floor was also assessed for a possible relation with the anteroposterior diameter (APD) of the squama temporalis (ST). Clinically, we applied our findings on the SS in MFA for different lesions. Results?A vertical line at the EAC divided the ST into the anterior part constituting 61% of the APD (i.e., two thirds) and the posterior part forming 39% (i.e., one third). The average ST height was 35.92 mm. The SS posterior limit at the supramastoid crest was located just anterior to the external projection of the petrous ridge in 35 skulls (58%) and exactly corresponded to it in 25 skulls (42%). The APD of the ST equals on average 97% of the APD of the lateral middle cranial fossa. Optimum exposure of the middle fossa was obtained without any further craniotomy extension. Conclusion?The SS serves as a consistent natural surface bony landmark for MFA. Optimum craniotomy, two thirds anterior to the EAC and one third posterior, is obtained following SS as a landmark. PMID:25685647

Alkhalili, Kenan; Tantawy, Mohammed; Nageeb, Mohab M; Ragaee, Mohamed A; Alshyal, Gasser H; Alcindor, Dunbar S; Chen, Douglas A; Aziz, Khaled M Abdel

2015-02-01

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Three-dimensional Anatomical Analysis of Surgical Landmarks for the Middle Cranial Fossa Approach.  

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This study describes the microsurgical anatomy of the middle cranial fossa approach using temporal bone three-dimensional (3D) computed tomography (CT) reconstruction, which should contribute to determining the drilling point for the internal auditory meatus (IAM) when bony landmarks are absent. Thirty temporal bone CT scans were reviewed retrospectively. We measured the shortest and longest distances to IAM from the petrous ridge, and measured the angle between the facial nerve and various labyrinth structures. Three-dimensional reconstructed images were obtained using high-resolution axial temporal bone CT (0.7-mm-thick slices, FOV 90 × 90, KVp 120, 305 mA, width 2,800, and level 800). The mean shortest and longest distances to IAM from the petrous ridge were 5.22 and 10.1 mm, respectively. The mean distance to the IAM from the cochlea was 9.91 mm. The mean angle between the IAM and superior semicircular canal was 47.21°, which was more acute than previously reported. The mean angle between the IAM and geniculate ganglion (GG) and external auditory canal was 113.8°, and the mean distance from the GG to the IAM was 15.44 mm. Understanding the 3D relationships among the microsurgical structures will help to decide the drilling point for the IAM when bony landmarks are absent. A preoperative evaluation might be useful for preserving important neurovascular structures while approaching the middle fossa. PMID:25032122

Choi, Bong Jin; Kim, Min Ju; Chang, Ki-Hong; Yeo, Sang Won; Jun, Beom Cho

2014-09-01

35

Surface landmarks of brachial plexus: ultrasound and magnetic resonance imaging for supraclavicular approach with anatomical correlation.  

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The present study is able to describe a certain line, under which brachial plexus (BP) lies underneath in the supraclavicular region. A line drawn between midpoint of the sternocleidomastoid muscle to the midpoint of the clavicle was considered for BP. Surface landmarks were evaluated by applying ultrasound (US) on 30 volunteers (15 female, 15 male). Axial and sagittal views of BP were taken and distances between skin and BP were measured. Coronal magnetic resonance (MR) sections were taken from 7 volunteers according to the second line after applying two fat capsules on each line. The sonographic views were seen at the same line. Mean distances from skin were found as 16.5+/-0.7 mm for male and 14.5+/-0.5 mm for female volunteers. MR images were obtained bilaterally, which were parallel and posterior from sonographic lines. Surface landmarks, as presented in this study, are simple to accomplish and are not dependent on structural variations as external jugular vein. PMID:11516629

Apan, A; Baydar, S; Yilmaz, S; Uz, A; Tekdemir, I; Güney, S; Elhan, A; Baydar, P; Yýlmaz, S; Tekdemir, Y; Güney, P

2001-07-01

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Neural Network Based Sensory Fusion for Landmark Detection  

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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

37

Landmark-based robot navigation enhanced with color interest operators  

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The most important and fascinating ability of natural vision systems is that they spend most of their time on interesting portions of their input, that is, on those aspects of an image which inform the task at hand. This helps a great deal in estimating the location of the system even under dynamic environmental conditions to which systems are subjected to in everyday life. We propose a model that incorporates such ability in robots. Landmark-based approach to robot navigation requires what we define as 'interest operators' to estimate the utility of a particular image region as an effective representative. We have chosen color as the distinguishing characteristic for landmarks. We present a color interest operator consisting of a weighted combination of heuristic scores which thereby selects those image regions or landmarks likely to be found again, even under a different viewing and/or different illumination conditions. The salient regions yield a robust representation for the recognition of a scene. The ability to reproduce regions selected by the operator can be of great help in eliminating environmental uncertainties. We also incorporate a novel color object algorithm, which surpasses all currently available algorithms in speed, robustness and performance to further quicken the response of the navigating robot.

Jagannathan, Hemanth; Narayana Bhaskar, P.

2000-06-01

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

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

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

39

Confirmation of needle placement within the piriformis muscle of a cadaveric specimen using anatomic landmarks and fluoroscopic guidance.  

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Of patients presenting to pain clinics, complaints are of low back or buttock pain with or without radicular leg symptoms is one of the most common. Piriformis syndrome may be a contributor in up to 8% of these patients. The mainstay of treatment is conservative management with physical therapy, anti-inflammatory medications, muscle relaxants, and correction of biomechanical abnormalities. However, in recalcitrant cases, a piriformis injection of anesthetic and/or corticosteroids may be considered. Because of its small size, proximity to neurovascular structures, and deep location, the piriformis muscle is often injected with the use of commuted tomography (CT), magnetic resonance imaging (MRI), ultrasound (US), fluoroscopy, electrical stimulators, or electromyography (EMG). Numerous techniques have been proposed using one or a combination of the above modalities. However, application of these techniques is limited by unavailability of CT, MRI, and EMG equipment as well as a paucity of trained physicians in US-guided procedures in many pain treatment centers throughout the United States. Fluoroscopy, however, is more widely available in this setting. This study utilized a cadaveric specimen to confirm proper needle placement for piriformis or peri-sciatic injection utilizing the previously documented landmarks for fluoroscopic guidance as described by Betts. An anteroposterior of the pelvis with inclusion of the acetabular region of the hip and the inferior aspect of the sacroiliac joint was obtained. The most superior-lateral aspect of the acetabulum and the inferior aspect of the sacroiliac joint were identified. A marker was placed one-third of the distance from the acetabular location to the inferior sacroiliac joint, indicating the target location. A 22-gauge, 3.5-inch spinal needle was directed through the gluteal muscles to the target location using intermittent fluoroscopic guidance. The posterior ileum was contacted and the needle was withdrawn 1 -2 mm. This approach found the needle within the piriformis muscle belly 2 -3 cm lateral to sciatic nerve. The present study was the first study, to our knowledge, that has confirmed the intramuscular position of the needle within the piriformis muscle of a cadaveric specimen using these anatomic landmarks and fluoroscopic guidance. PMID:18523503

Gonzalez, Peter; Pepper, Michelle; Sullivan, William; Akuthota, Venu

2008-01-01

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

International Nuclear Information System (INIS)

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

 
 
 
 
41

Is peritoneal reflection the best anatomical repair landmark in experimental colorectal surgery on rats? A reflexão peritoneal é o melhor reparo anatômico na cirurgia experimental colorretal em ratos?  

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Full Text Available PURPOSE: To validate Peyer's patch as an anatomical repair landmark for colorectal surgery in rats and to measure the collagen content in segments of the colon containing or not containing Peyer's patch. METHODS: The distance between Peyer's patch and the peritoneal reflection was measured in forty-five Wistar rats. The colon and rectum were resected for quantification of collagen content by means of computer-assisted image analysis in regions of the colon with and without Peyer's patch. RESULTS: There was great variation in the distance between Peyer's patch and the peritoneal reflection when the male and female rats were considered as a single group (p=0.04. Comparison between the genders showed that the distance between the patch and the peritoneal reflection was greater in female than in male rats (p=0.001. The colonic segment containing Peyer's patch was observed to have lower tissue collagen content than the segment in which this structure was not present (p=0.02. CONCLUSION: Peyer's patch can be indicated as an anatomical repair landmark, and there is a need to study the healing of colorectal anastomoses in rats based on differing quantities of tissue collagen existing in the colonic wall with or without this structure.OBJETIVO: Validar a placa de Peyer como reparo anatômico para a cirurgia colorretal em ratos e mensurar a quantidade de colágeno em segmentos da parede cólica que contém ou não a placa de Peyer. MÉTODOS: Foi aferida a distância entre a placa de Peyer e a reflexão peritoneal em 45 ratos Wistar. O cólon e o reto foram ressecados, para a quantificação do colágeno, por meio de análise de imagem assistida por computador, em regiões do cólon que continham ou não a placa de Peyer. RESULTADOS: Existe grande variação entre a distância da placa de Peyer e a reflexão peritoneal quando se consideraram os animais de ambos os gêneros como grupo único (p= 0.04, sendo a distância entre a placa e a reflexão peritoneal maior entre as fêmeas (p=0.001. Constatou-se que o segmento cólico que contém a placa de Peyer apresenta conteúdo menor de colágeno quando comparado ao segmento onde a estrutura não estava presente (p=0.02. CONCLUSÃO: A placa de Peyer pode ser indicada como reparo anatômico e no estudo da cicatrização de anastomoses colorretais em ratos, baseado nas diferentes quantidades de colágeno tecidual existente na parede cólica que contém ou não esta estrutura.

Denise Gonçalves Priolli

2009-12-01

42

Active shape models incorporating isolated landmarks for medical image annotation  

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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

43

Gait Recognition for Human Identification Using Fourier Descriptor and Anatomical Landmarks  

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Full Text Available This paper presents a gait recognition method which is based on spatio-temporal movement characteristics of human subject with respect to surveillance camera. Different measures, like leg rise from ground (LRFG, the angles created between the legs with the centre of Mass (ABLC, angles created between the Centre of Mass Knee and Ankle with the (CKA, angles created between Centre of Mass, Wrist and knee (CWK, the distances between the control points and centre of Mass (DCC have been taken as different features. Fourier descriptor has been used for shape extraction of individual frames of a subject. Statistical approach has been used for recognition of individuals based on the n feature vectors, each of size 23(collected from LRFG, ABLCs, CKA, CWK and DCCs for each video frame. It has been found that recognition result of our approach is encouraging with compared to other recent methods.

Mridul Ghosh

2015-01-01

44

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

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

T ahmine Razi

2013-05-01

45

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

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

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

2014-01-01

46

Indoor Localization System based on Artificial Landmarks and Monocular Vision  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents a visual localization approach well suited for the domestic and industrial environments due to its ability to provide an accurate, reliable and robust pose estimation.The mobile robot is equipped with a single camera to update their pose whenever a landmark is available on the field of view.The innovation presented by this research focus, especially, on the artificial landmark that has the ability to detect the presence of the robot, sinceboth entities communicates with ea...

Costa, Paulo G.; Paulo Moreira, A.; Pinto, Andry Maykol G.

2012-01-01

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Indoor Localization System based on Artificial Landmarks and Monocular Vision  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a visual localization approach well suited for the domestic and industrial environments due to its ability to provide an accurate, reliable and robust pose estimation.The mobile robot is equipped with a single camera to update their pose whenever a landmark is available on the field of view.The innovation presented by this research focus, especially, on the artificial landmark that has the ability to detect the presence of the robot, sinceboth entities communicates with each other using an infrared signal protocol modulated in frequency. Besides this communication ability, each landmark has several high intensity light-emitting diodes (leds that shine only for some instances according with the communication, which enables a synchronization between the camera shutter and the blinking of leds. This synchronization increases the system tolerance concerning to the changes in brightness of the ambient lights over time, independently of the landmarks location. The environment’s ceiling is populated with theselandmarks and an Extended Kalman Filter is usedto combine the dead-reckoning and landmark information. This increases the flexibility of the system by reducing the number of landmarks needed. The experimental evaluation of the proposed system was conducted in a real indoor environment with an autonomous wheelchair prototype.

Paulo G. Costa

2012-12-01

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

Directory of Open Access Journals (Sweden)

Full Text Available A method for robot indoor automatic positioning and orientating based on two-dimensional (2D barcode landmark is proposed. By using the scheme of the 2D barcode for reference, a special landmark is designed which is convenient to operate and easy to recognize, contain coordinates of their absolute positions and have some ability to automatically correct errors. Landmarks are placed over the “ceiling” and photographed by a camera mounted on the robot with its optical axis vertical to the ceiling plane. The coordinates and angle of the landmark is acquired through image segmentation, contour extracting, characteristic curves matching and landmark properties identifying, and then the robot’s current absolute position and heading angle is computed. The experiments proved the effectiveness of the method and shows that the method can meet accuracy requirements of indoor position and orientation.

Guoyu Lin

2011-06-01

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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

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The lower nasal base: an anatomical study.  

Science.gov (United States)

Currently, most rhinoplasty surgeons focus their analysis and operative techniques on the upper nasal base, with its alar cartilages. They tend to minimize the lower nasal base, composed of the columellar base, nostril sills, and alar lobules. The requisite operative techniques are often considered ancillary techniques. In this article, the authors describe anatomical composition of the columellar base, nostril sill, and alar lobule; discuss the presence of a distinct lower nasal base; and reevaluate the nasal musculature and the nasal superficial muscular aponeurotic system in an anatomical cadaver model. They also discuss the results of both a detailed literature review (for articles related to the levator labii superioris alaeque nasalis, orbicularis oris, depressor septi nasalis, myrtiformis, and dilator naris) and the results of their own dissection of 45 fresh cadavers. PMID:23335645

Daniel, Rollin K; Glasz, Tibor; Molnar, Gyongyver; Palhazi, Peter; Saban, Yves; Journel, Bertrand

2013-02-01

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Combining Speedup techniques based on Landmarks and Containers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Dijkstra’s algorithm [1] , which is applied in many real world problems like mobile routing, road maps, railway networks, etc,. is used to find the shortest path between source and destination. There are many techniques available to speedup the algorithm while guaranteeing the optimality of the solution. The main focus of the work is to implement landmark technique and Containers separately and compare the results with random graphs and planar graphs. The combined speedup technique whic...

Kalpana, R.; Thambidurai, Dr P.

2010-01-01

52

Anatomical landmarks for the localization of the greater palatine foramen--a study of 1200 head CTs, 150 dry skulls, systematic review of literature and meta-analysis.  

Science.gov (United States)

Accurate knowledge of greater palatine foramen (GPF) anatomy is necessary when performing a variety of anaesthesiological, dental or surgical procedures. The first aim of this study was to localize the GPF in relation to multiple anatomical landmarks. The second aim was to perform a systematic review of literature, and to conduct a meta-analysis on the subject of GPF position to aid clinicians in their practice. One-hundred and fifty dry, adult, human skulls and 1200 archived head computed tomography scans were assessed and measured in terms of GPF relation to other anatomical reference points. A systematic literature search was performed using the PubMed, Embase and Web of Science databases, and a meta-analysis on the subject of GPF relation to the maxillary molars was conducted. On average, in the Polish population, the GPF was positioned 15.9?±?1.5?mm from the midline maxillary suture (MMS), 3.0?±?1.2?mm from the alveolar ridge (AR) and 17.0?±?1.5?mm from the posterior nasal spine (PNS); 74.7% of GPF were positioned opposite the third maxillary molar (M3). Twenty-seven studies were included in the systematic review and 23 in the meta-analysis (n?=?6927 GPF). The pooled prevalence of the GPF being positioned opposite the M3 was 63.9% (95% confidence interval?=?56.6-70.9%). Concluding, the GPF is most often located opposite the M3 in the majority of the world's populations. The maxillary molars are the best landmarks for locating the GPF. In edentulous patients the most useful points for approximating the position of the GPF are the AR, MMS and PNS. This study introduces an easy and repeatable classification to reference the GPF to the maxillary molars. PMID:25131842

Tomaszewska, Iwona M; Tomaszewski, Krzysztof A; Kmiotek, Elizabeth K; Pena, Iwona Z; Urbanik, Andrzej; Nowakowski, Micha?; Walocha, Jerzy A

2014-10-01

53

Landmark-based Geodesic Computation for Heuristically Driven Path Planning  

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This paper presents a new method to quickly extract geodesic paths on images and 3D meshes. We use a heuristic to drive the front propagation procedure of the classical Fast Marching. This results in a modification of the Fast Marching algorithm that is similar to the A$^*$ algorithm used in artificial intelligence. In order to find very quickly geodesic paths between any given couples of points, we advocate for the initial computation of distance maps to a set of landmark points and make use...

Peyre?, Gabriel; Cohen, Laurent D.

2006-01-01

54

Landmark based registration of 18F FDG PET to CT in patients with head and neck cancer: Case reports  

International Nuclear Information System (INIS)

Previous studies have suggested that 18F-FDG PET can be of assistance in the monitoring of disease activity in patients with head and neck cancer undergoing radical radiotherapy treatment. Provided that an adequate period of time elapses between radiotherapy treatment and FDG-PET scanning, this metabolic imaging modality has distinct advantages over anatomical imaging modalities such as CT or MRI which rely largely on changes in size, contrast enhancement and radiodensity of residual mass. The distinction between radiation necrosis and residual tumour is particularly difficult with these modalities. Co-registration of anatomical images from CT or MRI with metabolic images from FDG-PET in this setting may help to locate residual tumour tissue more accurately than PET alone. THE PET scan was peformed on a Siemens 951/3t R PET scanner (6.5 mm in-plane resolution). Patients were positioned supine on the bed in the radiotherapy planning mask to hold the head and neck immobile. A three-bed transmission scan was peformed followed by an intravenous injection of 370 MBq of 18F-FDG. After a 45 min uptake period, a three-bed emission scan was performed to complete the study. Contrast enhanced CT was pedormed on a Picker PQ2000 helical CT scanner. Patients were scanned supine on the bed in the radiotherapy planning mask at a resolution of 21 line pairs/cm. Landmark based registration was used to co-register the PET mages to the CT images. The algorithm uses an analytic linear lea The algorithm uses an analytic linear least-squares solution for a 12 parameter fit of at least 12 operator defined anatomical homologous landmarks in the two image volumes. Both the CT and PET scans include an area of the patient from the base of the brain to the lung apices, thus providing sufficient landmarks for the registration algorithm. We present two patients in whom FDG-PET and CT were used as tools in monitoring disease activity

55

A landmark-based 3D calibration strategy for SPM  

Science.gov (United States)

We present a new method for the complete three-dimensional (3D) calibration of scanning probe microscopes (SPM) and other high-resolution microscopes, e.g., scanning electron microscopes (SEM) and confocal laser scanning microscopes (CLSM), by applying a 3D micrometre-sized reference structure with the shape of a cascade slope-step pyramid. The 3D reference structure was produced by focused ion beam induced metal deposition. In contrast to pitch featured calibration procedures that require separate lateral and vertical reference standards such as gratings and step height structures, the new method includes the use of landmarks, which are well established in calibration and measurement tasks on a larger scale. However, the landmarks applied to the new 3D reference structures are of sub-micrometre size, the so-called 'nanomarkers'. The nanomarker coordinates are used for a geometrical calibration of the scanning process of SPM as well as of other instrument types such as SEM and CLSM. For that purpose, a parameter estimation routine involving three scale factors and three coupling factors has been developed that allows lateral and vertical calibration in only one sampling step. With this new calibration strategy, we are able to detect deviations of SPM lateral scaling errors as well as coupling effects causing, e.g., a lateral coordinate shift depending on the measured height position of the probe.

Ritter, Martin; Dziomba, Thorsten; Kranzmann, Axel; Koenders, Ludger

2007-02-01

56

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

57

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

International Nuclear Information System (INIS)

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

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-09-15

59

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

60

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  

Directory of Open Access Journals (Sweden)

Full Text Available 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 carotid arteries diameters were studied with the aid of an electronic digital caliper. No differences were found between sides in any level studied. The CCA bifurcation level was measured in relation to clinically relevant anatomical landmarks (superior level of the thyroid cartilage, mandible angle and ear lobe and the bifurcation level according to the cervical vertebra level was also investigated. Our study shows that the superior border of the thyroid cartilage was the most stable anatomical landmark for predicting the CCA bifurcation level. It is important to mention that from all the landmarks studied, the cervical vertebra was the only one to show differences between sides, with the left side bifurcation level more variable than the right sideEn cirugías de cabeza y cuello, las arterias carótidas comunes son importantes puntos de referencia, para defnir el plano de disección, durante cirugías radicales de cuello. Los objetivos del presente estudio fueron agregar información sobre el diámetro de las arterias carótidas y correlacionar el nivel de bifurcación de la arteria carótida común (ACC con importantes puntos de referencia usados regularmente en la práctica clínica. Para la obtención de los objetivos planteados, fueron evaluados 46 cadáveres formolizados de individuos de sexo masculino. Se obtuvieron los diámetros de las arterias carótidas común, externa (ACE e interna (ACI, con el auxilio de un caliper digital. No hubo diferencias entre lados derecho e izquierdo, ni tampoco en los niveles estudiados. El nivel de bifurcación de la ACC fue medido en relación a puntos de reparos anatómicos relevantes en clínica (margen superior del cartílago tiroides, ángulo de la mandíbula y lóbulo del pabellón auricular, como también en relación al nivel vertebral. Nuestro estudio mostró que el margen superior del cartílago tiroides fue el punto de referencia más estable para inferir el nivel de bifurcación de la ACC. Es importante mencionar que, de todos los puntos de referencia estudiados, la vértebra cervical fue la única que mostró diferencias entre los lados, siendo más variable el nivel de bifurcación en el lado izquierdo

Rogério Alves Ribeiro

2006-09-01

 
 
 
 
61

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish En cirugías de cabeza y cuello, las arterias carótidas comunes son importantes puntos de referencia, para defnir el plano de disección, durante cirugías radicales de cuello. Los objetivos del presente estudio fueron agregar información sobre el diámetro de las arterias carótidas y correlacionar el n [...] ivel de bifurcación de la arteria carótida común (ACC) con importantes puntos de referencia usados regularmente en la práctica clínica. Para la obtención de los objetivos planteados, fueron evaluados 46 cadáveres formolizados de individuos de sexo masculino. Se obtuvieron los diámetros de las arterias carótidas común, externa (ACE) e interna (ACI), con el auxilio de un caliper digital. No hubo diferencias entre lados derecho e izquierdo, ni tampoco en los niveles estudiados. El nivel de bifurcación de la ACC fue medido en relación a puntos de reparos anatómicos relevantes en clínica (margen superior del cartílago tiroides, ángulo de la mandíbula y lóbulo del pabellón auricular), como también en relación al nivel vertebral. Nuestro estudio mostró que el margen superior del cartílago tiroides fue el punto de referencia más estable para inferir el nivel de bifurcación de la ACC. Es importante mencionar que, de todos los puntos de referencia estudiados, la vértebra cervical fue la única que mostró diferencias entre los lados, siendo más variable el nivel de bifurcación en el lado izquierdo Abstract in english 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 lev [...] el 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) carotid arteries diameters were studied with the aid of an electronic digital caliper. No differences were found between sides in any level studied. The CCA bifurcation level was measured in relation to clinically relevant anatomical landmarks (superior level of the thyroid cartilage, mandible angle and ear lobe) and the bifurcation level according to the cervical vertebra level was also investigated. Our study shows that the superior border of the thyroid cartilage was the most stable anatomical landmark for predicting the CCA bifurcation level. It is important to mention that from all the landmarks studied, the cervical vertebra was the only one to show differences between sides, with the left side bifurcation level more variable than the right side

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

2006-09-01

62

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 ony 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

63

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

64

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Introduction: One of the main problems in learning extraoral radiographic anatomic indexes is the long interval between presentation of radiology and human anatomy courses, resulting in forgetting anatomic regions. Therefore, radiographic indexes are formed as complete abstract and transient images in students’ minds; as a result, their learning and retention decrease. The aim of this study was to compare lecture with combination of computer-assisted learning and lecture of extra-oral radio...

Ahmine Razi, T.; Eza Sighari Deljavan, Ali R.

2013-01-01

65

Anatomically based lower limb nerve model for electrical stimulation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Functional Electrical Stimulation (FES) is a technique that aims to rehabilitate or restore functionality of skeletal muscles using external electrical stimulation. Despite the success achieved within the field of FES, there are still a number of questions that remain unanswered. One way of providing input to the answers is through the use of computational models. Methods This paper describes the development of an anatomically based computer ...

Soboleva Tanya K; Röhrle Oliver; Davidson John B; Hk, Kim Juliana; Pullan Andrew J

2007-01-01

66

An image-based method to automatically propagate bony landmarks: application to computational spine biomechanics.  

Science.gov (United States)

In attempts to elucidate the underlying mechanisms of spinal injuries and spinal deformities, several experimental and numerical studies have been conducted to understand the biomechanical behavior of the spine. However, numerical biomechanical studies suffer from uncertainties associated with hard- and soft-tissue anatomies. Currently, these parameters are identified manually on each mesh model prior to simulations. The determination of soft connective tissues on finite element meshes can be a tedious procedure, which limits the number of models used in the numerical studies to a few instances. In order to address these limitations, an image-based method for automatic morphing of soft connective tissues has been proposed. Results showed that the proposed method is capable to accurately determine the spatial locations of predetermined bony landmarks. The present method can be used to automatically generate patient-specific models, which may be helpful in designing studies involving a large number of instances and to understand the mechanical behavior of biomechanical structures across a given population. PMID:24960066

de Oliveira, Marcelo E; Netto, Luiz M G; Kistler, Michael; Brandenberger, Daniel; Büchler, Philippe; Hasler, Carol-C

2015-11-01

67

Reliability of lower limb alignment measures using an established landmark-based method with a customized computer software program  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The objective of the study was to evaluate the reliability of frontal plane lower limb alignment measures using a landmark-based method by (1) comparing inter- and intra-reader reliability between measurements of alignment obtained manually with those using a computer program, and (2) determining inter- and intra-reader reliability of computer-assisted alignment measures from full-limb radiographs. An established method for measuring alignment was used, involving selection of 10 femoral and t...

Sled, Elizabeth A.; Sheehy, Lisa M.; Felson, David T.; Costigan, Patrick A.; Lam, Miu; Cooke, T. Derek V.

2009-01-01

68

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

Directory of Open Access Journals (Sweden)

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

Xiaohong W. Gao

2007-01-01

69

Anatomically based lower limb nerve model for electrical stimulation  

Directory of Open Access Journals (Sweden)

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

Soboleva Tanya K

2007-12-01

70

Reliability of lower limb alignment measures using an established landmark-based method with a customized computer software program.  

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The objective of the study was to evaluate the reliability of frontal plane lower limb alignment measures using a landmark-based method by (1) comparing inter- and intra-reader reliability between measurements of alignment obtained manually with those using a computer program, and (2) determining inter- and intra-reader reliability of computer-assisted alignment measures from full-limb radiographs. An established method for measuring alignment was used, involving selection of 10 femoral and tibial bone landmarks. (1) To compare manual and computer methods, we used digital images and matching paper copies of five alignment patterns simulating healthy and malaligned limbs drawn using AutoCAD. Seven readers were trained in each system. Paper copies were measured manually and repeat measurements were performed daily for 3 days, followed by a similar routine with the digital images using the computer. (2) To examine the reliability of computer-assisted measures from full-limb radiographs, 100 images (200 limbs) were selected as a random sample from 1,500 full-limb digital radiographs which were part of the Multicenter Osteoarthritis Study. Three trained readers used the software program to measure alignment twice from the batch of 100 images, with two or more weeks between batch handling. Manual and computer measures of alignment showed excellent agreement (intraclass correlations [ICCs] 0.977-0.999 for computer analysis; 0.820-0.995 for manual measures). The computer program applied to full-limb radiographs produced alignment measurements with high inter- and intra-reader reliability (ICCs 0.839-0.998). In conclusion, alignment measures using a bone landmark-based approach and a computer program were highly reliable between multiple readers. PMID:19882339

Sled, Elizabeth A; Sheehy, Lisa M; Felson, David T; Costigan, Patrick A; Lam, Miu; Cooke, T Derek V

2011-01-01

71

Automatic localization of retinal landmarks.  

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Retinal landmark detection is a key step in retinal screening and computer-aided diagnosis for different types of eye diseases, such as glaucomma, age-related macular degeneration(AMD) and diabetic retinopathy. In this paper, we propose a semantic image transformation(SIT) approach for retinal representation and automatic landmark detection. The proposed SIT characterizes the local statistics of a fundus image and boosts the intrinsic retinal structures, such as optic disc(OD), macula. We propose our salient OD and macular models based on SIT for retinal landmark detection. Experiments on 5928 images show that our method achieves an accuracy of 99.44% in the detection of OD and an accuracy of 93.49% in the detection of macula, while having an accuracy of 97.33% for left and right eye classification. The proposed SIT can automatically detect the retinal landmarks and be useful for further eye-disease screening and diagnosis. PMID:23367039

Cheng, Xiangang; Wong, Damon Wing Kee; Liu, Jiang; Lee, Beng-Hai; Tan, Ngan Meng; Zhang, Jielin; Cheng, Ching Yu; Cheung, Gemmy; Wong, Tien Yin

2012-01-01

72

[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

73

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

74

Automatic computerized radiographic identification of cephalometric landmarks.  

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Computerized cephalometric analysis currently requires manual identification of landmark locations. This process is time-consuming and limited in accuracy. The purpose of this study was to develop and test a novel method for automatic computer identification of cephalometric landmarks. Spatial spectroscopy (SS) is a computerized method that identifies image structure on the basis of a convolution of the image with a set of filters followed by a decision method using statistical pattern recognition techniques. By this method, characteristic features are used to recognize anatomic structures. This study compared manual identification on a computer monitor and the SS automatic method for landmark identification on minimum resolution images (0.16 cm2 per pixel). Minimum resolution (defined as the lowest resolution at which a cephalometric structure could be identified) was used to reduce computational time and memory requirements during this development stage of the SS method. Fifteen landmarks were selected on a set of 14 test images. The results showed no statistical difference (p > 0.05) in mean landmark identification errors between manual identification on the computer display and automatic identification using SS. We conclude that SS shows potential for the automatic detection of landmarks, which is an important step in the development of a completely automatic cephalometric analysis. PMID:9484208

Rudolph, D J; Sinclair, P M; Coggins, J M

1998-02-01

75

Landmarks in Hybrid Planning  

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Although planning techniques achieved a significant progress during recent years, solving many planning problem still difficult even for modern planners. In this paper, we will adopt landmark concept to hybrid planning setting - a method that combines reasoning about procedural knowledge and causalities. Land-marks are a well-known concept in the realm of classical planning. Recently, they have been adapted to hierarchical approaches. Such landmarks can be extracted in a pre-processing step f...

Mohamed Elkawkagy; Heba Elbeh

2013-01-01

76

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

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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

77

Evaluation of pelvic lymph node coverage of conventional radiotherapy fields based on bony landmarks in Chinese cervical cancer patients using CT simulation  

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Objective: To evaluate the pelvic lymph node coverage of conventional pelvic fields based on bony landmarks in Chinese patients with cervical cancer by using computed tomography (CT) simulation images to contour pelvic vessels as substitutes for lymph nodes location. Methods: A retrospective review of CT simulation images and conventional pelvic radiation planning data sets was performed in 100 patients with cervical cancer at the International Federation of Gynecology and Obstetrics (FIGO) S...

