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Sample records for anatomic landmarks based

  1. Collaborative regression-based anatomical landmark detection

    Gao, Yaozong; Shen, Dinggang

    2015-12-01

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

  2. Determination of equine deep digital flexor muscle volume based on distances between anatomical landmarks.

    Hardeman, L C; van der Meij, B R; Lamers, A A H; van der Kolk, J H; Back, W; Wijnberg, I D

    2014-10-01

    In equine medicine the use of Botox® is experimental. Dosages are determined from human treatment-protocols and limited numbers of equine studies. Determination of target-muscle volume can be helpful to extrapolate human dosages. The aim of the study was to calculate a formula enabling the estimation of the deep digital flexor muscle (DDFM) volume based on distances between anatomical landmarks. Nineteen cadaveric limbs were collected and distance A (top of olecranon to Os carpi accessorium) and B (circumference of limb) were measured. Converting mathematical formulas, C was calculated: π × (((0.5B)/π)(2)) × A. DDFM volume was determined by water displacement. Linear Regression Analysis was used to analyse data. The line best fitting the observed points was: Ln(volume[ml]) = -1.89 + 0.98 × Ln(value C[cm(3)]). Correlation was highest when natural logarithm was applied to both variables and was 0.97. The calculated formula enables estimating DDFM volume of a living horse. This estimated volume can be useful to apply human Botox® treatment-protocols. PMID:25264361

  3. Automatic categorization of anatomical landmark-local appearances based on diffeomorphic demons and spectral clustering for constructing detector ensembles.

    Hanaoka, Shouhei; Masutani, Yoshitaka; Nemoto, Mitsutaka; Nomura, Yukihiro; Yoshikawa, Takeharu; Hayashi, Naoto; Ohtomo, Kuni

    2012-01-01

    A method for categorizing landmark-local appearances extracted from computed tomography (CT) datasets is presented. Anatomical landmarks in the human body inevitably have inter-individual variations that cause difficulty in automatic landmark detection processes. The goal of this study is to categorize subjects (i.e., training datasets) according to local shape variations of such a landmark so that each subgroup has less shape variation and thus the machine learning of each landmark detector is much easier. The similarity between each subject pair is measured based on the non-rigid registration result between them. These similarities are used by the spectral clustering process. After the clustering, all training datasets in each cluster, as well as synthesized intermediate images calculated from all subject-pairs in the cluster, are used to train the corresponding subgroup detector. All of these trained detectors compose a detector ensemble to detect the target landmark. Evaluation with clinical CT datasets showed great improvement in the detection performance. PMID:23286038

  4. Joint detection and localization of multiple anatomical landmarks through learning

    Dikmen, Mert; Zhan, Yiqiang; Zhou, Xiang Sean

    2008-03-01

    Reliable landmark detection in medical images provides the essential groundwork for successful automation of various open problems such as localization, segmentation, and registration of anatomical structures. In this paper, we present a learning-based system to jointly detect (is it there?) and localize (where?) multiple anatomical landmarks in medical images. The contributions of this work exist in two aspects. First, this method takes the advantage from the learning scenario that is able to automatically extract the most distinctive features for multi-landmark detection. Therefore, it is easily adaptable to detect arbitrary landmarks in various kinds of imaging modalities, e.g., CT, MRI and PET. Second, the use of multi-class/cascaded classifier architecture in different phases of the detection stage combined with robust features that are highly efficient in terms of computation time enables a seemingly real time performance, with very high localization accuracy. This method is validated on CT scans of different body sections, e.g., whole body scans, chest scans and abdominal scans. Aside from improved robustness (due to the exploitation of spatial correlations), it gains a run time efficiency in landmark detection. It also shows good scalability performance under increasing number of landmarks.

  5. Computed Tomography Analysis of Postsurgery Femoral Component Rotation Based on a Force Sensing Device Method versus Hypothetical Rotational Alignment Based on Anatomical Landmark Methods: A Pilot Study

    Kreuzer, Stefan W.; Amir Pourmoghaddam; Leffers, Kevin J.; Clint W. Johnson; Marius Dettmer

    2016-01-01

    Rotation of the femoral component is an important aspect of knee arthroplasty, due to its effects on postsurgery knee kinematics and associated functional outcomes. It is still debated which method for establishing rotational alignment is preferable in orthopedic surgery. We compared force sensing based femoral component rotation with traditional anatomic landmark methods to investigate which method is more accurate in terms of alignment to the true transepicondylar axis. Thirty-one patients ...

  6. Automated identification of anatomical landmarks on 3D bone models reconstructed from CT scan images.

    Subburaj, K; Ravi, B; Agarwal, Manish

    2009-07-01

    Identification of anatomical landmarks on skeletal tissue reconstructed from CT/MR images is indispensable in patient-specific preoperative planning (tumour referencing, deformity evaluation, resection planning, and implant alignment and anchoring) as well as intra-operative navigation (bone registration and instruments referencing). Interactive localisation of landmarks on patient-specific anatomical models is time-consuming and may lack in repeatability and accuracy. We present a computer graphics-based method for automatic localisation and identification (labelling) of anatomical landmarks on a 3D model of bone reconstructed from CT images of a patient. The model surface is segmented into different landmark regions (peak, ridge, pit and ravine) based on surface curvature. These regions are labelled automatically by an iterative process using a spatial adjacency relationship matrix between the landmarks. The methodology has been implemented in a software program and its results (automatically identified landmarks) are compared with those manually palpated by three experienced orthopaedic surgeons, on three 3D reconstructed bone models. The variability in location of landmarks was found to be in the range of 2.15-5.98 mm by manual method (inter surgeon) and 1.92-4.88 mm by our program. Both methods performed well in identifying sharp features. Overall, the performance of the automated methodology was better or similar to the manual method and its results were reproducible. It is expected to have a variety of applications in surgery planning and intra-operative navigation. PMID:19345065

  7. Anatomical landmarks accurately determine interfractional lymph node shifts during radiotherapy of lung cancer patients

    Background and purpose: Low contrast in the cone-beam computed tomography (CBCT) scans hampers fast online evaluation of interfractional changes in the lymph node position on a daily basis. In this study we have investigated whether high-contrast anatomical landmarks in the vicinity of the nodes may be used as surrogates for the lymph node positions. Materials and methods: Forty lung cancer patients were treated with an online CBCT-based setup strategy involving soft-tissue match on the primary tumor. One hundred and sixteen lymph nodes were delineated separately on the planning-CT scans and categorized according to the lymph node stations. Five anatomical landmarks were selected as surrogate structures and assigned to the individual nodes. In addition, the carina was delineated. Registrations between the planning-CT and the daily CBCTs were performed retrospectively and positional deviations between the nodes and the surrogate structures or the carina were registered. Results: The mean displacement between lymph nodes and surrogate structures was 1.6 mm with systematic/random errors of 0.7/0.7 mm, significantly smaller than the mean displacement between nodes and the carina. Conclusions: The position of the lymph nodes can be evaluated using selected anatomical landmarks on a daily basis using CBCT

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

    Sugawara, Yasushi; Harii, Kiyonori (Tokyo Univ. (Japan). Faculty of Medicine); Hirabayashi, Shinichi

    1994-05-01

    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 on the skull. (N.K.).

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

    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 on the skull. (N.K.)

  10. Propagation of anatomical landmark misplacement to knee kinematics: performance of single and double calibration.

    Stagni, Rita; Fantozzi, Silvia; Cappello, Angelo

    2006-10-01

    Soft tissue artefact and anatomical landmark misplacement have been recognized as the most critical sources of error in gait analysis. The double calibration method was recently proposed to compensate for soft tissue artefact in knee kinematics. This compensation method resulted very effective in the absence of anatomical landmark misplacement. The purpose of the present work was to assess the effectiveness of double calibration in reducing the effects of skin motion artefact on knee rotations and translations when anatomical landmark misplacement is present on the thigh and shank. The double calibration method was used to calculate knee kinematics of two subjects while they performed several motor tasks. The results were compared with those from conventional single calibration. The soft tissue artefact propagated to knee kinematics was quantified by simulating different misplacement errors using both single and double calibration. The double calibration method performed much better than the single calibration one in quantifying knee rotations and particularly translations, with misplacement error up to 15mm superimposed on the anatomical coordinates of the epicondyles. If misplacement errors were limited to just 5mm, the double calibration would be effective in providing kinematics accurate enough for orthopaedic biomechanic applications. PMID:16934471

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

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

    2010-06-15

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

  12. Combination of 2 three point articulators for preclinical work demonstration of teeth arrangement and anatomical landmarks.

    Leoney, A; Shastry, Y M

    2013-09-01

    The combination of 2 three point articulators was done to visualize and appreciate the various teeth setting principles and anatomical landmarks both in occlusion and out of occlusion. In other words this technique would give a simultaneous image of the various teeth arrangement principles at a glance. The various teeth arrangement principles highlighted in this article would be the following: individual tooth arrangement principles of anterior and posterior teeth, arch form, midline, incisive papilla, retromolar pad, overjet and overbite. PMID:24431744

  13. Combination of 2 Three Point Articulators for Preclinical Work Demonstration of Teeth Arrangement and Anatomical Landmarks

    Leoney, A.; Shastry, Y. M.

    2012-01-01

    The combination of 2 three point articulators was done to visualize and appreciate the various teeth setting principles and anatomical landmarks both in occlusion and out of occlusion. In other words this technique would give a simultaneous image of the various teeth arrangement principles at a glance. The various teeth arrangement principles highlighted in this article would be the following: individual tooth arrangement principles of anterior and posterior teeth, arch form, midline, incisiv...

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

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

  15. Anatomic Landmarks for Localization of the Vertical Segment of Facial Nerve on Multislice CT Multiplanar Reconstruction Images.

    Ren, Bichen; Bai, Peng; Li, Tenghai; Guo, Hanfei; Wang, Bin; Zhang, Siwen; Cheng, Kailiang; Li, Youqiong

    2015-10-01

    The facial nerve decompression via mastoid is simple and easy to expose the vertical segment of the facial nerve (VFN). The objective of this study was to find out the relationship between the VFN and anatomic landmarks to facilitate prediction of the location of VFN during facial nerve decompression. The different landmarks were cochlear window (CW), oval window (OW), promontorium tympani (PT), and mastoid antrum (MA). Parameters of 140 patients (280 observations) with healthy middle ears were measured on high-resolution spiral multislice computed tomographic multiplanar reconstruction (MPR) images that were parallel to the base plane. The data gained were analyzed by statistical method and were also analyzed with respect to side and gender. The angle between orientation of VFN to the CW of the longest distance and horizontal axis was larger on the left side than that of the right (P facial nerve decompression through mastoid. PMID:26468809

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

    Moshkelgosha V

    2014-12-01

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

  17. Efficacy and costs comparison of anatomical landmarks and ultrasonic guidance during brachial plexus block

    Objective: To compare the efficacy and costs of brachial plexus block (BPB) guided by ultrasound with that used anatomical landmarks. Methods: Eighty ASA Ⅰ or Ⅱ patients scheduled for upper extremity operation were prospectively randomized into 2 groups: Group A (n=40, BPB using anatomical landmarks) and group U (n=40, BPB guided in real time by a two-dimensional ultrasonic image). The time spent on performing the block, the onset time and duration of analgesia were measured. The proportion of successful and excellent blocks and the incidence of complications were assessed. The cost of anesthetic and the total cost of anesthesia were recorded. Results: Compared with group A, in group U the time spent on performing the block and the onset time of analgesia were significantly shorter, the duration of analgesia was significantly longer, the excellence rate of block was significantly higher (all P<0.05). 95.0% of patients in group A and 97.5% of patients in group U had a successful block (P >0.05). Four patients in group A and two patients in group U had occurred complications (P>0.05). The cost of anesthetic in group U was significantly less than in group A (P<0.01). There was no significant difference in the total cost of anesthesia between the two groups (P>0.05). Conclusion: BPB guided by ultrasound provides better block with more rapid performance and longer duration of analgesia as compared with that used anatomical landmarks. Ultrasound-guided BPB is suitable for upper extremity operation and lowers the anesthetic cost. (authors)

  18. Surgical Anatomical Landmarks of the Thoracolumbar Vertebral Column on Magnetic Resonance Imaging in Dogs.

    Yeamans, C L; Haley, A; Gutierrez-Quintana, R; Penderis, J

    2016-04-01

    Magnetic resonance imaging (MRI) in veterinary medicine profoundly improved spinal cord disease investigation in canine patients. We aimed to further describe the anatomical landmarks of the thoracolumbar junction in sagittal MRI sequences. MRI studies from 90 dogs were reviewed retrospectively, representing a broad cross section of breeds and body weights. The ratio of the distance from the dorsal aspect of the vertebral canal to the dorsal aspect of the transverse process or rib articulation relative to the length of L2 vertebra was determined for T12, T13, L1 and L2 vertebrae. A statistically significant difference was noted with the transverse processes being more ventrally located than the cranial fovea costalis. The lumbar transverse processes and rib articulations dramatically varied in shape, being oval or round, respectively. The sagittal image at the level of the lateral margin of the articular facet joint proved to be the most consistent for review of these structures. PMID:26105110

  19. Evaluation of anatomic landmarks and safe zones for screw placement in the atlas via the posterior arch

    Gebauer, Matthias; Barvencik, Florian; Briem, Daniel; Kolb, Jan P.; Seitz, Sebastian; Rueger, Johannes M.; Pschel, Klaus; Amling, Michael

    2009-01-01

    Several studies have evaluated quantitative anatomic data for direct lateral mass screw fixation. To analyze anatomic landmarks and safe zones for optimal screw placement through the posterior arc of the human atlas, morphometric parameters of 41 adult native human atlas specimens were quantitatively measured. Internal dimensions of the atlas (lateral mass, maximum and minimum intraosseous screw length), minimum height and width of the posterior arc and optimal screw insertion angles were def...

  20. Autonomous Robot Navigation based on Visual Landmarks

    Livatino, Salvatore

    2005-01-01

    autonomous navigation and self-localization using automatically selected landmarks. The thesis investigates autonomous robot navigation and proposes a new method which benefits from the potential of the visual sensor to provide accuracy and reliability to the navigation process while relying on naturally...... 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......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...

  1. The anatomic origin of the posterior cruciate ligament: where is it? Reference landmarks for PCL reconstruction.

    Morgan, C D; Kalman, V R; Grawl, D M

    1997-06-01

    There is a lack of defined reference points for reproducible femoral tunnel placement during posterior cruciate ligament (PCL) reconstruction. The PCL, consisting of two major bands, anterolateral (AL) and posteromedial (PM), has a femoral origin that spans 3 cm, which cannot be covered by a substitute graft positioned in one femoral tunnel to reconstruct the PCL. The purpose of this study was to define the location of the anatomic origin of both bands of the PCL in reference to local anatomy to develop landmarks that can be used to reproducibly position two femoral tunnels (one to each band's origin) during PCL reconstruction. The anatomy of the PCL origin was dissected and studied in 20 knees at the time of total knee replacement. The central origin point for each band was marked, and its distance was measured in reference to three axes. The AL band centrally originated 13 +/- 0.5 mm posterior to the medial articular cartilage-intercondylar wall interface and 13 +/- 0.5 mm inferior to the articular cartilage-intercondylar roof interface. The PM band centrally originated 8 +/- 0.5 mm posterior to the medial articular cartilage-intercondylar wall interface and 20 +/- 0.5 mm inferior to the articular cartilage-intercondylar roof interface. These distances were noted to be relatively constant despite varying knee morphologies and size. For this reason, referencing the articular cartilage-intercondylar roof, and wall interfaces may be used as a method to facilitate more reproducible anatomic femoral tunnel placements during PCL reconstruction. PMID:9195029

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

    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

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

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

    2010-11-15

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

  4. The mid-sternal length, a practical anatomical landmark for optimal positioning of long-term central venous catheters

    Salimi, Fereshte; Imani, Mohammad Reza; Ghasemi, Navab; Keshavarzian, Amir; Jazi, Amir Hosein Davarpanah

    2013-01-01

    Background: Long-term tunneled catheters are used for the hemodialysis or chemotherapy in many patients. Proper placement of the catheter tip could reduce early and late catheter related complications. Aim of the present study was to evaluate a new formula for proper placement of tunneled hemodialysis or infusion port device by using an external anatomic landmark. Materials and Methods: A total of 64 adult patients undergoing elective placement of tunneled Central Venous Catheter (CVC) requir...

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

    Abdurrahman Demirci; Esra Mercanoglu Efe; Gürkan Türker; Alp Gurbet; Fatma Nur Kaya; Ali Anil; İlker Çimen

    2014-01-01

    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 w...

  6. Evaluation and Comparison of Anatomical Landmark Detection Methods for Cephalometric X-Ray Images: A Grand Challenge.

    Wang, Ching-Wei; Huang, Cheng-Ta; Hsieh, Meng-Che; Li, Chung-Hsing; Chang, Sheng-Wei; Li, Wei-Cheng; Vandaele, Rmy; Mare, Raphal; Jodogne, Sbastien; Geurts, Pierre; Chen, Cheng; Zheng, Guoyan; Chu, Chengwen; Mirzaalian, Hengameh; Hamarneh, Ghassan; Vrtovec, Tomaz; Ibragimov, Bulat

    2015-09-01

    Cephalometric analysis is an essential clinical and research tool in orthodontics for the orthodontic analysis and treatment planning. This paper presents the evaluation of the methods submitted to the Automatic Cephalometric X-Ray Landmark Detection Challenge, held at the IEEE International Symposium on Biomedical Imaging 2014 with an on-site competition. The challenge was set to explore and compare automatic landmark detection methods in application to cephalometric X-ray images. Methods were evaluated on a common database including cephalograms of 300 patients aged six to 60 years, collected from the Dental Department, Tri-Service General Hospital, Taiwan, and manually marked anatomical landmarks as the ground truth data, generated by two experienced medical doctors. Quantitative evaluation was performed to compare the results of a representative selection of current methods submitted to the challenge. Experimental results show that three methods are able to achieve detection rates greater than 80% using the 4 mm precision range, but only one method achieves a detection rate greater than 70% using the 2 mm precision range, which is the acceptable precision range in clinical practice. The study provides insights into the performance of different landmark detection approaches under real-world conditions and highlights achievements and limitations of current image analysis techniques. PMID:25794388

  7. Adaptive Landmark-Based Navigation System Using Learning Techniques

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

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

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

    Purpose: To identify visible structures in the thorax which exhibit little internal motion during irradiation and, to determine random and systematic setup deviations in lung cancer patients with the use of these structures. Methods: Ten patients with lung cancer were set up in the supine position, and aligned using lasers. No immobilization devices were used. With an electronic portal imaging device (Siemens Beam ViewPLUS), 12 sequential images (exposure 0.54 sec.; processing time 1.5 sec.) were obtained during a single fraction of radiotherapy. These 'movie loops' were generated for the A-P fields during each of 3-5 fractions. In order to determine the mobility of internal structures during each fraction, visible structures such as the trachea, carina, the upper chest wall, aortic arch, clavicle and paraspinal line were contoured manually in each image and matched with the first image of the corresponding movie loop by means of a cross-correlation algorithm. Translations in the cranial and lateral directions and in-plane rotations were determined for each structure separately. As the reference image represents a random position, relative movements were determined by comparing the translations and rotation for every image to the calculated means per movie-loop. Standard deviations of the relative movements were determined for each structure and each patient. Patient setup was evaluated for 15 patients with lung cancer. Setup was not corrected at any time during the treatment. The electronic portal images of each fraction were matched with the digitized simulator films by using a combination of the structures which had been determined to be relatively stable in the infra-fractional analysis. Results: In the infra-fractional analysis 120 to 380 matches were made per structure (a total of 1400). The standard deviation (SD) of translations in the lateral direction was small (≤1 mm) for the trachea, thoracic wall, paraspinal line and aortic arch. This was also the case for the SD of the translations in the cranial direction of the clavicle, aortic arch and upper thoracic wall. The carina was found to be relatively mobile (up to 6 mm) in both directions. The SD for in-plane rotations was negligible (<0.5 deg.) for all structures. The interpatient variation was very small (SD < 0.5 mm). In a preliminary analysis of patient setup, the random errors for translations are 2.0 mm in the lateral direction and 2.4 mm in the cranial direction (1 SD). The standard deviations of systematic errors are about 3 mm in both directions. In plane rotations were found to be negligible. Conclusions: We have identified a number of structures which exhibit little internal motion in the frontal plane, and recommend that a combination of these structures be used as anatomic landmarks for setup verification during radiotherapy of thoracic tumors. Preliminary results indicate that setup errors of patients with lung cancer in our center appear to be acceptable, even though no specific immobilization devices were used

  9. Combining Speedup techniques based on Landmarks and Containers

    R. KALPANA

    2010-09-01

    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.

  10. Robust discriminative tracking via landmark-based label propagation.

    Wu, Yuwei; Pei, Mingtao; Yang, Min; Yuan, Junsong; Jia, Yunde

    2015-05-01

    The appearance of an object could be continuously changing during tracking, thereby being not independent identically distributed. A good discriminative tracker often needs a large number of training samples to fit the underlying data distribution, which is impractical for visual tracking. In this paper, we present a new discriminative tracker via landmark-based label propagation (LLP) that is nonparametric and makes no specific assumption about the sample distribution. With an undirected graph representation of samples, the LLP locally approximates the soft label of each sample by a linear combination of labels on its nearby landmarks. It is able to effectively propagate a limited amount of initial labels to a large amount of unlabeled samples. To this end, we introduce a local landmarks approximation method to compute the cross-similarity matrix between the whole data and landmarks. Moreover, a soft label prediction function incorporating the graph Laplacian regularizer is used to diffuse the known labels to all the unlabeled vertices in the graph, which explicitly considers the local geometrical structure of all samples. Tracking is then carried out within a Bayesian inference framework, where the soft label prediction value is used to construct the observation model. Both qualitative and quantitative evaluations on the benchmark data set containing 51 challenging image sequences demonstrate that the proposed algorithm outperforms the state-of-the-art methods. PMID:25706637

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

    Thiago Rodrigues

    2015-11-01

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

  12. Neural Network Based Sensory Fusion for Landmark Detection

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

    1997-01-01

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

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

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

  14. Referncias anatmicas na cirurgia do implante auditivo de tronco cerebral Anatomical landmarks in auditory brainstem implant surgery

    Rubens Vuono Brito Neto

    2005-06-01

    Full Text Available O implante auditivo de tronco cerebral uma opo os pacientes surdos que no tm a integridade das vias auditivas preservada. A cirurgia, por sua complexidade anatmica e funcional, requer treinamento especfico em laboratrio de anatomia por parte do cirurgio. OBJETIVOS: Estudar a anatomia cirrgica da cirurgia do implante auditivo de tronco cerebral. FORMA DE ESTUDO: Estudo anatmico. MATERIAL E MTODO: Neste estudo dissecamos cadver fresco preparado com soluo corante injetada nas artrias e veias intra-cranianas. O local de insero do eletrodo do implante auditivo de tronco cerebral foi estudado atravs do acesso translabirntico. RESULTADOS: A tcnica cirrgica utilizada para a implantao do eletrodo de tronco cerebral semelhante utilizada na remoo do shwannoma vestibular. O complexo de ncleo coclear, composto pelo ncleo coclear ventral e dorsal, o local para a colocao do eletrodo. O ncleo coclear ventral o principal ncleo de transmisso de impulsos neurais do VIII par e seus axnios formam a principal via ascendente do nervo coclear. Tanto o ncleo ventral como o dorsal no so visveis durante a cirurgia e sua localizao depende de identificao de estruturas anatmicas adjacentes. CONCLUSO: A regio de implantao do eletrodo do implante auditivo de tronco cerebral apresenta referncias anatmicas que permitem sua fcil identificao durante a cirurgia.Auditory brainstem implant (ABI is an option for deaf patients who do not have the whole auditory pathways preserved. The surgery, because of its anatomical and functional complexity, requires specific training of the surgeon in an anatomy lab. AIM: To study the surgical anatomy of the auditory brainstem implant surgery. STUDY DESIGN: Anatomic study. MATERIAL AND METHOD: In the present study, we dissected a fresh cadaver prepared with a dye solution injected into the arteries and intracranial veins. The location of the insertion of the ABI electrode was studied through translabyrinthine access. RESULTS: The surgical technique used for implanting the brainstem electrode is similar to that used in the removal of vestibular schwannoma. The cochlear nucleus complex, comprising ventral and dorsal cochlear nuclei, is the optimal electrode site. The ventral cochlear nucleus is the principal nucleus for transmission of neural impulses from the 8th pair and form the main ascending route of the cochlear nerve. Neither the ventral nor the dorsal nuclei are visible during surgery and their location depends on the identification of adjacent anatomical structures. CONCLUSION: The region for the implantation of the electrode in the auditory brainstem implant presents anatomical landmarks that allow its easy identification during surgery.

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

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

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

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

    2008-06-15

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

  17. Retzius-sparing robot-assisted laparoscopic radical prostatectomy: Critical appraisal of the anatomic landmarks for a complete intrafascial approach.

    Asimakopoulos, Anastasios D; Miano, Roberto; Galfano, Antonio; Bocciardi, Aldo Massimo; Vespasiani, Giuseppe; Spera, Enrico; Gaston, Richard

    2015-10-01

    To provide an overview of the anatomical landmarks needed to guide a retropubic (Retzius)-sparing robot-assisted laparoscopic prostatectomy (RALP), and a step-by-step description of the surgical technique that maximizes preservation of the periprostatic neural network. The anatomy of the pelvic fossae is presented, including the recto-vesical pouch (pouch of Douglas) created by the reflections of the peritoneum. The actual technique of the trans-Douglas, intrafascial nerve-sparing robotic radical prostatectomy is described. The technique allows the prostate gland to be shelled out from under the overlying detrusor apron and dorsal vascular complex (DVC-Santorini plexus), entirely avoiding the pubovesical ligaments. There is no need to control the DVC, since the line of dissection passes beneath the plexus. Three key points to ensure enhanced nerve preservation should be respected: (1) the tips of the seminal vesicles, enclosed in a "cage" of neuronal tissue; a seminal vesicle-sparing technique is therefore advised when oncologically safe; (2) the external prostate-vesicular angle; (3) the lateral surface of the prostate gland and the apex. The principles of tension and energy-free dissection should guide all the maneuvers in order to minimize neuropathy. Using robotic technology, a complete intrafascial dissection of the prostate gland can be achieved through the Douglas space, reducing surgical trauma and providing excellent functional and oncological outcomes. PMID:26194970

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

    Ghimire, Deepak; Lee, Joonwhoan

    2014-01-01

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

  19. Evaluating the reliability of anatomic landmarks in safe lumbar puncture using magnetic resonance imaging: does sex matter?

    Rahmani, Maryam; Vaziri Bozorg, Seyed Mehran; Ghasemi Esfe, Ahmad Reza; Morteza, Afsaneh; Khalilzadeh, Omid; Pedarzadeh, Elham; Shakiba, Madjid

    2011-01-01

    Aim. To determine the level of the conus medullaris-Tuffier's line, and conus medullaris-Tuffier's line distance using imaging and evaluate their relation to age and gender. Methods. We performed a cross-sectional study of 189 adult participants, who underwent MR imaging of lumbosacral spine. Each vertebra was divided into 3 equal segments (upper, middle, and lower), and intervertebral disc space was also assumed as one segment. All segments from T12 upper segment to L5S1 intervertebral disc were numbered consecutively. The position of conus medullaris and Tuffier's line was determined by the vertebral segment or intervertebral disc space at the same level. The patients were stratified into high/low conus medullaris position (cutpoint: L1 middle segment) and short/long conus-Tuffier's distance (cutpoint: 14 segments). Results. Women with low conus were significantly more than men, in patients older than 50 years old (72.7% in females versus 55.3% in males; P < .05), whereas there was not such a sexual dimorphism in patients younger than 50 years old. Similarly, short conus-Tuffier's distance was more frequent among women than men in patients older than 50 years old (59.7% in females versus 39.5% in males; P < .05), whereas there was not any gender difference in patients younger than 50 years old. Conus-Tuffier's distance was negatively correlated with age (r = -0.32, P < .001) in all studied population. Conclusion. Anatomical landmarks vary according to age and gender, with a lower end of conus medullaris in women, so clinicians should use more caution on the identification of the appropriate site for lumbar puncture, particularly in elderly women. PMID:21760769

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

    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

  1. Is peritoneal reflection the best anatomical repair landmark in experimental colorectal surgery on rats? / A reflexo peritoneal o melhor reparo anatmico na cirurgia experimental colorretal em ratos?

    Denise Gonalves, Priolli; Pamela Lcia Eiras da, Silva; Adriane Moro, Betini; Jos Aires, Pereira; Nelson Fontana, Margarido; Carlos Augusto Real, Martinez.

    2009-12-01

    Full Text Available OBJETIVO: Validar a placa de Peyer como reparo anatmico para a cirurgia colorretal em ratos e mensurar a quantidade de colgeno em segmentos da parede clica que contm ou no a placa de Peyer. MTODOS: Foi aferida a distncia entre a placa de Peyer e a reflexo peritoneal em 45 ratos Wistar. O cl [...] on e o reto foram ressecados, para a quantificao do colgeno, por meio de anlise de imagem assistida por computador, em regies do clon que continham ou no a placa de Peyer. RESULTADOS: Existe grande variao entre a distncia da placa de Peyer e a reflexo peritoneal quando se consideraram os animais de ambos os gneros como grupo nico (p= 0.04), sendo a distncia entre a placa e a reflexo peritoneal maior entre as fmeas (p=0.001). Constatou-se que o segmento clico que contm a placa de Peyer apresenta contedo menor de colgeno quando comparado ao segmento onde a estrutura no estava presente (p=0.02). CONCLUSO: A placa de Peyer pode ser indicada como reparo anatmico e no estudo da cicatrizao de anastomoses colorretais em ratos, baseado nas diferentes quantidades de colgeno tecidual existente na parede clica que contm ou no esta estrutura. Abstract in english 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.

  2. Is peritoneal reflection the best anatomical repair landmark in experimental colorectal surgery on rats? A reflexo peritoneal o melhor reparo anatmico na cirurgia experimental colorretal em ratos?

    Denise Gonalves Priolli

    2009-12-01

    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 anatmico para a cirurgia colorretal em ratos e mensurar a quantidade de colgeno em segmentos da parede clica que contm ou no a placa de Peyer. MTODOS: Foi aferida a distncia entre a placa de Peyer e a reflexo peritoneal em 45 ratos Wistar. O clon e o reto foram ressecados, para a quantificao do colgeno, por meio de anlise de imagem assistida por computador, em regies do clon que continham ou no a placa de Peyer. RESULTADOS: Existe grande variao entre a distncia da placa de Peyer e a reflexo peritoneal quando se consideraram os animais de ambos os gneros como grupo nico (p= 0.04, sendo a distncia entre a placa e a reflexo peritoneal maior entre as fmeas (p=0.001. Constatou-se que o segmento clico que contm a placa de Peyer apresenta contedo menor de colgeno quando comparado ao segmento onde a estrutura no estava presente (p=0.02. CONCLUSO: A placa de Peyer pode ser indicada como reparo anatmico e no estudo da cicatrizao de anastomoses colorretais em ratos, baseado nas diferentes quantidades de colgeno tecidual existente na parede clica que contm ou no esta estrutura.

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

    Roshan N. RAJAPAKSE

    2016-03-01

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

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

    T ahmine Razi

    2013-05-01

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

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

    Abdurrahman Demirci

    2014-10-01

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

  6. Validation of automatic landmark identification for atlas-based segmentation for radiation treatment planning of the head-and-neck region

    Leavens, Claudia; Vik, Torbjrn; Schulz, Heinrich; Allaire, Stphane; Kim, John; Dawson, Laura; O'Sullivan, Brian; Breen, Stephen; Jaffray, David; Pekar, Vladimir

    2008-03-01

    Manual contouring of target volumes and organs at risk in radiation therapy is extremely time-consuming, in particular for treating the head-and-neck area, where a single patient treatment plan can take several hours to contour. As radiation treatment delivery moves towards adaptive treatment, the need for more efficient segmentation techniques will increase. We are developing a method for automatic model-based segmentation of the head and neck. This process can be broken down into three main steps: i) automatic landmark identification in the image dataset of interest, ii) automatic landmark-based initialization of deformable surface models to the patient image dataset, and iii) adaptation of the deformable models to the patient-specific anatomical boundaries of interest. In this paper, we focus on the validation of the first step of this method, quantifying the results of our automatic landmark identification method. We use an image atlas formed by applying thin-plate spline (TPS) interpolation to ten atlas datasets, using 27 manually identified landmarks in each atlas/training dataset. The principal variation modes returned by principal component analysis (PCA) of the landmark positions were used by an automatic registration algorithm, which sought the corresponding landmarks in the clinical dataset of interest using a controlled random search algorithm. Applying a run time of 60 seconds to the random search, a root mean square (rms) distance to the ground-truth landmark position of 9.5 +/- 0.6 mm was calculated for the identified landmarks. Automatic segmentation of the brain, mandible and brain stem, using the detected landmarks, is demonstrated.

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

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

    2014-12-01

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

  8. Simulation of satellite landmark navigation on the base of optoelectronic image processing technique

    Dyblenko, Sergey; Janschek, Klaus; Kisselev, Anton; Sultanov, Albert; Tchernykh, Valeri

    2005-06-01

    Hybrid optoelectronic landmark navigation is proposed as backup navigation for Low Earth Orbit satellite. Optoelectronic navigation can use earth observation camera, originally not assigned for navigation purposes. The concept of the landmark navigation system is based on the onboard optical correlator application for real time matching of the earth images and pre-recorded images of landmarks with known coordinates. The software model of image processing by optical correlator has been developed to test the system operation in simulated experiments and to estimate the expected performance. The hardware model of the joint transform optical correlator has been manufactured and tested. The model uses commercially available optoelectronic components and works with PC, which performs all digital processing and data flow control. As a result ofthe model testing, the feasibility ofthe system concept and the adequacy ofthe software model have been proved. The image processing system which calculates satellite attitude and position on the base of correlation peaks measurements has been used for simulation of optoelectronic satellite landmark navigation. In the series of simulated experiments the navigation accuracy was estimated in presence of image distortions and noise for earth observation mission.

  9. A landmark-based algorithm for automatic pattern recognition and abnormality detection

    Huzurbazar, S.; Lee, Long; Kuang, Dongyang

    2016-01-01

    We study a class of mathematical and statistical algorithms with the aim of establishing a computer-based framework for fast and reliable automatic pattern recognition and abnormality detection. Under this framework, we propose a numerical algorithm for finding group averages where an average of a group is an estimator that is said to best represent the properties of interest of that group. A novelty of the proposed landmark-based algorithm is that the algorithm tracks information of the mome...

  10. Visual Homing in the Absence of Feature-Based Landmark Information

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

    2008-01-01

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

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

    udy P. Sendaydiego; Mark Anthony J. Torres; Cesar G. Demayo

    2013-01-01

    Insect wing morphology has been used in many studies to describe variations among species and populations using traditional morphometrics and more recently, geometric morphometrics. This study was conducted to determine intraspecific divergence in wing shape and venation in Aedes aegypti using landmark-based geometric morphometrics. In the Philippines, Ae. aegypti has been identified as a common dengue vector species. With the increasing cases of dengue, mosquito control programs are faced wi...

  12. 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

    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.)

  13. Bidirectional mereological reasoning in anatomical knowledge bases.

    Schulz, S.

    2001-01-01

    Mereological relationships--relationships between parts and wholes--are essential for ontological engineering in the anatomical domain. We propose a knowledge engineering approach that emulates mereological reasoning by taxonomic reasoning based on SEP triplets, a special data structure for the encoding of part-whole relations, which is fully embedded in the formal framework of standard description logics. We extend the SEP formalism in order to account not only for the part-of but also for the has-part relation, both being considered transitive in our domain. Furthermore we analyze the distinction between the ontological primitives singletons, collections and mass concepts in the anatomy domain and sketch how reasoning about these kinds of concepts can be accounted for in a knowledge representation language, using the extended SEP formalism. PMID:11825258

  14. Combining Speedup Techniques based on Landmarks and Containers with parallelised preprocessing in Random and Planar Graphs

    R. Kalpana

    2011-02-01

    Full Text Available The Dijkstra’s algorithm is applied in many real world problems like mobile routing, road maps,railway networks, etc,. There are many techniques available to speedup the algorithm while guaranteeingthe optimality of the solution. Almost all of the speedup techniques have a substantial amount of parallelism that can be exploited to decrease its running time. By suitably modifying portions of theexisting system various degrees of parallelism can be achieved. The rapidly growing field of multiprocessing systems and multi-core processors provide many opportunities for such improvements. Inthese techniques there’s always a demand for the running time and the time required for pre-processing.Space requirements for the pre-processing also have a major influence on the running time of thealgorithm. The main focus of the work is to implement landmark technique and to identify the segment of the code in landmark pre-processing which can be parallelized to obtain better speedup. The results are applied to the combined speedup technique which is based on landmarks and containers. The experimental results were compared and analysed for determining better performance improvements in random graphs and planar graphs.

  15. Midline as a landmark for the position of the superior sagittal sinus on the cranial vault: An anatomical and imaging study

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

    2015-01-01

    Background: Craniotomies involving the midline are regular practice in neurosurgery, during which injury to the superior sagittal sinus (SSS), an uncommon yet devastating event, may occur. The midline tends to be the most common landmark used to identify the position of the SSS. In this study we examined the reliability of the midline as a landmark for the SSS. Methods: We performed bilateral craniectomies on eight cadaveric heads, preserving the coronal, sagittal, and lambdoid sutures. The w...

  16. BasemapLandmarks_CEMETERY

    Vermont Center for Geographic Information — The BasemapLandmarks_CEMETERY point layer contains cemeteries in the state of Vermont. The data is based on VTrans Town Highway Maps. Some points have been moved to...

  17. Laparoscopic totally extraperitoneal (TEP) hernioplasty using two trocars: anatomical landmarks and surgical technique / Hernioplastia laparoscpica totalmente extraperitoneal (TEP) utilizando dois trocrteres: reparos anatmicos e tcnica cirrgica

    Leandro Ryuchi, IUAMOTO; Juliana Mika, KATO; Alberto, MEYER; Pierre, BLANC.

    2015-06-01

    Full Text Available RACIONAL: Dentre as correes endoscpicas das hrnias, as abordagens totalmente extraperitoneal (TEP) e transabdominal pr-peritoneal (TAPP) so amplamente aceitas como alternativas operao aberta, fornecendo menos dor no perodo ps-operatrio, menor tempo de permanncia hospitalar e retorno p [...] recoce ao trabalho. A tcnica TEP clssica requer trs incises na pele para a colocao de trs trocrteres na linha mdia ou em triangulao. OBJETIVO: Descrever uma tcnica utilizando apenas dois trocrteres para hernioplastia laparoscpica totalmente extraperitoneal (TEP). MTODO: Acesso extraperitoneal: so inseridos dois trocrteres sobre a linha mdia; um de 10 mm inserido no subcutneo em direo horizontal aps inciso infra-umbilical transversal e, em seguida, elevado ao ngulo de 60; outro de 5 mm inserido ao nvel do pubis com viso direta. Tempos operatrios: 1) disseco do espao preperitoneal: introduo da tica laparoscpica de 0 atravs da inciso infra-umbilical para visualizao e disseco pr-peritoneal; presso de insuflao inferior a 12 mmHg; 2) Disseco de alguns reparos anatmicos: pubis, linha arqueada e vasos epigstricos inferiores; 3) reconhecimento do "tringulo da dor" e "tringulo do desastre"; 4) Insero atravs do trocter de 10 mm de tela de polipropileno de 10x15 cm para cobrir o sitio da hrnia; 5) Reposicionamento do peritnio e da borda dorsal da tela para evitar dobras ou deslocamento da tela. No necessria a drenagem. RESULTADOS: Esta tcnica foi utilizada em nove pacientes e apresentou bom resultado sem necessidade de um cirurgio auxiliar para execut-la, apenas dois trocteres, menos material de sutura e de curativos. Alm disso, exigiu apenas duas incises, o que proporcionou melhor resultado esttico e menor dor no perodo ps-operatrio. CONCLUSO: A tcnica proposta utilizando dois trocrteres uma alternativa vivel, com melhora dos resultados cosmticos e financeiros. Abstract in english BACKGROUND: Among endoscopic hernioplasties, totally extraperitoneal (TEP) and transabdominal preperitoneal (TAPP) approach are widely accepted alternatives to open surgery, both providing less postoperative pain, hospital length of stay and early return to work. Classical TEP technique requires th [...] ree skin incisions for placement of three trocars in the midline or in triangulation. AIM: To describe a technique using only two trocars for laparoscopic total extraperitoneal for inguinal hernia repair. METHOD: Extraperitoneal access: place two regular trocars on the midline. The 10 mm is inserted into the subcutaneous in horizontal direction after a transverse infra-umbilical incision and then elevated at 60 angle. The 5 mm trocar is inserted at the same level of the pubis with direct vision. Preperitoneal space dissection: introduction 0 optical laparoscope through the infra-umbilical incision for visualization and preperitoneal dissection; insufflation pressure must be below 12 mmHg. Dissection of some anatomical landmarks: pubic bone, arcuate line and inferior epigastric vessels. Exposure of "triangle of pain" and "triangle of doom". Insertion through the 10 mm trocar polypropylene mesh of 10x15 cm to cover the hernia sites. Peritoneal sac and the dorsal edge of the mesh are repositioned in order to avoid bending or mesh displacement. It is also important to remember that the drainage is not necessary. RESULTS: The 2-port TEP required less financial costs than usual because it is not necessary an auxiliary surgeon to perform the technique. Trocars, suturing material and wound dressing were spared in comparison to the classical technique. Besides, there were only two incisions, which provides a better plastic result and less postoperative pain. CONCLUSION: The TEP technique using two trocars is an alternative technique which improves cosmetic and financial outcomes.

