Minimally invasive facial rejuvenation endolaser mid-face lift.

Science.gov (United States)

Badin, A Z; Casagrande, C; Roberts, T; Saltz, R; Moraes, L M; Santiago, M; Chiaratti, M G

2001-01-01

Endolaser mid-face lift was performed on patients in a multi-center study over a 36-month period (Feb. 1998 to Feb. 2001). It permits significant facial rejuvenation through small incisions. This technique achieves aesthetic results and wider rejuvenation while being less traumatic and creating minimal morbidity. Combined with other procedures, it rejuvenates the face by three strategic methods: soft tissue suspension, reversal of photo aging, and correction of the depletion of volume. To achieve this triple result, the mid-face lift is performed by endoscopic approach, and in every case is combined with the endoscopic lift of the frontal area. Laser resurfacing was used to reverse skin photo damage. The Ultrapulse CO2 laser and/or the Ultrafine Erbium YAG(Coherent, Inc, Palo Alto, CA) were used. The third combined procedure was the introduction of fat graft to compensate the atrophy/ptosis of fat and the depletion of bone mass (other filling materials besides fat may be used, depending on the preference of the surgeon). Our method of fixation using the Casagrande Needle (an evolution of Reverdin Needle) makes the mechanical purchase on the tissues to be suspended much easier, permitting the intra-oral and/or infra-orbital incisions to be eliminated. The present study of the technical evolution of the endolaser mid-face lift method allows us to conclude that a very satisfactory outcome has been reached, offering patients a minimally invasive procedure, which can be performed under local anesthesia, with low morbidity, imperceptible incisions, and an excellent long-term result.

Filling the Midface: Injectables.

Science.gov (United States)

Winslow, Catherine

2016-10-01

Volumizing the face has become commonplace on the facial aesthetic scene, with a rapid explosion of popularity in the field of nonsurgical rejuvenation. Three-dimensional enhancement of the midface with fillers provides the surgeon with a minimal downtime opportunity to treat early aging or reverse nonsurgical volume loss. With new products come advancements in techniques and the understanding of reversal of the effects of aging. While providing minimal downtime and risk, complications can occur and the physician must be able to recognize and treat these issues. It is crucial for the injector to understand and process these factors to ensure patient satisfaction and safety. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

[Midface alterations in childhood as pathogenesis of obstructive sleep apnea syndrome].

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Rangel Chávez, José de Jesús; Espinosa Martínez, Cynthia; Medina Serpa, Aldo Uzziel

The onset of nasal breathing sets a genetically determined impulse to aerate the face cavities or paranasal sinuses, which in turn initiate its growth creating the useful trafficable space for air during the development of the midface. Considering the evidence that the upper airway obstruction has a primary role in the pathogenesis of respiratory sleep disorders, any condition that causes a permanent difficulty to the nasal airflow during breathing will cause hypo-development of the required amplitude in this airway, reducing the growth stimulation of the sinus cavities and altering the development of the midface as a whole. Copyright © 2016 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

Current aspects in reconstructive surgery for nasal cavity and paranasal sinus cancer

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Shtin, V. I.; Novikov, V. A.; Gjunter, V. E.; Choinzonov, E. L.; Ryabova, A. I.; Sirkashev, V. A.; Surkova, P. V.; Vasilev, R. V.; Menkova, E. N.

2017-09-01

Tumors of the nasal cavity and paranasal sinuses present a challenge to treat them. A combination of surgery and radiation therapy can improve treatment outcomes in 49-56% [1, 2] of the patients with locally advanced nasal cavity and paranasal sinus cancer. The midface reconstruction poses a formidable challenge to the reconstructive surgeon due to the region's complex skeletal and soft-tissue anatomy. The rehabilitation program including the reconstruction of the resected orbital walls using the porous and mesh implants from titanium nickelid (TiNi) was developed at the Cancer Research institute jointly with the Research Institute of Medical Materials. The technique was proven effective, allowing the natural position of the eye and visual function to be preserved in 90% [1-3] of the patients. A long period of reparative processes and risk of developing inflammation in the implant area, as well as the need to decrease length of surgery, contributed to the development of a novel approach to repairing the midface bone structures using the implant based on the microporous wire and TiNi mesh. Eighteen patients with nasal cavity and paranasal sinus cancer were treated using the combined thin implants. The novel technique allowed the time of the implant installation to be reduced to 5-10 min. The structure of the implant contributed to prevention of inflammatory processes in 97% [1, 2] of cases. Thus, the natural position of the eyeball and visual function were preserved in 100% [1, 3, 4] of patients. The use of the TiNi implants in reconstructive surgery for patients with nasal cavity and paranasal sinus cancer led to reduced time of surgery and rehabilitation, increased level of social adaptation of patients and improved cosmetic and functional results.

Family-centred care during midface advancement with a rigid external device: what do families need?

Science.gov (United States)

Bredero-Boelhouwer, H; Joosten, K F M; van Veen-van der Hoek, M; Mathijssen, I M J

2013-08-01

Midface advancement with distraction osteogenesis using the rigid external device (RED) is an effective but invasive treatment to correct the hypoplastic midface. This study draws up an inventory of the stressors, needs and coping strategies of families during this treatment, to determine the best conditions for family-centred care. Data were collected by reviewing the patients' files and administering semi-structured interviews. The data were analysed using the software program Atlas.ti and were re-analysed by an independent researcher. Parents and patients were interviewed separately. Fourteen families participated. Four patients had an absolute indication for surgery. All families were eager to have the patient's facial appearance improved. Nevertheless, despite psychological counselling, they experienced stress when confronted with the changed facial appearance. Another stressor was weight loss. Six patients were in a state of acute malnutrition and needed supplementary feeding. We conclude that the best conditions for family-centred care should be aligned to the different phases of treatment. Leading up to surgery it is important to screen families' expectations regarding aesthetic, functional and social outcomes and to assess their capacity to cope with the long treatment and effects of changed facial appearance. Peer contact and psychosocial training to increase self-esteem are tools to enhance co-operation and satisfaction. During the distraction and stabilisation phase, we advise the monitoring of nutritional intake and weight. During all phases of treatment easy accessibility to the team is recommended. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

A 15-year review of midface reconstruction after total and subtotal maxillectomy: part I. Algorithm and outcomes.

Science.gov (United States)

Cordeiro, Peter G; Chen, Constance M

2012-01-01

Reconstruction of complex midfacial defects is best approached with a clear algorithm. The goals of reconstruction are functional and aesthetic. Over a 15-year period (1992 to 2006), a single surgeon (P.G.C.) performed 100 flaps to reconstruct the following midfacial defects: type I, limited maxillectomy (n = 20); type IIA, subtotal maxillectomy with resection of less than 50 percent of the palate (n = 8); type IIB, subtotal maxillectomy with resection of greater than 50 percent of the palate (n = 8); type IIIA, total maxillectomy with preservation of the orbital contents (n = 22); type IIIB, total maxillectomy with orbital exenteration (n = 23); and type IV, orbitomaxillectomy (n = 19). Free flaps were used in 94 cases (94 percent), and pedicled flaps were used in six (6 percent). One hundred flaps were performed in 96 patients (69 males, 72 percent; 27 females, 28 percent); four patients underwent a second flap reconstruction due to recurrent disease (n = 4, 4 percent). Average patient age was 49.2 years (range, 13 to 81 years). Free-flap survival was 100 percent, with one partial flap loss (1 percent). Five patients suffered systemic complications (5.2 percent), and four died within 30 days of hospitalization (4.2 percent). Over 50 percent of patients returned to normal diet and speech. Almost 60 percent were judged to have an excellent aesthetic result. Free-tissue transfer offers the most effective and reliable form of reconstruction for complex maxillectomy defects. Rectus abdominis and radial forearm free flaps in combination with immediate bone grafting or as osteocutaneous flaps consistently provide the best functional and aesthetic results. Therapeutic, IV.

Maxillary distraction osteogenesis in cleft lip and palate cases with midface hypoplasia using rigid external distractor: an alternative technique.

Science.gov (United States)

Dua, Gaurav; Navin Kumar, Andrews; Roy, Indranil Deb; Roy, Supriyo Kumar

2014-05-01

Patients with operated cleft lip and palate present with a problem of midface hypoplasia, and such patients have been traditionally treated with orthognathic surgery. Such a procedure has its own limitations of relapse and hence a newer modality of distraction osteogenesis with histiogenesis can be chosen to overcome such limitations for midfacial advancement. The purpose of this study is to evaluate an alternative technique and its postoperative stability in maxillary distraction osteogenesis in patients of cleft lip and cleft palate using a rigid external device (RED). Nine patients with midface bone stock deficiency were selected for maxillary advancement. At the first surgery under general anesthesia, after Le Fort I osteotomy, RED system was used with the alternative technique. After distraction, evaluation was done for ease of the procedure, stability, and complications. Lateral cephalograms were evaluated at 3 stages: T1, pre-distraction; T2, post-distraction; and T3, 1 year post-distraction. A mean 13.4-mm midface advancement was shown with bone formation at the pterygomaxillary region without losing the vector and having a standby mode in case the wire broke during distraction The results were stable even at 1 year of follow-up. Maxillary position improved in relation to the cranial base. This study showed that the RED was versatile in midface advancement.

SUBSTANTIATION OF SOLUTIONS PERTAINING TO COMPLEX PRODUCTION RECONSTRUCTION

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V. Y. Gurinovich

2011-01-01

Full Text Available While taking an example of reconstruction and modernization of OJSC «Construction and Mounting Trust No.16, Novopolotsk» the paper substantiates solutions for complex production reconstruction. The production reconstruction is divided in three start-up facilities ensuring continuous finished-product output.

Arthroscopic-Assisted Triangular Fibrocartilage Complex Reconstruction.

Science.gov (United States)

Chu-Kay Mak, Michael; Ho, Pak-Cheong

2017-11-01

Injury of the triangular fibrocartilage complex (TFCC) is a common cause of ulnar-sided wrist pain. Volar and dorsal radioulnar ligaments and their foveal insertion are the most important stabilizing components of the TFCC. In irreparable tears, anatomic reconstruction of the TFCC aims to restore normal biomechanics and stability of the distal radioulnar joint. We proposed a novel arthroscopic-assisted technique using a palmaris longus tendon graft. Arthroscopic-assisted TFCC reconstruction is a safe and effective approach with outcomes comparable to conventional open reconstruction and may result in a better range of motion from minimizing soft tissue dissection and subsequent scarring. Copyright © 2017 Elsevier Inc. All rights reserved.

Management of post midface distraction occlusal discrepancy using temporary anchorage devices in a cleft patient

Science.gov (United States)

Koteswara Prasad, N. K.; Hussain, Syed Altaf; Chitharanjan, Arun B.; Murthy, Jyotsna

2015-01-01

Open bite deformity following a successful midface advancement by distraction osteogenesis is a common complication. Temporary anchorage devices can be deployed during the distraction and post-distraction settling phases for restoring the occlusion even in severe cases. The following report describes the management of severe anterior open bite following maxillary distraction. PMID:25991895

Management of post midface distraction occlusal discrepancy using temporary anchorage devices in a cleft patient

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N K Koteswara Prasad

2015-01-01

Full Text Available Open bite deformity following a successful midface advancement by distraction osteogenesis is a common complication. Temporary anchorage devices can be deployed during the distraction and post-distraction settling phases for restoring the occlusion even in severe cases. The following report describes the management of severe anterior open bite following maxillary distraction.

Pattern of midface trauma with associated concomitant injuries in a Nigerian Referral Centre

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Samuel Udeabor

2014-01-01

Full Text Available Aim: The aim of this study was to determine the pattern of midface trauma with associated concomitant injuries seen in our environment. Methodology: This was a prospective analysis of trauma patients with midfacial injuries presenting at a referral center in South West Nigeria. In addition to socio-demographic data, the following information was also obtained: Mechanism of injuries, type of midfacial injuries, concomitant/associated injuries and treatment. Results: A total of 101 patients with midfacial injuries were involved. They were made up of 85 males and 16 females. The 20-29 year age group was mostly affected (44.6% and the most common cause of midface injuries was road traffic accident (91.1%. The zygoma was fractured more than any other midfacial bone (46.0%. A total of 144 associated injuries were recorded among these patients, head and ocular injuries accounted for 49 (34% and 35 (24.3% respectively. The patients were mostly treated conservatively or by closed reduction. Conclusion: The rate of head and ocular injuries among patients with midfacial injury was high. Knowledge of these associated injuries provides useful strategies for patient care and prevention of further complications. A multidisciplinary approach is important for optimum management of these patients.

Reconstruction of fiber grating refractive-index profiles from complex bragg reflection spectra.

Science.gov (United States)

Huang, D W; Yang, C C

1999-07-20

Reconstruction of the refractive-index profiles of fiber gratings from their complex Bragg reflection spectra is experimentally demonstrated. The amplitude and phase of the complex reflection spectrum were measured with a balanced Michelson interferometer. By integrating the coupled-mode equations, we built the relationship between the complex coupling coefficient and the complex reflection spectrum as an iterative algorithm for reconstructing the index profile. This method is expected to be useful for reconstructing the index profiles of fiber gratings with any apodization, chirp, or dc structures. An apodized chirped grating and a uniform grating with a depression of index modulation were used to demonstrate the technique.

Stability of midface fracture repair using absorbable plate and screw system pilot holes drilled and pin placement at angles other than 90°.

Science.gov (United States)

Carron, Michael A; Zuliani, Giancarlo; Pereira, Lucio; Abuhamdan, Maher; Thibault, Adrianna; Dau, Nathan; Bir, Cynthia

2014-01-01

Conventional plating systems use titanium plates for fixation of fractures, with benefits of strength and biocompatibility. However, titanium plates require that screws be placed at a 90° angle to the pilot holes. In the midface, this becomes extremely difficult. Today, a variety of craniomaxillofacial osteosynthesis systems are available, including resorbable plating systems. Specifically, the KLS Martin Sonic Weld system ultrasonically fuses the plate and the head of the pin when placed and will fill the pilot hole grooves completely even at less than 90° angles, which provides a tremendous advantage in midface fracture repair. To determine if the KLS Martin Sonic Weld system provides plate-screw construct stability in human heads even when placed at acute angles at the midface buttresses. DESIGN, SETTING, AND SPECIMENS: Twenty cadaveric head specimens with the mandible removed were prepared by creating osteotomies in the midface buttresses bilaterally. Specimens were defleshed and placed in a 2-part testing rig to hold and position the head for testing in a standard material testing system. Testing was performed at the Wayne State University Bioengineering test laboratories, Detroit, Michigan, using an Instron device and high-speed camera. Specimens were plated on one side of the midface using the KLS Martin Sonic Weld system with pilot holes and pins placed at 90° angles. On the contralateral side, the buttresses were plated with the KLS Martin Sonic Weld system at 60°, 45°, and 30° angles. Data were collected using the TDAS data acquisition system and were compared with matched pairs within each specimen. Ultrasonically vibrated pins placed into absorbable mini-plates at less than 90° angles with the KLS Martin Sonic Weld system were compared with the same amount of stress as the system placed at a 90° angle before demonstrating plate-screw construct failure. RESULTS Fifty-seven paired tests were collected, with 114 total tests. Twenty failures were

Sensor-Topology Based Simplicial Complex Reconstruction from Mobile Laser Scanning

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Guinard, S.; Vallet, B.

2018-05-01

We propose a new method for the reconstruction of simplicial complexes (combining points, edges and triangles) from 3D point clouds from Mobile Laser Scanning (MLS). Our main goal is to produce a reconstruction of a scene that is adapted to the local geometry of objects. Our method uses the inherent topology of the MLS sensor to define a spatial adjacency relationship between points. We then investigate each possible connexion between adjacent points and filter them by searching collinear structures in the scene, or structures perpendicular to the laser beams. Next, we create triangles for each triplet of self-connected edges. Last, we improve this method with a regularization based on the co-planarity of triangles and collinearity of remaining edges. We compare our results to a naive simplicial complexes reconstruction based on edge length.

Arthroscopic assisted tendon reconstruction for triangular fibrocartilage complex irreparable tears.

Science.gov (United States)

Luchetti, R; Atzei, A

2017-05-01

We report our 11-year experience of performing arthroscopically assisted triangular fibrocartilage complex reconstruction in the treatment of chronic distal radio-ulnar joint instability resulting from irreparable triangular fibrocartilage complex injuries. Eleven patients were treated. Three skin incisions were made in order to create radial and ulna tunnels for passage of the tendon graft, which is used to reconstruct the dorsal and palmar radio-ulnar ligaments, under fluoroscopic and arthroscopic guidance. At a mean follow-up of 68 months all but one had a stable distal radio-ulnar joint. Pain and grip strength, Mayo wrist score, Disability of the Arm Hand and Shoulder and patient-rated wrist and hand evaluation scores improved. The ranges of forearm rotation remained largely unchanged. Complications included an early tendon graft tear, two late-onset graft ruptures, one ulna styloid fracture during surgery and persistent wrist discomfort during forearm rotation requiring tendon graft revision in one case. An arthroscopic assisted approach for triangular fibrocartilage complex reconstruction appears safe and produces comparable results with the open technique. IV.

SENSOR-TOPOLOGY BASED SIMPLICIAL COMPLEX RECONSTRUCTION FROM MOBILE LASER SCANNING

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S. Guinard

2018-05-01

Full Text Available We propose a new method for the reconstruction of simplicial complexes (combining points, edges and triangles from 3D point clouds from Mobile Laser Scanning (MLS. Our main goal is to produce a reconstruction of a scene that is adapted to the local geometry of objects. Our method uses the inherent topology of the MLS sensor to define a spatial adjacency relationship between points. We then investigate each possible connexion between adjacent points and filter them by searching collinear structures in the scene, or structures perpendicular to the laser beams. Next, we create triangles for each triplet of self-connected edges. Last, we improve this method with a regularization based on the co-planarity of triangles and collinearity of remaining edges. We compare our results to a naive simplicial complexes reconstruction based on edge length.

Appearance of bony lesions on 3-D CT reconstructions: a case study in variable renderings

Science.gov (United States)

Mankovich, Nicholas J.; White, Stuart C.

1992-05-01

This paper discusses conventional 3-D reconstruction for bone visualization and presents a case study to demonstrate the dangers of performing 3-D reconstructions without careful selection of the bone threshold. The visualization of midface bone lesions directly from axial CT images is difficult because of the complex anatomic relationships. Three-dimensional reconstructions made from the CT to provide graphic images showing lesions in relation to adjacent facial bones. Most commercially available 3-D image reconstruction requires that the radiologist or technologist identify a threshold image intensity value that can be used to distinguish bone from other tissues. Much has been made of the many disadvantages of this technique, but it continues as the predominant method in producing 3-D pictures for clinical use. This paper is intended to provide a clear demonstration for the physician of the caveats that should accompany 3-D reconstructions. We present a case of recurrent odontogenic keratocyst in the anterior maxilla where the 3-D reconstructions, made with different bone thresholds (windows), are compared to the resected specimen. A DMI 3200 computer was used to convert the scan data from a GE 9800 CT into a 3-D shaded surface image. Threshold values were assigned to (1) generate the most clinically pleasing image, (2) produce maximum theoretical fidelity (using the midpoint image intensity between average cortical bone and average soft tissue), and (3) cover stepped threshold intensities between these two methods. We compared the computer lesions with the resected specimen and noted measurement errors of up to 44 percent introduced by inappropriate bone threshold levels. We suggest clinically applicable standardization techniques in the 3-D reconstruction as well as cautionary language that should accompany the 3-D images.

Applications of Computer Technology in Complex Craniofacial Reconstruction

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Kristopher M. Day, MD

2018-03-01

Conclusion:. Modern 3D technology allows the surgeon to better analyze complex craniofacial deformities, precisely plan surgical correction with computer simulation of results, customize osteotomies, plan distractions, and print 3DPCI, as needed. The use of advanced 3D computer technology can be applied safely and potentially improve aesthetic and functional outcomes after complex craniofacial reconstruction. These techniques warrant further study and may be reproducible in various centers of care.

Evaluation of two 3D virtual computer reconstructions for comparison of cleft lip and palate to normal fetal microanatomy.

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Landes, Constantin A; Weichert, Frank; Geis, Philipp; Helga, Fritsch; Wagner, Mathias

2006-03-01

Cleft lip and palate reconstructive surgery requires thorough knowledge of normal and pathological labial, palatal, and velopharyngeal anatomy. This study compared two software algorithms and their 3D virtual anatomical reconstruction because exact 3D micromorphological reconstruction may improve learning, reveal spatial relationships, and provide data for mathematical modeling. Transverse and frontal serial sections of the midface of 18 fetal specimens (11th to 32nd gestational week) were used for two manual segmentation approaches. The first manual segmentation approach used bitmap images and either Windows-based or Mac-based SURFdriver commercial software that allowed manual contour matching, surface generation with average slice thickness, 3D triangulation, and real-time interactive virtual 3D reconstruction viewing. The second manual segmentation approach used tagged image format and platform-independent prototypical SeViSe software developed by one of the authors (F.W.). Distended or compressed structures were dynamically transformed. Registration was automatic but allowed manual correction, such as individual section thickness, surface generation, and interactive virtual 3D real-time viewing. SURFdriver permitted intuitive segmentation, easy manual offset correction, and the reconstruction showed complex spatial relationships in real time. However, frequent software crashes and erroneous landmarks appearing "out of the blue," requiring manual correction, were tedious. Individual section thickness, defined smoothing, and unlimited structure number could not be integrated. The reconstruction remained underdimensioned and not sufficiently accurate for this study's reconstruction problem. SeViSe permitted unlimited structure number, late addition of extra sections, and quantified smoothing and individual slice thickness; however, SeViSe required more elaborate work-up compared to SURFdriver, yet detailed and exact 3D reconstructions were created.

Three-Dimensional Eyeball and Orbit Volume Modification After LeFort III Midface Distraction.

Science.gov (United States)

Smektala, Tomasz; Nysjö, Johan; Thor, Andreas; Homik, Aleksandra; Sporniak-Tutak, Katarzyna; Safranow, Krzysztof; Dowgierd, Krzysztof; Olszewski, Raphael

2015-07-01

The aim of our study was to evaluate orbital volume modification with LeFort III midface distraction in patients with craniosynostosis and its influence on eyeball volume and axial diameter modification. Orbital volume was assessed by the semiautomatic segmentation method based on deformable surface models and on 3-dimensional (3D) interaction with haptics. The eyeball volumes and diameters were automatically calculated after manual segmentation of computed tomographic scans with 3D slicer software. The mean, minimal, and maximal differences as well as the standard deviation and intraclass correlation coefficient (ICC) for intraobserver and interobserver measurements reliability were calculated. The Wilcoxon signed rank test was used to compare measured values before and after surgery. P eyeball volume were 0.87 and 0.86, respectively. The orbital volume increased significantly after surgery: 30.32% (mean, 5.96  mL) for the left orbit and 31.04% (mean, 6.31  mL) for the right orbit. The mean increase in eyeball volume was 12.3%. The mean increases in the eyeball axial dimensions were 7.3%, 9.3%, and 4.4% for the X-, Y-, and Z-axes, respectively. The Wilcoxon signed rank test showed that preoperative and postoperative eyeball volumes, as well as the diameters along the X- and Y-axes, were statistically significant. Midface distraction in patients with syndromic craniostenosis results in a significant increase (P eyeball volumes. The 2 methods (haptic-aided semiautomatic segmentation and manual 3D slicer segmentation) are reproducible techniques for orbit and eyeball volume measurements.

Promising results after single-stage reconstruction of the nipple and areola complex

DEFF Research Database (Denmark)

Børsen-Koch, Mikkel; Bille, Camilla; Thomsen, Jørn B

2013-01-01

Introduction: Reconstruction of the nipple-areola complex (NAC) traditionally marks the end of breast reconstruction. Several different surgical techniques have been described, but most are staged procedures. This paper describes a simple single-stage approach. Material and Methods: We used...... reconstruction was 43 min. (30-50 min.). Conclusion: This simple single-stage NAC reconstruction seems beneficial for both patient and surgeon as it seems to be associated with faster reconstruction and reduced procedure-related time without compromising the aesthetic outcome or the morbidity associated...

Prototype of a silicon nitride ceramic-based miniplate osteofixation system for the midface.

Science.gov (United States)

Neumann, Andreas; Unkel, Claus; Werry, Christoph; Herborn, Christoh U; Maier, Horst R; Ragoss, Christian; Jahnke, Klaus

2006-06-01

The favorable properties of silicon nitride (Si3N4) ceramics, such as high mean strength level and fracture toughness, suggest biomedical use as an implant material. Minor reservations about the biocompatibility of Si3N4 ceramics were cleared up by previous in vitro and in vivo investigations. A Si3N4 prototype minifixation system was manufactured and implanted for osteosynthesis of artificial frontal bone defects in 3 minipigs. After 3 months, histological sections, computed tomography (CT) scans, and magnetic resonance imaging (MRI) scans were obtained. Finite element modeling (FEM) was used to simulate stresses and strains on Si3N4 miniplates and screws to calculate survival probabilities. Si3N4 miniplates and screws showed satisfying intraoperative workability. There was no implant loss, displacement, or fracture. Bone healing was complete in all animals. The formation of new bone was observed in direct contact to the implants. The implants showed no artifacts on CT and MRI scanning. FEM simulation confirmed the mechanical reliability of the screws, whereas simulated plate geometries regarding pullout forces at maximum load showed limited safety in a bending situation. Si3N4 ceramics show a good biocompatibility outcome both in vitro and in vivo. In ENT surgery, this ceramic may serve as a biomaterial for osteosynthesis (eg, of the midface including reconstruction the floor of the orbit and the skull base). To our knowledge, this is the first introduction of a ceramic-based miniplate-osteofixation system. Advantages compared with titanium are no risk of implantation to bone with mucosal attachment, no need for explantation, and no interference with radiologic imaging. Disadvantages include the impossibility of individual bending of the miniplates.

Complex Empiricism and the Quantification of Uncertainty in Paleoclimate Reconstructions

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Brumble, K. C.

2014-12-01

Because the global climate cannot be observed directly, and because of vast and noisy data sets, climate science is a rich field to study how computational statistics informs what it means to do empirical science. Traditionally held virtues of empirical science and empirical methods like reproducibility, independence, and straightforward observation are complicated by representational choices involved in statistical modeling and data handling. Examining how climate reconstructions instantiate complicated empirical relationships between model, data, and predictions reveals that the path from data to prediction does not match traditional conceptions of empirical inference either. Rather, the empirical inferences involved are "complex" in that they require articulation of a good deal of statistical processing wherein assumptions are adopted and representational decisions made, often in the face of substantial uncertainties. Proxy reconstructions are both statistical and paleoclimate science activities aimed at using a variety of proxies to reconstruct past climate behavior. Paleoclimate proxy reconstructions also involve complex data handling and statistical refinement, leading to the current emphasis in the field on the quantification of uncertainty in reconstructions. In this presentation I explore how the processing needed for the correlation of diverse, large, and messy data sets necessitate the explicit quantification of the uncertainties stemming from wrangling proxies into manageable suites. I also address how semi-empirical pseudo-proxy methods allow for the exploration of signal detection in data sets, and as intermediary steps for statistical experimentation.

Fast Extended Depth-of-Field Reconstruction for Complex Holograms Using Block Partitioned Entropy Minimization

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Peter Wai Ming Tsang

2018-05-01

Full Text Available Optical scanning holography (OSH is a powerful and effective method for capturing the complex hologram of a three-dimensional (3-D scene. Such captured complex hologram is called optical scanned hologram. However, reconstructing a focused image from an optical scanned hologram is a difficult issue, as OSH technique can be applied to acquire holograms of wide-view and complicated object scenes. Solutions developed to date are mostly computationally intensive, and in so far only reconstruction of simple object scenes have been demonstrated. In this paper we report a low complexity method for reconstructing a focused image from an optical scanned hologram that is representing a 3-D object scene. Briefly, a complex hologram is back-propagated onto regular spaced images along the axial direction, and from which a crude, blocky depth map of the object scene is computed according to non-overlapping block partitioned entropy minimization. Subsequently, the depth map is low-pass filtered to decrease the blocky distribution, and employed to reconstruct a single focused image of the object scene for extended depth of field. The method proposed here can be applied to any complex holograms such as those obtained from standard phase-shifting holography.

The fusion of craniofacial reconstruction and microsurgery: a functional and aesthetic approach.

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Broyles, Justin M; Abt, Nicholas B; Shridharani, Sachin M; Bojovic, Branko; Rodriguez, Eduardo D; Dorafshar, Amir H

2014-10-01

Reconstruction of large, composite defects in the craniofacial region has evolved significantly over the past half century. During this time, there have been significant advances in craniofacial and microsurgical surgery. These contributions have often been in parallel; however, over the past 10 years, these two disciplines have begun to overlap more frequently, and the techniques of one have been used to advance the other. In the current review, the authors aim to describe the available options for free tissue reconstruction in craniofacial surgery. A review of microsurgical reconstructive options of aesthetic units within the craniofacial region was undertaken with attention directed toward surgeon flap preference. Anatomical areas analyzed included scalp, calvaria, forehead, frontal sinus, nose, maxilla and midface, periorbita, mandible, lip, and tongue. Although certain flaps such as the ulnar forearm flap and lateral circumflex femoral artery-based flaps were used in multiple reconstructive sites, each anatomical location possesses a unique array of flaps to maximize outcomes. Craniofacial surgery, like plastic surgery, has made tremendous advancements in the past 40 years. With innovations in technology, flap design, and training, microsurgery has become safer, faster, and more commonplace than at any time in history. Reconstructive microsurgery allows the surgeon to be creative in this approach, and free tissue transfer has become a mainstay of modern craniofacial reconstruction.

Midface swelling reveals nasofrontal dermal sinus

International Nuclear Information System (INIS)

Houneida, Zaghouani Ben Alaya; Manel, Limeme; Latifa, Harzallah; Habib, Amara; Dejla, Bakir; Chekib, Kraiem

2012-01-01

Nasofrontal dermal sinuses are very rare and generally occur in children. This congenital malformation can be revealed by midface swelling, which can be complicated by local infection or neuromeningitis. Such complications make the dermal sinus a life-threatening disease. Two cases of nasofrontal dermal sinuses are reported in this work. The first case is an 11-month-old girl who presented with left orbitonasal soft tissue swelling accompanied by inflammation. Physical examination found fever, left orbitonasal thickening, and a puncture hole letting out pus. Computed tomography revealed microabscesses located at the left orbitonasal soft tissues, a frontal bone defect, and an intracranial cyst. Magnetic resonance imaging showed the transosseous tract between the glabella and the brain and affirmed the epidermoid nature of the intracranial cyst. The second case is a 7-year-old girl who presented with a nasofrontal non-progressive mass that intermittently secreted a yellow liquid through an external orifice located at the glabella. MRI revealed a cystic mass located in the deep layer of the glabellar skin related to an epidermoid cyst with a nasofrontal dermal sinus tract. In both cases, surgical excision was performed, and pathological confirmation was made for the diagnoses of dermal sinuses. The postoperative course was favorable. Through these cases, the authors stress the role of imaging methods in confirming the diagnosis and looking for associated cysts (dermoid and epidermoid) to improve recognition of this rare disease. Knowledge of the typical clinical presentations, imaging manifestations, and most common sites of occurrence of this malformation are needed to formulate a differential diagnosis.

Intraoperative angiography provides objective assessment of skin perfusion in complex knee reconstruction.

Science.gov (United States)

Wyles, Cody C; Taunton, Michael J; Jacobson, Steven R; Tran, Nho V; Sierra, Rafael J; Trousdale, Robert T

2015-01-01

Wound necrosis is a potentially devastating complication of complex knee reconstruction. Laser-assisted indocyanine green angiography (LA-ICGA) is a technology that has been described in the plastic surgery literature to provide an objective assessment of skin perfusion in the operating room. This novel technology uses a plasma protein bound dye (ICG) and a camera unit that is calibrated to view the frequency emitted by the dye. The intention of this technology is to offer real-time visualization of blood flow to skin and soft tissue in a way that might help surgeons make decisions about closure or coverage of a surgical site based on blood flow, potentially avoiding soft tissue reconstruction while preventing skin necrosis or wound breakdown after primary closures, but its efficacy is untested in the setting of complex TKA. The purpose of this study was to evaluate perfusion borders and tension ischemia in a series of complex knee reconstructions to guide optimal wound management. Beginning in mid-2011, an LA-ICGA system was used to evaluate soft tissue viability in knee reconstruction procedures that were considered high risk for wound complications. Seven patients undergoing complex primary or revision TKA from 2011 to 2013 were included. These patients were chosen as a convenience sample of knee reconstruction procedures for which we obtained consultation with the plastic surgery service. The perfusion of skin and soft tissue coverage was evaluated intraoperatively for all patients with the LA-ICGA system, and the information was used to guide wound management. Followup was at a mean of 9 months (range, 6-17 months), no patients were lost to followup, and the main study endpoint was uneventful healing of the surgical incision. All seven closures went on to heal without necrosis. One patient, however, was subsequently revised for a deep periprosthetic infection 4 months after their knee reconstruction and underwent flap coverage at the time of that revision

Single stage reconstruction of complex anterior urethral strictures

Directory of Open Access Journals (Sweden)

Deepak Dubey

2001-01-01

Full Text Available Purpose: Single stage reconstruction of long, com-plex urethral strictures is technically demanding and may require the use of more than one tissue transfer technique. We describe our experience in the manage-ment of such strictures with a variety of urethroplasty techniques. Materials and Methods: Between 1989 and 1999, 25 men (mean age 38.5 years underwent single stage re-construction of panurethral, multiple segment or focally dense strictures [mean length 11.2 cm (range 8-17 cm]. 8 patients had combined substitution urethroplasty with a circumpenile fasciocutaneous flap and a free graft of bladder/buccal mucosa or tunica vaginalis . flap. In 10 patients a single tissue transfer technique was used. 3 patients underwent an augmented roof/floor strip ure-throplasty with a penile skin flap. 4 patients with multi-ple segment strictures (separate pendulous and bulbar underwent distal onlay flap and proximal anastomotic urethroplasty. Results: The median ,follow-up was 46.5 months (range 6-88 months. The mean postoperative flow rate improved to 22.5 ml/sec. 2 patients developed fistulae requiring repair. Recurrent stricture developed in 5 (20.8% patients, of which 2 were managed with visual internal urethrotomy, 2 with anastomotic urethroplasty and 1 with a two-stage procedure. Pseudodiverticulum and post-void dribbling were seen in 6 (25% patients. Conclusions: Successful outcome of single stage re-construction of long complex strictures can be achieved with a combination of various tissue transfer methods. The urologist who has a thorough knowledge of penile skin and urethral vascular anatomy and a wide array of substitution techniques in his armamentarium can un-dertake approach to such strictures.

Oblique Photogrammetry Supporting 3d Urban Reconstruction of Complex Scenarios

Science.gov (United States)

Toschi, I.; Ramos, M. M.; Nocerino, E.; Menna, F.; Remondino, F.; Moe, K.; Poli, D.; Legat, K.; Fassi, F.

2017-05-01

Accurate 3D city models represent an important source of geospatial information to support various "smart city" applications, such as space management, energy assessment, 3D cartography, noise and pollution mapping as well as disaster management. Even though remarkable progress has been made in recent years, there are still many open issues, especially when it comes to the 3D modelling of complex urban scenarios like historical and densely-built city centres featuring narrow streets and non-conventional building shapes. Most approaches introduce strong building priors/constraints on symmetry and roof typology that penalize urban environments having high variations of roof shapes. Furthermore, although oblique photogrammetry is rapidly maturing, the use of slanted views for façade reconstruction is not completely included in the reconstruction pipeline of state-of-the-art software. This paper aims to investigate state-of-the-art methods for 3D building modelling in complex urban scenarios with the support of oblique airborne images. A reconstruction approach based on roof primitives fitting is tested. Oblique imagery is then exploited to support the manual editing of the generated building models. At the same time, mobile mapping data are collected at cm resolution and then integrated with the aerial ones. All approaches are tested on the historical city centre of Bergamo (Italy).

Revision allograft reconstruction of the lateral collateral ligament complex in elbows with previous failed reconstruction and persistent posterolateral rotatory instability.

Science.gov (United States)

Baghdadi, Yaser M K; Morrey, Bernard F; O'Driscoll, Shawn W; Steinmann, Scott P; Sanchez-Sotelo, Joaquin

2014-07-01

Primary reconstruction of the lateral collateral ligament complex (LCLC) using graft tissue restores elbow stability in many, but not all, elbows with acute or chronic posterolateral rotatory instability (PLRI). Revision reconstruction using a tendon allograft is occasionally considered for persistent PLRI, but the outcome of revision ligament reconstruction in this setting is largely unknown. We determined whether revision allograft ligament reconstruction can (1) restore the stability and (2) result in improved elbow scores for patients with persistent PLRI of the elbow after a previous failed primary reconstructive attempt and in the context of the diverse pathology being addressed. Between 2001 and 2011, 160 surgical elbow procedures were performed at our institution for the LCLC reconstruction using allograft tissue. Only patients undergoing revision allograft reconstruction of the LCLC for persistent PLRI with a previous failed primary reconstructive attempt using graft tissue and at least I year of followup were included in the study. Eleven patients (11 elbows) fulfilled our inclusion criteria and formed our study cohort. The cohort consisted of six female patients and five male patients. The mean age at the time of revision surgery was 36 years (range, 14-59 years). The revision allograft reconstruction was carried out after a mean of 3 years (range, 2.5 months to 9 years) from a failed attempted reconstruction of the LCLC. Osseous deficiency to some extent was identified in the preoperative radiographs of eight elbows. Mean followup was 5 years (range, 1-12 years). Revision allograft reconstruction of the LCLC restored elbow stability in eight of the 11 elbows; two of the three elbows with persistent instability were operated on a third time (at 6 and 7 months after allograft revision reconstruction). For elbows with no persistent instability, the mean Mayo Elbow Performance Score at most recent followup was 83 points (range, 60-100 points), and

Secondary free-flap reconstruction following ablation for acute invasive fungal sinusitis.

Science.gov (United States)

Allensworth, Jordan J; Troob, Scott H; Weaver, Tyler S; Gonzalez, Javier D; Petrisor, Daniel; Wax, Mark K

2017-04-01

Acute invasive fungal sinusitis (AIFS) is a frequently fatal infection for which extensive and debilitating surgical debridement is a mainstay of therapy. Resulting defects are often composite in nature, mandating free tissue-transfer reconstruction. Outcomes data for free flap reconstruction are limited. The purpose of this study was to examine surgical outcomes and survival in patients undergoing free flap transfer following invasive fungal sinusitis. Retrospective case series. Between 1995 and 2015, patients undergoing operative debridement for AIFS were identified. Surgical records were used to identify survivors of acute infection who subsequently underwent free flap reconstructive surgery. Patient demographics, cause of immune compromise, defect description, flap type, perioperative complications, indications for revision surgery, functional outcomes, and long-term survival were reviewed. Forty-four patients were treated for AIFS, of those, 30 (68%) survived acute infection. Ten patients underwent maxillectomy, six with orbital exenteration, and were designated candidates for reconstruction. Eight patients underwent reconstruction. Median time from debridement to reconstruction was 67.5 days. Flap types included latissimus dorsi, scapula, anterolateral thigh, rectus, radial forearm, and fibula. Median follow-up was 7.7 months. No perioperative complications were encountered, and all subjects remained disease-free, able to speak and eat normally without prosthetic supplementation. Seven patients (87%) are currently alive. Reconstruction of defects left by invasive fungal sinusitis using free-tissue transfer resulted in successful flap survival, with no disease recurrence for all defects and flap types reviewed. Survivors of AIFS are able to tolerate midface reconstruction, with favorable functional outcomes and survival rates. 4. Laryngoscope, 127:815-819, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

[Reconstruction assisted by 3D printing in maxillofacial surgery].

Science.gov (United States)

Ernoult, C; Bouletreau, P; Meyer, C; Aubry, S; Breton, P; Bachelet, J-T

2015-04-01

3-dimensional models (3D) appeared in the medical field 20 years ago. The recent development of consumer 3D printers explains the renewed interest in this technology. We describe the technical and practical modalities of this surgical tool, illustrated by concrete examples. The OsiriX(®) software (version 5.8.5, Geneva, Switzerland) was used for 3D surface reconstruction of the area of interest, the generation and export of ".stl" file. The NetFabb(®) software (Basic version 5.1.1, Lupburg, Germany) provided the preparation of ".stl" file. The 3D-printer was an Up plus 2 Easy 120(®) (PP3DP, Beijing Technology Co. TierTime Ltd., Chine). The printer used fused deposition modeling. The softwar Up!(®) allowed the 3d impression as required. The first case illustrated the value of 3D printing in the upper (frontal sinus and orbital roof). The second case concerned the preconfiguration of the osteosynthesis material for a complex fracture of the midface through the "mirroring" system. The third case showed the conformation of a prereconstruction for segmental mandibulectomy. Current 3D-printers are easy to use and represent a promising solution for medical prototyping. The 3D printing will quickly become undeniable because of its advantages: information sharing, simulation, surgical guides, pedagogy. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Lessons Learned from Delayed Versus Immediate Microsurgical Reconstruction of Complex Maxillectomy and Midfacial Defects: Experience in a Tertiary Center in Mexico.

Science.gov (United States)

Santamaria, Eric; de la Concha, Erika

2016-10-01

Microsurgical reconstruction of complex midfacial and maxillectomy defects is among the most challenging procedures in plastic surgery, and it often requires composite flaps to improve functional and aesthetic results. Various factors have been identified as having influence in the outcome of microsurgical reconstruction. In this article, the authors present their experience with immediate and delayed reconstruction of complex maxillectomy defects in a tertiary center in Mexico. The authors present a total of 37 patients with microsurgical reconstruction of a complex maxillectomy defect; 13 patients had immediate and 24 had delayed reconstructions. The authors recommend doing immediate reconstruction when feasible. Copyright © 2016 Elsevier Inc. All rights reserved.

Three-Dimensional Changes in the Midface Following Malar Calcium Hydroxyapatite Injection in a Cadaver Model.

Science.gov (United States)

Gatherwright, James R; Brown, Matthew S; Katira, Kristopher M; Rowe, David J

2015-08-01

Three-dimensional (3D) changes in the midface following malar calcium hydroxyapatite (CaHa) injection have not been systematically analyzed. The authors analyzed 3D volume changes in midface and naso-labial fold (NLF) volume, as well as lateral movement in the NLF/naso-labial crease (NLC) junction following malar injection of CaHa in a cadaver model. A single surgeon injected CaHa in the supraperiosteal plane. Sequential images were obtained with the VECTRA 3D system pre- and post-1.5- and 3-cc CaHa injections. All measurements were performed by a single examiner. Injection location was verified anatomically. Injections were performed in 16 fresh cadaver hemi-faces. Maximal increases in projection were centered on the malar injection site, with associated decreases in projection and volume in the infero-medial locations. Relative mean increases in volume of 3.16 cc and 4.94 cc were observed following the 1.5-cc and 3-cc injections, respectively. There was a relative decrease in the volume of the NLF of -0.3 cc and -0.4 cc following the 1.5- and 3-cc injections, respectively. Injection of CaHa was associated with lateral movements of the NLF-NLC junction at the level of the nasal sill, philtral columns, and oral commissure, measuring 2.7, 2.5, and 1.9 mm and 2.8, 2.9, and 2.4 mm following the 1.5- and 3-cc injections, respectively. Anatomical dissection verified the location in the supraperiosteal space and within the middle malar fat pad. Following malar CaHa injection, 3D photographic analysis showed a measureable lifting effect with recruitment of ptotic tissue and lateral movement of the NLF-NLC junction in a cadaver model. © 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

Reducing the Computational Complexity of Reconstruction in Compressed Sensing Nonuniform Sampling

DEFF Research Database (Denmark)

Grigoryan, Ruben; Jensen, Tobias Lindstrøm; Arildsen, Thomas

2013-01-01

sparse signals, but requires computationally expensive reconstruction algorithms. This can be an obstacle for real-time applications. The reduction of complexity is achieved by applying a multi-coset sampling procedure. This proposed method reduces the size of the dictionary matrix, the size...

Stepladder Reconstructive Options in Post-Ablative Complex Surgical Defects in the Head and Neck

International Nuclear Information System (INIS)

EL MARAKBY, H.H.; NAGUIB, Sh.F.; EL-SAWY, A.F.; AMIN, A.A.

2008-01-01

Background: Reconstruction of head and neck defects can pose many challenges to the reconstructive head and neck surgeon. Achieving the best cosmetic and functional results without compromising the safety of oncologic surgery are the primary reconstructive goals. Speech and articulation are particularly important in oral reconstructive procedures. In addition, preservation of the integrity and function of the donor sites should always be considered in all reconstructive procedures. Aim of the Study: The aim of the study is to evaluate different reconstructive options in complex defects of the head and neck region after resection of malignant tumours. The feasibility of the reconstructive ladder starting from simple techniques such as local flaps and skin grafts up to free flaps will be assessed. Patients and Methods: In this study we evaluated different reconstructive procedures used in 50 patients with complex head and neck defects undertaken at the department of surgery at the National Cancer Institute between July 2003 and December 2007. Results: The average age of patients was 52 years and the range was 26-67 years. Most of the tumours were either squamous cell carcinoma (74%) or Basal cell carcinoma (20%). Tumour sites included the nose (6%), lip (10%), cheek (12%) scalp (6%) as well as mucosal defects of the oral cavity (40%) and the hypopharynx (20%). We used local flaps and skin grafts in reconstruction in 36% of cases and pedicled flaps in 32% while free flaps were used in 32% of cases. Complications occurred in 32% of patients of which total flaps loss constituted 6% and partial flap loss 4%. Minor complications such as oro-cutaneous fistulae, wound infection, seroma and haematoma were noticed in 22% and all of them were treated conservatively. The final functional and aesthetic results were satisfactory in 60% of cases while poor results were encountered in patients who suffered some degree of flap loss.

A stereotactic system for guiding complex craniofacial reconstruction.

Science.gov (United States)

Fialkov, J A; Phillips, J H; Gruss, J S; Kassel, E E; Zuker, R M

1992-02-01

A stereotactic system has been designed to address the problem of achieving symmetry in complex and extensive craniofacial defects. Preliminary testing suggests that such a system, which allows for the intraoperative application of preoperative CT planning, will be useful in guiding the reconstruction of congenital or acquired bony time, is being used to investigate the correlation of intraoperative globe position following enophthalmos correction with long-term outcome, particularly as it relates to the size and location of the orbital defect, and the timing of the procedure.

Perforator chimerism for the reconstruction of complex defects: A new chimeric free flap classification system.

Science.gov (United States)

Kim, Jeong Tae; Kim, Youn Hwan; Ghanem, Ali M

2015-11-01

Complex defects present structural and functional challenges to reconstructive surgeons. When compared to multiple free flaps or staged reconstruction, the use of chimeric flaps to reconstruct such defects have many advantages such as reduced number of operative procedures and donor site morbidity as well as preservation of recipient vessels. With increased popularity of perforator flaps, chimeric flaps' harvest and design has benefited from 'perforator concept' towards more versatile and better reconstruction solutions. This article discusses perforator based chimeric flaps and presents a practice based classification system that incorporates the perforator flap concept into "Perforator Chimerism". The authors analyzed a variety of chimeric patterns used in 31 consecutive cases to present illustrative case series and their new classification system. Accordingly, chimeric flaps are classified into four types. Type I: Classical Chimerism, Type II: Anastomotic Chimerism, Type III: Perforator Chimerism and Type IV Mixed Chimerism. Types I on specific source vessel anatomy whilst Type II requires microvascular anastomosis to create the chimeric reconstructive solution. Type III chimeric flaps utilizes the perforator concept to raise two components of tissues without microvascular anastomosis between them. Type IV chimeric flaps are mixed type flaps comprising any combination of Types I to III. Incorporation of the perforator concept in planning and designing chimeric flaps has allowed safe, effective and aesthetically superior reconstruction of complex defects. The new classification system aids reconstructive surgeons and trainees to understand chimeric flaps design, facilitating effective incorporation of this important reconstructive technique into the armamentarium of the reconstruction toolbox. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Distinct growth of the nasomaxillary complex in Au. sediba.

Science.gov (United States)

Lacruz, Rodrigo S; Bromage, Timothy G; O'Higgins, Paul; Toro-Ibacache, Viviana; Warshaw, Johanna; Berger, Lee R

2015-10-15

Studies of facial ontogeny in immature hominins have contributed significantly to understanding the evolution of human growth and development. The recently discovered hominin species Autralopithecus sediba is represented by a well-preserved and nearly complete facial skeleton of a juvenile (MH1) which shows a derived facial anatomy. We examined MH1 using high radiation synchrotron to interpret features of the oronasal complex pertinent to facial growth. We also analyzed bone surface microanatomy to identify and map fields of bone deposition and bone resorption, which affect the development of the facial skeleton. The oronasal anatomy (premaxilla-palate-vomer architecture) is similar to other Australopithecus species. However surface growth remodeling of the midface (nasomaxillary complex) differs markedly from Australopithecus, Paranthropus, early Homo and from KNM-WT 15000 (H. erectus/ergaster) showing a distinct distribution of vertically disposed alternating depository and resorptive fields in relation to anterior dental roots and the subnasal region. The ontogeny of the MH1 midface superficially resembles some H. sapiens in the distribution of remodeling fields. The facial growth of MH1 appears unique among early hominins representing an evolutionary modification in facial ontogeny at 1.9 my, or to changes in masticatory system loading associated with diet.

Palmar reconstruction of the triangular fibrocartilage complex for instability of the distal radioulnar joint: a biomechanical study.

Science.gov (United States)

Kataoka, T; Moritomo, H; Omokawa, S; Iida, A; Wada, T; Aoki, M

2013-06-01

We developed a new triangular fibrocartilage complex reconstruction technique for distal radioulnar joint instability in which the palmar portion of the triangular fibrocartilage complex was predominantly reconstructed, and evaluated whether such reconstruction can restore stability of the distal radioulnar joint in seven fresh cadaver upper extremities. Distal radioulnar joint instability was induced by cutting all soft-tissue stabilizers around the distal ulna. Using a palmar approach, a palmaris longus tendon graft was sutured to the remnant of the palmar radioulnar and ulnocarpal ligaments. The graft was then passed through a bone tunnel created at the fovea and was sutured. Loads were applied to the radius, and dorsopalmar displacements of the radius relative to the ulna were measured using an electromagnetic tracking device in neutral rotation, 60° supination and 60° pronation. We compared the dorsopalmar displacements before sectioning, before reconstruction and after reconstruction. Dorsopalmar instability produced by sectioning significantly improved in all forearm positions after reconstruction.

Statistical inference approach to structural reconstruction of complex networks from binary time series

Science.gov (United States)

Ma, Chuang; Chen, Han-Shuang; Lai, Ying-Cheng; Zhang, Hai-Feng

2018-02-01

Complex networks hosting binary-state dynamics arise in a variety of contexts. In spite of previous works, to fully reconstruct the network structure from observed binary data remains challenging. We articulate a statistical inference based approach to this problem. In particular, exploiting the expectation-maximization (EM) algorithm, we develop a method to ascertain the neighbors of any node in the network based solely on binary data, thereby recovering the full topology of the network. A key ingredient of our method is the maximum-likelihood estimation of the probabilities associated with actual or nonexistent links, and we show that the EM algorithm can distinguish the two kinds of probability values without any ambiguity, insofar as the length of the available binary time series is reasonably long. Our method does not require any a priori knowledge of the detailed dynamical processes, is parameter-free, and is capable of accurate reconstruction even in the presence of noise. We demonstrate the method using combinations of distinct types of binary dynamical processes and network topologies, and provide a physical understanding of the underlying reconstruction mechanism. Our statistical inference based reconstruction method contributes an additional piece to the rapidly expanding "toolbox" of data based reverse engineering of complex networked systems.

An iterative reconstruction method of complex images using expectation maximization for radial parallel MRI

International Nuclear Information System (INIS)

Choi, Joonsung; Kim, Dongchan; Oh, Changhyun; Han, Yeji; Park, HyunWook

2013-01-01

In MRI (magnetic resonance imaging), signal sampling along a radial k-space trajectory is preferred in certain applications due to its distinct advantages such as robustness to motion, and the radial sampling can be beneficial for reconstruction algorithms such as parallel MRI (pMRI) due to the incoherency. For radial MRI, the image is usually reconstructed from projection data using analytic methods such as filtered back-projection or Fourier reconstruction after gridding. However, the quality of the reconstructed image from these analytic methods can be degraded when the number of acquired projection views is insufficient. In this paper, we propose a novel reconstruction method based on the expectation maximization (EM) method, where the EM algorithm is remodeled for MRI so that complex images can be reconstructed. Then, to optimize the proposed method for radial pMRI, a reconstruction method that uses coil sensitivity information of multichannel RF coils is formulated. Experiment results from synthetic and in vivo data show that the proposed method introduces better reconstructed images than the analytic methods, even from highly subsampled data, and provides monotonic convergence properties compared to the conjugate gradient based reconstruction method. (paper)

Awful face of the war-impacted smoke bomb capsule in the face and systemic toxicity: reports from the conflict in Syria.

Science.gov (United States)

Yilmaz, Bahar; Yeşiloğlu, Nebil; Firincioğullari, Remzi; Gökkaya, Ali; Özbey, Rafet; Özgür, Mustafa

2015-01-01

In this study, a rare kind of injury due to smoke bomb capsule impaction to midface and under the cranial base is presented, and maneuvers to reduce mortality are discussed. Three male patients were presented with impacted smoke bomb capsules into the midface and under the cranial base structures. Midface structures, anterior cranial base, and, in 2 patients, unilateral eye were severely damaged. Two patients died after the initial emergency operations because their lung disease progressed to acute respiratory distress syndrome. One of the patients lived, and soft tissue reconstruction was achieved by using temporal transposition and cheek advancement skin flaps with split-thickness skin graft from donor site. However, craniofacial destruction is important in these patients; a multidisciplinary approach is needed for the treatment of direct smoke bomb injuries because the patients experienced chemical burn and acute trauma. The timing of maxillofacial reconstruction is also a question in these specific patients.

Pertinent anatomy and analysis for midface volumizing procedures.

Science.gov (United States)

Surek, Christopher C; Beut, Javier; Stephens, Robert; Jelks, Glenn; Lamb, Jerome

2015-05-01

The study was conducted to construct an anatomically inspired midfacial analysis facilitating safe, accurate, and dynamic nonsurgical rejuvenation. Emphasis is placed on determining injection target areas and adverse event zones. Twelve hemifacial fresh cadavers were dissected in a layered fashion. Dimensional measurements between the midfacial fat compartments, prezygomatic space, mimetic muscles, and neurovascular bundles were used to develop a topographic analysis for clinical injections. A longitudinal line from the base of the alar crease to the medial edge of the levator anguli oris muscle (1.9 cm), lateral edge of the levator anguli oris muscle (2.6 cm), and zygomaticus major muscle (4.6 cm) partitions the cheek into two aesthetic regions. A six-step facial analysis outlines three target zones and two adverse event zones and triangulates the point of maximum cheek projection. The lower adverse event zone yields an anatomical explanation to inadvertent jowling during anterior cheek injection. The upper adverse event zone localizes the palpebral branch of the infraorbital artery. The medial malar target area isolates quadrants for anterior cheek projection and tear trough effacement. The middle malar target area addresses lid-cheek blending and superficial compartment turgor. The lateral malar target area highlights lateral cheek projection and locates the prezygomatic space. This stepwise analysis illustrates target areas and adverse event zones to achieve midfacial support, contour, and profile in the repose position and simultaneous molding of a natural shape during animation. This reproducible method can be used both procedurally and in record-keeping for midface volumizing procedures.

A hybrid 3D SEM reconstruction method optimized for complex geologic material surfaces.

Science.gov (United States)

Yan, Shang; Adegbule, Aderonke; Kibbey, Tohren C G

2017-08-01

Reconstruction methods are widely used to extract three-dimensional information from scanning electron microscope (SEM) images. This paper presents a new hybrid reconstruction method that combines stereoscopic reconstruction with shape-from-shading calculations to generate highly-detailed elevation maps from SEM image pairs. The method makes use of an imaged glass sphere to determine the quantitative relationship between observed intensity and angles between the beam and surface normal, and the detector and surface normal. Two specific equations are derived to make use of image intensity information in creating the final elevation map. The equations are used together, one making use of intensities in the two images, the other making use of intensities within a single image. The method is specifically designed for SEM images captured with a single secondary electron detector, and is optimized to capture maximum detail from complex natural surfaces. The method is illustrated with a complex structured abrasive material, and a rough natural sand grain. Results show that the method is capable of capturing details such as angular surface features, varying surface roughness, and surface striations. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Complex skull defects reconstruction with САD/САМ titanium and polyetheretherketone (PEEK) implants].

Science.gov (United States)

Eolchiyan, S A

2014-01-01

Predictable and stable functional and aesthetic result is the aim of priority for the neurosurgeon dealing with the reconstruction of large cranial bone defects and complex-formed skull defects involving cranio-orbital region. the paper presents the experience with САD/САМ titanium and polyetheretherketone (PEEK) implants for complex-formed and large skull bone defects reconstruction. Between 2005 and 2013 nine patients (5 females and 4 males) underwent cranioplasty and cranio-facial reconstruction with insertion of the customized САD/САМ titanium and PEEK implants. Computer-assisted preoperative planning was undertaken by the surgeon and the engineer together in 3 cases to provide accurate implant design. Eight patients had complex-formed and large posttraumatic defects of fronto-orbital (7 cases) and parietal (one case) regions. In two of these cases one-step reconstruction surgery for posttraumatic fronto-orbital defects combined with adjacent orbital roof (one case) and orbito-zygomatic (one case) deformities was performed. One patient underwent one-step primary cranioplasty after cranio-orbital fibrous dysplasia focus resection. Titanium implants were used in 4 cases while PEEK implants - in 5 ones. The follow-up period ranged from 6 months till 8,5 years (median 4,4 years). The accuracy of the implant intraoperative fit was perfect in all cases. Postoperative wounds healed primary and there were no any complications in the series presented. Post-op clinical assessment and CT data testified to high implants precision, good functional and aesthetic outcomes in all patients. САD/САМ titanium and PEEK implants application should allow for optimal reconstruction in the challenging patients with complex-formed and large skull bone defects providing predictable good functional and aesthetic result together with surgery morbidity and duration reduction. Computer-assisted preoperative planning should be undertaken for САD/САМ implants creation in

Management of complex pediatric laryngotracheal stenosis with skin graft reconstruction.

Science.gov (United States)

Bowe, Sarah N; Wentland, Carissa J; Sandhu, G S; Hartnick, Christopher J

2018-05-01

For pediatric patients with laryngotracheal stenosis, the ultimate goal is creation of a safe, functional airway. Unfortunately, wound healing in a hollow structure can complicate repair attempts, leading to restenosis. Herein, we present our experience using skin-grafting techniques in two complex pediatric laryngotracheal stenosis cases, leading to successful decannulation or speech production. A chart review was performed examining the evaluation and management of two pediatric patients with laryngotracheal stenosis despite prior reconstructive attempts. Patient history, bronchoscopic evaluation, intra-operative technique, post-operative management, treatment outcomes, and complications were noted. Harvesting and preparation of the split-thickness skin grafts (STSG) proceeded in a similar manner for each case. Stenting material varied based on the clinical scenario. Using this technique, our patient with a Type 3 glottic web achieved substantial improvement in exercise tolerance, as well as vocal strength and quality. In addition, our aphonic patient could vocalize for the first time since her laryngotracheal injury. Temporary endoluminal stenting with skin graft lining can reproduce epithelial continuity and provide "biological inhibition" to enhance the wound healing process. When previous reconstructive efforts have failed, use of STSG can be considered in the management of complex pediatric laryngotracheal stenosis. Copyright © 2018. Published by Elsevier B.V.

Genome-reconstruction for eukaryotes from complex natural microbial communities.

Science.gov (United States)

West, Patrick T; Probst, Alexander J; Grigoriev, Igor V; Thomas, Brian C; Banfield, Jillian F

2018-04-01

Microbial eukaryotes are integral components of natural microbial communities, and their inclusion is critical for many ecosystem studies, yet the majority of published metagenome analyses ignore eukaryotes. In order to include eukaryotes in environmental studies, we propose a method to recover eukaryotic genomes from complex metagenomic samples. A key step for genome recovery is separation of eukaryotic and prokaryotic fragments. We developed a k -mer-based strategy, EukRep, for eukaryotic sequence identification and applied it to environmental samples to show that it enables genome recovery, genome completeness evaluation, and prediction of metabolic potential. We used this approach to test the effect of addition of organic carbon on a geyser-associated microbial community and detected a substantial change of the community metabolism, with selection against almost all candidate phyla bacteria and archaea and for eukaryotes. Near complete genomes were reconstructed for three fungi placed within the Eurotiomycetes and an arthropod. While carbon fixation and sulfur oxidation were important functions in the geyser community prior to carbon addition, the organic carbon-impacted community showed enrichment for secreted proteases, secreted lipases, cellulose targeting CAZymes, and methanol oxidation. We demonstrate the broader utility of EukRep by reconstructing and evaluating relatively high-quality fungal, protist, and rotifer genomes from complex environmental samples. This approach opens the way for cultivation-independent analyses of whole microbial communities. © 2018 West et al.; Published by Cold Spring Harbor Laboratory Press.

Rhinoplasty via the midface degloving approach for nasal deformity due to nasal polyps: A case report of Woakes’ syndrome

Directory of Open Access Journals (Sweden)

Misato Ueda, MD

2017-09-01

Full Text Available Nasal polyps are inflammatory proliferative tumors arising from the mucosa of the nasal cavity and paranasal sinuses. Although many cases concerning nasal polyps have been reported, those involving external nasal deformities are rare. We report a case of nasal polyposis filling the nasal cavity and paranasal sinuses, leading to external nasal and facial deformities. The condition above is known as Woakes’ syndrome, which is characterized by severe recurrent nasal polyps with deformity of the nasal pyramid, leading to broadening of the nose. We performed nasal osteotomy and facial bone-shaving via the midface degloving approach, which improved the patient’s facial appearance.

Localisation of deformations of the midfacial complex in subjects with class III malocclusions employing thin-plate spline analysis.

Science.gov (United States)

Singh, G D; McNamara, J A; Lozanoff, S

1997-11-01

This study determines deformations of the midface that contribute to a class III appearance, employing thinplate spline analysis. A total of 135 lateral cephalographs of prepubertal children of European-American descent with either class III malocclusions or a class I molar occlusion were compared. The cephalographs were traced and checked, and 7 homologous landmarks of the midface were identified and digitised. The data sets were scaled to an equivalent size and subjected to Procrustes analysis. These statistical tests indicated significant differences (P spline analysis indicated that both affine and nonaffine transformations contribute towards the total spline for the averaged midfacial configuration. For nonaffine transformations, partial warp 3 had the highest magnitude, indicating the large scale deformations of the midfacial configuration. These deformations affected the palatal landmarks, and were associated with compression of the midfacial complex in the anteroposterior plane predominantly. Partial warp 4 produced some vertical compression of the posterior aspect of the midfacial complex whereas partial warps 1 and 2 indicated localised shape changes of the maxillary alveolus region. large spatial-scale deformations therefore affect the midfacial complex in an anteroposterior axis, in combination with vertical compression and localised distortions. These deformations may represent a developmental diminution of the palatal complex anteroposteriorly that, allied with vertical shortening of midfacial height posteriorly, results in class III malocclusions with a retrusive midfacial profile.