Zhang, Xiang; Yu, Hua

2009-01-01

78

Landmarks in Hybrid Planning  

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Full Text Available Although planning techniques achieved a significant progress during recent years, solving many planning problem still difficult even for modern planners. In this paper, we will adopt landmark concept to hybrid planning setting - a method that combines reasoning about procedural knowledge and causalities. Land-marks are a well-known concept in the realm of classical planning. Recently, they have been adapted to hierarchical approaches. Such landmarks can be extracted in a pre-processing step from a declarative hierarchical planning domain and problem description. It was shown how this technique allows for a considerable reduction of the search space by eliminating futile plan development options before the actual planning. Therefore, we will present a new approach to in¬tegrate landmark pre-processing technique in the context of hierarchical planning with landmark technique in the classical planning. This integration allows to incorporate the ability of using extracted landmark tasks from hierarchical domain knowledge in the form of HTN and using landmark literals from classical planning. To this end, we will construct a transformation technique to transform the hybrid planning domain into a classical domain model. The method¬ologies in this paper have been implemented successfully, and we will present some experimental results that give evidence for the consid-erable performance increase gained through planning system.

Mohamed Elkawkagy

2013-11-01

79

Magnetic resonance imaging based rectal cancer classification: landmarks and technical standardization.  

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Rectal cancer classification is important to determine the preoperative chemoradiation therapy and to select appropriate surgical technique. We reviewed the Western and Japanese rectal cancer classification and we propose our new classification based of Magnetic resonance imaging (MRI). We determine the relation of the tumor to fixed parameters in MRI, which are peritoneal reflection and levator ani muscle. Then, we classify the rectal cancer into four levels based on tumor distal margin and invasion to MRI parameters. We applied all three classifications to 60 retrospectively collected patients of different rectal cancer distance and we compared our classifications to the others. Based on each level we standardize our surgical approach. For stages?I-III, We found that level?I?where tumor distal margin is located above the peritoneal reflection and all of them were received low anterior resection (LAR) without chemoradiation. Level II where tumor distal margin is located from the peritoneal reflection and above the levator ani insertion on the rectum. 90% of them were received LAR ± chemoradiation. Level III where tumor distal margin is located at the level of levator ani insertion or invading any part of the levator ani. 60% of them had ULAR + coloanal anastomosis ± chemoradiation. Level IV where the tumor distal margin is located below the levator ani insertion; 77% were received APR ± chemoradiation. The overall kappa for all levels between surgeons and radiologist was 0.93 (95%CI: 0.87-0.99), which is indicating almost perfect agreement. We concluded that the management of rectal tumors differed among each tumor level and our new MRI based classification might facilitate the prediction of surgical and chemoradiation management with better communication among a multidisciplinary team comparing to other classifications. PMID:25593457

Alasari, Sami; Lim, Daero; Kim, Nam Kyu

2015-01-14

80

Exploring the Anatomical Basis of Effective Connectivity Models with DTI-Based Fiber Tractography  

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Full Text Available Diffusion tensor imaging (DTI is considered to be a promising tool for revealing the anatomical basis of functional networks. In this study, we investigate the potential of DTI to provide the anatomical basis of paths that are used in studies of effective connectivity, using structural equation modeling. We have taken regions of interest from eight previously published studies, and examined the connectivity as defined by DTI-based fiber tractography between these regions. The resulting fiber tracts were then compared with the paths proposed in the original studies. For a substantial number of connections, we found fiber tracts that corresponded to the proposed paths. More importantly, we have also identified a number of cases in which tractography suggested direct connections which were not included in the original analyses. We therefore conclude that DTI-based fiber tractography can be a valuable tool to study the anatomical basis of functional networks.

Frans A. J. Verstraten

2008-05-01

 
 
 
 
81

Landmark Constrained Non-parametric Image Registration with Isotropic Tolerances  

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The incorporation of additional user knowledge into a nonrigid registration process is a promising topic in modern registration schemes. The combination of intensity based registration and some interactively chosen landmark pairs is a major approach in this direction. There exist different possibilities to incorporate landmark pairs into a variational non-parametric registration framework. As the interactive localization of point landmarks is always prone to errors, a demand for precise landmark matching is bound to fail. Here, the treatment of the distances of corresponding landmarks as penalties within a constrained optimization problem offers the possibility to control the quality of the matching of each landmark pair individually. More precisely, we introduce inequality constraints, which allow for a sphere-like tolerance around each landmark. We illustrate the performance of this new approach for artificial 2D images as well as for the challenging registration of preoperative CT data to intra-operative 3D ultrasound data of the liver.

Papenberg, Nils; Olesch, Janine; Lange, Thomas; Schlag, Peter M.; Fischer, Bernd

82

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

International Nuclear Information System (INIS)

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

83

View-based navigation in insects: how wood ants (Formica rufa L.) look at and are guided by extended landmarks.  

Science.gov (United States)

Bees, wasps and ants learn landmarks as views from particular vantage points, storing the retinal positions of landmark edges. By moving so as to minimise the difference between their stored and current view, they can return to the vantage point from which a view was taken. We have examined what wood ants learn about a laterally placed, extended landmark, a wall, while walking parallel to it to reach a feeder and how they use this stored information to guide their path. Manipulation of the height of the wall and the ant's starting distance from it reveals that ants maintain a desired distance from the wall by keeping the image of the top of the wall at a particular retinal elevation. Ants can thus employ image matching both for returning to a place and for following a fixed route. Unlike many flying insects, an ant's direction of motion while walking is always along its longitudinal body axis and, perhaps for this reason, it favours its frontal retina for viewing discrete landmarks. We find that ants also use their frontal retina for viewing a laterally placed wall. On a coarse scale, the ant's path along the wall is straight, but on a finer scale it is roughly sinusoidal, allowing the ant to scan the surrounding landscape with its frontal retina. The ant's side-to-side scanning means that the wall is viewed with its frontal retina for phases of the scanning cycle throughout its trajectory. Details of the scanning pattern depend on the scene. Ants scan further to the side that is empty of the wall than to the side containing the wall, and they scan further into the wall side when the wall is of a lower apparent height. We conclude that frontal retina is employed for image storage and for path control. PMID:12124373

Graham, Paul; Collett, Thomas S

2002-08-01

84

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

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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

85

FlyBase: anatomical data, images and queries  

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FlyBase () is a database of genetic and genomic data on the model organism Drosophila melanogaster and the entire insect family Drosophilidae. The FlyBase Consortium curates, annotates, integrates and maintains a wide variety of data within this domain. Access to the data is provided through graphical and textual user interfaces tailored to particular types of data. FlyBase data types include maps at the cytological, genetic and sequence levels, genes and alleles including their products, fun...

Grumbling, Gary; Strelets, Victor

2005-01-01

86

Quantified relationships of the radial nerve with the radial groove and selected humeral landmarks  

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Anatomical relationships between the radial nerve, the deltoid muscle insertions and several bony landmarks have been investigated to assess the feasibility of surgical transfer of the deltoid transfer during humeral osteotomy. Eleven embalmed human specimens were dissected. Each specimen included the whole thorax, both shoulders and upper limbs. Spatial position of the radial nerve along the radial groove, the deltoid muscle, and several anatomical landmarks was digitised using a three-dimen...

Sint Jan, Serge; Nguyen, D.; Rooze, Marcel

2008-01-01

87

Reproducibility and repeatability of upper limb landmarks palpation for junior operators  

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In human motion analysis, bone motions are usually expressed relatively to anatomical reference frames. The anatomical reference frames are constructed thanks to the localization of bony landmarks during a static phase prior to the acquisitions. These landmarks are identified by means of palpation. Accurate comparison between subjects and studies implies good reproducibility and repeatability of the palpation process. However, all investigators don’t have a long expe...

Schwartz, Ce?dric; Fedrigo, Tatiana; Bruls, Olivier; Cescotto, Serge; Denoe?l, Vincent; Croisier, Jean-louis; Forthomme, Be?ne?dicte

2011-01-01

88

Non-rigid landmark-based large-scale image registration in 3-D reconstruction of mouse and rat kidney nephrons  

DEFF Research Database (Denmark)

BACKGROUND: Serial histological sections are suffering from mechanical distortions that disturb the reconstruction of 3-D objects. We have corrected such artifacts with a non-rigid landmark-based method that respects the original geometry in the tissue block. The method is exemplified on a large scale in the registration of semi-thin serial sections of the mouse and rat kidneys, and has been tested on FFPE-sections. AIM: In this study of mouse and rat kidneys, we have measured and characterized the deformations introduced in the preparation of 2.5-?m-thick Epon sections and then eliminated them by a landmark-based non-rigid transformation (NRT). METHODS: We obtained 2.5-?m-thick serial Epon sections from three mouse kidneys and three rat kidneys for 3-D reconstruction of the nephron tubules. First, the images from 3000 serial mouse and 13,000 serial rat sections underwent a classic rigid registration (CRR), and the distortions were measured and indexed. The section images underwent a further NRT in order tocompensate for the deformations. The NRT used is a classic interactive landmark-based approach. The quality of the NRT was verified by comparing the geometry of the transformed images with corresponding block images. RESULTS: After CRR, the 2.5-?m-thick sections had a linear deformation of up to 2%, the tubular lengths were overestimated with up to 1.5×, and it was most difficult to trace the tubules from section to section. After the additional NRT, the geometry of the images reflected the original geometry in the block, the tubular lengths were no longer overestimated, and the NRT highly facilitated the tracing of the tubular system. CONCLUSIONS: NRT has facilitated the tracing of the tubular system in kidneys, a tracing, which would otherwise have been most difficult to perform. NRT has yielded substantial new knowledge to segmental and spatial nephron organization in the mouse and rat kidneys.

Zhang, Yan-Ling; Chang, Shi-Jie

2015-01-01

89

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

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

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

2008-01-01

90

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

91

Automatic localization of fovea in retinal images based on mathematical morphology and anatomic structures  

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Diabetic macular edema is one of the retinal abnormalities which affects the central vision of the person and causes total blindness in severe cases. Fovea (center of macula) localization is an important step in retinal image analysis especially for grading diabetic macular edema. This paper describes a method to automatically localize the fovea center in retinal fundus images. The method is mainly based on mathematical morphology along with the information of other anatomic structures such a...

Benadict Raja, J.; Ravichandran, C. G.

2014-01-01

92

Evaluation of three MRI-based anatomical priors for quantitative PET brain imaging.  

Science.gov (United States)

In emission tomography, image reconstruction and therefore also tracer development and diagnosis may benefit from the use of anatomical side information obtained with other imaging modalities in the same subject, as it helps to correct for the partial volume effect. One way to implement this, is to use the anatomical image for defining the a priori distribution in a maximum-a-posteriori (MAP) reconstruction algorithm. In this contribution, we use the PET-SORTEO Monte Carlo simulator to evaluate the quantitative accuracy reached by three different anatomical priors when reconstructing positron emission tomography (PET) brain images, using volumetric magnetic resonance imaging (MRI) to provide the anatomical information. The priors are: 1) a prior especially developed for FDG PET brain imaging, which relies on a segmentation of the MR-image (Baete , 2004); 2) the joint entropy-prior (Nuyts, 2007); 3) a prior that encourages smoothness within a position dependent neighborhood, computed from the MR-image. The latter prior was recently proposed by our group in (Vunckx and Nuyts, 2010), and was based on the prior presented by Bowsher (2004). The two latter priors do not rely on an explicit segmentation, which makes them more generally applicable than a segmentation-based prior. All three priors produced a compromise between noise and bias that was clearly better than that obtained with postsmoothed maximum likelihood expectation maximization (MLEM) or MAP with a relative difference prior. The performance of the joint entropy prior was slightly worse than that of the other two priors. The performance of the segmentation-based prior is quite sensitive to the accuracy of the segmentation. In contrast to the joint entropy-prior, the Bowsher-prior is easily tuned and does not suffer from convergence problems. PMID:22049363

Vunckx, Kathleen; Atre, Ameya; Baete, Kristof; Reilhac, Anthonin; Deroose, Christophe M; Van Laere, Koen; Nuyts, Johan

2012-03-01

93

Mesh-based approach for the 3D analysis of anatomical structures of interest in radiotherapy.  

Science.gov (United States)

In this paper a method based on mesh surfaces approximations for the 3D analysis of anatomical structures in Radiotherapy (RT) is presented. Parotid glands meshes constructed from Megavoltage CT (MVCT) images were studied in terms of volume, distance between center of mass (distCOM) of the right and left parotids, dice similarity coefficient (DICE), maximum distance between meshes (DMax) and the average symmetric distance (ASD). A comparison with the standard binary images approach was performed. While absence of significant differences in terms of volume, DistCOM and DICE indices suggests that both approaches are comparable, the fact that the ASD showed significant difference (p=0.002) and the DMax was almost significant (p=0.053) suggests that the mesh approach should be adopted to provide accurate comparison between 3D anatomical structures of interest in RT. PMID:23367431

Mejia-Rodriguez, Aldo R; Scalco, Elisa; Tresoldi, Daniele; Bianchi, Anna M; Arce-Santana, Edgar R; Mendez, Martin O; Rizzo, Giovanna

2012-01-01

94

Superior temporal sulcus anatomical abnormalities in childhood autism: a voxel-based morphometry MRI study.  

Science.gov (United States)

The underlying neurobiology of autism, a severe pervasive developmental disorder, remains unknown. Few neocortical brain MRI abnormalities have been reported. Using rest functional brain imaging, two independent studies have described localized bilateral temporal hypoperfusion in children with primary autism. In order to search for convergent evidence of anatomical abnormalities in autistic children, we performed an anatomical MRI study using optimized whole-brain voxel-based morphometry (VBM). High-resolution 3-D T1-weighted MRI data sets were acquired in 21 children with primary autism (mean age 9.3 +/- 2.2 years) and 12 healthy control children (mean age 10.8 +/- 2.7 years). By comparing autistic children to normal children, we found bilaterally significant decreases of grey matter concentration located in superior temporal sulcus (STS) (P < 0.05 corrected, after small volume correction; SVC). Children with autism were also found to have a decrease of white matter concentration located in the right temporal pole and in cerebellum (P < 0.05, corrected) compared to normal children. These results suggest that autism is associated with bilateral anatomical abnormalities localized in the STS and are remarkably consistent with functional hypoperfusion previously reported in children with autism. The multimodal STS areas are involved in highest level of cortical integration of both sensory and limbic information. Moreover, the STS is now recognized as a key cortical area of the "social brain" and is implicated in social perceptual skills that are characteristically impaired in autism. Therefore, the convergent anatomical and functional temporal abnormalities observed in autism may be important in the understanding of brain behavior relationships in this severe developmental disorder. PMID:15325384

Boddaert, N; Chabane, N; Gervais, H; Good, C D; Bourgeois, M; Plumet, M-H; Barthélémy, C; Mouren, M-C; Artiges, E; Samson, Y; Brunelle, F; Frackowiak, R S J; Zilbovicius, M

2004-09-01

95

Coexistence of the suprascapular notch and the suprascapular foramen--a rare anatomical variation and a new hypothesis on its formation based on anatomical and radiological studies.  

Science.gov (United States)

The suprascapular notch is the most common site of suprascapular nerve entrapment, which can manifest in disability and pain of the upper limb. Here, we present three cases of a very rare anatomical variation in the suprascapular region: the coexistence of the suprascapular notch and the suprascapular foramen. The variation was found during radiological and anatomical investigations. The suprascapular foramen was situated inferior to the suprascapular notch. A bony bridge lay between them, likely created by an ossified anterior coracoscapular ligament (ACSL). This anatomical variation probably increased the risk of suprascapular nerve entrapment by nerve irritation of the bony margins during passsage through the foramen and by a lack of the elasticity that the ACSL normally demonstrates. Also, a bony bridge passing through the middle part of the suprascapular notch reduces the space available for nerve passage (bony bridge decreases the space by about 36.5-38.6 %). One patient who underwent the radiological study had typical symptoms of suprascapular nerve entrapment. Based on his medical history and the presence of this rare variation of the suprascapular notch at the suprascapular region we suspect this neuropathy. PMID:23208271

Polguj, Micha?; J?drzejewski, Kazimierz; Majos, Agata; Topol, Miros?aw

2013-06-01

96

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

97

Application of a rules-based natural language parser to critical value reporting in anatomic pathology.  

Science.gov (United States)

Critical values in anatomic pathology are rare occurrences and difficult to define with precision. Nevertheless, accrediting institutions require effective and timely communication of all critical values generated by clinical and anatomic laboratories. Provisional gating criteria for potentially critical anatomic diagnoses have been proposed, with some success in their implementation reported in the literature. Ensuring effective communication is challenging, however, making the case for programmatic implementation of a turnkey-style integrated information technology solution. To address this need, we developed a generically deployable laboratory information system-based tool, using a tiered natural language processing predicate calculus inference engine to identify qualifying cases that meet criteria for critical diagnoses but lack an indication in the electronic medical record for an appropriate clinical discussion with the ordering physician of record. Using this tool, we identified an initial cohort of 13,790 cases over a 49-month period, which were further explored by reviewing the available electronic medical record for each patient. Of these cases, 35 (0.3%) were judged to require intervention in the form of direct communication between the attending pathologist and the clinical physician of record. In 8 of the 35 cases, this intervention resulted in the conveyance of new information to the requesting physician and/or a change in the patient's clinical plan. The very low percentage of such cases (0.058%) illustrates their rarity in daily practice, making it unlikely that manual identification/notification approaches alone can reliably manage them. The automated turnkey system was useful in avoiding missed handoffs of significant, clinically actionable diagnoses. PMID:22343338

Owens, Scott R; Balis, Ulysses G J; Lucas, David R; Myers, Jeffrey L

2012-03-01

98

Grüber's ligament as a useful landmark for the abducens nerve in the transnasal approach.  

Science.gov (United States)

OBJECT Extended endoscopic transnasal surgeries for skull base lesions have recently been performed. Some expert surgeons have attempted to remove tumors such as chordomas, meningiomas, and pituitary adenomas in the clival region using the transnasal approach and have reported abducens nerve injury as a common complication. There have been many microsurgical anatomical studies of the abducens nerve, but none of these studies has described an anatomical landmark of the abducens nerve in the transnasal approach. In this study the authors used cadaver dissections to describe Grüber's ligament as the most reliable landmark of the abducens nerve in the transnasal transclival view. METHODS The petroclival segment of the abducens nerve was dissected in the interdural space-which is also called Dorello's canal, the petroclival venous gulf, or the sphenopetroclival venous confluence-using the transnasal approach in 20 specimens obtained from 10 adult cadaveric heads. RESULTS The petroclival segment of the abducens nerve clearly crossed and attached to Grüber's ligament in the interdural space, as noted in the transnasal view. The average length of the dural porus to the intersection on the abducens nerve was 5.2 ± 1.0 mm. The length of the posterior clinoid process (PCP) to the intersection on Grüber's ligament was 6.4 ± 2.6 mm. The average width of Grüber's ligament at the midsection was 1.6 ± 0.5 mm. CONCLUSIONS Grüber's ligament is considered a useful landmark, and it is visible in most adults. Thus, surgeons can find the abducens nerve safely by visualizing inferolaterally along Grüber's ligament from the PCP. PMID:25380109

Tomio, Ryosuke; Toda, Masahiro; Sutiono, Agung Budi; Horiguchi, Takashi; Aiso, Sadakazu; Yoshida, Kazunari

2014-11-01

99

Anatomical evaluation of CT-MRI combined femoral model  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Both CT and MRI are complementary to each other in that CT can produce a distinct contour of bones, and MRI can show the shape of both ligaments and bones. It will be ideal to build a CT-MRI combined model to take advantage of complementary information of each modality. This study evaluated the accuracy of the combined femoral model in terms of anatomical inspection. Methods Six normal porcine femora (180 ± 10 days, 3 lefts and 3 rights with ball markers were scanned by CT and MRI. The 3D/3D registration was performed by two methods, i.e. the landmark-based 3 points-to-3 points and the surface matching using the iterative closest point (ICP algorithm. The matching accuracy of the combined model was evaluated with statistical global deviation and locally measure anatomical contour-based deviation. Statistical analysis to assess any significant difference between accuracies of those two methods was performed using univariate repeated measures ANOVA with the Turkey post hoc test. Results This study revealed that the local 2D contour-based measurement of matching deviation was 0.5 ± 0.3 mm in the femoral condyle, and in the middle femoral shaft. The global 3D contour matching deviation of the landmark-based matching was 1.1 ± 0.3 mm, but local 2D contour deviation through anatomical inspection was much larger as much as 3.0 ± 1.8 mm. Conclusion Even with human-factor derived errors accumulated from segmentation of MRI images, and limited image quality, the matching accuracy of CT-&-MRI combined 3D models was 0.5 ± 0.3 mm in terms of local anatomical inspection.

Kim Gyu-Ha

2008-01-01

100

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

 
 
 
 
101

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

DEFF Research Database (Denmark)

Background: Manual annotation of landmarks is a known source of variance, which exist in all fields of medical imaging, influencing the accuracy and interpretation of the results. However, the variability of human facial landmarks is only sparsely addressed in the current literature as opposed to e.g. the research fields of orthodontics and cephalometrics. We present a full facial 3D annotation procedure and a sparse set of manually annotated landmarks, in effort to reduce operator time and minimize the variance. Method: Facial scans from 36 voluntary unrelated blood donors from the Danish Blood Donor Study was randomly chosen. Six operators twice manually annotated 73 anatomical and pseudo-landmarks, using a three-step scheme producing a dense point correspondence map. We analyzed both the intra- and inter-operator variability, using mixed-model ANOVA. We then compared four sparse sets of landmarks in order to construct a dense correspondence map of the 3D scans with a minimum point variance. Results: The anatomical landmarks of the eye were associated with the lowest variance, particularly the center of the pupils. Whereas points of the jaw and eyebrows have the highest variation. We see marginal variability in regards to intra-operator and portraits. Using a sparse set of landmarks (n=14), that capture the whole face, the dense point mean variance was reduced from 1.92 to 0.54 mm. Conclusion: The inter-operator variability was primarily associated with particular landmarks, where more leniently landmarks had the highest variability. The variables embedded in the portray and the reliability of a trained operator did only have marginal influence on the variability. Further, using 14 of the annotated landmarks we were able to reduced the variability and create a dense correspondences mesh to capture all facial features.

Fagertun, Jens; Harder, Stine

2014-01-01

102

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

103

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

104

Utility of postmortem imaging system for anatomical education in skull base surgery.  

Science.gov (United States)

Although cadaver dissections are important for skull base surgeons to acquire anatomical knowledge and techniques, their opportunities are limited in Japan. The Autopsy Imaging Center of the University of Fukui Hospital has both a CT scanner and an MR unit solely for deceased patients. The authors applied the postmortem imaging to cadaver dissections and evaluated its usefulness in surgical education. Ten sides of five formalin-fixed cadaver heads were dissected by ten neurosurgeons. Five neurosurgeons were young, three were moderately experienced, and two were experts in skull base surgery. They performed orbitozygomatic, anterior transpetrosal, posterior transpetrosal, and transcondylar approaches. CT bone images were taken before and after dissections, and MR images were taken before dissection to merge with the CT bone images. The usefulness of the images for each neurosurgeon and for each skull base approach was evaluated. The postmortem imaging system was useful for all neurosurgeons, especially in anterior transpetrosal, posterior transpetrosal, and transcondylar approaches. They could find the insufficiency or excessiveness of their drilling of specific bony structures with the images. Even the experts in skull base surgery could identify regions in which they could add drilling safely to widen the surgical field more. The postmortem imaging system was useful for skull base cadaver dissections. This system is expected to be utilized for education and research on surgical anatomy. PMID:25240531

Kodera, Toshiaki; Arishima, Hidetaka; Kitai, Ryuhei; Kikuta, Ken-Ichiro; Iino, Satoshi; Noriki, Sakon; Naiki, Hironobu

2015-01-01

105

Landmarks GIScience for intelligent services  

CERN Document Server

This book covers the latest research on landmarks in GIS, including practical applications. It addresses perceptual and cognitive aspects of natural and artificial cognitive systems, computational aspects with respect to identifying or selecting landmarks for various purposes, and communication aspects of human-computer interaction for spatial information provision. Concise and organized, the book equips readers to handle complex conceptual aspects of trying to define and formally model these situations. The book provides a thorough review of the cognitive, conceptual, computational and commun

Richter, Kai-Florian

2014-01-01

106

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

Science.gov (United States)

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

Ma, Baoshun; Lutchen, Kenneth R

2009-02-01

107

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

108

Synchrotron-based phase-contrast images of zebrafish and its anatomical structures  

Science.gov (United States)

Images of vertebrates (zebrafish and zebrafish eye) have been obtained by using an X-ray phase-contrast imaging technique, namely, synchrotron-based diffraction-enhanced imaging (SY-DEI) (or analyzer based imaging) and synchrotron-based diffraction imaging in tomography mode (SY-DEI-CT). Due to the limitations of the conventional radiographic imaging in visualizing the internal complex feature of the sample, we utilized the upgraded SY-DEI and SY-DEI-CT systems to acquire the images at 20, 30 and 40 keV, to observe the enhanced contrast. SY-DEI and SY-DEI-CT techniques exploits the refraction properties, and have great potential in studies of soft biological tissues, in particular for low (Z) elements, such as, C, H, O and N, which constitutes the soft tissue. Recently, these techniques are characterized by its extraordinary image quality, with improved contrast, by imaging invertebrates. We have chosen the vertebrate sample of zebrafish (Danio rerio), a model organism widely used in developmental biology and oncology. For biological imaging, these techniques are most sensitive to enhance the contrast. For the present study, images of the sample, in planar and tomography modes offer more clarity on the contrast enhancement of anatomical features of the eye, especially the nerve bundle, swim bladder, grills and some internal organs in gut with more visibility.

Rao Donepudi, Venkateswara; Melumai, Bhaskaraiah; Thallapaka, Balasaidulu; Sandeep, Konam; Cesareo, Roberto; Brunetti, Antonio; Zhong, Zhong; Akatsuka, Takao; Yuasa, Tetsuya; Takeda, Tohoru; Gigante, Giovanni E.

2014-08-01

109

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

110

Aplicación bioantropológica para manipulación de landmarks faciales en 2D  

Digital Repository Infrastructure Vision for European Research (DRIVER)

La obtención de coordenadas de landmarks en 2 y 3D de modo automatizado y en bases de datos masivas se encuentra en un estado incipiente, a causa de las dificultades técnicas, económicas y operativas que se presentan: debe contarse con dispositivos caros, o no portátiles, capaces de tomar puntos sobre los objetos bajo estudio, y el proceso de landmarking suele ser hecho en forma manual por operadores entrenados, con el consiguiente costo en tiempo y riesgo de errores operativos. En est...

Cintas, Celia; Quinto Sa?nchez, Mirsha; Defosse?, Nahuel; Delrieux, Claudio; Gonza?lez Jose?, Rolando

2014-01-01

111

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

Directory of Open Access Journals (Sweden)

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

Beugnon Guy

2011-08-01

112

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

113

ANATOMICAL PRINCIPLES BEHIND PRESERVATION OF LARYNGEAL NERVES DURING THYROIDECTOMY  

Directory of Open Access Journals (Sweden)

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

114

Anatomically Anchored Template-Based Level Set Segmentation: Application to Quadriceps Muscles in MR Images from the Osteoarthritis Initiative  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, we present a semi-automated segmentation method for magnetic resonance images of the quadriceps muscles. Our method uses an anatomically anchored, template-based initialization of the level set-based segmentation approach. The method only requires the input of a single point from the user inside the rectus femoris. The templates are quantitatively selected from a set of images based on modes in the patient population, namely, sex and body type. For a given image to be segmented...

Prescott, Jeffrey W.; Best, Thomas M.; Swanson, Mark S.; Haq, Furqan; Jackson, Rebecca D.; Gurcan, Metin N.

2010-01-01

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)

116

Ultrasound-Guided Small Vessel Cannulation: Long-Axis Approach Is Equivalent to Short-Axis in Novice Sonographers Experienced with Landmark-Based Cannulation  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction: Our primary objective was to describe the time to vessel penetration and difficulty of long-axis and short-axis approaches for ultrasound-guided small vessel penetration in novice sonographers experienced with landmark-based small vessel penetration. Methods: This was a prospective, observational study of experienced certified emergency nurses attempting ultrasound-guided small vessel cannulation on a vascular access phantom. We conducted a standardized training, practice, and experiment session for each participant. Five long-axis and five short-axis approaches were attempted in alternating sequence. The primary outcome was time to vessel penetration. Secondary outcomes were number of skin penetrations and number of catheter redirections. We compared long-axis and short-axis approaches using multivariable regression adjusting for repeated measures, vessel depth, and vessel caliber. Results: Each of 10 novice sonographers made 10 attempts for a total of 100 attempts. Median time to vessel penetration in the long-axis and short-axis was 11 (95% confidence interval [CI] 7-12 and 10 (95% CI 6-13 seconds, respectively. Skin penetrations and catheter redirections were equivalent and near optimal between approaches. The median caliber of cannulated vessels in the long-axis and short-axis was 4.6 (95% CI 4.1-5.5 and 5.6 (95% CI 5.1-6.2 millimeters, respectively. Both axes had equal success rates of 100% for all 50 attempts. In multivariable regression analysis, long-axis attempts were 32% (95% CI 11%-48%; p=0.009 faster than short-axis attempts. Conclusion: Novice sonographers, highly proficient with peripheral IV cannulation, can perform after instruction ultrasound-guided small vessel penetration successfully with similar time to vessel penetration in either the long-axis or short-axis approach on phantom models. [West J Emerg Med. 2014;15(7:–0.

Catherine S. Erickson

2014-11-01

117

Coexistence of the suprascapular notch and the suprascapular foramen—a rare anatomical variation and a new hypothesis on its formation based on anatomical and radiological studies  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The suprascapular notch is the most common site of suprascapular nerve entrapment, which can manifest in disability and pain of the upper limb. Here, we present three cases of a very rare anatomical variation in the suprascapular region: the coexistence of the suprascapular notch and the suprascapular foramen. The variation was found during radiological and anatomical investigations. The suprascapular foramen was situated inferior to the suprascapular notch. A bony bridge lay between them, li...

Polguj, Micha?; Je?drzejewski, Kazimierz; Majos, Agata; Topol, Miros?aw

2013-01-01

118

Anatomic feature-based registration for patient set-up in head and neck cancer radiotherapy  

Science.gov (United States)

Modern radiotherapy equipment is capable of delivering high precision conformal dose distributions relative to isocentre. One of the barriers to precise treatments is accurate patient re-positioning before each fraction of treatment. At Massachusetts General Hospital, we perform daily patient alignment using radiographs, which are captured by flat panel imaging devices and sent to an analysis program. A trained therapist manually selects anatomically significant features in the skeleton, and couch movement is computed based on the image coordinates of the features. The current procedure takes about 5 to 10 min and significantly affects the efficiency requirement in a busy clinic. This work presents our effort to develop an improved, semi-automatic procedure that uses the manually selected features from the first treatment fraction to automatically locate the same features on the second and subsequent fractions. An implementation of this semi-automatic procedure is currently in clinical use for head and neck tumour sites. Radiographs collected from 510 patient set-ups were used to test this algorithm. A mean difference of 1.5 mm between manual and automatic localization of individual features and a mean difference of 0.8 mm for overall set-up were seen.