  18. Biomimetic bayesian models of navigation: How are environment geometry-based and landmark-based strategies articulated in humans?

    Diard, Julien; Panagiotaki, Panagiota; Berthoz, Alain

    2009-01-01

    We propose a computational model of human navigation, which encompasses both geometry-based and landmark-based navigation strategies. This model is based on a study of human cognitive strategies during a path memorization task in a Virtual Reality (VR) experiment. Participants were asked to memorize predefined paths in a large-scale virtual city (COSMOpoliS (c)). Our computational model qualitatively reproduces the results of this experiment. This model uses the Bayesian formalism, and focuses...

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

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

    2006-02-15

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

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

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

    2013-12-01

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

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

    Ritter, M.

    2007-04-27

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

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

    Bruner, Emiliano; Manzi, Giorgio

    2007-03-01

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

  3. Lymphedema: A General Outline of Its Anatomical Base.

    Amore, M; Tapia, L; Mercado, D; Pattarone, G; Ciucci, J

    2016-01-01

    The anatomic research of the lymphatic system has been a very controversial subject throughout due to the complexity of the methods for its visualization. More than 30 years ago, together with Prof. Caplan, we began the vascular anatomy research, focusing on the lymphatic anatomy, developing and adapting different techniques of injection. On the third Normal Anatomy Chair of Buenos Aires University, we summarized the lymphatic drainage of the breast and the limbs to interpret the anatomic bases of lymphedema. PMID:26375305

  4. Dissimilarity-based classification of anatomical tree structures

    Sørensen, Lauge Emil Borch Laurs; Lo, Pechin Chien Pau; Dirksen, Asger; Petersen, Jens; de Bruijne, Marleen

    2011-01-01

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

  5. Dissimilarity-based classification of anatomical tree structures

    Sørensen, Lauge Emil Borch Laurs; Lo, Pechin Chien Pau; Dirksen, Asger; Petersen, Jens; de Bruijne, Marleen

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

  6. Anatomic study and clinical significance of extended endonasal anterior skull base surgery

    Shousen Wang

    2014-01-01

    Full Text Available Objective: This study is to investigate the anatomical relationship of endonasal approach for anterior skull base surgery, and to determine the boundaries between anterior basicranial craniotomy and the security of operative techniques. Materials and Methods: A total of 10 adult dry skulls and 13 adult cadaveric heads processed by formalin were examined under operating microscope. The micro-anatomic structures of the turbinate, sphenoid sinus, ethmoid sinus, anterior ethmoidal artery, posterior ethmoidal artery and anterior skull base were observed. Artificial anatomy was performed and the deep-seated regions of the surgical approach were observed under operating microscope and endoscope. Results: Examined from the intracranial and intranasal aspects, it was found that the middle turbinate, uncinate process, ethmoid bulla, lamina papyracea, anterior ethmoid canal, posterior ethmoid canal, prominence of the optic canal and opticocarotid recess were all important anatomic landmarks for surgery. The horizontal distances between medial orbital wall on both sides at the level of crista galli, anterior ethmoid canal, and posterior ethmoid canal were (22.31 ± 3.08 mm, (23 ± 2.93 mm, and (26.25 ± 2.88 mm, respectively. The distance between the double optic canal cranial opening was (14.67 ± 3.82 mm. Conclusions: During the endonasal approach for anterior skull base surgery, full advantage of the surgical corridor made by the middle turbinate resection should be taken. To control intraoperative bleeding, it is critical to identify anterior and posterior ethmoidal artery. Identification and protection of medial orbital wall and the optic nerve, and controlling the ranges of anterior basicranial craniotomy are of great importance for surgical safety.

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

    Purpose: To demonstrate that high-dimensional voxel-to-voxel transformations, derived from continuum mechanics models of the underlying pelvic tissues, can be used to register computed tomography (CT) serial examinations into a single anatomic frame of reference for cumulative dose calculations. Methods and Materials: Three patients with locally advanced cervix cancer were treated with CT-compatible intracavitary (ICT) applicators. Each patient underwent five volumetric CT examinations: before initiating treatment, and immediately before and after the first and second ICT insertions, respectively. Each serial examination was rigidly registered to the patient's first ICT examination by aligning the bony anatomy. Detailed nonrigid alignment for organs (or targets) of interest was subsequently achieved by deforming the CT exams as a viscous-fluid, described by the Navier-Stokes equation, until the coincidence with the corresponding targets on CT image was maximized. In cases where ICT insertion induced very large and topologically complex rearrangements of pelvic organs, e.g., extreme uterine canal reorientation following tandem insertion, a viscous-fluid-landmark transformation was used to produce an initial registration. Results: For all three patients, reasonable registrations for organs (or targets) of interest were achieved. Fluid-landmark initialization was required in 4 of the 11 registrations. Relative to the best rigid bony landmark alignment, the viscous-fluid registration resulted in average soft-tissue displacements from 2.8 to 28.1 mm, and improved organ coincidence from the range of 5.2% to 72.2% to the range of 90.6% to 100%. Compared to the viscous-fluid transformation, global registration of bony anatomy mismatched 5% or more of the contoured organ volumes by 15-25 mm. Conclusion: Pelvic soft-tissue structures undergo large deformations and displacements during the external-beam and multiple-ICT course of radiation therapy for locally advanced cervix cancer. These changes cannot be modeled by the conventional rigid landmark transformation method. In the current study, we found that the deformable anatomic template registration method, based on continuum-mechanics models of deformation, successfully described these large anatomic shape changes before and after ICT. These promising modeling results indicate that realistic registration of the cumulative dose distribution to the organs (or targets) of interest for radiation therapy of cervical cancers is achievable

  8. Anatomically based lower limb nerve model for electrical stimulation

    Soboleva Tanya K; Rhrle Oliver; Davidson John B; Kim Juliana HK; Pullan Andrew J

    2007-01-01

    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 t...

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

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

    2011-01-01

    The objective of the study was to evaluate the reliability of frontal plane lower limb alignment measures using a landmark-based method by (1) comparing inter- and intra-reader reliability between measurements of alignment obtained manually with those using a computer program, and (2) determining inter- and intra-reader reliability of computer-assisted alignment measures from full-limb radiographs. An established method for measuring alignment was used, involving selection of 10 femoral and tibial bone landmarks. (1) To compare manual and computer methods, we used digital images and matching paper copies of five alignment patterns simulating healthy and malaligned limbs drawn using AutoCAD. Seven readers were trained in each system. Paper copies were measured manually and repeat measurements were performed daily for 3 days, followed by a similar routine with the digital images using the computer. (2) To examine the reliability of computer-assisted measures from full-limb radiographs, 100 images (200 limbs) were selected as a random sample from 1,500 full-limb digital radiographs which were part of the Multicenter Osteoarthritis 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

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

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

    2016-03-01

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

  11. Sparse Decomposition and Modeling of Anatomical Shape Variation

    Sjöstrand, Karl; Rostrup, Egill; Ryberg, Charlotte; Larsen, Rasmus; Studholme, Colin; Baezner, Hansjoerg; Ferro, Jose; Fazekas, Franz; Pantoni, Leonardo; Inzitari, Domenico; Waldemar, Gunhild

    2007-01-01

    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...

  12. Sparse decomposition and modeling of anatomical shape variation

    Sjöstrand, Karl; Rostrup, Egill; Ryberg, Charlotte; Larsen, Rasmus; Studholme, Colin; Baezner, Hansjoerg; Ferro, Jose; Fazekas, Franz; Pantoni, Leonardo; Inzitari, Domenico; Waldemar, Gunhild; NN, NN

    2007-01-01

    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...

  13. Anatomically based lower limb nerve model for electrical stimulation

    Soboleva Tanya K

    2007-12-01

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

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

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

    2015-03-15

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

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

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

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

    Doty, Keith L.

    1999-01-01

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

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

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

    2003-06-01

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

  18. Landmarks in Hybrid Planning

    Mohamed Elkawkagy

    2013-11-01

    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.

  19. Geodesic atlas-based labeling of anatomical trees

    Feragen, Aasa; Petersen, Jens; Owen, Megan; Lo, Pechin; Thomsen, Laura Hohwu; Wille, Mathilde Marie Winkler; Dirksen, Asger; de Bruijne, Marleen

    2015-01-01

    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...

  20. BasemapLandmarks_GEONAME

    Vermont Center for Geographic Information BasemapLandmarks_GEONAME is derived from the US Geological Survey's National Geographic Names Database (GNIS). The data were obtained by VCGI for distribution.

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

    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.

  2. Visual EKF-SLAM from Heterogeneous Landmarks

    Jorge Othón Esparza-Jiménez

    2016-04-01

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

  3. Visual EKF-SLAM from Heterogeneous Landmarks.

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

    2016-01-01

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

  4. Automatic Insall-Salvati ratio measurement on lateral knee x-ray images using model-guided landmark localization

    The Insall-Salvati ratio (ISR) is important for detecting two common clinical signs of knee disease: patella alta and patella baja. Furthermore, large inter-operator differences in ISR measurement make an objective measurement system necessary for better clinical evaluation. In this paper, we define three specific bony landmarks for determining the ISR and then propose an x-ray image analysis system to localize these landmarks and measure the ISR. Due to inherent artifacts in x-ray images, such as unevenly distributed intensities, which make landmark localization difficult, we hence propose a registration-assisted active-shape model (RAASM) to localize these landmarks. We first construct a statistical model from a set of training images based on x-ray image intensity and patella shape. Since a knee x-ray image contains specific anatomical structures, we then design an algorithm, based on edge tracing, for patella feature extraction in order to automatically align the model to the patella image. We can estimate the landmark locations as well as the ISR after registration-assisted model fitting. Our proposed method successfully overcomes drawbacks caused by x-ray image artifacts. Experimental results show great agreement between the ISRs measured by the proposed method and by orthopedic clinicians.

  5. Automatic Insall-Salvati ratio measurement on lateral knee x-ray images using model-guided landmark localization.

    Chen, Hsin-Chen; Lin, Chii-Jeng; Wu, Chia-Hsing; Wang, Chien-Kuo; Sun, Yung-Nien

    2010-11-21

    The Insall-Salvati ratio (ISR) is important for detecting two common clinical signs of knee disease: patella alta and patella baja. Furthermore, large inter-operator differences in ISR measurement make an objective measurement system necessary for better clinical evaluation. In this paper, we define three specific bony landmarks for determining the ISR and then propose an x-ray image analysis system to localize these landmarks and measure the ISR. Due to inherent artifacts in x-ray images, such as unevenly distributed intensities, which make landmark localization difficult, we hence propose a registration-assisted active-shape model (RAASM) to localize these landmarks. We first construct a statistical model from a set of training images based on x-ray image intensity and patella shape. Since a knee x-ray image contains specific anatomical structures, we then design an algorithm, based on edge tracing, for patella feature extraction in order to automatically align the model to the patella image. We can estimate the landmark locations as well as the ISR after registration-assisted model fitting. Our proposed method successfully overcomes drawbacks caused by x-ray image artifacts. Experimental results show great agreement between the ISRs measured by the proposed method and by orthopedic clinicians. PMID:21030753

  6. Automatic Insall-Salvati ratio measurement on lateral knee x-ray images using model-guided landmark localization

    Chen, Hsin-Chen; Wu, Chia-Hsing; Sun, Yung-Nien [Department of Computer Science and Information Engineering, National Cheng Kung University, 1 University Road, Tainan 701, Taiwan (China); Lin, Chii-Jeng [Department of Orthopedics, College of Medicine, National Cheng Kung University, 138 Sheng Li Road, Tainan 704, Taiwan (China); Wang, Chien-Kuo, E-mail: ynsun@mail.ncku.edu.t, E-mail: wale1212@gmail.co, E-mail: btmage@gmail.co, E-mail: mark@mail.ncku.edu.t, E-mail: n044206@mail.hosp.ncku.edu.t [Department of Radiology, National Cheng Kung University Hospital, 138 Sheng Li Road, Tainan 704, Taiwan (China)

    2010-11-21

    The Insall-Salvati ratio (ISR) is important for detecting two common clinical signs of knee disease: patella alta and patella baja. Furthermore, large inter-operator differences in ISR measurement make an objective measurement system necessary for better clinical evaluation. In this paper, we define three specific bony landmarks for determining the ISR and then propose an x-ray image analysis system to localize these landmarks and measure the ISR. Due to inherent artifacts in x-ray images, such as unevenly distributed intensities, which make landmark localization difficult, we hence propose a registration-assisted active-shape model (RAASM) to localize these landmarks. We first construct a statistical model from a set of training images based on x-ray image intensity and patella shape. Since a knee x-ray image contains specific anatomical structures, we then design an algorithm, based on edge tracing, for patella feature extraction in order to automatically align the model to the patella image. We can estimate the landmark locations as well as the ISR after registration-assisted model fitting. Our proposed method successfully overcomes drawbacks caused by x-ray image artifacts. Experimental results show great agreement between the ISRs measured by the proposed method and by orthopedic clinicians.

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

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

    2015-09-15

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

  8. 3D ultrasound-CT registration of the liver using combined landmark-intensity information

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

  9. FlyBase: anatomical data, images and queries

    Grumbling, Gary; Strelets, Victor; .. .

    2005-01-01

    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...

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

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

    2015-06-01

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

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

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

  12. Planning of landmark recognition of autonomous mobile robot (PLAS)

    Abe, Y.; Sakamoto, S. [Shinryo Corp., Tokyo (Japan); Fukuda, T.; Arai, F.; Ito, S. [Nagoya University, Nagoya (Japan)

    2000-05-25

    We have developed a novel nevigation system for autonomous mobile robots called the Planning of Landmark Sensing (PLAS) system which takes into account realistic environmental conditions. When a robot moves, the robot usually resets the accumulated position errors in its navigation model by sensing a landmark. In our previous work, these errors were estimated based on robot models, and a Kalman Filter was used to reset the errors after the landmark was sensed. In this method, only the spatial relation of the robot and the landmark was considered to influence the observation noise of the Kalman Filter. But, environmental conditions, like the lighting of the room, are likely to cause the misrecognition of a landmark. Therefore, we have incorporated environmental conditions into the model of the observation noise. This helps our system to recognize the possibility of a misrecognition in bad sensing environments. As a result, our navigation system allows robots to navigate precisely, even in environments not optimal for landmark sensing. (author)

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

    Abdul nazir

    2014-05-01

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

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

    Purpose: In this work, the authors introduce a novel framework, the anatomically constrained registration (AnCoR) scheme and apply it to create a fused anatomic-disease atlas of the prostate which the authors refer to as the prostatome. The prostatome combines a MRI based anatomic and a histology based disease atlas. Statistical imaging atlases allow for the integration of information across multiple scales and imaging modalities into a single canonical representation, in turn enabling a fused anatomical-disease representation which may facilitate the characterization of disease appearance relative to anatomic structures. While statistical atlases have been extensively developed and studied for the brain, approaches that have attempted to combine pathology and imaging data for study of prostate pathology are not extant. This works seeks to address this gap. Methods: The AnCoR framework optimizes a scoring function composed of two surface (prostate and central gland) misalignment measures and one intensity-based similarity term. This ensures the correct mapping of anatomic regions into the atlas, even when regional MRI intensities are inconsistent or highly variable between subjects. The framework allows for creation of an anatomic imaging and a disease atlas, while enabling their fusion into the anatomic imaging-disease atlas. The atlas presented here was constructed using 83 subjects with biopsy confirmed cancer who had pre-operative MRI (collected at two institutions) followed by radical prostatectomy. The imaging atlas results from mapping thein vivo MRI into the canonical space, while the anatomic regions serve as domain constraints. Elastic co-registration MRI and corresponding ex vivo histology provides “ground truth” mapping of cancer extent on in vivo imaging for 23 subjects. Results: AnCoR was evaluated relative to alternative construction strategies that use either MRI intensities or the prostate surface alone for registration. The AnCoR framework yielded a central gland Dice similarity coefficient (DSC) of 90%, and prostate DSC of 88%, while the misalignment of the urethra and verumontanum was found to be 3.45 mm, and 4.73 mm, respectively, which were measured to be significantly smaller compared to the alternative strategies. As might have been anticipated from our limited cohort of biopsy confirmed cancers, the disease atlas showed that most of the tumor extent was limited to the peripheral zone. Moreover, central gland tumors were typically larger in size, possibly because they are only discernible at a much later stage. Conclusions: The authors presented the AnCoR framework to explicitly model anatomic constraints for the construction of a fused anatomic imaging-disease atlas. The framework was applied to constructing a preliminary version of an anatomic-disease atlas of the prostate, the prostatome. The prostatome could facilitate the quantitative characterization of gland morphology and imaging features of prostate cancer. These techniques, may be applied on a large sample size data set to create a fully developed prostatome that could serve as a spatial prior for targeted biopsies by urologists. Additionally, the AnCoR framework could allow for incorporation of complementary imaging and molecular data, thereby enabling their careful correlation for population based radio-omics studies

  15. Texture-based approaches for identifying neuro-anatomical structures and electrode tracks.

    Xiang, Yongqing; Bttner-Ennever, Jean; Cohen, Bernard; Raphan, Theodore

    2004-06-01

    An automated approach to identifying electrode tracks and neuro-anatomical structures (nuclei) was developed using texture attributes of their neuro-anatomical stains. The properties that make up the texture features of the nuclei include size, shape and distribution of elemental structures. The electrode tracks are characterized by elongated darkened formations due to gliosis. Based on a Gabor wavelet transform, a texture feature vector was constructed, consisting of localized texture energies along different orientations at different scales. Stained images of brainstem sections in the vestibular nuclei were segmented using partitional clustering in feature space. A metric that computes the location of the tracks relative to the nuclei centers was then implemented. This methodology should be useful for quantifying and automating the procedure by which tracks are localized in anatomical structures. PMID:15135573

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

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

    2014-07-15

    Purpose: In this work, the authors introduce a novel framework, the anatomically constrained registration (AnCoR) scheme and apply it to create a fused anatomic-disease atlas of the prostate which the authors refer to as the prostatome. The prostatome combines a MRI based anatomic and a histology based disease atlas. Statistical imaging atlases allow for the integration of information across multiple scales and imaging modalities into a single canonical representation, in turn enabling a fused anatomical-disease representation which may facilitate the characterization of disease appearance relative to anatomic structures. While statistical atlases have been extensively developed and studied for the brain, approaches that have attempted to combine pathology and imaging data for study of prostate pathology are not extant. This works seeks to address this gap. Methods: The AnCoR framework optimizes a scoring function composed of two surface (prostate and central gland) misalignment measures and one intensity-based similarity term. This ensures the correct mapping of anatomic regions into the atlas, even when regional MRI intensities are inconsistent or highly variable between subjects. The framework allows for creation of an anatomic imaging and a disease atlas, while enabling their fusion into the anatomic imaging-disease atlas. The atlas presented here was constructed using 83 subjects with biopsy confirmed cancer who had pre-operative MRI (collected at two institutions) followed by radical prostatectomy. The imaging atlas results from mapping thein vivo MRI into the canonical space, while the anatomic regions serve as domain constraints. Elastic co-registration MRI and corresponding ex vivo histology provides “ground truth” mapping of cancer extent on in vivo imaging for 23 subjects. Results: AnCoR was evaluated relative to alternative construction strategies that use either MRI intensities or the prostate surface alone for registration. The AnCoR framework yielded a central gland Dice similarity coefficient (DSC) of 90%, and prostate DSC of 88%, while the misalignment of the urethra and verumontanum was found to be 3.45 mm, and 4.73 mm, respectively, which were measured to be significantly smaller compared to the alternative strategies. As might have been anticipated from our limited cohort of biopsy confirmed cancers, the disease atlas showed that most of the tumor extent was limited to the peripheral zone. Moreover, central gland tumors were typically larger in size, possibly because they are only discernible at a much later stage. Conclusions: The authors presented the AnCoR framework to explicitly model anatomic constraints for the construction of a fused anatomic imaging-disease atlas. The framework was applied to constructing a preliminary version of an anatomic-disease atlas of the prostate, the prostatome. The prostatome could facilitate the quantitative characterization of gland morphology and imaging features of prostate cancer. These techniques, may be applied on a large sample size data set to create a fully developed prostatome that could serve as a spatial prior for targeted biopsies by urologists. Additionally, the AnCoR framework could allow for incorporation of complementary imaging and molecular data, thereby enabling their careful correlation for population based radio-omics studies.

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

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

    2016-03-01

    Discovery of cryptic species using molecular tools has become common in many animal groups but it is rarely accompanied by morphological revision, creating ongoing problems in taxonomy and conservation. In copepods, cryptic species have been discovered in most groups where fast-evolving molecular markers were employed. In this study at Yeelirrie in Western Australia we investigate a subterranean species complex belonging to the harpacticoid genus Schizopera Sars, 1905, using both the barcoding mitochondrial COI gene and landmark-based two-dimensional geometric morphometrics. Integumental organs (sensilla and pores) are used as landmarks for the first time in any crustacean group. Complete congruence between DNA-based species delimitation and relative position of integumental organs in two independent morphological structures suggests the existence of three distinct evolutionary units. We describe two of them as new species, employing a condensed taxonomic format appropriate for cryptic species. We argue that many supposedly cryptic species might not be cryptic if researchers focus on analyzing morphological structures with multivariate tools that explicitly take into account geometry of the phenotype. A perceived supremacy of molecular methods in detecting cryptic species is in our view a consequence of disparity of investment and unexploited recent advancements in morphometrics among taxonomists. Our study shows that morphometric data alone could be used to find diagnostic morphological traits and gives hope to anyone studying small animals with a hard integument or shell, especially opening the door to assessing fossil diversity and rich museum collections. We expect that simultaneous use of molecular tools with geometry-oriented morphometrics may yield faster formal description of species. Decrypted species in this study are a good example for urgency of formal descriptions, as they display short-range endemism in small groundwater calcrete aquifers in a paleochannel, where their conservation may be threatened by proposed mining. PMID:26608965

  18. Landmark precision and reliability and accuracy of linear distances estimated by using 3D computed micro-tomography and the open-source TINA Manual Landmarking Tool software

    Simon, Monique Nouailhetas; Marroig, Gabriel

    2015-01-01

    Introduction The wider availability of non-destructive and high-resolution methods, such as micro-computed tomography (micro-CT), has prompted its use in anatomical and morphometric studies. Yet, because of the actual scanning procedure and the processing of CT data by software that renders 3D surfaces or volumes, systematic errors might be introduced in placing landmarks as well as in estimating linear distances. Here we assess landmark precision and measurement reliability and accuracy of u...

  19. Gastric bare area involvement by gastric carcinoma: CT features and anatomic-pathological bases

    Objective: To investigate the CT features of gastric bare area (GBA) involvement by gastric carcinoma and their anatomic-pathological bases. Methods: CT images of 110 consecutive proximal gastric carcinoma(PGC) cases were retrospectively studied. Of them, 46 cases of GBA involvement were confirmed by surgery and pathology. CT features of GBA involvement by gastric carcinoma and their anatomic-pathological bases were analyzed. Results: The lesion appeared as mass in bare area in 38 cases and as metastatic lymphadenopathy in 8 cases. CT features of GBA involvement included: (1) Gastric bare area was widened. The thin fat strip between gastric wall and diaphragm obscured, or even disappeared (36 cases). (2) Soft tissue density mass with heterogeneous enhancement (38 cases) or round lymph nodes (8 cases) was seen in GBA. (3) Left diaphragmatic crus or gastrophrenic ligament irregularly thickening was presented and could not be separated from mass tissue (25 cases). (4) Other metastatic lymph nodes located in subphrenic extra-peritoneal space might also be revealed (3 cases). Conclusion: GBA involvement by gastric carcinomas shows some characteristic CT signs. GBA involvement by gastric carcinoma attributes to anatomic location and lymphatic drainage of PGC, also may be relevant to poor prognosis. (authors)

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

    Tadinada, Aditya; Mahdian, Mina; Sheth, Sonam; Chandhoke, Taranpreet K.; Gopalakrishna, Aadarsh; Potluri, Anitha; Yadav, Sumit

    2015-01-01

    Purpose This study was performed to evaluate the reliability of the identification of anatomical landmarks in panoramic and lateral cephalometric radiographs on a standard medical grade picture archiving communication system (PACS) monitor and a tablet computer (iPad 5). Materials and Methods A total of 1000 radiographs, including 500 panoramic and 500 lateral cephalometric radiographs, were retrieved from the de-identified dataset of the archive of the Section of Oral and Maxillofacial Radio...

  1. Early fetal anatomical sonography.

    Donnelly, Jennifer C

    2012-10-01

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

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

    Queenilyn B. Albutra

    2012-06-01

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

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

    Resmana Lim

    2003-01-01

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

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

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

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

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

    2016-01-15

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

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

    Fagertun, Jens; Harder, Stine; Rosengren, Anders; Møller, Christian; Werge, Thomas; Paulsen, Rasmus Reinhold; Hansen, Thomas Fritz

    2014-01-01

    .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...... 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...

  7. Visual EKF-SLAM from Heterogeneous Landmarks

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

    2016-01-01

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

  8. Construction and Biomechanical Properties of PolyAxial Self-Locking Anatomical Plate Based on the Geometry of Distal Tibia

    Weiguo Liang; Weixiong Ye; Dongping Ye; Ziqiang Zhou; Zhiguang Chen; Aiguo Li; Zong-Han Xie; Lihai Zhang; Jiake Xu

    2014-01-01

    In order to provide scientific and empirical evidence for the clinical application of the polyaxial self-locking anatomical plate, 80 human tibias from healthy adults were scanned by spiral CT and their three-dimensional images were reconstructed using the surface shaded display (SSD) method. Firstly, based on the geometric data of distal tibia, a polyaxial self-locking anatomical plate for distal tibia was designed and constructed. Biomechanical tests were then performed by applying axial lo...

  9. 3D-based reconstruction using growing neural gas landmark: application to rapid prototyping in shoe last manufacturing

    Jimeno Morenilla, Antonio; García Rodríguez, José; Orts Escolano, Sergio; Davia Aracil, Miguel

    2013-01-01

    Customizing shoe manufacturing is one of the great challenges in the footwear industry. It is a production model change where design adopts not only the main role, but also the main bottleneck. It is therefore necessary to accelerate this process by improving the accuracy of current methods. Rapid prototyping techniques are based on the reuse of manufactured footwear lasts so that they can be modified with CAD systems leading rapidly to new shoe models. In this work, we present a shoe last fa...

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

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

    2012-03-01

    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

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

    Resmana Lim

    2003-01-01

    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 ...

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

    Beugnon Guy

    2011-08-01

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

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

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

    2016-02-01

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

  14. Landmark Discrimination Learning in the Dog

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

    1999-01-01

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

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

    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

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

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

    2014-02-15

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

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

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

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

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

    2012-02-01

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

  19. Anatomical basis for the intrahepatic glissonian approach during hepatectomies / Bases anatmicas para o acesso intra-heptico aos pedculos glissonianos durante hepatectomias

    Rodrigo Caada Trofo, SURJAN; Fbio Ferrari, MAKDISSI; Marcel Autran Cesar, MACHADO.

    2015-06-01

    Full Text Available RACIONAL: Resseces hepticas anatmicas so baseadas em alguns princpios tcnicos bsicos, como o controle vascular, delimitao de rea isqumica a ser ressecada e mxima preservao do parnquima. Isto pode ser obtido pelo acesso intra-heptico aos pedculos glissonianos, que consiste em contr [...] ole dos pedculos dos segmentos dentro do parnquima heptico. Pequenas incises ao redor da placa hilar, em marcos anatmicos bem definidos, so utilizadas para acesso aos pedculos, tornando desnecessria a disseco do hilo heptico. OBJETIVO: Analisar parmetros da anatomia do fgado relacionada com a tcnica cirrgica da abordagem intra-heptica aos pedculos glissonianos, para definir a anatomia normal relacionada ao procedimento e, assim, facilitar a realizao desta tcnica. MTODOS: Parmetros anatmicos relacionados abordagem intra-heptica aos pedculos glissonianos foram estudados em 37 cadveres. As medies foram realizadas com instrumentos de preciso. Os dados foram expressos em mdiadesvio-padro. Os indivduos foram divididos em grupos de acordo com o sexo e peso do fgado e os grupos foram comparados estatisticamente. RESULTADOS: Vinte e cinco cadveres eram do sexo masculino e 12 do feminino. No houve diferena estatisticamente significativa em praticamente todos os parmetros quando os grupos foram comparados. Isto demonstra a consistncia dos parmetros anatmicos relacionadas com a tcnica intra-heptica de acesso glissoniano. CONCLUSO: Os resultados obtidos neste estudo possibilitaram grandes avanos tcnicos na realizao de hepatectomias abertas e laparoscpicas com abordagem intra-heptica aos pedculos glissonianos, e pode ajudar cirurgies a realizar procedimentos seguros e eficazes por este mtodo. Abstract in english BACKGROUND: Anatomical liver resections are based on some basic technical principles such as vascular control, ischemic area delineation to be resected and maximum parenchymal preservation. These aspects are achieved by the intrahepatic glissonian approach, which consists in accessing the pedicles [...] of hepatic segments within the hepatic parenchyma. Small incisions on well-defined anatomical landmarks are performed to approach the pedicles, making dissection of the hilar plate unnecessary. AIM: Analyze parameters in liver anatomy related to intrahepatic surgical technique to glissonians pedicles, to set the normal anatomy related to the procedure and thereby facilitate the attainment of this technique. METHODS: Anatomical parameters related to the intrahepatic glissonian approach were studied in 37 cadavers. Measurements were performed with precision instruments. Data were expressed as meanstandard deviation. The subjects were divided into groups according to gender and liver weight and groups were compared statistically. RESULTS: Twenty-five cadavers were male and 12 female. No statistically significant difference was observed in virtually all parameters when groups were compared. This demonstrates the consistency of the anatomical parameters related to the intrahepatic glissonian approach. CONCLUSION: The results obtained in this study made possible major technical advances in the realization of open and laparoscopic hepatectomies with intrahepatic glissonian approach, and can help surgeons to perform liver resections by this method.

  20. Anatomía Artística: Bases Anatómicas del Retrato Escultórico Realista

    Jiménez Mateos, Miguel Ángel

    1999-01-01

    El saber sobre la estructura del organismo humano ha ido creciendo siguiendo las bases de cualquier otra ciencia. La curiosidad de los propios humanos los condujo a observar los organismos y a intentar indagar en ellos más allá de los límites de la observación superficial, penetrando en su interior dividiendo sus partes. “Anatomía: cortar repetidas veces”. La Anatomía analiza las relaciones causales que tanto la estructura como la función guardan entre sí, así como las modificaciones de índol...

  1. MIDA: A Multimodal Imaging-Based Detailed Anatomical Model of the Human Head and Neck.

    Iacono, Maria Ida; Neufeld, Esra; Akinnagbe, Esther; Bower, Kelsey; Wolf, Johanna; Vogiatzis Oikonomidis, Ioannis; Sharma, Deepika; Lloyd, Bryn; Wilm, Bertram J; Wyss, Michael; Pruessmann, Klaas P; Jakab, Andras; Makris, Nikos; Cohen, Ethan D; Kuster, Niels; Kainz, Wolfgang; Angelone, Leonardo M

    2015-01-01

    Computational modeling and simulations are increasingly being used to complement experimental testing for analysis of safety and efficacy of medical devices. Multiple voxel- and surface-based whole- and partial-body models have been proposed in the literature, typically with spatial resolution in the range of 1-2 mm and with 10-50 different tissue types resolved. We have developed a multimodal imaging-based detailed anatomical model of the human head and neck, named "MIDA". The model was obtained by integrating three different magnetic resonance imaging (MRI) modalities, the parameters of which were tailored to enhance the signals of specific tissues: i) structural T1- and T2-weighted MRIs; a specific heavily T2-weighted MRI slab with high nerve contrast optimized to enhance the structures of the ear and eye; ii) magnetic resonance angiography (MRA) data to image the vasculature, and iii) diffusion tensor imaging (DTI) to obtain information on anisotropy and fiber orientation. The unique multimodal high-resolution approach allowed resolving 153 structures, including several distinct muscles, bones and skull layers, arteries and veins, nerves, as well as salivary glands. The model offers also a detailed characterization of eyes, ears, and deep brain structures. A special automatic atlas-based segmentation procedure was adopted to include a detailed map of the nuclei of the thalamus and midbrain into the head model. The suitability of the model to simulations involving different numerical methods, discretization approaches, as well as DTI-based tensorial electrical conductivity, was examined in a case-study, in which the electric field was generated by transcranial alternating current stimulation. The voxel- and the surface-based versions of the models are freely available to the scientific community. PMID:25901747

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

    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

  3. PACS-based interface for 3D anatomical structure visualization and surgical planning

    Koehl, Christophe; Soler, Luc; Marescaux, Jacques

    2002-05-01

    The interpretation of radiological image is routine but it remains a rather difficult task for physicians. It requires complex mental processes, that permit translation from 2D slices into 3D localization and volume determination of visible diseases. An easier and more extensive visualization and exploitation of medical images can be reached through the use of computer-based systems that provide real help from patient admission to post-operative followup. In this way, we have developed a 3D visualization interface linked to a PACS database that allows manipulation and interaction on virtual organs delineated from CT-scan or MRI. This software provides the 3D real-time surface rendering of anatomical structures, an accurate evaluation of volumes and distances and the improvement of radiological image analysis and exam annotation through a negatoscope tool. It also provides a tool for surgical planning allowing the positioning of an interactive laparoscopic instrument and the organ resection. The software system could revolutionize the field of computerized imaging technology. Indeed, it provides a handy and portable tool for pre-operative and intra-operative analysis of anatomy and pathology in various medical fields. This constitutes the first step of the future development of augmented reality and surgical simulation systems.

  4. Patient Safety Curriculum for Anatomic Pathology Trainees: Recommendations Based on Institutional Experience.

    Samulski, Teresa D; Montone, Kathleen; LiVolsi, Virginia; Patel, Ketan; Baloch, Zubair

    2016-03-01

    Because of the unique systems and skills involved in patient care by the pathologist, it is challenging to design and implement relevant training in patient safety for pathology trainees. We propose a patient safety curriculum for anatomic pathology (AP) residents based on our institutional experience. The Hospital of the University of the Pennsylvania employs a self-reporting safety database. The occurrences from July 2013 to June 2015 recorded in this system that involved the division of AP were reviewed and cataloged as preanalytic, analytic, and postanalytic. The distribution of these occurrences was then used to create a framework for curriculum development in AP. We identified areas in which trainees are involved in the identification and prevention of common patient safety errors that occur in our AP department. Using these data-proven target areas, and employing current Accreditation Council for Graduate Medical Education recommendations and patient safety literature, a strategy for delivering relevant patient safety training is proposed. Teaching patient safety to pathology trainees is a challenging, yet necessary, component of AP training programs. By analyzing the patient safety errors that occur in the AP department, relevant and actionable training can be developed. This provides quality professional development and improves overall performance as trainees are integrated into laboratory systems. PMID:26849817

  5. ANATOMICAL PRINCIPLES BEHIND PRESERVATION OF LARYNGEAL NERVES DURING THYROIDECTOMY

    O. Fabian

    2011-08-01

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

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

    ANDI TANRA TELLU

    2005-04-01

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

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

    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

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

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

    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...

  9. Bases anatmicas vasculares de los colgajos perforantes cutneos Vascular anatomical basis of perforator skin flaps

    S. Morris

    2006-12-01

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

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

    MUH RAHMAD SUHARTANTO; SOBIR; ALFIN WIDIASTUTI

    2010-01-01

    Widiastuti A, Sobir, Suhartanto MR. 2010. Diversity analysis of mangosteen (Garcinia mangostana L.) irradiated by gamma-ray based on morphological and anatomical characteristics. Nusantara Bioscience 2: 23-33. The aim of this research was to increase genetic variability of mangosteen (Garcinia mangostana L.) irradiated by gamma rays dosage of 0 Gy, 20 Gy, 25 Gy, 30 Gy,35 Gy and 40 Gy. Plant materials used were seeds collected from Cegal Sub-village, Karacak Village, Leuwiliang Sub-district, B...

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

    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 tomography planning equipment, the prostatic apex can be easily and consistently identified, obviating the need to subject patients to retrograde urethrography

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

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

    2015-09-01

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

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

    Fifty-two patients with pathologic stage III Hodgkin's disease were studied in an effort to determine whether location of involved abdominal nodes influenced survival. Treatment consisted of total nodal radiotherapy with or without subsequent combination chemotherapy. The initial radiation field was the ''extended mantle,'' which included supradiaphragmatic nodes, the splenic hilar area, and paraaortic nodes to the level of L2-L4. Subsequently, lower paraaortic and iliac regions were treated (''lower inverted Y''). Patients with disease limited to the spleen and/or splenic, celiac, or portal nodes (''anatomic substage'' III1) had a more favorable 5-yr survival than did patients with involvement of paraaortic, iliac, or mesenteric nodes (''anatomic substage'' III2) : 93% versus 57%, respectively (p 2, but not of those in stage III1

  14. Elections and landmark policies in Tanzania and Uganda

    Kjær, Anne Mette; Therkildsen, Ole

    2013-01-01

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

  15. Critical anatomic region of nasopalatine canal based on tridimensional analysis: cone beam computed tomography

    Ana Fernández-Alonso; Juan Antonio Suárez-Quintanilla; Juan Muinelo-Lorenzo; Jesús Varela-Mallou; Ernesto Smyth Chamosa; María Mercedes Suárez-Cunqueiro

    2015-01-01

    The study aim of this was to define the critical anatomic region of the premaxilla by evaluating dimensions of nasopalatine canal, buccal bone plate (BBP) and palatal bone plate (PBP). 230 CBCTs were selected with both, one or no upper central incisors present (+/+, −/+, −/−) and periodontal condition was evaluated. T-student test, ANOVA, Pearson´s correlation and a multivariant-linear regression model (MLRM) were used. Regarding gender, significant differences at level 1 (lower NC) were foun...

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

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

    2012-01-01

    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 ...