Direct EIT reconstructions of complex admittivities on a chest-shaped domain in 2-D.

Science.gov (United States)

Hamilton, Sarah J; Mueller, Jennifer L

2013-04-01

Electrical impedance tomography (EIT) is a medical imaging technique in which current is applied on electrodes on the surface of the body, the resulting voltage is measured, and an inverse problem is solved to recover the conductivity and/or permittivity in the interior. Images are then formed from the reconstructed conductivity and permittivity distributions. In the 2-D geometry, EIT is clinically useful for chest imaging. In this work, an implementation of a D-bar method for complex admittivities on a general 2-D domain is presented. In particular, reconstructions are computed on a chest-shaped domain for several realistic phantoms including a simulated pneumothorax, hyperinflation, and pleural effusion. The method demonstrates robustness in the presence of noise. Reconstructions from trigonometric and pairwise current injection patterns are included.

Accurate reconstruction in digital holographic microscopy using Fresnel dual-tree complex wavelet transform

Science.gov (United States)

Zhang, Xiaolei; Zhang, Xiangchao; Yuan, He; Zhang, Hao; Xu, Min

2018-02-01

Digital holography is a promising measurement method in the fields of bio-medicine and micro-electronics. But the captured images of digital holography are severely polluted by the speckle noise because of optical scattering and diffraction. Via analyzing the properties of Fresnel diffraction and the topographies of micro-structures, a novel reconstruction method based on the dual-tree complex wavelet transform (DT-CWT) is proposed. This algorithm is shiftinvariant and capable of obtaining sparse representations for the diffracted signals of salient features, thus it is well suited for multiresolution processing of the interferometric holograms of directional morphologies. An explicit representation of orthogonal Fresnel DT-CWT bases and a specific filtering method are developed. This method can effectively remove the speckle noise without destroying the salient features. Finally, the proposed reconstruction method is compared with the conventional Fresnel diffraction integration and Fresnel wavelet transform with compressive sensing methods to validate its remarkable superiority on the aspects of topography reconstruction and speckle removal.

Efficacy and safety of a hyaluronic acid filler in subjects treated for correction of midface volume deficiency: a 24 month study

Directory of Open Access Journals (Sweden)

Callan P

2013-03-01

Full Text Available Peter Callan,1 Greg J Goodman,2 Ian Carlisle,3 Steven Liew,4 Peter Muzikants,5 Terrence Scamp,6 Michael B Halstead,7 John D Rogers71Peter Callan Plastic Surgery, Geelong, VIC, 2Dermatology Institute of Victoria, South Yarra, VIC, 3Erase Skin Rejuvenation Specialists, Malvern, VIC, 4Shape Clinic and Medispa, Darlinghurst, NSW, 5Ada Cosmetic Medicine, Glebe, NSW, 6Esteem Beauty and Day Spa, Main Beach, QLD, 7Allergan Medical Affairs, Gordon, ACT, AustraliaBackground: Hyaluronic acid (HA fillers are an established intervention for correcting facial volume deficiency. Few studies have evaluated treatment outcomes for longer than 6 months. The purpose of this study was to determine the durability of an HA filler in the correction of midface volume deficiency over 24 months, as independently evaluated by physician investigators and subjects.Methods: Subjects received treatment with Juvéderm™ Voluma™ to the malar area, based on the investigators' determination of baseline severity and aesthetic goals. The treatment was administered in one or two sessions over an initial 4-week period. Supplementary treatment was permissible at week 78, based on protocol-defined criteria. A clinically meaningful response was predefined as at least a one-point improvement on the MidFace Volume Deficit Scale (MFVDS and on the Global Aesthetic Improvement Scale (GAIS.Results: Of the 103 subjects enrolled, 84% had moderate or significant volume deficiency at baseline. At the first post-treatment evaluation (week 8, 96% were documented to be MFVDS responders, with 98% and 100% graded as GAIS responders when assessed by the subjects and investigators, respectively. At week 78, 81.7% of subjects were still MFVDS responders, with 73.2% and 78.1% being GAIS responders, respectively. Seventy-two subjects completed the 24-month study, of whom 45 did not receive supplementary Voluma™ at week 78. Forty-three of the 45 (95.6% subjects were MFVDS responders, with 82.2% and 91

Use of three-dimensional, CAD/CAM-assisted, virtual surgical simulation and planning in the pediatric craniofacial population.

Science.gov (United States)

Gray, Rachel; Gougoutas, Alexander; Nguyen, Vinh; Taylor, Jesse; Bastidas, Nicholas

2017-06-01

Virtual Surgical Planning (VSP) and computer-aided design/computer-aided manufacturing (CAD/CAM) have recently helped improve efficiency and accuracy in many different craniofacial surgeries. Research has mainly focused on the use in the adult population with the exception of the use for mandibular distractions and cranial vault remodeling in the pediatric population. This study aims to elucidate the role of VSP and CAD/CAM in complex pediatric craniofacial cases by exploring its use in the correction of midface hypoplasia, orbital dystopia, mandibular reconstruction, and posterior cranial vault expansion. A retrospective analysis of thirteen patients who underwent 3d, CAD/CAM- assisted preoperative surgical planning between 2012 and 2016 was performed. All CAD/CAM assisted surgical planning was done in conjunction with a third party vendor (either 3D Systems or Materialise). Cutting and positioning guides as well as models were produced based on the virtual plan. Surgeries included free fibula mandible reconstruction (n = 4), lefort I osteotomy and distraction (n = 2), lefort II osteotomy with monobloc distraction (n = 1), expansion of the posterior vault for correction of chiari malformation (n = 3), and secondary orbital and midface reconstruction for facial trauma (n = 3). The patient's age, diagnosis, previous surgeries, length of operating time, complications, and post-surgery satisfaction were determined. In all cases we found presurgical planning was helpful to improve accuracy and significantly decrease intra-operative time. In cases where distraction was used, the planned and actual vectors were found to be accurate with excellent clinical outcomes. There were no complications except for one patient who experienced a wound infection post-operatively which did not alter the ultimate reconstruction. All patients experienced high satisfaction with their outcomes and excellent subjective aesthetic results were achieved. Preoperative planning using

AFLP Markers as a tool to reconstruct complex relationships: a case study in Rosa (Rosaceae)

NARCIS (Netherlands)

Koopman, W.J.M.; Wissemann, V.; Cock, de K.; Huylenbroeck, van J.; Riek, de J.; Sabatino, G.J.H.; Visser, D.L.; Vosman, B.; Ritz, K.; Maes, B.; Werlemark, G.; Nybom, H.; Debener, T.; Linde, M.; Smulders, M.J.M.

2008-01-01

The genus Rosa has a complex evolutionary history caused by several factors, often in conjunction: extensive hybridization, recent radiation, incomplete lineage sorting, and multiple events of polyploidy. We examined the applicability of AFLP markers for reconstructing (species) relationships in

Kuwaiti reconstruction project unprecedented in size, complexity

Energy Technology Data Exchange (ETDEWEB)

Tippee, B.

1993-03-15

There had been no challenge like it: a desert emirate ablaze; its main city sacked; the economically crucial oil industry devastated; countryside shrouded in smoke from oil well fires and littered with unexploded ordnance, disabled military equipment, and unignited crude oil. Like the well-documented effort that brought 749 burning wells under control in less than 7 months, Kuwaiti reconstruction had no precedent. Unlike the firefight, reconstruction is no-where complete. It nevertheless has placed two of three refineries back on stream, restored oil production to preinvasion levels, and repaired or rebuilt 17 of 26 oil field gathering stations. Most of the progress has come since the last well fire went out on Nov. 6, 1991. Expatriates in Kuwait since the days of Al-Awda- the return,' in Arabic- attribute much of the rapid progress under Al-Tameer- the reconstruction'- to decisions and preparations made while the well fires still raged. The article describes the planning for Al-Awda, reentering the country, drilling plans, facilities reconstruction, and special problems.

[Custom-made implant for complex facial reconstruction: A case of total replacement of temporo-mandibular joint, zygomatic arch and malar bone].

Science.gov (United States)

Guillier, D; Moris, V; See, L-A; Girodon, M; Wajszczak, B-L; Zwetyenga, N

2017-02-01

Total prosthetic replacement of the temporo-mandibular joint (TMJ) has become a common procedure, but it is usually limited to the TMJ itself. We report about one case of complex prosthetic joint reconstruction extending to the neighbouring bony structures. A 57-year-old patient, operated several times for a cranio-facial fibrous dysplasia, presented with a recurring TMJ ankylosis and a complexe latero-facial bone loss on the right side. We performed a reconstruction procedure including the TMJ, the zygomatic arch and the malar bone by mean of custom made composite prosthesis (chrome-cobalt-molybdenum-titanium and polyethylene). Five years postoperatively, mouth opening, nutrition, pain and oral hygiene were significantly improved. Nowadays technical possibilities allow for complex facial alloplastic reconstructions with good medium term results. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Health-related quality of life after maxillectomy: obturator rehabilitation compared with flap reconstruction.

Science.gov (United States)

Breeze, J; Rennie, A; Morrison, A; Dawson, D; Tipper, J; Rehman, K; Grew, N; Snee, D; Pigadas, N

2016-10-01

Health-related quality of life (QoL) reported by patients has the potential to improve care after ablative surgery of the midface, as existing treatment algorithms still generally revolve around outcomes assessed traditionally only by clinicians. Decisions in particular relate to reconstruction with a flap compared with rehabilitation with an obturator, the need for adjuvant treatment, and morbidity related to the size of the defect. We prospectively collected health-related QoL assessments for 39 consecutive patients treated by maxillectomy between 01 January 2010 and 31 December 2014 using the University of Washington Quality of Life Questionnaire, and who had a mean (SD) duration of follow-up of 14 (4). We made sub-group analyses using paired t tests and analysis of variance (ANOVA) to compare reconstruction with a flap with rehabilitation with obturators, size of the vertical defect, and whether adjuvant treatment with radiotherapy or chemoradiotherapy adversely affected it. Overall there was a significant decrease in health-related QoL after treatment compared with before (p<0.001), but there was no significant difference in the effects of any of the paired reconstructive and rehabilitation treatments on it. Obturators remain an important option for rehabilitation in selected patients in addition to reconstruction with a flap. We found that neither increasing the size of the vertical defect (in an attempt to ensure clear margins) nor the use of postoperative radiotherapy seemed to have any adverse effect on QoL. More patients are required before we can conclude that the potential survival benefits of such measures may outweigh any adverse effects. Copyright © 2016 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Use of the "dual construct" for the management of complex spinal reconstructions.

Science.gov (United States)

Shen, Francis H; Qureshi, Rabia; Tyger, Rose; Lehman, Rebecca; Singla, Anuj; Shimer, Adam; Hassanzadeh, Hamid

2018-03-01

Surgical management of complex spinal reconstructions remains a clinical challenge, as pseudoarthrosis with subsequent rod breakage can occur. Increased rod density in the form of "satellite" or "outrigger" rods have been described; however, rod-fracture above or below satellite rods persist and can result in dissociation of the construct, loss of correction, and recurrence of deformity. The use of four distinct and mechanically independent rods (dual construct) reduces this concern. Since the original case description in 2006, there have been no other studies that use the dual construct for the surgical management of complex spinal reconstructions. The purpose of this study is to review the long-term experience and surgical technique using the dual construct, and to present our complications, rod fracture rates, and outcomes for the surgical management of complex spinal reconstructions. This study used a surgical technique with case series outcomes. Patients were from a single-institute who underwent dual construct between 2010 and 2014 and who were available for 2-year follow-up. Radiographic and functional outcomes, complications, rod fracture rates, and revision surgery rates were the outcome measures. A retrospective review was conducted from a single institution between 2010 and 2014, with a subsequent 2-year follow-up period. Extensive review of patients' medical record, radiographs, and advanced imaging where available was performed. Medical record was evaluated for patient demographics, surgical procedure, and complications. Radiographic measurements included presence or absence of implant failure and proximal junctional kyphosis or distal junctional kyphosis. A total of 36 patients underwent surgical reconstruction. The average estimated blood loss was 1,856 cc (range, 400-4,000 cc). The average length of stay was 7.3 days (range, 4-22 days). Clinical follow-up reported 21 patients (58.3%) with no or minimal pain. There were six deaths during the

Treatment of midfacial fractures

International Nuclear Information System (INIS)

Schubert, J.

2007-01-01

Fractures of the midface constitute half of all traumas involving facial bones. Computed tomography is very useful in primary diagnosis. Isolated fractures of the nasal bone and lateral midfacial structures may be diagnosed sufficiently by conventional X-rays. An exact description of the fracture lines along the midfacial buttresses is essential for treatment planning. For good aesthetics and function these have to be reconstructed accurately, which can be checked with X-rays. The treatment of midfacial fractures has been revolutionized over the last two decades. A stable three-dimensional reconstruction of the facial shape is now possible and the duration of treatment has shortened remarkably. The frequently occurring isolated fractures in the lateral part of the midface may be treated easily and effectively by semisurgical methods such as the Gillies procedure or hook-repositioning. (orig.)

Maxillary reconstruction with a double-barrel osteocutaneous fibular flap and arteriovenous saphenous loop after a globe-sparing total maxillectomy-A Case Report.

Science.gov (United States)

Chen, Szu-Han; Hung, Kuo-Shu; Lee, Yao-Chou

2017-05-01

Maxillary reconstruction using titanium mesh or bone grafts can invite unwanted complications, such as graft resorption, infection, and mesh exposure, especially for patients who require postoperative radiotherapy. Here, we reported a 58-year-old male patient who was diagnosed with maxillary sinus squamous cell carcinoma. The patient received cancer ablation by a globe-sparing total maxillectomy and was immediately reconstructed with a double-barrel osteocutaneous fibular flap to simultaneously restore the alveolar ridge, orbital support, and oro-sinonasal separation. The short pedicle length inherent in the double-barrel design of the fibular flap and the depletion of healthy recipient vessels in the midface after cancer ablation were overcome by creating an arteriovenous saphenous loop in the neck region. Though there was venous congestion on postoperative day 2, the postoperative recovery was uneventful after the revision of the venous anastomoses. During the 6-months follow-up, the outcome was functionally and aesthetically satisfactory. We believe that the double-barrel fibular osteocutaneous flap, which avoids using titanium mesh and bone grafts, may be a viable reconstructive option in cancer patients with globe-sparing total maxillectomy defects, especially for those who require postoperative radiotherapy. © 2015 Wiley Periodicals, Inc. Microsurgery 37:334-338, 2017. © 2015 Wiley Periodicals, Inc.

Management of complex long bone nonunions using limb reconstruction system

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Hiranya Kumar Seenappa

2013-01-01

Full Text Available Background: Management of complex nonunions is difficult due to the presence of infection, deformities, shortening and multiple surgeries in the past. Complex nonunions are traditionally managed by Ilizarov fixation. The disadvantages of Ilizarov are poor patient compliance, inconvenience of the frame and difficult frame construction. We conducted a study on 30 long bone complex nonunions treated by the limb reconstruction system (LRS. Materials and Methods: Between April 2009 and September 2012, we treated 30 cases of complex nonunion of long bone with the LRS. 28 were male and 2 females. Average shortening was 5.06 cm and 14 cases presented with infected implants. Initially we managed with implant removal, radical debridement followed by fixation with the LRS. In 16 cases, corticotomy and lengthening was done. The average duration of treatment was 9.68 months. We compressed the fracture site at the rate of 0.25 mm per day for 1-2 weeks and distracted the corticotomy at the rate of 1 mm/day till lengthening was achieved. Result: The union occurred in 89.28% cases and eradication of infection in 91.66% cases. Average lengthening done was 4.57 cm. We had 79% excellent, 11% good and 10% poor bony result and fnctional result was excellent in 40% cases, good in 50% and failure in 10% cases using ASAMI scoring system. Conclusion: LRS is an alternative to the Ilizarov fixation in their management of complex nonunion of long bones. It is less cumbersome to the patient and more surgeon and patient friendly.

Direct observation of surface reconstruction and termination on a complex metal oxide catalyst by electron microscopy

KAUST Repository

Zhu, Yihan

2012-03-19

On the surface: The surface reconstruction of an MoVTeO complex metal oxide catalyst was observed directly by various electron microscopic techniques and the results explain the puzzling catalytic behavior. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Safety and Efficacy of Cell-Assisted Fat Grafting to Traditional Fat Grafting in the Anterior Mid-Face: An Indirect Assessment by 3D Imaging.

Science.gov (United States)

Sasaki, Gordon H

2015-12-01

Numerous methodologies and algorithms have been suggested to enhance fat graft survival, including the usage of stromal vascular fraction (SVF) and platelet-rich plasma (PRP), but no long-term studies are available. This single-center prospective, case-controlled study investigated the safety and efficacy of combining a modified Baker-designed lateral SMASectomy or plication face lift with simultaneous anterior mid-face grafting into site-specific compartments by (1) conventional Coleman's technique or (2) Yoshimura's cell-assisted lipografting technique. On the voluntary principle, candidates selected one of four techniques for volumization of their mid-face: conventional fat grafting; PRP-assisted fat grafting; SVF-assisted fat grafting; and PRP/SVF- assisted fat grafting. For comparison data, comparable fat volumes, SVF volumes and nucleated cells, and PRP volumes and platelet concentrations were injected into each designated group. Indirect volume retentions were determined by standardized Vectra 3D analyses up to 1 year. PRP, SVF, and PRP/SVF cell supplementation of processed fat resulted in statistically significant percent mean graft retention over their baseline control at 12 months (p facial aesthetic surgery. With refinements in the entire grafting process and the potential benefits of autologous cell approaches with SVF and PRP, future evidence-based controlled studies under regulatory approval may improve graft survival in a safe and effective manner. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Analysis of protein-protein docking decoys using interaction fingerprints: application to the reconstruction of CaM-ligand complexes

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Uchikoga Nobuyuki

2010-05-01

Full Text Available Abstract Background Protein-protein docking for proteins with large conformational changes was analyzed by using interaction fingerprints, one of the scales for measuring similarities among complex structures, utilized especially for searching near-native protein-ligand or protein-protein complex structures. Here, we have proposed a combined method for analyzing protein-protein docking by taking large conformational changes into consideration. This combined method consists of ensemble soft docking with multiple protein structures, refinement of complexes, and cluster analysis using interaction fingerprints and energy profiles. Results To test for the applicability of this combined method, various CaM-ligand complexes were reconstructed from the NMR structures of unbound CaM. For the purpose of reconstruction, we used three known CaM-ligands, namely, the CaM-binding peptides of cyclic nucleotide gateway (CNG, CaM kinase kinase (CaMKK and the plasma membrane Ca2+ ATPase pump (PMCA, and thirty-one structurally diverse CaM conformations. For each ligand, 62000 CaM-ligand complexes were generated in the docking step and the relationship between their energy profiles and structural similarities to the native complex were analyzed using interaction fingerprint and RMSD. Near-native clusters were obtained in the case of CNG and CaMKK. Conclusions The interaction fingerprint method discriminated near-native structures better than the RMSD method in cluster analysis. We showed that a combined method that includes the interaction fingerprint is very useful for protein-protein docking analysis of certain cases.

Development of a Near-Field Bistatic Synthetic Aperture Radar for Complex Target Reconstruction

Directory of Open Access Journals (Sweden)

David G. Johnson

2012-01-01

Full Text Available This paper begins with a description of the design, construction, and characterization of a small electromagnetic anechoic chamber, developed specifically to house a bistatic ISAR system for the analysis of rock samples. Particular emphasis is given to the practicalities of construction, with the intention of assisting those in a similar position, wishing to build an anechoic chamber on a tight budget. The second part of the paper outlines efficient algorithms that may be applied to the tomographic and topographic reconstruction of complex targets within the viewing geometry of this ISAR system.

On the Complexity of Reconstructing Chemical Reaction Networks

DEFF Research Database (Denmark)

Fagerberg, Rolf; Flamm, Christoph; Merkle, Daniel

2013-01-01

The analysis of the structure of chemical reaction networks is crucial for a better understanding of chemical processes. Such networks are well described as hypergraphs. However, due to the available methods, analyses regarding network properties are typically made on standard graphs derived from...... the full hypergraph description, e.g. on the so-called species and reaction graphs. However, a reconstruction of the underlying hypergraph from these graphs is not necessarily unique. In this paper, we address the problem of reconstructing a hypergraph from its species and reaction graph and show NP...

Innovations in diabetic foot reconstruction using supermicrosurgery.

Science.gov (United States)

Suh, Hyun Suk; Oh, Tae Suk; Hong, Joon Pio

2016-01-01

The treatment of diabetic foot ulceration is complex with multiple factors involved, and it may often lead to limb amputation. Hence, a multidisciplinary approach is warranted to cover the spectrum of treatment for diabetic foot, but in complex wounds, surgical treatment is inevitable. Surgery may involve the decision to preserve the limb by reconstruction or to amputate it. Reconstruction involves preserving the limb with secure coverage. Local flaps usually are able to provide sufficient coverage for small or moderate sized wound, but for larger wounds, soft tissue coverage involves flaps that are distantly located from the wound. Reconstruction of distant flap usually involves microsurgery, and now, further innovative methods such as supermicrosurgery have further given complex wounds a better chance to be reconstructed and limbs salvaged. This article reviews the microsurgery involved in reconstruction and introduces the new method of supermicrosurgery. Copyright © 2016 John Wiley & Sons, Ltd.

Influence of Ultra-Low-Dose and Iterative Reconstructions on the Visualization of Orbital Soft Tissues on Maxillofacial CT.

Science.gov (United States)

Widmann, G; Juranek, D; Waldenberger, F; Schullian, P; Dennhardt, A; Hoermann, R; Steurer, M; Gassner, E-M; Puelacher, W

2017-08-01

Dose reduction on CT scans for surgical planning and postoperative evaluation of midface and orbital fractures is an important concern. The purpose of this study was to evaluate the variability of various low-dose and iterative reconstruction techniques on the visualization of orbital soft tissues. Contrast-to-noise ratios of the optic nerve and inferior rectus muscle and subjective scores of a human cadaver were calculated from CT with a reference dose protocol (CT dose index volume = 36.69 mGy) and a subsequent series of low-dose protocols (LDPs I-4: CT dose index volume = 4.18, 2.64, 0.99, and 0.53 mGy) with filtered back-projection (FBP) and adaptive statistical iterative reconstruction (ASIR)-50, ASIR-100, and model-based iterative reconstruction. The Dunn Multiple Comparison Test was used to compare each combination of protocols (α = .05). Compared with the reference dose protocol with FBP, the following statistically significant differences in contrast-to-noise ratios were shown (all, P ≤ .012) for the following: 1) optic nerve: LDP-I with FBP; LDP-II with FBP and ASIR-50; LDP-III with FBP, ASIR-50, and ASIR-100; and LDP-IV with FBP, ASIR-50, and ASIR-100; and 2) inferior rectus muscle: LDP-II with FBP, LDP-III with FBP and ASIR-50, and LDP-IV with FBP, ASIR-50, and ASIR-100. Model-based iterative reconstruction showed the best contrast-to-noise ratio in all images and provided similar subjective scores for LDP-II. ASIR-50 had no remarkable effect, and ASIR-100, a small effect on subjective scores. Compared with a reference dose protocol with FBP, model-based iterative reconstruction may show similar diagnostic visibility of orbital soft tissues at a CT dose index volume of 2.64 mGy. Low-dose technology and iterative reconstruction technology may redefine current reference dose levels in maxillofacial CT. © 2017 by American Journal of Neuroradiology.

Cloacal reconstruction after a complex treatment of perineal haemangioma in a variant of PELVIS syndrome.

Science.gov (United States)

Zalimas, Algirdas; Posiunas, Gintas; Strupas, Sigitas; Raugalas, Ramunas; Raistenskis, Juozas; Verkauskas, Gilvydas

2015-10-08

neurological monitoring. Large perineal hemangiomas are commonly associated with extracutaneous abnormalities. Successful reconstructive surgery is possible after significant reduction of hemangioma by complex treatment.

A method of reconstructing complex stratigraphic surfaces with multitype fault constraints

Science.gov (United States)

Deng, Shi-Wu; Jia, Yu; Yao, Xing-Miao; Liu, Zhi-Ning

2017-06-01

The construction of complex stratigraphic surfaces is widely employed in many fields, such as petroleum exploration, geological modeling, and geological structure analysis. It also serves as an important foundation for data visualization and visual analysis in these fields. The existing surface construction methods have several deficiencies and face various difficulties, such as the presence of multitype faults and roughness of resulting surfaces. In this paper, a surface modeling method that uses geometric partial differential equations (PDEs) is introduced for the construction of stratigraphic surfaces. It effectively solves the problem of surface roughness caused by the irregularity of stratigraphic data distribution. To cope with the presence of multitype complex faults, a two-way projection algorithm between threedimensional space and a two-dimensional plane is proposed. Using this algorithm, a unified method based on geometric PDEs is developed for dealing with multitype faults. Moreover, the corresponding geometric PDE is derived, and an algorithm based on an evolutionary solution is developed. The algorithm proposed for constructing spatial surfaces with real data verifies its computational efficiency and its ability to handle irregular data distribution. In particular, it can reconstruct faulty surfaces, especially those with overthrust faults.

Reconstructing Historical Land Cover Type and Complexity by Synergistic Use of Landsat Multispectral Scanner and CORONA

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Amir Reza Shahtahmassebi

2017-07-01

Full Text Available Survey data describing land cover information such as type and diversity over several decades are scarce. Therefore, our capacity to reconstruct historical land cover using field data and archived remotely sensed data over large areas and long periods of time is somewhat limited. This study explores the relationship between CORONA texture—a surrogate for actual land cover type and complexity—with spectral vegetation indices and texture variables derived from Landsat MSS under the Spectral Variation Hypothesis (SVH such as to reconstruct historical continuous land cover type and complexity. Image texture of CORONA was calculated using a mean occurrence measure while image textures of Landsat MSS were calculated by occurrence and co-occurrence measures. The relationship between these variables was evaluated using correlation and regression techniques. The reconstruction procedure was undertaken through regression kriging. The results showed that, as expected, texture based on the visible bands and corresponding indices indicated larger correlation with CORONA texture, a surrogate of land cover (correlation >0.65. In terms of prediction, the combination of the first-order mean of band green, second-order measure of tasseled cap brightness, second-order mean of Normalized Visible Index (NVI and second-order entropy of NIR yielded the best model with respect to Akaike’s Information Criterion (AIC, r-square, and variance inflation factors (VIF. The regression model was then used in regression kriging to map historical continuous land cover. The resultant maps indicated the type and degree of complexity in land cover. Moreover, the proposed methodology minimized the impacts of topographic shadow in the region. The performance of this approach was compared with two conventional classification methods: hard classifiers and continuous classifiers. In contrast to conventional techniques, the technique could clearly quantify land cover complexity and

Free Vastus Intermedius Muscle Flap: A Successful Alternative for Complex Reconstruction of the Neurocranium in Preoperated Patients.

Science.gov (United States)

Horn, Dominik; Freudlsperger, Christian; Berger, Moritz; Freier, Kolja; Ristow, Oliver; Hoffmann, Jürgen; Sakowitz, Oliver; Engel, Michael

2017-07-01

The reconstruction of large cranial and scalp defects is a surgical and esthetic challenge. Single autologous tissue transfer can be insufficient due to the defect size and the anatomic complexity of the recipient site. Alloplastic patient-specific preformed implants can be used to recover hard tissue defects of the neurocranium. Nevertheless, for long-term success adequate soft tissue support is required. In this brief clinical study, the authors describe calvarian reconstruction in a 33-year-old patient with wound healing disorder after an initial resection of ependymoma. The patient suffered from osteonecrosis and wound breakdown in the fronto-parietal region. An alloplastic polymethylmethacrylate implant for hard tissue support was manufactured based on 3-dimensional visualization of a computed tomography scan. After the resection of remaining pathologic bone from earlier surgical procedures, the alloplastic implant was inserted to achieve functional coverage of the brain. Due to anatomic variation of donor site vessels during anterolateral thigh flap preparation, the authors performed a vastus intermedius free flap as a new muscular flap for craniofacial reconstruction. The authors achieved excellent functional and esthetic results. The muscular vastus intermedius free flap in combination with a split skin graft proves to be a new alternative to the anterolateral thigh flap for soft tissue reconstruction of the neurocranium.

Comparison of Absorbable Mesh Plate versus Titanium-Dynamic Mesh Plate in Reconstruction of Blow-Out Fracture: An Analysis of Long-Term Outcomes

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Woon Il Baek

2014-07-01

Full Text Available Background A blow-out fracture is one of the most common facial injuries in midface trauma. Orbital wall reconstruction is extremely important because it can cause various functional and aesthetic sequelae. Although many materials are available, there are no uniformly accepted guidelines regarding material selection for orbital wall reconstruction. Methods From January 2007 to August 2012, a total of 78 patients with blow-out fractures were analyzed. 36 patients received absorbable mesh plates, and 42 patients received titanium-dynamic mesh plates. Both groups were retrospectively evaluated for therapeutic efficacy and safety according to the incidence of three different complications: enophthalmos, extraocular movement impairment, and diplopia. Results For all groups (inferior wall fracture group, medial wall fractrue group, and combined inferomedial wall fracture group, there were improvements in the incidence of each complication regardless of implant types. Moreover, a significant improvement of enophthalmos occurred for both types of implants in group 1 (inferior wall fracture group. However, we found no statistically significant differences of efficacy or complication rate in every groups between both implant types. Conclusions Both types of implants showed good results without significant differences in long-term follow up, even though we expected the higher recurrent enophthalmos rate in patients with absorbable plate. In conclusion, both types seem to be equally effective and safe for orbital wall reconstruction. In particular, both implant types significantly improve the incidence of enophthalmos in cases of inferior orbital wall fractures.

Secondary reconstruction of maxillofacial trauma.

Science.gov (United States)

Castro-Núñez, Jaime; Van Sickels, Joseph E

2017-08-01

Craniomaxillofacial trauma is one of the most complex clinical conditions in contemporary maxillofacial surgery. Vital structures and possible functional and esthetic sequelae are important considerations following this type of trauma and intervention. Despite the best efforts of the primary surgery, there are a group of patients that will have poor outcomes requiring secondary reconstruction to restore form and function. The purpose of this study is to review current concepts on secondary reconstruction to the maxillofacial complex. The evaluation of a posttraumatic patient for a secondary reconstruction must include an assessment of the different subunits of the upper face, middle face, and lower face. Virtual surgical planning and surgical guides represent the most important innovations in secondary reconstruction over the past few years. Intraoperative navigational surgery/computed-assisted navigation is used in complex cases. Facial asymmetry can be corrected or significantly improved by segmentation of the computerized tomography dataset and mirroring of the unaffected side by means of virtual surgical planning. Navigational surgery/computed-assisted navigation allows for a more precise surgical correction when secondary reconstruction involves the replacement of extensive anatomical areas. The use of technology can result in custom-made replacements and prebent plates, which are more stable and resistant to fracture because of metal fatigue. Careful perioperative evaluation is the key to positive outcomes of secondary reconstruction after trauma. The advent of technological tools has played a capital role in helping the surgical team perform a given treatment plan in a more precise and predictable manner.

Omphalocele, exstrophy of cloaca, imperforate anus, and spinal defect complex, multiple major reconstructive surgeries needed

Directory of Open Access Journals (Sweden)

Nada Neel

2018-01-01

Full Text Available OEIS complex is a rare combination of serious birth defects including omphalocele, exstrophy of cloaca, imperforate anus, and spinal defects. The aim of managements has shifted from merely providing survival to improve patient outcomes and quality of life with higher level of physical and social independence. Multiple complicated reconstructive surgeries always needed for achieving the goals of treatment. In this case report, we aimed to present our surgical approach for this rare abnormality to achieve functionally and socially acceptable outcome.

Involuntary movement during mastication in patients with long-term facial paralysis reanimated with a partial gracilis free neuromuscular flap innervated by the masseteric nerve.

Science.gov (United States)

Rozen, Shai; Harrison, Bridget

2013-07-01

Midface reanimation in patients with chronic facial paralysis is not always possible with an ipsilateral or contralateral facial nerve innervating a free neuromuscular tissue transfer. Alternate use of nonfacial nerves is occasionally indicated but may potentially result in inadvertent motions. The goal of this study was to objectively review videos of patients who underwent one-stage reanimation with a gracilis muscle transfer innervated by the masseteric nerve for (1) inadvertent motion during eating, (2) characterization of masticatory patterns, and (3) social hindrance perceived by the patients during meals. Between the years 2009 and 2012, 18 patients underwent midfacial reanimation with partial gracilis muscle transfer coapted to the masseter nerve for treatment of midfacial paralysis. Sixteen patients were videotaped in detail while eating. Involuntary midface movement on the reconstructed side and mastication patterns were assessed. In addition, 16 patients were surveyed as to whether involuntary motion constituted a problem in their daily lives. All 16 patients videotaped during mastication demonstrated involuntary motion on the reconstructed side while eating. Several unique masticatory patterns were noted as well. Only one of the 16 patients reported involuntary motion as a minor disturbance in daily life during meals. All patients with chronic facial paralysis who plan to undergo midface reanimation with a free tissue transfer innervated by the ipsilateral masseter nerve should be told that they would universally have involuntary animation during mastication. Most patients do not consider this a major drawback in their daily lives. Therapeutic, IV.

Towards comprehensive cell lineage reconstructions in complex organisms using light-sheet microscopy.

Science.gov (United States)

Amat, Fernando; Keller, Philipp J

2013-05-01

Understanding the development of complex multicellular organisms as a function of the underlying cell behavior is one of the most fundamental goals of developmental biology. The ability to quantitatively follow cell dynamics in entire developing embryos is an indispensable step towards such a system-level understanding. In recent years, light-sheet fluorescence microscopy has emerged as a particularly promising strategy for recording the in vivo data required to realize this goal. Using light-sheet fluorescence microscopy, entire complex organisms can be rapidly imaged in three dimensions at sub-cellular resolution, achieving high temporal sampling and excellent signal-to-noise ratio without damaging the living specimen or bleaching fluorescent markers. The resulting datasets allow following individual cells in vertebrate and higher invertebrate embryos over up to several days of development. However, the complexity and size of these multi-terabyte recordings typically preclude comprehensive manual analyses. Thus, new computational approaches are required to automatically segment cell morphologies, accurately track cell identities and systematically analyze cell behavior throughout embryonic development. We review current efforts in light-sheet microscopy and bioimage informatics towards this goal, and argue that comprehensive cell lineage reconstructions are finally within reach for many key model organisms, including fruit fly, zebrafish and mouse. © 2013 The Authors Development, Growth & Differentiation © 2013 Japanese Society of Developmental Biologists.

Image Reconstruction. Chapter 13

Energy Technology Data Exchange (ETDEWEB)

Nuyts, J. [Department of Nuclear Medicine and Medical Imaging Research Center, Katholieke Universiteit Leuven, Leuven (Belgium); Matej, S. [Medical Image Processing Group, Department of Radiology, University of Pennsylvania, Philadelphia, PA (United States)

2014-12-15

This chapter discusses how 2‑D or 3‑D images of tracer distribution can be reconstructed from a series of so-called projection images acquired with a gamma camera or a positron emission tomography (PET) system [13.1]. This is often called an ‘inverse problem’. The reconstruction is the inverse of the acquisition. The reconstruction is called an inverse problem because making software to compute the true tracer distribution from the acquired data turns out to be more difficult than the ‘forward’ direction, i.e. making software to simulate the acquisition. There are basically two approaches to image reconstruction: analytical reconstruction and iterative reconstruction. The analytical approach is based on mathematical inversion, yielding efficient, non-iterative reconstruction algorithms. In the iterative approach, the reconstruction problem is reduced to computing a finite number of image values from a finite number of measurements. That simplification enables the use of iterative instead of mathematical inversion. Iterative inversion tends to require more computer power, but it can cope with more complex (and hopefully more accurate) models of the acquisition process.

Accuracy of secondary maxillofacial reconstruction with prefabricated fibula grafts using 3D planning and guided reconstruction

NARCIS (Netherlands)

Schepers, Rutger H.; Kraeima, Joep; Vissink, Arjan; Lahoda, Lars U.; Roodenburg, Jan L. N.; Reintsema, Harry; Raghoebar, Gerry M.; Witjes, Max J.

Background: We compared the pre-operative 3D-surgical plan with the surgical outcome of complex two-stage secondary reconstruction of maxillofacial defects using inserted implants in the prefabricated fibula graft. Methods: Eleven reconstructions of maxillofacial defects with prefabricated fibulas

Three-dimensional CT of the mandible

International Nuclear Information System (INIS)

Zinreich, S.J.; Price, J.C.; Wang, H.; Ahn, H.S.; Kashima, H.

1988-01-01

Seventeen patients with mandibular oblation for facial neoplasia, primary neoplasm, and trauma were evaluated with CT and three-dimensional CT. In eight of these patients, a computerized acrylic model was generated for preoperative planning and postoperative reconstruction. The ramus and body of the mandible were reconstructed with mirror image and fusion techniques. Reconstructions of the anterior mandible were generated from models including the midface, skull based, and residual mandibular fragments. The results are preliminary; however, the authors believe that these represent a powerful new tool and a significant advance in mandibular reconstructive technique, reduced anesthesia time, and the optimized restoration of dental alignment and facial contour

Reconstruction of hyperspectral reflectance for optically complex turbid inland lakes: test of a new scheme and implications for inversion algorithms.

Science.gov (United States)

Sun, Deyong; Hu, Chuanmin; Qiu, Zhongfeng; Wang, Shengqiang

2015-06-01

A new scheme has been proposed by Lee et al. (2014) to reconstruct hyperspectral (400 - 700 nm, 5 nm resolution) remote sensing reflectance (Rrs(λ), sr-1) of representative global waters using measurements at 15 spectral bands. This study tested its applicability to optically complex turbid inland waters in China, where Rrs(λ) are typically much higher than those used in Lee et al. (2014). Strong interdependence of Rrs(λ) between neighboring bands (≤ 10 nm interval) was confirmed, with Pearson correlation coefficient (PCC) mostly above 0.98. The scheme of Lee et al. (2014) for Rrs(λ) re-construction with its original global parameterization worked well with this data set, while new parameterization showed improvement in reducing uncertainties in the reconstructed Rrs(λ). Mean absolute error (MAERrs(λi)) in the reconstructed Rrs(λ) was mostly -1 between 400 and 700nm, and mean relative error (MRERrs(λi)) was rs(λ) spectra. When Rrs(λ) at the MODIS bands were used to reconstruct the hyperspectral Rrs(λ), MAERrs(λi) was -1 and MRERrs(λi) was rs(λ) at the MERIS bands were used, MAERrs(λi) in the reconstructed hyperspectral Rrs(λ) was -1 and MRERrs(λi) was rs(λ) data using spectral bands that may not exist on satellite sensors.

Can the Diagnostics of Triangular Fibrocartilage Complex Lesions Be Improved by MRI-Based Soft-Tissue Reconstruction? An Imaging-Based Workup and Case Presentation.

Science.gov (United States)

Hammer, Niels; Hirschfeld, Ulrich; Strunz, Hendrik; Werner, Michael; Wolfskämpf, Thomas; Löffler, Sabine

2017-01-01

Introduction . The triangular fibrocartilage complex (TFCC) provides both mobility and stability of the radiocarpal joint. TFCC lesions are difficult to diagnose due to the complex anatomy. The standard treatment for TFCC lesions is arthroscopy, posing surgery-related risks onto the patients. This feasibility study aimed at developing a workup for soft-tissue reconstruction using clinical imaging, to verify these results in retrospective patient data. Methods . Microcomputed tomography ( μ -CT), 3 T magnetic resonance imaging (MRI), and plastination were used to visualize the TFCC in cadaveric specimens applying segmentation-based 3D reconstruction. This approach further trialed the MRI dataset of a patient with minor radiological TFCC alterations but persistent pain. Results . TFCC reconstruction was impossible using μ -CT only but feasible using MRI, resulting in an appreciation of its substructures, as seen in the plastinates. Applying this approach allowed for visualizing a Palmer 2C lesion in a patient, confirming ex postum the arthroscopy findings, being markedly different from MRI (Palmer 1B). Discussion . This preliminary study showed that image-based TFCC reconstruction may help to identify pathologies invisible in standard MRI. The combined approach of μ -CT, MRI, and plastination allowed for a three-dimensional appreciation of the TFCC. Image quality and time expenditure limit the approach's usefulness as a diagnostic tool.

Organización en el tratamiento del traumatismo panfacial y de las fracturas complejas del tercio medio Organization of treatment in panfacial trauma and complex midfacial fractures

Directory of Open Access Journals (Sweden)

J. Muñoz i Vidal

2009-03-01

between 2005 and 2006. There were 14 patients with midface high energy trauma, 4 of those associated to mandible or upper face subunit fractures. Extraocular motility, air way, correct oclussal relationship, minimum aesthetic sequel and correct recreating of facial dimensions define our goals. A multidisciplinary approach to these patients is imperative. Due to the complexity of these cases, there is not place allowed for improvisation and a previous accurate anamnesis, exploration and order of treatment is absolutely required. This leads to a proper management, an anatomic bone threedimensional reconstruction, preservation of soft structures according to previous patient's anthropometry and minimum aesthetic sequel in a single surgery time.

Reconstructing Topological Graphs and Continua

OpenAIRE

Gartside, Paul; Pitz, Max F.; Suabedissen, Rolf

2015-01-01

The deck of a topological space $X$ is the set $\\mathcal{D}(X)=\\{[X \\setminus \\{x\\}] \\colon x \\in X\\}$, where $[Z]$ denotes the homeomorphism class of $Z$. A space $X$ is topologically reconstructible if whenever $\\mathcal{D}(X)=\\mathcal{D}(Y)$ then $X$ is homeomorphic to $Y$. It is shown that all metrizable compact connected spaces are reconstructible. It follows that all finite graphs, when viewed as a 1-dimensional cell-complex, are reconstructible in the topological sense, and more genera...

Can the Diagnostics of Triangular Fibrocartilage Complex Lesions Be Improved by MRI-Based Soft-Tissue Reconstruction? An Imaging-Based Workup and Case Presentation

Directory of Open Access Journals (Sweden)

Niels Hammer

2017-01-01

Full Text Available Introduction. The triangular fibrocartilage complex (TFCC provides both mobility and stability of the radiocarpal joint. TFCC lesions are difficult to diagnose due to the complex anatomy. The standard treatment for TFCC lesions is arthroscopy, posing surgery-related risks onto the patients. This feasibility study aimed at developing a workup for soft-tissue reconstruction using clinical imaging, to verify these results in retrospective patient data. Methods. Microcomputed tomography (μ-CT, 3 T magnetic resonance imaging (MRI, and plastination were used to visualize the TFCC in cadaveric specimens applying segmentation-based 3D reconstruction. This approach further trialed the MRI dataset of a patient with minor radiological TFCC alterations but persistent pain. Results. TFCC reconstruction was impossible using μ-CT only but feasible using MRI, resulting in an appreciation of its substructures, as seen in the plastinates. Applying this approach allowed for visualizing a Palmer 2C lesion in a patient, confirming ex postum the arthroscopy findings, being markedly different from MRI (Palmer 1B. Discussion. This preliminary study showed that image-based TFCC reconstruction may help to identify pathologies invisible in standard MRI. The combined approach of μ-CT, MRI, and plastination allowed for a three-dimensional appreciation of the TFCC. Image quality and time expenditure limit the approach’s usefulness as a diagnostic tool.

Rigid external maxillary distraction and rhinoplasty for pyknodysostosis.

Science.gov (United States)

Varol, Altan; Sabuncuoglu, Fidan Alakus; Sencimen, Metin; Akcam, Timur; Olmez, Hüseyin; Basa, Selçuk

2011-05-01

This article reports the treatment of an 33-year-old female patient with pyknodysostosis by rigid external distraction II midface distraction system. The patient with pyknodysostosis described in this report had severe midfacial hypoplasia. Correction of this by use of routine orthognathic surgery would require osteosynthesis and bone grafting. Risk of infection and/or nonunion after such a surgical procedure was considered too great, and therefore the possibility of treatment by distraction osteogenesis of the maxilla was evaluated. The rigid external distraction II midface distraction system was used to relocate the hypoplastic maxilla at anterior-inferior projection. Distraction osteogenesis should be considered as the primary reconstructive method for maxillofacial deformities in patients with sclerosing bone dysplasias, since this is the second reported case treated successfully with rigid external distraction.

Improved data illustration in complex multi-ligament knee reconstruction surgery: using the historical principles of Florence Nightingale and John Venn.

Science.gov (United States)

Meyers, Paul D; McNicholas, Mike J

2008-04-01

The collection of multi-ligament knee reconstruction procedure data generates long tabulated lists of featureless abbreviations, which are often difficult to interpret and present. As demonstrated with the launch of the Scandinavian anterior cruciate ligament registries, such data are under increasing scrutiny. When developing a visual tool to improve the interpretation, presentation, and ongoing collection of data within this field, much can be learnt from the historical teachings of Florence Nightingale and John Venn. Unknown to many, Florence Nightingale was a pioneer of graphic data illustration, becoming a Fellow of the Royal Statistical Society in 1858. Further advances in the visualization of complex data relations were made by John Venn, who introduced the Venn diagram in 1880. With this background in mind, the present work has been based upon the senior author's case series of 70 patients undergoing complex knee-ligament reconstruction at Warrington Hospital, from 2001 to the present time. Although obviously not negating the need for tabulated data, the graphic representation put forward here successfully supplements featureless tabulated lists of abbreviations and can be updated easily and regularly. Providing a clear, bright illustration that is free from patient identifiers, it can be used in presentations and publications, and freely accessed by a multidisciplinary team. It assists in the identification of injury patterns, can accommodate illustration of associated factors such as meniscal injury, and clearly demonstrates each hospital's multi-ligament knee reconstruction experience. This facilitates comparison and collaboration between hospitals and promotes research.

Technical basis for dose reconstruction

International Nuclear Information System (INIS)

Anspaugh, L.R.

1996-01-01

The purpose of this paper is to consider two general topics: Technical considerations of why dose-reconstruction studies should or should not be performed and methods of dose reconstruction. The first topic is of general and growing interest as the number of dose-reconstruction studies increases, and one asks the question whether it is necessary to perform a dose reconstruction for virtually every site at which, for example, the Department of Energy (DOE) has operated a nuclear-related facility. And there is the broader question of how one might logically draw the line at performing or not performing dose-reconstruction (radiological and chemical) studies for virtually every industrial complex in the entire country. The second question is also of general interest. There is no single correct way to perform a dose-reconstruction study, and it is important not to follow blindly a single method to the point that cheaper, faster, more accurate, and more transparent methods might not be developed and applied. 90 refs., 4 tabs

Technical basis for dose reconstruction

International Nuclear Information System (INIS)

Anspaugh, L.R.

1996-01-01

The purpose of this paper is to consider two general topics: technical considerations of why dose-reconstruction studies should or should not be performed and methods of dose reconstruction. The first topic is of general and growing interest as the number of dose-reconstruction studies increases, and one asks the question whether it is necessary to perform a dose reconstruction for virtually every site at which, for example, the Department of Energy (DOE) has operated a nuclear-related facility. And there is the broader question of how one might logically draw the line at performing or not performing dose-reconstruction (radiological and chemical) studies for virtually every industrial complex in the entire country. The second question is also of general interest. There is no single correct way to perform a dose-reconstruction study, and it is important not to follow blindly a single method to the point that cheaper, faster, more accurate, and more transparent methods might not be developed and applied

Reconstruction of Complex Post-Traumatic Perineal/Pelvic Defects ...

African Journals Online (AJOL)

of the pelvic diaphragm). A composite pedicled. ALT flap was considered adequate for the initial reconstruction and stabilization, with the option of using a free fibular flap later, should the pelvic ring remain unstable. The fascia was used to complete the pelvic ring. It also provided anterior support to the pelvic diaphragm.

Design of low complexity sharp MDFT filter banks with perfect reconstruction using hybrid harmony-gravitational search algorithm

Directory of Open Access Journals (Sweden)

V. Sakthivel

2015-12-01

Full Text Available The design of low complexity sharp transition width Modified Discrete Fourier Transform (MDFT filter bank with perfect reconstruction (PR is proposed in this work. The current trends in technology require high data rates and speedy processing along with reduced power consumption, implementation complexity and chip area. Filters with sharp transition width are required for various applications in wireless communication. Frequency response masking (FRM technique is used to reduce the implementation complexity of sharp MDFT filter banks with PR. Further, to reduce the implementation complexity, the continuous coefficients of the filters in the MDFT filter banks are represented in discrete space using canonic signed digit (CSD. The multipliers in the filters are replaced by shifters and adders. The number of non-zero bits is reduced in the conversion process to minimize the number of adders and shifters required for the filter implementation. Hence the performances of the MDFT filter bank with PR may degrade. In this work, the performances of the MDFT filter banks with PR are improved using a hybrid Harmony-Gravitational search algorithm.

Core nucleosomes by digestion of reconstructed histone-DNA complexes

Energy Technology Data Exchange (ETDEWEB)

Bryan, P N; Wright, E B; Olins, D E

1979-04-01

Reconstructed complexes of the inner histones (H2A, H2B, H3, H4) and a variety of DNAs were digested with micrococcal nuclease to yield very homogeneous populations of core nucleosomes (..nu../sub 1/). Nucleosomes containing Micrococcus luteus DNA (72% G+C); chicken DNA (43% G+C), Clostridium perfringens DNA (29% G+C); or poly(dA-dT).poly(dA-dT) have been examined by circular dichroism, thermal denaturation, electron microscopy, and DNAse I digestion. Circular dichroism spectra of all particles show a typically suppressed ellipticity at 260 to 280 nm and a prominent ..cap alpha..-helix signal at 222 nm. All particles show biphasic melting except ..nu../sub 1/(dA-dT), which show three prominent melting transitions at ionic strength less than or equal to 1 mM. DNAse I digestion of ..nu../sub 1/ (dA-dT) produces a ladder of DNA fragments differing in length by one base residue. ..nu../sub 1/ (dA-dT) contain 146 base pairs of DNA and exhibit an average DNA helix pitch of 10.4 to 10.5 bases per turn. There appear to be two regions of different DNA pitch within ..nu../sub 1/ (dA-dT). It is suggested that the two regions of DNA pitch might correspond to the two regions of the melting profiles.

[Reconstructive methods after Fournier gangrene].

Science.gov (United States)

Wallner, C; Behr, B; Ring, A; Mikhail, B D; Lehnhardt, M; Daigeler, A

2016-04-01

Fournier's gangrene is a variant of the necrotizing fasciitis restricted to the perineal and genital region. It presents as an acute life-threatening disease and demands rapid surgical debridement, resulting in large soft tissue defects. Various reconstructive methods have to be applied to reconstitute functionality and aesthetics. The objective of this work is to identify different reconstructive methods in the literature and compare them to our current concepts for reconstructing defects caused by Fournier gangrene. Analysis of the current literature and our reconstructive methods on Fournier gangrene. The Fournier gangrene is an emergency requiring rapid, calculated antibiotic treatment and radical surgical debridement. After the acute phase of the disease, appropriate reconstructive methods are indicated. The planning of the reconstruction of the defect depends on many factors, especially functional and aesthetic demands. Scrotal reconstruction requires a higher aesthetic and functional reconstructive degree than perineal cutaneous wounds. In general, thorough wound hygiene, proper pre-operative planning, and careful consideration of the patient's demands are essential for successful reconstruction. In the literature, various methods for reconstruction after Fournier gangrene are described. Reconstruction with a flap is required for a good functional result in complex regions as the scrotum and penis, while cutaneous wounds can be managed through skin grafting. Patient compliance and tissue demand are crucial factors in the decision-making process.

Animated Reconstruction of Forensic Animation

OpenAIRE

Hala, Albert; Unver, Ertu

1998-01-01

An animated accident display in court can be significant evidentiary tool. Computer graphics animation reconstructions which can be shown in court are cost effective, save valuable time and illustrate complex and technical issues, are realistic and can prove or disprove arguments or theories with reference to the perplexing newtonian physics involved in many accidents: this technology may well revolutionise accident reconstruction, thus enabling prosecution and defence to be more effective in...

Demonstration of the Effectiveness of Augmented Reality Telesurgery in Complex Hand Reconstruction in Gaza

Science.gov (United States)

Luck, Joshua; Billingsley, Michael L.; Heyes, Richard; Smith, Oliver J.; Mosahebi, Afshin; Khoussa, Abu; Abu-Sittah, Ghassan; Hachach-Haram, Nadine

2018-01-01

Summary: Augmented reality (AR) is defined as “a technology that superimposes a computer-generated image on a user’s view of the real world, thus providing a composite view.”1 This case report describes how emerging AR telesurgery technologies may be used to facilitate international surgeon–surgeon collaboration and training. Here, we illustrate how a remote surgeon in Beirut, Lebanon, was able to offer assistance to a surgeon in Gaza, Palestine, during a complex hand reconstruction case following a bomb-blast injury in an 18-year-old male. We discuss the implications of AR technology on the future of global surgery and how it may be used to reduce structural inequities in access to safe surgical care. PMID:29707463

Demonstration of the Effectiveness of Augmented Reality Telesurgery in Complex Hand Reconstruction in Gaza

Directory of Open Access Journals (Sweden)

Max J. Greenfield, BSc

2018-03-01

Full Text Available Summary:. Augmented reality (AR is defined as “a technology that superimposes a computer-generated image on a user’s view of the real world, thus providing a composite view.”1 This case report describes how emerging AR telesurgery technologies may be used to facilitate international surgeon–surgeon collaboration and training. Here, we illustrate how a remote surgeon in Beirut, Lebanon, was able to offer assistance to a surgeon in Gaza, Palestine, during a complex hand reconstruction case following a bomb-blast injury in an 18-year-old male. We discuss the implications of AR technology on the future of global surgery and how it may be used to reduce structural inequities in access to safe surgical care.

The retrograde transverse cervical artery as a recipient vessel for free tissue transfer in complex head and neck reconstruction with a vessel-depleted neck.

Science.gov (United States)

Ciudad, Pedro; Agko, Mouchammed; Manrique, Oscar J; Date, Shivprasad; Kiranantawat, Kidakorn; Chang, Wei Ling; Nicoli, Fabio; Lo Torto, Federico; Maruccia, Michele; Orfaniotis, Georgios; Chen, Hung-Chi

2017-11-01

Reconstruction in a vessel-depleted neck is challenging. The success rates can be markedly decreased because of unavailability of suitable recipient vessels. In order to obtain a reliable flow, recipient vessels away from the zone of fibrosis, radiation, or infection need to be explored. The aim of this report is to present our experience and clinical outcomes using the retrograde flow coming from the distal transverse cervical artery (TCA) as a source for arterial inflow for complex head and neck reconstruction in patients with a vessel-depleted neck. Between July 2010 and June 2016, nine patients with a vessel-depleted neck underwent secondary head and neck reconstruction using the retrograde TCA as recipient vessel for microanastomosis. The mean age was 49.6 years (range, 36 to 68 years). All patients had previous bilateral neck dissections and all, except one, had also received radiotherapy. Indications included neck contracture release (n = 3), oral (n = 1), mandibular (n = 3) and pharyngoesophageal (n = 2) reconstruction necessitating free anterolateral thigh (n = 3) and medial sural artery (n = 1) perforator flaps, fibula (n = 3) and ileocolon (n = 2) flaps respectively. There was 100% flap survival rate with no re-exploration or any partial flap loss. One case of intra-operative arterial vasospasm at the anastomotic suture line was managed intra-operatively with vein graft interposition. There were no other complications or donor site morbidity during the follow-up period. In a vessel-depleted neck, the reverse flow of the TCA may be a reliable option for complex secondary head and neck reconstruction in selected patients. © 2017 Wiley Periodicals, Inc.

Use of customized polyetheretherketone (PEEK) implants in the reconstruction of complex maxillofacial defects.

Science.gov (United States)

Kim, Michael M; Boahene, Kofi D O; Byrne, Patrick J

2009-01-01

Extensive maxillofacial defects resulting from trauma or oncologic resection present reconstructive challenges. Various autografts and alloplastic materials in conjunction with standard soft-tissue techniques have been used in the reconstruction of these types of defects. Polyetheretherketone (PEEK) is a semicrystalline polyaromatic linear polymer exhibiting an excellent combination of strength, stiffness, durability, and environmental resistance. Recent investigations of PEEK as a biomaterial resulted in the successful treatment of cervical disk disease. We describe a series of 4 patients whose defects were reconstructed using customized PEEK implants. All had excellent postoperative aesthetic and functional results without complications such as infections or extrusions. Because PEEK implants are customizable, easily workable, inert, and nonporous, they represent an ideal alloplastic material for maxillofacial reconstruction.

Sensing of complex buildings and reconstruction into photo-realistic 3D models

NARCIS (Netherlands)

Heredia Soriano, F.J.

2012-01-01

The 3D reconstruction of indoor and outdoor environments has received an interest only recently, as companies began to recognize that using reconstructed models is a way to generate revenue through location-based services and advertisements. A great amount of research has been done in the field of

Surface Reconstruction from Parallel Curves with Application to Parietal Bone Fracture Reconstruction.

Directory of Open Access Journals (Sweden)

Abdul Majeed

Full Text Available Maxillofacial trauma are common, secondary to road traffic accident, sports injury, falls and require sophisticated radiological imaging to precisely diagnose. A direct surgical reconstruction is complex and require clinical expertise. Bio-modelling helps in reconstructing surface model from 2D contours. In this manuscript we have constructed the 3D surface using 2D Computerized Tomography (CT scan contours. The fracture part of the cranial vault are reconstructed using GC1 rational cubic Ball curve with three free parameters, later the 2D contours are flipped into 3D with equidistant z component. The constructed surface is represented by contours blending interpolant. At the end of this manuscript a case report of parietal bone fracture is also illustrated by employing this method with a Graphical User Interface (GUI illustration.

Maxillofacial osseous reconstruction using the angular branch of the thoracodorsal vessels.

LENUS (Irish Health Repository)

Dolderer, Jürgen H

2010-09-01

Mandibular and maxillary resections can produce complex three-dimensional defects requiring skeletal, soft tissue, and epithelial reconstruction. The subscapular vascular axis offers a source of skin, bone, and muscle on a single pedicle for microvascular flap transfer. We reviewed four cases where the subscapular vascular pedicle was used as a source of tissue for complex facial reconstructions in maxillofacial defects. Reconstruction of these complex defects was performed with a latissimus dorsi muscle or myocutaneous flap in combination with the lateral border of the scapula, harvested on the angular branch of the thoracodorsal vessels. There were three cases of maxillectomy and one case of partial mandibulectomy for malignant tumors. In each case, the angular branch of the thoracodorsal artery supplied 6 to 8 cm of the lateral border of the scapula and a latissimus dorsi myocutaneous flap was used for soft tissue reconstruction. Follow-up ranged from 9 months to 3 years and in all cases there was successful bony union. Shoulder movement was normal. This series encourages the further use of subscapular axis flaps as flexible sources of combined myocutaneous and osseous flaps on a single vascular pedicle in cases of complex maxillofacial reconstruction.

Reconstruction of massive facial avulsive injury, secondary to animal bite.

Science.gov (United States)

Motamed, Sadrollah; Niazi, Feizollah; Moosavizadeh, Seyed Mehdi; Gholizade Pasha, Abdolhamid; Motamed, Ali

2014-02-01

Management of facial soft tissue trauma requires complex reconstruction surgery. Animal bite on face is a common cause of facial tissue trauma with severe destruction. Evaluation of unit involvement is the first effort, followed by designation of reconstruction. In this case, we performed multiple reconstruction options.

Soft Tissue Coverage of the Hand and Upper Extremity: The Reconstructive Elevator.

Science.gov (United States)

Miller, Erin Anne; Friedrich, Jeffrey

2016-07-01

Soft tissue reconstruction of the upper extremity is a complex topic because every defect has multiple potential solutions. Whereas the often-cited reconstructive ladder advised selection of the simplest reconstruction of the defect, the newer concept of the reconstructive elevator allows freedom to choose a more complex reconstruction to account for specialized function and aesthetic outcome. An algorithm for assessment of the defect is presented and demonstrated in this review, using 6 case examples to highlight key concepts. Representative flaps are presented and a discussion of functional and aesthetic outcomes is undertaken to provide a framework for achieving the patient's and surgeon's goals of reconstruction. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Oral and Oropharyngeal Reconstruction with a Free Flap.

Science.gov (United States)

Jeong, Woo Shik; Oh, Tae Suk

2016-06-01

Extensive surgical resection of the aerodigestive track can result in a large and complex defect of the oropharynx, which represents a significant reconstructive challenge for the plastic surgery. Development of microsurgical techniques has allowed for free flap reconstruction of oropharyngeal defects, with superior outcomes as well as decreases in postoperative complications. The reconstructive goals for oral and oropharyngeal defects are to restore the anatomy, to maintain continuity of the intraoral surface and oropharynx, to protect vital structures such as carotid arteries, to cover exposed portions of internal organs in preparation for adjuvant radiation, and to preserve complex functions of the oral cavity and oropharynx. Oral and oropharyngeal cancers should be treated with consideration of functional recovery. Multidisciplinary treatment strategies are necessary for maximizing disease control and preserving the natural form and function of the oropharynx.

Biomechanical Comparison of an Intramedullary and Extramedullary Free-Tissue Graft Reconstruction of the Acromioclavicular Joint Complex

Science.gov (United States)

Garg, Rishi; Javidan, Pooya; Lee, Thay Q.

2013-01-01

Background Several different surgical techniques have been described to address the coracoclavicular (CC) ligaments in acromioclavicular (AC) joint injuries. However, very few techniques focus on reconstructing the AC ligaments, despite its importance in providing stability. The purpose of our study was to compare the biomechanical properties of two free-tissue graft techniques that reconstruct both the AC and CC ligaments in cadaveric shoulders, one with an extramedullary AC reconstruction and the other with an intramedullary AC reconstruction. We hypothesized intramedullary AC reconstruction will provide greater anteroposterior translational stability and improved load to failure characteristics than an extramedullary technique. Methods Six matched cadaveric shoulders underwent translational testing at 10 N and 15 N in the anteroposterior and superoinferior directions, under AC joint compression loads of 10 N, 20 N, and 30 N. After the AC and CC ligaments were transected, one of the specimens was randomly assigned the intramedullary free-tissue graft reconstruction while its matched pair received the extramedullary graft reconstruction. Both reconstructed specimens then underwent repeat translational testing, followed by load to failure testing, via superior clavicle distraction, at a rate of 50 mm/min. Results Intramedullary reconstruction provided significantly greater translational stability in the anteroposterior direction than the extramedullary technique for four of six loading conditions (p < 0.05). There were no significant differences in translational stability in the superoinferior direction for any loading condition. The intramedullary reconstructed specimens demonstrated improved load to failure characteristics with the intramedullary reconstruction having a lower deformation at yield and a higher ultimate load than the extramedullary reconstruction (p < 0.05). Conclusions Intramedullary reconstruction of the AC joint provides greater stability in the

Breast Reconstruction Following Cancer Treatment.