Sharp, Gregory C.; Kollipara, Sashidhar; Madden, Thomas; Jiang, Steve B.; Rosenthal, Stanley J.

2005-10-01

119

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)

120

Automatic localization of fovea in retinal images based on mathematical morphology and anatomic structures  

Directory of Open Access Journals (Sweden)

Full Text Available Diabetic macular edema is one of the retinal abnormalities which affects the central vision of the person and causes total blindness in severe cases. Fovea (center of macula localization is an important step in retinal image analysis especially for grading diabetic macular edema. This paper describes a method to automatically localize the fovea center in retinal fundus images. The method is mainly based on mathematical morphology along with the information of other anatomic structures such as blood vessel and optic disc. Initially, the vascular structure and optic disc center are extracted, and then the morphological operations are employed on the gray scale image of green channel for fovea candidates’ selection. The candidates’ satisfying area, density and distance criteria are considered for the final stage. In the final stage, the candidate having lesser vessel pixels was considered as fovea region. The proposed method was evaluated on the two publicly available DRIVE and STARE databases. The method was able to obtain 100% of fovea localization accuracy on DRIVE database with 2.88 seconds average computation time.

J.Benadict Raja

2014-10-01

 
 
 
 
121

Anatomically based approach for endovascular treatment of vertebro-vertebral arteriovenous fistula.  

Science.gov (United States)

Vertebro-vertebral arteriovenous fistula (VV-AVF) is a rare vascular disorder with an abnormal high-flow shunt between the extracranial vertebral artery (VA), its muscular or radicular branches and an adjacent vein. To date, there are no guidelines on the best treatment for VV-AVF. We present our experience of VV-AVF treatment with covered stents in three patients and detachable coils in two patients. One patient with fistula at the V3 segment had rapid fistula recurrence one week after covered stent treatment. The possible causes of failed treatment in this patient are discussed. The currently available treatment modalities for VV-AVF are also summarized after a literature review. At the end of this article, we propose a new concept of anatomically based approach for endovascular treatment of VV-AVF. Fistula in the V1-2 segments of vertebral artery could be treated safely and effectively by covered stent with the benefit of preserving VA patency. Embolization with variable embolizers should be considered first for fistula in the V3 segment because of the tortuous course and flexibility of the VA in this segment. PMID:25496689

Yeh, Chih-Hua; Chen, Yao-Liang; Wu, Yi-Ming; Huang, Yu-Chieh; Wong, Ho-Fai

2014-12-01

122

Anatomical bases for the radiological delineation of lymph node areas. Major collecting trunks, head and neck  

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 tumor location is an important information for treatment preparation and execution. This first part describes the major collecting trunks of the lymphatic system and then the lymphatics of the head and neck providing anatomical bases for the radiological delineation of lymph node areas in the cervical region, it adds to the existing nomenclature of six nodal levels (I-VI), three new areas listed as parotid, buccal and external jugular levels

123

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

Science.gov (United States)

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

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

2013-07-01

124

Anatomical considerations of high jugular bulb in lateral skull base surgery.  

Science.gov (United States)

In order to study high jugular bulb management in lateral skull base surgery, an anatomical study was conducted on 30 temporal bones by examining the relationship between the internal auditory canal (IAC) and the jugular bulb. The following parameters were measured: 1) Height of the jugular bulb (H)... distance between the level of jugular bulb dome and the line passing through the confluence of the sigmoid sinus with the jugular bulb (SS-JB), 2) Mastoid length (ML)... distance between the mastoid process and middle cranial fossa dura, 3) Distance between the most inferior part of the porus acousticus and jugular bulb dome (A), 4) Distance between the porus acousticus and SS-JB (B). The jugular bulb was defined as high when it occupied more than two thirds of (B). The incidence of a high jugular bulb was 23 per cent in this study. When the jugular bulb was high, the mean (H) and (A) were 9.4 +/- 1.9 mm and 2.7 +/- 0.5 mm, respectively. (H) was higher on the right side than on the left side. No statistically significant difference was found between small and large mastoids (t-test: p > 0.05). It was concluded that when a high jugular bulb was encountered during lateral skull base surgery, the jugular bulb position allows a very small working area inferior to the IAC. In these cases, a 3 or 4 mm depression of the jugular bulb is necessary in order to expose the lower cranial nerves. This can be accomplished by lowering the jugular bulb with the technique already described. PMID:9176613

Aslan, A; Falcioni, M; Russo, A; De Donato, G; Balyan, F R; Taibah, A; Sanna, M

1997-04-01

125

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

126

Geodesic atlas-based labeling of anatomical trees : Application and evaluation on airways extracted from CT  

DEFF Research Database (Denmark)

We present a fast and robust atlas-based algorithm for labeling airway trees, using geodesic distances in a geometric tree-space. Possible branch label configurations for an unlabeled airway tree are evaluated using distances to a training set of labeled airway trees. In tree-space, airway tree topology and geometry change continuously, giving a natural automatic handling of anatomical differences and noise. A hierarchical approach makes the algorithm efficient, assigning labels from the trachea and downwards. Only the airway centerline tree is used, which is relatively unaffected by pathology. The algorithm is evaluated on 80 segmented airway trees from 40 subjects at two time points, labeled by 3 medical experts each, testing accuracy, reproducibility and robustness in patients with Chronic Obstructive Pulmonary Disease (COPD). The accuracy of the algorithm is statistically similar to that of the experts and not significantly correlated with COPD severity. The reproducibility of the algorithm is significantly better than that of the experts, and negatively correlated with COPD severity. Evaluation of the algorithm on a longitudinal set of 8724 trees from a lung cancer screening trial shows that the algorithm can be used in large scale studies with high reproducibility, and that the negative correlation of reproducibility with COPD severity can be explained by missing branches, for instance due to segmentation problems in COPD patients. We conclude that the algorithm is robust to COPD severity given equally complete airway trees, and comparable in performance to that of experts in pulmonary medicine, emphasizing the suitability of the labeling algorithm for clinical use.

Feragen, Aasa; Petersen, Jens

2014-01-01

127

Functional-anatomical validation and individual variation of diffusion tractography-based segmentation of the human thalamus.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Parcellation of the human thalamus based on cortical connectivity information inferred from non-invasive diffusion-weighted images identifies sub-regions that we have proposed correspond to nuclei. Here we test the functional and anatomical validity of this proposal by comparing data from diffusion tractography, cytoarchitecture and functional imaging. We acquired diffusion imaging data in eleven healthy subjects and performed probabilistic tractography from voxels within the thalamus. Cortic...

Johansen-berg, H.; Behrens, Te; Sillery, E.; Ciccarelli, O.; Thompson, Aj; Smith, Sm; Matthews, Pm

2005-01-01

128

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.

2006-12-01

129

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

130

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

Science.gov (United States)

Southern blot hybridizations of genomic DNA were introduced as a relatively simple fossil-DNA-based approach to classify remains of Neanderthals. When hybridized with genomic DNA of either human or Neanderthal origin, DNA extracted from two Neanderthal finds-the Os parietale, from Warendorf-Neuwarendorf, Germany, and a clavicula, from Krapina, Croatia-was shown to yield hybridization signals that differ by at least a factor of two compared to the signals obtained with the use of fossil DNA of an early Homo sapiens from the Vogelherd cave (Stetten I), Germany. When labeled chimpanzee DNA was used as a probe, Neanderthal and human DNA, however, revealed hybridization signals of similar intensity. Thus, the genome of Neanderthals is expected to differ significantly from the genome of anatomically modern man, because of the contrasting composition of repetitive DNA. These data support the hypothesis that Neanderthals were not ancestors of anatomically modern man. PMID:10788336

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

2000-06-01

131

Anatomical study of perforator arteries in the distally based radial forearm fasciosubcutaneous flap.  

Science.gov (United States)

We investigated the anatomical vascular basis of the forearm fasciosubcutaneous flap (FSC-F), fed by the distal perforator arteries of the fascia. This type of flap was proposed, in hand reconstructive surgery, to avoid the disadvantages caused by axial-pattern reverse radial forearm fasciocutaneous flap, based on ligation and rotation of the radial artery (RA). In eight fresh cadaveric forearms, the RA was injected slowly with acrylic resin and the superficial flexor compartment was dissected. Then the FSC-F was raised from the lateral margins of the sample to the median RA axis, and the collaterals of the RA (number, interval of origin, and caliber) were evaluated. The fascial branches of RA (mean number +/- SD: 20 +/- 3) originated mainly from the radial and ulnar sides of the RA. In the distal forearm the vessels were more numerous (mean value = 11.3 vs. 8.9; Student's t-test, P perforator arteries forked in a T-shape following the main axis of the forearm and anastomosed in the fascial plane, forming longitudinal fan-shaped arterial chains giving rise to the vascular epifascial network. Histological (hematoxylin-eosin, azan-Mallory, Weigert) and immunohistochemical (anti-von Willebrand factor) study of the FSC-F at different levels of sampling was also carried out. The epifascial branches of distal sections were smaller in diameter (78.3 +/- 35.5 microm) than those of intermediate (105.7 +/- 28.7 microm; Newman-Keuls test, P perforator arteries and epifascial branches are smaller in the distal forearm, so that during surgical dissection, the safety distance from the radial styloid should take into account that also in the presence of a sufficient number of vessels in the distal forearm their caliber could be inadequate to the hemodynamic request of the flap. Thus, rather than on a theoretic distance from the radial styloid, the length of the flap should be based on an accurate evaluation of the individual vascularization of the forearm case by case. PMID:15495170

Tiengo, Cesare; Macchi, Veronica; Porzionato, Andrea; Bassetto, Francesco; Mazzoleni, Franco; De Caro, Raffaele

2004-11-01

132

Dynamic prediction by landmarking in competing risks.  

Science.gov (United States)

We propose an extension of the landmark model for ordinary survival data as a new approach to the problem of dynamic prediction in competing risks with time-dependent covariates. We fix a set of landmark time points tLM within the follow-up interval. For each of these landmark time points tLM , we create a landmark data set by selecting individuals at risk at tLM ; we fix the value of the time-dependent covariate in each landmark data set at tLM . We assume Cox proportional hazard models for the cause-specific hazards and consider smoothing the (possibly) time-dependent effect of the covariate for the different landmark data sets. Fitting this model is possible within the standard statistical software. We illustrate the features of the landmark modelling on a real data set on bone marrow transplantation. PMID:23086627

Nicolaie, M A; van Houwelingen, J C; de Witte, T M; Putter, H

2013-05-30

133

Evaluation of contrast reproduction method based on the anatomical guidance of the cerebral images reconstruction in positron emission tomography  

International Nuclear Information System (INIS)

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)

134

Anatomically based computational models of the male and female pelvic floor and anal canal.  

Science.gov (United States)

The understanding of the pelvic floor and anal canal, in the study of incontinence, has been limited by the inability to integrate both anatomy and physiology into a unified bioengineering model. However, this integration has been achieved in the study of other organs in the body, most notably the heart. In this study we construct three-dimensional anatomically realistic models of both the male and female pelvic floor and anal canal regions using similar techniques to those used in cardiac modelling. Anatomical data from the Visible Human Project was used to provide the anatomical positioning of each model component within the region of interest. A C1 continuous cubic Hermite finite element mesh was then created using an iterative linear fitting procedure (Root Mean Square (RMS) error of fit pelvic floor, and the abnormalities associated with the defecation disorders fecal incontinence and obstructed defecation, thereby providing a tool to further the education of clinicians, patients, and students and enabling virtual planning of corrective surgery. PMID:17945803

Noakes, K F; Bissett, I P; Pullan, A J; Cheng, L K

2006-01-01

135

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

136

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

137

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

138

The Mandibular Landmarks about the Facial Artery and Vein with Multidetector Computed Tomography Angiography (MDCTA): an Anatomical and Radiological Morphometric Study Puntos de Referencia de la Mandíbula Relacionados a la Arteria y Vena Facial con Angiografía por Tomografía Computarizada Multidetector (ATCM): un Estudio Morfométrico Anatómico y Radiológico  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of this study was to investigate the course of the facial vessels according to several mandibular landmarks in living individuals using multidetector computed tomography angiography (MDCTA) to determine these related to sex and side. This study was conducted in the Radiology Department, Meram Faculty of Medicine, Necmettin Erbakan University (Konya, Turkey). In total, sixty faces from 30 specimens (15 males and 15 females) with symptoms and signs of vascular disease were evaluated for...

Aynur Emine Cicekcibasi; Mehmet Tugrul Yilmaz; Demet Kiresi; Muzaffer Seker

2012-01-01

139

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

Science.gov (United States)

Modern methods allow a geometric representation of forms, separating size and shape. In entomology, as well as in many other fields involving arthropod studies, shape variation has proved useful for species identification and population characterization. In medical entomology, it has been applied to very specific questions such as population structure, reinfestation of insecticide-treated areas and cryptic species recognition. For shape comparisons, great importance is given to the quality of landmarks in terms of comparability. Two conceptually and statistically separate approaches are: (i) landmark-based morphometrics, based on the relative position of a few anatomical "true" or "traditional" landmarks, and (ii) outline-based morphometrics, which captures the contour of forms through a sequence of close "pseudo-landmarks". Most of the studies on insects of medical, veterinary or economic importance make use of the landmark approach. The present survey makes a case for the outline method, here based on elliptic Fourier analysis. The collection of pseudo-landmarks may require the manual digitization of many points and, for this reason, might appear less attractive. It, however, has the ability to compare homologous organs or structures having no landmarks at all. This strength offers the possibility to study a wider range of anatomical structures and thus, a larger range of arthropods. We present a few examples highlighting its interest for separating close or cryptic species, or characterizing conspecific geographic populations, in a series of different vector organisms. In this simple application, i.e. the recognition of close or cryptic forms, the outline approach provided similar scores as those obtained by the landmark-based approach. PMID:25111609

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

2014-12-01

140

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

Scientific Electronic Library Online (English)

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

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

2012-02-01

 
 
 
 
141

Anatomic-Based Three-Dimensional Planning Precludes Use of Catheter-Delivered Contrast for Treatment of Prostate Cancer  

International Nuclear Information System (INIS)

Purpose: Retrograde urethrography is a standard method to identify the prostatic apex during planning for prostate cancer radiotherapy. This is an invasive and uncomfortable procedure. With modern three-dimensional computed tomography planning, we explored whether retrograde urethrography was still necessary to accurately identify the prostatic apex. Methods and Materials: Fifteen patients underwent computed tomography simulation with and without bladder, urethral, and rectal contrast. The prostatic base and apex were identified on both scans, using contrast and anatomy, respectively. The anatomic location of the prostatic apex as defined by these methods was confirmed in another 57 patients with postbrachytherapy imaging. Results: The prostatic base and apex were within a mean of 3.8 mm between the two scans. In every case, the beak of the retrograde urethrogram abutted the line drawn parallel to, and bisecting, the pubic bone on the lateral films. With these anatomic relationships defined, in the postbrachytherapy patients, the distance from the prostatic apex to the point at which the urethra traversed the pelvic floor was an average of 11.7 mm. On lateral films, we found that the urethra exited the pelvis an average of 16.6 mm below the posterior-most fusion of the pubic symphysis. On axial images, this occurred at a mean separation of the ischia of about 25 mm. Conclusion: With a knowledge of the anatomic relationships and modern three-dimensional computed tomogrd modern three-dimensional computed tomography planning equipment, the prostatic apex can be easily and consistently identified, obviating the need to subject patients to retrograde urethrography

142

Landmark navigation rule, a new navigation device.  

Science.gov (United States)

Two new methods of landmark navigation were recently presented. The landmarks are assumed to be within sight of the navigator but with unknown positions. Both methods require computations which are time consuming when a computer is not available. This correspondence presents the concept of a new navigation device called 'landmark navigation rule' which eliminates all the computation effort required in both new methods. The device is simple in construction, lightweight, and consumes no power.

Hung, J. C.; Bennett, J. E.

1972-01-01

143

Radiobiological model-based bio-anatomical quality assurance in intensity-modulated radiation therapy for prostate cancer  

International Nuclear Information System (INIS)

A bio-anatomical quality assurance (QA) method employing tumor control probability (TCP) and normal tissue complication probability (NTCP) is described that can integrate radiobiological effects into intensity-modulated radiation therapy (IMRT). We evaluated the variations in the radiobiological effects caused by random errors (r-errors) and systematic errors (s-errors) by evaluating TCP and NTCP in two groups: patients with an intact prostate (Gintact) and those who have undergone prostatectomy (Gtectomy). The r-errors were generated using an isocenter shift of ±1 mm to simulate a misaligned patient set-up. The s-errors were generated using individual leaves that were displaced inwardly and outwardly by 1 mm on multileaf collimator field files. Subvolume-based TCP and NTCP were visualized on computed tomography (CT) images to determine the radiobiological effects on the principal structures. The bio-anatomical QA using the TCP and NTCP maps differentiated the critical radiobiological effects on specific volumes, particularly at the anterior rectal walls and planning target volumes. The s-errors showed a TCP variation of -40-25% in Gtectomy and -30-10% in Gintact, while the r-errors were less than 1.5% in both groups. The r-errors for the rectum and bladder showed higher NTCP variations at ±20% and ±10%, respectively, and the s-errors were greater than ±65% for both. This bio-anatomical method, as a patient-specific IMRTcal method, as a patient-specific IMRT QA, can provide distinct indications of clinically significant radiobiological effects beyond the minimization of probable physical dose errors in phantoms. (author)

144

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

International Nuclear Information System (INIS)

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

145

Interoperator test for anatomical annotation of earprints.  

Science.gov (United States)

As part of the Forensic Ear Identification (FearID) research project, which aims to obtain estimators for the strength of evidence of earmarks found on crime scenes, a large database of earprints (over 1200 donors) has been collected. Starting from a knowledge-based approach where experts add anatomical annotations of minutiae and landmarks present in prints, comparison of pairs of prints is done using the method of Vector Template Matching (VTM). As the annotation process is subjective, a validation experiment was performed to study its stability. Comparing prints on the basis of VTM, it appears that there are interoperator effects, individual operators yielding significantly more consistent results when annotating prints than different operators. The operators being well trained and educated, the observed variation on both clicking frequency and choice of annotation points suggests that implementation of the above is not the best way to go about objectifying earprint comparison. Processes like the above are relevant for any forensic science dealing with identification (e.g., of glass, tool marks, fibers, faces, fingers, handwriting, speakers) where manual (nonautomated) processes play a role. In these cases, results may be operator dependent and the dependencies need to be studied. PMID:17199610

Alberink, Ivo B; Ruifrok, Arnout C C; Kieckhoefer, Hartmut

2006-11-01

146

MEG source reconstruction based on identification of directed source interactions on whole-brain anatomical networks.  

Science.gov (United States)

We present an MEG source reconstruction method that simultaneously reconstructs source amplitudes and identifies source interactions across the whole brain. In the proposed method, a full multivariate autoregressive (MAR) model formulates directed interactions (i.e., effective connectivity) between sources. The MAR coefficients (the entries of the MAR matrix) are constrained by the prior knowledge of whole-brain anatomical networks inferred from diffusion MRI. Moreover, to increase the accuracy and robustness of our method, we apply an fMRI prior on the spatial activity patterns and a sparse prior on the MAR coefficients. The observation process of MEG data, the source dynamics, and a series of the priors are combined into a Bayesian framework using a state-space representation. The parameters, such as the source amplitudes and the MAR coefficients, are jointly estimated from a variational Bayesian learning algorithm. By formulating the source dynamics in the context of MEG source reconstruction, and unifying the estimations of source amplitudes and interactions, we can identify the effective connectivity without requiring the selection of regions of interest. Our method is quantitatively and qualitatively evaluated on simulated and experimental data, respectively. Compared with non-dynamic methods, in which the interactions are estimated after source reconstruction with no dynamic constraints, the proposed dynamic method improves most of the performance measures in simulations, and provides better physiological interpretation and inter-subject consistency in real data applications. PMID:25290887

Fukushima, Makoto; Yamashita, Okito; Knösche, Thomas R; Sato, Masa-Aki

2015-01-15

147

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

Directory of Open Access Journals (Sweden)

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

148

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

Directory of Open Access Journals (Sweden)

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

149

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 fthe 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)

150

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

Energy Technology Data Exchange (ETDEWEB)

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)

Tinniswood, A.D.; Furse, C.M.; Gandhi, O.P. [Department of Electrical Engineering, University of Utah, Salt Lake City, UT 84112 (United States)

1998-08-01

151

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

Science.gov (United States)

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. PMID:9725610

Tinniswood, A D; Furse, C M; Gandhi, O P

1998-08-01

152

Quantification of accuracy of the automated nonlinear image matching and anatomical labeling (ANIMAL) nonlinear registration algorithm for 4D CT images of lung.  

Science.gov (United States)

The performance of the ANIMAL (Automated Nonlinear Image Matching and Anatomical Labeling) nonlinear registration algorithm for registration of thoracic 4D CT images was investigated. The algorithm was modified to minimize the incidence of deformation vector discontinuities that occur during the registration of lung images. Registrations were performed between the inhale and exhale phases for five patients. The registration accuracy was quantified by the cross-correlation of transformed and target images and distance to agreement (DTA) measured based on anatomical landmarks and triangulated surfaces constructed from manual contours. On average, the vector DTA between transformed and target landmarks was 1.6 mm. Comparing transformed and target 3D triangulated surfaces derived from planning contours, the average target volume (GTV) center-of-mass shift was 2.0 mm and the 3D DTA was 1.6 mm. An average DTA of 1.8 mm was obtained for all planning structures. All DTA metrics were comparable to inter observer uncertainties established for landmark identification and manual contouring. PMID:18072506

Heath, E; Collins, D L; Keall, P J; Dong, L; Seuntjens, J

2007-11-01

153

Quantification of accuracy of the automated nonlinear image matching and anatomical labeling (ANIMAL) nonlinear registration algorithm for 4D CT images of lung  

International Nuclear Information System (INIS)

The performance of the ANIMAL (Automated Nonlinear Image Matching and Anatomical Labeling) nonlinear registration algorithm for registration of thoracic 4D CT images was investigated. The algorithm was modified to minimize the incidence of deformation vector discontinuities that occur during the registration of lung images. Registrations were performed between the inhale and exhale phases for five patients. The registration accuracy was quantified by the cross-correlation of transformed and target images and distance to agreement (DTA) measured based on anatomical landmarks and triangulated surfaces constructed from manual contours. On average, the vector DTA between transformed and target landmarks was 1.6 mm. Comparing transformed and target 3D triangulated surfaces derived from planning contours, the average target volume (GTV) center-of-mass shift was 2.0 mm and the 3D DTA was 1.6 mm. An average DTA of 1.8 mm was obtained for all planning structures. All DTA metrics were comparable to inter observer uncertainties established for landmark identification and manual contouring

154

Teaching and work productivity: recovering landmarks founders  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, we aim to make a rescue of some historical landmarks founders productivity at work and in education to better understand the logic legitimizes reaching the core of the teaching activity. The advance of the criteria on the productive worker training has its first expressions in the 1940s, even during the dictatorship of the Estado Novo. Firstly, we make a brief presentation of the concept of productivity; after that, some of its founders landmarks in the history of the country are shown, and, lastly, there is a presentation of the particularity of one of these landmarks: the presence of CBAI (Brazilian-American Commission of Industrial Education .

Maria Ciavatta

2013-09-01

155

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

156

Clinical correlates of the anatomical relationships of the foramen ovale: a radioanatomical study.  

Science.gov (United States)

Introduction Endonasal endoscopic transpterygoid approaches are commonly used techniques to access the infratemporal fossa and parapharyngeal space. Important endoscopic endonasal landmarks for the poststyloid parapharyngeal space, hence the internal carotid artery, include the mandibular nerve at the level of foramen ovale and the lateral pterygoid plate. This study aims to define the anatomical relationships of the foramen ovale, establishing its distance to other important anatomical landmarks such as the pterygoid process and columella. Methods Distances between the foramen ovale, foramen rotundum, and fixed anatomical landmarks like the columella and pterygoid process were measured using computed tomography (CT) scans and cadaveric dissections of the pterygopalatine and infratemporal fossae. Results The mean distances from the foramen ovale to columella and from the foramen rotundum to columella were found to be 9.15 cm and 7.09 cm, respectively. Analysis of radiologic measurements detected no statistically significant differences between sides or gender. Conclusions The pterygoid plates and V3 are prominent landmarks of the endonasal endoscopic approach to the infratemporal fossa and poststyloid parapharyngeal space. A better understanding of the endoscopic anatomy of the infratemporal fossa and awareness of the approximate distances and geometry among anatomical landmarks facilitates a safe and complete resection of lesions arising or extending to these regions. PMID:25452902

Youssef, Ahmed; Carrau, Ricardo L; Tantawy, Ahmed; Ibrahim, Ahmed Ali; Prevedello, Daniel M; Otto, Bradley A; Solares, Arturo C; Ditzel Filho, Leo F S; Rompaey, Jason

2014-12-01

157

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.

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

2003-06-01

158

The periodization of wheat embryogenesis on the base of anatomical, morphological and time criterions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The periodization of wheat embryogenesis on the base of anatomy-morphological and temporal criterions has been proposed. The stages of non-differentiated embryo, embryo differentiation and differentiated embryo were described.

Kruglova, Natalia N.

2013-01-01

159

Design Guidelines for Landmarks to Support Navigation in Virtual Environments  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Unfamiliar, large-scale virtual environments are difficult to navigate. This paper presents design guidelines to ease navigation in such virtual environments. The guidelines presented here focus on the design and placement of landmarks in virtual environments. Moreover, the guidelines are based primarily on the extensive empirical literature on navigation in the real world. A rationale for this approach is provided by the similarities between navigational behavior in real an...

Vinson, Norman G.

2003-01-01

160

Three-dimensional segmentation of anatomical structures in MR images on large data bases.  

Science.gov (United States)

In this paper an image-based method founded on mathematical morphology is presented in order to facilitate the segmentation of cerebral structures over large data bases of 3D magnetic resonance images (MRIs). The segmentation is described as an immersion simulation, applied to the modified gradient image, modeled by a generated 3D-region adjacency graph (RAG). The segmentation relies on two main processes: homotopy modification and contour decision. The first one is achieved by a marker extraction stage where homogeneous 3D-regions are identified. This stage uses contrasted regions from morphological reconstruction and labeled flat regions constrained by the RAG. Then, the decision stage intends to precisely locate the contours of regions detected by the marker extraction. This decision is performed by a 3D extension of the watershed transform. The method has been applied on a data base of 3D brain MRIs composed of fifty patients. Results are illustrated by segmenting the ventricles, corpus callosum, cerebellum, hippocampus, pons, medulla and midbrain on our data base and the approach is validated on two phantom 3D MRIs. PMID:11295349

Bueno, G; Musse, O; Heitz, F; Armspach, J P

2001-01-01

 
 
 
 
161

Quality-Aware Estimation of Facial Landmarks in Video Sequences  

DEFF Research Database (Denmark)

Face alignment in video is a primitive step for facial image analysis. The accuracy of the alignment greatly depends on the quality of the face image in the video frames and low quality faces are proven to cause erroneous alignment. Thus, this paper proposes a system for quality aware face alignment by using a Supervised Decent Method (SDM) along with a motion based forward extrapolation method. The proposed system first extracts faces from video frames. Then, it employs a face quality assessment technique to measure the face quality. If the face quality is high, the proposed system uses SDM for facial landmark detection. If the face quality is low the proposed system corrects the facial landmarks that are detected by SDM. Depending upon the face velocity in consecutive video frames and face quality measure, two algorithms are proposed for correction of landmarks in low quality faces by using an extrapolation polynomial. Experimental results illustrate the competency of the proposed method while comparing with the state-of-theart methods including an SDM-based method (from CVPR-2013) and a very recent method (from CVPR-2014) that uses parallel cascade of linear regression (Par-CLR).

Haque, Mohammad Ahsanul; Nasrollahi, Kamal

2015-01-01

162

Hypothenar flap based on a cutaneous perforator branch of the ulnar artery: an anatomic study.  

Science.gov (United States)

This study describes a constant cutaneous perforator branch of the ulnar artery of the hand and a hypothenar arterial flap based on it. Eighteen amputated hands of 10 fresh cadavers were used for the study. Red latex was injected into the axillary arteries of nine specimens and radiopaque lead oxide-gelatin mixture into the remaining nine. Then, the cutaneous perforator branch of the ulnar artery was identified by marginal dissection and radiographed. The cutaneous perforator branch was found constantly in all 18 specimens and was named the "hypothenar perforator" (HP). On radiograph, a coordinate was set up with an origin (pisiform), a transverse x (through the pisiform and hamate of the carpal bones), and a proximal to distal y (through the pisiform and 4th interdigital web) axes. The HP was situated at 10.1 +/- 3.6 mm lateral to the pisiform (on the x axis) and 20.0 +/- 7.0 mm distal (on the y axis). A hypothenar flap based on the HP is suitable for covering small defects of the fingers, and the donor site can be closed primarily. PMID:15971163

Hwang, Kun; Han, Jin Yi; Chung, In Hyuk

2005-07-01

163

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2011-09-15

164

Safe and successful bone marrow biopsy: an anatomical and CT-based cadaver study.  

Science.gov (United States)

Bone marrow biopsy is generally a safe procedure. However, infrequently the procedure is associated with serious injuries that are attributed to inadvertent needle penetration of the iliac bone's inner cortex. An evidence-based approach to needle orientation during iliac crest biopsy does not exist. In our study, the posterior to anterior path of the bone marrow needle from the posterior superior iliac spine (PSIS) was studied in human cadavers in two orientations: (1) perpendicularly to the coronal plane (the perpendicular approach) and (2) laterally toward the ipsilateral anterior superior iliac spine (ASIS) (the lateral approach). The biopsy needle was deliberately advanced through the inner ilial cortex in both approaches. Dissections and imaging studies were done to identify the relationship of the penetrating needle to internal structures. Both approaches begin with a perpendicular puncture of the outer cortex at the PSIS. The perpendicular approach proceeds anteriorly whereas in the lateral approach the needle is reoriented toward the ipsilateral ASIS before advancing. The lateral approach caused less damage to neurovascular structures and avoided the sacroiliac joint compared to the perpendicular approach. This procedure is best done in the lateral decubitus position. Proper use of the lateral approach should obviate many of the complications reported in the literature. PMID:24942104

Konda, Bhavana; Pathak, Swati; Edwin, Inga; Mishall, Priti; Downie, Sherry A; Olson, Todd R; Reed, Louis J; Friedman, Ellen W

2014-10-01

165

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

Directory of Open Access Journals (Sweden)

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

166

The fifth metatarsal base: anatomic evaluation regarding fracture mechanism and treatment algorithms.  