  17. Critical anatomic region of nasopalatine canal based on tridimensional analysis: cone beam computed tomography.

    Fernández-Alonso, Ana; Suárez-Quintanilla, Juan Antonio; Muinelo-Lorenzo, Juan; Varela-Mallou, Jesús; Smyth Chamosa, Ernesto; Suárez-Cunqueiro, María Mercedes

    2015-01-01

    The study aim of this was to define the critical anatomic region of the premaxilla by evaluating dimensions of nasopalatine canal, buccal bone plate (BBP) and palatal bone plate (PBP). 230 CBCTs were selected with both, one or no upper central incisors present (+/+, -/+, -/-) and periodontal condition was evaluated. T-student test, ANOVA, Pearson's correlation and a multivariant-linear regression model (MLRM) were used. Regarding gender, significant differences at level 1 (lower NC) were found for: buccal-palatal, transversal and sagittal NC diameters, and NC length (NCL). Regarding dental status, significant differences were found for: total BBP length (tBL) and PBP width (PW2) at level 2 (NCL midpoint). NCL was correlated with PW2, tBL, and PBP length at level 3 (foramina of Stenson level). An MLRM had a high prediction value for NCL (69.3%). Gender is related to NC dimensions. Dental status has an influence on BBP dimensions, but does not influence on NC and PBP. Periodontal condition should be evaluated for precise premaxillae analysis NC diameters at the three anatomical planes are related to each other, while NCL is related to BBP and PBP lengths. A third of premaxilla is taken up by NC, thus, establishing the critical anatomic region. PMID:26245884

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

    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)

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

    MUH RAHMAD SUHARTANTO

    2010-01-01

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

  20. Conservative management of large avulsions of the lip and local landmarks.

    Rhee, Samuel T; Colville, Christopher; Buchman, Steven R

    2004-01-01

    Large lip avulsion injuries that involve significant tissue loss to the lip vermilion and other local landmarks can often pose a surgical dilemma for the reconstructive surgeon. Immediate reconstruction of these injuries are frequently performed using local flaps and adjacent tissue transfer to close the defect, but these repairs frequently suffer from the unfortunate consequence of increased associated scarring and further permanent distortion of the local anatomy. We present 2 patients sustaining dog bite injuries associated with extensive traumatic tissue loss to the lip vermilion and other local landmarks. These patients were treated conservatively with excellent functional and cosmetic results. A single minor surgical revision of 1 patient's cupid's bow was performed 1 year after injury. In cases of significant traumatic avulsion involving the lip vermilion and the perioral composite soft tissue, even with injuries including delicate anatomic landmarks, healing by secondary intention can be instituted as the initial treatment of choice in younger patients, often providing optimal results. PMID:14716166

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

    Purpose : To investigate the effects of the composition and geometry of ocular media and tissues surrounding the eye on dose distributions for COMS eye plaque brachytherapy with125I, 103Pd, or 131Cs seeds, and to investigate doses to ocular structures. Methods : An anatomically and compositionally realistic voxelized eye model with a medial tumor is developed based on a literature review. Mass energy absorption and attenuation coefficients for ocular media are calculated. Radiation transport and dose deposition are simulated using the EGSnrc Monte Carlo user-code BrachyDose for a fully loaded COMS eye plaque within a water phantom and our full eye model for the three radionuclides. A TG-43 simulation with the same seed configuration in a water phantom neglecting the plaque and interseed effects is also performed. The impact on dose distributions of varying tumor position, as well as tumor and surrounding tissue media is investigated. Each simulation and radionuclide is compared using isodose contours, dose volume histograms for the lens and tumor, maximum, minimum, and average doses to structures of interest, and doses to voxels of interest within the eye. Results : Mass energy absorption and attenuation coefficients of the ocular media differ from those of water by as much as 12% within the 2030 keV photon energy range. For all radionuclides studied, average doses to the tumor and lens regions in the full eye model differ from those for the plaque in water by 8%10% and 13%14%, respectively; the average doses to the tumor and lens regions differ between the full eye model and the TG-43 simulation by 2%17% and 29%34%, respectively. Replacing the surrounding tissues in the eye model with water increases the maximum and average doses to the lens by 2% and 3%, respectively. Substituting the tumor medium in the eye model for water, soft tissue, or an alternate melanoma composition affects tumor dose compared to the default eye model simulation by up to 16%. In the full eye model simulations, the average dose to the lens is larger by 7%9% than the dose to the center of the lens, and the maximum dose to the optic nerve is 17%22% higher than the dose to the optic disk for all radionuclides. In general, when normalized to the same prescription dose at the tumor apex, doses delivered to all structures of interest in the full eye model are lowest for103Pd and highest for 131Cs, except for the tumor where the average dose is highest for 103Pd and lowest for 131Cs. Conclusions : The eye is not radiologically water-equivalent, as doses from simulations of the plaque in the full eye model differ considerably from doses for the plaque in a water phantom and from simulated TG-43 calculated doses. This demonstrates the importance of model-based dose calculations for eye plaque brachytherapy, for which accurate elemental compositions of ocular media are necessary

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

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

    2014-02-15

    Purpose : To investigate the effects of the composition and geometry of ocular media and tissues surrounding the eye on dose distributions for COMS eye plaque brachytherapy with{sup 125}I, {sup 103}Pd, or {sup 131}Cs seeds, and to investigate doses to ocular structures. Methods : An anatomically and compositionally realistic voxelized eye model with a medial tumor is developed based on a literature review. Mass energy absorption and attenuation coefficients for ocular media are calculated. Radiation transport and dose deposition are simulated using the EGSnrc Monte Carlo user-code BrachyDose for a fully loaded COMS eye plaque within a water phantom and our full eye model for the three radionuclides. A TG-43 simulation with the same seed configuration in a water phantom neglecting the plaque and interseed effects is also performed. The impact on dose distributions of varying tumor position, as well as tumor and surrounding tissue media is investigated. Each simulation and radionuclide is compared using isodose contours, dose volume histograms for the lens and tumor, maximum, minimum, and average doses to structures of interest, and doses to voxels of interest within the eye. Results : Mass energy absorption and attenuation coefficients of the ocular media differ from those of water by as much as 12% within the 2030 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.

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

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

    2014-02-15

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

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

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

    1977-06-01

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

  5. Landmark Finding Algorithms for Indoor Autonomous Mobile Robot Localization

    L. Tóth

    2015-12-01

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

  6. Landmark analysis of clear and conversational speaking styles

    Boyce, Suzanne; Bradlow, Ann; MacAuslan, Joel

    2005-09-01

    Speakers appear to adjust speech production according to tradeoffs between intelligibility and economy of effort [Lindblom (1992)]. Recently, there has been much interest in investigation of differences between the clear style of speech addressed to disadvantaged listeners (non-native speakers, hearing impaired listeners, etc.) and ordinary, or conversational speaking style. Clear speech has been shown to be more intelligible across a wide range of listener types [Bradlow et al., (2002); Bradlow et al., (2003)], but the full range of parameters of variation remain undetermined. Recently also, the use of abrupt changes in the speech signal, i.e., acoustic landmarks, as an organizing principle for speech recognition has garnered attention [Espy-Wilson (2005)]. Using a landmark analysis procedure based on that of Stevens (1991) and Liu (1995), we present evidence that clear and conversational speaking styles can be distinguished in terms of the distribution of particular clusters of landmarks, corresponding very roughly to syllable-sized units. The implications of this differential distribution of landmarks across speaking styles for the organization of speech production will be discussed.

  7. Landmarks selection in street map design

    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

  8. Detection, visualization and animation of abnormal anatomic structure with a deformable probabilistic brain atlas based on random vector field transformations.

    Thompson, P M; Toga, A W

    1997-09-01

    This paper describes the design, implementation and preliminary results of a technique for creating a comprehensive probabilistic atlas of the human brain based on high-dimensional vector field transformations. The goal of the atlas is to detect and quantify distributed patterns of deviation from normal anatomy, in a 3-D brain image from any given subject. The algorithm analyzes a reference population of normal scans and automatically generates color-coded probability maps of the anatomy of new subjects. Given a 3-D brain image of a new subject, the algorithm calculates a set of high-dimensional volumetric maps (with typically 384(2) x 256 x 3 approximately 10(8) degrees of freedom) elastically deforming this scan into structural correspondence with other scans, selected one by one from an anatomic image database. The family of volumetric warps thus constructed encodes statistical properties and directional biases of local anatomical variation throughout the architecture of the brain. A probability space of random transformations, based on the theory of anisotropic Gaussian random fields, is then developed to reflect the observed variability in stereotaxic space of the points whose correspondences are found by the warping algorithm. A complete system of 384(2) x 256 probability density functions is computed, yielding confidence limits in stereotaxic space for the location of every point represented in the 3-D image lattice of the new subject's brain. Color-coded probability maps are generated, densely defined throughout the anatomy of the new subject. These indicate locally the probability of each anatomic point being unusually situated, given the distributions of corresponding points in the scans of normal subjects. 3-D MRI and high-resolution cryosection volumes are analyzed from subjects with metastatic tumors and Alzheimer's disease. Gradual variations and continuous deformations of the underlying anatomy are simulated and their dynamic effects on regional probability maps are animated in video format (on the accompanying CD-ROM). Applications of the deformable probabilistic atlas include the transfer of multi-subject 3-D functional, vascular and histologic maps onto a single anatomic template, the mapping of 3-D atlases onto the scans of new subjects, and the rapid detection, quantification and mapping of local shape changes in 3-D medical images in disease and during normal or abnormal growth and development. PMID:9873911

  9. A framework for evaluation of deformable image registration spatial accuracy using large landmark point sets

    Expert landmark correspondences are widely reported for evaluating deformable image registration (DIR) spatial accuracy. In this report, we present a framework for objective evaluation of DIR spatial accuracy using large sets of expert-determined landmark point pairs. Large samples (>1100) of pulmonary landmark point pairs were manually generated for five cases. Estimates of inter- and intra-observer variation were determined from repeated registration. Comparative evaluation of DIR spatial accuracy was performed for two algorithms, a gradient-based optical flow algorithm and a landmark-based moving least-squares algorithm. The uncertainty of spatial error estimates was found to be inversely proportional to the square root of the number of landmark point pairs and directly proportional to the standard deviation of the spatial errors. Using the statistical properties of this data, we performed sample size calculations to estimate the average spatial accuracy of each algorithm with 95% confidence intervals within a 0.5 mm range. For the optical flow and moving least-squares algorithms, the required sample sizes were 1050 and 36, respectively. Comparative evaluation based on fewer than the required validation landmarks results in misrepresentation of the relative spatial accuracy. This study demonstrates that landmark pairs can be used to assess DIR spatial accuracy within a narrow uncertainty range.

  10. A framework for evaluation of deformable image registration spatial accuracy using large landmark point sets

    Castillo, Richard [Department of Imaging Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Castillo, Edward [Department of Mathematics, University of California, Irvine, CA (United States); Guerra, Rudy [Department of Statistics, Rice University, Houston, TX (United States); Johnson, Valen E [Department of Biostatistics and Applied Mathematics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); McPhail, Travis [Department of Computer Science, Rice University, Houston, TX (United States); Garg, Amit K; Guerrero, Thomas [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)], E-mail: tguerrero@mdanderson.org

    2009-04-07

    Expert landmark correspondences are widely reported for evaluating deformable image registration (DIR) spatial accuracy. In this report, we present a framework for objective evaluation of DIR spatial accuracy using large sets of expert-determined landmark point pairs. Large samples (>1100) of pulmonary landmark point pairs were manually generated for five cases. Estimates of inter- and intra-observer variation were determined from repeated registration. Comparative evaluation of DIR spatial accuracy was performed for two algorithms, a gradient-based optical flow algorithm and a landmark-based moving least-squares algorithm. The uncertainty of spatial error estimates was found to be inversely proportional to the square root of the number of landmark point pairs and directly proportional to the standard deviation of the spatial errors. Using the statistical properties of this data, we performed sample size calculations to estimate the average spatial accuracy of each algorithm with 95% confidence intervals within a 0.5 mm range. For the optical flow and moving least-squares algorithms, the required sample sizes were 1050 and 36, respectively. Comparative evaluation based on fewer than the required validation landmarks results in misrepresentation of the relative spatial accuracy. This study demonstrates that landmark pairs can be used to assess DIR spatial accuracy within a narrow uncertainty range.

  11. Landmark perception planning for mobile robot localization

    Armingol, José M.; MORENO, LUIS; Escalera, Arturo de la; Salichs, Miguel A.

    1998-01-01

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

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

    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 IMRT QA, can provide distinct indications of clinically significant radiobiological effects beyond the minimization of probable physical dose errors in phantoms. (author)

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

    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)

  14. 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

    Thomas Frigeri

    2014-10-01

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

  15. The Incisive Papilla: A Significant Landmark in Prosthodontics

    Solomon, E. G. R.; Arunachalam, K. S.

    2012-01-01

    Several investigators have studied the horizontal relationship between incisive papilla and maxillary central incisor and measured the papilla incisor distance in dentate subjects to extrapolate this distance as a guide to place maxillary central incisors in complete dentures. Based on this premise, incisive papilla is recognized as an important landmark in complete denture construction. Papilla incisor measurements were made either from the middle or posterior border of the papilla and certa...

  16. Detection of point landmarks in multidimensional tensor data☆

    Ruiz-Alzola, J.; Kikinis, R.; Westin, C.-F.

    2015-01-01

    This paper describes a unified approach to the detection of point landmarks—whose neighborhoods convey discriminant information—including multidimensional scalar, vector, and higher-order tensor data. The method is based on the interpretation of generalized correlation matrices derived from the gradient of tensor functions, a probabilistic interpretation of point landmarks, and the application of tensor algebra. Results on both synthetic and real tensor data are presented. PMID:26005233

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

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

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

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

    2015-05-15

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

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

    Goffinet François

    2011-10-01

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

  20. Landmark Analysis Of Leaf Shape Using Polygonal Approximation

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

    2016-01-01

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

  1. Fluence-to-dose conversion coefficients for monoenergetic proton beams based on the VIP-Man anatomical model

    A new set of fluence-to-absorbed dose and fluence-to-effective dose conversion coefficients has been calculated for high-energy protons using the whole-body anatomical model VIP-Man, which was developed from the high-resolution transverse colour photographic images of the National Library of Medicine's Visible Human Project. For 10 monoenergetic proton beams between 20 and 10,000 MeV, organ dose calculations were performed using the Monte Carlo code MCNPX under six different irradiation geometries: anterior-posterior, posterior-anterior, left lateral, right lateral, isotropic and rotational. The absorbed dose results for 24 major organs of VIP-Man are presented and compared with those based on mathematical phantoms reported in the literature. The discrepancies (generally within 40%) in organ dose and effective dose estimates are attributed to the use of different transport models employed by different Monte Carlo codes. (authors)

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

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

    2000-06-01

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

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

    Schunke Anja C

    2012-04-01

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

  4. Applications of neural networks to landmark detection in 3-D surface data

    Arndt, Craig M.

    1992-09-01

    The problem of identifying key landmarks in 3-dimensional surface data is of considerable interest in solving a number of difficult real-world tasks, including object recognition and image processing. The specific problem that we address in this research is to identify the specific landmarks (anatomical) in human surface data. This is a complex task, currently performed visually by an expert human operator. In order to replace these human operators and increase reliability of the data acquisition, we need to develop a computer algorithm which will utilize the interrelations between the 3-dimensional data to identify the landmarks of interest. The current presentation describes a method for designing, implementing, training, and testing a custom architecture neural network which will perform the landmark identification task. We discuss the performance of the net in relationship to human performance on the same task and how this net has been integrated with other AI and traditional programming methods to produce a powerful analysis tool for computer anthropometry.

  5. High-risk human papillomavirus infection involving multiple anatomic sites of the female lower genital tract: a multiplex real-time polymerase chain reaction-based study.

    Hui, Yiang; Manna, Pradip; Ou, Joyce J; Kerley, Spencer; Zhang, Cunxian; Sung, C James; Lawrence, W Dwayne; Quddus, M Ruhul

    2015-09-01

    High-risk human papillomavirus infection usually is seen at one anatomic site in an individual. Rarely, infection at multiple anatomic sites of the female lower genital tract in the same individual is encountered either simultaneously and/or at a later date. The current study identifies the various subtypes of high-risk human papillomavirus infection in these scenarios and analyzes the potential significance of these findings. High-risk human papillomavirus infection involving 22 anatomic sites from 7 individuals was identified after institutional review board approval. Residual paraffin-embedded tissue samples were retrieved, and all 15 high-risk human papillomavirus were identified and viral load quantified using multiplex real-time polymerase chain reaction-based method. Multiple high-risk human papillomavirus subtypes were identified in 32% of the samples and as many as 5 different subtypes of high-risk human papillomavirus infection in a single anatomic site. In general, each anatomic site has unique combination of viral subtypes, although one individual showed overlapping subtypes in the vagina, cervix, and vulvar samples. Higher viral load and rare subtypes are more frequent in younger patients and in dysplasia compared with carcinoma. Follow-up ranging from 3 to 84 months revealed persistent high-risk human papillomavirus infection in 60% of cases. PMID:26220161

  6. Landmark papers on photorefractive nonlinear optics

    Yeh, Pochi

    1995-01-01

    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.

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

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

    2009-02-15

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

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

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

  9. Remembered landmarks enhance the precision of path integration

    Shannon O´Leary

    2005-01-01

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

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

    Walmsley, R.; Monkhouse, W S

    1988-01-01

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

  11. Automated localization of pelvic anatomical coordinate system from 3D CT data of the hip using statistical atlas

    Localization of the pelvic anatomical coordinate system is a prerequisite for patient-specific preoperative planning and joint motion simulation for hip surgery. Our aim is to automate localization of the pelvic anatomical coordinate system from 3D CT data. In this paper, we propose a statistical atlas-based method that consists of three steps. The first step is spatial normalization using a probabilistic atlas. The second step is feature point recognition using a statistical landmark model. The final step is coordinate system refinement using a standard CT atlas. We applied the proposed method to 39 datasets. Compared to manual localization by an experienced surgeon, the average positional error was 2.371.30 mm and the average orientation error was 1.070.50 degrees. These results demonstrate the usefulness of the proposed method. (author)

  12. Ultrasound of the elbow: A systematic approach using bony landmarks

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

  13. Validation of landmark sets and their use for registration in mouse brain imaging

    Marina Sergejeva

    2010-06-01

    Full Text Available In the time when genetic engineering is flourishing, and numerous strains of mutant mice are being created for research purposes, a world-wide accessible reference system which would enable comparison of the data of various types from different working groups is very desirable. Several attempts have been made for such mouse brain atlases ranging from the gold standard of the Paxinos printed atlas (2nd edition 2001 to ABA (www.brain-map.org etc. The INCF (incf.org/ has launched the Digital Atlasing Program (incf.org/core/programs/atlasing which came up with the Waxholm space (WHS: 2008, which is an up-to-date computer-based common reference space for adult C57BL/6J mice. This reference space, available to the public, consists of very high resolution undistorted MRI datasets of different contrasts (T1: 21,5 m, T2, T2*, 43 m together with Nissl histology (20 m of the very same specimen, all fully 3D from A. Johnson (Duke, www.civm.duhs.duke.edu/. Very recently, population based datasets including DTI have been made available by A. Johnson (www.civm.duhs.duke.edu/neuro200902/index.html. One desirable application of a computerized digital atlas is to bring ones own data into this reference system to gain full advantage of the information available in the system. This process is called registration. Fully automatic registration processes only exist for very limited use of datasets with hard constrains (dimensionality, modality, contrast etc.. Moreover, the parameterization of these algorithms is complex and high computational power (up to several hours is needed. An alternative approach, which I is much faster, II can be performed by everybody, III leads to sufficient accuracy for many applications, is a registration based on landmarks or fiducials. In imaging technology, a fiducial is part of an image serving as a point of reference i.e. characteristic internal anatomic structure of the brain easily identified. Practically and to enhance the spatial precision, the fiducials are often reduced to a single point (see Fig. 1. Defining a corresponding set of fiducials in a source and target (reference dataset determines the transformation of the source to the target dataset. Moreover, this landmark based registration may first, enhance performance of the computational intense automatic registration and second, these fiducials allow for validation of any other registration procedure. Therefore, the aim of this study is to identify set(s of fiducials primarily allowing the registration of any 3D datasets to WHS. These should be unambiguously recognizable: to different individuals in different image modalities (T1, T2, T2* in various specimens in different cutting directions in different image resolutions in various mouse strains Consequently, we started with "medium" resolution MR datasets (T1, T2, T2*, 256x256x128, 80 m. Using ImageJ (rsbweb.nih.gov/ij/index.html and its point identification tool, anatomical experts defined an initial set of fiducials (T1: 36, T2: 65, T2*: 51. Next a group of 13 subjects (among them anatomical novice, physicists, vets and biologists identified these landmarks on the same dataset, using a guide to find and set the fiducials. We achieved a very high precision of around 1.5 voxel deviation across all fiducials. In addition, the same group of people had to identify these fiducials on different datasets of the same mouse strain. In this case, for T1-90 %, T2-100%, and T2*-97% of these same fiducials could be found. A web-based version of our fiducial point effort is online to encourage user participation (http://smartatlas.crbs.ucsd.edu:8080 /mapserver-services/pages/imageviewer/incf1.html. This study allows us to get insight into accuracy of manually identifiable fiducials, and therefore their reliability. Establishing an easy to use landmark registration to WHS should facilitate cooperation of mouse imagers all over the world.

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

    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.

  15. Landmarks GIScience for intelligent services

    Richter, Kai-Florian

    2014-01-01

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

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

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

    2013-03-01

    The present study aimed to investigate whether brain morphological differences exist between adult hypothyroid subjects and age-matched controls using voxel-based morphometry (VBM) with diffeomorphic anatomic registration via an exponentiated lie algebra algorithm (DARTEL) approach. High-resolution structural magnetic resonance images were taken in ten healthy controls and ten hypothyroid subjects. The analysis was conducted using statistical parametric mapping. The VBM study revealed a reduction in grey matter volume in the left postcentral gyrus and cerebellum of hypothyroid subjects compared to controls. A significant reduction in white matter volume was also found in the cerebellum, right inferior and middle frontal gyrus, right precentral gyrus, right inferior occipital gyrus and right temporal gyrus of hypothyroid patients compared to healthy controls. Moreover, no meaningful cluster for greater grey or white matter volume was obtained in hypothyroid subjects compared to controls. Our study is the first VBM study of hypothyroidism in an adult population and suggests that, compared to controls, this disorder is associated with differences in brain morphology in areas corresponding to known functional deficits in attention, language, motor speed, visuospatial processing and memory in hypothyroidism. PMID:23057474

  17. Anatomical differences in empathy related brain areas: A voxel-based morphometry study

    Jean Decety

    2015-02-01

    Full Text Available Understanding empathy from a neuroscientific perspective has taken precedence recently with several fMRI studies associating different brain regions with different components of empathy. A recent meta-analysis across 40 fMRI studies revealed that affective empathy (vicariously sharing others emotions is most often associated with activity in the insula, whereas cognitive empathy (reasoning about others emotions is most often associated with activity in the dorsal anterior cingulate cortex and adjacent dorsomedial prefrontal cortex (dACC/dmPFC; Fan et al., 2011. To date, however, it remains unclear whether individual differences in brain morphometry in these regions underlie different capabilities in affective and cognitive empathy. In order to test this hypothesis, we used voxel-based morphometry (VBM to analyse grey matter density using scores from an established empathy measure (Questionnaire of Cognitive and Affective Empathy; QCAE as regressors. One hundred and seventy-six participants completed the QCAE and underwent MRI in order to acquire a high-resolution, three-dimensional T1-weighted image. A factor analysis of the questionnaire scores revealed two distinct factors of empathy, affective and cognitive, which confirmed the validity of the QCAE. VBM results revealed grey matter density differences associated with the different constructs of empathy, whereby, higher scores of affective empathy were related to greater grey matter density in the insula and higher scores of cognitive empathy were related to greater grey matter density in the dACC/dmPFC. Taken together, the results shown here provide validation for empathy being a multi-component construct, suggesting that affective and cognitive empathy are differentially represented in brain morphometry.

  18. Original Rehabilitation Programme after Anatomical ACL Reconstruction Based on MRI Evaluated Graft Remodelling

    Plenzler, Marcin; Straszewski, Dariusz; Ciszkowska-Łysoń, Beata; Śmigielski, Robert; Popieluch, Marcin

    2014-01-01

    Objectives: This study was carried out to design a rehabilitation program allowing for complete functional post-surgical recovery of the limb, that would not affect the remodelling process of the transplanted graft evaluated on MRI imaging. The main reason for changing the rehabilitation protocol was the 14 months of observation of the MRI images (a series of 9 MRIs performed over a two year period) among the patients after ACL reconstruction, in whom the adverse characteristics in remodelling of the graft were observed in line with the implementation of the traditional rehabilitation program. Methods: A 23 years old patient, a professional hi-rank skateboarder, took part in this pilot study. He had a torsion injury of the left knee joint. The main concepts of the rehabilitation program were: functional training in CKC that would involve muscles of the entire kinetic chain of the operated limb; the co-contraction training under the axial load, active extension training, the avoidance of static flexor stretching for at least 24 weeks after the surgery, no passive movements while exercising, the use of posterior translation of the tibia while doing the exercises, and no knee joint extensor strengthening activities in OKC for at least six months after the surgery. In order to evaluate the remodelling of the graft, seven oblique axial MR images (DOA) were taken, on which the graft’s cross-sectional area was measured. The MRI's were performed in the second, sixth, and twelfth week; then in the fourth, sixth, and ninth month, and, finally a year after the surgery. The angle of the graft and PCL was also measured. Additionally, the quality of tendon signal was assessed. For the functional evaluation, isokinetic and isometric tests of the knee extensor and the flexor muscles, along with the tibial rotator functions were performed using Humac Norm device. Postural stability based on COP parameter was established, as well, using the stabilometric platform HUR. For the dynamic stabilography assessment Biodex Balance System device was used. In order to indicate the subjective functional evaluation by the patient, the Lyshom scale and IKDC questionnaires were used. Results: The MRI 12 months after the surgery showed good tendon signal, and no significant changes characteristic for the anterior subluxation of the tibia were observed. In the functional evaluation, very good values of flexor and extensor muscle strength were recorded. These values were comparable to those achieved by the opposing limb. The strength of the left knee rotator muscles was comparable to that of the opposite limb. Additionally, very good stability index was recorded in both static and dynamic conditions. The results the two limbs were comparable. Patient’s subjective evaluation was also assessed to be on a very good level (the results of the IKDC questionnaires were 98,85 and 100/100 on the Lysholm’s scale). Conclusion: The original rehabilitation program in CMC seems to be a valuable protocol conditioning the return to sport activities without disrupting the the remodelling process of the graft. The case described is a part of a bigger project which includes the total of over 30 patients.

  19. Agreement between anatomic and ultrasound measurements of femoral trochlear depth

    Miles, James Edward; Westrup, Ulrik; Eriksen, Thomas

    Assessments of trochlear depth for patients with medial patellar luxation have traditionally been estimated from skyline radiographs or visually during surgery. Ultrasound offers a non-invasive evaluation method which could avoid the need for arthrotomy. We compared anatomic, radiographic and ult...... respective DICOM files which restricts ultrasonographic landmark resolution. Further work on quantifying interobserver variation and repeat measurement variation is required to ensure confidence in this technique....

  20. Anatomical Factors Influencing Pneumatization of the Petrous Apex

    Lee, Dong-Hee; Kim, Min-ju; Lee, Seunghun; Choi, Hana

    2015-01-01

    Objectives Aim of the present study was to define the relationship between petrous apex pneumatization and the nearby major anatomical landmarks using temporal bone computed tomography (CT) images. Methods This retrospective, Institutional Review Board-approved study analyzed CT images of 84 patients that showed normal findings bilaterally. Pneumatization of the petrous apex was classified using two methods. Eight parameters were as follows: angle between the posterior cranial fossa and inter...

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

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

    2015-12-01

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

  2. Landmarking and feature localization in spine x-rays

    Long, L. Rodney; Thoma, George R.

    2001-10-01

    The general problem of developing algorithms for the automated or computer-assisted indexing of images by structural contents is a significant research challenge. This is particularly so in the case of biomedical images, where the structures of interest are commonly irregular, overlapping, and partially occluded. Examples are the images created by digitizing film x-rays of the human cervical and lumbar spines. We have begun work toward the indexing of 17 000 such spine images for features of interest in the osteoarthritis and vertebral morphometry research communities. This work requires the segmentation of the images into vertebral structures with sufficient accuracy to distinguish pathology on the basis of shape, labeling of the segmented structures by proper anatomical name, and classification of the segmented, labeled structures into groups corresponding to high level semantic features of interest, using training data provided by biomedical experts. In this paper, we provide a technical characterization of the cervical spine images and the biomedical features of interest, describe the evolving technical approach for the segmentation and indexing problem, and provide results of algorithms to acquire basic landmark data and localization of spine regions in the images.

  3. 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

    Jansen Casper L

    2011-07-01

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

  4. Anatomic Total Shoulder System

    Full Text Available ... In a few moments, you'll be able to watch a live global AP anatomic total shoulder ... neck, angle, and version variability which allows adaptability to a patient's unique anatomical makeup. Dr. Gerald R. ...

  5. Morphology of the Canine Omentum Part 1: Arterial Landmarks that Define the Omentum.

    Doom, M; de Rooster, H; van Bergen, T; Gielen, I; Kromhout, K; Simoens, P; Cornillie, P

    2016-02-01

    Although the omentum remains an enigmatic organ, research during the last decades has revealed its fascinating functions including fat storage, fluid drainage, immune activity, angiogenesis and adhesion. While clinicians both in human and veterinary medicine are continuously exploring new potential omental applications, detailed anatomical data on the canine omentum are currently lacking, and information is often retrieved from human medicine. In this study, the topographic anatomy of the canine greater and lesser omentum is explored in depth. Current nomenclature is challenged, and a more detailed terminology is proposed. Consistent arteries that are contained within folds of the superficial omental wall are documented, described and named, as they can provide the anatomical landmarks that are necessary for unambiguous scientific communication on the canine omentum. In an included dissection video, the conclusions and in situ findings described in this study are demonstrated. PMID:25516017

  6. The behavioural relevance of landmark texture for honeybee homing

    Laura Dittmar

    2011-04-01

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

  7. Anatomical imaging for radiotherapy

    The goal of radiation therapy is to achieve maximal therapeutic benefit expressed in terms of a high probability of local control of disease with minimal side effects. Physically this often equates to the delivery of a high dose of radiation to the tumour or target region whilst maintaining an acceptably low dose to other tissues, particularly those adjacent to the target. Techniques such as intensity modulated radiotherapy (IMRT), stereotactic radiosurgery and computer planned brachytherapy provide the means to calculate the radiation dose delivery to achieve the desired dose distribution. Imaging is an essential tool in all state of the art planning and delivery techniques: (i) to enable planning of the desired treatment, (ii) to verify the treatment is delivered as planned and (iii) to follow-up treatment outcome to monitor that the treatment has had the desired effect. Clinical imaging techniques can be loosely classified into anatomic methods which measure the basic physical characteristics of tissue such as their density and biological imaging techniques which measure functional characteristics such as metabolism. In this review we consider anatomical imaging techniques. Biological imaging is considered in another article. Anatomical imaging is generally used for goals (i) and (ii) above. Computed tomography (CT) has been the mainstay of anatomical treatment planning for many years, enabling some delineation of soft tissue as well as radiation attenuation estimation for dose prediction. Magnetic resonance imaging is fast becoming widespread alongside CT, enabling superior soft-tissue visualization. Traditionally scanning for treatment planning has relied on the use of a single snapshot scan. Recent years have seen the development of techniques such as 4D CT and adaptive radiotherapy (ART). In 4D CT raw data are encoded with phase information and reconstructed to yield a set of scans detailing motion through the breathing, or cardiac, cycle. In ART a set of scans is taken on different days. Both allow planning to account for variability intrinsic to the patient. Treatment verification has been carried out using a variety of technologies including: MV portal imaging, kV portal/fluoroscopy, MVCT, conebeam kVCT, ultrasound and optical surface imaging. The various methods have their pros and cons. The four x-ray methods involve an extra radiation dose to normal tissue. The portal methods may not generally be used to visualize soft tissue, consequently they are often used in conjunction with implanted fiducial markers. The two CT-based methods allow measurement of inter-fraction variation only. Ultrasound allows soft-tissue measurement with zero dose but requires skilled interpretation, and there is evidence of systematic differences between ultrasound and other data sources, perhaps due to the effects of the probe pressure. Optical imaging also involves zero dose but requires good correlation between the target and the external measurement and thus is often used in conjunction with an x-ray method. The use of anatomical imaging in radiotherapy allows treatment uncertainties to be determined. These include errors between the mean position at treatment and that at planning (the systematic error) and the day-to-day variation in treatment set-up (the random error). Positional variations may also be categorized in terms of inter- and intra-fraction errors. Various empirical treatment margin formulae and intervention approaches exist to determine the optimum strategies for treatment in the presence of these known errors. Other methods exist to try to minimize error margins drastically including the currently available breath-hold techniques and the tracking methods which are largely in development. This paper will review anatomical imaging techniques in radiotherapy and how they are used to boost the therapeutic benefit of the treatment. (topical review)

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

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

    2014-01-01

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

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

    Dongdong Deng; Peifeng Jiao; Xuesong Ye; Ling Xia

    2012-01-01

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

  10. Using landmarks to support older people in navigation

    Goodman, J.; Gray, P.D.G.; Khammampad, K.; Brewster, S.

    2004-01-01

    Although landmarks are an integral aspect of navigation, they have rarely been used within electronic navigation aids. This paper describes the design of a pedestrian navigation aid for a handheld computer, which guides the user along a route using photographs of landmarks, together with audio and text instructions that reference these landmarks. This aid was designed with older users in mind who often find their mobility hampered by declines in sensory, cognitive and motor abilities. It was ...

  11. Detection of natural landmarks through multiscale opponent features

    Todt, Eduardo; Torras Genís, Carme

    2000-01-01

    This work presents a landmark detection system for the walking robot operating in unknown unstructured outdoor environments. Most landmark detection approaches are not adequate for this application, since they rely on either structured information or a priori knowledge about the landmarks. Instead, the proposed system makes use of visual saliency concepts stemming from studies of animal and human perception. Thus, biologically inspired opponent features (in color and orientation) are searched...

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

    Hyukdoo Choi

    2014-01-01

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

  13. Vascular landmark detection in 3D CT data

    Liu, David; Zhou, S. Kevin; Bernhardt, Dominik; Comaniciu, Dorin

    2011-03-01

    This work presents novel methods to accurately placing landmarks inside the vessel lumen. This task is an important prerequisite to automatic centerline tracing. Methods have been proposed in the past to determine the location of organ landmarks, and yet several challenges remain for vascular landmarks. First, placing landmarks inside the lumen could be challenging for narrow vessels. Second, contrast-enhanced arteries could be tightly surrounded by bones with similar intensity profiles, making detection difficult compared to arteries surrounded only by darker tissues. Third, landmarks not located at bifurcations could be ill-defined as they have high uncertainty in position. We first present a method to detect landmarks that are located at vessel bifurcations. Such landmarks have well-defined positions, and we detect them using machine learning techniques. We then present a method to detect vascular landmarks not located at bifurcations. First, a segment detector is created to detect a vessel segment. Annotating multiple points along a vessel segment is easier than annotating a single landmark position, as there is no well-defined position along a vessel. This resolves the ambiguity issue mentioned above. Second, spatial features are computed from the segment detector's response map, and a regression model is created which takes as input the local spatial features surrounding a voxel, and outputs a confidence score of how likely this voxel is inside the lumen. We evaluate the system on a set of 94 3D CT datasets.

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

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

    2015-01-01

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

  15. Selenium-based digital radiography of the cervical spine. Comparison with screen-film radiography for the depiction of anatomic details

    Purpose: To compare selenium-based digital radiography with conventional screen-film radiography of the cervical spine. Materials and Methods: In a prospective study X-ray images of the cervical spine were obtained in 25 patients using selenium-based digital radiography and conventional screen-film radiography. All images were clinically indicated. Selenium-based digital radiography and conventional screen-film radiography were used in a randomized order. Four radiologists independently evaluated all 50 examinations for the visibility of 76 anatomic details according to a five-level confidence scale (1=not visible, 5=very good visibility). From the evaluation of these anatomic details scores for the upper and middle cervical spine, the cervicothoracic junction and the cervical soft tissues were calculated. The scores for selenium-based digital radiography and conventional screen-film radiography were compared using Wilcoxon's signed rank test. Results: From a total of 15,200 observations (608 per patient) the following scores were calculated for selenium-based digital radiography and for screen-film radiography, respectively: Upper cervical spine 3.88 and 3.94; middle cervical spine 4.60 and 4.48; cervico-thoracic junction 3.64 and 2.62; cervical soft tissue 4.47 and 3.46. The differences between the last two scores were statistically significant (p<0.05). Conclusion: the use of selenium-based digital radiography is superior to conventional screen-film radiography in the depiction of anatomic details of the cervicothoracic junction and the cervical soft tissues. (orig.)

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

    Hernan F. Garcia

    2013-02-01

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

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

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

    2014-01-01

    Lateral cephalograms in orthodontic practice display an area cranial of the base of the skull that is not required for diagnostic evaluation. Attempts have been made to reduce the radiation dose to the patient using collimators combining the shielding of the areas above the base of the skull and below the mandible. These so-called "wedge-shaped" collimators have not become standard equipment in orthodontic offices, possibly because these collimators were not designed for today's combination panoramic-cephalometric imaging systems. It also may be that the anatomical variability of the area below the mandible makes this area unsuitable for standardized collimation. In addition, a wedge-shaped collimator shields the cervical vertebrae; therefore, assessment of skeletal maturation, which is based on the stage of development of the cervical vertebrae, cannot be performed. In this report, we describe our investigations into constructing a collimator to be attached to the cephalostat and shield the cranial area of the skull, while allowing the visualization of diagnostically relevant structures and markedly reducing the size of the irradiated area. The shape of the area shielded by this "anatomically shaped cranial collimator" (ACC) was based on mean measurements of cephalometric landmarks of 100 orthodontic patients. It appeared that this collimator reduced the area of irradiation by almost one-third without interfering with the imaging system or affecting the quality of the image. Further research is needed to validate the clinical efficacy of the collimator. PMID:24170799

  18. Midline Incisional Hernia. Anatomical Repairs for the Treatment with Prothesis

    Madeo, Sergio Damián

    2012-09-01

    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.

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

    Gutierrez, José A

    2007-01-01

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

  20. Diabetic nephropathy: landmark clinical trials and tribulations.

    Chan, Gary C W; Tang, Sydney C W

    2016-03-01

    Diabetic nephropathy remains the most common cause of end-stage renal disease worldwide. The current standard of therapy for diabetic nephropathy involves stringent blood pressure control via blockade of the renin-angiotensin system and control of hyperglycemia. Despite these strategies, diabetic nephropathy is still seen to progress relentlessly. A pressing need for novel therapeutic agents has fueled endless basic science research projects and clinical trials in the quest for a more specific therapy. Throughout the process, only a handful of ancillary agents have shown experimental promise and even fewer have demonstrated an impact in human trials. This review article aims to summarize the available data from landmark studies for the main therapeutic approaches investigated. PMID:25637638

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

    DiMagno, Eugene P; DiMagno, Matthew J

    2016-01-01

    On May 16, 2015 at the invitation of the American Gastroenterological Association Institute Council E.P.D. presented a state-of-the-art lecture at Digestive Disease Week 2015. The aims were to discuss a selection of landmark papers in chronic pancreatitis (CP) that influence modern management and to conclude by suggesting some future directions. This is based on that presentation. We will specifically review the following: duct anatomy and pancreas divisum, description of chronic relapsing pancreatitis and its differentiation from recurrent acute pancreatitis and established CP (ECP), natural histories and gene discoveries of alcoholic, idiopathic and hereditary pancreatitis, development of pancreatic cancer in CP, exocrine pancreatic insufficiency and calculation of dose and delivery of enzymes, endoscopic ultrasonography, and autoimmune pancreatitis. With some exceptions, we exclude basic science and surgery. PMID:27077713

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

    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)

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

    Purpose: The quantification of body fat plays an important role in the study of numerous diseases. It is common current practice to use the fat area at a single abdominal computed tomography (CT) slice as a marker of the body fat content in studying various disease processes. This paper sets out to answer three questions related to this issue which have not been addressed in the literature. At what single anatomic slice location do the areas of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) estimated from the slice correlate maximally with the corresponding fat volume measures? How does one ensure that the slices used for correlation calculation from different subjects are at the same anatomic location? Are there combinations of multiple slices (not necessarily contiguous) whose area sum correlates better with volume than does single slice area with volume? Methods: The authors propose a novel strategy for mapping slice locations to a standardized anatomic space so that same anatomic slice locations are identified in different subjects. The authors then study the volume-to-area correlations and determine where they become maximal. To address the third issue, the authors carry out similar correlation studies by utilizing two and three slices for calculating area sum. Results: Based on 50 abdominal CT data sets, the proposed mapping achieves significantly improved consistency of anatomic localization compared to current practice. Maximum correlations are achieved at different anatomic locations for SAT and VAT which are both different from the L4-L5 junction commonly utilized currently for single slice area estimation as a marker. Conclusions: The maximum area-to-volume correlation achieved is quite high, suggesting that it may be reasonable to estimate body fat by measuring the area of fat from a single anatomic slice at the site of maximum correlation and use this as a marker. The site of maximum correlation is not at L4-L5 as commonly assumed, but is more superiorly located at T12-L1 for SAT and at L3-L4 for VAT. Furthermore, the optimal anatomic locations for SAT and VAT estimation are not the same, contrary to common assumption. The proposed standardized space mapping achieves high consistency of anatomic localization by accurately managing nonlinearities in the relationships among landmarks. Multiple slices achieve greater improvement in correlation for VAT than for SAT. The optimal locations in the case of multiple slices are not contiguous

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

    Martin Egelhaaf

    2014-09-01

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

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

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

    2011-01-01

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

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

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

  7. Comparison of Different Computer–Aided Surgery Systems in Skull Base Surgery

    Ecke, U.; Luebben, B.; Maurer, J; Boor, S; Mann, W. J.

    2003-01-01

    Computer–aided surgery (CAS) based on high–resolution imaging techniques represents an important adjunct to precise intraoperative orientation when anatomical landmarks are distorted or missing. Several commercial systems, mostly based on optical or electromagnetic navigation principles, are on the market. This study investigated the application of EasyGuide®, VectorVision®, and InstaTrak® CAS systems in ENT surgery under practical and laboratory conditions. System accuracy, time required, ha...