Science.gov (United States)

Gerber, Bernd; Marx, Mario; Untch, Michael; Faridi, Andree

2015-08-31

About 8000 breast reconstructions after mastectomy are per - formed in Germany each year. It has become more difficult to advise patients because of the wide variety of heterologous and autologous techniques that are now available and because of changes in the recommendations about radiotherapy. This article is based on a review of pertinent articles (2005-2014) that were retrieved by a selective search employing the search terms "mastectomy" and "breast reconstruction." The goal of reconstruction is to achieve an oncologically safe and aestically satisfactory result for the patient over the long term. Heterologous, i.e., implant-based, breast reconstruction (IBR) and autologous breast reconstruction (ABR) are complementary techniques. Immediate reconstruction preserves the skin of the breast and its natural form and prevents the psychological trauma associated with mastectomy. If post-mastectomy radiotherapy (PMRT) is not indicated, implant-based reconstruction with or without a net/acellular dermal matrix (ADM) is a common option. Complications such as seroma formation, infection, and explantation are significantly more common when an ADM is used (15.3% vs. 5.4% ). If PMRT is performed, then the complication rate of implant-based breast reconstruction is 1 to 48% ; in particular, Baker grade III/IV capsular fibrosis occurs in 7 to 22% of patients, and the prosthesis must be explanted in 9 to 41% . Primary or, preferably, secondary autologous reconstruction is an alternative. The results of ABR are more stable over the long term, but the operation is markedly more complex. Autologous breast reconstruction after PMRT does not increase the risk of serious complications (20.5% vs. 17.9% without radiotherapy). No randomized controlled trials have yet been conducted to compare the reconstructive techniques with each other. If radiotherapy will not be performed, immediate reconstruction with an implant is recommended. On the other hand, if post-mastectomy radiotherapy

Medial sural artery as a salvage recipient vessel for complex post traumatic microvascular lower limb reconstruction.

Science.gov (United States)

Baliarsing, Amresh; Date, Shivprasad; Ciudad, Pedro

2018-02-01

Complex lower extremity trauma still poses a formidable challenge for micro vascular reconstruction. The extensive surrounding zone of trauma can make it difficult to find a suitable recipient pedicle for anastomosis. A need was felt for exploration of newer recipient vessels in lower extremity which could be harnessed for reliable and tension free micro anastomosis. The purpose of the present report is to highlight the possibility of using medial sural artery for safe micro vascular anastomosis in selected scenarios like vessel depleted extremity. Between 2008 and 2013, we used the medial sural vessels for micro anastomosis in 10 cases of lower extremity trauma. All the cases had severe soft tissue trauma with or without a bony defect. A computed tomography angiogram (CTA) of the involved extremity revealed either severe perivascular scarring around the standard recipient vessels or patency of just a single vessel. However, in all cases a patent medial sural pedicle was identified on CTA. Interposition vein grafts (IVGs) were used in most cases to ensure a tension free anastomosis. In all cases, unscarred medial sural vessels were identified with average dissected length and diameter being 6.2 cm (range 4 to 7.5 cm) and 2 mm (range 1.5 to 2.5 mm) respectively. Vein graft [average length 5.6 cm (range 4 to 15 cm)] was interposed in seven cases, while in remaining three, long saphenous vein was used for vein anastomosis. All the flaps survived after the surgery. There was one re-exploration for evacuation of peri-anastomotic hematoma with no adverse effect on flap survival. The mean follow up period was 27.6 months. In the four cases with bone reconstruction, bony union was seen between 5 and 8 months. They were able to walk without aids and resume work after 10-14 months, following a structured rehabilitation program. The patients with soft tissue reconstruction (6 cases) could carry out aid free locomotion and resume their routine after 4-6 weeks. There were no

Single-stage soft tissue reconstruction and orbital fracture repair for complex facial injuries.

Science.gov (United States)

Wu, Peng Sen; Matoo, Reshvin; Sun, Hong; Song, Li Yuan; Kikkawa, Don O; Lu, Wei

2017-02-01

Orbital fractures with open periorbital wounds cause significant morbidity. Timing of debridement with fracture repair and soft tissue reconstruction is controversial. This study focuses on the efficacy of early single-stage repair in combined bony and soft tissue injuries. Retrospective review. Twenty-three patients with combined open soft tissue wounds and orbital fractures were studied for single-stage orbital reconstruction and periorbital soft tissue repair. Inclusion criteria were open soft tissue wounds with clinical and radiographic evidence of orbital fractures and repair performed within 48 h after injury. Surgical complications and reconstructive outcomes were assessed over 6 months. The main outcome measures were enophthalmos, pre- and post-CT imaging of orbits, scar evaluation, presence of diplopia, and eyelid position. Enophthalmos was corrected in 16/19 cases and improved in 3/19 cases. 3D reconstruction of CT images showed markedly improved orbital alignment with objective measurements of the optic foramen to cornea distance (mm) in reconstructed orbits relative to intact orbits of 0.66, 95% confidence interval [CI] (lower 0.33, upper 0.99) mm. The mean baseline of Stony Brook Scar Evaluation Scale was 0.6, 95%CI (0.30-0.92), and for 6 months, the mean score was 3.4, 95%CI (3.05-3.73). Residual diplopia in secondary gazes was present in two patients; one patient had ectropion. Complications included one case of local wound infection. An early single-stage repair of combined soft tissue and orbital fractures yields satisfactory functional and aesthetic outcomes. Complications are low and likely related to trauma severity. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

An analytical statistical approach to the 3D reconstruction problem

Energy Technology Data Exchange (ETDEWEB)

Cierniak, Robert [Czestochowa Univ. of Technology (Poland). Inst. of Computer Engineering

2011-07-01

The presented here approach is concerned with the reconstruction problem for 3D spiral X-ray tomography. The reconstruction problem is formulated taking into considerations the statistical properties of signals obtained in X-ray CT. Additinally, image processing performed in our approach is involved in analytical methodology. This conception significantly improves quality of the obtained after reconstruction images and decreases the complexity of the reconstruction problem in comparison with other approaches. Computer simulations proved that schematically described here reconstruction algorithm outperforms conventional analytical methods in obtained image quality. (orig.)

Maxillary Anterior Segmental Distraction Osteogenesis to Correct Maxillary Deficiencies in a Patient With Cleft Lip and Palate.

Science.gov (United States)

Kageyama-Iwata, Asuka; Haraguchi, Seiji; Iida, Seiji; Aikawa, Tomonao; Yamashiro, Takashi

2017-07-01

This report describes a case of successful orthodontic treatment using maxillary anterior segmental distraction osteogenesis with an internal maxillary distractor and bilateral sagittal split ramus osteotomy in a girl with cleft lip and palate. A 16-year-old girl with unilateral cleft lip and palate exhibited midface retrusion because of growth inhibition of the maxillary complex and mandibular excess. After the presurgical orthodontic treatment, 6.0-mm advancement of the maxillary anterior segment and 4.0-mm set back of the mandible were performed. After a retention period, the patient's midface convexity was greatly improved and the velopharyngeal competence was preserved without relapse.

The medial patellofemoral complex.

Science.gov (United States)

Loeb, Alexander E; Tanaka, Miho J

2018-06-01

The purpose of this review is to describe the current understanding of the medial patellofemoral complex, including recent anatomic advances, evaluation of indications for reconstruction with concomitant pathology, and surgical reconstruction techniques. Recent advances in our understanding of MPFC anatomy have found that there are fibers that insert onto the deep quadriceps tendon as well as the patella, thus earning the name "medial patellofemoral complex" to allow for the variability in its anatomy. In MPFC reconstruction, anatomic origin and insertion points and appropriate graft length are critical to prevent overconstraint of the patellofemoral joint. The MPFC is a crucial soft tissue checkrein to lateral patellar translation, and its repair or reconstruction results in good restoration of patellofemoral stability. As our understanding of MPFC anatomy evolves, further studies are needed to apply its relevance in kinematics and surgical applications to its role in maintaining patellar stability.

Three-dimensional reconstruction of highly complex microscopic samples using scanning electron microscopy and optical flow estimation.

Directory of Open Access Journals (Sweden)

Ahmadreza Baghaie

Full Text Available Scanning Electron Microscope (SEM as one of the major research and industrial equipment for imaging of micro-scale samples and surfaces has gained extensive attention from its emerge. However, the acquired micrographs still remain two-dimensional (2D. In the current work a novel and highly accurate approach is proposed to recover the hidden third-dimension by use of multi-view image acquisition of the microscopic samples combined with pre/post-processing steps including sparse feature-based stereo rectification, nonlocal-based optical flow estimation for dense matching and finally depth estimation. Employing the proposed approach, three-dimensional (3D reconstructions of highly complex microscopic samples were achieved to facilitate the interpretation of topology and geometry of surface/shape attributes of the samples. As a byproduct of the proposed approach, high-definition 3D printed models of the samples can be generated as a tangible means of physical understanding. Extensive comparisons with the state-of-the-art reveal the strength and superiority of the proposed method in uncovering the details of the highly complex microscopic samples.

Effects of knee immobilization on morphological changes in the semitendinosus muscle-tendon complex after hamstring harvesting for anterior cruciate ligament reconstruction. Evaluation using three-dimensional computed tomography

International Nuclear Information System (INIS)

Nakamae, Atsuo; Adachi, Nobuo; Nakasa, Tomoyuki; Nishimori, Makoto; Ochi, Mitsuo; Deie, Masataka

2012-01-01

It is desirable to maintain the morphology of the semitendinosus muscle-tendon complex after tendon harvesting for anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to evaluate the effect of knee immobilization on morphological changes in the semitendinosus muscle-tendon complex. In total, 39 patients who underwent ACL reconstruction with autologous semitendinosus tendons were included in this study. After surgery, the knee was immobilized for 3 days in 1 group of patients (group 1; 24 patients; control group) and for a longer period (10-14 days) in the other group (group 2; 15 patients). Three-dimensional computed tomography (3D CT) examination was performed at 6 and/or 12 months after the surgery for all patients. Morphological changes in the semitendinosus muscle-tendon complex (proximal shift of the semitendinosus muscle-tendon junction, width of the regenerated semitendinosus tendons, re-insertion sites of the regenerated tendons, and rate of semitendinosus tendon regeneration) were evaluated. Successful regeneration of the semitendinosus tendon was confirmed in all patients in group 2. In group 1, 3D CT showed that regeneration of the semitendinosus tendon was unsuccessful in 1 of the 24 patients. The average length of the proximal shift of the semitendinosus muscle-tendon junction was 7.3±2.5 cm in group 1 and 7.2±1.9 cm in group 2. There were no significant differences between the 2 groups with regard to the morphological changes in the semitendinosus muscle-tendon complex. This study showed that the structure of regenerated tendons could be clearly identified in 38 of 39 cases (97.4%) after ACL reconstruction. However, prolonged knee immobilization (10-14 days) could not prevent morphological changes in the semitendinosus muscle-tendon complex. (author)

Ifcwall Reconstruction from Unstructured Point Clouds

Science.gov (United States)

Bassier, M.; Klein, R.; Van Genechten, B.; Vergauwen, M.

2018-05-01

The automated reconstruction of Building Information Modeling (BIM) objects from point cloud data is still ongoing research. A key aspect is the creation of accurate wall geometry as it forms the basis for further reconstruction of objects in a BIM. After segmenting and classifying the initial point cloud, the labelled segments are processed and the wall topology is reconstructed. However, the preocedure is challenging due to noise, occlusions and the complexity of the input data.In this work, a method is presented to automatically reconstruct consistent wall geometry from point clouds. More specifically, the use of room information is proposed to aid the wall topology creation. First, a set of partial walls is constructed based on classified planar primitives. Next, the rooms are identified using the retrieved wall information along with the floors and ceilings. The wall topology is computed by the intersection of the partial walls conditioned on the room information. The final wall geometry is defined by creating IfcWallStandardCase objects conform the IFC4 standard. The result is a set of walls according to the as-built conditions of a building. The experiments prove that the used method is a reliable framework for wall reconstruction from unstructured point cloud data. Also, the implementation of room information reduces the rate of false positives for the wall topology. Given the walls, ceilings and floors, 94% of the rooms is correctly identified. A key advantage of the proposed method is that it deals with complex rooms and is not bound to single storeys.

Titanium template for scaphoid reconstruction.

Science.gov (United States)

Haefeli, M; Schaefer, D J; Schumacher, R; Müller-Gerbl, M; Honigmann, P

2015-06-01

Reconstruction of a non-united scaphoid with a humpback deformity involves resection of the non-union followed by bone grafting and fixation of the fragments. Intraoperative control of the reconstruction is difficult owing to the complex three-dimensional shape of the scaphoid and the other carpal bones overlying the scaphoid on lateral radiographs. We developed a titanium template that fits exactly to the surfaces of the proximal and distal scaphoid poles to define their position relative to each other after resection of the non-union. The templates were designed on three-dimensional computed tomography reconstructions and manufactured using selective laser melting technology. Ten conserved human wrists were used to simulate the reconstruction. The achieved precision measured as the deviation of the surface of the reconstructed scaphoid from its virtual counterpart was good in five cases (maximal difference 1.5 mm), moderate in one case (maximal difference 3 mm) and inadequate in four cases (difference more than 3 mm). The main problems were attributed to the template design and can be avoided by improved pre-operative planning, as shown in a clinical case. © The Author(s) 2014.

Track Simulation and Reconstruction in the ATLAS experiment

CERN Document Server

Salzburger, Andreas; Elsing, Markus

The reconstruction and simulation of particle trajectories is an inevitable part of the analysis strate- gies for data taken with the ATLAS detector. Many aspects and necessary parts of a high-quality track reconstruction will be presented and discussed in this work. At first, the technical realisation of the data model and the reconstruction geometry will be given; the reconstruction geometry is charac- terised by a newly developed navigation model and an automated procedure for the synchronisation of the detailed simulation geometry description with the simplified reconstruction geometry model, which allows a precise description of the tracker material in track reconstruction. Both components help the coherent and fast integration of material effects in a newly established track extrapolation package, that is discussed in the following. The extrapolation engine enables a highly precise trans- port of the track parameterisation and the associated covariances through the complex magnetic field and the detec...

Reconstrucción del complejo areola-pezón: revisión de 60 casos Nipple-areola complex reconstruction: revision of 60 cases

Directory of Open Access Journals (Sweden)

R. Fernández García

2007-06-01

hay ninguna cuyos resultados se sobrepongan a las demás, pero sí una vez que se reconstruye la areola siendo la técnica que más satisface la del injerto inguinal. A pesar de ello, el aspecto más notable a mejorar está en la reconstrucción del pezón, dada la frecuente disconformidad de las pacientes con la proyección conseguida a lo largo del tiempo por la posible reabsorción del mismo.The creation of the nipple-areola complex is the latest time in breast reconstruction, transforming the reconstruction of the breast mound into a real breast. We have to consider the reconstruction of the areola and the nipple as the culmination of breast reconstruction. There are a lot of documented techniques for nipple-areola complex reconstruction. The aim of this study is to determine the grade of psychological satisfaction of patients after this reconstruction This study was designed as a retrospective clinic review of 60 patients. After reviewing medical histories, the patients were interviewed and asked to complete a questionnaire. The most common desired aspect was to correct the absence/lost of nipple projection. However, 22% of patients answered they would not change anything regarding their reconstruction. The satisfaction with the mammary mound was excellent or good for 68%, normal for 23 % and poor for 9 %. On the other hand, satisfaction for the nippleareola complex reconstruction was excellent or good for 50%, normal for 45% and poor for 5%. There were no statistical differences among the different techniques depending on the time between the mastectomy intervention and the third reconstruction (p=0,06. For nipple reconstruction, the contralateral nipple donation technique offered more satisfaction (2.67 points and projection (7.23 points. In spite of the differences in their means, there were no statistically significant differences. Taking into account the technique used for the areola reconstruction, the donation-graft of inguinal skin was the one that

Fully 3D GPU PET reconstruction

Energy Technology Data Exchange (ETDEWEB)

Herraiz, J.L., E-mail: joaquin@nuclear.fis.ucm.es [Grupo de Fisica Nuclear, Departmento Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Espana, S. [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Cal-Gonzalez, J. [Grupo de Fisica Nuclear, Departmento Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Vaquero, J.J. [Departmento de Bioingenieria e Ingenieria Espacial, Universidad Carlos III, Madrid (Spain); Desco, M. [Departmento de Bioingenieria e Ingenieria Espacial, Universidad Carlos III, Madrid (Spain); Unidad de Medicina y Cirugia Experimental, Hospital General Universitario Gregorio Maranon, Madrid (Spain); Udias, J.M. [Grupo de Fisica Nuclear, Departmento Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain)

2011-08-21

Fully 3D iterative tomographic image reconstruction is computationally very demanding. Graphics Processing Unit (GPU) has been proposed for many years as potential accelerators in complex scientific problems, but it has not been used until the recent advances in the programmability of GPUs that the best available reconstruction codes have started to be implemented to be run on GPUs. This work presents a GPU-based fully 3D PET iterative reconstruction software. This new code may reconstruct sinogram data from several commercially available PET scanners. The most important and time-consuming parts of the code, the forward and backward projection operations, are based on an accurate model of the scanner obtained with the Monte Carlo code PeneloPET and they have been massively parallelized on the GPU. For the PET scanners considered, the GPU-based code is more than 70 times faster than a similar code running on a single core of a fast CPU, obtaining in both cases the same images. The code has been designed to be easily adapted to reconstruct sinograms from any other PET scanner, including scanner prototypes.

Fully 3D GPU PET reconstruction

International Nuclear Information System (INIS)

Herraiz, J.L.; Espana, S.; Cal-Gonzalez, J.; Vaquero, J.J.; Desco, M.; Udias, J.M.

2011-01-01

Fully 3D iterative tomographic image reconstruction is computationally very demanding. Graphics Processing Unit (GPU) has been proposed for many years as potential accelerators in complex scientific problems, but it has not been used until the recent advances in the programmability of GPUs that the best available reconstruction codes have started to be implemented to be run on GPUs. This work presents a GPU-based fully 3D PET iterative reconstruction software. This new code may reconstruct sinogram data from several commercially available PET scanners. The most important and time-consuming parts of the code, the forward and backward projection operations, are based on an accurate model of the scanner obtained with the Monte Carlo code PeneloPET and they have been massively parallelized on the GPU. For the PET scanners considered, the GPU-based code is more than 70 times faster than a similar code running on a single core of a fast CPU, obtaining in both cases the same images. The code has been designed to be easily adapted to reconstruct sinograms from any other PET scanner, including scanner prototypes.

Linkage group-chromosome correlations in Sordaria macrospora: Chromosome identification by three dimensional reconstruction of their synaptonemal complex.

Science.gov (United States)

Zickler, D; Leblon, G; Haedens, V; Collard, A; Thuriaux, P

1984-01-01

Reconstruction of serially sectioned zygotene and pachytene nuclei has allowed, by measuring the lengths of synaptonemal complexes, an assignment of the 7 linkage (LG) groups to the 7 chromosomes in the fungus Sordaria macrospora. The 7 LG have been established using 19 mutants showing low second division segregation frequencies. Eight chromosomal rearrangements mapped on the 7 LG were used to identify the chromosomes involved. The following one to one assignment of the 7 LG to specific chromosomes was obtained: LG a: chromosome (chr) 1, LG b: chr5, LG c: chr6, LG d: chr7, LG e: chr4, LG f: chr3 and LG g: chr2 (the chromosome carrying the nucleolus organizer region).

Social consciousness in post-conflict reconstruction.

NARCIS (Netherlands)

Gans, Ben; Rutkowski, Anne; Kaminski, B.; Kersten, G.E.; Szapiro, T.

This paper sheds light on the complexities intergovernmental organizations are facing during post-conflict reconstruction. The article discusses the added-value of Social Responsibility in the context of the Comprehensive Approach, involving collaboration amongst defense, diplomacy and development.

Block Compressed Sensing of Images Using Adaptive Granular Reconstruction

Directory of Open Access Journals (Sweden)

Ran Li

2016-01-01

Full Text Available In the framework of block Compressed Sensing (CS, the reconstruction algorithm based on the Smoothed Projected Landweber (SPL iteration can achieve the better rate-distortion performance with a low computational complexity, especially for using the Principle Components Analysis (PCA to perform the adaptive hard-thresholding shrinkage. However, during learning the PCA matrix, it affects the reconstruction performance of Landweber iteration to neglect the stationary local structural characteristic of image. To solve the above problem, this paper firstly uses the Granular Computing (GrC to decompose an image into several granules depending on the structural features of patches. Then, we perform the PCA to learn the sparse representation basis corresponding to each granule. Finally, the hard-thresholding shrinkage is employed to remove the noises in patches. The patches in granule have the stationary local structural characteristic, so that our method can effectively improve the performance of hard-thresholding shrinkage. Experimental results indicate that the reconstructed image by the proposed algorithm has better objective quality when compared with several traditional ones. The edge and texture details in the reconstructed image are better preserved, which guarantees the better visual quality. Besides, our method has still a low computational complexity of reconstruction.

Orbital Reconstruction: Patient-Specific Orbital Floor Reconstruction Using a Mirroring Technique and a Customized Titanium Mesh.

Science.gov (United States)

Tarsitano, Achille; Badiali, Giovanni; Pizzigallo, Angelo; Marchetti, Claudio

2016-10-01

Enophthalmos is a severe complication of primary reconstruction of orbital floor fractures. The goal of secondary reconstruction procedures is to restore symmetrical globe positions to recover function and aesthetics. The authors propose a new method of orbital floor reconstruction using a mirroring technique and a customized titanium mesh, printed using a direct metal laser-sintering method. This reconstructive protocol involves 4 steps: mirroring of the healthy orbit at the affected site, virtual design of a patient-specific orbital floor mesh, CAM procedures for direct laser-sintering of the customized titanium mesh, and surgical insertion of the device. Using a computed tomography data set, the normal, uninjured side of the craniofacial skeleton was reflected onto the contralateral injured side, and a reconstructive orbital floor mesh was designed virtually on the mirrored orbital bone surface. The solid-to-layer files of the mesh were then manufactured using direct metal laser sintering, which resolves the shaping and bending biases inherent in the indirect method. An intraoperative navigation system ensured accuracy of the entire procedure. Clinical outcomes were assessed using 3dMD photogrammetry and computed tomography data in 7 treated patients. The technique described here appears to be a viable method to correct complex orbital floor defects needing delayed reconstruction. This study represents the first step in the development of a wider experimental protocol for orbital floor reconstruction using computer-assisted design-computer-assisted manufacturing technology.

Calibration of reconstruction parameters in atom probe tomography using a single crystallographic orientation

International Nuclear Information System (INIS)

Suram, Santosh K.; Rajan, Krishna

2013-01-01

The purpose of this work is to develop a methodology to estimate the APT reconstruction parameters when limited crystallographic information is available. Reliable spatial scaling of APT data currently requires identification of multiple crystallographic poles from the field desorption image for estimating the reconstruction parameters. This requirement limits the capacity of accurately reconstructing APT data for certain complex systems, such as highly alloyed systems and nanostructured materials wherein more than one pole is usually not observed within one grain. To overcome this limitation, we develop a quantitative methodology for calibrating the reconstruction parameters in an APT dataset by ensuring accurate inter-planar spacing and optimizing the curvature correction for the atomic planes corresponding to a single crystallographic orientation. We validate our approach on an aluminum dataset and further illustrate its capabilities by computing geometric reconstruction parameters for W and Al–Mg–Sc datasets. - Highlights: ► Quantitative approach is developed to accurately reconstruct APT data. ► Curvature of atomic planes in APT data is used to calibrate the reconstruction. ► APT reconstruction parameters are determined from a single crystallographic axis. ► Quantitative approach is demonstrated on W, Al and Al–Mg–Sc systems. ► Accurate APT reconstruction of complex materials is now possible

Reconstructing the complex evolutionary history of mobile plasmids in red algal genomes

Science.gov (United States)

Lee, JunMo; Kim, Kyeong Mi; Yang, Eun Chan; Miller, Kathy Ann; Boo, Sung Min; Bhattacharya, Debashish; Yoon, Hwan Su

2016-01-01

The integration of foreign DNA into algal and plant plastid genomes is a rare event, with only a few known examples of horizontal gene transfer (HGT). Plasmids, which are well-studied drivers of HGT in prokaryotes, have been reported previously in red algae (Rhodophyta). However, the distribution of these mobile DNA elements and their sites of integration into the plastid (ptDNA), mitochondrial (mtDNA), and nuclear genomes of Rhodophyta remain unknown. Here we reconstructed the complex evolutionary history of plasmid-derived DNAs in red algae. Comparative analysis of 21 rhodophyte ptDNAs, including new genome data for 5 species, turned up 22 plasmid-derived open reading frames (ORFs) that showed syntenic and copy number variation among species, but were conserved within different individuals in three lineages. Several plasmid-derived homologs were found not only in ptDNA but also in mtDNA and in the nuclear genome of green plants, stramenopiles, and rhizarians. Phylogenetic and plasmid-derived ORF analyses showed that the majority of plasmid DNAs originated within red algae, whereas others were derived from cyanobacteria, other bacteria, and viruses. Our results elucidate the evolution of plasmid DNAs in red algae and suggest that they spread as parasitic genetic elements. This hypothesis is consistent with their sporadic distribution within Rhodophyta. PMID:27030297

Split-Bregman-based sparse-view CT reconstruction

Energy Technology Data Exchange (ETDEWEB)

Vandeghinste, Bert; Vandenberghe, Stefaan [Ghent Univ. (Belgium). Medical Image and Signal Processing (MEDISIP); Goossens, Bart; Pizurica, Aleksandra; Philips, Wilfried [Ghent Univ. (Belgium). Image Processing and Interpretation Research Group (IPI); Beenhouwer, Jan de [Ghent Univ. (Belgium). Medical Image and Signal Processing (MEDISIP); Antwerp Univ., Wilrijk (Belgium). The Vision Lab; Staelens, Steven [Ghent Univ. (Belgium). Medical Image and Signal Processing (MEDISIP); Antwerp Univ., Edegem (Belgium). Molecular Imaging Centre Antwerp

2011-07-01

Total variation minimization has been extensively researched for image denoising and sparse view reconstruction. These methods show superior denoising performance for simple images with little texture, but result in texture information loss when applied to more complex images. It could thus be beneficial to use other regularizers within medical imaging. We propose a general regularization method, based on a split-Bregman approach. We show results for this framework combined with a total variation denoising operator, in comparison to ASD-POCS. We show that sparse-view reconstruction and noise regularization is possible. This general method will allow us to investigate other regularizers in the context of regularized CT reconstruction, and decrease the acquisition times in {mu}CT. (orig.)

[3D bioprinting of cartilage: challenges concerning the reconstruction of a burned ear].

Science.gov (United States)

Visscher, Dafydd O; Bos, Ernst J; van Zuijlen, Paul P M

2015-01-01

Reconstruction of a severely maimed ear is a major challenge. The ear is highly flexible yet tough, and has a very complex three-dimensional shape. Reconstruction of a patient's burned ear is even more complex due to surrounding tissue damage. Not only does this hamper reconstruction options, it also increases the likelihood of issues when using synthetic implant materials. In such cases, rib cartilage is the preferred option, but this tissue has practical limitations too. For these reasons, tissue engineering and 3D bioprinting may have the potential to create personalized cartilage implants for burns patients. However, 3D bioprinting is a tool to facilitate the reconstruction, and not by itself the Holy Grail. The clinical application of this technique is still at a very early stage. Nevertheless, we expect that 3D bioprinting can be utilised for facial reconstruction following burns come 2020.

Iterative reconstruction of magnetic induction using Lorentz transmission electron tomography

International Nuclear Information System (INIS)

Phatak, C.; Gürsoy, D.

2015-01-01

Intense ongoing research on complex nanomagnetic structures requires a fundamental understanding of the 3D magnetization and the stray fields around the nano-objects. 3D visualization of such fields offers the best way to achieve this. Lorentz transmission electron microscopy provides a suitable combination of high resolution and ability to quantitatively visualize the magnetization vectors using phase retrieval methods. In this paper, we present a formalism to represent the magnetic phase shift of electrons as a Radon transform of the magnetic induction of the sample. Using this formalism, we then present the application of common tomographic methods particularly the iterative methods, to reconstruct the 3D components of the vector field. We present an analysis of the effect of missing wedge and the limited angular sampling as well as reconstruction of complex 3D magnetization in a nanowire using simulations. - Highlights: • We present a formalism to represent electron-optical magnetic phase shift as a Radon transform of the 3D magnetic induction of the nano-object. • We have analyzed four different tomographic reconstruction methods for vectorial data reconstruction. • Reconstruction methods were tested for varying experimental limitations such as limited tilt range and limited angular sampling. • The analysis showed that Gridrec and SIRT methods performed better with lower errors than other reconstruction methods

3D reconstruction modeling of bulk heterojunction organic photovoltaic cells: Effect of the complexity of the boundary on the morphology

Science.gov (United States)

Kim, Sung-Jin; Jeong, Daun; Kim, SeongMin; Choi, Yeong Suk; Ihn, Soo-Ghang; Yun, Sungyoung; Lim, Younhee; Lee, Eunha; Park, Gyeong-Su

2016-02-01

Although the morphology of the active layer in bulk heterojunction organic photovoltaic (BHJ-OPV) cells is critical for determining the quantum efficiency (QE), predicting the real QE for a 3-dimensional (3D) morphology has long been difficult because structural information on the composition complexity of donor (D): acceptor (A) blends with small domain size is limited to 2D observations via various image-processing techniques. To overcome this, we reconstruct the 3D morphology by using an isotropic statistical approach based on 2D energy-filtered transmission electron microscopy (EF-TEM) images. This new reconstruction method is validated to obtain the internal QE by using a dynamic Monte Carlo simulation in the BHJ-OPV system with different additives such as 4 vol% 1-chloronaphthalene (CN) and 4 vol% 1,8-diiodooctane (DIO) (compared to the case of no additive); the resulting trend is compared with the experimental QE. Therefore, our developed method can be used to predict the real charge transport performance in the OPV system accurately.

Clip reconstruction of a large right MCA bifurcation aneurysm. Case report

Directory of Open Access Journals (Sweden)

Giovani A.

2014-06-01

Full Text Available We report a case of complex large middle cerebral artery (MCA bifurcation aneurysm that ruptured during dissection from the very adherent MCA branches but was successfully clipped and the MCA bifurcation reconstructed using 4 Yasargill clips. Through a right pterional craniotomy the sylvian fissure was largely opened as to allow enough workspace for clipping the aneurysm and placing a temporary clip on M1. The pacient recovered very well after surgery and was discharged after 1 week with no neurological deficit. Complex MCA bifurcation aneurysms can be safely reconstructed using regular clips, without the need of using fenestrated clips or complex by-pass procedures.

Modeling fade patterns of nipple areola complex tattoos following breast reconstruction.

Science.gov (United States)

Levites, Heather A; Fourman, Mitchell S; Phillips, Brett T; Fromm, Indira M; Khan, Sami U; Dagum, Alexander B; Bui, Duc T

2014-12-01

Nipple-areolar complex (NAC) tattoos are an effective cosmetic solution for creating a finished look following breast reconstruction procedures. NAC tattoos are prone to significant fading, leading patients to seek revisions. This study was designed to quantify changes in NAC tattoo appearance over time. A total of 71 images of 39 patients were analyzed for NAC tattoo color and shape by 5 blinded medical student graders using a customized scoring system. Subsequently, each image was analyzed using ColorPic software (Iconico, New York, NY). Red/green/blue and hue/saturation/value color parameters were collected. Color quantities were normalized to the individual patient's skin tone to control for variability in lighting. Spearman correlations and nonlinear regressions were calculated utilizing GraphPad Prism 6.0 (GraphPad, La Jolla, CA). The length of time after tattoo placement inversely correlated with color score (P tattoo placement was also inversely correlated with all quantitative color parameters. Each color parameter fit a 1-phase exponential decay model. The decline in qualitative color and shape score agrees with clinical experience of tattoo quality declining over time. The color qualities of the tattoo approach those of the patient's skin over time, ultimately reaching a plateau. This can be modeled using a 1-phase decay equation. In practice, tattoo colors may be selected that compensate for the predictable changes that will occur. The results of this study will help optimize tattoo color and may alleviate the need for NAC tattoo revisions.

Optimisation of the ATLAS Track Reconstruction Software for Run-2

CERN Document Server

Salzburger, Andreas; The ATLAS collaboration

2015-01-01

Track reconstruction is one of the most complex element of the reconstruction of events recorded by ATLAS from collisions delivered by the LHC. It is the most time consuming reconstruction component in high luminosity environments. The flat budget projections for computing resources for Run-2 of the LHC together with the demands of reconstructing higher pile-up collision data at rates more than double those in Run-1 (an increase from 400 Hz to 1 kHz in trigger output) have put stringent requirements on the track reconstruction software. The ATLAS experiment has performed a two year long software campaign which aimed to reduce the reconstruction rate by a factor of three to meet the resource limitations for Run-2: the majority of the changes to achieve this were improvements to the track reconstruction software. The CPU processing time of ATLAS track reconstruction was reduced by more than a factor of three during this campaign without any loss of output information of the track reconstruction. We present the ...

RMP: Reduced-set matching pursuit approach for efficient compressed sensing signal reconstruction

Directory of Open Access Journals (Sweden)

Michael M. Abdel-Sayed

2016-11-01

Full Text Available Compressed sensing enables the acquisition of sparse signals at a rate that is much lower than the Nyquist rate. Compressed sensing initially adopted ℓ1 minimization for signal reconstruction which is computationally expensive. Several greedy recovery algorithms have been recently proposed for signal reconstruction at a lower computational complexity compared to the optimal ℓ1 minimization, while maintaining a good reconstruction accuracy. In this paper, the Reduced-set Matching Pursuit (RMP greedy recovery algorithm is proposed for compressed sensing. Unlike existing approaches which either select too many or too few values per iteration, RMP aims at selecting the most sufficient number of correlation values per iteration, which improves both the reconstruction time and error. Furthermore, RMP prunes the estimated signal, and hence, excludes the incorrectly selected values. The RMP algorithm achieves a higher reconstruction accuracy at a significantly low computational complexity compared to existing greedy recovery algorithms. It is even superior to ℓ1 minimization in terms of the normalized time-error product, a new metric introduced to measure the trade-off between the reconstruction time and error. RMP superior performance is illustrated with both noiseless and noisy samples.

RMP: Reduced-set matching pursuit approach for efficient compressed sensing signal reconstruction.

Science.gov (United States)

Abdel-Sayed, Michael M; Khattab, Ahmed; Abu-Elyazeed, Mohamed F

2016-11-01

Compressed sensing enables the acquisition of sparse signals at a rate that is much lower than the Nyquist rate. Compressed sensing initially adopted [Formula: see text] minimization for signal reconstruction which is computationally expensive. Several greedy recovery algorithms have been recently proposed for signal reconstruction at a lower computational complexity compared to the optimal [Formula: see text] minimization, while maintaining a good reconstruction accuracy. In this paper, the Reduced-set Matching Pursuit (RMP) greedy recovery algorithm is proposed for compressed sensing. Unlike existing approaches which either select too many or too few values per iteration, RMP aims at selecting the most sufficient number of correlation values per iteration, which improves both the reconstruction time and error. Furthermore, RMP prunes the estimated signal, and hence, excludes the incorrectly selected values. The RMP algorithm achieves a higher reconstruction accuracy at a significantly low computational complexity compared to existing greedy recovery algorithms. It is even superior to [Formula: see text] minimization in terms of the normalized time-error product, a new metric introduced to measure the trade-off between the reconstruction time and error. RMP superior performance is illustrated with both noiseless and noisy samples.

Duct-to-duct biliary reconstruction after radical resection of Bismuth IIIa hilar cholangiocarcinoma.

Science.gov (United States)

Wu, Wen-Guang; Gu, Jun; Dong, Ping; Lu, Jian-Hua; Li, Mao-Lan; Wu, Xiang-Song; Yang, Jia-Hua; Zhang, Lin; Ding, Qi-Chen; Weng, Hao; Ding, Qian; Liu, Ying-Bin

2013-04-21

At present, radical resection remains the only effective treatment for patients with hilar cholangiocarcinoma. The surgical approach for R0 resection of hilar cholangiocarcinoma is complex and diverse, but for the biliary reconstruction after resection, almost all surgeons use Roux-en-Y hepaticojejunostomy. A viable alternative to Roux-en-Y reconstruction after radical resection of hilar cholangiocarcinoma has not yet been proposed. We report a case of performing duct-to-duct biliary reconstruction after radical resection of Bismuth IIIa hilar cholangiocarcinoma. End-to-end anastomosis between the left hepatic duct and the distal common bile duct was used for the biliary reconstruction, and a single-layer continuous suture was performed along the bile duct using 5-0 prolene. The patient was discharged favorably without biliary fistula 2 wk later. Evidence for tumor recurrence was not found after an 18 mo follow-up. Performing bile duct end-to-end anastomosis in hilar cholangiocarcinoma can simplify the complex digestive tract reconstruction process.

Bartsocas-Papas Syndrome: A Case Report and Review of the Literature.

Science.gov (United States)

Erturan, Gurhan; Holton, James; Wall, Steven; Giele, Henk

2016-04-01

Bartsocas-Papas syndrome (BPS) is an autosomal recessively inherited form of the popliteal pterygium syndrome characterized by severe growth retardation, midface hypoplasia, popliteal pterygia, and syndactyly. Almost all affected babies die in utero or infancy. We report the difficulties of reconstruction and ongoing plastic surgical management in an 8-year-old child with BPS. With increasingly sophisticated resuscitation and supportive techniques, it is possible that more patients with BPS will survive beyond the neonatal period. This raises new challenges with reconstruction highlighted by this case with a difficult balance between trying to overcome some of the profound effects of the syndrome versus diminishing quality of life for the child by repeated and often unsuccessful surgical procedures.

Tomographic reconstruction of melanin structures of optical coherence tomography via the finite-difference time-domain simulation

Science.gov (United States)

Huang, Shi-Hao; Wang, Shiang-Jiu; Tseng, Snow H.

2015-03-01

Optical coherence tomography (OCT) provides high resolution, cross-sectional image of internal microstructure of biological tissue. We use the Finite-Difference Time-Domain method (FDTD) to analyze the data acquired by OCT, which can help us reconstruct the refractive index of the biological tissue. We calculate the refractive index tomography and try to match the simulation with the data acquired by OCT. Specifically, we try to reconstruct the structure of melanin, which has complex refractive indices and is the key component of human pigment system. The results indicate that better reconstruction can be achieved for homogenous sample, whereas the reconstruction is degraded for samples with fine structure or with complex interface. Simulation reconstruction shows structures of the Melanin that may be useful for biomedical optics applications.

Recent advances in iterative reconstruction for clinical SPECT/PET and CT.

Science.gov (United States)

Hutton, Brian F

2011-08-01

Statistical iterative reconstruction is now widely used in clinical practice and has contributed to significant improvement in image quality in recent years. Although primarily used for reconstruction in emission tomography (both single photon emission computed tomography (SPECT) and positron emission tomography (PET)) there is increasing interest in also applying similar algorithms to x-ray computed tomography (CT). There is increasing complexity in the factors that are included in the reconstruction, a demonstration of the versatility of the approach. Research continues with exploration of methods for further improving reconstruction quality with effective correction for various sources of artefact.

WARACS: Wrappers to Automate the Reconstruction of Ancestral Character States.

Science.gov (United States)

Gruenstaeudl, Michael

2016-02-01

Reconstructions of ancestral character states are among the most widely used analyses for evaluating the morphological, cytological, or ecological evolution of an organismic lineage. The software application Mesquite remains the most popular application for such reconstructions among plant scientists, even though its support for automating complex analyses is limited. A software tool is needed that automates the reconstruction and visualization of ancestral character states with Mesquite and similar applications. A set of command line-based Python scripts was developed that (a) communicates standardized input to and output from the software applications Mesquite, BayesTraits, and TreeGraph2; (b) automates the process of ancestral character state reconstruction; and (c) facilitates the visualization of reconstruction results. WARACS provides a simple tool that streamlines the reconstruction and visualization of ancestral character states over a wide array of parameters, including tree distribution, character state, and optimality criterion.

Search for 'Little Higgs' and reconstruction algorithms developments in Atlas

International Nuclear Information System (INIS)

Rousseau, D.

2007-05-01

This document summarizes developments of framework and reconstruction algorithms for the ATLAS detector at the LHC. A library of reconstruction algorithms has been developed in a more and more complex environment. The reconstruction software originally designed on an optimistic Monte-Carlo simulation, has been confronted with a more detailed 'as-built' simulation. The 'Little Higgs' is an effective theory which can be taken for granted, or as an opportunity to study heavy resonances. In several cases, these resonances can be detected in original channels like tZ, ZH or WH. (author)

Reconstruction method for data protection in telemedicine systems

Science.gov (United States)

Buldakova, T. I.; Suyatinov, S. I.

2015-03-01

In the report the approach to protection of transmitted data by creation of pair symmetric keys for the sensor and the receiver is offered. Since biosignals are unique for each person, their corresponding processing allows to receive necessary information for creation of cryptographic keys. Processing is based on reconstruction of the mathematical model generating time series that are diagnostically equivalent to initial biosignals. Information about the model is transmitted to the receiver, where the restoration of physiological time series is performed using the reconstructed model. Thus, information about structure and parameters of biosystem model received in the reconstruction process can be used not only for its diagnostics, but also for protection of transmitted data in telemedicine complexes.

Shredded banknotes reconstruction using AKAZE points.

Science.gov (United States)

Nabiyev, Vasif V; Yılmaz, Seçkin; Günay, Asuman; Muzaffer, Gül; Ulutaş, Güzin

2017-09-01

Shredded banknote reconstruction is a recent topic and can be viewed as solving large-scale jigsaw puzzles. Also, problems such as reconstruction of fragmented documents, photographs and historical artefacts are closely related with this topic. The high computational complexity of these problems increases the need for the development of new methods Reconstruction of shredded banknotes consists of three main stages. (1) Matching fragments with a reference banknote. (2) Aligning the fragments by rotating at certain angles. (3) Assembling the fragments. The existing methods can successfully applied to synthetic banknote fragments which are created in computer environment. But when real banknote reconstruction problem is considered, different sub problems arise and make the existing methods inadequate. In this study, a keypoint based method, named AKAZE, was used to make the matching process effective. This is the first study that uses the AKAZE method in the reconstruction of shredded banknotes. A new method for fragment alignment has also been proposed. In this method, the convex hulls that contain all true matched AKAZE keypoints were found on reference banknote and fragments. The orientations of fragments were estimated accurately by comparing these convex polygons. Also, a new criterion was developed to reveal the success rates of reconstructed banknotes. In addition, two different data sets including real and synthetic banknote fragments of different countries were created to test the success of proposed method. Copyright © 2017 Elsevier B.V. All rights reserved.

Reconstructing the paleo-topography and paleo-environmental features of the Sarno River plain (Italy) before the AD 79 eruption of Somma-Vesuvius volcanic complex

Science.gov (United States)

Vogel, Sebastian; Märker, Michael

2010-05-01

SSP1.4 Understanding mixed siliciclastic-volcaniclastic depositional systems and their relationships with geodynamics or GD2.3/CL4.14/GM5.8/MPRG22/SSP3.5 Reconstruction of ancient continents: Dating and characterization of paleosurfaces Reconstructing the paleo-topography and paleo-environmental features of the Sarno River plain (Italy) before the AD 79 eruption of Somma-Vesuvius volcanic complex Sebastian Vogel[1] & Michael Märker[1] [1] Heidelberg Academy of Sciences and Humanities c/o University of Tübingen, Rümelinstraße 19-23, D-72070 Tübingen, Germany. Within the geoarchaeological research project "Reconstruction of the Ancient Cultural Landscape of the Sarno River Plain" undertaken by the German Archaeological Institute in cooperation with the Heidelberg Academy of Sciences and Humanities/University of Tübingen a methodology was developed to model the spatial dispersion of volcanic deposits of Somma-Vesuvius volcanic complex since its Plinian eruption AD 79. Eventually, this was done to reconstruct the paleo-topography and paleo-environment of the Sarno River plain before the eruption AD 79. We collected, localized and digitized more than 1,800 core drillings to gain a representative network of stratigraphical information covering the entire plain. Besides other stratigraphical data including the characteristics of the pre-AD 79 stratum, the depth to the pre-AD 79 paleo-surface was identified from the available drilling documentation. Instead of applying a simple interpolation of the drilling data, we reconstructed the pre-AD 79 paleo-surface with a sophisticated geostatistical methodology using a machine based learning approach based on classification and regression trees. We hypothesize that the present-day topography reflects the ancient topography, because the eruption of AD 79 coated the ancient topography, leaving ancient physiographic elements of the Sarno River plain still recognizable in the present-day topography. Therefore, a high resolution

Exploring Normalization and Network Reconstruction Methods using In Silico and In Vivo Models

Science.gov (United States)

Abstract: Lessons learned from the recent DREAM competitions include: The search for the best network reconstruction method continues, and we need more complete datasets with ground truth from more complex organisms. It has become obvious that the network reconstruction methods t...

Parametric boundary reconstruction algorithm for industrial CT metrology application.

Science.gov (United States)

Yin, Zhye; Khare, Kedar; De Man, Bruno

2009-01-01

High-energy X-ray computed tomography (CT) systems have been recently used to produce high-resolution images in various nondestructive testing and evaluation (NDT/NDE) applications. The accuracy of the dimensional information extracted from CT images is rapidly approaching the accuracy achieved with a coordinate measuring machine (CMM), the conventional approach to acquire the metrology information directly. On the other hand, CT systems generate the sinogram which is transformed mathematically to the pixel-based images. The dimensional information of the scanned object is extracted later by performing edge detection on reconstructed CT images. The dimensional accuracy of this approach is limited by the grid size of the pixel-based representation of CT images since the edge detection is performed on the pixel grid. Moreover, reconstructed CT images usually display various artifacts due to the underlying physical process and resulting object boundaries from the edge detection fail to represent the true boundaries of the scanned object. In this paper, a novel algorithm to reconstruct the boundaries of an object with uniform material composition and uniform density is presented. There are three major benefits in the proposed approach. First, since the boundary parameters are reconstructed instead of image pixels, the complexity of the reconstruction algorithm is significantly reduced. The iterative approach, which can be computationally intensive, will be practical with the parametric boundary reconstruction. Second, the object of interest in metrology can be represented more directly and accurately by the boundary parameters instead of the image pixels. By eliminating the extra edge detection step, the overall dimensional accuracy and process time can be improved. Third, since the parametric reconstruction approach shares the boundary representation with other conventional metrology modalities such as CMM, boundary information from other modalities can be directly

Rapid maximum likelihood ancestral state reconstruction of continuous characters: A rerooting-free algorithm.

Science.gov (United States)

Goolsby, Eric W

2017-04-01

Ancestral state reconstruction is a method used to study the evolutionary trajectories of quantitative characters on phylogenies. Although efficient methods for univariate ancestral state reconstruction under a Brownian motion model have been described for at least 25 years, to date no generalization has been described to allow more complex evolutionary models, such as multivariate trait evolution, non-Brownian models, missing data, and within-species variation. Furthermore, even for simple univariate Brownian motion models, most phylogenetic comparative R packages compute ancestral states via inefficient tree rerooting and full tree traversals at each tree node, making ancestral state reconstruction extremely time-consuming for large phylogenies. Here, a computationally efficient method for fast maximum likelihood ancestral state reconstruction of continuous characters is described. The algorithm has linear complexity relative to the number of species and outperforms the fastest existing R implementations by several orders of magnitude. The described algorithm is capable of performing ancestral state reconstruction on a 1,000,000-species phylogeny in fewer than 2 s using a standard laptop, whereas the next fastest R implementation would take several days to complete. The method is generalizable to more complex evolutionary models, such as phylogenetic regression, within-species variation, non-Brownian evolutionary models, and multivariate trait evolution. Because this method enables fast repeated computations on phylogenies of virtually any size, implementation of the described algorithm can drastically alleviate the computational burden of many otherwise prohibitively time-consuming tasks requiring reconstruction of ancestral states, such as phylogenetic imputation of missing data, bootstrapping procedures, Expectation-Maximization algorithms, and Bayesian estimation. The described ancestral state reconstruction algorithm is implemented in the Rphylopars

Experimental reconstruction of a highly reflecting fiber Bragg grating by using spectral regularization and inverse scattering.

Science.gov (United States)

Rosenthal, Amir; Horowitz, Moshe; Kieckbusch, Sven; Brinkmeyer, Ernst

2007-10-01

We demonstrate experimentally, for the first time to our knowledge, a reconstruction of a highly reflecting fiber Bragg grating from its complex reflection spectrum by using a regularization algorithm. The regularization method is based on correcting the measured reflection spectrum at the Bragg zone frequencies and enables the reconstruction of the grating profile using the integral-layer-peeling algorithm. A grating with an approximately uniform profile and with a maximum reflectivity of 99.98% was accurately reconstructed by measuring only its complex reflection spectrum.

Surface Topology Reconstruction From The White Light Interferogram By Means Of Prony Analysis

Directory of Open Access Journals (Sweden)

Khoma Anna

2015-12-01

Full Text Available The paper presents a new method of surface topology reconstruction from a white light interferogram. The method is based on interferogram modelling by complex exponents (Prony method. The compatibility of white light interferogram and Prony models has already been proven. Effectiveness of the method was tested by modelling and examining reconstruction of tilted and spherical surfaces, and by estimating the reconstruction accuracy.

Optimisation of the ATLAS Track Reconstruction Software for Run-2

CERN Document Server

Salzburger, Andreas; The ATLAS collaboration

2015-01-01

The reconstruction of particle trajectories in the tracking detectors of experiments at the Large Hadron Collider (LHC) is one of the most complex parts in analysing the collected data from beam-beam collisions. To achieve the desired integrated luminosity during Run-1 of the LHC data taking period, the number of simultaneous proton-proton interactions per beam crossing (pile-up) was steadily increased. The track reconstruction is the most time consuming reconstruction component and scales non-linear in high luminosity environments. Flat budget projections (at best) for computing resources during the upcoming Run-2 of the LHC together with the demands of reconstructing higher pile-up collision data at rates more than double compared to Run-1 have put pressure on the track reconstruction software to stay within the available computing resources. The ATLAS experiment has thus performed a two year long software campaign which led to a reduction of the reconstruction time for Run-2 conditions by a factor of four:...

Photorealistic large-scale urban city model reconstruction.

Science.gov (United States)

Poullis, Charalambos; You, Suya

2009-01-01

The rapid and efficient creation of virtual environments has become a crucial part of virtual reality applications. In particular, civil and defense applications often require and employ detailed models of operations areas for training, simulations of different scenarios, planning for natural or man-made events, monitoring, surveillance, games, and films. A realistic representation of the large-scale environments is therefore imperative for the success of such applications since it increases the immersive experience of its users and helps reduce the difference between physical and virtual reality. However, the task of creating such large-scale virtual environments still remains a time-consuming and manual work. In this work, we propose a novel method for the rapid reconstruction of photorealistic large-scale virtual environments. First, a novel, extendible, parameterized geometric primitive is presented for the automatic building identification and reconstruction of building structures. In addition, buildings with complex roofs containing complex linear and nonlinear surfaces are reconstructed interactively using a linear polygonal and a nonlinear primitive, respectively. Second, we present a rendering pipeline for the composition of photorealistic textures, which unlike existing techniques, can recover missing or occluded texture information by integrating multiple information captured from different optical sensors (ground, aerial, and satellite).

A Novel Nipple Reconstruction Technique for Maintaining Nipple Projection: The Boomerang Flap

Directory of Open Access Journals (Sweden)

Young-Eun Kim

2016-09-01

Full Text Available Nipple-areolar complex (NAC reconstruction is the final step in the long journey of breast reconstruction for mastectomy patients. Successful NAC reconstruction depends on the use of appropriate surgical techniques that are simple and reliable. To date, numerous techniques have been used for nipple reconstruction, including contralateral nipple sharing and various local flaps. Recently, it has been common to utilize local flaps. However, the most common nipple reconstruction problem encountered with local flaps is the loss of nipple projection; there can be approximately 50% projection loss in reconstructed nipples over long-term follow-up. Several factors might contribute to nipple projection loss, and we tried to overcome these factors by performing nipple reconstructions using a boomerang flap technique, which is a modified C–V flap that utilizes the previous mastectomy scar to maintain long-term nipple projection.

A Novel Nipple Reconstruction Technique for Maintaining Nipple Projection: The Boomerang Flap.

Science.gov (United States)

Kim, Young-Eun; Hong, Ki Yong; Minn, Kyung Won; Jin, Ung Sik

2016-09-01

Nipple-areolar complex (NAC) reconstruction is the final step in the long journey of breast reconstruction for mastectomy patients. Successful NAC reconstruction depends on the use of appropriate surgical techniques that are simple and reliable. To date, numerous techniques have been used for nipple reconstruction, including contralateral nipple sharing and various local flaps. Recently, it has been common to utilize local flaps. However, the most common nipple reconstruction problem encountered with local flaps is the loss of nipple projection; there can be approximately 50% projection loss in reconstructed nipples over long-term follow-up. Several factors might contribute to nipple projection loss, and we tried to overcome these factors by performing nipple reconstructions using a boomerang flap technique, which is a modified C-V flap that utilizes the previous mastectomy scar to maintain long-term nipple projection.

Data based identification and prediction of nonlinear and complex dynamical systems

Science.gov (United States)

Wang, Wen-Xu; Lai, Ying-Cheng; Grebogi, Celso

2016-07-01

The problem of reconstructing nonlinear and complex dynamical systems from measured data or time series is central to many scientific disciplines including physical, biological, computer, and social sciences, as well as engineering and economics. The classic approach to phase-space reconstruction through the methodology of delay-coordinate embedding has been practiced for more than three decades, but the paradigm is effective mostly for low-dimensional dynamical systems. Often, the methodology yields only a topological correspondence of the original system. There are situations in various fields of science and engineering where the systems of interest are complex and high dimensional with many interacting components. A complex system typically exhibits a rich variety of collective dynamics, and it is of great interest to be able to detect, classify, understand, predict, and control the dynamics using data that are becoming increasingly accessible due to the advances of modern information technology. To accomplish these goals, especially prediction and control, an accurate reconstruction of the original system is required. Nonlinear and complex systems identification aims at inferring, from data, the mathematical equations that govern the dynamical evolution and the complex interaction patterns, or topology, among the various components of the system. With successful reconstruction of the system equations and the connecting topology, it may be possible to address challenging and significant problems such as identification of causal relations among the interacting components and detection of hidden nodes. The "inverse" problem thus presents a grand challenge, requiring new paradigms beyond the traditional delay-coordinate embedding methodology. The past fifteen years have witnessed rapid development of contemporary complex graph theory with broad applications in interdisciplinary science and engineering. The combination of graph, information, and nonlinear dynamical

Data based identification and prediction of nonlinear and complex dynamical systems

Energy Technology Data Exchange (ETDEWEB)

Wang, Wen-Xu [School of Systems Science, Beijing Normal University, Beijing, 100875 (China); Business School, University of Shanghai for Science and Technology, Shanghai 200093 (China); Lai, Ying-Cheng, E-mail: Ying-Cheng.Lai@asu.edu [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ 85287 (United States); Department of Physics, Arizona State University, Tempe, AZ 85287 (United States); Institute for Complex Systems and Mathematical Biology, King’s College, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom); Grebogi, Celso [Institute for Complex Systems and Mathematical Biology, King’s College, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom)

2016-07-12

The problem of reconstructing nonlinear and complex dynamical systems from measured data or time series is central to many scientific disciplines including physical, biological, computer, and social sciences, as well as engineering and economics. The classic approach to phase-space reconstruction through the methodology of delay-coordinate embedding has been practiced for more than three decades, but the paradigm is effective mostly for low-dimensional dynamical systems. Often, the methodology yields only a topological correspondence of the original system. There are situations in various fields of science and engineering where the systems of interest are complex and high dimensional with many interacting components. A complex system typically exhibits a rich variety of collective dynamics, and it is of great interest to be able to detect, classify, understand, predict, and control the dynamics using data that are becoming increasingly accessible due to the advances of modern information technology. To accomplish these goals, especially prediction and control, an accurate reconstruction of the original system is required. Nonlinear and complex systems identification aims at inferring, from data, the mathematical equations that govern the dynamical evolution and the complex interaction patterns, or topology, among the various components of the system. With successful reconstruction of the system equations and the connecting topology, it may be possible to address challenging and significant problems such as identification of causal relations among the interacting components and detection of hidden nodes. The “inverse” problem thus presents a grand challenge, requiring new paradigms beyond the traditional delay-coordinate embedding methodology. The past fifteen years have witnessed rapid development of contemporary complex graph theory with broad applications in interdisciplinary science and engineering. The combination of graph, information, and nonlinear

Data based identification and prediction of nonlinear and complex dynamical systems

International Nuclear Information System (INIS)

Wang, Wen-Xu; Lai, Ying-Cheng; Grebogi, Celso

2016-01-01

The problem of reconstructing nonlinear and complex dynamical systems from measured data or time series is central to many scientific disciplines including physical, biological, computer, and social sciences, as well as engineering and economics. The classic approach to phase-space reconstruction through the methodology of delay-coordinate embedding has been practiced for more than three decades, but the paradigm is effective mostly for low-dimensional dynamical systems. Often, the methodology yields only a topological correspondence of the original system. There are situations in various fields of science and engineering where the systems of interest are complex and high dimensional with many interacting components. A complex system typically exhibits a rich variety of collective dynamics, and it is of great interest to be able to detect, classify, understand, predict, and control the dynamics using data that are becoming increasingly accessible due to the advances of modern information technology. To accomplish these goals, especially prediction and control, an accurate reconstruction of the original system is required. Nonlinear and complex systems identification aims at inferring, from data, the mathematical equations that govern the dynamical evolution and the complex interaction patterns, or topology, among the various components of the system. With successful reconstruction of the system equations and the connecting topology, it may be possible to address challenging and significant problems such as identification of causal relations among the interacting components and detection of hidden nodes. The “inverse” problem thus presents a grand challenge, requiring new paradigms beyond the traditional delay-coordinate embedding methodology. The past fifteen years have witnessed rapid development of contemporary complex graph theory with broad applications in interdisciplinary science and engineering. The combination of graph, information, and nonlinear

Challenges in the reconstruction of bilateral maxillectomy defects.

Science.gov (United States)

Joseph, Shawn T; Thankappan, Krishnakumar; Buggaveeti, Rahul; Sharma, Mohit; Mathew, Jimmy; Iyer, Subramania

2015-02-01

Bilateral maxillectomy defects, if not adequately reconstructed, can result in grave esthetic and functional problems. The purpose of this study was to investigate the outcome of reconstruction of such defects. This is a retrospective case series. The defects were analyzed for their components and the flaps used for reconstruction. Outcomes for flap loss and functional indices, including oral diet, speech, and dental rehabilitation, also were evaluated. Ten consecutive patients who underwent bilateral maxillectomy reconstruction received 14 flaps. Six patients had malignancies of the maxilla, and 4 patients had nonmalignant indications. Ten bony free flaps were used. Four soft tissue flaps were used. The fibula free flap was the most common flap used. Three patients had total flap loss. Seven patients were alive and available for functional evaluation. Of these, 4 were taking an oral diet with altered consistency and 2 were on a regular diet. Speech was intelligible in all patients. Only 2 patients opted for dental rehabilitation with removable dentures. Reconstruction after bilateral maxillectomy is essential to prevent esthetic and functional problems. Bony reconstruction is ideal. The fibula bone free flap is commonly used. The complexity of the defect makes reconstruction difficult and the initial success rate of free flaps is low. Secondary reconstructions after the initial flap failures were successful. A satisfactory functional outcome can be achieved. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Computational reconstruction reveals a candidate magnetic biocompass to be likely irrelevant for magnetoreception

DEFF Research Database (Denmark)

Friis, Ida; Sjulstok, Emil; Solov'yov, Ilia A

2017-01-01

is supposedly facilitated through an iron rich polymer complex which couples to multiple cryptochromes. The present investigation aims to independently reconstruct this complex and describe its interaction with Drosophila melanogaster cryptochromes. The polymer complex consists of ISCA1 protein monomers...

Surgery for failed cervical spine reconstruction.

Science.gov (United States)

Helgeson, Melvin D; Albert, Todd J

2012-03-01

Review article. To review the indications, operative strategy, and complications of revision cervical spine reconstruction. With many surgeons expanding their indications for cervical spine surgery, the number of patients being treated operatively has increased. Unfortunately, the number of patients requiring revision procedures is also increasing, but very little literature exists reviewing changes in the indications or operative planning for revision reconstruction. Narrative and review of the literature. In addition to the well-accepted indications for primary cervical spine surgery (radiculopathy, myelopathy, instability, and tumor), we have used the following indications for revision surgery: pseudarthrosis, adjacent segment degeneration, inadequate decompression, iatrogenic instability, and deformity. Our surgical goal for pseudarthrosis is obviously to obtain a fusion, which can usually be performed with an approach not done previously. Our surgical goals for instability and deformity are more complex, with a focus on decompression of any neurologic compression, correction of deformity, and stability. Revision cervical spine reconstruction is safe and effective if performed for the appropriate indications and with proper planning.

Reconstruction of Nasal Cleft Deformities Using Expanded Forehead Flaps: A Case Series.

Science.gov (United States)

Ramanathan, Manikandhan; Sneha, Pendem; Parameswaran, Ananthnarayanan; Jayakumar, Naveen; Sailer, Hermann F

2014-12-01

Reconstruction of the nasal clefts is a challenging task considering the nasal anatomic complexity and their possible association with craniofacial defects. The reconstruction of these defects needs extensive amounts of soft tissue that warrant the use of forehead flaps. Often presence of cranial defects and low hairline compromise the amount of tissue available for reconstruction warrenting tissue expansion. To evaluate the efficacy of tissue expansion in reconstruction of congenital nasal clefts. 9 patients with congenital nasal clefts involving multiple sub units were taken up for nasal reconstruction with expanded forehead flaps. The average amount of expansion needed was 200 ml. The reconstruction was performed in 3 stages. Expanded forehead flaps proved to be best modality for reconstruction providing the skin cover needed for ala, columella and dorsum with minimal scarring at the donor site. Expansion of the forehead flap is a viable option for multiple sub unit reconstruction in congenital nasal cleft deformities.

Reconstructing events, from electronic signals to tracks

CERN Multimedia

CERN. Geneva

2015-01-01

Reconstructing tracks in the events taken by LHC experiments is one of the most challenging and computationally expensive software tasks to be carried out in the data processing chain. A typical LHC event is composed of multiple p-p interactions, each leaving signals from many charged particles in the detector and jus building up an environment of unprecedented complexity. In the lecture I will give an overview of event reconstruction in a typical High Energy Physics experiment. After an introduction to particle tracking detectors I will discuss the concepts and techniques required to master the tracking challenge at the LHC. I will explain how track propagation in a realistic detector works, present different techniques for track fitting and track finding. At the end we will see how all of those techniques play together in the ATLAS track reconstruction application.

Direct 2-D reconstructions of conductivity and permittivity from EIT data on a human chest.

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Herrera, Claudia N L; Vallejo, Miguel F M; Mueller, Jennifer L; Lima, Raul G

2015-01-01

A novel direct D-bar reconstruction algorithm is presented for reconstructing a complex conductivity distribution from 2-D EIT data. The method is applied to simulated data and archival human chest data. Permittivity reconstructions with the aforementioned method and conductivity reconstructions with the previously existing nonlinear D-bar method for real-valued conductivities depicting ventilation and perfusion in the human chest are presented. This constitutes the first fully nonlinear D-bar reconstructions of human chest data and the first D-bar permittivity reconstructions of experimental data. The results of the human chest data reconstructions are compared on a circular domain versus a chest-shaped domain.

Individualized Plastic Reconstruction Strategy for Patients With Ectodermal Dysplasia Syndrome.