Science.gov (United States)

Fractures occurring within the 1.5-cm proximal portion of the fifth metatarsal are commonly considered avulsion fractures. The exact mechanisms of such fractures are controversial. The present study focused on determining the likely mechanism of fracture according to the exact anatomy to allow for more successful treatment. The research sample included 10 frozen cadaveric specimens. The lateral band of the plantar fascia, peroneus brevis, and articular surface were identified and separated from their attachments, thereby splitting the fifth metatarsal base into zones A, B, and C. In zone A, the attachment of the plantar fascia was 6.6 ± 2.2 mm from the inferior aspect, 9.5 ± 2.9 mm from the proximal aspect, and 11.5 ± 0.9 mm from the lateral aspect. In zone B, the attachment of the peroneus brevis was 12.0 ± 2.2 mm from the inferior aspect, 10.2 ± 2.2 mm from the proximal aspect, and 11.5 ± 0.9 mm from the lateral aspect. Zone C was measured from the border of zone B and encompassed the articulation of the fifth metatarsal to the cuboid. We propose that fractures occurring in the most proximal end of the fifth metatarsal, zone A, are caused by a lateral band of plantar fascia and might be able to be treated conservatively by immobilization with weightbearing. We also propose that fractures occurring in zones B and C result from traumatic tension on peroneus brevis and might need to be treated with strict immobilization and non-weightbearing or open reduction internal fixation. PMID:25441854

DeVries, J George; Taefi, Erfan; Bussewitz, Bradly W; Hyer, Christopher F; Lee, Thomas H

2015-01-01

167

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

Science.gov (United States)

This paper presents the algorithm, Locally Linear Diffeomorphic Metric Embedding (LLDME), for constructing efficient and compact representations of surface-based brain shapes whose variations are characterized using Large Deformation Diffeomorphic Metric Mapping (LDDMM). Our hypothesis is that the shape variations in the infinite-dimensional diffeomorphic metric space can be captured by a low-dimensional space. To do so, traditional Locally Linear Embedding (LLE) that reconstructs a data point from its neighbors in Euclidean space is extended to LLDME that requires interpolating a shape from its neighbors in the infinite-dimensional diffeomorphic metric space. This is made possible through the conservation law of momentum derived from LDDMM. It indicates that initial momentum, a linear transformation of the initial velocity of diffeomorphic flows, at a fixed template shape determines the geodesic connecting the template to a subject's shape in the diffeomorphic metric space and becomes the shape signature of an individual subject. This leads to the compact linear representation of the nonlinear diffeomorphisms in terms of the initial momentum. Since the initial momentum is in a linear space, a shape can be approximated by a linear combination of its neighbors in the diffeomorphic metric space. In addition, we provide efficient computations for the metric distance between two shapes through the first order approximation of the geodesic using the initial momentum as well as for the reconstruction of a shape given its low-dimensional Euclidean coordinates using the geodesic shooting with the initial momentum as the initial condition. Experiments are performed on the hippocampal shapes of 302 normal subjects across the whole life span (18-94years). Compared with Principal Component Analysis and ISOMAP, LLDME provides the most compact and efficient representation of the age-related hippocampal shapes. Even though the hippocampal volumes among young adults are as variable as those in older adults, LLDME disentangles the hippocampal local shape variation from the hippocampal size and thus reveals the nonlinear relationship of the hippocampal morphometry with age. PMID:21281721

Yang, Xianfeng; Goh, Alvina; Qiu, Anqi

2011-05-01

168

Anatomic Total Shoulder System  

Medline Plus

Full Text Available ... off the humeral osteophyte so that we can identify the anatomic neck. And I think it's important ... BOARDMAN III, MD: What makes one patient a candidate for an anatomic versus a reverse arthroplasty? 00: ...

169

Anatomic Total Shoulder System  

Medline Plus

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

170

Anatomic Total Shoulder System  

Medline Plus

Full Text Available ... anatomic neck, and so the best place to define the anatomic neck is here in this anterior ... prominent piece of bone and really rip -- either fracture a glenoid or pop the reamer out of ...

171

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english There is a wide range of values reported in volumetric studies of the amygdala. The use of single plane thick magnetic resonance imaging (MRI) may prevent the correct visualization of anatomic landmarks and yield imprecise results. To assess whether there is a difference between volumetric analysis [...] of the amygdala performed with single plane MRI 3-mm slices and with multiplanar analysis of MRI 1-mm slices, we studied healthy subjects and patients with temporal lobe epilepsy. We performed manual delineation of the amygdala on T1-weighted inversion recovery, 3-mm coronal slices and manual delineation of the amygdala on three-dimensional volumetric T1-weighted images with 1-mm slice thickness. The data were compared using a dependent t-test. There was a significant difference between the volumes obtained by the coronal plane-based measurements and the volumes obtained by three-dimensional analysis (P

L., Bonilha; E., Kobayashi; F., Cendes; L.M., Li.

2005-03-01

172

The Mandibular Landmarks about the Facial Artery and Vein with Multidetector Computed Tomography Angiography (MDCTA: an Anatomical and Radiological Morphometric Study Puntos de Referencia de la Mandíbula Relacionados a la Arteria y Vena Facial con Angiografía por Tomografía Computarizada Multidetector (ATCM: un Estudio Morfométrico Anatómico y Radiológico  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this study was to investigate the course of the facial vessels according to several mandibular landmarks in living individuals using multidetector computed tomography angiography (MDCTA to determine these related to sex and side. This study was conducted in the Radiology Department, Meram Faculty of Medicine, Necmettin Erbakan University (Konya, Turkey. In total, sixty faces from 30 specimens (15 males and 15 females with symptoms and signs of vascular disease were evaluated for the facial vessels by MDCTA scan. The facial vessel parameters were measured according to the reference points (mandibular angle, mental protuberance, mental foramen and facial midline. The distance from the point at which the facial artery first appears in the lower margin of the mandible to the mandibular angle for right and left facial artery were observed as 3.53±0.66 cm and 3.31±0.73 cm in males, respectively. These distances were determined as 2.91±0.52 cm and 3.35±0.48 cm in females. MDCTA is a new, powerful, safe and noninvasive test to demonstrate the vasculature of the head. Bony structures and neighboring vessel morphology can be evaluated by this technique in cases of trauma with suspected vessel injuries and when considering patient selection for flap surgery.El objetivo de este estudio fue investigar el curso de los vasos faciales de acuerdo con varios puntos de referencias mandibulares en sujetos vivos mediante angiografía por tomografía computarizada multidetector (ATCM para determinar si éstos están relacionados con el sexo y el lado. El estudio se llevó a cabo en el Departamento de Radiología, Facultad de Medicina de Meram en Necmettin Erbakan (Konya, Turkey. En total, sesenta caras de 30 sujetos (15 hombres y 15 mujeres, que presentaban síntomas y signos de la enfermedad vascular fueron evaluados para explorar los vasos faciales por ATCM. Los parámetros sobre los vasos faciales se midieron en relación a puntos de referencia (ángulo de la mandíbula, proceso mental, foramen mental y línea mediana facial. La distancia desde el punto en el que la arteria facial aparece por primera vez en el margen inferior de la mandíbula hasta el ángulo mandibular de la arteria facial derecha y izquierda fueron 3,53±0,66 cm y 3,31±0,73 cm en hombres, respectivamente. En mujeres fueron 2,91±0,52 cm y 3,35± 0,48 cm. La ATCM es un examen nuevo, poderoso, seguro y no invasivo para demostrar la vascularización de la cabeza. Las estructuras óseas y la morfología de los vasos vecinos pueden ser evaluados por esta técnica en casos de trauma con sospecha de lesiones de los vasos y se puede considerar de selección en pacientes para realizar cirugías de colgajo.

Aynur Emine Cicekcibasi

2012-06-01

173

The Mandibular Landmarks about the Facial Artery and Vein with Multidetector Computed Tomography Angiography (MDCTA): an Anatomical and Radiological Morphometric Study / Puntos de Referencia de la Mandíbula Relacionados a la Arteria y Vena Facial con Angiografía por Tomografía Computarizada Multidetector (ATCM): un Estudio Morfométrico Anatómico y Radiológico  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish El objetivo de este estudio fue investigar el curso de los vasos faciales de acuerdo con varios puntos de referencias mandibulares en sujetos vivos mediante angiografía por tomografía computarizada multidetector (ATCM) para determinar si éstos están relacionados con el sexo y el lado. El estudio se [...] llevó a cabo en el Departamento de Radiología, Facultad de Medicina de Meram en Necmettin Erbakan (Konya, Turkey). En total, sesenta caras de 30 sujetos (15 hombres y 15 mujeres), que presentaban síntomas y signos de la enfermedad vascular fueron evaluados para explorar los vasos faciales por ATCM. Los parámetros sobre los vasos faciales se midieron en relación a puntos de referencia (ángulo de la mandíbula, proceso mental, foramen mental y línea mediana facial). La distancia desde el punto en el que la arteria facial aparece por primera vez en el margen inferior de la mandíbula hasta el ángulo mandibular de la arteria facial derecha y izquierda fueron 3,53±0,66 cm y 3,31±0,73 cm en hombres, respectivamente. En mujeres fueron 2,91±0,52 cm y 3,35± 0,48 cm. La ATCM es un examen nuevo, poderoso, seguro y no invasivo para demostrar la vascularización de la cabeza. Las estructuras óseas y la morfología de los vasos vecinos pueden ser evaluados por esta técnica en casos de trauma con sospecha de lesiones de los vasos y se puede considerar de selección en pacientes para realizar cirugías de colgajo. Abstract in english The aim of this study was to investigate the course of the facial vessels according to several mandibular landmarks in living individuals using multidetector computed tomography angiography (MDCTA) to determine these related to sex and side. This study was conducted in the Radiology Department, Mera [...] m Faculty of Medicine, Necmettin Erbakan University (Konya, Turkey). In total, sixty faces from 30 specimens (15 males and 15 females) with symptoms and signs of vascular disease were evaluated for the facial vessels by MDCTA scan. The facial vessel parameters were measured according to the reference points (mandibular angle, mental protuberance, mental foramen and facial midline). The distance from the point at which the facial artery first appears in the lower margin of the mandible to the mandibular angle for right and left facial artery were observed as 3.53±0.66 cm and 3.31±0.73 cm in males, respectively. These distances were determined as 2.91±0.52 cm and 3.35±0.48 cm in females. MDCTA is a new, powerful, safe and noninvasive test to demonstrate the vasculature of the head. Bony structures and neighboring vessel morphology can be evaluated by this technique in cases of trauma with suspected vessel injuries and when considering patient selection for flap surgery.

Aynur Emine, Cicekcibasi; Mehmet Tugrul, Yilmaz; Demet, Kiresi; Muzaffer, Seker.

2012-06-01

174

Landmark papers on photorefractive nonlinear optics  

CERN Document Server

This book, intended for students, researchers and engineers, is a collection of classic papers on photorefractive nonlinear optics. Included are landmark papers on fundamental photorefractive phenomena, two-wave mixing, four-wave mixing, phase conjugators and resonators, material growth and physics, and applications in image processing, optical storage and optical computing.

Yeh, Pochi

1995-01-01

175

Automated landmark-guided deformable image registration  

Science.gov (United States)

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

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

2015-01-01

176

Sparse decomposition and modeling of anatomical shape variation  

DEFF Research Database (Denmark)

Recent advances in statistics have spawned powerful methods for regression and data decomposition that promote sparsity, a property that facilitates interpretation of the results. Sparse models use a small subset of the available variables and may perform as well or better than their full counterparts if constructed carefully. In most medical applications, models are required to have both good statistical performance and a relevant clinical interpretation to be of value. Morphometry of the corpus callosum is one illustrative example. This paper presents a method for relating spatial features to clinical outcome data. A set of parsimonious variables is extracted using sparse principal component analysis, producing simple yet characteristic features. The relation of these variables with clinical data is then established using a regression model. The result may be visualized as patterns of anatomical variation related to clinical outcome. In the present application, landmark-based shape data of the corpus callosum is analyzed in relation to age, gender, and clinical tests of walking speed and verbal fluency. To put the data-driven sparse principal component method into perspective, we consider two alternative techniques, one where features are derived using a model-based wavelet approach, and one where the original variables are regressed directly on the outcome.

Sjöstrand, Karl; Rostrup, Egill

2007-01-01

177

Sparse Decomposition and Modeling of Anatomical Shape Variation  

DEFF Research Database (Denmark)

Recent advances in statistics have spawned powerful methods for regression and data decomposition that promote sparsity, a property that facilitates interpretation of the results. Sparse models use a small subset of the available variables and may perform as well or better than their full counterparts if constructed carefully. In most medical applications, models are required to have both good statistical performance and a relevant clinical interpretation to be of value. Morphometry of the corpus callosum is one illustrative example. This paper presents a method for relating spatial features to clinical outcome data. A set of parsimonious variables is extracted using sparse principal component analysis, producing simple yet characteristic features. The relation of these variables with clinical data is then established using a regression model. The result may be visualized as patterns of anatomical variation related to clinical outcome. In the present application, landmark-based shape data of the corpus callosum is analyzed in relation to age, gender, and clinical tests of walking speed and verbal fluency. To put the data-driven sparse principal component method into perspective, we consider two alternative techniques, one where features are derived using a model-based wavelet approach, and one where the original variables are regressed directly on the outcome.

Sjöstrand, Karl; Rostrup, Egill

2007-01-01

178

Landmark matching via large deformation diffeomorphisms.  

Science.gov (United States)

This paper describes the generation of large deformation diffeomorphisms phi:Omega=[0,1]3Omega for landmark matching generated as solutions to the transport equation dphi(x,t)/dt=nu(phi(x,t),t),epsilon[0,1] and phi(x,0)=x, with the image map defined as phi(.,1) and therefore controlled via the velocity field nu(.,t),epsilon[0,1]. Imagery are assumed characterized via sets of landmarks {xn, yn, n=1, 2, ..., N}. The optimal diffeomorphic match is constructed to minimize a running smoothness cost parallelLnu parallel2 associated with a linear differential operator L on the velocity field generating the diffeomorphism while simultaneously minimizing the matching end point condition of the landmarks. Both inexact and exact landmark matching is studied here. Given noisy landmarks xn matched to yn measured with error covariances Sigman, then the matching problem is solved generating the optimal diffeomorphism phi;(x,1)=integral0(1)nu(phi(x,t),t)dt+x where nu(.)=argmin(nu.)integral1(0) integralOmega parallelLnu(x,t) parallel2dxdt +Sigman=1N[yn-phi(xn,1)] TSigman(-1)[yn-phi(xn,1)]. Conditions for the existence of solutions in the space of diffeomorphisms are established, with a gradient algorithm provided for generating the optimal flow solving the minimum problem. Results on matching two-dimensional (2-D) and three-dimensional (3-D) imagery are presented in the macaque monkey. PMID:18262973

Joshi, S C; Miller, M I

2000-01-01

179

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 estimaue 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)

180

Dissemination of Prostate Adenocarcinoma to the Skull Base Mimicking Giant Trigeminal Schwannoma: Anatomic Relevance of the Extradural Neural Axis Component  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We report an unusual case of a large metastatic lesion from prostate adenocarcinoma with its epicenter located in Meckel's cave. The patient presented with acute neurological deterioration due to pontomesencephalic, cranial nerve, and temporal lobe compression. This lesion radiologically mimicked a giant trigeminal schwannoma. Complete surgical resection was achieved with improvement in the performance status of the patient. The anatomic relevance the extradural neural axis component in the p...

Gasco, Jaime; Kew, Yvonne; Livingston, Andrew; Rose, James; Zhang, Yi Jonathan

2009-01-01

 
 
 
 
181

4D measurement system for automatic location of anatomical structures  

Science.gov (United States)

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

Witkowski, Marcin; Sitnik, Robert; Kujawi?ska, Ma?gorzata; Rapp, Walter; Kowalski, Marcin; Haex, Bart; Mooshake, Sven

2006-04-01

182

Endoscopic telovelar approach to the fourth ventricle: anatomic study.  

Science.gov (United States)

The telovelar approach allows reliable access to the fourth ventricle and avoids the splitting of the vermis and its associated "posterior vermal split syndrome." Our objective was to describe the endoscopic topographical anatomy of the telovelum approach to the fourth ventricle as accessed by the cerebellomedullary corridor. A series of 20 fresh and fixed injected anatomical specimens were used. The endoscopic equipment consisted of rigid endoscopes with different lens angles, while the extradural step required the use of the microscope and/or the exoscope. All the anatomical landmarks and relationships within the fourth ventricle and the cerebellomedullary fissure were identified by means of the endoscopic microscope/exoscope-assisted telovelar approach. In conclusion, we showed that the endoscope is a valid tool to gain an anatomic understanding of the fourth ventricle reached by means of the telovelar approach. PMID:22170179

Di Ieva, Antonio; Komatsu, Mika; Komatsu, Fuminari; Tschabitscher, Manfred

2012-07-01

183

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

184

Iliohypogastric/ilioinguinal nerve block in inguinal hernia repair for postoperative pain management: comparison of the anatomical landmark and ultrasound guided techniques / Bloqueo de los nervios ileohipogástrico/ilioinguinal en corrección de hernia inguinal para el tratamiento del dolor en el postoperatorio: comparación entre la técnica de marcas anatómicas y la guiada por ultrasonido / Bloqueio dos nervos ílio-hipogástrico/ilioinguinal em correção de hérnia inguinal para tratamento da dor no pós-operatório: comparação entre a técnica de marcos anatômicos e a guiada por ultrassom  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Objetivo: Comparar a eficácia de bloqueios dos nervos ílio-hipogástrico/ilioinguinal feitos com a técnica guiada por ultrassom e a de marcos anatômicos para o manejo da dor no pós-operatório em casos de herniorrafia inguinal em adultos. Métodos: Foram randomicamente divididos 40 pacientes, estado f [...] ísico ASA I-II, em dois grupos iguais: nos grupos AN (técnica de marcos anatômicos) e US (técnica guiada por ultrassom), o bloqueio dos nervos ílio-hipogástrico/ilioinguinal foi feito com 20 mL de levobupivacaína a 0,5% antes da cirurgia com as técnicas especificadas. Escore de dor na avaliação pós-operatória, tempo de primeira mobilização, tempo de internação hospitalar, escore de satisfação com a analgesia no pós-operatório, efeitos colaterais induzidos por opiáceos e complicações relacionadas ao bloqueio foram avaliados durante 24 horas de pós-operatório. Resultados: Escores EVAem repouso na sala de recuperação e todos os valores clínicos durante o acompanhamento foram significativamente menores no grupo ultrassom (p Abstract in spanish Objetivo: El objetivo de este estudio fue comparar la eficacia de bloqueos de los nervios ileohipogástrico/ilioinguinal realizados con la técnica guiada por ultrasonido y la de marca anatómicas para el manejo del dolor en el postoperatorio en casos de herniorrafia inguinal en adultos. Métodos: 40 p [...] acientes, estado físico ASA I-II, fueron aleatoriamente divididos en 2 grupos iguales: grupos con técnica de marcas anatómicas) y grupo con técnica guiada por ultrasonido. El bloqueo de los nervios iliohipogástrico/ilioinguinal fue realizado con 20 mL de levobupivacaína al 0,5% antes de la cirugía con las técnicas especificadas. La puntuación de dolor en la evaluación postoperatoria, tiempo de primera movilización, tiempo de ingreso hospitalario, puntuación de satisfacción con la analgesia en el postoperatorio, efectos colaterales inducidos por opiáceos y complicaciones relacionadas con el bloqueo fueron evaluados durante 24 h de postoperatorio. Resultados: Las puntuaciones EVA en reposo en la sala de recuperación y todos los valores clínicos durante el seguimiento fueron significativamente menores en el grupo con técnica guiada por ultrasonido (p Abstract in english Objectives: The purpose of this study is to compare the efficacy of iliohypogastric/ilioinguinal nerve blocks performed with the ultrasound guided and the anatomical landmark techniques for postoperative pain management in cases of adult inguinal herniorrhaphy. Methods: 40 patients, ASA I-II status [...] were randomized into two groups equally: in Group AN (anatomical landmark technique) and in Group ultrasound (ultrasound guided technique), iliohypogastric/ilioinguinal nerve block was performed with 20 ml of 0.5% levobupivacaine prior to surgery with the specified techniques. Pain score in postoperative assessment, first mobilization time, duration of hospital stay, score of postoperative analgesia satisfaction, opioid induced side effects and complications related to block were assessed for 24 h postoperatively. Results: VAS scores at rest in the recovery room and all the clinical follow-up points were found significantly less in Group ultrasound (p

Abdurrahman, Demirci; Esra Mercanoglu, Efe; Gürkan, Türker; Alp, Gurbet; Fatma Nur, Kaya; Ali, Anil; & #304; lker, Çimen.

2014-09-01

185

Fluence-to-dose conversion coefficients from monoenergetic neutrons below 20 MeV based on the VIP-Man anatomical model  

International Nuclear Information System (INIS)

A new set of fluence-to-absorbed dose and fluence-to-effective dose conversion coefficients have been calculated for neutrons below 20 MeV using a whole-body anatomical model, VIP-Man, developed from the high-resolution transverse colour photographic images of the National Library of Medicine's Visible Human Project. Organ dose calculations were performed using the Monte Carlo code MCNP for 20 monoenergetic neutron beams between 1x10-9 MeV and 20 MeV under six different irradiation geometries: anterior-posterior, posterior-anterior, right lateral, left lateral, rotational and isotropic. The absorbed dose for 24 major organs and effective dose results based on the realistic VIP-Man are presented and compared with those based on the simplified MIRD-based phantoms reported in the literature. Effective doses from VIP-Man are not significantly different from earlier results for neutrons in the energy range studied. There are, however, remarkable deviations in organ doses due to the anatomical differences between the image-based and the earlier mathematical models. (author)

186

Description of two new Ecuadorian Zilchistrophia Weyrauch, 1960, with the clarification of the systematic position of the genus based on anatomical data (Gastropoda, Stylommatophora, Scolodontidae).  

Science.gov (United States)

Two new species of the genus Zilchistrophia Weyrauch, 1960 are described from Eastern Ecuadorian rain forest: Zilchistrophiahilaryae sp. n. and Zilchistrophiashiwiarorum sp. n. These two new species extend the distribution of the genus considerably northwards, because congeners have been reported from Peru only. For the first time we present anatomical data (radula, buccal mass, morphology of the foot and the genital structure) of Zilchistrophia species. According to these, the genus belongs to the family Scolodontidae, subfamily Scolodontinae (="Systrophiini"). The previously assumed systematic relationship of Zilchistrophia with the Asian Corillidae and Plectopylidae based on the similarly looking palatal plicae is not supported. PMID:25493057

Páll-Gergely, Barna; Asami, Takahiro

2014-01-01

187

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

188

3D BSM for face segmentation and landmarks detection  

Science.gov (United States)

An extension of Bayesian Shape Models (BSM) to 3D space is presented. The extension is based on the inclusion of shape information into the fitting functions. Shape information consists of 3D shape descriptors they are derived from curvature, and were selected by considering the relevance of the feature. We also introduce the use of functions to define the separation of face regions. In order to extract the features, the 3D BSM is deformed iteratively by looking for the vertices that best match the shape, by using a point model distribution obtained from train dataset. As result of the fitting process, a 3D face model oriented in frontal position and segmented in 48 regions is obtained, over this model 15 landmarks are extracted. The 3D BSM was trained with 150 3D face models from two different databases, and evaluated using a leave-one-out scheme. The model segmentation and the landmark location were compared against a ground truth segmentation and point location. From this comparison it is possible to affirm that the proposed system has an accuracy of approximately one millimeter, and the orientation of the models in frontal position has an average error of more or less 1.5 degrees.

Salazar, Augusto E.; Prieto, Flavio A.

2010-02-01

189

The use of radial symmetry to localize retinal landmarks.  

Science.gov (United States)

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

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

2013-01-01

190

The anatomical school of Padua.  

Science.gov (United States)

The University of Padua is one of the most ancient in the world, being founded in 1222, and the most important anatomists of the XVI, XVII, and XVIII centuries studied and taught here. Probably, the first professor of anatomy and surgery was Bruno da Longobucco (c. 1200-c. 1286), who had previously studied at the Salerno School of Medicine. While professor in Padua, Andreas Vesalius (1514-1564) published De Humani Corporis Fabrica (1543), which is considered as the birth of the modern anatomy. Following professors were Realdo Colombo (c. 1516-1559), Gabriel Fallopius (1523-1562), Hieronymus Fabricius ab Aquapendente (1533-1619), Iulius Casserius (1552-1616), Johann Wesling (1598-1649), and Johann Georg Wirsung (1589-1643). Many other foreign scholars studied in the University of Padua, such as Thomas Linacre (c. 1460-1524), the founder of the Royal College of Physicians, Werner Rolfinck (1599-1673), and Olof Rudbeck (1630-1702), who created anatomical theatres in Germany and Sweden, respectively, on the basis of the Paduan model. The anatomy of the XVII century characteristically widened the scope of its enquiry to function, as in the Exercitatio Anatomica De Motu Cordis et Sanguinis in Animalibus (1628) by William Harvey (1578-1657). Further evolution was then given by the anatomy in the XVIII century, which tried to correlate alterations of structure with clinical symptoms. The most important anatomist of this century is Giovanni Battista Morgagni (1682-1771), whose masterpiece De Sedibus et Causis Morborum per Anatomen Indagatis (1761) is a landmark contribution that is viewed as the beginning of modern pathologic anatomy. This year falls the 300th anniversary of Morgagni's inaugural lecture on medical education, Nova Institutionum Medicarum Idea (1712), which is still relevant in its effort to stress the importance of a deep knowledge of all the preclinical and clinical aspects of medical science. PMID:22581496

Porzionato, Andrea; Macchi, Veronica; Stecco, Carla; Parenti, Anna; De Caro, Raffaele

2012-06-01

191

Simulating Deformations of MR Brain Images for Validation of Atlas-based Segmentation and Registration Algorithms  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Simulated deformations and images can act as the gold standard for evaluating various template-based image segmentation and registration algorithms. Traditional deformable simulation methods, such as the use of analytic deformation fields or the displacement of landmarks followed by some form of interpolation, are often unable to construct rich (complex) and/or realistic deformations of anatomical organs. This paper presents new methods aiming to automatically simulate realistic inter- and in...

Xue, Zhong; Shen, Dinggang; Karacali, Bilge; Stern, Joshua; Rottenberg, David; Davatzikos, Christos

2006-01-01

192

Anatomic description of the middle meatus and classification of the hiatus semilunaris into five types based upon morphological characteristics.  

Science.gov (United States)

Anatomical variation of the lateral nasal wall, including the pathway from the frontal, ethmoidal, and maxillary sinuses may affect the communication between the paranasal sinuses and the nasal cavity. The middle meatus and hiatus semilunaris are areas where variations can occur which predispose patients to recurring sinusitis. Endoscopy allows for visualization of the entire nasal cavity, for both diagnostic and therapeutic uses. The purpose of this study was to provide an accurate characterization of the middle meatus and hiatus semilunaris for the purposes of endoscopic procedures. Ninety seven cadaveric lateral nasal walls were observed. The middle meatus was measured at three distinct points. Cranial length was also recorded. A 3D digitizer was used to record spatial relationships for the openings of the paranasal sinuses and the morphology of the hiatus semilunaris. The average widths for the middle meatus were 1.69-mm anteriorly, 2.83 mm at the transition angle, and 4.74-mm posteriorly. The posterior width was significantly larger than either of the two other measurements. The length of the hiatus semilunaris was found to be shorter on both left-sides and in females. The hiatus semilunaris was categorized into five types according to the varying morphologies. Given that the middle meatus was significantly wider posteriorly, our findings support the recommendation that entering the middle meatus posteriorly may allow an endoscopic surgeon easier access to the structures of the lateral nasal wall. Knowing the discrepancy of hiatus semilunaris lengths between right and left sides and males versus females may guide advancement of endoscopic instruments into the nasal cavity. Describing the five distinct types of the hiatus semilunaris allows the distinction of normal variation in this anatomic space versus pathologic condition. PMID:23836582

Dahlstrom, Kelly; Olinger, Anthony

2014-03-01

193

The orbits--anatomical features in view of innovative surgical methods.  

Science.gov (United States)

The aim of this article is to update on anatomical key elements of the orbits in reference to surgical innovations. This is a selective literature review supplemented with the personal experience of the authors, using illustrations and photographs of anatomical dissections. The seven osseous components of the orbit can be conceptualized into a simple geometrical layout of a four-sided pyramid with the anterior aditus as a base and the posterior cone as apex. All neurovascular structures pass through bony openings in the sphenoid bone before diversification in the mid and anterior orbit. A set of landmarks such as the optic and maxillary strut comes into new focus. Within the topographical surfaces of the internal orbit the lazy S-shaped floor and the posteromedial bulge are principal determinants for the ocular globe position. The inferomedial orbital strut represents a discernible sagittal buttress. The periorbita and orbital soft tissue contents--extraocular muscles, septae, neurovasculature--are detailed and put into context with periorbital dissection. PMID:25397705

Cornelius, Carl-Peter; Mayer, Peter; Ehrenfeld, Michael; Metzger, Marc Christian

2014-10-01

194

Longwall automation - an ACARP Landmark Project  

Energy Technology Data Exchange (ETDEWEB)

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

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

2002-07-01

195

Landmark experiments in twentieth-century physics  

CERN Document Server

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

Trigg, George L

2013-01-01

196

EXPLOITING 3D ULTRASOUND FOR FETAL DIAGNOSTIC PURPOSE THROUGH FACIAL LANDMARKING  

Directory of Open Access Journals (Sweden)

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

Enrico Vezzetti

2014-06-01

197

Computer-aided diagnostic scheme for the detection of lung nodules on chest radiographs: Localized search method based on anatomical classification  

International Nuclear Information System (INIS)

We developed an advanced computer-aided diagnostic (CAD) scheme for the detection of various types of lung nodules on chest radiographs intended for implementation in clinical situations. We used 924 digitized chest images (992 noncalcified nodules) which had a 500x500 matrix size with a 1024 gray scale. The images were divided randomly into two sets which were used for training and testing of the computerized scheme. In this scheme, the lung field was first segmented by use of a ribcage detection technique, and then a large search area (448x448 matrix size) within the chest image was automatically determined by taking into account the locations of a midline and a top edge of the segmented ribcage. In order to detect lung nodule candidates based on a localized search method, we divided the entire search area into 7x7 regions of interest (ROIs: 64x64 matrix size). In the next step, each ROI was classified anatomically into apical, peripheral, hilar, and diaphragm/heart regions by use of its image features. Identification of lung nodule candidates and extraction of image features were applied for each localized region (128x128 matrix size), each having its central part (64x64 matrix size) located at a position corresponding to a ROI that was classified anatomically in the previous step. Initial candidates were identified by use of the nodule-enhanced image obtained with the average radial-gradient filtering technique, in which the filter size was varied adaptively depenhe filter size was varied adaptively depending on the location and the anatomical classification of the ROI. We extracted 57 image features from the original and nodule-enhanced images based on geometric, gray-level, background structure, and edge-gradient features. In addition, 14 image features were obtained from the corresponding locations in the contralateral subtraction image. A total of 71 image features were employed for three sequential artificial neural networks (ANNs) in order to reduce the number of false-positive candidates. All parameters for ANNs, i.e., the number of iterations, slope of sigmoid functions, learning rate, and threshold values for removing the false positives, were determined automatically by use of a bootstrap technique with training cases. We employed four different combinations of training and test image data sets which was selected randomly from the 924 cases. By use of our localized search method based on anatomical classification, the average sensitivity was increased to 92.5% with 59.3 false positives per image at the level of initial detection for four different sets of test cases, whereas our previous technique achieved an 82.8% of sensitivity with 56.8 false positives per image. The computer performance in the final step obtained from four different data sets indicated that the average sensitivity in detecting lung nodules was 70.1% with 5.0 false positives per image for testing cases and 70.4% sensitivity with 4.2 false positives per image for training cases. The advanced CAD scheme involving the localized search method with anatomical classification provided improved detection of pulmonary nodules on chest radiographs for 924 lung nodule cases

198

Anatomic Total Shoulder System  

Medline Plus

Full Text Available ... the needles off. Now we're going to tie that one first, because that's going to anatomically ... Brent to hold that with a needle driver. Tie this off. And cut that. And I will ...