  8. Validation of anatomically shaped cranial collimation (ACC) in orthodontic lateral cephalography.

    Hoogeveen, R C; Guicherit, P J; Gopie, S R; van der Stelt, P F; Berkhout, W E R

    2014-01-01

    The use of an anatomically shaped cranial collimator (ACC) to reduce patient dose in orthodontic lateral cephalography was investigated in this study. The aim was to evaluate the potential interference of the ACC on landmark identification for orthodontic cephalometry. Consecutive orthodontic patients underwent a total of 100 cephalograms using an ACC mounted on a Veraviewepocs(®) 3D X550 (J. Morita Co., Kyoto, Japan) X-ray unit. 10 observers were asked whether the identification of 5 landmarks close to the collimated area was hindered or rendered impossible by the presence of the collimator. Of the 500 landmarks that were judged by the 10 observers, 496 (99.2%) were reported to lack hindrance. In three landmarks, a minority of the observers reported hindrance. In 1 landmark, 8 of the 10 observers reported hindrance by the collimator. In no instance did the observers state that the identification of landmarks was impossible as a result of the collimation. Application of the ACC on the cephalostat of the X-ray unit is a viable way of reducing patient dose, as it only marginally interferes with the diagnostic yield of the exposure. The need to retake images when the ACC is applied was found to be extremely low. PMID:24720607

  9. Anatomical Abnormalities in Autism?

    Haar, Shlomi; Berman, Sigal; Behrmann, Marlene; Dinstein, Ilan

    2016-04-01

    Substantial controversy exists regarding the presence and significance of anatomical abnormalities in autism spectrum disorders (ASD). The release of the Autism Brain Imaging Data Exchange (∼1000 participants, age 6-65 years) offers an unprecedented opportunity to conduct large-scale comparisons of anatomical MRI scans across groups and to resolve many of the outstanding questions. Comprehensive univariate analyses using volumetric, thickness, and surface area measures of over 180 anatomically defined brain areas, revealed significantly larger ventricular volumes, smaller corpus callosum volume (central segment only), and several cortical areas with increased thickness in the ASD group. Previously reported anatomical abnormalities in ASD including larger intracranial volumes, smaller cerebellar volumes, and larger amygdala volumes were not substantiated by the current study. In addition, multivariate classification analyses yielded modest decoding accuracies of individuals' group identity (<60%), suggesting that the examined anatomical measures are of limited diagnostic utility for ASD. While anatomical abnormalities may be present in distinct subgroups of ASD individuals, the current findings show that many previously reported anatomical measures are likely to be of low clinical and scientific significance for understanding ASD neuropathology as a whole in individuals 6-35 years old. PMID:25316335

  10. The accuracy of the central landmark used for central venous catheterization of the internal jugular vein.

    Bailey, Peter L; Whitaker, Emmett E; Palmer, Linda S; Glance, Laurent G

    2006-05-01

    We simulated needle paths based on the central landmark used for central venous catheterization of the internal jugular vein. We obtained ultrasound images to quantify the landmark's accuracy (precision and bias) in 107 subjects placed in Trendelenburg position with their heads turned 30-35 degrees. We also determined the frequency of simulated carotid artery puncture. The simulated needle path missed the middle 80% of the lumen of the internal jugular vein in 34% of subjects (95% confidence interval [CI], 25% to 44%) and traversed the carotid artery in 26% of subjects (95% CI, 18% to 35%). Both events occurred in 20% of subjects (95% CI, 13%-29%). The landmark had a medial bias of 3.7 mm (95% CI, 2.7 to 4.8); it was more often (77 of 104 subjects) medial to the center of the right internal jugular vein (P yield frequent success on first needle pass without risk of carotid puncture because of its imprecision and bias. The measured bias should be considered when the central landmark is used for central venous catheterization. PMID:16632804

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

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

    1987-06-01

    We report the results of a study aimed at quantifying the differences in the perceived pattern of maxillary remodeling that are observed when different methods are used to superimpose maxillary images in roentgenographic cephalometrics. In a previous article, we reported cumulative changes in the positions of anterior nasal spine (ANS), posterior nasal spine (PNS), and Point A for a sample of 31 subjects with maxillary metallic implants. Measurements had been made on lateral cephalograms taken at annual intervals relative to superimposition on the implants. In the present article, we quantify the differences in the perceived displacement of the same landmarks in the same sample when a standard "anatomical best bit" rule was used in lieu of superimposition on the implants. The anatomical best fit superimposition as herein defined was found in this sample to lose important information on the downward remodeling of the superior surface of the maxilla that had been detected when the implant superimposition was used. In fact, we observed a small artifactual upward displacement of the ANS-PNS line. In the anteroposterior direction, the tendency toward backward displacement of skeletal landmarks through time that had been detected with the implant superimposition was replaced by a small forward displacement of ANS and Point A together with reduced backward displacement of PNS. To the extent that the implant superimposition is to be considered the true and correct one, the anatomical best fit superimposition appears to understate the true downward remodeling of the palate by an average of about 0.3 and 0.4 mm per year, although this value differs at different ages and timepoints. The anatomical best fit superimposition also misses entirely the small mean tendency toward backward remodeling that was observed when the implant superimposition was used. In situations in which there are no implants, clinicians and research workers must necessarily continue to use anatomically based superimpositions with definitions more or less similar to that of the anatomical best fit superimposition used here. When they do so, some systematic errors will be incurred. For grouped data, we believe that the best currently available estimates of the mean errors involved in using the anatomical best fit superimposition to approximate an implant superimposition are the "bias" values included in Table IIC. The secondary implications of these differences to the perceived displacements of the maxillary teeth will be considered in our next article. PMID:3473926

  12. Some historical landmarks in nuclear and radiochemistry

    The study of conduction of electricity through evacuated tubes led to the discovery of cathode rays by Plucker in 1858. No outstanding results were produced in the study of these rays until 1895-1896 when incisive minds of Roentgen and Thomson led, respectively, to the Nobel prize winning discoveries of x-rays and electron. Fortutious linking of phosphorescence with x-ray emission led Becquerel to discover uranic rays and his colleagues M. Curie an P. Curie to their research on radiation phenomenon. A gigantic forward wave of human knowledge ensued from these discoveries. The postulation of nuclear atom by Rutherford was an important landmark in this forward movement. Rutherford and Soddy postulated that the spontaneous emission of radiations (γ and β) by atoms is accompanied by chemical changes. Subsequent studies by Rutherford and his colleagues in England, Curie-Joliot team in France, Fermi et al. in Italy and Hahn et al. in Germany established transmutation of atomic nuclei by nuclear radiations (γ and n). This article is an attempt to pay a humble tribute to the pioneers who opened the gates to the world of nuclear sciences. (author). 135 refs., 1 fig

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

    Kim, Min Sun; Lee, Eun Joo; Song, In Ja; Lee, Jae-Seo; Kang, Byung-Cheol

    2015-01-01

    Purpose The purpose of this study was to evaluate the influence of methods of establishing the midsagittal reference plane (MRP) on the locations of midfacial landmarks in the three-dimensional computed tomography (CT) analysis of facial asymmetry. Materials and Methods A total of 24 patients (12 male and 12 female; mean age, 22.5 years; age range, 18.2-29.7 years) with facial asymmetry were included in this study. The MRP was established using two different methods on each patient's CT image. The x-coordinates of four midfacial landmarks (the menton, nasion, upper incisor, and lower incisor) were obtained by measuring the distance and direction of the landmarks from the MRP, and the two methods were compared statistically. The direction of deviation and the severity of asymmetry found using each method were also compared. Results The x-coordinates of the four anatomic landmarks all showed a statistically significant difference between the two methods of establishing the MRP. For the nasion and lower incisor, six patients (25.0%) showed a change in the direction of deviation. The severity of asymmetry also changed in 16 patients (66.7%). Conclusion The results of this study suggest that the locations of midfacial landmarks change significantly according to the method used to establish the MRP. PMID:26730370

  14. Trade-offs between leaf hydraulic capacity and drought vulnerability: morpho-anatomical bases, carbon costs and ecological consequences.

    Nardini, Andrea; Pedà, Giulia; La Rocca, Nicoletta

    2012-11-01

    Leaf hydraulic conductance (K(leaf) ) and vulnerability constrain plant productivity, but no clear trade-off between these fundamental functional traits has emerged in previous studies. We measured K(leaf) on a leaf area (K(leaf_area)) and mass basis (K(leaf_mass)) in six woody angiosperms, and compared these values with species' distribution and leaf tolerance to dehydration in terms of P(50), that is, the leaf water potential inducing 50% loss of K(leaf) . We also measured several morphological and anatomical traits associated with carbon investment in leaf construction and water transport efficiency. Clear relationships emerged between K(leaf_mass), P(50), and leaf mass per unit area (LMA), suggesting that increased tolerance to hydraulic dysfunction implies increased carbon costs for leaf construction and water use. Low P(50) values were associated with narrower and denser vein conduits, increased thickness of conduit walls, and increased vein density. This, in turn, was associated with reduced leaf surface area. Leaf P(50) was closely associated with plants' distribution over a narrow geographical range, suggesting that this parameter contributes to shaping vegetation features. Our data also highlight the carbon costs likely to be associated with increased leaf tolerance to hydraulic dysfunction, which confers on some species the ability to thrive under reduced water availability but decreases their competitiveness in high-resource habitats. PMID:22978628

  15. Anatomic Total Shoulder System

    Full Text Available ... Orthopedics is continually advancing the standard of orthopedic patient care. In a few moments, you'll be ... and version variability which allows adaptability to a patient's unique anatomical makeup. Dr. Gerald R. Williams, Jr., ...

  16. Anatomic Total Shoulder System

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

  17. Anatomic Total Shoulder System

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

  18. Anatomic Total Shoulder System

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

  19. Anatomic Total Shoulder System

    Full Text Available ... moments, you'll be able to watch a live global AP anatomic total shoulder surgery from Methodist ... specialist, Dr. Douglas Boardman III will moderate. OR-Live makes it easy for you to learn more. ...

  20. Anatomic Total Shoulder System

    Full Text Available ... watch a live global AP anatomic total shoulder surgery from Methodist Hospital in Philadelphia. A revolution in ... m Jerry Williams. I'll be performing the surgery today, and we have lots of help. We ...

  1. Anatomic Total Shoulder System

    ... by almost ten years, is shoulders. So by definition, the average shoulder-replacement patient is almost ten ... Anatomic Total Shoulder surgery, which featured the latest innovation in shoulder surgery from DePuy Orthopedics. OR-Live ...

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

    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 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

  3. Detailed Anatomical Orientations for Certain Types of Morphometric Measurements Can Be Determined Automatically With Geometric Algorithms.

    Boyer, Doug M; Winchester, Julia M; Glynn, Chris; Puente, Jesus

    2015-11-01

    Morphometric datasets only convey useful information about variation when measurement landmarks and relevant anatomical axes are clearly defined. We propose that anatomical axes of 3D digital models of bones can be standardized prior to measurement using an algorithm that automatically finds a universal geometric alignment among sampled bones. As a case study, we use teeth of "prosimian" primates. In this sample, equivalent occlusal planes are determined automatically using the R-package auto3dgm. The area of projection into the occlusal plane for each tooth is the measurement of interest. This area is used in computation of a shape metric called relief index (RFI), the natural log of the square root of crown area divided by the square root of occlusal plane projection area. We compare mean and variance parameters of area and RFI values computed from these automatically orientated tooth models with values computed from manually orientated tooth models. According to our results, the manual and automated approaches yield extremely similar mean and variance parameters. The only differences that plausibly modify interpretations of biological meaning slightly favor the automated treatment because a greater proportion of differences among subsamples in the automated treatment are correlated with dietary differences. We conclude that-at least for dental topographic metrics-automated alignment recovers a variance pattern that has meaning similar to previously published datasets based on manual data collection. Therefore, future applications of dental topography can take advantage of automatic alignment to increase objectivity and repeatability. PMID:26228692

  4. US of the Peripheral Nerves of the Upper Extremity: A Landmark Approach.

    Brown, Jordan M; Yablon, Corrie M; Morag, Yoav; Brandon, Catherine J; Jacobson, Jon A

    2016-01-01

    Ultrasonography (US) has become a first-line modality for the evaluation of the peripheral nerves of the upper extremity. The benefits of US over magnetic resonance (MR) imaging include higher soft-tissue resolution, cost effectiveness, portability, real-time and dynamic imaging, and the ability to scan an entire extremity quickly and efficiently. US can be performed on patients who are not eligible for MR imaging. Metallic implant artifacts are usually not problematic. US has been shown to have equal specificity and greater sensitivity than MR imaging in the evaluation of peripheral nerves. Any abnormal findings can be easily compared with the contralateral side. The published literature has shown that US has demonstrated clinical utility in patients with suspected peripheral nerve disease by guiding diagnostic and therapeutic decisions as well as by confirming electrodiagnostic findings. Common indications for upper extremity peripheral nerve US are the evaluation for injury due to penetrating trauma, entrapment by scar tissue, and tumor. US of the upper extremity is most commonly performed to evaluate carpal and cubital tunnel syndrome. It is important for the radiologist or sonographer to have a detailed knowledge of anatomy and specific anatomic landmarks for each nerve to efficiently and accurately perform an examination. The goal of this article is to introduce readers to the basics of US of the peripheral nerves of the upper extremity with a focus on the median, ulnar, and radial nerves. Common sites of disease and the location of important anatomic landmarks will be reviewed. (©)RSNA, 2016. PMID:26963456

  5. Tracking in anatomic pathology.

    Pantanowitz, Liron; Mackinnon, Alexander C; Sinard, John H

    2013-12-01

    Bar code-based tracking solutions, long present in clinical pathology laboratories, have recently made an appearance in anatomic pathology (AP) laboratories. Tracking of AP "assets" (specimens, blocks, slides) can enhance laboratory efficiency, promote patient safety, and improve patient care. Routing of excess clinical material into research laboratories and biorepositories are other avenues that can benefit from tracking of AP assets. Implementing tracking is not as simple as installing software and turning it on. Not all tracking solutions are alike. Careful analysis of laboratory workflow is needed before implementing tracking to assure that this solution will meet the needs of the laboratory. Such analysis will likely uncover practices that may need to be modified before a tracking system can be deployed. Costs that go beyond simply that of purchasing software will be incurred and need to be considered in the budgeting process. Finally, people, not technology, are the key to assuring quality. Tracking will require significant changes in workflow and an overall change in the culture of the laboratory. Preparation, training, buy-in, and accountability of the people involved are crucial to the success of this process. This article reviews the benefits, available technology, underlying principles, and implementation of tracking solutions for the AP and research laboratory. PMID:23634908

  6. Landmarks of History of Soil Science in Sri Lanka

    Mapa, R.

    2012-04-01

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

  7. Landmark Detection in Orbital Images Using Salience Histograms

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

    2010-01-01

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

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

    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 (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.)

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

    Wang, Jue

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

  10. Model-based automatic detection of the anterior and posterior commissures on MRI scans.

    Ardekani, Babak A; Bachman, Alvin H

    2009-07-01

    The projections of the anterior and posterior commissures (AC/PC) on the mid-sagittal plane of the human brain are important landmarks in neuroimaging. They can be used, for example, during MRI scanning for acquiring the imaging sections in a standard orientation. In post-acquisition image processing, these landmarks serve to establish an anatomically-based frame of reference within the brain that can be extremely useful in designing automated image analysis algorithms such as image segmentation and registration methods. This paper presents a fully automatic model-based algorithm for AC/PC detection on MRI scans. The algorithm utilizes information from a number of model images on which the locations of the AC/PC and a reference point (the vertex of the superior pontine sulcus) are known. This information is then used to locate the landmarks on test scans by template matching. The algorithm is designed to be fast, robust, and accurate. The method is flexible in that it can be trained to work on different image contrasts, optimized for different populations, or scanning modes. To assess the effectiveness of this technique, we compared automatically and manually detected landmark locations on 84 T(1)-weighted and 42 T(2)-weighted test scans. Overall, the average Euclidean distance between automatically and manually detected landmarks was 1.1 mm. A software implementation of the algorithm is freely available online at www.nitrc.org/projects/art. PMID:19264138

  11. An anatomically oriented breast model for MRI

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

    2015-03-01

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

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

    Greess, H.; Baum, U.; Lell, M.; Bautz, W.A. [Inst. of Diagnostic Radiology, Univ. of Erlangen (Germany); Wolf, H.; Kalender, W. [Inst. of Medical Physics, Univ. of Erlangen (Germany); Pirkl, M. [Inst. of Radiation Therapy, Univ. of Erlangen (Germany)

    2000-02-01

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

  13. Landmark learning by the Ozark zigzag salamander Plethodon angusticlavius

    Adam L. CRANE, Alicia MATHIS

    2011-08-01

    Full Text Available Although salamanders have been shown to respond to classical conditioning, spatial learning has been largely unstudied. We tested whether salamanders could learn to locate foraging areas by using landmarks. We trained 10 salamanders Plethodon angusticlavius to use landmarks (small rocks to locate patches within the arena containing food (blackworms Lumbriculus variegatus. At the corners of each square testing arena were four plastic dishes, one containing blackworms and the other three empty. A rock was placed in front of the dish containing blackworms, and the location of the food-dish was randomly chosen for each training trial. A control group was also trained to feed on blackworms in the presence of a rock, but the rock was positioned randomly among the four dish locations so that the rock was not a reliable landmark for the worms. Although the length of the training period for individual salamanders varied (2238 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: 485490, 2011].

  14. Anatomic Total Shoulder System

    Full Text Available ... AP ANATOMIC TOTAL SHOULDER SYSTEM METHODIST HOSPITAL PHILADELPHIA, PA April 17, 2008 00:00:10 ANNOUNCER: DePuy ... you don't make a bunch of small passes at the lesser tuberosity and make it a ...

  15. Pedro Ara anatomic museum.

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

    2006-03-01

    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

  16. Anatomic Total Shoulder System

    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: ...

  17. Anatomic Total Shoulder System

    Full Text Available ... we'll put in an anatomic Global AP stem on the humeral side. And if you'll ... So we're going to use a 14 stem, a 52x21 head with a ball taper offset. ... position of the taper with respect to the stem. So then we take this off. We take ...

  18. Anatomic Total Shoulder System

    Full Text Available ... not in the United States. They might in Europe, but they don't here. Patients who get ... Anatomic Total Shoulder surgery, which featured the latest innovation in shoulder surgery from DePuy Orthopedics. OR-Live ...

  19. Anatomic Total Shoulder System

    Full Text Available ... I think we're right at the cut service of the osteotomy. Now everybody out, we're ... Anatomic Total Shoulder surgery, which featured the latest innovation in shoulder surgery from DePuy Orthopedics. OR-Live ...

  20. Anatomic Total Shoulder System

    Full Text Available ... by almost ten years, is shoulders. So by definition, the average shoulder-replacement patient is almost ten ... Anatomic Total Shoulder surgery, which featured the latest innovation in shoulder surgery from DePuy Orthopedics. OR-Live ...

  1. On landmark selection and sampling in high-dimensional data analysis

    Belabbas, Mohamed-Ali

    2009-01-01

    In recent years, the spectral analysis of appropriately defined kernel matrices has emerged as a principled way to extract the low-dimensional structure often prevalent in high-dimensional data. Here we provide an introduction to spectral methods for linear and nonlinear dimension reduction, emphasizing ways to overcome the computational limitations currently faced by practitioners with massive datasets. In particular, a data subsampling or landmark selection process is often employed to construct a kernel based on partial information, followed by an approximate spectral analysis termed the Nystrom extension. We provide a quantitative framework to analyse this procedure, and use it to demonstrate algorithmic performance bounds on a range of practical approaches designed to optimize the landmark selection process. We compare the practical implications of these bounds by way of real-world examples drawn from the field of computer vision, whereby low-dimensional manifold structure is shown to emerge from high-di...

  2. Anatomical demonstration of the Internal Thoracic Artery and its implication in the Myocardial Revascularization Surgery

    Fernández Aramburu, Julián; Villegas, Lucas; Mas, Antonela; Froján, Diego; Gaillard, Juan Manuel; Loccisano, Matías

    2012-01-01

    The internal thoracic artery (ITA), also known as internal mammary artery (IMA) is often used in coronary artery bypass graft. The knowledge of its morphology, thus its major side branches, is essential to the cardiovascular surgeon. The aim of this work is to provide a description of the collateral branches of the ITA, providing anatomical landmarks for its identification (in our case the transversus thoracis muscle) and quantification as a basis for myocardial revascularization surgery usin...

  3. Three-dimensional study of pelvic asymmetry on anatomical specimens and its clinical perspectives

    Boulay, C.; Tardieu, C; Benaim, C.; Hecquet, J.; MARTY C.; Prat-Pradal, D.; Legaye, Jean; Duval-Beaupère, Ginette; Pelissier, J.

    2006-01-01

    The aim of this study was to assess pelvic asymmetry (i.e. to determine whether the right iliac bone and the right part of the sacrum are mirror images of the left), both quantitatively and qualitatively, using three-dimensional measurements. Pelvic symmetry was described osteologically using a common reference coordinate system for a large sample of pelvises. Landmarks were established on 12 anatomical specimens with an electromagnetic Fastrak system. Seventy-one paired variables were tested...

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

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

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

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

    2013-07-15

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

  6. Anatomical variations in the aortic bifurcation in new zealand white rabbits on arteriography.

    Balastegui, Maria Teresa; Ramos-Pl, Juan Jos; Ferrer-Puchol, Maria Dolores; Carrillo, Jose Maria; Monteagudo-Franco, Sergio Pedro; Esteban, Enrique; Liste, Fernando

    2014-04-01

    The radiologic anatomy of the aortic bifurcation in the rabbit has received little study but it is important as this anatomical area is widely used in atherosclerosis research. Thirty rabbits were used to study the aortic bifurcation and subsequent branching patterns on arteriography. Fifteen different arteries were identified. Mean arterial diameters of 2.88 0.7 and 2.27 0.55 mm were obtained for the aorta and external iliac arteries, respectively. The cranial and middle aspects at the seventh lumbar vertebra (L7) were the most frequent anatomical landmarks (53.3% of the cases) for aortic and common iliac bifurcations, respectively. The caudal aspect of L6 was the most frequent origin (50% of the cases) for the median sacral artery. Deep circumflex iliac arteries originated from common iliac arteries and not the abdominal aorta in the rabbit, showing anatomical asymmetry in 73.3% of the cases. No gender disparity was found in the anatomical location of any of the arteries of the study. Knowledge of normal vascular landmarks for the aortic bifurcation as well as anatomical variations should be helpful to future experimental studies. PMID:24478216

  7. Acute Pancreatitis: Landmark Studies, Management Decisions, and the Future.

    Banks, Peter A

    2016-01-01

    A great deal of progress has been made in the last 50 years in the diagnosis and treatment of acute pancreatitis. Many landmark studies have been published and have focused on the classification of acute pancreatitis, markers of severity, important roles of imaging and endoscopy, and improvements in our treatment. This report will review several landmark studies, describe ongoing controversies in management decisions including standards of early fluid resuscitation and appropriate use of enteral feeding, and outline what will be required in the future to improve the care of patients with acute pancreatitis. PMID:27077712

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

    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.

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

    Vincenzo Puppo

    2011-01-01

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

  10. Reference Man anatomical model

    Cristy, M.

    1994-10-01

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

  11. Assessment of organ doses from exposure to neutrons using the Monte Carlo technique and an image-based anatomical model

    Bozkurt, Ahmet

    The distribution of absorbed doses in the body can be computationally determined using mathematical or tomographic representations of human anatomy. A whole- body model was developed from the color images of the National Library of Medicine's Visible Human Project® for simulating the transport of radiation in the human body. The model, called Visible Photographic Man (VIP-Man), has sixty-one organs and tissues represented in the Monte Carlo code MCNPX at 4-mm voxel resolution. Organ dose calculations from external neutron sources were carried out using VIP-man and MCNPX to determine a new set of dose conversion coefficients to be used in radiation protection. Monoenergetic neutron beams between 10-9 MeV and 10 GeV were studied under six different irradiation geometries: anterior-posterior, posterior-anterior, right lateral, left lateral, rotational and isotropic. The results for absorbed doses in twenty-four organs and the effective doses based on twelve critical organs are presented in tabular form. A comprehensive comparison of the results with those from the mathematical models show discrepancies that can be attributed to the variations in body modeling (size, location and shape of the individual organs) and the use of different nuclear datasets or models to derive the reaction cross sections, as well as the use of different transport packages for simulation radiation effects. The organ dose results based on the realistic VIP-Man body model allow the existing radiation protection dosimetry on neutrons to be re-evaluated and improved.

  12. Anatomical consideration of Dhamani marma in Ayurveda

    Bhan Pratap Yadaw

    2014-09-01

    Full Text Available Ayurveda is an ancient health science devoted to the cure on human suffering and for the care of the health of the people. Injuries involving various types of the structures in the body like dhamanis (arteries, muscles, nerves, bones and the visceral organs in general and when in combination specifying marma. Among the hidden sciences of India, marma science is the most important. Marmas are not superficial landmarks on the body surface but these are deep-seated important physio-anatomical structures. Marma in Ayurvedic classics is illustrated as the vital point in human body, the injury of which leads to termination of life. Descriptions of 107 marmas given by all acharyas being classified into five varieties on the basis of structure involved; five on the basis of effect of injury and five on the basis of location on the body. According to anatomical consideration marmas can be divided into mansa-marma, sira-marma, snayu-marma, sandhi-marma, and asthi-marma (respectively, marma of muscle, blood vessel, ligament, joint and bone. According to Vagabhatta there are six types of marma. He has enumerated a sixth group of marma known as dhamani marma. Dhamani marma is one such vital region in human anatomy which falls under the classification on the basis of structure involved. This study is aimed to emphasize on why Ashtanga Hridaya has considered a separate group called dhamani marmas of which other acharyas have considered under different groups & finally to conclude with clearing out the controversy & thereby to fulfill the lacuna in the subject.

  13. Investigation of factors affecting hypothermic pelvic tissue cooling using bio-heat simulation based on MRI-segmented anatomic models.

    Lin, Yuting; Lin, Wei-Ching; Fwu, Peter T; Shih, Tzu-Ching; Yeh, Lee-Ren; Su, Min-Ying; Chen, Jeon-Hor

    2015-10-01

    This study applied a simulation method to map the temperature distribution based on magnetic resonance imaging (MRI) of individual patients, and investigated the influence of different pelvic tissue types as well as the choice of thermal property parameters on the efficiency of endorectal cooling balloon (ECB). MR images of four subjects with different prostate sizes and pelvic tissue compositions, including fatty tissue and venous plexus, were analyzed. The MR images acquired using endorectal coil provided a realistic geometry of deformed prostate that resembled the anatomy in the presence of ECB. A single slice with the largest two-dimensional (2D) cross-sectional area of the prostate gland was selected for analysis. The rectal wall, prostate gland, peri-rectal fatty tissue, peri-prostatic fatty tissue, peri-prostatic venous plexus, and urinary bladder were manually segmented. Pennes' bioheat thermal model was used to simulate the temperature distribution dynamics, by using an in-house finite element mesh based solver written in MATLAB. The results showed that prostate size and periprostatic venous plexus were two major factors affecting ECB cooling efficiency. For cases with negligible amount of venous plexus and small prostate, the average temperature in the prostate and neurovascular bundles could be cooled down to 25 C within 30 min. For cases with abundant venous plexus and large prostate, the temperature could not reach 25 C at the end of 3 h cooling. Large prostate made the cooling difficult to propagate through. The impact of fatty tissue on cooling effect was small. The filling of bladder with warm urine during the ECB cooling procedure did not affect the temperature in the prostate or NVB. In addition to the 2D simulation, in one case a 3D pelvic model was constructed for volumetric simulation. It was found that the 2D slice with the largest cross-sectional area of prostate had the most abundant venous plexus, and was the most difficult slice to cool, thus it may provide a conservative prediction of the cooling effect. This feasibility study demonstrated that the simulation tool could potentially be used for adjusting the setting of ECB for individual patients during hypothermic radical prostatectomy. Further studies using MR thermometry are required to validate the in silico results obtained using simulation. PMID:26198131

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

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

    2014-06-01

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

  15. What Factors Shape "by" Ratings in Relation to Landmarks?

    Hund, Alycia M.

    2010-01-01

    Two experiments investigated how absolute and relative distance shape adults' and young children's ratings concerning the extent to which the term "by" describes the relation between locations. Three- and 4-year-old children and adults were asked to rate how well the word "by" described the relation between several blocks and a landmark. The

  16. The Landmark Decision that Faded into Historical Obscurity

    Nance, Molly

    2007-01-01

    This article takes a look at the Mendez v. Westminster School District, a landmark case that faded into historical obscurity. In the 1940s, Gonzalo and Felicita Mendez wanted their three children to attend the school nearest their farm, which was the 17th Street Elementary School in Westminster. But in the Westminster, Orange County, El Medina,

  17. On-line SLAM using clustered landmarks with omnidirectional vision

    Jun, Okamoto Jr.; Vitor Campanholo, Guizilini.

    2010-12-01

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

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

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

    2012-01-01

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

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

    Cronk Quentin CB

    2011-01-01

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

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

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

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

    Hvidtfeldt, Mogens; Pedersen, Steen

    1999-01-01

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

  2. Information geometry for landmark shape analysis: unifying shape representation and deformation.

    Peter, Adrian M; Rangarajan, Anand

    2009-02-01

    Shape matching plays a prominent role in the comparison of similar structures. We present a unifying framework for shape matching that uses mixture models to couple both the shape representation and deformation. The theoretical foundation is drawn from information geometry wherein information matrices are used to establish intrinsic distances between parametric densities. When a parameterized probability density function is used to represent a landmark-based shape, the modes of deformation are automatically established through the information matrix of the density. We first show that given two shapes parameterized by Gaussian mixture models (GMMs), the well-known Fisher information matrix of the mixture model is also a Riemannian metric (actually, the Fisher-Rao Riemannian metric) and can therefore be used for computing shape geodesics. The Fisher-Rao metric has the advantage of being an intrinsic metric and invariant to reparameterization. The geodesiccomputed using this metricestablishes an intrinsic deformation between the shapes, thus unifying both shape representation and deformation. A fundamental drawback of the Fisher-Rao metric is that it is not available in closed form for the GMM. Consequently, shape comparisons are computationally very expensive. To address this, we develop a new Riemannian metric based on generalized \\phi-entropy measures. In sharp contrast to the Fisher-Rao metric, the new metric is available in closed form. Geodesic computations using the new metric are considerably more efficient. We validate the performance and discriminative capabilities of these new information geometry-based metrics by pairwise matching of corpus callosum shapes. We also study the deformations of fish shapes that have various topological properties. A comprehensive comparative analysis is also provided using other landmark-based distances, including the Hausdorff distance, the Procrustes metric, landmark-based diffeomorphisms, and the bending energies of the thin-plate (TPS) and Wendland splines. PMID:19110497

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

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

    2014-03-01

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

  4. Developmental Changes in Young Children's Spatial Memory and Language in Relation to Landmarks

    Hund, Alycia M.; Naroleski, Amber R.

    2008-01-01

    Two experiments investigated how young children and adults understand whether objects are "by" a landmark and remember their locations. Three- and 4-year-old children and adults were asked to judge whether several blocks were "by" a landmark. The blocks were arranged so that their absolute and relative distances from the landmark varied. Later,

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

    Morosolli, Aline; Pittayapat, Pisha; Bolstad, Napat; Ferreira, Afonso P.; Jacobs, Reinhilde

    2015-01-01

    Purpose The aim this study was to compare the accuracy of orthodontists and dentomaxillofacial radiologists in identifying 17 commonly used cephalometric landmarks, and to determine the extent of variability associated with each of those landmarks. Materials and Methods Twenty digital lateral cephalometric radiographs were evaluated by two groups of dental specialists, and 17 cephalometric landmarks were identified. The x and y coordinates of each landmark were recorded. The mean value for each landmark was considered the best estimate and used as the standard. Variation in measurements of the distance between landmarks and measurements of the angles associated with certain landmarks was also assessed by a subset of two observers, and intraobserver and interobserver agreement were evaluated. Results Intraclass correlation coefficients were excellent for intraobserver agreement, but only good for interobserver agreement. The least reliable landmark for orthodontists was the gnathion (Gn) point (standard deviation [SD], 5.92 mm), while the orbitale (Or) was the least reliable landmark (SD, 4.41 mm) for dentomaxillofacial radiologists. Furthermore, the condylion (Co)-Gn plane was the least consistent (SD, 4.43 mm). Conclusion We established that some landmarks were not as reproducible as others, both horizontally and vertically. The most consistently identified landmark in both groups was the lower incisor border, while the least reliable points were Co, Gn, Or, and the anterior nasal spine. Overall, a lower level of reproducibility in the identification of cephalometric landmarks was observed among orthodontists. PMID:26730368

  6. Solving small spaces: investigating the use of landmark cues in brown capuchins (Cebus apella).

    Hughes, Kelly D; Mullo, Enma; Santos, Laurie R

    2013-09-01

    Some researchers have recently argued that humans may be unusual among primates in preferring to use landmark information when reasoning about some kinds of spatial problems. Some have explained this phenomenon by positing that our species' tendency to prefer landmarks stems from a human-unique trait: language. Here, we test this hypothesis-that preferring to use landmarks to solve such tasks is related to language ability-by exploring landmark use in a spatial task in one non-human primate, the brown capuchin monkey (Cebus apella). We presented our subjects with the rotational displacement task, in which subjects attempt to relocate a reward hidden within an array of hiding locations which are subsequently rotated to a new position. Over several experiments, we varied the availability and the salience of a landmark cue within the array. Specifically, we varied (1) visual access to the array during rotation, (2) the type of landmark, (3) the consistency of the landmark qualities, and (4) the amount of exposure to the landmark. Across Experiments 1 through 4, capuchins did not successfully use landmarks cues, suggesting that non-linguistic primates may not spontaneously use landmarks to solve some spatial problems, as in this case of a small-scale dynamic spatial task. Importantly, we also observed that capuchins demonstrated some capacity to learn to use landmarks in Experiment 4, suggesting that non-linguistic creatures may be able to use some landmarks cues in similar spatial tasks with extensive training. PMID:23430144

  7. Development of IDL-based software for multimodal image registration

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

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

    Juan Pablo Sorolla P

    2012-12-01

    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.

  9. Validation of a Model-Based Segmentation Approach to Propagating Normal Anatomic Regions of Interest Through the 10 Phases of Respiration

    Purpose: To validate a model-based segmentation (MBS) algorithm in a commercial radiation treatment planning system for use in propagating the contours of normal anatomic regions of interest (ROIs) through the respiratory phases that constitute a four-dimensional (4D) computed tomography (CT) image data set. Methods and Materials: The 4D CT data sets for 12 patients treated for non-small-cell lung cancer were acquired. Five ROIs were selected for delineation: right and left lungs, spinal cord, heart, and esophagus. These ROIs were manually delineated on the CT data set corresponding to the end-inspiration respiratory phase (0%). An MBS algorithm implemented on the treatment planning system propagated the ROIs sequentially through the respiratory phases that constituted the 4D CT data sets, concluding with the 0% phase data set, which was propagated from the 90% phase data set. The propagated ROIs on the 0% phase were compared with the original ROIs on that phase by using visual assessment and a quantitative measure of coincidence. Results: Acceptable propagation accuracy within 1 mm of uncertainty was achieved for lungs and spinal cord. Propagation of the heart produced slightly larger contours that were similar to interphysician variations in contouring the heart. The esophagus was poorly propagated because of lack of tissue contrast and definitive shape. Conclusions: The MBS propagation is a promising tool for efficiently propagating contours through the different phases of respiration. However, propagating the esophagus through this technique may be difficult because of the lack of definitive shape and clearer boundaries from surrounding tissue

  10. Automated extraction of skeletal muscles from torso X-ray CT images based on anatomical positional information between skeleton and skeletal muscles

    We propose an automated approach to extract skeletal muscles in torso X-ray CT images. It transforms 3-D anatomy into 2-D stretched images for simplifying anatomical relationships to getting pathognomonical points. The experimental results show that the proposed method was effective to extract skeletal muscles. (author)

  11. Impact of daily anatomical changes on EPID-based in vivo dosimetry of VMAT treatments of head-and-neck cancer

    Background and purpose: Target dose verification for VMAT treatments of head-and-neck (H&N) cancer using 3D in vivo EPID dosimetry is expected to be affected by daily anatomical changes. By including these anatomical changes through cone-beam CT (CBCT) information, the magnitude of this effect is investigated. Materials and methods: For 20 VMAT-treated H&N cancer patients, all plan-CTs (pCTs), 633 CBCTs and 1266 EPID movies were used to compare four dose distributions per fraction: treatment planning system (TPS) calculated dose and EPID reconstructed in vivo dose, both determined using the pCT and using the CBCT. D2, D50 and D98 of the planning target volume (PTV) were determined per dose distribution. Results: When including daily anatomical information, D2, D50 and D98 of the PTV change on average by 0.0 ± 0.4% according to TPS calculations; the standard deviation of the difference between EPID and TPS target dose changes from 2.5% (pCT) to 2.1% (CBCT). Small time trends are seen for both TPS and EPID dose distributions when using the pCT, which disappear when including CBCT information. Conclusions: Daily anatomical changes hardly influence the target dose distribution for H&N VMAT treatments according to TPS recalculations. Including CBCT information in EPID dose reconstructions slightly improves the agreement with TPS calculations

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

    Korda, Amichai

    2014-01-01

    Maps displayed on hand held devices, such as smartphones; provide limited visibility due to their small screen display. In order to overcome display limitations, researchers have developed new techniques that point users to objects and landmarks located off-screen, which is known as an “off-screen interface”. Since this is a new type of map interface, there is little information regarding the effect it has on the user’s perception of the environment and spatial orientation abilities. This ...

  13. Discovering landmark preferences and movement patterns from photo postings

    Jankowski, Piotr; Andrienko, Natalia; Andrienko, Gennady; Kisilevich, Vachislav

    2010-01-01

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

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

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

    2015-01-01

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

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

    Simon Karpenko

    2015-11-01

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

  16. Anatomically Plausible Surface Alignment and Reconstruction

    Paulsen, Rasmus R.; Larsen, Rasmus

    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 ...

  17. Automated anatomical labeling of MRI brain data using spatial atlas warping in a finite-element framework

    Meier, Dominik S.; Fisher, Elizabeth; Tkach, Jean A.; Masaryk, Thomas J.; Cohen, Jeffrey A.; Cornhill, J. Fredrick

    1998-06-01

    Identification of anatomical structures in magnetic resonance (MR) images of the human brain is achieved either by manual delineation of by applying coordinate system transformations to map the brain to a pre-labeled atlas. Manual segmentation of 3D MR data is a tedious task made additionally difficult by limitations in visualization. Affine transforms, like the Talairach stereotaxic space, perform a linear scaling of the brain based on manually selected landmarks. This often results in unsatisfactory accuracy for structures further away from the selected landmarks, particularly in pathological cases. It is also based on the trivializing assumption that the brain can be represented as a linearly scalable structure. In the effort to achieve a more accurate and consistent labeling, an algorithm has been designed for the automated alignment of a pre-labeled 3D brain atlas with a sample MRI volume. Alignment is achieved by elastically warping a finite element model of the atlas. The deformation is driven by a set of displacement constraints on the surface of individual brain structures. Solving this model results in a 3D displacement field for the entire atlas brain that aligns the segmented brain structure while extrapolating the deformation field to neighboring structures. The use of finite element modeling assures that this extrapolation occurs in a physically meaningful manner. The algorithm's performance was tested by matching the atlas image to warped versions of itself and to an individual sample brain. The amount of structural overlap achieved by a linear Talairach transform is also given for comparison. Elastic warping showed better performance compared to an affine transform alone or the Talairach method. Overlap increases with subsequent iterations with improvement directly related to the amount of model deformation.

  18. Dung beetles ignore landmarks for straight-line orientation.

    Dacke, Marie; Byrne, Marcus; Smolka, Jochen; Warrant, Eric; Baird, Emily

    2013-01-01

    Upon locating a suitable dung pile, ball-rolling dung beetles shape a piece of dung into a ball and roll it away in a straight line. This guarantees that they will not return to the dung pile, where they risk having their ball stolen by other beetles. Dung beetles are known to use celestial compass cues such as the sun, the moon and the pattern of polarised light formed around these light sources to roll their balls of dung along straight paths. Here, we investigate whether terrestrial landmarks have any influence on straight-line orientation in dung beetles. We find that the removal or re-arrangement of landmarks has no effect on the beetle's orientation precision. Celestial compass cues dominate straight-line orientation in dung beetles so strongly that, under heavily overcast conditions or when prevented from seeing the sky, the beetles can no longer orient along straight paths. To our knowledge, this is the only animal with a visual compass system that ignores the extra orientation precision that landmarks can offer. PMID:23076443

  19. AUTOMATIC DETECTION AND CLASSIFICATION OF RETINAL VASCULAR LANDMARKS

    Hadi Hamad

    2014-06-01

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

  20. Anatomical study of spinal accessory nerve using ultrasonography

    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

  1. Anatomical study of spinal accessory nerve using ultrasonography

    Canella, Clarissa [Service de Radiologie et d’Imagerie Musculosquelettique, Centre de Consultations et d’Imagerie de l’Appareil Locomoteur, CHRU, 59037, Lille (France); Serviço de Radiologia e Diagnostico por Imagem, Universitadade Federal do Rio de Janeiro, Rio de janeiro (Brazil); Demondion, Xavier [Service de Radiologie et d’Imagerie Musculosquelettique, Centre de Consultations et d’Imagerie de l’Appareil Locomoteur, CHRU, 59037, Lille (France); Laboratoire d’Anatomie, Faculté de Médecine de Lille, 59037, Lille (France); Abreu, Evandro [Service de Radiologie et d’Imagerie Musculosquelettique, Centre de Consultations et d’Imagerie de l’Appareil Locomoteur, CHRU, 59037, Lille (France); Marchiori, Edson [Serviço de Radiologia e Diagnostico por Imagem, Universitadade Federal do Rio de Janeiro, Rio de janeiro (Brazil); Cotten, Hervé [Anatomie et cytologie pathologiques, Bd de la Liberté, 59000, Lille (France); Cotten, Anne, E-mail: anne.cotten@chru-lille.fr [Service de Radiologie et d’Imagerie Musculosquelettique, Centre de Consultations et d’Imagerie de l’Appareil Locomoteur, CHRU, 59037, Lille (France)

    2013-01-15

    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.

