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Sample records for bloc spondylectomy reconstructions

  1. Two-stage multilevel en bloc spondylectomy with resection and replacement of the aorta.

    Science.gov (United States)

    Gösling, Thomas; Pichlmaier, Maximilian A; Länger, Florian; Krettek, Christian; Hüfner, Tobias

    2013-05-01

    We report a case of multilevel spondylectomy in which resection and replacement of the adjacent aorta were done. Although spondylectomy is nowadays an established technique, no report on a combined aortic resection and replacement has been reported so far. The case of a 43-year-old man with a primary chondrosarcoma of the thoracic spine is presented. The local pathology necessitated resection of the aorta. We did a two-stage procedure with resection and replacement of the aorta using a heart-lung machine followed by secondary tumor resection and spinal reconstruction. The procedure was successful. A tumor-free margin was achieved. The patient is free of disease 48 months after surgery. En bloc spondylectomy in combination with aortic resection is feasible and might expand the possibility of producing tumor-free margins in special situations.

  2. Treatment of Renal Cell Carcinoma with 2-Stage Total en bloc Spondylectomy after Marked Response to Molecular Target Drugs

    Directory of Open Access Journals (Sweden)

    Yasuhiro Inoue

    2013-01-01

    Full Text Available Metastatic renal cell carcinoma of the bone occurs at a high rate, and the prognosis is poor. In general, total en bloc spondylectomy is considered when there is only one vertebral metastasis and the primary disease is treated. However, palliative surgery is selected when the primary disease is not being treated or metastasis occurs to an important organ. We encountered a patient in whom lung and vertebra metastases were already present at the time of the first examination at our department and the prognosis was considered poor. However, molecular targeted therapy was markedly effective and enabled 2-stage total en bloc spondylectomy. As of one year after total en bloc spondylectomy, the condition has improved to cane gait, and surgery for lung metastasis is planned. Molecular target drugs might markedly change the current therapeutic strategy for renal cell carcinoma.

  3. The transmission of stress to grafted bone inside a titanium mesh cage used in anterior column reconstruction after total spondylectomy: a finite-element analysis.

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    Akamaru, Tomoyuki; Kawahara, Norio; Sakamoto, Jiro; Yoshida, Akira; Murakami, Hideki; Hato, Taizo; Awamori, Serina; Oda, Juhachi; Tomita, Katsuro

    2005-12-15

    A finite-element study of posterior alone or anterior/posterior combined instrumentation following total spondylectomy and replacement with a titanium mesh cage used as an anterior strut. To compare the effect of posterior instrumentation versus anterior/posterior instrumentation on transmission of the stress to grafted bone inside a titanium mesh cage following total spondylectomy. The most recent reconstruction techniques following total spondylectomy for malignant spinal tumor include a titanium mesh cage filled with autologous bone as an anterior strut. The need for additional anterior instrumentation with posterior pedicle screws and rods is controversial. Transmission of the mechanical stress to grafted bone inside a titanium mesh cage is important for fusion and remodeling. To our knowledge, there are no published reports comparing the load-sharing properties of the different reconstruction methods following total spondylectomy. A 3-dimensional finite-element model of the reconstructed spine (T10-L4) following total spondylectomy at T12 was constructed. A Harms titanium mesh cage (DePuy Spine, Raynham, MA) was positioned as an anterior replacement, and 3 types of the reconstruction methods were compared: (1) multilevel posterior instrumentation (MPI) (i.e., posterior pedicle screws and rods at T10-L2 without anterior instrumentation); (2) MPI with anterior instrumentation (MPAI) (i.e., MPAI [Kaneda SR; DePuy Spine] at T11-L1); and (3) short posterior and anterior instrumentation (SPAI) (i.e., posterior pedicle screws and rods with anterior instrumentation at T11-L1). The mechanical energy stress distribution exerted inside the titanium mesh cage was evaluated and compared by finite-element analysis for the 3 different reconstruction methods. Simulated forces were applied to give axial compression, flexion, extension, and lateral bending. In flexion mode, the energy stress distribution in MPI was higher than 3.0 x 10 MPa in 73.0% of the total volume inside

  4. Comparison between mono-bloc and bi-bloc mandibular advancement devices for obstructive sleep apnea.

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    Lee, Woo Hyun; Wee, Jee Hye; Lee, Chul Hee; Kim, Min-Su; Rhee, Chae-Seo; Yun, Pil-Young; Yoon, In-Young; Kim, Jeong-Whun

    2013-11-01

    Although mandibular advancement device (MAD) is widely used, there are a few papers comparing the efficacy and compliance at the same time according to the type of MAD. The aim of this study is to compare the efficacy and compliance between mono-bloc and bi-bloc MAD in the treatment of obstructive sleep apnea (OSA). Ninety-three patients who treated with mono-bloc MAD and 60 patients with bi-bloc MAD from January 2007 through September 2011 were retrospectively enrolled. All the patients underwent full-night polysomnography(PSG) before and 3 months after MAD was applied. The response rate was significantly higher in the patients using mono-bloc than those using bi-bloc MAD (77.4 vs. 58.3 %; P = 0.012). In contrast, the compliance rate of MAD use was significantly higher in the patients using bi-bloc than those using mono-bloc MAD (68.8 vs. 83.3 %; P = 0.044) at 1 year. According to the severity of OSA, the response rate was significantly higher in severe OSA than in mild to moderate OSA (P = 0.033 for mono-bloc MAD and P = 0.048 for bi-bloc MAD). However, there was no difference in the compliance between mild to moderate OSA and severe OSA. Our study showed that mono-bloc MAD was superior to bi-bloc MAD in efficacy while bi-bloc MAD is superior to mono-bloc MAD in compliance. We propose that both the efficacy and compliance should be considered in using MAD for treatment of OSA.

  5. En bloc urinary bladder resection for locally advanced colorectal cancer: a 17-year experience.

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    Li, Jimmy C M; Chong, Charing C N; Ng, Simon S M; Yiu, Raymond Y C; Lee, Janet F Y; Leung, Ka Lau

    2011-09-01

    En bloc bladder resection is often required for treating colorectal cancer with suspected urinary bladder invasion. Our aim was to review our institutional experience in en bloc resection of locally advanced colorectal cancer involving the urinary bladder over a period of 17 years. The hospital records of 72 patients with locally advanced colorectal cancer who underwent en bloc urinary bladder resection at our institution between July 1987 and December 2004 were retrospectively reviewed. Clinical and oncologic outcomes were evaluated. The mean duration of follow-up was 64.3 months. Genuine tumor invasion into the urinary bladder was confirmed in 34 patients (47%) by histopathology. Forty patients (56%) underwent primary closure of the urinary bladder, while 32 patients (44%) required various kinds of urologic reconstructive procedures. Operative mortality occurred in four patients (6%). The overall postoperative morbidity rate was significantly higher in patients undergoing urologic reconstruction (81% vs. 45%, p = 0.002) when compared to that in patients undergoing primary closure. This was mostly attributable to significantly higher rates of urinary anastomotic leak (21.9% vs. 0%, p = 0.002) and urinary tract infection (50% vs. 18%, p = 0.003) in the urologic reconstruction group. For the 57 patients (79%) who underwent curative resection, the 5-year overall survival rate was 59%, and the local recurrence at 5 years was 15%. Both parameters were not significantly affected by the presence of pathologic bladder invasion or the extent of surgical procedures. En bloc bladder resection for locally advanced colorectal cancer involving the urinary bladder can produce reasonable long-term local control and patient survival.

  6. Spondylectomy and lateral lumbar interbody fusion for thoracolumbar kyphosis in an adult with achondroplasia

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    Miyazaki, Masashi; Kanezaki, Shozo; Notani, Naoki; Ishihara, Toshinobu; Tsumura, Hiroshi

    2017-01-01

    Abstract Rationale: Fixed thoracolumbar kyphosis with spinal stenosis in adult patients with achondroplasia presents a challenging issue. We describe the first case in which spondylectomy and minimally invasive lateral access interbody arthrodesis were used for the treatment of fixed severe thoracolumbar kyphosis and lumbar spinal canal stenosis in an adult with achondroplasia. Patient concerns: A 61-year-old man with a history of achondroplastic dwarfism presented with low back pain and radiculopathy and neurogenic claudication. Diagnoses: Plain radiographs revealed a high-grade thoracolumbar kyphotic deformity with diffuse degenerative changes in the lumbar spine. The apex was located at L2, the local kyphotic angle from L1 to L3 was 105°, and the anterior area was fused from the L1 to L3 vertebrae. MRI revealed significant canal and lateral recess stenosis secondary to facet hypertrophy. Interventions: We planned a front-back correction of the anterior and posterior spinal elements. We first performed anterior release at the fused part from L1 to L3 and XLIF at L3/4 and L4/5. Next, the patient was placed in the prone position. Spondylectomy at the L2 vertebra and posterior fusion from T10 to L5 were performed. Postoperative radiographs revealed L1 to L3 kyphosis of 32°. Outcomes: No complications occurred during or after surgery. Postoperatively, the patient's low back pain and neurological claudication were resolved. No worsening of kyphosis was observed 24 months postoperatively. Lessons: Circumferential decompression of the spinal cord at the apical vertebral level and decompression of lumbar canal stenosis were necessary. Front-back correction of the anterior and posterior spinal elements via spondylectomy and lateral lumbar interbody fusion is a reasonable surgical option for thoracolumbar kyphosis and developmental canal stenosis in patients with achondroplasia. PMID:29245270

  7. [Reimplantation of devitalized tumor-bearing bone in pelvic reconstruction after en-bloc tumor resection].

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    Yang, Yi; Guo, Wei; Yang, Rongli; Tang, Xiaodong; Yan, Taiqiang; Ji, Tao; Wei, Ran

    2014-10-01

    To analyze the clinical outcome of an operative technique using recycling bones to reconstruct pelvis after primary malignant pelvic tumor resection. Fifteen patients who presented with malignant pelvic tumors were treated by wide or marginal resection and reconstruction using recycling bone in our institute from January 2003 to December 2011. The median age was 31 (15-62) years, and the most common diagnosis was chondrosarcoma, followed by Ewing sarcoma. The operative technique consisted of en-bloc excision of the pelvic tumor, removal of soft tissue, curettage of the tumor, incubated in 65 °C 20% hypertonic saline for 30 minutes, reimplantation of recycling bone, and internal fixation with plates, screws and/or total hip replacement. Bone cement was used to augment bone strength when necessary. Bone healing features and function of lower limbs were evaluated with the International Society of Limb Salvage (ISOLS) graft evaluation method and Musculoskeletal Tumor Society (MSTS) score, respectively. Adjuvant therapies were used according to the type and extension of the primary tumor. One patient died of severe peri-operative bleeding 2 days after operation, and the other patients were followed-up for 6 to 96 months (mean 40.4 months), and 5 patients died of local recurrence or metastasis. Eleven operations were followed by complications of any kind. Most mechanical complications were related to the use of hip arthroplasties, where implant breakdown and dislocation were the commonest.Infection was seen in 7 cases (superficial 4 cases and deep 3 cases). Healing and functional scores were fair. The median ISOLS score and MSTS score were 81.0% (range 30.0% to 95.0%) and 60.0% (range 23.0% to 93.0%), respectively. Recycling reconstruction technique is valid for young patients with low-grade chondrosarcoma or other chemo-sensitive tumor in pelvis. Although many complications are seen, this method remains our treatment of choice.

  8. CORPOR- AND SPONDYLECTOMYIN SYSTEM OF SURGICAL TREATMENT OF VERTEBRAL TUMORS

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    V. D. Usikov

    2010-01-01

    Full Text Available The authors have reported the 10-years experience of treatment of 571 patient with spinal tumors. Radical resection (en bloc of tumors was done in 114 cases (65 - corpectomy, 55 - spondylectomy. The rate of tumors recurrence was - 9%, it depended from type of tumors and it's size.

  9. Spondylectomy and lateral lumbar interbody fusion for thoracolumbar kyphosis in an adult with achondroplasia: A case report.

    Science.gov (United States)

    Miyazaki, Masashi; Kanezaki, Shozo; Notani, Naoki; Ishihara, Toshinobu; Tsumura, Hiroshi

    2017-12-01

    Fixed thoracolumbar kyphosis with spinal stenosis in adult patients with achondroplasia presents a challenging issue. We describe the first case in which spondylectomy and minimally invasive lateral access interbody arthrodesis were used for the treatment of fixed severe thoracolumbar kyphosis and lumbar spinal canal stenosis in an adult with achondroplasia. A 61-year-old man with a history of achondroplastic dwarfism presented with low back pain and radiculopathy and neurogenic claudication. Plain radiographs revealed a high-grade thoracolumbar kyphotic deformity with diffuse degenerative changes in the lumbar spine. The apex was located at L2, the local kyphotic angle from L1 to L3 was 105°, and the anterior area was fused from the L1 to L3 vertebrae. MRI revealed significant canal and lateral recess stenosis secondary to facet hypertrophy. We planned a front-back correction of the anterior and posterior spinal elements. We first performed anterior release at the fused part from L1 to L3 and XLIF at L3/4 and L4/5. Next, the patient was placed in the prone position. Spondylectomy at the L2 vertebra and posterior fusion from T10 to L5 were performed. Postoperative radiographs revealed L1 to L3 kyphosis of 32°. No complications occurred during or after surgery. Postoperatively, the patient's low back pain and neurological claudication were resolved. No worsening of kyphosis was observed 24 months postoperatively. Circumferential decompression of the spinal cord at the apical vertebral level and decompression of lumbar canal stenosis were necessary. Front-back correction of the anterior and posterior spinal elements via spondylectomy and lateral lumbar interbody fusion is a reasonable surgical option for thoracolumbar kyphosis and developmental canal stenosis in patients with achondroplasia.

  10. Pelvic reconstruction with allogeneic bone graft after tumor resection

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    Wang, Wei; Bi, Wen Zhi; Yang, Jing; Han, Gang; Jia, Jin Peng

    2013-01-01

    OBJECTIVES : Pelvic reconstruction after tumor resection is challenging. METHODS: A retrospective study had been preformed to compare the outcomes among patients who received pelvic reconstructive surgery with allogeneic bone graft after en bloc resection of pelvic tumors and patients who received en bloc resection only. RESULTS: Patients without reconstruction had significantly lower functional scores at 3 months (10 vs. 15, P = 0.001) and 6 months after surgery (18.5 vs. 22, P = 0.0024), a shorter duration of hospitalization (16 day vs. 40 days, P 0.05). CONCLUSIONS : Pelvic reconstruction with allogeneic bone graft after surgical management of pelvic tumors is associated with satisfactory surgical and functional outcomes. Further clinical studies are required to explore how to select the best reconstruction method. Level of Evidence IV, Case Series. PMID:24453659

  11. Creation of false pedicles and a neo-pelvis for lumbopelvic reconstruction following en bloc resection of an iliosacral chondrosarcoma with lumbar spine extension: technical note.

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    Mendel, Ehud; Nathoo, Narendra; Scharschmidt, Thomas; Schmidt, Carl; Boehmler, James; Mayerson, Joel L

    2014-03-01

    En bloc resection with negative tumor margins remains the principal treatment option for control or cure of primary pelvic chondrosarcomas, as current adjuvant therapies remain ineffective. Iliosacral chondrosarcomas with involvement of the sciatic notch are sufficiently challenging tumors. However, when there is concomitant lumbar extension requiring resection of the pedicles to maintain negative surgical margins, transpedicular screw fixation is not possible, making reconstruction of the lumbopelvic junction extremely challenging. A patient with an iliosacral chondrosarcoma with lumbar spine extension is presented in this report to illustrate a novel lumbopelvic spinal construct. Following combined external pelvectomy and hemisacrectomy with contralateral L3-5 hemilaminectomy and ipsilateral pediculotomy, bicortical transvertebral body screws were substituted for the missing pedicles, resulting in the creation of "false pedicles," which were further supplemented with an autologous vascularized fibular strut graft from the amputated lower limb and applied to the lateral aspect of the vertebral bodies. The creation of false pedicles allowed for a robust reconstruction of the lumbopelvic junction, including maintaining pelvic ring integrity with a "neo-pelvis", creating a functional load-bearing construct adequate for early mobilization and ambulation. The biomechanical dynamics of this unique construct are also discussed.

  12. Nuclear power in the Soviet Bloc

    International Nuclear Information System (INIS)

    Davey, W.G.

    1982-03-01

    The growth of Soviet Bloc nuclear power generation to the end of the century is evaluated on the basis of policy statements of objectives, past and current nuclear power plant construction, and trends in the potential for future construction. Central to this study is a detailed examination of individual reactor construction and site development that provides specific performance data not given elsewhere. A major commitment to nuclear power is abundantly clear and an expansion of ten times in nuclear electric generation is estimated between 1980 and 2000. This rate of growth is likely to have significant impact upon the total energy economy of the Soviet Bloc including lessening demands for use of coal, oil, and gas for electricity generation

  13. Nuclear power in the Soviet Bloc

    Energy Technology Data Exchange (ETDEWEB)

    Davey, W.G.

    1982-03-01

    The growth of Soviet Bloc nuclear power generation to the end of the century is evaluated on the basis of policy statements of objectives, past and current nuclear power plant construction, and trends in the potential for future construction. Central to this study is a detailed examination of individual reactor construction and site development that provides specific performance data not given elsewhere. A major commitment to nuclear power is abundantly clear and an expansion of ten times in nuclear electric generation is estimated between 1980 and 2000. This rate of growth is likely to have significant impact upon the total energy economy of the Soviet Bloc including lessening demands for use of coal, oil, and gas for electricity generation.

  14. Reconstruction of the Midfoot Using a Free Vascularized Fibular Graft After En Bloc Excision for Giant Cell Tumor of the Tarsal Bones: A Case Report.

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    Hara, Hitomi; Kawamoto, Teruya; Onishi, Yasuo; Fujioka, Hiroyuki; Nishida, Kotaro; Kuroda, Ryosuke; Kurosaka, Masahiro; Akisue, Toshihiro

    2016-01-01

    We report the case of a 32-year-old Japanese female with a giant cell tumor of bone involving multiple midfoot bones. Giant cell tumors of bone account for approximately 5% of all primary bone tumors and most often arise at the ends of long bones. The small bones, such as those of the hands and feet, are rare sites for giant cell tumors. Giant cell tumors of the small bones tend to exhibit more aggressive clinical behavior than those of the long bones. The present patient underwent en bloc tumor excision involving multiple tarsals and metatarsals. We reconstructed the longitudinal arch of the foot with a free vascularized fibular graft. At the 2-year follow-up visit, bony union had been achieved, with no tumor recurrence. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  15. Eficacia del proceso de esterilización de los Mini-Endo-bloc

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    Maritza Eraso Rodríguez

    2017-01-01

    Full Text Available El Mini-Endo-Bloc® es un elemento usado para mediar las limas durante la endodoncia, presenta muchas concavidades y orificios que dificultan el proceso de esterilización y pueden promover la infección cruzada o comprometer el pronóstico del tratamiento endodóntico. Objetivo: Observar la eficacia de la esterilización de los Mini-Endo-Bloc® utilizados en la clínica de la Federación Odontológica Colombiana (FOC. Métodos: Se recolectaron 60 Mini-Endo-Bloc® utilizados en pacientes que presentaban diagnósticos de necrosis pulpar y periodontitis apical, lo cuales se dividieron en dos grupos: Grupo control: 12 Mini-Endo-Bloc® desinfectados y no esterilizados. Grupo experimental: 48 Mini-Endo-Bloc® desinfectados y esterilizados, se realizó, según lo recomendado por la Farmacopea USPXXXV, prueba de esterilidad en Caldo Thioglycollate a 37°C, medio de caldo Casoy a 37°C y medio de caldo Casoy a 25°C para determinar presencia de bacterias, levaduras y hongos. Resultados: Al someter los Mini-Endo-Bloc® al protocolo de esterilización establecido por la FOC y teniendo en cuenta los parámetros de las pruebas de esterilidad, en el grupo experimental el 50% (n=24, fueron reprobadas (crecimiento microorganismos y 50% (n = 24 fueron aprobadas (no crecimiento de microorganismos. Discusión: la mitad de las muestras fueron reprobadas, estos resultados pueden ser por fallas en el proceso de desinfección mecánica manual directa, el cual se dificulta en los Mini-Endo-Bloc®, debido a su estructura y diseño, permitiendo que residuos biológicos permanezcan en la superficie del instrumento, evitando que el vapor saturado entre en contacto con el material o los microorganismos durante la esterilización.

  16. Oncological superiority of hilar en bloc resection for the treatment of hilar cholangiocarcinoma.

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    Neuhaus, Peter; Thelen, Armin; Jonas, Sven; Puhl, Gero; Denecke, Timm; Veltzke-Schlieker, Wilfried; Seehofer, Daniel

    2012-05-01

    Long-term results after liver resection for hilar cholangiocarcinoma are still not satisfactory. Previously, we described a survival advantage of patients who undergo combined right trisectionectomy and portal vein resection, a procedure termed "hilar en bloc resection." The present study was conducted to analyze its oncological effectiveness compared to conventional hepatectomy. During hilar en bloc resection, the extrahepatic bile ducts were resected en bloc with the portal vein bifurcation, the right hepatic artery, and liver segments 1 and 4 to 8. With this "no-touch" technique, preparation of the hilar vessels in the vicinity of the tumor was avoided. The long-term outcome of 50 consecutive patients who underwent curative (R0) hilar en bloc resection between 1990 and 2004 was compared to that of 50 consecutive patients who received curative conventional major hepatectomy for hilar cholangiocarcinoma (perioperative deaths excluded). The 1-, 3-, and 5-year survival rates after hilar en bloc resection were 87%, 70%, and 58%, respectively, which was significantly higher than after conventional major hepatectomy. In the latter group, 1-, 3-, and 5-year survival rates were 79%, 40%, and 29%, respectively (P = 0.021). Tumor characteristics were comparable in both groups. A high number of pT3 and pT4 tumors and patients with positive regional lymph nodes were present in both groups. Multivariate analysis identified hilar en bloc resection as an independent prognostic factor for long-term survival (P = 0.036). In patients with central bile duct carcinomas, hilar en bloc resection is oncologically superior to conventional major hepatectomy, providing a chance of long-term survival even in advanced tumors.

  17. En Bloc Resection of Primary Malignant Bone Tumor in the Cervical Spine Based on 3-Dimensional Printing Technology.

    Science.gov (United States)

    Xiao, Jian-Ru; Huang, Wen-Ding; Yang, Xing-Hai; Yan, Wang-Jun; Song, Dian-Wen; Wei, Hai-Feng; Liu, Tie-Long; Wu, Zhi-Peng; Yang, Cheng

    2016-05-01

    To investigate the feasibility and safety of en bloc resection of cervical primary malignant bone tumors by a combined anterior and posterior approach based on a three-dimensional (3-D) printing model. Five patients with primary malignant bone tumors of the cervical spine underwent en bloc resection via a one-stage combined anteroposterior approach in our hospital from March 2013 to June 2014. They comprised three men and two women of mean age 47.2 years (range, 26-67 years). Three of the tumors were chondrosarcomas and two chordomas. Preoperative 3-D printing models were created by 3-D printing technology. Sagittal en bloc resections were planned based on these models and successfully performed. A 360° reconstruction was performed by spinal instrumentation in all cases. Surgical margins, perioperative complications, local control rate and survival rate were assessed. All patients underwent en bloc excision via a combined posterior and anterior approach in one stage. Mean operative time and estimated blood loss were 465 minutes and 1290 mL, respectively. Mean follow-up was 21 months. Wide surgical margins were achieved in two patients and marginal resection in three; these three patients underwent postoperative adjuvant radiation therapy. One vertebral artery was ligated and sacrificed in each of three patients. Nerve root involved by tumor was sacrificed in three patients with preoperative upper extremity weakness. One patient (Case 3) had significant transient radiculopathy with paresis postoperatively. Another (Case 4) with C 4 and C 5 chordoma had respiratory difficulties and pneumonia after surgery postoperatively. He recovered completely after 2 weeks' management with a tracheotomy tube and antibiotics in the intensive care unit. No cerebrovascular complications and wound infection were observed. No local recurrence or instrumentation failure were detected during follow-up. Though technically challenging, it is feasible and safe to perform en

  18. BLOC-3 mutated in Hermansky-Pudlak syndrome is a Rab32/38 guanine nucleotide exchange factor.

    Science.gov (United States)

    Gerondopoulos, Andreas; Langemeyer, Lars; Liang, Jin-Rui; Linford, Andrea; Barr, Francis A

    2012-11-20

    Hermansky-Pudlak syndrome (HPS) is a human disease characterized by partial loss of pigmentation and impaired blood clotting. These symptoms are caused by defects in the biogenesis of melanosomes and platelet dense granules, often referred to as lysosome-related organelles. Genes mutated in HPS encode subunits of the biogenesis of lysosome-related organelles complexes (BLOCs). BLOC-1 and BLOC-2, together with the AP-3 clathrin adaptor complex, act at early endosomes to sort components required for melanin formation and melanosome biogenesis away from the degradative lysosomal pathway toward early stage melanosomes. However the molecular functions of the Hps1-Hps4 complex BLOC-3 remain mysterious. Like other trafficking pathways, melanosome biogenesis and transport of enzymes involved in pigmentation involves specific Rab GTPases, in this instance Rab32 and Rab38. We now demonstrate that BLOC-3 is a Rab32 and Rab38 guanine nucleotide exchange factor (GEF). Silencing of the BLOC-3 subunits Hps1 and Hps4 results in the mislocalization of Rab32 and Rab38 and reduction in pigmentation. In addition, we show that BLOC-3 can promote specific membrane recruitment of Rab32/38. BLOC-3 therefore defines a novel Rab GEF family with a specific function in the biogenesis of lysosome-related organelles. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. [En bloc renal transplant from infant donors to adults].

    Science.gov (United States)

    Gómez Vegas, A; Blázquez Izquierdo, J; Pérez Contín, M J; Grimalt Alvarez, J; Rabadán Marina, M; Hermida Gutiérrez, J F; Prats, D; Resel Estévez, L

    1998-12-01

    To analyze the medium-term outcome of en bloc transplantation of pediatric kidneys into adult patients, including the incidence and type of surgical complications. From November 1991 to December 1997, we performed 37 en bloc transplantation of pediatric kidneys into adult patients. The kidneys were harvested from donors less that 3 years old and/or weighing 15 kg. The mean follow-up was 24 months. Grafting was achieved by end-to-side anastomosis of the donor cava to the receptor external iliac and the aortic patch to the external iliac artery. Three grafts failed, probably due to hilar torsion; the remaining were initially functioning well. Seven transplant removal were performed; 6 were due to thrombosis. The actuarial graft survival was 89.1% at one month, 80.83% at 12 months and 80.83% at 24 months. The medium-term results of en bloc transplantation of pediatric kidneys into adult patients were excellent and demonstrate the efficacy of this type of grafts. Arterial and venous thrombosis were the most important complications, quantitatively and qualitatively.

  20. [Three-dimensional finite element modeling and biomechanical simulation for evaluating and improving postoperative internal instrumentation of neck-thoracic vertebral tumor en bloc resection].

    Science.gov (United States)

    Qinghua, Zhao; Jipeng, Li; Yongxing, Zhang; He, Liang; Xuepeng, Wang; Peng, Yan; Xiaofeng, Wu

    2015-04-07

    To employ three-dimensional finite element modeling and biomechanical simulation for evaluating the stability and stress conduction of two postoperative internal fixed modeling-multilevel posterior instrumentation ( MPI) and MPI with anterior instrumentation (MPAI) with neck-thoracic vertebral tumor en bloc resection. Mimics software and computed tomography (CT) images were used to establish the three-dimensional (3D) model of vertebrae C5-T2 and simulated the C7 en bloc vertebral resection for MPI and MPAI modeling. Then the statistics and images were transmitted into the ANSYS finite element system and 20N distribution load (simulating body weight) and applied 1 N · m torque on neutral point for simulating vertebral displacement and stress conduction and distribution of motion mode, i. e. flexion, extension, bending and rotating. With a better stability, the displacement of two adjacent vertebral bodies of MPI and MPAI modeling was less than that of complete vertebral modeling. No significant differences existed between each other. But as for stress shielding effect reduction, MPI was slightly better than MPAI. From biomechanical point of view, two internal instrumentations with neck-thoracic tumor en bloc resection may achieve an excellent stability with no significant differences. But with better stress conduction, MPI is more advantageous in postoperative reconstruction.

  1. Trade Blocs, Currency Blocs and the Disintegration of World Trade in the 1930s

    OpenAIRE

    Eichengreen, Barry; Irwin, Douglas

    1993-01-01

    The dramatic implosion and regionalization of international trade during the 1930s has often been blamed on the trade and foreign exchange policies that emerged in the interwar period. We provide new evidence on the impact of trade and currency blocs on trade flows from 1928 1938 that suggests a blanket indictment of interwar trade policies and payments arrangements is not warranted. Discriminatory trade policies and international monetary arrangements had neither a uniformly favorable nor un...

  2. The Reconfiguration of the Transnational Power Bloc in the Crisis

    DEFF Research Database (Denmark)

    Ougaard, Morten

    2016-01-01

    The current political conjuncture is analysed as a crisis of hegemony in the transnational power bloc. The previous hegemonic crisis of the 1970s lasted about ten years before the neo-liberal hegemonic project was firmly established. This new regime evolved in two stages, the first marked......’ and ‘black’ capital, and between the old industrialised countries and the emerging economies. Using patterns of political contestation and policy development as indicators of changes in power relations it is concluded that finance is still part of the power bloc but no longer hegemonic; that green capital...

  3. Periprosthetic soft tissue recurrence of chondroblastoma after attempted en bloc excision from the proximal humerus

    Energy Technology Data Exchange (ETDEWEB)

    Hammond, G.W.; Tehranzadeh, J.; Hoang, B.H. [University of California, Irvine, Department of Orthopaedic Surgery, Orange (United States); Gu, M. [University of California, Irvine, Department of Pathology, Orange (United States)

    2006-01-01

    A case of soft tissue recurrence of chondroblastoma after attempted en bloc excision and endoprosthetic replacement is described. This tumor in the proximal humerus recurred after initial curettage and was subsequently treated by attempted en bloc excision with positive microscopic margins. The patient then presented with a large soft tissue recurrence surrounding the endoprosthesis. This periprosthetic recurrence necessitated re-excision and revision of the endoprosthesis. Recurrence is not uncommon following curettage of chondroblastoma. However, less is known about soft tissue recurrence after en bloc resection of this tumor with positive margins. A subset of chondroblastoma may exist with more locally aggressive behavior. (orig.)

  4. En bloc resection of extra-peritoneal soft tissue neoplasms incorporating a type III internal hemipelvectomy: a novel approach

    Directory of Open Access Journals (Sweden)

    Reddy Sanjay S

    2012-10-01

    Full Text Available Abstract Background A type III hemipelvectomy has been utilized for the resection of tumors arising from the superior or inferior pubic rami. Methods In eight patients, we incorporated a type III internal hemipelvectomy to achieve an en bloc R0 resection for tumors extending through the obturator foramen or into the ischiorectal fossa. The pelvic ring was reconstructed utilizing marlex mesh. This allowed for pelvic stability and abdominal wall reconstruction with obliteration of the obturator space to prevent herniations. Results All eight patients had an R0 resection with an overall survival of 88% and with average follow up of 9.5 years. Functional evaluation utilizing the Enneking classification system, which evaluates motion, pain, stability and strength of the affected extremity, revealed a 62% excellent result and a 37% good result. No significant complications were associated with the operative procedure. Marlex mesh reconstruction provided pelvic stability and eliminated all hernial defects. Conclusion The superior and inferior pubic rami provide a barrier to a resection for tumors that arise in the extra-peritoneal pelvis extending through the obturator foramen or ischiorectal fossa. Incorporating a type III internal hemipelvectomy with a simple marlex mesh reconstruction allows for complete tumor resection without functional compromise, acute infectious issues, obturator or abdominal hernia defects.

  5. Reconstruction of maxillary cemento-ossifying fibroma defect with buccal pad of fat.

    Science.gov (United States)

    Sivaraj, Subramonian; Jeevadhas, Pratheep

    2013-07-01

    A cemento-ossifying fibroma (COF) is a rare benign neoplasm of maxilla when compared with mandible (World Health Organization, 1992). COF of maxilla may be quite large and locally very aggressive lesion. These tumor mass was peeled out by en-bloc excision using gentle blunt dissection. This paper presents 35-year-old male patient who had a gradually expanding lobular mass in the left maxillary posterior region for past 1 year. He has been treated successfully by surgical en-bloc resection. Various techniques were used to reconstruction the defect. Buccal pad of fat is a simple technique having advantages like good vascularity, adaptability, good closure of the defect with favorable prognosis.

  6. En bloc kidney transplantation: ultrasonography assessment

    International Nuclear Information System (INIS)

    Arenal, F.; Ganado, T.; Merino, M.S.; Contreras, E.; Hernandez, J.; Prats, D.

    1997-01-01

    The objective of our study is to assess the utility of ultrasonography in the study of the complications associated with en bloc kidney transplantation. Twenty-three recipients of double transplants from donors under the age of 3 years were studied. Ultrasound (mode B: pulsed Doppler and color Doppler) was performed within the first three postoperative days and was repeated at 6 and 12 months. The morphology of the graft and renal blood flow were assessed, and the indices of pulsatility, resistance and acceleration were measured. Four patients required graft explanation: three due to massive hemorrhagic infarction and one due to venous thrombosis. Vascular complications were detected in five transplants (21.7%), urological complications in four (17.4%) and medical complications in two (8.7%). The most common vascular complication was unilateral renal artery stenosis. Color Doppler ultrasound diagnosed all the medical and urological complications and three of the five cases of vascular pathology (60%). Renal size was seen to be increased during the first postoperative year. The ultrasonographic study is more difficult to perform in en bloc kidney transplantation than in single kidney grafting: however, given its marked sensitivity in the detection of postransplantation complications. Doppler ultrasound is the imaging technique of choice in the determination of the cause of deteriorated kidney function. (Author) 15 refs

  7. Soviet Diplomacy and Its Role in Creation and Activity of the National Bloc in Iran (1922-1924

    Directory of Open Access Journals (Sweden)

    Yuriy A. Demin

    2017-10-01

    Full Text Available The article deals with the history of the National bloc in Iran that demonstrates an example of the combination of ideological and pragmatic inclinations in the Soviet foreign policy of the early 1920s. The renunciation of the “export of revolution” strategy and the transition to the support of the Iranian independence demanded the appropriate forms of work with the local political forces. B.Z. Shumyatsky, a creator of the bloc, conceived it as a social basis for the “national” government to come, which would set Iran on the path of development and independence. However, during the first months of its existence, the National bloc confronted with a number of contradictions, which contributed to its final defeat. Shumyatsky’s striving to overthrow Qavam al-Saltaneh led to the extension of the bloc ranks in the Majles with the representatives of the various rival groups and made it an amorphous and unstable coalition. Similarly, the slogan for the struggle against “foreigners” charged against the bloc, when the cabinet of Mostoufi al-Mamalek was discredited by the opponents as the Moscow’s protйgй. At the same time, structural and ideological feebleness of the Iranian parties and the trade unions of those years hampered the bloc’s transformation into the mass and centralized political power. The influence of war minister (later Prime Minister Reza Khan and Moscow’s support of his centralization activity led the National bloc into the alliance with that political figure. As a result, the bloc quickly passed the way from the separate political project to the junior partner of the coalition and finally faced with the changed plans of the military dictator to leave the political stage.

  8. Idabloki unustatud kino : Ülevaade konverentiskogumikust "Via Transversa : Lost Cinema of the Former Eastern Bloc" / Martin Oja

    Index Scriptorium Estoniae

    Oja, Martin, 1978-

    2009-01-01

    2007. a. oktoobris Tallinnas toimunud konverentsi "Via Transversa : Lost Cinema of the Former Eastern Bloc" ettekannetel põhinevast kogumikust: Via Transversa : Lost Cinema of the Former Eastern Bloc / editors Eva Näripea, Andreas Trossek. Tallinn : Eesti Kunstiakadeemia, 2008. (Koht ja paik ; 7)

  9. Surgical technique for en bloc transurethral resection of bladder tumour with a Hybrid Knife(®).

    Science.gov (United States)

    Islas-García, J J O; Campos-Salcedo, J G; López-Benjume, B I; Torres-Gómez, J J; Aguilar-Colmenero, J; Martínez-Alonso, I A; Gil-Villa, S A

    2016-05-01

    Bladder cancer is the second most common malignancy of the urinary tract and the 9th worldwide. Latin American has an incidence of 5.6 per 100,000 inhabitants per year. Seventy-five percent of newly diagnosed cases are nonmuscle invasive bladder cancer, and 25% of cases present as muscle invasive. The mainstay of treatment for nonmuscle invasive bladder cancer is loop transurethral resection. In 2013, the group led by Dr Mundhenk of the University Hospital of Tübingen, Germany, was the first to describe the Hybrid Knife(®) equipment for performing en bloc bladder tumour resection, with favourable functional and oncological results. To describe the surgical technique of en bloc bladder tumour resection with a Hybrid Knife(®) as an alternative treatment for nonmuscle invasive bladder tumours. A male patient was diagnosed by urotomography and urethrocystoscopy with a bladder tumour measuring 2×1cm on the floor. En bloc transurethral resection of the bladder tumour was performed with a Hybrid Knife(®). Surgery was performed for 35min, with 70 watts for cutting and 50 watts for coagulation, resecting and evacuating en bloc the bladder tumour, which macroscopically included the muscle layer of the bladder. There were no complications. The technique of en bloc bladder tumour resection with Hybrid Knife(®) is an effective alternative to bipolar loop transurethral resection. Resection with a Hybrid Knife(®) is a procedure with little bleeding and good surgical vision and minimises the risk of bladder perforation and tumour implants. The procedure facilitates determining the positivity of the neoplastic process, vascular infiltration and bladder muscle invasion in the histopathology study. Copyright © 2015 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. Corrupt Organizational Hierarchies in the Former Soviet Bloc

    OpenAIRE

    Osipian, Ararat

    2007-01-01

    Increasing scale and scope of corruption in the former Soviet Bloc, as well as numerous other countries, urges better understanding of the problem within the context of socio-economic transformations as it touches upon issues of organizational structures. This paper presents an overview of the research on corruption in organizations and develops models of corrupt organizations, including the vertical structure, the horizontal structure, and the hierarchy, as applied to transition economies.