199

Anatomic Total Shoulder System  

Medline Plus

Full Text Available ... options with an arrange of neck, angle, and version variability which allows adaptability to a patient's unique ... we can put the glenoid component in neutral version and we'll put in an anatomic Global ...

200

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

Directory of Open Access Journals (Sweden)

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

Martin Egelhaaf

2014-09-01

 
 
 
 
201

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

Science.gov (United States)

Bees use visual memories to find the spatial location of previously learnt food sites. Characteristic learning flights help acquiring these memories at newly discovered foraging locations where landmarks-salient objects in the vicinity of the goal location-can play an important role in guiding the animal's homing behavior. Although behavioral experiments have shown that bees can use a variety of visual cues to distinguish objects as landmarks, the question of how landmark features are encoded by the visual system is still open. Recently, it could be shown that motion cues are sufficient to allow bees localizing their goal using landmarks that can hardly be discriminated from the background texture. Here, we tested the hypothesis that motion sensitive neurons in the bee's visual pathway provide information about such landmarks during a learning flight and might, thus, play a role for goal localization. We tracked learning flights of free-flying bumblebees (Bombus terrestris) in an arena with distinct visual landmarks, reconstructed the visual input during these flights, and replayed ego-perspective movies to tethered bumblebees while recording the activity of direction-selective wide-field neurons in their optic lobe. By comparing neuronal responses during a typical learning flight and targeted modifications of landmark properties in this movie we demonstrate that these objects are indeed represented in the bee's visual motion pathway. We find that object-induced responses vary little with object texture, which is in agreement with behavioral evidence. These neurons thus convey information about landmark properties that are useful for view-based homing. PMID:25309374

Mertes, Marcel; Dittmar, Laura; Egelhaaf, Martin; Boeddeker, Norbert

2014-01-01

202

A Multi-Atlas Based Method for Automated Anatomical Rat Brain MRI Segmentation and Extraction of PET Activity  

Science.gov (United States)

Introduction Preclinical in vivo imaging requires precise and reproducible delineation of brain structures. Manual segmentation is time consuming and operator dependent. Automated segmentation as usually performed via single atlas registration fails to account for anatomo-physiological variability. We present, evaluate, and make available a multi-atlas approach for automatically segmenting rat brain MRI and extracting PET activies. Methods High-resolution 7T 2DT2 MR images of 12 Sprague-Dawley rat brains were manually segmented into 27-VOI label volumes using detailed protocols. Automated methods were developed with 7/12 atlas datasets, i.e. the MRIs and their associated label volumes. MRIs were registered to a common space, where an MRI template and a maximum probability atlas were created. Three automated methods were tested: 1/registering individual MRIs to the template, and using a single atlas (SA), 2/using the maximum probability atlas (MP), and 3/registering the MRIs from the multi-atlas dataset to an individual MRI, propagating the label volumes and fusing them in individual MRI space (propagation & fusion, PF). Evaluation was performed on the five remaining rats which additionally underwent [18F]FDG PET. Automated and manual segmentations were compared for morphometric performance (assessed by comparing volume bias and Dice overlap index) and functional performance (evaluated by comparing extracted PET measures). Results Only the SA method showed volume bias. Dice indices were significantly different between methods (PF>MP>SA). PET regional measures were more accurate with multi-atlas methods than with SA method. Conclusions Multi-atlas methods outperform SA for automated anatomical brain segmentation and PET measure’s extraction. They perform comparably to manual segmentation for FDG-PET quantification. Multi-atlas methods are suitable for rapid reproducible VOI analyses. PMID:25330005

Lancelot, Sophie; Roche, Roxane; Slimen, Afifa; Bouillot, Caroline; Levigoureux, Elise; Langlois, Jean-Baptiste; Zimmer, Luc; Costes, Nicolas

2014-01-01

203

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

204

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

205

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

International Nuclear Information System (INIS)

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.

206

Evaluating the City Image: A Focus on Landmarks of Kuala Lumpur, Malaysia  

Directory of Open Access Journals (Sweden)

Full Text Available One of the main issues that have been considered about Kuala Lumpur city is its indistinguishable identity and image, partly due to the rapid development and expansion of the city structure over many decades. Inevitably, forming a distinctive city image is not an easy task as it depends primarily on the manner of reciprocal interactions between people and their surrounding built environment. This paper examines the relationship and interaction between people and the city structure, specifically through public evaluation of landmarks as one of the five elements of the city image. The people’s background and their evaluation of the landmarks’ features are examined in this study. To achieve this objective, both quantitative and qualitative data were collected using mixed-techniques involving a questionnaire survey of 120 respondents followed by an unstructured interview. The results show significant differences in the public evaluation of landmarks based on the respondents’ nationality and ethnicity. Differences in the evaluation are related to the landmark factors namely unique; memorable; legible; historic; design; scale; meaningful and color. Much effort by the local authorities is necessary to create a distinguishable image of Kuala Lumpur that reflects the city’s fusion of modern and traditional lifestyles, and diversified cultures and values.

Ahmed Raad Al Shams

2014-01-01

207

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2003-01-01

208

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

International Nuclear Information System (INIS)

To determine the relationship between sites of calcaneal plantar enthesophytes and surrounding fascial and soft tissue structures using routine radiography, MR imaging, and data derived from cadaveric and paleopathologic specimens.Design and patients. Two observers analyzed the MR imaging studies of 40 ankles in 38 patients (35 males, 3 females; mean age 48.3 years) with plantar calcaneal enthesophytes that were selected from all the ankle MR examinations performed during the past year. Data derived from these MR examinations were the following: the size of the enthesophyte; its location in relation to the plantar fascia (PF) and flexor muscles; and the thickness and signal of the PF. The corresponding radiographs of the ankles were evaluated at a different time by the same observers for the presence or absence of plantar enthesophytes and, when present, their measurements. A third observer reviewed all the discordant observations of MR imaging and radiographic examinations. Two observers analyzed 22 calcaneal specimens with plantar enthesophytes at an anthropology museum to determine the orientation of each plantar enthesophyte. MR imaging of a cadaveric foot with a plantar enthesophyte with subsequent sagittal sectioning was performed to provide further anatomic understanding.Results. With regard to MR imaging, the mean size of the plantar enthesophytes was 4.41 mm (SD 2.4). Twenty (50%) enthesophytes were located above the PF, 16 (40%) between the fascia and abductPF, 16 (40%) between the fascia and abductor digiti minimi, flexor digitorum brevis and abductor hallucis muscles, and only one (3%) was located within the PF. In three (8%) cases the location was not determined. The size of enthesophytes seen with MR imaging and radiographs was highly correlated (P0.8, kappa >0.9). Eleven of the 22 bone specimens had plantar enthesophytes oriented in the direction of the abductor digiti minimi and 11 oriented in the direction of the flexor digitorum brevis and PF. The cadaveric sections revealed different types of enthesophytes.Conclusions. Plantar calcaneal enthesophytes arise in five different locations: at the insertion sites of abductor digiti minimi and flexor digitorum brevis muscles; between the PF and these muscles; and, less frequently, within the PF and at the insertion site of the short plantar ligament. (orig.)

209

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

210

Pedro Ara anatomic museum.  

Science.gov (United States)

Museums where anatomical pieces are exhibited are disappearing. The advance of the computer together with the advance of conventional and three-dimensional radiology makes the organs to be exposed without practicing dissection and the virtual images replace the real ones in the educational process. Some current laws that restrict the use of corpses and fetuses for obituary and exhibition studies have also contributed to the tendency. The anatomical museum, today named Pedro Ara, was founded in December 1920 and it exhibits anatomic works from the embryonic stage to old age, contributing unbeatable teachings to the medical sciences and the general public. The museum is located in the Angel Roque Suarez Anatomic Institute in the Clinical National Hospital which depends on the National University of Cordoba. It is visited daily by hundreds of people from all over the world. The museum owns 1211 pieces that combine ethical, scientific, aesthetical and educational values achieving a realization that received international acknowledgement. The most valuable exhibited work is 'Old man's head' made by Professor Pedro Ara in 1928-1929 (Figure 1), which, owing to its high quality, is in an impeccable and unharmed condition despite being exhibited for 80 years. Other authors, such as Professor Humberto Fracassi, also enriched the museum with their work and we, convinced that it favors and will favor our human formation and professional training, have the privilege of being their heirs and the responsibility of being their followers. PMID:16551427

Montenegro, V A; Trefilio, D E; Borghino, V N; Páez, R E; Aranega, C I

2006-03-01

211

Anatomic Total Shoulder System  

Medline Plus

Full Text Available ... Anatomic Total Shoulder surgery, which featured the latest innovation in shoulder surgery from DePuy Orthopedics. OR-Live makes it easy for you to learn more. Just click on the "Request Information" button on your webcast screen and open the door to informed medical care. 01:21: ...

212

Anatomic Total Shoulder System  

Medline Plus

Full Text Available ... DePuy Orthopedics is continually advancing the standard of orthopedic patient care. In a few moments, you'll be ... Methodist Hospital in Philadelphia. A revolution in shoulder orthopedics, the ... to a patient's unique anatomical makeup. Dr. Gerald R. Williams, Jr., ...

213

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.

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

2012-12-01

214

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 Santiago 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.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 and 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.

Juan Pablo Sorolla P

2012-12-01

215

Landmark-driven parameter optimization for non-linear image registration  

Science.gov (United States)

Image registration is one of the most common research areas in medical image processing. It is required for example for image fusion, motion estimation, patient positioning, or generation of medical atlases. In most intensity-based registration approaches, parameters have to be determined, most commonly a parameter indicating to which extend the transformation is required to be smooth. Its optimal value depends on multiple factors like the application and the occurrence of noise in the images, and may therefore vary from case to case. Moreover, multi-scale approaches are commonly applied on registration problems and demand for further adjustment of the parameters. In this paper, we present a landmark-based approach for automatic parameter optimization in non-linear intensity-based image registration. In a first step, corresponding landmarks are automatically detected in the images to match. The landmark-based target registration error (TRE), which is shown to be a valid metric for quantifying registration accuracy, is then used to optimize the parameter choice during the registration process. The approach is evaluated for the registration of lungs based on 22 thoracic 4D CT data sets. Experiments show that the TRE can be reduced on average by 0.07 mm using automatic parameter optimization.

Schmidt-Richberg, Alexander; Werner, René; Ehrhardt, Jan; Wolf, Jan-Christoph; Handels, Heinz

2011-03-01

216

36 CFR 62.7 - Natural landmark modifications.  

Science.gov (United States)

...appropriate. For example...better documentation of the...e) Minor technical corrections...proposed minor technical boundary...changes in documentation, as described...is a minor technical correction to landmark documentation that...

2010-07-01

217

Landmarks of History of Soil Science in Sri Lanka  

Science.gov (United States)

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

218

3D face analysis : landmarking, expression recognition and beyond  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

219

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Scholz, M.; Bachmann, L.; Nicholson, G. J.; Bachmann, J.; Giddings, I.; Ru?schoff-thale, B.; Czarnetzki, A.; Pusch, C. M.

2000-01-01

220

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

Science.gov (United States)

The study aims to investigate the techniques of design and construction of CT 3D reconstructional data-based polycaprolactone (PCL)-hydroxyapatite (HA) scaffold. Femoral and lumbar spinal specimens of eight male New Zealand white rabbits were performed CT and laser scanning data-based 3D printing scaffold processing using PCL-HA powder. Each group was performed eight scaffolds. The CAD-based 3D printed porous cylindrical stents were 16 piece × 3 groups, including the orthogonal scaffold, the Pozi-hole scaffold and the triangular hole scaffold. The gross forms, fiber scaffold diameters and porosities of the scaffolds were measured, and the mechanical testing was performed towards eight pieces of the three kinds of cylindrical scaffolds, respectively. The loading force, deformation, maximum-affordable pressure and deformation value were recorded. The pore-connection rate of each scaffold was 100 % within each group, there was no significant difference in the gross parameters and micro-structural parameters of each scaffold when compared with the design values (P > 0.05). There was no significant difference in the loading force, deformation and deformation value under the maximum-affordable pressure of the three different cylinder scaffolds when the load was above 320 N. The combination of CT and CAD reverse technology could accomplish the design and manufacturing of complex bone tissue engineering scaffolds, with no significant difference in the impacts of the microstructures towards the physical properties of different porous scaffolds under large load. PMID:25596860

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

2015-01-01

 
 
 
 
221

Measure of Landmark Semantic Salience through Geosocial Data Streams  

Directory of Open Access Journals (Sweden)

Full Text Available Research in the area of spatial cognition demonstrated that references to landmarks are essential in the communication and the interpretation of wayfinding instructions for human being. In order to detect landmarks, a model for the assessment of their salience has been previously developed by Raubal and Winter. According to their model, landmark salience is divided into three categories: visual, structural, and semantic. Several solutions have been proposed to automatically detect landmarks on the basis of these categories. Due to a lack of relevant data, semantic salience has been frequently reduced to objects’ historical and cultural significance. Social dimension (i.e., the way an object is practiced and recognized by a person or a group of people is systematically excluded from the measure of landmark semantic salience even though it represents an important component. Since the advent of mobile Internet and smartphones, the production of geolocated content from social web platforms—also described as geosocial data—became commonplace. Actually, these data allow us to have a better understanding of the local geographic knowledge. Therefore, we argue that geosocial data, especially Social Location Sharing datasets, represent a reliable source of information to precisely measure landmark semantic salience in urban area.

Teriitutea Quesnot

2014-12-01

222

Landmark Detection in Orbital Images Using Salience Histograms  

Science.gov (United States)

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

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

2010-01-01

223

Modeling and matching of landmarks for automation of Mars Rover localization  

Science.gov (United States)

The Mars Exploration Rover (MER) mission, begun in January 2004, has been extremely successful. However, decision-making for many operation tasks of the current MER mission and the 1997 Mars Pathfinder mission is performed on Earth through a predominantly manual, time-consuming process. Unmanned planetary rover navigation is ideally expected to reduce rover idle time, diminish the need for entering safe-mode, and dynamically handle opportunistic science events without required communication to Earth. Successful automation of rover navigation and localization during the extraterrestrial exploration requires that accurate position and attitude information can be received by a rover and that the rover has the support of simultaneous localization and mapping. An integrated approach with Bundle Adjustment (BA) and Visual Odometry (VO) can efficiently refine the rover position. However, during the MER mission, BA is done manually because of the difficulty in the automation of the cross-sitetie points selection. This dissertation proposes an automatic approach to select cross-site tie points from multiple rover sites based on the methods of landmark extraction, landmark modeling, and landmark matching. The first step in this approach is that important landmarks such as craters and rocks are defined. Methods of automatic feature extraction and landmark modeling are then introduced. Complex models with orientation angles and simple models without those angles are compared. The results have shown that simple models can provide reasonably good results. Next, the sensitivity of different modeling parameters is analyzed. Based on this analysis, cross-site rocks are matched through two complementary stages: rock distribution pattern matching and rock model matching. In addition, a preliminary experiment on orbital and ground landmark matching is also briefly introduced. Finally, the reliability of the cross-site tie points selection is validated by fault detection, which considers the mapping capability of MER cameras and the reason for mismatches. Fault detection strategies are applied in each step of the cross-site tie points selection to automatically verify the accuracy. The mismatches are excluded and localization errors are minimized. The method proposed in this dissertation is demonstrated with the datasets from the 2004 MER mission (traverse of 318 m) as well as the simulated test data at Silver Lake (traverse of 5.5 km), California. The accuracy analysis demonstrates that the algorithm is efficient at automatically selecting a sufficient number of well-distributed high-quality tie points to link the ground images into an image network for BA. The method worked successfully along with a continuous 1.1 km stretch. With the BA performed, highly accurate maps can be created to help the rover to navigate precisely and automatically. The method also enables autonomous long-range Mars rover localization.

Wang, Jue

224

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

225

Motion estimation in cardiac fluorescence imaging with scale-space landmarks and optical flow: a comparative study.  

Science.gov (United States)

Motion artifacts are a major disadvantage of cardiac optical mapping studies. Pixel misalignment due to contraction is a main cause of the presence of gross motion artifacts in action potential recordings. This study is focused on methods for identifying landmarks and tracking the motion of cardiac tissue for preparations in optical mapping recordings. This is a first step toward our long-term goal to implement a landmark-based image registration technique to correct for pixel misalignment in cardiac optical mapping fluorescence videos and, hence, for gross motion artifacts. Preliminary results for the registration step are presented as an initial proof of concept. The characteristics of the optical mapping images are challenging, since their lack of contrast and well-defined features impose a limitation on the techniques than can be used for landmark selection and motion tracking. This paper compares results of motion estimation of the cardiac surface with two approaches that do not rely on high-contrast features: 1) Scale-invariant feature transform (SIFT) detected "keypoints," to be used as landmarks for motion tracking, as well as 2) a classical global optical flow (OF) algorithm. Both are applied to low-contrast and low-resolution cardiac fluorescence images. We demonstrate that the performance of SIFT is superior to that of OF for pixel motion tracking in cardiac optical mapping images with simulated motion. Results for action potential recovery and action potential duration calculation after landmark-based image registration show that SIFT landmark-based registration yields superior performance in this regard as well. PMID:25350913

Rodriguez, M P; Nygren, A

2015-02-01

226

Landmark-free statistical analysis of the shape of plant leaves.  

Science.gov (United States)

The shapes of plant leaves are important features to biologists, as they can help in distinguishing plant species, measuring their health, analyzing their growth patterns, and understanding relations between various species. Most of the methods that have been developed in the past focus on comparing the shape of individual leaves using either descriptors or finite sets of landmarks. However, descriptor-based representations are not invertible and thus it is often hard to map descriptor variability into shape variability. On the other hand, landmark-based techniques require automatic detection and registration of the landmarks, which is very challenging in the case of plant leaves that exhibit high variability within and across species. In this paper, we propose a statistical model based on the Squared Root Velocity Function (SRVF) representation and the Riemannian elastic metric of Srivastava et al. (2011) to model the observed continuous variability in the shape of plant leaves. We treat plant species as random variables on a non-linear shape manifold and thus statistical summaries, such as means and covariances, can be computed. One can then study the principal modes of variations and characterize the observed shapes using probability density models, such as Gaussians or Mixture of Gaussians. We demonstrate the usage of such statistical model for (1) efficient classification of individual leaves, (2) the exploration of the space of plant leaf shapes, which is important in the study of population-specific variations, and (3) comparing entire plant species, which is fundamental to the study of evolutionary relationships in plants. Our approach does not require descriptors or landmarks but automatically solves for the optimal registration that aligns a pair of shapes. We evaluate the performance of the proposed framework on publicly available benchmarks such as the Flavia, the Swedish, and the ImageCLEF2011 plant leaf datasets. PMID:25123432

Laga, Hamid; Kurtek, Sebastian; Srivastava, Anuj; Miklavcic, Stanley J

2014-12-21

227

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

Science.gov (United States)

How do honeybees use visual odometry and goal-defining landmarks to guide food search? In one experiment, bees were trained to forage in an optic-flow-rich tunnel with a landmark positioned directly above the feeder. Subsequent food-search tests indicated that bees searched much more accurately when both odometric and landmark cues were available than when only odometry was available. When the two cue sources were set in conflict, by shifting the position of the landmark in the tunnel during test, bees overwhelmingly used landmark cues rather than odometry. In another experiment, odometric cues were removed by training and testing in axially striped tunnels. The data show that bees did not weight landmarks as highly as when odometric cues were available, tending to search in the vicinity of the landmark for shorter periods. A third experiment, in which bees were trained with odometry but without a landmark, showed that a novel landmark placed anywhere in the tunnel during testing prevented bees from searching beyond the landmark location. Two further experiments, involving training bees to relatively longer distances with a goal-defining landmark, produced similar results to the initial experiment. One caveat was that, with the removal of the familiar landmark, bees tended to overshoot the training location, relative to the case where bees were trained without a landmark. Taken together, the results suggest that bees assign appropriate significance to odometric and landmark cues in a more flexible and dynamic way than previously envisaged. PMID:16244171

Vladusich, Tony; Hemmi, Jan M; Srinivasan, Mandyam V; Zeil, Jochen

2005-11-01

228

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

229

Anatomical changes in the pharyngeal constrictors after chemo-irradiation of head and neck cancer and their dose-effect relationships: MRI-based study  

International Nuclear Information System (INIS)

Purpose: Dysfunction of pharyngeal constrictors (PCs) after chemo-irradiation of head and neck (HN) cancer has been proposed as major cause of dysphagia. We conducted prospective MRI study to evaluate anatomical changes in the PCs after chemo-irradiation, to gain insight of the mechanism of their dysfunction and their dose-effect relationships. The PCs were compared to the sternocleidomastoid muscles (SCMs), which receive high doses but do not relate to swallowing. Patients and methods: Twelve patients with stage III-IV HN cancer underwent MRI before and 3 months after completing chemo-irradiation. T1- and T2-weighted signals and muscle thickness were evaluated for PCs (superior, middle, and inferior), and SCMs. Mean muscle doses were determined after registration with the planning CT. Results: T1-weighted signals decreased in both PCs and SCMs receiving >50 Gy (p 2 = 0.34, p = 0.01). The T2 signal changes in the PCs were significantly higher than the T2 changes in the SCMs (p 50 Gy gaining significantly more thickness than PCs receiving lesser doses (p = 0.02). In contrast, the SCM thickness decreased post-therapy (p = 0.002). Conclusions: These MRI-based findings, notably the differences between PCs and SCMs, suggest that underlying causes of PC dysfuncggest that underlying causes of PC dysfunction are inflammation and edema, likely consequential to acute mucositis affecting the submucosa-lying PCs. These results support reducing mean PC doses to ?50 Gy, as well as reducing acute mucositis, to improve long-term dysphagia.

230

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)

231

Anatomical variations of the saphenous vein arc.  

Directory of Open Access Journals (Sweden)

Full Text Available There are many anatomical variations presented by the tributaries of the saphenous vein at the saphenous – femoral junction .In anatomical texts, they are plotted as usual tributaries to the femoral vein, presentations that are not found during routine surgical practice. Knowledge of the sapheno- femoral vein junction is imperative for the surgeon when operating the venous system of lower limbs, in order to avoid accidents and prevent intraoperative varicose recurrences. The aim of the present paper is to demonstrate which of the anatomical variations of the arc of the great saphenous vein is shown more often, contributing to the description of the anatomy of the region and its name in the anatomical terminology. The present work is based on experience of one hundred dissections (n = 100 of the femoral inguinal region in human cadavers fixed with formol aqueous solution of 5% v / v, twenty (n = 20 of which were filled with latex via endovascular before its fixation. The basic scheme of the arc of the great saphenous vein receives the following tributaries: the superficial circumflex iliac vein, superficial epigastric vein [subcutaneous abdominal vein], external pudendal veins, accessory vein of the thigh [dorsal thigh], inter saphenous vein [Giacomini vein]. Inter saphenous vein was observed [Giacomini vein] in a large percentage of the sample (66%. On 77% of the cases, a single saphenous trunk was found, 22% of duplication and triplication 1%. Exceptionally small caliber veins reach the common femoral vein on its inner side, draining the pudendal region, may correspond to the third vein pudendal described by Vilanova, or a tributary of the arc that ends in isolation while the rest of the arc remains on the basic disposition. Successful surgery of the saphenous vein arc is based on an optimal anatomical knowledge of the sapheno - femoral junction, its anatomical variations and relationships.

José Luis Ciucci

2010-11-01

232

Anatomical and functional imaging in endocrine hypertension  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In endocrine hypertension, hormonal excess results in clinically significant hypertension. The functional imaging (such as radionuclide imaging) complements anatomy-based imaging (such as ultrasound, computed tomography, and magnetic resonance imaging) to facilitate diagnostic localization of a lesion causing endocrine hypertension. The aim of this review article is to familiarize general radiologists, endocrinologists, and clinicians with various anatomical and functional imaging techniques ...

Chaudhary, Vikas; Bano, Shahina

2012-01-01

233

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

2007-04-01

234

Anatomical organization of aortic arch variations in the India: embryological basis and review / Organização anatômica das variações do arco aórtico na população indiana: base e revisão embriológica  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese OBJETIVOS: Determinar a porcentagem e o tipo de variações do arco aórtico em indivíduos indianos, bem como sua importância clínica e cirúrgica e base embriológica. PACIENTES E MÉTODOS: Em nossa investigação, os padrões de ramificação do arco aórtico foram estudados em 62 cadáveres fixados em formali [...] na de ambos os sexos, de origem indiana e com idade entre 45 e 79 anos. As dissecações foram realizadas em cadáveres preservados em formalina, e as variações do arco aórtico foram observadas após a exposição das regiões torácica e cervical durante a dissecação de rotina de alunos da graduação do Kasturba Medical College, Mangalore, Índia. RESULTADOS: O arco aórtico normal de três ramificações foi encontrado em 56 cadáveres (91,4%); as variações foram encontradas em seis cadáveres (9,6%); 4,8% apresentavam origem comum das artérias carótidas; 1,6% tinham seqüência binominada, e o mesmo espécime tinha a origem da artéria coronária esquerda diretamente no arco aórtico; 1,6% apresentavam a origem da artéria subclávia direita diretamente na aorta; 1,6% tinham como ramificação do arco aórtico uma artéria vertebral esquerda. Cinco de seis cadáveres com padrão de ramificação anômalo do arco aórtico eram do sexo feminino. Um cadáver do sexo masculino apresentou origem anômala da artéria vertebral esquerda diretamente no arco. CONCLUSÃO: O amplo espectro de variações nos padrões anatômicos das ramificações do arco aórtico na população indiana estava em concordância com outras populações mundiais. Embora as origens anômalas das ramificações do arco aórtico sejam meramente variações anatômicas, informações precisas sobre elas é essencial para a cirurgia vascular na região do tórax, cabeça e pescoço. Abstract in english OBJECTIVES: To determine the percentage and type of aortic arch variations in Indian subjects and their clinical and surgical importance and embryological basis. PATIENTS AND METHOD: In our investigation, branching patterns of the aortic arch were studied in 62 formalin-fixed cadavers of both sexes [...] of Indian origin, aged 45-79. The dissections were carried out in formalin-preserved cadavers and the aortic arch variations were observed after exposing the thoracic and cervical region during routine dissection of undergraduate students of Indian origin in Kasturba Medical College, Mangalore. RESULTS: The usual three-branched aortic arch was found in 56 cadavers (91.4%); variations were found in six cadavers (9.6%); 4.8% presented common origin of the carotid arteries; 1.6% had bi-innominate sequence, and the same specimen had left coronary artery arising from arch of aorta directly; 1.6% presented right subclavian artery arising directly from the aorta; 1.6% had left vertebral artery a branch of aortic arch. Five out of six cadavers with anomalous aortic arch branching pattern were females. One male cadaver presented anomalous origin of left vertebral artery directly from the arch. CONCLUSION: The wide spectrum of variations in the anatomical arrangements of the aortic arch branches in the Indian population was at par with other populations of the world. Although anomalous origins of the aortic arch branches are merely anatomic variants, accurate information about them is vital for vascular surgery in the thorax, head and neck region.

Soubhagya R., Nayak; Mangala M., Pai; Latha V., Prabhu; Sujatha, D' Costa; Prakash, Shetty.

2006-06-01

235

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.)

236

[Ultrasound-guided interscalene block in a patient with supraclavicular anatomical abnormalities due to radiotherapy and surgery].  

Science.gov (United States)

Regional blocks can be difficult in surgical patients with certain superficial anatomical abnormalities. Such blocks may be possible, however, under ultrasound guidance. We report a case in which a man with a fractured right humerus required an ultrasound-guided interscalene brachial plexus block. Secondary to radiotherapy, the patient had right cervical and facial abnormalities that had altered the location of external anatomical landmarks. We describe the approach used to insert the catheter and the exploration of the region by ultrasound. Nerve stimulation was not used to avoid painful contractions. Analgesia was excellent during surgery and over the following 24 hours. PMID:21688510

Errando, C L; Muñoz-Devesa, L; Soldado, M A

2011-05-01

237

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

238

Anatomical study of spinal accessory nerve using ultrasonography  

International Nuclear Information System (INIS)

Objective: The purpose of our study was to demonstrate that ultrasonography may allow a precise assessment of the course and relationships of the spinal accessory nerve (SAN). Material and methods: This study, initially undertaken in 7 cadavers, was followed by high-resolution ultrasonographic study in 15 volunteers (30 nerves) by two radiologists in consensus. The location, course and relations to the adjacent anatomic structures of the SAN were analyzed. Results: The precise course of the SAN between the lateroposterior border of the sternocleidomastoid muscle and the anterior border of the trapezius muscle could be identified by high-resolution ultrasonography. In contrast, clinical bone landmarks were not found helpful for the identification of the nerve. Conclusion: The SAN can be clearly depicted by means of ultrasonography. Knowledge of the nerve's precise location, which may evidence individual variations, may have useful clinical applications

239

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

240

Occipital neuralgia: anatomic considerations.  

Science.gov (United States)

Occipital neuralgia is a debilitating disorder first described in 1821 as recurrent headaches localized in the occipital region. Other symptoms that have been associated with this condition include paroxysmal burning and aching pain in the distribution of the greater, lesser, or third occipital nerves. Several etiologies have been identified in the cause of occipital neuralgia and include, but are not limited to, trauma, fibrositis, myositis, fracture of the atlas, and compression of the C-2 nerve root, C1-2 arthrosis syndrome, atlantoaxial lateral mass osteoarthritis, hypertrophic cervical pachymeningitis, cervical cord tumor, Chiari malformation, and neurosyphilis. The management of occipital neuralgia can include conservative approaches and/or surgical interventions. Occipital neuralgia is a multifactorial problem where multiple anatomic areas/structures may be involved with this pathology. A review of these etiologies may provide guidance in better understanding occipital neuralgia. PMID:25244129

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

2015-01-01

 
 
 
 
241

Slice-based supine-to-standing posture deformation for chinese anatomical models and the dosimetric results with wide band frequency electromagnetic field exposure: Simulation  

International Nuclear Information System (INIS)

Standing Chinese adult anatomical models are obtained from supine-postured cadaver slices. This paper presents the dosimetric differences between the supine and the standing postures over wide band frequencies and various incident configurations. Both the body level and the tissue/organ level differences are reported for plane wave and the 3T magnetic resonance imaging radiofrequency electromagnetic field exposure. The influence of posture on the whole body specific absorption rate and tissue specified specific absorption rate values is discussed. . (authors)

242

Identifying landmark articles for advancing the practice of geriatrics.  