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

    Purpose: In the treatment of cervical cancer, large anatomical deformations, caused by, e.g., tumor shrinkage, bladder and rectum filling changes, organ sliding, and the presence of the brachytherapy (BT) applicator, prohibit the accumulation of external beam radiotherapy (EBRT) and BT dose distributions. This work proposes a structure-wise registration with vector field integration (SW+VF) to map the largely deformed anatomies between EBRT and BT, paving the way for 3D dose accumulation between EBRT and BT. Methods: T2w-MRIs acquired before EBRT and as a part of the MRI-guided BT procedure for 12 cervical cancer patients, along with the manual delineations of the bladder, cervix-uterus, and rectum-sigmoid, were used for this study. A rigid transformation was used to align the bony anatomy in the MRIs. The proposed SW+VF method starts by automatically segmenting features in the area surrounding the delineated organs. Then, each organ and feature pair is registered independently using a feature-based nonrigid registration algorithm developed in-house. Additionally, a background transformation is calculated to account for areas far from all organs and features. In order to obtain one transformation that can be used for dose accumulation, the organ-based, feature-based, and the background transformations are combined into one vector field using a weighted sum, where the contribution of each transformation can be directly controlled by its extent of influence (scope size). The optimal scope sizes for organ-based and feature-based transformations were found by an exhaustive analysis. The anatomical correctness of the mapping was independently validated by measuring the residual distances after transformation for delineated structures inside the cervix-uterus (inner anatomical correctness), and for anatomical landmarks outside the organs in the surrounding region (outer anatomical correctness). The results of the proposed method were compared with the results of the rigid transformation and nonrigid registration of all structures together (AST). Results: The rigid transformation achieved a good global alignment (mean outer anatomical correctness of 4.3 mm) but failed to align the deformed organs (mean inner anatomical correctness of 22.4 mm). Conversely, the AST registration produced a reasonable alignment for the organs (6.3 mm) but not for the surrounding region (16.9 mm). SW+VF registration achieved the best results for both regions (3.5 and 3.4 mm for the inner and outer anatomical correctness, respectively). All differences were significant (p < 0.02, Wilcoxon rank sum test). Additionally, optimization of the scope sizes determined that the method was robust for a large range of scope size values. Conclusions: The novel SW+VF method improved the mapping of large and complex deformations observed between EBRT and BT for cervical cancer patients. Future studies that quantify the mapping error in terms of dose errors are required to test the clinical applicability of dose accumulation by the SW+VF method

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

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

    2015-01-15

    Purpose: In the treatment of cervical cancer, large anatomical deformations, caused by, e.g., tumor shrinkage, bladder and rectum filling changes, organ sliding, and the presence of the brachytherapy (BT) applicator, prohibit the accumulation of external beam radiotherapy (EBRT) and BT dose distributions. This work proposes a structure-wise registration with vector field integration (SW+VF) to map the largely deformed anatomies between EBRT and BT, paving the way for 3D dose accumulation between EBRT and BT. Methods: T2w-MRIs acquired before EBRT and as a part of the MRI-guided BT procedure for 12 cervical cancer patients, along with the manual delineations of the bladder, cervix-uterus, and rectum-sigmoid, were used for this study. A rigid transformation was used to align the bony anatomy in the MRIs. The proposed SW+VF method starts by automatically segmenting features in the area surrounding the delineated organs. Then, each organ and feature pair is registered independently using a feature-based nonrigid registration algorithm developed in-house. Additionally, a background transformation is calculated to account for areas far from all organs and features. In order to obtain one transformation that can be used for dose accumulation, the organ-based, feature-based, and the background transformations are combined into one vector field using a weighted sum, where the contribution of each transformation can be directly controlled by its extent of influence (scope size). The optimal scope sizes for organ-based and feature-based transformations were found by an exhaustive analysis. The anatomical correctness of the mapping was independently validated by measuring the residual distances after transformation for delineated structures inside the cervix-uterus (inner anatomical correctness), and for anatomical landmarks outside the organs in the surrounding region (outer anatomical correctness). The results of the proposed method were compared with the results of the rigid transformation and nonrigid registration of all structures together (AST). Results: The rigid transformation achieved a good global alignment (mean outer anatomical correctness of 4.3 mm) but failed to align the deformed organs (mean inner anatomical correctness of 22.4 mm). Conversely, the AST registration produced a reasonable alignment for the organs (6.3 mm) but not for the surrounding region (16.9 mm). SW+VF registration achieved the best results for both regions (3.5 and 3.4 mm for the inner and outer anatomical correctness, respectively). All differences were significant (p < 0.02, Wilcoxon rank sum test). Additionally, optimization of the scope sizes determined that the method was robust for a large range of scope size values. Conclusions: The novel SW+VF method improved the mapping of large and complex deformations observed between EBRT and BT for cervical cancer patients. Future studies that quantify the mapping error in terms of dose errors are required to test the clinical applicability of dose accumulation by the SW+VF method.

  4. Necessity Of Anatomical Knowledge In Thoracic Surgery.

    Arribalzaga, Eduardo B.

    2011-09-01

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

  5. Standardized anatomic space for abdominal fat quantification

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

    2014-03-01

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

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

    Zhenghua Chen

    2015-01-01

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

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

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

    2015-01-01

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

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

    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)

  9. Digital selenium r[iography: Comparison of image quality of thoracic X-rays in normal and reduced image formats, based on structural anatomic details

    Purpose: Is there a loss of information when using selenium r[iographic images displayed with reduced image format compared to full format? Results: Format reduction did not result in a loss of information in diagnostically relevant anatomic details. Conclusions: Displaying digital sellenium r[iographic data sets of thoracic view in two planes on one film presumably does not le[ to a loss of diagnostic information. This procedure may help to reduce film costs. (orig./AJ)

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

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

    2007-04-15

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

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

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

  12. Skull base tumors

    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.)

  13. Developing patient-specific anatomic models for validation of cardiac ablation guidance procedures

    Holmes, David, III; Rettmann, Maryam; Cameron, Bruce; Camp, Jon; Robb, Richard

    2008-03-01

    Image-guided cardiac ablation has the potential to decrease procedure times and improve clinical outcome for patients with cardiac arrhythmias. There are several proposed methods for integrating patient-specific anatomy into the cardiac ablation procedure; however, these methods require thorough validation. One of the primary challenges in validation is determining ground truth as a standard for comparison. Some validation protocols have been developed for animals models and even in patients; however, these methods can be costly to implement and may increase the risk to patients. We have developed an approach to building realistic patient-specific anatomic models at a low-cost in order to validate the guidance procedure without introducing additional risk to the patients. Using a pre-procedural cardiac computed tomography scan, the blood pool of the left and right atria of a patient are segmented semi-manually. In addition, several anatomical landmarks are identified in the image data. The segmented atria and landmarks are converted into a polygonalized model which is used to build a thin-walled patient-specific blood pool model in a stereo-lithography system. Thumbscrews are inserted into the model at the landmarks. The entire model is embedded in a platinum silicone material which has been shown to have tissue-mimicking properties relative to ultrasound. Once the pliable mold has set, the blood pool model is extracted by dissolving the rigid material. The resulting physical model correctly mimics a specific patient anatomy with embedded fiducals which can be used for validation experiments. The patient-specific anatomic model approach may also be used for pre-surgical practice and training of new interventionalists.

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

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

  15. Review of the Historical Evolution of Anatomical Terms

    Algieri, Rubén D.

    2011-12-01

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

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

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

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

    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)

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

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

    2010-07-01

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

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

    Sutton, Jennifer E.

    2006-01-01

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

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

    Sutton, Jennifer E.

    2006-01-01

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

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

    Rosalia Leonardi

    2009-01-01

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

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

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

    2011-01-01

    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…

  3. 75 FR 16837 - Public Review of Draft United States Thoroughfare, Landmark, and Postal Address Data Standard

    2010-04-02

    ... Address Data Standard AGENCY: Department of the Interior, U.S. Geological Survey. ACTION: Notice; request for comments on draft United States Thoroughfare, Landmark, and Postal Address Data Standard through... the draft United States Thoroughfare, Landmark, and Postal Address Data Standard. The United...

  4. Applying the functional abnormality ontology pattern to anatomical functions

    Hoehndorf Robert

    2010-03-01

    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.

  5. 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

    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

  6. Landmark constrained registration of high-genus surfaces applied to vestibular system morphometry.

    Wen, Chengfeng; Wang, Defeng; Shi, Lin; Chu, Winnie C W; Cheng, Jack C Y; Lui, Lok Ming

    2015-09-01

    The analysis of the vestibular system (VS) is an important research topic in medical image analysis. VS is a sensory structure in the inner ear for the perception of spatial orientation. It is believed several diseases, such as the Adolescent Idiopathic Scoliosis (AIS), are due to the impairment of the VS function. The morphology of the VS is thus of great research significance. A major challenge is that the VS is a genus-3 surface. The high-genus topology of the VS poses great challenges to find accurate pointwise correspondences between the surfaces and whereby perform accurate shape analysis. In this paper, we present a method to obtain the landmark constrained diffeomorphic registration between the VS surfaces based on the quasi-conformal theory. Given a set of corresponding landmarks on the VS surfaces, a diffeomorphism between the VS surfaces that matches the features consistently can be obtained. The basic idea is to iteratively search for an admissible Beltrami coefficient, which is associated to our desired landmark matching registration. With the obtained surface registrations, vertex-wise morphometric analysis can be carried out. Two types of geometric features are used for shape comparison. One is the collection of homotopic loops on each canals of the VS, which can be used to measure the local thickness of the canals. From the homotopic loops, centerlines can be extracted. By examining the deviations of the centerlines from the best fit planes, bendings of the canals can be detected. The second geometric feature is the minimal surface enclosed by the homotopic loop. From the minimal surfaces of each homotopic loops, cross-sectional area of the canals can be evaluated. To study the local shape difference more comprehensively, a complete shape index, which is defined using the Beltrami coefficients and surface curvatures, is used. We test proposed registration method on 15 VS of normal control subjects and 12 VS of patients suffering from AIS. Experimental results show the efficacy and accuracy of the proposed algorithm to compute the VS surface registration. Shape analysis has also been carried out using the proposed geometric features and shape index, which reveals shape differences in the posterior canal between normal and diseased AIS groups. PMID:26069905

  7. Landmark and route knowledge in children's spatial representation of a virtual environment.

    Nys, Marion; Gyselinck, Valérie; Orriols, Eric; Hickmann, Maya

    2014-01-01

    This study investigates the development of landmark and route knowledge in complex wayfinding situations. It focuses on how children (aged 6, 8, and 10 years) and young adults (n = 79) indicate, recognize, and bind landmarks and directions in both verbal and visuo-spatial tasks after learning a virtual route. Performance in these tasks is also related to general verbal and visuo-spatial abilities as assessed by independent standardized tests (attention, working memory, perception of direction, production and comprehension of spatial terms, sentences and stories). The results first show that the quantity and quality of landmarks and directions produced and recognized by participants in both verbal and visuo-spatial tasks increased with age. In addition, an increase with age was observed in participants' selection of decisional landmarks (i.e., landmarks associated with a change of direction), as well as in their capacity to bind landmarks and directions. Our results support the view that children first acquire landmark knowledge, then route knowledge, as shown by their late developing ability to bind knowledge of directions and landmarks. Overall, the quality of verbal and visuo-spatial information in participants' spatial representations was found to vary mostly with their visuo-spatial abilities (attention and perception of directions) and not with their verbal abilities. Interestingly, however, when asked to recognize landmarks encountered during the route, participants show an increasing bias with age toward choosing a related landmark of the same category, regardless of its visual characteristics, i.e., they incorrectly choose the picture of another fountain. The discussion highlights the need for further studies to determine more precisely the role of verbal and visuo-spatial knowledge and the nature of how children learn to represent and memorize routes. PMID:25667573

  8. Exploring brain function from anatomical connectivity

    Gorka Zamora-López

    2011-06-01

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

  9. On the new anatomical nomenclature.

    Mareckov, E; Simon, F; Cerven, L

    2001-05-01

    The present paper is concerned with the linguistic aspect of the new anatomical nomenclature (Terminologia Anatomica 1998). Orthographic, morphological, syntactic, lexical, and terminological comments are presented. In the authors' opinion, shortcomings might have been effectively avoided by cooperation with linguists. PMID:11396787

  10. 3D CT-based cephalometric analysis: 3D cephalometric theoretical concept and software

    We present an original three-dimensional cephalometric analysis based on a transformation of a classical two dimensional topological cephalometry. To validate the three-dimensional cephalometric CT based concept we systematically compared the alignments of anatomic structures. We used digital lateral radiography to perform the classical two-dimensional cephalometry, and a three-dimensional CT surface model for the three-dimensional cephalometry. Diagnoses based on both two-dimensional and three-dimensional analyses were adequate, but the three-dimensional analysis gave more information such as the possibility of comparing the right and left side of the skull. Also the anatomic structures were not superimposed which improved the visibility of the reference landmarks. We demonstrated that three-dimensional analysis gives the same results as two-dimensional analysis using the same skull. We also present possible applications of the method. (orig.)

  11. Anatomical terminology and nomenclature: past, present and highlights.

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

    2008-08-01

    The anatomical terminology is a base for medical communication. It is elaborated into a nomenclature in Latin. Its history goes back to 1895, when the first Latin anatomical nomenclature was published as Basiliensia Nomina Anatomica. It was followed by seven revisions (Jenaiensia Nomina Anatomica 1935, Parisiensia Nomina Anatomica 1955, Nomina Anatomica 2nd to 6th edition 1960-1989). The last revision, Terminologia Anatomica, (TA) created by the Federative Committee on Anatomical Terminology and approved by the International Federation of Associations of Anatomists, was published in 1998. Apart from the official Latin anatomical terminology, it includes a list of recommended English equivalents. In this article, major changes and pitfalls of the nomenclature are discussed, as well as the clinical anatomy terms. The last revision (TA) is highly recommended to the attention of not only teachers, students and researchers, but also to clinicians, doctors, translators, editors and publishers to be followed in their activities. PMID:18488135

  12. Volume and landmark analysis: comparison of MRI measurements obtained with an endorectal coil and with a phased-array coil

    Aim: To compare prostate volumes and distances between anatomical landmarks on MRI images obtained with a phased-array coil (PAC) only and with a PAC and an endorectal coil (ERC). Materials and methods: Informed consent was waived for this Health Insurance Portability and Accountability Act-compliant study. Fifty-nine men underwent PAC-MRI and ERC-MRI at 1.5 (n = 3) or 3 T (n = 56). On MRI images, two radiologists independently measured prostate volume and distances between the anterior rectal wall (ARW) and symphysis pubis at the level of the verumontanum; ARW and symphysis pubis at the level of the mid-symphysis pubis; and bladder neck and mid-symphysis pubis. Differences between measurements from PAC-MRI and ERC-MRI were assessed with the Wilcoxon RANK SUM test. Inter-reader agreement was assessed using the concordance correlation coefficient (CCC). Results: Differences in prostate volume between PAC-MRI and ERC-MRI [median: −0.75 mm3 (p = 0.10) and median: −0.84 mm3 (p = 0.06) for readers 1 and 2, respectively] were not significant. For readers 1 and 2, median differences between distances were as follows: −10.20 and −12.75 mm, respectively, ARW to symphysis pubis at the level of the verumontanum; −6.60 and −6.08 mm, respectively, ARW to symphysis pubis at the level of the mid-symphysis pubis; −3 and −3 mm respectively, bladder neck to mid-symphysis pubis. All differences in distance were significant for both readers (p ≤ 0.0005). Distances were larger on PAC-MRI (p ≤ 0.0005). Inter-reader agreement regarding prostate volume was almost perfect on PAC-MRI (CCC: 0.99; 95% CI: 0.98–1.00) and ERC-MRI (CCC: 0.99; 95% CI: 0.99–1.00); inter-reader agreement for distance measurements varied (CCCs: 0.54–0.86). Conclusion: Measurements of distances between anatomical landmarks differed significantly between ERC-MRI and PAC-MRI, although prostate volume measurements did not. - Highlights: • Measurements of prostate geometry are compared on MRI with two coil arrangements. • Prostate volume did not differ significantly between the two coil arrangements. • Distances differed significantly between the two coil arrangements

  13. Anatomically Correct Surface Recovery

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

    We present a method for 3D surface recovery in partial surface scans. The method is based on an Active Shape Model, which is used to predict missing data. The model is constructed using a bootstrap framework, where an initially small collection of hand-annotated samples is used to fit to and...... using the learned statistics. A quantitative evaluation is performed on a data set of 10 laser scans of ear canal impressions with minimal noise and artificial holes. We also present a qualitative evaluation on authentic partial scans from an actual direct in ear scanner prototype. Compared to a state......-of-the-art surface reconstruction algorithm, the presented method gives matching prediction results for the synthetic evaluation samples and superior results for the direct scanner data....

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

    Logullo Carlos

    2010-02-01

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

  15. Anatomical or mirror mode imitation? A behavioral approach.

    Pierpaoli, C; Ferrante, L; Manzoni, T; Fabri, M

    2014-03-01

    Imitation can occur in at least two forms: one, which can be defined as anatomical, is based primarily on the mental construct of the body schema and allows recognition of correspondences between own body anatomy and that of other individuals. The other form, defined as specular or mirror mode, is most probably based on the allocation of some form of attention to the same region of the environmental space both by model and imitator, and to the objects it contains. This study investigated the behavioral strategy of imitation in normal subjects, to assess whether they carried out task instructions using an anatomical or a mirror perspective. Twenty seven adults were asked to imitate intransitive meaningful and meaningless gestures shown by a model in video clips. Instructions about how to perform them were provided before each trial. Trials were free (intended to produce spontaneous imitation) or driven (intended to produce anatomical imitation); further driven trials were administered to verify participants' knowledge of bodily laterality and were used as control. Performances were interpreted as anatomical or mirror imitation, according to the observation of anatomical or spatial reference frames between stimulus and imitator. The results revealed that in spontaneous imitation the mirror mode was more frequent (61% of responses), in line with previous studies. The novel finding was the prevalence (93% of responses) of anatomical imitation in tasks involving detailed driven instructions. PMID:25181594

  16. Anatomical correlates of blepharospasm

    Horovitz Silvina G

    2012-06-01

    Full Text Available Abstract Background Focal dystonia is a neurological disorder characterized by unwanted muscle spasms. Blepharospasm is a focal dystonia producing an involuntary closure of the eyelid. Its etiology is unknown. Objective To investigate if there are structural changes in the white and grey matter of blepharospasm patients, and if the changes are related to disease features. Methods T1 and diffusion-weighted magnetic resonance imaging scans were collected from 14 female blepharospasm patients and 14 healthy matched controls. Grey matter volumes, fractional anisotropy (FA, and mean diffusivity maps were compared between the groups. Based on grey matter differences within the facial portion of the primary motor cortex, the corticobulbar tract was traced and compared between groups. Results Changes in grey matter in patients included the facial portion of the sensorimotor area and anterior cingulate gyrus. These changes did not correlate with disease duration. Corticobulbar tract volume and peak tract connectivity were decreased in patients compared with controls. There were no significant differences in FA or mean diffusivity between groups. Conclusions Grey matter changes within the primary sensorimotor and the anterior cingulate cortices in blepharospasm patients may help explain involuntary eyelid closure and the abnormal sensations often reported in this condition.

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

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

    1997-06-01

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

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

    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

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

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

    2013-11-15

    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.

  20. Generalized multiresolution hierarchical shape models via automatic landmark clusterization.

    Cerrolaza, Juan J; Villanueva, Arantxa; Reyes, Mauricio; Cabeza, Rafael; Gonzlez Ballester, Miguel Angel; Linguraru, Marius George

    2014-01-01

    Point Distribution Models (PDM) are some of the most popular shape description techniques in medical imaging. However, to create an accurate shape model it is essential to have a representative sample of the underlying population, which is often challenging. This problem is particularly relevant as the dimensionality of the modeled structures increases, and becomes critical when dealing with complex 3D shapes. In this paper, we introduce a new generalized multiresolution hierarchical PDM (GMRH-PDM) able to efficiently address the high-dimension-low-sample-size challenge when modeling complex structures. Unlike previous approaches, our new and general framework extends hierarchical modeling to any type of structure (multi- and single-object shapes) allowing to describe efficiently the shape variability at different levels of resolution. Importantly, the configuration of the algorithm is automatized thanks to the new agglomerative landmark clustering method presented here. Our new and automatic GMRH-PDM framework performed significantly better than classical approaches, and as well as the state-of-the-art with the best manual configuration. Evaluations have been studied for two different cases, the right kidney, and a multi-object case composed of eight subcortical structures. PMID:25320775

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

    Martin Pyka; Sebastian Klatt

    2014-01-01

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

  2. Brain Anatomical Network and Intelligence

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

    2009-01-01

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

  3. Digital photography in anatomical pathology

    Leong F; Leong A

    2004-01-01

    Digital imaging has made major inroads into the routine practice of anatomical pathology and replaces photographic prints and Kodachromes for reporting and conference purposes. More advanced systems coupled to computers allow greater versatility and speed of turnaround as well as lower costs of incorporating macroscopic and microscopic pictures into pathology reports and publications. Digital images allow transmission to remote sites via the Internet for consultation, quality assurance and ed...

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

    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

    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

  5. Variation of the ferret skull (Mustela putorius furo L.) in relation to stereotaxic landmarks.

    Lawes, I N; Andrews, P L

    1987-01-01

    The ferret skull was investigated to identify reliable extracranial landmarks for stereotaxy. The skulls of 56 ferrets of both sexes were measured in a stereotaxic apparatus. Neither body weight nor an index of skull length proved to be reliable predictors of intracranial location. Sutures fused too early in life for lambda and bregma to be useful as landmarks in adult ferrets. The position of extracranial features was used to predict the position of intracranial features. For rostral intracr...

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

    Blundell, R.; A.E. Felice

    2006-01-01

    Since no information of the Maltese goat genome is available, RAPD technique has been used to identify a number of DNA landmarks. Genome Landmarks have been obtained from the DNA of 66 Maltese goats which were studied with Random Amplification of Polymorphic DNA (RAPD). Eleven (11) reproducible RAPD polymorphic zones were identified. For sequencing, the RAPD zones were cloned into the Puc 18 vector utilising E. coli and then sequenced using both the forward (universal) and reverse primers spe...

  7. Reliability and reproducibility of three-dimensional cephalometric landmarks using CBCT: a systematic review

    Cinthia de Oliveira, LISBOA; Daniele, MASTERSON; Andra Fonseca Jardim, MOTTA; Alexandre Trindade, MOTTA.

    2015-04-01

    Full Text Available Objective : The aim of this study was to review the reliability and reproducibility of 3D-CBCT (cone beam computed tomography) cephalometric landmark identification. Methods : Electronic databases (Pubmed, Scopus, Web of Science) were searched for papers published from 1998 to October 2014. Specifi [...] c strategies were developed for each database, with the guidance of a librarian. Two reviewers independently analyzed the titles and abstracts for inclusion. The articles that met the inclusion and exclusion criteria were selected for full-text reading, and the selected articles went through methodological quality evaluation. After the exclusion of repeated articles, the titles of the remaining ones were read and 1,328 of them were excluded. The abstracts of 173 articles were read, of which 43 were selected, read in full and submitted to the inclusion and exclusion criteria. Fourteen articles or studies with reliable methodology and reproducibility remained. The data were collected, organized into figures and analyzed for determination of the reliability and reproducibility of the three-dimensional cephalometric landmarks. Results : Overall, the landmarks on the median sagittal line and dental landmarks had the highest reliability, while the landmarks on the condyle, porion and the orbitale presented lower levels of reliability. Point S must be marked in the multiplanar views associated with visualization in 3D reconstruction. Further studies are necessary for evaluating soft tissue landmarks.

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

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

  9. TOPICAL REVIEW: Anatomical imaging for radiotherapy

    Evans, Philip M.

    2008-06-01

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

  10. Anatomic variability of groin innervation.

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

    2013-08-01

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

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

    Xin-Bao Wu

    2015-01-01

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

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

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

    2015-01-01

    Background: Old pelvis fractures are among the most challenging fractures to treat because of their complex anatomy, difficult-to-access surgical sites, and the relatively low incidence of such cases. Proper evaluation and surgical planning are necessary to achieve the pelvic ring symmetry and stable fixation of the fracture. The goal of this study was to assess the use of three-dimensional (3D) printing techniques for surgical management of old pelvic fractures. Methods: First, 16 dried human cadaveric pelvises were used to confirm the anatomical accuracy of the 3D models printed based on radiographic data. Next, nine clinical cases between January 2009 and April 2013 were used to evaluate the surgical reconstruction based on the 3D printed models. The pelvic injuries were all type C, and the average time from injury to reconstruction was 11 weeks (range: 8–17 weeks). The workflow consisted of: (1) Printing patient-specific bone models based on preoperative computed tomography (CT) scans, (2) virtual fracture reduction using the printed 3D anatomic template, (3) virtual fracture fixation using Kirschner wires, and (4) preoperatively measuring the osteotomy and implant position relative to landmarks using the virtually defined deformation. These models aided communication between surgical team members during the procedure. This technique was validated by comparing the preoperative planning to the intraoperative procedure. Results: The accuracy of the 3D printed models was within specification. Production of a model from standard CT DICOM data took 7 hours (range: 6–9 hours). Preoperative planning using the 3D printed models was feasible in all cases. Good correlation was found between the preoperative planning and postoperative follow-up X-ray in all nine cases. The patients were followed for 3–29 months (median: 5 months). The fracture healing time was 9–17 weeks (mean: 10 weeks). No delayed incision healing, wound infection, or nonunions occurred. The results were excellent in two cases, good in five, and poor in two based on the Majeed score. Conclusions: The 3D printing planning technique for pelvic surgery was successfully integrated into a clinical workflow to improve patient-specific preoperative planning by providing a visual and haptic model of the injury and allowing patient-specific adaptation of each osteosynthesis implant to the virtually reduced pelvis. PMID:25673449

  13. Developing an anatomical model of the human laryngeal cartilages from magnetic resonance imaging.

    Selbie, W Scott; Gewalt, Sally L; Ludlow, Christy L

    2002-09-01

    The purpose of this work was to construct a three-dimensional anatomical framework of the cartilages of the human larynx. The framework included representative surface models of the four laryngeal cartilages and estimated attachment points for the intrinsic laryngeal muscles. High-resolution magnetic resonance imaging (MRI) was used to scan one female and four male human cadaveric larynges. The cartilages were segmented manually from the MRI volume for analysis. Two of these larynges were subsequently dissected and the landmark distances on the cartilages measured for comparison with the MRI measures and previous studies. The MRI measures were 8% smaller than the anatomical measures and 12% smaller than data reported in the literature. A laryngeal coordinate system was defined using the plane of symmetry of the cricoid cartilage. Measures of cricoid cartilage symmetry had less than 3% difference between the two sides for a series of measures. An algorithm for registering larynges that minimized the root-mean-square distance between the surface of a reference cricoid cartilage and the surfaces of nonisotropically scaled candidate cricoid cartilages was evaluated. This study provided an anatomical framework for registering different larynges to the same coordinate space. PMID:12243156

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

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

    2013-01-15

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

  15. 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

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

  16. Anatomical entity mention recognition at literature scale

    Pyysalo, Sampo; Ananiadou, Sophia

    2013-01-01

    Motivation: Anatomical entities ranging from subcellular structures to organ systems are central to biomedical science, and mentions of these entities are essential to understanding the scientific literature. Despite extensive efforts to automatically analyze various aspects of biomedical text, there have been only few studies focusing on anatomical entities, and no dedicated methods for learning to automatically recognize anatomical entity mentions in free-form text have been introduced. Res...

  17. The early history of keratoconus prior to Nottingham's landmark 1854 treatise on conical cornea: a review.

    Grzybowski, Andrzej; McGhee, Charles N J

    2013-03-01

    In an era of scientific method, precision of nomenclature and an electronically accessible publication record, the early history of keratoconus still remains, in parts, as complex and perplexing as the disease itself. Historically, the disease has been somewhat confusingly referred to by several different terms, including hyperkeratosis, ochlodes, conical formed cornea, cornea conica, corne conique, sugar loaf cornea, prolapses corneae, procidentia corneae, staphyloma transparent de la corne, staphyloma pellucidum, staphyloma corneae totale conicum pellucidum, staphyloma diaphanum, keratconus and keratoconus. In his major 1854 treatise on conical cornea, John Nottingham is widely cited as the first author to succinctly define keratoconus and its associations; however, for 150 years prior to this landmark publication, others had been slowly deciphering elements of keratoconus and distilling their knowledge in a series of publications obscured by the passage of years. Uncritical re-writing of core information and references without their full verification has also led to confusion in the published literature in the 150 years since Nottingham's comprehensive description of keratoconus. In the light of the preceding limitations in the established literature, the authors conducted an historical survey, based on the analysis of original sources, to more fully establish the chronology of early descriptions of keratoconus prior to 1854, with particular focus on the works of Duddell, Taylor, Mauchart, Scarpa, Wardrop, Lyall, MacKenzie, Lawrence, Schmidt, von Ammon and Pickford. This review attempts to place the observations of these practitioners and others both in the context of contemporary ophthalmic practice and historical precedent. PMID:23414219

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

    Bataille, F

    2007-04-15

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

  19. 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

    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)

  20. 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

    Pain, F; Dhenain, M; Gurden, H; Routier, A L; Lefebvre, F; Mastrippolito, R; Laniece, P [UMR8165 Imagerie et Modelisation en Cancerologie et Neurobiologie, Universites Paris 11/Paris 7, Campus d' Orsay Bat 104/440 91406 Orsay Cedex (France)

    2008-10-07

    The {beta}-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 {sup 18}F, {sup 11}C and {sup 15}O 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 {beta}-microprobe reports. In the context of realistic experiments (binding of {sup 11}C-Raclopride to D2 dopaminergic receptors in the striatum; local glucose metabolic rate measurement with {sup 18}F-FDG and H{sub 2}O{sup 15} 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 {beta}-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 {sup 11}C-Raclopride to D2 dopaminergic receptors in the striatum; binding of {sup 18}F-MPPF to 5HT1A receptors in the dorsal raphe nucleus)

  1. Anatomical correlations of the international 10-20 sensor placement system in infants.

    Kabdebon, C; Leroy, F; Simmonet, H; Perrot, M; Dubois, J; Dehaene-Lambertz, G

    2014-10-01

    Developmental research, as well as paediatric clinical activity crucially depends on non-invasive and painless brain recording techniques, such as electroencephalography (EEG), and near infrared spectroscopy (NIRS). However, both of these techniques measure cortical activity from the scalp without precise knowledge of the recorded cerebral structures. An accurate and reliable mapping between external anatomical landmarks and internal cerebral structures is therefore fundamental to localise brain sources in a non-invasive way. Here, using MRI, we examined the relations between the 10-20 sensor placement system and cerebral structures in 16 infants (3-17 weeks post-term). We provided an infant template parcelled in 94 regions on which we reported the variability of sensors locations, concurrently with the anatomical variability of six main cortical sulci (superior and inferior frontal sulcus, central sulcus, sylvian fissure, superior temporal sulcus, and intraparietal sulcus) and of the distances between the sensors and important cortical landmarks across these infants. The main difference between infants and adults was observed for the channels O1-O2, T5-T6, which projected over lower structures than in adults. We did not find any asymmetry in the distances between the scalp and the brain envelope. However, because of the Yakovlean torque pushing dorsally and frontally the right sylvian fissure, P3-P4 were not at the same distance from the posterior end of this structure. This study should help to refine hypotheses on functional cognitive development by providing an accurate description of the localization of standardised channels relative to infants' brain structures. Template and atlas are publicly available on our Web site (http://www.unicog.org/pm/pmwiki.php/Site/InfantTemplate). PMID:24862070

  2. A Catalytic Role for Mod5 in the Formation of the Tea1 Cell Polarity Landmark

    Bicho, Claudia C.; Kelly, David A.; Snaith, Hilary A.; Goryachev, Andrew B.; Sawin, Kenneth E.

    2010-01-01

    Summary Many systems regulating cell polarity involve stable landmarks defined by internal cues [1–5]. In the rod-shaped fission yeast Schizosaccharomyces pombe, microtubules regulate polarized vegetative growth via a landmark involving the protein Tea1 [6–9]. Tea1 is delivered to cell tips as packets of molecules associated with growing microtubule ends [10] and anchored at the plasma membrane via a mechanism involving interaction with the membrane protein Mod5 [11, 12]. Tea1 and Mod5 are hi...

  3. Atlas Toolkit: Fast registration of 3D morphological datasets in the absence of landmarks

    Grocott, Timothy; Thomas, Paul; Mnsterberg, Andrea E.

    2016-01-01

    Image registration is a gateway technology for Developmental Systems Biology, enabling computational analysis of related datasets within a shared coordinate system. Many registration tools rely on landmarks to ensure that datasets are correctly aligned; yet suitable landmarks are not present in many datasets. Atlas Toolkit is a Fiji/ImageJ plugin collection offering elastic group-wise registration of 3D morphological datasets, guided by segmentation of the interesting morphology. We demonstrate the method by combinatorial mapping of cell signalling events in the developing eyes of chick embryos, and use the integrated datasets to predictively enumerate Gene Regulatory Network states. PMID:26864723

  4. Atlas Toolkit: Fast registration of 3D morphological datasets in the absence of landmarks.

    Grocott, Timothy; Thomas, Paul; Münsterberg, Andrea E

    2016-01-01

    Image registration is a gateway technology for Developmental Systems Biology, enabling computational analysis of related datasets within a shared coordinate system. Many registration tools rely on landmarks to ensure that datasets are correctly aligned; yet suitable landmarks are not present in many datasets. Atlas Toolkit is a Fiji/ImageJ plugin collection offering elastic group-wise registration of 3D morphological datasets, guided by segmentation of the interesting morphology. We demonstrate the method by combinatorial mapping of cell signalling events in the developing eyes of chick embryos, and use the integrated datasets to predictively enumerate Gene Regulatory Network states. PMID:26864723

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

    EliaFormisano

    2014-07-01

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

  6. Surgeon's view of the skull base from the lateral approach.

    Goldenberg, R A

    1984-12-01

    This paper presents the surgical anatomy of the skull base and infratemporal fossa. The information has been derived from the author's own experience in surgical and cadaver dissection, standard anatomical references, and selected experience of other skull base surgeons. Because the lateral approach has become the utilitarian method of exposure, the intricate detailed anatomy is demonstrated from this view at five levels of dissection, so the surgeon may gain a practical understanding of the surgical relationship of critical structures. Consistent anatomical landmarks can be used by the surgeon in the location of these critical structures. The styloid process, sphenoidal spine, and middle meningeal artery identify the internal carotid artery as it enters the carotid canal. The bony or fibrous septum that divides the jugular foramen into neural and vascular compartments may be used to better identify nerves IX, X, and XI. The zygomatic root is useful for location of the middle fossa dura. The lateral pterygoid plate leads directly to the foramen ovale. The increased precision of dissection permitted by use of the microscope requires an increased level of knowledge of anatomical structures in this area. It is hoped that the information presented in this paper will assist surgeons in the meticulous and thorough removal of skull base tumors and in the preservation of neural and vascular structures that are presently being sacrificed. PMID:6503585

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

    Feragen, Aasa; Petersen, Jens; Owen, Megan; Lo, Pechin Chien Pau; Thomsen, Laura; Wille, Mathilde; Dirksen, Asger; de Bruijne, Marleen

    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....... 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....

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

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

    2015-10-01

    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

  9. Obstacles Facing Promoting Tourism for Islamic Landmarks from the Perspective of Tour Operators in Egypt

    Suzan Bakri Hassan

    2015-05-01

    Full Text Available The UNESCO launched a campaign #unite4heritage in Egypt to defeat extremism and intolerance. The message of such campaigne is peace, dialogue and unity embedded in cultural heritage. As culture and tourism are linked together, such message could be delivered through improving culture heritage tourism in Egypt. Islamic landmarks are considered as a part of human heritage. Therefore, the purpose of this study is to identify how much tour operators in Egypt include Islamic landmarks in their programs to determine the obstacles facing promoting cultural tourism in Islamic landmarks' areas. Additionally, the study would identify positive results in the case of developing heritage tourism in Egypt. To achieve a high result, a survey approach was employed to collect data from 100 tour operators, using a completed questionnaire technique as well as a Likert Scale and statistical models in order to test and interpret the research outcomes. The research findings indicated that although tour operators in Egypt are convinced of the significance of the Islamic landmarks, there is no contradiction between creating global understanding and at the same time achieving benefit to the local community. However, there is a range of obstacles facing promoting such type of tourism in Egypt. Keywords: Culture heritage tourism, community, Egypt, Islamic civilization.

  10. Ethmomaxillary sinus: a particular anatomic variation of the paranasal sinuses

    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

    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.)

  11. Pattern recognition of anatomical shapes in CT scans

    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

  12. Automatic aortic root landmark detection in CTA images for preprocedural planning of transcatheter aortic valve implantation.

    Elattar, Mustafa; Wiegerinck, Esther; van Kesteren, Floortje; Dubois, Lucile; Planken, Nils; Vanbavel, Ed; Baan, Jan; Marquering, Henk

    2016-03-01

    Transcatheter aortic valve implantation is currently a well-established minimal invasive treatment option for patients with severe aortic valve stenosis. CT Angiography is used for the pre-operative planning and sizing of the prosthesis. To reduce the inconsistency in sizing due to interobserver variability, we introduce and evaluate an automatic aortic root landmarks detection method to determine the sizing parameters. The proposed algorithm detects the sinotubular junction, two coronary ostia, and three valvular hinge points on a segmented aortic root surface. Using these aortic root landmarks, the automated method determines annulus radius, annulus orientation, and distance from annulus plane to right and left coronary ostia. Validation is performed by the comparison with manual measurements of two observers for 40 CTA image datasets. Detection of landmarks showed high accuracy where the mean distance between the automatically detected and reference landmarks was 2.81 ± 2.08 mm, comparable to the interobserver variation of 2.67 ± 2.52 mm. The mean annulus to coronary ostium distance was 16.9 ± 3.3 and 17.1 ± 3.3 mm for the automated and the reference manual measurements, respectively, with a mean paired difference of 1.89 ± 1.71 mm and interobserver mean paired difference of 1.38 ± 1.52 mm. Automated detection of aortic root landmarks enables automated sizing with good agreement with manual measurements, which suggests applicability of the presented method in current clinical practice. PMID:26498339

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

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

  14. Introducing International Journal of Anatomical Variations

    Tunali S

    2008-01-01

    Welcome to International Journal of Anatomical Variations (IJAV) - an annual journal of anatomical variations and clinical anatomy case reports. After having a notable experience for eight years in NEUROANATOMY, we are pleased to introduce you IJAV. We are eventually announcing our new journal after three years of feasibility and background study period. We hope that IJAV will fill in the gap in anatomy journals’ bunch. IJAV is an annual, open access journal having electronic version only. De...

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

    Sihn, Kyu Hwan

    2012-04-30

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

  16. 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

    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

    {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.