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Hou, Yikang; Jin, Yunbo; Lin, Xiaoxi; Chai, Gang; Zhang, Yan; Qi, Zuoliang

2017-06-01

Ectodermal dysplasia syndrome is a hereditary disease of ectodermal origin. Appearances of nail dystrophy, alopecia or hypotrichosis, saddle nose deformity, and palmoplantar hyperkeratosis are usually associated with a lack of sweat glands as well as partial or complete absence of teeth. These manifestations are usually corrected only with oral rehabilitation by mounting dentures. In this study, plastic rehabilitation was developed to correct the special features of patients with ectodermal dysplasia. Four men and 1 woman with ectodermal dysplasia syndrome were treated. Four patients showed dysostosis of the midface, and rhinoplasty with costal bone was performed, whereas cosmetic operation aiming to repair soft tissue defects was adopted for the last patient. After plastic corrections, all 5 patients were satisfied with the results and had no social embarrassment.

Use of the Anterolateral Thigh in Cranio-Orbitofacial Reconstruction

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William J. Parkes

2011-01-01

Full Text Available Objective. To detail the clinical outcomes of a series of patients having undergone free flap reconstruction of the orbit and periorbita and highlight the anterolateral thigh (ALT as a workhorse for addressing defects in this region. Methods. A review of 47 patients who underwent free flap reconstruction for orbital or periorbital defects between September 2006 and May 2011 was performed. Data reviewed included demographics, defect characteristics, free flap used, additional reconstructive techniques employed, length of stay, complications, and follow-up. The ALT subset of the case series was the focus of the data reviewed for this paper. Selected cases were described to highlight some of the advantages of employing the ALT for cranio-orbitofacial reconstruction. Results. 51 free flaps in 47 patients were reviewed. 38 cases required orbital exenteration. The ALT was used in 33 patients. Complications included 1 hematoma, 2 wound infections, 3 CSF leaks, and 3 flap failures. Conclusions. Free tissue transfer allows for the safe and effective reconstruction of complex defects of the orbit and periorbital structures. Reconstructive choice is dependent upon the extent of soft tissue loss, midfacial bone loss, and skullbase involvement. The ALT provides a versatile option to reconstruct the many cranio-orbitofacial defects encountered.

Low-Cost 3D Printing Orbital Implant Templates in Secondary Orbital Reconstructions.

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Callahan, Alison B; Campbell, Ashley A; Petris, Carisa; Kazim, Michael

Despite its increasing use in craniofacial reconstructions, three-dimensional (3D) printing of customized orbital implants has not been widely adopted. Limitations include the cost of 3D printers able to print in a biocompatible material suitable for implantation in the orbit and the breadth of available implant materials. The authors report the technique of low-cost 3D printing of orbital implant templates used in complex, often secondary, orbital reconstructions. A retrospective case series of 5 orbital reconstructions utilizing a technique of 3D printed orbital implant templates is presented. Each patient's Digital Imaging and Communications in Medicine data were uploaded and processed to create 3D renderings upon which a customized implant was designed and sent electronically to printers open for student use at our affiliated institutions. The mock implants were sterilized and used intraoperatively as a stencil and mold. The final implant material was chosen by the surgeons based on the requirements of the case. Five orbital reconstructions were performed with this technique: 3 tumor reconstructions and 2 orbital fractures. Four of the 5 cases were secondary reconstructions. Molded Medpor Titan (Stryker, Kalamazoo, MI) implants were used in 4 cases and titanium mesh in 1 case. The stenciled and molded implants were adjusted no more than 2 times before anchored in place (mean 1). No case underwent further revision. The technique and cases presented demonstrate 1) the feasibility and accessibility of low-cost, independent use of 3D printing technology to fashion patient-specific implants in orbital reconstructions, 2) the ability to apply this technology to the surgeon's preference of any routinely implantable material, and 3) the utility of this technique in complex, secondary reconstructions.

Image reconstruction of fluorescent molecular tomography based on the tree structured Schur complement decomposition

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Wang Jiajun

2010-05-01

Full Text Available Abstract Background The inverse problem of fluorescent molecular tomography (FMT often involves complex large-scale matrix operations, which may lead to unacceptable computational errors and complexity. In this research, a tree structured Schur complement decomposition strategy is proposed to accelerate the reconstruction process and reduce the computational complexity. Additionally, an adaptive regularization scheme is developed to improve the ill-posedness of the inverse problem. Methods The global system is decomposed level by level with the Schur complement system along two paths in the tree structure. The resultant subsystems are solved in combination with the biconjugate gradient method. The mesh for the inverse problem is generated incorporating the prior information. During the reconstruction, the regularization parameters are adaptive not only to the spatial variations but also to the variations of the objective function to tackle the ill-posed nature of the inverse problem. Results Simulation results demonstrate that the strategy of the tree structured Schur complement decomposition obviously outperforms the previous methods, such as the conventional Conjugate-Gradient (CG and the Schur CG methods, in both reconstruction accuracy and speed. As compared with the Tikhonov regularization method, the adaptive regularization scheme can significantly improve ill-posedness of the inverse problem. Conclusions The methods proposed in this paper can significantly improve the reconstructed image quality of FMT and accelerate the reconstruction process.

Similar Fracture Patterns in Human Nose and Gothic Cathedral.

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Lee, Shu Jin; Tse, Kwong Ming; Lee, Heow Pueh

2015-10-01

This study proposes that the bony anatomy of the human nose and masonry structure of the Gothic cathedral are geometrically similar, and have common fracture patterns. We also aim to correlate the fracture patterns observed in patients' midface structures with those seen in the Gothic cathedral using computational approach. CT scans of 33 patients with facial fractures were examined and compared with computer simulations of both the Gothic cathedral and human nose. Three similar patterns were found: (1) Cracks of the nasal arch with crumpling of the vertical buttresses akin to the damage seen during minor earthquakes; (2) lateral deviation of the central nasal arch and collapse of the vertical buttresses akin to those due to lateral forces from wind and in major earthquakes; and (3) Central arch collapse seen as a result of collapse under excessive dead weight. Interestingly, the finding of occult nasal and septal fractures in the mandible fractures with absence of direct nasal trauma highlights the possibility of transmission of forces from the foundation to the arch leading to structural failure. It was also found that the structural buttresses of the Gothic cathedral delineate the vertical buttresses in the human midface structure. These morphologic similarities between the human nose and Gothic cathedral will serve as a basis to study the biomechanics of nasal fractures. Identification of structural buttresses in a skeletal structure has important implications for reconstruction as reestablishment of structural continuity restores normal anatomy and architectural stability of the human midface structure. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

WARACS: Wrappers to Automate the Reconstruction of Ancestral Character States1

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Gruenstaeudl, Michael

2016-01-01

Premise of the study: Reconstructions of ancestral character states are among the most widely used analyses for evaluating the morphological, cytological, or ecological evolution of an organismic lineage. The software application Mesquite remains the most popular application for such reconstructions among plant scientists, even though its support for automating complex analyses is limited. A software tool is needed that automates the reconstruction and visualization of ancestral character states with Mesquite and similar applications. Methods and Results: A set of command line–based Python scripts was developed that (a) communicates standardized input to and output from the software applications Mesquite, BayesTraits, and TreeGraph2; (b) automates the process of ancestral character state reconstruction; and (c) facilitates the visualization of reconstruction results. Conclusions: WARACS provides a simple tool that streamlines the reconstruction and visualization of ancestral character states over a wide array of parameters, including tree distribution, character state, and optimality criterion. PMID:26949580

Blind compressed sensing image reconstruction based on alternating direction method

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Liu, Qinan; Guo, Shuxu

2018-04-01

In order to solve the problem of how to reconstruct the original image under the condition of unknown sparse basis, this paper proposes an image reconstruction method based on blind compressed sensing model. In this model, the image signal is regarded as the product of a sparse coefficient matrix and a dictionary matrix. Based on the existing blind compressed sensing theory, the optimal solution is solved by the alternative minimization method. The proposed method solves the problem that the sparse basis in compressed sensing is difficult to represent, which restrains the noise and improves the quality of reconstructed image. This method ensures that the blind compressed sensing theory has a unique solution and can recover the reconstructed original image signal from a complex environment with a stronger self-adaptability. The experimental results show that the image reconstruction algorithm based on blind compressed sensing proposed in this paper can recover high quality image signals under the condition of under-sampling.

Direct fourier methods in 3D-reconstruction from cone-beam data

International Nuclear Information System (INIS)

Axelsson, C.

1994-01-01

The problem of 3D-reconstruction is encountered in both medical and industrial applications of X-ray tomography. A method able to utilize a complete set of projections complying with Tuys condition was proposed by Grangeat. His method is mathematically exact and consists of two distinct phases. In phase 1 cone-beam projection data are used to produce the derivative of the radon transform. In phase 2, after interpolation, the radon transform data are used to reconstruct the three-dimensional object function. To a large extent our method is an extension of the Grangeat method. Our aim is to reduce the computational complexity, i.e. to produce a faster method. The most taxing procedure during phase 1 is computation of line-integrals in the detector plane. By applying the direct Fourier method in reverse for this computation, we reduce the complexity of phase 1 from O(N 4 ) to O(N 3 logN). Phase 2 can be performed either as a straight 3D-reconstruction or as a sequence of two 2D-reconstructions in vertical and horizontal planes, respectively. Direct Fourier methods can be applied for the 2D- and for the 3D-reconstruction, which reduces the complexity of phase 2 from O(N 4 ) to O(N 3 logN) as well. In both cases, linogram techniques are applied. For 3D-reconstruction the inversion formula contains the second derivative filter instead of the well-known ramp-filter employed in the 2D-case. The derivative filter is more well-behaved than the 2D ramp-filter. This implies that less zeropadding is necessary which brings about a further reduction of the computational efforts. The method has been verified by experiments on simulated data. The image quality is satisfactory and independent of cone-beam angles. For a 512 3 volume we estimate that our method is ten times faster than Grangeats method

Mastectomy Skin Necrosis After Breast Reconstruction: A Comparative Analysis Between Autologous Reconstruction and Implant-Based Reconstruction.

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Sue, Gloria R; Lee, Gordon K

2018-05-01

Mastectomy skin necrosis is a significant problem after breast reconstruction. We sought to perform a comparative analysis on this complication between patients undergoing autologous breast reconstruction and patients undergoing 2-stage expander implant breast reconstruction. A retrospective review was performed on consecutive patients undergoing autologous breast reconstruction or 2-stage expander implant breast reconstruction by the senior author from 2006 through 2015. Patient demographic factors including age, body mass index, history of diabetes, history of smoking, and history of radiation to the breast were collected. Our primary outcome measure was mastectomy skin necrosis. Fisher exact test was used for statistical analysis between the 2 patient cohorts. The treatment patterns of mastectomy skin necrosis were then analyzed. We identified 204 patients who underwent autologous breast reconstruction and 293 patients who underwent 2-stage expander implant breast reconstruction. Patients undergoing autologous breast reconstruction were older, heavier, more likely to have diabetes, and more likely to have had prior radiation to the breast compared with patients undergoing implant-based reconstruction. The incidence of mastectomy skin necrosis was 30.4% of patients in the autologous group compared with only 10.6% of patients in the tissue expander group (P care in the autologous group, only 3.2% were treated with local wound care in the tissue expander group (P skin necrosis is significantly more likely to occur after autologous breast reconstruction compared with 2-stage expander implant-based breast reconstruction. Patients with autologous reconstructions are more readily treated with local wound care compared with patients with tissue expanders, who tended to require operative treatment of this complication. Patients considering breast reconstruction should be counseled appropriately regarding the differences in incidence and management of mastectomy skin

Tomographic reconstruction of OH* chemiluminescence in two interacting turbulent flames

International Nuclear Information System (INIS)

Worth, Nicholas A; Dawson, James R

2013-01-01

The tomographic reconstruction of OH* chemiluminescence was performed on two interacting turbulent premixed bluff-body stabilized flames under steady flow conditions and acoustic excitation. These measurements elucidate the complex three-dimensional (3D) vortex–flame interactions which have previously not been accessible. The experiment was performed using a single camera and intensifier, with multiple views acquired by repositioning the camera, permitting calculation of the mean and phase-averaged volumetric OH* distributions. The reconstructed flame structure and phase-averaged dynamics are compared with OH planar laser-induced fluorescence and flame surface density measurements for the first time. The volumetric data revealed that the large-scale vortex–flame structures formed along the shear layers of each flame collide when the two flames meet, resulting in complex 3D flame structures in between the two flames. With a fairly simple experimental setup, it is shown that the tomographic reconstruction of OH* chemiluminescence in forced flames is a powerful tool that can yield important physical insights into large-scale 3D flame dynamics that are important in combustion instability. (paper)

Super resolution reconstruction of infrared images based on classified dictionary learning

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Liu, Fei; Han, Pingli; Wang, Yi; Li, Xuan; Bai, Lu; Shao, Xiaopeng

2018-05-01

Infrared images always suffer from low-resolution problems resulting from limitations of imaging devices. An economical approach to combat this problem involves reconstructing high-resolution images by reasonable methods without updating devices. Inspired by compressed sensing theory, this study presents and demonstrates a Classified Dictionary Learning method to reconstruct high-resolution infrared images. It classifies features of the samples into several reasonable clusters and trained a dictionary pair for each cluster. The optimal pair of dictionaries is chosen for each image reconstruction and therefore, more satisfactory results is achieved without the increase in computational complexity and time cost. Experiments and results demonstrated that it is a viable method for infrared images reconstruction since it improves image resolution and recovers detailed information of targets.

Nipple-sparing mastectomy with immediate implant reconstruction: cosmetic outcomes and technical refinements.

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Salgarello, Marzia; Visconti, Giuseppe; Barone-Adesi, Liliana

2010-11-01

Nipple-sparing mastectomy is gaining widespread popularity, as it could allow improved aesthetic outcome without increasing oncologic risk. To investigate the reconstructive issues experienced with immediate implant reconstruction, the authors reviewed the cosmetic outcomes of their series. The authors retrospectively analyzed the data on 33 cases of nipple-sparing mastectomy for both cancer and prophylaxis with immediate implant reconstruction using the submusculo-subfascial pocket. Cosmetic evaluation methods were clinical and photography-based assessments and a patient-satisfaction survey. The average follow-up period was 26.8 months. No nipple-areola complex cancer involvement was registered. The reconstructive outcomes ranged from good to excellent in 83 percent of the cases. Patients' satisfaction was high to very high, except in one patient who experienced total nipple-areola complex loss (one breast, 2.4 percent). Overall, early minor complications were registered in four breasts (9.5 percent) and late minor complications in five cases (12 percent). The authors' series suggest that nipple-sparing mastectomy is an option for carefully selected and screened patients. Larger studies with longer follow-up are needed, however. On the whole, the immediate one-stage implant reconstruction with hyperprojected anatomical gel implants represents a valid option. The skin incision algorithm proposed, which is based on the breast size, shape, and previous scars, might aid in the decision-making process to achieve satisfying results using this procedure. The radial approaches represent a good compromise between the oncologic and reconstructive procedures.

Evolution of design considerations in complex craniofacial reconstruction using patient-specific implants.

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Peel, Sean; Bhatia, Satyajeet; Eggbeer, Dominic; Morris, Daniel S; Hayhurst, Caroline

2017-06-01

Previously published evidence has established major clinical benefits from using computer-aided design, computer-aided manufacturing, and additive manufacturing to produce patient-specific devices. These include cutting guides, drilling guides, positioning guides, and implants. However, custom devices produced using these methods are still not in routine use, particularly by the UK National Health Service. Oft-cited reasons for this slow uptake include the following: a higher up-front cost than conventionally fabricated devices, material-choice uncertainty, and a lack of long-term follow-up due to their relatively recent introduction. This article identifies a further gap in current knowledge - that of design rules, or key specification considerations for complex computer-aided design/computer-aided manufacturing/additive manufacturing devices. This research begins to address the gap by combining a detailed review of the literature with first-hand experience of interdisciplinary collaboration on five craniofacial patient case studies. In each patient case, bony lesions in the orbito-temporal region were segmented, excised, and reconstructed in the virtual environment. Three cases translated these digital plans into theatre via polymer surgical guides. Four cases utilised additive manufacturing to fabricate titanium implants. One implant was machined from polyether ether ketone. From the literature, articles with relevant abstracts were analysed to extract design considerations. In all, 19 frequently recurring design considerations were extracted from previous publications. Nine new design considerations were extracted from the case studies - on the basis of subjective clinical evaluation. These were synthesised to produce a design considerations framework to assist clinicians with prescribing and design engineers with modelling. Promising avenues for further research are proposed.

A new method of morphological comparison for bony reconstructive surgery: maxillary reconstruction using scapular tip bone

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Chan, Harley; Gilbert, Ralph W.; Pagedar, Nitin A.; Daly, Michael J.; Irish, Jonathan C.; Siewerdsen, Jeffrey H.

2010-02-01

esthetic appearance is one of the most important factors for reconstructive surgery. The current practice of maxillary reconstruction chooses radial forearm, fibula or iliac rest osteocutaneous to recreate three-dimensional complex structures of the palate and maxilla. However, these bone flaps lack shape similarity to the palate and result in a less satisfactory esthetic. Considering similarity factors and vasculature advantages, reconstructive surgeons recently explored the use of scapular tip myo-osseous free flaps to restore the excised site. We have developed a new method that quantitatively evaluates the morphological similarity of the scapula tip bone and palate based on a diagnostic volumetric computed tomography (CT) image. This quantitative result was further interpreted as a color map that rendered on the surface of a three-dimensional computer model. For surgical planning, this color interpretation could potentially assist the surgeon to maximize the orientation of the bone flaps for best fit of the reconstruction site. With approval from the Research Ethics Board (REB) of the University Health Network, we conducted a retrospective analysis with CT image obtained from 10 patients. Each patient had a CT scans including the maxilla and chest on the same day. Based on this image set, we simulated total, subtotal and hemi palate reconstruction. The procedure of simulation included volume segmentation, conversing the segmented volume to a stereo lithography (STL) model, manual registration, computation of minimum geometric distances and curvature between STL model. Across the 10 patients data, we found the overall root-mean-square (RMS) conformance was 3.71+/- 0.16 mm

Visual reconstruction of Hampi Temple - Construed Graphically, Pictorially and Digitally

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Meera Natampally

2014-05-01

Full Text Available The existing temple complex in Hampi, Karnataka, India was extensively studied, analyzed and documented. The complex was measured-drawn and digitized by plotting its edges and vertices using AutoCAD to generate 2d drawings. The graphic 2d elements developed were extended into 3 dimensional objects using Google sketch-up. The tool has been used to facilitate the visual re-construction to achieve the architecture of the temple in its original form. 3D virtual modelling / visual reconstruction helps us to visualize the structure in its original form giving a holistic picture of the Vijayanagara Empire in all its former glory. The project is interpreted graphically using Auto-CAD drawings, pictorially, digitally using Sketch-Up model and Kinect.

Mid-Face Volumization With Hyaluronic Acid: Injection Technique and Safety Aspects from a Controlled, Randomized, Double-Blind Clinical Study.

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Prager, Welf; Agsten, Karla; Kravtsov, Maria; Kerscher, Prof Martina

2017-04-01

BACKGROUND: Injection of hyaluronic acid (HA) volumizing fillers in the malar area is intended for rejuvenation of the mid-face. The choice of products, depth, and technique of injection depends on the desired level of volume enhancement and practitioners' preferences. OBJECTIVE: To describe a volumizing injection technique in the scope of a controlled, randomized, double-blind, single-center, split-face clinical study. A total of 45 subjects with bilateral symmetrical moderate to severe volume loss in the malar area received a single 2 mL injection of CPM®-26 (Cohesive Polydensified Matrix®) on one side and VYC®-20 (VYCROSS®) on the contralateral side of the face. The same injection technique was applied for both sides of the face. Use of anesthetics, overcorrection, and touch-ups were not permitted. The investigator completed a product satisfaction questionnaire. Adverse events (AE) and injection-site reactions (ISRs) were reported during the study. RESULTS: The products were placed at the epiperiosteal depth in 88.9% (n=40), at the subdermal depth in 8.9% (n=4) and at both levels in 2.2% (n=1) of subjects. Fanning technique using cannulae was applied in most cases (97.8%, n=44). Results of the investigator satisfaction questionnaire allowed to characterize CPM-26 in comparison to other volumizing gels. Both study products were generally well tolerated. Local reactions were transient and of mild to moderate intensity, with the most frequent ones being redness, pain, and swelling. CONCLUSION: Adequate injection technique in volumizing treatments is essential to create a natural aesthetic rejuvenation while respecting the safety aspect of the procedures. A 22G blunt cannula used with CPM-26 was preferred due to an easier and a more homogeneous distribution of the product. The investigator also appreciated CPM-26 for its ease of injection, positioning, lifting, and volumizing capacity. J Drugs Dermatol. 2017;16(4):351-357..

Bessel Fourier Orientation Reconstruction (BFOR): An Analytical Diffusion Propagator Reconstruction for Hybrid Diffusion Imaging and Computation of q-Space Indices

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Hosseinbor, A. Pasha; Chung, Moo K.; Wu, Yu-Chien; Alexander, Andrew L.

2012-01-01

The ensemble average propagator (EAP) describes the 3D average diffusion process of water molecules, capturing both its radial and angular contents. The EAP can thus provide richer information about complex tissue microstructure properties than the orientation distribution function (ODF), an angular feature of the EAP. Recently, several analytical EAP reconstruction schemes for multiple q-shell acquisitions have been proposed, such as diffusion propagator imaging (DPI) and spherical polar Fourier imaging (SPFI). In this study, a new analytical EAP reconstruction method is proposed, called Bessel Fourier orientation reconstruction (BFOR), whose solution is based on heat equation estimation of the diffusion signal for each shell acquisition, and is validated on both synthetic and real datasets. A significant portion of the paper is dedicated to comparing BFOR, SPFI, and DPI using hybrid, non-Cartesian sampling for multiple b-value acquisitions. Ways to mitigate the effects of Gibbs ringing on EAP reconstruction are also explored. In addition to analytical EAP reconstruction, the aforementioned modeling bases can be used to obtain rotationally invariant q-space indices of potential clinical value, an avenue which has not yet been thoroughly explored. Three such measures are computed: zero-displacement probability (Po), mean squared displacement (MSD), and generalized fractional anisotropy (GFA). PMID:22963853

Managing dysphonia in paediatric patients with complex airway conditions.

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Ojha, S; Setlur, J; Bunting, G; Hartnick, C J

2015-08-01

To suggest a phonosurgical management strategy that can be used for children who have previously undergone laryngotracheal reconstruction. This cases series describes three children who presented with complex, multi-level airway stenosis and marked dysphonia. Phonosurgical intervention involved endoscopic and open approaches, and was combined with voice therapy. A phonosurgical reconstruction management algorithm is suggested for evaluating and treating these complex conditions. Pre-operative assessment is critical, and should involve voice analysis and glottal anatomy assessment using office laryngoscopy and stroboscopy. The risks must be weighed up against the benefit of vocal improvement. Surgical intervention should involve combined endoscopic and open approaches. Voice restoration after paediatric airway reconstruction is a complex challenge. Surgical intervention should be conducted in a step-by-step manner to reduce the risk of worsening dysphonia and airway compromise. The risks and benefits must be carefully explored and discussed.

Accurate reconstruction in digital holographic microscopy using antialiasing shift-invariant contourlet transform

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Zhang, Xiaolei; Zhang, Xiangchao; Xu, Min; Zhang, Hao; Jiang, Xiangqian

2018-03-01

The measurement of microstructured components is a challenging task in optical engineering. Digital holographic microscopy has attracted intensive attention due to its remarkable capability of measuring complex surfaces. However, speckles arise in the recorded interferometric holograms, and they will degrade the reconstructed wavefronts. Existing speckle removal methods suffer from the problems of frequency aliasing and phase distortions. A reconstruction method based on the antialiasing shift-invariant contourlet transform (ASCT) is developed. Salient edges and corners have sparse representations in the transform domain of ASCT, and speckles can be recognized and removed effectively. As subsampling in the scale and directional filtering schemes is avoided, the problems of frequency aliasing and phase distortions occurring in the conventional multiscale transforms can be effectively overcome, thereby improving the accuracy of wavefront reconstruction. As a result, the proposed method is promising for the digital holographic measurement of complex structures.

A Comprehensive Approach to Post-Conflict Reconstruction: German Experience in Afghanistan

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Philip Olegovich Trunov

2016-12-01

Full Text Available As a part of a larger research project on complex linkages between security and development implemented by the Center for Security and Development Studies at the Lomonosov Moscow State University, this paper examines the complex dilemmas of pursuing comprehensive approach to post-conflict reconstruction with an example of Federal Republic of Germany’s experience with the Provincial Reconstruction Teams (PRTs in Afghanistan after the terrorist attacks of 9/11. The first section depicts the background of deployment of the PRTs on Afghan territory. The second section compares the U.S., British and German models of PRTs and assesses the role of those teams as vehicles of close civil-military, interagency coordination. The third and the fourth sections identify respectively characteristic features of the German PRTs’ activities in Kunduz and Badakhshan provinces and the main obstacles that hindered the achievement of key objectives. The conclusion contains a concise assessment of effectiveness and efficiency of PRTs as a mechanism of addressing complex challenges of post-conflict reconstruction and transition to peaceful development. It also postulates that the PRT model, regardless of some objective difficulties faced by various German agencies, may be very relevant in the future in fulfilling a revised agenda of the German foreign and defense policies in the XXI century.

Vacuum-assisted closure downgrades reconstructive demands in high-risk patients with severe lower extremity injuries.

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Kakagia, D; Karadimas, E; Drosos, G; Ververidis, A; Kazakos, D; Lazarides, M; Verettas, D

2009-01-01

Primary soft tissue reconstruction in complex leg injuries is mandatory in order to protect exposed tissues; however, it may be precluded by the patient's clinical status or by local wound conditions. This retrospective study aims to evaluate the use of negative pressure as an adjunct to delayed soft tissue reconstruction in patients with complex lower limb trauma. Forty-two patients with 49 complex lower limb injuries were treated with Vacuum assisted closure (VAC) 48 hours after bone fixation, vascular repair and surgical debridement. Wound swab cultures were obtained before and after every VAC application. Duration of therapy, wound flora, final reconstructive technique required, outcome and follow-up period were retrieved from medical records. Twenty-four male and eighteen female patients were recruited, with a mean age of 47 years. All were treated with VAC therapy for 15-42 days. Reconstruction was delayed due to the patients' critical condition, advanced age, medical co-morbidities, heavily exuding wounds and questionable viability of soft tissues. Patients were followed up for 90-895 days. Two wounds healed spontaneously, 6 were managed with delayed direct suture, 31 with split thickness skin grafts and 9 required local cutaneous, fasciocutaneous or muscular flaps. One patient died due to fat embolism. Wound bacterial flora progressively decreased in all but one patient. Scar formation was aesthetically acceptable by the patients while function depended on the initial injury. Negative pressure is a safe and effective adjunct to delayed soft tissue reconstruction in high-risk patients with severe lower extremity injuries, minimizing reconstructive requirements and therefore postoperative morbidity.

Color-coded volume rendering for three-dimensional reconstructions of CT data

International Nuclear Information System (INIS)

Rieker, O.; Mildenberger, P.; Thelen, M.

1999-01-01

Purpose: To evaluate a technique of colored three-dimensional reconstructions without segmentation. Material and methods: Color-coded volume rendered images were reconstructed from the volume data of 25 thoracic, abdominal, musculoskeletal, and vascular helical CT scans using commercial software. The CT volume rendered voxels were encoded with color in the following manner. Opacity, hue, lightness, and chroma were assigned to each of four classes defined by CT number. Color-coded reconstructions were compared to the corresponding grey-scale coded reconstructions. Results: Color-coded volume rendering enabled realistic visualization of pathologic findings when there was sufficient difference in CT density. Segmentation was necessary in some cases to demonstrate small details in a complex volume. Conclusion: Color-coded volume rendering allowed lifelike visualisation of CT volumes without the need of segmentation in most cases. (orig.) [de

Genital reconstruction in exstrophy patients

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R B Nerli

2012-01-01

Full Text Available Introduction: Surgery for bladder exstrophy has been evolving over the last four to five decades. Because survival has become almost universal, the focus has changed in the exstrophy-epispadias complex to improving quality of life. The most prevalent problem in the long-term function of exstrophy patients is the sexual activity of the adolescent and adult males. The penis in exstrophy patients appears short because of marked congenital deficiency of anterior corporal tissue. Many patients approach for genital reconstruction to improve cosmesis as well as to correct chordee. We report our series of male patients seeking genital reconstruction following exstrophy repair in the past. Materials and Methods: Fourteen adolescent/adult male patients attended urology services during the period January 2000-December 2009 seeking genital reconstruction following exstrophy repair in the past. Results: Three patients underwent epispadias repair, four patients had chordee correction with cosmetic excision of skin tags and seven patients underwent chordee correction with penile lengthening. All patients reported satisfaction in the answered questionnaire. Patients undergoing penile lengthening by partial corporal dissection achieved a mean increase in length of 1.614 ± 0.279 cm dorsally and 1.543 ± 0.230 cm ventrally. The satisfactory rate assessed by the Short Form-36 (SF-36 showed that irrespective of the different genital reconstructive procedures done, the patients were satisfied with cosmetic and functional outcome. Conclusions: Surgical procedures have transformed the management in these patients with bladder exstrophy. Bladders can be safely placed within the pelvis, with most patients achieving urinary continence and cosmetically acceptable external genitalia. Genital reconstruction in the form of correction of chordee, excision of ugly skin tags and lengthening of penis can be performed to give the patients a satisfactory cosmetic and functional

A Practical Algorithm for Reconstructing Level-1 Phylogenetic Networks

NARCIS (Netherlands)

K.T. Huber; L.J.J. van Iersel (Leo); S.M. Kelk (Steven); R. Suchecki

2010-01-01

htmlabstractRecently much attention has been devoted to the construction of phylogenetic networks which generalize phylogenetic trees in order to accommodate complex evolutionary processes. Here we present an efficient, practical algorithm for reconstructing level-1 phylogenetic networks - a type of

A practical algorithm for reconstructing level-1 phylogenetic networks

NARCIS (Netherlands)

Huber, K.T.; Iersel, van L.J.J.; Kelk, S.M.; Suchecki, R.

2011-01-01

Recently, much attention has been devoted to the construction of phylogenetic networks which generalize phylogenetic trees in order to accommodate complex evolutionary processes. Here, we present an efficient, practical algorithm for reconstructing level-1 phylogenetic networks-a type of network

GPU-accelerated Kernel Regression Reconstruction for Freehand 3D Ultrasound Imaging.

Science.gov (United States)

Wen, Tiexiang; Li, Ling; Zhu, Qingsong; Qin, Wenjian; Gu, Jia; Yang, Feng; Xie, Yaoqin

2017-07-01

Volume reconstruction method plays an important role in improving reconstructed volumetric image quality for freehand three-dimensional (3D) ultrasound imaging. By utilizing the capability of programmable graphics processing unit (GPU), we can achieve a real-time incremental volume reconstruction at a speed of 25-50 frames per second (fps). After incremental reconstruction and visualization, hole-filling is performed on GPU to fill remaining empty voxels. However, traditional pixel nearest neighbor-based hole-filling fails to reconstruct volume with high image quality. On the contrary, the kernel regression provides an accurate volume reconstruction method for 3D ultrasound imaging but with the cost of heavy computational complexity. In this paper, a GPU-based fast kernel regression method is proposed for high-quality volume after the incremental reconstruction of freehand ultrasound. The experimental results show that improved image quality for speckle reduction and details preservation can be obtained with the parameter setting of kernel window size of [Formula: see text] and kernel bandwidth of 1.0. The computational performance of the proposed GPU-based method can be over 200 times faster than that on central processing unit (CPU), and the volume with size of 50 million voxels in our experiment can be reconstructed within 10 seconds.

Use of the Anterolateral Thigh and Vertical Rectus Abdominis Musculocutaneous Flaps as Utility Flaps in Reconstructing Large Groin Defects

Directory of Open Access Journals (Sweden)

Edwin Jonathan Aslim

2014-09-01

Full Text Available BackgroundGroin dissections result in large wounds with exposed femoral vessels requiring soft tissue coverage, and the reconstructive options are diverse. In this study we reviewed our experience with the use of the pedicled anterolateral thigh and vertical rectus abdominis musculocutaneous flaps in the reconstruction of large groin wounds.MethodsGroin reconstructions performed over a period of 10 years were evaluated, with a mean follow up of two years. We included all cases with large or complex (involving perineum defects, which were reconstructed with the pedicled anterolateral thigh musculocutaneous or the vertical rectus abdominis musculocutaneous (VRAM flaps. Smaller wounds which were covered with skin grafts, locally based flaps and pedicled muscle flaps were excluded.ResultsTwenty-three reconstructions were performed for large or complex groin defects, utilising the anterolateral thigh (n=10 and the vertical rectus abdominis (n=13 pedicled musculocutaneous flaps. Femoral vein reconstruction with a prosthetic graft was required in one patient, and a combination flap (VRAM and gracilis muscle flap was performed in another. Satisfactory coverage was achieved in all cases without major complications. No free flaps were used in our series.ConclusionsThe anterolateral thigh and vertical rectus abdominis pedicled musculocutaneous flaps yielded consistent results with little morbidity in the reconstruction of large and complex groin defects. A combination of flaps can be used in cases requiring extensive cover.

Probability Density Function Method for Observing Reconstructed Attractor Structure

Institute of Scientific and Technical Information of China (English)

陆宏伟; 陈亚珠; 卫青

2004-01-01

Probability density function (PDF) method is proposed for analysing the structure of the reconstructed attractor in computing the correlation dimensions of RR intervals of ten normal old men. PDF contains important information about the spatial distribution of the phase points in the reconstructed attractor. To the best of our knowledge, it is the first time that the PDF method is put forward for the analysis of the reconstructed attractor structure. Numerical simulations demonstrate that the cardiac systems of healthy old men are about 6 - 6.5 dimensional complex dynamical systems. It is found that PDF is not symmetrically distributed when time delay is small, while PDF satisfies Gaussian distribution when time delay is big enough. A cluster effect mechanism is presented to explain this phenomenon. By studying the shape of PDFs, that the roles played by time delay are more important than embedding dimension in the reconstruction is clearly indicated. Results have demonstrated that the PDF method represents a promising numerical approach for the observation of the reconstructed attractor structure and may provide more information and new diagnostic potential of the analyzed cardiac system.

Application of CT three-dimensional reconstruction in elbow injury

International Nuclear Information System (INIS)

Liang Wenhua; Qian Li

2009-01-01

Objective: To investigate the application of multi-slice spiral CT in fracture of elbow, and to study the value of different methods of the reconstruction. Methods: Thin line cross-section spiral CT scan was carried out in 13 cases with elbow injury, three-dimensional reconstruction was completed later. Several reconstructed image quality to display f the elbow fracture and dislocation were analyzed and compared. Results: 13 cases (17) elbow trauma included humeral media epicondyle fracture, humeral external epicondyle fracture, intercondylar fracture, olecranal fracture and radial head fracture. Among them, X-ray film showed negative in three sites, showed suspect fractures in 2 cases, and only showed single fracture in 2 cases. MPR reconstruction image could not only identify the diagnosis of fracture, but also provide further multi-angle display on fracture line and the extent of articular surface involvement. Surface reconstruction technology could exclude the impact of passive elbow flexion and display elbow injury more intuitively. Conclusion The elbow fracture dislocation could be showed clearly in multi-slice spiral CT, especially for complex fractures, with unmatched advantages compared to X-ray for clinical diagnosis and treatment determination. (authors)

Matrix completion-based reconstruction for undersampled magnetic resonance fingerprinting data.

Science.gov (United States)

Doneva, Mariya; Amthor, Thomas; Koken, Peter; Sommer, Karsten; Börnert, Peter

2017-09-01

An iterative reconstruction method for undersampled magnetic resonance fingerprinting data is presented. The method performs the reconstruction entirely in k-space and is related to low rank matrix completion methods. A low dimensional data subspace is estimated from a small number of k-space locations fully sampled in the temporal direction and used to reconstruct the missing k-space samples before MRF dictionary matching. Performing the iterations in k-space eliminates the need for applying a forward and an inverse Fourier transform in each iteration required in previously proposed iterative reconstruction methods for undersampled MRF data. A projection onto the low dimensional data subspace is performed as a matrix multiplication instead of a singular value thresholding typically used in low rank matrix completion, further reducing the computational complexity of the reconstruction. The method is theoretically described and validated in phantom and in-vivo experiments. The quality of the parameter maps can be significantly improved compared to direct matching on undersampled data. Copyright © 2017 Elsevier Inc. All rights reserved.

Simultaneous reconstruction of permittivity and conductivity using multi-frequency admittance measurement in electrical capacitance tomography

International Nuclear Information System (INIS)

Zhang, Maomao; Soleimani, Manuchehr

2016-01-01

Electrical capacitance tomography (ECT) is an imaging method mainly capable of reconstructing dielectric permittivity. Generally, the reactance part of complex admittance is measured in a selected frequency. This paper presents for the first time an in depth and systematic analysis of complex admittance data for simultaneous reconstruction of both electrical conductivity and dielectric permittivity. A complex-valued forward model, Jacobian matrix and inverse solution are developed in the time harmonic excitation mode to allow for multi-frequency measurements. Realistic noise models are used to evaluate the performance of complex admittance ECT in a range of excitation frequencies. This paper demonstrates far greater potential for ECT as a versatile imaging tool through novel analysis of complex admittance imaging using a dual conductivity permittivity inversion method. The paper demonstrates that various classes of contactless capacitance based measurement devices can be analysed through complex multi-frequency ECT. (paper)

Reconstruction of the parameters of V0 particles

International Nuclear Information System (INIS)

Ierusalimov, A.P.

2009-01-01

The procedure of reconstruction of the parameters of V 0 particles is considered for CBM setup that is planned to build up at the FAIR complex (GSI, Germany). It was shown that the use of various kinematic cuts permits one to improve essentially the selection of V 0 particles and to increase the signal/background ratio. The use of the kinematic fit procedure gives still more considerable improvement of the accuracy of V 0 parameters. The procedure of the selection of Ξ - hyperons is also examined. The considered algorithm can be used practically without changes to reconstruct the parameters of V 0 particles and Ω - /Ξ - hyperons in MPD/NICA

Reconstruction of Double-Exposed Terahertz Hologram of Non-isolated Object

Science.gov (United States)

Hu, Jiaqi; Li, Qi; Chen, Guanghao

2016-04-01

When the non-isolated imaging objects are complex or critical imaging precision is required, single-exposure digital hologram technique may be insufficient. So in this paper, double-exposure method is adopted in 2.52-THz inline digital holography simulations and experiments. Experimental results indicate that, compared with the results reconstructed by single-exposure amplitude-constrained phase retrieval algorithm (S-APRA), double-exposure phase-constrained phase retrieval algorithm (D-PPRA) increases the contrast of the reconstruction image by 0.146 and double-exposure amplitude-constrained phase retrieval algorithm (D-APRA) increases the contrast by 0.225. In addition, when applied to non-isolated object reconstruction, phase retrieval algorithms with only amplitude constraint on the object plane work better than those with both amplitude and phase constraints.

Reducing the effects of acoustic heterogeneity with an iterative reconstruction method from experimental data in microwave induced thermoacoustic tomography

International Nuclear Information System (INIS)

Wang, Jinguo; Zhao, Zhiqin; Song, Jian; Chen, Guoping; Nie, Zaiping; Liu, Qing-Huo

2015-01-01

Purpose: An iterative reconstruction method has been previously reported by the authors of this paper. However, the iterative reconstruction method was demonstrated by solely using the numerical simulations. It is essential to apply the iterative reconstruction method to practice conditions. The objective of this work is to validate the capability of the iterative reconstruction method for reducing the effects of acoustic heterogeneity with the experimental data in microwave induced thermoacoustic tomography. Methods: Most existing reconstruction methods need to combine the ultrasonic measurement technology to quantitatively measure the velocity distribution of heterogeneity, which increases the system complexity. Different to existing reconstruction methods, the iterative reconstruction method combines time reversal mirror technique, fast marching method, and simultaneous algebraic reconstruction technique to iteratively estimate the velocity distribution of heterogeneous tissue by solely using the measured data. Then, the estimated velocity distribution is used subsequently to reconstruct the highly accurate image of microwave absorption distribution. Experiments that a target placed in an acoustic heterogeneous environment are performed to validate the iterative reconstruction method. Results: By using the estimated velocity distribution, the target in an acoustic heterogeneous environment can be reconstructed with better shape and higher image contrast than targets that are reconstructed with a homogeneous velocity distribution. Conclusions: The distortions caused by the acoustic heterogeneity can be efficiently corrected by utilizing the velocity distribution estimated by the iterative reconstruction method. The advantage of the iterative reconstruction method over the existing correction methods is that it is successful in improving the quality of the image of microwave absorption distribution without increasing the system complexity

One-stage nipple and breast reconstruction following areola-sparing mastectomy.

Science.gov (United States)

Kim, Hye Ri; Lim, Jin Soo; Kim, Sue Min; Jung, Sung No; Yoo, Gyeol; Rha, Eun Young

2013-09-01

Skin-sparing mastectomy with immediate breast reconstruction is increasingly becoming a proven surgical option for early-stage breast cancer patients. Areola-sparing mastectomy (ASM) has also recently become a popular procedure. The purpose of this article is to investigate the reconstructive and aesthetic issues experienced with one-stage nipple and breast reconstruction using ASM. Among the patients who underwent mastectomy between March 2008 and March 2010, 5 women with a low probability of nipple-areolar complex malignant involvement underwent ASM and immediate breast reconstruction with simultaneous nipple reconstruction using the modified C-V flap. The cosmetic outcomes of this series were reviewed by plastic surgeons and patient self-assessment and satisfaction were assessed via telephone interview. During the average 11-month follow-up period, there were no cases of cancer recurrence, the aesthetic outcomes were graded as excellent to very good, and all of the patients were satisfied. Two patients developed a gutter-like depression around the reconstructed nipple, and one patient developed skin erosion in a small area of the areola, which healed with conservative dressing. The other complications, such as necrosis of the skin flap or areola, seroma, hematoma, or fat necrosis did not occur. Since one-stage nipple and breast reconstruction following ASM is an oncologically safe, cost-effective, and aesthetically satisfactory procedure, it is a good surgical option for early breast cancer patients.

[Stereomodel-assisted fibula free flap harvest and mandibular reconstruction: A technical note. Literature review of CAS and CAM applied to mandibular reconstruction.

Science.gov (United States)

Pauchot, J; Lachat, J; Floret, F; Badet, J-M; Tavernier, L; Aubry, S

2013-08-05

Mandibular reconstruction with fibula free flap harvest is currently the reference technique. Various preoperative processes have been developed to optimize this reconstruction. We report our experience with a simple, inexpensive, preoperative technique requiring a 3D printer, a device for maintaining mandibular reduction, a paper-cutting guide. Stereomodels of the mandible were obtained from computed tomography scan data and printed 3D in ABS. It allowed planning mandibular osteotomies, determine the angle between two bone fragments, and preoperatively modeling the osteosynthesis plate. A paper-cutting guide, and a simple device for maintaining mandibular reduction were also built. Two patients were operated on with this technique, with follow-up at 6 and 8 months. Reconstructions were successful with good clinical outcome in terms of mandibular contour and reconstructed segments positions. Preoperative planning of reconstruction may be used for mandibular osteotomies, fibular osteotomies, maintaining mandibular reduction, osteosynthesis, or placing implants for dental rehabilitation. The most complex procedures can virtually plan all these steps, but they are expensive and long to implement. Nevertheless, such procedures are quite expansive and require time not always compatible with carcinoma. Using a mandibular stereomodel is fast, easy, and cheap. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Object oriented approach to B reconstruction

International Nuclear Information System (INIS)

Katayama, N.

1992-01-01

The complexity of full and partial reconstruction of B mesons has led CLEO to use object oriented techniques to do physics data analyses. An object oriented language for HEP data analysis was designed, a compiler which translates the user code into C++ source code, has been written using the UNIX tools, lex and yacc. The resulting C++ code can be linked and run in the normal CLEO data analysis system

Electrical Impedance Tomography: 3D Reconstructions using Scattering Transforms

DEFF Research Database (Denmark)

Delbary, Fabrice; Hansen, Per Christian; Knudsen, Kim

2012-01-01

In three dimensions the Calderon problem was addressed and solved in theory in the 1980s. The main ingredients in the solution of the problem are complex geometrical optics solutions to the conductivity equation and a (non-physical) scattering transform. The resulting reconstruction algorithm...

Renovation of the hotel complex

OpenAIRE

DRHA, Aleš

2012-01-01

The theme of this work is reconstruction the hotel complex. The theoretical part informs readers about tourism, marketing and how to build a business plan. Analytical part shows the issue of tourism in the region and technical condition of the hotel. In the synthetic part is suggested business plan to hotel reconstruction, marketing mix for tourism and financial plan, that shows operating costs and revenues. The investment could be paid off by the 13th year since the start of the hotel service.

A Two-Stage Reconstruction Processor for Human Detection in Compressive Sensing CMOS Radar.

Science.gov (United States)

Tsao, Kuei-Chi; Lee, Ling; Chu, Ta-Shun; Huang, Yuan-Hao

2018-04-05

Complementary metal-oxide-semiconductor (CMOS) radar has recently gained much research attraction because small and low-power CMOS devices are very suitable for deploying sensing nodes in a low-power wireless sensing system. This study focuses on the signal processing of a wireless CMOS impulse radar system that can detect humans and objects in the home-care internet-of-things sensing system. The challenges of low-power CMOS radar systems are the weakness of human signals and the high computational complexity of the target detection algorithm. The compressive sensing-based detection algorithm can relax the computational costs by avoiding the utilization of matched filters and reducing the analog-to-digital converter bandwidth requirement. The orthogonal matching pursuit (OMP) is one of the popular signal reconstruction algorithms for compressive sensing radar; however, the complexity is still very high because the high resolution of human respiration leads to high-dimension signal reconstruction. Thus, this paper proposes a two-stage reconstruction algorithm for compressive sensing radar. The proposed algorithm not only has lower complexity than the OMP algorithm by 75% but also achieves better positioning performance than the OMP algorithm especially in noisy environments. This study also designed and implemented the algorithm by using Vertex-7 FPGA chip (Xilinx, San Jose, CA, USA). The proposed reconstruction processor can support the 256 × 13 real-time radar image display with a throughput of 28.2 frames per second.

A Two-Stage Reconstruction Processor for Human Detection in Compressive Sensing CMOS Radar

Directory of Open Access Journals (Sweden)

Kuei-Chi Tsao

2018-04-01

Full Text Available Complementary metal-oxide-semiconductor (CMOS radar has recently gained much research attraction because small and low-power CMOS devices are very suitable for deploying sensing nodes in a low-power wireless sensing system. This study focuses on the signal processing of a wireless CMOS impulse radar system that can detect humans and objects in the home-care internet-of-things sensing system. The challenges of low-power CMOS radar systems are the weakness of human signals and the high computational complexity of the target detection algorithm. The compressive sensing-based detection algorithm can relax the computational costs by avoiding the utilization of matched filters and reducing the analog-to-digital converter bandwidth requirement. The orthogonal matching pursuit (OMP is one of the popular signal reconstruction algorithms for compressive sensing radar; however, the complexity is still very high because the high resolution of human respiration leads to high-dimension signal reconstruction. Thus, this paper proposes a two-stage reconstruction algorithm for compressive sensing radar. The proposed algorithm not only has lower complexity than the OMP algorithm by 75% but also achieves better positioning performance than the OMP algorithm especially in noisy environments. This study also designed and implemented the algorithm by using Vertex-7 FPGA chip (Xilinx, San Jose, CA, USA. The proposed reconstruction processor can support the 256 × 13 real-time radar image display with a throughput of 28.2 frames per second.

Semantically Documenting Virtual Reconstruction: Building a Path to Knowledge Provenance

Science.gov (United States)

Bruseker, G.; Guillem, A.; Carboni, N.

2015-08-01

The outcomes of virtual reconstructions of archaeological monuments are not just images for aesthetic consumption but rather present a scholarly argument and decision making process. They are based on complex chains of reasoning grounded in primary and secondary evidence that enable a historically probable whole to be reconstructed from the partial remains left in the archaeological record. This paper will explore the possibilities for documenting and storing in an information system the phases of the reasoning, decision and procedures that a modeler, with the support of an archaeologist, uses during the virtual reconstruction process and how they can be linked to the reconstruction output. The goal is to present a documentation model such that the foundations of evidence for the reconstructed elements, and the reasoning around them, are made not only explicit and interrogable but also can be updated, extended and reused by other researchers in future work. Using as a case-study the reconstruction of a kitchen in a Roman domus in Grand, we will examine the necessary documentation requirements, and the capacity to express it using semantic technologies. For our study we adopt the CIDOC-CRM ontological model, and its extensions CRMinf, CRMBa and CRMgeo as a starting point for modelling the arguments and relations.

Complex single step skull reconstruction in Gorham's disease - a technical report and review of the literature.

Science.gov (United States)

Ohla, Victoria; Bayoumi, Ahmed B; Hefty, Markus; Anderson, Matthew; Kasper, Ekkehard M

2015-03-11

Gorham's disease is a rare osteolytic disorder characterized by progressive resorption of bone and replacement of osseous matrix by a proliferative non-neoplastic vascular or lymphatic tissue. A standardized treatment protocol has not yet been defined due to the unpredictable natural history of the disease and variable clinical presentations. No single treatment has proven to be superior in arresting the course of the disease. Trials have included surgery, radiation and medical therapies using drugs such as calcium salts, vitamin D supplements and hormones. We report on our advantageous experience in the management of this osteolyic disorder in a case when it affected only the skull vault. A brief review of pertinent literature about Gorham's disease with skull involvement is provided. A 25-year-old Caucasian male presented with a skull depression over the left fronto-temporal region. He noticed progressive enlargement of the skull defect associated with local pain and mild headache. Physical examination revealed a tender palpable depression of the fronto-temporal convexity. Conventional X-ray of the skull showed widespread loss of bone substance. Subsequent CT scans showed features of patchy erosions indicative of an underlying osteolysis. MRI also revealed marginal enhancement at the site of the defect. The patient was in need of a pathological diagnosis as well as complex reconstruction of the afflicted area. A density graded CT scan was done to determine the variable degrees of osteolysis and a custom made allograft was designed for cranioplasty preoperatively to allow for a single step excisional craniectomy with synchronous skull repair. Gorham's disease was diagnosed based on histopathological examination. No neurological deficit or wound complications were reported postoperatively. Over a two-year follow up period, the patient had no evidence of local recurrence or other systemic involvement. A single step excisional craniectomy and cranioplasty can be an

Software compensation in Particle Flow reconstruction

CERN Document Server

Lan Tran, Huong; Sefkow, Felix; Green, Steven; Marshall, John; Thomson, Mark; Simon, Frank

2017-01-01

The Particle Flow approach to calorimetry requires highly granular calorimeters and sophisticated software algorithms in order to reconstruct and identify individual particles in complex event topologies. The high spatial granularity, together with analog energy information, can be further exploited in software compensation. In this approach, the local energy density is used to discriminate electromagnetic and purely hadronic sub-showers within hadron showers in the detector to improve the energy resolution for single particles by correcting for the intrinsic non-compensation of the calorimeter system. This improvement in the single particle energy resolution also results in a better overall jet energy resolution by improving the energy measurement of identified neutral hadrons and improvements in the pattern recognition stage by a more accurate matching of calorimeter energies to tracker measurements. This paper describes the software compensation technique and its implementation in Particle Flow reconstruct...

Multi-level damage identification with response reconstruction

Science.gov (United States)

Zhang, Chao-Dong; Xu, You-Lin

2017-10-01

Damage identification through finite element (FE) model updating usually forms an inverse problem. Solving the inverse identification problem for complex civil structures is very challenging since the dimension of potential damage parameters in a complex civil structure is often very large. Aside from enormous computation efforts needed in iterative updating, the ill-condition and non-global identifiability features of the inverse problem probably hinder the realization of model updating based damage identification for large civil structures. Following a divide-and-conquer strategy, a multi-level damage identification method is proposed in this paper. The entire structure is decomposed into several manageable substructures and each substructure is further condensed as a macro element using the component mode synthesis (CMS) technique. The damage identification is performed at two levels: the first is at macro element level to locate the potentially damaged region and the second is over the suspicious substructures to further locate as well as quantify the damage severity. In each level's identification, the damage searching space over which model updating is performed is notably narrowed down, not only reducing the computation amount but also increasing the damage identifiability. Besides, the Kalman filter-based response reconstruction is performed at the second level to reconstruct the response of the suspicious substructure for exact damage quantification. Numerical studies and laboratory tests are both conducted on a simply supported overhanging steel beam for conceptual verification. The results demonstrate that the proposed multi-level damage identification via response reconstruction does improve the identification accuracy of damage localization and quantization considerably.

Human stem cells for craniomaxillofacial reconstruction.

Science.gov (United States)

Jalali, Morteza; Kirkpatrick, William Niall Alexander; Cameron, Malcolm Gregor; Pauklin, Siim; Vallier, Ludovic

2014-07-01

Human stem cell research represents an exceptional opportunity for regenerative medicine and the surgical reconstruction of the craniomaxillofacial complex. The correct architecture and function of the vastly diverse tissues of this important anatomical region are critical for life supportive processes, the delivery of senses, social interaction, and aesthetics. Craniomaxillofacial tissue loss is commonly associated with inflammatory responses of the surrounding tissue, significant scarring, disfigurement, and psychological sequelae as an inevitable consequence. The in vitro production of fully functional cells for skin, muscle, cartilage, bone, and neurovascular tissue formation from human stem cells, may one day provide novel materials for the reconstructive surgeon operating on patients with both hard and soft tissue deficit due to cancer, congenital disease, or trauma. However, the clinical translation of human stem cell technology, including the application of human pluripotent stem cells (hPSCs) in novel regenerative therapies, faces several hurdles that must be solved to permit safe and effective use in patients. The basic biology of hPSCs remains to be fully elucidated and concerns of tumorigenicity need to be addressed, prior to the development of cell transplantation treatments. Furthermore, functional comparison of in vitro generated tissue to their in vivo counterparts will be necessary for confirmation of maturity and suitability for application in reconstructive surgery. Here, we provide an overview of human stem cells in disease modeling, drug screening, and therapeutics, while also discussing the application of regenerative medicine for craniomaxillofacial tissue deficit and surgical reconstruction.

Algebraic reconstruction techniques for spectral reconstruction in diffuse optical tomography

International Nuclear Information System (INIS)

Brendel, Bernhard; Ziegler, Ronny; Nielsen, Tim

2008-01-01

Reconstruction in diffuse optical tomography (DOT) necessitates solving the diffusion equation, which is nonlinear with respect to the parameters that have to be reconstructed. Currently applied solving methods are based on the linearization of the equation. For spectral three-dimensional reconstruction, the emerging equation system is too large for direct inversion, but the application of iterative methods is feasible. Computational effort and speed of convergence of these iterative methods are crucial since they determine the computation time of the reconstruction. In this paper, the iterative methods algebraic reconstruction technique (ART) and conjugated gradients (CGs) as well as a new modified ART method are investigated for spectral DOT reconstruction. The aim of the modified ART scheme is to speed up the convergence by considering the specific conditions of spectral reconstruction. As a result, it converges much faster to favorable results than conventional ART and CG methods

Iterative feature refinement for accurate undersampled MR image reconstruction

Science.gov (United States)

Wang, Shanshan; Liu, Jianbo; Liu, Qiegen; Ying, Leslie; Liu, Xin; Zheng, Hairong; Liang, Dong

2016-05-01

Accelerating MR scan is of great significance for clinical, research and advanced applications, and one main effort to achieve this is the utilization of compressed sensing (CS) theory. Nevertheless, the existing CSMRI approaches still have limitations such as fine structure loss or high computational complexity. This paper proposes a novel iterative feature refinement (IFR) module for accurate MR image reconstruction from undersampled K-space data. Integrating IFR with CSMRI which is equipped with fixed transforms, we develop an IFR-CS method to restore meaningful structures and details that are originally discarded without introducing too much additional complexity. Specifically, the proposed IFR-CS is realized with three iterative steps, namely sparsity-promoting denoising, feature refinement and Tikhonov regularization. Experimental results on both simulated and in vivo MR datasets have shown that the proposed module has a strong capability to capture image details, and that IFR-CS is comparable and even superior to other state-of-the-art reconstruction approaches.

Iterative feature refinement for accurate undersampled MR image reconstruction

International Nuclear Information System (INIS)

Wang, Shanshan; Liu, Jianbo; Liu, Xin; Zheng, Hairong; Liang, Dong; Liu, Qiegen; Ying, Leslie

2016-01-01

Accelerating MR scan is of great significance for clinical, research and advanced applications, and one main effort to achieve this is the utilization of compressed sensing (CS) theory. Nevertheless, the existing CSMRI approaches still have limitations such as fine structure loss or high computational complexity. This paper proposes a novel iterative feature refinement (IFR) module for accurate MR image reconstruction from undersampled K-space data. Integrating IFR with CSMRI which is equipped with fixed transforms, we develop an IFR-CS method to restore meaningful structures and details that are originally discarded without introducing too much additional complexity. Specifically, the proposed IFR-CS is realized with three iterative steps, namely sparsity-promoting denoising, feature refinement and Tikhonov regularization. Experimental results on both simulated and in vivo MR datasets have shown that the proposed module has a strong capability to capture image details, and that IFR-CS is comparable and even superior to other state-of-the-art reconstruction approaches. (paper)

Transient recycling of resected bone to facilitate mandibular reconstruction--a technical note.

Science.gov (United States)

Lee, Jing-Wei; Tsai, Shin-Sheng; Kuo, Yao-Lung

2006-10-01

Mandibular reconstruction requires considerable sculptural skills. The intriguingly complex configuration of the structure is difficult to reproduce. It is thus imperative for surgeons to seek a technique that improves the precision of the reconstruction. A 55-year-old male presented with a full thickness cancer (T4+) of his left cheek. Radical ablative surgery resulted in an extensive loss of bone and soft tissue mandating major reconstruction. The resected bony specimen was thoroughly denuded, autoclaved, and then placed back into its original site so that the mandible resumed its pre-surgical configuration. A reconstruction plate was applied to maintain structural stability, then the "recycled bone" was used as a template and replaced with a free fibular graft. The patient fared well and a follow-up panoramic radiograph demonstrated good alignment and symmetry of the reconstructed mandible. This method is a viable option for segmental mandibulectomy defect repair in selected cases. Using this technique, it is possible to restore the original bony contour expediently and accurately.

Artificial urinary sphincter implantation: an important component of complex surgery for urinary tract reconstruction in patients with refractory urinary incontinence.

Science.gov (United States)

Zhang, Fan; Liao, Limin

2018-01-08

We review our outcomes and experience of artificial urinary sphincter implantation for patients with refractory urinary incontinence from different causes. Between April 2002 and May 2017, a total of 32 patients (median age, 40.8 years) with urinary incontinence had undergone artificial urinary sphincter placement during urinary tract reconstruction. Eighteen patients (56.3%) were urethral injuries associated urinary incontinence, 9 (28.1%) had neurogenic urinary incontinence and 5 (15.6%) were post-prostatectomy incontinence. Necessary surgeries were conducted before artificial urinary sphincter placement as staged procedures, including urethral strictures incision, sphincterotomy, and augmentation cystoplasty. The mean follow-up time was 39 months. At the latest visit, 25 patients (78.1%) maintained the original artificial urinary sphincter. Four patients (12.5%) had artificial urinary sphincter revisions. Explantations were performed in three patients. Twenty-four patients were socially continent, leading to the overall success rate as 75%. The complication rate was 28.1%; including infections (n = 4), erosions (n = 4), and mechanical failure (n = 1). The impact of urinary incontinence on the quality of life measured by the visual analogue scale dropped from 7.0 ± 1.2 to 2.2 ± 1.5 (P urinary sphincter implantation in our center are unique, and the procedure is an effective treatment as a part of urinary tract reconstruction in complicated urinary incontinence cases with complex etiology.

Reconstruction of the Cranial Vault Contour Using Tissue Expander and Castor Oil Prosthesis.

Science.gov (United States)

de Moraes, Sylvio Luiz Costa; Afonso, Alexandre Maurity de Paula; Santos, Roberto Gomes Dos; Mattos, Ricardo Pereira; Duarte, E Bruno Gomes

2017-09-01

Nowadays the reconstruction of craniofacial defects can be performed with different kinds of materials, which include the bone and the so-called biomaterials, which have the advantage of not needing a surgical site donor. Among these materials, great attention is given to polymers. In this large group, current attention is focused on the castor oil polymer, since this polymer is biocompatible, low cost, and has adequate strength for reconstruction of the craniomaxillofacial complex. This study aims to report the use of a prosthetic castor oil polymer for reconstruction of extensive defect, caused by a trauma, in the temporoparietal region.

Cavlectometry: Towards holistic reconstruction of large mirror objects

KAUST Repository

Balzer, Jonathan

2014-12-01

We introduce a method based on the deflectometry principle for the reconstruction of specular objects exhibiting significant size and geometric complexity. A key feature of our approach is the deployment of an Automatic Virtual Environment (CAVE) as pattern generator. To unfold the full power of this experimental setup, an optical encoding scheme is developed which accounts for the distinctive topology of the CAVE. Furthermore, we devise an algorithm for detecting the object of interest in raw deflectometric images. The segmented foreground is used for single-view reconstruction, the background for estimation of the camera pose, necessary for calibrating the sensor system. Experiments suggest a significant gain of coverage in single measurements compared to previous methods. © 2014 IEEE.

A Fourier reconstruction algorithm with constant attenuation compensation using 1800 acquisition data for SPECT

International Nuclear Information System (INIS)

Tang Qiulin; Zeng, Gengsheng L; Gullberg, Grant T

2007-01-01

In this paper, we develop an approximate analytical reconstruction algorithm that compensates for uniform attenuation in 2D parallel-beam SPECT with a 180 0 acquisition. This new algorithm is in the form of a direct Fourier reconstruction. The complex variable central slice theorem is used to derive this algorithm. The image is reconstructed with the following steps: first, the attenuated projection data acquired over 180 deg. are extended to 360 deg. and the value for the uniform attenuator is changed to a negative value. The Fourier transform (FT) of the image in polar coordinates is obtained from the Fourier transform of an analytic function interpolated from an extension of the projection data according to the complex central slice theorem. Finally, the image is obtained by performing a 2D inverse Fourier transform. Computer simulations and comparison studies with a 360 deg. full-scan algorithm are provided

A Graph-Based Approach for 3D Building Model Reconstruction from Airborne LiDAR Point Clouds

Directory of Open Access Journals (Sweden)

Bin Wu

2017-01-01

Full Text Available 3D building model reconstruction is of great importance for environmental and urban applications. Airborne light detection and ranging (LiDAR is a very useful data source for acquiring detailed geometric and topological information of building objects. In this study, we employed a graph-based method based on hierarchical structure analysis of building contours derived from LiDAR data to reconstruct urban building models. The proposed approach first uses a graph theory-based localized contour tree method to represent the topological structure of buildings, then separates the buildings into different parts by analyzing their topological relationships, and finally reconstructs the building model by integrating all the individual models established through the bipartite graph matching process. Our approach provides a more complete topological and geometrical description of building contours than existing approaches. We evaluated the proposed method by applying it to the Lujiazui region in Shanghai, China, a complex and large urban scene with various types of buildings. The results revealed that complex buildings could be reconstructed successfully with a mean modeling error of 0.32 m. Our proposed method offers a promising solution for 3D building model reconstruction from airborne LiDAR point clouds.