Science.gov (United States)

Landmark articles from the peer-reviewed literature can be used to teach the fundamental principles of geriatric medicine. Three approaches were used in sequential combination to identify landmark articles as a resource for geriatricians and other healthcare practitioners. Candidate articles were identified first through a literature review and expert opinion survey of geriatric medicine faculty. Candidate articles in a winnowed list (n = 30) were then included in a bibliometric analysis that incorporated the journal impact factor and average monthly citation index. Finally, a consensus panel reviewed articles to assess each manuscript's clinical relevance. For each article, a final score was determined by averaging, with equal weight, the opinion survey, bibliometric analysis, and consensus panel review. This process ultimately resulted in the identification of 27 landmark articles. Overall, there was weak correlation between articles that the expert opinion survey and bibliometric analysis both rated highly. This process demonstrates a feasible method combining subjective and objective measures that can be used to identify landmark papers in geriatric medicine for the enhancement of geriatrics education and practice. PMID:25366821

Vaughan, Camille P; Fowler, Rachel; Goodman, Richard A; Graves, Taylor R; Flacker, Jonathan M; Johnson, Theodore M

2014-11-01

243

An Adaptive Algorithm for Finding Frequent Sets in Landmark Windows  

DEFF Research Database (Denmark)

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

Dang, Xuan-Hong; Ong, Kok-Leong

2012-01-01

244

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)

245

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

246

Proposed European anatomical collections network  

Directory of Open Access Journals (Sweden)

Full Text Available Universities, colleges, medical institutions and professional societies in the past used their museums as tools to establish themselves as the rightful producers of anatomical knowledge. Anatomical and medical museums, nearly ubiquitous in the cities of Europe and the United States, exhibited and preserved anatomical specimens as well as models and sculptures – some displaying great artistic and technical finesse – which depicted human anatomy in graphic detail. A European anatomical collection network proposes to obtain, collect, and analyze a wide range of information about anatomical collections in Europe. For our proposal it is important to focus the attention on ‘how’ as well as ‘what’ has been collected, to the strategies adopted for showing the collections, to the people who had access to the collections and the degree to which their prior experiences and expectations may have shaped their responses to it. It is also important to consider the geographical location and origins of anatomical collections, their anatomical models and specimens, the contents of lectures, the audiences targeted and also the questions raised in historical, sociological and anthropological literature about anatomy.

Elena Corradini

2012-10-01

247

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

International Nuclear Information System (INIS)

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

248

Review of the Historical Evolution of Anatomical Terms  

Directory of Open Access Journals (Sweden)

Full Text Available Most of the medical terms of Greek origin are traditionally attributed to Hippocrates (460-370 BC. Claudius Galen of Pergamum (130-200 BC developed a classification of bones and joints and described different brain areas. His teachings have remained unchanged for over a thousand years. Andreas Vesalius of Brussels (1514-1564, through the systematic study of human body structure, changed many concepts. He published his work in his production "De humani corporis fabrica libri septem", where a special attention is evident to the discovery and description of new anatomical facts. From here there is a revolution in the morphological sciences, where the same anatomical structure passed to receive different names. In the nineteenth century, the different anatomists in the world decide to meet in order to unify criteria regarding the anatomical structures and determine a only one universal language in the anatomical sciences. In 1895, in Basel (Switzerland it’s approved a list of 5.573 terms, called Basle Nomina Anatomica (BNA and was written in Latin. Eponyms were deleted. In 1903, he founded the International Federation of Associations of anatomists (IFAA. In 1935, in Jena (Germany, approving the Jena Nomina Anatomica (JNA. In 1950, in Oxford, formed the Committee of the International Anatomical Nomenclature (IANC. In 1955, in Paris (France it is agreed to adopt a Latin nomenclature based on the BNA, the Paris Nomina Anatomica (PNA. In 1980, for the first time in Latin America, takes place on the 11th International Congress of Anatomists, Mexico. In 1989, the International Committee of Anatomical Nomenclature, published the sixth edition of the Nomina Anatomica, without review by the IFAA. The same year, the latter established a Federative International Committee of Anatomical Terminology (FICAT. In 1998, he published a new list FICAT: International Anatomical Terminology (TAI, with the structures named in Latin language and their equivalence in English, listing which updates and supersedes all previous nomenclatures. In September 2001, the Spanish Anatomical Society translated this International Anatomical Terminology into Spanish language.The study of the historical backgrounds in the worldwide development of Anatomical Terms, give us valuable data about the origin and foundation of the names. It is necessary to raise awareness about the implementation of a unified, updated and uniform anatomical terminology, when conducting scientific communications and publications. As specialists in this discipline, we must study and know the existence of the official list of anatomical terms of use worldwide (International Anatomical Terminology, its equivalence with previous classifications, keeping us updated about its changes to teach it to new generations of health professionals.

Algieri, Rubén D.

2011-12-01

249

Delineating anatomical boundaries using the boundary fragment model.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper we present a method to automatically isolate relevant anatomical boundary positions in an image using only the structure of edges. The purpose of this method is to facilitate model-based segmentation algorithms which rely on accurate initialisation and assume that the correct anatomical boundary positions are close to the current model surface. The method is built around a weak parts-based shape model - the Boundary Fragment Model (BFM) - which represents an object by sections o...

Stebbing, Rv; Noble, Ja

2013-01-01

250

Automated annotation of landmark images using community contributed datasets and web resources  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A novel solution to the challenge of automatic image annotation is described. Given an image with GPS data of its location of capture, our system returns a semantically-rich annotation comprising tags which both identify the landmark in the image, and provide an interesting fact about it, e.g. "A view of the Eiffel Tower, which was built in 1889 for an international exhibition in Paris". This exploits visual and textual web mining in combination with content-based image analysis and natura...

Jones, Gareth J. F.; Byrne, Daragh; Hughes, Mark; O Connor, Noel E.; Salway, Andrew

2010-01-01

251

The avascular plane of the Achilles tendon: A quantitative anatomic and angiographic approach and a base for a possible new treatment option after rupture  

International Nuclear Information System (INIS)

Introduction: Achilles tendon ruptures, especially ruptures caused by pathologic conditions and also by achillotendinitis are often attributed to the alleged hypovascularisation of the Achilles tendon. Anatomic studies often mention an avascular plane. The purpose of this study was to re-investigate the arterial supply of the Achilles tendon. Material and methods: Lower legs of 28 anatomic specimen were injected with a radiologic contrast agent and subsequently an arterial angiography was performed. Afterwards the legs were embalmed and later anatomically dissected. The origin of arteries entering the paratenon of the tendo calcanei branching off from either the anterior (TA) or the posterior tibial artery (TP) was determined. The distance between the points of commencement of these nutrient arteries and a specific reference point, i.e. the insertion of the Achilles tendon into the tuber calcanei, was measured digitally on the radiographs and again with a slide-gauge on the dissected specimens. Results: As revealed by angiographic analysis, the TA gave off 5 vessels (v) at a frequency and median distance to the tuber calcanei (in cm) of v1: 50%, 6.01 cm; v2: 39.3%, 7.88 cm; v3: 35.7%, 9.71 cm; v4: 17.9%, 12.7 cm; v5: 10.7%, 14.6 cm. The TP contributed to the arterial supply of the Achilles tendon by means of 7 inserting arteries branching off at a frequency and mean distances of v1: 67.9%, 4.53 cm; v2: 60.7%, 6.97 cm, v3: 50%, 9.58 cm; v4: 35.7%, 10.89 cm; v5: 25%, 12 9.58 cm; v4: 35.7%, 10.89 cm; v5: 25%, 12.65 cm; v6: 10.7%, 16.94 cm; v7: 3.6%, 18.7 cm proximal to the tuber calcanei. However, due to the small diameter of these branches, by anatomic dissection no nutrient arteries commencing from the TA could be detected. On the other hand, a maximum of 7 vessels originating from the TP, larger than the former vessels, had been also revealed by anatomic dissection (frequency and mean distances, v1: 100%, 6.8 cm; v2: 82.1%, 7.7 cm; v3: 71.4%, 9.5 cm; v4: 35.7%, 11.3 cm; v5: 17.9%, 9.9 cm; v6: 7.1, 10.5 cm; v7: 3.6%, 12.0 cm). Conclusion: A dense net of small arteries inserts into the paratenon of the Achilles tendon in its lower 20 cm. The angiographic method was more specific and showed vessels that could not be identified as arteries originating from the TA by macroscopic anatomic dissection.

252

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

253

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

Science.gov (United States)

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

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

2015-01-01

254

National Bladder Cancer Study - 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.

255

Probabilistic anatomical labeling of brain structures using statistical probabilistic anatomical maps  

International Nuclear Information System (INIS)

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

256

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

257

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

258

Applying the functional abnormality ontology pattern to anatomical functions  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Several biomedical ontologies cover the domain of biological functions, including molecular and cellular functions. However, there is currently no publicly available ontology of anatomical functions. Consequently, no explicit relation between anatomical structures and their functions is expressed in the anatomy ontologies that are available for various species. Such an explicit relation between anatomical structures and their functions would be useful both for defining the classes of the anatomy and the phenotype ontologies accurately. Results We provide an ontological analysis of functions and functional abnormalities. From this analysis, we derive an approach to the automatic extraction of anatomical functions from existing ontologies which uses a combination of natural language processing, graph-based analysis of the ontologies and formal inferences. Additionally, we introduce a new relation to link material objects to processes that realize the function of these objects. This relation is introduced to avoid a needless duplication of processes already covered by the Gene Ontology in a new ontology of anatomical functions. Conclusions Ontological considerations on the nature of functional abnormalities and their representation in current phenotype ontologies show that we can extract a skeleton for an ontology of anatomical functions by using a combination of process, phenotype and anatomy ontologies automatically. We identify several limitations of the current ontologies that still need to be addressed to ensure a consistent and complete representation of anatomical functions and their abnormalities. Availability The source code and results of our analysis are available at http://bioonto.de.

Hoehndorf Robert

2010-03-01

259

AUTOMATIC DETECTION AND CLASSIFICATION OF RETINAL VASCULAR LANDMARKS  

Directory of Open Access Journals (Sweden)

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

Hadi Hamad

2014-06-01

260

Snapshot memories and landmark guidance in wood ants.  

Science.gov (United States)

Insects are thought to pinpoint a place by using memorized "snapshots," i.e., two-dimensional retinotopic views of the surrounding landmarks recorded when at the place (reviewed in ). Insects then reach the place by moving until their current view matches their snapshot. To determine when snapshots are recalled, and how differences between view and snapshot are translated into appropriate movements, we analyzed the approaches of wood ants to a feeding site that was located in the center of an array of two or three cylinders. In ants, contrary to flying hymenopterans, body orientation and direction of travel are collinear, so that an ant approaching an object always looks at it with frontal visual field. On their way to a food site, ants fixated and approached a cylinder predominantly when its angular size was smaller than when viewed from the food site. This finding implies that ants store snapshots at this place while fixating landmarks with frontal retina, so simplifying the later alignment of snapshots with their current view. It also means that ants recall snapshots well in advance of reaching the place. Although snapshots are centered on a landmark, we show that they extend at least 120 degrees into the periphery. PMID:13678592

Durier, Virginie; Graham, Paul; Collett, Thomas S

2003-09-16

 
 
 
 
261

Slice-based supine to standing postured deformation for Chinese anatomical models and the dosimetric results by wide band frequency electromagnetic field exposure: morphing.  

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Digital human models are frequently obtained from supine-postured medical images or cadaver slices, but many applications require standing models. This paper presents the work of reconstructing standing Chinese adult anatomical models from supine postured slices. Apart from the previous studies, the deformation works on 2-D segmented slices. The surface profile of the standing posture is adjusted by population measurement data. A non-uniform texture amplification approach is applied on the 2-D slices to recover the skin contour and to redistribute the internal tissues. Internal organ shift due to postures is taken into account. The feet are modified by matrix rotation. Then, the supine and standing models are utilised for the evaluation of electromagnetic field exposure over wide band frequency and different incident directions. PMID:22899214

Wu, Tongning; Tan, Liwen; Shao, Qing; Li, Ying; Yang, Lei; Zhao, Chen; Xie, Yi; Zhang, Shaoxiang

2013-04-01

262

Slice-based supine to standing postured deformation for chinese anatomical models and the dosimetric results by wide band frequency electromagnetic field exposure: Morphing  

International Nuclear Information System (INIS)

Digital human models are frequently obtained from supine-postured medical images or cadaver slices, but many applications require standing models. This paper presents the work of reconstructing standing Chinese adult anatomical models from supine postured slices. Apart from the previous studies, the deformation works on 2-D segmented slices. The surface profile of the standing posture is adjusted by population measurement data. A non-uniform texture amplification approach is applied on the 2-D slices to recover the skin contour and to redistribute the internal tissues. Internal organ shift due to postures is taken into account. The feet are modified by matrix rotation. Then, the supine and standing models are utilised for the evaluation of electromagnetic field exposure over wide band frequency and different incident directions. . (authors)

263

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

264

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

International Nuclear Information System (INIS)

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

265

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.

2010-07-01

266

Anatomic Imaging of the Prostate  

Science.gov (United States)

The important role of magnetic resonance imaging (MRI) in the anatomic evaluation, detection, and staging of prostate cancer is well established. This paper focuses on the pertinent embryologic, anatomic, and imaging facts regarding both the normal prostate and the several examples of prostate cancers as well as staging implications. The discussion primarily includes findings related to T2-weighted imaging as opposed to the other functional sequences, including diffusion weighted imaging (DWI) or dynamic contrast enhanced MRI and MR spectroscopic imaging, respectively. PMID:25243174

Bhavsar, Anil; Verma, Sadhna

2014-01-01

267

Anatomic Total Shoulder System  

Medline Plus

Full Text Available ... the superglenoid tubercle and have incised the rotator interval all the way to the base of the ... We then use a freer to find the interval between subscap and capsule. Small Cobb. We'll ...

268

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

269

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish 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 paci [...] entes 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 Abstract in english 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 O [...] phthalmology, 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

Neisy, Bernal Reyes; Luis, Curbelo Cunill; Alejandro, Arias Díaz.

2009-12-01

270

PET image reconstruction with anatomical edge guided level set prior  

International Nuclear Information System (INIS)

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 he 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.

271

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

272

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Computational models of neural networks can be based on a variety of different parameters. These parameters include, for example, the 3d shape of neuron layers, the neurons' spatial projection patterns, spiking dynamics and neurotransmitter systems. While many well-developed approaches are available to model, for example, the spiking dynamics, there is a lack of approaches for modeling the anatomical layout of neurons and their projections. We present a new method, called Parametric Anatomica...

Martin Pyka; Sebastian Klatt

2014-01-01

273

Proposal of anatomical terminology to call the arteries of the base of the encephalon in the monkey (Cebus paella L., 1766 Nomenclatura proposta para denominar as artérias da base do encéfalo do macaco-prego (Cebus apella L., 1766  

Directory of Open Access Journals (Sweden)

Full Text Available Arteries of the encephalon basis of 30 monkeys (Cebus paella were studied. Arteries were injected with colored latex, fixed in formaldehyde solution at 10% and dissected under magnifying lenses. Since the animals died from natural causes they had been previously used in other experiments. Human and veterinary anatomical terminology and literature were used as a reference for the determination of vessels studied in the primates. Arteries of the encephalon base represent division branches of three vascular pedicules: the right and left internal carotid arteries and the basilar system. Vessels in the basilar system of the animal were called vertebral arteries; anterior spinal artery; anterior and posterior cerebelar arteries; pontine arteries; satellite cerebelar arteries; caudal and cranial cerebelar arteries. The basilar artery bifurcates into two posterior cerebral arteries (100%. The caudal area of the encephalon’s arterial circuit is thus constituted. Linking between the vertebro-basilar and the carotid segments is done by the posterior communicating artery, that caudally anastomizes (100% with the posterior cerebral artery. The internal carotid artery gives origin to the posterior communicating artery. The right and left internal carotid artery (intracranial portion compounds the carotid system. The following vessels were identified: middle cerebral artery; anterior cerebral artery; interhemispheric artery; olfactory arteries. Results report that Cebus paella presents an arterial pattern of relative morphological stabilityEstudaram-se as artérias da base do encéfalo do Cebus apella em 30 animais, vindos a óbito por morte natural no Zoológico de São Paulo e coletados durante 10 anos. O material recebeu injeção de látex corado, fixado em formol a 10%, e foi dissecado sob lupa. Encontramos dificuldade e denominar estes vasos. As terminologias anatômicas humana e veterinária e a recuperação da literatura nos serviram de base para sugerirmos uma denominação que se adequasse ao modelo arterial desse primata. Os resultados nos permitiram verificar, no circuito arterial da base do encéfalo, segmento caudal ou vértebro-basilar as artérias (a: a. vertebral, suas partes (pé-vertebral, cervical, atlântica e intracraniana com ramos meníngeos e seus ramos (a. espinhal anterior, a. cerebelar inferior caudal, ramos para a medula oblonga; a. basilar e seus ramos (a. cerebelar inferior rostral, a. pontinas, a. cerebelar superior satélite, ilhas artérias, a. cerebelar anterior, a. cerebelar posterior; e no segmento rostral ou carótico os vasos: a. carótida interna (parte cerebral; a. comunicante posterior; a. coróidea; a. cerebral média; a. cerebral anterior; a. olfatória; a. inter-hemisférica. A análise dos resultados nos permitiu considerar que o Cebus apella apresentou um padrão arterial de relativa estabilidade morfológica em função das poucas variações encontradas nos vasos formadores dos circuitos arteriais considerados

Jussara Rocha Ferreira

2001-05-01

274

Anatomical structure of Polystichum Roth ferns rachises  

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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

275

Anatomical structure of Polystichum Roth ferns rachises  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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.

Tyshchenko, Oksana V.; Vasheka, Olena V.; Polyshchuk, Iryna O.

2012-01-01

276

Learned predictiveness training modulates biases towards using boundary or landmark cues during navigation.  

Science.gov (United States)

A number of navigational theories state that learning about landmark information should not interfere with learning about shape information provided by the boundary walls of an environment. A common test of such theories has been to assess whether landmark information will overshadow, or restrict, learning about shape information. Whilst a number of studies have shown that landmarks are not able to overshadow learning about shape information, some have shown that landmarks can, in fact, overshadow learning about shape information. Given the continued importance of theories that grant the shape information that is provided by the boundary of an environment a special status during learning, the experiments presented here were designed to assess whether the relative salience of shape and landmark information could account for the discrepant results of overshadowing studies. In Experiment 1, participants were first trained that either the landmarks within an arena (landmark-relevant), or the shape information provided by the boundary walls of an arena (shape-relevant), were relevant to finding a hidden goal. In a subsequent stage, when novel landmark and shape information were made relevant to finding the hidden goal, landmarks dominated behaviour for those given landmark-relevant training, whereas shape information dominated behaviour for those given shape-relevant training. Experiment 2, which was conducted without prior relevance training, revealed that the landmark cues, unconditionally, dominated behaviour in our task. The results of the present experiments, and the conflicting results from previous overshadowing experiments, are explained in terms of associative models that incorporate an attention variant. PMID:25409751

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

2014-11-20

277

Landmark Learning in a Navigation Task Is Not Affected by the Female Rats' Estrus Cycle  

Science.gov (United States)

In two experiments rats were required to escape from a circular pool by swimming to an invisible platform that was located in the same place relative to one configuration of two landmarks (X and Y). The two landmarks were placed relatively far and equidistant from the hidden platform. Training could be either on consecutive days (Experiment 1) or…

Rodriguez, Clara A.; Aguilar, Raul; Chamizo, V. D.

2011-01-01

278

Reorientation in the Real World: The Development of Landmark Use and Integration in a Natural Environment  

Science.gov (United States)

An influential series of studies have argued that young children are unable to use landmark information to reorient. However, these studies have used artificial experimental environments that may lead to an underestimation of the children's ability. We tested whether young children could reorient using landmarks in an ecologically valid setting.…

Smith, Alastair D.; Gilchrist, Iain D.; Cater, Kirsten; Ikram, Naimah; Nott, Kylie; Hood, Bruce M.

2008-01-01

279

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

Science.gov (United States)

Computational models of neural networks can be based on a variety of different parameters. These parameters include, for example, the 3d shape of neuron layers, the neurons' spatial projection patterns, spiking dynamics and neurotransmitter systems. While many well-developed approaches are available to model, for example, the spiking dynamics, there is a lack of approaches for modeling the anatomical layout of neurons and their projections. We present a new method, called Parametric Anatomical Modeling (PAM), to fill this gap. PAM can be used to derive network connectivities and conduction delays from anatomical data, such as the position and shape of the neuronal layers and the dendritic and axonal projection patterns. Within the PAM framework, several mapping techniques between layers can account for a large variety of connection properties between pre- and post-synaptic neuron layers. PAM is implemented as a Python tool and integrated in the 3d modeling software Blender. We demonstrate on a 3d model of the hippocampal formation how PAM can help reveal complex properties of the synaptic connectivity and conduction delays, properties that might be relevant to uncover the function of the hippocampus. Based on these analyses, two experimentally testable predictions arose: (i) the number of neurons and the spread of connections is heterogeneously distributed across the main anatomical axes, (ii) the distribution of connection lengths in CA3-CA1 differ qualitatively from those between DG-CA3 and CA3-CA3. Models created by PAM can also serve as an educational tool to visualize the 3d connectivity of brain regions. The low-dimensional, but yet biologically plausible, parameter space renders PAM suitable to analyse allometric and evolutionary factors in networks and to model the complexity of real networks with comparatively little effort. PMID:25309338

Pyka, Martin; Klatt, Sebastian; Cheng, Sen

2014-01-01

280

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

Directory of Open Access Journals (Sweden)

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

Martin Pyka

2014-09-01

 
 
 
 
281

Robust Morphological Averages in Three Dimensions for Anatomical Atlas Construction  

Science.gov (United States)

We present original methods for obtaining robust, anatomical shape-based averages of features of the human head anatomy from a normal population. Our goals are computerized atlas construction with representative anatomical features and morphopometry for specific populations. A method for true-morphological averaging is proposed, consisting of a suitable blend of shape-related information for N objects to obtain a progressive average. It is made robust by penalizing, in a morphological sense, the contributions of features less similar to the current average. Morphological error and similarity, as well as penalization, are based on the same paradigm as the morphological averaging.

Márquez, Jorge; Bloch, Isabelle; Schmitt, Francis

2004-09-01

282

Histology to microCT data matching using landmarks and a density biased RANSAC.  

Science.gov (United States)

The fusion of information from different medical imaging techniques plays an important role in data analysis. Despite the many proposed registration algorithms the problem of registering 2D histological images to 3D CT or MR imaging data is still largely unsolved. In this paper we propose a computationally efficient automatic approach to match 2D histological images to 3D micro Computed Tomography data. The landmark-based approach in combination with a density-driven RANSAC plane-fitting allows efficient localization of the histology images in the 3D data within less than four minutes (single-threaded MATLAB code) with an average accuracy of 0.25 mm for orrect and 2.21mm for mismatched slices. The approach managed to uccessfully localize 75% of the histology images in our database. The proposed algorithm is an important step towards solving the problem of registering 2D histology sections to 3D data fully automatically. PMID:25333124

Chicherova, Natalia; Fundana, Ketut; Müller, Bert; Cattin, Philippe C

2014-01-01

283

Anatomical study of the pigs temporal bone by microdissection  

Scientific Electronic Library Online (English)

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

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

284

Anatomical study of the pigs temporal bone by microdissection  

Scientific Electronic Library Online (English)

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

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

285

TOPICAL REVIEW: Anatomical imaging for radiotherapy  

Science.gov (United States)

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.

Evans, Philip M.

2008-06-01

286

Anatomically Plausible Surface Alignment and Reconstruction  

DEFF Research Database (Denmark)

With the increasing clinical use of 3D surface scanners, there is a need for accurate and reliable algorithms that can produce anatomically plausible surfaces. In this paper, a combined method for surface alignment and reconstruction is proposed. It is based on an implicit surface representation combined with a Markov Random Field regularisation method. Conceptually, the method maintains an implicit ideal description of the sought surface. This implicit surface is iteratively updated by realigning the input point sets and Markov Random Field regularisation. The regularisation is based on a prior energy that has earlier proved to be particularly well suited for human surface scans. The method has been tested on full cranial scans of ten test subjects and on several scans of the outer human ear.

Paulsen, Rasmus R.; Larsen, Rasmus

2010-01-01

287

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

International Nuclear Information System (INIS)

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 dosinclusions: 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.

288

Anatomical and surgical aspects of splenic segmentectomies.  

Science.gov (United States)

Based upon the anatomicosurgical segments of the spleen, suggested by DiDio and demonstrated in cadavers, classified and named by Neder (1958) and Zappalá (1958, 1959, 1963), the normal segmental organization was anatomically and radiologically confirmed in 51 human spleens, after studying corrosion casts and radiograms of intraparenchymal vessels (Christo, 1959 a, b, 1960, 1962, 1963, 1993). From 1958 to 1965, pioneer segmental resections were performed successfully in 34 dogs and in 9 patients to safely remove traumatic injured splenic segments. At the same time, the overwhelming postsplenectomy infection (OPSI) became well identified. Consequently, to save normally functioning splenic parenchyma became the most important issue in the management of splenic injuries. The anatomical basis for partial splenectomy and splenic segmentectomy is discussed. The term "splenorrhaphy" was employed to designate all conservative or parenchyma saving operations of spleen based upon its vascular supply: from topical packings to splenic sutures including "cappings" and partial splenectomies. From analysis of 38 consecutive reports in 20 years, covering 4,076 patients, it was concluded that "splenorrhaphies" had been electively employed in 46% of the injuries and partial splenectomies were identified in 8.6% of these surgical interventions. However, the critical minimal mass of splenic tissue to be preserved after partial splenectomies is still to be defined. Postoperative complications directly related to "splenorrhaphies" are rare. Uncommonly performed after splenectomies, the heterotopical splenic autotransplantation has presented dubious results. Trials with nonoperative management of splenic blunt trauma injuries have been safer among children, whose spleens are predominantly transversally disrupted and have a higher relationship "capsular resistance/parenchymal bulk". Splenectomies have been most frequently the ultimate result of delayed laparotomy and underlying risks of growing blood requirements may surpass the advantages of preventing OPSI. PMID:9341954

Christo, M C; DiDio, L J

1997-10-01

289

Landmark discrimination learning in the dog: effects of age, an antioxidant fortified food, and cognitive strategy.  

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The landmark discrimination learning test can be used to assess the ability to utilize allocentric spatial information to locate targets. The present experiments examined the role of various factors on performance of a landmark discrimination learning task in beagle dogs. Experiments 1 and 2 looked at the effects of age and food composition. Experiments 3 and 4 were aimed at characterizing the cognitive strategies used in performance on this task and in long-term retention. Cognitively equivalent groups of old and young dogs were placed into either a test group maintained on food enriched with a broad-spectrum of antioxidants and mitochondrial cofactors, or a control group maintained on a complete and balanced food formulated for adult dogs. Following a wash-in period, the dogs were tested on a series of problems, in which reward was obtained when the animal responded selectively to the object closest to a thin wooden block, which served as a landmark. In Experiment 1, dogs were first trained to respond to a landmark placed directly on top of coaster, landmark 0 (L0). In the next phase of testing, the landmark was moved at successively greater distances (1, 4 or 10 cm) away from the reward object. Learning varied as a function of age group, food group, and task. The young dogs learned all of the tasks more quickly than the old dogs. The aged dogs on the enriched food learned L0 significantly more rapidly than aged dogs on control food. A higher proportion of dogs on the enriched food learned the task, when the distance was increased to 1cm. Experiment 2 showed that accuracy decreased with increased distance between the reward object and landmark, and this effect was greater in old animals. Experiment 3 showed stability of performance, despite using a novel landmark, and new locations, indicating that dogs learned the landmark concept. Experiment 4 found age impaired long-term retention of the landmark task. These results indicate that allocentric spatial learning is impaired in an age-dependent manner in dogs, and that age also affects performance when the distance between the landmark and target is increased. In addition, these results both support a role of oxidative damage in the development of age-associated cognitive dysfunction and indicate that short-term administration of a food enriched with supplemental antioxidants and mitochondrial cofactors can partially reverse the deleterious effects of aging on cognition. PMID:12479842

Milgram, Norton W; Head, E; Muggenburg, B; Holowachuk, D; Murphey, H; Estrada, J; Ikeda-Douglas, C J; Zicker, S C; Cotman, C W

2002-10-01

290

Technical note: the design of a stereotactic frame for direct MRI-anatomical correlation of the brachial plexus.  

Science.gov (United States)

The purpose of this study was to identify optimal magnetic resonance imaging (MRI) conditions to visualize discrete alterations of brachial plexus components, as part of a biomechanical study of minor nerve compression syndromes. A method was developed allowing direct comparison between the MRI image and the subsequently obtained matching anatomic section of the same specimen. We designed a stereotactic frame to obtain the precise orientation of the MRI plane with reference to the specimen and adapted a vertical band saw for multiplanar sectioning of cadaveric specimens. Two cadaveric upper quadrants were examined by MRI (TR 450 ms, TE 13 ms, pixel matrix 512 x 512 and FOV 23-26 cm) and anatomical slices were produced. One specimen was sectioned axially, while the second specimen was sectioned in an oblique plane corresponding to the natural longitudinal axis of the upper part of the brachial plexus. MR images and the corresponding slices exhibited a strong correlation. This correlation was checked by using vitamin A pearls as landmarks. MR images revealed more detail after the correlating anatomical slices were analyzed. The present study shows that the method is suited for direct MRI-anatomic comparison of the brachial plexus and is also proposed for application to other topographical regions. PMID:16249823

Van Hoof, Tom; Mabilde, Cyriel; Leybaert, Luc; Verstraete, Koenraad; D'Herde, Katharina

2005-12-01

291

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

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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 prim...

Blundell, R.; Felice, A. E.

2006-01-01

292

Clinically relevant landmarks of the frontotemporal branch of the facial nerve: a three-dimensional study.  