  11. Outcomes following attempted en bloc resection of cervical chordomas in the C-1 and C-2 region versus the subaxial region: a multiinstitutional experience.

    Science.gov (United States)

    Molina, Camilo A; Ames, Christopher P; Chou, Dean; Rhines, Laurence D; Hsieh, Patrick C; Zadnik, Patricia L; Wolinsky, Jean-Paul; Gokaslan, Ziya L; Sciubba, Daniel M

    2014-09-01

    Chordomas involving the mobile spine are ideally managed via en bloc resection with reconstruction to optimize local control and possibly offer cure. In the cervical spine, local anatomy poses unique challenges, limiting the feasibility of aggressive resection. The authors present a multi-institutional series of 16 cases of cervical chordomas removed en bloc. Particular attention was paid to clinical outcome, complications, and recurrence. In addition, outcomes were assessed according to position of tumor at the C1-2 level versus the subaxial (SA) spine (C3-7). The authors reviewed cases involving patients who underwent en bloc resection of cervical chordoma at 4 large spine centers. Patients were included if the lesion epicenter involved the C-1 to C-7 vertebral bodies. Demographic data and details of surgery, follow-up course, exposure to adjuvant therapy, and complications were obtained. Outcome was correlated with presence of tumor in C1-2 versus subaxial spine via a Student t-test. Sixteen patients were identified (mean age at presentation 55 ± 14 years). Seven cases (44%) cases involved C1-2, and 16 involved the subaxial spine. Median survival did not differ significantly different between the C1-2 (72 months) and SA (60 months) groups (p = 0.65). A combined (staged anteroposterior) approach was used in 81% of the cases. Use of the combined approach was significantly more common in treatment of subaxial than C1-2 tumors (100% vs 57%, p = 0.04). En bloc resection was attempted via an anterior approach in 6% of cases (C1-2: 14.3%; SA: 0%; p = 0.17) and a posterior approach in 13% of cases (C1-2: 29%; SA: 0%; p = 0.09). The most commonly reported margin classification was marginal (56% of cases), followed by violated (25%) and wide (19%). En bloc excision of subaxial tumors was significantly more likely to result in marginal margins than excision of C1-2 tumors (C1-2: 29%; SA: 78%; p = 0.03). C1-2 tumors were associated with significantly higher rates of

  12. Corruption Hierarchies in Higher Education in the Former Soviet Bloc

    Science.gov (United States)

    Osipian, Ararat L.

    2009-01-01

    Corruption in higher education is known but not described theoretically. Decentralization and privatization of higher education and the increasing scale and scope of corruption in higher education in the former Soviet Bloc, as well as numerous other countries, urges better understanding of the problem within the context of socio-economic…

  13. Human Capital--Economic Growth Nexus in the Former Soviet Bloc

    Science.gov (United States)

    Osipian, Ararat L.

    2007-01-01

    This study analyses the role and impact of higher education on per capita economic growth in the Former Soviet Bloc. It attempts to estimate the significance of educational levels for initiating substantial economic growth that now takes place in these two countries. This study estimates a system of linear and log-linear equations that account for…

  14. En-bloc Transplantation: an Eligible Technique for Unilateral Dual Kidney Transplantation.

    Science.gov (United States)

    Salehipour, M; Bahador, A; Nikeghbalian, S; Kazemi, K; Shamsaeifar, A R; Ghaffaripour, S; Sahmeddini, M A; Salahi, H; Bahreini, A; Janghorban, P; Gholami, S; Malek-Hosseini, S A

    2012-01-01

    Kidney transplantation is the best available treatment for patients with end-stage renal disease. To evaluate the en bloc anastomosis technique for unilateral dual kidney transplantation (DKT). From May to October 2011, 5 patients (4 women and 1 man) with mean age of 31.8 years underwent unilateral DKT with this technique in which distal end of the aorta and proximal end of inferior vena cava (IVC) were closed with running sutures. Then, proximal end of the aorta and distal end of the IVC were anastomosed to internal (or external) iliac artery and external iliac vein, respectively. Post-operative course was uneventful. No vascular and urologic complications developed; all patient had acceptable serum creatinine at discharge time and up of 2-6 months of post-operation follow up. Unilateral DKT is a safe method for performing DKT. The proposed en bloc anastomosis can improve the outcome of the graft by reducing the cold ischemia and the operation time.

  15. Phrenic nerve reconstruction in complete video-assisted thoracic surgery.

    Science.gov (United States)

    Kawashima, Shun; Kohno, Tadasu; Fujimori, Sakashi; Yokomakura, Naoya; Ikeda, Takeshi; Harano, Takashi; Suzuki, Souichiro; Iida, Takahiro; Sakai, Emi

    2015-01-01

    Primary or metastatic lung cancer or mediastinal tumours may at times involve the phrenic nerve and pericardium. To remove the pathology en bloc, the phrenic nerve must be resected. This results in phrenic nerve paralysis, which in turn reduces pulmonary function and quality of life. As a curative measure of this paralysis and thus a preventive measure against decreased pulmonary function and quality of life, we have performed immediate phrenic nerve reconstruction under complete video-assisted thoracic surgery, and with minimal additional stress to the patient. This study sought to ascertain the utility of this procedure from an evaluation of the cases experienced to date. We performed 6 cases of complete video-assisted thoracic surgery phrenic nerve reconstruction from October 2009 to December 2013 in patients who had undergone phrenic nerve resection or separation to remove tumours en bloc. In all cases, it was difficult to separate the phrenic nerve from the tumour. Reconstruction involved direct anastomosis in 3 cases and intercostal nerve interposition anastomosis in the remaining 3 cases. In the 6 patients (3 men, 3 women; mean age 50.8 years), we performed two right-sided and four left-sided procedures. The mean anastomosis time was 5.3 min for direct anastomosis and 35.3 min for intercostal nerve interposition anastomosis. Postoperative phrenic nerve function was measured on chest X-ray during inspiration and expiration. Direct anastomosis was effective in 2 of the 3 patients, and intercostal nerve interposition anastomosis was effective in all 3 patients. Diaphragm function was confirmed on X-ray to be improved in these 5 patients. Complete video-assisted thoracic surgery phrenic nerve reconstruction was effective for direct anastomosis as well as for intercostal nerve interposition anastomosis in a small sample of selected patients. The procedure shows promise for phrenic nerve reconstruction and further data should be accumulated over time. © The

  16. Primary antral carcinoma managed by en-bloc radical maxillectomy with orbital exenteration

    Directory of Open Access Journals (Sweden)

    Sajal Kumar Sarkar

    2014-01-01

    Full Text Available The prognosis of maxillary sinus carcinomas is not very promising. Maxillary sinus carcinomas are usually diagnosed at advanced stages and the proximity of important organs such as the eyes and cranial nerves makes complete surgical resection difficult. We here present a case that presented late with squamous cell carcinoma and was treated by radiotherapy (RT followed by radical maxillectomy with en-bloc orbital exenteration. Patients who undergo RT followed by en-bloc radical maxillectomy with orbital exenteration as salvage, in these cases may have promising results. We had raised forehead fascio cutaneous flap and translocated it deep to the upper eyelid to bridge the cutaneous defect. Forehead defect was covered with split-thickness skin taken from left thigh. No microvascular surgery was done, but cosmetic results were comparable. In rural setups of developing countries where facilities for microvascular surgery are lacking flap translocation may have a positive outcome.

  17. Exploitation of the bloc 17: development schemes for Rosa-Lirio; L'exploitation du bloc 17: des schemas de developpement pour Rosa-Lirio

    Energy Technology Data Exchange (ETDEWEB)

    Legros, E.

    2002-12-01

    New developments are expected on the prolific bloc 17 of the Angola offshore. Among the tenth of discoveries that followed the discovery of the Girassol giant field, TotalFinaElf initially selected the Dalia field, for which engineering studies started in December 2000. However, it is still not excluded that the development of the Rosa-Lirio field will start first. This article describes the specific characteristics of this field and the solutions proposed for its exploitation. (J.S.)

  18. Nonmetastatic Ewing’s Sarcoma of the Lumbar Spine in an Adult Patient

    Directory of Open Access Journals (Sweden)

    Maurizio Iacoangeli

    2012-01-01

    Full Text Available Although the spine is frequently involved in metastatic Ewing's sarcoma, primary involvement of the spine, beside sacrum, is much less frequent, especially in adult patients. Because of the low incidence of these tumors, there are currently no clinical guidelines outlining their management and a multitude of therapeutic strategies have been employed with varying success. The definitive management of Ewing's sarcoma of the spine, as in other locations, could include the combination of three main modalities: aggressive surgery, radiotherapy, and combined chemotherapy. Whenever possible, en bloc spondylectomy or extralesional resection is preferable, providing a better oncological result with a longer survival and a better preservation of the spine biomechanics. This is the lesson we learned about the case, we present here, of nonmetastatic lumbar localization by Ewing’s sarcoma in as adult patient.

  19. En bloc ligation of renal vessels is safe and reduces duration of surgery

    DEFF Research Database (Denmark)

    Azawi, Nessn Htum; Hult, Mariam Annalisa Skibsted; Dahl, Claus

    2016-01-01

    INTRODUCTION: Conventionally, individual ligation of the renal vessels with clips is performed during laparoscopic nephrectomy (LN). Concomitant ligation of the vessels is not a standard procedure due to an expected risk of stapler dysfunction and the development of arteriovenous fistulas (AVF......). Using the EndoGIA stapler 45/2.5 mm, we compared en bloc ligation with individual ligation during LN and nephroureterectomy (LNU) with a special focus on the development of AVF and technique safety. METHODS: This was a retrospective study of all patients undergoing LN or LNU at the Department of Urology......, Roskilde Hospital, Denmark, between January 2010 and April 2014. The follow-up period was minimum six months. RESULTS: A total of 228 patients underwent LN and 56 patients underwent LNU. In the LN group, 77 patients underwent en bloc ligation. The mean surgical time was significantly reduced to 89 minutes...

  20. Chaîne de blocs | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    7 déc. 2017 ... Des édutiants dans une salle de classe, Tambon Mae La, Myanmar. Zi Jian Lim. La technologie des chaînes de blocs pourrait appuyer et améliorer la gouvernance démocratique et les programmes de développement, mais le degré élevé de sophistication et les exigences complexes du point de vue de ...

  1. En Bloc Hilar Dissection of the Right Hepatic Artery in Continuity with the Bile Duct: a Technique to Reduce Biliary Complications After Adult Living-Donor Liver Transplantation.

    Science.gov (United States)

    Abu-Gazala, Samir; Olthoff, Kim M; Goldberg, David S; Shaked, Abraham; Abt, Peter L

    2016-04-01

    Techniques that preserve the right hepatic artery and the common bile duct in continuity during the dissection may be associated with lower rates of biliary complications in living-donor liver transplants. This study sought to determine whether en bloc hilar dissections were associated with fewer biliary complications in living-donor liver transplants. This was a retrospective review of 41 adult LDLTs performed in a single, liver transplant center between February 2007 and September 2014. The primary outcome of interest was the occurrence of at least one of the following biliary complications: anastomotic leak, stricture, or biloma. The primary predictor of interest was the hilar dissection technique: conventional hilar dissection vs. en bloc hilar dissection. A total of 41 LDLTs were identified, 24 had a conventional, and 17 an en bloc hilar biliary dissection. The occurrence of any biliary complication was significantly more common in the conventional hilar dissection group compared to the en bloc hilar dissection group (66.7 vs. 35.3%, respectively, p = 0.047). In particularly, anastomotic strictures were significantly more common in the conventional hilar dissection group compared to the en bloc hilar dissection group (54.2 vs. 23.5%., respectively, p = 0.049). En bloc hilar dissection technique may decrease biliary complication rates in living donor liver transplants.

  2. Giant desmoid tumour of the thorax following latissimus dorsi and implant breast reconstruction: case report and review of the literature

    LENUS (Irish Health Repository)

    Collins, AM

    2017-03-01

    The case of a giant thoracic desmoid tumour in a 44-year-old woman, who presented two years following a breast reconstruction with a latissimus dorsi (LD) flap and implant, is reported. Clinical findings included a rapidly growing, painless mass. Computed tomography (CT) suggested skin and intercostal soft tissue invasion. The tumour was resected en bloc with the LD muscle, implant capsule and underlying rib segments. The resultant thoracic and abdominal wall defects were reconstructed with Dualmesh® and polypropylene meshes respectively. There was no evidence of recurrence at thirty-six months follow-up.

  3. Utility of Amplatzer Vascular Plug with Preoperative Common Hepatic Artery Embolization for Distal Pancreatectomy with En Bloc Celiac Axis Resection

    Energy Technology Data Exchange (ETDEWEB)

    Toguchi, Masafumi, E-mail: e024163@yahoo.co.jp; Tsurusaki, Masakatsu; Numoto, Isao; Hidaka, Syojiro; Yamakawa, Miho [Kindai University, Department of Radiology, Faculty of Medicine (Japan); Asato, Nobuyuki [Kindai University, Department of Radiology, Faculty of Medicine, Nara Hospital (Japan); Im, SungWoon; Yagyu, Yukinobu; Matsuki, Mitsuru [Kindai University, Department of Radiology, Faculty of Medicine (Japan); Takeyama, Yoshifumi [Kindai University, Department of Surgery, Faculty of Medicine (Japan); Murakami, Takamichi [Kindai University, Department of Radiology, Faculty of Medicine (Japan)

    2017-03-15

    PurposeTo evaluate the feasibility and safety of the Amplatzer vascular plug (AVP) for preoperative common hepatic embolization (CHA) before distal pancreatectomy with en bloc celiac axis resection (DP-CAR) to redistribute blood flow to the stomach and liver via the superior mesenteric artery (SMA).Materials and MethodsFour patients (3 males, 1 female; median age 69 years) with locally advanced pancreatic body cancer underwent preoperative CHA embolization with AVP. After embolization, SMA arteriography was performed to confirm the alteration of blood flow from the SMA to the proper hepatic artery.ResultsIn three of four patients, technical successes were achieved with sufficient margin from the origin of gastroduodenal artery. In one patient, the margin was less than 5 mm, although surgery was successfully performed without any problem. Eventually, all patients underwent the DP-CAR without arterial reconstruction or liver ischemia.ConclusionsAVP application is feasible and safe as an embolic procedure for preoperative CHA embolization of DP-CAR.

  4. Utility of Amplatzer Vascular Plug with Preoperative Common Hepatic Artery Embolization for Distal Pancreatectomy with En Bloc Celiac Axis Resection

    International Nuclear Information System (INIS)

    Toguchi, Masafumi; Tsurusaki, Masakatsu; Numoto, Isao; Hidaka, Syojiro; Yamakawa, Miho; Asato, Nobuyuki; Im, SungWoon; Yagyu, Yukinobu; Matsuki, Mitsuru; Takeyama, Yoshifumi; Murakami, Takamichi

    2017-01-01

    PurposeTo evaluate the feasibility and safety of the Amplatzer vascular plug (AVP) for preoperative common hepatic embolization (CHA) before distal pancreatectomy with en bloc celiac axis resection (DP-CAR) to redistribute blood flow to the stomach and liver via the superior mesenteric artery (SMA).Materials and MethodsFour patients (3 males, 1 female; median age 69 years) with locally advanced pancreatic body cancer underwent preoperative CHA embolization with AVP. After embolization, SMA arteriography was performed to confirm the alteration of blood flow from the SMA to the proper hepatic artery.ResultsIn three of four patients, technical successes were achieved with sufficient margin from the origin of gastroduodenal artery. In one patient, the margin was less than 5 mm, although surgery was successfully performed without any problem. Eventually, all patients underwent the DP-CAR without arterial reconstruction or liver ischemia.ConclusionsAVP application is feasible and safe as an embolic procedure for preoperative CHA embolization of DP-CAR.

  5. MUST ONCOLOGICAL PRINCIPLES BE IN THE SURGERY OF MENINGIOMAS? EN BLOC REMOVAL OF GIANT RIGHT FRONTAL MENINGIOMA WITH EXTRACRANIAL SPREAD. DESCRIPTION OF A CLINICAL CASE

    Directory of Open Access Journals (Sweden)

    V. B. Karakhan

    2014-01-01

    Full Text Available The use of the oncological principle – en bloc ablastic tumor resection – can expect a breakthrough in the treatment of baseline unfavorable patient groups. In the described case of atypical meningioma, its en bloc resection presents significant technical difficulties when accomplishing the task associated with the giant sizes of a tumor as an iceberg growing outside and into the cranial cavity, its rich vascularization from both the internal and external carotid artery system, with the involvement of the superior sagittal sinus, the presence of a dense bone crown that combines the three-component construction of a neoplasm, which made difficult safe mobilization and scanning in the cranial cavity.In such topographic variants, the criteria for the Simpson radical meningioma resection are inapplicable and only en bloc tumor resection may reflect the oncological principles of surgery. The technologies of en bloc resection of intracranial meningiomas should be more frequently used because preoperative neurovisualization and even histological diagnosis does not always allow the grade of meningiomas to be specified.

  6. [En bloc resection and vaporization techniques for the treatment of bladder cancer].

    Science.gov (United States)

    Struck, J P; Karl, A; Schwentner, C; Herrmann, T R W; Kramer, M W

    2018-04-12

    Modifications in resection techniques may overcome obvious limitations of conventionally performed transurethral resection (e. g., tumor fragmentation) of bladder tumors or provide an easier patient treatment algorithm (e. g., tumor vaporization). The present review article summarizes the current literature in terms of en bloc resection techniques, histopathological quality, complication rates, and oncological outcomes. A separate data search was performed for en bloc resection (ERBT, n = 27) and vaporization (n = 15) of bladder tumors. In most cases, ERBT is performed in a circumferential fashion. Alternatively, ERBT may be performed by undermining the tumor base via antegrade application of short energy impulses. Based on high rates of detrusor in specimens of ERBT (90-100%), a better histopathological quality is assumed. Significant differences in perioperative complication rates have not been observed, although obturator-nerve-based bladder perforations are not seen when laser energy is used. There is a nonstatistically significant trend towards lower recurrence rates in ERBT groups. Tumor vaporization may provide a less invasive technique for older patients with recurrences of low-risk bladder cancer. It can be performed in an outpatient setting. ERBT may provide better histopathological quality. Tumor vaporization is performed in health care systems where reimbursement is adequate.

  7. Clinical features and surgical management of spinal osteoblastoma: a retrospective study in 18 cases.

    Directory of Open Access Journals (Sweden)

    Zhonghai Li

    Full Text Available OBJECTIVES: To investigate the clinical manifestation and surgical outcome of spinal osteoblastoma. METHODS: From June 2006 to July 2011, 18 patients with spinal osteoblastoma treated surgically were analyzed retrospectively. There were 11 males and 7 females with an average age of 27.5 years(range, 16-38 years. The tumors were located at C5 in 7, C6 in 6, C7 in 3, C6-T1 1 in 1 and T11 in 1. Based on WBB classification, 16 were 1-3 or 10-12 and 2 were 4-9 and 1-3. 18 operations had been performed with en bloc resection. A posterior approach was used for 16 patients, and a combined posterior and anterior approach was used for 2 patients. Reconstruction using instrumentation and fusion was performed using spinal instrumentation in 13 patients. We used visual analogue scales (VAS to evaluate the change of pain before and after the operation, and the McCormick System to assess functional status of the spine. Imaging test was used to review the stability and recurrence rate of spine cord, and the confluence of graft bones. RESULTS: All cases were followed up for 24-80 months (average, 38.4 months. The average surgical time was 120.8 minutes (range, 80-220 minutes, with the average intraoperative blood loss of 520 ml (range, 300-1200 ml. During the follow-up period, the VAS grade reduced from 6.46±1.32 to 2.26±1.05 (P <0.05. 15 patients had neurological function improved and 3 remained no change which was evaluated by McCormick scale for spinal function status at final follow-up. CONCLUSIONS: Spinal osteoblastoma has its own specific radiographic features. There is some recurrence in simple curettage of tumor lesion. The thoroughly en bloc resection of tumor or spondylectomy, bone fusion and strong in Ter fixation are the key points for successful surgical treatment.

  8. Outcome of urinary bladder recurrence after partial cystectomy for en bloc urinary bladder adherent colorectal cancer resection.

    Science.gov (United States)

    Luo, Hao Lun; Tsai, Kai Lung; Lin, Shung Eing; Chiang, Po Hui

    2013-05-01

    Around 10 % of colorectal cancers are locally advanced at diagnosis. There are higher incidences for sigmoid and rectal cancer adhered to urinary bladder (UB) rather than other segments of colon cancer. Surgeons often performed partial cystectomy as possible for preservation of patient's life quality. This study investigates prognostic factors in patients who underwent bladder preservation en bloc resection for UB adherent colorectal cancer. From 2000 to 2011, 123 patients with clinically UB involvement colorectal cancer underwent primary colorectal cancer with urinary bladder resection. Seventeen patients were excluded because of the concurrent distant metastasis at diagnosis and another 22 patients were excluded because of total cystectomy with uretero-ileal urinary diversion. Finally, 84 patients with clinical stage IIIC (T4bN0M0, according to AJCC 7th edition) that underwent en bloc colorectal cancer resection with partial cystectomy were enrolled into this study for further analysis. Preoperative colovesical fistula and positive CT result were significantly more in the urinary bladder invasion group (p = 0.043 and 0.010, respectively). Pathological UB invasion is an independent predictor of intravesical recurrence (p = 0.04; HR, 10.71; 95 % CI = 1.12∼102.94) and distant metastasis (p = 0.016; HR, 4.85; 95 % CI = 1.34 ∼ 17.53) in multivariate analysis. For bladder preservation en bloc resection of urinary bladder adherent colorectal cancer, the pathological urinary bladder invasion is significantly associated with more urinary bladder recurrence and distant metastasis. This result helps surgeons make decisions at surgical planning and establish follow-up protocol.

  9. Esophageal circumferential en bloc endoscopic submucosal dissection: assessment of a new technique.

    Science.gov (United States)

    Barret, Maximilien; Pratico, Carlos Alberto; Beuvon, Frédéric; Mangialavori, Luigi; Chryssostalis, Ariane; Camus, Marine; Chaussade, Stanislas; Prat, Frédéric

    2013-10-01

    Endoscopic esophageal piecemeal mucosectomy for high-grade dysplasia on Barrett's esophagus leads to suboptimal histologic evaluation, as well as recurrence on remaining mucosa. Circumferential en bloc mucosal resection would significantly improve the management of dysplastic Barrett's esophagus. Our aim was to describe a new method of esophageal circumferential endoscopic en bloc submucosal dissection (CESD) in a swine model. After submucosal injection, circumferential incision was performed at each end of the esophageal segment to be removed. Mechanical submucosal dissection was performed from the proximal to the distal incision, using a mucosectomy cap over the endoscope. The removed mucosal ring was retrieved. Clinical, endoscopic, and histologic data were prospectively collected. Esophageal CESD was conducted on 5 pigs. A median mucosal length of 6.5 cm (range, 4 to 8 cm) was removed in the lower third of the esophagus. The mean duration of the procedure was 36 minutes (range, 17 to 80 min). No procedure-related complication, including perforation, was observed. All animals exhibited a mild esophageal stricture at day 7, and a severe symptomatic stricture at day 14. Necropsy confirmed endoscopic findings with cicatricial fibrotic strictures. On histologic examination, an inflammatory cell infiltrate, diffuse fibrosis reaching the muscular layer, and incomplete reepithelialization were observed. CESD enables expeditious resection and thorough examination of large segments of esophageal mucosa in safe procedural conditions, but esophageal strictures occur in the majority of the cases. Efficient methods for stricture prevention are needed for this technique to be developed in humans.

  10. Interkosmos the Eastern bloc's early space program

    CERN Document Server

    Burgess, Colin

    2016-01-01

    This book focuses on the Interkosmos program, which was formed in 1967, marking a fundamentally new era of cooperation by socialist countries, led by the Soviet Union, in the study and exploration of space. The chapters shed light on the space program that was at that time a prime outlet for the Soviet Union's aims at becoming a world power. Interkosmos was a highly publicized Russian space program that rapidly became a significant propaganda tool for the Soviet Union in the waning years of communism. Billed as an international “research-cosmonaut” imperative, it was also a high-profile means of displaying solidarity with the nine participating Eastern bloc countries. Those countries contributed pilots who were trained in Moscow for week-long “guest” missions on orbiting Salyut stations. They did a little subsidiary science and were permitted only the most basic mechanical maneuvers. In this enthralling new book, and following extensive international research, the authors fully explore ...

  11. Laparoscopic Transvesical Resection of an En Bloc Bladder Cuff and Distal Ureter during Nephroureterectomy

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    Stilianos Giannakopoulos

    2012-01-01

    Full Text Available Objective. The most appropriate technique for excising the distal ureter and bladder cuff during laparoscopic nephroureterectomy is still debated. We report our experience with a pure laparoscopic transvesical method that duplicates the long-standing open transvesical approach. Materials and Methods. Seven men and three women diagnosed with upper tract transitional cell carcinoma were treated with this procedure. Three intravesical ports were inserted, and pneumovesicum was established at 12 mmHg. Transvesical laparoscopic circumferential detachment of the bladder cuff and en bloc mobilization of the last centimeters of the distal ureter were performed, followed by the closure of the bladder defect. Subsequently, a nephrectomy was performed either laparoscopically or using an open flank approach. Results. The median age was 68.5 years. The procedure was completed uneventfully in all cases. The median operating time for distal ureter excision was 82.5 minutes (range 55–120. No complications directly related to the pneumovesicum method were recorded. The median follow-up period was 31 months (range 12–55. During the follow-up period, two patients (20% died from the disease, and a bladder tumor developed in three cases (30%. Conclusion. The laparoscopic transvesical resection of the en bloc bladder cuff and distal ureter is a reliable, effective, and oncologically safe technique, at least in the midterm.

  12. Leiomyosarcoma of the inferior vena cava level II involvement: curative resection and reconstruction of renal veins

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    Wang Quan

    2012-06-01

    Full Text Available Abstract Leiomyosarcoma of the inferior vena cava (IVCL is a rare retroperitoneal tumor. We report two cases of level II (middle level, renal veins to hepatic veins IVCL, who underwent en bloc resection with reconstruction of bilateral or left renal venous return using prosthetic grafts. In our cases, IVCL is documented to be occluded preoperatively, therefore, radical resection of tumor and/or right kidney was performed and the distal end of inferior vena cava was resected and without caval reconstruction. None of the patients developed edema or acute renal failure postoperatively. After surgical resection, adjuvant radiation therapy was administrated. The patients have been free of recurrence 2 years and 3 months, 9 months after surgery, respectively, indicating the complete surgical resection and radiotherapy contribute to the better survival. The reconstruction of inferior vena cava was not considered mandatory in level II IVCL, if the retroperitoneal venous collateral pathways have been established. In addition to the curative resection of IVCL, the renal vascular reconstruction minimized the risks of procedure-related acute renal failure, and was more physiologically preferable. This concept was reflected in the treatment of the two patients reported on.

  13. Extended Distal Pancreatectomy with En Bloc Resection of the Celiac Axis for Locally Advanced Pancreatic Cancer: A Case Report and Review of the Literature

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    Patrick H. Alizai

    2012-01-01

    Full Text Available Due to a lack of early symptoms, pancreatic cancers of the body and tail are discovered mostly at advanced stages. These locally advanced cancers often involve the celiac axis or the common hepatic artery and are therefore declared unresectable. The extended distal pancreatectomy with en bloc resection of the celiac artery may offer a chance of complete resection. We present the case of a 48-year-old female with pancreatic body cancer invading the celiac axis. The patient underwent laparoscopy to exclude hepatic and peritoneal metastasis. Subsequently, a selective embolization of the common hepatic artery was performed to enlarge arterial flow to the hepatobiliary system and the stomach via the pancreatoduodenal arcades from the superior mesenteric artery. Fifteen days after embolization, the extended distal pancreatectomy with splenectomy and en bloc resection of the celiac axis was carried out. The postoperative course was uneventful, and complete tumor resection was achieved. This case report and a review of the literature show the feasibility and safety of the extended distal pancreatectomy with en bloc resection of the celiac axis. A preoperative embolization of the celiac axis may avoid ischemia-related complications of the stomach or the liver.

  14. Complete en bloc urinary exenteration for synchronous multicentric transitional cell carcinoma with sarcomatoid features in a hemodialysis patient

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    Tiberio M. Siqueira Jr

    2006-10-01

    Full Text Available The incidence of transitional cell carcinoma (TCC in patients submitted to hemodialysis is low. The presence of TCC with sarcomatoid features in this cohort is even scarcer. Herein, we describe a very rare case of synchronous multicentric muscle invasive bladder carcinoma with prostate invasion in a hemodialysis patient, submitted to complete en bloc urinary exenteration.

  15. En bloc resection of huge cemento-ossifying fibroma of mandible: avoiding lower lip split incision.

    Science.gov (United States)

    Ayub, Tahera; Katpar, Shahjahan; Shafique, Salman; Mirza, Talat

    2011-05-01

    Cemento-ossifying Fibroma (COF) is an osteogenic benign neoplasm affecting the jaws and other craniofacial bones. It commonly presents as a progressively slow growing pathology, which can sometimes attain an enormous size, causing facial deformity. A case of a huge cemento-ossifying fibroma, appearing as a mandibular dumbell tumour in a male patient is documented, which caused massive bone destruction and deformity. It was surgically removed by performing en bloc resection of mandible avoiding the splitting of lower lip incision technique, thereby maintaining his normal facial appearance.

  16. Right trisectionectomy with principle en bloc portal vein resection for right-sided hilar cholangiocarcinoma: no-touch technique.

    Science.gov (United States)

    Machado, Marcel Autran; Makdissi, Fabio F; Surjan, Rodrigo C

    2012-04-01

    The most favorable long-term survival rate for hilar cholangiocarcinoma is achieved by a R0 resection. A surgical concept involving a no-touch technique, with extended right hepatic resections and principle en bloc portal vein resection was described by Neuhaus et al. According to Neuhaus et al., their technique may increase the chance of R0, because the right branch of the portal vein and hepatic artery is in close contact with the tumor and is frequently infiltrated. The left artery runs on the left margin of the hilum and often is free. The 5-year survival rate for their patients is 61% but 60-day mortality rate is 8%. Given the increased morbidity, some authors do not agree with routine resection of portal vein and may perform the resection of portal vein only on demand, after intraoperative assessment and confirmation of portal vein invasion. This video shows en bloc resection of extrahepatic bile ducts, portal vein bifurcation, and right hepatic artery, together with extended right trisectionectomy (removal of segments 1, 4, 5, 6, 7, and 8). A 75-year-old man with progressive jaundice due to right-sided hilar cholangiocarcinoma underwent percutaneous biliary drainage with metallic stents for palliation. The patient was referred for a second opinion. Serum bilirubin levels were normal, and CT scan showed a resectable tumor, but volumetry showed a small left liver remnant. Right portal vein embolization was then performed, and CT scan performed after 4 weeks showed adequate compensatory hypertrophy of the future liver remnant (segments 2 and 3). Surgical decision was to perform a right trisectionectomy with en bloc portal vein and bile duct resection using the no-touch technique. The operation began with hilar lymphadenectomy. The common bile duct is sectioned. Right hepatic artery is ligated. Left hepatic artery is encircled. Portal vein is dissected and encircled. Right liver is mobilized and detached from retrohepatic vena cava. Right and middle hepatic

  17. A Test of Endogenous Trade Bloc Formation Theory on EU Data

    Directory of Open Access Journals (Sweden)

    Richard Edward Baldwin

    2007-12-01

    Full Text Available This paper empirically confronts one explanation of spreading regionalism with the European experience. The domino theory asserts that forming a preferential trade area, or deepening an existing one, produces trade diversion that generates new political-economy forces in third nations as third-nation exporters seek to redress the new discrimination and profit from newly deepened preferences. The pressure increases with the bloc’s size, yet bloc size depends upon how many nations join, so a single incidence of regionalism may trigger several rounds of membership requests from nations that were previously happy to stay out. We estimate a time-series of EU trade creation and diversion over the last five decades and use these to estimate a model of EU membership demands. The results provide broad support for the model and show that trade diversion has a more powerful impact on membership than trade creation.

  18. Teacher Resource Book for Population Pressure in Indonesia, Problems of Industrialization in Eurasia, Power Blocs in Eurasia. Man on the Earth Series.

    Science.gov (United States)

    Gunn, Angus

    This teacher's resource book is a guide to three intermediate texts about Eurasia entitled Population Pressure in Indonesia, Problems of Industrialization in Eurasia, and Power Blocs in Eurasia. The texts are part of the series, Man on the Earth, which probes broad-based issues confronting mankind. The resource book distinguishes 18 major concepts…

  19. Calcul statistique du volume des blocs matriciels d'un gisement fissuré The Statistical Computing of Matrix Block Volume in a Fissured Reservoir

    Directory of Open Access Journals (Sweden)

    Guez F.

    2006-11-01

    Full Text Available La recherche des conditions optimales d'exploitation d'un gisement fissuré repose sur une bonne description de la fissuration. En conséquence il est nécessaire de définir les dimensions et volumes des blocs matriciels en chaque point d'une structure. Or la géométrie du milieu (juxtaposition et formes des blocs est généralement trop complexe pour se prêter au calcul. Aussi, dans une précédente communication, avons-nous dû tourner cette difficulté par un raisonnement sur des moyennes (pendages, azimuts, espacement des fissures qui nous a conduits à un ordre de grandeur des volumes. Cependant un volume moyen ne peut pas rendre compte d'une loi de répartition des volumes des blocs. Or c'est cette répartition qui conditionne le choix d'une ou plusieurs méthodes successives de récupération. Aussi présentons-nous ici une méthode originale de calcul statistique de la loi de distribution des volumes des blocs matriciels, applicable en tout point d'un gisement. La part de gisement concernée par les blocs de volume donné en est déduite. La connaissance générale du phénomène de la fracturation sert de base au modèle. Les observations de subsurface sur la fracturation du gisement en fournissent les données (histogramme d'orientation et d'espacement des fissures.Une application au gisement d'Eschau (Alsace, France est rapportée ici pour illustrer la méthode. The search for optimum production conditions for a fissured reservoir depends on having a good description of the fissure pattern. Hence the sizes and volumes of the matrix blocks must be defined at all points in a structure. However, the geometry of the medium (juxtaposition and shapes of blocks in usually too complex for such computation. This is why, in a previous paper, we got around this problem by reasoning on the bases of averages (clips, azimuths, fissure spacing, and thot led us to an order of magnitude of the volumes. Yet a mean volume cannot be used to explain

  20. Top 50 most cited articles on primary tumors of the spine.

    Science.gov (United States)

    Alan, Nima; Cohen, Jonathan; Ozpinar, Alp; Agarwal, Nitin; Kanter, Adam S; Okonkwo, David O; Hamilton, D Kojo

    2017-08-01

    Citation analysis was performed in order to identify the top 50 most cited articles pertaining to the field of primary spinal tumors. This collection of articles highlights important trends in the neurosurgical literature. We searched the Thomson Reuters Web of Knowledge in order to identify articles pertaining to primary tumors of the spine. Impertinent articles were removed. The top 50 most cited articles were identified. Thereafter, article characteristics were determined including article type, article topic, level of evidence, and citation rate. The selected articles were published between 1951 and 2008. The most productive year was 1997 with 6 publications. The top 50 articles were published in twenty-two different journals, most commonly in Neurosurgery (12), Journal of Neurosurgery (8), and Spine (6). The most frequently cited article was by Tomita et al. written in 1997 which described total en bloc spondylectomy as a novel surgical technique in management of primary tumors of the vertebral column. We identified the 50 most-cited articles in the field of primary spinal tumors. This collection of articles serves as a reference for recognizing impactful studies in the field. Copyright © 2017. Published by Elsevier Ltd.

  1. En-bloc pelvic resection with concomitant rectosigmoid colectomy and immediate anastomosis as part of primary cytoreductive surgery for patients with advanced ovarian cancer.

    Science.gov (United States)

    Yildirim, Y; Ertas, I E; Nayki, U; Ulug, P; Nayki, C; Yilmaz, I; Gultekin, E; Dogan, A; Aykas, A; Ulug, S; Ozdemir, A; Solmaz, U

    2014-01-01

    To assess the authors' experiences in en bloc pelvic resection with concomitant rectosigmoid colectomy and primary anastomosis as a part of primary cytoreductive surgery for patients with advanced ovarian cancer. Atotal of 22 patients with FIGO Stage IIB-IV epithelial ovarian cancer who underwent en bloc pelvic resection with anastomosis were retrospectively reviewed. Data analyses were carried out using SPSS 10.0 and descriptive statistics, Kaplan-Meier survival curves, and Log Rank (Mantel-Cox) test were used for statistical estimations. Median age was 58.8 years. FIGO stage distribution of the patients was; one (4.5%) IIB, three (13.7%) IIC, three (13.7%) IIIA, six (27.3%) IIIB, and nine (40.9%) IIIC. Median peritoneal cancer index (PCI) was 8 (range 5-22) and optimal cytoreduction was achieved in 18 patients (81.8%) of whom 13 (59.1%) had no macroscopic residual disease (complete cytoreduction). There was no perioperative mortality. A total of nine complications occurred in seven (31.8%) patients. Anastomotic leakage was observed in one (4.5%) patient. There was no re-laparotomy. Mean follow-up time was 60 months. There were 15 (68.2%) recurrences of which 12 (80%) presented in extra-pelvic localizations. Mean disease-free survival (DFS) and overall survival (OVS) were estimated as 43.6 and 50.5 months, respectively. Patients with complete cytoreduction had a better DFS (p = 0.006) and OVS (p = 0.003) than those with incomplete cytoreduction. En bloc pelvic resection, as a part of surgical cytoreduction, seems to be a safe and effective procedure in many patients with advanced ovarian cancer if required. Despite relatively high general complication rate, anastomosis-related morbidity of this procedure is low as 0.8%. Nevertheless, surgical plan and perioperative care should be personalized according to medical and surgical conditions of the patient.