Reconstruction CT imaging of the hypopharynx and the larynx

International Nuclear Information System (INIS)

Okuno, Tetsuji; Fujimura, Akiko; Murakami, Yasushi; Shiga, Hayao

1986-01-01

The multiplanar reconstruction CT imaging of the hypopharynx and the larynx was performed on a total of 20 cases: 8 with laryngeal carcinomas, 6 with hypopharyngeal carcinomas, 4 with vocal cord paralyses due to various causes, 1 with laryngeal amyloidosis, 1 with inflammatory granuloma of the hypopharynx. Coronal, segittal, and parasagittal reconstruction images were obtained from either 1 or 2 mm overlapping axial scans with 4 or 5 mm slice thickness (3 cases) using 5 sec scan times during queit breathing. In 15 cases with coronal reconstruction imaging, the anatomical derangements of the laryngopharyngeal structures especially along the undersurface of the true vocal cord to the false cord level, the lateral wall of the pyriform sinus, and the paraglottic space were demonstrated more clearly than the axial CT imaging. In 5 cases with sagittal reconstruction imaging, the vertical extension of the lesions through the anterior commisure was more clearly depicted than the axial CT imaging. In 8 cases with parasagittal reconstruction imaging, which is along the vocal fold or across the aryepiglottic fold, pathological changes along the aryepiglottic fold, the arytenoid-corniculate cartilage complex, and the tip of the pyriform sinus were more clearly demonstrated than the axial CT imaging. In determining the feasibility of conservation surgery of the larynx and the hypopharynx, reconstruction CT imaging is recommended as the diagnostic procedure of a choice, which would supplement the findings of the routine axial CT imaging. (author)

One-Stage Nipple and Breast Reconstruction Following Areola-Sparing Mastectomy

Directory of Open Access Journals (Sweden)

Hye Ri Kim

2013-09-01

Full Text Available BackgroundSkin-sparing mastectomy with immediate breast reconstruction is increasingly becoming a proven surgical option for early-stage breast cancer patients. Areola-sparing mastectomy (ASM has also recently become a popular procedure. The purpose of this article is to investigate the reconstructive and aesthetic issues experienced with one-stage nipple and breast reconstruction using ASM.MethodsAmong the patients who underwent mastectomy between March 2008 and March 2010, 5 women with a low probability of nipple-areolar complex malignant involvement underwent ASM and immediate breast reconstruction with simultaneous nipple reconstruction using the modified C-V flap. The cosmetic outcomes of this series were reviewed by plastic surgeons and patient self-assessment and satisfaction were assessed via telephone interview.ResultsDuring the average 11-month follow-up period, there were no cases of cancer recurrence, the aesthetic outcomes were graded as excellent to very good, and all of the patients were satisfied. Two patients developed a gutter-like depression around the reconstructed nipple, and one patient developed skin erosion in a small area of the areola, which healed with conservative dressing. The other complications, such as necrosis of the skin flap or areola, seroma, hematoma, or fat necrosis did not occur.ConclusionsSince one-stage nipple and breast reconstruction following ASM is an oncologically safe, cost-effective, and aesthetically satisfactory procedure, it is a good surgical option for early breast cancer patients.

Re-telling, Re-evaluating and Re-constructing

Directory of Open Access Journals (Sweden)

Gorana Tolja

2013-11-01

Full Text Available 'Graphic History: Essays on Graphic Novels and/as History '(2012 is a collection of 14 unique essays, edited by scholar Richard Iadonisi, that explores a variety of complex issues within the graphic novel medium as a means of historical narration. The essays address the issues of accuracy of re-counting history, history as re-constructed, and the ethics surrounding historical narration.

Stability indicators in network reconstruction.

Directory of Open Access Journals (Sweden)

Michele Filosi

Full Text Available The number of available algorithms to infer a biological network from a dataset of high-throughput measurements is overwhelming and keeps growing. However, evaluating their performance is unfeasible unless a 'gold standard' is available to measure how close the reconstructed network is to the ground truth. One measure of this is the stability of these predictions to data resampling approaches. We introduce NetSI, a family of Network Stability Indicators, to assess quantitatively the stability of a reconstructed network in terms of inference variability due to data subsampling. In order to evaluate network stability, the main NetSI methods use a global/local network metric in combination with a resampling (bootstrap or cross-validation procedure. In addition, we provide two normalized variability scores over data resampling to measure edge weight stability and node degree stability, and then introduce a stability ranking for edges and nodes. A complete implementation of the NetSI indicators, including the Hamming-Ipsen-Mikhailov (HIM network distance adopted in this paper is available with the R package nettools. We demonstrate the use of the NetSI family by measuring network stability on four datasets against alternative network reconstruction methods. First, the effect of sample size on stability of inferred networks is studied in a gold standard framework on yeast-like data from the Gene Net Weaver simulator. We also consider the impact of varying modularity on a set of structurally different networks (50 nodes, from 2 to 10 modules, and then of complex feature covariance structure, showing the different behaviours of standard reconstruction methods based on Pearson correlation, Maximum Information Coefficient (MIC and False Discovery Rate (FDR strategy. Finally, we demonstrate a strong combined effect of different reconstruction methods and phenotype subgroups on a hepatocellular carcinoma miRNA microarray dataset (240 subjects, and we

Data-Driven Neural Network Model for Robust Reconstruction of Automobile Casting

Science.gov (United States)

Lin, Jinhua; Wang, Yanjie; Li, Xin; Wang, Lu

2017-09-01

In computer vision system, it is a challenging task to robustly reconstruct complex 3D geometries of automobile castings. However, 3D scanning data is usually interfered by noises, the scanning resolution is low, these effects normally lead to incomplete matching and drift phenomenon. In order to solve these problems, a data-driven local geometric learning model is proposed to achieve robust reconstruction of automobile casting. In order to relieve the interference of sensor noise and to be compatible with incomplete scanning data, a 3D convolution neural network is established to match the local geometric features of automobile casting. The proposed neural network combines the geometric feature representation with the correlation metric function to robustly match the local correspondence. We use the truncated distance field(TDF) around the key point to represent the 3D surface of casting geometry, so that the model can be directly embedded into the 3D space to learn the geometric feature representation; Finally, the training labels is automatically generated for depth learning based on the existing RGB-D reconstruction algorithm, which accesses to the same global key matching descriptor. The experimental results show that the matching accuracy of our network is 92.2% for automobile castings, the closed loop rate is about 74.0% when the matching tolerance threshold τ is 0.2. The matching descriptors performed well and retained 81.6% matching accuracy at 95% closed loop. For the sparse geometric castings with initial matching failure, the 3D matching object can be reconstructed robustly by training the key descriptors. Our method performs 3D reconstruction robustly for complex automobile castings.

Using the T-scan III system to analyze occlusal function in mandibular reconstruction patients: A pilot study

Directory of Open Access Journals (Sweden)

Chao-Wei Liu

2015-02-01

Full Text Available Background: This study was designed to analyze the post-rehabilitation occlusal function of subjects treated with complex mandibular resection and subsequently rehabilitated with fibula osteoseptocutaneous flaps, dental implants, and fixed prostheses utilizing the T-scan system. Methods: Ten mandibular complex resection cases that adopted fibula osteoseptocutaneous flaps, dental implants, and fixed prostheses to reconstruct occlusal function were analyzed. The mandibular reconstructions were divided into three groups based on size: full mandibular reconstructions, mandibular reconstructions larger than half of the arch, and mandibular reconstructions smaller than half of the arch. The T-scan III system was used to measure maximum occlusal force, occlusal time, anterior-posterior as well as left-right occlusal force asymmetries, and anterior-posterior as well as left-right asymmetrical locations of occlusal centers. Results: Subjects with larger mandibular reconstructions and dental implants with fixed partial dentures demonstrated decreased average occlusal force; however, the difference did not reach the statistically significant level (p > 0.05. The most significant asymmetry of occlusal center location occurred among subjects with mandibular reconstructed areas larger than half of the mandibular arch. Conclusions: Comparison of the parameters of T-scan system used to analyze the occlusal function showed that the occlusal force was not an objective reference. Measurements of the location of the occlusal center appeared more repeatable, and were less affected by additional factors. The research results of this study showed that the size of a reconstruction did not affect the occlusal force after reconstruction and larger reconstructed areas did not decrease the average occlusal force. The most significant parameter was left and right asymmetry of the occlusion center (LROC and was measured in subjects with reconstruction areas larger than half

Residual motion compensation in ECG-gated interventional cardiac vasculature reconstruction

Science.gov (United States)

Schwemmer, C.; Rohkohl, C.; Lauritsch, G.; Müller, K.; Hornegger, J.

2013-06-01

Three-dimensional reconstruction of cardiac vasculature from angiographic C-arm CT (rotational angiography) data is a major challenge. Motion artefacts corrupt image quality, reducing usability for diagnosis and guidance. Many state-of-the-art approaches depend on retrospective ECG-gating of projection data for image reconstruction. A trade-off has to be made regarding the size of the ECG-gating window. A large temporal window is desirable to avoid undersampling. However, residual motion will occur in a large window, causing motion artefacts. We present an algorithm to correct for residual motion. Our approach is based on a deformable 2D-2D registration between the forward projection of an initial, ECG-gated reconstruction, and the original projection data. The approach is fully automatic and does not require any complex segmentation of vasculature, or landmarks. The estimated motion is compensated for during the backprojection step of a subsequent reconstruction. We evaluated the method using the publicly available CAVAREV platform and on six human clinical datasets. We found a better visibility of structure, reduced motion artefacts, and increased sharpness of the vessels in the compensated reconstructions compared to the initial reconstructions. At the time of writing, our algorithm outperforms the leading result of the CAVAREV ranking list. For the clinical datasets, we found an average reduction of motion artefacts by 13 ± 6%. Vessel sharpness was improved by 25 ± 12% on average.

Inferring network topology from complex dynamics

International Nuclear Information System (INIS)

Shandilya, Srinivas Gorur; Timme, Marc

2011-01-01

Inferring the network topology from dynamical observations is a fundamental problem pervading research on complex systems. Here, we present a simple, direct method for inferring the structural connection topology of a network, given an observation of one collective dynamical trajectory. The general theoretical framework is applicable to arbitrary network dynamical systems described by ordinary differential equations. No interference (external driving) is required and the type of dynamics is hardly restricted in any way. In particular, the observed dynamics may be arbitrarily complex; stationary, invariant or transient; synchronous or asynchronous and chaotic or periodic. Presupposing a knowledge of the functional form of the dynamical units and of the coupling functions between them, we present an analytical solution to the inverse problem of finding the network topology from observing a time series of state variables only. Robust reconstruction is achieved in any sufficiently long generic observation of the system. We extend our method to simultaneously reconstructing both the entire network topology and all parameters appearing linear in the system's equations of motion. Reconstruction of network topology and system parameters is viable even in the presence of external noise that distorts the original dynamics substantially. The method provides a conceptually new step towards reconstructing a variety of real-world networks, including gene and protein interaction networks and neuronal circuits.

Stochastic microstructure characterization and reconstruction via supervised learning

International Nuclear Information System (INIS)

Bostanabad, Ramin; Bui, Anh Tuan; Xie, Wei; Apley, Daniel W.; Chen, Wei

2016-01-01

Microstructure characterization and reconstruction have become indispensable parts of computational materials science. The main contribution of this paper is to introduce a general methodology for practical and efficient characterization and reconstruction of stochastic microstructures based on supervised learning. The methodology is general in that it can be applied to a broad range of microstructures (clustered, porous, and anisotropic). By treating the digitized microstructure image as a set of training data, we generically learn the stochastic nature of the microstructure via fitting a supervised learning model to it (we focus on classification trees). The fitted supervised learning model provides an implicit characterization of the joint distribution of the collection of pixel phases in the image. Based on this characterization, we propose two different approaches to efficiently reconstruct any number of statistically equivalent microstructure samples. We test the approach on five examples and show that the spatial dependencies within the microstructures are well preserved, as evaluated via correlation and lineal-path functions. The main advantages of our approach stem from having a compact empirically-learned model that characterizes the stochastic nature of the microstructure, which not only makes reconstruction more computationally efficient than existing methods, but also provides insight into morphological complexity.

Video: two novel endoscopic esophageal lengthening and reconstruction techniques.

Science.gov (United States)

Perretta, Silvana; Wall, James K; Dallemagne, Bernard; Harrison, Michael; Becmeur, François; Marescaux, Jacques

2011-10-01

Esophageal reconstruction presents a significant clinical challenge in patients ranging from neonates with long-gap esophageal atresia to adults after esophageal resection. Both gastric and colonic replacement conduits carry significant morbidity. As emerging organ-sparring techniques become established for early stage esophageal tumors, less morbid reconstruction techniques are warranted. We present two novel endoscopic approaches for esophageal lengthening and reconstruction in a porcine model. Two models of esophageal defects were created in pigs (30-35 kg) under general anesthesia and subsequently reconstructed with the novel techniques. The first model was a segmental defect of the esophagus created by thoracoscopically transecting the esophagus above the gastroesophageal (GE) junction. The first reconstruction technique involved bilateral submucosal endoscopic lengthening myotomies (BSELM) with a magnetic compression anastomosis (MAGNAMOSIS™). The second model was a wedge defect in the anterior esophagus created above the GE junction through a laparotomy. The second reconstruction technique involved an inverted mucosal-submucosal sleeve transposition graft (IMSTG) that crossed the esophageal gap and was secured in place with a self-expandable covered esophageal stent. Both techniques were feasible in the pig model. The BSELM approach lengthened the esophagus 1 cm for every 2 cm length of myotomy. The myotomy targeted only the inner circular fibers of the esophagus, with preservation of the longitudinal layer to protect against long-term dilation and pouching. The IMSTG approach generated a vascularized mucosal graft almost as long as the esophagus itself. Emerging endoscopic capabilities are enabling complex endoluminal esophageal procedures. BSELM and IMSTG are two novel and technically feasible approaches to esophageal lengthening and reconstruction. Further survival studies are needed to establish the safety and efficacy of these techniques.

Robustness and Optimization of Complex Networks : Reconstructability, Algorithms and Modeling

NARCIS (Netherlands)

Liu, D.

2013-01-01

The infrastructure networks, including the Internet, telecommunication networks, electrical power grids, transportation networks (road, railway, waterway, and airway networks), gas networks and water networks, are becoming more and more complex. The complex infrastructure networks are crucial to our

Review of Nipple Reconstruction Techniques and Introduction of V to Y Technique in a Bilateral Wise Pattern Mastectomy or Reduction Mammaplasty

OpenAIRE

Riccio, Charles A.; Zeiderman, Matthew R.; Chowdhry, Saeed; Wilhelmi, Bradon J.

2015-01-01

Introduction: Nipple-areola complex reconstruction (NAR) is the final procedure in breast reconstruction after the majority of mastectomies. Many methods of NAR have been described, each with inherent advantages and disadvantages depending on local healthy tissue availability, previous scarring and procedures, and the operative morbidity of the NAR technique. Nipple reconstructions may be complicated by scars or previous nipple reconstruction, making the procedure more challenging. We propose...

Nucleocapsid-like structures of Ebola virus reconstructed using electron tomography

International Nuclear Information System (INIS)

Noda, T.; Aoyama, K.; Sagara, H.; Kida, H.; Kawaoka, Y.

2005-01-01

Electron tomography (ET) is a new technique for high resolution, three-dimensional (3D) reconstruction of pleiomocphic mac. n)molecular complexes, such as virus components. By employing this technique, we resolved the 3D structure of Ebola virus nucleocapsid-like (NC-like) structures in the cytoplasm of cells expressing NP, VP24, and VP35: the minimum components required to form these NC-like structures. Reconstruction of these tubular NC-like structures of Ebola virus showed them to be composed of left-handed helices spaced at short intervals, which is structurally consistent with other non-segmented negative-strand RNA viruses

Prefabricated fibula free flap with dental implants for mandibular reconstruction.

Science.gov (United States)

Pauchet, D; Pigot, J-L; Chabolle, F; Bach, C-A

2018-03-02

Free fibula transplant is routinely used for mandibular reconstruction in head and neck cancer. Dental rehabilitation, the objective of mandibular reconstruction, requires the use of dental implants as supports for fixed or removable dentures. Positioning of fibular bone grafts and implants determines implant osseointegration and the possibilities of dental rehabilitation. Prefabrication of a fibula free flap with dental implants prior to harvesting as a free flap can promote implant osseointegration. The position of the implants must then be precisely planned. Virtual surgery and computer-assisted design and prefabrication techniques are used to plan the reconstruction and then reproduce this planning by means of tailored fibula and mandible cutting guides, thereby ensuring correct positioning of fibular bone fragments and implants. The prefabricated fibula free flap technique requires two surgical procedures (prefabrication and flap transfer) and precise preoperative planning. Prefabricated fibula free flap with dental implants, by improving the quality of osseointegration of the implants before flap transfer, extends the possibilities of prosthetic rehabilitation in complex secondary mandibular reconstructions. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

A Multi-Data Source and Multi-Sensor Approach for the 3D Reconstruction and Web Visualization of a Complex Archaelogical Site: The Case Study of “Tolmo De Minateda”

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Jose Alberto Torres-Martínez

2016-06-01

Full Text Available The complexity of archaeological sites hinders creation of an integral model using the current Geomatic techniques (i.e., aerial, close-range photogrammetry and terrestrial laser scanner individually. A multi-sensor approach is therefore proposed as the optimal solution to provide a 3D reconstruction and visualization of these complex sites. Sensor registration represents a riveting milestone when automation is required and when aerial and terrestrial datasets must be integrated. To this end, several problems must be solved: coordinate system definition, geo-referencing, co-registration of point clouds, geometric and radiometric homogeneity, etc. The proposed multi-data source and multi-sensor approach is applied to the study case of the “Tolmo de Minateda” archaeological site. A total extension of 9 ha is reconstructed, with an adapted level of detail, by an ultralight aerial platform (paratrike, an unmanned aerial vehicle, a terrestrial laser scanner and terrestrial photogrammetry. Finally, a mobile device (e.g., tablet or smartphone has been used to integrate, optimize and visualize all this information, providing added value to archaeologists and heritage managers who want to use an efficient tool for their works at the site, and even for non-expert users who just want to know more about the archaeological settlement.

Direct numerical reconstruction of conductivities in three dimensions using scattering transforms

DEFF Research Database (Denmark)

Bikowski, Jutta; Knudsen, Kim; Mueller, Jennifer L

2011-01-01

A direct three-dimensional EIT reconstruction algorithm based on complex geometrical optics solutions and a nonlinear scattering transform is presented and implemented for spherically symmetric conductivity distributions. The scattering transform is computed both with a Born approximation and from...

Biofabrication and biomaterials for urinary tract reconstruction

Directory of Open Access Journals (Sweden)

Elsawy MM

2017-05-01

Full Text Available Moustafa M Elsawy,1–3 Achala de Mel1 1Division of Surgery and Interventional Science, Royal Free Hospital, NHS Trust, University College London (UCL, 2Division of Reconstructive Urology, University College London Hospitals (uclh, London, UK; 3Urology Department, School of Medicine, Alexandria, University, Alexandria, EgyptAbstract: Reconstructive urologists are constantly facing diverse and complex pathologies that require structural and functional restoration of urinary organs. There is always a demand for a biocompatible material to repair or substitute the urinary tract instead of using patient’s autologous tissues with its associated morbidity. Biomimetic approaches are tissue-engineering tactics aiming to tailor the material physical and biological properties to behave physiologically similar to the urinary system. This review highlights the different strategies to mimic urinary tissues including modifications in structure, surface chemistry, and cellular response of a range of biological and synthetic materials. The article also outlines the measures to minimize infectious complications, which might lead to graft failure. Relevant experimental and preclinical studies are discussed, as well as promising biomimetic approaches such as three-dimensional bioprinting. Keywords: reconstruction, biofunctionalization, tissue engineering, urinary tract

Virtual planning of complex head and neck reconstruction results in satisfactory match between real outcomes and virtual models.

Science.gov (United States)

Hanken, Henning; Schablowsky, Clemens; Smeets, Ralf; Heiland, Max; Sehner, Susanne; Riecke, Björn; Nourwali, Ibrahim; Vorwig, Oliver; Gröbe, Alexander; Al-Dam, Ahmed

2015-04-01

The reconstruction of large facial bony defects using microvascular transplants requires extensive surgery to achieve full rehabilitation of form and function. The purpose of this study is to measure the agreement between virtual plans and the actual results of maxillofacial reconstruction. This retrospective cohort study included 30 subjects receiving maxillofacial reconstruction with a preoperative virtual planning. Parameters including defect size, position, angle and volume of the transplanted segments were compared between the virtual plan and the real outcome using paired t test. A total of 63 bone segments were transplanted. The mean differences between the virtual planning and the postoperative situation were for the defect sizes 1.17 mm (95 % confidence interval (CI) (-.21 to 2.56 mm); p = 0.094), for the resection planes 1.69 mm (95 % CI (1.26-2.11); p = 0.033) and 10.16° (95 % CI (8.36°-11.96°); p satisfactory postoperative results are the basis for an optimal functional and aesthetic reconstruction in a single surgical procedure. The technique should be further investigated in larger study populations and should be further improved.

Experience with esthetic reconstruction of complex facial soft tissue trauma: application of the pulsed dye laser.

Science.gov (United States)

Ebrahimi, Ali; Kazemi, Hossein Mohammad; Nejadsarvari, Nasrin

2014-08-01

Facial soft tissue injury can be one of the most challenging cases presenting to the plastic surgeon. The life quality and self-esteem of the patients with facial injury may be compromised temporarily or permanently. Immediate reconstruction of most defects leads to better restoration of form and function as well as early rehabilitation. The aim of this study was to present our experience in management of facial soft tissue injuries from different causes. We prospectively studied patients treated by plastic surgeons from 2010 to 2012 suffering from different types of blunt or sharp (penetrating) facial soft tissue injuries to the different areas of the face. All soft tissue injuries were treated primarily. Photography from all patients before, during, and after surgical reconstruction was performed and the results were collected. We used early pulsed dye laser (PDL) post-operatively. In our study, 63 patients including 18 (28.5%) women and 45 (71.5%) men aged 8-70 years (mean 47 years) underwent facial reconstruction due to soft tissue trauma in different parts of the face. Sharp wounds were seen in 15 (23%) patients and blunt trauma lacerations were seen in 52 (77%) patients. Overall, 65% of facial injuries were repaired primary and the remainder were reconstructed with local flaps or skin graft from adjacent tissues. Postoperative PDL therapy done two weeks following surgery for all scars yielded good results in our cases. Analysis of the injury including location, size, and depth of penetration as well as presence of associated injuries can aid in the formulation of a proper surgical plan. We recommend PDL in the early post operation period (two weeks) after suture removal for better aesthetic results.

Breast reconstruction after mastectomy

Directory of Open Access Journals (Sweden)

Daniel eSchmauss

2016-01-01

Full Text Available Breast cancer is the leading cause of cancer death in women worldwide. Its surgical approach has become less and less mutilating in the last decades. However, the overall number of breast reconstructions has significantly increased lately. Nowadays breast reconstruction should be individualized at its best, first of all taking into consideration oncological aspects of the tumor, neo-/adjuvant treatment and genetic predisposition, but also its timing (immediate versus delayed breast reconstruction, as well as the patient’s condition and wish. This article gives an overview over the various possibilities of breast reconstruction, including implant- and expander-based reconstruction, flap-based reconstruction (vascularized autologous tissue, the combination of implant and flap, reconstruction using non-vascularized autologous fat, as well as refinement surgery after breast reconstruction.

Breast reconstruction - implants

Science.gov (United States)

Breast implants surgery; Mastectomy - breast reconstruction with implants; Breast cancer - breast reconstruction with implants ... harder to find a tumor if your breast cancer comes back. Getting breast implants does not take as long as breast reconstruction ...

Visual image reconstruction from human brain activity: A modular decoding approach

International Nuclear Information System (INIS)

Miyawaki, Yoichi; Uchida, Hajime; Yamashita, Okito; Sato, Masa-aki; Kamitani, Yukiyasu; Morito, Yusuke; Tanabe, Hiroki C; Sadato, Norihiro

2009-01-01

Brain activity represents our perceptual experience. But the potential for reading out perceptual contents from human brain activity has not been fully explored. In this study, we demonstrate constraint-free reconstruction of visual images perceived by a subject, from the brain activity pattern. We reconstructed visual images by combining local image bases with multiple scales, whose contrasts were independently decoded from fMRI activity by automatically selecting relevant voxels and exploiting their correlated patterns. Binary-contrast, 10 x 10-patch images (2 100 possible states), were accurately reconstructed without any image prior by measuring brain activity only for several hundred random images. The results suggest that our approach provides an effective means to read out complex perceptual states from brain activity while discovering information representation in multi-voxel patterns.

Human eyeball model reconstruction and quantitative analysis.

Science.gov (United States)

Xing, Qi; Wei, Qi

2014-01-01

Determining shape of the eyeball is important to diagnose eyeball disease like myopia. In this paper, we present an automatic approach to precisely reconstruct three dimensional geometric shape of eyeball from MR Images. The model development pipeline involved image segmentation, registration, B-Spline surface fitting and subdivision surface fitting, neither of which required manual interaction. From the high resolution resultant models, geometric characteristics of the eyeball can be accurately quantified and analyzed. In addition to the eight metrics commonly used by existing studies, we proposed two novel metrics, Gaussian Curvature Analysis and Sphere Distance Deviation, to quantify the cornea shape and the whole eyeball surface respectively. The experiment results showed that the reconstructed eyeball models accurately represent the complex morphology of the eye. The ten metrics parameterize the eyeball among different subjects, which can potentially be used for eye disease diagnosis.

Tilted cone-beam reconstruction with row-wise fan-to-parallel rebinning

International Nuclear Information System (INIS)

Hsieh Jiang; Tang Xiangyang

2006-01-01

Reconstruction algorithms for cone-beam CT have been the focus of many studies. Several exact and approximate reconstruction algorithms were proposed for step-and-shoot and helical scanning trajectories to combat cone-beam related artefacts. In this paper, we present a new closed-form cone-beam reconstruction formula for tilted gantry data acquisition. Although several algorithms were proposed in the past to combat errors induced by the gantry tilt, none of the algorithms addresses the scenario in which the cone-beam geometry is first rebinned to a set of parallel beams prior to the filtered backprojection. We show that the image quality advantages of the rebinned parallel-beam reconstruction are significant, which makes the development of such an algorithm necessary. Because of the rebinning process, the reconstruction algorithm becomes more complex and the amount of iso-centre adjustment depends not only on the projection and tilt angles, but also on the reconstructed pixel location. In this paper, we first demonstrate the advantages of the row-wise fan-to-parallel rebinning and derive a closed-form solution for the reconstruction algorithm for the step-and-shoot and constant-pitch helical scans. The proposed algorithm requires the 'warping' of the reconstruction matrix on a view-by-view basis prior to the backprojection step. We further extend the algorithm to the variable-pitch helical scans in which the patient table travels at non-constant speeds. The algorithm was tested extensively on both the 16- and 64-slice CT scanners. The efficacy of the algorithm is clearly demonstrated by multiple experiments

Flap Lymphedema after Successful Reconstruction of the Chronic Inguinal Wound with a Vertical Rectus Abdominis Flap (VRAM

Directory of Open Access Journals (Sweden)

Yalcin Kulahci

2012-07-01

Full Text Available The reconstruction of extensive and complex wounds represents a challenging problem for reconstructive surgeon. The reconstructive options to provide cover-age following debridment of these complicated wounds are local, distant flaps, or freetissue transfer. Vertical rectus abdominis flaps have been used succes-sully to repair defects in the groin, hip, perineal, trunk, and breast regions. We encountered flap lymphedema after successful reconstruction of the chronic in-guinal wound with a vertical rectus abdominis (VRAM flap. As far as were able to ascertain, there is no report in the literature related to flap lymphedema.

Surgical outcomes and nipple projection using the modified skate flap for nipple-areolar reconstruction in a series of 422 implant reconstructions.

Science.gov (United States)

Zhong, Toni; Antony, Anu; Cordeiro, Peter

2009-05-01

Numerous techniques have been used in an attempt to achieve long-term nipple projection following nipple-areolar reconstruction (NAR). A common setback, however, is the diminution of projection over time; this phenomenon is particularly evident following implant based breast reconstruction. The purpose of this report was thus to evaluate surgical outcomes and long-term nipple projection with the use of "modified skate flap" technique in exclusively implant based postmastectomy reconstructions. A retrospective review was performed for the period between 1993 and 2007. All consecutive patients with 2-staged tissue expander/implant reconstructions followed by NAR using the modified skate flap technique performed by the senior author (P.C.) were identified in a prospectively maintained breast reconstruction database. Only patients with a minimum of 1-year follow-up were included in the study. Patients with a history of irradiation to the breast were excluded from nipple projection assessment. Clinical outcome measurements included long-term nipple projection as well as incidence of complications from the NAR procedure using the modified skate flap technique. Over the 15-year study period, 475 patients underwent 2-staged tissue expander/implant reconstruction followed by NAR using the modified skate flap technique. Of these, there was a total of 292 patients with the minimum requirement of 1-year follow-up post NAR (61% follow-up rate). The total number of reconstructed nipple areolar complexes evaluated in this series was 422 (130 bilateral and 162 unilateral NAR). Forty patients (28 unilateral and 12 bilateral NAR) who received radiation to their breasts were excluded from nipple projection assessment. At a median follow-up of 44 months (range: 12-84 months), mean nipple projection was 2.5 mm (range: 1-4 mm). Minor complications occurred in 7.2% of the patients (n = 292). Skin graft donor site dehiscence was the most common complication (3.1%) followed by partial skin

Microstructural Quantification, Property Prediction, and Stochastic Reconstruction of Heterogeneous Materials Using Limited X-Ray Tomography Data

Science.gov (United States)

Li, Hechao

An accurate knowledge of the complex microstructure of a heterogeneous material is crucial for quantitative structure-property relations establishment and its performance prediction and optimization. X-ray tomography has provided a non-destructive means for microstructure characterization in both 3D and 4D (i.e., structural evolution over time). Traditional reconstruction algorithms like filtered-back-projection (FBP) method or algebraic reconstruction techniques (ART) require huge number of tomographic projections and segmentation process before conducting microstructural quantification. This can be quite time consuming and computationally intensive. In this thesis, a novel procedure is first presented that allows one to directly extract key structural information in forms of spatial correlation functions from limited x-ray tomography data. The key component of the procedure is the computation of a "probability map", which provides the probability of an arbitrary point in the material system belonging to specific phase. The correlation functions of interest are then readily computed from the probability map. Using effective medium theory, accurate predictions of physical properties (e.g., elastic moduli) can be obtained. Secondly, a stochastic optimization procedure that enables one to accurately reconstruct material microstructure from a small number of x-ray tomographic projections (e.g., 20 - 40) is presented. Moreover, a stochastic procedure for multi-modal data fusion is proposed, where both X-ray projections and correlation functions computed from limited 2D optical images are fused to accurately reconstruct complex heterogeneous materials in 3D. This multi-modal reconstruction algorithm is proved to be able to integrate the complementary data to perform an excellent optimization procedure, which indicates its high efficiency in using limited structural information. Finally, the accuracy of the stochastic reconstruction procedure using limited X

Adaptive algebraic reconstruction technique

International Nuclear Information System (INIS)

Lu Wenkai; Yin Fangfang

2004-01-01

Algebraic reconstruction techniques (ART) are iterative procedures for reconstructing objects from their projections. It is proven that ART can be computationally efficient by carefully arranging the order in which the collected data are accessed during the reconstruction procedure and adaptively adjusting the relaxation parameters. In this paper, an adaptive algebraic reconstruction technique (AART), which adopts the same projection access scheme in multilevel scheme algebraic reconstruction technique (MLS-ART), is proposed. By introducing adaptive adjustment of the relaxation parameters during the reconstruction procedure, one-iteration AART can produce reconstructions with better quality, in comparison with one-iteration MLS-ART. Furthermore, AART outperforms MLS-ART with improved computational efficiency

Reconstructive approach for patients with augmentation mammaplasty undergoing nipple-sparing mastectomy.

Science.gov (United States)

Alperovich, Michael; Choi, Mihye; Frey, Jordan D; Karp, Nolan S

2014-09-01

Nipple-sparing mastectomy (NSM) is a recent advance in the therapeutic and prophylactic management of breast cancer; however, the procedure is associated with increased reconstructive complications. Data on NSM after previous breast augmentation are limited. The authors compared reconstructive complications after NSM between patients with previously augmented breasts and a larger cohort that had not undergone prior augmentation. An approach to NSM that involves 2-stage reconstruction in augmented patients is also described. Medical records of NSMs performed at New York University Langone Medical Center from 2006 to 2013 were reviewed. Data points evaluated included patient characteristics, comorbidities, breast implant plane, and reconstructive complications. Fisher's exact and t tests were used for the comparisons. During the study period, NSMs were performed in 17 augmented breasts at this institution. After NSM, 15 of these breasts underwent implant-based reconstruction and 2 breasts underwent microvascular free flaps. Reconstructive complications included 1 hematoma managed nonoperatively (5.9%) and 1 partial necrosis of the nipple-areola complex (NAC) (5.9%). Compared with the larger nonaugmented cohort (n=332), patients with previously augmented breasts had fewer complications, and there were no statistically significant differences in the rates of mastectomy flap necrosis, partial NAC necrosis, complete NAC necrosis, hematoma, capsular contracture, explantation, implant displacement, seroma, or breast cellulitis. The results indicate that NSM reconstruction is associated with minimal complications in patients with previous augmentation mammaplasty. 4. © 2014 The American Society for Aesthetic Plastic Surgery, Inc.

Residual motion compensation in ECG-gated interventional cardiac vasculature reconstruction

International Nuclear Information System (INIS)

Schwemmer, C; Müller, K; Hornegger, J; Rohkohl, C; Lauritsch, G

2013-01-01

Three-dimensional reconstruction of cardiac vasculature from angiographic C-arm CT (rotational angiography) data is a major challenge. Motion artefacts corrupt image quality, reducing usability for diagnosis and guidance. Many state-of-the-art approaches depend on retrospective ECG-gating of projection data for image reconstruction. A trade-off has to be made regarding the size of the ECG-gating window. A large temporal window is desirable to avoid undersampling. However, residual motion will occur in a large window, causing motion artefacts. We present an algorithm to correct for residual motion. Our approach is based on a deformable 2D–2D registration between the forward projection of an initial, ECG-gated reconstruction, and the original projection data. The approach is fully automatic and does not require any complex segmentation of vasculature, or landmarks. The estimated motion is compensated for during the backprojection step of a subsequent reconstruction. We evaluated the method using the publicly available CAVAREV platform and on six human clinical datasets. We found a better visibility of structure, reduced motion artefacts, and increased sharpness of the vessels in the compensated reconstructions compared to the initial reconstructions. At the time of writing, our algorithm outperforms the leading result of the CAVAREV ranking list. For the clinical datasets, we found an average reduction of motion artefacts by 13 ± 6%. Vessel sharpness was improved by 25 ± 12% on average. (paper)

Automatic system for 3D reconstruction of the chick eye based on digital photographs.

Science.gov (United States)

Wong, Alexander; Genest, Reno; Chandrashekar, Naveen; Choh, Vivian; Irving, Elizabeth L

2012-01-01

The geometry of anatomical specimens is very complex and accurate 3D reconstruction is important for morphological studies, finite element analysis (FEA) and rapid prototyping. Although magnetic resonance imaging, computed tomography and laser scanners can be used for reconstructing biological structures, the cost of the equipment is fairly high and specialised technicians are required to operate the equipment, making such approaches limiting in terms of accessibility. In this paper, a novel automatic system for 3D surface reconstruction of the chick eye from digital photographs of a serially sectioned specimen is presented as a potential cost-effective and practical alternative. The system is designed to allow for automatic detection of the external surface of the chick eye. Automatic alignment of the photographs is performed using a combination of coloured markers and an algorithm based on complex phase order likelihood that is robust to noise and illumination variations. Automatic segmentation of the external boundaries of the eye from the aligned photographs is performed using a novel level-set segmentation approach based on a complex phase order energy functional. The extracted boundaries are sampled to construct a 3D point cloud, and a combination of Delaunay triangulation and subdivision surfaces is employed to construct the final triangular mesh. Experimental results using digital photographs of the chick eye show that the proposed system is capable of producing accurate 3D reconstructions of the external surface of the eye. The 3D model geometry is similar to a real chick eye and could be used for morphological studies and FEA.

MODIS Land Surface Temperature time series reconstruction with Open Source GIS: A new quality of temperature based ecological indicators in complex terrain (Invited)

Science.gov (United States)

Neteler, M.

2009-12-01

In complex terrain like the Central European Alps, meteorological stations and ground surveys are usually sparsely and/or irregularly distributed and often favor agricultural areas. The application of traditional geospatial interpolation methods in complex terrain remains challenging and difficult to optimize. An alternative data source is remote sensing: high temporal resolution satellite data are continuously gaining interest since these data are intrinsically spatialized: continuous field of observations is obtained with this tool instead of point data. The increasing data availability suggests using these time series as surrogate to certain measures from meteorological stations, especially for temperature and related derivatives. The Terra and Aqua satellites with the Moderate Resolution Imaging Spectroradiometer (MODIS) provide four Earth coverages per day at various resolutions. We analyzed 8 years (2000 to 2008) of daily land surface temperature (LST) data from MODIS in an area located in the Southern European Alps. A method was developed to reconstruct incomplete maps (cloud coverage, invalid pixels) based on image statistics and on a model that includes additional GIS layers. The original LST map resolution of 1000m could be improved to 200m in this process which renders the resulting LST maps applicable at regional scales. We propose the use of these reconstructed daily LST time series as surrogate to meteorological observations especially in the area of epidemiological modeling where data are typically aggregated to decadal indicators. From these daily LST map series, derivable indicators include: 1) temperatures minima, means and maxima for annual/monthly/decadal periods; 2) unusual hot summers;3) the calculation of growing degree days, and 4) spring temperature increase or autumnal temperature decrease. Since more than 8 years of MODIS LST data are available today, even preliminary gradients can be extracted to assess multi-annual temperature trends

Soft Tissue Reconstruction of Complete Circumferential Defects of the Upper Extremity

Directory of Open Access Journals (Sweden)

Zhi Yang Ng

2017-03-01

Full Text Available BackgroundUpper extremity soft tissue defects with complete circumferential involvement are not common. Coupled with the unique anatomy of the upper extremity, the underlying etiology of such circumferential soft tissue defects represent additional reconstructive challenges that require treatment to be tailored to both the patient and the wound. The aim of this study is to review the various options for soft tissue reconstruction of complete circumferential defects in the upper extremity.MethodsA literature review of PubMed and MEDLINE up to December 2016 was performed. The current study focuses on forearm and arm defects from the level at or proximal to the wrist and were assessed based on Tajima's classification (J Trauma 1974. Data reviewed for analysis included patient demographics, causality, defect size, reconstructive technique(s employed, and postoperative follow-up and functional outcomes (when available.ResultsIn accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 14 unique articles were identified for a total of 50 patients (mean=28.1 years. Underlying etiologies varied from extensive thermal or electrical burns to high impact trauma leading to degloving or avulsion, crush injuries, or even occur iatrogenically after tumor extirpation or extensive debridement. Treatment options ranged from the application of negative pressure wound dressings to the opposite end of the spectrum in hand transplantation.ConclusionsWith the evolution of reconstructive techniques over time, the extent of functional and aesthetic rehabilitation of these complex upper extremity injuries has also improved. The proposed management algorithm comprehensively addresses the inherent challenges associated with these complex cases.

Current Concepts in Filler Injection.

Science.gov (United States)

Moradi, Amir; Watson, Jeffrey

2015-11-01

When evaluating the face in thirds, the upper face, midface, and lower face, one may assume the lateral the temple, midface, and lateral mandible as the pillars of these subdivisions. Many of our facial aesthetic procedures address these regions, including the lateral brow lift, midface lift, and lateral face lift. As the use of facial fillers has advanced, more emphasis is placed on the correction of the temples, midlateral face, and lateral jaw line. This article is dedicated to these facial aesthetic pillars. Copyright © 2015 Elsevier Inc. All rights reserved.

New possibilities of three-dimensional reconstruction of computed tomography scans

International Nuclear Information System (INIS)

Herman, M.; Tarjan, Z.; Pozzi-Mucelli, R.S.

1996-01-01

Three-dimensional (3D) computed tomography (CT) scan reconstructions provide impressive and illustrative images of various parts of the human body. Such images are reconstructed from a series of basic CT scans by dedicated software. The state of the art in 3D computed tomography is demonstrated with emphasis on the imaging of soft tissues. Examples are presented of imaging the craniofacial and maxillofacial complex, central nervous system, cardiovascular system, musculoskeletal system, gastrointestinal and urogenital systems, and respiratory system, and their potential in clinical practice is discussed. Although contributing no new essential diagnostic information against conventional CT scans, 3D scans can help in spatial orientation. 11 figs., 25 refs

Airway management after maxillectomy with free flap reconstruction.

Science.gov (United States)

Brickman, Daniel S; Reh, Douglas D; Schneider, Daniel S; Bush, Ben; Rosenthal, Eben L; Wax, Mark K

2013-08-01

Maxillectomy defects require complex 3-dimensional reconstructions often best suited to microvascular free tissue transfer. Postoperative airway management during this procedure has little discussion in the literature and is often dictated by surgical dogma. The purpose of this article was to review our experience in order to evaluate the effect of airway management on perioperative outcomes in patients undergoing maxillectomy with free flap reconstruction. A retrospective chart review was performed on patients receiving maxillectomy with microvascular reconstruction at 2 institutions between 1999 and 2011. Patient's airways were managed with or without elective tracheotomy at the surgical team's discretion and different perioperative outcomes were measured. The primary outcome was incidence of airway complication including pneumonia and need for further airway intervention. Secondary outcome was measured as factors leading to perioperative performance of the tracheotomy. Seventy-nine of 143 patients received elective tracheotomy perioperatively. The incidence of airway complication was equivalent between groups (10.1% vs 9.4%; p = .89). Patients with cardiopulmonary comorbidities were more likely to receive perioperative tracheotomy (74.1% vs 50.9%; p = .03) without a difference in airway complications. Other patient cofactors did not have an impact on perioperative tracheotomy or airway complication rate. Elective tracheotomy may safely be avoided in a subset of patients undergoing maxillectomy with microvascular reconstruction. Elective tracheotomy should be considered in patients with cardiopulmonary risk factors. Copyright © 2012 Wiley Periodicals, Inc.

Three-Dimensional Anatomic Evaluation of the Anterior Cruciate Ligament for Planning Reconstruction

Directory of Open Access Journals (Sweden)

Yuichi Hoshino

2012-01-01

Full Text Available Anatomic study related to the anterior cruciate ligament (ACL reconstruction surgery has been developed in accordance with the progress of imaging technology. Advances in imaging techniques, especially the move from two-dimensional (2D to three-dimensional (3D image analysis, substantially contribute to anatomic understanding and its application to advanced ACL reconstruction surgery. This paper introduces previous research about image analysis of the ACL anatomy and its application to ACL reconstruction surgery. Crucial bony landmarks for the accurate placement of the ACL graft can be identified by 3D imaging technique. Additionally, 3D-CT analysis of the ACL insertion site anatomy provides better and more consistent evaluation than conventional “clock-face” reference and roentgenologic quadrant method. Since the human anatomy has a complex three-dimensional structure, further anatomic research using three-dimensional imaging analysis and its clinical application by navigation system or other technologies is warranted for the improvement of the ACL reconstruction.

Obesity Should Not Prevent from TRAM Flap Breast Reconstruction in Developing Countries.

Science.gov (United States)

Alipour, Sadaf; Omranipour, Ramesh; Akrami, Rahim

2015-12-01

Transverse rectus abdominis musculocutaneous (TRAM) flap is the most common procedure performed for breast reconstruction after mastectomy for breast cancer. Obesity is a relative contraindication, and complex modifications have been proposed in the pedicled technique for obese patients. We studied ischemic complications in our patients to investigate the effect of body weight on the outcome of TRAM flap breast reconstruction. Pertinent data from medical records of patients receiving a TRAM flap surgery from 1986 to 2011 were extracted. Patients were divided into three groups based on the body mass index (BMI): normal (obese (>30 kg/m(2)). Flap necrosis is defined as any visible nonviable tissue in the reconstructed breast. It was observed that 117 patients had received TRAM flap reconstruction. Fifty-eight patients were excluded. Of the remaining 59 cases, 24 had normal BMI, 21 were overweight, and 14 were obese. No patient was found to develop flap necrosis. Outcome of TRAM flap breast reconstruction in obese patients is similar to nonobese patients. No major necrosis in need of reoperation was identified in the studied obese patients. It was concluded that categorizing obesity as a relative contraindication to TRAM flap breast reconstruction should be revisited based on larger cohort studies.

The Transmission Disequilibrium/Heterogeneity Test with Parental-Genotype Reconstruction for Refined Genetic Mapping of Complex Diseases

Directory of Open Access Journals (Sweden)

Jing Han

2012-01-01

Full Text Available In linkage analysis for mapping genetic diseases, the transmission/disequilibrium test (TDT uses the linkage disequilibrium (LD between some marker and trait loci for precise genetic mapping while avoiding confounding due to population stratification. The sib-TDT (S-TDT and combined-TDT (C-TDT proposed by Spielman and Ewens can combine data from families with and without parental marker genotypes (PMGs. For some families with missing PMG, the reconstruction-combined TDT (RC-TDT proposed by Knapp may be used to reconstruct missing parental genotypes from the genotypes of their offspring to increase power and to correct for potential bias. In this paper, we propose a further extension of the RC-TDT, called the reconstruction-combined transmission disequilibrium/heterogeneity (RC-TDH test, to take into account the identical-by-descent (IBD sharing information in addition to the LD information. It can effectively utilize families with missing or incomplete parental genetic marker information. An application of this proposed method to Genetic Analysis Workshop 14 (GAW14 data sets and extensive simulation studies suggest that this approach may further increase statistical power which is particularly valuable when LD is unknown and/or when some or all PMGs are not available.

Pore-scale study on flow and heat transfer in 3D reconstructed porous media using micro-tomography images

International Nuclear Information System (INIS)

Liu, Zhenyu; Wu, Huiying

2016-01-01

Highlights: • The complex porous domain has been reconstructed with the micro CT scan images. • Pore-scale numerical model based on LB method has been established. • The correlations for flow and heat transfer were derived from the predictions. • The numerical approach developed in this work is suitable for complex porous media. - Abstract: This paper presents the numerical study on fluid flow and heat transfer in reconstructed porous media at the pore-scale with the double-population thermal lattice Boltzmann (LB) method. The porous geometry was reconstructed using micro-tomography images from micro-CT scanner. The thermal LB model was numerically tested before simulation and a good agreement was achieved by compared with the existing results. The detailed distributions of velocity and temperature in complex pore spaces were obtained from the pore-scale simulation. The correlations for flow and heat transfer in the specific porous media sample were derived based on the numerical results. The numerical method established in this work provides a promising approach to predict pore-scale flow and heat transfer characteristics in reconstructed porous domain with real geometrical effect, which can be extended for the continuum modeling of the transport process in porous media at macro-scale.

Reconstruction of the Frauenkirche in Dresden

Directory of Open Access Journals (Sweden)

Fernando Vegas López-Manzanares

1999-04-01

Full Text Available The complexity and the combination of many factors involved in this case of reconstruction make it unwise to jump to conclusions or apply hackneyed labels and worth reflecting about deeply. This purpose of this article is to look into the temple’s polysemy starting from its origin and history to point out its uniqueness and later moving on to technical, urbanistic and theoretical considerations that have to do with this building and provide a basis to estimate the excellence of the intervention.

Structure-based bayesian sparse reconstruction

KAUST Repository

Quadeer, Ahmed Abdul

2012-12-01

Sparse signal reconstruction algorithms have attracted research attention due to their wide applications in various fields. In this paper, we present a simple Bayesian approach that utilizes the sparsity constraint and a priori statistical information (Gaussian or otherwise) to obtain near optimal estimates. In addition, we make use of the rich structure of the sensing matrix encountered in many signal processing applications to develop a fast sparse recovery algorithm. The computational complexity of the proposed algorithm is very low compared with the widely used convex relaxation methods as well as greedy matching pursuit techniques, especially at high sparsity. © 1991-2012 IEEE.

Making Stability Operations Less Complex While Improving Interoperability

National Research Council Canada - National Science Library

Chaum, Erik; Christman, Gerard

2008-01-01

Military support for stability, security, transition, and reconstruction as well as humanitarian assistance / disaster relief operations is as important and complex an endeavor as is major combat operations...

Computed Tomography Image Quality Evaluation of a New Iterative Reconstruction Algorithm in the Abdomen (Adaptive Statistical Iterative Reconstruction-V) a Comparison With Model-Based Iterative Reconstruction, Adaptive Statistical Iterative Reconstruction, and Filtered Back Projection Reconstructions.

Science.gov (United States)

Goodenberger, Martin H; Wagner-Bartak, Nicolaus A; Gupta, Shiva; Liu, Xinming; Yap, Ramon Q; Sun, Jia; Tamm, Eric P; Jensen, Corey T

The purpose of this study was to compare abdominopelvic computed tomography images reconstructed with adaptive statistical iterative reconstruction-V (ASIR-V) with model-based iterative reconstruction (Veo 3.0), ASIR, and filtered back projection (FBP). Abdominopelvic computed tomography scans for 36 patients (26 males and 10 females) were reconstructed using FBP, ASIR (80%), Veo 3.0, and ASIR-V (30%, 60%, 90%). Mean ± SD patient age was 32 ± 10 years with mean ± SD body mass index of 26.9 ± 4.4 kg/m. Images were reviewed by 2 independent readers in a blinded, randomized fashion. Hounsfield unit, noise, and contrast-to-noise ratio (CNR) values were calculated for each reconstruction algorithm for further comparison. Phantom evaluation of low-contrast detectability (LCD) and high-contrast resolution was performed. Adaptive statistical iterative reconstruction-V 30%, ASIR-V 60%, and ASIR 80% were generally superior qualitatively compared with ASIR-V 90%, Veo 3.0, and FBP (P ASIR-V 60% with respective CNR values of 5.54 ± 2.39, 8.78 ± 3.15, and 3.49 ± 1.77 (P ASIR 80% had the best and worst spatial resolution, respectively. Adaptive statistical iterative reconstruction-V 30% and ASIR-V 60% provided the best combination of qualitative and quantitative performance. Adaptive statistical iterative reconstruction 80% was equivalent qualitatively, but demonstrated inferior spatial resolution and LCD.

One-Stage Nipple and Breast Reconstruction Following Areola-Sparing Mastectomy

Directory of Open Access Journals (Sweden)

Hye Ri Kim

2013-09-01

Full Text Available Background Skin-sparing mastectomy with immediate breast reconstruction is increasinglybecoming a proven surgical option for early-stage breast cancer patients. Areola-sparingmastectomy (ASM has also recently become a popular procedure. The purpose of this articleis to investigate the reconstructive and aesthetic issues experienced with one-stage nippleand breast reconstruction using ASM.Methods Among the patients who underwent mastectomy between March 2008 and March2010, 5 women with a low probability of nipple-areolar complex malignant involvement underwentASM and immediate breast reconstruction with simultaneous nipple reconstructionusing the modified C-V flap. The cosmetic outcomes of this series were reviewed by plasticsurgeons and patient self-assessment and satisfaction were assessed via telephone interview.Results During the average 11-month follow-up period, there were no cases of cancer recurrence,the aesthetic outcomes were graded as excellent to very good, and all of the patientswere satisfied. Two patients developed a gutter-like depression around the reconstructednipple, and one patient developed skin erosion in a small area of the areola, which healedwith conservative dressing. The other complications, such as necrosis of the skin flap or areola,seroma, hematoma, or fat necrosis did not occur.Conclusions Since one-stage nipple and breast reconstruction following ASM is an oncologicallysafe, cost-effective, and aesthetically satisfactory procedure, it is a good surgical optionfor early breast cancer patients.

Complex amplitude reconstruction by iterative amplitude-phase retrieval algorithm with reference

Science.gov (United States)

Shen, Cheng; Guo, Cheng; Tan, Jiubin; Liu, Shutian; Liu, Zhengjun

2018-06-01

Multi-image iterative phase retrieval methods have been successfully applied in plenty of research fields due to their simple but efficient implementation. However, there is a mismatch between the measurement of the first long imaging distance and the sequential interval. In this paper, an amplitude-phase retrieval algorithm with reference is put forward without additional measurements or priori knowledge. It gets rid of measuring the first imaging distance. With a designed update formula, it significantly raises the convergence speed and the reconstruction fidelity, especially in phase retrieval. Its superiority over the original amplitude-phase retrieval (APR) method is validated by numerical analysis and experiments. Furthermore, it provides a conceptual design of a compact holographic image sensor, which can achieve numerical refocusing easily.

BIOLOGICAL AND SYNTHETIC MATERIALS IN RECONSTRUCTIVE SURGERY FOR BREAST CANCER TREATMENT (LITERATURE REVIEW

Directory of Open Access Journals (Sweden)

A. D. Zikiryakhodzhaev

2018-01-01

Full Text Available During the last years has been a worldwide trend towards rejuvenating breast cancer, and the evolution of reconstructive breast surgery is proceeding at a rapid pace. The surgical method is the primary method in the combined and complex treatment of breast cancer, and radical mastectomy is still the main option for surgical treatment in most Russian clinics. Most women who need a mastectomy prefer a one-stage breast reconstruction, because the woman is quickly rehabilitated psychologically and physically after this operation. Nevertheless, the use of silicone endoprostheses did not solve the problems of breast reconstruction in combined treatment in oncology. The issue remains unresolved of various complications, related not only to infections, but also to the development of capsular contracture after radiotherapy. Many patients with a one-stage breast reconstruction using a silicone endoprostheses lack the volume of their own tissues for reliable shelter of the endoprosthesis. In such cases, synthetic reticulated implants, biological implants or autologous flaps are used to cover and strengthen the lower slope of the reconstructed breast.

An assessment of particle filtering methods and nudging for climate state reconstructions

NARCIS (Netherlands)

S. Dubinkina (Svetlana); H. Goosse

2013-01-01

htmlabstractUsing the climate model of intermediate complexity LOVECLIM in an idealized framework, we assess three data-assimilation methods for reconstructing the climate state. The methods are a nudging, a particle filter with sequential importance resampling, and a nudging proposal particle

Photogrammetry for rapid prototyping: development of noncontact 3D reconstruction technologies

Science.gov (United States)

Knyaz, Vladimir A.

2002-04-01

An important stage of rapid prototyping technology is generating computer 3D model of an object to be reproduced. Wide variety of techniques for 3D model generation exists beginning with manual 3D models generation and finishing with full-automated reverse engineering system. The progress in CCD sensors and computers provides the background for integration of photogrammetry as an accurate 3D data source with CAD/CAM. The paper presents the results of developing photogrammetric methods for non-contact spatial coordinates measurements and generation of computer 3D model of real objects. The technology is based on object convergent images processing for calculating its 3D coordinates and surface reconstruction. The hardware used for spatial coordinates measurements is based on PC as central processing unit and video camera as image acquisition device. The original software for Windows 9X realizes the complete technology of 3D reconstruction for rapid input of geometry data in CAD/CAM systems. Technical characteristics of developed systems are given along with the results of applying for various tasks of 3D reconstruction. The paper describes the techniques used for non-contact measurements and the methods providing metric characteristics of reconstructed 3D model. Also the results of system application for 3D reconstruction of complex industrial objects are presented.

Estimation of 3D reconstruction errors in a stereo-vision system

Science.gov (United States)

Belhaoua, A.; Kohler, S.; Hirsch, E.

2009-06-01

The paper presents an approach for error estimation for the various steps of an automated 3D vision-based reconstruction procedure of manufactured workpieces. The process is based on a priori planning of the task and built around a cognitive intelligent sensory system using so-called Situation Graph Trees (SGT) as a planning tool. Such an automated quality control system requires the coordination of a set of complex processes performing sequentially data acquisition, its quantitative evaluation and the comparison with a reference model (e.g., CAD object model) in order to evaluate quantitatively the object. To ensure efficient quality control, the aim is to be able to state if reconstruction results fulfill tolerance rules or not. Thus, the goal is to evaluate independently the error for each step of the stereo-vision based 3D reconstruction (e.g., for calibration, contour segmentation, matching and reconstruction) and then to estimate the error for the whole system. In this contribution, we analyze particularly the segmentation error due to localization errors for extracted edge points supposed to belong to lines and curves composing the outline of the workpiece under evaluation. The fitting parameters describing these geometric features are used as quality measure to determine confidence intervals and finally to estimate the segmentation errors. These errors are then propagated through the whole reconstruction procedure, enabling to evaluate their effect on the final 3D reconstruction result, specifically on position uncertainties. Lastly, analysis of these error estimates enables to evaluate the quality of the 3D reconstruction, as illustrated by the shown experimental results.

Missing data reconstruction using Gaussian mixture models for fingerprint images

Science.gov (United States)

Agaian, Sos S.; Yeole, Rushikesh D.; Rao, Shishir P.; Mulawka, Marzena; Troy, Mike; Reinecke, Gary

2016-05-01

Publisher's Note: This paper, originally published on 25 May 2016, was replaced with a revised version on 16 June 2016. If you downloaded the original PDF, but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance. One of the most important areas in biometrics is matching partial fingerprints in fingerprint databases. Recently, significant progress has been made in designing fingerprint identification systems for missing fingerprint information. However, a dependable reconstruction of fingerprint images still remains challenging due to the complexity and the ill-posed nature of the problem. In this article, both binary and gray-level images are reconstructed. This paper also presents a new similarity score to evaluate the performance of the reconstructed binary image. The offered fingerprint image identification system can be automated and extended to numerous other security applications such as postmortem fingerprints, forensic science, investigations, artificial intelligence, robotics, all-access control, and financial security, as well as for the verification of firearm purchasers, driver license applicants, etc.

Macromolecular 3D SEM reconstruction strategies: Signal to noise ratio and resolution

International Nuclear Information System (INIS)

Woodward, J.D.; Wepf, R.A.

2014-01-01

Three-dimensional scanning electron microscopy generates quantitative volumetric structural data from SEM images of macromolecules. This technique provides a quick and easy way to define the quaternary structure and handedness of protein complexes. Here, we apply a variety of preparation and imaging methods to filamentous actin in order to explore the relationship between resolution, signal-to-noise ratio, structural preservation and dataset size. This information can be used to define successful imaging strategies for different applications. - Highlights: • F-actin SEM datasets were collected using 8 different preparation/ imaging techniques. • Datasets were reconstructed by back projection and compared/analyzed • 3DSEM actin reconstructions can be produced with <100 views of the asymmetric unit. • Negatively stained macromolecules can be reconstructed by 3DSEM to ∼3 nm resolution

Imagined affordance: reconstructing a keyword for communication theory

OpenAIRE

Neff, G; Nagy, P

2015-01-01

In this essay, we reconstruct a keyword for communication—affordance. Affordance, adopted from ecological psychology, is now widely used in technology studies, yet the term lacks a clear definition. This is especially problematic for scholars grappling with how to theorize the relationship between technology and sociality for complex socio-technical systems such as machine-learning algorithms, pervasive computing, the Internet of Things, and other such “smart” innovations. Within technology s...

STAR reconstruction improvements for tracking with the heavy flavor tracker

Science.gov (United States)

Webb, Jason C.; Lauret, Jérôme; Perevotchikov, Victor; Smirnov, Dmitri; Van Buren, Gene

2017-10-01

The reconstruction and identification of charmed hadron decays provides an important tool for the study of heavy quark behavior in the Quark Gluon Plasma. Such measurements require high resolution to topologically identify decay daughters at vertices displaced demands on track reconstruction software. To enable these measurements at RHIC, the STAR experiment has designed and employed the Heavy Flavor Tracker (HFT). It is composed of silicon-based tracking detectors, providing four layers of high-precision position measurements which are used in combination with hits from the Time Projection Chamber (TPC) to reconstruct track candidates. The STAR integrated tracking software (Sti) has delivered a decade of world-class physics. It was designed to leverage the discrete azimuthal symmetry of the detector and its simple radial ordering of components, permitting a flat representation of the detector geometry in terms of concentric cylinders and planes, and an approximate track propagation code. These design choices reflected a careful balancing of competing priorities, trading precision for speed in track reconstruction. To simplify the task of integrating new detectors, tools were developed to automatically generate the Sti geometry model, tying both reconstruction and simulation to the single source AgML geometry model. The increased precision and complexity of the HFT detector required a careful reassessment of this single geometry path and implementation choices. In this paper we will discuss the test suite and regression tools developed to improve reconstruction with the HFT, our lessons learned in tracking with high precision detectors and the tradeoffs between precision, speed and ease of use which were required.

Reconstruction of Nasal Skin Cancer Defects with Local Flaps

Directory of Open Access Journals (Sweden)

A. C. Salgarelli

2011-01-01

Full Text Available Reconstruction of nasal defects must preserve the integrity of complex facial functions and expressions, as well as facial symmetry and a pleasing aesthetic outcome. The reconstructive modality of choice will depend largely on the location, size, and depth of the surgical defect. Individualized therapy is the best course, and numerous flaps have been designed to provide coverage of a variety of nasal-specific defects. We describe our experience in the aesthetic reconstruction of nasal skin defects following oncological surgery. The use of different local flaps for nasal skin cancer defects is reported in 286 patients. Complications in this series were one partial flap dehiscence that healed by secondary intention, two forehead flaps, and one bilobed flap with minimal rim necrosis that resulted in an irregular scar requiring revision. Aesthetic results were deemed satisfactory by all patients and the operating surgeons. The color and texture matches were aesthetically good, and the nasal contour was distinct in all patients. All scars were inconspicuous and symmetrical. No patient had tenting or a flat nose.

Reconstruction of Nasal Skin Cancer Defects with Local Flaps

International Nuclear Information System (INIS)

Salgarelli, A. C.; Bellini, P.; Multinu, A.; Consolo, U.; Magnoni, C.; Francomano, M.; Fantini, F.; Seidenari, S.

2011-01-01

Reconstruction of nasal defects must preserve the integrity of complex facial functions and expressions, as well as facial symmetry and a pleasing aesthetic outcome. The reconstructive modality of choice will depend largely on the location, size, and depth of the surgical defect. Individualized therapy is the best course, and numerous flaps have been designed to provide coverage of a variety of nasal-specific defects. We describe our experience in the aesthetic reconstruction of nasal skin defects following oncological surgery. The use of different local flaps for nasal skin cancer defects is reported in 286 patients. Complications in this series were one partial flap dehiscence that healed by secondary intention, two forehead flaps, and one bilobed flap with minimal rim necrosis that resulted in an irregular scar requiring revision. Aesthetic results were deemed satisfactory by all patients and the operating surgeons. The color and texture matches were aesthetically good, and the nasal contour was distinct in all patients. All scars were inconspicuous and symmetrical. No patient had tenting or a flat nose.

Complex Reconstruction After Sarcoma Resection and the Role of the Plastic Surgeon: A Case Series of 298 Patients Treated at a Single Center.