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

    Martnez, Fernando

    2013-03-01

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

  18. Three-dimensional study of pelvic asymmetry on anatomical specimens and its clinical perspectives.

    Boulay, Christophe; Tardieu, Christine; Bénaim, Charles; Hecquet, Jérome; Marty, Catherine; Prat-Pradal, Dominique; Legaye, Jean; Duval-Beaupère, Ginette; Pélissier, Jacques

    2006-01-01

    The aim of this study was to assess pelvic asymmetry (i.e. to determine whether the right iliac bone and the right part of the sacrum are mirror images of the left), both quantitatively and qualitatively, using three-dimensional measurements. Pelvic symmetry was described osteologically using a common reference coordinate system for a large sample of pelvises. Landmarks were established on 12 anatomical specimens with an electromagnetic Fastrak system. Seventy-one paired variables were tested with a paired t-test and a non-parametric test (Wilcoxon). A Pearson correlation matrix between the right and left values of the same variable was applied exclusively to values that were significantly asymmetric in order to calculate a dimensionless asymmetry index, ABGi, for each variable. Fifteen variables were significantly asymmetric and correlated with the right vs. left sides for the following anatomical regions: sacrum, iliac blades, iliac width, acetabulum and the superior lunate surface of the acetabulum. ABGi values above a threshold of +/- 4.8% were considered significantly asymmetric in seven variables of the pelvic area. Total asymmetry involving the right and the left pelvis seems to follow a spiral path in the pelvis; in the upper part, the iliac blades rotate clockwise, and in the lower part, the pubic symphysis rotates anticlockwise. Thus, pelvic asymmetry may be evaluated in clinical examinations by measuring iliac crest orientation. PMID:16420376

  19. Three-dimensional study of pelvic asymmetry on anatomical specimens and its clinical perspectives

    Boulay, Christophe; Tardieu, Christine; Bénaim, Charles; Hecquet, Jérome; Marty, Catherine; Prat-Pradal, Dominique; Legaye, Jean; Duval-Beaupère, Ginette; Pélissier, Jacques

    2006-01-01

    The aim of this study was to assess pelvic asymmetry (i.e. to determine whether the right iliac bone and the right part of the sacrum are mirror images of the left), both quantitatively and qualitatively, using three-dimensional measurements. Pelvic symmetry was described osteologically using a common reference coordinate system for a large sample of pelvises. Landmarks were established on 12 anatomical specimens with an electromagnetic Fastrak system. Seventy-one paired variables were tested with a paired t-test and a non-parametric test (Wilcoxon). A Pearson correlation matrix between the right and left values of the same variable was applied exclusively to values that were significantly asymmetric in order to calculate a dimensionless asymmetry index, ABGi, for each variable. Fifteen variables were significantly asymmetric and correlated with the right vs. left sides for the following anatomical regions: sacrum, iliac blades, iliac width, acetabulum and the superior lunate surface of the acetabulum. ABGi values above a threshold of ± 4.8% were considered significantly asymmetric in seven variables of the pelvic area. Total asymmetry involving the right and the left pelvis seems to follow a spiral path in the pelvis; in the upper part, the iliac blades rotate clockwise, and in the lower part, the pubic symphysis rotates anticlockwise. Thus, pelvic asymmetry may be evaluated in clinical examinations by measuring iliac crest orientation. PMID:16420376

  20. Restriction landmark genomic scanning: analysis of CpG islands in genomes by 2D gel electrophoresis.

    Costello, Joseph F; Hong, Chibo; Plass, Christoph; Smiraglia, Dominic J

    2009-01-01

    Restriction landmark genomic scanning (RLGS) is a method that provides a quantitative genetic and epigenetic (cytosine methylation) assessment of thousands of CpG islands in a single gel without prior knowledge of gene sequence. The method is based on two-dimensional separation of radiolabeled genomic DNA into nearly 2,000 discrete fragments that have a high probability of containing gene sequences. Genomic DNA is digested with an infrequently cutting restriction enzyme, such as NotI or AscI, radiolabeled at the cleaved ends, digested with a second restriction enzyme, and then electrophoresed through a narrow, 60-cm-long agarose tube-shaped gel. The DNA in the tube gel is then digested by a third, more frequently cutting restriction enzyme and electrophoresed, in a direction perpendicular to the first separation, through a 5% nondenaturing polyacrylamide gel, and the gel is autoradiographed. Radiolabeled NotI or AscI sites are frequently used as "landmarks" because NotI or AscI cannot cleave methylated sites and since an estimated 89% and 83% of the recognition sites, respectively, are found within CpG islands. Using a methylation-sensitive enzyme, the technique has been termed RLGS-M. The resulting RLGS profile displays both the copy number and methylation status of the CpG islands. Integrated with high-resolution gene copy-number analyses, RLGS enables one to define genetic or epigenetic alteration in cells. These profiles are highly reproducible and are therefore amenable to inter- and intraindividual DNA sample comparisons. RLGS was the first of many technologies to allow large-scale DNA methylation analysis of CpG islands. PMID:18987812

  1. Analysis of anatomic variability in children with low mathematical skills

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

    2008-03-01

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

  2. Generalized metrics induced anatomical prior for MAP PET image reconstruction

    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.)

  3. Bicycle Chain Shape Models

    Sommer, Stefan Horst; Tatu, Aditya Jayant; Chen, Chen; Jørgensen, Dan; de Bruijne, Marleen; Loog, Marco; Nielsen, Mads; Lauze, Francois Bernard

    In this paper we introduce landmark-based preshapes which allow mixing of anatomical landmarks and pseudo-landmarks, constraining consecutive pseudo-landmarks to satisfy planar equidistance relations. This defines naturally a structure of Riemannian manifold on these preshapes, with a natural act...

  4. Lumbar hernia: anatomical route assessed by computed tomography.

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

    2002-02-01

    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

  5. Anatomic Correlates of Stereotypies in Frontotemporal Lobar Degeneration

    Josephs, Keith A.; Whitwell, Jennifer L; Jack, Clifford R

    2007-01-01

    Stereotypies are common in frontotemporal lobar degeneration (FTLD) however the anatomical correlates of stereotypies are unknown. We therefore set out to compare patterns of grey matter volume loss in FTLD subjects with and without stereotypies. Subjects with a diagnosis of FTLD that met international consensus criteria were prospectively recruited and separated into those with and without stereotypies. MRI and cognitive measures were obtained and voxel-based morphometry was used to assess t...

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

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

    2006-01-01

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

  7. Performance Evaluation of Color Models in the Fusion of Functional and Anatomical Images.

    Ganasala, Padma; Kumar, Vinod; Prasad, A D

    2016-05-01

    Fusion of the functional image with an anatomical image provides additional diagnostic information. It is widely used in diagnosis, treatment planning, and follow-up of oncology. Functional image is a low-resolution pseudo color image representing the uptake of radioactive tracer that gives the important metabolic information. Whereas, anatomical image is a high-resolution gray scale image that gives structural details. Fused image should consist of all the anatomical details without any changes in the functional content. This is achieved through fusion in de-correlated color model and the choice of color model has greater impact on the fusion outcome. In the present work, suitability of different color models for functional and anatomical image fusion is studied. After converting the functional image into de-correlated color model, the achromatic component of functional image is fused with an anatomical image by using proposed nonsubsampled shearlet transform (NSST) based image fusion algorithm to get new achromatic component with all the anatomical details. This new achromatic and original chromatic channels of functional image are converted to RGB format to get fused functional and anatomical image. Fusion is performed in different color models. Different cases of SPECT-MRI images are used for this color model study. Based on visual and quantitative analysis of fused images, the best color model for the stated purpose is determined. PMID:27037686

  8. 16 landmarks of the mouse brain have been validated as fiducials for registration to WHS

    Marina Sergejeva

    2014-02-01

    Full Text Available A standard space for describing coordinate-based knowledge about the rodent brain is urgently needed. The INCF Digital Atlasing Program has yielded an open access 3D atlas reference system for the mouse brain - Waxholm Space (WHS and a supporting Digital Atlasing Infrastructure (DAI for sharing of multimodal data (genomic, proteomic, imaging from research groups around the world. We need convenient methods that permit researchers to register their own data to WHS. Existing automatic registration processes are rather complex. In addition, we propose an easier and faster approach: registration based on well recognizable brain landmarks (LMs or fiducials. Here we present a set of LMs validated as fiducials, as they were reliably identified by different individuals (anatomy specialists and novice in different MR imaging modalities (T1, T2, T2* in various specimens by different cutting directions by different image resolutions. On coronal MR datasets (T1, T2, T2*, 256x256x128, 80 ?m from an adult C57BL/6J male we defined an initial set of LMs recognizable in all 3 modalities and rendered descriptions how to find them. 15 guessers identified these LMs according to the descriptions on datasets from two C57BL/6J males, visualized in ImageJ as coronal slices. The probability of finding them, mean values for x, y and z coordinates and deviations from the mean were calculated for every LM. Finally, we excluded LMs with a deviation of more than 1,5 voxels in the x and y directions in both animals and ended up with 16 potential fiducials. Their average deviations were: 1,0 (x, 0,6 (y and 1,5 (z, the probability of finding was > 95%. Further, we located these 16 LMs on the canonical WHS datasets, and presented them in the web-based atlasing tool Scalable Brain Atlas (http://scalablebrainatlas.incf.org/WHS10. WHS images have a four times higher resolution and a different inclination than ours, but despite the differences all LMs were well identifiable according to our definitions. This supports their validity as fiducials. We also evaluated the classical LMs, Bregma and Lambda derived from the skull 3D CT datasets coregistered to brain MRI datasets of five mice. We found that positions of these LMs with respect to brain anatomy vary considerably between the mice. The largest distance between Bregma z-positions was 1,2 mm, and between Lambda z-positions - 1,68 mm. Thus, we cannot accept these two LMs as fiducials.

  9. Importancia de la Sabiduría Didáctica Práctica como Fuente de Conocimiento Base para la Enseñanza de la Anatomía Importance of Teaching Practical Wisdom as a Source of Knowledge Base for Teaching Anatomy

    Mario Pellón Arcaya; Juan Mansilla Sepúlveda; Daniel San Martín Cantero

    2010-01-01

    La sabiduría práctica es uno de los conocimientos base que se propone para generar prácticas de enseñanza de calidad en el campo de la medicina. Se planteó un diseño metodológico cualitativo ­ comprehensivo con el propósito de describir la importancia de la sabiduría didáctica práctica como fuente de conocimiento base para la enseñanza de la anatomía en docentes de la Universidad Mayor de Temuco, esto al amparo de la teoría fundamentada, el método comparativo constante y los principios de tri...

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

    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)

  11. Landmark clinical trials influencing surgical management of non-invasive and invasive breast cancer.

    Julian, Thomas B; Venditti, Charis A; Duggal, Shivani

    2015-01-01

    The surgical management of breast cancer has changed considerably since the use of the Halstedian radical mastectomy early in the 20th century. Over the last 50 years, several landmark clinical trials from the USA and Europe have resulted in a paradigm shift in the management of breast cancer toward less radical forms of surgery with the combined use of multi-modality treatments including systemic chemotherapy, endocrine therapy, and radiotherapy. Advances in such research have established a new worldwide standard of care for breast cancer surgical management and treatment, which has become more patient centric and which places a higher emphasis on cosmesis and improved patient quality of life. In this chapter, we review the landmark clinical trials that have influenced surgical management for non-invasive and invasive breast cancer and that serve to guide current clinical practices to date. PMID:25521007

  12. Molecular architecture of classical cytological landmarks: Centromeres and telomeres

    Meyne, J.

    1994-11-01

    Both the human telomere repeat and the pericentromeric repeat sequence (GGAAT)n were isolated based on evolutionary conservation. Their isolation was based on the premise that chromosomal features as structurally and functionally important as telomeres and centromeres should be highly conserved. Both sequences were isolated by high stringency screening of a human repetitive DNA library with rodent repetitive DNA. The pHuR library (plasmid Human Repeat) used for this project was enriched for repetitive DNA by using a modification of the standard DNA library preparation method. Usually DNA for a library is cut with restriction enzymes, packaged, infected, and the library is screened. A problem with this approach is that many tandem repeats don`t have any (or many) common restriction sites. Therefore, many of the repeat sequences will not be represented in the library because they are not restricted to a viable length for the vector used. To prepare the pHuR library, human DNA was mechanically sheared to a small size. These relatively short DNA fragments were denatured and then renatured to C{sub o}t 50. Theoretically only repetitive DNA sequences should renature under C{sub o}t 50 conditions. The single-stranded regions were digested using S1 nuclease, leaving the double-stranded, renatured repeat sequences.

  13. Eyewitness to history: Landmarks in the development of computerized electrocardiography.

    Rautaharju, Pentti M

    2016-01-01

    The use of digital computers for ECG processing was pioneered in the early 1960s by two immigrants to the US, Hubert Pipberger, who initiated a collaborative VA project to collect an ECG-independent Frank lead data base, and Cesar Caceres at NIH who selected for his ECAN program standard 12-lead ECGs processed as single leads. Ray Bonner in the early 1970s placed his IBM 5880 program in a cart to print ECGs with interpretation, and computer-ECG programs were developed by Telemed, Marquette, HP-Philips and Mortara. The "Common Standards for quantitative Electrocardiography (CSE)" directed by Jos Willems evaluated nine ECG programs and eight cardiologists in clinically-defined categories. The total accuracy by a representative "average" cardiologist (75.5%) was 5.8% higher than that of the average program (69.7, pcomputer-based and expert reader performance are likely to show evolving results with continuing improvement of computer-ECG algorithms and changing expertise of ECG interpreters. PMID:26620728

  14. Anatomical models for space radiation applications: An overview

    Atwell, W.

    1994-10-01

    Extremely detailed computerized anatomical male (CAM) and female (CAF) models that have been developed for use in space radiation analyses are discussed and reviewed. Recognizing that the level of detail may currently be inadequate for certain radiological applications, one of the purposes of this paper is to elicit specific model improvements or requirements from the scientific user-community. Methods and rationale are presented which describe the approach used in the Space Shuttle program to extrapolate dosimetry measurements (skin doses) to realistic astronaut body organ doses. Several mission scenarios are presented which demonstrate the utility of the anatomical models for obtaining specific body organ exposure estimates and can be used for establishing cancer morbidity and mortality risk assessments. These exposure estimates are based on the trapped Van Allen belt and galactic cosmic radiation environment models and data from the major historical solar particle events.

  15. Characterization of Capsicum species using anatomical and molecular data.

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

    2013-01-01

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

  16. Cell cycle dynamics of histone variants at the centromere, a model for chromosomal landmarks.

    Boyarchuk, Ekaterina; Montes De Oca, Rocío; Almouzni, Geneviève

    2011-01-01

    Classical heterochromatin chromosomal landmarks, such as centromeres and telomeres, are characterized by specific chromatin signatures. Among these, the incorporation of histone variants has recently emerged as an important feature. Using the centromere as a paradigm, we consider the role of histone variant dynamics in locus-specific chromatin organization. We describe the distinct location and dynamics of CenH3, H3.3, and H2AZ at the centromere during the cell cycle. This leads us to present...

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

    Fukushi, T; Wehner, R

    2004-01-01

    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 releas...

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

    Tiago Santos Telles; Sonia Carmela Falci Dechen; Maria Ftima de Guimares

    2013-01-01

    The problem of soil erosion in Brazil has been a focus of agricultural scientific research since the 19th century. The aim of this study was to provide a historical overview of the institutional landmarks which gave rise to the first studies in soil erosion and established the foundations of agricultural research in Brazil. The 19th century and beginning of the 20th century saw the founding of a series of institutions in Brazil, such as Botanical Gardens, executive institutions, research inst...

  19. Superficial cortical landmarks for localization of the hippocampus: Application for temporal lobectomy and amygdalohippocampectomy

    R. Shane Tubbs; Marios Loukas; Barbaro, Nicholas M.; Aaron A Cohen-Gadol

    2015-01-01

    Background: Accessing the hippocampus for amygdalohippocampectomy and procedures such as depth electrode placement requires accurate knowledge regarding the location of the hippocampus. Methods: The authors removed 10 human cadaveric brains (20 sides) from their crania, noted relationships between the lateral temporal neocortex and underlying hippocampus, and measured the distance between the hippocampus and superficial landmarks. Results: Mean distances were as follows: 3.8 cm from t...

  20. A low-cost test-bed for real-time landmark tracking

    Csaszar, Ambrus; Hanan, Jay C.; Moreels, Pierre; Assad, Christopher

    2007-04-01

    A low-cost vehicle test-bed system was developed to iteratively test, refine and demonstrate navigation algorithms before attempting to transfer the algorithms to more advanced rover prototypes. The platform used here was a modified radio controlled (RC) car. A microcontroller board and onboard laptop computer allow for either autonomous or remote operation via a computer workstation. The sensors onboard the vehicle represent the types currently used on NASA-JPL rover prototypes. For dead-reckoning navigation, optical wheel encoders, a single axis gyroscope, and 2-axis accelerometer were used. An ultrasound ranger is available to calculate distance as a substitute for the stereo vision systems presently used on rovers. The prototype also carries a small laptop computer with a USB camera and wireless transmitter to send real time video to an off-board computer. A real-time user interface was implemented that combines an automatic image feature selector, tracking parameter controls, streaming video viewer, and user generated or autonomous driving commands. Using the test-bed, real-time landmark tracking was demonstrated by autonomously driving the vehicle through the JPL Mars yard. The algorithms tracked rocks as waypoints. This generated coordinates calculating relative motion and visually servoing to science targets. A limitation for the current system is serial computing-each additional landmark is tracked in order-but since each landmark is tracked independently, if transferred to appropriate parallel hardware, adding targets would not significantly diminish system speed.

  1. Independent effects of geometry and landmark in a spontaneous reorientation task: a study of two species of fish.

    Lee, Sang Ah; Vallortigara, Giorgio; Ruga, Vincenza; Sovrano, Valeria A

    2012-09-01

    While disoriented humans and animals use both landmarks and environmental geometry to guide their navigation, it is not clear what kinds of cognitive mechanisms underlie these behaviors. Because traditional tests of trained navigation behavior in environments containing both landmarks and geometric information may cloud our insight into the nature of these processes, the present study tested the spontaneous use of landmarks and environmental shape by two species of fish-Redtail Splitfins (Xenotoca eiseni) and Zebrafish (Danio rerio). The results suggest that while geometry is spontaneously used by both species and both sexes to compute relative position or direction, the spontaneous use of landmarks is limited to direct beaconing and complicated by attraction to features and variability across species and sex. These findings support the view that while multiple cues may ultimately guide behavior, the computation of orientation and relative positions is specified by geometric input and is independent from other navigation processes such as beaconing. PMID:22610461

  2. Cardiac Anatomic Considerations in Pediatric Electrophysiology

    Samuel J. Asirvatham

    2008-05-01

    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.

  3. Anatomic Breast Coordinate System for Mammogram Analysis

    Karemore, Gopal Raghunath; Brandt, S; Karssemeijer, N; Nielsen, Mads

    2011-01-01

    inside the breast. Most of the risk assessment and CAD modules use a breast region in a image centered Cartesian x,y coordinate system. Nevertheless, anatomical structure follows curve-linear trajectories. We examined an anatomical breast coordinate system that preserves the anatomical correspondence...... represented by geodesic distance (s) from nipple and parametric angle (¿) as shown in figure 1. The scoring technique called MTR (mammographic texture resemblance marker) used this breast coordinate system to extract Gaussian derivative features. The features extracted using the (x,y) and the curve...... and without the curve-linear coordinate system by computing the ROC curve. We assessed the use of the curve-linear breast coordinate system in registering the pairs of baseline and follow-up mammograms in a longitudinal study by comparing it with well-established registration measures such as mutual...

  4. Freehand Thoracic Pedicle Screw Placement: Review of Existing Strategies and a Step-by-Step Guide Using Uniform Landmarks for All Levels.

    Avila, Mauricio J; Baaj, Ali A

    2016-01-01

    Pedicle screw fixation in the thoracic spine presents certain challenges due to the critical regional neurovascular anatomy as well as the narrow pedicular corridor that typically exists. With increased awareness of the dangers of intraoperative radiation, the ability to place pedicle screws with anatomic landmarks alone is paramount. In this study, we reviewed the literature from 1990 to 2015 for studies that included freehand pedicle screw placement in the thoracic spine with special emphasis on entry points and the trajectories of the screws. We excluded studies that used fluoroscopy guidance, navigation techniques, cadaveric and biomechanical articles, case reports, and experimental studies on animals. The search retrieved 40 articles, and after careful selection, seven articles were analyzed. Over 8,000 screws were placed in the different studies. The mean accuracy for placement of the thoracic screws was 93.3%. However, there is little consensus between studies in entry points, sagittal, and axial trajectories of the screws. We complete this review by presenting our step-by-step technique for the placement of freehand pedicle screws in the thoracic spine. PMID:27014535

  5. Congenital neck masses: embryological and anatomical perspectives

    Zahida Rasool

    2013-08-01

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

  6. Anatomical basis for Wilms tumor surgery

    Trobs R

    2009-01-01

    Full Text Available Wilms tumor surgery requires meticulous planning and sophisticated surgical technique. Detailed anatomical knowledge can facilitate the uneventful performance of tumor nephrectomy and cannot be replaced by advanced and sophisticated imaging techniques. We can define two main goals for surgery: (1 exact staging as well as (2 safe and complete resection of tumor without spillage. This review aims to review the anatomical basis for Wilms tumor surgery. It focuses on the surgical anatomy of retroperitoneal space, aorta, vena cava and their large branches with lymphatics. Types and management of vascular injuries are discussed.

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

    Andréia Luciana Martins Ramos

    2008-03-01

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

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

    Yoon, Kaeng Won; Yoon, Suk Ja; Kang, Byung Cheol; Kook, Min Suk; Lee, Jae Seo [School of Dentistry, Dental Science Research Institute, Chonnam National University, Gwangju (Korea, Republic of); Kim, Young Hee [Dept. of Oral and Maxillofacial Radiology, Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of); Palomo, Juan Martin [Dept. of Orthodontics, School of Dental Medicine, Case Western Reserve University, Cleveland (Korea, Republic of)

    2014-09-15

    This study aimed to investigate the deviation of landmarks from horizontal or midsagittal reference planes according to the methods of establishing reference planes. Computed tomography (CT) scans of 18 patients who received orthodontic and orthognathic surgical treatment were reviewed. Each CT scan was reconstructed by three methods for establishing three orthogonal reference planes (namely, the horizontal, midsagittal, and coronal reference planes). The horizontal (bilateral porions and bilateral orbitales) and midsagittal (crista galli, nasion, prechiasmatic point, opisthion, and anterior nasal spine) landmarks were identified on each CT scan. Vertical deviation of the horizontal landmarks and horizontal deviation of the midsagittal landmarks were measured. The porion and orbitale, which were not involved in establishing the horizontal reference plane, were found to deviate vertically from the horizontal reference plane in the three methods. The midsagittal landmarks, which were not used for the midsagittal reference plane, deviated horizontally from the midsagittal reference plane in the three methods. In a three-dimensional facial analysis, the vertical and horizontal deviations of the landmarks from the horizontal and midsagittal reference planes could vary depending on the methods of establishing reference planes.

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

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

    2014-11-18

    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

  10. Anatomical basis for sciatic nerve block at the knee level / Bases anatmicas para el bloqueo anestsico del nervio isquitico al nivel de la rodilla / Bases anatmicas para o bloqueio anestsico do nervo isquitico no nvel do joelho

    Fabiano Timb, Barbosa; Tatiana Rosa Bezerra Wanderley, Barbosa; Rafael Martins da, Cunha; Amanda Karine Barros, Rodrigues; Fernando Wagner da Silva, Ramos; Clio Fernando de, Sousa-Rodrigues.

    2015-06-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: Recentemente a feitura de bloqueio do nervo isquitico tem sido revista devido ao potencial benfico para analgesia ps-operatria e satisfao dos pacientes aps o advento da ultrassonografia. O objetivo deste estudo foi descrever as relaes anatmicas do nervo isquiti [...] co na fossa popltea para determinar a distncia ideal em que a agulha deve ser posicionada para a feitura do bloqueio anestsico do nervo isquitico anterior a sua bifurcao em nervo tibial e fibular comum. MTODO: O trabalho foi feito por meio de disseco de fossa popltea de cadveres humanos, fixados em formol a 10%, provenientes do Laboratrio de Anatomia Humana dos departamentos de Morfologia da Universidade Federal de Alagoas e da Universidade de Cincias da Sade de Alagoas. Obteve-se acesso ao nervo isquitico. RESULTADOS: Foram analisadas 44 fossas poplteas. Observou-se a bifurcao do nervo isquitico em relao ao pice da fossa. Houve bifurcao em 67,96% abaixo do pice, 15,90% acima do pice, 11,36% prxima ao pice e 4,78% na regio gltea. CONCLUSES: A bifurcao do nervo isquitico em seus ramos ocorre em vrios nveis e a chance de se obter sucesso quando a agulha usada entre 5 e 7 cm acima da fossa popltea de 95,22%. Abstract in spanish JUSTIFICACIN Y OBJETIVOS: Recientemente la realizacin de bloqueo del nervio isquitico ha sido nuevamente analizada debido al potencial beneficioso para la analgesia postoperatoria y por la satisfaccin de los pacientes despus del advenimiento de la ecografa. El objetivo de este estudio fue des [...] cribir las relaciones anatmicas del nervio isquitico en la fosa popltea para determinar la distancia ideal en que la aguja debe ser posicionada para la realizacin del bloqueo anestsico del nervio isquitico anterior a su bifurcacin en el nervio tibial y fibular comn. MTODO: El trabajo se hizo por medio de la diseccin de la fosa popltea de cadveres humanos, empapados en formol al 10%, provenientes del Laboratorio de Anatoma Humana de los departamentos de Morfologa de la Universidad Federal de Alagoas y de la Universidad de Ciencias de la Salud de Alagoas. Se obtuvo el acceso al nervio isquitico. RESULTADOS: Fueron analizadas 44 fosas poplteas. Se observ la bifurcacin del nervio isquitico con relacin al pice de la fosa. Hubo una bifurcacin en un 67,96% por debajo del pice, un 15,90% por encima del pice, un 11,36% cercana al pice y un 4,78% en la regin gltea. CONCLUSIONES: La bifurcacin del nervio isquitico en sus ramas se da en varios niveles y la probabilidad de que se obtenga xito cuando la aguja se usa entre 5 y 7 cm por encima de la fosa popltea es de un 95,22%. Abstract in english BACKGROUND AND OBJECTIVES: Recently, administration of sciatic nerve block has been revised due to the potential benefit for postoperative analgesia and patient satisfaction after the advent of ultrasound. The aim of this study was to describe the anatomical relations of the sciatic nerve in the po [...] pliteal fossa to determine the optimal distance the needle must be positioned in order to realize the sciatic nerve block anterior to its bifurcation into the tibial and common fibular nerve. METHOD: The study was conducted by dissection of human cadavers' popliteal fossa, fixed in 10% formalin, from the Laboratory of Human Anatomy and Morphology Departments of the Universidade Federal de Alagoas and Universidade de Cincias da Sade de Alagoas. Access to the sciatic nerve was obtained. RESULTS: 44 popliteal fossa were analyzed. The bifurcation of the sciatic nerve in relation to the apex of the fossa was observed. There was bifurcation in: 67.96% below the apex, 15.90% above the apex, 11.36% near the apex, and 4.78% in the gluteal region. CONCLUSIONS: The sciatic nerve bifurcation to its branches occurs at various levels, and the chance to succeed when the needle is placed between 5 and 7 cm above the popliteal is 95.22%.

  11. Report of a rare anatomic variant

    De Brucker, Y; Ilsen, B; Muylaert, C; Goethals, L; Nieboer, K; Fares, A; Jager, T; de Mey, Jo

    2015-01-01

    We report the CT findings in a case of partial anomalous pulmonary venous return (PAPVR) from the left upper lobe in an adult. PAPVR is an anatomic variant in which one to three pulmonary veins drain into the right atrium or its tributaries, rather than into the left atrium. This results in a left...

  12. HPV Vaccine Effective at Multiple Anatomic Sites

    A new study from NCI researchers finds that the HPV vaccine protects young women from infection with high-risk HPV types at the three primary anatomic sites where persistent HPV infections can cause cancer. The multi-site protection also was observed at l

  13. Evolution of the Anatomical Theatre in Padova

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

    2014-01-01

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

  14. Handbook of anatomical models for radiation dosimetry

    Eckerman, Keith F

    2010-01-01

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

  15. Magnetic resonance angiography: infrequent anatomic variants

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

  16. Anatomical single bundle anterior cruciate ligament reconstruction

    Carmont, Michael R.; Scheffler, Sven; Spalding, Tim; Brown, Jeremy; Sutton, Paul M

    2011-01-01

    We present a review of the literature looking at the anatomy of the Anterior Cruciate Ligament, the biomechanical aspects of ACL reconstruction, review the outcomes of single and double bundle ACL reconstruction and present the current techniques for anatomic single bundle reconstruction.

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

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

    2008-04-15

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

  18. Functional Versus Anatomic Imaging of CAD: Lessons Learned from Recent Clinical Trials.

    Gewirtz, Henry

    2016-01-01

    Recent clinical trials directed at imaging of coronary artery disease (CAD) have demonstrated a paradigm shift away from endpoints related to detection of CAD in favor of those related to clinical outcomes. The objective of such trials has been to determine whether physiological metrics are superior to anatomical ones for guiding therapy and improving outcomes in patients with known or suspected CAD. The present review focuses on selected trials in this area in particular DEFER, FAME 1 and 2, a meta-analysis comparing FFR to anatomically guided treatment outcomes and COURAGE SPECT MPI sub study. The rationale for using physiological as opposed to anatomical endpoints to optimize patient management, in particular coronary revascularization decisions, is emphasized. The results of the FFR-based trials are concordant and indicate physiological metrics are superior to anatomical ones for guiding therapy and improving clinical outcomes in patients with known or suspected CAD. PMID:26699631

  19. Historical evolution of anatomical terminology from ancient to modern.

    Sakai, Tatsuo

    2007-06-01

    The historical development of anatomical terminology from the ancient to the modern can be divided into five stages. The initial stage is represented by the oldest extant anatomical treatises by Galen of Pergamon in the Roman Empire. The anatomical descriptions by Galen utilized only a limited number of anatomical terms, which were essentially colloquial words in the Greek of this period. In the second stage, Vesalius in the early 16th century described the anatomical structures in his Fabrica with the help of detailed magnificent illustrations. He coined substantially no anatomical terms, but devised a system that distinguished anatomical structures with ordinal numbers. The third stage of development in the late 16th century was marked by innovation of a large number of specific anatomical terms especially for the muscles, vessels and nerves. The main figures at this stage were Sylvius in Paris and Bauhin in Basel. In the fourth stage between Bauhin and the international anatomical terminology, many anatomical textbooks were written mainly in Latin in the 17th century, and in modern languages in the 18th and 19th centuries. Anatomical terms for the same structure were differently expressed by different authors. The last stage began at the end of the 19th century, when the first international anatomical terminology in Latin was published as Nomina anatomica. The anatomical terminology was revised repeatedly until the current Terminologia anatomica both in Latin and English. PMID:17585563

  20. Historic landmarks in radiation chemistry since early observations by Marie Sklodowska-Curie and Pierre Curie

    The origin of the radiation chemistry history is contemporary with the X-rays and uranic rays discoveries. The complexity of the phenomena induced by the radiation effects, which involve electrons, ions and free radicals and a specific spatial distribution of the energy deposit along the tracks, was progressively understood, particularly when pulse radiolysis and time-resolved detection permitted to observe the short-lived transient species and to explain the chemical or biochemical mechanism. This short review summarizes the most important landmarks of the concepts and their applications. (author)

  1. Reliability of bony landmarks for restoration of the joint line in revision knee arthroplasty.

    Servien, Elvire; Viskontas, Darius; Giuffr, Bruno M; Coolican, Myles R J; Parker, David A

    2008-03-01

    The aim of this study was to determine the reliability of bone landmarks for restoring the joint line in revision knee arthroplasty. The relationship of the femoral epicondyles, the tibial tubercle (TT) and the fibular head (FH) to the joint line was measured on 200 magnetic resonance imaging (MRI, 100 females, 100 males), including assessment on intraobserver and interobserver reliability. MRI scans demonstrating chondral lesions and osteoarthritis were excluded, as were patients with immature skeletons or a history of previous knee surgery. Sequences in sagittal, coronal and axial planes were used as well as cross-referencing with the same computer software. In order to account for size differences between patients, each bony landmark measurement was converted to a ratio relative to the femoral or/and tibial width. We found a transepicondylar axis equal to 3.11 degrees (+/-1.9). The average distance from the epicondyles to the joint line was respectively 23 mm on the lateral side and 28 mm on the medial side. However there was a variation of distance from the epicondyles of the joint line up to 11 mm and a significative difference was found between male and female. We determined the distances from the tip of the FH and from the TT to the joint line. The joint line-FH distance averaged 14 mm (range 4.1-22.13) with no gender difference. The joint line-TT distance was averaged 22 mm (range 10.61-32.09). We determined an epicondylar ratio (distance from the lateral epicondyle to the joint line related to the femoral width). We found this ratio averaged 28% with no gender difference (P = 0.09). There is a large variation of bony landmarks depending on the size of the individual. Considering this findings, the FH is not a reliable guide for the joint line in revision surgery. Previous studies have measured the absolute values from various landmarks to the joint line. This study provides a significant advantage, in that the level of the joint line can be determined for each individual by using a ratio to account for gender and size differences. PMID:18046537

  2. Performance Characterization of a Landmark Measurement System for ARRM Terrain Relative Navigation

    Shoemaker, Michael; Wright, Cinnamon; Liounis, Andrew; Getzandanner, Kenneth; Van Eepoel, John; Deweese, Keith

    2016-01-01

    This paper describes the landmark measurement system being developed for terrain relative navigation on NASAs Asteroid Redirect Robotic Mission (ARRM),and the results of a performance characterization study given realistic navigational and model errors. The system is called Retina, and is derived from the stereophotoclinometry methods widely used on other small-body missions. The system is simulated using synthetic imagery of the asteroid surface and discussion is given on various algorithmic design choices. Unlike other missions, ARRMs Retina is the first planned autonomous use of these methods during the close-proximity and descent phase of the mission.

  3. DESIGN OF 3D MODEL OF CUSTOMIZED ANATOMICALLY ADJUSTED IMPLANTS

    Miodrag Manić; Zoran Stamenković; Milorad Mitković; Miloš Stojković; Duncan E.T. Shephard

    2015-01-01

    Design and manufacturing of customized implants is a field that has been rapidly developing in recent years. This paper presents an originally developed method for designing a 3D model of customized anatomically adjusted implants. The method is based upon a CT scan of a bone fracture. A CT scan is used to generate a 3D bone model and a fracture model. Using these scans, an indicated location for placing the implant is recognized and the design of a 3D model of customized implants is made. Wit...

  4. Strong links between genomic and anatomical diversity in both mammalian olfactory chemosensory systems.

    Garrett, Eva C; Steiper, Michael E

    2014-05-22

    Mammalian olfaction comprises two chemosensory systems: the odorant-detecting main olfactory system (MOS) and the pheromone-detecting vomeronasal system (VNS). Mammals are diverse in their anatomical and genomic emphases on olfactory chemosensation, including the loss or reduction of these systems in some orders. Despite qualitative evidence linking the genomic evolution of the olfactory systems to specific functions and phenotypes, little work has quantitatively tested whether the genomic aspects of the mammalian olfactory chemosensory systems are correlated to anatomical diversity. We show that the genomic and anatomical variation in these systems is tightly linked in both the VNS and the MOS, though the signature of selection is different in each system. Specifically, the MOS appears to vary based on absolute organ and gene family size while the VNS appears to vary according to the relative proportion of functional genes and relative anatomical size and complexity. Furthermore, there is little evidence that these two systems are evolving in a linked fashion. The relationships between genomic and anatomical diversity strongly support a role for natural selection in shaping both the anatomical and genomic evolution of the olfactory chemosensory systems in mammals. PMID:24718758

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

    Li Dongmei

    2009-05-01

    Full Text Available Abstract Background Universally accepted landmark stages are necessary to highlight key events in plant reproductive development and to facilitate comparisons among species. Domestication and selection of tomato resulted in many varieties that differ in fruit shape and size. This diversity is useful to unravel underlying molecular and developmental mechanisms that control organ morphology and patterning. The tomato fruit shape gene SUN controls fruit elongation. The most dramatic effect of SUN on fruit shape occurs after pollination and fertilization although a detailed investigation into the timing of the fruit shape change as well as gene expression profiles during critical developmental stages has not been conducted. Results We provide a description of floral and fruit development in a red-fruited closely related wild relative of tomato, Solanum pimpinellifolium accession LA1589. We use established and propose new floral and fruit landmarks to present a framework for tomato developmental studies. In addition, gene expression profiles of three key stages in floral and fruit development are presented, namely floral buds 10 days before anthesis (floral landmark 7, anthesis-stage flowers (floral landmark 10 and fruit landmark 1, and 5 days post anthesis fruit (fruit landmark 3. To demonstrate the utility of the landmarks, we characterize the tomato shape gene SUN in fruit development. SUN controls fruit shape predominantly after fertilization and its effect reaches a maximum at 8 days post-anthesis coinciding with fruit landmark 4 representing the globular embryo stage of seed development. The expression profiles of the NILs that differ at sun show that only 34 genes were differentially expressed and most of them at a less than 2-fold difference. Conclusion The landmarks for flower and fruit development in tomato were outlined and integrated with the effect of SUN on fruit shape. Although we did not identify many genes differentially expressed in the NILs that differ at the sun locus, higher or lower transcript levels for many genes involved in phytohormone biosynthesis or signaling as well as organ identity and patterning of tomato fruit were found between developmental time points.

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

    Xiao, Han; Radovich, Cheryll; Welty, Nicholas; Hsu, Jason; Li, Dongmei; Meulia, Tea; van der Knaap, Esther

    2009-01-01

    Background Universally accepted landmark stages are necessary to highlight key events in plant reproductive development and to facilitate comparisons among species. Domestication and selection of tomato resulted in many varieties that differ in fruit shape and size. This diversity is useful to unravel underlying molecular and developmental mechanisms that control organ morphology and patterning. The tomato fruit shape gene SUN controls fruit elongation. The most dramatic effect of SUN on fruit shape occurs after pollination and fertilization although a detailed investigation into the timing of the fruit shape change as well as gene expression profiles during critical developmental stages has not been conducted. Results We provide a description of floral and fruit development in a red-fruited closely related wild relative of tomato, Solanum pimpinellifolium accession LA1589. We use established and propose new floral and fruit landmarks to present a framework for tomato developmental studies. In addition, gene expression profiles of three key stages in floral and fruit development are presented, namely floral buds 10 days before anthesis (floral landmark 7), anthesis-stage flowers (floral landmark 10 and fruit landmark 1), and 5 days post anthesis fruit (fruit landmark 3). To demonstrate the utility of the landmarks, we characterize the tomato shape gene SUN in fruit development. SUN controls fruit shape predominantly after fertilization and its effect reaches a maximum at 8 days post-anthesis coinciding with fruit landmark 4 representing the globular embryo stage of seed development. The expression profiles of the NILs that differ at sun show that only 34 genes were differentially expressed and most of them at a less than 2-fold difference. Conclusion The landmarks for flower and fruit development in tomato were outlined and integrated with the effect of SUN on fruit shape. Although we did not identify many genes differentially expressed in the NILs that differ at the sun locus, higher or lower transcript levels for many genes involved in phytohormone biosynthesis or signaling as well as organ identity and patterning of tomato fruit were found between developmental time points. PMID:19422692

  7. Anatomical variations in radiation induced jute mutants

    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)

  8. Anatomic distribution of pulmonary vascular compliance.

    Presson, R G; Audi, S H; Hanger, C C; Zenk, G M; Sidner, R A; Linehan, J H; Wagner, W W; Dawson, C A

    1998-01-01

    Previously, the pressure changes after arterial and venous occlusion have been used to characterize the longitudinal distribution of pulmonary vascular resistance with respect to vascular compliance using compartmental models. However, the compartments have not been defined anatomically. Using video microscopy of the subpleural microcirculation, we have measured the flow changes in approximately 40-micron arterioles and venules after venous, arterial, and double occlusion maneuvers. The quasi-steady flows through these vessels after venous occlusion permitted an estimation of the compliance in three anatomic segments: arteries > 40 microns, veins > 40 microns, and vessels < 40 microns in diameter. We found that approximately 65% of the total pulmonary vascular compliance was in vessels < 40 microns, presumably mostly capillaries. The transient portions of the pressure and flow data after venous, arterial, and double occlusion were consistent with most of the arterial compliance being upstream from most of the arterial resistance and most of the venous compliance being downstream from most of the venous resistance. PMID:9451650

  9. PolyAlign: A Versatile LC-MS Data Alignment Tool for Landmark-Selected and -Automated Use

    Vhmaa, Heidi; Koskinen, Ville R.; Hosia, Waltteri; Moulder, Robert; Nevalainen, Olli S.; Lahesmaa, Riitta; Aittokallio, Tero; Salmi, Jussi

    2011-01-01

    We present a versatile user-friendly software tool, PolyAlign, for the alignment of multiple LC-MS signal maps with the option of manual landmark setting or automated alignment. One of the spectral images is selected as a reference map, and after manually setting the landmarks, the program warps the images using either polynomial or Hermite transformation. The software provides an option for automated landmark finding. The software includes a very fast zoom-in function synchronized between the images, which facilitate detecting correspondences between the adjacent images. Such an interactive visual process enables the analyst to decide when the alignment is satisfactory and to correct known irregularities. We demonstrate that the software provides significant improvements in the alignment of LC-MALDI data, with 1015 landmark pairs, and it is also applicable to correcting electrospray LC-MS data. The results with practical data show substantial improvement in peak alignment compared to MZmine, which was among the best analysis packages in a recent assessment. The PolyAlign software is freely available and easily accessible as an integrated component of the popular MZmine software, and also as a simpler stand-alone Perl implementation to preview data and apply landmark directed polynomial transformation. PMID:22084688

  10. Altered Functional and Anatomical Connectivity in Schizophrenia

    Camchong, Jazmin; MacDonald, Angus W.; Bell, Christopher; Mueller, Bryon A.; Lim, Kelvin O.

    2009-01-01

    Background: Schizophrenia is characterized by a lack of integration between thought, emotion, and behavior. A disruption in the connectivity between brain processes may underlie this schism. Functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) were used to evaluate functional and anatomical brain connectivity in schizophrenia. Methods: In all, 29 chronic schizophrenia patients (11 females, age: mean = 41.3, SD = 9.28) and 29 controls (11 females, age: mean = 41.1, S...