Science.gov (United States)

The frontotemporal branch of the facial nerve (FTN) is vulnerable during craniofacial surgeries due to its superficial course and variable distribution. Surface landmarks that correlate with the underlying course of the FTN can assist in surgical planning. Estimates of the course of FTN commonly rely on Pitanguy's line (PL), which utilizes variable soft-tissue landmarks. The purpose of this study was to evaluate palpable surface landmarks to predict the course and distribution of FTN using 3D modeling. Fifteen half-heads were used. In five formalin-embalmed specimens, surface topography was obtained using a FARO® scanner and landmarks corresponding to PL, porion, supraorbital notch, frontozygomatic and zygomaticotemporal sutures, and supraorbitomeatal line (SOML) and infraorbitomeatal line (IOML) were demarcated/digitized using a Microscribe™ digitizer. A preauricular flap was raised, and branches of FTN were isolated and digitized. The data were reconstructed into 3D models (Geomagic®/Maya®) to quantify landmarks. In 10 Thiel-embalmed specimens, four independent raters identified/palpated and pinned the frontozygomatic and zygomaticotemporal sutures and PL. Data were collected and analyzed using the same protocol as in the first part of the study. Landmarking of PL was inconsistent between raters and not representative of FTN distribution. The easily identifiable surface landmarks defined in this study, a line 12 mm anterior to the porion along the SOML and IOML and a line joining the zygomaticotemporal and frontozygomatic sutures, comprehensively captured the distribution of FTN. The raters found a mean of 21 ± 2 branches between the lines out of a total of 22 ± 2 branches. These landmarks may be used clinically to avoid injury to FTN. PMID:22991167

Davies, Joel C; Fattah, Adel; Ravichandiran, Mayoorendra; Agur, Anne M

2012-10-01

293

Learning Compact Visual Descriptors for Low Bit Rate Mobile Landmark Search  

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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

294

Early effects of combretastatin A4 phosphate assessed by anatomic and carbogen-based functional magnetic resonance imaging on rat bladder tumors implanted in nude mice.  

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Combretastatin A4 phosphate (CA4P) causes rapid disruption of the tumor vasculature and is currently being evaluated for antivascular therapy. We describe the initial results obtained with a noninvasive multiparametric magnetic resonance imaging (MRI) approach to assess the early effects of CA4P on rat bladder tumors implanted on nude mice. MRI (4.7 T) comprised a fast spin-echo sequence for growth curve assessment; a multislice multiecho sequence for T2 measurement before, 15 minutes after, and 24 hours after CA4P (100 mg/kg); and a fast T2w* gradient-echo sequence to assess MR signal modification under carbogen breathing before, 35 minutes after, and 24 hours after CA4P. The tumor fraction with increased T2w* signal intensity under carbogen (T+) was used to quantify CA4P effect on functional vasculature. CA4P slowed tumor growth over 24 hours and accelerated necrosis development. T+ decrease was observed already at 35 minutes post-CA4P. Early T2 increase was observed in regions becoming necrotic at 24 hours post-CA4P, as confirmed by high T2 and histology. These regions exhibited, under carbogen, a switch from T2w* signal increase before CA4P to a decrease postCA4P. The combination of carbogen-based functional MRI and T2 measurement may be useful for the early follow-up of antivascular therapy without the administration of contrast agents. PMID:16867221

Thomas, Carole D; Walczak, Christine; Kaffy, Julia; Pontikis, Renée; Jouanneau, Jacqueline; Volk, Andreas

2006-07-01

295

Early Effects of Combretastatin A4 Phosphate Assessed by Anatomic and Carbogen-Based Functional Magnetic Resonance Imaging on Rat Bladder Tumors Implanted in Nude Mice  

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Full Text Available Combretastatin A4 phosphate (CA4P causes rapid disruption of the tumor vasculature and is currently being evaluated for antivascular therapy. We describe the initial results obtained with a noninvasive multiparametric magnetic resonance imaging (MRI approach to assess the early effects of CA4P on rat bladder tumors implanted on nude mice. MRI (4.7 T comprised a fast spin-echo sequence for growth curve assessment; a multislice multiecho sequence for T2 measurement before, 15 minutes after, 24 hours after CA4P (100 mg/kg; and a fast T2W* gradient-echo sequence to assess MR signal modification under carbogen breathing before, 35 minutes after, 24 hours after CA4P. The tumor fraction with increased T2W* signal intensity under carbogen (T+ was used to quantify CA4P effect on functional vasculature. CA4P slowed tumor growth over 24 hours and accelerated necrosis development. T+ decrease was observed already at 35 minutes post-CA4P. Early T2 increase was observed in regions becoming necrotic at 24 hours post-CA4P, as confirmed by high T2 and histology. These regions exhibited, under carbogen, a switch from T2W* signal increase before CA4P to a decrease postCA4P. The combination of carbogen-based functional MRI and T2 measurement may be useful for the early follow-up of antivascular therapy without the administration of contrast agents.

Carole D. Thomas

2006-07-01

296

Early Effects of Combretastatin A4 Phosphate Assessed by Anatomic and Carbogen-Based Functional Magnetic Resonance Imaging on Rat Bladder Tumors Implanted in Nude Mice1  

Science.gov (United States)

Abstract Combretastatin A4 phosphate (CA4P) causes rapid disruption of the tumor vasculature and is currently being evaluated for antivascular therapy. We describe the initial results obtained with a noninvasive multi-parametric magnetic resonance imaging (MRI) approach to assess the early effects of CA4P on rat bladder tumors implanted on nude mice. MRI (4.7 T) comprised a fast spin-echo sequence for growth curve assessment; a multislice multiecho sequence for T2 measurement before, 15 minutes after, and 24 hours after CA4P (100 mg/kg); and a fast T2w* gradient-echo sequence to assess MR signal modification under carbogen breathing before, 35 minutes after, and 24 hours after CA4P. The tumor fraction with increased T2w* signal intensity under carbogen (T+) was used to quantify CA4P effect on functional vasculature. CA4P slowed tumor growth over 24 hours and accelerated necrosis development. T+ decrease was observed already at 35 minutes post-CA4P. Early T2 increase was observed in regions becoming necrotic at 24 hours post-CA4P, as confirmed by high T2 and histology. These regions exhibited, under carbogen, a switch from T2w* signal increase before CA4P to a decrease post-CA4P. The combination of carbogen-based functional MRI and T2 measurement may be useful for the early follow-up of antivascular therapy without the administration of contrast agents. PMID:16867221

Thomas, Carole D.; Walczak, Christine; Kaffy, Julia; Pontikis, Renée; Jouanneau, Jacqueline; Volk, Andreas

2006-01-01

297

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

298

A method based on Monte Carlo simulations and voxelized anatomical atlases to evaluate and correct uncertainties on radiotracer accumulation quantitation in beta microprobe studies in the rat brain  

Science.gov (United States)

The ?-microprobe is a simple and versatile technique complementary to small animal positron emission tomography (PET). It relies on local measurements of the concentration of positron-labeled molecules. So far, it has been successfully used in anesthetized rats for pharmacokinetics experiments and for the study of brain energetic metabolism. However, the ability of the technique to provide accurate quantitative measurements using 18F, 11C and 15O tracers is likely to suffer from the contribution of 511 keV gamma rays background to the signal and from the contribution of positrons from brain loci surrounding the locus of interest. The aim of the present paper is to provide a method of evaluating several parameters, which are supposed to affect the quantification of recordings performed in vivo with this methodology. We have developed realistic voxelized phantoms of the rat whole body and brain, and used them as input geometries for Monte Carlo simulations of previous ?-microprobe reports. In the context of realistic experiments (binding of 11C-Raclopride to D2 dopaminergic receptors in the striatum; local glucose metabolic rate measurement with 18F-FDG and H2O15 blood flow measurements in the somatosensory cortex), we have calculated the detection efficiencies and corresponding contribution of 511 keV gammas from peripheral organs accumulation. We confirmed that the 511 keV gammas background does not impair quantification. To evaluate the contribution of positrons from adjacent structures, we have developed ?-Assistant, a program based on a rat brain voxelized atlas and matrices of local detection efficiencies calculated by Monte Carlo simulations for several probe geometries. This program was used to calculate the 'apparent sensitivity' of the probe for each brain structure included in the detection volume. For a given localization of a probe within the brain, this allows us to quantify the different sources of beta signal. Finally, since stereotaxic accuracy is crucial for quantification in most microprobe studies, the influence of stereotaxic positioning error was studied for several realistic experiments in favorable and unfavorable experimental situations (binding of 11C-Raclopride to D2 dopaminergic receptors in the striatum; binding of 18F-MPPF to 5HT1A receptors in the dorsal raphe nucleus).

Pain, F.; Dhenain, M.; Gurden, H.; Routier, A. L.; Lefebvre, F.; Mastrippolito, R.; Lanièce, P.

2008-10-01

299

Precise anatomical resection of the ventral part of Segment VIII  

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INTRODUCTION Anatomical resection of the ventral part of Segment VIII (S8vent) is demanding and there are no accurate methods to identify the demarcation line inside the liver. The current authors have proposed a method to solve the problem. PRESENTATION OF CASE The tumor was located in the S8vent and was 4 cm in size. One tributary of the middle hepatic vein (MHV), designated V8i, was running between S8vent and the dorsal part of Segment VIII (S8dor). Another tributary of the MHV, designated V8-5i, was running between S8vent and the ventral part of S5 (S5vent). About 5 ml of indigo carmine dye was injected into the proximal part of P8vent. After the small tributary of V8-5i was exposed, it was followed all the way to the main trunk of the MHV. The portal pedicle of S8vent was then ligated and divided. Next, the V8i was gradually exposed from the distal MHV to its trunk. DISCUSSION A recent study showed that the subsegmental border visualized between the ventral and dorsal region always coincided with the plane of V8i, so the subsegmental plane can be divided along with V8i by preserving the very small tributaries near the liver surface and following them to determine where they meet as they run into V8i. Also, the landmark vein of V8-5i in the transverse S8–S5 intersegmental plane was determined for the first time. CONCLUSION Proposed here is a more accurate method of dividing the liver parenchyma along the intersegmental and intersubsegmental demarcation. PMID:25460437

Xiang, Canhong; Liu, Zhe; Dong, Jiahong; Sano, Keiji; Makuuchi, Masatoshi

2014-01-01

300

Pattern recognition of anatomical shapes in CT scans  

International Nuclear Information System (INIS)

In medical image processing pattern recognition has become of major value in anatomical analysis and in computer aided information processing. Specifically, pattern recognition techniques simplify software development by means of which clinicians can manipulate anatomical relationships. As part of an overall CT pattern recognition system, a sequential edge tracking routine was devised together with a normalized Fourier descriptor analysis of identified shapes. A collection of shapes were extracted from CT scans of two patients and entered into an anatomic shape dictionary. This dictionary was employed in pattern matching experiments and in three-dimensional anatomical reconstruction. A sequential-edge tracking algorithm of high reliability, consistency, and image invariance, capable of utilizing heuristic and statistical rules, was demonstrated. Tests of pattern matching algorithms based on Fourier descriptors provided rapid and accurate body organ recognition of shapes extracted from de novo images using the shape dictionary. Results indicate that automated contour extraction and object recognition from cross-sectional images of human anatomy can be performed effectively, reliably, and rapidly. This abstract discusses an image processing environment that circumvents manual and subjective shape extraction, by substituting automatic and quantitative shape extraction, pattern matching and object recognition

 
 
 
 
301

Ethmomaxillary sinus: a particular anatomic variation of the paranasal sinuses  

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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

302

Atlas-driven scan planning for high-resolution micro-SPECT data acquisition based on multi-view photographs: a pilot study  

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Highly focused Micro-SPECT scanners enable the acquisition of functional small animal data with very high-resolution. To acquire a maximum of emitted photons from a specific structure of interest and at the same time minimize the required acquisition time, typically only a small subvolume of the animal is scanned that contains the organs of interest. This Volume of Interest (VOI) can be defined manually based on photographs of the animal taken prior to SPECT scanning, for example two lateral views and a top view. In these photographs however, only the surface of the animal is visible and therefore visual estimation of the location of these organs may be difficult. In this paper, we propose a novel atlas-based technique for estimating the organ VOI for the major organs by mapping a small animal atlas to optical scout images. The user is required to outline the animal contour in one lateral view, and to mark two lateral landmarks in the top view photograph. These landmarks subsequently serve as fiducial landmarks to define a 3D Thin-Plate-Spline mapping of an anatomical mouse atlas to the photographic coordinate space. Planar projections of the mapped atlas organs on the photographs greatly facilitate the estimation of the size and position of the target organ. To validate the proposed approach, the estimated organ VOIs were compared to manually drawn organ outlines in a Micro-CT scan, which was co-registered to the scout photographs using physical landmarks. The results demonstrate a highly promising volume correspondence between the real and the estimated organ VOIs.

Baiker, Martin; Vastenhouw, Brendan; Branderhorst, Woutjan; Reiber, Johan H. C.; Beekman, Freek; Lelieveldt, Boudewijn P. F.

2009-02-01

303

Effects of Instructional Strategies Using Cross Sections on the Recognition of Anatomical Structures in Correlated CT and MR Images  

Science.gov (United States)

This research is an effort to best utilize the interactive anatomical images for instructional purposes based on cognitive load theory. Three studies explored the differential effects of three computer-based instructional strategies that use anatomical cross-sections to enhance the interpretation of radiological images. These strategies include:…

Khalil, Mohammed K.; Paas, Fred; Johnson, Tristan E.; Su, Yung K.; Payer, Andrew F.

2008-01-01

304

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

305

[The anatomical revolution and the transition of anatomical conception in late imperial china].  

Science.gov (United States)

This paper aimed to examine the anatomical revolution from Yilingaicuo (Correcting the Errors of Medicine) and Quantixinlun(Outline of Anatomy and Physiology) in late imperial China. As the cephalocentrism which the brain superintend human operation of the mind was diffused in China since 16th century, the cephalocentrism and the cardiocentrism had competed for the hegemony of anatomical conception. Because of the advent of Yilingaicuo and Quantixinlun, the cephalocentrism became the main stream in the anatomical conception. The supporters of the Wang Yangming's Xinxue(the Learning of Heart and Mind) argued that the heart was the central organ of perception, sensitivity, and morality of the human body in medicine since 16th century. Even reformist and revolutionary intellectuals like Tan sitong and Mao zedong who had supported the Wang Yangming's Xinxue embraced the cephalocentrism in the late 19th century and the early 20th century. May Fourth intellectuals had not obsessed metaphysical interpretation of human body any more in the New Culture Movement in 1910s. They regarded human body as the object of research and writing. The anatomy was transformed into the instrumental knowledge for mutilation of the body. Yilingaicuo challenged the traditional conception of body, and Chinese intellectuals drew interest in the anatomy knowledge based on real mutilation. Quantixinlun based on Western medicine fueled a controversy about anatomy. Though new knowledge of anatomy was criticized by traditional Chinese medical doctors from the usefulness and morality of anatomy, nobody disavowed new knowledge of anatomy from the institutionalization of Western medicine in medical school. The internal development of cephalocentrism and positivism had influence on anatomy in China since 16th century. The advent of Yilingaicuo and Quantixinlun provided the milestone of new anatomy, though both sides represented traditional Chinese medicine and Western medicine respectively. They contributed to the development of new knowledge of anatomy, getting over the metaphysical system of knowledge. Based on the internal development of anatomy, Chinese anatomy was half century late than Japanese anatomy founded on Dutch anatomy. PMID:22739627

Sihn, Kyu Hwan

2012-04-30

306

Lumbar hernia: anatomical route assessed by computed tomography.  

Science.gov (United States)

Lumbar hernia is classically described as arising from the superior (Grynfeltt's) lumbar triangle or the inferior (Jean-Louis Petit's) lumbar triangle. The present anatomical study based on a computed tomography examination performed in a patient with lumbar hernia, has led to the suggestion that lumbar hernias cross the lumbar wall through a musculoaponeurotic tunnel, whose deep and superficial openings are the superior and inferior lumbar triangles, respectively. PMID:12197011

Guillem, P; Czarnecki, E; Duval, G; Bounoua, F; Fontaine, C

2002-02-01

307

The aspects regarding Chrysanthemum vitro- and exvitroplantlets anatomical structure  

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Full Text Available This study was consecrate to observe the histoanatomical structure of roots stems and leafs of Chrysanthemum vitroplantlets, in their vitroculture period and of exvitroplantlets, at 30 days from their septic medium transfer. The registered observations were compared with those realized at similar organs level of greenhouse plants (control lot. The noted differences between vitroplantlets anatomical structure and that greenhouse plants had, in special, ontogenetic bases.

Adriana PETRUS-VANCEA

2007-05-01

308

Morphological and anatomical studies of Cyani herba  

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Full Text Available Morphological and anatomical investigation were carried out on stem, leaves, flowers and bracts of the species Centaurea cyanusL. The diagnostic parameters of vegetal product Cyani herbawere defined.

Tatiana Chiru

2013-04-01

309

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

310

Estimativas da composição anatômica da carcaça de frangos de corte com base no nível de proteína da ração e peso da carcaça Estimation of the carcasses anatomical composition of broiler from diet quality and carcass weight  

Directory of Open Access Journals (Sweden)

Full Text Available Um experimento foi desenvolvido com o objetivo de estimar as proporções dos cortes nobres da carcaça de frangos de corte pelo modelo linear. Foram utilizados 842 frangos machos da linhagem Avian Farms, de 22 a 42 dias de idade, distribuídos num delineamento inteiramente ao acaso em esquema fatorial 3x4. Foram fornecidas rações formuladas à base de milho e farelo de soja para conter 2.900 kcal de EM e 15,43; 17,26; 19,60; e 22,60% de PB; 3.100 kcal de EM e 16,49; 18,45; 20,95; e 24,22% de PB; e 3300 kcal de EM e 17,55; 19,64; 22,30; e 25,78% de PB, totalizando doze tratamentos. Cada tratamento foi constituído por quatro repetições de 18 aves. Fortes correlações foram observadas entre o peso vivo aos 42 dias e o peso da carcaça (r = 0,958, o peso da carcaça e o peso de pernas (r = 0,991, peso de peito+osso+pele (r = 0,965 e peso de peito desossado (r = 0,950. A porcentagem de lipídio foi negativamente correlacionada com a porcentagem de umidade da carcaça (r = -0,880. A equação linear é recomendada para a predição dos componentes anatômicos da carcaça de frangos de corte.An experiment was carried out to estimate the relations between broiler carcass weight and thighs+drumsticks, breast+bone+skin, and breast meat by the linear model. Eight hundred and sixty and four male poultry of Arbor Acres strain, from 22 to 42 days of age, were assigned to a completely randomized design in 3x4factorial scheme. Corn and soybean meal based diets were prepared to contain 2900 kcal ME and 15.43; 17.26; 19.60; and 22.60% CP; 3,100 kcal ME and 16.49; 18.45; 20.95; and 24.22%CP; and 3300 kcal ME and 17.55; 19.64; 22.30; and 25.78% CP, resulting in twelve treatments. Each treatment was constituted of four replicates of 18 birds. High correlations were observed between live weight at 42 days old and carcass weight (r = 0.958, carcass weight and thighs+drumsticks (r = 0.991, breast+bone+skin (r = 0.965 and deboned breast meat weight (r = 0.950. The lipid percentage was negatively correlated to the moisture percentage (r = -0.880. The linear equation is recommended to estimate carcass anatomical components in broiler chickens.

José Humberto Vilar da Silva

2003-04-01

311

Review of Functional/ Anatomic Imaging in Oncology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Patient management in oncology increasingly relies upon imaging for diagnosis, response assessment, and follow-up. The clinical availability of combined functional-anatomic imaging modalities, which integrate the benefits of visualizing tumor biology with those of high-resolution structural imaging, revolutionized clinical management of oncologic patients.[1–6] Conventional high resolution anatomic imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) exce...

Histed, Stephanie N.; Lindenberg, Maria L.; Mena, Esther; Turkbey, Baris; Choyke, Peter L.; Kurdziel, Karen A.

2012-01-01

312

Engineering anatomically shaped human bone grafts  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The ability to engineer anatomically correct pieces of viable and functional human bone would have tremendous potential for bone reconstructions after congenital defects, cancer resections, and trauma. We report that clinically sized, anatomically shaped, viable human bone grafts can be engineered by using human mesenchymal stem cells (hMSCs) and a “biomimetic” scaffold-bioreactor system. We selected the temporomandibular joint (TMJ) condylar bone as our tissue model, because of its clini...

Grayson, Warren L.; Fro?hlich, Mirjam; Yeager, Keith; Bhumiratana, Sarindr; Chan, M. Ete; Cannizzaro, Christopher; Wan, Leo Q.; Liu, X. Sherry; Guo, X. Edward; Vunjak-novakovic, Gordana

2009-01-01

313

The Architectural Features and Prevalence of Contemporary Landmarks in Kaunas City  

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Full Text Available The article focuses on contemporary architectural accents and their architectural features in Kaunas city. The paper also analyses the prevalence of contemporary architectural accents in the city. Some tendencies towards creating Kaunas landmarks, relationship between them and the built environment and aesthetic measures are discussed on the basis of analyzing the most important and characteristic sacral, commercial, industrial and residential architecture patterns. It can be concluded that contemporary materials as well as a lightweight construction and the courage of architects helped with producing the image of modern architectural landmark, though the spread of Kaunas contemporary landmarks has a chaotic character and the cityscape has not been enriched by the powerful dominants of space structure.Article in Lithuanian

Almantas Bružas

2011-03-01

314

Anatomic connectivity assessed using pathway radial diffusivity is related to functional connectivity in monosynaptic pathways.  

Science.gov (United States)

This work presents a pathway-dependent anatomic and functional connectivity analysis in 19 patients with relapse-remitting multiple sclerosis (MS) and 16 age-, education-, and gender-matched controls. An MS population is used in this study as a model for anatomic connectivity, permitting us to observe relationships between anatomic and functional connectivity more easily. A combined resting-state functional magnetic resonance imaging (fMRI) and whole-brain, high angular resolution diffusion imaging analysis is performed in three independent, monosynaptic pathways. The pathways chosen were transcallosal pathway connecting the bilateral primary sensorimotor regions, right and left posterior portion of the Papez circuit, connecting the posterior cingulate cortex and hippocampus. The Papez circuit is known to be involved in memory function, one of the most frequently impacted cognitive domains in patients with MS. We show that anatomic connectivity, as measured with diffusion-weighted imaging, and functional connectivity, as measured with resting-state fMRI, are significantly reduced in patients as compared with controls for at least some of the pathways considered. In addition when all pathway measures are combined, anatomic and functional connectivity are significantly correlated in patients with MS as well as healthy controls. We suggest that anatomic and functional connectivity are related for monosynaptic pathways and that radial diffusivity, as a diffusion-tensor-based measure of white matter integrity, is a robust measure of anatomic connectivity in the general population. PMID:25117651

Lowe, Mark J; Koenig, Katherine A; Beall, Erik B; Sakaie, Ken A; Stone, Lael; Bermel, Robert; Phillips, Michael D

2014-09-01

315

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)

316

Ontological Labels for Automated Location of Anatomical Shape Differences  

Science.gov (United States)

A method for automated location of shape differences in diseased anatomical structures via high resolution biomedical atlases annotated with labels from formal ontologies is described. In particular, a high resolution magnetic resonance image of the myocardium of the human left ventricle was segmented and annotated with structural terms from an extracted subset of the Foundational Model of Anatomy ontology. The atlas was registered to the end systole template of a previous study of left ventricular remodeling in cardiomyopathy using a diffeomorphic registration algorithm. The previous study used thresholding and visual inspection to locate a region of statistical significance which distinguished patients with ischemic cardiomyopathy from those with nonischemic cardiomyopathy. Using semantic technologies and the deformed annotated atlas, this location was more precisely found. Although this study used only a cardiac atlas, it provides a proof-of-concept that ontologically labeled biomedical atlases of any anatomical structure can be used to automate location-based inferences. PMID:22490168

Steinert-Threlkeld, Shane; Ardekani, Siamak; Mejino, Jose L.V.; Detwiler, Landon Todd; Brinkley, James F.; Halle, Michael; Kikinis, Ron; Winslow, Raimond L.; Miller, Michael I.; Ratnanather, J. Tilak

2012-01-01

317

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

318

Indexing Anatomical Phrases in Neuro-Radiology Reports to the UMLS 2005AA  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This work describes a methodology to index anatomical phrases to the 2005AA release of the Unified Medical Language System (UMLS). A phrase chunking tool based on Natural Language Processing (NLP) was developed to identify semantically coherent phrases within medical reports. Using this phrase chunker, a set of 2,551 unique anatomical phrases was extracted from brain radiology reports. These phrases were mapped to the 2005AA release of the UMLS using a vector space model. Pr...

Bashyam, Vijayaraghavan; Taira, Ricky K.

2005-01-01

319

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

320

Anatomical accuracy of brain connections derived from diffusion MRI tractography is inherently limited.  

Science.gov (United States)

Tractography based on diffusion-weighted MRI (DWI) is widely used for mapping the structural connections of the human brain. Its accuracy is known to be limited by technical factors affecting in vivo data acquisition, such as noise, artifacts, and data undersampling resulting from scan time constraints. It generally is assumed that improvements in data quality and implementation of sophisticated tractography methods will lead to increasingly accurate maps of human anatomical connections. However, assessing the anatomical accuracy of DWI tractography is difficult because of the lack of independent knowledge of the true anatomical connections in humans. Here we investigate the future prospects of DWI-based connectional imaging by applying advanced tractography methods to an ex vivo DWI dataset of the macaque brain. The results of different tractography methods were compared with maps of known axonal projections from previous tracer studies in the macaque. Despite the exceptional quality of the DWI data, none of the methods demonstrated high anatomical accuracy. The methods that showed the highest sensitivity showed the lowest specificity, and vice versa. Additionally, anatomical accuracy was highly dependent upon parameters of the tractography algorithm, with different optimal values for mapping different pathways. These results suggest that there is an inherent limitation in determining long-range anatomical projections based on voxel-averaged estimates of local fiber orientation obtained from DWI data that is unlikely to be overcome by improvements in data acquisition and analysis alone. PMID:25368179

Thomas, Cibu; Ye, Frank Q; Irfanoglu, M Okan; Modi, Pooja; Saleem, Kadharbatcha S; Leopold, David A; Pierpaoli, Carlo

2014-11-18

 
 
 
 
321

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)

322

Estimativas da composição anatômica da carcaça de frangos de corte com base no nível de proteína da ração e peso da carcaça / Estimation of the carcasses anatomical composition of broiler from diet quality and carcass weight  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Um experimento foi desenvolvido com o objetivo de estimar as proporções dos cortes nobres da carcaça de frangos de corte pelo modelo linear. Foram utilizados 842 frangos machos da linhagem Avian Farms, de 22 a 42 dias de idade, distribuídos num delineamento inteiramente ao acaso em esquema fatorial [...] 3x4. Foram fornecidas rações formuladas à base de milho e farelo de soja para conter 2.900 kcal de EM e 15,43; 17,26; 19,60; e 22,60% de PB; 3.100 kcal de EM e 16,49; 18,45; 20,95; e 24,22% de PB; e 3300 kcal de EM e 17,55; 19,64; 22,30; e 25,78% de PB, totalizando doze tratamentos. Cada tratamento foi constituído por quatro repetições de 18 aves. Fortes correlações foram observadas entre o peso vivo aos 42 dias e o peso da carcaça (r = 0,958), o peso da carcaça e o peso de pernas (r = 0,991), peso de peito+osso+pele (r = 0,965) e peso de peito desossado (r = 0,950). A porcentagem de lipídio foi negativamente correlacionada com a porcentagem de umidade da carcaça (r = -0,880). A equação linear é recomendada para a predição dos componentes anatômicos da carcaça de frangos de corte. Abstract in english An experiment was carried out to estimate the relations between broiler carcass weight and thighs+drumsticks, breast+bone+skin, and breast meat by the linear model. Eight hundred and sixty and four male poultry of Arbor Acres strain, from 22 to 42 days of age, were assigned to a completely randomize [...] d design in 3x4factorial scheme. Corn and soybean meal based diets were prepared to contain 2900 kcal ME and 15.43; 17.26; 19.60; and 22.60% CP; 3,100 kcal ME and 16.49; 18.45; 20.95; and 24.22%CP; and 3300 kcal ME and 17.55; 19.64; 22.30; and 25.78% CP, resulting in twelve treatments. Each treatment was constituted of four replicates of 18 birds. High correlations were observed between live weight at 42 days old and carcass weight (r = 0.958), carcass weight and thighs+drumsticks (r = 0.991), breast+bone+skin (r = 0.965) and deboned breast meat weight (r = 0.950). The lipid percentage was negatively correlated to the moisture percentage (r = -0.880). The linear equation is recommended to estimate carcass anatomical components in broiler chickens.

José Humberto Vilar da, Silva; Luís Fernando Teixeira, Albino; Adriana Helena do, Nascimento.

2003-04-01

323

Cardiac Anatomic Considerations in Pediatric Electrophysiology  

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Full Text Available Although interventional electrophysiology and the use of radiofrequency energy to cure various arrhythmias primarily developed in the adult population, similar applications in children have grown dramatically over the last decade. The anatomic basis for various arrhythmias is critically important for the pediatric ablationists to appreciate. Such understanding allows the use of alternative technique to affect cure while avoiding complications. Further, because of the relatively small heart and less thick myocardium in children, without the appreciation of the underlying cardiac anatomic relationships, collateral injury, for example to the arterial system, may occur. In this review, the cardiac anatomic consideration important in approaching various supraventricular and ventricular arrhythmias in the normal heart is discussed.

Samuel J. Asirvatham

2008-05-01

324

Navigation in wood ants Formica japonica: context dependent use of landmarks.  

Science.gov (United States)

Wood ants Formica japonica can steer their outbound (foraging) and inbound (homing) courses without using celestial compass information, by relying exclusively on landmark cues. This is shown by training ants to run back and forth between the nest and an artificial feeder, and later displacing the trained ants either from the nest (when starting their foraging runs: outbound full-vector ants) or from the feeder (when starting their home runs: inbound full-vector ants) to various nearby release sites. In addition, ants that have already completed their foraging and homing runs are displaced after arrival either at the feeder (outbound zero-vector ants) or at the nest (inbound zero-vector ants), respectively, to the very same release sites. Upon release, the full-vector ants steer their straight courses by referring to panoramic landmark cues, while the zero-vector ants presented with the very same visual scenery immediately search for local landmark cues defining their final goal. Hence, it depends on the context, in this case on the state of the forager's round-trip cycle, what visual cues are picked out from a given set of landmarks and used for navigation. PMID:15326219

Fukushi, Tsukasa; Wehner, Rüdiger

2004-09-01

325

Reproducibility of Acetabular Landmarks and a Standardized Coordinate System Obtained from 3D Hip Ultrasound.  