Science.gov (United States)

Leckenby, Jonathan I; Deegan, Rachel; Grobbelaar, Adriaan O

2018-01-01

More than 1000 new patients present to the London Sarcoma Unit each year and between 5% and 10% require plastic surgery intervention. Advancements in radiotherapy and chemotherapy protocols combined with higher expectations for limb preservation has led to increased reconstructive challenges. Frequently, primary closure is achievable; however, larger tumors often require specialist reconstruction. A retrospective chart review of all referred patients from the London Sarcoma Unit requiring reconstruction between February 2006 and January 2015 was performed. Patients who underwent primary amputation were excluded. The total number of operations performed was 298 and the mean follow-up was 16 months (12-46 months). 51% of patients had major comorbidities. Patients could be separated into early (0-1 week postoperatively, n = 167) and late reconstructions (>1 week postoperatively, n = 131). 32 patients were reconstructed with skin grafts, 137 patients were managed with regional flaps and 129 patients were treated with free flaps. A patient with 3 or more major comorbidities resulted in a significantly increased risk of reconstructive failure (P < 0.05). Our experience has lead us to adhere to the following guidelines: (1) All patients should be reviewed in a multidisciplinary team meeting. (2) After primary excision, patients should be managed with a vacuum dressing until margins are clear. (3) Definitive reconstruction should be performed by a specialist reconstructive surgeon.

Superficial temporal artery flap for reconstruction of complex facial defects: A new algorithm

Directory of Open Access Journals (Sweden)

Tarek M. Elbanoby

2018-03-01

Full Text Available Background A variety of island flaps can be based on the superficial temporal artery with variable tissue composition. They can be used for defect reconstruction, cavity resurfacing, facial hair restoration, or contracture release. Methods Seventy-two patients underwent facial reconstruction using a superficial temporal artery island flap from October 2010 to October 2014. The defects had various etiologies, including trauma, burns, tumors, exposed hardware, and congenital causes. We classified the patients by indication into 5 groups: cavity resurfacing, contracture release, facial hair restoration, skin coverage, and combined. The demographic data of the patients, defect characteristics, operative procedures, postoperative results, and complications were retrospectively documented. The follow-up period ranged from 24 to 54 months. Results A total of 24 females and 48 males were included in this study. The mean age of the patients was 33.7±15.6 years. The flaps were used for contracture release in 13 cases, cavity resurfacing in 10 cases, skin coverage in 17 cases, facial hair restoration in 19 cases, and combined defects in 13 cases. No major complications were reported. Conclusion: Based on our experiences with the use of superficial temporal artery island flaps, we have developed a detailed approach for the optimal management of patients with composite facial defects. The aim of this article is to provide the reader with a systematic algorithm to use for such patients.

Coordinate reconstruction using box reconstruction and projection of X-ray photo

International Nuclear Information System (INIS)

Achmad Suntoro

2011-01-01

Some mathematical formula have been derived for a process of reconstruction to define the coordinate of any point relative to a pre set coordinate system. The process of reconstruction uses a reconstruction box in which each edge's length of the box is known, each top-bottom face and left-right face of the box having a cross marker, and the top face and the right face of the box as plane projections by X-ray source in perspective projection -system. Using the data of the two X-ray projection images, any point inside the reconstruction box, as long as its projection is recorded in the two photos, will be determined its coordinate relative to the midpoint of the reconstruction box as the central point coordinates. (author)

The NIOSH Radiation Dose Reconstruction Project: managing technical challenges.

Science.gov (United States)

Moeller, Matthew P; Townsend, Ronald D; Dooley, David A

2008-07-01

Approximately two years after promulgation of the Energy Employees Occupational Illness Compensation Program Act, the National Institute for Occupational Safety and Health Office of Compensation and Analysis Support selected a contractor team to perform many aspects of the radiation dose reconstruction process. The project scope and schedule necessitated the development of an organization involving a comparatively large number of health physicists. From the initial stages, there were many technical and managerial challenges that required continuous planning, integration, and conflict resolution. This paper identifies those challenges and describes the resolutions and lessons learned. These insights are hopefully useful to managers of similar scientific projects, especially those requiring significant data, technical methods, and calculations. The most complex challenge has been to complete defensible, individualized dose reconstructions that support timely compensation decisions at an acceptable production level. Adherence to applying claimant-favorable and transparent science consistent with the requirements of the Act has been the key to establishing credibility, which is essential to this large and complex project involving tens of thousands of individual stakeholders. The initial challenges included garnering sufficient and capable scientific staff, developing an effective infrastructure, establishing necessary methods and procedures, and integrating activities to ensure consistent, quality products. The continuing challenges include maintaining the project focus on recommending a compensation determination (rather than generating an accurate dose reconstruction), managing the associated very large data and information management challenges, and ensuring quality control and assurance in the presence of an evolving infrastructure. The lessons learned concern project credibility, claimant favorability, project priorities, quality and consistency, and critical

Enhanced capital-asset pricing model for the reconstruction of bipartite financial networks

NARCIS (Netherlands)

Squartini, Tiziano; Almog, Assaf; Caldarelli, Guido; Van Lelyveld, Iman; Garlaschelli, Diego; Cimini, Giulio

2017-01-01

Reconstructing patterns of interconnections from partial information is one of the most important issues in the statistical physics of complex networks. A paramount example is provided by financial networks. In fact, the spreading and amplification of financial distress in capital markets are

Voting based object boundary reconstruction

Science.gov (United States)

Tian, Qi; Zhang, Like; Ma, Jingsheng

2005-07-01

A voting-based object boundary reconstruction approach is proposed in this paper. Morphological technique was adopted in many applications for video object extraction to reconstruct the missing pixels. However, when the missing areas become large, the morphological processing cannot bring us good results. Recently, Tensor voting has attracted people"s attention, and it can be used for boundary estimation on curves or irregular trajectories. However, the complexity of saliency tensor creation limits its applications in real-time systems. An alternative approach based on tensor voting is introduced in this paper. Rather than creating saliency tensors, we use a "2-pass" method for orientation estimation. For the first pass, Sobel d*etector is applied on a coarse boundary image to get the gradient map. In the second pass, each pixel puts decreasing weights based on its gradient information, and the direction with maximum weights sum is selected as the correct orientation of the pixel. After the orientation map is obtained, pixels begin linking edges or intersections along their direction. The approach is applied to various video surveillance clips under different conditions, and the experimental results demonstrate significant improvement on the final extracted objects accuracy.

Viability of permanent PMMA spacer with combined free fasciocutaneous tissue transfer for failed charcot reconstruction: A 38 month prospective case report

Directory of Open Access Journals (Sweden)

Tammer Elmarsafi

Full Text Available Introduction: Charcot Neuroarthropathy is a complex lower extremity pathology which predisposes the afflicted limb to ulcerations, osteomyelitis, and risk of major amputation. Charcot Neuroarthropathy often requires osseous reconstruction, which can be complicated with osteomyelitis and hardware infection. When soft tissue and osseous deficits must be concomitantly addressed, the use of PMMA spacers can be combined with free tissue transfers. Presentation of case: 71 year old Caucasian male with Diabetic Charcot Neuroarthopathy underwent osseous reconstruction with internal hardware. The surgical site was complicated by acute infection, osteomyelitis, exposed hardware requiring removal, and multiple surgical débridement. The degree of soft tissue and osseous deficit post-débridement required complex reconstruction. Discussion: The osseous deficit was addressed with the use of a permanent PMMA cement spacer. The soft tissue deficit was reconstructed with a free tissue transfer. This case report demonstrates the long term viability and utility of the use of permanent cement spacers when combined with free tissue transfer for closure of complex diabetic foot wounds. This case is an example of a multidisciplinary team approach to limb salvage with successful long term outcome; a plantigrade stable functional foot in an ambulatory highly active patient. Follow up time since initial intervention was 38 months. Conclusion: The use of a permanent PMMA cement spacer does not preclude free tissue transfer in complex host lower extremity reconstruction. A multidisciplinary team approach is a vital component to successful salvage outcomes. Keywords: Diabetes, Charcot neuroarthropathy, Ulcer, Cement spacer, Free tissue transfer, Osteomyelitis

Craniofacial stability in patients with Crouzon or Apert syndrome after Le Fort III distraction osteogenesis

NARCIS (Netherlands)

Reitsma, J.H.; Ongkosuwito, E.M.; Buschang, P.H.; van Adrichem, L.N.A.; Prahl-Andersen, B.

2013-01-01

Objective: Le Fort III osteotomy with distraction osteogenesis (DO) is used to improve the retruded midface in patients with Crouzon or Apert syndrome. This study aimed to evaluate sagittal and vertical preoperative and postoperative cephalometric changes of DO of the midface in patients with

Craniofacial stability in patients with crouzon or apert syndrome after le fort III distraction osteogenesis

NARCIS (Netherlands)

J.H. Reitsma (Jacobus Harmen); E.M. Ongkosuwito (Edwin); P.H. Buschang (Peter); L.N.A. V Adrichem (Léon); B. Prahl-Andersen (Birte)

2013-01-01

textabstractObjective: Le Fort III osteotomy with distraction osteogenesis (DO) is used to improve the retruded midface in patients with Crouzon or Apert syndrome. This study aimed to evaluate sagittal and vertical preoperative and postoperative cephalometric changes of DO of the midface in patients

Segmentation-DrivenTomographic Reconstruction

DEFF Research Database (Denmark)

Kongskov, Rasmus Dalgas

such that the segmentation subsequently can be carried out by use of a simple segmentation method, for instance just a thresholding method. We tested the advantages of going from a two-stage reconstruction method to a one stage segmentation-driven reconstruction method for the phase contrast tomography reconstruction......The tomographic reconstruction problem is concerned with creating a model of the interior of an object from some measured data, typically projections of the object. After reconstructing an object it is often desired to segment it, either automatically or manually. For computed tomography (CT...

Resolving the Complexity of Human Skin Metagenomes Using Single-Molecule Sequencing

Directory of Open Access Journals (Sweden)

Yu-Chih Tsai

2016-02-01

Full Text Available Deep metagenomic shotgun sequencing has emerged as a powerful tool to interrogate composition and function of complex microbial communities. Computational approaches to assemble genome fragments have been demonstrated to be an effective tool for de novo reconstruction of genomes from these communities. However, the resultant “genomes” are typically fragmented and incomplete due to the limited ability of short-read sequence data to assemble complex or low-coverage regions. Here, we use single-molecule, real-time (SMRT sequencing to reconstruct a high-quality, closed genome of a previously uncharacterized Corynebacterium simulans and its companion bacteriophage from a skin metagenomic sample. Considerable improvement in assembly quality occurs in hybrid approaches incorporating short-read data, with even relatively small amounts of long-read data being sufficient to improve metagenome reconstruction. Using short-read data to evaluate strain variation of this C. simulans in its skin community at single-nucleotide resolution, we observed a dominant C. simulans strain with moderate allelic heterozygosity throughout the population. We demonstrate the utility of SMRT sequencing and hybrid approaches in metagenome quantitation, reconstruction, and annotation.

Resolving the Complexity of Human Skin Metagenomes Using Single-Molecule Sequencing

Science.gov (United States)

Tsai, Yu-Chih; Deming, Clayton; Segre, Julia A.; Kong, Heidi H.; Korlach, Jonas

2016-01-01

ABSTRACT Deep metagenomic shotgun sequencing has emerged as a powerful tool to interrogate composition and function of complex microbial communities. Computational approaches to assemble genome fragments have been demonstrated to be an effective tool for de novo reconstruction of genomes from these communities. However, the resultant “genomes” are typically fragmented and incomplete due to the limited ability of short-read sequence data to assemble complex or low-coverage regions. Here, we use single-molecule, real-time (SMRT) sequencing to reconstruct a high-quality, closed genome of a previously uncharacterized Corynebacterium simulans and its companion bacteriophage from a skin metagenomic sample. Considerable improvement in assembly quality occurs in hybrid approaches incorporating short-read data, with even relatively small amounts of long-read data being sufficient to improve metagenome reconstruction. Using short-read data to evaluate strain variation of this C. simulans in its skin community at single-nucleotide resolution, we observed a dominant C. simulans strain with moderate allelic heterozygosity throughout the population. We demonstrate the utility of SMRT sequencing and hybrid approaches in metagenome quantitation, reconstruction, and annotation. PMID:26861018

Automating 3D reconstruction using a probabilistic grammar

Science.gov (United States)

Xiong, Hanwei; Xu, Jun; Xu, Chenxi; Pan, Ming

2015-10-01

3D reconstruction of objects from point clouds with a laser scanner is still a laborious task in many applications. Automating 3D process is an ongoing research topic and suffers from the complex structure of the data. The main difficulty is due to lack of knowledge of real world objects structure. In this paper, we accumulate such structure knowledge by a probabilistic grammar learned from examples in the same category. The rules of the grammar capture compositional structures at different levels, and a feature dependent probability function is attached for every rule. The learned grammar can be used to parse new 3D point clouds, organize segment patches in a hierarchal way, and assign them meaningful labels. The parsed semantics can be used to guide the reconstruction algorithms automatically. Some examples are given to explain the method.

Evaluation of digital breast tomosynthesis reconstruction algorithms using synchrotron radiation in standard geometry

International Nuclear Information System (INIS)

Bliznakova, K.; Kolitsi, Z.; Speller, R. D.; Horrocks, J. A.; Tromba, G.; Pallikarakis, N.

2010-01-01

Purpose: In this article, the image quality of reconstructed volumes by four algorithms for digital tomosynthesis, applied in the case of breast, is investigated using synchrotron radiation. Methods: An angular data set of 21 images of a complex phantom with heterogeneous tissue-mimicking background was obtained using the SYRMEP beamline at ELETTRA Synchrotron Light Laboratory, Trieste, Italy. The irradiated part was reconstructed using the multiple projection algorithm (MPA) and the filtered backprojection with ramp followed by hamming windows (FBR-RH) and filtered backprojection with ramp (FBP-R). Additionally, an algorithm for reducing the noise in reconstructed planes based on noise mask subtraction from the planes of the originally reconstructed volume using MPA (MPA-NM) has been further developed. The reconstruction techniques were evaluated in terms of calculations and comparison of the contrast-to-noise ratio (CNR) and artifact spread function. Results: It was found that the MPA-NM resulted in higher CNR, comparable with the CNR of FBP-RH for high contrast details. Low contrast objects are well visualized and characterized by high CNR using the simple MPA and the MPA-NM. In addition, the image quality of the reconstructed features in terms of CNR and visual appearance as a function of the initial number of projection images and the reconstruction arc was carried out. Slices reconstructed with more input projection images result in less reconstruction artifacts and higher detail CNR, while those reconstructed from projection images acquired in reduced angular range causes pronounced streak artifacts. Conclusions: Of the reconstruction algorithms implemented, the MPA-NM and MPA are a good choice for detecting low contrast objects, while the FBP-RH, FBP-R, and MPA-NM provide high CNR and well outlined edges in case of microcalcifications.

Universal Spatial Correlation Functions for Describing and Reconstructing Soil Microstructure

Science.gov (United States)

Skvortsova, Elena B.; Mallants, Dirk

2015-01-01

Structural features of porous materials such as soil define the majority of its physical properties, including water infiltration and redistribution, multi-phase flow (e.g. simultaneous water/air flow, or gas exchange between biologically active soil root zone and atmosphere) and solute transport. To characterize soil microstructure, conventional soil science uses such metrics as pore size and pore-size distributions and thin section-derived morphological indicators. However, these descriptors provide only limited amount of information about the complex arrangement of soil structure and have limited capability to reconstruct structural features or predict physical properties. We introduce three different spatial correlation functions as a comprehensive tool to characterize soil microstructure: 1) two-point probability functions, 2) linear functions, and 3) two-point cluster functions. This novel approach was tested on thin-sections (2.21×2.21 cm2) representing eight soils with different pore space configurations. The two-point probability and linear correlation functions were subsequently used as a part of simulated annealing optimization procedures to reconstruct soil structure. Comparison of original and reconstructed images was based on morphological characteristics, cluster correlation functions, total number of pores and pore-size distribution. Results showed excellent agreement for soils with isolated pores, but relatively poor correspondence for soils exhibiting dual-porosity features (i.e. superposition of pores and micro-cracks). Insufficient information content in the correlation function sets used for reconstruction may have contributed to the observed discrepancies. Improved reconstructions may be obtained by adding cluster and other correlation functions into reconstruction sets. Correlation functions and the associated stochastic reconstruction algorithms introduced here are universally applicable in soil science, such as for soil classification

Sparse dynamical Boltzmann machine for reconstructing complex networks with binary dynamics

Science.gov (United States)

Chen, Yu-Zhong; Lai, Ying-Cheng

2018-03-01

Revealing the structure and dynamics of complex networked systems from observed data is a problem of current interest. Is it possible to develop a completely data-driven framework to decipher the network structure and different types of dynamical processes on complex networks? We develop a model named sparse dynamical Boltzmann machine (SDBM) as a structural estimator for complex networks that host binary dynamical processes. The SDBM attains its topology according to that of the original system and is capable of simulating the original binary dynamical process. We develop a fully automated method based on compressive sensing and a clustering algorithm to construct the SDBM. We demonstrate, for a variety of representative dynamical processes on model and real world complex networks, that the equivalent SDBM can recover the network structure of the original system and simulates its dynamical behavior with high precision.

Software compensation in particle flow reconstruction

Energy Technology Data Exchange (ETDEWEB)

Tran, Huong Lan; Krueger, Katja; Sefkow, Felix [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Green, Steven; Marshall, John; Thomson, Mark [Cavendish Laboratory, Cambridge (United Kingdom); Simon, Frank [Max-Planck-Institut fuer Physik, Muenchen (Germany)

2017-10-15

The particle flow approach to calorimetry benefits from highly granular calorimeters and sophisticated software algorithms in order to reconstruct and identify individual particles in complex event topologies. The high spatial granularity, together with analogue energy information, can be further exploited in software compensation. In this approach, the local energy density is used to discriminate electromagnetic and purely hadronic sub-showers within hadron showers in the detector to improve the energy resolution for single particles by correcting for the intrinsic non-compensation of the calorimeter system. This improvement in the single particle energy resolution also results in a better overall jet energy resolution by improving the energy measurement of identified neutral hadrons and improvements in the pattern recognition stage by a more accurate matching of calorimeter energies to tracker measurements. This paper describes the software compensation technique and its implementation in particle flow reconstruction with the Pandora Particle Flow Algorithm (PandoraPFA). The impact of software compensation on the choice of optimal transverse granularity for the analogue hadronic calorimeter option of the International Large Detector (ILD) concept is also discussed.

Software compensation in particle flow reconstruction

Energy Technology Data Exchange (ETDEWEB)

Tran, Huong Lan; Krueger, Katja; Sefkow, Felix [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Green, Steven; Marshall, John; Thomson, Mark [Cavendish Laboratory, Cambridge (United Kingdom); Simon, Frank [Max-Planck-Institut fuer Physik, Muenchen (Germany)

2017-10-15

The particle flow approach to calorimetry benefits from highly granular calorimeters and sophisticated software algorithms in order to reconstruct and identify individual particles in complex event topologies. The high spatial granularity, together with analogue energy information, can be further exploited in software compensation. In this approach, the local energy density is used to discriminate electromagnetic and purely hadronic sub-showers within hadron showers in the detector to improve the energy resolution for single particles by correcting for the intrinsic non-compensation of the calorimeter system. This improvement in the single particle energy resolution also results in a better overall jet energy resolution by improving the energy measurement of identified neutral hadrons and improvements in the pattern recognition stage by a more accurate matching of calorimeter energies to tracker measurements. This paper describes the software compensation technique and its implementation in particle flow reconstruction with the Pandora Particle Flow Algorithm (PandoraPFA). The impact of software compensation on the choice of optimal transverse granularity for the analogue hadronic calorimeter option of the International Large Detector (ILD) concept is also discussed. (orig.)

Software compensation in particle flow reconstruction

International Nuclear Information System (INIS)

Tran, Huong Lan; Krueger, Katja; Sefkow, Felix; Green, Steven; Marshall, John; Thomson, Mark; Simon, Frank

2017-10-01

The particle flow approach to calorimetry benefits from highly granular calorimeters and sophisticated software algorithms in order to reconstruct and identify individual particles in complex event topologies. The high spatial granularity, together with analogue energy information, can be further exploited in software compensation. In this approach, the local energy density is used to discriminate electromagnetic and purely hadronic sub-showers within hadron showers in the detector to improve the energy resolution for single particles by correcting for the intrinsic non-compensation of the calorimeter system. This improvement in the single particle energy resolution also results in a better overall jet energy resolution by improving the energy measurement of identified neutral hadrons and improvements in the pattern recognition stage by a more accurate matching of calorimeter energies to tracker measurements. This paper describes the software compensation technique and its implementation in particle flow reconstruction with the Pandora Particle Flow Algorithm (PandoraPFA). The impact of software compensation on the choice of optimal transverse granularity for the analogue hadronic calorimeter option of the International Large Detector (ILD) concept is also discussed.

Reconstruction formula for a 3-d phaseless inverse scattering problem for the Schrodinger equation

OpenAIRE

Klibanov, Michael V.; Romanov, Vladimir G.

2014-01-01

The inverse scattering problem of the reconstruction of the unknown potential with compact support in the 3-d Schr\\"odinger equation is considered. Only the modulus of the scattering complex valued wave field is known, whereas the phase is unknown. It is shown that the unknown potential can be reconstructed via the inverse Radon transform. Therefore, a long standing problem posed in 1977 by K. Chadan and P.C. Sabatier in their book "Inverse Problems in Quantum Scattering Theory" is solved.

Vaginal reconstruction

International Nuclear Information System (INIS)

Lesavoy, M.A.

1985-01-01

Vaginal reconstruction can be an uncomplicated and straightforward procedure when attention to detail is maintained. The Abbe-McIndoe procedure of lining the neovaginal canal with split-thickness skin grafts has become standard. The use of the inflatable Heyer-Schulte vaginal stent provides comfort to the patient and ease to the surgeon in maintaining approximation of the skin graft. For large vaginal and perineal defects, myocutaneous flaps such as the gracilis island have been extremely useful for correction of radiation-damaged tissue of the perineum or for the reconstruction of large ablative defects. Minimal morbidity and scarring ensue because the donor site can be closed primarily. With all vaginal reconstruction, a compliant patient is a necessity. The patient must wear a vaginal obturator for a minimum of 3 to 6 months postoperatively and is encouraged to use intercourse as an excellent obturator. In general, vaginal reconstruction can be an extremely gratifying procedure for both the functional and emotional well-being of patients

Economics of abdominal wall reconstruction.

Science.gov (United States)

Bower, Curtis; Roth, J Scott

2013-10-01

The economic aspects of abdominal wall reconstruction are frequently overlooked, although understandings of the financial implications are essential in providing cost-efficient health care. Ventral hernia repairs are frequently performed surgical procedures with significant economic ramifications for employers, insurers, providers, and patients because of the volume of procedures, complication rates, the significant rate of recurrence, and escalating costs. Because biological mesh materials add significant expense to the costs of treating complex abdominal wall hernias, the role of such costly materials needs to be better defined to ensure the most cost-efficient and effective treatments for ventral abdominal wall hernias. Copyright © 2013 Elsevier Inc. All rights reserved.

Automatic Indoor Building Reconstruction from Mobile Laser Scanning Data

Science.gov (United States)

Xie, L.; Wang, R.

2017-09-01

Indoor reconstruction from point clouds is a hot topic in photogrammetry, computer vision and computer graphics. Reconstructing indoor scene from point clouds is challenging due to complex room floorplan and line-of-sight occlusions. Most of existing methods deal with stationary terrestrial laser scanning point clouds or RGB-D point clouds. In this paper, we propose an automatic method for reconstructing indoor 3D building models from mobile laser scanning point clouds. The method includes 2D floorplan generation, 3D building modeling, door detection and room segmentation. The main idea behind our approach is to separate wall structure into two different types as the inner wall and the outer wall based on the observation of point distribution. Then we utilize a graph cut based optimization method to solve the labeling problem and generate the 2D floorplan based on the optimization result. Subsequently, we leverage an ?-shape based method to detect the doors on the 2D projected point clouds and utilize the floorplan to segment the individual room. The experiments show that this door detection method can achieve a recognition rate at 97% and the room segmentation method can attain the correct segmentation results. We also evaluate the reconstruction accuracy on the synthetic data, which indicates the accuracy of our method is comparable to the state-of-the art.

Reconstruction of blood propagation in three-dimensional rotational X-ray angiography (3D-RA).

Science.gov (United States)

Schmitt, Holger; Grass, Michael; Suurmond, Rolf; Köhler, Thomas; Rasche, Volker; Hähnel, Stefan; Heiland, Sabine

2005-10-01

-RA images in cases of complex AVMs. The concentration of injected contrast agent was often not sufficient to provide highly contrasted vessels in 3D-RA images. Another segmentation-related problem is known as 'kissing vessels' [19]. Kissing vessel artifacts introduce artificial vessel junctions and thereby distort the feeding structure of the vessel. This may finally cause implausible flow reconstruction results and inverse flow directions in vessel segments. We are currently planning to validate our reconstruction results using particle imaging velocimetry (PIV). PIV experiments with phantoms, for which the true flow parameters are known, will allow for the assessment of the accuracy of our contrast agent based method. In the context of computational fluid dynamics techniques, the potential of the presented flow reconstruction method is high. Flow reconstruction results based on the presented method could be used both as boundary conditions for simulations and as a reference for the validation of simulation results. Computational fluid dynamics provide useful information such as arterial wall shear stress and complex flow patterns in aneurysms.

Three-diemensional materials science: An intersection of three-dimensional reconstructions and simulations

DEFF Research Database (Denmark)

Thornton, Katsuyo; Poulsen, Henning Friis

2008-01-01

The recent development of experimental techniques that rapidly reconstruct the three-dimensional microstructures of solids has given rise to new possibilities for developing a deeper understanding of the evolution of microstructures and the effects of microstructures on materials properties. Comb...... an overview of this emerging field of materials science, as well as brief descriptions of selected methods and their applicability.......The recent development of experimental techniques that rapidly reconstruct the three-dimensional microstructures of solids has given rise to new possibilities for developing a deeper understanding of the evolution of microstructures and the effects of microstructures on materials properties....... Combined with three-dimensional (3D) simulations and analyses that are capable of handling the complexity of these microstructures, 3D reconstruction, or tomography, has become a powerful tool that provides clear insights into materials processing and properties. This introductory article provides...

Breast Reconstruction After Mastectomy

Science.gov (United States)

... Cancer Prevention Genetics of Breast & Gynecologic Cancers Breast Cancer Screening Research Breast Reconstruction After Mastectomy On This Page What is breast reconstruction? How do surgeons use implants to reconstruct a woman’s breast? How do surgeons ...

Practices of Built Heritage Post-Disaster Reconstruction for Resilient Cities

Directory of Open Access Journals (Sweden)

Tomasz Jeleński

2018-03-01

Full Text Available The concept of resilience has become increasingly important to our understanding of sustainable planning. Post-disaster urban and architectural reconstruction might be treated as a strategy for resilient cities, helping them to reinvent themselves after possible destruction. The purpose of this study is to analyse several cases of nearly total reconstruction of historical urban complexes. Specifically, it explores how urban heritage conservation and recreation could contribute to the resilience agenda, giving traumatised societies a sense of continuity and localness. It analyses the changes in the conservation doctrine, highlighting the growing acceptance of architectural reconstructions. Drawing on historical examples, mainly derived from the Polish School of Conservation practice, this paper argues that the methods and processes attempted to regain identity for the thoroughly rebuilt structures proved effective in recreating the identity of such cities as Kalisz, Warsaw, Gdańsk, and Wrocław. The article argues that while processes at the governmental level emphasised the strengthening of national identity, the experiences of the reconstructed townscapes eventually involved forms of more diverse municipal identities. The article highlights that the strategy of recreating traditional images of cities after their mutilation in disastrous events might be a key to becoming a more resilient city and the formation of the post-disaster citizenry.

Surgical reconstruction of pelvic floor descent: anatomic and functional aspects.

Science.gov (United States)

Wagenlehner, F M E; Bschleipfer, T; Liedl, B; Gunnemann, A; Petros, P; Weidner, W

2010-01-01

The human pelvic floor is a complex structure and pelvic floor dysfunction is seen frequently in females. This review focuses on the surgical reconstruction of the pelvic floor employing recent findings on functional anatomy. A selective literature research was performed by the authors. Pelvic floor activity is regulated by 3 main muscular forces that are responsible for vaginal tension and suspension of the pelvic floor organs, bladder and rectum. A variety of symptoms can derive from pelvic floor dysfunctions, such as urinary urge and stress incontinence, abnormal bladder emptying, fecal incontinence, obstructive bowel disease syndrome and pelvic pain. These symptoms mainly derive, for different reasons, from laxity in the vagina or its supporting ligaments as a result of altered connective tissue. Pelvic floor reconstruction is nowadays driven by the concept that in case of pelvic floor symptoms, restoration of the anatomy will translate into restoration of the physiology and ultimately improve patients' symptoms. The surgical reconstruction of the anatomy is almost exclusively focused on the restoration of the lax pelvic floor ligaments. Exact preoperative identification of the anatomical lesions is necessary to allow for exact anatomical reconstruction with respect to the muscular forces of the pelvic floor. Copyright 2010 S. Karger AG, Basel.

Evidence-Based ACL Reconstruction

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E. Carlos RODRIGUEZ-MERCHAN

2015-01-01

Full Text Available There is controversy in the literature regarding a number of topics related to anterior cruciate ligament (ACLreconstruction. The purpose of this article is to answer the following questions: 1 Bone patellar tendon bone (BPTB reconstruction or hamstring reconstruction (HR; 2 Double bundle or single bundle; 3 Allograft or authograft; 4 Early or late reconstruction; 5 Rate of return to sports after ACL reconstruction; 6 Rate of osteoarthritis after ACL reconstruction. A Cochrane Library and PubMed (MEDLINE search of systematic reviews and meta-analysis related to ACL reconstruction was performed. The key words were: ACL reconstruction, systematic reviews and meta-analysis. The main criteria for selection were that the articles were systematic reviews and meta-analysesfocused on the aforementioned questions. Sixty-nine articles were found, but only 26 were selected and reviewed because they had a high grade (I-II of evidence. BPTB-R was associated with better postoperative knee stability but with a higher rate of morbidity. However, the results of both procedures in terms of functional outcome in the long-term were similar. The double-bundle ACL reconstruction technique showed better outcomes in rotational laxity, although functional recovery was similar between single-bundle and double-bundle. Autograft yielded better results than allograft. There was no difference between early and delayed reconstruction. 82% of patients were able to return to some kind of sport participation. 28% of patients presented radiological signs of osteoarthritis with a follow-up of minimum 10 years.

Reconstruction of action potential of repolarization in patients with congenital long-QT syndrome

International Nuclear Information System (INIS)

Kandori, Akihiko; Shimizu, Wataru; Yokokawa, Miki; Kamakura, Shiro; Miyatake, Kunio; Murakami, Masahiro; Miyashita, Tsuyoshi; Ogata, Kuniomi; Tsukada, Keiji

2004-01-01

A method for reconstructing an action potential during the repolarization period was developed. This method uses a current distribution-plotted as a current-arrow map (CAM)-calculated using magnetocardiogram (MCG) signals. The current arrows are summarized during the QRS complex period and subtracted during the ST-T wave period in order to reconstruct the action-potential waveform. To ensure the similarity between a real action potential and the reconstructed action potential using CAM, a monophasic action potential (MAP) and an MCG of the same patient with type-I long-QT syndrome were measured. Although the MAP had one notch that was associated with early afterdepolarization (EAD), the reconstructed action potential had two large and small notches. The small notch timing agreed with the occurrence of the EAD in the MAP. On the other hand, the initiation time of an abnormal current distribution coincides with the appearance timing of the first large notch, and its end time coincides with that of the second small notch. These results suggest that a simple reconstruction method using a CAM based on MCG data can provide a similar action-potential waveform to a MAP waveform without having to introduce a catheter

WASS: An open-source pipeline for 3D stereo reconstruction of ocean waves

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Bergamasco, Filippo; Torsello, Andrea; Sclavo, Mauro; Barbariol, Francesco; Benetazzo, Alvise

2017-10-01

Stereo 3D reconstruction of ocean waves is gaining more and more popularity in the oceanographic community and industry. Indeed, recent advances of both computer vision algorithms and computer processing power now allow the study of the spatio-temporal wave field with unprecedented accuracy, especially at small scales. Even if simple in theory, multiple details are difficult to be mastered for a practitioner, so that the implementation of a sea-waves 3D reconstruction pipeline is in general considered a complex task. For instance, camera calibration, reliable stereo feature matching and mean sea-plane estimation are all factors for which a well designed implementation can make the difference to obtain valuable results. For this reason, we believe that the open availability of a well tested software package that automates the reconstruction process from stereo images to a 3D point cloud would be a valuable addition for future researches in this area. We present WASS (http://www.dais.unive.it/wass), an Open-Source stereo processing pipeline for sea waves 3D reconstruction. Our tool completely automates all the steps required to estimate dense point clouds from stereo images. Namely, it computes the extrinsic parameters of the stereo rig so that no delicate calibration has to be performed on the field. It implements a fast 3D dense stereo reconstruction procedure based on the consolidated OpenCV library and, lastly, it includes set of filtering techniques both on the disparity map and the produced point cloud to remove the vast majority of erroneous points that can naturally arise while analyzing the optically complex nature of the water surface. In this paper, we describe the architecture of WASS and the internal algorithms involved. The pipeline workflow is shown step-by-step and demonstrated on real datasets acquired at sea.

Integrating sequencing technologies in personal genomics: optimal low cost reconstruction of structural variants.

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Jiang Du

2009-07-01

Full Text Available The goal of human genome re-sequencing is obtaining an accurate assembly of an individual's genome. Recently, there has been great excitement in the development of many technologies for this (e.g. medium and short read sequencing from companies such as 454 and SOLiD, and high-density oligo-arrays from Affymetrix and NimbelGen, with even more expected to appear. The costs and sensitivities of these technologies differ considerably from each other. As an important goal of personal genomics is to reduce the cost of re-sequencing to an affordable point, it is worthwhile to consider optimally integrating technologies. Here, we build a simulation toolbox that will help us optimally combine different technologies for genome re-sequencing, especially in reconstructing large structural variants (SVs. SV reconstruction is considered the most challenging step in human genome re-sequencing. (It is sometimes even harder than de novo assembly of small genomes because of the duplications and repetitive sequences in the human genome. To this end, we formulate canonical problems that are representative of issues in reconstruction and are of small enough scale to be computationally tractable and simulatable. Using semi-realistic simulations, we show how we can combine different technologies to optimally solve the assembly at low cost. With mapability maps, our simulations efficiently handle the inhomogeneous repeat-containing structure of the human genome and the computational complexity of practical assembly algorithms. They quantitatively show how combining different read lengths is more cost-effective than using one length, how an optimal mixed sequencing strategy for reconstructing large novel SVs usually also gives accurate detection of SNPs/indels, how paired-end reads can improve reconstruction efficiency, and how adding in arrays is more efficient than just sequencing for disentangling some complex SVs. Our strategy should facilitate the sequencing of

[Use and versatility of titanium for the reconstruction of the thoracic wall].

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Córcoles Padilla, Juan Manuel; Bolufer Nadal, Sergio; Kurowski, Krzysztof; Gálvez Muñoz, Carlos; Rodriguez Paniagua, José Manuel

2014-02-01

Chest wall deformities/defects and chest wall resections, as well as complex rib fractures require reconstruction with various prosthetic materials to ensure the basic functions of the chest wall. Titanium provides many features that make it an ideal material for this surgery. The aim is to present our initial results with this material in several diseases. From 2008 to 2012, 14 patients were operated on and titanium was used for reconstruction of the chest wall. A total of 7 patients had chest wall tumors, 2 with sternal resection, 4 patients with chest wall deformities/defects and 3 patients with severe rib injury due to traffic accident. The reconstruction was successful in all cases, with early extubation without detecting problems in the functionality of the chest wall at a respiratory level. Patients with chest wall tumors including sternal resections were extubated in the operating room as well as the chest wall deformities. Chest trauma cases were extubated within 24h from internal rib fixation. There were no complications related to the material used and the method of implementation. Titanium is an ideal material for reconstruction of the chest wall in several clinical situations allowing for great versatility and adaptability in different chest wall reconstructions. Copyright © 2013 AEC. Published by Elsevier Espana. All rights reserved.

Combination of expansion and orthognathic surgery in a severe hyperdivergent skeletal Class III malocclusion

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Anadha Gujar

2016-01-01

Full Text Available Class III malocclusions with a severe hyperdivergent growth pattern are very complex to plan and treat. This case report describes the treatment of an adult with a skeletal Class III malocclusion with a midface deficiency, severe bilateral posterior crossbite, and a severe hyperdivergent growth pattern by a combination of a bonded rapid maxillary expansion appliance and surgical procedure of Le Fort I osteotomy for maxillary advancement.

Phylogenomic reconstruction supports supercontinent origins for Leishmania.

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Harkins, Kelly M; Schwartz, Rachel S; Cartwright, Reed A; Stone, Anne C

2016-03-01

Leishmania, a genus of parasites transmitted to human hosts and mammalian/reptilian reservoirs by an insect vector, is the causative agent of the human disease complex leishmaniasis. The evolutionary relationships within the genus Leishmania and its origins are the source of ongoing debate, reflected in conflicting phylogenetic and biogeographic reconstructions. This study employs a recently described bioinformatics method, SISRS, to identify over 200,000 informative sites across the genome from newly sequenced and publicly available Leishmania data. This dataset is used to reconstruct the evolutionary relationships of this genus. Additionally, we constructed a large multi-gene dataset, using it to reconstruct the phylogeny and estimate divergence dates for species. We conclude that the genus Leishmania evolved at least 90-100 million years ago, supporting a modified version of the Multiple Origins hypothesis that we call the Supercontinent hypothesis. According to this scenario, separate Leishmania clades emerged prior to, and during, the breakup of Gondwana. Additionally, we confirm that reptile-infecting Leishmania are derived from mammalian forms and that the species that infect porcupines and sloths form a clade long separated from other species. Finally, we firmly place the guinea-pig infecting species, Leishmaniaenriettii, the globally dispersed Leishmaniasiamensis, and the newly identified Australian species from a kangaroo, as sibling species whose distribution arises from the ancient connection between Australia, Antarctica, and South America. Copyright © 2015 Elsevier B.V. All rights reserved.

Collective cognition in humans: groups outperform their best members in a sentence reconstruction task.

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Romain J G Clément

Full Text Available Group-living is widespread among animals and one of the major advantages of group-living is the ability of groups to solve cognitive problems that exceed individual ability. Humans also make use of collective cognition and have simultaneously developed a highly complex language to exchange information. Here we investigated collective cognition of human groups regarding language use in a realistic situation. Individuals listened to a public announcement and had to reconstruct the sentence alone or in groups. This situation is often encountered by humans, for instance at train stations or airports. Using recent developments in machine speech recognition, we analysed how well individuals and groups reconstructed the sentences from a syntactic (i.e., the number of errors and semantic (i.e., the quality of the retrieved information perspective. We show that groups perform better both on a syntactic and semantic level than even their best members. Groups made fewer errors and were able to retrieve more information when reconstructing the sentences, outcompeting even their best group members. Our study takes collective cognition studies to the more complex level of language use in humans.

Stress field reconstruction in an active mudslide

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Baroň, Ivo; Kernstocková, Markéta; Melichar, Rostislav

2017-07-01

Meso-scale structures from gravitational slope deformation observed in landslides and deep-seated gravitational slope failures are very similar to those of endogenous ones. Therefore we applied palaeostress analysis of fault-slip data for reconstructing the stress field of an active mudslide in Pechgraben, Austria. This complex compound landslide has developed in clayey colluvium and shale and was activated after a certain period of dormancy in June 2013. During the active motion on June 12, 2013, 73 fault-slip traces at 9 locations were measured within the landslide body. The heterogeneous fault-slip data were processed in term of palaeostresses, the reconstructed palaeostress tensor being characterized by the orientations of the three principal stress axes and the stress ratio (which provides the shape of the stress ellipsoid). The results of the palaeostress analysis were compared to airborne laser scan digital terrain models that revealed dynamics and superficial displacements of the moving mass prior and after our survey. The results were generally in good agreement with the observed landslide displacement pattern and with the anticipated stress regime according to Mohr-Coulomb failure criteria and Anderson's theory. The compressional regime was mostly registered at the toe in areas, where a compressional stress field is expected during previous mass-movement stages, or at margins loaded by subsequent landslide bodies from above. On the other hand, extension regimes were identified at the head scarps of secondary slides, subsequently on bulged ridges at the toe and in the zone of horst-and-graben structures in the lower central part of the main landslide body, where the basal slip surface probably had locally convex character. Strike-slip regimes, as well as oblique normal or oblique reverse regimes were observed at the lateral margins of the landslide bodies. The directions of principal stresses could be used as markers of landslide movement directions

MR imaging appearances of soft tissue flaps following reconstructive surgery of the lower extremity

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Magerkurth, Olaf [Dept. of Radiology, Hospital Baden, Baden (Switzerland); Girish, Gandikota; Jacobson, Jon A.; Kim, Sung Moon; Brigido, Monica; Dong, Qian; Jamadar, David A. [Dept. of Radiology, University of Michigan Hospitals, Ann Arbor (United States)

2015-02-15

MR imaging appearances of different types of reconstructive muscle flaps following reconstructive surgery of the lower extremity with associated post-surgical changes due to altered anatomy, radiation, and potential complications, can be challenging. A multidisciplinary therapeutic approach to tumors allows for limb salvage therapy in a majority of the patients. Decision-making for specific types of soft tissue reconstruction is based on the body region affected, as well as the size and complexity of the defect. Hematomas and infections are early complications that can jeopardize flap viability. The local recurrence of a tumor within six months after a complete resection with confirmed tumor-free margins and adjuvant radiation therapy is rare. Identification of a new lesion similar to the initial tumor favors a finding of tumor recurrence.

Calibration-free quantitative surface topography reconstruction in scanning electron microscopy.

Science.gov (United States)

Faber, E T; Martinez-Martinez, D; Mansilla, C; Ocelík, V; Hosson, J Th M De

2015-01-01

This work presents a new approach to obtain reliable surface topography reconstructions from 2D Scanning Electron Microscopy (SEM) images. In this method a set of images taken at different tilt angles are compared by means of digital image correlation (DIC). It is argued that the strength of the method lies in the fact that precise knowledge about the nature of the rotation (vector and/or magnitude) is not needed. Therefore, the great advantage is that complex calibrations of the measuring equipment are avoided. The paper presents the necessary equations involved in the methods, including derivations and solutions. The method is illustrated with examples of 3D reconstructions followed by a discussion on the relevant experimental parameters. Copyright © 2014 Elsevier B.V. All rights reserved.

Shaping the breast in secondary microsurgical breast reconstruction: single- vs. two-esthetic unit reconstruction.

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Gravvanis, Andreas; Smith, Roger W

2010-10-01

The esthetic outcome is dictated essentially not only by the position, size, and shape of the reconstructed breast, but also by the extra scaring involved. In the present study, we conducted a visual analog scale survey to compare the esthetic outcome in delayed autologous breast reconstruction following two different abdominal flaps inset. Twenty-five patients had their reconstruction using the Single-esthetic Unit principle and were compared with 25 patients that their breast was reconstructed using the Two-Esthetic Unit principle. Photographic images were formulated to a PowerPoint presentation and cosmetic outcomes were assessed from 30 physicians, by means of a Questionnaire and a visual analog scale. Our data showed that the single-esthetic unit breast reconstruction presents significant advantages over the traditional two-esthetic units, due to inconspicuous flap reconstruction, better position of the inframammary fold, and more natural transition from native and reconstructed tissues. Moreover, patient self-evaluation of esthetic outcome and quality of life showed that single-esthetic unit reconstruction is associated with higher patient satisfaction, therefore should be considered the method of choice. © 2010 Wiley-Liss, Inc.

Complex dynamic in ecological time series

Science.gov (United States)

Peter Turchin; Andrew D. Taylor

1992-01-01

Although the possibility of complex dynamical behaviors-limit cycles, quasiperiodic oscillations, and aperiodic chaos-has been recognized theoretically, most ecologists are skeptical of their importance in nature. In this paper we develop a methodology for reconstructing endogenous (or deterministic) dynamics from ecological time series. Our method consists of fitting...

Statistical Reconstruction of Gas Oil Cuts Reconstruction statistique de coupes gazoles

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Hudebine D.

2009-11-01

Full Text Available Gas oil cuts are extremely complex mixtures of several thousands of different chemical species. Consequently, conventional petroleum analyses do not allow to obtain the molecular detail that is required for the development of robust and predictive kinetic models. Recently, two-dimensional Gas Chromatographic techniques (GC2D have greatly improved the knowledge in the field of characterization of gas oils. However, they remain R&D tools and are hardly utilized in the refining industry. Hence, the goal of the statistical reconstruction of gas oils is to provide a surrogate for this GC2D analysis. To this aim, the gas oil cuts are characterized by means of matrices of molar fractions of pseudo-compounds, which are classified by chemical family and by carbon atom number. The input analyses are the Fitzgerald mass spectrometry, the sulfur speciation (one-dimensional gas chromatography coupled to a specific sulfur chemiluminescence detector and the total nitrogen and basic nitrogen contents, and allow to quantify the proportions of all the chemical families present in the matrix. The simulated distillation is also used in order to introduce information on the volatility of the gas oil cut. The reconstruction method proposed in this paper is mainly based on a reference statistical distribution of the number of carbon atoms for the side chains connected to the naphtheno-aromatic cores. For each chemical family, the knowledge of the number of potential side chains and the estimation of the maximum length of these alkyl chains allow to determine the carbon number distribution by adjusting of the reference distribution. After reconstruction, the properties of the resulting molar fractions matrix are very close to the analyses used for the reconstruction. Moreover, the method allows to predict, with a high precision, complementary analyses such as the hydrogen content, the aromatic carbon content and the density at 15 ˚C. Finally, the matrix can be

Our Clinical Experience in Lower Eyelid Reconstruction and Comparison of Reconstruction Techniques.

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Erol Kesiktas

2011-03-01

Full Text Available Lower eyelid reconstruction after tumor resection or trauma is extremely important in order to obtain the protection of the globe and it requires extra care. The aim of this study is to evaluate the techniques that we use in lower eyelid reconstruction. Between the years of 1999-2009, a total of 23 patients who had lower eyelid defects due to tumor resection (21 patients or trauma (2 patients were reconstructed by the use of various flaps. Eleven of the patients were women and twelve of them were men. Average age was 60.7. For the reconstruction 13 Mustarde flap, 9 bipedicled Tripier flap, 1 Tenzel flap and 1 bipedicled infraorbital flaps were used. Average postoperative follow up interval was 35 months. (18-47 months. Flap necrosis, function loss in the lower lid were not experienced in any of the patients. Cosmetically satisfactory results were obtained. In lower eyelid reconstruction, the size of the defect and the amount of skin around must be carefully evaluated and should be considered while planning the reconstruction. [Cukurova Med J 2011; 36(1: 15-23

A New Local Flap Nipple Reconstruction Technique Using Dermal Bridge and Preoperatively Designed Tattoo

Science.gov (United States)

Iwahira, Yoshiko

2017-01-01

Background: Nipple–areolar reconstruction is the final step in breast reconstruction. Reconstruction using local flaps and tattooing is useful in cases of bilateral reconstruction, a small nipple–areolar complex (NAC) as the donor site, and avoiding disturbance of the normal side and other body parts. However, this method can cause projection loss and color fading of the nipple. Moreover, the breast mound is reconstructed with an implant. Methods: We performed nipple–areolar reconstruction of 90 nipples using clover-designed flaps oriented at 120 degrees and tattooing after breast silicone implantation in 64 women. The tattoo was designed before flap operation and stained darker. Following donor site closure, a dermal flap was made as a bridge for nipple support. The nipple space was separated by the dermal flap from the breast mound and was filled with subcutaneous tissue. The size of the reconstructed nipple projection was measured postoperatively and 1 year later. The projection maintenance rate was calculated. Results: The heights of the nipple projection were 11.3 ± 1.8 mm (95% confidence interval [CI]: 10.9–11.7) just after the operation and 6.09 ± 2.4 mm (95% CI: 5.6–6.6) 1 year later. The actual range of nipple projection between these 2 heights was 5.2 ± 2.4 mm (95% CI: 4.7–5.7). The maintenance rate of the reconstructed nipple projection after 12 months was 54.1 ± 20.9 (95% CI: 49.7–58.5). The nipple color was maintained for over a year. Conclusions: Our nipple–areolar reconstruction technique could maintain the projection and color of the reconstructed nipple for a long period. Good outcomes were obtained in this implant-based breast reconstruction. PMID:28507843

Extended Hemi-Hepatectomy with Portal Vein Reconstruction in a Patient with Situs Ambiguous

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Keishi Sugimachi

2008-03-01

Full Text Available We report a case of far-advanced hepatocellular carcinoma (HCC with situs ambiguous, complex visceral and vascular anomalies, who was successfully managed by extended hemi-hepatectomy. A 67-year-old man was referred to our hospital with a large liver mass. Abdominal ultrasonography, computed tomography and angiography revealed HCC with a diameter of 10 cm, with tumor thrombus in the main and first branch of the portal vein. Multiple complex anomalies in the abdomen were determined preoperatively. He had right-sided spleens-stomach-duodenum, liver at midline, inferior vena cava interruption with azygous continuation, and hepatic arterial anomaly. Extended left lobectomy of the liver with reconstruction of the portal vein was performed. Postoperatively, the patient recovered without major complications, and he was discharged on postoperative day 21. We report the first successful extended hepatectomy with portal vein reconstruction for HCC in a patient with rare situs anomalies.

The SENSE-Isomorphism Theoretical Image Voxel Estimation (SENSE-ITIVE) Model for Reconstruction and Observing Statistical Properties of Reconstruction Operators

Science.gov (United States)

Bruce, Iain P.; Karaman, M. Muge; Rowe, Daniel B.

2012-01-01

The acquisition of sub-sampled data from an array of receiver coils has become a common means of reducing data acquisition time in MRI. Of the various techniques used in parallel MRI, SENSitivity Encoding (SENSE) is one of the most common, making use of a complex-valued weighted least squares estimation to unfold the aliased images. It was recently shown in Bruce et al. [Magn. Reson. Imag. 29(2011):1267–1287] that when the SENSE model is represented in terms of a real-valued isomorphism, it assumes a skew-symmetric covariance between receiver coils, as well as an identity covariance structure between voxels. In this manuscript, we show that not only is the skew-symmetric coil covariance unlike that of real data, but the estimated covariance structure between voxels over a time series of experimental data is not an identity matrix. As such, a new model, entitled SENSE-ITIVE, is described with both revised coil and voxel covariance structures. Both the SENSE and SENSE-ITIVE models are represented in terms of real-valued isomorphisms, allowing for a statistical analysis of reconstructed voxel means, variances, and correlations resulting from the use of different coil and voxel covariance structures used in the reconstruction processes to be conducted. It is shown through both theoretical and experimental illustrations that the miss-specification of the coil and voxel covariance structures in the SENSE model results in a lower standard deviation in each voxel of the reconstructed images, and thus an artificial increase in SNR, compared to the standard deviation and SNR of the SENSE-ITIVE model where both the coil and voxel covariances are appropriately accounted for. It is also shown that there are differences in the correlations induced by the reconstruction operations of both models, and consequently there are differences in the correlations estimated throughout the course of reconstructed time series. These differences in correlations could result in meaningful

A temporal interpolation approach for dynamic reconstruction in perfusion CT

International Nuclear Information System (INIS)

Montes, Pau; Lauritsch, Guenter

2007-01-01

This article presents a dynamic CT reconstruction algorithm for objects with time dependent attenuation coefficient. Projection data acquired over several rotations are interpreted as samples of a continuous signal. Based on this idea, a temporal interpolation approach is proposed which provides the maximum temporal resolution for a given rotational speed of the CT scanner. Interpolation is performed using polynomial splines. The algorithm can be adapted to slow signals, reducing the amount of data acquired and the computational cost. A theoretical analysis of the approximations made by the algorithm is provided. In simulation studies, the temporal interpolation approach is compared with three other dynamic reconstruction algorithms based on linear regression, linear interpolation, and generalized Parker weighting. The presented algorithm exhibits the highest temporal resolution for a given sampling interval. Hence, our approach needs less input data to achieve a certain quality in the reconstruction than the other algorithms discussed or, equivalently, less x-ray exposure and computational complexity. The proposed algorithm additionally allows the possibility of using slow rotating scanners for perfusion imaging purposes

Calibration-free quantitative surface topography reconstruction in scanning electron microscopy

International Nuclear Information System (INIS)

Faber, E.T.; Martinez-Martinez, D.; Mansilla, C.; Ocelík, V.; Hosson, J.Th.M. De

2015-01-01

This work presents a new approach to obtain reliable surface topography reconstructions from 2D Scanning Electron Microscopy (SEM) images. In this method a set of images taken at different tilt angles are compared by means of digital image correlation (DIC). It is argued that the strength of the method lies in the fact that precise knowledge about the nature of the rotation (vector and/or magnitude) is not needed. Therefore, the great advantage is that complex calibrations of the measuring equipment are avoided. The paper presents the necessary equations involved in the methods, including derivations and solutions. The method is illustrated with examples of 3D reconstructions followed by a discussion on the relevant experimental parameters. - Highlights: • A novel method for quantitative 3D surface reconstruction in SEM is described. • This method uses at least 3 SEM images acquired at different sample tilts. • This method does not need calibration from the movement of the sample holder. • Mathematical background and examples of application are presented

X-ray computed tomography reconstruction on non-standard trajectories for robotized inspection

International Nuclear Information System (INIS)

Banjak, Hussein

2016-01-01

The number of industrial applications of computed tomography (CT) is large and rapidly increasing with typical areas of use in the aerospace, automotive and transport industry. To support this growth of CT in the industrial field, the identified requirements concern firstly software development to improve the reconstruction algorithms and secondly the automation of the inspection process. Indeed, the use of robots gives more flexibility in the acquisition trajectory and allows the control of large and complex objects, which cannot be inspected using classical CT systems. In this context of new CT trend, a robotic platform has been installed at CEA LIST to better understand and solve specific challenges linked to the robotization of the CT process. The considered system integrates two robots that move the X-ray generator and detector. This thesis aims at achieving this new development. In particular, the objective is to develop and implement analytical and iterative reconstruction algorithms adapted to such robotized trajectories. The main focus of this thesis is concerned with helical-like scanning trajectories. We consider two main problems that could occur during acquisition process: truncated and limited-angle data. We present in this work experimental results for reconstruction on such non-standard trajectories. CIVA software is used to simulate these complex inspections and our developed algorithms are integrated as reconstruction tools. This thesis contains three parts. In the first part, we introduce the basic principles of CT and we present an overview of existing analytical and iterative algorithms for non-standard trajectories. In the second part, we modify the approximate helical FDK algorithm to deal with transversely truncated data and we propose a modified FDK algorithm adapted to reverse helical trajectory with the scan range less than 360 degrees. For iterative reconstruction, we propose two algebraic methods named SART-FISTA-TV and DART

Fast image reconstruction for Compton camera using stochastic origin ensemble approach.

Science.gov (United States)

Andreyev, Andriy; Sitek, Arkadiusz; Celler, Anna

2011-01-01

Compton camera has been proposed as a potential imaging tool in astronomy, industry, homeland security, and medical diagnostics. Due to the inherent geometrical complexity of Compton camera data, image reconstruction of distributed sources can be ineffective and/or time-consuming when using standard techniques such as filtered backprojection or maximum likelihood-expectation maximization (ML-EM). In this article, the authors demonstrate a fast reconstruction of Compton camera data using a novel stochastic origin ensembles (SOE) approach based on Markov chains. During image reconstruction, the origins of the measured events are randomly assigned to locations on conical surfaces, which are the Compton camera analogs of lines-of-responses in PET. Therefore, the image is defined as an ensemble of origin locations of all possible event origins. During the course of reconstruction, the origins of events are stochastically moved and the acceptance of the new event origin is determined by the predefined acceptance probability, which is proportional to the change in event density. For example, if the event density at the new location is higher than in the previous location, the new position is always accepted. After several iterations, the reconstructed distribution of origins converges to a quasistationary state which can be voxelized and displayed. Comparison with the list-mode ML-EM reveals that the postfiltered SOE algorithm has similar performance in terms of image quality while clearly outperforming ML-EM in relation to reconstruction time. In this study, the authors have implemented and tested a new image reconstruction algorithm for the Compton camera based on the stochastic origin ensembles with Markov chains. The algorithm uses list-mode data, is parallelizable, and can be used for any Compton camera geometry. SOE algorithm clearly outperforms list-mode ML-EM for simple Compton camera geometry in terms of reconstruction time. The difference in computational time

Hierarchical Bayesian sparse image reconstruction with application to MRFM.

Science.gov (United States)

Dobigeon, Nicolas; Hero, Alfred O; Tourneret, Jean-Yves

2009-09-01

This paper presents a hierarchical Bayesian model to reconstruct sparse images when the observations are obtained from linear transformations and corrupted by an additive white Gaussian noise. Our hierarchical Bayes model is well suited to such naturally sparse image applications as it seamlessly accounts for properties such as sparsity and positivity of the image via appropriate Bayes priors. We propose a prior that is based on a weighted mixture of a positive exponential distribution and a mass at zero. The prior has hyperparameters that are tuned automatically by marginalization over the hierarchical Bayesian model. To overcome the complexity of the posterior distribution, a Gibbs sampling strategy is proposed. The Gibbs samples can be used to estimate the image to be recovered, e.g., by maximizing the estimated posterior distribution. In our fully Bayesian approach, the posteriors of all the parameters are available. Thus, our algorithm provides more information than other previously proposed sparse reconstruction methods that only give a point estimate. The performance of the proposed hierarchical Bayesian sparse reconstruction method is illustrated on synthetic data and real data collected from a tobacco virus sample using a prototype MRFM instrument.

A Survey of Orthodontic Treatment in Team Care for Patients With Syndromic Craniosynostosis in Japan.

Science.gov (United States)

Susami, Takafumi; Fukawa, Toshihiko; Miyazaki, Haruyo; Sakamoto, Teruo; Morishita, Tadashi; Sato, Yoshiaki; Kinno, Yoshiaki; Kurata, Kazuyuki; Watanabe, Keiichiro; Asahito, Toshikazu; Saito, Isao

2018-04-01

To understand the actual condition of orthodontic treatment in team care for patients with syndromic craniosynostosis (SCS) in Japan. A nationwide collaborative survey. Twenty-four orthodontic clinics in Japan. A total of 246 patients with SCS. Treatment history was examined based on orthodontic records using common survey sheets. Most patients first visited the orthodontic clinic in the deciduous or mixed dentition phase. Midface advancement was performed without visiting the orthodontic clinic in about a quarter of the patients, and more than a half of the patients underwent "surgery-first" midface advancement. First-phase orthodontic treatment was carried out in about a half of the patients, and maxillary expansion and protraction were performed. Tooth extraction was required in about two-thirds of patients, and the extraction of maxillary teeth was required in most patients. Tooth abnormalities were found in 37.8% of patients, and abnormalities of maxillary molars were frequently (58.3%) found in patients who had undergone midface surgery below the age of 6 years. Many patients underwent "surgery-first" midface advancement, and visiting the orthodontic clinic at least before advancement was considered desirable. First-phase orthodontic treatment should be performed considering the burden of care. Midface advancement below the age of 6 years had a high risk of injury to the maxillary molars. This survey is considered useful for improving orthodontic treatment in team care of patients with SCS.

Permutationally invariant state reconstruction

DEFF Research Database (Denmark)

Moroder, Tobias; Hyllus, Philipp; Tóth, Géza

2012-01-01

Feasible tomography schemes for large particle numbers must possess, besides an appropriate data acquisition protocol, an efficient way to reconstruct the density operator from the observed finite data set. Since state reconstruction typically requires the solution of a nonlinear large-scale opti...... optimization, which has clear advantages regarding speed, control and accuracy in comparison to commonly employed numerical routines. First prototype implementations easily allow reconstruction of a state of 20 qubits in a few minutes on a standard computer.......-scale optimization problem, this is a major challenge in the design of scalable tomography schemes. Here we present an efficient state reconstruction scheme for permutationally invariant quantum state tomography. It works for all common state-of-the-art reconstruction principles, including, in particular, maximum...

Precipitate shape fitting and reconstruction by means of 3D Zernike functions

Science.gov (United States)

Callahan, P. G.; De Graef, M.

2012-01-01

3D Zernike functions are defined and used for the reconstruction of precipitate shapes. These functions are orthogonal over the unit ball and allow for an arbitrary shape, scaled to fit inside an embedding sphere, to be decomposed into 3D harmonics. Explicit expressions are given for the general Zernike moments, correcting typographical errors in the literature. Explicit expressions of the Zernike moments for the ellipsoid and the cube are given. The 3D Zernike functions and moments are applied to the reconstruction of γ' precipitate shapes in two Ni-based superalloys, one with nearly cuboidal precipitate shapes, and one with more complex dendritic shapes.

Precipitate shape fitting and reconstruction by means of 3D Zernike functions

International Nuclear Information System (INIS)

Callahan, P G; De Graef, M

2012-01-01

3D Zernike functions are defined and used for the reconstruction of precipitate shapes. These functions are orthogonal over the unit ball and allow for an arbitrary shape, scaled to fit inside an embedding sphere, to be decomposed into 3D harmonics. Explicit expressions are given for the general Zernike moments, correcting typographical errors in the literature. Explicit expressions of the Zernike moments for the ellipsoid and the cube are given. The 3D Zernike functions and moments are applied to the reconstruction of γ' precipitate shapes in two Ni-based superalloys, one with nearly cuboidal precipitate shapes, and one with more complex dendritic shapes

An innovative method of planning and displaying flap volume in DIEP flap breast reconstructions

NARCIS (Netherlands)

Hummelink, S.L.; Verhulst, A.C.; Maal, T.J.J.; Hoogeveen, Y.L.; Schultze Kool, L.J.; Ulrich, D.J.O.

2017-01-01

BACKGROUND: Determining the ideal volume of the harvested flap to achieve symmetry in deep inferior epigastric artery perforator (DIEP) flap breast reconstructions is complex. With preoperative imaging techniques such as 3D stereophotogrammetry and computed tomography angiography (CTA) available

Outcomes in Anterior Cruciate Ligament Reconstruction Surgery

Directory of Open Access Journals (Sweden)

Roman Mihai

2016-11-01

Full Text Available Improving the outcomes in reconstructive surgery of the anterior cruciate ligament (ACL requires a rigorous and permanent assessment of specific parameters. Therefore, we can increase the degree of reproducibility of the procedure and identify particular aspects in order to achieve an adequate and individualized therapeutic approach for each case. In order to accomplish this goal, the use of complex means (scores of quantifying results is required. That includes objective means of verifying the parameters in knee surgery, and a subjective evaluation of the patient in order to compare the results.

Fast implementations of reconstruction-based scatter compensation in fully 3D SPECT image reconstruction

International Nuclear Information System (INIS)

Kadrmas, Dan J.; Karimi, Seemeen S.; Frey, Eric C.; Tsui, Benjamin M.W.