  2. Giant Cell Tumors of the Axial Skeleton

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    Maurice Balke

    2012-01-01

    Full Text Available Background. We report on 19 cases of giant cell tumor of bone (GCT affecting the spine or sacrum and evaluate the outcome of different treatment modalities. Methods. Nineteen patients with GCT of the spine (=6 or sacrum (=13 have been included in this study. The mean followup was 51.6 months. Ten sacral GCT were treated by intralesional procedures of which 4 also received embolization, and 3 with irradiation only. All spinal GCT were surgically treated. Results. Two (15.4% patients with sacral and 4 (66.7% with spinal tumors had a local recurrence, two of the letter developed pulmonary metastases. One local recurrence of the spine was successfully treated by serial arterial embolization, a procedure previously described only for sacral tumors. At last followup, 9 patients had no evidence of disease, 8 had stable disease, 1 had progressive disease, 1 died due to disease. Six patients had neurological deficits. Conclusions. GCT of the axial skeleton have a high local recurrence rate. Neurological deficits are common. En-bloc spondylectomy combined with embolization is the treatment of choice. In case of inoperability, serial arterial embolization seems to be an alternative not only for sacral but also for spinal tumors.

  3. Autoclaved Tumor Bone for Skeletal Reconstruction in Paediatric Patients: A Low Cost Alternative in Developing Countries

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    Masood Umer

    2013-01-01

    Full Text Available We reviewed in this series forty patients of pediatric age who underwent resection for malignant tumors of musculoskeletal system followed by biological reconstruction. Our surgical procedure for reconstruction included (1 wide en bloc resection of the tumor; (2 curettage of tumor from the resected bone; (3 autoclaving for 8 minutes (4 bone grafting from the fibula (both vascularized and nonvascularized fibular grafts used; (5 reimplantation of the autoclaved bone into the host bone defect and fixation with plates. Functional evaluation was done using MSTS scoring system. At final followup of at least 18 months (mean 29.2 months, 31 patients had recovered without any complications. Thirty-eight patients successfully achieved a solid bony union between the graft and recipient bone. Three patients had surgical site infection. They were managed with wound debridement and flap coverage of the defect. Local recurrence and nonunion occurred in two patients each. One patient underwent disarticulation at hip due to extensive local disease and one died of metastasis. For patients with non-union, revision procedure with bone graft and compression plates was successfully used. The use of autoclaved tumor grafts provides a limb salvage option that is inexpensive and independent of external resources and is a viable option for musculoskeletal tumor management in developing countries.

  4. Urachal-sigmoid fistula managed by laparoscopic assisted high anterior resection, primary anastomosis and en bloc resection of the urachal cyst and involved bladder.

    Science.gov (United States)

    Sakata, Shinichiro; Grundy, Joshua; Naidu, Sanjeev; Gillespie, Christopher

    2016-08-01

    Sigmoid-urachal fistula is exceedingly rare in adults and only a few cases have been reported in the world literature. We present the case of a 54-year-old man with symptomatic sigmoid-urachal fistula managed successfully with a laparoscopic assisted high anterior resection, primary anastomosis and an en bloc resection of the urachal cyst and the involved cuff of bladder. © 2016 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and John Wiley & Sons Australia, Ltd.

  5. Saving a Child’s Elbow Joint: A Novel Reconstruction for a Tumour of the Distal Humerus

    Directory of Open Access Journals (Sweden)

    Calogero Graci

    2015-01-01

    Full Text Available Reconstruction after wide resection of a malignant bone tumor can be obtained using several techniques such as the use of prostheses, allograft, autograft, or combined procedure. We describe a 12-year-old girl with parosteal osteosarcoma of the distal right humerus treated by en bloc resection, intraoperative extracorporeal irradiation, and implantation. We inserted a nonvascularised fibular autograft through the middle of irradiated graft to obtain a greater stability. We have not recorded any complication associated with this technique such as nonunion, pathological fracture, infection, and bone necrosis and we obtained an excellent functional result. 10 years after surgery, the patient had no recurrence. Extracorporeal irradiation and reimplantation is a valid and inexpensive technique for the treatment of bone tumors when there is reasonable residual bone stock. With this procedure we have a precise fit being the patient’s own bone. In this way we avoid all the problems related to the adaptation of the shape and size.

  6. Clear Cell Adenocarcinoma Arising from Endometriosis in the Groin: Wide Resection and Reconstruction with a Fascia Lata Tensor Muscle Skin Flap

    Directory of Open Access Journals (Sweden)

    Shozo Yoshida

    2018-01-01

    Full Text Available We herein report a case of clear cell carcinoma arising from endometriosis in the groin in a 53-year-old woman. The findings of MRI and FDG/PET-CT indicated a malignant tumor, and surgical biopsy confirmed adenocarcinoma of the female genital tract. The tumor including a part of the abdominal rectus muscle and rectus sheath, subcutaneous fat, skin, and the right inguinal ligament was resected en bloc. The defect in the abdominal wall was reconstructed with a fascia lata tensor muscle skin flap. The tumor was composed of clear cell adenocarcinoma arising from extrapelvic endometriosis. The patient received chemotherapy with gemcitabine and carboplatin for 6 cycles and had no evidence of recurrence 7 months after the treatment. We herein described the diagnosis and surgical management of endometriosis-associated carcinoma in the groin.

  7. SURGICAL TREATMENT AND RECONSTRUCTION FOR CENTRAL GIANT CELL GRANULOMA OF MANDIBLE - case report and literature review.

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    Elitsa G. Deliverska

    2013-11-01

    Full Text Available Introduction: Central giant cell granuloma (CGCG is a benign aggressive destructive osteolytic lesion of osteoclastic origin. The central giant cell granuloma is often found in the mandible, anterior to the first molars. It most commonly occurs in patients under the age of 30, with a clear female prevalencePurpose: To present a case of CGCG of the lower jaw in Department of Oral and maxillofacial surgery, University Hospital "St. Anna". Although en bloc resection provides the lowest recurrence rate, only a few single case reports describe the use of this technique followed by reconstruction with autogenous bone grafts.Material and methods: The medical history of a 28 years patient with a large central giant cell granuloma in the mandible. Biopsy specimen taken from the lesion showed CGCG followed by curettage with peripheral ostectomy with preservation of the continuity of the mandible.Result: At the 1-year clinical and radiological follow up there was no sign of recurrence. Conclusion: After complete healing of the graft, prosthetic rehabilitation with implants will be perfomed. This allows the best functional and aesthetic results.

  8. Chest-wall reconstruction in case of infection of the operative site: is there any interest in titanium rib osteosynthesis?

    Science.gov (United States)

    Berthet, Jean-Philippe; Solovei, Laurence; Tiffet, Olivier; Gomez-Caro, Abel; Bommart, Sébastien; Canaud, Ludovic; Alric, Pierre; Marty-Ané, Charles-Henri

    2013-11-01

    To describe the management of thoracic reconstructions in the presence of primary chest-wall infection (PCWI) or secondary deep chest-wall infection (SCWI), focussing on local tolerance of a titanium rib osteosynthesis system. PCWI included infected chest wall tumours (CWT), infected T3 non-small-cell lung carcinoma (NSCLC) and open flail chest. SCWI was defined by deep infection of previous thoracic-wall reconstructions. Infection was identified by preoperative bacterial analysis of the tumour or surgical site. In PCWI, a one-step procedure combined extensive resection of infected tissues and rigid reconstruction of the defect; skeletal rigidity was achieved using titanium implants. In SCWI, we removed all synthetic material except titanium implants. In both groups, the surgical field was thoroughly cleaned and implants were wrapped or covered by flaps. From January 2005 to December 2011, 11 patients (54 ± 10.2 years) with either PCWI (3 CWT, 3 T3 NSCLC, 1 open flail chest) or SCWI (3 CWT, 1 funnel chest) were treated. Infection was polymicrobial in all but 1 case. Bacteria observed in PCWI patients were multidrug resistant. In PCWI, we resected 4.2 ± 0.6 ribs en bloc with the lung (n = 5), the skin and the pectoralis major and then used mesh and 2.1 ± 1.2 titanium implants for reconstruction (n = 6). The mean defect was 1154.4 ± 318 cm(3). Surgical SCWI management removed polytetrafluoroethylene-mesh and preserved the titanium implants. A Vicryl mesh (n = 3) and greater omentum flap (n = 3) were added. One of the 2 postoperative deaths in the PCWI group was related to infection recurrence. No other patient had infection at the 6-month follow-up with leucocyte-labelled scintigraphy. Titanium rib osteosynthesis is reliable in two complex and life-threatening situations: PCWIs and SCWIs. In combination with a flap, this allows rapid, reliable, rigid reconstruction of infected full-thickness chest-wall defects in a single-step procedure.

  9. Auxiliary en-bloc liver-small bowel transplantation with partial pancreas preservation in pigs

    Institute of Scientific and Technical Information of China (English)

    Zhen-Yu Yin; Xiao-Dong Ni; Feng Jiang; Ning Li; You-Sheng Li; Xiao-Ming Wang; Jie-Shou Li

    2004-01-01

    AIM: The aim of this study was to describe an auxiliary combined liver-small bowel transplantation model with the preservation of duodenum, head of pancreas and hepatic biliary system in pigs. The technique, feasibility, security and immunosuppression were commented.METHODS: Forty outbred long-white pigs were randomized into two groups, and the auxiliary composite liver/small bowel allotransplantations were undertaken in 10 long-white pigs in each group with the recipient liver preserved.Group A was not treated with immunosuppressive drugs while group B was treated with cyclosporine A and methylprednisolone after operation. The hemodynamic changes and amylase of body fluid (including blood, urine and abdominal drain) were analyzed.RESULTS: The average survival time of the animals was 10±1.929 d (6 to 25 d) in group A while more than 30 d in group B. The pigs could tolerate the hemodynamic fluctuation during operation and the hemodynamic parameters recovered to normal 2 h after blood reperfusion. The transient high amylase level was decreased to normal one week after operation and autopsy showed no pancreatitis.CONCLUSION: Auxiliary en-bloc liver-small bowel transplantation with partial pancreas preservation is a feasible and safe model with simplified surgical techniques for composite liver/small bowel transplantation. This model may be used as a preclinical training model for clinical transplantation method, clinical liver-small bowel transplantation related complication research, basic research including immunosuppressive treatment, organ preservation, acute rejection, chronic rejection, immuno-tolerance and xenotransplantation.

  10. Vítězslav Orel (1926-2015): Gregor Mendel's biographer and the rehabilitation of genetics in the Communist Bloc.

    Science.gov (United States)

    Paleček, Pavel

    2016-09-01

    At almost 90 years of age, we have lost the author of the founding historical works on Johann Gregor Mendel. Vítězslav Orel served for almost 30 years as the editor of the journal Folia Mendeliana. His work was beset by the wider problems associated with Mendel's recognition in the Communist Bloc, and by the way in which narratives of the history of science could be co-opted into the service of Cold War and post-Cold War political agendas. Orel played a key role in the organization of the Mendel symposium of 1965 in Brno, and has made a strong contribution to the rehabilitation of genetics generally, and to championing the work of Johann Gregor Mendel in particular. With Jaroslav Kříženecký, he cofounded the Mendelianum in Brno, which for decades has served as an intellectual bridge between the East and West. Orel's involvement with this institution exposed him to dangers both during and after the Cold War.

  11. Study of radioactivity diffusion for bitumen-coated blocks produced by an industrial coating plant; Etude de la diffusion de la radioactivite de blocs d'enrobes bitumineux en provenance d'un atelier d'enrobage industriel

    Energy Technology Data Exchange (ETDEWEB)

    Rodier, J; Lefillatre, G [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule

    1969-07-01

    The solidification by bitumen of chemical coprecipitation sludges from the Marcoule waste treatment station has been studied in the laboratory and has led to the construction of an industrial coating plant. The quality of the coated material obtained has been controlled by the lixiviation test carried out with ordinary water and with sea-water on 45 ml laboratory samples and on industrial coated blocks of 150 litres. Tests on blocks of such a size have necessitated the installation of three special tanks. Two, each of 2000 litres capacity, contain ordinary and sea-water which was continuously recycled at a rate of 2.5 cm/hr and renewed periodically. In the third tank having a capacity of 11000 litres, the coated block was buried in earth and sprinkled with ordinary water with a view to studying the migration of radioelements in soil. The results of these tests confirm those obtained during the laboratory experiments. (authors) [French] La solidification par le bitume des boues de coprecipitation chimique de la station de traitement des effluents du Centre de Marcoule, etudiee en laboratoire, a conduit a la realisation d'une installation industrielle d'enrobage. La qualite de l'enrobe obtenu a ete controlee par le test de lixiviation qui a ete effectue en eau ordinaire et en eau de mer sur des echantillons de laboratoire de 45 ml et sur des blocs d'enrobe industriel de 150 litres. L'experimentation sur des blocs de telles dimensions a necessite l'installation de 3 cuves speciales. Deux, d'une capacite de 2000 litres, contiennent de l'eau ordinaire et de l'eau de mer recyclees en permanence a une vitesse de 2.5 cm/h et renouvelees periodiquement. Dans la 3eme cuve d'une capacite de 11000 litres, le bloc d'enrobe a ete enfoui dans de la terre et asperge d'eau ordinaire afin d'etudier la migration des radioelements dans le sol. Les resultats de ces essais confirment ceux obtenus au cours des tests de laboratoire. (auteurs)

  12. A economia política dos governos FHC, Lula e Dilma: dominância financeira, bloco no poder e desenvolvimento econômico Economic policy during the Cardoso, Lula, and Rousseff administrations: financial dominance, power blocs and economic development

    Directory of Open Access Journals (Sweden)

    Rodrigo Alves Teixeira

    2012-12-01

    Full Text Available O presente texto analisa a relação da política macroeconômica e o desenvolvimento econômico com seus condicionantes políticos, desde 1995 até os dias atuais (governos FHC, Lula e Dilma, por meio da abordagem da economia política, aplicando os conceitos de dominância financeira, dependência e bloco no poder. Ao adotar tal método, partiu-se do pressuposto de que a adoção de determinada política econômica é decorrência: i dos condicionantes externos, atrelados, no caso brasileiro, à sua condição periférica; ii dos condicionantes internos associados à interação e conflitos de interesses econômicos e políticos das frações de classe no bloco no poder e em seus desenlaces no Estado. O texto conclui que as mudanças recentes no bloco no poder, entre o final do governo Lula e início do governo Dilma, conferiram maior autonomia ao Estado, especialmente diante da fração bancário-financeira, até então hegemônica, o que abre espaço para a retomada das políticas de desenvolvimento.This paper analyzes the relationship between macroeconomic policy and economic development and the political constraints of that relationship from 1995 until present day ( Cardoso, Lula and Dilma Rousseff. This analysis relies on the political economy approach, applying the concepts of financial domination, dependence and power blocs. By virute of this method, we assume that the adoption of certain economic policy is the result of: i the external constraints (which, in Brazil, are coupled with the country's status as a peripheral and dependent economy and ii the constraints associated with the internal interaction and conflicts of economic and political interests of class fractions in the power bloc and its influence on the State. The paper concludes that recent changes to the power bloc between the end of the Lula administration and the beginning of the Rousseff administration gave the government greater autonomy, particularly in relation to the

  13. Hydatid disease of scapula and upper third of humerus treated by en bloc excision and fibular bone grafting

    Directory of Open Access Journals (Sweden)

    Chari P

    2007-01-01

    Full Text Available 35-year-old male patient presented with gradually increasing painful swelling of the right shoulder, which was incised and drained and wound persisted as a discharging sinus on the anterolateral aspect of the deltoid region with seropurulent discharge. A clinical diagnosis of tuberculosis of the shoulder was made. Plain skiagram of the right shoulder revealed multicystic lesion involving the entire scapula and upper third of the humerus with loss of joint space and pathological fracture at the junction of upper one-third and lower two-thirds of the humerus. A clinico-radiological diagnosis of hydatid disease was made. In view of the extensive involvement of the scapula with stiff shoulder and an active sinus, a two-stage surgical procedure was performed. Stage 1 consisted of en bloc excision of the scapula, upper half of the humerus and lateral end of the clavicle. Stage II surgery, consisting of fibular bone grafting. Tablet albendazole (400 mg, thrice daily was given as systemic scolicidal agent. This case is reported in view of it′s rarity and to highlight the management.

  14. TRANSPLANTE RENAL EM BLOCO DE DOADORES-CADÁVERES INFANTIS: EXPERIÊNCIA DO HCFMRP-USP IN BLOC KIDNEY TRANSPLANTATION FROM PEDIATRIC DONORS THE HCFMRP-USP EXPERIENCE

    Directory of Open Access Journals (Sweden)

    A.A.Jr Rodrigues

    2001-01-01

    Full Text Available A grande procura de órgãos para transplante tornou necessária a aceitação de potenciais doadores pediátricos a fim de aumentar a oferta. Trabalhos anteriores relatando menor sobrevida do enxerto e taxas maiores de complicação fizeram com que cirurgiões considerassem o assunto com cautela. Esse é um estudo retrospectivo com o objetivo de analisar os resultados de transplantes renais em bloco de doadores infantis (The high demand for organs for transplantation has made it necessary to consider using the youngest of potential donors in order to increase the organ supply. Previous reports of decreased graft survival and increased complication rates have made surgeons wary of using such kidneys. This is a chart review with the objective to analyse the results achieved with transplantation of children kidneys (< 2 years in the HCFMRP-USP from 1998 to 2000. A total of 5 pacients received en bloc renal transplants from donors aged 9 months to 2 years old, weighthing between 8 and 14 kg. Results: Only one patient lost the allograft within 8 days of transplantation due to allograft trombosis. Two patients had ureteral complications, one with ureteral necrosis and urinary fistula and the other with total ureterovesical anastomosis disrupture. Both were successfully repaired. Intra operatory complication was experienced in one pacient, with arterial anastomosis rupture. In loco reperfusion and repair was made. Another patient had inferior renal pole rupture, treated with polar nefrectomy at the 4º PO. Despite such problems, mean follow up of 20,7 months showed serum creatinine ranging from 0,9 to 2 mg/100ml, with no serious complications. Conclusion: Our data support the use of en bloc child cadaveric kidneys, even from infant donors less than two year of age, when the organ necessity supplant the higher rates of complications.

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

    Science.gov (United States)

    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

  16. 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

  17. Early primary lymphoedema treated by en bloc excision: A case report

    Directory of Open Access Journals (Sweden)

    J.A. García-Espinoza

    2018-04-01

    Full Text Available Introduction: Lymphoedema is a pathological condition with a low global incidence where protein-rich fluid accumulates in the interstitium, causing inflammation and degenerative changes in the affected limbs. It is divided into primary and secondary; worldwide the most common causes are cancer or its treatment and filariasis infection. It is diagnosed through the patient's medical history and treatment depends on the severity. Case report: Twenty-one-year-old male with the condition for 8 years, with a gradual increase in volume in the right lower limb, seen in the emergency department due to functional disability; en bloc excision plus split-thickness grafting was performed, fixed with sutures and ABThera, with 85% integration and functional improvement. Conclusions: Lymphoedema has a high socio-economic impact. Its treatment involves several specialists and must be multidisciplinary, who then find the cause and propose management according to the stage. Combined medical and surgical therapy is the best choice for advanced stages. Resumen: Introducción: El linfedema es una condición patológica de baja incidencia mundial, que acumula líquido rico en proteínas en el intersticio, provocando inflamación y cambios degenerativos en las extremidades afectas. Se divide en primario y secundario, la causa global más frecuente es el cáncer o su tratamiento y la infección por filarias. El diagnostico se realiza a través de historia clínica y el tratamiento depende del grado de severidad. Caso clínico: Masculino de 21 años con padecimiento de 8 años, con aumento progresivo de volumen en extremidad inferior derecha, acude a urgencias por incapacidad funcional; se realizó escisión en bloque más aplicación de injertos de espesor parcial, fijados con suturas y Abthera, con integración de 85% y mejoría funcional. Conclusiones: El linfedema tiene alto impacto socioeconómico, su tratamiento involucra diversos especialistas, debe ser

  18. En bloc resection for treatment of tumor-induced osteomalacia: a case presentation and a systematic review.

    Science.gov (United States)

    Meng, Tong; Zhou, Wang; Li, Bo; Yin, Huabin; Li, Zhenxi; Zhou, Lei; Kong, Jinhai; Yan, Wangjun; Yang, Xinghai; Liu, Tielong; Song, Dianwen; Xiao, Jianru

    2015-05-08

    Tumor-induced osteomalacia (TIO) is a rare disorder, which is commonly found in craniofacial locations and in the extremities. To the best of our knowledge, only 16 cases have been described in the spine, and this is the first report to describe a case of patient with TIO in the thoracic spine combined with a mesenchymal hamartoma which had confused the therapeutic strategies to date. We report the case of a 60-year-old patient with hypophosphatemia and presented with limb weakness. Treating with phosphate did not correct the hypophosphatemia and an (111)In pentetreotide scintigraphy (octreotide scan) revealed an increased uptake at the right forearm. The tumor was resected totally, and the histopathology revealed a mesenchymal hamartoma, but we noticed that hypophosphatemia was not corrected after the tumor resection. Then a whole-body magnetic resonance imaging (WB-MRI) was performed and the results revealed tumorous tissues at the right T1 vertebral pedicle. The tumor was removed with an en bloc method, and the pathology showed phosphaturic mesenchymal tumor. Follow-up at 1 year after surgery revealed no recurrence, and the serum phosphorus level of the patient was normal. Tumor-induced osteomalacia is exceedingly rare with only 16 cases in spine published in the literature. It is difficult to find and leads to years of suffering debilitating complications. In this regard, the WB-MRI is a better method to locate the real tumor. Treating with phosphate can only relieve symptoms, and a complete surgical removal remains the gold standard treatment.

  19. Postoperative dysesthesia in lumbar three-column resection osteotomies.

    Science.gov (United States)

    Zhang, Zhengfeng; Wang, Honggang; Zheng, Wenjie

    2016-08-01

    Three-column lumbar spinal resection osteotomies including pedicle subtraction osteotomy (PSO), vertebral column resection (VCR), and total en bloc spondylectomy (TES) can potentially lead to dorsal root ganglion (DRG) injury which may cause postoperative dysesthesia (POD). The purpose of retrospective study was to describe the uncommon complication of POD in lumbar spinal resection osteotomies. Between January 2009 and December 2013, 64 patients were treated with lumbar three-column spinal resection osteotomies (PSO, n = 31; VCR, n = 29; TES, n = 4) in investigator group. POD was defined as dysesthetic pain or burning dysesthesia at a proper DRG innervated region, whether spontaneous or evoked. Non-steroidal antiinflammatory drugs, central none-opioid analgesic agent, neuropathic pain drugs and/or intervertebral foramen block were selectively used to treat POD. There were 5 cases of POD (5/64, 7.8 %), which consisted of 1 patient in PSO (1/31, 3.2 %), 3 patients in PVCR (3/29, 10.3 %), and 1 patient in TES (1/4, 25 %). After the treatment by drugs administration plus DRG block, all patients presented pain relief with duration from 8 to 38 days. A gradual pain moving to distal end of a proper DRG innervated region was found as the beginning of end. Although POD is a unique and rare complication and maybe misdiagnosed as nerve root injury in lumbar spinal resection osteotomies, combination drug therapy and DRG block have an effective result of pain relief. The appearance of a gradual pain moving to distal end of a proper DRG innervated region during recovering may be used as a sign for the good prognosis.

  20. 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.

  1. 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 ...

  2. 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

  3. MRI Reconstructions of Human Phrenic Nerve Anatomy and Computational Modeling of Cryoballoon Ablative Therapy.

    Science.gov (United States)

    Goff, Ryan P; Spencer, Julianne H; Iaizzo, Paul A

    2016-04-01

    The primary goal of this computational modeling study was to better quantify the relative distance of the phrenic nerves to areas where cryoballoon ablations may be applied within the left atria. Phrenic nerve injury can be a significant complication of applied ablative therapies for treatment of drug refractory atrial fibrillation. To date, published reports suggest that such injuries may occur more frequently in cryoballoon ablations than in radiofrequency therapies. Ten human heart-lung blocs were prepared in an end-diastolic state, scanned with MRI, and analyzed using Mimics software as a means to make anatomical measurements. Next, generated computer models of ArticFront cryoballoons (23, 28 mm) were mated with reconstructed pulmonary vein ostias to determine relative distances between the phrenic nerves and projected balloon placements, simulating pulmonary vein isolation. The effects of deep seating balloons were also investigated. Interestingly, the relative anatomical differences in placement of 23 and 28 mm cryoballoons were quite small, e.g., the determined difference between mid spline distance to the phrenic nerves between the two cryoballoon sizes was only 1.7 ± 1.2 mm. Furthermore, the right phrenic nerves were commonly closer to the pulmonary veins than the left, and surprisingly tips of balloons were further from the nerves, yet balloon size choice did not significantly alter calculated distance to the nerves. Such computational modeling is considered as a useful tool for both clinicians and device designers to better understand these associated anatomies that, in turn, may lead to optimization of therapeutic treatments.

  4. A-Frame free Vascularized Fibular Graft and Femoral Lengthening for Osteosarcoma Pediatric Patients.

    Science.gov (United States)

    Cashin, Megan; Coombs, Christopher; Torode, Ian

    2018-02-01

    Pediatric limb reconstruction after resection of a malignant tumor presents specific challenges. Multiple surgical techniques have been used to treat these patients. This paper describes a staged surgical technique for the reconstruction of large distal femoral defects due to tumor resection in skeletally immature patients. Three pediatric patients with osteosarcoma of the distal femur underwent staged reconstruction. Neoadjuvant chemotherapy was followed by en bloc tumor resection and immediate reconstruction of the distal femoral defect with a vascularized free fibular autograft utilizing a unique A-frame construct combined with intramedullary nail fixation. The second stage was a planned gradual lengthening of the healed construct, over a custom-made magnetically driven expandable intramedullary nail. All patients achieved bony union and satisfactory length with minimal complications. The patients all returned to full, unlimited physical activities. The early results confirm that the described technique is a safe and reliable procedure for the reconstruction of large femoral defects in pediatric patients with osteosarcoma. Level IV-therapeutic.

  5. 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.

  6. Intraosseous focal venous malformation of the mandibular body: Cone beam computed tomography planning followed by piezoelectric knife resection and free bone graft reconstruction

    Directory of Open Access Journals (Sweden)

    Nikolić Živorad S.

    2017-01-01

    Full Text Available Introduction. Intraosseous vascular malformation could be life-threatening due to uncontrolled hemorrhage after tooth extraction. According to biological behavior of this lesion, adequate diagnostic and treatment strategies are necessary in order to avoid possible complications. We reported cone beam computed tomography (CBCT planning of an urgent en bloc resection of an intraosseous venous malformation by piezoelectric knife. Case report. A 55-year-old man was submitted to CBCT planning followed by piezoelectric knife resection of an intraosseous focal venous malformation of the mandibular body. Immediate reconstruction of the defect using iliac bone free graft was performed. The surgical treatment was uneventful and a 2-year follow-up revealed no signs of recurrence. Conclusion. Piezoelectric knife could provide precise, safe and bloodless procedure which is especially important in this pathology. Advantages of this technique are: lower risk of damaging soft tissue structures, precise osteotomy and bloodless surgery. Moreover, using piezosurgery bone knife, blood transfusion and blood transmitted diseases could be avoided. This case highlights the importance of CBCT as planning tool for resection of the mandible, using piezoelectric knife as safe method to achieve bloodless surgery. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 175075

  7. First experiments results about the engineering model of Rapsodie; Premiers resultats d'essais interessant le bloc pile de rapsodie

    Energy Technology Data Exchange (ETDEWEB)

    Chalot, A; Ginier, R; Sauvage, M [Association Euratom-CEA Cadarache (France). Centre d' Etudes Nucleaires

    1964-07-01

    This report deals with the first series of experiments carried out on the engineering model of Rapsodie and on an associated sodium facility set in a laboratory hall of Cadarache. It conveys more precisely: 1/ - The difficulties encountered during the erection and assembly of the engineering model and a compilation of the results of the first series of experiments and tests carried out on this installation (loading of the subassemblies preheating, thermal chocks...). 2/ - The experiments and tests carried out on the two prototypes control rod drive mechanisms which brought to the choice for the design of the definitive drive mechanism. As a whole, the results proved the validity of the general design principles adopted for Rapsodie. (authors) [French] Ce rapport traite des premiers essais realises sur la maquette du bloc pile de Rapsodie et sur une installation annexe de sodium, implantees dans un hall d'essais de Cadarache. Il fait part: 1/- Des difficultes eprouvees lors du montage de la maquette et rassemble les resultats des premiers essais effectues sur cette installation (chargement des assemblages, prechauffage, chocs thermiques...). 2/- Des essais realises sur deux prototypes de mecanisme de barre de controle qui ont conduit a la conception du mecanisme definitif. L'ensemble des resultats obtenus a permis de confirmer la validite des principes adoptes pour la pile Rapsodie. (auteurs)

  8. En bloc pancreaticoduodenectomy and right hemicolectomy for locally advanced right-sided colon cancer.

    Science.gov (United States)

    Kaneda, Yuji; Noda, Hiroshi; Endo, Yuhei; Kakizawa, Nao; Ichida, Kosuke; Watanabe, Fumiaki; Kato, Takaharu; Miyakura, Yasuyuki; Suzuki, Koichi; Rikiyama, Toshiki

    2017-09-15

    To assess the usefulness of en bloc right hemicolectomy with pancreaticoduodenectomy (RHCPD) for locally advanced right-sided colon cancer (LARCC). We retrospectively reviewed the database of Saitama Medical Center, Jichi Medical University, between January 2009 and December 2016. During this time, 299 patients underwent radical right hemicolectomy for right-sided colon cancer. Among them, 5 underwent RHCPD for LARCC with tumor infiltration to adjacent organs. Preoperative computed tomography (CT) was routinely performed to evaluate local tumor infiltration into adjacent organs. During the operation, we evaluated the resectability and the amount of infiltration into the adjacent organs without dissecting the adherent organs from the cancer. When we confirmed that radical resection was feasible and could lead to R0 resection, we performed RHCPD. The clinical data were carefully reviewed, and the demographic variables, intraoperative data, and postoperative parameters were recorded. The median age of the 5 patients who underwent RHCPD for LARCC was 70 years. The tumors were located in the ascending colon (three patients) and transverse colon (two patients). Preoperative CT revealed infiltration of the tumor into the duodenum in all patients, the pancreas in four patients, the superior mesenteric vein (SMV) in two patients, and tumor thrombosis in the SMV in one patient. We performed RHCPD plus SMV resection in three patients. Major postoperative complications occurred in 3 patients (60%) as pancreatic fistula (grade B and grade C, according to International Study Group on Pancreatic Fistula Definition) and delayed gastric empty. None of the patients died during their hospital stay. A histological examination confirmed malignant infiltration into the duodenum and/or pancreas in 4 patients (80%), and no patients showed any malignant infiltration into the SMV. Two patients were histologically confirmed to have tumor thrombosis in the SMV. All of the tumors had clear

  9. 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.

  10. 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)

  11. 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...

  12. 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

  13. 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 ...

  14. Evidence-Based ACL Reconstruction

    Directory of Open Access Journals (Sweden)

    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.

  15. En bloc excision of nonpalpable breast lesions using the advanced breast biopsy instrumentation system: an alternative to needle guided surgery?

    International Nuclear Information System (INIS)

    Lifrange, E.; Colin, C.; Dondelinger, R.F.; Fridman, V.

    2001-01-01

    This study was prospectively conducted to evaluate the clinical potential of the advanced breast biopsy instrumentation (ABBI) system as an alternative to needle localization and open surgery in the management of nonpalpable breast lesions (NPBL). One hundred and eighty-six consecutive patients were referred for management of NPBL. Thirty-six underwent an ABBI procedure, offered as a first step before possible surgery for lesions which would in any case have required complete excision. The 18 patients with a malignant ABBI biopsy underwent re-excision of the biopsy site and axillary dissection was carried out in cases of infiltrating carcinoma. The other 150 patients underwent image-guided needle biopsy. Following these procedures, 60/150 (40 %) patients underwent needle-guided surgery. Finally, 96/186 (51 %) patients required complete excision. A total of 43 benign lesions and 53 carcinomas were confirmed. Thirty-six out of 96 (38 %) excisions were obtained with the ABBI system; 17/43 (40 %) benign lesions and 11/53 (21 %) carcinomas were completely removed with the ABBI system. Out of 9 malignant specimens with a pathological size less than 10 mm, 5/9 (55 %) had tumor-free margins and in 8/9 (89 %) no residual disease was found at re-excision. The preliminary results of this study suggest that, in selected cases, en bloc excision using the ABBI procedure could be an alternative to conventional surgery. (orig.)

  16. [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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  19. Surgical Consideration for Adolescents and Young Adults With Cervical Chordoma.

    Science.gov (United States)

    Zhong, Nanzhe; Yang, Xinghai; Yang, Jian; Meng, Tong; Yang, Cheng; Yan, Wangjun; Xiao, Jianru

    2017-05-15

    Retrospective study. The aim of this study was to compare the clinical outcomes between adolescent and young adult (AYA) patients and old adult patients with cervical chordoma who were treated surgically and present the surgical consideration for adolescents and young adults with cervical chordoma. With predominance in senior patients, chordoma is distinctively rare in AYAs. Because of the rarity of AYA chordoma, individual case report represents most of the literature on this disease entity on mobile spine and lack of long-term follow up, which leads to the paucity of clinical evidence for treatment planning and prognosis prediction. A retrospective study was conducted to investigate the prognosis of AYA patients with cervical chordoma who were treated surgically. We collected the clinical data of these patients and their older counterparts, and further compared the prognosis of the patients in different age groups. To estimate survival curves, Kaplan-Meier method was used, and significance was assessed using a log-rank test. Forty consecutive patients with chordoma of the cervical spine treated in our institution were included in the study. Two groups were identified according to age. Group 1 comprised children and adolescents (age ≤ 25 yrs; n = 9) and Group 2 comprised adults (age > 25 years; n = 31). In comparison, Group 1 was featured by significantly higher rate of recurrence and shorter overall survival, although no difference found in the surgical modality between two groups. There is a dismal prognosis in young patients with chordoma, and thus support the notion that as radical a total en bloc spondylectomy (TES) of the lesions as possible may benefit the overall survival of these young patients. Although the ensuing neurological deficits may be devastating, it will be worth sacrificing if the life expectancy of these young patients is prolonged. 4.

  20. 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

  1. 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...

  2. 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)

  3. 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.

  4. A Case of Chondrosarcoma Arising in the Temporomandibular Joint

    Directory of Open Access Journals (Sweden)

    Tsutomu Nomura

    2015-01-01

    Full Text Available Chondrosarcoma is a malignant tumor originating in cartilaginous cells. And there are only few reports of the case of chondrosarcoma in temporomandibular joint. We discuss a case of chondrosarcoma in temporomandibular joint in a 28-year-old man. Tumor was in contact with the dura, but en bloc resection was performed. After surgical resection of the tumor, face defect was reconstructed by rectus abdominis-free flap. And there is no recurrence after ten years from the resection.

  5. 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.

  6. 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

  7. Limited arthrodesis of the wrist for treatment of giant cell tumor of the distal radius.

    Science.gov (United States)

    Flouzat-Lachaniette, Charles-Henri; Babinet, Antoine; Kahwaji, Antoine; Anract, Philippe; Biau, David-Jean

    2013-08-01

    To present the functional results of a technique of radiocarpal arthrodesis and reconstruction with a structural nonvascularized autologous bone graft after en bloc resection of giant cell tumors of the distal radius. A total of 13 patients with a mean age of 37 years with aggressive giant cell tumor (Campanacci grade III) of distal radius were managed with en bloc resection and reconstruction with a structural nonvascularized bone graft. The primary outcome measure was the disability evaluated by the Musculoskeletal Tumor Society rating score of limb salvage. Secondary outcomes included survival of the reconstruction measured from the date of the operation to revision procedure for any reason (mechanical, infectious, or oncologic). Other outcomes included active wrist motion and ability to resume work. Mean follow-up period was 6 years (range, 2-14 y). The median arc of motion at the midcarpal joint was 40°, median wrist flexion was 20°, and median extension was 10°. The median Musculoskeletal Tumor Society score based on the analysis of factors pertinent to the patient as a whole (pain, functional activities, and emotional acceptance) and specific to the upper limb (positioning of the hand, manual dexterity, and lifting ability) was 86%. Five patients underwent a second surgical procedure. The cumulative probability of reoperation for mechanical reason was 31% at similar follow-up times at 2, 5, and 10 years. This technique provided a stable wrist and partially restored wrist motion with limited pain. However, further surgical procedures may be necessary to reach this goal. Therapeutic IV. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  8. Hybrid spectral CT reconstruction.

    Directory of Open Access Journals (Sweden)

    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

  9. 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

  10. 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)

  11. 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)

  12. 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....

  13. 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

  14. 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

  15. 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.