  11. Simple landmark for preservation of the cochlea during maximum drilling of the petrous apex through the anterior transpetrosal approach

    The cochlea is one of the most important organs to preserve during skull base surgery. However, no definite landmark for the cochlea has been identified during maximum drilling of the petrous apex such as anterior transpetrosal approach. The relationship between the cochlea and the petrous portion of the internal carotid artery (ICA) was assessed with computed tomography (CT) in 70 petrous bones of 35 patients, 16 males and 19 females aged 12-85 years (mean 48.6 years). After accumulation of volume data with multidetector CT, axial bone window images of 1-mm thickness were obtained to identify the cochlea and the horizontal petrous portion of the ICA. The distance was measured between the extended line of the posteromedial side of the horizontal petrous portion of the ICA and the basal turn of the cochlea. If the cochlea was located posteromedial to the ICA, the distance was expressed as a positive number, but if anterolateral, as a negative number. The mean distance was 0.6 mm (range -4.9 to 3.9 mm) and had no significant correlation with sex or age. The cochlea varies in location compared with the horizontal petrous portion of the ICA. Measurement of the depth and distance between the extended line of the posteromedial side of the horizontal intrapetrous ICA and the cochlea before surgery will save time, increase safety, and maximize bone evacuation during drilling of the petrous apex. (author)

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

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

  13. Anatomical MRI with an atomic magnetometer

    Savukov, I

    2012-01-01

    Ultra-low field (ULF) MRI is a promising method for inexpensive medical imaging with various additional advantages over conventional instruments such as low weight, low power, portability, absence of artifacts from metals, and high contrast. Anatomical ULF MRI has been successfully implemented with SQUIDs, but SQUIDs have the drawback of cryogen requirement. Atomic magnetometers have sensitivity comparable to SQUIDs and can be in principle used for ULF MRI to replace SQUIDs. Unfortunately some problems exist due to the sensitivity of atomic magnetometers to magnetic field and gradients. At low frequency, noise is also substantial and a shielded room is needed for improving sensitivity. In this paper, we show that at 85 kHz, the atomic magnetometer can be used to obtain anatomical images. This is the first demonstration of any use of atomic magnetometers for anatomical MRI. The demonstrated resolution is 1.1x1.4 mm2 in about six minutes of acquisition with SNR of 10. Some applications of the method are discuss...

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

    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

  15. Anatomical description and clinical significance of unilateral triheaded sternocleidomastoid muscle

    Preeti Goswami

    2014-06-01

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

  16. Management of neovascular Age-related macular degeneration: A review on landmark randomized controlled trials

    Aniruddha Agarwal

    2016-01-01

    Full Text Available In the last decade, a number of prospective clinical trials with carefully designed study protocols have been conducted for the treatment of neovascular age.related macular degeneration (AMD. These landmark clinical trials such as ANCHOR and MARINA and, more recently, the Comparison of AMD Treatment Trials and VIEW studies have revolutionized the management of neovascular AMD. While AMD continues to remain a leading cause of severe visual loss worldwide, advances in pharmacotherapeutics have led to substantial improvements in the outcome of these patients. The introduction of anti.vascular endothelial growth factor agents has resulted in improvement of visual outcomes and has had a positive impact on the quality of life among elderly population. While the contemporary management of neovascular AMD has been successful in tremendously reducing the visual morbidity, the financial burden of therapy has increased exponentially. To overcome these challenges, newer pharmacologic agents are evaluated for their efficacy and safety in AMD. Ground.breaking advances in bench to bedside research have led to discovery of new pathways that appear to be viable targets for preventing visual loss in AMD. In this review, study designs and results of landmark clinical trials in AMD from the past decade have been summarized.

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

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

    2015-12-01

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

  18. Evaluation of facial nerve and its landmarks in adult temporal bones

    Saeid Soheilipour

    2010-06-01

    Full Text Available Introduction: The aim of this study was to identify variations of different segments of facial nerve in temporal bone. Materials and Methods: In this descriptive study that conducted on drilled bones in the temporal bone center of the Al-Zahra Hospital of Isfahan University of Medical Sciences, the landmarks of facial nerve in temporal bone were identified as separate variables and their distances from outer cortex of temporal bone and Henles spine and distances between different segments of nerve were recorded. Results: In the 50 temporal bones dissected, the distance between the tip of incus short process to the cortex was 14.21.96 mm, the distance between the facial recess from the facial nerve to the cortex was 14.52.58 mm, the distance between the stylomastoid foramen to the cortex was 20.62.49 mm, the distance between the lateral semicircular canal to the cortex was 15.92.31 mm and the distance between the sigmoid sinus dome to the cortex was 14.082.83 mm. The mean length of tympanic and mastoid segments (2nd and 3rd segments of facial nerve were 11.350.68 mm and 13.281.11mm, respectively. Conclusion: The mean lengths of segment of facial nerve and distant of landmarks from outer cortex of temporal bone are partially similar compared to those described in the western literature and text books, but different compared to eastern researches.

  19. Management of Neovascular Age-related Macular Degeneration: A Review on Landmark Randomized Controlled Trials.

    Agarwal, Aniruddha; Aggarwal, Kanika; Gupta, Vishali

    2016-01-01

    In the last decade, a number of prospective clinical trials with carefully designed study protocols have been conducted for the treatment of neovascular age-related macular degeneration (AMD). These landmark clinical trials such as ANCHOR and MARINA and, more recently, the Comparison of AMD Treatment Trials and VIEW studies have revolutionized the management of neovascular AMD. While AMD continues to remain a leading cause of severe visual loss worldwide, advances in pharmacotherapeutics have led to substantial improvements in the outcome of these patients. The introduction of anti-vascular endothelial growth factor agents has resulted in improvement of visual outcomes and has had a positive impact on the quality of life among elderly population. While the contemporary management of neovascular AMD has been successful in tremendously reducing the visual morbidity, the financial burden of therapy has increased exponentially. To overcome these challenges, newer pharmacologic agents are evaluated for their efficacy and safety in AMD. Ground-breaking advances in bench to bedside research have led to discovery of new pathways that appear to be viable targets for preventing visual loss in AMD. In this review, study designs and results of landmark clinical trials in AMD from the past decade have been summarized. PMID:26957836

  20. Anatomical relation between anterior ethmoidal sinus and lacrimal sac fossa on high resolution CT

    To evaluate the anatomical relation between anterior ethmoidal sinus and the lacrimal sac fossa, and thus help prevent complications during dacryocystorhinostomy. Fifty three people without previous history of trauma, surgery, or paranasal sinus disease were randomly selected, and the 106 lacrimal sac fossas of these subjects were evaluated by high resolution CT. A series of three 2-mm thick axial sections at least 2mm from the inferior orbital wall were obtained. The bony landmarks of the lacrimal sac fossa were established and the location of the most anterior ethmoid sinus was classified as one of three types. In type 1, no sinuses were anterior to the posterior lacrimal crest. While in type 2, sinuses extended anterior to this crest but remained behind the suture at the anterior edge of the lacrimal bone. In type 3, sinuses extended into the frontal process of the maxilla, anterior to the lacrimal bone suture. In addition, the category of both orbits of the same patient was compared. Among the 106 orbits examined, only seven (6.6%) were classified as type 1, with no ethmoid air cells postioned under the lacrimal sac fossa. Seventy six (71.7%) qualified as type 2, while the remaining 23 (21.7%) were type 3, demonstration anterior ethmoid air cells within the nasal process of the maxilla. The position of the air cells was symmetric in 41 of the 53 subjects (77.4%) and asymmetric in 12 (22.6%). In cases involving surgery of the lacrimal sac fossa, such as dacryocystorhinostomy, a knowledge of the consistent anatomic relationship between the anterior ethmoidal sinus and the lacrimal sac fossa is invaluable

  1. Anatomical versus Non-Anatomical Single Bundle Anterior Cruciate Ligament Reconstruction: A Cadaveric Study of Comparison of Knee Stability

    Lim, Hong-Chul; Yoon, Yong-Cheol; Wang, Joon-Ho; Bae, Ji-Hoon

    2012-01-01

    Background The purpose of this study was to compare the initial stability of anatomical and non-anatomical single bundle anterior cruciate ligament (ACL) reconstruction and to determine which would better restore intact knee kinematics. Our hypothesis was that the initial stability of anatomical single bundle ACL reconstruction would be superior to that of non-anatomical single bundle ACL reconstruction. Methods Anterior tibial translation (ATT) and internal rotation of the tibia were measure...

  2. Introducing International Journal of Anatomical Variations

    Tunali S

    2008-06-01

    Full Text Available Welcome to International Journal of Anatomical Variations (IJAV - an annual journal of anatomical variations and clinical anatomy case reports. After having a notable experience for eight years in NEUROANATOMY, we are pleased to introduce you IJAV. We are eventually announcing our new journal after three years of feasibility and background study period. We hope that IJAV will fill in the gap in anatomy journals’ bunch. IJAV is an annual, open access journal having electronic version only. Despite of unavailability of a budget for publishing IJAV, the evaluation of submissions and access to the full text articles is totally free of charge.Our vision for IJAV is to constitute an online compendium for anatomical variations in gross, radiological and surgical anatomy, neuroanatomy and case reports in clinical anatomy. We believe that cases have an important role in clinical anatomy education. In this aspect, we aim to serve as an open source of case reports. We hope that IJAV will be cited in most of the case reports related to clinical anatomy and anatomical variations in near future.In NEUROANATOMY, we encouraged the submission of case reports in the area of neuroanatomy. Whereas in IJAV, besides neuroanatomy, we will consider case reports in any area related to human anatomy. The scope of IJAV will encompass any anatomical variations in gross, radiological and surgical anatomy. Case reports in clinical anatomy are also welcome.All submitted articles will be peer-reviewed. No processing fee will be charged from authors. One of the most important features of IJAV will be speedy review and rapid publication. We strive to publish an accepted manuscript within three weeks of initial submission. Our young and dynamic Scientific Advisory Board will achieve this objective.A few remarks about our logo and page design: Prof. Dr. M. Mustafa ALDUR designed our logo, being inspired by a quadricuspid aortic valve case, reported by Francesco FORMICA et al. [Formica F, Sangalli F, Ferro O, Paolini G. A rare cause of severe aortic regurgitation: quadricuspid aortic valve. Interact. Cardiovasc. Thorac. Surg. 2004; 3: 672-674]. We appreciate their contribution to our journal. The typeface in our logo and index page is Papyrus. The irregular margins of this font symbolize the non-uniformity in anatomy. The background in the menu bar is parchment; with Papyrus typeface, they refer to the old medical books in the ancient Egypt.As we mentioned earlier, our aim is to constitute an online compendium for anatomical variations similar to the invaluable book written by Ronald A. BERGMAN, Adel K. AFIFI and Ryosuke MIYAUCHI [Bergman RA, Afifi AK, Miyauchi R. Compendium of human anatomical variation. Baltimore, Urban and Schwarzenberg. 1988]. To realize this vision, we need you to submit your case reports to IJAV and encourage your colleagues to do so. As we did in NEUROANATOMY, we hope to be indexed in international indexes beginning from our first issue.Last but not least, I would like to thank to Dr. M. Mustafa ALDUR for his superhuman efforts and everlasting support to IJAV. Moreover, I would like to voice my special gratitude to the members of Scientific Advisory Board, who have accepted to take the road with us in this arduous journey.We look forward to receiving your manuscripts.Yours sincerely,Selcuk TUNALI, MD, PhDEditor-in-Chief and Publisher, IJAV

  3. Polarised skylight and the landmark panorama provide night-active bull ants with compass information during route following.

    Reid, Samuel F; Narendra, Ajay; Hemmi, Jan M; Zeil, Jochen

    2011-02-01

    Navigating animals are known to use a number of celestial and terrestrial compass cues that allow them to determine and control their direction of travel. Which of the cues dominate appears to depend on their salience. Here we show that night-active bull ants attend to both the pattern of polarised skylight and the landmark panorama in their familiar habitat. When the two directional cues are in conflict, ants choose a compromise direction. However, landmark guidance appears to be the primary mechanism of navigation used by forager ants, with those cues in the direction of heading having the greatest influence on navigation. Different colonies respond to the removal of these cues to different degrees, depending on the directional information provided by the local landmark panorama. Interestingly, other parts of the surrounding panorama also influence foraging speed and accuracy, suggesting that they too play a role in navigation. PMID:21228195

  4. [Intraoperative Evaluation of Total Knee Arthroplasty: Anatomic and Kinematic Assessment with Trial Components].

    von Roth, P; Pfitzner, T; Fuchs, M; Perka, C

    2015-06-01

    The intraoperative use of trial components in total knee arthroplasty (TKA) is of paramount importance to prevent inadequate ligament balance and to achieve optimal position of the definitive components. This review demonstrates an 8-step algorithm to assess the anatomy of the femoral, tibial and patellar component as well as the kinematics of the tibiofemoral and patellofemoral joints. Trial components allow an easy assessment of the anatomic fit of the final implants. Upon the trials insertion, bone coverage and the component overhang should be evaluated. The femoral rotation should be assessed using the transepicondylar axis and for the tibial component rotation assessment, the tibial tuberosity would be the most reliable bony landmark. Addressing the patella, sizing and bone coverage should be thoroughly evaluated. In order to restore physiological kinematics the remnants of the meniscus rim can be used to determine the correct reconstruction of the joint line. A tight extension gap results in limited extension, whereas a tight or unbalanced flexion gap leads to "booking" or "spin-out" of the inlay. The POLO test (pull-out, lift- off) allows an easy assessment of the posterior cruciate ligament tension and the size of the flexion gap as well. To prevent postoperative dislocation and overstuffing, specific tests for correct patellar positioning and tracking support should be performed. The anatomy and kinematics of total knee arthroplasty have to be evaluated by trial components on a routine basis before inserting the final implants in order to identify implant positioning errors and inadequate ligament balance. PMID:26114563

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

    O'Connor, Maeve

    2012-01-31

    BACKGROUND: The parasacral approach to sciatic blockade is reported to be easy to learn and perform, with a high success rate and few complications. METHODS: Using magnetic resonance imaging, we evaluated the accuracy of a simulated needle (perpendicular to skin) in contacting the sacral plexus with this approach in 10 volunteers. Intrapelvic structures encountered during the simulated parasacral blocks were also recorded. RESULTS: The sacral plexus was contacted by the simulated needle in 4 of the 10 volunteers, and the sciatic nerve itself in one volunteer. The plexus was accurately located adjacent to a variety of visceral structures, including small bowel, blood vessels, and ovary. In the remaining five volunteers (in whom the plexus was not contacted on first needle pass), small bowel, rectum, blood vessels, seminal vesicles, and bony structures were encountered. Historically, when plexus is not encountered, readjustment of the needle insertion point more caudally has been recommended. We found that such an adjustment resulted in simulated perforation of intrapelvic organs or the perianal fossa. CONCLUSIONS: These findings question the reliability of the anatomical landmarks of the parasacral block and raise the possibility of frequent visceral puncture using this technique.

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

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

    2015-07-01

    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

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

    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 ...

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

    Mitsuhiro Isaka

    2014-05-01

    Full Text Available Canine medial patellar luxation (MPL is a very common orthopedic disease in small animals. Because the pathophysiology of this disease involves various pathways, the surgical techniques and results vary according to the veterinarian. Further, the landmark for block recession is not completely clear. We retrospectively evaluated 75 dogs (107 limbs with MPL in whom our landmark for block recession was used from July 2008 to May 2013. Information regarding the breed, age, sex, body weight, body condition score (BCS, lateral vs bilateral, pre-operative grading, surgical techniques, removal of implants, concomitance with anterior cruciate ligament (ACL rupture, re-luxation, re-operation, and rehabilitation was obtained from the medical records. The breeds were as follows: Chihuahua (n=23, Pomeranian (n=12, Yorkshire Terrier (n=9, and so on. The study group consisted of 33 males (castrated n=13 and 42 females (spayed n=21. The median age was 53.3±35.9 months (32-146 months; 13 cases were less than 12 months of age (17.3%. The pre-surgical BCSs were as follows: 1 (n=0, 2 (n=20, 3 (n=24, 4 (n=24 and 5 (n=7. The body weight was 4.51±3.48 kg (1.34-23.0 kg; 71 cases (94.7% were less than 10 kg. The MPL grades (each limb were G1 (n=1, G2 (n=18, G3 (n=78, and G4 (n=10; 32 cases were bilateral and 43 cases were unilateral (right n=27; left n=16. The specific surgical procedure (distal femoral osteotomy was 3 stifles in Chihuahuas. Concurrent with ACL rupture was 16/107 stifles (15.0% corrected with the over-the-top method or the extracapsular method in Papillons (5/6, Chihuahuas (5/23, and so on. The occurrences of re-luxation and re-operation were 3 out of 107 stifles (2.8% and 0%, respectively. In this retrospective study, we present a potentially good surgical landmark for block recession of MPL in dogs.

  9. Talocalcaneal luxation: an anatomic and clinical study

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

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

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

    2006-01-01

    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

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

    Soto-Prez-de-Celis, E

    2008-11-01

    In 1979, smallpox officially became the first disease ever to be eradicated by mankind. The global efforts to defeat this dreadful pandemic, however, started almost two centuries before. One of the most important, and sometimes forgotten, events in the fight against smallpox was the Royal Philanthropic Expedition of the Vaccine, commissioned by Charles IV of Spain to physicians Francisco Xavier Balmis y Berenguer and Jose Salvany in 1804. The aim of this expedition was to take the smallpox vaccine, discovered by Jenner, to Spain's territories in the Americas and in the Far East. After several years of vaccination in modern day Puerto Rico, Cuba, Venezuela, Ecuador, Peru, Bolivia, Chile, Mexico and the Philippines, the expedition returned to Europe. To this day, the Balmis and Salvany expedition remains a great example of international cooperation, and a landmark in the history of public health. PMID:19103818

  12. Global polity in adult education and UNESCO: landmarking, brokering, and framing policy

    Milana, Marcella

    2015-01-01

    Taking into account the complexity and multidimensionality of local-global interconnections, the author argues for the adoption of a global polity perspective in adult education, which is applied to study mobilization processes that occur through UNESCO. The findings point to three processes......, neither within nor outside, but across geo-political borders and professional interests: landmarking, by which a shared sense of a common past in adult education is created; brokering, which helps shape a common future direction in adult education; and framing, which is used to convert ideational...... landscapes into material government-led actions. Both the theoretical perspectives and the analytical insights presented here could be used in analogous studies in other areas of education or with a focus on different political actors....

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

    Robert Adair's lecture on Landmarks in Particle Physics at Brookhaven National Laboratory (BNL) is a commemoration of the 40th Anniversary of Brookhaven National Laboratory. Adair describes ten researches in elementary particle physics at Brookhaven that had a revolutionary impact on the understanding of elementary particles. Two of the discoveries were made in 1952 and 1956 at the Cosmotron, BNL's first proton accelerator. Four were made in 1962 and 1964 at the Alternating Gradient Synchrotron, the Cosmotron's replacement. Two other discoveries in 1954 and 1956 were theoretical, and strong focusing (1952) is the only technical discovery. One discovery (1958) happened in an old barrack. Four of the discoveries were awarded the Nobel prize in Physics. Adair believes that all of the discoveries are worthy of the Nobel prize. 14 figs

  14. Mobile Robot Positioning Based on ZigBee Wireless Sensor Networks and Vision Sensor

    Hongbo, Wang

    2010-01-01

    A positioning method of the mobile robot based on the ZigBee wireless sensor networks and vision sensor was presented. Using the ZigBee positioning system, the rough absolute positioning could be obtained. The positioning system and positioning theory of ZigBee were described. In order to obtain the accurate positioning, the ceiling lights were chosen as landmarks and the vision sensor was used to recognize the landmarks. The positioning method using the ceiling light landmarks was proposed. ...

  15. 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

    Choi, Sang Hyoun

    2007-08-15

    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 mm{sup 3}. 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 mm{sup 3}. 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.

  16. DESIGN OF 3D MODEL OF CUSTOMIZED ANATOMICALLY ADJUSTED IMPLANTS

    Miodrag Manić

    2015-12-01

    Full Text Available Design and manufacturing of customized implants is a field that has been rapidly developing in recent years. This paper presents an originally developed method for designing a 3D model of customized anatomically adjusted implants. The method is based upon a CT scan of a bone fracture. A CT scan is used to generate a 3D bone model and a fracture model. Using these scans, an indicated location for placing the implant is recognized and the design of a 3D model of customized implants is made. With this method it is possible to design volumetric implants used for replacing a part of the bone or a plate type for fixation of a bone part. The sides of the implants, this one lying on the bone, are fully aligned with the anatomical shape of the bone surface which neighbors the fracture. The given model is designed for implants production utilizing any method, and it is ideal for 3D printing of implants.

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

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

    2012-12-01

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

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

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

  19. Selection of Laryngoscope Blade Size by Using Facial Landmark for Pediatric Intubation

    S Soltani Mohammadi

    2006-08-01

    Full Text Available Background: The study evaluates whether facial landmarks can be used to estimate an appropriate laryngoscope blade length for oral endotracheal intubation in children. We tested the hypothesis that the laryngoscope blade measuring 10 mm or less distal or proximal to the angle of the mandible (when the flat portion of the blade follows the facial contour from the upper incisor teeth to the angle of the mandible will demonstrate greater success and ease of oral tracheal intubation. Methods: In an observational and prospective study, 60 children 8 years old or younger were undergoing direct laryngoscopy for oral endotracheal intubation in the operating room, were enrolled in the study. Intubation at first time considered successful and intubation with more than one attempt considered unsuccessful. Ease and success of oral tracheal intubation were compared with distance measurements from the angle of the mandible to the tip of the laryngoscope blade. Blade lengths considered too short (blade lengths >10 mm proximal to the angle of the mandible and too long extending longer than 10 mm past the angle of the mandible. Finding: Only 66% of the intubations using the shorter blade were performed on the first attempt as compared with 88.3% of the intubations using the recommended length or 81.2 % of the intubations using blades extending longer than 10 mm past the angle of the mandible (Chi-square, p=0.02. Fisher exact test showed that recommended blade was more successful than longer blade (p=0.048. Conclusion: Our findings suggest that facial landmarks seem to be excellent clinical criteria for laryngoscope blade length selection for pediatric intubations. When the blade is placed at the upper midline incisor teeth and the tip is located within 1 cm proximal or distal to the angle of the mandible, oral tracheal intubations can be accomplished on the first attempt.

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

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

    2012-01-01

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

  1. Effects of Spatial Ability, Gender Differences, and Pictorial Training on Children Using 2-D and 3-D Environments to Recall Landmark Locations from Memory

    Kopcha, Theodore J.; Otumfuor, Beryl A.; Wang, Lu

    2015-01-01

    This study examines the effects of spatial ability, gender differences, and pictorial training on fourth grade students' ability to recall landmark locations from memory. Ninety-six students used Google Earth over a 3-week period to locate landmarks (3-D) and mark their location on a 2-D topographical map. Analysis of covariance on posttest scores…

  2. Anatomic Optical Coherence Tomography of Upper Airways

    Chin Loy, Anthony; Jing, Joseph; Zhang, Jun; Wang, Yong; Elghobashi, Said; Chen, Zhongping; Wong, Brian J. F.

    The upper airway is a complex and intricate system responsible for respiration, phonation, and deglutition. Obstruction of the upper airways afflicts an estimated 12-18 million Americans. Pharyngeal size and shape are important factors in the pathogenesis of airway obstructions. In addition, nocturnal loss in pharyngeal muscular tone combined with high pharyngeal resistance can lead to collapse of the airway and periodic partial or complete upper airway obstruction. Anatomical optical coherence tomography (OCT) has the potential to provide high-speed three-dimensional tomographic images of the airway lumen without the use of ionizing radiation. In this chapter we describe the methods behind endoscopic OCT imaging and processing to generate full three dimensional anatomical models of the human airway which can be used in conjunction with numerical simulation methods to assess areas of airway obstruction. Combining this structural information with flow dynamic simulations, we can better estimate the site and causes of airway obstruction and better select and design surgery for patients with obstructive sleep apnea.

  3. Digital imaging applications in anatomic pathology.

    Leong, F Joel W-M; Leong, Anthony S-Y

    2003-03-01

    Digital imaging has progressed at a rapid rate and is likely to eventually replace chemical photography in most areas of professional and amateur digital image acquisition. In pathology, digital microscopy has implications beyond that of taking a photograph. The arguments for adopting this new medium are compelling, and given similar developments in other areas of pathology and radiologic imaging, acceptance of the digital medium should be viewed as a component of the technological evolution of the laboratory. A digital image may be stored, replicated, catalogued, employed for educational purposes, transmitted for further interpretation (telepathology), analyzed for salient features (medical vision/image analysis), or form part of a wider digital healthcare strategy. Despite advances in digital camera technology, good image acquisition still requires good microscope optics and the correct calibration of all system components, something which many neglect. The future of digital imaging in pathology is very promising and new applications in the fields of automated quantification and interpretation are likely to have profound long-term influence on the practice of anatomic pathology. This paper discusses the state of the art of digital imaging in anatomic pathology. PMID:12605090

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

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

  5. Asynchrony of the early maturation of white matter bundles in healthy infants: Quantitative landmarks revealed noninvasively by diffusion tensor imaging

    Normal cognitive development in infants follows a well-known temporal sequence, which is assumed to be correlated with the structural maturation of underlying functional networks. Postmortem studies and, more recently, structural MR imaging studies have described qualitatively the heterogeneous spatio-temporal progression of white matter myelination. However, in vivo quantification of the maturation phases of fiber bundles is still lacking. We used noninvasive diffusion tensor MR imaging and tractography in twenty-three 1-4-month-old healthy infants to quantify the early maturation of the main cerebral fascicles. A specific maturation model, based on the respective roles of different maturational processes on the diffusion phenomena, was designed to highlight asynchronous maturation across bundles by evaluating the time-course of mean diffusivity and anisotropy changes over the considered developmental period. Using an original approach, a progression of maturation in four relative stages was determined in each tract by estimating the maturation state and speed, from the diffusion indices over the infants group compared with an adults group on one hand, and in each tract compared with the average over bundles on the other hand. Results were coherent with, and extended previous findings in 8 of 11 bundles, showing the anterior limb of the internal capsule and cingulum as the most immature, followed by the optic radiations, arcuate and inferior longitudinal fascicles, then the spino-thalamic tract and fornix, and finally the cortico-spinal tract as the most mature bundle. Thus, this approach provides new quantitative landmarks for further noninvasive research on brain-behavior relationships during normal and abnormal development. (authors)

  6. Internuclear ophthalmoplegia: MR imaging and anatomic correlation

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

  7. [Antique anatomical collections for contemporary museums].

    Nesi, Gabriella; Santi, Raffaella

    2013-01-01

    Anatomy and Pathology Museum collections display a great biological value and offer unique samples for research purposes. Pathological specimens may be investigated by means of modern radiological and molecular biology techniques in order to provide the etiological background of disease, with relevance to present-day knowledge. Meanwhile, historical resources provide epidemiologic data regarding the socio-economic conditions of the resident populations, the more frequently encountered illnesses and dietary habits. These multidisciplinary approaches lead to more accurate diagnoses also allowing new strategies in cataloguing and musealization of anatomical specimens. Further, once these data are gathered, they may constitute the basis of riedited Museum catalogues feasible to be digitalized and displayed via the Web. PMID:25807710

  8. A "Second Life" for Gross Anatomy: Applications for Multiuser Virtual Environments in Teaching the Anatomical Sciences

    Richardson, April; Hazzard, Matthew; Challman, Sandra D.; Morgenstein, Aaron M.; Brueckner, Jennifer K.

    2011-01-01

    This article describes the emerging role of educational multiuser virtual environments, specifically Second Life[TM], in anatomical sciences education. Virtual worlds promote inquiry-based learning and conceptual understanding, potentially making them applicable for teaching and learning gross anatomy. A short introduction to Second Life as an…

  9. MRI anatomical variants of mammillary bodies.

    Tagliamonte, Micaela; Sestieri, Carlo; Romani, Gian Luca; Gallucci, Massimo; Caulo, Massimo

    2015-01-01

    The mammillary bodies (MBs) are classically defined as a pair of small round structures located on the undersurface of the diencephalon. The systematic observation of MR brain images of patients with neurological diseases, but also of healthy subjects enrolled in research protocols, reveals, however, a greater anatomical variability. The aim of the present study was to define the spectrum of such variability using spatial normalized 3D TFE T1-weighted MR images in a group of 151 healthy right-handed young subjects (78 females, age range 16-39 years). The MBs were identified on reformatted coronal and axial images and classified according to morphological, positional and numerical criteria. On the basis of coronal images, MBs were first divided into symmetrical (86.1 %) and asymmetrical (13.9 %), depending on their respective height. Symmetrical MBs were further subdivided into three variants [type A (2.7 %), B (76.2 %), C (7.3 %)] according to the depth of the intermammillary sulcus. Two morphological variants were defined on axial images, depending on whether the MBs were circular (63.6 %) or elliptic (36.4 %). This latter group was further divided in two subgroups, depending on whether the MBs were parallel (21.9 %) or convergent (14.6 %). Finally, two subjects (1.3 %) presented a supernumeral MB. The transverse size of the third ventricle was greater in the type A compared to the type B and C groups. Gender did not significantly affect the frequency of MBs variants, except for the three symmetrical subgroups in which the variants A and C were more frequent in males than in females. These findings suggest the presence of an anatomical variability of the MBs, in contrast to their classical definition. Therefore, atypical presentation of MBs can be the expression of this variability rather than a marker of neurological disorders (i.e. cerebral malformation, mesial temporal sclerosis, Wernicke-Korsakoff syndrome). PMID:24072163

  10. Foundations of Intonational Meaning: Anatomical and Physiological Factors.

    Gussenhoven, Carlos

    2016-04-01

    Like non-verbal communication, paralinguistic communication is rooted in anatomical and physiological factors. Paralinguistic form-meaning relations arise from the way these affect speech production, with some fine-tuning by the cultural and linguistic context. The effects have been classified as "biological codes," following the terminological lead of John Ohala's Frequency Code. Intonational morphemes, though arguably non-arbitrary in principle, are in fact heavily biased toward these paralinguistic meanings. Paralinguistic and linguistic meanings for four biological codes are illustrated. In addition to the Frequency Code, the Effort Code, and the Respiratory Code, the Sirenic Code is introduced here, which is based on the use of whispery phonation, widely seen as being responsible for the signaling and perception of feminine attractiveness and sometimes used to express interrogativity in language. In the context of the evolution of language, the relations between physiological conditions and the resulting paralinguistic and linguistic meanings will need to be clarified. PMID:27016315

  11. FDG-PET-based radiotherapy planning in lung cancer. Optimum breathing protocol and patient positioning - an intraindividual comparison

    FDG-PET and PET / CT is increasingly used for radiotherapy (RT) planning in non-small-cell lung carcinoma (NSCLC). The planning process is often based on separately-acquired FDG-PET / CT and planning CT. We compared intraindividual differences between PET acquired in diagnostic and radiotherapy treatment position coregistered with planning CTs acquired using different breathing protocols. Sixteen patients with NSCLC underwent two PET acquisitions (diagnostic position-D-PET, radiotherapy position-RT-PET) and three planning-CT acquisitions (expiration-EXP, inspiration-INS, mid-breathhold-MID) on the same day. All scans were rigidly coregistered resulting in six fused datasets: D-INS, D-EXP, D-MID, RT-INS, RT-EXP and RT-MID. Fusion accuracy was assessed by three readers at eight anatomical landmarks: lung apices, aortic arch, heart, spine, sternum, carina, diaphragm and tumor using an alignment score ranging from 1 (no alignment) to 5 (exact alignment). RT-PET showed better alignment with any CT than D-PET (p < 0.001). With regard to breathing, RT-MID showed the best mean alignment score (3.7 1.0) followed by RT-EXP (3.5 0.9) and RT-INS (3.0 0.8), all differences being significant (p < 0.001). Comparing the alignment scores with regard to anatomical landmarks, the largest deviations were found at diaphragm, heart and apices. Overall, there was a fair agreement (? = 0.48; p < 0.001) among the three readers. Significantly better fusion of PET and planning-CT can be reached with PET acquired in RT-position. The best intraindividual fusion results are obtained with the planning-CT performed during mid-breathhold. Our data justify the acquisition of a separate planning-PET in RT-treatment position if only a diagnostic PET-scan is available. (orig.)

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

    Trung-Hau Le Thua

    2014-12-01

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

  13. An Investigation of Anatomical Competence in Junior Medical Doctors

    Vorstenbosch, Marc A. T. M.; Kooloos, Jan G. M.; Bolhuis, Sanneke M.; Laan, Roland F. J. M.

    2016-01-01

    Because of a decrease of the time available for anatomy education, decisions need to be made to reduce the relevant content of the anatomy curriculum. Several expert consensus initiatives resulted in lists of structures, lacking analysis of anatomical competence. This study aims to explore the use of anatomical knowledge by medical doctors in an…

  14. Surgery without consent or miscommunication? A new look at a landmark legal case.

    Chervenak, Judith; McCullough, Laurence B; Chervenak, Frank A

    2015-05-01

    Schloendorff v Society of New York Hospital is regarded widely as a landmark in the history of informed consent because it is thought to have established individual self-determination as the legal basis of consent and respect for patient autonomy as the ethical basis of consent. For a century, it has been understood as a laparotomy done without consent when a pelvic mass was discovered unexpectedly in an anesthetized patient after an examination. We believe it was a case of surgeons failing to communicate properly with each other and their patient. To support this reinterpretation, we present evidence from the original medical and surgical records, letters of key participants in the case, and the trial court record. We also consider the case from the perspective of the modern culture of safety in gynecologic surgery. Contrary to what is commonly assumed, Ms Schloendorff lost her legal case, and her surgery might not have been performed at all had her clinicians known, understood, communicated, documented, and reaffirmed what the patient actually wanted. This new perspective on Schloendorff is important for gynecologic surgeons because it vividly documents the perils of implicit consent, delegating the obtaining of consent, and miscommunication among clinicians. The Schloendorff case underscores the constant need for continuous quality improvement to reduce medical errors and the risk of litigation by improving communication among surgeons. PMID:24995772

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

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

  16. RTS,S: Toward a first landmark on the Malaria Vaccine Technology Roadmap.

    Kaslow, David C; Biernaux, Sophie

    2015-12-22

    The Malaria Vaccine Technology Roadmap calls for a 2015 landmark goal of a first-generation malaria vaccine that has protective efficacy against severe disease and death, lasting longer than one year. This review focuses on product development efforts over the last five years of RTS,S, a pre-erythrocytic, recombinant subunit, adjuvanted, candidate malaria vaccine designed with this goal of a first-generation malaria vaccine in mind. RTS,S recently completed a successful pivotal Phase III safety, efficacy and immunogenicity study. Although vaccine efficacy was found to be modest, a substantial number of cases of clinical malaria were averted over a 3-4 years period, particularly in settings of significant disease burden. European regulators have subsequently adopted a positive opinion under the Article 58 procedure for an indication of active immunization of children aged 6 weeks up to 17 months against malaria caused by Plasmodium falciparum and against hepatitis B. Further evaluations of the benefit, risk, feasibility and cost-effectiveness of RTS,S are now anticipated through policy and financing reviews at the global and national levels. PMID:26431982

  17. The teleost anatomy ontology: anatomical representation for the genomics age.

    Dahdul, Wasila M; Lundberg, John G; Midford, Peter E; Balhoff, James P; Lapp, Hilmar; Vision, Todd J; Haendel, Melissa A; Westerfield, Monte; Mabee, Paula M

    2010-07-01

    The rich knowledge of morphological variation among organisms reported in the systematic literature has remained in free-text format, impractical for use in large-scale synthetic phylogenetic work. This noncomputable format has also precluded linkage to the large knowledgebase of genomic, genetic, developmental, and phenotype data in model organism databases. We have undertaken an effort to prototype a curated, ontology-based evolutionary morphology database that maps to these genetic databases (http://kb.phenoscape.org) to facilitate investigation into the mechanistic basis and evolution of phenotypic diversity. Among the first requirements in establishing this database was the development of a multispecies anatomy ontology with the goal of capturing anatomical data in a systematic and computable manner. An ontology is a formal representation of a set of concepts with defined relationships between those concepts. Multispecies anatomy ontologies in particular are an efficient way to represent the diversity of morphological structures in a clade of organisms, but they present challenges in their development relative to single-species anatomy ontologies. Here, we describe the Teleost Anatomy Ontology (TAO), a multispecies anatomy ontology for teleost fishes derived from the Zebrafish Anatomical Ontology (ZFA) for the purpose of annotating varying morphological features across species. To facilitate interoperability with other anatomy ontologies, TAO uses the Common Anatomy Reference Ontology as a template for its upper level nodes, and TAO and ZFA are synchronized, with zebrafish terms specified as subtypes of teleost terms. We found that the details of ontology architecture have ramifications for querying, and we present general challenges in developing a multispecies anatomy ontology, including refinement of definitions, taxon-specific relationships among terms, and representation of taxonomically variable developmental pathways. PMID:20547776

  18. Design and use of numerical anatomical atlases for radiotherapy

    The main objective of this thesis is to provide radio-oncology specialists with automatic tools for delineating organs at risk of a patient undergoing a radiotherapy treatment of cerebral or head and neck tumors. To achieve this goal, we use an anatomical atlas, i.e. a representative anatomy associated to a clinical image representing it. The registration of this atlas allows us to segment automatically the patient structures and to accelerate this process. Contributions in this method are presented on three axes. First, we want to obtain a registration method which is as independent as possible from the setting of its parameters. This setting, done by the clinician, indeed needs to be minimal while guaranteeing a robust result. We therefore propose registration methods allowing a better control of the obtained transformation, using rejection techniques of inadequate matching or locally affine transformations. The second axis is dedicated to the consideration of structures associated with the presence of the tumor. These structures, not present in the atlas, indeed lead to local errors in the atlas-based segmentation. We therefore propose methods to delineate these structures and take them into account in the registration. Finally, we present the construction of an anatomical atlas of the head and neck region and its evaluation on a database of patients. We show in this part the feasibility of the use of an atlas for this region, as well as a simple method to evaluate the registration methods used to build an atlas. All this research work has been implemented in a commercial software (Imago from DOSIsoft), allowing us to validate our results in clinical conditions. (author)

  19. "Where to?" remote memory for spatial relations and landmark identity in former taxi drivers with Alzheimer's disease and encephalitis.