1998-01-01

Accurate scatter compensation in SPECT can be performed by modelling the scatter response function during the reconstruction process. This method is called reconstruction-based scatter compensation (RBSC). It has been shown that RBSC has a number of advantages over other methods of compensating for scatter, but using RBSC for fully 3D compensation has resulted in prohibitively long reconstruction times. In this work we propose two new methods that can be used in conjunction with existing methods to achieve marked reductions in RBSC reconstruction times. The first method, coarse-grid scatter modelling, significantly accelerates the scatter model by exploiting the fact that scatter is dominated by low-frequency information. The second method, intermittent RBSC, further accelerates the reconstruction process by limiting the number of iterations during which scatter is modelled. The fast implementations were evaluated using a Monte Carlo simulated experiment of the 3D MCAT phantom with 99m Tc tracer, and also using experimentally acquired data with 201 Tl tracer. Results indicated that these fast methods can reconstruct, with fully 3D compensation, images very similar to those obtained using standard RBSC methods, and in reconstruction times that are an order of magnitude shorter. Using these methods, fully 3D iterative reconstruction with RBSC can be performed well within the realm of clinically realistic times (under 10 minutes for 64x64x24 image reconstruction). (author)

Update on orbital reconstruction.

Science.gov (United States)

Chen, Chien-Tzung; Chen, Yu-Ray

2010-08-01

Orbital trauma is common and frequently complicated by ocular injuries. The recent literature on orbital fracture is analyzed with emphasis on epidemiological data assessment, surgical timing, method of approach and reconstruction materials. Computed tomographic (CT) scan has become a routine evaluation tool for orbital trauma, and mobile CT can be applied intraoperatively if necessary. Concomitant serious ocular injury should be carefully evaluated preoperatively. Patients presenting with nonresolving oculocardiac reflex, 'white-eyed' blowout fracture, or diplopia with a positive forced duction test and CT evidence of orbital tissue entrapment require early surgical repair. Otherwise, enophthalmos can be corrected by late surgery with a similar outcome to early surgery. The use of an endoscope-assisted approach for orbital reconstruction continues to grow, offering an alternative method. Advances in alloplastic materials have improved surgical outcome and shortened operating time. In this review of modern orbital reconstruction, several controversial issues such as surgical indication, surgical timing, method of approach and choice of reconstruction material are discussed. Preoperative fine-cut CT image and thorough ophthalmologic examination are key elements to determine surgical indications. The choice of surgical approach and reconstruction materials much depends on the surgeon's experience and the reconstruction area. Prefabricated alloplastic implants together with image software and stereolithographic models are significant advances that help to more accurately reconstruct the traumatized orbit. The recent evolution of orbit reconstruction improves functional and aesthetic results and minimizes surgical complications.

MO-C-18A-01: Advances in Model-Based 3D Image Reconstruction

International Nuclear Information System (INIS)

Chen, G; Pan, X; Stayman, J; Samei, E

2014-01-01

Recent years have seen the emergence of CT image reconstruction techniques that exploit physical models of the imaging system, photon statistics, and even the patient to achieve improved 3D image quality and/or reduction of radiation dose. With numerous advantages in comparison to conventional 3D filtered backprojection, such techniques bring a variety of challenges as well, including: a demanding computational load associated with sophisticated forward models and iterative optimization methods; nonlinearity and nonstationarity in image quality characteristics; a complex dependency on multiple free parameters; and the need to understand how best to incorporate prior information (including patient-specific prior images) within the reconstruction process. The advantages, however, are even greater – for example: improved image quality; reduced dose; robustness to noise and artifacts; task-specific reconstruction protocols; suitability to novel CT imaging platforms and noncircular orbits; and incorporation of known characteristics of the imager and patient that are conventionally discarded. This symposium features experts in 3D image reconstruction, image quality assessment, and the translation of such methods to emerging clinical applications. Dr. Chen will address novel methods for the incorporation of prior information in 3D and 4D CT reconstruction techniques. Dr. Pan will show recent advances in optimization-based reconstruction that enable potential reduction of dose and sampling requirements. Dr. Stayman will describe a “task-based imaging” approach that leverages models of the imaging system and patient in combination with a specification of the imaging task to optimize both the acquisition and reconstruction process. Dr. Samei will describe the development of methods for image quality assessment in such nonlinear reconstruction techniques and the use of these methods to characterize and optimize image quality and dose in a spectrum of clinical

Fully 3-dimensional digitally planned reconstruction of a mandible with a free vascularized fibula and immediate placement of an implant-supported prosthetic construction

NARCIS (Netherlands)

Schepers, Rutger H.; Raghoebar, Gerry M.; Vissink, Arjan; Lahoda, Lars U.; Van der Meer, W. Joerd; Roodenburg, Jan L.; Reintsema, Harry; Witjes, Max J.

Background Reconstruction of craniofacial defects becomes complex when dental implants are included for functional rehabilitation. We describe a fully 3-dimensional (3D) digitally planned reconstruction of a mandible and immediate prosthetic loading with a fibula graft in a 2-step surgical approach.

Photography, between oblivion and reconstruction of the complex of the Messina's Pawnshop

Directory of Open Access Journals (Sweden)

Francesca Fatta

2013-10-01

Full Text Available The Pawnshop palace in Messina, designed by Natale Masuccio and built starting in 1616, was severely damaged by the 1908 earthquake. Currently remains only the facade of the ground floor and some rooms behind. The aim of this research is to introduce some of the computing power in the field of "digital reconstruction of architecture" for documentation, recovery and the "conscious use" of architecture severely degraded or compromised compared to its original configuration. The reading of the monument, intended as a document, has allowed us a comparison between photography and survey to retrace, through operations analysis and breakdown of the parties, the three phases of a project more recognizable to many hands of his long and troubled history.

3D Topography of the Young Adult Anal Sphincter Complex Reconstructed from Undeformed Serial Anatomical Sections

NARCIS (Netherlands)

Wu, Yi; Dabhoiwala, Noshir F.; Hagoort, Jaco; Shan, Jin-Lu; Tan, Li-Wen; Fang, Bin-Ji; Zhang, Shao-Xiang; Lamers, Wouter H.

2015-01-01

Pelvic-floor anatomy is usually studied by artifact-prone dissection or imaging, which requires prior anatomical knowledge. We used the serial-section approach to settle contentious issues and an interactive 3D-pdf to make the results widely accessible. 3D reconstructions of undeformed thin serial

Combination of Complex-Based and Magnitude-Based Multiecho Water-Fat Separation for Accurate Quantification of Fat-Fraction

Science.gov (United States)

Yu, Huanzhou; Shimakawa, Ann; Hines, Catherine D. G.; McKenzie, Charles A.; Hamilton, Gavin; Sirlin, Claude B.; Brittain, Jean H.; Reeder, Scott B.

2011-01-01

Multipoint water–fat separation techniques rely on different water–fat phase shifts generated at multiple echo times to decompose water and fat. Therefore, these methods require complex source images and allow unambiguous separation of water and fat signals. However, complex-based water–fat separation methods are sensitive to phase errors in the source images, which may lead to clinically important errors. An alternative approach to quantify fat is through “magnitude-based” methods that acquire multiecho magnitude images. Magnitude-based methods are insensitive to phase errors, but cannot estimate fat-fraction greater than 50%. In this work, we introduce a water–fat separation approach that combines the strengths of both complex and magnitude reconstruction algorithms. A magnitude-based reconstruction is applied after complex-based water–fat separation to removes the effect of phase errors. The results from the two reconstructions are then combined. We demonstrate that using this hybrid method, 0–100% fat-fraction can be estimated with improved accuracy at low fat-fractions. PMID:21695724

Implementation techniques and acceleration of DBPF reconstruction algorithm based on GPGPU for helical cone beam CT

International Nuclear Information System (INIS)

Shen Le; Xing Yuxiang

2010-01-01

The derivative back-projection filtered algorithm for a helical cone-beam CT is a newly developed exact reconstruction method. Due to its large computational complexity, the reconstruction is rather slow for practical use. General purpose graphic processing unit (GPGPU) is an SIMD paralleled hardware architecture with powerful float-point operation capacity. In this paper,we propose a new method for PI-line choice and sampling grid, and a paralleled PI-line reconstruction algorithm implemented on NVIDIA's Compute Unified Device Architecture (CUDA). Numerical simulation studies are carried out to validate our method. Compared with conventional CPU implementation, the CUDA accelerated method provides images of the same quality with a speedup factor of 318. Optimization strategies for the GPU acceleration are presented. Finally, influence of the parameters of the PI-line samples on the reconstruction speed and image quality is discussed. (authors)

Automatic reconstruction of fault networks from seismicity catalogs including location uncertainty

International Nuclear Information System (INIS)

Wang, Y.

2013-01-01

provide the best agreement with independently observed focal mechanisms. Tests on synthetic catalogues allow qualification of the performance of the fitting method and of the various validation procedures. The ACLUD method is able to provide solutions that are close to the expected ones, especially for the BIC and focal mechanism-based techniques. The clustering method complemented by the validation step based on focal mechanisms provides good solutions even in the presence of a significant spatial background seismicity rate. As the new clustering method is able to deal with most of the information contained in modern earthquake catalogues, the geometry of the local station network may improve or alter the reconstruction of the underlying fault system. This is illustrated by using the highest-quality data selected using station network criteria which results in reconstructed fault planes of higher quality and accuracy. Using lower-quality data can lead to unstable and unreliable fault networks and may introduce artefacts, in particular in regions of a complex fault structure. The results highlight the need to carefully assess the quality and reliability of reconstructed fault networks from real data that unavoidably involve the clustering of data of heterogeneous quality. Based on realistic tests with synthetic fault network structures, the results also stress the importance of accounting for under-sampled sub-fault structures as well as for spatially-inhomogeneous location uncertainties. The fault reconstruction method is applied to two real datasets at two very different spatial scales, i.e. the 1992 Landers M7 earthquake sequence in Southern California, and the Basel (Switzerland) induced seismicity sequence. In both case studies, fault network results reasonably compare with independent structural analysis data, suggesting highly complex fault structures for both, at the scale of the Landers earthquake covering a volume of about 70,000 km 3 and in the volume of the

Automatic reconstruction of fault networks from seismicity catalogs including location uncertainty

Energy Technology Data Exchange (ETDEWEB)

Wang, Y.

2013-07-01

provide the best agreement with independently observed focal mechanisms. Tests on synthetic catalogues allow qualification of the performance of the fitting method and of the various validation procedures. The ACLUD method is able to provide solutions that are close to the expected ones, especially for the BIC and focal mechanism-based techniques. The clustering method complemented by the validation step based on focal mechanisms provides good solutions even in the presence of a significant spatial background seismicity rate. As the new clustering method is able to deal with most of the information contained in modern earthquake catalogues, the geometry of the local station network may improve or alter the reconstruction of the underlying fault system. This is illustrated by using the highest-quality data selected using station network criteria which results in reconstructed fault planes of higher quality and accuracy. Using lower-quality data can lead to unstable and unreliable fault networks and may introduce artefacts, in particular in regions of a complex fault structure. The results highlight the need to carefully assess the quality and reliability of reconstructed fault networks from real data that unavoidably involve the clustering of data of heterogeneous quality. Based on realistic tests with synthetic fault network structures, the results also stress the importance of accounting for under-sampled sub-fault structures as well as for spatially-inhomogeneous location uncertainties. The fault reconstruction method is applied to two real datasets at two very different spatial scales, i.e. the 1992 Landers M7 earthquake sequence in Southern California, and the Basel (Switzerland) induced seismicity sequence. In both case studies, fault network results reasonably compare with independent structural analysis data, suggesting highly complex fault structures for both, at the scale of the Landers earthquake covering a volume of about 70,000 km{sup 3} and in the volume of

Post-disaster housing reconstruction: Perspectives of the NGO and local authorities on delay issues

Science.gov (United States)

Khalid, Khairin Norhashidah; Nifa, Faizatul Akmar Abdul; Ismail, Risyawati Mohamed; Lin, Chong Khai

2016-08-01

Post disaster reconstruction is complex, dynamic and chaotic in nature and as such represents many challenges because it is unlike normal construction. However, the time scale of reconstruction is shorter than the normal construction, but it often deals with uncertainties and the scale of the construction activities required is relatively high. After a disaster impacts a country, many governments, institutions and aid organizations cooperate and involved with the reconstruction process. This is seen as a tool for applying policies and programs designed to remedy the weakness in developmental policies, infrastructure and institutional arrangements. This paper reports a part of an on-going research on post-disaster housing reconstruction in Malaysia. An extensive literature review and pilot interviews were undertaken to establish the factors that contribute to the delay in post-disaster reconstruction project. Accordingly, this paper takes the perspective of recovery from non-government organization (NGO) and local authorities which act as providers of social services, builders of infrastructure, regulators of economic activity and managers of the natural environment. As a result, it is important on how those decisions are made, who is involved in the decision-making, and what are the consequences of this decision.

Identify the Rotating Stall in Centrifugal Compressors by Fractal Dimension in Reconstructed Phase Space

Directory of Open Access Journals (Sweden)

Le Wang

2015-11-01

Full Text Available Based on phase space reconstruction and fractal dynamics in nonlinear dynamics, a method is proposed to extract and analyze the dynamics of the rotating stall in the impeller of centrifugal compressor, and some numerical examples are given to verify the results as well. First, the rotating stall of an existing low speed centrifugal compressor (LSCC is numerically simulated, and the time series of pressure in the rotating stall is obtained at various locations near the impeller outlet. Then, the phase space reconstruction is applied to these pressure time series, and a low-dimensional dynamical system, which the dynamics properties are included in, is reconstructed. In phase space reconstruction, C–C method is used to obtain the key parameters, such as time delay and the embedding dimension of the reconstructed phase space. Further, the fractal characteristics of the rotating stall are analyzed in detail, and the fractal dimensions are given for some examples to measure the complexity of the flow in the post-rotating stall. The results show that the fractal structures could reveal the intrinsic dynamics of the rotating stall flow and could be considered as a characteristic to identify the rotating stall.

Comparing and improving reconstruction methods for proxies based on compositional data

Science.gov (United States)

Nolan, C.; Tipton, J.; Booth, R.; Jackson, S. T.; Hooten, M.

2017-12-01

Many types of studies in paleoclimatology and paleoecology involve compositional data. Often, these studies aim to use compositional data to reconstruct an environmental variable of interest; the reconstruction is usually done via the development of a transfer function. Transfer functions have been developed using many different methods. Existing methods tend to relate the compositional data and the reconstruction target in very simple ways. Additionally, the results from different methods are rarely compared. Here we seek to address these two issues. First, we introduce a new hierarchical Bayesian multivariate gaussian process model; this model allows for the relationship between each species in the compositional dataset and the environmental variable to be modeled in a way that captures the underlying complexities. Then, we compare this new method to machine learning techniques and commonly used existing methods. The comparisons are based on reconstructing the water table depth history of Caribou Bog (an ombrotrophic Sphagnum peat bog in Old Town, Maine, USA) from a new 7500 year long record of testate amoebae assemblages. The resulting reconstructions from different methods diverge in both their resulting means and uncertainties. In particular, uncertainty tends to be drastically underestimated by some common methods. These results will help to improve inference of water table depth from testate amoebae. Furthermore, this approach can be applied to test and improve inferences of past environmental conditions from a broad array of paleo-proxies based on compositional data

A Phase Current Reconstruction Approach for Three-Phase Permanent-Magnet Synchronous Motor Drive

Directory of Open Access Journals (Sweden)

Hao Yan

2016-10-01

Full Text Available Three-phase permanent-magnet synchronous motors (PMSMs are widely used in renewable energy applications such as wind power generation, tidal energy and electric vehicles owing to their merits such as high efficiency, high precision and high reliability. To reduce the cost and volume of the drive system, techniques of reconstructing three-phase current using a single current sensor have been reported for three-phase alternating current (AC control system using the power converts. In existing studies, the reconstruction precision is largely influenced by reconstructing dead zones on the Space Vector Pulse Width Modulation (SVPWM plane, which requires other algorithms to compensate either by modifying PWM modulation or by phase-shifting of the PWM signal. In this paper, a novel extended phase current reconstruction approach for PMSM drive is proposed. Six novel installation positions are obtained by analyzing the sampling results of the current paths between each two power switches. By arranging the single current sensor at these positions, the single current sensor is sampled during zero voltage vectors (ZVV without modifying the PWM signals. This proposed method can reconstruct the three-phase currents without any complex algorithms and is available in the sector boundary region and low modulation region. Finally, this method is validated by experiments.

Incomplete projection reconstruction of computed tomography based on the modified discrete algebraic reconstruction technique

Science.gov (United States)

Yang, Fuqiang; Zhang, Dinghua; Huang, Kuidong; Gao, Zongzhao; Yang, YaFei

2018-02-01

Based on the discrete algebraic reconstruction technique (DART), this study aims to address and test a new improved algorithm applied to incomplete projection data to generate a high quality reconstruction image by reducing the artifacts and noise in computed tomography. For the incomplete projections, an augmented Lagrangian based on compressed sensing is first used in the initial reconstruction for segmentation of the DART to get higher contrast graphics for boundary and non-boundary pixels. Then, the block matching 3D filtering operator was used to suppress the noise and to improve the gray distribution of the reconstructed image. Finally, simulation studies on the polychromatic spectrum were performed to test the performance of the new algorithm. Study results show a significant improvement in the signal-to-noise ratios (SNRs) and average gradients (AGs) of the images reconstructed from incomplete data. The SNRs and AGs of the new images reconstructed by DART-ALBM were on average 30%-40% and 10% higher than the images reconstructed by DART algorithms. Since the improved DART-ALBM algorithm has a better robustness to limited-view reconstruction, which not only makes the edge of the image clear but also makes the gray distribution of non-boundary pixels better, it has the potential to improve image quality from incomplete projections or sparse projections.

Source coding for transmission of reconstructed dynamic geometry: a rate-distortion-complexity analysis of different approaches

NARCIS (Netherlands)

R.N. Mekuria (Rufael); P.S. Cesar Garcia (Pablo Santiago); D.C.A. Bulterman (Dick)

2014-01-01

htmlabstractLive 3D reconstruction of a human as a 3D mesh with commodity electronics is becoming a reality. Immersive applications (i.e. cloud gaming, tele-presence) benefit from effective transmission of such content over a bandwidth limited link. In this paper we outline different approaches for

A maximum entropy reconstruction technique for tomographic particle image velocimetry

International Nuclear Information System (INIS)

Bilsky, A V; Lozhkin, V A; Markovich, D M; Tokarev, M P

2013-01-01

This paper studies a novel approach for reducing tomographic PIV computational complexity. The proposed approach is an algebraic reconstruction technique, termed MENT (maximum entropy). This technique computes the three-dimensional light intensity distribution several times faster than SMART, using at least ten times less memory. Additionally, the reconstruction quality remains nearly the same as with SMART. This paper presents the theoretical computation performance comparison for MENT, SMART and MART, followed by validation using synthetic particle images. Both the theoretical assessment and validation of synthetic images demonstrate significant computational time reduction. The data processing accuracy of MENT was compared to that of SMART in a slot jet experiment. A comparison of the average velocity profiles shows a high level of agreement between the results obtained with MENT and those obtained with SMART. (paper)

Reconstructive options in pelvic tumours

Directory of Open Access Journals (Sweden)

Mayilvahanan N

2005-01-01

Full Text Available Background: Pelvic tumours present a complex problem. It is difficult to choose between limb salvage and hemipelvectomy. Method: Forty three patients of tumours of pelvis underwent limb salvage resection with reconstruction in 32 patients. The majority were chondrosarcomas (20 cases followed by Ewing sarcoma. Stage II B was the most common stage in malignant lesions and all the seven benign lesions were aggressive (B3. Surgical margins achieved were wide in 31 and marginal in 12 cases. Ilium was involved in 51% of cases and periacetabular involvement was seen in 12 patients. The resections done were mostly of types I &II of Enneking′s classification of pelvic resection. Arthrodesis was attempted in 24 patients. Customized Saddle prosthesis was used in seven patients and no reconstruction in 12 patients. Adjuvant chemotherapy was given to all high-grade malignant tumours, combined with radiotherapy in 7 patients. Results: With a mean follow up of 48.5 months and one patient lost to follow up, the recurrence rate among the evaluated cases was 16.6%. Oncologically, 30 patients were continuously disease free with 7 local recurrences and 4 deaths due to disseminated disease and 2 patients died of other causes. During the initial years, satisfactory functional results were achieved with prosthetic replacement. Long-term functional result of 36 patients who were alive at the time of latest follow up was satisfactory in 75% who underwent arthrodesis and in those where no reconstruction was used. We also describe a method of new classification of pelvic resections that clarifies certain shortcomings of the previous systems of classification. Conclusion: Selection of a procedure depends largely on the patient factors, the tumour grade, the resultant defect and the tissue factors. Resection with proper margins gives better functional and oncological results

BES-II fast data reconstruction

International Nuclear Information System (INIS)

Rong Gang; Zhang Jiawen; Guo Yiqing; Zhang Shaoqiang; Zhao Dixin

2002-01-01

The BES-II fast data reconstruction is reported. Based on PC FARM and/or a 'Distributed Clustered Linux PC System', BES-II fast data reconstruction system is set up. With this system the BES-II data can be fully reconstructed in about 20 minutes after data collection. It takes only 12 minutes to fully reconstruct 30000 events, collected with BES-II detector at BEPC Collider, with a P III-800 PC. The detector performance can be examined based on fully reconstructed data in about 20 minutes after data taking in the BES-II experiment

Level-set reconstruction algorithm for ultrafast limited-angle X-ray computed tomography of two-phase flows.

Science.gov (United States)

Bieberle, M; Hampel, U

2015-06-13

Tomographic image reconstruction is based on recovering an object distribution from its projections, which have been acquired from all angular views around the object. If the angular range is limited to less than 180° of parallel projections, typical reconstruction artefacts arise when using standard algorithms. To compensate for this, specialized algorithms using a priori information about the object need to be applied. The application behind this work is ultrafast limited-angle X-ray computed tomography of two-phase flows. Here, only a binary distribution of the two phases needs to be reconstructed, which reduces the complexity of the inverse problem. To solve it, a new reconstruction algorithm (LSR) based on the level-set method is proposed. It includes one force function term accounting for matching the projection data and one incorporating a curvature-dependent smoothing of the phase boundary. The algorithm has been validated using simulated as well as measured projections of known structures, and its performance has been compared to the algebraic reconstruction technique and a binary derivative of it. The validation as well as the application of the level-set reconstruction on a dynamic two-phase flow demonstrated its applicability and its advantages over other reconstruction algorithms. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

A wavelet-based regularized reconstruction algorithm for SENSE parallel MRI with applications to neuroimaging

International Nuclear Information System (INIS)

Chaari, L.; Pesquet, J.Ch.; Chaari, L.; Ciuciu, Ph.; Benazza-Benyahia, A.

2011-01-01

To reduce scanning time and/or improve spatial/temporal resolution in some Magnetic Resonance Imaging (MRI) applications, parallel MRI acquisition techniques with multiple coils acquisition have emerged since the early 1990's as powerful imaging methods that allow a faster acquisition process. In these techniques, the full FOV image has to be reconstructed from the resulting acquired under sampled k-space data. To this end, several reconstruction techniques have been proposed such as the widely-used Sensitivity Encoding (SENSE) method. However, the reconstructed image generally presents artifacts when perturbations occur in both the measured data and the estimated coil sensitivity profiles. In this paper, we aim at achieving accurate image reconstruction under degraded experimental conditions (low magnetic field and high reduction factor), in which neither the SENSE method nor the Tikhonov regularization in the image domain give convincing results. To this end, we present a novel method for SENSE-based reconstruction which proceeds with regularization in the complex wavelet domain by promoting sparsity. The proposed approach relies on a fast algorithm that enables the minimization of regularized non-differentiable criteria including more general penalties than a classical l 1 term. To further enhance the reconstructed image quality, local convex constraints are added to the regularization process. In vivo human brain experiments carried out on Gradient-Echo (GRE) anatomical and Echo Planar Imaging (EPI) functional MRI data at 1.5 T indicate that our algorithm provides reconstructed images with reduced artifacts for high reduction factors. (authors)

Promising Technique for Facial Nerve Reconstruction in Extended Parotidectomy

Directory of Open Access Journals (Sweden)

Ithzel Maria Villarreal

2015-11-01

Full Text Available Introduction: Malignant tumors of the parotid gland account scarcely for 5% of all head and neck tumors. Most of these neoplasms have a high tendency for recurrence, local infiltration, perineural extension, and metastasis. Although uncommon, these malignant tumors require complex surgical treatment sometimes involving a total parotidectomy including a complete facial nerve resection. Severe functional and aesthetic facial defects are the result of a complete sacrifice or injury to isolated branches becoming an uncomfortable distress for patients and a major challenge for reconstructive surgeons.   Case Report: A case of a 54-year-old, systemically healthy male patient with a 4 month complaint of pain and swelling on the right side of the face is presented. The patient reported a rapid increase in the size of the lesion over the past 2 months. Imaging tests and histopathological analysis reported an adenoid cystic carcinoma. A complete parotidectomy was carried out with an intraoperative notice of facial nerve infiltration requiring a second intervention for nerve and defect reconstruction. A free ALT flap with vascularized nerve grafts was the surgical choice. A 6 month follow-up showed partial facial movement recovery and the facial defect mended.   Conclusion:  It is of critical importance to restore function to patients with facial nerve injury.  Vascularized nerve grafts, in many clinical and experimental studies, have shown to result in better nerve regeneration than conventional non-vascularized nerve grafts. Nevertheless, there are factors that may affect the degree, speed and regeneration rate regarding the free fasciocutaneous flap. In complex head and neck defects following a total parotidectomy, the extended free fasciocutaneous ALT (anterior-lateral thigh flap with a vascularized nerve graft is ideally suited for the reconstruction of the injured site.  Donor–site morbidity is low and additional surgical time is minimal

Promising Technique for Facial Nerve Reconstruction in Extended Parotidectomy.

Science.gov (United States)

Villarreal, Ithzel Maria; Rodríguez-Valiente, Antonio; Castelló, Jose Ramon; Górriz, Carmen; Montero, Oscar Alvarez; García-Berrocal, Jose Ramon

2015-11-01

Malignant tumors of the parotid gland account scarcely for 5% of all head and neck tumors. Most of these neoplasms have a high tendency for recurrence, local infiltration, perineural extension, and metastasis. Although uncommon, these malignant tumors require complex surgical treatment sometimes involving a total parotidectomy including a complete facial nerve resection. Severe functional and aesthetic facial defects are the result of a complete sacrifice or injury to isolated branches becoming an uncomfortable distress for patients and a major challenge for reconstructive surgeons. A case of a 54-year-old, systemically healthy male patient with a 4 month complaint of pain and swelling on the right side of the face is presented. The patient reported a rapid increase in the size of the lesion over the past 2 months. Imaging tests and histopathological analysis reported an adenoid cystic carcinoma. A complete parotidectomy was carried out with an intraoperative notice of facial nerve infiltration requiring a second intervention for nerve and defect reconstruction. A free ALT flap with vascularized nerve grafts was the surgical choice. A 6 month follow-up showed partial facial movement recovery and the facial defect mended. It is of critical importance to restore function to patients with facial nerve injury. Vascularized nerve grafts, in many clinical and experimental studies, have shown to result in better nerve regeneration than conventional non-vascularized nerve grafts. Nevertheless, there are factors that may affect the degree, speed and regeneration rate regarding the free fasciocutaneous flap. In complex head and neck defects following a total parotidectomy, the extended free fasciocutaneous ALT (anterior-lateral thigh) flap with a vascularized nerve graft is ideally suited for the reconstruction of the injured site. Donor-site morbidity is low and additional surgical time is minimal compared with the time of a single ALT flap transfer.

How do precision medicine and system biology response to human body's complex adaptability?

Science.gov (United States)

Yuan, Bing

2016-12-01

In the field of life sciences, although system biology and "precision medicine" introduce some complex scientifific methods and techniques, it is still based on the "analysis-reconstruction" of reductionist theory as a whole. Adaptability of complex system increase system behaviour uncertainty as well as the difficulties of precise identifification and control. It also put systems biology research into trouble. To grasp the behaviour and characteristics of organism fundamentally, systems biology has to abandon the "analysis-reconstruction" concept. In accordance with the guidelines of complexity science, systems biology should build organism model from holistic level, just like the Chinese medicine did in dealing with human body and disease. When we study the living body from the holistic level, we will fifind the adaptability of complex system is not the obstacle that increases the diffificulty of problem solving. It is the "exceptional", "right-hand man" that helping us to deal with the complexity of life more effectively.

Precise signal amplitude retrieval for a non-homogeneous diagnostic beam using complex interferometry approach

Science.gov (United States)

Krupka, M.; Kalal, M.; Dostal, J.; Dudzak, R.; Juha, L.

2017-08-01

Classical interferometry became widely used method of active optical diagnostics. Its more advanced version, allowing reconstruction of three sets of data from just one especially designed interferogram (so called complex interferogram) was developed in the past and became known as complex interferometry. Along with the phase shift, which can be also retrieved using classical interferometry, the amplitude modifications of the probing part of the diagnostic beam caused by the object under study (to be called the signal amplitude) as well as the contrast of the interference fringes can be retrieved using the complex interferometry approach. In order to partially compensate for errors in the reconstruction due to imperfections in the diagnostic beam intensity structure as well as for errors caused by a non-ideal optical setup of the interferometer itself (including the quality of its optical components), a reference interferogram can be put to a good use. This method of interferogram analysis of experimental data has been successfully implemented in practice. However, in majority of interferometer setups (especially in the case of the ones employing the wavefront division) the probe and the reference part of the diagnostic beam would feature different intensity distributions over their respective cross sections. This introduces additional error into the reconstruction of the signal amplitude and the fringe contrast, which cannot be resolved using the reference interferogram only. In order to deal with this error it was found that additional separately recorded images of the intensity distribution of the probe and the reference part of the diagnostic beam (with no signal present) are needed. For the best results a sufficient shot-to-shot stability of the whole diagnostic system is required. In this paper, efficiency of the complex interferometry approach for obtaining the highest possible accuracy of the signal amplitude reconstruction is verified using the computer

ORGANIZATIONAL STRUCTURE FOR BUILDINGS RECONSTRUCTION OF HISTORICAL BUILDING OF ODESSA

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POSTERNAK I. М.

2016-12-01

Full Text Available Formulation of the problem. As one of perspective forms of integration various complexes act in town-planning structure. In the course of formation of plans of social and economic development of large cities even more often there is a situation when for increase of efficiency of used resources concentration of efforts is necessary not simply, but also new progressive forms of the organization of building manufacture. Purpose. To offer the organizational structure using in practice the saved up scientific and technical potential for reconstruction of buildings of historical building of Odessa 1820 … 1920 years under standards power efficiency and to execute researches engineering architectonics residential buildings of historical building of a city of Odessa. Conclusion. It is offered to create in the city of Odessa "the Corporate scientific and technical complex town-planning power reconstruction "CSTC T-PPR", as innovative organizational structure which uses in practice the saved up scientific and technical potential for reconstruction of buildings of historical building of Odessa under standards power efficiency. It is considered engineering architectonics residential buildings of historical building of a city of Odessa, in particular, not looking on diverse buildings of inhabited appointment of Odessa, for them there are defining factors on which probably to make their grouping and at the same time to allocate the general lines inherent to a housing estate as a whole. It is resulted a general characteristic and classification of residential buildings of historical building of a city of Odessa ХІХ … beginnings ХХ centuries It is allocated and expanded classification of such buildings of inhabited appointment by duration of residing at them.

ORGANIZATIONAL STRUCTURE FOR RECONSTRUCTION OF BUILDINGS HISTORICAL BUILDING OF ODESSA

Directory of Open Access Journals (Sweden)

POSTERNAK I. М.

2017-05-01

Full Text Available Summary. Raising of problem. As one of perspective forms of integration various complexes act in town- planning structure. In the course of formation of plans of social and economic development of large cities even more often there is a situation when for increase of efficiency of used resources concentration of efforts is necessary not simply, but also new progressive forms of the organization of building manufacture. Purpose. To offer the organizational structure using in practice the saved up scientific and technical potential for reconstruction of buildings of historical building of Odessa 1820 … 1920 years under standards power efficiency and to execute researches engineering architectonics residential buildings of historical building of a city of Odessa. Conclusion. It is offered to create in the city of Odessa "the Corporate scientific and technical complex town-planning power reconstruction "CSTC T-PPR", as innovative organizational structure which uses in practice the saved up scientific and technical potential for reconstruction of buildings of historical building of Odessa under standards power efficiency. It is considered engineering architectonics residential buildings of historical building of a city of Odessa, in particular, not looking on diverse buildings of inhabited appointment of Odessa, for them there are defining factors on which probably to make their grouping and at the same time to allocate the general lines inherent to a housing estate as a whole. It is resulted a general characteristic and classification of residential buildings of historical building of a city of Odessa ХІХ beginnings ХХ centuries It is allocated and expanded classification of such buildings of inhabited appointment by duration of residing at them.

Local System Matrix Compression for Efficient Reconstruction in Magnetic Particle Imaging

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T. Knopp

2015-01-01

Full Text Available Magnetic particle imaging (MPI is a quantitative method for determining the spatial distribution of magnetic nanoparticles, which can be used as tracers for cardiovascular imaging. For reconstructing a spatial map of the particle distribution, the system matrix describing the magnetic particle imaging equation has to be known. Due to the complex dynamic behavior of the magnetic particles, the system matrix is commonly measured in a calibration procedure. In order to speed up the reconstruction process, recently, a matrix compression technique has been proposed that makes use of a basis transformation in order to compress the MPI system matrix. By thresholding the resulting matrix and storing the remaining entries in compressed row storage format, only a fraction of the data has to be processed when reconstructing the particle distribution. In the present work, it is shown that the image quality of the algorithm can be considerably improved by using a local threshold for each matrix row instead of a global threshold for the entire system matrix.

RECONSTRUCTION OF CALCINED Zn -Al LAYERED DOUBLE HYDROXIDES DURING TETRACYCLINE ADSORPSION

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G. M. Starukh

2015-12-01

Full Text Available Zn-Al mixed oxides containing ZnO different degree crystallinity were obtained by calcinations of Zn-Al layered double hydroxides (LDHs. The reconstruction of calcined Zn-Al LDHs has been performed under stirring in aqueous suspensions. The assynthesized LDHs, its decomposition products, as well as the reconstructed solids upon hydration were characterized by XRD, N2adsorption, differential and thermal gravimetric analysis. It was found that the ability of Zn-Al LDHs to recover a layered structure under the hydration of mixed oxides depends on the degree of ZnO crystallinity. The partial reconstruction of Zn-Al layered structure occurs in tetracycline solutions irrespective to the degree of ZnO crystallinity in calcined LDHs. Calcined Zn-Al LDHs demonstrate the higher adsorption capacity to tetracycline in comparison with as-prepared Zn-Al LDHs. The adsorption of TC on calcined and uncalcined ZnAl LDHs occurs on the centers of one particular type. It is suggested that surface complexation of the A-ring ligand of TC with Al-OH centers takes place.

A Case Series of Rapid Prototyping and Intraoperative Imaging in Orbital Reconstruction

Science.gov (United States)

Lim, Christopher G.T.; Campbell, Duncan I.; Cook, Nicholas; Erasmus, Jason

2014-01-01

In Christchurch Hospital, rapid prototyping (RP) and intraoperative imaging are the standard of care in orbital trauma and has been used since February 2013. RP allows the fabrication of an anatomical model to visualize complex anatomical structures which is dimensionally accurate and cost effective. This assists diagnosis, planning, and preoperative implant adaptation for orbital reconstruction. Intraoperative imaging involves a computed tomography scan during surgery to evaluate surgical implants and restored anatomy and allows the clinician to correct errors in implant positioning that may occur during the same procedure. This article aims to demonstrate the potential clinical and cost saving benefits when both these technologies are used in orbital reconstruction which minimize the need for revision surgery. PMID:26000080

A case series of rapid prototyping and intraoperative imaging in orbital reconstruction.

Science.gov (United States)

Lim, Christopher G T; Campbell, Duncan I; Cook, Nicholas; Erasmus, Jason

2015-06-01

In Christchurch Hospital, rapid prototyping (RP) and intraoperative imaging are the standard of care in orbital trauma and has been used since February 2013. RP allows the fabrication of an anatomical model to visualize complex anatomical structures which is dimensionally accurate and cost effective. This assists diagnosis, planning, and preoperative implant adaptation for orbital reconstruction. Intraoperative imaging involves a computed tomography scan during surgery to evaluate surgical implants and restored anatomy and allows the clinician to correct errors in implant positioning that may occur during the same procedure. This article aims to demonstrate the potential clinical and cost saving benefits when both these technologies are used in orbital reconstruction which minimize the need for revision surgery.

Perioperative care following complex laryngotracheal reconstruction in infants and children

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Gupta Punkaj

2010-01-01

Full Text Available Laryngotracheal reconstruction (LTR involves surgical correction of a stenotic airway with cartilage interpositional grafting, followed by either placement of a tracheostomy and an intraluminal stent (two-stage LTR or placement of an endotracheal tube with postoperative sedation and mechanical ventilation for an extended period of time (single-stage LTR. With single-stage repair, there may be several perioperative challenges including the provision of adequate sedation, avoidance of the development of tolerance to sedative and analgesia agents, the need to use neuromuscular blocking agents, the maintenance of adequate pulmonary toilet to avoid perioperative nosocomial infections, and optimization of postoperative respiratory function to facilitate successful tracheal extubation. We review the perioperative management of these patients, discuss the challenges during the postoperative period, and propose recommendations for the prevention of reversible causes of extubation failure in this article. Optimization to ensure a timely tracheal extubation and successful weaning of mechanical ventilator, remains the primary key to success in these surgeries as extubation failure or the need for prolonged postoperative mechanical ventilation can lead to failure of the graft site, the need for prolonged Pediatric Intensive Care Unit care, and in some cases, the need for a tracheostomy to maintain an adequate airway.

Hybrid spectral CT reconstruction.

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Darin P Clark

Full Text Available Current photon counting x-ray detector (PCD technology faces limitations associated with spectral fidelity and photon starvation. One strategy for addressing these limitations is to supplement PCD data with high-resolution, low-noise data acquired with an energy-integrating detector (EID. In this work, we propose an iterative, hybrid reconstruction technique which combines the spectral properties of PCD data with the resolution and signal-to-noise characteristics of EID data. Our hybrid reconstruction technique is based on an algebraic model of data fidelity which substitutes the EID data into the data fidelity term associated with the PCD reconstruction, resulting in a joint reconstruction problem. Within the split Bregman framework, these data fidelity constraints are minimized subject to additional constraints on spectral rank and on joint intensity-gradient sparsity measured between the reconstructions of the EID and PCD data. Following a derivation of the proposed technique, we apply it to the reconstruction of a digital phantom which contains realistic concentrations of iodine, barium, and calcium encountered in small-animal micro-CT. The results of this experiment suggest reliable separation and detection of iodine at concentrations ≥ 5 mg/ml and barium at concentrations ≥ 10 mg/ml in 2-mm features for EID and PCD data reconstructed with inherent spatial resolutions of 176 μm and 254 μm, respectively (point spread function, FWHM. Furthermore, hybrid reconstruction is demonstrated to enhance spatial resolution within material decomposition results and to improve low-contrast detectability by as much as 2.6 times relative to reconstruction with PCD data only. The parameters of the simulation experiment are based on an in vivo micro-CT experiment conducted in a mouse model of soft-tissue sarcoma. Material decomposition results produced from this in vivo data demonstrate the feasibility of distinguishing two K-edge contrast agents with

Hybrid spectral CT reconstruction

Science.gov (United States)

Clark, Darin P.

2017-01-01

Current photon counting x-ray detector (PCD) technology faces limitations associated with spectral fidelity and photon starvation. One strategy for addressing these limitations is to supplement PCD data with high-resolution, low-noise data acquired with an energy-integrating detector (EID). In this work, we propose an iterative, hybrid reconstruction technique which combines the spectral properties of PCD data with the resolution and signal-to-noise characteristics of EID data. Our hybrid reconstruction technique is based on an algebraic model of data fidelity which substitutes the EID data into the data fidelity term associated with the PCD reconstruction, resulting in a joint reconstruction problem. Within the split Bregman framework, these data fidelity constraints are minimized subject to additional constraints on spectral rank and on joint intensity-gradient sparsity measured between the reconstructions of the EID and PCD data. Following a derivation of the proposed technique, we apply it to the reconstruction of a digital phantom which contains realistic concentrations of iodine, barium, and calcium encountered in small-animal micro-CT. The results of this experiment suggest reliable separation and detection of iodine at concentrations ≥ 5 mg/ml and barium at concentrations ≥ 10 mg/ml in 2-mm features for EID and PCD data reconstructed with inherent spatial resolutions of 176 μm and 254 μm, respectively (point spread function, FWHM). Furthermore, hybrid reconstruction is demonstrated to enhance spatial resolution within material decomposition results and to improve low-contrast detectability by as much as 2.6 times relative to reconstruction with PCD data only. The parameters of the simulation experiment are based on an in vivo micro-CT experiment conducted in a mouse model of soft-tissue sarcoma. Material decomposition results produced from this in vivo data demonstrate the feasibility of distinguishing two K-edge contrast agents with a spectral

Cloacal reconstruction after a complex treatment of perineal haemangioma in a variant of PELVIS syndrome

OpenAIRE

Žalimas, Algirdas; Pošiūnas, Gintas; Strupas, Sigitas; Raugalas, Ramūnas; Raistenskis, Juozas; Verkauskas, Gilvydas

2015-01-01

Background PELVIS is an acronym defining the association of perineal hemangioma, malformations of external genitalia, lipomyelomeningocele, vesicorenal abnormalities, imperforate anus and skin tag. Eleven cases have been reported according to the Orphanet data. Acronyms of LUMBAR and SACRAL syndrome have been used and most probably represent a spectrum of the same entity. Very little is known about the success and timing of cloacal reconstruction after the treatment of hemangioma. We present ...

Le Fort III Distraction With Internal vs External Distractors: A Cephalometric Analysis.

Science.gov (United States)

Robertson, Kevin J; Mendez, Bernardino M; Bruce, William J; McDonnell, Brendan D; Chiodo, Michael V; Patel, Parit A

2018-05-01

This study compares the change in midface position following Le Fort III advancement using either rigid external distraction (group 1) or internal distraction (group 2). We hypothesized that, with reference to right-facing cephalometry, internal distraction would result in increased clockwise rotation and inferior displacement of the midface. Le Fort III osteotomies and standardized distraction protocols were performed on 10 cadaveric specimens per group. Right-facing lateral cephalograms were traced and compared across time points to determine change in position at points orbitale, anterior nasal spine (ANS), A-point, and angle ANB. Institutional. Twenty cadaveric head specimens. Standard subcranial Le Fort III osteotomies were performed from a coronal approach and adequately mobilized. The specified distraction mechanism was applied and advanced by 15 mm. Changes of position were calculated at various skeletal landmarks: orbitale, ANS, A-point, and ANB. Group 1 demonstrated relatively uniform x-axis advancement with minimal inferior repositioning at the A-point, ANS, and orbitale. Group 2 demonstrated marked variation in x-axis advancement among the 3 points, along with a significant inferior repositioning and clockwise rotation of the midface ( P External distraction resulted in more uniform advancement of the midface, whereas internal distraction resulted in greater clockwise rotation and inferior displacement. External distraction appears to provide increased vector control of the midface, which is important in creating a customized distraction plan based on the patient's individual occlusal and skeletal needs.

Iterative reconstruction of transcriptional regulatory networks: an algorithmic approach.

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Christian L Barrett

2006-05-01

Full Text Available The number of complete, publicly available genome sequences is now greater than 200, and this number is expected to rapidly grow in the near future as metagenomic and environmental sequencing efforts escalate and the cost of sequencing drops. In order to make use of this data for understanding particular organisms and for discerning general principles about how organisms function, it will be necessary to reconstruct their various biochemical reaction networks. Principal among these will be transcriptional regulatory networks. Given the physical and logical complexity of these networks, the various sources of (often noisy data that can be utilized for their elucidation, the monetary costs involved, and the huge number of potential experiments approximately 10(12 that can be performed, experiment design algorithms will be necessary for synthesizing the various computational and experimental data to maximize the efficiency of regulatory network reconstruction. This paper presents an algorithm for experimental design to systematically and efficiently reconstruct transcriptional regulatory networks. It is meant to be applied iteratively in conjunction with an experimental laboratory component. The algorithm is presented here in the context of reconstructing transcriptional regulation for metabolism in Escherichia coli, and, through a retrospective analysis with previously performed experiments, we show that the produced experiment designs conform to how a human would design experiments. The algorithm is able to utilize probability estimates based on a wide range of computational and experimental sources to suggest experiments with the highest potential of discovering the greatest amount of new regulatory knowledge.

Tomographic reconstruction by using FPSIRT (Fast Particle System Iterative Reconstruction Technique)

Energy Technology Data Exchange (ETDEWEB)

Moreira, Icaro Valgueiro M.; Melo, Silvio de Barros; Dantas, Carlos; Lima, Emerson Alexandre; Silva, Ricardo Martins; Cardoso, Halisson Alberdan C., E-mail: ivmm@cin.ufpe.br, E-mail: sbm@cin.ufpe.br, E-mail: rmas@cin.ufpe.br, E-mail: hacc@cin.ufpe.br, E-mail: ccd@ufpe.br, E-mail: eal@cin.ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

2015-07-01

The PSIRT (Particle System Iterative Reconstruction Technique) is a method of tomographic image reconstruction primarily designed to work with configurations suitable for industrial applications. A particle system is an optimization technique inspired in real physical systems that associates to the reconstructing material a set of particles with certain physical features, subject to a force eld, which can produce movement. The system constantly updates the set of particles by repositioning them in such a way as to approach the equilibrium. The elastic potential along a trajectory is a function of the difference between the attenuation coefficient in the current configuration and the corresponding input data. PSIRT has been successfully used to reconstruct simulated and real objects subject to sets of parallel and fanbeam lines in different angles, representing typical gamma-ray tomographic arrangements. One of PSIRT's limitation was its performance, too slow for real time scenarios. In this work, it is presented a reformulation in PSIRT's computational model, which is able to grant the new algorithm, the FPSIRT - Fast System Iterative Reconstruction Technique, a performance up to 200-time faster than PSIRT's. In this work a comparison of their application to real and simulated data from the HSGT, High Speed Gamma Tomograph, is presented. (author)

Tomographic reconstruction by using FPSIRT (Fast Particle System Iterative Reconstruction Technique)

International Nuclear Information System (INIS)

Moreira, Icaro Valgueiro M.; Melo, Silvio de Barros; Dantas, Carlos; Lima, Emerson Alexandre; Silva, Ricardo Martins; Cardoso, Halisson Alberdan C.

2015-01-01

The PSIRT (Particle System Iterative Reconstruction Technique) is a method of tomographic image reconstruction primarily designed to work with configurations suitable for industrial applications. A particle system is an optimization technique inspired in real physical systems that associates to the reconstructing material a set of particles with certain physical features, subject to a force eld, which can produce movement. The system constantly updates the set of particles by repositioning them in such a way as to approach the equilibrium. The elastic potential along a trajectory is a function of the difference between the attenuation coefficient in the current configuration and the corresponding input data. PSIRT has been successfully used to reconstruct simulated and real objects subject to sets of parallel and fanbeam lines in different angles, representing typical gamma-ray tomographic arrangements. One of PSIRT's limitation was its performance, too slow for real time scenarios. In this work, it is presented a reformulation in PSIRT's computational model, which is able to grant the new algorithm, the FPSIRT - Fast System Iterative Reconstruction Technique, a performance up to 200-time faster than PSIRT's. In this work a comparison of their application to real and simulated data from the HSGT, High Speed Gamma Tomograph, is presented. (author)

Simultaneous malaroplasty with porous polyethylene implants and orthognathic surgery for correction of malar deficiency.

Science.gov (United States)

Robiony, M; Costa, F; Demitri, V; Politi, M

1998-06-01

Patients with skeletal malrelationships caused by maxillary anteroposterior defect and midface hypoplasia may present with an alteration of cheekbone contour. High osteotomies, segmental osteotomies of the zygomatic complex, and malar expansion with alloplastic materials can be performed to improve facial aesthetics. This article describes the restoration of cheekbone-nasal base-lip contour by performing a malaroplasty using an alloplastic implant in addition to orthognathic surgery. From 1995 to 1996, 17 patients with maxillomandibular malrelationships and deficient cheekbone contour were tested by malar augmentation with porous high-density polyethylene in association with maxillary advancement and mandibular setback. The diagnosis of cheekbone contour alteration was made after observing the patient from a lateral, frontal, and oblique point of view. The position of the implant was determined by using Mladick's point, with lateral or medial extension in relation to the depressed area. By the restoration of normal cheekbone-nasal base-upper lip contour produced excellent aesthetic results in all patients. Malaroplasty in association with bimaxillary orthognathic surgery seems to be an effective procedure for treating midface skeletal deficiencies.

Craniofacial reconstruction using patient-specific implants polyether ether ketone with computer-assisted planning.

Science.gov (United States)

Manrique, Oscar J; Lalezarzadeh, Frank; Dayan, Erez; Shin, Joseph; Buchbinder, Daniel; Smith, Mark

2015-05-01

Reconstruction of bony craniofacial defects requires precise understanding of the anatomic relationships. The ideal reconstructive technique should be fast as well as economical, with minimal donor-site morbidity, and provide a lasting and aesthetically pleasing result. There are some circumstances in which a patient's own tissue is not sufficient to reconstruct defects. The development of sophisticated software has facilitated the manufacturing of patient-specific implants (PSIs). The aim of this study was to analyze the utility of polyether ether ketone (PEEK) PSIs for craniofacial reconstruction. We performed a retrospective chart review from July 2009 to July 2013 in patients who underwent craniofacial reconstruction using PEEK-PSIs using a virtual process based on computer-aided design and computer-aided manufacturing. A total of 6 patients were identified. The mean age was 46 years (16-68 y). Operative indications included cancer (n = 4), congenital deformities (n = 1), and infection (n = 1). The mean surgical time was 3.7 hours and the mean hospital stay was 1.5 days. The mean surface area of the defect was 93.4 ± 43.26 cm(2), the mean implant cost was $8493 ± $837.95, and the mean time required to manufacture the implants was 2 weeks. No major or minor complications were seen during the 4-year follow-up. We found PEEK implants to be useful in the reconstruction of complex calvarial defects, demonstrating a low complication rate, good outcomes, and high patient satisfaction in this small series of patients. Polyether ether ketone implants show promising potential and warrant further study to better establish the role of this technology in cranial reconstruction.

Reconstruction for Skull Base Defect Using Fat-Containing Perifascial Areolar Tissue.

Science.gov (United States)

Choi, Woo Young; Sung, Ki Wook; Kim, Young Seok; Hong, Jong Won; Roh, Tai Suk; Lew, Dae Hyun; Chang, Jong Hee; Lee, Kyu Sung

2017-06-01

Skull base reconstruction is a challenging task. The method depends on the anatomical complexity and size of the defect. We obtained tissue by harvesting fat-containing perifascial areolar tissue (PAT) for reconstruction of limited skull base defects and volume augmentation. We demonstrated the effective option for reconstruction of limited skull base defects and volume augmentation. From October 2013 to November 2015, 5 patients underwent operations using fat-containing PAT to fill the defect in skull base and/or perform volume replacement in the forehead. Perifascial areolar tissue with 5- to 10-mm fat thickness was harvested from the inguinal region. The fat-containing PAT was grafted to the defect contacting the vascularized wound bed. Patients were followed up in terms of their clinical symptoms and postoperative magnetic resonance imaging findings. Four patients were treated using fat-containing PAT after tumor resection. One patient was treated for a posttraumatic forehead depression deformity. The fat-containing PAT included 5- to 9-mm fat thickness in all cases. The mean size of grafted PAT was 65.6 cm (28-140 cm). The mean follow-up period was 18.6 months (12-31 months). There was no notable complication. There was no donor site morbidity. We can harvest PAT with fat easily and obtain the sufficient volume to treat the defect. It also could be used with other reconstructive method, such as a free flap or a regional flap to fill the left dead space. Therefore, fat-containing PAT could be additional options to reconstruction of skull base defect.

The evolving breast reconstruction

DEFF Research Database (Denmark)

Thomsen, Jørn Bo; Gunnarsson, Gudjon Leifur

2014-01-01

The aim of this editorial is to give an update on the use of the propeller thoracodorsal artery perforator flap (TAP/TDAP-flap) within the field of breast reconstruction. The TAP-flap can be dissected by a combined use of a monopolar cautery and a scalpel. Microsurgical instruments are generally...... not needed. The propeller TAP-flap can be designed in different ways, three of these have been published: (I) an oblique upwards design; (II) a horizontal design; (III) an oblique downward design. The latissimus dorsi-flap is a good and reliable option for breast reconstruction, but has been criticized...... for oncoplastic and reconstructive breast surgery and will certainly become an invaluable addition to breast reconstructive methods....

Reconstructing see-saw models

International Nuclear Information System (INIS)

Ibarra, Alejandro

2007-01-01

In this talk we discuss the prospects to reconstruct the high-energy see-saw Lagrangian from low energy experiments in supersymmetric scenarios. We show that the model with three right-handed neutrinos could be reconstructed in theory, but not in practice. Then, we discuss the prospects to reconstruct the model with two right-handed neutrinos, which is the minimal see-saw model able to accommodate neutrino observations. We identify the relevant processes to achieve this goal, and comment on the sensitivity of future experiments to them. We find the prospects much more promising and we emphasize in particular the importance of the observation of rare leptonic decays for the reconstruction of the right-handed neutrino masses

Linear single-step image reconstruction in the presence of nonscattering regions

Science.gov (United States)

Dehghani, H.; Delpy, D. T.

2002-06-01

There is growing interest in the use of near-infrared spectroscopy for the noninvasive determination of the oxygenation level within biological tissue. Stemming from this application, there has been further research in using this technique for obtaining tomographic images of the neonatal head, with the view of determining the level of oxygenated and deoxygenated blood within the brain. Because of computational complexity, methods used for numerical modeling of photon transfer within tissue have usually been limited to the diffusion approximation of the Boltzmann transport equation. The diffusion approximation, however, is not valid in regions of low scatter, such as the cerebrospinal fluid. Methods have been proposed for dealing with nonscattering regions within diffusing materials through the use of a radiosity-diffusion model. Currently, this new model assumes prior knowledge of the void region; therefore it is instructive to examine the errors introduced in applying a simple diffusion-based reconstruction scheme in cases where a nonscattering region exists. We present reconstructed images, using linear algorithms, of models that contain a nonscattering region within a diffusing material. The forward data are calculated by using the radiosity-diffusion model, and the inverse problem is solved by using either the radiosity-diffusion model or the diffusion-only model. When using data from a model containing a clear layer and reconstructing with the correct model, one can reconstruct the anomaly, but the qualitative accuracy and the position of the reconstructed anomaly depend on the size and the position of the clear regions. If the inverse model has no information about the clear regions (i.e., it is a purely diffusing model), an anomaly can be reconstructed, but the resulting image has very poor qualitative accuracy and poor localization of the anomaly. The errors in quantitative and localization accuracies depend on the size and location of the clear regions.

Mandibular kinematics and maximum voluntary bite force following segmental resection of the mandible without or with reconstruction.

Science.gov (United States)

Linsen, Sabine S; Oikonomou, Annina; Martini, Markus; Teschke, Marcus

2018-05-01

The purpose was to analyze mandibular kinematics and maximum voluntary bite force in patients following segmental resection of the mandible without and with reconstruction (autologous bone, alloplastic total temporomandibular joint replacement (TMJ TJR)). Subjects operated from April 2002 to August 2014 were enrolled in the study. Condylar (CRoM) and incisal (InRoM) range of motion and deflection during opening, condylar retrusion, incisal lateral excursion, mandibular rotation angle during opening, and maximum voluntary bite force were determined on the non-affected site and compared between groups. Influence of co-factors (defect size, soft tissue deficit, neck dissection, radiotherapy, occlusal contact zones (OCZ), and time) was determined. Twelve non-reconstructed and 26 reconstructed patients (13 autologous, 13 TMJ TJR) were included in the study. InRoM opening and bite force were significantly higher (P ≤ .024), and both condylar and incisal deflection during opening significantly lower (P ≤ .027) in reconstructed patients compared with non-reconstructed. Differences between the autologous and the TMJ TJR group were statistically not significant. Co-factors defect size, soft tissue deficit, and neck dissection had the greatest impact on kinematics and number of OCZs on bite force. Reconstructed patients (both autologous and TMJ TJR) have better overall function than non-reconstructed patients. Reconstruction of segmental mandibular resection has positive effects on mandibular function. TMJ TJR seems to be a suitable technique for the reconstruction of mandibular defects including the TMJ complex.

High-performance blob-based iterative three-dimensional reconstruction in electron tomography using multi-GPUs

Directory of Open Access Journals (Sweden)

Wan Xiaohua

2012-06-01

Full Text Available Abstract Background Three-dimensional (3D reconstruction in electron tomography (ET has emerged as a leading technique to elucidate the molecular structures of complex biological specimens. Blob-based iterative methods are advantageous reconstruction methods for 3D reconstruction in ET, but demand huge computational costs. Multiple graphic processing units (multi-GPUs offer an affordable platform to meet these demands. However, a synchronous communication scheme between multi-GPUs leads to idle GPU time, and a weighted matrix involved in iterative methods cannot be loaded into GPUs especially for large images due to the limited available memory of GPUs. Results In this paper we propose a multilevel parallel strategy combined with an asynchronous communication scheme and a blob-ELLR data structure to efficiently perform blob-based iterative reconstructions on multi-GPUs. The asynchronous communication scheme is used to minimize the idle GPU time so as to asynchronously overlap communications with computations. The blob-ELLR data structure only needs nearly 1/16 of the storage space in comparison with ELLPACK-R (ELLR data structure and yields significant acceleration. Conclusions Experimental results indicate that the multilevel parallel scheme combined with the asynchronous communication scheme and the blob-ELLR data structure allows efficient implementations of 3D reconstruction in ET on multi-GPUs.

Reconstruction of the mandible and the maxilla: the evolution of surgical technique.

Science.gov (United States)

Genden, Eric M

2010-01-01

The upper and lower jaws play an essential role in mastication, articulation, and cosmetic form. The mandible provides support for tongue position and elevation of the larynx during swallowing, while the maxilla provides support for the nasal structures as well as an opposing structure to the mandible during mastication. The evolution of mandibular and maxillary reconstruction dates back to the early 19th century. Before the introduction of free tissue transfer, a variety of local flaps, regional flaps, and prosthetics were introduced, yet each was met with eventual failure. Since the introduction of free tissue transfer, mandibular and maxillary reconstruction has become as much of an art as it has a science. Whether the mandibular or the palatomaxillary defects are a result of trauma, congenital deformity, or tumor extirpation, the resultant effect often disrupts both form and function. With these considerations taken together, jaw reconstruction is a unique undertaking in which the artistic reconstruction of the facial skeleton is met with the science of reestablishing the mechanics of mastication. The site, size, and associated soft-tissue defects represent the 3 most important factors in determining the impact of a given defect on function and aesthetics. There is also an inherent difference between defects that are sustained in a controlled fashion, such as during cancer ablation, and those that result from trauma. The consideration of these complexities in jaw reconstruction is reflected in the wide variety of approaches and techniques that have evolved over the past century.

Reconstructing the long-term cosmic ray intensity: linear relations do not work

Directory of Open Access Journals (Sweden)

K. Mursula

2003-04-01

Full Text Available It was recently suggested (Lockwood, 2001 that the cosmic ray intensity in the neutron monitor energy range is linearly related to the coronal source flux, and can be reconstructed for the last 130 years using the long-term coronal flux estimated earlier. Moreover, Lockwood (2001 reconstructed the coronal flux for the last 500 years using a similar linear relation between the flux and the concentration of cosmogenic 10 Be isotopes in polar ice. Here we show that the applied linear relations are oversimplified and lead to unphysical results on long time scales. In particular, the cosmic ray intensity reconstructed by Lockwood (2001 for the last 130 years has a steep trend which is considerably larger than the trend estimated from observations during the last 65 years. Accordingly, the reconstructed cosmic ray intensity reaches or even exceeds the local interstellar cosmic ray flux around 1900. We argue that these unphysical results obtained when using linear relations are due to the oversimplified approach which does not take into account the complex and essentially nonlinear nature of long-term cosmic ray modulation in the heliosphere. We also compare the long-term cosmic ray intensity based on a linear treatment with the reconstruction based on a recent physical model which predicts a considerably lower cosmic ray intensity around 1900.Key words. Interplanetary physics (cosmic rays; heliopause and solar wind termination – Geomagnetism and paleomagnetism (time variations, secular and long-term

Reconstruction efficiency and precision for the events detected by the BIS-2 installation using the Perun pattern recognition program

International Nuclear Information System (INIS)

Burilkov, D.T.; Genchev, V.I.; Markov, P.K.; Likhachev, M.F.; Takhtamyshev, G.G.; Todorov, P.T.; Trayanov, P.K.

1982-01-01

Results of studying the efficiency and accuracy of the track and event reconstruction with the Perun pattern recognition program used in the experiments carried out at the BIS-2 installation are presented. The Monte Carlo method is used for simulating the processes of neutron interactions with matter. The con-- clusion is made that the Perun program correctly, with good accuracy and high efficiency reconstructs complex multiparticle events [ru

Features of the method of large-scale paleolandscape reconstructions

Science.gov (United States)

Nizovtsev, Vyacheslav; Erman, Natalia; Graves, Irina

2017-04-01

The method of paleolandscape reconstructions was tested in the key area of the basin of the Central Dubna, located at the junction of the Taldom and Sergiev Posad districts of the Moscow region. A series of maps was created which shows paleoreconstructions of the original (indigenous) living environment of initial settlers during main time periods of the Holocene age and features of human interaction with landscapes at the early stages of economic development of the territory (in the early and middle Holocene). The sequence of these works is as follows. 1. Comprehensive analysis of topographic maps of different scales and aerial and satellite images, stock materials of geological and hydrological surveys and prospecting of peat deposits, archaeological evidence on ancient settlements, palynological and osteological analysis, analysis of complex landscape and archaeological studies. 2. Mapping of factual material and analyzing of the spatial distribution of archaeological sites were performed. 3. Running of a large-scale field landscape mapping (sample areas) and compiling of maps of the modern landscape structure. On this basis, edaphic properties of the main types of natural boundaries were analyzed and their resource base was determined. 4. Reconstruction of lake-river system during the main periods of the Holocene. The boundaries of restored paleolakes were determined based on power and territorial confinement of decay ooze. 5. On the basis of landscape and edaphic method the actual paleolandscape reconstructions for the main periods of the Holocene were performed. During the reconstructions of the original, indigenous flora we relied on data of palynological studies conducted on the studied area or in similar landscape conditions. 6. The result was a retrospective analysis and periodization of the settlement process, economic development and the formation of the first anthropogenically transformed landscape complexes. The reconstruction of the dynamics of the

Pre-operative planning for mandibular reconstruction - A full digital planning workflow resulting in a patient specific reconstruction

Science.gov (United States)

2011-01-01

Objectives Reconstruction of large mandiblular defects following ablative oncologic surgery could be done by using vascularized bone transfer or, more often, primarily with simultaneous or delayed bone grafting, using load bearing reconstruction plates. Bending of these reconstruction plates is typically directed along the outer contour of the original mandible. Simultaneously or in a second operation vascularized or non-vascularized bone is fixed to the reconstruction plate. However, the prosthodontic-driven backward planning to ease bony reconstruction of the mandible in terms of dental rehabilitation using implant-retained overdentures might be an eligible solution. The purpose of this work was to develop, establish and clinically evaluate a novel 3D planning procedure for mandibular reconstruction. Materials and methods Three patients with tumors involving the mandible, which included squamous cell carcinoma in the floor of the mouth and keratocystic odontogenic tumor, were treated surgically by hemimandibulectomy. Results In primary alloplastic mandible reconstruction, shape and size of the reconstruction plate could be predefined and prebent prior to surgery. Clinical relevance This study provides modern treatment strategies for mandibular reconstruction. PMID:21968330

A Stochastic Geometry Method for Pylon Reconstruction from Airborne LiDAR Data

Directory of Open Access Journals (Sweden)

Bo Guo

2016-03-01

Full Text Available Object detection and reconstruction from remotely sensed data are active research topic in photogrammetric and remote sensing communities. Power engineering device monitoring by detecting key objects is important for power safety. In this paper, we introduce a novel method for the reconstruction of self-supporting pylons widely used in high voltage power-line systems from airborne LiDAR data. Our work constructs pylons from a library of 3D parametric models, which are represented using polyhedrons based on stochastic geometry. Firstly, laser points of pylons are extracted from the dataset using an automatic classification method. An energy function made up of two terms is then defined: the first term measures the adequacy of the objects with respect to the data, and the second term has the ability to favor or penalize certain configurations based on prior knowledge. Finally, estimation is undertaken by minimizing the energy using simulated annealing. We use a Markov Chain Monte Carlo sampler, leading to an optimal configuration of objects. Two main contributions of this paper are: (1 building a framework for automatic pylon reconstruction; and (2 efficient global optimization. The pylons can be precisely reconstructed through energy optimization. Experiments producing convincing results validated the proposed method using a dataset of complex structure.