  16. 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

  17. 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

  18. 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)

  19. 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)

  20. Resection of recurrent neck cancer with carotid artery replacement.

    Science.gov (United States)

    Illuminati, Giulio; Schneider, Fabrice; Minni, Antonio; Calio, Francesco G; Pizzardi, Giulia; Ricco, Jean-Baptiste

    2016-05-01

    The management of patients with recurrent neck cancer invading the carotid artery is controversial. The purpose of this study was to evaluate overall survival rate, primary patency of vascular reconstructions, and quality-adjusted life-years (QALYs) after en bloc resection of the carotid artery and tumor with in-line polytetrafluoroethylene (PTFE) carotid grafting, followed by radiotherapy. From 2000 to 2014, 31 consecutive patients with recurrent neck cancer invading the carotid artery underwent en bloc resection and simultaneous carotid artery reconstruction with a PTFE graft, which was associated in 18 cases with a myocutaneous flap. The primary tumor was a squamous cell carcinoma of the larynx in 17 patients and of the hypopharynx in 7, an undifferentiated carcinoma of unknown origin in 4, and an anaplastic carcinoma of the thyroid in 3. All of the patients underwent postoperative radiotherapy (50-70 Gy), and 10 of them also underwent chemotherapy (doxorubicin and cisplatin). None of the patients died or sustained a stroke during the first 30 days after the index procedure. Postoperative morbidity consisted of 6 transitory dysphagias, 3 vocal cord palsies, 2 wound dehiscences, 1 transitory mandibular claudication, and 1 partial myocutaneous flap necrosis. No graft infection occurred during follow-up. Fifteen patients (48%) died from metastatic cancer during a mean follow-up of 45.4 months (range, 8-175 months). None of the patients showed evidence of local recurrence, stroke, or thrombosis of the carotid reconstruction. The 5-year survival rate was 49 ± 10%. The overall number of QALYs was 3.12 (95% confidence interval, 1.87-4.37) with a significant difference between patients without metastasis at the time of redo surgery (n = 26; QALYs, 3.74) and those with metastasis (n = 5; QALYs, 0.56; P = .005). QALYs were also significantly improved in patients with cancer of the larynx (n = 17; QALYs, 4.69) compared to patients presenting with other types of

  1. Learning Curve in a Western Training Center of the Circumferential En Bloc Esophageal Endoscopic Submucosal Dissection in an In Vivo Animal Model

    Directory of Open Access Journals (Sweden)

    Miguel A. Tanimoto

    2011-01-01

    Full Text Available Aim. Evaluate the feasibility to overcome the learning curve in a western training center of the en bloc circumferential esophageal (ECE- ESD in an in vivo animal model. Methods. ECE-ESD was performed on ten canine models under general anesthesia on artificial lesions at the esophagus marked with coagulation points. After the ESD each canine model was euthanized and surgical resection of the esophagus and stomach was carried out according to “the Principles of Humane Experimental Technique, Russel and Burch.” The specimen was fixed with needles on cork submerged in formalin with the esophagus and stomach then delivered to the pathology department to be analyzed. Results. ECE-ESD was completed without complications in the last 3/10 animal models. Mean duration for the procedures was 192±35 minutes (range 140–235 minutes. All the procedures were done at the animal lab surgery room with cardio pulmonary monitoring and artificial ventilation by staff surgery members and a staff member of the Gastroenterology department trained during 1999–2001 at the Fujigaoka hospital of the Showa U. in Yokohama, Japan, length (range 15–18 mm and 51±6.99 width (range 40–60 mm. Conclusion. ECE-ESD training is feasible in canine models for postgraduate endoscopy fellows.

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. Breast reconstruction following mastectomy: current status in Australia.

    Science.gov (United States)

    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

  11. Petz recovery versus matrix reconstruction

    Science.gov (United States)

    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.

  12. 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.

  13. Comparison of the efficacy and feasibility of en bloc transurethral resection of bladder tumor versus conventional transurethral resection of bladder tumor: A meta-analysis.

    Science.gov (United States)

    Wu, Yu-Peng; Lin, Ting-Ting; Chen, Shao-Hao; Xu, Ning; Wei, Yong; Huang, Jin-Bei; Sun, Xiong-Lin; Zheng, Qing-Shui; Xue, Xue-Yi; Li, Xiao-Dong

    2016-11-01

    The aim of this meta-analysis was to compare the feasibility of en bloc transurethral resection of bladder tumor (ETURBT) versus conventional transurethral resection of bladder tumor (CTURBT). Relevant trials were identified in a literature search of MEDLINE, EMBASE, Cochrane Library, Web of Science, and Google Scholar using appropriate search terms. All comparative studies reporting participant demographics, tumor characteristics, study characteristics, and outcome data were included. Seven trials with 886 participants were included, 438 underwent ETURBT and 448 underwent CTURBT. There was no significant difference in operation time between 2 groups (P = 0.38). The hospitalization time (HT) and catheterization time (CT) were shorter in ETURBT group (mean difference[MD] -1.22, 95% confidence interval [CI] -1.63 to -0.80, P analysis, and 24-month RR in CTURBT is higher than that in ETURBT in mitomycin intravesical irrigation group (P = 0.02). The first meta-analysis indicates that ETURBT might prove to be preferable alternative to CTURBT management of nonmuscle invasive bladder carcinoma. ETURBT is associated with shorter HT and CT, less complication rate, and lower recurrence-free rate. Moreover, it can provide high-qualified specimen for the pathologic diagnosis. Well designed randomized controlled trials are needed to make results comparable.

  14. 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

  15. 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.

  16. 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.

  17. Graft infections after surgical aortic reconstructions

    OpenAIRE

    Berger, P.

    2015-01-01

    Prosthetic vascular grafts are frequently used to reconstruct (part) of the aorta. Every surgical procedure caries a certain risk for infection and when a prosthetic aortic graft is implanted, this may lead to an aortic graft infection (AGI). Endovascular techniques have gradually replaced open surgical reconstructions as first line of treatment for aorto-iliac diseases. Nowadays, open reconstructions are primarily reserved for patients unsuitable for endovascular reconstructions or for redo ...

  18. REGEN: Ancestral Genome Reconstruction for Bacteria

    OpenAIRE

    Yang, Kuan; Heath, Lenwood S.; Setubal, João C.

    2012-01-01

    Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deleti...

  19. Craniofacial Reconstruction Evaluation by Geodesic Network

    OpenAIRE

    Zhao, Junli; Liu, Cuiting; Wu, Zhongke; Duan, Fuqing; Wang, Kang; Jia, Taorui; Liu, Quansheng

    2014-01-01

    Craniofacial reconstruction is to estimate an individual’s face model from its skull. It has a widespread application in forensic medicine, archeology, medical cosmetic surgery, and so forth. However, little attention is paid to the evaluation of craniofacial reconstruction. This paper proposes an objective method to evaluate globally and locally the reconstructed craniofacial faces based on the geodesic network. Firstly, the geodesic networks of the reconstructed craniofacial face and the or...

  20. Overview of image reconstruction

    International Nuclear Information System (INIS)

    Marr, R.B.

    1980-04-01

    Image reconstruction (or computerized tomography, etc.) is any process whereby a function, f, on R/sup n/ is estimated from empirical data pertaining to its integrals, ∫f(x) dx, for some collection of hyperplanes of dimension k < n. The paper begins with background information on how image reconstruction problems have arisen in practice, and describes some of the application areas of past or current interest; these include radioastronomy, optics, radiology and nuclear medicine, electron microscopy, acoustical imaging, geophysical tomography, nondestructive testing, and NMR zeugmatography. Then the various reconstruction algorithms are discussed in five classes: summation, or simple back-projection; convolution, or filtered back-projection; Fourier and other functional transforms; orthogonal function series expansion; and iterative methods. Certain more technical mathematical aspects of image reconstruction are considered from the standpoint of uniqueness, consistency, and stability of solution. The paper concludes by presenting certain open problems. 73 references

  1. Virtual 3-D Facial Reconstruction

    Directory of Open Access Journals (Sweden)

    Martin Paul Evison

    2000-06-01

    Full Text Available Facial reconstructions in archaeology allow empathy with people who lived in the past and enjoy considerable popularity with the public. It is a common misconception that facial reconstruction will produce an exact likeness; a resemblance is the best that can be hoped for. Research at Sheffield University is aimed at the development of a computer system for facial reconstruction that will be accurate, rapid, repeatable, accessible and flexible. This research is described and prototypical 3-D facial reconstructions are presented. Interpolation models simulating obesity, ageing and ethnic affiliation are also described. Some strengths and weaknesses in the models, and their potential for application in archaeology are discussed.

  2. Image quality of iterative reconstruction in cranial CT imaging: comparison of model-based iterative reconstruction (MBIR) and adaptive statistical iterative reconstruction (ASiR).

    Science.gov (United States)

    Notohamiprodjo, S; Deak, Z; Meurer, F; Maertz, F; Mueck, F G; Geyer, L L; Wirth, S

    2015-01-01

    The purpose of this study was to compare cranial CT (CCT) image quality (IQ) of the MBIR algorithm with standard iterative reconstruction (ASiR). In this institutional review board (IRB)-approved study, raw data sets of 100 unenhanced CCT examinations (120 kV, 50-260 mAs, 20 mm collimation, 0.984 pitch) were reconstructed with both ASiR and MBIR. Signal-to-noise (SNR) and contrast-to-noise (CNR) were calculated from attenuation values measured in caudate nucleus, frontal white matter, anterior ventricle horn, fourth ventricle, and pons. Two radiologists, who were blinded to the reconstruction algorithms, evaluated anonymized multiplanar reformations of 2.5 mm with respect to depiction of different parenchymal structures and impact of artefacts on IQ with a five-point scale (0: unacceptable, 1: less than average, 2: average, 3: above average, 4: excellent). MBIR decreased artefacts more effectively than ASiR (p ASiR was 2 (p ASiR (p ASiR. As CCT is an examination that is frequently required, the use of MBIR may allow for substantial reduction of radiation exposure caused by medical diagnostics. • Model-Based iterative reconstruction (MBIR) effectively decreased artefacts in cranial CT. • MBIR reconstructed images were rated with significantly higher scores for image quality. • Model-Based iterative reconstruction may allow reduced-dose diagnostic examination protocols.

  3. REGEN: Ancestral Genome Reconstruction for Bacteria.

    Science.gov (United States)

    Yang, Kuan; Heath, Lenwood S; Setubal, João C

    2012-07-18

    Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deletion and replicon fission and fusion. The reconstruction can be performed by either a maximum parsimony or a maximum likelihood method. Gene content reconstruction is based on the concept of neighboring gene pairs. REGEN was designed to be used with any set of genomes that are sufficiently related, which will usually be the case for bacteria within the same taxonomic order. We evaluated REGEN using simulated genomes and genomes in the Rhizobiales order.

  4. REGEN: Ancestral Genome Reconstruction for Bacteria

    Directory of Open Access Journals (Sweden)

    João C. Setubal

    2012-07-01

    Full Text Available Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deletion and replicon fission and fusion. The reconstruction can be performed by either a maximum parsimony or a maximum likelihood method. Gene content reconstruction is based on the concept of neighboring gene pairs. REGEN was designed to be used with any set of genomes that are sufficiently related, which will usually be the case for bacteria within the same taxonomic order. We evaluated REGEN using simulated genomes and genomes in the Rhizobiales order.

  5. Computer Based Road Accident Reconstruction Experiences

    Directory of Open Access Journals (Sweden)

    Milan Batista

    2005-03-01

    Full Text Available Since road accident analyses and reconstructions are increasinglybased on specific computer software for simulationof vehicle d1iving dynamics and collision dynamics, and forsimulation of a set of trial runs from which the model that bestdescribes a real event can be selected, the paper presents anoverview of some computer software and methods available toaccident reconstruction experts. Besides being time-saving,when properly used such computer software can provide moreauthentic and more trustworthy accident reconstruction, thereforepractical experiences while using computer software toolsfor road accident reconstruction obtained in the TransportSafety Laboratory at the Faculty for Maritime Studies andTransport of the University of Ljubljana are presented and discussed.This paper addresses also software technology for extractingmaximum information from the accident photo-documentationto support accident reconstruction based on the simulationsoftware, as well as the field work of reconstruction expertsor police on the road accident scene defined by this technology.

  6. Data-parallel tomographic reconstruction : A comparison of filtered backprojection and direct Fourier reconstruction

    NARCIS (Netherlands)

    Roerdink, J.B.T.M.; Westenberg, M.A

    1998-01-01

    We consider the parallelization of two standard 2D reconstruction algorithms, filtered backprojection and direct Fourier reconstruction, using the data-parallel programming style. The algorithms are implemented on a Connection Machine CM-5 with 16 processors and a peak performance of 2 Gflop/s.

  7. Vertex Reconstruction in ATLAS Run II

    CERN Document Server

    Zhang, Matt; The ATLAS collaboration

    2016-01-01

    Vertex reconstruction is the process of taking reconstructed tracks and using them to determine the locations of proton collisions. In this poster we present the performance of our current vertex reconstruction algorithm, and look at investigations into potential improvements from a new seed finding method.

  8. Photoacoustic image reconstruction via deep learning

    Science.gov (United States)

    Antholzer, Stephan; Haltmeier, Markus; Nuster, Robert; Schwab, Johannes

    2018-02-01

    Applying standard algorithms to sparse data problems in photoacoustic tomography (PAT) yields low-quality images containing severe under-sampling artifacts. To some extent, these artifacts can be reduced by iterative image reconstruction algorithms which allow to include prior knowledge such as smoothness, total variation (TV) or sparsity constraints. These algorithms tend to be time consuming as the forward and adjoint problems have to be solved repeatedly. Further, iterative algorithms have additional drawbacks. For example, the reconstruction quality strongly depends on a-priori model assumptions about the objects to be recovered, which are often not strictly satisfied in practical applications. To overcome these issues, in this paper, we develop direct and efficient reconstruction algorithms based on deep learning. As opposed to iterative algorithms, we apply a convolutional neural network, whose parameters are trained before the reconstruction process based on a set of training data. For actual image reconstruction, a single evaluation of the trained network yields the desired result. Our presented numerical results (using two different network architectures) demonstrate that the proposed deep learning approach reconstructs images with a quality comparable to state of the art iterative reconstruction methods.

  9. Beard reconstruction: A surgical algorithm.

    Science.gov (United States)

    Ninkovic, M; Heidekrueger, P I; Ehrl, D; von Spiegel, F; Broer, P N

    2016-06-01

    Facial defects with loss of hair-bearing regions can be caused by trauma, infection, tumor excision, or burn injury. The presented analysis evaluates a series of different surgical approaches with a focus on male beard reconstruction, emphasizing the role of tissue expansion of regional and free flaps. Locoregional and free flap reconstructions were performed in 11 male patients with 14 facial defects affecting the hair-bearing bucco-mandibular or perioral region. In order to minimize donor-site morbidity and obtain large amounts of thin, pliable, hair-bearing tissue, pre-expansion was performed in five of 14 patients. Eight of 14 patients were treated with locoregional flap reconstructions and six with free flap reconstructions. Algorithms regarding pre- and intraoperative decision making are discussed and long-term (mean follow-up 1.5 years) results analyzed. Major complications, including tissue expander infection with the need for removal or exchange, partial or full flap loss, occurred in 0% (0/8) of patients with locoregional flaps and in 17% (1/6) of patients undergoing free flap reconstructions. Secondary refinement surgery was performed in 25% (2/8) of locoregional flaps and in 67% (4/6) of free flaps. Both locoregional and distant tissue transfers play a role in beard reconstruction, while pre-expansion remains an invaluable tool. Paying attention to the presented principles and considering the significance of aesthetic facial subunits, range of motion, aesthetics, and patient satisfaction were improved long term in all our patients while minimizing donor-site morbidity. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  10. Forensic Facial Reconstruction: The Final Frontier.

    Science.gov (United States)

    Gupta, Sonia; Gupta, Vineeta; Vij, Hitesh; Vij, Ruchieka; Tyagi, Nutan

    2015-09-01

    Forensic facial reconstruction can be used to identify unknown human remains when other techniques fail. Through this article, we attempt to review the different methods of facial reconstruction reported in literature. There are several techniques of doing facial reconstruction, which vary from two dimensional drawings to three dimensional clay models. With the advancement in 3D technology, a rapid, efficient and cost effective computerized 3D forensic facial reconstruction method has been developed which has brought down the degree of error previously encountered. There are several methods of manual facial reconstruction but the combination Manchester method has been reported to be the best and most accurate method for the positive recognition of an individual. Recognition allows the involved government agencies to make a list of suspected victims'. This list can then be narrowed down and a positive identification may be given by the more conventional method of forensic medicine. Facial reconstruction allows visual identification by the individual's family and associates to become easy and more definite.

  11. Alternative reconstruction after pancreaticoduodenectomy

    Directory of Open Access Journals (Sweden)

    Cooperman Avram M

    2008-01-01

    Full Text Available Abstract Background Pancreaticoduodenectomy is the procedure of choice for tumors of the head of the pancreas and periampulla. Despite advances in surgical technique and postoperative care, the procedure continues to carry a high morbidity rate. One of the most common morbidities is delayed gastric emptying with rates of 15%–40%. Following two prolonged cases of delayed gastric emptying, we altered our reconstruction to avoid this complication altogether. Subsequently, our patients underwent a classic pancreaticoduodenectomy with an undivided Roux-en-Y technique for reconstruction. Methods We reviewed the charts of our last 13 Whipple procedures evaluating them for complications, specifically delayed gastric emptying. We compared the outcomes of those patients to a control group of 15 patients who underwent the Whipple procedure with standard reconstruction. Results No instances of delayed gastric emptying occurred in patients who underwent an undivided Roux-en-Y technique for reconstruction. There was 1 wound infection (8%, 1 instance of pneumonia (8%, and 1 instance of bleeding from the gastrojejunal staple line (8%. There was no operative mortality. Conclusion Use of the undivided Roux-en-Y technique for reconstruction following the Whipple procedure may decrease the incidence of delayed gastric emptying. In addition, it has the added benefit of eliminating bile reflux gastritis. Future randomized control trials are recommended to further evaluate the efficacy of the procedure.

  12. Study of DNA reconstruction enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Sekiguchi, M [Kyushu Univ., Fukuoka (Japan). Faculty of Science

    1976-12-01

    Description was made of the characteristics and mechanism of 3 reconstructive enzymes which received from M. luteus or E. coli or T4, and of which natures were clarified as reconstructive enzymes of DNA irradiated with ultraviolet rays. As characteristics, the site of breaking, reaction, molecular weight, electric charge in the neutrality and a specific adhesion to DNA irradiated with ultraviolet rays were mentioned. As to mutant of ultraviolet ray sensitivity, hereditary control mechanism of removal and reconstruction by endo-nuclease activation was described, and suggestion was referred to removal and reconstruction of cells of xedoderma pigmentosum which is a hereditary disease of human. Description was also made as to the mechanism of exonuclease activation which separates dimer selectively from irradiated DNA.

  13. Reconstructing random media

    International Nuclear Information System (INIS)

    Yeong, C.L.; Torquato, S.

    1998-01-01

    We formulate a procedure to reconstruct the structure of general random heterogeneous media from limited morphological information by extending the methodology of Rintoul and Torquato [J. Colloid Interface Sci. 186, 467 (1997)] developed for dispersions. The procedure has the advantages that it is simple to implement and generally applicable to multidimensional, multiphase, and anisotropic structures. Furthermore, an extremely useful feature is that it can incorporate any type and number of correlation functions in order to provide as much morphological information as is necessary for accurate reconstruction. We consider a variety of one- and two-dimensional reconstructions, including periodic and random arrays of rods, various distribution of disks, Debye random media, and a Fontainebleau sandstone sample. We also use our algorithm to construct heterogeneous media from specified hypothetical correlation functions, including an exponentially damped, oscillating function as well as physically unrealizable ones. copyright 1998 The American Physical Society

  14. Industrial dynamic tomographic reconstruction

    International Nuclear Information System (INIS)

    Oliveira, Eric Ferreira de

    2016-01-01

    The state of the art methods applied to industrial processes is currently based on the principles of classical tomographic reconstructions developed for tomographic patterns of static distributions, or is limited to cases of low variability of the density distribution function of the tomographed object. Noise and motion artifacts are the main problems caused by a mismatch in the data from views acquired in different instants. All of these add to the known fact that using a limited amount of data can result in the presence of noise, artifacts and some inconsistencies with the distribution under study. One of the objectives of the present work is to discuss the difficulties that arise from implementing reconstruction algorithms in dynamic tomography that were originally developed for static distributions. Another objective is to propose solutions that aim at reducing a temporal type of information loss caused by employing regular acquisition systems to dynamic processes. With respect to dynamic image reconstruction it was conducted a comparison between different static reconstruction methods, like MART and FBP, when used for dynamic scenarios. This comparison was based on a MCNPx simulation as well as an analytical setup of an aluminum cylinder that moves along the section of a riser during the process of acquisition, and also based on cross section images from CFD techniques. As for the adaptation of current tomographic acquisition systems for dynamic processes, this work established a sequence of tomographic views in a just-in-time fashion for visualization purposes, a form of visually disposing density information as soon as it becomes amenable to image reconstruction. A third contribution was to take advantage of the triple color channel necessary to display colored images in most displays, so that, by appropriately scaling the acquired values of each view in the linear system of the reconstruction, it was possible to imprint a temporal trace into the regularly

  15. [Pelvic reconstructions after bone tumor resection].

    Science.gov (United States)

    Anract, Philippe; Biau, David; Babinet, Antoine; Tomeno, Bernard

    2014-02-01

    The three more frequent primitive malignant bone tumour which concerned the iliac bone are chondrosarcoma, following Ewing sarcoma and osteosarcoma. Wide resection remains the most important part of the treatment associated with chemotherapy for osteosarcoma and the Ewing sarcoma. Iliac wing resections and obdurate ring don't required reconstruction. However, acetabular resections and iliac wing resection with disruption of the pelvic ring required reconstruction to provide acceptable functional result. Acetabular reconstruction remains high technical demanding challenge. After isolated acetabular resection or associated to obdurate ring, our usual method of reconstruction is homolateral proximal femoral autograft and total hip prosthesis but it is possible to also used : saddle prosthesis, Mac Minn prosthesis with auto or allograft, modular prosthesis or custom made prosthesis, massive allograft with or without prosthesis and femoro-ilac arthrodesis. After resection of the iliac wing plus acetabulum, reconstruction can be performed by femoro-obturatrice and femora-sacral arthrodesis, homolateral proximal femoral autograft and prosthesis, femoral medialisation, massive allograft and massive allograft. Carcinological results are lesser than resection for distal limb tumor, local recurrence rate range 17 to 45%. Functional results after Iliac wing and obdurate ring are good. However, acetabular reconstruction provide uncertain functional results. The lesser results arrive after hemipelvic or acetabular and iliac wing resection-reconstruction, especially when gluteus muscles were also resected. The most favourable results arrive after isolated acetabular or acetabular plus obturateur ring resection-reconstruction.

  16. Maxillary reconstruction: Current concepts and controversies

    Directory of Open Access Journals (Sweden)

    Subramania Iyer

    2014-01-01

    Full Text Available Maxillary reconstruction is still an evolving art when compared to the reconstruction of the mandible. The defects of maxilla apart from affecting the functions of the speech, swallowing and mastication also cause cosmetic disfigurement. Rehabilitation of the form and function in patients with maxillary defects is either by using an obturator prosthesis or by a surgical reconstruction. Literature is abundant with a variety of reconstructive methods. The classification systems are also varied, with no universal acceptance of any one of them. The oncologic safety of these procedures is still debated, and conclusive evidence in this regard has not emerged yet. Management of the orbit is also not yet addressed properly. Tissue engineering, that has been hyped to be one of the possible solutions for this vexing reconstructive problem, has not come out with reliable and reproducible results so far. This review article discusses the rationale and oncological safety of the reconstructing the maxillary defects, critically analyzes the classification systems, offers the different reconstructive methods and touches upon the controversies in this subject. The management of the retained and exenterated orbit associated with maxillectomy is reviewed. The surgical morbidity, complications and the recent advances in this field are also looked into. An algorithm, based on our experience, is presented.

  17. Maxillary reconstruction: Current concepts and controversies

    Science.gov (United States)

    Iyer, Subramania; Thankappan, Krishnakumar

    2014-01-01

    Maxillary reconstruction is still an evolving art when compared to the reconstruction of the mandible. The defects of maxilla apart from affecting the functions of the speech, swallowing and mastication also cause cosmetic disfigurement. Rehabilitation of the form and function in patients with maxillary defects is either by using an obturator prosthesis or by a surgical reconstruction. Literature is abundant with a variety of reconstructive methods. The classification systems are also varied, with no universal acceptance of any one of them. The oncologic safety of these procedures is still debated, and conclusive evidence in this regard has not emerged yet. Management of the orbit is also not yet addressed properly. Tissue engineering, that has been hyped to be one of the possible solutions for this vexing reconstructive problem, has not come out with reliable and reproducible results so far. This review article discusses the rationale and oncological safety of the reconstructing the maxillary defects, critically analyzes the classification systems, offers the different reconstructive methods and touches upon the controversies in this subject. The management of the retained and exenterated orbit associated with maxillectomy is reviewed. The surgical morbidity, complications and the recent advances in this field are also looked into. An algorithm, based on our experience, is presented. PMID:24987199

  18. Iterative reconstruction reduces abdominal CT dose

    International Nuclear Information System (INIS)

    Martinsen, Anne Catrine Trægde; Sæther, Hilde Kjernlie; Hol, Per Kristian; Olsen, Dag Rune; Skaane, Per

    2012-01-01

    Objective: In medical imaging, lowering radiation dose from computed tomography scanning, without reducing diagnostic performance is a desired achievement. Iterative image reconstruction may be one tool to achieve dose reduction. This study reports the diagnostic performance using a blending of 50% statistical iterative reconstruction (ASIR) and filtered back projection reconstruction (FBP) compared to standard FBP image reconstruction at different dose levels for liver phantom examinations. Methods: An anthropomorphic liver phantom was scanned at 250, 185, 155, 140, 120 and 100 mA s, on a 64-slice GE Lightspeed VCT scanner. All scans were reconstructed with ASIR and FBP. Four readers evaluated independently on a 5-point scale 21 images, each containing 32 test sectors. In total 672 areas were assessed. ROC analysis was used to evaluate the differences. Results: There was a difference in AUC between the 250 mA s FBP images and the 120 and 100 mA s FBP images. ASIR reconstruction gave a significantly higher diagnostic performance compared to standard reconstruction at 100 mA s. Conclusion: A blending of 50–90% ASIR and FBP may improve image quality of low dose CT examinations of the liver, and thus give a potential for reducing radiation dose.

  19. Image reconstruction by domain-transform manifold learning

    Science.gov (United States)

    Zhu, Bo; Liu, Jeremiah Z.; Cauley, Stephen F.; Rosen, Bruce R.; Rosen, Matthew S.

    2018-03-01

    Image reconstruction is essential for imaging applications across the physical and life sciences, including optical and radar systems, magnetic resonance imaging, X-ray computed tomography, positron emission tomography, ultrasound imaging and radio astronomy. During image acquisition, the sensor encodes an intermediate representation of an object in the sensor domain, which is subsequently reconstructed into an image by an inversion of the encoding function. Image reconstruction is challenging because analytic knowledge of the exact inverse transform may not exist a priori, especially in the presence of sensor non-idealities and noise. Thus, the standard reconstruction approach involves approximating the inverse function with multiple ad hoc stages in a signal processing chain, the composition of which depends on the details of each acquisition strategy, and often requires expert parameter tuning to optimize reconstruction performance. Here we present a unified framework for image reconstruction—automated transform by manifold approximation (AUTOMAP)—which recasts image reconstruction as a data-driven supervised learning task that allows a mapping between the sensor and the image domain to emerge from an appropriate corpus of training data. We implement AUTOMAP with a deep neural network and exhibit its flexibility in learning reconstruction transforms for various magnetic resonance imaging acquisition strategies, using the same network architecture and hyperparameters. We further demonstrate that manifold learning during training results in sparse representations of domain transforms along low-dimensional data manifolds, and observe superior immunity to noise and a reduction in reconstruction artefacts compared with conventional handcrafted reconstruction methods. In addition to improving the reconstruction performance of existing acquisition methodologies, we anticipate that AUTOMAP and other learned reconstruction approaches will accelerate the development

  20. A Reduction of the Graph Reconstruction Conjecture

    Directory of Open Access Journals (Sweden)

    Monikandan S.

    2014-08-01

    Full Text Available A graph is said to be reconstructible if it is determined up to isomor- phism from the collection of all its one-vertex deleted unlabeled subgraphs. Reconstruction Conjecture (RC asserts that all graphs on at least three vertices are reconstructible. In this paper, we prove that interval-regular graphs and some new classes of graphs are reconstructible and show that RC is true if and only if all non-geodetic and non-interval-regular blocks G with diam(G = 2 or diam(Ḡ = diam(G = 3 are reconstructible

  1. 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...

  2. Delayed breast implant reconstruction

    DEFF Research Database (Denmark)

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne

    2012-01-01

    We evaluated the association between radiation therapy and severe capsular contracture or reoperation after 717 delayed breast implant reconstruction procedures (288 1- and 429 2-stage procedures) identified in the prospective database of the Danish Registry for Plastic Surgery of the Breast during...... of radiation therapy was associated with a non-significantly increased risk of reoperation after both 1-stage (HR = 1.4; 95% CI: 0.7-2.5) and 2-stage (HR = 1.6; 95% CI: 0.9-3.1) procedures. Reconstruction failure was highest (13.2%) in the 2-stage procedures with a history of radiation therapy. Breast...... reconstruction approaches other than implants should be seriously considered among women who have received radiation therapy....

  3. Accuracy of fibula reconstruction using patient-specific CAD/CAM reconstruction plates and dental implants : A new modality for functional reconstruction of mandibular defects

    NARCIS (Netherlands)

    Schepers, Rutger H.; Raghoebar, Gerry M.; Vissink, Arjan; Stenekes, Martin W.; Kraeima, Joep; Roodenburg, Jan L.; Reintsema, Harry; Witjes, Max J.

    Background: The purpose of this study was to analyze the accuracy of mandibular reconstruction using patient-specific computer-aided designed and computer-aided manufactured (CAD/CAM) reconstruction plates as a guide to place fibula grafts and dental implants in a one-stage procedure using

  4. Alpha image reconstruction (AIR): A new iterative CT image reconstruction approach using voxel-wise alpha blending

    International Nuclear Information System (INIS)

    Hofmann, Christian; Sawall, Stefan; Knaup, Michael; Kachelrieß, Marc

    2014-01-01

    Purpose: Iterative image reconstruction gains more and more interest in clinical routine, as it promises to reduce image noise (and thereby patient dose), to reduce artifacts, or to improve spatial resolution. Among vendors and researchers, however, there is no consensus of how to best achieve these aims. The general approach is to incorporatea priori knowledge into iterative image reconstruction, for example, by adding additional constraints to the cost function, which penalize variations between neighboring voxels. However, this approach to regularization in general poses a resolution noise trade-off because the stronger the regularization, and thus the noise reduction, the stronger the loss of spatial resolution and thus loss of anatomical detail. The authors propose a method which tries to improve this trade-off. The proposed reconstruction algorithm is called alpha image reconstruction (AIR). One starts with generating basis images, which emphasize certain desired image properties, like high resolution or low noise. The AIR algorithm reconstructs voxel-specific weighting coefficients that are applied to combine the basis images. By combining the desired properties of each basis image, one can generate an image with lower noise and maintained high contrast resolution thus improving the resolution noise trade-off. Methods: All simulations and reconstructions are performed in native fan-beam geometry. A water phantom with resolution bar patterns and low contrast disks is simulated. A filtered backprojection (FBP) reconstruction with a Ram-Lak kernel is used as a reference reconstruction. The results of AIR are compared against the FBP results and against a penalized weighted least squares reconstruction which uses total variation as regularization. The simulations are based on the geometry of the Siemens Somatom Definition Flash scanner. To quantitatively assess image quality, the authors analyze line profiles through resolution patterns to define a contrast

  5. [Reconstructive surgery of cranio-orbital injuries].

    Science.gov (United States)

    Eolchiian, S A; Potapov, A A; Serova, N K; Kataev, M G; Sergeeva, L A; Zakharova, N E; Van Damm, P

    2011-01-01

    The aim of study was to optimize evaluation and surgery of cranioorbital injuries in different periods after trauma. Material and methods. We analyzed 374 patients with cranioorbital injuries treated in Burdenko Neurosurgery Institute in different periods after trauma from January 1998 till April 2010. 288 (77%) underwent skull and facial skeleton reconstructive surgery within 24 hours - 7 years after trauma. Clinical and CT examination data were used for preoperative planning and assessment of surgery results. Stereolithographic models (STLM) were applied for preoperative planning in 89 cases. The follow-up period ranged from 4 months up to 10 years. Results. In 254 (88%) of 288 patients reconstruction of anterior skull base, upper and/or midface with restoration of different parts of orbit was performed. Anterior skull base CSF leaks repair, calvarial vault reconstruction, maxillar and mandibular osteosynthesis were done in 34 (12%) cases. 242 (84%) of 288 patients underwent one reconstructive operation, while 46 (16%)--two and more (totally 105 operations). The patients with extended frontoorbital and midface fractures commonly needed more than one operation--in 27 (62.8%) cases. Different plastic materials were used for reconstruction in 233 (80.9%) patients, of those in 147 (51%) cases split calvarial bone grafts were preferred. Good functional and cosmetic results were achieved in 261 (90.6%) of 288 patients while acceptable were observed in 27 (9.4%). Conclusion. Active single-stage surgical management for repair of combined cranioorbital injury in acute period with primary reconstruction optimizes functional and cosmetic outcomes and prevents the problems of delayed or secondary reconstruction. Severe extended anterior skull base, upper and midface injuries when intracranial surgery is needed produced the most challenging difficulties for adequate reconstruction. Randomized trial is required to define the extent and optimal timing of reconstructive surgery

  6. Compressed Sensing, Pseudodictionary-Based, Superresolution Reconstruction

    Directory of Open Access Journals (Sweden)

    Chun-mei Li

    2016-01-01

    Full Text Available The spatial resolution of digital images is the critical factor that affects photogrammetry precision. Single-frame, superresolution, image reconstruction is a typical underdetermined, inverse problem. To solve this type of problem, a compressive, sensing, pseudodictionary-based, superresolution reconstruction method is proposed in this study. The proposed method achieves pseudodictionary learning with an available low-resolution image and uses the K-SVD algorithm, which is based on the sparse characteristics of the digital image. Then, the sparse representation coefficient of the low-resolution image is obtained by solving the norm of l0 minimization problem, and the sparse coefficient and high-resolution pseudodictionary are used to reconstruct image tiles with high resolution. Finally, single-frame-image superresolution reconstruction is achieved. The proposed method is applied to photogrammetric images, and the experimental results indicate that the proposed method effectively increase image resolution, increase image information content, and achieve superresolution reconstruction. The reconstructed results are better than those obtained from traditional interpolation methods in aspect of visual effects and quantitative indicators.

  7. Distributed MRI reconstruction using Gadgetron-based cloud computing.

    Science.gov (United States)

    Xue, Hui; Inati, Souheil; Sørensen, Thomas Sangild; Kellman, Peter; Hansen, Michael S

    2015-03-01

    To expand the open source Gadgetron reconstruction framework to support distributed computing and to demonstrate that a multinode version of the Gadgetron can be used to provide nonlinear reconstruction with clinically acceptable latency. The Gadgetron framework was extended with new software components that enable an arbitrary number of Gadgetron instances to collaborate on a reconstruction task. This cloud-enabled version of the Gadgetron was deployed on three different distributed computing platforms ranging from a heterogeneous collection of commodity computers to the commercial Amazon Elastic Compute Cloud. The Gadgetron cloud was used to provide nonlinear, compressed sensing reconstruction on a clinical scanner with low reconstruction latency (eg, cardiac and neuroimaging applications). The proposed setup was able to handle acquisition and 11 -SPIRiT reconstruction of nine high temporal resolution real-time, cardiac short axis cine acquisitions, covering the ventricles for functional evaluation, in under 1 min. A three-dimensional high-resolution brain acquisition with 1 mm(3) isotropic pixel size was acquired and reconstructed with nonlinear reconstruction in less than 5 min. A distributed computing enabled Gadgetron provides a scalable way to improve reconstruction performance using commodity cluster computing. Nonlinear, compressed sensing reconstruction can be deployed clinically with low image reconstruction latency. © 2014 Wiley Periodicals, Inc.

  8. 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.

  9. 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.

  10. 3-D image reconstruction in radiology

    International Nuclear Information System (INIS)

    Grangeat, P.