    Rosenbaum, R Shayna; Gao, Fuqiang; Richards, Brian; Black, Sandra E; Moscovitch, Morris

    2005-03-01

    Recent research suggests that the hippocampus is not needed for the maintenance and recovery of extensively used environments learned long ago. Instead, a network of neocortical regions differentially supports memory for locationnavigation knowledge and visual appearance of well-known places. In this study, we present a patient, S. B., who was diagnosed with probable Alzheimer's disease long after retiring from his 40 years as a taxi driver in downtown Toronto, a place that he has visited rarely, if ever, in the last decade. His performance was compared to that of two other retired taxi drivers, L. R., who developed encephalitis after retirement, and I. L., who is without neurological illness, and a group of eight healthy control participants who were never taxi drivers but all of whom worked or lived in downtown Toronto until at least 10 years ago. Despite S. B.'s widespread atrophy, which has affected mainly his hippocampus and part of his occipitotemporal cortex, he performed at least as well as all other participants on remote memory tests of spatial location and mental navigation between well-known Toronto landmarks. Unlike the comparison populations, however, he was unable to discriminate between the appearances of landmarks that he had visited frequently in his many years as a taxi driver from unknown buildings. This profound deficit extended to famous world landmarks but not to famous faces and does not appear to be semantic in nature. These findings add further support to the claim that the hippocampus is not necessary for mental navigation of old environments and suggest that expertise is not sufficient to protect against landmark agnosia. PMID:15814004

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

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

    2014-01-01

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

  1. Anatomical challenges for transcatheter mitral valve intervention.

    DE Backer, Ole; Luk, Ngai H; Søndergaard, Lars

    2016-06-01

    Following the success of transcatheter aortic and pulmonary valve implantation, there is a large interest in transcatheter mitral valve interventions to treat severe mitral regurgitation (MR). With the exception for the MitraClipTM (Abbott, Abbott Park, IL, USA) edge-to-edge leaflet plication system, most of these transcatheter mitral valve interventions are still in their early clinical or preclinical development phase. Challenges arising from the complex anatomy of the mitral valve and the interplay of the mitral apparatus with the left ventricle (LV) have contributed to a more difficult development process and mixed clinical results with these novel technologies. This review aims to discuss the several anatomical aspects and challenges related to transcatheter mitral valve intervention - the relevant anatomy will be reviewed in relation to specific requirements for device design and procedural aspects of transcatheter mitral valve interventions. To date, experience with these novel therapeutic modalities are still limited and resolution of many challenges are pending. Future studies have to evaluate for whom the transcatheter approach is a feasible and preferred treatment and which patients will benefit from either transcatheter mitral valve repair or replacement. Nevertheless, technological developments are anticipated to drive the transcatheter approach forward into a clinically feasible alternative to surgery for selected patients with severe MR. PMID:27028333

  2. CBCT with specification of imaging dose and CNR by anatomical volume of interest

    Leary, Del, E-mail: dleary@dal.ca [Department of Physics and Atmospheric Science, Dalhousie University, 5820 University Avenue, Halifax, Nova Scotia B3H 1V7 (Canada); Robar, James L., E-mail: james.robar@cdha.nshealth.ca [Department of Radiation Oncology and Department of Physics and Atmospheric Science, Dalhousie University, 5820 University Avenue, Halifax, Nova Scotia B3H 1V7 (Canada)

    2014-01-15

    Purpose: A novel method has been developed for volume of interest (VOI) cone-beam CT (CBCT) imaging using a 2.35 MV/Carbon target linac imaging beam line combined with dynamic multileaf collimator sequences. Methods: The authors demonstrate the concept of acquisition of multiple, separate imaging volumes, where volumes can be either completely separated or nested, and are associated with predetermined imaging dose and contrast-to-noise ratio (CNR) characteristics. Two individual MLC sequences were established in the planning system (Eclipse, Varian Medical) to collimate the beam according to a defined inner VOI (e.g., containing a target volume under image guidance) and an outer VOI (e.g., including surrounding landmarks or organs-at-risk). MLC sequences were interleaved as a function of gantry angle to produce a reconstructed CBCT image with nested VOIs. By controlling the ratio of inner-to-outer ratio of MLC segments (and thus Monitor Units) during acquisition, the relative dose and CNR in the two volumes can be controlled. Inner-to-outer ratios of 2:1 to 6:1 were examined. Results: The concept was explored using an anatomical head phantom to assess image quality. A geometric phantom was used to quantify absolute dose and CNR values for the various sequences. The authors found that the dose in the outer VOI decreased by a functional relationship dependent on the inner-to-outer sequence ratio, while the CNR varied by the square root of dose, as expected. Conclusions: In this study the authors demonstrate flexibility in VOI CBCT by tailoring the imaging dose and CNR distribution in separate volumes within the patient anatomy. This would allow for high quality imaging of a target volume for alignment purposes, with simultaneous low dose imaging of the surrounding anatomy (e.g., for coregistration)

  3. Anatomical Study of The Sacum for Transsacral Block of Sacral Nerves

    D S Patil

    2012-08-01

    Full Text Available Inroduction: For transsacral block of sacral nerves in analgesia and anesthesia of the rectal, anal or urethral region the dorsal sacral foramina are used.To find solution of this by identifying additional anatomical landmarks and measurements of dorsal sacral foramina for transsacral nerve block. Materials & Method: Total 100 complete and undamaged adult, dry sacrums were measured with a vernier caliper (accurate to 0.1 mm. Dorsal sacral foramina of the sacrum were taken as points. Calculations and analyses were expressed as mean (SD, median and range using Open Office 3.2.0 spreadsheet version for Linux (Ubuntu 10.04. Results: The average distance between the two superolateral sacral crests was 60.61 (SD 6.71 mm. Distance between dorsal sacral foramina vertical right side 1st to 2nd 14.05 (SD 2.35mm, 2nd to 3rd 12.33 (SD 1.84mm, 3rd to 4th 11.26 (SD 2.35mm and vertical left side 1st to 2nd 14.18 (SD 2.61mm, 2nd to 3rd 12.18 (SD 1.95mm, 3rd to 4th 10.78 (SD2.42mm. Transverse distance between dorsal sacral foramina 1st to 1st 34.72 (SD 3.97mm, 2nd to 2nd 29.43 (SD 3.51mm, 3rd to 3rd 25.58 (SD 3.46mm, 4th to 4th 24.63 (SD 3.22mm. Conclusion: Measurements of dorsal sacral foramina can be used for transsacral nerve block. [Natl J of Med Res 2012; 2(4.000: 501-503

  4. Somaclonal variation and comparison to mutation induced by X-rays in rice (Oryza sativa L.) by using rice landmarker

    By using rice DNA clones of landmarker set 1, set 2 and new set, RFLP analysis was carried out in plants of cv. Tsugaruotome and cv. Mutsuhomare which were derived from 300 Gy of X-ray-irradiated seeds. In the three landmarker sets were consisted of 106 genomic DNA clones and 235 cDNA clones. Each cultivar has five plants which showed polymorphism. It is considered that the occurrence of some mutation of gene concerned with DNA repairing because certain plants showed polymorphism by many landmarkers as probes. Activity of retrotransposon such as Tos17 and alteration of methylation pattern were not observed on any plants derived from X-ray-irradiated seeds. On the other hand, in plants regenerated from cultured calli, it was found the movement of Tos17 to certain area of hot spot and alteration of methylation pattern. Furthermore, it has been reported that amplification of repeated DNA segment which was not observed in the mutation induced by X-rays. Thus, on plant breeding the somaclonal variation may be more useful than the mutation induced by X-rays

  5. Anatomically Realistic Three-Dimensional Meshes of the Pelvic Floor & Anal Canal for Finite Element Analysis

    Noakes, Kimberley F.; Bissett, Ian P; Pullan, Andrew J.; Cheng, Leo K.

    2008-01-01

    Three anatomically realistic meshes, suitable for finite element analysis, of the pelvic floor and anal canal regions have been developed to provide a framework with which to examine the mechanics, via finite element analysis of normal function within the pelvic floor. Two cadaver-based meshes were produced using the Visible Human Project (male and female) cryosection data sets, and a third mesh was produced based on MR image data from a live subject. The Visible Man (VM) me...

  6. Use of contextual inquiry to understand anatomic pathology workflow: Implications for digital pathology adoption

    Jonhan Ho; Orly Aridor; Anil V Parwani

    2012-01-01

    Background: For decades anatomic pathology (AP) workflow have been a highly manual process based on the use of an optical microscope and glass slides. Recent innovations in scanning and digitizing of entire glass slides are accelerating a move toward widespread adoption and implementation of a workflow based on digital slides and their supporting information management software. To support the design of digital pathology systems and ensure their adoption into pathology practice, the needs of ...

  7. [Landmarks of physiological development of the voice in childhood and adolescense (Part 1)].

    Fuchs, M

    2008-01-01

    The area of the functioning of the voice is a fundamental element of human communication apart from language, speaking, hearing and perceiving. Detailed knowledge of normal vocal development is a prerequisite for the diagnosis and therapy of vocal dysfunctions among children and adolescents by means of methods suitable for their age and their stages of development. In an overview, the landmarks of physiological development with normal value ranges relevant to practice are presented--from the newborn baby's first cry up to the age of young adults. The effects of various degrees of vocal activity on the part of children and adolescents on the parameters of vocal capacity and quality are taken into account, as well as the relationship between physical and vocal development. Furthermore, an overview of diagnostic methods suitable for this age group is given. Specialists for ENT and for Phoniatrics and Pediatric Audiology should be able to assess suitability for increased vocal activity and to care for vocal development during the vulnerable phase of the voice change. Manifold socio-cultural and pedagogical influences are already possible in early childhood and throughout the phase of the "voice in growth". They should be taken advantage of prophylactically--also with regard to the learning of physiological vocal behavior as a prerequisite for dealing with possible subsequent strain in vocally intensive professions. In the following second part of this publication, the fundamentals described here are applied to diagnostics and therapy of vocal dysfunctions in this age group by means of methods suitable for this stage of development. PMID:18080235

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

    Tiago Santos Telles

    2013-12-01

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

  9. SU-E-J-191: Automated Detection of Anatomic Changes in H'N Patients

    Purpose: To develop a novel statistics-based method for automated detection of anatomical changes using cone-beam CT data. A method was developed that can provide a reliable and automated early warning system that enables a “just-in-time” adaptation of the treatment plan. Methods: Anatomical changes were evaluated by comparing the original treatment planning CT with daily CBCT images taken prior treatment delivery. The external body contour was computed on a given CT slice and compared against the corresponding contour on the daily CBCT. In contrast to threshold-based techniques, a statistical approach was employed to evaluate the difference between the contours using a given confidence level. The detection tool used the two-sample Kolmogorov-Smirnov test, which is a non-parametric technique that compares two samples drawn from arbitrary probability distributions. 11 H'N patients were retrospectively selected from a clinical imaging database with a total of 186 CBCT images. Six patients in the database were confirmed to have anatomic changes during the course of radiotherapy. Five of the H'N patients did not have significant changes. The KS test was applied to the contour data using a sliding window analysis. The confidence level of 0.99 was used to moderate false detection. Results: The algorithm was able to correctly detect anatomical changes in 6 out of 6 patients with an excellent spatial accuracy as early as at the 14th elapsed day. The algorithm provided a consistent and accurate delineation of the detected changes. The output of the anatomical change tool is easy interpretable, and can be shown overlaid on a 3D rendering of the patient's anatomy. Conclusion: The detection method provides the basis for one of the key components of Adaptive Radiation Therapy. The method uses tools that are readily available in the clinic, including daily CBCT imaging, and image co-registration facilities

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

    Gamble, Jennifer; Lagravère, Manuel O.; Major, Paul W; Heo, Giseon

    2012-01-01

    Objective To describe a statistical method of three-dimensional landmark configuration data and apply it to an orthodontic data set comparing two types of rapid maxillary expansion (RME) treatments. Materials and Methods Landmark configurations obtained from cone beam CT scans were used to represent patients in two types (please describe what were two types) of RME groups and a control group over four time points. A method using tools from persistent homology and dimensionality reduction is p...

  11. Reviewing Landmark Nitrogen Cap and Trade Legislation in New Zealand's Taupo Catchment: What Have We Learned after 5+ Years?

    Baisden, W. T.; Hamilton, D. P.

    2014-12-01

    In 2007, the first cap and trade legislation for a catchment nitrogen (N) budget was enacted to protect water quality in New Zealand's iconic Lake Taupo. The clarity of the 616 km² N-limited oligotrophic lake was declining due to human-induced increases in N losses from the 3,487 km² catchment. Focus was placed on reversing increases in N inputs from agriculture, and to a lesser degree sewerage sources. The legislation imposed a cap equal to 20% reduction in the N inputs to the lake, and enabled trading. The landmark legislation could have failed during appeal. Sources of disagreement included the N budgeting model and grand-parenting method that benchmarked the N leaching of individual farms. The N leaching rates for key land uses were also a major battleground, with strong effects on the viability of trading and relative value of enterprises. Sufficient science was applied to resolve the substantive issues in the appeal by 2008. Crucially, the decision recognized that N inputs to the "N cascade" mattered more than leaching evidence including land-use legacies. Other catchment cap-and-trade schemes followed. Rotorua Lakes had already capped inputs and established a ~33% N input reduction target after acceptance of a trading scheme compatible with groundwater lag times. In the Upper Manawatu catchment, a cap-and-trade scheme now governs river N loads in a more typical farming region, with an innovative allocation scheme based on the natural capital of soils. Collectively, these schemes have succeeded in imposing a cap, and signaling the intention of reductions over time. I conclude with common themes in the successes, and examine the role of science in the success and ongoing implementation. Central to success has been the role of science in framing N budgets at farm and catchment scales. Long-term data has been invaluable, despite the need to correct biases. Cap-and-trade policies alter future science needs toward reducing uncertainty in overall budgets, the ability to measure success or failure in innovative source reductions at a management scale, and defining quantitative measures of aquatic health. Broadly, the schemes have enabled a culture of innovation, in farming and research. For example, recent evidence suggests it may be possible to flip the Rotorua Lakes into a P limitation regime through alum dosing.

  12. Anatomical prognostic factors after abdominal perineal resection

    The natural history of 153 patients with rectosigmoid adenocarcinoma treated by abdominal perineal resection was retrospectively studied with emphasis on survival, clinical signs and symptoms of recurrence distantly and in the pelvis. We analyzed diagnostic factors that might predict tumor stage preoperatively and anatomical factors of the tumor itself that might predict behaviour of the lesion. Age, sex, tumor size, and distance from the anal verge were not useful in predicting stage. Constriction of the lesion tended to occur with high stage, but was not a reliable predictor. The grade or differentiation of the biopsy (when noted) did not correlate with either the grade of the resected specimen or the stage. The highest grade of the resected specimen was quite predictive of subsequent outcome. Seventy-three percent of the poorly differentiated tumors were Stage C or D, though a lower grade specimen did not rule out high stage. The Astler-Coller stage was reliable in predicting the likelihood of survival, pelvic recurrence, and distant metastases. In Stage C patients, the number of positive lymph node metastases strongly affected prognosis: if only one node was positive, survival was intermediate between Stages B and C; if more than seven nodes were positive, no patient survived. Of the evaluable cases, 48% survived clinically free of disease five or more years; 43% failed (died of the rectosigmoid tumor); 22% developed pelvic recurrence (6% pelvis only, 16% pelvis plus distant metastases). Fifty-two percent of the patients failing had tumor in the pelvis. Seven of the 56 failures (13%) occurred at or after five years; six of these seven failed locally, usually with metastases. Patients under age 40 or over age 80 and the same results as the group in general. Sixteen percent of the entire group had major complications, 52% minor. There were eight postoperative deaths (5%); 18 patients (12%) required reoperation

  13. The peroneocuboid joint: morphogenesis and anatomical study.

    Guimer, V; Lafuente, A; Zambrana, L; Rodriguez-Niedenfhr, M; Saudo, J R; Vazquez, T

    2015-01-01

    The peroneocuboid joint, between the peroneus longus tendon and the cuboid bone, has not been anatomically well-defined and no embryological study has been published. Furthermore, the ossification of the os peroneum (a sesamoid inside the peroneus longus tendon) and its associated pathology has been considered to be generated by orthostatic and/or mechanical loads. A light microscopy analysis of serially sectioned human embryonic and fetal feet, the analysis of human adult feet by means of standard macroscopic dissection, X-ray and histological techniques have been carried out. The peroneus longus tendon was fully visible until its insertion in the 1st metatarsal bone already at embryonic stage 23 (56-57days). The peroneocuboid joint cavity appeared at the transition of the embryonic to the fetal period (8-9th week of gestation) and was independent of the proximal synovial sheath. The joint cavity extended from the level of the calcaneocuboid joint all the way to the insertion of the peroneus longus tendon in the 1st metatarsal bone. The frenular ligaments, fixing the peroneus longus tendon to the 5th metatarsal bone or the long calcaneocuboid ligament, developed in the embryonic period. The peroneus longus tendon presented a thickening in the area surrounding the cuboid bone as early as the fetal period. This thickening may be considered the precursor of the os peroneum and was similar in shape and in size relation to the tendon, to the os peroneum observed in adults. To the best of our knowledge, this is the first study to show that the os peroneum, articular facets of the peroneus longus tendon and cuboid bone, the peroneocuboid joint and the frenular ligaments appear during the embryonic/fetal development period and therefore they can not be generated exclusively by orthostatic and mechanical forces or pathological processes. PMID:25384452

  14. Connectivity-based segmentation of occipito-temporal face selective area

    Maria Bobes

    2011-11-01

    Full Text Available A wide swath of human occipito-temporal cortex is selectively activated by faces. Within this face-selective territory, two segments have has been singled out: the occipital face area (OFA and the fusiform face area (FFA. The boundaries between these two areas are fuzzy and difficult to establish with certainty. However they have different functional properties, so a reasonable hypothesis is that each area is connected to other parts of the brain with a unique pattern. Therefore, a better way to segment the face-selective territory is by clustering voxels according to their anatomical connections. Here, face selective territory was identified by functional magnetic resonance imaging (fMRI in 10 subjects. Active voxels were then used as seeding points in a diffusion tensor imaging (DTI probabilistic tractography analysis to ascertain connectivity patterns with 46 other cortical areas. The connections found between face selective voxels and other cortical regions were reproducible between individuals. These face selective voxels were clustered with the FSL procedure (Beherens et al., 2003, revealing distinct subregions within the face-selective occipito-temporal cortex. The clusters encompassing the centroids of OFA and FFA have boundaries that do not correspond with traditional segmentations based on anatomical landmarks.

  15. 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

    Jussara Rocha Ferreira

    2001-05-01

    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

  16. Automatic anatomically selective image enhancement in digital chest radiography

    The authors develop a technique for automatic anatomically selective enhancement of digital chest radiographs. Anatomically selective enhancement is motivated by the desire to simultaneously meet the different enhancement requirements of the lung field and the mediastinum. A recent peak detection algorithm and a set of rules are applied to the image histogram to determine automatically a gray-level threshold between the lung field and mediastinum. The gray-level threshold facilitates anatomically selective gray-scale modification and/or unsharp masking. Further, in an attempt to suppress possible white-band or black-band artifacts due to unsharp masking at sharp edges, local-contrast adaptivity is incorporated into anatomically selective unsharp masking by designing an anatomy-sensitive emphasis parameter which varies asymmetrically with positive and negative values of the local image contrast

  17. Individual variability in the anatomical distribution of nodes participating in rich club structural networks

    Ezequiel Gleichgerrcht

    2015-04-01

    Full Text Available With recent advances in computational analyses of structural neuroimaging, it is possible to comprehensively map neural connectivity, i.e., the brain connectome. The architectural organization of the connectome is believed to play an important role in several biological processes. Central to the conformation of the connectome are connectivity hubs, which are likely to be organized in accordance with the rich club phenomenon, as evidenced by graph theory analyses of neural architecture. It is yet unclear whether rich club connectivity hubs are consistently organized in the same anatomical framework across healthy adults. We constructed the brain connectome from 43 healthy adults, based on T1-weighted and diffusion tensor MRI data. Probabilistic fiber tractography was used to evaluate connectivity between each possible pair of cortical anatomical regions of interest. Connectivity hubs were identified in accordance with the rich club phenomenon applied to binarized matrices, and the variability in frequency of hub participation was assessed node-wise across all subjects. The anatomical location of nodes participating in rich club networks was fairly consistent across subjects. The most common locations for rich club nodes were identified in integrative areas, such as the cingulate and pericingulate regions, medial aspect of the occipital areas and precuneus; or else, they were found in important and specialized brain regions (such as the oribitofrontal cortex, caudate, fusiform gyrus and hippocampus. Marked anatomical consistency exists across healthy brains in terms of nodal participation and location of rich club networks. The consistency of connections between integrative areas and specialized brain regions highlights a fundamental connectivity pattern shared among healthy brains. We propose that approaching brain connectivity with this framework of anatomical consistencies may have clinical implications for early detection of individual variability.

  18. Ultrasound of the rotator cuff with MRI and anatomic correlation

    Magnetic resonance imaging and high-resolution ultrasound (US) are frequently used for the detection of rotator cuff tears. The diagnostic yield of US is influenced by several factors as technique, knowledge of the imaging characteristics of anatomic and pathologic findings and of pitfalls. The purpose of this article is to illustrates that the standardized high-resolution US examination of the shoulder covers the entire rotator cuff and correlates with MR imaging and anatomic sections

  19. Anatomic anterior cruciate ligament reconstruction using an individualized approach

    Carola F. van Eck; Fu, Freddie H

    2014-01-01

    Anterior cruciate ligament (ACL) reconstruction is one of the most commonly performed orthopaedic procedures. Recently, there has been a shift in interest towards reconstruction techniques that more closely restore the native anatomy of the ACL. This review paper discusses our approach to individualized anatomic ACL reconstruction, including the anatomy of the ACL, the physical exam, imaging modalities, the surgical technique for anatomic reconstruction including pre- and intraoperative consi...

  20. Anatomically Shaped Tooth and Periodontal Regeneration by Cell Homing

    Kim, K.; Lee, C. H.; Kim, B. K.; Mao, J.J.

    2010-01-01

    Tooth regeneration by cell delivery encounters translational hurdles. We hypothesized that anatomically correct teeth can regenerate in scaffolds without cell transplantation. Novel, anatomically shaped human molar scaffolds and rat incisor scaffolds were fabricated by 3D bioprinting from a hybrid of poly-ε-caprolactone and hydroxyapatite with 200-µm-diameter interconnecting microchannels. In each of 22 rats, an incisor scaffold was implanted orthotopically following mandibular incisor extrac...

  1. Identification of Salicornia population: Anatomical characterization and RAPD fingerprinting

    Milić Dubravka; Luković Jadranka; Đan Mihajla; Zorić Lana; Obreht Dragana; Veselić Sanja; Anačkov G.; Petanidou Theodora

    2011-01-01

    Anatomical and Random Amplified Polymorphic DNA (RAPD) analysis of two typical populations of Salicornia europaea from Montenegro and Greece (Lesvos), one typical population of S. ramosissima from Spain and one population that belongs to the Salicornia genus from Serbia, was undertaken to develop a new strategy for identifying Salicornia plants. Anatomical variability and differentiation were examined using Principal Component Analysis (PCA) and Multivariate Discriminant Function Analys...

  2. Enhancements of anatomical information in UMLS knowledge sources.

    Rosse, C.; Ben Said, M.; Eno, K.R.; Brinkley, J. F.

    1995-01-01

    Although anatomical terminology forms a part of biomedical structured vocabularies, available sources lack the requisite granularity, semantic types and relationships for comprehensively and consistently representing anatomical concepts in machine readable form. Thoracic angiology was selected as a proof of concept experiment for in depth representation of symbolic information in gross anatomy through the enhancement of semantic types, concepts and relationships in UMLS. Provided the represen...

  3. Ultrasound of the rotator cuff with MRI and anatomic correlation

    Rutten, Matthieu J.C.M. [Department of Radiology, Jeroen Bosch Hospital, Nieuwstraat 34, 5211 NL ' s-Hertogenbosch (Netherlands)]. E-mail: M.Rutten@JBZ.nl; Maresch, Bas J. [Department of Radiology, Hospital Gelderse Vallei, Willy Brandtlaan 10, 6710 HN Ede (Netherlands)]. E-mail: MareschB@zgv.nl; Jager, Gerrit J. [Department of Radiology, Jeroen Bosch Hospital, Nieuwstraat 34, 5211 NL ' s-Hertogenbosch (Netherlands)]. E-mail: G.Jager@JBZ.nl; Blickman, Johan G. [Department of Radiology, University Medical Center Nijmegen, Geert Grooteplein Zuid 18, 6500 HB Nijmegen (Netherlands)]. E-mail: J.Blickman@rad.umcn.nl; Holsbeeck, Marnix T. van [Department of Radiology, Henry Ford Hospital, 2799 W Grand Boulevard, Detroit, MI 48202 (United States)]. E-mail: vanholsbeeck@comcast.net

    2007-06-15

    Magnetic resonance imaging and high-resolution ultrasound (US) are frequently used for the detection of rotator cuff tears. The diagnostic yield of US is influenced by several factors as technique, knowledge of the imaging characteristics of anatomic and pathologic findings and of pitfalls. The purpose of this article is to illustrates that the standardized high-resolution US examination of the shoulder covers the entire rotator cuff and correlates with MR imaging and anatomic sections.

  4. Anatomic anterior cruciate ligament reconstruction using an individualized approach

    Carola F. van Eck

    2014-01-01

    Full Text Available Anterior cruciate ligament (ACL reconstruction is one of the most commonly performed orthopaedic procedures. Recently, there has been a shift in interest towards reconstruction techniques that more closely restore the native anatomy of the ACL. This review paper discusses our approach to individualized anatomic ACL reconstruction, including the anatomy of the ACL, the physical exam, imaging modalities, the surgical technique for anatomic reconstruction including pre- and intraoperative considerations and our postoperative rehabilitation protocol.

  5. Terminologia anatmica utilizada em oftalmologia Anatomical terminology in Ophthalmology

    Fernando Csar Abib; Fernando Orfice

    2005-01-01

    O objetivo deste artigo informar classe oftalmolgica a existncia da edio em lngua portuguesa da Terminologia Anatmica Internacional, editada pela Federation Committee on Anatomical Terminology (FCAT). No Brasil a Terminologia Anatmica Internacional traduzida pela Comisso de Terminologia Anatmica (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 t...

  6. Toledo School of Translators and their influence on anatomical terminology.

    Arráez-Aybar, Luis-Alfonso; Bueno-López, José-L; Raio, Nicolas

    2015-03-01

    Translation facilitates transmission of knowledge between cultures. The fundamental transfer of anatomic terminology from the Ancient Greek and Islamic Golden Age cultures, to medieval Latin Christendom took place in the so-called Toledo School of Translators in the 12th-13th centuries. Translations made in Toledo circulated widely across Europe. They were the foundation of scientific thinking that was born in the boards of first universities. In Toledo, Gerard of Cremona translated Avicenna's Canon of Medicine, the key work of Islamic Golden Age of medicine. Albertus Magnus, Mondino de Luzzi and Guy de Chauliac, the leading authors of anatomical Latin words in the Middle Ages, founded their books on Gerard's translations. The anatomical terms of the Canon retain auctoritas up to the Renaissance. Thus, terms coined by Gerard such as diaphragm, orbit, pupil or sagittal remain relevant in the current official anatomical terminology. The aim of the present paper is to bring new attention to the highly significant influence that the Toledo School of Translators had in anatomical terminology. For this, we shall review here the onomastic origins of a number of anatomical terms (additamentum; coracoid process; coxal; false ribs; femur; panniculus; spondylus; squamous sutures; thorax; xiphoid process, etc.) which are still used today. PMID:25667112

  7. Anatomical Findings in Patients with Infective Endocarditis Diagnosed at Autopsy

    Miguel Angel Serra Valds

    2013-12-01

    Full Text Available Background: Infective endocarditis continues to challenge modern medicine despite its rare occurrence in the general population. Its incidence depends on risk groups. Correlation of anatomical and pathological findings with clinical and epidemiological elements may explain the current features of this condition. Objective: to describe the anatomical features of patients with infective endocarditis diagnosed at autopsy. Methods: A descriptive study including cases of infective endocarditis diagnosed at autopsy between 1986 and 2008 was conducted in the Provincial Clinical-Surgical Hospital Celia Sanchez, Granma. The variables analyzed were: age, sex, previous anatomical lesions, location of vegetations, multi-organ embolic infarcts and embolic abscesses, complications, culture of lesions and direct causes of death. Results: frequency of infective endocarditis diagnosed at necropsy ranged annually from 0.4 to 1.5%. Native valve endocarditis without previous damage was the most frequent. The anatomical findings were more common in the left side of the heart. Right-sided nosocomial endocarditis accounted for almost a third of the deceased patients and risk factors were identified. Embolic lesions affecting various organs, systemic complications and direct causes of death showed acute infectious endocarditis. The most common pathogen was Staphylococcus aureus. Conclusion: knowing the anatomical findings may contribute to the understanding of the clinical and epidemiological aspects of this condition. Correlation between anatomical and clinical findings was low; therefore difficulties in establishing the diagnosis during life are inferred.

  8. The linguistic roots of Modern English anatomical terminology.

    Turmezei, Tom D

    2012-11-01

    Previous research focusing on Classical Latin and Greek roots has shown that understanding the etymology of English anatomical terms may be beneficial for students of human anatomy. However, not all anatomical terms are derived from Classical origins. This study aims to explore the linguistic roots of the Modern English terminology used in human gross anatomy. By reference to the Oxford English Dictionary, etymologies were determined for a lexicon of 798 Modern English gross anatomical terms from the 40(th) edition of Gray's Anatomy. Earliest traceable language of origin was determined for all 798 terms; language of acquisition was determined for 747 terms. Earliest traceable languages of origin were: Classical Latin (62%), Classical Greek (24%), Old English (7%), Post-Classical Latin (3%), and other (4%). Languages of acquisition were: Classical Latin (42%), Post-Classical Latin (29%), Old English (8%), Modern French (6%), Classical Greek (5%), Middle English (3%), and other (7%). While the roots of Modern English anatomical terminology mostly lie in Classical languages (accounting for the origin of 86% of terms), the anatomical lexicon of Modern English is actually much more diverse. Interesting and perhaps less familiar examples from these languages and the methods by which such terms have been created and absorbed are discussed. The author suggests that awareness of anatomical etymologies may enhance the enjoyment and understanding of human anatomy for students and teachers alike. PMID:22461143

  9. [Ten years after the latest revision International Anatomical Terminology].

    Kachlk, D; Bozdechov, I; Cech, P; Musil, V; Bca, V

    2008-01-01

    Ten years ago, the latest revision of the Latin anatomical nomenclature was approved and published as Terminologia Anatomica (International Anatomical Terminology), and is acknowledged by the organization uniting national anatomical societies--International Federation of Associations of Anatomists. The authors concentrate on new terms included in the nomenclature and on the linguistic changes of terminology. The most frequent errors done by medical specialists in the usage of the Latin anatomical terminology are emphasized and the situation of eponyms in contemporary anatomy is discussed in detail as well. The last version of the nomenclature makes its way very slowly in the professional community and it is necessary to refer to positive changes and advantages it has brought. The usage of this Latin anatomical nomenclature version is suggested by the International Federation to follow in theoretical and clinical fields of medicine. The authors of the article strongly recommend using the recent revision of the Latin anatomical nomenclature both in the oral and written forms, when educating and publishing. PMID:18630187

  10. ANATOMIC STUDY OF THE PROXIMAL THIRD OF THE FEMUR: FEMOROACETABULAR IMPACT AND THE CAM EFFECT

    Labronici, Pedro José; Alves, Sergio Delmonte; da Silva, Anselmo Fernandes; Giuberti, Gilberto Ribeiro; de Azevedo Neto, Justino Nóbrega; Mezzalira Penedo, Jorge Luiz

    2015-01-01

    To analyze anatomical variations of the proximal end of femur that could cause a femoroacetabular impact. Methods: 199 skeletically mature anatomical specimens of femurs were used. The femurs were measured in order to determine the anteversion angle of the femoral neck, neckshaft angle, sphericity of the femoral head at anteroposterior and superoinferior, angle between epiphysis and the anterior femoral neck, angle between epiphysis and the neck at lateral plane, anteroposterior distance at 5mm of the head and neck junction and anteroposterior distance of the neck base. Results: we found that the impact subgroup presented a significantly larger junction diameter of 5mm (p = 0.0001) and cam-head (%) (p= 0.0001), while base-cam (%) (p = 0.0001) showed a significantly smaller diameter than the subgroup without impact. It was identified that cam-head (%) ≤ 80 e base-cam (%) ≤ 73 were identified as the optimal impact points. Conclusion: our study showed that the effect cam, caused by anatomical variations of the proximal femoral end focused the head-neck junction and base of the neck-junction head-neck. These rates can be predictive factors of the impact.

  11. AnatomicalTerms.info: heading for an online solution to the anatomical synonym problem hurdles in data-reuse from the Terminologia Anatomica and the foundational model of anatomy and potentials for future development.

    Gobe, O Paul; Jansma, Danil; DeRuiter, Marco C

    2011-10-01

    The many synonyms for anatomical structures confuse medical students and complicate medical communication. Easily accessible translations would alleviate this problem. None of the presently available resources-Terminologia Anatomica (TA), digital terminologies such as the Foundational Model of Anatomy (FMA), and websites-are fully satisfactory to this aim. Internet technologies offer new possibilities to solve the problem. Several authors have called for an online TA. An online translation resource should be easily accessible, user-friendly, comprehensive, expandable, and its quality determinable. As first step towards this goal, we built a translation website that we named www.AnatomicalTerms.info, based on the database of the FMA. It translates between English, Latin, eponyms, and to a lesser extent other languages, and presently contains over 31,000 terms for 7,250 structures, covering 95% of TA. In addition, it automatically presents searches for images, documents and anatomical variations regarding the sought structure. Several terminological and conceptual issues were encountered in transferring data from TA and FMA into AnatomicalTerms.info, resultant from these resources' different set-ups (paper versus digital) and targets (machine versus human-user). To the best of our knowledge, AnatomicalTerms.info is unique in its combination of user-friendliness and comprehensiveness. As next step, wiki-like expandability will be added to enable open contribution of clinical synonyms and terms in different languages. Specific quality measures will be taken to strike a balance between open contribution and quality assurance. AnatomicalTerms.info's mechanism that "translates" terms to structures furthermore may enhance targeted searching by linking images, descriptions, and other anatomical resources to the structures. PMID:21678495

  12. Anatomical connectivity of the basal ganglia : methodological developments and application to motor disorders

    Kacem, Linda

    2011-01-01

    The recent advances in magnetic resonance imaging helped understanding brain anatomy and function. Today, MR imaging is a key tool for inferring imaging-based biomarkers for most neuropathologies. In this work, we focused on the anatomical connectivity of the basal ganglia which are involved in several cortico-subcortical loops and which dysfunction is the origin of motor disorders like Huntington and Parkinson diseases and Gilles de la Tourette syndrome. We developed several tools allowing t...

  13. Root Anatomical Characters of Herbal Drug Sophora (Fabaceae) Using Resin Embedding

    Sophia Wan-Pyo Hong

    2012-01-01

    Sophora root has been used for many years in traditional herbal medicine both as a pain reliever and also as a treatment for cancer and thus there is a need for rapid and accurate identification of individual species. Other workers have shown that stem xylem characteristics of Sophora are informative at intraspecific levels. As stem and root woods share similar properties, we report studies based on anatomical characteristics of root specimens from Sophora to develop an identification tool fo...

  14. Magnetic Resonance Imaging of the Newborn Brain: Automatic Segmentation of Brain Images into 50 Anatomical Regions

    Gousias, Ioannis S.; Hammers, Alexander; Counsell, Serena J.; Srinivasan, Latha; Rutherford, Mary A.; Heckemann, Rolf A; Hajnal, Jo V; RUECKERT, Daniel; Edwards, A. David

    2013-01-01

    We studied methods for the automatic segmentation of neonatal and developing brain images into 50 anatomical regions, utilizing a new set of manually segmented magnetic resonance (MR) images from 5 term-born and 15 preterm infants imaged at term corrected age called ALBERTs. Two methods were compared: individual registrations with label propagation and fusion; and template based registration with propagation of a maximum probability neonatal ALBERT (MPNA). In both cases we evaluated the perfo...

  15. Gray Matter Alterations in Obsessive–Compulsive Disorder: An Anatomic Likelihood Estimation Meta-Analysis

    Rotge, Jean-Yves; Langbour, Nicolas; Guehl, Dominique; Bioulac, Bernard; Jaafari, Nematollah; Allard, Michele; Aouizerate, Bruno; Burbaud, Pierre

    2009-01-01

    Many voxel-based morphometry (VBM) studies have found abnormalities in gray matter density (GMD) in obsessive–compulsive disorder (OCD). Here, we performed a quantitative meta-analysis of VBM studies contrasting OCD patients with healthy controls (HC). A literature search identified 10 articles that included 343 OCD patients and 318 HC. Anatomic likelihood estimation meta-analyses were performed to assess GMD changes in OCD patients relative to HC. GMD was smaller in parieto-frontal cortical ...

  16. The Oldest Anatomically Modern Humans from Far Southeast Europe: Direct Dating, Culture and Behavior

    Prat, Sandrine; Péan, Stéphane C.; Crépin, Laurent; Drucker, Dorothée G.; Puaud, Simon J.; Valladas, Hélène; Lázničková-Galetová, Martina; van der Plicht, Johannes; Yanevich, Alexander

    2011-01-01

    Background Anatomically Modern Humans (AMHs) are known to have spread across Europe during the period coinciding with the Middle to Upper Paleolithic transition. Whereas their dispersal into Western Europe is relatively well established, evidence of an early settlement of Eastern Europe by modern humans are comparatively scarce. Methodology/Principal Finding Based on a multidisciplinary approach for the study of human and faunal remains, we describe here the oldest AMH remains from the extrem...

  17. Estimating the age of Calliphora vicina eggs (Diptera: Calliphoridae): determination of embryonic morphological landmarks and preservation of egg samples.

    Martín-Vega, Daniel; Hall, Martin J R

    2016-05-01

    Blow fly eggs may sometimes be the only entomological evidence recovered in a forensic case, especially in cooler weather when hatching might take several days: hence, a method for estimating their age is greatly needed. However, developmental data on blow fly eggs are mainly limited to records of the time to larval hatching. The current paper describes the morphological changes occurring during embryogenesis of the blow fly Calliphora vicina Robineau-Desvoidy and their timing in relation to temperature, in order to determine those characters which can be used for simple egg age estimation using light microscopy. At 7.3 and 25 °C, 15 easily visualised morphological landmarks were determined in C. vicina living embryos, allowing for their age estimation with a resolution of 10-20 % of total egg developmental time. The observed age intervals were compared to the embryonic stages described for the fruit fly Drosophila melanogaster Meigen, which are used as reference data in multiple developmental studies. Moreover, current guidelines for preservation of egg samples, which recommend the placement of living eggs directly into 80 % ethanol, were tested against the hot water killing (HWK) method prior to preservation in 80 % ethanol, recommended for larval and pupal specimens. Direct placement of eggs into 80 % ethanol caused marked decomposition of samples, and no morphological landmarks were discernible. On the other hand, HWK fixation prior to preservation in 80 % ethanol enabled visualisation of 11 of the 15 age-specific morphological landmarks that were discernible in living embryos. Therefore, HWK fixation prior to preservation in 80 % ethanol is recommended for egg samples, thus unifying the protocols for collecting entomological evidence. PMID:26753872

  18. Heart region segmentation from low-dose CT scans: an anatomy based approach

    Reeves, Anthony P.; Biancardi, Alberto M.; Yankelevitz, David F.; Cham, Matthew D.; Henschke, Claudia I.

    2012-02-01

    Cardiovascular disease is a leading cause of death in developed countries. The concurrent detection of heart diseases during low-dose whole-lung CT scans (LDCT), typically performed as part of a screening protocol, hinges on the accurate quantification of coronary calcification. The creation of fully automated methods is ideal as complete manual evaluation is imprecise, operator dependent, time consuming and thus costly. The technical challenges posed by LDCT scans in this context are mainly twofold. First, there is a high level image noise arising from the low radiation dose technique. Additionally, there is a variable amount of cardiac motion blurring due to the lack of electrocardiographic gating and the fact that heart rates differ between human subjects. As a consequence, the reliable segmentation of the heart, the first stage toward the implementation of morphologic heart abnormality detection, is also quite challenging. An automated computer method based on a sequential labeling of major organs and determination of anatomical landmarks has been evaluated on a public database of LDCT images. The novel algorithm builds from a robust segmentation of the bones and airways and embodies a stepwise refinement starting at the top of the lungs where image noise is at its lowest and where the carina provides a good calibration landmark. The segmentation is completed at the inferior wall of the heart where extensive image noise is accommodated. This method is based on the geometry of human anatomy and does not involve training through manual markings. Using visual inspection by an expert reader as a gold standard, the algorithm achieved successful heart and major vessel segmentation in 42 of 45 low-dose CT images. In the 3 remaining cases, the cardiac base was over segmented due to incorrect hemidiaphragm localization.

  19. Kinematic Analysis of a Six-Degrees-of-Freedom Model Based on ISB Recommendation: A Repeatability Analysis and Comparison with Conventional Gait Model

    Żuk, Magdalena; Pezowicz, Celina

    2015-01-01

    Objective. The purpose of the present work was to assess the validity of a six-degrees-of-freedom gait analysis model based on the ISB recommendation on definitions of joint coordinate systems (ISB 6DOF) through a quantitative comparison with the Helen Hays model (HH) and repeatability assessment. Methods. Four healthy subjects were analysed with both marker sets: an HH marker set and four marker clusters in ISB 6DOF. A navigated pointer was used to indicate the anatomical landmark position in the cluster reference system according to the ISB recommendation. Three gait cycles were selected from the data collected simultaneously for the two marker sets. Results. Two protocols showed good intertrial repeatability, which apart from pelvic rotation did not exceed 2°. The greatest differences between protocols were observed in the transverse plane as well as for knee angles. Knee internal/external rotation revealed the lowest subject-to-subject and interprotocol repeatability and inconsistent patterns for both protocols. Knee range of movement in transverse plane was overestimated for the HH set (the mean is 34°), which could indicate the cross-talk effect. Conclusions. The ISB 6DOF anatomically based protocol enabled full 3D kinematic description of joints according to the current standard with clinically acceptable intertrial repeatability and minimal equipment requirements.

  20. Ontology-based image navigation: exploring 3.0-T MR neurography of the brachial plexus using AIM and RadLex.

    Wang, Kenneth C; Salunkhe, Aditya R; Morrison, James J; Lee, Pearlene P; Mejino, José L V; Detwiler, Landon T; Brinkley, James F; Siegel, Eliot L; Rubin, Daniel L; Carrino, John A

    2015-01-01

    Disorders of the peripheral nervous system have traditionally been evaluated using clinical history, physical examination, and electrodiagnostic testing. In selected cases, imaging modalities such as magnetic resonance (MR) neurography may help further localize or characterize abnormalities associated with peripheral neuropathies, and the clinical importance of such techniques is increasing. However, MR image interpretation with respect to peripheral nerve anatomy and disease often presents a diagnostic challenge because the relevant knowledge base remains relatively specialized. Using the radiology knowledge resource RadLex®, a series of RadLex queries, the Annotation and Image Markup standard for image annotation, and a Web services-based software architecture, the authors developed an application that allows ontology-assisted image navigation. The application provides an image browsing interface, allowing users to visually inspect the imaging appearance of anatomic structures. By interacting directly with the images, users can access additional structure-related information that is derived from RadLex (eg, muscle innervation, muscle attachment sites). These data also serve as conceptual links to navigate from one portion of the imaging atlas to another. With 3.0-T MR neurography of the brachial plexus as the initial area of interest, the resulting application provides support to radiologists in the image interpretation process by allowing efficient exploration of the MR imaging appearance of relevant nerve segments, muscles, bone structures, vascular landmarks, anatomic spaces, and entrapment sites, and the investigation of neuromuscular relationships. PMID:25590394