Science.gov (United States)

Two-dimensional (2D) ultrasound detection of developmental dysplasia of the hip (DDH) is limited by variation in acetabular appearance and alpha angle measurements, which change with position of the ultrasound probe. Three-dimensional (3D) ultrasound captures the entire acetabular shape, and a reproducible "standard central plane" may be generated, from two landmarks located on opposite ends of the acetabulum, for measurement of alpha angle and other indices. Two users identified landmarks on 51 3D ultrasounds, with ranging severity of disease, and inter- and intra-observer reproducibility of landmark and "standard plane" locations was compared; landmarks were chosen within 2 mm, and the "standard plane" rotation was reproducible within 10° between observers. We observed no difference in variability between alpha angles measured on the "standard plane" in comparison with 2D ultrasound. Applications of the standardized 3D ultrasound central plane will be to fuse serial ultrasounds for follow-up and development of new indices of 3D deformity. PMID:25394808

Mabee, Myles; Dulai, Sukhdeep; Thompson, Richard B; Jaremko, Jacob L

2014-11-13

326

Smells like home: Desert ants, Cataglyphis fortis, use olfactory landmarks to pinpoint the nest  

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Full Text Available Abstract Background Cataglyphis fortis ants forage individually for dead arthropods in the inhospitable salt-pans of Tunisia. Locating the inconspicuous nest after a foraging run of more than 100 meters demands a remarkable orientation capability. As a result of high temperatures and the unpredictable distribution of food, Cataglyphis ants do not lay pheromone trails. Instead, path integration is the fundamental system of long-distance navigation. This system constantly informs a foraging ant about its position relative to the nest. In addition, the ants rely on visual landmarks as geocentric navigational cues to finally pinpoint the nest entrance. Results Apart from the visual cues within the ants' habitat, we found potential olfactory landmark information with different odour blends coupled to various ground structures. Here we show that Cataglyphis ants can use olfactory information in order to locate their nest entrance. Ants were trained to associate their nest entrance with a single odour. In a test situation, they focused their nest search on the position of the training odour but not on the positions of non-training odours. When trained to a single odour, the ants were able to recognise this odour within a mixture of four odours. Conclusion The uniform salt-pans become less homogenous if one takes olfactory landmarks into account. As Cataglyphis ants associate environmental odours with the nest entrance they can be said to use olfactory landmarks in the vicinity of the nest for homing.

Knaden Markus

2009-02-01

327

Anatomical Studies in Relation to Taxonomy of Persian Linum Species  

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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

328

Congenital neck masses: embryological and anatomical perspectives  

Directory of Open Access Journals (Sweden)

Full Text Available Neck masses are a common problem in paediatric age group. They tend to occur frequently and pose a diagnostic dilemma to the ENT surgeons. Although the midline and lateral neck masses differ considerably in their texture and presentation but the embryological perspective of these masses is not mostly understood along with the fundamental anatomical knowledge. The article tries to correlate the embryological, anatomical and clinical perspectives for the same. [Int J Res Med Sci 2013; 1(4.000: 329-332

Zahida Rasool

2013-08-01

329

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

330

Image-guided robotic skull base surgery.  

Science.gov (United States)

Objectives?To describe the potential uses of computed tomography image guidance in concert with the surgical robot for skull base surgery. Design?An anatomical study was conducted. Setting?Tertiary academic center. Participants?Cadaveric skull. Main Outcome Measures?The primary outcome measure was to measure the accuracy of robotic arm positioning to anatomical landmarks on a skull using image guidance and the surgical robot synchronously. Instruments with different angles of rotations were used. Estimated systematic error was calculated and compared with achieved errors. Clinical applications of metachronous image guidance and robotic system were discussed. Results?The skull model approximated?robotic arm positioning. Increased angles of instruments from 20 to 60 degrees on the robotic system revealed more significant increases in error than estimated. Conclusions?Image guidance may be useful for transoral robotic approaches. Precise movements are improved by limiting the angle of deviation. Future studies will help optimize the combined technologies before validating the study in clinical settings. PMID:25093145

Austin, Grace Kim; McKinney, Kibwei A; Ebert, Charles S; Zanation, Adam M

2014-08-01

331

Simulating deformations of MR brain images for validation of atlas-based segmentation and registration algorithms.  

Science.gov (United States)

Simulated deformations and images can act as the gold standard for evaluating various template-based image segmentation and registration algorithms. Traditional deformable simulation methods, such as the use of analytic deformation fields or the displacement of landmarks followed by some form of interpolation, are often unable to construct rich (complex) and/or realistic deformations of anatomical organs. This paper presents new methods aiming to automatically simulate realistic inter- and intra-individual deformations. The paper first describes a statistical approach to capturing inter-individual variability of high-deformation fields from a number of examples (training samples). In this approach, Wavelet-Packet Transform (WPT) of the training deformations and their Jacobians, in conjunction with a Markov random field (MRF) spatial regularization, are used to capture both coarse and fine characteristics of the training deformations in a statistical fashion. Simulated deformations can then be constructed by randomly sampling the resultant statistical distribution in an unconstrained or a landmark-constrained fashion. The paper also describes a model for generating tissue atrophy or growth in order to simulate intra-individual brain deformations. Several sets of simulated deformation fields and respective images are generated, which can be used in the future for systematic and extensive validation studies of automated atlas-based segmentation and deformable registration methods. The code and simulated data are available through our Web site. PMID:16997578

Xue, Zhong; Shen, Dinggang; Karacali, Bilge; Stern, Joshua; Rottenberg, David; Davatzikos, Christos

2006-11-15

332

The trabecula septomarginalis (Leonardo’s cord) in abnormal ventriculo-arterial connections: anatomic and morphogenetic implications  

Science.gov (United States)

Background The abnormal ventriculo-arterial connections in atrio-ventricular concordance and situs solitus with two well developed ventricles include the range from tetralogy of Fallot throughout the different forms of double outlet right ventricle to transposition of great arteries. The infundibular septum and the trabecula septomarginalis are the fundamental anatomical landmarks for the segmental analysis. In these abnormalities there is a pathological progressive counter-clockwise rotation of the infundibular septum which divorces from the antero-superior limb of the trabecula septomarginalis and achieves his identity. Is there any anatomical evidence of a simultaneous abnormal counter-clockwise rotation of the trabecula septomarginalis? Methods Malposition of great arteries is a generic term since all relationships have to be expected. We present specimens with anatomical evidence of a progressive counter-clockwise rotation from 0° to about 180°of the plane passing throughout the trabecula septomarginalis’s limbs. Results We can observe sequentially: 1. Malformations in which the posterior limb of the trabecula septomarginalis is committed to the ventriculo infundibular fold: (tetralogy of Fallot, double outlet right ventricle with sub-aortic ventricular septal defect, truncus arteriosus and doubly committed ventricular septal defect); 2. Malformations in which the posterior limb of the trabecula septomarginalis is committed to the infundibular septum (double outlet right ventricle with sub-pulmonary ventricular septal defect, transposition of great arteries). Conclusions 1. The sequential-segmental analysis identify all the morphologies. 2. The trabecula septomarginalis plane presents a progressive counter-clockwise twist on the long axis. 3. Since the trabeculated portions of the ventricles are the oldest developmental components, our observations support the hypothesis that the abnormal ventriculo-arterial connections could be in relation with a pathological myocardial process during early cardio-genesis. We are promoting new studies to investigate our anatomical observations. PMID:24750982

2014-01-01

333

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

334

Anatomical Pathways for Auditory Memory in Primates  

Directory of Open Access Journals (Sweden)

Full Text Available 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 that, like the ‘visual ventral stream’ for which the connections of the inferior temporal gyrus with the perirhinal cortex are necessary for visual recognition in monkeys, direct connections between the auditory association areas of the superior temporal gyrus and the hippocampal formation and with the parahippocampal region (temporal pole, perhirinal, and posterior parahippocampal cortices might also underlie recognition memory for sounds. Alternatively, the anatomical organization of memory could be different in audition. This alternative ‘indirect stream’ hypothesis posits that, unlike the visual association cortex, the majority of auditory association cortex makes one or more synapses in intermediate, polymodal areas, where they may integrate information from other sensory modalities, before reaching the medial temporal memory system. This review considers anatomical studies that can support either one or both hypotheses – focusing on anatomical studies on the primate brain that have reported not only direct auditory association connections with medial temporal areas, but, importantly, also possible indirect pathways for auditory information to reach the medial temporal lobe memory system.

RicardoInsausti

2010-10-01

335

Anatomical research of pine trees' sprouts  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present about Pinus sylvestris, Picea abies, Larix ecidua wood's sprouts or bark anatomical characteristic in the bachhelour's report.Using 16 dyes is determined that the parachemic cells'walls have the most celulose and lignines concentrates on thin disher or fibres'walls.

Brazyte?-gorochoviene?, Violeta

2004-01-01

336

Accuracy of three-dimensional, paper-based models generated using a low-cost, three-dimensional printer.  

Science.gov (United States)

Our study aimed to determine the accuracy of a low-cost, paper-based 3D printer by comparing a dry human mandible to its corresponding three-dimensional (3D) model using a 3D measuring arm. One dry human mandible and its corresponding printed model were evaluated. The model was produced using DICOM data from cone beam computed tomography. The data were imported into Maxilim software, wherein automatic segmentation was performed, and the STL file was saved. These data were subsequently analysed, repaired, cut and prepared for printing with netfabb software. These prepared data were used to create a paper-based model of a mandible with an MCor Matrix 300 printer. Seventy-six anatomical landmarks were chosen and measured 20 times on the mandible and the model using a MicroScribe G2X 3D measuring arm. The distances between all the selected landmarks were measured and compared. Only landmarks with a point inaccuracy less than 30% were used in further analyses. The mean absolute difference for the selected 2016 measurements was 0.36 ± 0.29 mm. The mean relative difference was 1.87 ± 3.14%; however, the measurement length significantly influenced the relative difference. The accuracy of the 3D model printed using the paper-based, low-cost 3D Matrix 300 printer was acceptable. The average error was no greater than that measured with other types of 3D printers. The mean relative difference should not be considered the best way to compare studies. The point inaccuracy methodology proposed in this study may be helpful in future studies concerned with evaluating the accuracy of 3D rapid prototyping models. PMID:25176496

Olszewski, Raphael; Szymor, Piotr; Kozakiewicz, Marcin

2014-12-01

337

The Accuracy of the New Landmark Using Respiratory Jugular Venodilation and Direct Palpation in Right Internal Jugular Vein Access  

Science.gov (United States)

Background Although ultrasonography is recommended in internal jugular vein (IJV) catheterization, the landmark-guided technique should still be considered. The central landmark using the two heads of the sternocleidomastoid muscle is widely used, but it is inaccurate for IJV access. As an alternative landmark, we investigated the accuracy of the new landmark determined by inspection of the respiratory jugular venodilation and direct IJV palpation in right IJV access by ultrasonography. Methods and Findings Thirty patients were enrolled. After induction of anesthesia, the central landmark was marked at the cricoid cartilage level (M1) and the alternative landmark determined by inspection of the respiratory jugular venodilation and direct palpation of IJV was also marked at the same level (M2). Using ultrasonography, the location of IJV was identified (M3) and the distance between M1 and M3 as well as between M2 and M3 were measured. The median (interquartile range) distance between the M2 and M3 was 3.5 (2.0–6.0) mm, compared to 17.5 (12.8–21.3) mm between M1 and M3. (P<0.001) The dispersion of distances between M2 and M3 was significantly smaller than between M1 and M3. (P<0.001) The visibility of respiratory jugular venodilation was associated with CVP more than 4 mmHg. Limitations of the present study are that the inter-observer variability was not investigated and that the visibility of the alternative landmark can be limited to right IJV in adults. Conclusion The alternative landmark may allow shorter distance for the right side IJV access than the central landmark and can offer advantages in right IJV catheterization when ultrasound device is unavailable. Trial Registration Clinical Research Informational Service KCT0000812 PMID:25050554

Seo, Hyungseok; Jang, Dong-Min; Yi, Jung-Min; Min, Hong-Gi; Hwang, Jai-Hyun

2014-01-01

338

Computer-assisted analysis of anatomical relationships of the ethmoidal foramina and optic canal along the medial orbital wall.  

Science.gov (United States)

Typically, the medial orbital wall contains an anterior ethmoidal foramen (EF) and a posterior EF, but may also have multiple EFs transmitting the arteries and nerves between the orbit and the anterior cranial fossa. The aim of this study is to determine a patient-friendly landmark of the medial orbital wall and to specify a precise location of the ethmoidal foramens (EF) in order to standardize certain anatomical marks as safe ethmoidal arteries. Orientation points on the anterior ethmoidal foramen (AEF), posterior ethmoidal foramen (PEF) and middle ethmoidal foramen (MEF) were investigated in 262 orbits. Using a software program, distances between each foramen and the midpoint of the anterior lacrimal crest (ALC), the optic canal (OC), and some important angles were measured. The EFs were identified as single in 0.8 %, double in 73.7 %, triple 24,4 % and quadruple in 1.1 % specimens. The mean distances between ALC and AEF, ALC and PEF and ALC and MEF were 27.7, 10.6, and 12.95 mm, respectively. The distances from ALC-AEF, AEF-PEF, and PEF-OC were 27.7 ± 2.8, 10.6 ± 3.3, 5.4 ± 1 mm. The angles from the plane of the EF to the medial border of the OC were calculated as 13.2° and 153°, respectively. The angle from the AEF to the medial border of the OC was based on the plane between the ALC and AEF was 132°. The occurrence of multiple EF with an incidence of 25 % narrows the borders of the safe region in the medial orbital wall. Safe distance of the ALC-EF was measured as 22.1 mm on medial wall. The line of the location of the EF was calculated 16.2 mm. In this study, it was possible to investigate the variability of the orbital orifice of the EF and the feasibility of the EA, to observe various angles of the orbital wall bones and to calculate the lengths of some parameters with the help of certain software. PMID:25367707

Celik, Servet; Ozer, Mehmet Asim; Kazak, Zuhal; Govsa, Figen

2014-11-01

339

Augmented reality for anatomical education.  

Science.gov (United States)

The use of Virtual Environments has been widely reported as a method of teaching anatomy. Generally such environments only convey the shape of the anatomy to the student. We present the Bangor Augmented Reality Education Tool for Anatomy (BARETA), a system that combines Augmented Reality (AR) technology with models produced using Rapid Prototyping (RP) technology, to provide the student with stimulation for touch as well as sight. The principal aims of this work were to provide an interface more intuitive than a mouse and keyboard, and to evaluate such a system as a viable supplement to traditional cadaver based education. PMID:20297908

Thomas, Rhys Gethin; John, Nigel William; Delieu, John Michael

2010-03-01

340

Computer tomographic imaging and anatomic correlation of the human brain: A comparative atlas of thin CT-scan sections and correlated neuro-anatomic preparations  

International Nuclear Information System (INIS)

It is of the greatest importance to the radiologist, the neurologist and the neurosurgeon to be able to localize topographically a pathological brain process on the CT scan as precisely as possible. For that purpose, the identification of as many anatomical structures as possible on the CT scan image are necessary and indispensable. In this atlas a great number of detailed anatomical data on frontal horizontal CT scan sections, each being only 2 mm thick, are indicated, e.g. the cortical gyri, the basal ganglia, details of the white matter, extracranial muscles and blood vessels, parts of the base and the vault of the skull, etc. The very precise topographical description of the numerous CT scan images was realized by the author by confrontation of these images with the corresponding anatomical sections of the same brain specimen, performed by an original technique

 
 
 
 
341

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 orientt 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.)

342

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

343

Cortical projection of the inferior choroidal point as a reliable landmark to place the corticectomy and reach the temporal horn through a middle temporal gyrus approach / Projeção cortical do ponto coroideo inferior como uma referência anatômica confiável para a realização da corticectomia e abordagem do corno temporal através do giro temporal médio.  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Objetivo Estabelecer a projeção cortical do ponto coiroideo inferior e usá-la como referência para realizar a corticectomia e a abordagem do corno temporal do ventrículo lateral em cirurgias para o tratamento da epilepsia temporal mesial. Método A projeção cortical do ponto coroideo inferior foi [...] utilizada por um dos autores seniors em mais de 300 casos de epilepsia temporal mesial para atingir o corno temporal do ventrículo lateral. Conclusão A projeção cortical do ponto coroideo inferior foi útil e confiável na abordagem do corno temporal do ventrículo lateral e ela está geralmente localizada na margem inferior do giro temporal médio, em média, a 4,52 cm posterior ao polo temporal. Abstract in english Objective To establish preoperatively the localization of the cortical projection of the inferior choroidal point (ICP) and use it as a reliable landmark when approaching the temporal horn through a middle temporal gyrus access. To review relevant anatomical features regarding selective amigdalohip [...] pocampectomy (AH) for treatment of mesial temporal lobe epilepsy (MTLE). Method The cortical projection of the inferior choroidal point was used in more than 300 surgeries by one authors as a reliable landmark to reach the temporal horn. In the laboratory, forty cerebral hemispheres were examined. Conclusion The cortical projection of the ICP is a reliable landmark for reaching the temporal horn.

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

2014-10-01

344

PAVA: Physiological and Anatomical Visual Analytics for Mapping of Tissue-Specific Concentration and Time-Course Data  

Science.gov (United States)

We describe the development and implementation of a Physiological and Anatomical Visual Analytics tool (PAVA), a web browser-based application, used to visualize experimental/simulated chemical time-course data (dosimetry), epidemiological data and Physiologically-Annotated Data ...

345

Development of a landmark recognition system for the posture measurement of mobile robots  

International Nuclear Information System (INIS)

A landmark recognition system, consisting of retroreflective landmarks, a CCD camera, a strobe unit, an image processing board, and processing software, has been developed to solve the problem of the posture (position and orientation) identification of mobile robots in manufacturing environments. The binary image processing technique instead of gray image technique has been adapted in this system to perform the fast posture measurement of the robots. The experimental results demonstrated real-time measurement capability of this system while maintaining good reliability and reasonable accuracy. A camera calibration technique has been described to reduce the effects of unwanted measurement error sources. The system after camera calibration procedure has demonstrated enhanced performance in terms of error component in posture measurement. (Author)

346

Variantes anatómicas relevantes en tomografía computarizada de cavidades perinasales / Remarkable anatomic variations on paranasal CT scans  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish Introducción: La anatomía ósea de las cavidades perinasales (CPN) es altamente variable, pudiendo ser causa o factor predisponente de patología rinosinusal, o servir de reparo anatómico para la cirugía endoscópica nasal (CEN). Objetivos: Conocer la frecuencia de variaciones anatómicas en pacientes q [...] ue consultan en nuestra Red de Salud. Material y método: Revisión retrospectiva de todas las tomog rafias computarizadas (TC) de CPN, realizadas en el Servicio de Radiología de la Red de Salud UC entre abril y junio de 2009. Resultados: Se encontraron las distintas variantes anatómicas en frecuencias similares a las descritas en la literatura internacional. Se estudió también la trayectoria de la arteria etmoidal anterior (AEA), y la configuración del techo etmoidal, utilizando la clasificación de Keros. Conclusiones: La frecuencia de variaciones anatómicas encontrada en nuestra revisión es similar a la descrita en la literatura internacional. La mayoría de nuestros pacientes presenta configuración de techo etmoidal tipo Keros I, hallazgo diferente al reportado en otras series. El estudio metódico de las variantes anatómicas en TC de CPN nos permitiría evitar complicaciones quirúrgicas. Abstract in english Introduction: Paranasal sinus anatomy is quite variable. Some variations are involved in rinosinusal pathology, others are landmarks ofFESS (functional endoscopic sinus surgery). Aim: To determine the frecuency of paranasal anatomic variations in our consulting population. Material and method: Retro [...] spective revision of all paranasal CT scans achieved in our Radiology Service during a two month period during 2009. Results: We found most of ethmoid anatomic variations, with similar frecuencies as described in literature. We also studied anterior ethmoidal artery anatomy, and ethmoid roof configuration, using Keros classification Conclusions: We found, in general, similar frecuencies as described in foreign series. More than half of our patients had Keros I ethmoid roof configuration type, a differing result from most of other series. Every ENT surgeon should be trained in routine search of these variations, helping to avoid possible surgical complications.

Rodrigo, Cabezón A; Ricardo, Vaidés S; Hayo, Breinbauer K; Constanza, Ramírez R; Carolina, Grau L; Rodrigo, Iñíguez C.

2010-12-01

347

SEER-Medicare Linked Database - 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.

348

Prostate-Specific Antigen (PSA) Testing - 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.

349

Black/White Cancer Survival Study - 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.

350

Cancer and Steroid Hormone Study - 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.

351

Lifetime Risk of Breast 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.

352

Using artificial landmarks to reduce the ambiguity in the environment of a mobile robot  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Robust and reliable localization is a fundamental prerequisite for many applications of mobile robots. Although there exist many solutions to the localization problem, structurally symmetrical or featureless environments can prevent different locations from being distinguishable given the data obtained with the robot’s sensors. Such ambiguities typically make localization approaches more likely to fail. In this paper, we investigate how artificial landmarks can be utilized to reduce the amb...

Meyer-delius, D.; Beinhofer, M.; Kleiner, Alexander; Burgard, W.

2011-01-01

353

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

354

Anatomical variations in radiation induced jute mutants  

International Nuclear Information System (INIS)

Eight different anatomical criteria, namely, number of layers, length and breadth of fibre bundle, number of fibre cells per bundle, length and breadth of fibre cell, lumen size and fibre wall thickness, were studied in 38 radiation induced mutants of Corchorus olitorium cv.JRO 632. Thirty four of these mutants exhibited significant variation from the controls for one or more of the criteria studied. Alternations pertaining to the individual fibre cell characters were significantly lower than those affecting the fibre bundle characters. The criteria showing the maximum variability were number of layers, number of cells r bundle and fibre wall thickness. In general, mutants with drastic morphological changes exhibited variability for larger number of anatomical criteria. (author)

355

Comparison of Image Registration Based Measures of Regional Lung Ventilation from Dynamic Spiral CT with Xe-CT  

CERN Document Server

Purpose: Regional lung volume change as a function of lung inflation serves as an index of parenchymal and airway status as well as an index of regional ventilation and can be used to detect pathologic changes over time. In this article, we propose a new regional measure of lung mechanics --- the specific air volume change by corrected Jacobian. Methods: 4DCT and Xe-CT data sets from four adult sheep are used in this study. Nonlinear, 3D image registration is applied to register an image acquired near end inspiration to an image acquired near end expiration. Approximately 200 annotated anatomical points are used as landmarks to evaluate registration accuracy. Three different registration-based measures of regional lung mechanics are derived and compared: the specific air volume change calculated from the Jacobian (SAJ); the specific air volume change calculated by the corrected Jacobian (SACJ); and the specific air volume change by intensity change (SAI). Results: After registration, the mean registration err...

Ding, Kai; Fuld, Matthew K; Du, Kaifang; Christensen, Gary E; Hoffman, Eric A; Reinhardt, Joseph M

2012-01-01

356

Cardiac Anatomic Considerations in Pediatric Electrophysiology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Although interventional electrophysiology and the use of radiofrequency energy to cure various arrhythmias primarily developed in the adult population, similar applications in children have grown dramatically over the last decade. The anatomic basis for various arrhythmias is critically important for the pediatric ablationists to appreciate. Such understanding allows the use of alternative technique to affect cure while avoiding complications. Further, because of the relatively small heart an...

Asirvatham, Samuel J.

2008-01-01

357

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.)

358

Evolution of the anatomical theatre in Padova.  

Science.gov (United States)

The anatomical theatre played a pivotal role in the evolution of medical education, allowing students to directly observe and participate in the process of dissection. Due to the increase of training programs in clinical anatomy, the Institute of Human Anatomy at the University of Padova has renovated its dissecting room. The main guidelines in planning a new anatomical theatre included: (1), the placement of the teacher and students on the same level in a horizontal anatomical theatre where it is possible to see (theatre) and to perform (dissecting room); (2), in the past, dissection activities were concentrated at the center of the theatre, while in the new anatomical theatre, such activities have been moved to the periphery through projection on surrounding screens-thus, students occupy the center of the theatre between the demonstration table, where the dissection can be seen in real time, and the wall screens, where particular aspects are magnified; (3), three groups of tables are placed with one in front with two lateral flanking tables in regards to the demonstration table, in a semicircular arrangement, and not attached to the floor, which makes the room multifunctional for surgical education, medical students and physician's continued professional development courses; (4), a learning station to introduce the students to the subject of the laboratory; (5), cooperation between anatomists and architects in order to combine the practical needs of a dissection laboratory with new technologies; (6), involvement of the students, representing the clients' needs; and (7), creation of a dissecting room of wide measurements with large windows, since a well-illuminated space could reduce the potentially negative psychological impact of the dissection laboratory on student morale. PMID:24706523

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

2014-01-01

359

Validation of probabilistic anatomical shape atlases  

Science.gov (United States)

Registration of anatomical images is useful for many applications including image segmentation, characterization of normal and abnormal shape, and creating deformable anatomical shape atlases. The usefulness of the information derived from image registration depends on the degree of anatomically meaningful correspondence between the images. We assume that an ideal image registration algorithm can determine an unique correspondence mapping between any two image volumes imaged from a homogeneous population of anatomies; and that these transformations have the properties of invertibility and transitivity. Unfortunately, current image registration algorithms are far from ideal. In this paper we test the invertibility and transitivity of transformations computed from a 'traditional' and a consistent linear-elastic registration algorithm. Invertibility of the transformations was evaluated by comparing the composition of transformations from image A-to-B and B-to-A to the identity mapping. Transitivity of the transformations was evaluated by measuring the difference between the identity mapping and the composition the transformations from image A-to-B, B-to-C, and C-to-A. Transformations were generated by matching computer generated phantoms, CT data of infant heads, and MRI data of adult brains. The consistent algorithm out performed the 'traditional' algorithm by 8 to 16 times for the invertibility test and 2 to 5 times for the transitivity test.

Johnson, Hans J.; Christensen, Gary E.; Marsh, Jeffrey L.; Vannier, Michael W.

2000-06-01

360

Anatomical description and clinical significance of unilateral triheaded sternocleidomastoid muscle  

Directory of Open Access Journals (Sweden)

Full Text Available Objective of this report is to observe and report unusual pattern of origin of sternal and clavicular heads of Sternocleidomastoid (SCM. An embryological insight into the possible causes for present anomaly is elucidated. The neck region of an adult male cadaver during gross anatomy teaching program. An abnormal Sternocleidomastoid (SCM was observed while dissecting the neck region of an adult. Additional clavicular head of SCM muscle were found on the right side. The accessory clavicular head coursed deep to the sternal head whereas the some fibres of main clavicular head joined the accessory belly and together they fused with the main sternal head of SCM. There was another slip arising from sternal head and merge with deep cervical fascia near base of mandible. The topographical anatomy of SCM is extremely important, particularly because it serves as a useful surgical landmark and its relation to crucial neuro-vascular structures of the neck. The usage of SCM in reconstruction operations for covering defects is discussed. A detailed knowledge of the anatomy of SCM proves vital for radiological studies of the neck. [Int J Res Med Sci 2014; 2(3.000: 1161-1164

Preeti Goswami

2014-06-01

 
 
 
 
361

Anatomical and histomorphometric observations on the transfer of the anterior interosseous nerve to the deep branch of the ulnar nerve.  

Science.gov (United States)

This study focuses on the anatomical and histomorphometric features of the transfer of the anterior interosseous nerve to the deep motor branch of the ulnar nerve. The transfer was carried out in 15 cadaver specimens and is described using relevant anatomical landmarks. Nerve samples of donor and target nerves were histomorphometrically analysed and compared. The superficial and the deep ulnar branches had to be separated from each other for a length of 67?mm (SD 12; range 50-85) to reach the site of coaptation. We identified a suitable site for coaptation lying proximal to the pronator quadratus muscle, 202?mm (SD 15; range 185-230) distal to the medial epicondyle of the humerus. The features of the anterior interosseous nerve included a smaller nerve diameter, smaller cross-sectional area of fascicles, fewer fascicles and axons, but a similar axon density. The histomorphometric inferiority of the anterior interosseous nerve raises a question about whether it should be transferred only to selected parts of the deep motor branch of the ulnar nerve. Level III. PMID:25261412

Schenck, T L; Stewart, J; Lin, S; Aichler, M; Machens, H-G; Giunta, R E

2014-09-26

362

A hierarchical scheme for geodesic anatomical labeling of airway trees  

DEFF Research Database (Denmark)

We present a fast and robust supervised algorithm for label- ing anatomical airway trees, based on geodesic distances in a geometric tree-space. Possible branch label configurations for a given unlabeled air- way tree are evaluated based on the distances to a training set of labeled airway trees. In tree-space, the airway tree topology and geometry change continuously, giving a natural way to automatically handle anatomical differences and noise. The algorithm is made efficient using a hierarchical approach, in which labels are assigned from the top down. We only use features of the airway centerline tree, which is relatively unaffected by pathology. A thorough leave-one-patient-out evaluation of the algorithm is made on 40 segmented airway trees from 20 subjects labeled by 2 medical experts. We evaluate accuracy, reproducibility and robustness in patients with Chronic Obstructive Pulmonary Disease (COPD). Performance is statis- tically similar to the inter- and intra-expert agreement, and we found no significant correlation between COPD stage and labeling accuracy.

Feragen, Aasa; Petersen, Jens

2012-01-01

363

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

364

Terminologia anatômica utilizada em oftalmologia / Anatomical terminology in Ophthalmology  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo deste artigo é informar à classe oftalmológica a existência da edição em língua portuguesa da Terminologia Anatômica Internacional, editada pela Federation Committee on Anatomical Terminology (FCAT). No Brasil a Terminologia Anatômica Internacional é traduzida pela Comissão de Terminologi [...] a Anatômica (CTA) da Sociedade Brasileira de Anatomia (SBA). Abstract in english The purpose of this article is inform ophthalmologists of the International Anatomical Terminology in the Portuguese language edited by the Federation Committee on Anatomical Terminology (FCAT). In Brazil the International Anatomical Terminology was translated by the Anatomical Terminology Commissio [...] n of the Brazilian Society of Anatomy.

Fernando César, Abib; Fernando, Oréfice.

2005-04-01

365

Terminologia anatômica utilizada em oftalmologia Anatomical terminology in Ophthalmology  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo deste artigo é informar à classe oftalmológica a existência da edição em língua portuguesa da Terminologia Anatômica Internacional, editada pela Federation Committee on Anatomical Terminology (FCAT. No Brasil a Terminologia Anatômica Internacional é traduzida pela Comissão de Terminologia Anatômica (CTA da Sociedade Brasileira de Anatomia (SBA.The purpose of this article is inform ophthalmologists of the International Anatomical Terminology in the Portuguese language edited by the Federation Committee on Anatomical Terminology (FCAT. In Brazil the International Anatomical Terminology was translated by the Anatomical Terminology Commission of the Brazilian Society of Anatomy.

Fernando César Abib

2005-04-01

366

Assistance to planning in deep brain stimulation: data fusion method for locating anatomical targets in MRI.  

Science.gov (United States)

Symptoms of Parkinson's disease can be relieved through deep brain stimulation. This neurosurgical technique relies on high precision positioning of electrodes in specific areas of the basal ganglia and the thalamus. In order to identify these anatomical targets, which are located deep within the brain, we developed a semi-automated method of image analysis, based on data fusion. Information provided by both anatomical magnetic resonance images and expert knowledge is managed in a common possibilistic frame, using a fuzzy logic approach. More specifically, a graph-based virtual atlas modeling theoretical anatomical knowledge is matched to the image data from each patient, through a research algorithm (or strategy) which simultaneously computes an estimation of the location of every structures, thus assisting the neurosurgeon in defining the optimal target. The method was tested on 10 images, with promising results. Location and segmentation results were statistically assessed, opening perspectives for enhancements. PMID:17946793

Villéger, Alice; Ouchchane, Lemlih; Lemaire, Jean-Jacques; Boire, Jean-Yves

2006-01-01

367

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 pod [...] em 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. Abstract in spanish JUSTIFICATIVA Y OBJETIVOS: Buscamos demostrar en este es