    1999-01-01

    In this course, we present highlights on fully 3-D image reconstruction algorithms used in 3-D X-ray Computed Tomography (3-D-CT) and 3-D Rotational Radiography (3-D-RR). We first consider the case of spiral CT with a one-row detector. Starting from the 2-D fan-beam inversion formula for a circular trajectory, we introduce spiral CT 3-D image reconstruction algorithm using axial interpolation for each transverse slice. In order to improve the X-ray detection efficiency and to speed the acquisition process, the future is to use multi-row detectors associated with small angle cone-beam geometry. The generalization of the 2-D fan-beam image reconstruction algorithm to cone beam defined direct inversion formula referred as Feldkamp's algorithm for a circular trajectory and Wang's algorithm for a spiral trajectory. However, large area detectors does exist such as Radiological Image Intensifiers or in a near future solid state detectors. To get a larger zoom effect, it defines a cone-beam geometry associated with a large aperture angle. For this case, we introduce indirect image reconstruction algorithm by plane re-binning in the Radon domain. We will present some results from a prototype MORPHOMETER device using the RADON reconstruction software. Lastly, we consider the special case of 3-D Rotational Digital Subtraction Angiography with a restricted number of views. We introduce constraint optimization algorithm using quadratic, entropic or half-quadratic constraints. Generalized ART (Algebraic Reconstruction Technique) iterative reconstruction algorithm can be derived from the Bregman algorithm. We present reconstructed vascular trees from a prototype MORPHOMETER device. (author)

  11. Sensation Following Immediate Breast Reconstruction with Implants.

    Science.gov (United States)

    Lagergren, Jakob; Wickman, Marie; Hansson, Per

    2010-01-01

    Sensation is a neglected aspect of the outcome of breast reconstructions with implants. The aim of this prospective study was to evaluate the cutaneous somatosensory status in breasts following mastectomy and immediate reconstruction with permanent adjustable prostheses and to analyze the patients' subjective experience of the sensation. Twenty-four consecutive patients diagnosed with invasive or in situ breast carcinoma were examined preoperatively and 2 years after mastectomy and reconstruction, for assessment of perception thresholds for touch, cold, warmth, and heat pain above and below the areola. Von Frey filaments and a Peltier element-based thermode were used. The patients completed a questionnaire concerning their experienced sensation in the reconstructed breast. Using quantitative somato-sensory testing, the sensation to all the examined modalities was significantly impaired compared to preoperatively. Most affected was the area above the areola. Patients given postoperative radiotherapy (n = 9) did not differ from those without radiotherapy (n = 15) regarding any of the modalities. All patients reported reduced sensation in the reconstructed breast compared to that preoperatively. Twenty-three patients stated that the reconstructed breast felt different from the other breast; nevertheless 16 reported that the reconstructed breast felt like a real breast. The study revealed sensation impairment following mastectomy and immediate reconstruction with implants. Patients should be informed about this effect preoperatively to allow adequate expectations regarding the sensation outcome. However, two-thirds of the study patients considered that the reconstructed breast felt like a real breast, which must be one of the main purposes of a breast reconstruction.

  12. No economic benefit of early knee reconstruction over optional delayed reconstruction for ACL tears

    DEFF Research Database (Denmark)

    Kiadaliri, Aliasghar A; Englund, Martin; Stefan Lohmander, L.

    2016-01-01

    Background To analyse 5-year cost-effectiveness of early versus optional delayed acute anterior cruciate ligament (ACL) reconstruction. Methods 121 young, active adults with acute ACL injury to a previously uninjured knee were randomised to early ACL reconstruction (n=62, within 10 weeks of injur...

  13. Controversies in orbital reconstruction-III. Biomaterials for orbital reconstruction : a review with clinical recommendations

    NARCIS (Netherlands)

    Dubois, L.; Steenen, S. A.; Gooris, P. J. J.; Bos, R. R. M.; Becking, A. G.

    The goal of orbital reconstruction is to repair trauma defects, to correct the position of the eye anatomically, avoiding enophthalmos, and to restore ocular function. For the reconstruction of (trauma) defects, many surgeons recommend materials that can be bent into an anatomical shape and that

  14. Breast reconstruction and post-mastectomy radiation practice

    International Nuclear Information System (INIS)

    Chen, Susie A; Hiley, Crispin; Nickleach, Dana; Petsuksiri, Janjira; Andic, Fundagul; Riesterer, Oliver; Switchenko, Jeffrey M; Torres, Mylin A

    2013-01-01

    The goal of this study was to explore the perspectives and practice of radiation oncologists who treat breast cancer patients who have had breast reconstruction. In 2010, an original electronic survey was sent to all physician members of the American Society of Radiation Oncology, National Cancer Research Institute-Breast Cancer Studies Group in the United Kingdom, Thai Society of Therapeutic Radiology and Oncology, Swiss Society of Radiation Oncology, and Turkish Radiation Oncology Society. We identified factors associated with radiation oncologists who treat breast cancer patients with reconstruction performed prior to radiation and obtained information regarding radiation management of the breast reconstruction. 358 radiation oncologists responded, and 60% of the physicians were from the United States. While 64% of participants agree or strongly agree that breast image affects a woman’s quality of life during radiation, 57% feel that reconstruction challenges their ability to deliver effective breast radiation. Compared with other countries, treatment within the United States was associated with a high reconstruction rate (>/= 50% of mastectomy patients) prior to radiation (p < 0.05). Delayed-immediate reconstruction with a temporary tissue expander was more common in the United States than in other countries (52% vs. 23%, p = 0.01). Among physicians who treat patients with tissue expanders, the majority (60%) prefer a moderately inflated implant with 150-250 cc of fluid rather than a completely deflated (13%) or inflated expander (28%) during radiation. Among radiation oncologists who treat reconstructions, 49% never use bolus and 40% never boost a breast reconstruction. United States physicians were more likely than physicians from other countries to boost or bolus the reconstruction irrespective of the type of reconstruction seen in their clinic patients (p < 0.01). Great variation in practice is evident from our study of radiation treatment for breast

  15. Boomerang flap reconstruction for the breast.

    Science.gov (United States)

    Baumholtz, Michael A; Al-Shunnar, Buthainah M; Dabb, Richard W

    2002-07-01

    The boomerang-shaped latissimus dorsi musculocutaneous flap for breast reconstruction offers a stable platform for breast reconstruction. It allows for maximal aesthetic results with minimal complications. The authors describe a skin paddle to obtain a larger volume than either the traditional elliptical skin paddle or the extended latissimus flap. There are three specific advantages to the boomerang design: large volume, conical shape (often lacking in the traditional skin paddle), and an acceptable donor scar. Thirty-eight flaps were performed. No reconstruction interfered with patient's ongoing oncological regimen. The most common complication was seroma, which is consistent with other latissimus reconstructions.

  16. Additive manufacturing technology in reconstructive surgery.

    Science.gov (United States)

    Fuller, Scott C; Moore, Michael G

    2016-10-01

    Technological advances have been part and parcel of modern reconstructive surgery, in that practitioners of this discipline are continually looking for innovative ways to perfect their craft and improve patient outcomes. We are currently in a technological climate wherein advances in computers, imaging, and science have coalesced with resulting innovative breakthroughs that are not merely limited to improved outcomes and enhanced patient care, but may provide novel approaches to training the next generation of reconstructive surgeons. New developments in software and modeling platforms, imaging modalities, tissue engineering, additive manufacturing, and customization of implants are poised to revolutionize the field of reconstructive surgery. The interface between technological advances and reconstructive surgery continues to expand. Additive manufacturing techniques continue to evolve in an effort to improve patient outcomes, decrease operative time, and serve as instructional tools for the training of reconstructive surgeons.

  17. Complications in Postmastectomy Breast Reconstruction: One-year Outcomes of the Mastectomy Reconstruction Outcomes Consortium (MROC) Study.

    Science.gov (United States)

    Wilkins, Edwin G; Hamill, Jennifer B; Kim, Hyungjin M; Kim, John Y; Greco, Richard J; Qi, Ji; Pusic, Andrea L

    2018-01-01

    In postmastectomy reconstruction, procedure choice is heavily influenced by the relative risks of the various options. This study sought to evaluate complications in a large, multicenter patient population. Previous studies have reported widely varying complication rates, but have been limited by their single center designs and inadequate controlling for confounders in their analyses. Eleven sites enrolled women undergoing first time, immediate, or delayed reconstruction following mastectomy for cancer treatment or prophylaxis. Procedures included expander/implant, latissimus dorsi (LD), pedicle transverse rectus abdominis musculocutaneous (PTRAM), free TRAM (FTRAM), and deep inferior epigastric perforator (DIEP) techniques. Data were gathered pre- and postoperatively from medical records. Separate logistic regressions were conducted for all complications and major complications (those requiring rehospitalization and/or reoperation) within 1 year. Odds ratios (ORs) were calculated for procedure type, controlling for site, demographic, and clinical variables. Complication rates for 2234 patients were analyzed. Compared with expander/implant reconstructions, LD (OR) 1.95, P = 0.026), PTRAM (OR 1.89, P = 0.025), FTRAM (OR 1.94, P = 0.011), and DIEP (OR 2.22, P procedures were associated with higher risks of complications. Significantly higher risks were also associated with older age, higher body mass index (BMI), immediate reconstruction, bilateral procedures, and radiation. For major complications, regression showed significantly greater risks for PTRAM (OR 1.86, P = 0.044) and DIEP (OR 1.75, P = 0.004), than expander/implant reconstructions. Failure rates were relatively low, ranging from 0% for PTRAM to 5.9% for expander/implant reconstructions. In this multicenter analysis, procedure choice and other patient variables were significant predictors of 1-year complications in breast reconstruction. These findings should be considered in counseling patients on

  18. Progressive Reconstruction: A Methodology for Stabilization and Reconstruction Operations

    National Research Council Canada - National Science Library

    Rohr, Karl C

    2006-01-01

    ... these nations in accordance with stated United States' goals. The argument follows closely current and developing United States military doctrine on stabilization, reconstruction, and counterinsurgency operations...

  19. 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.

  20. Dynamic dual-tracer PET reconstruction.

    Science.gov (United States)

    Gao, Fei; Liu, Huafeng; Jian, Yiqiang; Shi, Pengcheng

    2009-01-01

    Although of important medical implications, simultaneous dual-tracer positron emission tomography reconstruction remains a challenging problem, primarily because the photon measurements from dual tracers are overlapped. In this paper, we propose a simultaneous dynamic dual-tracer reconstruction of tissue activity maps based on guidance from tracer kinetics. The dual-tracer reconstruction problem is formulated in a state-space representation, where parallel compartment models serve as continuous-time system equation describing the tracer kinetic processes of dual tracers, and the imaging data is expressed as discrete sampling of the system states in measurement equation. The image reconstruction problem has therefore become a state estimation problem in a continuous-discrete hybrid paradigm, and H infinity filtering is adopted as the estimation strategy. As H infinity filtering makes no assumptions on the system and measurement statistics, robust reconstruction results can be obtained for the dual-tracer PET imaging system where the statistical properties of measurement data and system uncertainty are not available a priori, even when there are disturbances in the kinetic parameters. Experimental results on digital phantoms, Monte Carlo simulations and physical phantoms have demonstrated the superior performance.

  1. Connected Filtering by Reconstruction : Basis and New Advances

    NARCIS (Netherlands)

    Wilkinson, Michael H.F.

    2008-01-01

    Openings-by-reconstruction are the oldest connected filters, and indeed, reconstruction methodology lies at the heart of many connected operators such as levelings. Starting out from the basic reconstruction principle of iterated geodesic dilations, extensions such as the use of reconstruction

  2. CONNECTED FILTERING BY RECONSTRUCTION : BASIS AND NEW ADVANCES

    NARCIS (Netherlands)

    Wilkinson, Michael H. F.

    2008-01-01

    Openings-by-reconstruction are the oldest connected filters, and indeed, reconstruction methodology lies at the heart of many connected operators such as levelings. Starting out from the basic reconstruction principle of iterated geodesic dilations, extensions such as the use of reconstruction

  3. Tomographic reconstruction of binary fields

    International Nuclear Information System (INIS)

    Roux, Stéphane; Leclerc, Hugo; Hild, François

    2012-01-01

    A novel algorithm is proposed for reconstructing binary images from their projection along a set of different orientations. Based on a nonlinear transformation of the projection data, classical back-projection procedures can be used iteratively to converge to the sought image. A multiscale implementation allows for a faster convergence. The algorithm is tested on images up to 1 Mb definition, and an error free reconstruction is achieved with a very limited number of projection data, saving a factor of about 100 on the number of projections required for classical reconstruction algorithms.

  4. Labral reconstruction: when to perform and how

    Directory of Open Access Journals (Sweden)

    Brian J White

    2015-07-01

    Full Text Available Over the past decade, the understanding of the anatomy and function of the hip joint has continuously evolved, and surgical treatment options for the hip have significantly progressed. Originally, surgical treatment of the hip primarily involved resection of damaged tissue. Procedures that maintain and preserve proper hip anatomy, such as labral repair and femoroacetabular impingement (FAI correction, have shown superior results, in terms of pain reduction, increased function, and ability to return to activities. Labral reconstruction is a treatment option that uses a graft to reconstruct the native labrum. The technique and outcomes of labral reconstruction have been described relatively recently, and labral reconstruction is a cutting edge procedure that has shown promising early outcomes. The aim of this article is to review the current literature on hip labral reconstruction. We will review the indications for labral reconstruction, surgical technique and graft options, and surgical outcomes that have been described to date. Labral reconstruction provides an alternative treatment option for challenging intra-articular hip problems. Labral reconstruction restores the original anatomy of the hip and has the potential to preserve the longevity of the hip joint. This technique is an important tool in the orthopaedic surgeon’s arsenal for hip joint treatment and preservation.

  5. CURRENT CONCEPTS IN ACL RECONSTRUCTION

    Directory of Open Access Journals (Sweden)

    Freddie H. Fu

    2008-09-01

    Full Text Available Current Concepts in ACL Reconstruction is a complete reference text composed of the most thorough collection of topics on the ACL and its surgical reconstruction compiled, with contributions from some of the world's experts and most experienced ACL surgeons. Various procedures mentioned throughout the text are also demonstrated in an accompanying video CD-ROM. PURPOSE Composing a single, comprehensive and complete information source on ACL including basic sciences, clinical issues, latest concepts and surgical techniques, from evaluation to outcome, from history to future, editors and contributors have targeted to keep the audience pace with the latest concepts and techniques for the evaluation and the treatment of ACL injuries. FEATURES The text is composed of 27 chapters in 6 sections. The first section is mostly about basic sciences, also history of the ACL, imaging, clinical approach to adolescent and pediatric patients are subjected. In the second section, Graft Choices and Arthroscopy Portals for ACL Reconstruction are mentioned. The third section is about the technique and the outcome of the single-bundle ACL reconstruction. The fourth chapter includes the techniques and outcome of the double-bundle ACL reconstruction. In the fifth chapter revision, navigation technology, rehabilitation and the evaluation of the outcome of ACL reconstruction is subjected. The sixth/the last chapter is about the future advances to reach: What We Have Learned and the Future of ACL Reconstruction. AUDIENCE Orthopedic residents, sports traumatology and knee surgery fellows, orthopedic surgeons, also scientists in basic sciences or clinicians who are studying or planning a research on ACL forms the audience group of this book. ASSESSMENT This is the latest, the most complete and comprehensive textbook of ACL reconstruction produced by the editorial work up of two pioneer and masters "Freddie H. Fu MD and Steven B. Cohen MD" with the contribution of world

  6. Climate Reconstructions

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Paleoclimatology Program archives reconstructions of past climatic conditions derived from paleoclimate proxies, in addition to the Program's large holdings...

  7. Top reconstruction and boosted top experimental overview

    CERN Document Server

    Skinnari, Louise

    2015-01-01

    An overview of techniques used to reconstruct resolved and boosted top quarks is presented. Techniques for resolved top quark reconstruction include kinematic likelihood fitters and pseudo- top reconstruction. Many tools and methods are available for the reconstruction of boosted top quarks, such as jet grooming techniques, jet substructure variables, and dedicated top taggers. Different techniques as used by ATLAS and CMS analyses are described and the performance of different variables and top taggers are shown.

  8. Sparse Image Reconstruction in Computed Tomography

    DEFF Research Database (Denmark)

    Jørgensen, Jakob Sauer

    In recent years, increased focus on the potentially harmful effects of x-ray computed tomography (CT) scans, such as radiation-induced cancer, has motivated research on new low-dose imaging techniques. Sparse image reconstruction methods, as studied for instance in the field of compressed sensing...... applications. This thesis takes a systematic approach toward establishing quantitative understanding of conditions for sparse reconstruction to work well in CT. A general framework for analyzing sparse reconstruction methods in CT is introduced and two sets of computational tools are proposed: 1...... contributions to a general set of computational characterization tools. Thus, the thesis contributions help advance sparse reconstruction methods toward routine use in...

  9. Medical image reconstruction. A conceptual tutorial

    International Nuclear Information System (INIS)

    Zeng, Gengsheng Lawrence

    2010-01-01

    ''Medical Image Reconstruction: A Conceptual Tutorial'' introduces the classical and modern image reconstruction technologies, such as two-dimensional (2D) parallel-beam and fan-beam imaging, three-dimensional (3D) parallel ray, parallel plane, and cone-beam imaging. This book presents both analytical and iterative methods of these technologies and their applications in X-ray CT (computed tomography), SPECT (single photon emission computed tomography), PET (positron emission tomography), and MRI (magnetic resonance imaging). Contemporary research results in exact region-of-interest (ROI) reconstruction with truncated projections, Katsevich's cone-beam filtered backprojection algorithm, and reconstruction with highly undersampled data with l 0 -minimization are also included. (orig.)

  10. Reconstruction design before tumour resection: A new concept of through-and-through cheek defect reconstruction.

    Science.gov (United States)

    Gong, Zhao-Jian; Ren, Zhen-Hu; Wang, Kai; Tan, Hong-Yu; Zhang, Sheng; Wu, Han-Jiang

    2017-11-01

    To explore a new method of reconstruction of through-and-through cheek defects and to evaluate this method's efficacy and patient prognosis. This retrospective study included 70 patients who underwent reconstruction of through-and-through cheek defects. The surgical approach, design of facial skin incisions, selection and design of flaps, postoperative quality of life and prognosis of patients were recorded and reported. Postoperative quality of life gradually increased over time, and the mean scores of University of Washington Quality of Life (UW-QOL) Questionnaire was more than 80 at 1-year postoperatively. The appearance, oral competence, chewing, swallowing, speech and other oral functions were well recovered in about 90% of patients at 1-year postoperatively. This new idea of reconstruction before tumour resection, brings the effect of plastic and reconstructive surgery to a new height. Copyright © 2017. Published by Elsevier Ltd.

  11. Considerations on Xi- reconstruction in LHCb

    CERN Document Server

    Brochu, F.M.

    2016-01-01

    This paper describes an alternative method of charged hyperon reconstruction applicable to the LHCb experiment. It extends the seminal work of the FOCUS collaboration to the specific detector layout of LHCb and addresses the reconstruction ambiguities reported in their earlier work, leading to improvements in the reconstruction efficiency for the specific cases of Xi- and Omega- baryon decays to a charged meson and a Lambda baryon.

  12. A biomechanical modeling-guided simultaneous motion estimation and image reconstruction technique (SMEIR-Bio) for 4D-CBCT reconstruction

    Science.gov (United States)

    Huang, Xiaokun; Zhang, You; Wang, Jing

    2018-02-01

    Reconstructing four-dimensional cone-beam computed tomography (4D-CBCT) images directly from respiratory phase-sorted traditional 3D-CBCT projections can capture target motion trajectory, reduce motion artifacts, and reduce imaging dose and time. However, the limited numbers of projections in each phase after phase-sorting decreases CBCT image quality under traditional reconstruction techniques. To address this problem, we developed a simultaneous motion estimation and image reconstruction (SMEIR) algorithm, an iterative method that can reconstruct higher quality 4D-CBCT images from limited projections using an inter-phase intensity-driven motion model. However, the accuracy of the intensity-driven motion model is limited in regions with fine details whose quality is degraded due to insufficient projection number, which consequently degrades the reconstructed image quality in corresponding regions. In this study, we developed a new 4D-CBCT reconstruction algorithm by introducing biomechanical modeling into SMEIR (SMEIR-Bio) to boost the accuracy of the motion model in regions with small fine structures. The biomechanical modeling uses tetrahedral meshes to model organs of interest and solves internal organ motion using tissue elasticity parameters and mesh boundary conditions. This physics-driven approach enhances the accuracy of solved motion in the organ’s fine structures regions. This study used 11 lung patient cases to evaluate the performance of SMEIR-Bio, making both qualitative and quantitative comparisons between SMEIR-Bio, SMEIR, and the algebraic reconstruction technique with total variation regularization (ART-TV). The reconstruction results suggest that SMEIR-Bio improves the motion model’s accuracy in regions containing small fine details, which consequently enhances the accuracy and quality of the reconstructed 4D-CBCT images.

  13. Updates in Head and Neck Reconstruction.

    Science.gov (United States)

    Largo, Rene D; Garvey, Patrick B

    2018-02-01

    After reading this article, the participant should be able to: 1. Have a basic understanding of virtual planning, rapid prototype modeling, three-dimensional printing, and computer-assisted design and manufacture. 2. Understand the principles of combining virtual planning and vascular mapping. 3. Understand principles of flap choice and design in preoperative planning of free osteocutaneous flaps in mandible and midface reconstruction. 4. Discuss advantages and disadvantages of computer-assisted design and manufacture in reconstruction of advanced oncologic mandible and midface defects. Virtual planning and rapid prototype modeling are increasingly used in head and neck reconstruction with the aim of achieving superior surgical outcomes in functionally and aesthetically critical areas of the head and neck compared with conventional reconstruction. The reconstructive surgeon must be able to understand this rapidly-advancing technology, along with its advantages and disadvantages. There is no limit to the degree to which patient-specific data may be integrated into the virtual planning process. For example, vascular mapping can be incorporated into virtual planning of mandible or midface reconstruction. Representative mandible and midface cases are presented to illustrate the process of virtual planning. Although virtual planning has become helpful in head and neck reconstruction, its routine use may be limited by logistic challenges, increased acquisition costs, and limited flexibility for intraoperative modifications. Nevertheless, the authors believe that the superior functional and aesthetic results realized with virtual planning outweigh the limitations.

  14. 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.

  15. Clinical applications of iterative reconstruction

    International Nuclear Information System (INIS)

    Eberl, S.

    1998-01-01

    Expectation maximisation (EM) reconstruction largely eliminates the hot and cold streaking artifacts characteristic of filtered-back projection (FBP) reconstruction around localised hot areas, such as the bladder. It also substantially reduces the problem of decreased inferior wall counts in MIBI myocardial perfusion studies due to ''streaking'' from high liver uptake. Non-uniform attenuation and scatter correction, resolution recovery, anatomical information, e.g. from MRI or CT tracer kinetic modelling, can all be built into the EM reconstruction imaging model. The properties of ordered subset EM (OSEM) have also been used to correct for known patient motion as part of the reconstruction process. These uses of EM are elaborated more fully in some of the other abstracts of this meeting. Currently we use OSEM routinely for: (i) studies where streaking is a problem, including all MIBI myocardial perfusion studies, to avoid hot liver inferior wall artifact, (ii) all whole body FDG PET, all lung V/Q SPECT (which have a short acquisition time) and all gated 201 TI myocardial perfusion studies due to improved noise characteristics of OSEM in these studies; (iii) studies with measured, non-uniform attenuation correction. With the accelerated OSEM algorithm, iterative reconstruction is practical for routine clinical applications and we have found OSEM to provide clearly superior reconstructions for the areas listed above and are investigating its application to other studies. In clinical use, we have not found OSEM to introduce artifacts which would not also occur with FBP, e.g. uncorrected patient motion will cause artifacts with both OSEM and FBP

  16. Sustained Weight Loss with Vagal Nerve Blockade but Not with Sham: 18-Month Results of the ReCharge Trial

    Directory of Open Access Journals (Sweden)

    Scott A. Shikora

    2015-01-01

    Full Text Available Background/Objectives. Vagal block therapy (vBloc is effective for moderate to severe obesity at one year. Subjects/Methods. The ReCharge trial is a double-blind, randomized controlled clinical trial of 239 participants with body mass index (BMI of 40 to 45 kg/m or 35 to 40 kg/m with one or more obesity-related conditions. Interventions were implantation of either vBloc or Sham devices and weight management counseling. Mixed models assessed percent excess weight loss (%EWL and total weight loss (%TWL in intent-to-treat analyses. At 18 months, 142 (88% vBloc and 64 (83% Sham patients remained enrolled in the study. Results. 18-month weight loss was 23% EWL (8.8% TWL for vBloc and 10% EWL (3.8% TWL for Sham (P<0.0001. vBloc patients largely maintained 12-month weight loss of 26% EWL (9.7% TWL. Sham regained over 40% of the 17% EWL (6.4% TWL by 18 months. Most weight regain preceded unblinding. Common adverse events of vBloc through 18 months were heartburn/dyspepsia and abdominal pain; 98% of events were reported as mild or moderate and 79% had resolved. Conclusions. Weight loss with vBloc was sustained through 18 months, while Sham regained weight between 12 and 18 months. vBloc is effective with a low rate of serious complications.

  17. Polaron-Driven Surface Reconstructions

    Directory of Open Access Journals (Sweden)

    Michele Reticcioli

    2017-09-01

    Full Text Available Geometric and electronic surface reconstructions determine the physical and chemical properties of surfaces and, consequently, their functionality in applications. The reconstruction of a surface minimizes its surface free energy in otherwise thermodynamically unstable situations, typically caused by dangling bonds, lattice stress, or a divergent surface potential, and it is achieved by a cooperative modification of the atomic and electronic structure. Here, we combined first-principles calculations and surface techniques (scanning tunneling microscopy, non-contact atomic force microscopy, scanning tunneling spectroscopy to report that the repulsion between negatively charged polaronic quasiparticles, formed by the interaction between excess electrons and the lattice phonon field, plays a key role in surface reconstructions. As a paradigmatic example, we explain the (1×1 to (1×2 transition in rutile TiO_{2}(110.

  18. MR image reconstruction via guided filter.

    Science.gov (United States)

    Huang, Heyan; Yang, Hang; Wang, Kang

    2018-04-01

    Magnetic resonance imaging (MRI) reconstruction from the smallest possible set of Fourier samples has been a difficult problem in medical imaging field. In our paper, we present a new approach based on a guided filter for efficient MRI recovery algorithm. The guided filter is an edge-preserving smoothing operator and has better behaviors near edges than the bilateral filter. Our reconstruction method is consist of two steps. First, we propose two cost functions which could be computed efficiently and thus obtain two different images. Second, the guided filter is used with these two obtained images for efficient edge-preserving filtering, and one image is used as the guidance image, the other one is used as a filtered image in the guided filter. In our reconstruction algorithm, we can obtain more details by introducing guided filter. We compare our reconstruction algorithm with some competitive MRI reconstruction techniques in terms of PSNR and visual quality. Simulation results are given to show the performance of our new method.

  19. High resolution x-ray CMT: Reconstruction methods

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J.K.

    1997-02-01

    This paper qualitatively discusses the primary characteristics of methods for reconstructing tomographic images from a set of projections. These reconstruction methods can be categorized as either {open_quotes}analytic{close_quotes} or {open_quotes}iterative{close_quotes} techniques. Analytic algorithms are derived from the formal inversion of equations describing the imaging process, while iterative algorithms incorporate a model of the imaging process and provide a mechanism to iteratively improve image estimates. Analytic reconstruction algorithms are typically computationally more efficient than iterative methods; however, analytic algorithms are available for a relatively limited set of imaging geometries and situations. Thus, the framework of iterative reconstruction methods is better suited for high accuracy, tomographic reconstruction codes.

  20. A fast image reconstruction technique based on ART

    International Nuclear Information System (INIS)

    Zhang Shunli; Zhang Dinghua; Wang Kai; Huang Kuidong; Li Weibin

    2007-01-01

    Algebraic Reconstruction Technique (ART) is an iterative method for image reconstruction. Improving its reconstruction speed has been one of the important researching aspects of ART. For the simplified weight coefficients reconstruction model of ART, a fast grid traverse algorithm is proposed, which can determine the grid index by simple operations such as addition, subtraction and comparison. Since the weight coefficients are calculated at real time during iteration, large amount of storage is saved and the reconstruction speed is greatly increased. Experimental results show that the new algorithm is very effective and the reconstruction speed is improved about 10 times compared with the traditional algorithm. (authors)

  1. Flip-avoiding interpolating surface registration for skull reconstruction.

    Science.gov (United States)

    Xie, Shudong; Leow, Wee Kheng; Lee, Hanjing; Lim, Thiam Chye

    2018-03-30

    Skull reconstruction is an important and challenging task in craniofacial surgery planning, forensic investigation and anthropological studies. Existing methods typically reconstruct approximating surfaces that regard corresponding points on the target skull as soft constraints, thus incurring non-zero error even for non-defective parts and high overall reconstruction error. This paper proposes a novel geometric reconstruction method that non-rigidly registers an interpolating reference surface that regards corresponding target points as hard constraints, thus achieving low reconstruction error. To overcome the shortcoming of interpolating a surface, a flip-avoiding method is used to detect and exclude conflicting hard constraints that would otherwise cause surface patches to flip and self-intersect. Comprehensive test results show that our method is more accurate and robust than existing skull reconstruction methods. By incorporating symmetry constraints, it can produce more symmetric and normal results than other methods in reconstructing defective skulls with a large number of defects. It is robust against severe outliers such as radiation artifacts in computed tomography due to dental implants. In addition, test results also show that our method outperforms thin-plate spline for model resampling, which enables the active shape model to yield more accurate reconstruction results. As the reconstruction accuracy of defective parts varies with the use of different reference models, we also study the implication of reference model selection for skull reconstruction. Copyright © 2018 John Wiley & Sons, Ltd.

  2. Vertex Reconstruction and Performance in ATLAS

    CERN Document Server

    Whitmore, Ben William; The ATLAS collaboration

    2017-01-01

    Efficient and precise reconstruction of the primary vertices in LHC collisions is essential in both the reconstruction of the full kinematic properties of a hard-scatter event and of soft interactions as a measure of the amount of pile-up. The reconstruction of the primary vertices in the busy, high pile up environment of the LHC is a challenging task. The challenges and novel methods developed by the ATLAS experiment to reconstruct vertices in such environments will be presented. The performance of the current vertexing algorithms using Run-2 data will be presented and compared to results from simulation. Additionally, data-driven methods to evaluate vertex resolution, and details of upgrades to the ATLAS inner detector will be presented.

  3. Reconstructing Nearly Simple Polytopes from their Graph

    OpenAIRE

    Doolittle, Joseph

    2017-01-01

    We present a partial description of which polytopes are reconstructible from their graphs. This is an extension of work by Blind and Mani (1987) and Kalai (1988), which showed that simple polytopes can be reconstructed from their graphs. In particular, we introduce a notion of $h$-nearly simple and prove that 1-nearly simple and 2-nearly simple polytopes are reconstructible from their graphs. We also give an example of a 3-nearly simple polytope which is not reconstructible from its graph. Fu...

  4. Anatomic Double-bundle ACL Reconstruction

    NARCIS (Netherlands)

    Schreiber, Verena M.; van Eck, Carola F.; Fu, Freddie H.

    2010-01-01

    Rupture of the anterior cruciate ligament (ACL) is one of the most frequent forms of knee trauma. The traditional surgical treatment for ACL rupture is single-bundle reconstruction. However, during the past few years there has been a shift in interest toward double-bundle reconstruction to closely

  5. Rational reconstructions of modern physics

    CERN Document Server

    Mittelstaedt, Peter

    2013-01-01

    Newton’s classical physics and its underlying ontology are loaded with several metaphysical hypotheses that cannot be justified by rational reasoning nor by experimental evidence. Furthermore, it is well known that some of these hypotheses are not contained in the great theories of Modern Physics, such as the theory of Special Relativity and Quantum Mechanics. This book shows that, on the basis of Newton’s classical physics and by rational reconstruction, the theory of Special Relativity as well as Quantum Mechanics can be obtained by partly eliminating or attenuating the metaphysical hypotheses. Moreover, it is shown that these reconstructions do not require additional hypotheses or new experimental results. In the second edition the rational reconstructions are completed with respect to General Relativity and Cosmology. In addition, the statistics of quantum objects is elaborated in more detail with respect to the rational reconstruction of quantum mechanics. The new material completes the approach of t...

  6. Simulation and track reconstruction for beam telescopes

    CERN Document Server

    Maqbool, Salman

    2017-01-01

    Beam telescopes are used for testing new detectors under development. Sensors are placed and a particle beam is passed through them. To test these novel detectors and determine their properties, the particle tracks need to be reconstructed from the known detectors in the telescope. Based on the reconstructed track, it’s predicted hits on the Device under Test (DUT) are compared with the actual hits on the DUT. Several methods exist for track reconstruction, but most of them don’t account for the effects of multiple scattering. General Broken Lines is one such algorithm which incorporates these effects during reconstruction. The aim of this project was to simulate the beam telescope and extend the track reconstruction framework for the FE-I4 telescope, which takes these effects into account. Section 1 introduces the problem, while section 2 focuses on beam telescopes. This is followed by the Allpix2 simulation framework in Section 3. And finally, Section 4 introduces the Proteus track reconstruction framew...

  7. Evaluation of proxy-based millennial reconstruction methods

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Terry C.K.; Tsao, Min [University of Victoria, Department of Mathematics and Statistics, Victoria, BC (Canada); Zwiers, Francis W. [Environment Canada, Climate Research Division, Toronto, ON (Canada)

    2008-08-15

    A range of existing statistical approaches for reconstructing historical temperature variations from proxy data are compared using both climate model data and real-world paleoclimate proxy data. We also propose a new method for reconstruction that is based on a state-space time series model and Kalman filter algorithm. The state-space modelling approach and the recently developed RegEM method generally perform better than their competitors when reconstructing interannual variations in Northern Hemispheric mean surface air temperature. On the other hand, a variety of methods are seen to perform well when reconstructing surface air temperature variability on decadal time scales. An advantage of the new method is that it can incorporate additional, non-temperature, information into the reconstruction, such as the estimated response to external forcing, thereby permitting a simultaneous reconstruction and detection analysis as well as future projection. An application of these extensions is also demonstrated in the paper. (orig.)

  8. Quadriceps Tendon Autograft Medial Patellofemoral Ligament Reconstruction.

    Science.gov (United States)

    Fink, Christian; Steensen, Robert; Gföller, Peter; Lawton, Robert

    2018-06-01

    Critically evaluate the published literature related to quadriceps tendon (QT) medial patellofemoral ligament (MPFL) reconstruction. Hamstring tendon (HT) MPFL reconstruction techniques have been shown to successfully restore patella stability, but complications including patella fracture are reported. Quadriceps tendon (QT) reconstruction techniques with an intact graft pedicle on the patella side have the advantage that patella bone tunnel drilling and fixation are no longer needed, reducing risk of patella fracture. Several QT MPFL reconstruction techniques, including minimally invasive surgical (MIS) approaches, have been published with promising clinical results and fewer complications than with HT techniques. Parallel laboratory studies have shown macroscopic anatomy and biomechanical properties of QT are more similar to native MPFL than hamstring (HS) HT, suggesting QT may more accurately restore native joint kinematics. Quadriceps tendon MPFL reconstruction, via both open and MIS techniques, have promising clinical results and offer valuable alternatives to HS grafts for primary and revision MPFL reconstruction in both children and adults.

  9. Simulation and Track Reconstruction for Beam Telescopes

    CERN Document Server

    Maqbool, Salman

    2017-01-01

    Beam telescopes are an important tool to test new detectors under development in a particle beam. To test these novel detectors and determine their properties, the particle tracks need to be reconstructed from the known detectors in the telescope. Based on the reconstructed track, its predicted position on the Device under Test (DUT) are compared with the actual hits on the DUT. Several methods exist for track reconstruction, but most of them do not account for the effects of multiple scattering. General Broken Lines is one such algorithm which incorporates these effects during reconstruction. The aim of this project was to simulate the beam telescope and extend the track reconstruction framework for the FE-I4 telescope, which takes these effects into account. Section 1 introduces the problem, while section 2 focuses on beam telescopes. This is followed by the Allpix2 simulation framework in Section 3. And finally, Section 4 introduces the Proteus track reconstruction framework along with the General Broken ...

  10. Method for position emission mammography image reconstruction

    Science.gov (United States)

    Smith, Mark Frederick

    2004-10-12

    An image reconstruction method comprising accepting coincidence datat from either a data file or in real time from a pair of detector heads, culling event data that is outside a desired energy range, optionally saving the desired data for each detector position or for each pair of detector pixels on the two detector heads, and then reconstructing the image either by backprojection image reconstruction or by iterative image reconstruction. In the backprojection image reconstruction mode, rays are traced between centers of lines of response (LOR's), counts are then either allocated by nearest pixel interpolation or allocated by an overlap method and then corrected for geometric effects and attenuation and the data file updated. If the iterative image reconstruction option is selected, one implementation is to compute a grid Siddon retracing, and to perform maximum likelihood expectation maiximization (MLEM) computed by either: a) tracing parallel rays between subpixels on opposite detector heads; or b) tracing rays between randomized endpoint locations on opposite detector heads.

  11. Computed tomography imaging with the Adaptive Statistical Iterative Reconstruction (ASIR) algorithm: dependence of image quality on the blending level of reconstruction.

    Science.gov (United States)

    Barca, Patrizio; Giannelli, Marco; Fantacci, Maria Evelina; Caramella, Davide

    2018-06-01

    Computed tomography (CT) is a useful and widely employed imaging technique, which represents the largest source of population exposure to ionizing radiation in industrialized countries. Adaptive Statistical Iterative Reconstruction (ASIR) is an iterative reconstruction algorithm with the potential to allow reduction of radiation exposure while preserving diagnostic information. The aim of this phantom study was to assess the performance of ASIR, in terms of a number of image quality indices, when different reconstruction blending levels are employed. CT images of the Catphan-504 phantom were reconstructed using conventional filtered back-projection (FBP) and ASIR with reconstruction blending levels of 20, 40, 60, 80, and 100%. Noise, noise power spectrum (NPS), contrast-to-noise ratio (CNR) and modulation transfer function (MTF) were estimated for different scanning parameters and contrast objects. Noise decreased and CNR increased non-linearly up to 50 and 100%, respectively, with increasing blending level of reconstruction. Also, ASIR has proven to modify the NPS curve shape. The MTF of ASIR reconstructed images depended on tube load/contrast and decreased with increasing blending level of reconstruction. In particular, for low radiation exposure and low contrast acquisitions, ASIR showed lower performance than FBP, in terms of spatial resolution for all blending levels of reconstruction. CT image quality varies substantially with the blending level of reconstruction. ASIR has the potential to reduce noise whilst maintaining diagnostic information in low radiation exposure CT imaging. Given the opposite variation of CNR and spatial resolution with the blending level of reconstruction, it is recommended to use an optimal value of this parameter for each specific clinical application.