Reconstruction of emission coefficients for a non-axisymmetric coupling arc by algebraic reconstruction technique

International Nuclear Information System (INIS)

Zhang Guangjun; Xiong Jun; Gao Hongming; Wu Lin

2011-01-01

A preliminary investigation of tomographic reconstruction of an asymmetric arc plasma has been carried out. The objective of this work aims at reconstructing emission coefficients of a non-axisymmetric coupling arc from measured intensities by means of an algebraic reconstruction technique (ART). In order to define the optimal experimental scheme for good quality with limited views, the dependence of the reconstruction quality on three configurations (four, eight, ten projection angles) are presented and discussed via a displaced Gaussian model. Then, the emission coefficients of a free burning arc are reconstructed by the ART with the ten-view configuration and an Abel inversion, respectively, and good agreement is obtained. Finally, the emission coefficient profiles of the coupling arc are successfully achieved with the ten-view configuration. The results show that the distribution of emission coefficient for the coupling arc is different from centrosymmetric shape. The ART is perfectly suitable for reconstructing emission coefficients of the coupling arc with the ten-view configuration, proving the feasibility and utility of the ART to characterize an asymmetric arc.

Palaeomagnetism of the Early Permian Mount Leyshon Intrusive Complex and Tuckers Igneous Complex, North Queensland, Australia

Science.gov (United States)

Clark, D. A.; Lackie, M. A.

2003-06-01

This study provides reliable, precisely defined and well-dated Early Permian (286 +/- 6 Ma) palaeomagnetic poles for Australia from the Mount Leyshon Intrusive Complex (MLIC) and the Tuckers Igneous Complex (TIC). Both complexes are associated with prominent negative magnetic anomalies, indicating the presence of rocks carrying stable remanence of reverse polarity, with a Koenigsberger ratio greater than unity. The characteristic remanence carried by the intrusive phases and by locally remagnetized, contact-metamorphosed host rocks is always of reverse polarity, consistent with acquisition during the Permo-Carboniferous (Kiaman) Reverse Superchron. The corresponding palaeopoles confirm that Australia occupied high latitudes in the Early Permian. The pole positions are: MLIC: lat. = 43.2 °S, long. = 137.3 °E dp = 6.0°, dm = 6.4° Q= 6; TIC: lat. = 47.5 °S, long. = 143.0 °E, dp = 6.0°, dm = 6.6° Q= 6. Permian palaeomagnetic overprinting is detectable at considerable distances from the MLIC (2-3 km), well beyond the zone of visible alteration. The primary nature of the Early Permian palaeomagnetic signature is established by full baked contact/aureole tests at both localities. Other new data from Australia are consistent with the poles reported here. Comparison of the Australian, African and South American Apparent Polar Wander Paths (APWP) suggests that mean Permian and Triassic poles from West Gondwana, particularly from South America, are biased by remagnetization in the Jurassic-Cretaceous and that the Late Palaeozoic-Mesozoic APWP for Gondwana is best defined by Australian data. The Australian APWP exhibits substantial movement through the Mesozoic. Provided only that the time-averaged palaeofield was zonal, the Early Triassic palaeomagnetic data from Australia provide an important palaeogeographic constraint that the south geographic pole was within, or very close to, SE Australia around 240 Ma. The new Early Permian poles are apparently more consistent

Ancestral sequence reconstruction in primate mitochondrial DNA: compositional bias and effect on functional inference.

Science.gov (United States)

Krishnan, Neeraja M; Seligmann, Hervé; Stewart, Caro-Beth; De Koning, A P Jason; Pollock, David D

2004-10-01

Reconstruction of ancestral DNA and amino acid sequences is an important means of inferring information about past evolutionary events. Such reconstructions suggest changes in molecular function and evolutionary processes over the course of evolution and are used to infer adaptation and convergence. Maximum likelihood (ML) is generally thought to provide relatively accurate reconstructed sequences compared to parsimony, but both methods lead to the inference of multiple directional changes in nucleotide frequencies in primate mitochondrial DNA (mtDNA). To better understand this surprising result, as well as to better understand how parsimony and ML differ, we constructed a series of computationally simple "conditional pathway" methods that differed in the number of substitutions allowed per site along each branch, and we also evaluated the entire Bayesian posterior frequency distribution of reconstructed ancestral states. We analyzed primate mitochondrial cytochrome b (Cyt-b) and cytochrome oxidase subunit I (COI) genes and found that ML reconstructs ancestral frequencies that are often more different from tip sequences than are parsimony reconstructions. In contrast, frequency reconstructions based on the posterior ensemble more closely resemble extant nucleotide frequencies. Simulations indicate that these differences in ancestral sequence inference are probably due to deterministic bias caused by high uncertainty in the optimization-based ancestral reconstruction methods (parsimony, ML, Bayesian maximum a posteriori). In contrast, ancestral nucleotide frequencies based on an average of the Bayesian set of credible ancestral sequences are much less biased. The methods involving simpler conditional pathway calculations have slightly reduced likelihood values compared to full likelihood calculations, but they can provide fairly unbiased nucleotide reconstructions and may be useful in more complex phylogenetic analyses than considered here due to their speed and

NGO collaboration in community post-disaster reconstruction: field research following the 2008 Wenchuan earthquake in China.

Science.gov (United States)

Lu, Yi; Xu, Jiuping

2015-04-01

The number of communities affected by disasters has been rising. As a result, non-governmental organisations (NGOs) that attend community post-disaster reconstruction are often unable to deliver all requirements and have to develop cooperative approaches. However, this collaboration can cause problems because of the complex environments, the fight for limited resources and uncoordinated management, all of which result in poor service delivery to the communities, adding to their woes. From extensive field research and case studies conducted in the post-Wenchuan earthquake-stricken communities, this paper introduces an integrated collaboration framework for community post-disaster reconstruction with the focus on three types of NGOs: international, government organised and civil. The proposed collaboration framework examines the three interrelated components of organisational structure, operational processes and reconstruction goals/implementation areas. Of great significance in better promoting collaborative participation between NGOs are the crucial concepts of participatory reconstruction, double-layer collaborative networks, and circular review and revision. © 2015 The Author(s). Disasters © Overseas Development Institute, 2015.

Delayed reconstruction of mangled lower extremities: soft tissue management

OpenAIRE

Tiftikçioğlu, Yiğit Özer; Erçin, Burak Sercan; Erdem, Mehmet; Biçer, Ahmet; Özkayın, Nadir; Özek, Cüneyt

2018-01-01

Objectives: This study aims to propose a new, practical and versatile algorithm for the management of traumatic lower limb soft tissue wounds for patients who did not undergo early reconstruction.Materials and methods: A total of 81 patients (54 males, 27 females; mean age 37.1 years; range 11 to 64 years) managed due to complex lower limb injuries at our institution between January 2008 and December 2012 were analyzed retrospectively in this study. Age and gender of the patients, type of tra...

Local self-similarity descriptor for point-of-interest reconstruction of real-world scenes

International Nuclear Information System (INIS)

Gao, Xianglu; Wan, Weibing; Zhao, Qunfei; Zhang, Xianmin

2015-01-01

Scene reconstruction is utilized commonly in close-range photogrammetry, with diverse applications in fields such as industry, biology, and aerospace industries. Presented surfaces or wireframe three-dimensional (3D) model reconstruction applications are either too complex or too inflexible to accommodate various types of real-world scenes, however. This paper proposes an algorithm for acquiring point-of-interest (referred to throughout the study as POI) coordinates in 3D space, based on multi-view geometry and a local self-similarity descriptor. After reconstructing several POIs specified by a user, a concise and flexible target object measurement method, which obtains the distance between POIs, is described in detail. The proposed technique is able to measure targets with high accuracy even in the presence of obstacles and non-Lambertian surfaces. The method is so flexible that target objects can be measured with a handheld digital camera. Experimental results further demonstrate the effectiveness of the algorithm. (paper)

Three-dimensional ICT reconstruction

International Nuclear Information System (INIS)

Zhang Aidong; Li Ju; Chen Fa; Sun Lingxia

2005-01-01

The three-dimensional ICT reconstruction method is the hot topic of recent ICT technology research. In the context, qualified visual three-dimensional ICT pictures are achieved through multi-piece two-dimensional images accumulation by, combining with thresholding method and linear interpolation. Different direction and different position images of the reconstructed pictures are got by rotation and interception respectively. The convenient and quick method is significantly instructive to more complicated three-dimensional reconstruction of ICT images. (authors)

Three-dimensional ICT reconstruction

International Nuclear Information System (INIS)

Zhang Aidong; Li Ju; Chen Fa; Sun Lingxia

2004-01-01

The three-dimensional ICT reconstruction method is the hot topic of recent ICT technology research. In the context qualified visual three-dimensional ICT pictures are achieved through multi-piece two-dimensional images accumulation by order, combining with thresholding method and linear interpolation. Different direction and different position images of the reconstructed pictures are got by rotation and interception respectively. The convenient and quick method is significantly instructive to more complicated three-dimensional reconstruction of ICT images. (authors)

Multislice helical CT (MSCT) for mid-facial trauma: optimization of parameters for scanning and reconstruction

International Nuclear Information System (INIS)

Dammert, S.; Funke, M.; Obernauer, S.; Grabbe, E.; Merten, H.A.

2002-01-01

Purpose: To determine the optimal scan parameters in multislice helical CT (MSCT) of the facial bone complex for both axial scanning and multiplanar reconstructions. Material and Methods: An anthropomorphic skull phantom was examined with a MSCT. Axial scans were performed with continuously increasing collimations (4 x 1.25 - 4 x 2.5 mm), tube current (20 - 200 mA) and table speeds (3.75 mm/rot. and 7.5 mm/rot.). Multiplanar reconstructions in coronal and parasagittal planes with different reconstruction increment and slice thickness were evaluated in terms of image noise, contour artifacts and visualisation of anatomical structures. Results: The best image quality was obtained with a collimation of 4 x 1.25 mm and a - table speed of 3.75 mm/rot. A reconstruction increment of 0.6 mm achieved the best time to image quality relation. With these parameters the bone structures were depicted in an optimal way without artifacts. The tube current could be reduced to 50 mA without significant loss of image quality. The optimized protocol was used for regular routine examinations in patients with facial trauma (n = 66). Conclusions: Low-dose MSCT using thin collimation, low table speed and small reconstruction increments provides excellent data for both axial images and multiplanar reconstructions in patients with facial trauma. An additional examination in coronal orientation is therefore no longer necessary. (orig.) [de

Quantum mechanics: why complex Hilbert space?

Science.gov (United States)

Cassinelli, G.; Lahti, P.

2017-10-01

We outline a programme for an axiomatic reconstruction of quantum mechanics based on the statistical duality of states and effects that combines the use of a theorem of Solér with the idea of symmetry. We also discuss arguments favouring the choice of the complex field. This article is part of the themed issue `Second quantum revolution: foundational questions'.

Investigation of various reconstruction parameters for algebraic reconstruction technique in a newly developed chest digital tomosynthesis

International Nuclear Information System (INIS)

Lee, H.; Choi, S.; Kim, Y.-S.; Park, H.-S.; Seo, C.-W.; Kim, H.-J.; Lee, D.; Lee, Y.

2017-01-01

Chest digital tomosynthesis (CDT) is a promising new modality that provides 3D information by reconstructing limited projection views. CDT systems have been developed to improve the limitations of conventional radiography such as image degradation and low sensitivity. However, the development of reconstruction methods is challenging because of the limited projection views within various angular ranges. Optimization of reconstruction parameters for various reconsturction methods in CDT system also is needed. The purpose of this study was to investigate the feasibility of algebraic reconstruction technique (ART) method, and to evaluate the effect of the reconstruction parameters for our newly developed CDT system. We designed ART method with 41 projection views over an angular range of ±20°. To investigate the effect of reconstruction parameters, we measured the contrast-to-noise ratio (CNR), artifact spread function (ASF), and quality factor (QF) using LUNGMAN phantom included tumors. We found that the proper choice of reconstruction parameters such as relaxation parameter, initial guess, and number of iterations improved the quality of reconstructed images from the same projection views. Optimal values of ART relaxation parameter with uniform (UI) and back-projection (BP) initial guesses were 0.4 and 0.6, respectively. BP initial guess improved image quality in comparison with UI initial guess, in terms of providing a higher CNR and QF values with a faster speed. CNR and QF values improved with increasing number of iteration. Particularly, ART method with BP initial guess (when β = 0.6) after 3-terations provide satisfactory reconstructed image. In conclusion, the use of ART method with proper reconstruction parameters provided better image quality than FBP method as well as conventional radiography. These results indicated that the ART method with optimal reconstruction parameters could improve image quality for nodule detection using the CDT system.

Investigation of various reconstruction parameters for algebraic reconstruction technique in a newly developed chest digital tomosynthesis

Science.gov (United States)

Lee, H.; Choi, S.; Lee, D.; Kim, Y.-s.; Park, H.-S.; Lee, Y.; Seo, C.-W.; Kim, H.-J.

2017-08-01

Chest digital tomosynthesis (CDT) is a promising new modality that provides 3D information by reconstructing limited projection views. CDT systems have been developed to improve the limitations of conventional radiography such as image degradation and low sensitivity. However, the development of reconstruction methods is challenging because of the limited projection views within various angular ranges. Optimization of reconstruction parameters for various reconsturction methods in CDT system also is needed. The purpose of this study was to investigate the feasibility of algebraic reconstruction technique (ART) method, and to evaluate the effect of the reconstruction parameters for our newly developed CDT system. We designed ART method with 41 projection views over an angular range of ±20°. To investigate the effect of reconstruction parameters, we measured the contrast-to-noise ratio (CNR), artifact spread function (ASF), and quality factor (QF) using LUNGMAN phantom included tumors. We found that the proper choice of reconstruction parameters such as relaxation parameter, initial guess, and number of iterations improved the quality of reconstructed images from the same projection views. Optimal values of ART relaxation parameter with uniform (UI) and back-projection (BP) initial guesses were 0.4 and 0.6, respectively. BP initial guess improved image quality in comparison with UI initial guess, in terms of providing a higher CNR and QF values with a faster speed. CNR and QF values improved with increasing number of iteration. Particularly, ART method with BP initial guess (when β = 0.6) after 3-terations provide satisfactory reconstructed image. In conclusion, the use of ART method with proper reconstruction parameters provided better image quality than FBP method as well as conventional radiography. These results indicated that the ART method with optimal reconstruction parameters could improve image quality for nodule detection using the CDT system.

COMPARISON OF HOLOGRAPHIC AND ITERATIVE METHODS FOR AMPLITUDE OBJECT RECONSTRUCTION

Directory of Open Access Journals (Sweden)

I. A. Shevkunov

2015-01-01

Full Text Available Experimental comparison of four methods for the wavefront reconstruction is presented. We considered two iterative and two holographic methods with different mathematical models and algorithms for recovery. The first two of these methods do not use a reference wave recording scheme that reduces requirements for stability of the installation. A major role in phase information reconstruction by such methods is played by a set of spatial intensity distributions, which are recorded as the recording matrix is being moved along the optical axis. The obtained data are used consistently for wavefront reconstruction using an iterative procedure. In the course of this procedure numerical distribution of the wavefront between the planes is performed. Thus, phase information of the wavefront is stored in every plane and calculated amplitude distributions are replaced for the measured ones in these planes. In the first of the compared methods, a two-dimensional Fresnel transform and iterative calculation in the object plane are used as a mathematical model. In the second approach, an angular spectrum method is used for numerical wavefront propagation, and the iterative calculation is carried out only between closely located planes of data registration. Two digital holography methods, based on the usage of the reference wave in the recording scheme and differing from each other by numerical reconstruction algorithm of digital holograms, are compared with the first two methods. The comparison proved that the iterative method based on 2D Fresnel transform gives results comparable with the result of common holographic method with the Fourier-filtering. It is shown that holographic method for reconstructing of the object complex amplitude in the process of the object amplitude reduction is the best among considered ones.

The born approximation and Calderón's method for reconstruction of conductivities in 3-D

DEFF Research Database (Denmark)

Knudsen, Kim; Mueller, Jennifer L.

2011-01-01

Two algorithms for the direct reconstruction of conductivities in a bounded domain in [\\mathbb{R}^3] from surface measurements of the solutions to the conductivity equation are presented. The algorithms are based on complex geometrical optics solutions and a nonlinear scattering transform. We test...

Direct Reconstruction of CT-based Attenuation Correction Images for PET with Cluster-Based Penalties

Science.gov (United States)

Kim, Soo Mee; Alessio, Adam M.; De Man, Bruno; Asma, Evren; Kinahan, Paul E.

2015-01-01

Extremely low-dose CT acquisitions for the purpose of PET attenuation correction will have a high level of noise and biasing artifacts due to factors such as photon starvation. This work explores a priori knowledge appropriate for CT iterative image reconstruction for PET attenuation correction. We investigate the maximum a posteriori (MAP) framework with cluster-based, multinomial priors for the direct reconstruction of the PET attenuation map. The objective function for direct iterative attenuation map reconstruction was modeled as a Poisson log-likelihood with prior terms consisting of quadratic (Q) and mixture (M) distributions. The attenuation map is assumed to have values in 4 clusters: air+background, lung, soft tissue, and bone. Under this assumption, the MP was a mixture probability density function consisting of one exponential and three Gaussian distributions. The relative proportion of each cluster was jointly estimated during each voxel update of direct iterative coordinate decent (dICD) method. Noise-free data were generated from NCAT phantom and Poisson noise was added. Reconstruction with FBP (ramp filter) was performed on the noise-free (ground truth) and noisy data. For the noisy data, dICD reconstruction was performed with the combination of different prior strength parameters (β and γ) of Q- and M-penalties. The combined quadratic and mixture penalties reduces the RMSE by 18.7% compared to post-smoothed iterative reconstruction and only 0.7% compared to quadratic alone. For direct PET attenuation map reconstruction from ultra-low dose CT acquisitions, the combination of quadratic and mixture priors offers regularization of both variance and bias and is a potential method to derive attenuation maps with negligible patient dose. However, the small improvement in quantitative accuracy relative to the substantial increase in algorithm complexity does not currently justify the use of mixture-based PET attenuation priors for reconstruction of CT

Reconstruction of Building Outlines in Dense Urban Areas Based on LIDAR Data and Address Points

Science.gov (United States)

Jarzabek-Rychard, M.

2012-07-01

The paper presents a comprehensive method for automated extraction and delineation of building outlines in densely built-up areas. A novel approach to outline reconstruction is the use of geocoded building address points. They give information about building location thus highly reduce task complexity. Reconstruction process is executed on 3D point clouds acquired by airborne laser scanner. The method consists of three steps: building detection, delineation and contours refinement. The algorithm is tested against a data set that presents the old market town and its surroundings. The results are discussed and evaluated by comparison to reference cadastral data.

Entropy and transverse section reconstruction

International Nuclear Information System (INIS)

Gullberg, G.T.

1976-01-01

A new approach to the reconstruction of a transverse section using projection data from multiple views incorporates the concept of maximum entropy. The principle of maximizing information entropy embodies the assurance of minimizing bias or prejudice in the reconstruction. Using maximum entropy is a necessary condition for the reconstructed image. This entropy criterion is most appropriate for 3-D reconstruction of objects from projections where the system is underdetermined or the data are limited statistically. This is the case in nuclear medicine time limitations in patient studies do not yield sufficient projections

Breast reconstruction - natural tissue

Science.gov (United States)

... flap; TRAM; Latissimus muscle flap with a breast implant; DIEP flap; DIEAP flap; Gluteal free flap; Transverse upper gracilis flap; TUG; Mastectomy - breast reconstruction with natural tissue; Breast cancer - breast reconstruction with natural tissue

Combined treatment for complex intracranial aneurysm

Directory of Open Access Journals (Sweden)

Chiriac A.

2015-06-01

Full Text Available Complex aneurysms often cannot be completely excluded by a single approaches. Today successful treatment of these lesions requires a combination between microsurgical and endovascular techniques. Planning of combined treatment require a very good understanding of aneurysm anatomy and a close collaboration between neurosurgeon and neuroendovascular interventionist. Endovascular coiling can usually be used as early treatment for a partially aneurysm occlusion including the ruptured area and followed by definitive clipping. On the other hand microsurgical clipping also can be used as first treatment for complex aneurysm neck reconstruction, allowing successful secondary placement of coils inside the remnant aneurysm sac

16 multi-slice CT three-dimensional and multiplanar reconstruction for evaluation of pediatric congenital scoliosis

International Nuclear Information System (INIS)

Peng Yun; Zhang Ningning; Zhang Xuejun; Sun Guoqiang; Zeng Jinjin

2006-01-01

Objective: Our study is to use of 16 MSCT three-dimensional images and multiplanar reconstruction images in the preoperative investigation of patients with congenital scoliosis, to study its technical advantage and work out surgical plan. Methods: Twenty-seven pediatric patients with congenital scoliosis processing between April to October 2004 were reviewed, including 13 boys and 14 girls. X-ray plain film and sixteen multi-slice CT examination on curved/standard multiplanar reconstruction and three- dimensional computed tomographic imaging may offer, many potential advantages for defining congenital spine anomalies liable to cause progression of scoliosis, including visualization of the deformity in any plane, from any angle, with the overlying structures subtracted. Results: Ten patients had segmentation defects, 6 patients underwent formation defects, 11 patients had complex, unclassifiable anomalies. The patients of rib deformity were found in 15 patients, the most prominent part of the rib cage deformity was at the same level as the most rotated vertebra in 7 patients; 8 patients had vertebral anomalies accompanied with diastematomyelie, including 6 patients with uncompleted or completed bony spur. In 19 of 27 cases, the muhiplanar reconstruction and three-dimensional images allowed identification of unrecognized malformations and completely evaluated the degree of scoliosis, during conventional X-ray images and axial CT images, including volume 3D imaging evaluated approximately classification and modality of complex anomalies in 11 cases, which were unclassifiable malformation in 7 cases and unsegmented bar with contralateral hemivertebrae; 4 children had segmentation defects revealed unilateral unsegmented bar (3 cases) and bilateral block vertebra (1 case) in volume 3D reconstruction images; 2 children were found occultation hemivertebrae which were not been discovered during conventional X-ray images and axial CT images; and 2 children were revaluated

Jini service to reconstruct tomographic data

Science.gov (United States)

Knoll, Peter; Mirzaei, S.; Koriska, K.; Koehn, H.

2002-06-01

A number of imaging systems rely on the reconstruction of a 3- dimensional model from its projections through the process of computed tomography (CT). In medical imaging, for example magnetic resonance imaging (MRI), positron emission tomography (PET), and Single Computer Tomography (SPECT) acquire two-dimensional projections of a three dimensional projections of a three dimensional object. In order to calculate the 3-dimensional representation of the object, i.e. its voxel distribution, several reconstruction algorithms have been developed. Currently, mainly two reconstruct use: the filtered back projection(FBP) and iterative methods. Although the quality of iterative reconstructed SPECT slices is better than that of FBP slices, such iterative algorithms are rarely used for clinical routine studies because of their low availability and increased reconstruction time. We used Jini and a self-developed iterative reconstructions algorithm to design and implement a Jini reconstruction service. With this service, the physician selects the patient study from a database and a Jini client automatically discovers the registered Jini reconstruction services in the department's Intranet. After downloading the proxy object the this Jini service, the SPECT acquisition data are reconstructed. The resulting transaxial slices are visualized using a Jini slice viewer, which can be used for various imaging modalities.

Single-shot full resolution region-of-interest (ROI) reconstruction in image plane digital holographic microscopy

Science.gov (United States)

Singh, Mandeep; Khare, Kedar

2018-05-01

We describe a numerical processing technique that allows single-shot region-of-interest (ROI) reconstruction in image plane digital holographic microscopy with full pixel resolution. The ROI reconstruction is modelled as an optimization problem where the cost function to be minimized consists of an L2-norm squared data fitting term and a modified Huber penalty term that are minimized alternately in an adaptive fashion. The technique can provide full pixel resolution complex-valued images of the selected ROI which is not possible to achieve with the commonly used Fourier transform method. The technique can facilitate holographic reconstruction of individual cells of interest from a large field-of-view digital holographic microscopy data. The complementary phase information in addition to the usual absorption information already available in the form of bright field microscopy can make the methodology attractive to the biomedical user community.

Rapid prototyping-assisted maxillofacial reconstruction.

Science.gov (United States)

Peng, Qian; Tang, Zhangui; Liu, Ousheng; Peng, Zhiwei

2015-05-01

Rapid prototyping (RP) technologies have found many uses in dentistry, and especially oral and maxillofacial surgery, due to its ability to promote product development while at the same time reducing cost and depositing a part of any degree of complexity theoretically. This paper provides an overview of RP technologies for maxillofacial reconstruction covering both fundamentals and applications of the technologies. Key fundamentals of RP technologies involving the history, characteristics, and principles are reviewed. A number of RP applications to the main fields of oral and maxillofacial surgery, including restoration of maxillofacial deformities and defects, reduction of functional bone tissues, correction of dento-maxillofacial deformities, and fabrication of maxillofacial prostheses, are discussed. The most remarkable challenges for development of RP-assisted maxillofacial surgery and promising solutions are also elaborated.

A high-throughput system for high-quality tomographic reconstruction of large datasets at Diamond Light Source.

Science.gov (United States)

Atwood, Robert C; Bodey, Andrew J; Price, Stephen W T; Basham, Mark; Drakopoulos, Michael

2015-06-13

Tomographic datasets collected at synchrotrons are becoming very large and complex, and, therefore, need to be managed efficiently. Raw images may have high pixel counts, and each pixel can be multidimensional and associated with additional data such as those derived from spectroscopy. In time-resolved studies, hundreds of tomographic datasets can be collected in sequence, yielding terabytes of data. Users of tomographic beamlines are drawn from various scientific disciplines, and many are keen to use tomographic reconstruction software that does not require a deep understanding of reconstruction principles. We have developed Savu, a reconstruction pipeline that enables users to rapidly reconstruct data to consistently create high-quality results. Savu is designed to work in an 'orthogonal' fashion, meaning that data can be converted between projection and sinogram space throughout the processing workflow as required. The Savu pipeline is modular and allows processing strategies to be optimized for users' purposes. In addition to the reconstruction algorithms themselves, it can include modules for identification of experimental problems, artefact correction, general image processing and data quality assessment. Savu is open source, open licensed and 'facility-independent': it can run on standard cluster infrastructure at any institution.

Anisotropic modeling and joint-MAP stitching for improved ultrasound model-based iterative reconstruction of large and thick specimens

Energy Technology Data Exchange (ETDEWEB)

Almansouri, Hani [Purdue University; Venkatakrishnan, Singanallur V. [ORNL; Clayton, Dwight A. [ORNL; Polsky, Yarom [ORNL; Bouman, Charles [Purdue University; Santos-Villalobos, Hector J. [ORNL

2018-04-01

One-sided non-destructive evaluation (NDE) is widely used to inspect materials, such as concrete structures in nuclear power plants (NPP). A widely used method for one-sided NDE is the synthetic aperture focusing technique (SAFT). The SAFT algorithm produces reasonable results when inspecting simple structures. However, for complex structures, such as heavily reinforced thick concrete structures, SAFT results in artifacts and hence there is a need for a more sophisticated inversion technique. Model-based iterative reconstruction (MBIR) algorithms, which are typically equivalent to regularized inversion techniques, offer a powerful framework to incorporate complex models for the physics, detector miscalibrations and the materials being imaged to obtain high quality reconstructions. Previously, we have proposed an ultrasonic MBIR method that signifcantly improves reconstruction quality compared to SAFT. However, the method made some simplifying assumptions on the propagation model and did not disucss ways to handle data that is obtained by raster scanning a system over a surface to inspect large regions. In this paper, we propose a novel MBIR algorithm that incorporates an anisotropic forward model and allows for the joint processing of data obtained from a system that raster scans a large surface. We demonstrate that the new MBIR method can produce dramatic improvements in reconstruction quality compared to SAFT and suppresses articfacts compared to the perviously presented MBIR approach.

BREAST RECONSTRUCTIONS AFTER BREAST CANCER TREATING

Directory of Open Access Journals (Sweden)

Erik Vrabič

2018-02-01

Full Text Available Background. Breasts are an important symbol of physical beauty, feminity, mothering and sexual desire through the entire history of mankind. Lost of the whole or part of the breast is functional and aesthetic disturbance for woman. It is understandable, that the woman, who is concerned over breast loss, is as appropriate as another person´s concern over the loss of a limb or other body part. Before the 1960, breast reconstruction was considered as a dangerous procedure and it was almost prohibited. Considering the psychological importance of the breast in modern society, the possibility of breast reconstruction for the woman about to undergo a mastectomy is a comforting alternative. We can perform breast reconstruction with autologous tissue (autologous reconstruction, with breast implants and combination of both methods. For autologous reconstruction we can use local tissue (local flaps, or tissue from distant parts of the body (free vascular tissue transfer. Tissue expansion must be performed first, in many cases of breast reconstructions with breast implants. Conclusions. Possibility of breast reconstruction made a big progress last 3 decades. Today we are able to reconstruct almost every defect of the breast and the entire breast. Breast reconstruction rise the quality of life for breast cancer patients. Breast reconstruction is a team work of experts from many medicine specialites. In Slovenia we can offer breast reconstruction for breast cancer patients in Ljubljana, where plastic surgeons from Clinical Department for Plastic Surgery and Burns cooperate with oncologic surgeons. Ten years ago a similar cooperation between plastic surgeons and surgeons of the Centre for Breast Diseases was established in Maribor.

Evaluation of an intact, an ACL-deficient, and a reconstructed human knee joint finite element model.

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Vairis, Achilles; Stefanoudakis, George; Petousis, Markos; Vidakis, Nectarios; Tsainis, Andreas-Marios; Kandyla, Betina

2016-02-01

The human knee joint has a three-dimensional geometry with multiple body articulations that produce complex mechanical responses under loads that occur in everyday life and sports activities. Understanding the complex mechanical interactions of these load-bearing structures is of use when the treatment of relevant diseases is evaluated and assisting devices are designed. The anterior cruciate ligament (ACL) in the knee is one of four main ligaments that connects the femur to the tibia and is often torn during sudden twisting motions, resulting in knee instability. The objective of this work is to study the mechanical behavior of the human knee joint and evaluate the differences in its response for three different states, i.e., intact, ACL-deficient, and surgically treated (reconstructed) knee. The finite element models corresponding to these states were developed. For the reconstructed model, a novel repair device was developed and patented by the author in previous work. Static load cases were applied, as have already been presented in a previous work, in order to compare the calculated results produced by the two models the ACL-deficient and the surgically reconstructed knee joint, under the exact same loading conditions. Displacements were calculated in different directions for the load cases studied and were found to be very close to those from previous modeling work and were in good agreement with experimental data presented in literature. The developed finite element model for both the intact and the ACL-deficient human knee joint is a reliable tool to study the kinematics of the human knee, as results of this study show. In addition, the reconstructed human knee joint model had kinematic behavior similar to the intact knee joint, showing that such reconstruction devices can restore human knee stability to an adequate extent.

Reconstruction of a ring applicator using CT imaging: impact of the reconstruction method and applicator orientation

International Nuclear Information System (INIS)

Hellebust, Taran Paulsen; Tanderup, Kari; Bergstrand, Eva Stabell; Knutsen, Bjoern Helge; Roeislien, Jo; Olsen, Dag Rune

2007-01-01

The purpose of this study is to investigate whether the method of applicator reconstruction and/or the applicator orientation influence the dose calculation to points around the applicator for brachytherapy of cervical cancer with CT-based treatment planning. A phantom, containing a fixed ring applicator set and six lead pellets representing dose points, was used. The phantom was CT scanned with the ring applicator at four different angles related to the image plane. In each scan the applicator was reconstructed by three methods: (1) direct reconstruction in each image (DR) (2) reconstruction in multiplanar reconstructed images (MPR) and (3) library plans, using pre-defined applicator geometry (LIB). The doses to the lead pellets were calculated. The relative standard deviation (SD) for all reconstruction methods was less than 3.7% in the dose points. The relative SD for the LIB method was significantly lower (p < 0.05) than for the DR and MPR methods for all but two points. All applicator orientations had similar dose calculation reproducibility. Using library plans for applicator reconstruction gives the most reproducible dose calculation. However, with restrictive guidelines for applicator reconstruction the uncertainties for all methods are low compared to other factors influencing the accuracy of brachytherapy

Delayed vaginal reconstruction in the fibrotic pelvis following radiation or previous reconstruction

International Nuclear Information System (INIS)

Berek, J.S.; Hacker, N.F.; Lagasse, L.D.; Smith, M.L.

1983-01-01

Vaginal reconstruction was performed in 14 patients who had developed vaginal stenosis secondary to extensive pelvic fibrosis after pelvic radiation therapy (12 patients) or prior vaginal reconstruction (2 patients). Sixteen procedures were performed using a split-thickness skin graft. All patients had satisfactory vaginal restoration, and 12 patients reported good vaginal function. No fistula developed as a result of the operative procedure, but one patient later developed a rectovaginal fistula resulting from tumor recurrence. Successful vaginal reconstruction can be achieved even years after initial therapy in patients who develop an obliterated vagina from previous radiation or surgery

Three dimensional image reconstruction of computed tomograms of the head and neck in the pediatric age group

International Nuclear Information System (INIS)

Armstrong, E.A.; Smith, T.H.; Salyer, K.E.

1985-01-01

Between August 1983, and April 1984, we have clinically evaluated an experimental computed tomography (CT) software package capable of producing three dimensional (3-D) reconstructed images from axial CT scans. Three dimensional reconstructions have been performed in 115 patient CT examinations for congenital or acquired craniofacial abnormalities, 103 patients; intracranial neoplasms, 6 patients: and the cervical spine and craniocervical junction, 6 patients. Several patients have had studies pre- and postoperatively to plan craniofacial surgery and later evaluate its results on both the bone and soft tissue structures. The results indicate that three dimensional reconstruction using a low dose technique yields information valuable to conceptualize and demonstrate to clinicians the spatial relationships of often complex anatomical relationships in the craniofacial and craniocervical areas [fr

Upgrade to iterative image reconstruction (IR) in abdominal MDCT imaging. A clinical study for detailed parameter optimization beyond vendor recommendations using the adaptive statistical iterative reconstruction environment (ASIR)

International Nuclear Information System (INIS)

Mueck, F.G.; Koerner, M.; Scherr, M.K.; Geyer, L.L.; Deak, Z.; Linsenmaier, U.; Reiser, M.; Wirth, S.

2012-01-01

To compare the image quality of dose-reduced 64-row abdominal CT reconstructed at different levels of adaptive statistical iterative reconstruction (ASIR) to full-dose baseline examinations reconstructed with filtered back-projection (FBP) in a clinical setting and upgrade situation. Abdominal baseline examinations (noise index NI = 29; LightSpeed VCT XT, GE) were intra-individually compared to follow-up studies on a CT with an ASIR option (NI = 43; Discovery HD750, GE), n = 42. Standard-kernel images were calculated with ASIR blendings of 0 - 100 % in slice and volume mode, respectively. Three experienced radiologists compared the image quality of these 567 sets to their corresponding full-dose baseline examination (-2: diagnostically inferior, -1: inferior, 0: equal, +1: superior, +2: diagnostically superior). Furthermore, a phantom was scanned. Statistical analysis used the Wilcoxon - the Mann-Whitney U-test and the intra-class correlation (ICC). The mean CTDIvol decreased from 19.7 ± 5.5 to 12.2 ± 4.7 mGy (p 0.10). Volume mode performed 73 % slower than slice mode (p < 0.01). After the system upgrade, the vendor recommendation of ASIR 50 % in slice mode allowed for a dose reduction of 38 % in abdominal CT with comparable image quality and time expenditure. However, there is still further dose reduction potential for more complex reconstruction settings. (orig.)

Breast reconstruction following mastectomy: current status in Australia.

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Sandelin, Kerstin; King, Elizabeth; Redman, Sally

2003-09-01

Although breast reconstruction provides some advantages for women following mastectomy, few Australian breast cancer patients currently receive reconstruction. In Australia, the routine provision of breast reconstruction will require the development of specific health service delivery models. The present paper reports an analysis of the provision of breast reconstruction in eight sites in Australia. A semi-structured telephone interview was conducted with 10 surgeons offering breast reconstruction as part of their practice, including nine breast or general surgeons and one plastic surgeon. Surgeons reported offering breast reconstruction to all women facing mastectomy; the proportion of women deciding to have breast reconstruction varied between sites with up to 50% of women having a reconstruction at some sites. Most sites offered three types of reconstruction. Two pathways emerged: either the breast surgeon performed the breast surgery in a team with the plastic surgeon who undertook the breast reconstruction or the breast surgeon provided both the breast surgery and the reconstruction. Considerable waiting times for breast reconstruction were reported in the public sector particularly for delayed reconstruction. Surgeons reported receiving training in breast reconstruction from plastic surgeons or from a breast surgery team that performed reconstructions; a number had been trained overseas. No audits of breast reconstruction were being undertaken. Breast reconstruction can be offered on a routine basis in Australia in both the private and public sectors. Women may be more readily able to access breast reconstruction when it is provided by a breast surgeon alone, but the range of reconstruction options may be more limited. If access to breast reconstruction is to be increased, there will be a need to: (i) develop effective models for the rural sector taking account of the lack of plastic surgeons; (ii) address waiting times for reconstruction surgery in the

Optimizing Outcomes in Pharyngoesophageal Reconstruction and Neck Resurfacing: 10-Year Experience of 294 Cases.

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Sharaf, Basel; Xue, Amy; Solari, Mario G; Boa, Olivier; Liu, Jun; Hanasono, Matthew M; Skoracki, Roman; Yu, Peirong; Selber, Jesse C

2017-01-01

Pharyngoesophageal reconstruction is a complex endeavor that poses many challenges. This 10-year series examines factors impacting the need for neck skin resurfacing and evaluates the impact of reconstructive modalities on outcomes. A review identified 294 patients who underwent pharyngoesophageal reconstruction from 2002 to 2012. Patients were divided based on neck skin resurfacing requirements. Patients undergoing neck resurfacing were further subdivided into reconstructive technique, including a second skin paddle or muscle component from the same free flap pedicle, a local flap, or a second free flap. All groups were compared by comorbidities, complications, and functional outcomes. Of 294 patients, 179 (60.9 percent) required neck skin resurfacing. In the resurfaced group, there were 90 circumferential defects (50.3 percent) and 89 partial defects (49.7 percent). In the resurfaced group, 110 (61.4 percent) underwent reconstruction with a second skin paddle from the same free flap pedicle, 21 (11.7 percent) underwent reconstruction with a muscle component from the same pedicle, and 25 (13.9 percent) received a pectoralis major flap. There were five external paddle flap losses in the resurfaced group (2.8 percent) and no internal flap losses. Overall complications were similar among groups. The resurfaced group had a lower pharyngocutaneous fistula rate (4.5 percent) compared with the primary closure group (11.3 percent) (p = 0.026). Prior neck surgery and radiation therapy were strong predictors of neck skin resurfacing (p resurfacing is often required in salvage pharyngoesophageal reconstruction. Providing additional vascularized tissue over the neoconduit is predictive of lower pharyngocutaneous fistula rates. An algorithmic approach to neck resurfacing is presented.

Tomographic image reconstruction and rendering with texture-mapping hardware

International Nuclear Information System (INIS)

Azevedo, S.G.; Cabral, B.K.; Foran, J.

1994-07-01

The image reconstruction problem, also known as the inverse Radon transform, for x-ray computed tomography (CT) is found in numerous applications in medicine and industry. The most common algorithm used in these cases is filtered backprojection (FBP), which, while a simple procedure, is time-consuming for large images on any type of computational engine. Specially-designed, dedicated parallel processors are commonly used in medical CT scanners, whose results are then passed to graphics workstation for rendering and analysis. However, a fast direct FBP algorithm can be implemented on modern texture-mapping hardware in current high-end workstation platforms. This is done by casting the FBP algorithm as an image warping operation with summing. Texture-mapping hardware, such as that on the Silicon Graphics Reality Engine (TM), shows around 600 times speedup of backprojection over a CPU-based implementation (a 100 Mhz R4400 in this case). This technique has the further advantages of flexibility and rapid programming. In addition, the same hardware can be used for both image reconstruction and for volumetric rendering. The techniques can also be used to accelerate iterative reconstruction algorithms. The hardware architecture also allows more complex operations than straight-ray backprojection if they are required, including fan-beam, cone-beam, and curved ray paths, with little or no speed penalties

A Visual Framework for Digital Reconstruction of Topographic Maps

KAUST Repository

Thabet, Ali Kassem

2014-09-30

We present a framework for reconstructing Digital Elevation Maps (DEM) from scanned topographic maps. We first rectify the images to ensure that maps fit together without distortion. To segment iso-contours, we have developed a novel semi-automated method based on mean-shifts that requires only minimal user interaction. Contour labels are automatically read using an OCR module. To reconstruct the output DEM from scattered data, we generalize natural neighbor interpolation to handle the transfinite case (contours and points). To this end, we use parallel vector propagation to compute a discrete Voronoi diagram of the constraints, and a modified floodfill to compute virtual Voronoi tiles. Our framework is able to handle tens of thousands of contours and points and can generate DEMs comprising more than 100 million samples. We provide quantitative comparison to commercial software and show the benefits of our approach. We furthermore show the robustness of our method on a massive set of old maps predating satellite acquisition. Compared to other methods, our framework is able to accurately and efficiently generate a final DEM despite inconsistencies, sparse or missing contours even for highly complex and cluttered maps. Therefore, this method has broad applicability for digitization and reconstruction of the world\\'s old topographic maps that are often the only record of past landscapess and cultural heritage before their destruction under modern development.

Aesthetic refinements and reoperative procedures following 370 consecutive DIEP and SIEA flap breast reconstructions: important considerations for patient consent.

Science.gov (United States)

Enajat, Morteza; Smit, Jeroen M; Rozen, Warren M; Hartman, Ed H M; Liss, Anders; Kildal, Morten; Audolfsson, Thorir; Acosta, Rafael

2010-06-01

Breast reconstruction often requires multiple operations. In addition to potential complications requiring reoperation, additional procedures are frequently essential in order to complete the reconstructive process, with aesthetic outcome and breast symmetry shown to be the most important factors in patient satisfaction. Despite the importance of these reoperations in decision-making and the consent process, a thorough review of the need for such operations has not been definitively explored. A review of 370 consecutive autologous breast reconstructions (326 patients) was undertaken, comprising 365 deep inferior epigastric artery perforator (DIEP) flaps and 5 superficial inferior epigastric artery (SIEA) flaps. The need for additional procedures for either complications or aesthetic refinement following initial breast reconstruction was assessed. Overall, there was an average of 1.06 additional interventions for every patient carried out after primary reconstructive surgery. Of 326 patients, 46 underwent early postoperative operations for surgical complications (0.17 additional operations per patient as a consequence of complications). Procedures for aesthetic refinement included those performed on the reconstructed breast, contralateral breast, or abdominal donor site. Procedures for aesthetic refinement included nipple reconstruction, nipple-areola complex tattooing, dog-ear correction, liposuction, lipofilling, scar revision, mastopexy, and reduction mammaplasty. While DIEP flap surgery for breast reconstruction provides favorable results, patients frequently require additional procedures to improve aesthetic outcomes. The need for reoperation is an important part of the consent process prior to reconstructive surgery, and patients should recognize the likelihood of at least one additional procedure following initial reconstruction.

Petz recovery versus matrix reconstruction

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Holzäpfel, Milan; Cramer, Marcus; Datta, Nilanjana; Plenio, Martin B.

2018-04-01

The reconstruction of the state of a multipartite quantum mechanical system represents a fundamental task in quantum information science. At its most basic, it concerns a state of a bipartite quantum system whose subsystems are subjected to local operations. We compare two different methods for obtaining the original state from the state resulting from the action of these operations. The first method involves quantum operations called Petz recovery maps, acting locally on the two subsystems. The second method is called matrix (or state) reconstruction and involves local, linear maps that are not necessarily completely positive. Moreover, we compare the quantities on which the maps employed in the two methods depend. We show that any state that admits Petz recovery also admits state reconstruction. However, the latter is successful for a strictly larger set of states. We also compare these methods in the context of a finite spin chain. Here, the state of a finite spin chain is reconstructed from the reduced states of a few neighbouring spins. In this setting, state reconstruction is the same as the matrix product operator reconstruction proposed by Baumgratz et al. [Phys. Rev. Lett. 111, 020401 (2013)]. Finally, we generalize both these methods so that they employ long-range measurements instead of relying solely on short-range correlations embodied in such local reduced states. Long-range measurements enable the reconstruction of states which cannot be reconstructed from measurements of local few-body observables alone and hereby we improve existing methods for quantum state tomography of quantum many-body systems.

Quartet-net: a quartet-based method to reconstruct phylogenetic networks.

Science.gov (United States)

Yang, Jialiang; Grünewald, Stefan; Wan, Xiu-Feng

2013-05-01

Phylogenetic networks can model reticulate evolutionary events such as hybridization, recombination, and horizontal gene transfer. However, reconstructing such networks is not trivial. Popular character-based methods are computationally inefficient, whereas distance-based methods cannot guarantee reconstruction accuracy because pairwise genetic distances only reflect partial information about a reticulate phylogeny. To balance accuracy and computational efficiency, here we introduce a quartet-based method to construct a phylogenetic network from a multiple sequence alignment. Unlike distances that only reflect the relationship between a pair of taxa, quartets contain information on the relationships among four taxa; these quartets provide adequate capacity to infer a more accurate phylogenetic network. In applications to simulated and biological data sets, we demonstrate that this novel method is robust and effective in reconstructing reticulate evolutionary events and it has the potential to infer more accurate phylogenetic distances than other conventional phylogenetic network construction methods such as Neighbor-Joining, Neighbor-Net, and Split Decomposition. This method can be used in constructing phylogenetic networks from simple evolutionary events involving a few reticulate events to complex evolutionary histories involving a large number of reticulate events. A software called "Quartet-Net" is implemented and available at http://sysbio.cvm.msstate.edu/QuartetNet/.

An Algorithmic Approach for the Reconstruction of Nasal Skin Defects: Retrospective Analysis of 130 Cases

Directory of Open Access Journals (Sweden)

Berrak Akşam

2016-06-01

Full Text Available Objective: Most of the malignant cutaneous carcinomas are seen in the nasal region. Reconstruction of nasal defects is challenging because of the unique anatomic properties and complex structure of this region. In this study, we present our algorithm for the nasal skin defects that occurred after malignant skin tumor excisions. Material and Methods: Patients whose nasal skin was reconstructed after malignant skin tumor excision were included in the study. These patients were evaluated by their age, gender, comorbities, tumor location, tumor size, reconstruction type, histopathological diagnosis, and tumor recurrence. Results: A total of 130 patients (70 female, 60 male were evaluated. The average age of the patients was 67.8 years. Tumors were located mostly at the dorsum, alar region, and tip of the nose. When reconstruction methods were evaluated, primary closure was preferred in 14.6% patients, full thickness skin grafts were used in 25.3% patients, and reconstruction with flaps were the choice in 60% patients. Different flaps were used according to the subunits. Mostly, dorsal nasal flaps, bilobed flaps, nasolabial flaps, and forehead flaps were used. Conclusion: The defect-only reconstruction principle was accepted in this study. Previously described subunits, such as the dorsum, tip, alar region, lateral wall, columella, and soft triangles, of the nose were further divided into subregions by their anatomical relations. An algorithm was planned with these sub regions. In nasal skin reconstruction, this algorithm helps in selection the methods for the best results and minimize the complications.

Preoperative Planning Using 3D Reconstructions and Virtual Endoscopy for Location of the Frontal Sinus

Directory of Open Access Journals (Sweden)

Abreu, João Paulo Saraiva

2011-01-01

Full Text Available Introduction: Computed tomography (TC generated tridimensional (3D reconstructions allow the observation of cavities and anatomic structures of our body with detail. In our specialty there have been attempts to carry out virtual endoscopies and laryngoscopies. However, such application has been practically abandoned due to its complexity and need for computers with high power of graphic processing. Objective: To demonstrate the production of 3D reconstructions from CTs of patients in personal computers, with a free specific program and compare them to the surgery actual endoscopic images. Method: Prospective study in which the CTs proper files of 10 patients were reconstructed with the program Intage Realia, version 2009, 0, 0, 702 (KGT Inc., Japan. The reconstructions were carried out before the surgeries and a virtual endoscopy was made to assess the recess and frontal sinus region. After this study, the surgery was digitally performed and stored. The actual endoscopic images of the recess and frontal sinus region were compared to the virtual images. Results: The 3D reconstruction and virtual endoscopy were made in 10 patients submitted to the surgery. The virtual images had a large resemblance with the actual surgical images. Conclusion: With relatively simple tools and personal computer, we demonstrated the possibility to generate 3D reconstructions and virtual endoscopies. The preoperative knowledge of the frontal sinus natural draining path location may generate benefits during the performance of surgeries. However, more studies must be developed for the evaluation of the real roles of such 3D reconstructions and virtual endoscopies.

Freestyle multiple propeller flap reconstruction (jigsaw puzzle approach) for complicated back defects.

Science.gov (United States)

Park, Sung Woo; Oh, Tae Suk; Eom, Jin Sup; Sun, Yoon Chi; Suh, Hyun Suk; Hong, Joon Pio

2015-05-01

The reconstruction of the posterior trunk remains to be a challenge as defects can be extensive, with deep dead space, and fixation devices exposed. Our goal was to achieve a tension-free closure for complex defects on the posterior trunk. From August 2006 to May 2013, 18 cases were reconstructed with multiple flaps combining perforator(s) and local skin flaps. The reconstructions were performed using freestyle approach. Starting with propeller flap(s) in single or multilobed design and sequentially in conjunction with adjacent random pattern flaps such as fitting puzzle. All defects achieved tensionless primary closure. The final appearance resembled a jigsaw puzzle-like appearance. The average size of defect was 139.6 cm(2) (range, 36-345 cm(2)). A total of 26 perforator flaps were used in addition to 19 random pattern flaps for 18 cases. In all cases, a single perforator was used for each propeller flap. The defect and the donor site all achieved tension-free closure. The reconstruction was 100% successful without flap loss. One case of late infection was noted at 12 months after surgery. Using multiple lobe designed propeller flaps in conjunction with random pattern flaps in a freestyle approach, resembling putting a jigsaw puzzle together, we can achieve a tension-free closure by distributing the tension to multiple flaps, supplying sufficient volume to obliterate dead space, and have reliable vascularity as the flaps do not need to be oversized. This can be a viable approach to reconstruct extensive defects on the posterior trunk. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Breast Reconstruction After Solid Organ Transplant.

Science.gov (United States)

Koonce, Stephanie L; Giles, Brian; McLaughlin, Sarah A; Perdikis, Galen; Waldorf, James; Lemaine, Valerie; TerKonda, Sarvam

2015-09-01

Solid organ transplant patients frequently develop posttransplant malignancies including breast cancer. They may desire breast reconstruction after mastectomy, which could potentially be complicated by their transplant status, immunosuppressive regimen, and previous operations. We review our experience with patients who have undergone solid organ transplant and subsequent breast reconstruction after mastectomy After institutional review board approval, we queried our prospective breast reconstruction and solid organ transplant databases for corresponding patients. Inclusion criteria comprised breast reconstruction after solid organ transplant. A chart review was conducted of identified patients. Seventeen patients were identified: 1 pulmonary transplant, 4 cardiac transplants, 2 liver transplants, 1 pancreas transplant, 2 combined kidney/pancreas transplants, and 7 kidney transplants. Indications for mastectomy included posttransplant malignancy and prophylaxis. Median time from transplant to completion of reconstruction was 186 months (range, 11-336 months). Median age at transplant was 34.5 years (range, 21-65 years) with the median age of the patients at reconstructive surgery 51.5 years (range, 34-71 years). Median body mass index was 25.3 (range, 21.3-46.5). No significant complications were noted after reconstructive surgery. All patients were on full immunosuppression at time of reconstruction. Breast reconstruction is a viable option for transplant patients after mastectomy and should not be refused based on their transplant status. Close coordination with the transplant team and careful preoperative planning is essential for optimal outcomes.

Skin-Reducing Mastectomy in Immediate Reconstruction: How to Limit Complications and Failures.

Science.gov (United States)

Pechevy, Lolita; Carloni, Raphael; Guerid, Samia; Vincent, Pierre-Luc; Toussoun, Gilles; Delay, Emmanuel

2017-06-01

In hypertrophic and/or very ptotic breasts, skin-reducing mastectomy (SRM) is challenging and the risk of complications is high. Few publications have reported the use of an autologous latissimus dorsi flap (ALDF) in this indication. Most studies opt for implant reconstructions, with a high failure rate. We aimed to identify and present the technical refinements that reduce the risk of reconstruction failure in patients with hypertrophic and/or ptotic breasts with breast cancer or at risk of breast cancer after SRM with immediate breast reconstruction (IBR) utilizing an ALDF. Our retrospective study, covering a period of 18 years, included a series of 60 patients with hypertrophic and/or ptotic breasts who underwent 67 SRM and IBR procedures utilizing an ALDF. The complications were recorded and the risk factors analyzed. Sixty-seven SRMs were reviewed. Forty-nine procedures were performed with an inverted-T scar technique and 18 with a vertical scar technique. The nipple-areola complex (NAC) was preserved in 10 cases. There were eight (11.9%) cases of minor mastectomy flap necrosis after skin-reducing reconstructions, 16 (23.8%) wound dehiscences, no infections, no breast seromas, and no reconstruction failures. Smoking increased the risk of minor mastectomy flap necrosis (P = 0.048) and wound dehiscence (P = 0.002). Previous radiotherapy was associated with minor mastectomy flap necrosis (P = 0.001). The use of an ALDF together with technical refinements that preserve the vascular supply of the skin envelope leads to successful IBR with consistently good aesthetic results. Above all, it avoids failure of the reconstruction in very large or ptotic breasts. © 2017 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com

Imaging of high-energy midfacial trauma: what the surgeon needs to know

Energy Technology Data Exchange (ETDEWEB)

Linnau, Ken F.; Stanley, Robert B.; Hallam, Danial K.; Gross, Joel A.; Mann, F.A. E-mail: famann@u.washington.edu

2003-10-01

Treatment goals in severe midfacial trauma are restoration of function and appearance. Restoration of function is directed at multiple organ systems, which support visual acuity, airway patency, mastication, lacrimation, smelling, tasting, hearing, and facial expression. Victims of blunt facial trauma expect to look the same after surgical treatment as before injury. Delicate soft tissues of the midface often make cosmetic reconstructive surgery technically challenging. Generally, clinical evaluation alone does not suffice to fully characterize facial fractures associated with extensive swelling, and the deeper midface is not accessible to physical examination. Properly performed computed tomography (CT) overcomes most limitations of presurgical examination. Thus, operative approaches and sequencing of surgical repair are guided by imaging information displayed by CT. Restoration of function and appearance relies on recreating normal maxillofacial skeletal anatomy, with particular attention to position of the malar eminences, mandibular condyles, vertical dimension and orbital morphology. Due to its pivotal role in surgical planning, CT scans obtained for the evaluation of severe midfacial trauma should be designed to easily depict the imaging information necessary for clinical decision making. Learning objectives: 1. Understand the facial skeletal buttress system; 2. Understand how the pattern of derangement of the buttress system determines the need for and choice of operative approach for repair of fractures in the middle third of the face; 3. Understand the role and importance of CT and CT reformations in the detection and classification of the pattern of buttress system derangement.

Imaging of high-energy midfacial trauma: what the surgeon needs to know

International Nuclear Information System (INIS)

Linnau, Ken F.; Stanley, Robert B.; Hallam, Danial K.; Gross, Joel A.; Mann, F.A.

2003-01-01

Treatment goals in severe midfacial trauma are restoration of function and appearance. Restoration of function is directed at multiple organ systems, which support visual acuity, airway patency, mastication, lacrimation, smelling, tasting, hearing, and facial expression. Victims of blunt facial trauma expect to look the same after surgical treatment as before injury. Delicate soft tissues of the midface often make cosmetic reconstructive surgery technically challenging. Generally, clinical evaluation alone does not suffice to fully characterize facial fractures associated with extensive swelling, and the deeper midface is not accessible to physical examination. Properly performed computed tomography (CT) overcomes most limitations of presurgical examination. Thus, operative approaches and sequencing of surgical repair are guided by imaging information displayed by CT. Restoration of function and appearance relies on recreating normal maxillofacial skeletal anatomy, with particular attention to position of the malar eminences, mandibular condyles, vertical dimension and orbital morphology. Due to its pivotal role in surgical planning, CT scans obtained for the evaluation of severe midfacial trauma should be designed to easily depict the imaging information necessary for clinical decision making. Learning objectives: 1. Understand the facial skeletal buttress system; 2. Understand how the pattern of derangement of the buttress system determines the need for and choice of operative approach for repair of fractures in the middle third of the face; 3. Understand the role and importance of CT and CT reformations in the detection and classification of the pattern of buttress system derangement

Prosthetic breast reconstruction: indications and update

Science.gov (United States)

Quinn, Tam T.; Miller, George S.; Rostek, Marie; Cabalag, Miguel S.; Rozen, Warren M.

2016-01-01

Background Despite 82% of patients reporting psychosocial improvement following breast reconstruction, only 33% patients choose to undergo surgery. Implant reconstruction outnumbers autologous reconstruction in many centres. Methods A systematic review of the literature was undertaken. Inclusion required: (I) Meta-analyses or review articles; (II) adult patients aged 18 years or over undergoing alloplastic breast reconstruction; (III) studies including outcome measures; (IV) case series with more than 10 patients; (V) English language; and (VI) publication after 1st January, 2000. Results After full text review, analysis and data extraction was conducted for a total of 63 articles. Definitive reconstruction with an implant can be immediate or delayed. Older patients have similar or even lower complication rates to younger patients. Complications include capsular contracture, hematoma and infection. Obesity, smoking, large breasts, diabetes and higher grade tumors are associated with increased risk of wound problems and reconstructive failure. Silicone implant patients have higher capsular contracture rates but have higher physical and psychosocial function. There were no associations made between silicone implants and cancer or systemic disease. There were no differences in outcomes or complications between round and shaped implants. Textured implants have a lower risk of capsular contracture than smooth implants. Smooth implants are more likely to be displaced as well as having higher rates of infection. Immediate breast reconstruction (IBR) gives the best aesthetic outcome if radiotherapy is not required but has a higher rate of capsular contracture and implant failure. Delayed-immediate reconstruction patients can achieve similar aesthetic results to IBR whilst preserving the breast skin if radiotherapy is required. Delayed breast reconstruction (DBR) patients have fewer complications than IBR patients. Conclusions Implant reconstruction is a safe and popular

Quantum mechanics: why complex Hilbert space?

Science.gov (United States)

Cassinelli, G; Lahti, P

2017-11-13

We outline a programme for an axiomatic reconstruction of quantum mechanics based on the statistical duality of states and effects that combines the use of a theorem of Solér with the idea of symmetry. We also discuss arguments favouring the choice of the complex field.This article is part of the themed issue 'Second quantum revolution: foundational questions'. © 2017 The Author(s).

Right adrenal vein: comparison between adaptive statistical iterative reconstruction and model-based iterative reconstruction.

Science.gov (United States)

Noda, Y; Goshima, S; Nagata, S; Miyoshi, T; Kawada, H; Kawai, N; Tanahashi, Y; Matsuo, M

2018-06-01

To compare right adrenal vein (RAV) visualisation and contrast enhancement degree on adrenal venous phase images reconstructed using adaptive statistical iterative reconstruction (ASiR) and model-based iterative reconstruction (MBIR) techniques. This prospective study was approved by the institutional review board, and written informed consent was waived. Fifty-seven consecutive patients who underwent adrenal venous phase imaging were enrolled. The same raw data were reconstructed using ASiR 40% and MBIR. The expert and beginner independently reviewed computed tomography (CT) images. RAV visualisation rates, background noise, and CT attenuation of the RAV, right adrenal gland, inferior vena cava (IVC), hepatic vein, and bilateral renal veins were compared between the two reconstruction techniques. RAV visualisation rates were higher with MBIR than with ASiR (95% versus 88%, p=0.13 in expert and 93% versus 75%, p=0.002 in beginner, respectively). RAV visualisation confidence ratings with MBIR were significantly greater than with ASiR (pASiR (pASiR (p=0.0013 and 0.02). Reconstruction of adrenal venous phase images using MBIR significantly reduces background noise, leading to an improvement in the RAV visualisation compared with ASiR. Copyright © 2018 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Maxillary reconstruction

Directory of Open Access Journals (Sweden)

Brown James

2007-12-01

Full Text Available This article aims to discuss the various defects that occur with maxillectomy with a full review of the literature and discussion of the advantages and disadvantages of the various techniques described. Reconstruction of the maxilla can be relatively simple for the standard low maxillectomy that does not involve the orbital floor (Class 2. In this situation the structure of the face is less damaged and the there are multiple reconstructive options for the restoration of the maxilla and dental alveolus. If the maxillectomy includes the orbit (Class 4 then problems involving the eye (enopthalmos, orbital dystopia, ectropion and diplopia are avoided which simplifies the reconstruction. Most controversy is associated with the maxillectomy that involves the orbital floor and dental alveolus (Class 3. A case is made for the use of the iliac crest with internal oblique as an ideal option but there are other methods, which may provide a similar result. A multidisciplinary approach to these patients is emphasised which should include a prosthodontist with a special expertise for these defects.

Analysis of Variance of the Effects of a Project’s Location on Key Issues and Challenges in Post-Disaster Reconstruction Projects

Directory of Open Access Journals (Sweden)

Dzulkarnaen Ismail

2017-11-01

Full Text Available After a disaster, the reconstruction phase is driven by immediate challenges. One of the main challenges in the post-disaster period is the way that reconstruction projects are implemented. Reconstruction cannot move forward until some complex issues are settled. The purposes of this research are to highlight the issues and challenges in post-disaster reconstruction (PDR projects and to determine the significant differences between the issues and challenges in different locations where PDR projects are carried out. The researchers collected data within international non-governmental organisations (INGOs on their experience of working with PDR projects. The findings of this research provide the foundation on which to build strategies for avoiding project failures; this may be useful for PDR project practitioners in the future.