  12. Reconstruction of convex bodies from surface tensors

    DEFF Research Database (Denmark)

    Kousholt, Astrid; Kiderlen, Markus

    We present two algorithms for reconstruction of the shape of convex bodies in the two-dimensional Euclidean space. The first reconstruction algorithm requires knowledge of the exact surface tensors of a convex body up to rank s for some natural number s. The second algorithm uses harmonic intrinsic...... volumes which are certain values of the surface tensors and allows for noisy measurements. From a generalized version of Wirtinger's inequality, we derive stability results that are utilized to ensure consistency of both reconstruction procedures. Consistency of the reconstruction procedure based...

  13. EIT image reconstruction with four dimensional regularization.

    Science.gov (United States)

    Dai, Tao; Soleimani, Manuchehr; Adler, Andy

    2008-09-01

    Electrical impedance tomography (EIT) reconstructs internal impedance images of the body from electrical measurements on body surface. The temporal resolution of EIT data can be very high, although the spatial resolution of the images is relatively low. Most EIT reconstruction algorithms calculate images from data frames independently, although data are actually highly correlated especially in high speed EIT systems. This paper proposes a 4-D EIT image reconstruction for functional EIT. The new approach is developed to directly use prior models of the temporal correlations among images and 3-D spatial correlations among image elements. A fast algorithm is also developed to reconstruct the regularized images. Image reconstruction is posed in terms of an augmented image and measurement vector which are concatenated from a specific number of previous and future frames. The reconstruction is then based on an augmented regularization matrix which reflects the a priori constraints on temporal and 3-D spatial correlations of image elements. A temporal factor reflecting the relative strength of the image correlation is objectively calculated from measurement data. Results show that image reconstruction models which account for inter-element correlations, in both space and time, show improved resolution and noise performance, in comparison to simpler image models.

  14. 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.

  15. 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.

  16. Org.Lcsim: Event Reconstruction in Java

    International Nuclear Information System (INIS)

    Graf, Norman

    2011-01-01

    Maximizing the physics performance of detectors being designed for the International Linear Collider, while remaining sensitive to cost constraints, requires a powerful, efficient, and flexible simulation, reconstruction and analysis environment to study the capabilities of a large number of different detector designs. The preparation of Letters Of Intent for the International Linear Collider involved the detailed study of dozens of detector options, layouts and readout technologies; the final physics benchmarking studies required the reconstruction and analysis of hundreds of millions of events. We describe the Java-based software toolkit (org.lcsim) which was used for full event reconstruction and analysis. The components are fully modular and are available for tasks from digitization of tracking detector signals through to cluster finding, pattern recognition, track-fitting, calorimeter clustering, individual particle reconstruction, jet-finding, and analysis. The detector is defined by the same xml input files used for the detector response simulation, ensuring the simulation and reconstruction geometries are always commensurate by construction. We discuss the architecture as well as the performance.

  17. Reconstruction of the midface and maxilla.

    Science.gov (United States)

    Dalgorf, Dustin; Higgins, Kevin

    2008-08-01

    To review the current classification systems and reconstructive options available for restoration of maxillectomy defects. Defects involving the midface can have a great functional and aesthetic impact on the patient. Adequate restoration of the complex three-dimensional maxillary structure is required to replace form and function of the native tissue. An in-depth discussion of appropriate recipient vessel selection and reconstructive options are included in this article. The superficial temporal vessel system is presented as a reliable anastomosis site for restoration of midfacial defects. In addition, the complications of vein grafting, arteriovenous fistula loops and alternative recipient vessels sites are addressed to manage the challenge of the vessel-depleted neck. The current indications, advantages and disadvantages of local, regional and free-flap reconstructive options available for maxillectomy defects are highlighted in order to aid the surgeon in appropriate flap selection. A myriad of reconstructive options are available to restore maxillectomy defects. The surgeon must consider each defect and the needs of the individual patient when choosing the best suited reconstructive technique.

  18. Quality of life before reconstructive breast surgery: A preoperative comparison of patients with immediate, delayed, and major revision reconstruction.

    Science.gov (United States)

    Rosson, Gedge D; Shridharani, Sachin M; Magarakis, Michael; Manahan, Michele A; Basdag, Basak; Gilson, Marta M; Pusic, Andrea L

    2013-05-01

    Women undergo breast reconstruction at different time-points in their cancer care; knowing patients' preoperative quality of life (QoL) is critical in the overall care of the patient with breast cancer. Our objective was to describe presurgical QoL among women undergoing immediate, delayed, or major revision breast reconstructive surgery at our institution. From March 2008 to February 2009, we administered preoperative BREAST-Q questionnaires to women who presented to our institution for breast reconstruction. Univariate and multivariate analyses were performed to compare patient cohorts across multiple QoL domains including body image, physical well-being, psychosocial well-being, and sexual well-being. Of the 231 patients who presented for preoperative consultation, 176 returned the questionnaire (response rate 76%; 117 from the immediate, 21 from the delayed, and 32 from the major revision reconstruction groups, plus 6 mixed or unknown). The three groups differed significantly (P < 0.05) across four of the six domains: body image (satisfaction with breasts), psychosocial well-being, sexual well-being, and physical well-being of the chest and upper body. The immediate reconstruction group had higher (better) scores than the delayed reconstruction group, which had higher (better) scores than the major revision group. These data suggest that women presenting for breast reconstruction at different stages of reconstruction have different baseline QoL. Such data may help us better understand patient selection, education, and expectations, and may lead to improved patient-surgeon communication. Copyright © 2013 Wiley Periodicals, Inc.

  19. Reconstruction of convex bodies from surface tensors

    DEFF Research Database (Denmark)

    Kousholt, Astrid; Kiderlen, Markus

    2016-01-01

    We present two algorithms for reconstruction of the shape of convex bodies in the two-dimensional Euclidean space. The first reconstruction algorithm requires knowledge of the exact surface tensors of a convex body up to rank s for some natural number s. When only measurements subject to noise...... of surface tensors are available for reconstruction, we recommend to use certain values of the surface tensors, namely harmonic intrinsic volumes instead of the surface tensors evaluated at the standard basis. The second algorithm we present is based on harmonic intrinsic volumes and allows for noisy...... measurements. From a generalized version of Wirtinger's inequality, we derive stability results that are utilized to ensure consistency of both reconstruction procedures. Consistency of the reconstruction procedure based on measurements subject to noise is established under certain assumptions on the noise...

  20. Emissions trading with offset markets and free quota allocations

    Energy Technology Data Exchange (ETDEWEB)

    Rosendahl, Knut Einar; Strand, Jon

    2012-07-01

    We study interactions between a 'policy bloc's' emissions quota market and an offset market where emissions offsets can be purchased from a non-policy 'fringe' of countries (such as for the CDM under the Kyoto Protocol). Policy-bloc firms are assumed to benefit from free quota allocations that are updated according to either past emissions or past outputs. We show that both overall abatement, and the allocation of given abatement between the policy bloc and the fringe, tend to be inefficient. When the policy-bloc quota market and offset markets are fully integrated (and firms buy offsets directly from the fringe), and all quotas and offsets must be traded at a single price, it is optimal for the policy bloc to either not constrain the offset market whatsoever, or to ban offsets completely. The former (latter) case occurs when free allocation of quotas is not too generous (very generous), and the offset market can profitably deliver large (only a small) quota amounts. Governments of policy countries would however instead prefer to buy offsets directly from the fringe at a price below the policy-bloc quota price. The offset price will then be below the marginal damage cost of emissions, and the quota price in the policy bloc above marginal damage cost. This solution is also inefficient as the policy bloc (acting as a monopsonist) purchases too few offsets from the fringe.(Author)

  1. 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

  2. Orbital floor reconstruction with free flaps after maxillectomy.

    Science.gov (United States)

    Sampathirao, Leela Mohan C S R; Thankappan, Krishnakumar; Duraisamy, Sriprakash; Hedne, Naveen; Sharma, Mohit; Mathew, Jimmy; Iyer, Subramania

    2013-06-01

    Background The purpose of this study is to evaluate the outcome of orbital floor reconstruction with free flaps after maxillectomy. Methods This was a retrospective analysis of 34 consecutive patients who underwent maxillectomy with orbital floor removal for malignancies, reconstructed with free flaps. A cross-sectional survey to assess the functional and esthetic outcome was done in 28 patients who were alive and disease-free, with a minimum of 6 months of follow-up. Results Twenty-six patients had bony reconstruction, and eight had soft tissue reconstruction. Free fibula flap was the commonest flap used (n = 14). Visual acuity was normal in 86%. Eye movements were normal in 92%. Abnormal globe position resulted in nine patients. Esthetic satisfaction was good in 19 patients (68%). Though there was no statistically significant difference in outcome of visual acuity, eye movement, and patient esthetic satisfaction between patients with bony and soft tissue reconstruction, more patients without bony reconstruction had abnormal globe position (p = 0.040). Conclusion Free tissue transfer has improved the results of orbital floor reconstruction after total maxillectomy, preserving the eye. Good functional and esthetic outcome was achieved. Though our study favors a bony orbital reconstruction, a larger study with adequate power and equal distribution of patients among the groups would be needed to determine this. Free fibula flap remains the commonest choice when a bony reconstruction is contemplated.

  3. Simultaneous maximum a posteriori longitudinal PET image reconstruction

    Science.gov (United States)

    Ellis, Sam; Reader, Andrew J.

    2017-09-01

    Positron emission tomography (PET) is frequently used to monitor functional changes that occur over extended time scales, for example in longitudinal oncology PET protocols that include routine clinical follow-up scans to assess the efficacy of a course of treatment. In these contexts PET datasets are currently reconstructed into images using single-dataset reconstruction methods. Inspired by recently proposed joint PET-MR reconstruction methods, we propose to reconstruct longitudinal datasets simultaneously by using a joint penalty term in order to exploit the high degree of similarity between longitudinal images. We achieved this by penalising voxel-wise differences between pairs of longitudinal PET images in a one-step-late maximum a posteriori (MAP) fashion, resulting in the MAP simultaneous longitudinal reconstruction (SLR) method. The proposed method reduced reconstruction errors and visually improved images relative to standard maximum likelihood expectation-maximisation (ML-EM) in simulated 2D longitudinal brain tumour scans. In reconstructions of split real 3D data with inserted simulated tumours, noise across images reconstructed with MAP-SLR was reduced to levels equivalent to doubling the number of detected counts when using ML-EM. Furthermore, quantification of tumour activities was largely preserved over a variety of longitudinal tumour changes, including changes in size and activity, with larger changes inducing larger biases relative to standard ML-EM reconstructions. Similar improvements were observed for a range of counts levels, demonstrating the robustness of the method when used with a single penalty strength. The results suggest that longitudinal regularisation is a simple but effective method of improving reconstructed PET images without using resolution degrading priors.

  4. The PRISM3D paleoenvironmental reconstruction

    Science.gov (United States)

    Dowsett, H.; Robinson, M.; Haywood, A.M.; Salzmann, U.; Hill, Daniel; Sohl, L.E.; Chandler, M.; Williams, Mark; Foley, K.; Stoll, D.K.

    2010-01-01

    The Pliocene Research, Interpretation and Synoptic Mapping (PRISM) paleoenvironmental reconstruction is an internally consistent and comprehensive global synthesis of a past interval of relatively warm and stable climate. It is regularly used in model studies that aim to better understand Pliocene climate, to improve model performance in future climate scenarios, and to distinguish model-dependent climate effects. The PRISM reconstruction is constantly evolving in order to incorporate additional geographic sites and environmental parameters, and is continuously refined by independent research findings. The new PRISM three dimensional (3D) reconstruction differs from previous PRISM reconstructions in that it includes a subsurface ocean temperature reconstruction, integrates geochemical sea surface temperature proxies to supplement the faunal-based temperature estimates, and uses numerical models for the first time to augment fossil data. Here we describe the components of PRISM3D and describe new findings specific to the new reconstruction. Highlights of the new PRISM3D reconstruction include removal of Hudson Bay and the Great Lakes and creation of open waterways in locations where the current bedrock elevation is less than 25m above modern sea level, due to the removal of the West Antarctic Ice Sheet and the reduction of the East Antarctic Ice Sheet. The mid-Piacenzian oceans were characterized by a reduced east-west temperature gradient in the equatorial Pacific, but PRISM3D data do not imply permanent El Niño conditions. The reduced equator-to-pole temperature gradient that characterized previous PRISM reconstructions is supported by significant displacement of vegetation belts toward the poles, is extended into the Arctic Ocean, and is confirmed by multiple proxies in PRISM3D. Arctic warmth coupled with increased dryness suggests the formation of warm and salty paleo North Atlantic Deep Water (NADW) and a more vigorous thermohaline circulation system that may

  5. 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

  6. Structure Assisted Compressed Sensing Reconstruction of Undersampled AFM Images

    DEFF Research Database (Denmark)

    Oxvig, Christian Schou; Arildsen, Thomas; Larsen, Torben

    2017-01-01

    reconstruction algorithms that enables the use of our proposed structure model in the reconstruction process. Through a large set of reconstructions, the general reconstruction capability improvement achievable using our structured model is shown both quantitatively and qualitatively. Specifically, our...

  7. Reconstruction of electric systems (ELE)

    International Nuclear Information System (INIS)

    Kohutovic, P.

    2001-01-01

    The original design of WWER-230 units consisted of a single common system EEPS (essential electric power supply system) per unit. The establishment of redundancy 2 x 100% EEPS was a global task. The task was started during the 'Small reconstruction' - MR V1, continued in 'Gradual reconstruction' and finished in the year 2000. (author)

  8. Optimizing Aesthetic Outcomes in Delayed Breast Reconstruction

    Directory of Open Access Journals (Sweden)

    Wojciech Dec, MD

    2017-08-01

    Conclusions:. Optimal aesthetic results can be achieved with: (1 restoration of breast skin envelope with tissue expansion when possible, (2 optimal positioning of a small skin paddle to be later incorporated entirely into a nipple areola reconstruction when adequate breast skin surface area is present, (3 limiting the reconstructed breast mound to 2 skin tones when large area skin resurfacing is required, (4 increasing breast volume by deepithelializing, not discarding, the inferior mastectomy flap skin, (5 eccentric division of abdominal flaps when an immediate and delayed bilateral breast reconstructions are performed simultaneously; and (6 performing second-stage breast reconstruction revisions and fat grafting.

  9. Tomographic image reconstruction using Artificial Neural Networks

    International Nuclear Information System (INIS)

    Paschalis, P.; Giokaris, N.D.; Karabarbounis, A.; Loudos, G.K.; Maintas, D.; Papanicolas, C.N.; Spanoudaki, V.; Tsoumpas, Ch.; Stiliaris, E.

    2004-01-01

    A new image reconstruction technique based on the usage of an Artificial Neural Network (ANN) is presented. The most crucial factor in designing such a reconstruction system is the network architecture and the number of the input projections needed to reconstruct the image. Although the training phase requires a large amount of input samples and a considerable CPU time, the trained network is characterized by simplicity and quick response. The performance of this ANN is tested using several image patterns. It is intended to be used together with a phantom rotating table and the γ-camera of IASA for SPECT image reconstruction

  10. 3D noise power spectrum applied on clinical MDCT scanners: effects of reconstruction algorithms and reconstruction filters

    Science.gov (United States)

    Miéville, Frédéric A.; Bolard, Gregory; Benkreira, Mohamed; Ayestaran, Paul; Gudinchet, François; Bochud, François; Verdun, Francis R.

    2011-03-01

    The noise power spectrum (NPS) is the reference metric for understanding the noise content in computed tomography (CT) images. To evaluate the noise properties of clinical multidetector (MDCT) scanners, local 2D and 3D NPSs were computed for different acquisition reconstruction parameters. A 64- and a 128-MDCT scanners were employed. Measurements were performed on a water phantom in axial and helical acquisition modes. CT dose index was identical for both installations. Influence of parameters such as the pitch, the reconstruction filter (soft, standard and bone) and the reconstruction algorithm (filtered-back projection (FBP), adaptive statistical iterative reconstruction (ASIR)) were investigated. Images were also reconstructed in the coronal plane using a reformat process. Then 2D and 3D NPS methods were computed. In axial acquisition mode, the 2D axial NPS showed an important magnitude variation as a function of the z-direction when measured at the phantom center. In helical mode, a directional dependency with lobular shape was observed while the magnitude of the NPS was kept constant. Important effects of the reconstruction filter, pitch and reconstruction algorithm were observed on 3D NPS results for both MDCTs. With ASIR, a reduction of the NPS magnitude and a shift of the NPS peak to the low frequency range were visible. 2D coronal NPS obtained from the reformat images was impacted by the interpolation when compared to 2D coronal NPS obtained from 3D measurements. The noise properties of volume measured in last generation MDCTs was studied using local 3D NPS metric. However, impact of the non-stationarity noise effect may need further investigations.

  11. ACL Reconstruction

    Science.gov (United States)

    ... in moderate exercise and recreational activities, or play sports that put less stress on the knees. ACL reconstruction is generally recommended if: You're an athlete and want to continue in your sport, especially if the sport involves jumping, cutting or ...

  12. Position reconstruction in LUX

    Science.gov (United States)

    Akerib, D. S.; Alsum, S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Brás, P.; Byram, D.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; Dobi, A.; Druszkiewicz, E.; Edwards, B. N.; Fallon, S. R.; Fan, A.; Fiorucci, S.; Gaitskell, R. J.; Genovesi, J.; Ghag, C.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Jacobsen, R. G.; Ji, W.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Palladino, K. J.; Pease, E. K.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solmaz, M.; Solovov, V. N.; Sorensen, P.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W. C.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Velan, V.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Xu, J.; Yazdani, K.; Young, S. K.; Zhang, C.

    2018-02-01

    The (x, y) position reconstruction method used in the analysis of the complete exposure of the Large Underground Xenon (LUX) experiment is presented. The algorithm is based on a statistical test that makes use of an iterative method to recover the photomultiplier tube (PMT) light response directly from the calibration data. The light response functions make use of a two dimensional functional form to account for the photons reflected on the inner walls of the detector. To increase the resolution for small pulses, a photon counting technique was employed to describe the response of the PMTs. The reconstruction was assessed with calibration data including 83mKr (releasing a total energy of 41.5 keV) and 3H (β- with Q = 18.6 keV) decays, and a deuterium-deuterium (D-D) neutron beam (2.45 MeV) . Within the detector's fiducial volume, the reconstruction has achieved an (x, y) position uncertainty of σ = 0.82 cm and σ = 0.17 cm for events of only 200 and 4,000 detected electroluminescence photons respectively. Such signals are associated with electron recoils of energies ~0.25 keV and ~10 keV, respectively. The reconstructed position of the smallest events with a single electron emitted from the liquid surface (22 detected photons) has a horizontal (x, y) uncertainty of 2.13 cm.

  13. Vertex Reconstruction for AEGIS’ FACT Detector

    CERN Document Server

    Themistokleous, Neofytos

    2017-01-01

    My project dealt with the development of a vertex reconstruction technique to discriminate antihydrogen from background signals in the AEGIS apparatus. It involved the creation of a Toy Monte-Carlo to simulate particle annihilation events, and a vertex reconstruction utility based on the Bayesian theory of probability. The first results based on 107 generated events with single track in the detector are encouraging. For such events, the algorithm can reconstruct the z-coordinate accurately , while for the r-coordinate the result is less accurate.

  14. Advanced reconstruction algorithms for electron tomography: From comparison to combination

    Energy Technology Data Exchange (ETDEWEB)

    Goris, B. [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Roelandts, T. [Vision Lab, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk (Belgium); Batenburg, K.J. [Vision Lab, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk (Belgium); Centrum Wiskunde and Informatica, Science Park 123, NL-1098XG Amsterdam (Netherlands); Heidari Mezerji, H. [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Bals, S., E-mail: sara.bals@ua.ac.be [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2013-04-15

    In this work, the simultaneous iterative reconstruction technique (SIRT), the total variation minimization (TVM) reconstruction technique and the discrete algebraic reconstruction technique (DART) for electron tomography are compared and the advantages and disadvantages are discussed. Furthermore, we describe how the result of a three dimensional (3D) reconstruction based on TVM can provide objective information that is needed as the input for a DART reconstruction. This approach results in a tomographic reconstruction of which the segmentation is carried out in an objective manner. - Highlights: ► A comparative study between different reconstruction algorithms for tomography is performed. ► Reconstruction algorithms that uses prior knowledge about the specimen have a superior result. ► One reconstruction algorithm can provide the prior knowledge for a second algorithm.

  15. The reconstruction of male hair-bearing facial regions.

    Science.gov (United States)

    Ridgway, Emily B; Pribaz, Julian J

    2011-01-01

    Loss of hair-bearing regions of the face caused by trauma, tumor resection, or burn presents a difficult reconstructive task for plastic surgeons. The ideal tissue substitute should have the same characteristics as the facial area affected, consisting of thin, pliable tissue with a similar color match and hair-bearing quality. This is a retrospective study of 34 male patients who underwent reconstruction of hair-bearing facial regions performed by the senior author (J.J.P.). Local and pedicled flaps were used primarily to reconstruct defects after tumor extirpation, trauma, infections, and burns. Two patients had irradiation before reconstruction. Two patients had prior facial reconstruction with free flaps. The authors found that certain techniques of reconstructing defects in hair-bearing facial regions were more successful than others in particular facial regions and in different sizes of defects. The authors were able to develop a simple algorithm for management of facial defects involving the hair-bearing regions of the eyebrow, sideburn, beard, and mustache that may prospectively aid the planning of reconstructive strategy in these cases.

  16. Tensor-based dictionary learning for dynamic tomographic reconstruction

    International Nuclear Information System (INIS)

    Tan, Shengqi; Wu, Zhifang; Zhang, Yanbo; Mou, Xuanqin; Wang, Ge; Cao, Guohua; Yu, Hengyong

    2015-01-01

    In dynamic computed tomography (CT) reconstruction, the data acquisition speed limits the spatio-temporal resolution. Recently, compressed sensing theory has been instrumental in improving CT reconstruction from far few-view projections. In this paper, we present an adaptive method to train a tensor-based spatio-temporal dictionary for sparse representation of an image sequence during the reconstruction process. The correlations among atoms and across phases are considered to capture the characteristics of an object. The reconstruction problem is solved by the alternating direction method of multipliers. To recover fine or sharp structures such as edges, the nonlocal total variation is incorporated into the algorithmic framework. Preclinical examples including a sheep lung perfusion study and a dynamic mouse cardiac imaging demonstrate that the proposed approach outperforms the vectorized dictionary-based CT reconstruction in the case of few-view reconstruction. (paper)

  17. Tensor-based Dictionary Learning for Dynamic Tomographic Reconstruction

    Science.gov (United States)

    Tan, Shengqi; Zhang, Yanbo; Wang, Ge; Mou, Xuanqin; Cao, Guohua; Wu, Zhifang; Yu, Hengyong

    2015-01-01

    In dynamic computed tomography (CT) reconstruction, the data acquisition speed limits the spatio-temporal resolution. Recently, compressed sensing theory has been instrumental in improving CT reconstruction from far few-view projections. In this paper, we present an adaptive method to train a tensor-based spatio-temporal dictionary for sparse representation of an image sequence during the reconstruction process. The correlations among atoms and across phases are considered to capture the characteristics of an object. The reconstruction problem is solved by the alternating direction method of multipliers. To recover fine or sharp structures such as edges, the nonlocal total variation is incorporated into the algorithmic framework. Preclinical examples including a sheep lung perfusion study and a dynamic mouse cardiac imaging demonstrate that the proposed approach outperforms the vectorized dictionary-based CT reconstruction in the case of few-view reconstruction. PMID:25779991

  18. 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.

  19. The Economics of Prepectoral Breast Reconstruction.

    Science.gov (United States)

    Glasberg, Scot Bradley

    2017-12-01

    The world of breast reconstruction over the last several years has seen a dramatic shift in focus to discussion and the application of placing tissue expanders and implants back into the prepectoral space. Although this technique failed during the early advent of breast reconstruction, newer technologies such as advances in fat grafting, improved acellular dermal matrices, better methods of assessing breast flap viability, and enhanced implants appear to have set the stage for the resurgence and positive early results seen with this technique. The main benefits of a switch to prepectoral breast reconstruction clinically appears to be less associated pain, lower incidence of animation deformities, and its associated symptoms as well as presumably better aesthetics. Early data suggest that the results are extremely promising and early adopters have attempted to define the ideal patients for prepectoral breast reconstruction. As with any new operative procedure, an assessment of finances and costs are crucial to its successful implementation. Although current data are minimal, this article attempts to build the fundamentals of an economic model that exhibits and displays potential savings through the use of prepectoral breast reconstruction.

  20. Baryon Acoustic Oscillations reconstruction with pixels

    Energy Technology Data Exchange (ETDEWEB)

    Obuljen, Andrej [SISSA—International School for Advanced Studies, Via Bonomea 265, 34136 Trieste (Italy); Villaescusa-Navarro, Francisco [Center for Computational Astrophysics, 160 5th Ave, New York, NY, 10010 (United States); Castorina, Emanuele [Berkeley Center for Cosmological Physics, University of California, Berkeley, CA 94720 (United States); Viel, Matteo, E-mail: aobuljen@sissa.it, E-mail: fvillaescusa@simonsfoundation.org, E-mail: ecastorina@berkeley.edu, E-mail: viel@oats.inaf.it [INAF, Osservatorio Astronomico di Trieste, via Tiepolo 11, I-34131 Trieste (Italy)

    2017-09-01

    Gravitational non-linear evolution induces a shift in the position of the baryon acoustic oscillations (BAO) peak together with a damping and broadening of its shape that bias and degrades the accuracy with which the position of the peak can be determined. BAO reconstruction is a technique developed to undo part of the effect of non-linearities. We present and analyse a reconstruction method that consists of displacing pixels instead of galaxies and whose implementation is easier than the standard reconstruction method. We show that this method is equivalent to the standard reconstruction technique in the limit where the number of pixels becomes very large. This method is particularly useful in surveys where individual galaxies are not resolved, as in 21cm intensity mapping observations. We validate this method by reconstructing mock pixelated maps, that we build from the distribution of matter and halos in real- and redshift-space, from a large set of numerical simulations. We find that this method is able to decrease the uncertainty in the BAO peak position by 30-50% over the typical angular resolution scales of 21 cm intensity mapping experiments.

  1. Patient-specific reconstruction plates are the missing link in computer-assisted mandibular reconstruction: A showcase for technical description.

    Science.gov (United States)

    Cornelius, Carl-Peter; Smolka, Wenko; Giessler, Goetz A; Wilde, Frank; Probst, Florian A

    2015-06-01

    Preoperative planning of mandibular reconstruction has moved from mechanical simulation by dental model casts or stereolithographic models into an almost completely virtual environment. CAD/CAM applications allow a high level of accuracy by providing a custom template-assisted contouring approach for bone flaps. However, the clinical accuracy of CAD reconstruction is limited by the use of prebent reconstruction plates, an analogue step in an otherwise digital workstream. In this paper the integration of computerized, numerically-controlled (CNC) milled, patient-specific mandibular plates (PSMP) within the virtual workflow of computer-assisted mandibular free fibula flap reconstruction is illustrated in a clinical case. Intraoperatively, the bone segments as well as the plate arms showed a very good fit. Postoperative CT imaging demonstrated close approximation of the PSMP and fibular segments, and good alignment of native mandible and fibular segments and intersegmentally. Over a follow-up period of 12 months, there was an uneventful course of healing with good bony consolidation. The virtual design and automated fabrication of patient-specific mandibular reconstruction plates provide the missing link in the virtual workflow of computer-assisted mandibular free fibula flap reconstruction. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  2. Simulated annealing image reconstruction for positron emission tomography

    International Nuclear Information System (INIS)

    Sundermann, E.; Lemahieu, I.; Desmedt, P.

    1994-01-01

    In Positron Emission Tomography (PET) images have to be reconstructed from moisy projection data. The noise on the PET data can be modeled by a Poison distribution. In this paper, we present the results of using the simulated annealing technique to reconstruct PET images. Various parameter settings of the simulated annealing algorithm are discussed and optimized. The reconstructed images are of good quality and high contrast, in comparison to other reconstruction techniques. (authors)

  3. Isolated Roux-en-Y anastomosis of the pancreatic stump in a duct-to-mucosa fashion in patients with distal pancreatectomy with en-bloc celiac axis resection.

    Science.gov (United States)

    Okada, Ken-Ichi; Kawai, Manabu; Tani, Masaji; Hirono, Seiko; Miyazawa, Motoki; Shimizu, Atsushi; Kitahata, Yuji; Yamaue, Hiroki

    2014-03-01

    A pancreatic fistula is one of the most serious complications in distal pancreatectomy with en bloc celiac axis resection (DP-CAR), because the pancreatic transection is performed on the right side of the portal vein, which results in a large cross-section surface, and because post-pancreatectomy hemorrhage is hard to treat by interventional radiology. Therefore, a procedure to decrease the incidence of postoperative pancreatic fistula is urgently needed. Twenty-six consecutive patients who underwent DP-CAR between April 2008 and August 2012 were reviewed retrospectively. The first 13 consecutive patients underwent DP-CAR with no anastomosis, and the subsequent 13 consecutive patients were treated with Roux-en-Y pancreaticojejunostomy (PJ) in a duct-to-mucosa fashion. Extremely high amylase levels (>4000 IU/l) of all drainage fluid specimens on postoperative day (POD) 1, 3 and 4 were detected more frequently in cases with no anastomosis (n = 7) compared to those with PJ (n = 1) (P = 0.056). The incidence of grade B/C pancreatic fistulas was 15.4% in cases with isolated Roux-en-Y anastomosis of the pancreatic stump performed in a duct-to-mucosa fashion, and we are currently examining whether this anastomosis method reduces the pancreatic fistula rate in a multicenter, randomized controlled trial for distal pancreatectomy patients (ClinicalTrials.gov NCT01384617). © 2013 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  4. Mandibular reconstruction in adults: a review.

    NARCIS (Netherlands)

    Goh, B.T.; Lee, S.; Tideman, H.; Stoelinga, P.J.W.

    2008-01-01

    Mandibular defects may result from trauma, inflammatory disease and benign or malignant tumours. Mastication, speech and facial aesthetics are often severely compromised without reconstruction. The goal of mandibular reconstruction is to restore facial form and function, implying repair of

  5. 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.

  6. Church, mission and reconstruction: Being a church with integrity in reconstruction discourse in post-colonial Zimbabwe

    Directory of Open Access Journals (Sweden)

    Canon B. Shambare

    2018-05-01

    Full Text Available The church in Africa, like its counterparts elsewhere in the world, is called to fulfil the mission of God as expressed in the call ‘Missio Dei’ and influentially remains with the integrity of the mission of Christ (Missio Christos, which is liberative and practical. For Christ was not only concerned with the spiritual needs of the people, but also with their material well-being. The following question therefore arises: how can the church in Africa, in general, and in Zimbabwe, in particular, actively do God’s mission and remain with integrity in the midst of the reality of suffering. Furthermore, how can the church for mission and reconstruction be understood in a post-colonial Zimbabwe given the contextual realities of political crises, corruption, poverty, moral decadence, defined or censored truth, leadership crises and no freedom of expression? This article argues that, although the church is faced with these arduous realities, it remains called by God to do God’s mission. While in post-colonial Zimbabwe the socio-political, socio-economic and socio-religious situation might seem hopeless, the church has remained vibrant and alive for reconstruction theology. The transformation of society is possible given the authority and mission mandate of the church. This article argues that the church is a key player in reconstruction theology and in the transformation of society. For transformation to be possible, the church should witness to the gospel of Christ without fear of being labelled, castrated and persecuted. The article asserts that the spirit of the Bible should be revived in a time of reconstruction in Zimbabwe. The assumption in this article is that Zimbabwe is ready for reconstruction discourse. For this to happen, the researchers argue that the church as a critical relevant player in reconstruction needs to ‘be church’ in its missional mandates. Integrity is essential if a church wants to be relevantly missional and

  7. HEEL BONE RECONSTRUCTIVE OSTEOSYNTHESIS

    Directory of Open Access Journals (Sweden)

    A. N. Svetashov

    2010-01-01

    Full Text Available To detect the most appropriate to heel bone injury severity variants of reconstructive osteosynthesis it was analyzed treatment results of 56 patients. In 15 (26.8% patients classic methods of surgical service were applied, in 41 (73.2% cases to restore the defect porous implants were used. Osteosynthesis without heel bone plastic restoration accomplishment was ineffective in 60% patients from control group. Reconstructive osteosynthesis method ensures long-term good functional effect of rehabilitation in 96.4% patients from the basic group.

  8. Vertex reconstruction in CMS

    International Nuclear Information System (INIS)

    Chabanat, E.; D'Hondt, J.; Estre, N.; Fruehwirth, R.; Prokofiev, K.; Speer, T.; Vanlaer, P.; Waltenberger, W.

    2005-01-01

    Due to the high track multiplicity in the final states expected in proton collisions at the LHC experiments, novel vertex reconstruction algorithms are required. The vertex reconstruction problem can be decomposed into a pattern recognition problem ('vertex finding') and an estimation problem ('vertex fitting'). Starting from least-squares methods, robustifications of the classical algorithms are discussed and the statistical properties of the novel methods are shown. A whole set of different approaches for the vertex finding problem is presented and compared in relevant physics channels

  9. Simulated annealing image reconstruction for positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Sundermann, E; Lemahieu, I; Desmedt, P [Department of Electronics and Information Systems, University of Ghent, St. Pietersnieuwstraat 41, B-9000 Ghent, Belgium (Belgium)

    1994-12-31

    In Positron Emission Tomography (PET) images have to be reconstructed from moisy projection data. The noise on the PET data can be modeled by a Poison distribution. In this paper, we present the results of using the simulated annealing technique to reconstruct PET images. Various parameter settings of the simulated annealing algorithm are discussed and optimized. The reconstructed images are of good quality and high contrast, in comparison to other reconstruction techniques. (authors). 11 refs., 2 figs.

  10. DART: a practical reconstruction algorithm for discrete tomography.

    Science.gov (United States)

    Batenburg, Kees Joost; Sijbers, Jan

    2011-09-01

    In this paper, we present an iterative reconstruction algorithm for discrete tomography, called discrete algebraic reconstruction technique (DART). DART can be applied if the scanned object is known to consist of only a few different compositions, each corresponding to a constant gray value in the reconstruction. Prior knowledge of the gray values for each of the compositions is exploited to steer the current reconstruction towards a reconstruction that contains only these gray values. Based on experiments with both simulated CT data and experimental μCT data, it is shown that DART is capable of computing more accurate reconstructions from a small number of projection images, or from a small angular range, than alternative methods. It is also shown that DART can deal effectively with noisy projection data and that the algorithm is robust with respect to errors in the estimation of the gray values.

  11. 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...

  12. Reconstruction of a ring applicator using CT imaging: impact of the reconstruction method and applicator orientation

    DEFF Research Database (Denmark)

    Hellebust, Taran Paulsen; Tanderup, Kari; Bergstrand, Eva Stabell

    2007-01-01

    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...

  13. SUBSTANTIATION OF SOLUTIONS PERTAINING TO COMPLEX PRODUCTION RECONSTRUCTION

    Directory of Open Access Journals (Sweden)

    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.

  14. Iterative concurrent reconstruction algorithms for emission computed tomography

    International Nuclear Information System (INIS)

    Brown, J.K.; Hasegawa, B.H.; Lang, T.F.

    1994-01-01

    Direct reconstruction techniques, such as those based on filtered backprojection, are typically used for emission computed tomography (ECT), even though it has been argued that iterative reconstruction methods may produce better clinical images. The major disadvantage of iterative reconstruction algorithms, and a significant reason for their lack of clinical acceptance, is their computational burden. We outline a new class of ''concurrent'' iterative reconstruction techniques for ECT in which the reconstruction process is reorganized such that a significant fraction of the computational processing occurs concurrently with the acquisition of ECT projection data. These new algorithms use the 10-30 min required for acquisition of a typical SPECT scan to iteratively process the available projection data, significantly reducing the requirements for post-acquisition processing. These algorithms are tested on SPECT projection data from a Hoffman brain phantom acquired with a 2 x 10 5 counts in 64 views each having 64 projections. The SPECT images are reconstructed as 64 x 64 tomograms, starting with six angular views. Other angular views are added to the reconstruction process sequentially, in a manner that reflects their availability for a typical acquisition protocol. The results suggest that if T s of concurrent processing are used, the reconstruction processing time required after completion of the data acquisition can be reduced by at least 1/3 T s. (Author)

  15. Weight Multispectral Reconstruction Strategy for Enhanced Reconstruction Accuracy and Stability With Cerenkov Luminescence Tomography.

    Science.gov (United States)

    Hongbo Guo; Xiaowei He; Muhan Liu; Zeyu Zhang; Zhenhua Hu; Jie Tian

    2017-06-01

    Cerenkov luminescence tomography (CLT) provides a novel technique for 3-D noninvasive detection of radiopharmaceuticals in living subjects. However, because of the severe scattering of Cerenkov light, the reconstruction accuracy and stability of CLT is still unsatisfied. In this paper, a modified weight multispectral CLT (wmCLT) reconstruction strategy was developed which split the Cerenkov radiation spectrum into several sub-spectral bands and weighted the sub-spectral results to obtain the final result. To better evaluate the property of the wmCLT reconstruction strategy in terms of accuracy, stability and practicability, several numerical simulation experiments and in vivo experiments were conducted and the results obtained were compared with the traditional multispectral CLT (mCLT) and hybrid-spectral CLT (hCLT) reconstruction strategies. The numerical simulation results indicated that wmCLT strategy significantly improved the accuracy of Cerenkov source localization and intensity quantitation and exhibited good stability in suppressing noise in numerical simulation experiments. And the comparison of the results achieved from different in vivo experiments further indicated significant improvement of the wmCLT strategy in terms of the shape recovery of the bladder and the spatial resolution of imaging xenograft tumors. Overall the strategy reported here will facilitate the development of nuclear and optical molecular tomography in theoretical study.

  16. Rates of Reconstruction Failure in Patients Undergoing Immediate Reconstruction With Tissue Expanders and/or Implants and Postmastectomy Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Fowble, Barbara, E-mail: BFowble@radonc.ucsf.edu [Department of Radiation Oncology, University of California San Francisco, San Francisco, California (United States); Park, Catherine [Department of Radiation Oncology, University of California San Francisco, San Francisco, California (United States); Wang, Frederick; Peled, Anne [Division of Plastic and Reconstructive Surgery, University of California San Francisco, San Francisco, California (United States); Alvarado, Michael; Ewing, Cheryl; Esserman, Laura [Carol Franc Buck Breast Care Center, Department of Surgery, University of California San Francisco, San Francisco, California (United States); Foster, Robert; Sbitany, Hani [Division of Plastic and Reconstructive Surgery, University of California San Francisco, San Francisco, California (United States); Hanlon, Alex [University of Pennsylvania School of Nursing, Philadelphia, Pennsylvania (United States)

    2015-07-01

    Objectives: Mastectomy rates for breast cancer have increased, with a parallel increase in immediate reconstruction. For some women, tissue expander and implant (TE/I) reconstruction is the preferred or sole option. This retrospective study examined the rate of TE/I reconstruction failure (ie, removal of the TE or I with the inability to replace it resulting in no final reconstruction or autologous tissue reconstruction) in patients receiving postmastectomy radiation therapy (PMRT). Methods and Materials: Between 2004 and 2012, 99 women had skin-sparing mastectomies (SSM) or total nipple/areolar skin-sparing mastectomies (TSSM) with immediate TE/I reconstruction and PMRT for pathologic stage II to III breast cancer. Ninety-seven percent had chemotherapy (doxorubicin and taxane-based), 22% underwent targeted therapies, and 78% had endocrine therapy. Radiation consisted of 5000 cGy given in 180 to 200 cGy to the reconstructed breast with or without treatment to the supraclavicular nodes. Median follow-up was 3.8 years. Results: Total TE/I failure was 18% (12% without final reconstruction, 6% converted to autologous reconstruction). In univariate analysis, the strongest predictor of reconstruction failure (RF) was absence of total TE/I coverage (acellular dermal matrix and/or serratus muscle) at the time of radiation. RF occurred in 32.5% of patients without total coverage compared to 9% with coverage (P=.0069). For women with total coverage, the location of the mastectomy scar in the inframammary fold region was associated with higher RF (19% vs 0%, P=.0189). In multivariate analysis, weight was a significant factor for RF, with lower weight associated with a higher RF. Weight appeared to be a surrogate for the interaction of total coverage, thin skin flaps, interval to exchange, and location of the mastectomy scar. Conclusions: RFs in patients receiving PMRT were lowered with total TE/I coverage at the time of radiation by avoiding inframammary fold incisions and

  17. Final results of the gradual reconstruction of Bohunice VI in Slovakia and evaluation of the reconstruction by international missions

    International Nuclear Information System (INIS)

    Ferenc, M.

    2001-01-01

    The gradual reconstruction of the Bohunice V1 nuclear power plant (Slovakia) represents the most extensive reconstruction of a nuclear power plant in operation as implemented worldwide up to now. Extensive reconstruction works in both civil construction and process parts, in instrumentation and control part, and in electric part enhanced both nuclear safety and operational reliability of Bohunice V1 in a significant way.(author)

  18. Track reconstruction in CMS high luminosity environment

    CERN Document Server

    AUTHOR|(CDS)2067159

    2016-01-01

    The CMS tracker is the largest silicon detector ever built, covering 200 square meters and providing an average of 14 high-precision measurements per track. Tracking is essential for the reconstruction of objects like jets, muons, electrons and tau leptons starting from the raw data from the silicon pixel and strip detectors. Track reconstruction is widely used also at trigger level as it improves objects tagging and resolution.The CMS tracking code is organized in several levels, known as iterative steps, each optimized to reconstruct a class of particle trajectories, as the ones of particles originating from the primary vertex or displaced tracks from particles resulting from secondary vertices. Each iterative step consists of seeding, pattern recognition and fitting by a kalman filter, and a final filtering and cleaning. Each subsequent step works on hits not yet associated to a reconstructed particle trajectory.The CMS tracking code is continuously evolving to make the reconstruction computing load compat...

  19. Track reconstruction in CMS high luminosity environment

    CERN Document Server

    Goetzmann, Christophe

    2014-01-01

    The CMS tracker is the largest silicon detector ever built, covering 200 square meters and providing an average of 14 high-precision measurements per track. Tracking is essential for the reconstruction of objects like jets, muons, electrons and tau leptons starting from the raw data from the silicon pixel and strip detectors. Track reconstruction is widely used also at trigger level as it improves objects tagging and resolution.The CMS tracking code is organized in several levels, known as iterative steps, each optimized to reconstruct a class of particle trajectories, as the ones of particles originating from the primary vertex or displaced tracks from particles resulting from secondary vertices. Each iterative step consists of seeding, pattern recognition and fitting by a kalman filter, and a final filtering and cleaning. Each subsequent step works on hits not yet associated to a reconstructed particle trajectory.The CMS tracking code is continuously evolving to make the reconstruction computing load compat...

  20. Current Strategies in Reconstruction of Maxillectomy Defects

    Science.gov (United States)

    Andrades, Patricio; Militsakh, Oleg; Hanasono, Matthew M.; Rieger, Jana; Rosenthal, Eben L.

    2014-01-01

    Objective To outline a contemporary review of defect classification and reconstructive options. Design Review article. Setting Tertiary care referral centers. Results Although prosthetic rehabilitation remains the standard of care in many institutions, the discomfort of wearing, removing, and cleaning a prosthesis; the inability to retain a prosthesis in large defects; and the frequent need for readjustments often limit the value of this cost-effective and successful method of restoring speech and mastication. However, flap reconstruction offers an option for many, although there is no agreement as to which techniques should be used for optimal reconstruction. Flap reconstruction also involves a longer recovery time with increased risk of surgical complications, has higher costs associated with the procedure, and requires access to a highly experienced surgeon. Conclusion The surgeon and reconstructive team must make individualized decisions based on the extent of the maxillectomy defect (eg, the resection of the infraorbital rim, the extent of palate excision, skin compromise) and the need for radiation therapy. PMID:21844415

  1. Reconstructing baryon oscillations: A Lagrangian theory perspective

    International Nuclear Information System (INIS)

    Padmanabhan, Nikhil; White, Martin; Cohn, J. D.

    2009-01-01

    Recently Eisenstein and collaborators introduced a method to 'reconstruct' the linear power spectrum from a nonlinearly evolved galaxy distribution in order to improve precision in measurements of baryon acoustic oscillations. We reformulate this method within the Lagrangian picture of structure formation, to better understand what such a method does, and what the resulting power spectra are. We show that reconstruction does not reproduce the linear density field, at second order. We however show that it does reduce the damping of the oscillations due to nonlinear structure formation, explaining the improvements seen in simulations. Our results suggest that the reconstructed power spectrum is potentially better modeled as the sum of three different power spectra, each dominating over different wavelength ranges and with different nonlinear damping terms. Finally, we also show that reconstruction reduces the mode-coupling term in the power spectrum, explaining why miscalibrations of the acoustic scale are reduced when one considers the reconstructed power spectrum.

  2. Primary Vertex Reconstruction at the ATLAS Experiment

    CERN Document Server

    Grimm, Kathryn; The ATLAS collaboration

    2016-01-01

    Efficient and precise reconstruction of the primary vertex in an LHC collision is essential in both the reconstruction of the full kinematic properties of a hard-scatter event and of soft interactions as a measure of the amount of pile-up. The reconstruction of primary vertices in the busy, high pile-up environment of Run-2 of the LHC is a challenging task. New methods have been developed by the ATLAS experiment to reconstruct vertices in such environments. Advances in vertex seeding include methods taken from medical imaging, which allow for reconstruction of multiple vertices with small spatial separation. The adoption of this new seeding algorithm within the ATLAS adaptive vertex finding and fitting procedure will be discussed, and the first results of the new techniques from Run-2 data will be presented. Additionally, data-driven methods to evaluate vertex resolution will be presented with special focus on correct methods to evaluate the effect of the beam spot constraint; results from these methods in Ru...

  3. Model-Based Reconstructive Elasticity Imaging Using Ultrasound

    Directory of Open Access Journals (Sweden)

    Salavat R. Aglyamov

    2007-01-01

    Full Text Available Elasticity imaging is a reconstructive imaging technique where tissue motion in response to mechanical excitation is measured using modern imaging systems, and the estimated displacements are then used to reconstruct the spatial distribution of Young's modulus. Here we present an ultrasound elasticity imaging method that utilizes the model-based technique for Young's modulus reconstruction. Based on the geometry of the imaged object, only one axial component of the strain tensor is used. The numerical implementation of the method is highly efficient because the reconstruction is based on an analytic solution of the forward elastic problem. The model-based approach is illustrated using two potential clinical applications: differentiation of liver hemangioma and staging of deep venous thrombosis. Overall, these studies demonstrate that model-based reconstructive elasticity imaging can be used in applications where the geometry of the object and the surrounding tissue is somewhat known and certain assumptions about the pathology can be made.

  4. Outcome of different facial nerve reconstruction techniques

    OpenAIRE

    Mohamed, Aboshanif; Omi, Eigo; Honda, Kohei; Suzuki, Shinsuke; Ishikawa, Kazuo

    2016-01-01

    Abstract Introduction: There is no technique of facial nerve reconstruction that guarantees facial function recovery up to grade III. Objective: To evaluate the efficacy and safety of different facial nerve reconstruction techniques. Methods: Facial nerve reconstruction was performed in 22 patients (facial nerve interpositional graft in 11 patients and hypoglossal-facial nerve transfer in another 11 patients). All patients had facial function House-Brackmann (HB) grade VI, either caused by...

  5. An Intelligent Actuator Fault Reconstruction Scheme for Robotic Manipulators.

    Science.gov (United States)

    Xiao, Bing; Yin, Shen

    2018-02-01

    This paper investigates a difficult problem of reconstructing actuator faults for robotic manipulators. An intelligent approach with fast reconstruction property is developed. This is achieved by using observer technique. This scheme is capable of precisely reconstructing the actual actuator fault. It is shown by Lyapunov stability analysis that the reconstruction error can converge to zero after finite time. A perfect reconstruction performance including precise and fast properties can be provided for actuator fault. The most important feature of the scheme is that, it does not depend on control law, dynamic model of actuator, faults' type, and also their time-profile. This super reconstruction performance and capability of the proposed approach are further validated by simulation and experimental results.

  6. Multicore Performance of Block Algebraic Iterative Reconstruction Methods

    DEFF Research Database (Denmark)

    Sørensen, Hans Henrik B.; Hansen, Per Christian

    2014-01-01

    Algebraic iterative methods are routinely used for solving the ill-posed sparse linear systems arising in tomographic image reconstruction. Here we consider the algebraic reconstruction technique (ART) and the simultaneous iterative reconstruction techniques (SIRT), both of which rely on semiconv......Algebraic iterative methods are routinely used for solving the ill-posed sparse linear systems arising in tomographic image reconstruction. Here we consider the algebraic reconstruction technique (ART) and the simultaneous iterative reconstruction techniques (SIRT), both of which rely...... on semiconvergence. Block versions of these methods, based on a partitioning of the linear system, are able to combine the fast semiconvergence of ART with the better multicore properties of SIRT. These block methods separate into two classes: those that, in each iteration, access the blocks in a sequential manner...... a fixed relaxation parameter in each method, namely, the one that leads to the fastest semiconvergence. Computational results show that for multicore computers, the sequential approach is preferable....

  7. Pediatric thermal injury: acute care and reconstruction update.

    Science.gov (United States)

    Armour, Alexis D; Billmire, David A

    2009-07-01

    The acute and reconstructive care of each pediatric burn patient presents unique challenges to the plastic surgeon and the burn care team. : The purpose of this review article is to highlight the interdependence between the acute and reconstructive needs of pediatric burn patients as it pertains to each anatomical site. Relevant principles of acute pediatric burn care and burn reconstruction are outlined, based on the authors' experience and review of the literature. The need for late reconstruction in pediatric burn survivors is significantly influenced by the acute surgical and rehabilitative treatments. With their vulnerability to airway swelling, hypothermia, pulmonary edema, and ischemia-reperfusion injury, pediatric patients with large burns require precise, life-saving treatment in the acute phase. Decision-making in pediatric burn reconstruction must take into account the patient's future growth, maturity, and often lack of suitable donor sites. Appropriately selected reconstructive techniques are essential to optimize function, appearance, and quality of life in pediatric burn survivors.

  8. Advances in Bioprinting Technologies for Craniofacial Reconstruction.

    Science.gov (United States)

    Visscher, Dafydd O; Farré-Guasch, Elisabet; Helder, Marco N; Gibbs, Susan; Forouzanfar, Tymour; van Zuijlen, Paul P; Wolff, Jan

    2016-09-01

    Recent developments in craniofacial reconstruction have shown important advances in both the materials and methods used. While autogenous tissue is still considered to be the gold standard for these reconstructions, the harvesting procedure remains tedious and in many cases causes significant donor site morbidity. These limitations have subsequently led to the development of less invasive techniques such as 3D bioprinting that could offer possibilities to manufacture patient-tailored bioactive tissue constructs for craniofacial reconstruction. Here, we discuss the current technological and (pre)clinical advances of 3D bioprinting for use in craniofacial reconstruction and highlight the challenges that need to be addressed in the coming years. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Vertex Reconstruction in CMS

    CERN Document Server

    Chabanat, E; D'Hondt, J; Vanlaer, P; Prokofiev, K; Speer, T; Frühwirth, R; Waltenberger, W

    2005-01-01

    Because of the high track multiplicity in the final states expected in proton collisions at the LHC experiments, novel vertex reconstruction algorithms are required. The vertex reconstruction problem can be decomposed into a pattern recognition problem ("vertex finding") and an estimation problem ("vertex fitting"). Starting from least-square methods, ways to render the classical algorithms more robust are discussed and the statistical properties of the novel methods are shown. A whole set of different approaches for the vertex finding problem is presented and compared in relevant physics channels.

  10. Algorithms for Reconstruction of Undersampled Atomic Force Microscopy Images Supplementary Material

    DEFF Research Database (Denmark)

    2017-01-01

    Two Jupyter Notebooks showcasing reconstructions of undersampled atomic force microscopy images. The reconstructions were obtained using a variety of interpolation and reconstruction methods.......Two Jupyter Notebooks showcasing reconstructions of undersampled atomic force microscopy images. The reconstructions were obtained using a variety of interpolation and reconstruction methods....

  11. RECONSTRUCTING WOMANHOOD IN TONY MORRISON'S BELOVED

    Directory of Open Access Journals (Sweden)

    Setefanus Suprajitno

    2000-01-01

    Full Text Available Tony Morrison's fifth novel, Beloved (1987, explores the degradation of slavery imposed upon slaves, even when they were owned by a "humane" slave master. The novel is set in the Reconstruction period, the period after the American civil war. The word reconstruction may be used for the Afro-Americans, especially for the Afro-American women who face double discrimination for being black and women. In dealing with women's oppression, Afro-American women have to reconstruct themselves as an act of survival, and to be aware of the horrors of the experiences which their ancestors had to go through.

  12. GEODESIC RECONSTRUCTION, SADDLE ZONES & HIERARCHICAL SEGMENTATION

    Directory of Open Access Journals (Sweden)

    Serge Beucher

    2011-05-01

    Full Text Available The morphological reconstruction based on geodesic operators, is a powerful tool in mathematical morphology. The general definition of this reconstruction supposes the use of a marker function f which is not necessarily related to the function g to be built. However, this paper deals with operations where the marker function is defined from given characteristic regions of the initial function f, as it is the case, for instance, for the extrema (maxima or minima but also for the saddle zones. Firstly, we show that the intuitive definition of a saddle zone is not easy to handle, especially when digitised images are involved. However, some of these saddle zones (regional ones also called overflow zones can be defined, this definition providing a simple algorithm to extract them. The second part of the paper is devoted to the use of these overflow zones as markers in image reconstruction. This reconstruction provides a new function which exhibits a new hierarchy of extrema. This hierarchy is equivalent to the hierarchy produced by the so-called waterfall algorithm. We explain why the waterfall algorithm can be achieved by performing a watershed transform of the function reconstructed by its initial watershed lines. Finally, some examples of use of this hierarchical segmentation are described.

  13. Craniofacial Reconstruction Evaluation by Geodesic Network

    Directory of Open Access Journals (Sweden)

    Junli Zhao

    2014-01-01

    Full Text Available Craniofacial reconstruction is to estimate an individual’s face model from its skull. It has a widespread application in forensic medicine, archeology, medical cosmetic surgery, and so forth. However, little attention is paid to the evaluation of craniofacial reconstruction. This paper proposes an objective method to evaluate globally and locally the reconstructed craniofacial faces based on the geodesic network. Firstly, the geodesic networks of the reconstructed craniofacial face and the original face are built, respectively, by geodesics and isogeodesics, whose intersections are network vertices. Then, the absolute value of the correlation coefficient of the features of all corresponding geodesic network vertices between two models is taken as the holistic similarity, where the weighted average of the shape index values in a neighborhood is defined as the feature of each network vertex. Moreover, the geodesic network vertices of each model are divided into six subareas, that is, forehead, eyes, nose, mouth, cheeks, and chin, and the local similarity is measured for each subarea. Experiments using 100 pairs of reconstructed craniofacial faces and their corresponding original faces show that the evaluation by our method is roughly consistent with the subjective evaluation derived from thirty-five persons in five groups.

  14. Accelerated Compressed Sensing Based CT Image Reconstruction.

    Science.gov (United States)

    Hashemi, SayedMasoud; Beheshti, Soosan; Gill, Patrick R; Paul, Narinder S; Cobbold, Richard S C

    2015-01-01

    In X-ray computed tomography (CT) an important objective is to reduce the radiation dose without significantly degrading the image quality. Compressed sensing (CS) enables the radiation dose to be reduced by producing diagnostic images from a limited number of projections. However, conventional CS-based algorithms are computationally intensive and time-consuming. We propose a new algorithm that accelerates the CS-based reconstruction by using a fast pseudopolar Fourier based Radon transform and rebinning the diverging fan beams to parallel beams. The reconstruction process is analyzed using a maximum-a-posterior approach, which is transformed into a weighted CS problem. The weights involved in the proposed model are calculated based on the statistical characteristics of the reconstruction process, which is formulated in terms of the measurement noise and rebinning interpolation error. Therefore, the proposed method not only accelerates the reconstruction, but also removes the rebinning and interpolation errors. Simulation results are shown for phantoms and a patient. For example, a 512 × 512 Shepp-Logan phantom when reconstructed from 128 rebinned projections using a conventional CS method had 10% error, whereas with the proposed method the reconstruction error was less than 1%. Moreover, computation times of less than 30 sec were obtained using a standard desktop computer without numerical optimization.

  15. Accelerated Compressed Sensing Based CT Image Reconstruction

    Directory of Open Access Journals (Sweden)

    SayedMasoud Hashemi

    2015-01-01

    Full Text Available In X-ray computed tomography (CT an important objective is to reduce the radiation dose without significantly degrading the image quality. Compressed sensing (CS enables the radiation dose to be reduced by producing diagnostic images from a limited number of projections. However, conventional CS-based algorithms are computationally intensive and time-consuming. We propose a new algorithm that accelerates the CS-based reconstruction by using a fast pseudopolar Fourier based Radon transform and rebinning the diverging fan beams to parallel beams. The reconstruction process is analyzed using a maximum-a-posterior approach, which is transformed into a weighted CS problem. The weights involved in the proposed model are calculated based on the statistical characteristics of the reconstruction process, which is formulated in terms of the measurement noise and rebinning interpolation error. Therefore, the proposed method not only accelerates the reconstruction, but also removes the rebinning and interpolation errors. Simulation results are shown for phantoms and a patient. For example, a 512 × 512 Shepp-Logan phantom when reconstructed from 128 rebinned projections using a conventional CS method had 10% error, whereas with the proposed method the reconstruction error was less than 1%. Moreover, computation times of less than 30 sec were obtained using a standard desktop computer without numerical optimization.

  16. UV Reconstruction Algorithm And Diurnal Cycle Variability

    Science.gov (United States)

    Curylo, Aleksander; Litynska, Zenobia; Krzyscin, Janusz; Bogdanska, Barbara

    2009-03-01

    UV reconstruction is a method of estimation of surface UV with the use of available actinometrical and aerological measurements. UV reconstruction is necessary for the study of long-term UV change. A typical series of UV measurements is not longer than 15 years, which is too short for trend estimation. The essential problem in the reconstruction algorithm is the good parameterization of clouds. In our previous algorithm we used an empirical relation between Cloud Modification Factor (CMF) in global radiation and CMF in UV. The CMF is defined as the ratio between measured and modelled irradiances. Clear sky irradiance was calculated with a solar radiative transfer model. In the proposed algorithm, the time variability of global radiation during the diurnal cycle is used as an additional source of information. For elaborating an improved reconstruction algorithm relevant data from Legionowo [52.4 N, 21.0 E, 96 m a.s.l], Poland were collected with the following instruments: NILU-UV multi channel radiometer, Kipp&Zonen pyranometer, radiosonde profiles of ozone, humidity and temperature. The proposed algorithm has been used for reconstruction of UV at four Polish sites: Mikolajki, Kolobrzeg, Warszawa-Bielany and Zakopane since the early 1960s. Krzyscin's reconstruction of total ozone has been used in the calculations.

  17. Postmastectomy reconstruction: comparative analysis of the psychosocial, functional, and cosmetic effects of transverse rectus abdominis musculocutaneous flap versus breast implant reconstruction.

    Science.gov (United States)

    Cederna, P S; Yates, W R; Chang, P; Cram, A E; Ricciardelli, E J

    1995-11-01

    Over 40,000 postmastectomy breast reconstructions are performed annually. In this study, we investigated the psychosocial, functional, and cosmetic effects of transverse rectus abdominis musculocutaneous (TRAM) flap versus breast implant reconstruction. Thirty-three women who had undergone postmastectomy breast reconstruction were contacted by telephone and agreed to participate in the study. Twenty-two women completed the self-assessment questionnaires regarding their quality of life, psychological symptoms, functional status, body image, and global satisfaction. The TRAM and implant groups contained 8 and 14 patients, respectively. The groups were well matched for age, employment status, marital status, race, religion, and severity of medical and surgical illnesses. The average follow-up was 36 months. Statistical analysis of the responses revealed that women who had undergone TRAM flap reconstruction were more satisfied with how their reconstructed breast felt to the touch (p = .01), and there was a trend toward greater satisfaction with the appearance of their reconstructed breast (p = .08). However, these same patients identified more difficulties as far as functioning at work or school, performing vigorous physical activities, participating in community or religious activities, visiting with relatives, and interacting with male friends (p physical impairments as a result of their reconstruction.

  18. CT angiography after carotid artery stenting: assessment of the utility of adaptive statistical iterative reconstruction and model-based iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Kuya, Keita; Shinohara, Yuki; Fujii, Shinya; Ogawa, Toshihide [Tottori University, Division of Radiology, Department of Pathophysiological Therapeutic Science, Faculty of Medicine, Yonago (Japan); Sakamoto, Makoto; Watanabe, Takashi [Tottori University, Division of Neurosurgery, Department of Brain and Neurosciences, Faculty of Medicine, Yonago (Japan); Iwata, Naoki; Kishimoto, Junichi [Tottori University, Division of Clinical Radiology Faculty of Medicine, Yonago (Japan); Kaminou, Toshio [Osaka Minami Medical Center, Department of Radiology, Osaka (Japan)

    2014-11-15

    Follow-up CT angiography (CTA) is routinely performed for post-procedure management after carotid artery stenting (CAS). However, the stent lumen tends to be underestimated because of stent artifacts on CTA reconstructed with the filtered back projection (FBP) technique. We assessed the utility of new iterative reconstruction techniques, such as adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR), for CTA after CAS in comparison with FBP. In a phantom study, we evaluated the differences among the three reconstruction techniques with regard to the relationship between the stent luminal diameter and the degree of underestimation of stent luminal diameter. In a clinical study, 34 patients who underwent follow-up CTA after CAS were included. We compared the stent luminal diameters among FBP, ASIR, and MBIR, and performed visual assessment of low attenuation area (LAA) in the stent lumen using a three-point scale. In the phantom study, stent luminal diameter was increasingly underestimated as luminal diameter became smaller in all CTA images. Stent luminal diameter was larger with MBIR than with the other reconstruction techniques. Similarly, in the clinical study, stent luminal diameter was larger with MBIR than with the other reconstruction techniques. LAA detectability scores of MBIR were greater than or equal to those of FBP and ASIR in all cases. MBIR improved the accuracy of assessment of stent luminal diameter and LAA detectability in the stent lumen when compared with FBP and ASIR. We conclude that MBIR is a useful reconstruction technique for CTA after CAS. (orig.)

  19. CT angiography after carotid artery stenting: assessment of the utility of adaptive statistical iterative reconstruction and model-based iterative reconstruction

    International Nuclear Information System (INIS)

    Kuya, Keita; Shinohara, Yuki; Fujii, Shinya; Ogawa, Toshihide; Sakamoto, Makoto; Watanabe, Takashi; Iwata, Naoki; Kishimoto, Junichi; Kaminou, Toshio

    2014-01-01

    Follow-up CT angiography (CTA) is routinely performed for post-procedure management after carotid artery stenting (CAS). However, the stent lumen tends to be underestimated because of stent artifacts on CTA reconstructed with the filtered back projection (FBP) technique. We assessed the utility of new iterative reconstruction techniques, such as adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR), for CTA after CAS in comparison with FBP. In a phantom study, we evaluated the differences among the three reconstruction techniques with regard to the relationship between the stent luminal diameter and the degree of underestimation of stent luminal diameter. In a clinical study, 34 patients who underwent follow-up CTA after CAS were included. We compared the stent luminal diameters among FBP, ASIR, and MBIR, and performed visual assessment of low attenuation area (LAA) in the stent lumen using a three-point scale. In the phantom study, stent luminal diameter was increasingly underestimated as luminal diameter became smaller in all CTA images. Stent luminal diameter was larger with MBIR than with the other reconstruction techniques. Similarly, in the clinical study, stent luminal diameter was larger with MBIR than with the other reconstruction techniques. LAA detectability scores of MBIR were greater than or equal to those of FBP and ASIR in all cases. MBIR improved the accuracy of assessment of stent luminal diameter and LAA detectability in the stent lumen when compared with FBP and ASIR. We conclude that MBIR is a useful reconstruction technique for CTA after CAS. (orig.)

  20. The Theory of Variances in Equilibrium Reconstruction

    International Nuclear Information System (INIS)

    Zakharov, Leonid E.; Lewandowski, Jerome; Foley, Elizabeth L.; Levinton, Fred M.; Yuh, Howard Y.; Drozdov, Vladimir; McDonald, Darren

    2008-01-01

    The theory of variances of equilibrium reconstruction is presented. It complements existing practices with information regarding what kind of plasma profiles can be reconstructed, how accurately, and what remains beyond the abilities of diagnostic systems. The σ-curves, introduced by the present theory, give a quantitative assessment of quality of effectiveness of diagnostic systems in constraining equilibrium reconstructions. The theory also suggests a method for aligning the accuracy of measurements of different physical nature

  1. Impact of Reconstruction Algorithms on CT Radiomic Features of Pulmonary Tumors: Analysis of Intra- and Inter-Reader Variability and Inter-Reconstruction Algorithm Variability.

    Science.gov (United States)

    Kim, Hyungjin; Park, Chang Min; Lee, Myunghee; Park, Sang Joon; Song, Yong Sub; Lee, Jong Hyuk; Hwang, Eui Jin; Goo, Jin Mo

    2016-01-01

    To identify the impact of reconstruction algorithms on CT radiomic features of pulmonary tumors and to reveal and compare the intra- and inter-reader and inter-reconstruction algorithm variability of each feature. Forty-two patients (M:F = 19:23; mean age, 60.43±10.56 years) with 42 pulmonary tumors (22.56±8.51mm) underwent contrast-enhanced CT scans, which were reconstructed with filtered back projection and commercial iterative reconstruction algorithm (level 3 and 5). Two readers independently segmented the whole tumor volume. Fifteen radiomic features were extracted and compared among reconstruction algorithms. Intra- and inter-reader variability and inter-reconstruction algorithm variability were calculated using coefficients of variation (CVs) and then compared. Among the 15 features, 5 first-order tumor intensity features and 4 gray level co-occurrence matrix (GLCM)-based features showed significant differences (palgorithms. As for the variability, effective diameter, sphericity, entropy, and GLCM entropy were the most robust features (CV≤5%). Inter-reader variability was larger than intra-reader or inter-reconstruction algorithm variability in 9 features. However, for entropy, homogeneity, and 4 GLCM-based features, inter-reconstruction algorithm variability was significantly greater than inter-reader variability (palgorithms. Inter-reconstruction algorithm variability was greater than inter-reader variability for entropy, homogeneity, and GLCM-based features.

  2. One stage revision single-bundle anterior cruciate ligament reconstruction with impacted morselized bone graft following a failed double-bundle reconstruction

    Directory of Open Access Journals (Sweden)

    Ho Jong Ra

    2017-01-01

    Full Text Available Although double-bundle anterior cruciate ligament (ACL reconstruction has theoretical benefits such as more accurate reproduction of ACL anatomy, it is technically more demanding surgery. This report describes the case of a one stage revision single-bundle ACL reconstruction after primary double-bundle ACL reconstruction. A professional dancer had an ACL previously reconstructed with a double-bundle technique, but the femoral tunnels were malpositioned resulting in residual laxity and rotational instability. The previous femoral tunnel positions were vertical and widened. The previous vertical tunnels were filled with impacted bone graft and a revision single-bundle ACL reconstruction was performed via the new femoral tunnel with a 2 O'clock position between the previous two tunnels. After 10 months of postoperative rehabilitation, the patient returned to professional dancing with sound bony union and without any residual instability.

  3. Interactive reconstruction in single-photon tomography

    International Nuclear Information System (INIS)

    Miller, T.R.; Wallis, J.W.; Wilson, A.D.

    1989-01-01

    A new method is described to allow interactive selection of the reconstruction filter at the time of interpretation of images from single-photon tomography. In the filtered back projection algorithm, the only part of the reconstruction process requiring user interaction is the selection of the window function. Since the ramp and window filters have different purposes, they can be separated, placing the window at the end of the reconstruction process as a three-dimensional filter. All stages of reconstruction except the window filtering are performed before the physician begins to interpret the study. The three-dimensional filtering is performed very rapidly with use of the Chebyshev convolution algorithm. A 64 x 64 x 64 pixel cube of data is filtered in 13-33 s using filters of 3-11 lengths. Smaller volumes of image data can be filtered in less than 1 s; thus, the user can interactively choose any desired filter for a given tomographic study at the time of interpretation of the images. (orig.)

  4. IRVE-II Post-Flight Trajectory Reconstruction

    Science.gov (United States)

    O'Keefe, Stephen A.; Bose, David M.

    2010-01-01

    NASA s Inflatable Re-entry Vehicle Experiment (IRVE) II successfully demonstrated an inflatable aerodynamic decelerator after being launched aboard a sounding rocket from Wallops Flight Facility (WFF). Preliminary day of flight data compared well with pre-flight Monte Carlo analysis, and a more complete trajectory reconstruction performed with an Extended Kalman Filter (EKF) approach followed. The reconstructed trajectory and comparisons to an attitude solution provided by NASA Sounding Rocket Operations Contract (NSROC) personnel at WFF are presented. Additional comparisons are made between the reconstructed trajectory and pre and post-flight Monte Carlo trajectory predictions. Alternative observations of the trajectory are summarized which leverage flight accelerometer measurements, the pre-flight aerodynamic database, and on-board flight video. Finally, analysis of the payload separation and aeroshell deployment events are presented. The flight trajectory is reconstructed to fidelity sufficient to assess overall project objectives related to flight dynamics and overall, IRVE-II flight dynamics are in line with expectations

  5. DD4Hep based event reconstruction

    CERN Document Server

    AUTHOR|(SzGeCERN)683529; Frank, Markus; Gaede, Frank-Dieter; Hynds, Daniel; Lu, Shaojun; Nikiforou, Nikiforos; Petric, Marko; Simoniello, Rosa; Voutsinas, Georgios Gerasimos

    The DD4HEP detector description toolkit offers a flexible and easy-to-use solution for the consistent and complete description of particle physics detectors in a single system. The sub-component DDREC provides a dedicated interface to the detector geometry as needed for event reconstruction. With DDREC there is no need to define an additional, separate reconstruction geometry as is often done in HEP, but one can transparently extend the existing detailed simulation model to be also used for the reconstruction. Based on the extension mechanism of DD4HEP, DDREC allows one to attach user defined data structures to detector elements at all levels of the geometry hierarchy. These data structures define a high level view onto the detectors describing their physical properties, such as measurement layers, point resolutions, and cell sizes. For the purpose of charged particle track reconstruction, dedicated surface objects can be attached to every volume in the detector geometry. These surfaces provide the measuremen...

  6. Reconstructing warm inflation

    Science.gov (United States)

    Herrera, Ramón

    2018-03-01

    The reconstruction of a warm inflationary universe model from the scalar spectral index n_S(N) and the tensor to scalar ratio r( N) as a function of the number of e-folds N is studied. Under a general formalism we find the effective potential and the dissipative coefficient in terms of the cosmological parameters n_S and r considering the weak and strong dissipative stages under the slow roll approximation. As a specific example, we study the attractors for the index n_S given by nS-1∝ N^{-1} and for the ratio r∝ N^{-2}, in order to reconstruct the model of warm inflation. Here, expressions for the effective potential V(φ ) and the dissipation coefficient Γ (φ ) are obtained.

  7. 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.

  8. Lower limb edema after arterial reconstruction, a comparison with lymph, reconstruction and DVT edema by RI scintigram

    International Nuclear Information System (INIS)

    Ojiro, M.; Takenosita, M.; Toshinaga, R.; Shimazu, H.; Nakajo, M.; Iwasita, S.

    1991-01-01

    Postoperative lower limb edema after arterial-reconstruction is common complication. However the precise mechanism of this process is not fully understood. In order to investigate this pathogenesis, it was studied whether the postoperative edema was affected by the various types of reconstruction, the materials, the degree of preoperative ischemia and the grade of improvement of ankle pressure index (API) after reconstruction retrospectively. Furthermore, by pertechnetate anion the difference of scintigraph pattern was studied in the lower limb and was compared with postoperative edema, lymph edema and acute deep vein thrombosis (DVT) with swelling limb. (author). 4 refs.; 2 figs

  9. A modified discrete algebraic reconstruction technique for multiple grey image reconstruction for limited angle range tomography.

    Science.gov (United States)

    Liang, Zhiting; Guan, Yong; Liu, Gang; Chen, Xiangyu; Li, Fahu; Guo, Pengfei; Tian, Yangchao

    2016-03-01

    The `missing wedge', which is due to a restricted rotation range, is a major challenge for quantitative analysis of an object using tomography. With prior knowledge of the grey levels, the discrete algebraic reconstruction technique (DART) is able to reconstruct objects accurately with projections in a limited angle range. However, the quality of the reconstructions declines as the number of grey levels increases. In this paper, a modified DART (MDART) was proposed, in which each independent region of homogeneous material was chosen as a research object, instead of the grey values. The grey values of each discrete region were estimated according to the solution of the linear projection equations. The iterative process of boundary pixels updating and correcting the grey values of each region was executed alternately. Simulation experiments of binary phantoms as well as multiple grey phantoms show that MDART is capable of achieving high-quality reconstructions with projections in a limited angle range. The interesting advancement of MDART is that neither prior knowledge of the grey values nor the number of grey levels is necessary.

  10. 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...

  11. RIB FRACTURE AFTER BREAST RECONSTRUCTION WITH TISSUE EXPANDER

    Directory of Open Access Journals (Sweden)

    Uroš Ahčan

    2009-08-01

    Full Text Available Breast reconstruction with tissue expansion and later exchange with prosthesis is one of the most common methods for breast reconstruction. Women that are not appropriate for reconstruction with autologous tissue, women that have small breast or have a positive family history for breast cancer are most suitable for this type of reconstruction. Surgical technique of tissue expansion is relatively easy. Complications are rarely seen. With this case report we want to show the common, although occult existence of skeletal deformities in thorax after breast tissue expansion that may lead to rib fractures.

  12. Time-based Reconstruction of Free-streaming Data in CBM

    Science.gov (United States)

    Akishina, Valentina; Kisel, Ivan; Vassiliev, Iouri; Zyzak, Maksym

    2018-02-01

    Traditional latency-limited trigger architectures typical for conventional experiments are inapplicable for the CBM experiment. Instead, CBM will ship and collect time-stamped data into a readout buffer in a form of a time-slice of a certain length and deliver it to a large computer farm, where online event reconstruction and selection will be performed. Grouping measurements into physical collisions must be performed in software and requires reconstruction not only in space, but also in time, the so-called 4-dimensional track reconstruction and event building. The tracks, reconstructed with 4D Cellular Automaton track finder, are combined into event-corresponding clusters according to the estimated time in the target position and the errors, obtained with the Kalman Filter method. The reconstructed events are given as inputs to the KF Particle Finder package for short-lived particle reconstruction. The results of time-based reconstruction of simulated collisions in CBM are presented and discussed in details.

  13. Spiral scan long object reconstruction through PI line reconstruction

    International Nuclear Information System (INIS)

    Tam, K C; Hu, J; Sourbelle, K

    2004-01-01

    The response of a point object in a cone beam (CB) spiral scan is analysed. Based on the result, a reconstruction algorithm for long object imaging in spiral scan cone beam CT is developed. A region-of-interest (ROI) of the long object is scanned with a detector smaller than the ROI, and a portion of it can be reconstructed without contamination from overlaying materials. The top and bottom surfaces of the ROI are defined by two sets of PI lines near the two ends of the spiral path. With this novel definition of the top and bottom ROI surfaces and through the use of projective geometry, it is straightforward to partition the cone beam image into regions corresponding to projections of the ROI, the overlaying objects or both. This also simplifies computation at source positions near the spiral ends, and makes it possible to reduce radiation exposure near the spiral ends substantially through simple hardware collimation. Simulation results to validate the algorithm are presented

  14. Distributed 3-D iterative reconstruction for quantitative SPECT

    International Nuclear Information System (INIS)

    Ju, Z.W.; Frey, E.C.; Tsui, B.M.W.

    1995-01-01

    The authors describe a distributed three dimensional (3-D) iterative reconstruction library for quantitative single-photon emission computed tomography (SPECT). This library includes 3-D projector-backprojector pairs (PBPs) and distributed 3-D iterative reconstruction algorithms. The 3-D PBPs accurately and efficiently model various combinations of the image degrading factors including attenuation, detector response and scatter response. These PBPs were validated by comparing projection data computed using the projectors with that from direct Monte Carlo (MC) simulations. The distributed 3-D iterative algorithms spread the projection-backprojection operations for all the projection angles over a heterogeneous network of single or multi-processor computers to reduce the reconstruction time. Based on a master/slave paradigm, these distributed algorithms provide dynamic load balancing and fault tolerance. The distributed algorithms were verified by comparing images reconstructed using both the distributed and non-distributed algorithms. Computation times for distributed 3-D reconstructions running on up to 4 identical processors were reduced by a factor approximately 80--90% times the number of the processors participating, compared to those for non-distributed 3-D reconstructions running on a single processor. When combined with faster affordable computers, this library provides an efficient means for implementing accurate reconstruction and compensation methods to improve quality and quantitative accuracy in SPECT images

  15. Reconstruction of convex bodies from surface tensors

    DEFF Research Database (Denmark)

    Kousholt, Astrid; Kiderlen, Markus

    . The output of the reconstruction algorithm is a polytope P, where the surface tensors of P and K are identical up to rank s. We establish a stability result based on a generalization of Wirtinger’s inequality that shows that for large s, two convex bodies are close in shape when they have identical surface...... that are translates of each other. An algorithm for reconstructing an unknown convex body in R 2 from its surface tensors up to a certain rank is presented. Using the reconstruction algorithm, the shape of an unknown convex body can be approximated when only a finite number s of surface tensors are available...... tensors up to rank s. This is used to establish consistency of the developed reconstruction algorithm....

  16. Primary vertex reconstruction with the ATLAS detector

    International Nuclear Information System (INIS)

    Meloni, F.

    2016-01-01

    Efficient and precise reconstruction of the primary vertex in a LHC collision is essential for determining the full kinematic properties of a hard-scatter event and of soft interactions as a measure of the amount of pile-up. The reconstruction of primary vertices in the busy, high pile-up environment of Run-2 of the LHC is a challenging task. The algorithms developed by the ATLAS experiments to reconstruct multiple vertices with small spatial separation are presented.

  17. Porous media microstructure reconstruction using pixel-based and object-based simulated annealing: comparison with other reconstruction methods

    Energy Technology Data Exchange (ETDEWEB)

    Diogenes, Alysson N.; Santos, Luis O.E. dos; Fernandes, Celso P. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil); Appoloni, Carlos R. [Universidade Estadual de Londrina (UEL), PR (Brazil)

    2008-07-01

    The reservoir rocks physical properties are usually obtained in laboratory, through standard experiments. These experiments are often very expensive and time-consuming. Hence, the digital image analysis techniques are a very fast and low cost methodology for physical properties prediction, knowing only geometrical parameters measured from the rock microstructure thin sections. This research analyzes two methods for porous media reconstruction using the relaxation method simulated annealing. Using geometrical parameters measured from rock thin sections, it is possible to construct a three-dimensional (3D) model of the microstructure. We assume statistical homogeneity and isotropy and the 3D model maintains porosity spatial correlation, chord size distribution and d 3-4 distance transform distribution for a pixel-based reconstruction and spatial correlation for an object-based reconstruction. The 2D and 3D preliminary results are compared with microstructures reconstructed by truncated Gaussian methods. As this research is in its beginning, only the 2D results will be presented. (author)

  18. An Electrosurgical Endoknife with a Water-Jet Function (Flushknife Proves Its Merits in Colorectal Endoscopic Submucosal Dissection Especially for the Cases Which Should Be Removed En Bloc

    Directory of Open Access Journals (Sweden)

    Yoji Takeuchi

    2013-01-01

    Full Text Available Background. Previously, we reported that the Flushknife (electrosurgical endoknife with a water-jet function could reduce the operation time of colorectal endoscopic submucosal dissection (ESD however, suitable situation for the Flushknife was obscure. This subgroup analysis of a prospective randomized controlled trial was aimed to investigate the suitable situation for the Flushknife. Methods. A total of 48 superficial colorectal neoplasms that underwent ESD using either the Flexknife or the Flushknife in a referral center were enrolled. The differences of operation time between the Flexknife and the Flushknife groups in each subgroup (tumor size, location, and macroscopic type were analyzed. Results. Median (95% CI operation time calculated using survival curves was significantly shorter in the Flushknife group than in the Flexknife group (55.5 min [41, 78] versus 74.0 [57, 90] min; , Hazard Ratio HR: 0.53; 95% CI (0.29–0.97. In particular, the HR in patients with laterally spreading tumors-nongranular type (LST-NG in the Flushknife group was significantly smaller than in the Flexknife group (HR: 0.1650.17; 95% CI (0.04–0.66. There was a trend of decreasing HRs according to larger lesion size. Conclusions. The Flushknife proved its merits in colorectal ESD especially for the lesions which should be removed en bloc (LST-NG and large lesion.

  19. Reconstruction of Defects After Fournier Gangrene: A Systematic Review.

    Science.gov (United States)

    Karian, Laurel S; Chung, Stella Y; Lee, Edward S

    2015-01-01

    Reconstruction of scrotal defects after Fournier gangrene is often achieved with skin grafts or flaps, but there is no general consensus on the best method of reconstruction or how to approach the exposed testicle. We systematically reviewed the literature addressing methods of reconstruction of Fournier defects after debridement. PubMed and Cochrane databases were searched from 1950 to 2013. Inclusion criteria were reconstruction for Fournier defects, patients 18 to 90 years old, and reconstructive complication rates reported as whole numbers or percentages. Exclusion criteria were studies focused on methods of debridement or other phases of care rather than reconstruction, studies with fewer than 5 male patients with Fournier defects, literature reviews, and articles not in English. The initial search yielded 982 studies, which was refined to 16 studies with a total pool of 425 patients. There were 25 (5.9%) patients with defects that healed by secondary intention, 44 (10.4%) with delayed primary closure, 36 (8.5%) with implantation of the testicle in a medial thigh pocket, 6 (1.4%) with loose wound approximation, 96 (22.6%) with skin grafts, 68 (16.0%) with scrotal advancement flaps, 128 (30.1%) with flaps, and 22 (5.2%) with flaps or skin grafts in combination with tissue adhesives. Four outcomes were evaluated: number of patients, defect size, method of reconstruction, and wound-healing complications. Most reconstructive techniques provide reliable coverage and protection of testicular function with an acceptable cosmetic result. There is no conclusive evidence to support flap coverage of exposed testes rather than skin graft. A reconstructive algorithm is proposed. Skin grafting or flap reconstruction is recommended for defects larger than 50% of the scrotum or extending beyond the scrotum, whereas scrotal advancement flap reconstruction or healing by secondary intention is best for defects confined to less than 50% of the scrotum that cannot be closed

  20. High-speed reconstruction of compressed images

    Science.gov (United States)

    Cox, Jerome R., Jr.; Moore, Stephen M.

    1990-07-01

    A compression scheme is described that allows high-definition radiological images with greater than 8-bit intensity resolution to be represented by 8-bit pixels. Reconstruction of the images with their original intensity resolution can be carried out by means of a pipeline architecture suitable for compact, high-speed implementation. A reconstruction system is described that can be fabricated according to this approach and placed between an 8-bit display buffer and the display's video system thereby allowing contrast control of images at video rates. Results for 50 CR chest images are described showing that error-free reconstruction of the original 10-bit CR images can be achieved.

  1. Two-and three-dimensional CT reconstruction

    International Nuclear Information System (INIS)

    Fishman, E.K.; Ney, D.R.; Magid, D.

    1990-01-01

    This paper determines the optimal imaging sequence for creating two- and three-dimensional (2D/3D) skeletal reconstructions from CT data. A cadaver femur, a bone phantom, and a surgically created fracture were scanned with varying protocols to determine the optimal protocol for creating 2D/3D images. The scanning protocols used varying section thickness (2, 4, and 8 mm) as well as scan spacing (2, 3, 4 and 8 mm). All images were reconstructed into 2D data sets with a bicubic interpolation and 3D datasets with volumetric rendering. The results were reviewed by two reviewers to determine the quality of images reconstruction

  2. 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.

  3. The Reconstruction Toolkit (RTK), an open-source cone-beam CT reconstruction toolkit based on the Insight Toolkit (ITK)

    International Nuclear Information System (INIS)

    Rit, S; Vila Oliva, M; Sarrut, D; Brousmiche, S; Labarbe, R; Sharp, G C

    2014-01-01

    We propose the Reconstruction Toolkit (RTK, http://www.openrtk.org), an open-source toolkit for fast cone-beam CT reconstruction, based on the Insight Toolkit (ITK) and using GPU code extracted from Plastimatch. RTK is developed by an open consortium (see affiliations) under the non-contaminating Apache 2.0 license. The quality of the platform is daily checked with regression tests in partnership with Kitware, the company supporting ITK. Several features are already available: Elekta, Varian and IBA inputs, multi-threaded Feldkamp-David-Kress reconstruction on CPU and GPU, Parker short scan weighting, multi-threaded CPU and GPU forward projectors, etc. Each feature is either accessible through command line tools or C++ classes that can be included in independent software. A MIDAS community has been opened to share CatPhan datasets of several vendors (Elekta, Varian and IBA). RTK will be used in the upcoming cone-beam CT scanner developed by IBA for proton therapy rooms. Many features are under development: new input format support, iterative reconstruction, hybrid Monte Carlo / deterministic CBCT simulation, etc. RTK has been built to freely share tomographic reconstruction developments between researchers and is open for new contributions.

  4. Model-based iterative reconstruction for reduction of radiation dose in abdominopelvic CT: comparison to adaptive statistical iterative reconstruction.

    Science.gov (United States)

    Yasaka, Koichiro; Katsura, Masaki; Akahane, Masaaki; Sato, Jiro; Matsuda, Izuru; Ohtomo, Kuni

    2013-12-01

    To evaluate dose reduction and image quality of abdominopelvic computed tomography (CT) reconstructed with model-based iterative reconstruction (MBIR) compared to adaptive statistical iterative reconstruction (ASIR). In this prospective study, 85 patients underwent referential-, low-, and ultralow-dose unenhanced abdominopelvic CT. Images were reconstructed with ASIR for low-dose (L-ASIR) and ultralow-dose CT (UL-ASIR), and with MBIR for ultralow-dose CT (UL-MBIR). Image noise was measured in the abdominal aorta and iliopsoas muscle. Subjective image analyses and a lesion detection study (adrenal nodules) were conducted by two blinded radiologists. A reference standard was established by a consensus panel of two different radiologists using referential-dose CT reconstructed with filtered back projection. Compared to low-dose CT, there was a 63% decrease in dose-length product with ultralow-dose CT. UL-MBIR had significantly lower image noise than L-ASIR and UL-ASIR (all pASIR and UL-ASIR (all pASIR in diagnostic acceptability (p>0.65), or diagnostic performance for adrenal nodules (p>0.87). MBIR significantly improves image noise and streak artifacts compared to ASIR, and can achieve radiation dose reduction without severely compromising image quality.

  5. LHCb jet reconstruction

    International Nuclear Information System (INIS)

    Francisco, Oscar; Rangel, Murilo; Barter, William; Bursche, Albert; Potterat, Cedric; Coco, Victor

    2012-01-01

    Full text: The Large Hadron Collider (LHC) is the most powerful particle accelerator in the world. It has been designed to collide proton beams at an energy up to 14 TeV in the center of mass. In 2011, the data taking was done with a center of mass energy of 7 TeV, the instant luminosity has reached values greater than 4 X 10 32 cm -2 s -1 and the integrated luminosity reached the value of 1,02fb -1 on the LHCb. The jet reconstruction is fundamental to observe events that can be used to test perturbative QCD (pQCD). It also provides a way to observe standard model channels and searches for new physics like SUSY. The anti-kt algorithm is a jet reconstruction algorithm that is based on the distance of the particles on the space ηX φ and on the transverse momentum of particles. To maximize the energy resolution all information about the trackers and the colorimeters are used on the LHCb experiment to create objects called particle flow objects that are used as input to anti-kt algorithm. The LHCb is specially interesting for jets studies because its η region is complementary to the others main experiments on LHC. We will present the first results of jet reconstruction using 2011 LHCb data. (author)

  6. LHCb jet reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Francisco, Oscar; Rangel, Murilo [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Barter, William [University of Cambridge, Cambridge (United Kingdom); Bursche, Albert [Universitat Zurich, Zurich (Switzerland); Potterat, Cedric [Universitat de Barcelona, Barcelona (Spain); Coco, Victor [Nikhef National Institute for Subatomic Physics, Amsterdam (Netherlands)

    2012-07-01

    Full text: The Large Hadron Collider (LHC) is the most powerful particle accelerator in the world. It has been designed to collide proton beams at an energy up to 14 TeV in the center of mass. In 2011, the data taking was done with a center of mass energy of 7 TeV, the instant luminosity has reached values greater than 4 X 10{sup 32} cm{sup -2}s{sup -1} and the integrated luminosity reached the value of 1,02fb{sup -1} on the LHCb. The jet reconstruction is fundamental to observe events that can be used to test perturbative QCD (pQCD). It also provides a way to observe standard model channels and searches for new physics like SUSY. The anti-kt algorithm is a jet reconstruction algorithm that is based on the distance of the particles on the space {eta}X {phi} and on the transverse momentum of particles. To maximize the energy resolution all information about the trackers and the colorimeters are used on the LHCb experiment to create objects called particle flow objects that are used as input to anti-kt algorithm. The LHCb is specially interesting for jets studies because its {eta} region is complementary to the others main experiments on LHC. We will present the first results of jet reconstruction using 2011 LHCb data. (author)

  7. Denoising multicriterion iterative reconstruction in emission spectral tomography

    Science.gov (United States)

    Wan, Xiong; Yin, Aihan

    2007-03-01

    In the study of optical testing, the computed tomogaphy technique has been widely adopted to reconstruct three-dimensional distributions of physical parameters of various kinds of fluid fields, such as flame, plasma, etc. In most cases, projection data are often stained by noise due to environmental disturbance, instrumental inaccuracy, and other random interruptions. To improve the reconstruction performance in noisy cases, an algorithm that combines a self-adaptive prefiltering denoising approach (SPDA) with a multicriterion iterative reconstruction (MCIR) is proposed and studied. First, the level of noise is approximately estimated with a frequency domain statistical method. Then the cutoff frequency of a Butterworth low-pass filter was established based on the evaluated noise energy. After the SPDA processing, the MCIR algorithm was adopted for limited-view optical computed tomography reconstruction. Simulated reconstruction of two test phantoms and a flame emission spectral tomography experiment were employed to evaluate the performance of SPDA-MCIR in noisy cases. Comparison with some traditional methods and experiment results showed that the SPDA-MCIR combination had obvious improvement in the case of noisy data reconstructions.

  8. Recovery after abdominal wall reconstruction

    DEFF Research Database (Denmark)

    Jensen, Kristian Kiim

    2017-01-01

    Incisional hernia is a common long-term complication to abdominal surgery, occurring in more than 20% of all patients. Some of these hernias become giant and affect patients in several ways. This patient group often experiences pain, decreased perceived body image, and loss of physical function......, which results in a need for surgical repair of the giant hernia, known as abdominal wall reconstruction. In the current thesis, patients with a giant hernia were examined to achieve a better understanding of their physical and psychological function before and after abdominal wall reconstruction. Study...... was lacking. Study II was a case-control study of the effects of an enhanced recovery after surgery pathway for patients undergoing abdominal wall reconstruction for a giant hernia. Sixteen consecutive patients were included prospectively after the implementation of a new enhanced recovery after surgery...

  9. 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 ...

  10. Trends in Materials Science for Ligament Reconstruction.

    Science.gov (United States)

    Sava, Oana Roxana; Sava, Daniel Florin; Radulescu, Marius; Albu, Madalina Georgiana; Ficai, Denisa; Veloz-Castillo, Maria Fernanda; Mendez-Rojas, Miguel Angel; Ficai, Anton

    2017-01-01

    The number of ligament injuries increases every year and concomitantly the need for materials or systems that can reconstruct the ligament. Limitations imposed by autografts and allografts in ligament reconstruction together with the advances in materials science and biology have attracted a lot of interest for developing systems and materials for ligament replacement or reconstruction. This review intends to synthesize the major steps taken in the development of polymer-based materials for anterior cruciate ligament, their advantages and drawbacks and the results of different in vitro and in vivo tests. Until present, there is no successful polymer system for ligament reconstruction implanted in humans. The developing field of synthetic polymers for ligament reconstruction still has a lot of potential. In addition, several nano-structured materials, made of nanofibers or in the form of ceramic/polymeric nanocomposites, are attracting the interest of several groups due to their potential use as engineered scaffolds that mimic the native environment of cells, increasing the chances for tissue regeneration. Here, we review the last 15 years of literature in order to obtain a better understanding on the state-of-the-art that includes the usage of nano- and poly-meric materials for ligament reconstruction, and to draw perspectives on the future development of the field. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  11. Breast reconstruction: current and future options

    Directory of Open Access Journals (Sweden)

    Paul Jr H

    2011-08-01

    Full Text Available Henry Paul Jr1, Tahira I Prendergast2, Bryson Nicholson2, Shenita White2, Wayne AI Frederick2,31Departments of Plastic Surgery, 2General Surgery, Howard University Hospital, 3Cancer Center, Howard University, Washington, DC, USAAbstract: When initiated by the devastating diagnosis of cancer, post ablative breast restoration has at its core the goal of restoring anatomic normalcy. The concepts of body image, wholeness, and overall well-being have been introduced to explain the paramount psychological influence the breast has on both individuals and society as a whole. Hence, a growing subspecialty has been established to recreate or simulate the lost breast. At least one third of breast cancer victims consider breast reconstruction. Breast reconstruction post mastectomy may be offered at the time of mastectomy or delayed post mastectomy after adjuvant therapy. This may be utilizing autologous tissues or implants and each has risks and benefits, especially when considering adjuvant therapy. In addition, there has been a move away from a traditional mastectomy to less invasive, but still curative procedures, such as skin-sparing and nipple-sparing mastectomy. These procedures provide the breast envelope to facilitate reconstruction. This paper reviews the primary issues in breast reconstruction, as well as their psychologic, oncologic, and social impact.Keywords: breast restoration, body image, breast reconstruction, mastectomy

  12. Distance weighting for improved tomographic reconstructions

    International Nuclear Information System (INIS)

    Koeppe, R.A.; Holden, J.E.

    1984-01-01

    An improved method for the reconstruction of emission computed axial tomography images has been developed. The method is a modification of filtered back-projection, where the back projected values are weighted to reflect the loss of formation, with distance from the camera, which is inherent in gamma camera imaging. This information loss is a result of: loss of spatial resolution with distance, attenuation, and scatter. The weighting scheme can best be described by considering the contributions of any two opposing views to the reconstruction image pixels. The weight applied to the projections of one view is set to equal the relative amount of the original activity that was initially received in that projection, assuming a uniform attenuating medium. This yields a weighting value which is a function of distance into the image with a value of one for pixels ''near the camera'', a value of .5 at the image center, and a value of zero on the opposite side. Tomographic reconstructions produced with this method show improved spatial resolution when compared to conventional 360 0 reconstructions. The improvement is in the tangential direction, where simulations have indicated a FWHM improvement of 1 to 1.5 millimeters. The resolution in the radial direction is essentially the same for both methods. Visual inspection of the reconstructed images show improved resolution and contrast

  13. Photoacoustic image reconstruction: a quantitative analysis

    Science.gov (United States)

    Sperl, Jonathan I.; Zell, Karin; Menzenbach, Peter; Haisch, Christoph; Ketzer, Stephan; Marquart, Markus; Koenig, Hartmut; Vogel, Mika W.

    2007-07-01

    Photoacoustic imaging is a promising new way to generate unprecedented contrast in ultrasound diagnostic imaging. It differs from other medical imaging approaches, in that it provides spatially resolved information about optical absorption of targeted tissue structures. Because the data acquisition process deviates from standard clinical ultrasound, choice of the proper image reconstruction method is crucial for successful application of the technique. In the literature, multiple approaches have been advocated, and the purpose of this paper is to compare four reconstruction techniques. Thereby, we focused on resolution limits, stability, reconstruction speed, and SNR. We generated experimental and simulated data and reconstructed images of the pressure distribution using four different methods: delay-and-sum (DnS), circular backprojection (CBP), generalized 2D Hough transform (HTA), and Fourier transform (FTA). All methods were able to depict the point sources properly. DnS and CBP produce blurred images containing typical superposition artifacts. The HTA provides excellent SNR and allows a good point source separation. The FTA is the fastest and shows the best FWHM. In our study, we found the FTA to show the best overall performance. It allows a very fast and theoretically exact reconstruction. Only a hardware-implemented DnS might be faster and enable real-time imaging. A commercial system may also perform several methods to fully utilize the new contrast mechanism and guarantee optimal resolution and fidelity.

  14. Charge reconstruction in large-area photomultipliers

    Science.gov (United States)

    Grassi, M.; Montuschi, M.; Baldoncini, M.; Mantovani, F.; Ricci, B.; Andronico, G.; Antonelli, V.; Bellato, M.; Bernieri, E.; Brigatti, A.; Brugnera, R.; Budano, A.; Buscemi, M.; Bussino, S.; Caruso, R.; Chiesa, D.; Corti, D.; Dal Corso, F.; Ding, X. F.; Dusini, S.; Fabbri, A.; Fiorentini, G.; Ford, R.; Formozov, A.; Galet, G.; Garfagnini, A.; Giammarchi, M.; Giaz, A.; Insolia, A.; Isocrate, R.; Lippi, I.; Longhitano, F.; Lo Presti, D.; Lombardi, P.; Marini, F.; Mari, S. M.; Martellini, C.; Meroni, E.; Mezzetto, M.; Miramonti, L.; Monforte, S.; Nastasi, M.; Ortica, F.; Paoloni, A.; Parmeggiano, S.; Pedretti, D.; Pelliccia, N.; Pompilio, R.; Previtali, E.; Ranucci, G.; Re, A. C.; Romani, A.; Saggese, P.; Salamanna, G.; Sawy, F. H.; Settanta, G.; Sisti, M.; Sirignano, C.; Spinetti, M.; Stanco, L.; Strati, V.; Verde, G.; Votano, L.

    2018-02-01

    Large-area PhotoMultiplier Tubes (PMT) allow to efficiently instrument Liquid Scintillator (LS) neutrino detectors, where large target masses are pivotal to compensate for neutrinos' extremely elusive nature. Depending on the detector light yield, several scintillation photons stemming from the same neutrino interaction are likely to hit a single PMT in a few tens/hundreds of nanoseconds, resulting in several photoelectrons (PEs) to pile-up at the PMT anode. In such scenario, the signal generated by each PE is entangled to the others, and an accurate PMT charge reconstruction becomes challenging. This manuscript describes an experimental method able to address the PMT charge reconstruction in the case of large PE pile-up, providing an unbiased charge estimator at the permille level up to 15 detected PEs. The method is based on a signal filtering technique (Wiener filter) which suppresses the noise due to both PMT and readout electronics, and on a Fourier-based deconvolution able to minimize the influence of signal distortions—such as an overshoot. The analysis of simulated PMT waveforms shows that the slope of a linear regression modeling the relation between reconstructed and true charge values improves from 0.769 ± 0.001 (without deconvolution) to 0.989 ± 0.001 (with deconvolution), where unitary slope implies perfect reconstruction. A C++ implementation of the charge reconstruction algorithm is available online at [1].

  15. Tumescent mastectomy technique in autologous breast reconstruction.

    Science.gov (United States)

    Vargas, Christina R; Koolen, Pieter G L; Ho, Olivia A; Ricci, Joseph A; Tobias, Adam M; Lin, Samuel J; Lee, Bernard T

    2015-10-01

    Use of the tumescent mastectomy technique has been reported to facilitate development of a hydrodissection plane, reduce blood loss, and provide adjunct analgesia. Previous studies suggest that tumescent dissection may contribute to adverse outcomes after immediate implant reconstruction; however, its effect on autologous microsurgical reconstruction has not been established. A retrospective review was conducted of all immediate microsurgical breast reconstruction procedures at a single academic center between January 2004 and December 2013. Records were queried for age, body mass index, mastectomy weight, diabetes, hypertension, smoking, preoperative radiation, reconstruction flap type, and autologous flap weight. Outcomes of interest were mastectomy skin necrosis, complete and partial flap loss, return to the operating room, breast hematoma, seroma, and infection. There were 730 immediate autologous breast reconstructions performed during the study period; 46% with the tumescent dissection technique. Groups were similar with respect to baseline patient and procedural characteristics. Univariate analysis revealed no significant difference in the incidence of mastectomy skin necrosis, complete or partial flap loss, return to the operating room, operative time, estimated blood loss, recurrence, breast hematoma, seroma, or infection in patients undergoing tumescent mastectomy. Multivariate analysis also demonstrated no significant association between the use of tumescent technique and postoperative breast mastectomy skin necrosis (P = 0.980), hematoma (P = 0.759), or seroma (P = 0.340). Use of the tumescent dissection technique during mastectomy is not significantly associated with adverse outcomes after microsurgical breast reconstruction. Despite concern for its impact on implant reconstruction, our findings suggest that this method can be used safely preceding autologous procedures. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Algorithms for reconstructing images for industrial applications

    International Nuclear Information System (INIS)

    Lopes, R.T.; Crispim, V.R.

    1986-01-01

    Several algorithms for reconstructing objects from their projections are being studied in our Laboratory, for industrial applications. Such algorithms are useful locating the position and shape of different composition of materials in the object. A Comparative study of two algorithms is made. The two investigated algorithsm are: The MART (Multiplicative - Algebraic Reconstruction Technique) and the Convolution Method. The comparison are carried out from the point view of the quality of the image reconstructed, number of views and cost. (Author) [pt

  17. Ways of improving preparatory stage and reconstruction of coking plants

    Energy Technology Data Exchange (ETDEWEB)

    Rozenfel' d, M.S.; Martynenko, V.M.; Svyatogorov, A.A.; Kvitkin, I.A.; Zhurba, A.I.; Gurtovnik, P.F.

    1987-06-01

    Discusses economic and technological aspects of coking plant reconstruction and modernization in the USSR. Effects of standardized technologies on plant reconstruction are analyzed. A standardized planning procedure jointly developed by research institutes in the USSR for plant modernization or reconstruction is discussed: selecting the optimum reconstruction and repair time, sequence of operations without stoppage of a coke oven battery, coke oven cooling, repair of coke oven liners, heating systems, coke oven equipment, drying, initial heating, testing battery equipment. The procedure is aimed at reducing coke losses and eliminating delays during reconstruction operations. A graphic method for modelling plant reconstruction is discussed.

  18. RECONSTRUCTION OF THE SOUND CONDUCTING MECHANISM ...

    African Journals Online (AJOL)

    In this progress report on a new tympanoplastic procedure for reconstructing a disrupted sound conducting mechanism characterized by destruction of the handle of the malleus, it is shown that by reconstructing a tympanic membrane and a handle of the malleus from a patient's own tissue and by utilizing a prosthesis for ...

  19. Predicting supramolecular self-assembly on reconstructed metal surfaces

    Science.gov (United States)

    Roussel, Thomas J.; Barrena, Esther; Ocal, Carmen; Faraudo, Jordi

    2014-06-01

    The prediction of supramolecular self-assembly onto solid surfaces is still challenging in many situations of interest for nanoscience. In particular, no previous simulation approach has been capable to simulate large self-assembly patterns of organic molecules over reconstructed surfaces (which have periodicities over large distances) due to the large number of surface atoms and adsorbing molecules involved. Using a novel simulation technique, we report here large scale simulations of the self-assembly patterns of an organic molecule (DIP) over different reconstructions of the Au(111) surface. We show that on particular reconstructions, the molecule-molecule interactions are enhanced in a way that long-range order is promoted. Also, the presence of a distortion in a reconstructed surface pattern not only induces the presence of long-range order but also is able to drive the organization of DIP into two coexisting homochiral domains, in quantitative agreement with STM experiments. On the other hand, only short range order is obtained in other reconstructions of the Au(111) surface. The simulation strategy opens interesting perspectives to tune the supramolecular structure by simulation design and surface engineering if choosing the right molecular building blocks and stabilising the chosen reconstruction pattern.The prediction of supramolecular self-assembly onto solid surfaces is still challenging in many situations of interest for nanoscience. In particular, no previous simulation approach has been capable to simulate large self-assembly patterns of organic molecules over reconstructed surfaces (which have periodicities over large distances) due to the large number of surface atoms and adsorbing molecules involved. Using a novel simulation technique, we report here large scale simulations of the self-assembly patterns of an organic molecule (DIP) over different reconstructions of the Au(111) surface. We show that on particular reconstructions, the molecule

  20. Parallel CT image reconstruction based on GPUs

    International Nuclear Information System (INIS)

    Flores, Liubov A.; Vidal, Vicent; Mayo, Patricia; Rodenas, Francisco; Verdú, Gumersindo

    2014-01-01

    In X-ray computed tomography (CT) iterative methods are more suitable for the reconstruction of images with high contrast and precision in noisy conditions from a small number of projections. However, in practice, these methods are not widely used due to the high computational cost of their implementation. Nowadays technology provides the possibility to reduce effectively this drawback. It is the goal of this work to develop a fast GPU-based algorithm to reconstruct high quality images from under sampled and noisy projection data. - Highlights: • We developed GPU-based iterative algorithm to reconstruct images. • Iterative algorithms are capable to reconstruct images from under sampled set of projections. • The computer cost of the implementation of the developed algorithm is low. • The efficiency of the algorithm increases for the large scale problems

  1. 3D reconstruction based on light field images

    Science.gov (United States)

    Zhu, Dong; Wu, Chunhong; Liu, Yunluo; Fu, Dongmei

    2018-04-01

    This paper proposed a method of reconstructing three-dimensional (3D) scene from two light field images capture by Lytro illium. The work was carried out by first extracting the sub-aperture images from light field images and using the scale-invariant feature transform (SIFT) for feature registration on the selected sub-aperture images. Structure from motion (SFM) algorithm is further used on the registration completed sub-aperture images to reconstruct the three-dimensional scene. 3D sparse point cloud was obtained in the end. The method shows that the 3D reconstruction can be implemented by only two light field camera captures, rather than at least a dozen times captures by traditional cameras. This can effectively solve the time-consuming, laborious issues for 3D reconstruction based on traditional digital cameras, to achieve a more rapid, convenient and accurate reconstruction.

  2. Time-of-flight PET image reconstruction using origin ensembles

    Science.gov (United States)

    Wülker, Christian; Sitek, Arkadiusz; Prevrhal, Sven

    2015-03-01

    The origin ensemble (OE) algorithm is a novel statistical method for minimum-mean-square-error (MMSE) reconstruction of emission tomography data. This method allows one to perform reconstruction entirely in the image domain, i.e. without the use of forward and backprojection operations. We have investigated the OE algorithm in the context of list-mode (LM) time-of-flight (TOF) PET reconstruction. In this paper, we provide a general introduction to MMSE reconstruction, and a statistically rigorous derivation of the OE algorithm. We show how to efficiently incorporate TOF information into the reconstruction process, and how to correct for random coincidences and scattered events. To examine the feasibility of LM-TOF MMSE reconstruction with the OE algorithm, we applied MMSE-OE and standard maximum-likelihood expectation-maximization (ML-EM) reconstruction to LM-TOF phantom data with a count number typically registered in clinical PET examinations. We analyzed the convergence behavior of the OE algorithm, and compared reconstruction time and image quality to that of the EM algorithm. In summary, during the reconstruction process, MMSE-OE contrast recovery (CRV) remained approximately the same, while background variability (BV) gradually decreased with an increasing number of OE iterations. The final MMSE-OE images exhibited lower BV and a slightly lower CRV than the corresponding ML-EM images. The reconstruction time of the OE algorithm was approximately 1.3 times longer. At the same time, the OE algorithm can inherently provide a comprehensive statistical characterization of the acquired data. This characterization can be utilized for further data processing, e.g. in kinetic analysis and image registration, making the OE algorithm a promising approach in a variety of applications.

  3. DIEP Flap Breast Reconstruction in Patients with Breast Ptosis: 2-Stage Reconstruction Using 3-Dimensional Surface Imaging and a Printed Mold

    Directory of Open Access Journals (Sweden)

    Koichi Tomita, MD, PhD

    2017-10-01

    Conclusions:. The method described here may allow even inexperienced surgeons to achieve reconstruction of symmetrical, non-ptotic breasts with ease and in a short time. While the requirement of two surgeries is a potential disadvantage, our method will be particularly useful in cases involving TEs, i.e., delayed reconstruction or immediate reconstruction involving significant skin resection.

  4. Low dose reconstruction algorithm for differential phase contrast imaging.

    Science.gov (United States)

    Wang, Zhentian; Huang, Zhifeng; Zhang, Li; Chen, Zhiqiang; Kang, Kejun; Yin, Hongxia; Wang, Zhenchang; Marco, Stampanoni

    2011-01-01

    Differential phase contrast imaging computed tomography (DPCI-CT) is a novel x-ray inspection method to reconstruct the distribution of refraction index rather than the attenuation coefficient in weakly absorbing samples. In this paper, we propose an iterative reconstruction algorithm for DPCI-CT which benefits from the new compressed sensing theory. We first realize a differential algebraic reconstruction technique (DART) by discretizing the projection process of the differential phase contrast imaging into a linear partial derivative matrix. In this way the compressed sensing reconstruction problem of DPCI reconstruction can be transformed to a resolved problem in the transmission imaging CT. Our algorithm has the potential to reconstruct the refraction index distribution of the sample from highly undersampled projection data. Thus it can significantly reduce the dose and inspection time. The proposed algorithm has been validated by numerical simulations and actual experiments.

  5. Three-dimensional dictionary-learning reconstruction of (23)Na MRI data.

    Science.gov (United States)

    Behl, Nicolas G R; Gnahm, Christine; Bachert, Peter; Ladd, Mark E; Nagel, Armin M

    2016-04-01

    To reduce noise and artifacts in (23)Na MRI with a Compressed Sensing reconstruction and a learned dictionary as sparsifying transform. A three-dimensional dictionary-learning compressed sensing reconstruction algorithm (3D-DLCS) for the reconstruction of undersampled 3D radial (23)Na data is presented. The dictionary used as the sparsifying transform is learned with a K-singular-value-decomposition (K-SVD) algorithm. The reconstruction parameters are optimized on simulated data, and the quality of the reconstructions is assessed with peak signal-to-noise ratio (PSNR) and structural similarity (SSIM). The performance of the algorithm is evaluated in phantom and in vivo (23)Na MRI data of seven volunteers and compared with nonuniform fast Fourier transform (NUFFT) and other Compressed Sensing reconstructions. The reconstructions of simulated data have maximal PSNR and SSIM for an undersampling factor (USF) of 10 with numbers of averages equal to the USF. For 10-fold undersampling, the PSNR is increased by 5.1 dB compared with the NUFFT reconstruction, and the SSIM by 24%. These results are confirmed by phantom and in vivo (23)Na measurements in the volunteers that show markedly reduced noise and undersampling artifacts in the case of 3D-DLCS reconstructions. The 3D-DLCS algorithm enables precise reconstruction of undersampled (23)Na MRI data with markedly reduced noise and artifact levels compared with NUFFT reconstruction. Small structures are well preserved. © 2015 Wiley Periodicals, Inc.

  6. ELUCID—Exploring the Local Universe with the reConstructed Initial Density Field. II. Reconstruction Diagnostics, Applied to Numerical Halo Catalogs

    Energy Technology Data Exchange (ETDEWEB)

    Tweed, Dylan; Yang, Xiaohu; Li, Shijie; Jing, Y. P. [Center for Astronomy and Astrophysics, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang, Huiyuan [Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei, Anhui 230026 (China); Cui, Weiguang [Departamento de Física Teórica, Módulo 15, Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Zhang, Youcai [Shanghai Astronomical Observatory, Nandan Road 80, Shanghai 200030 (China); Mo, H. J., E-mail: dtweed@sjtu.edu.cn [Department of Astronomy, University of Massachusetts, Amherst MA, 01003-9305 (United States)

    2017-05-20

    The ELUCID project aims to build a series of realistic cosmological simulations that reproduce the spatial and mass distributions of the galaxies as observed in the Sloan Digital Sky Survey. This requires powerful reconstruction techniques to create constrained initial conditions (ICs). We test the reconstruction method by applying it to several N -body simulations. We use two medium-resolution simulations, which each produced three additional constrained N -body simulations. We compare the resulting friend-of-friend catalogs by using the particle indexes as tracers, and quantify the quality of the reconstruction by varying the main smoothing parameter. The cross-identification method we use proves to be efficient, and the results suggest that the most massive reconstructed halos are effectively traced from the same Lagrangian regions in the ICs. A preliminary time-dependence analysis indicates that high-mass-end halos converge only at a redshift close to the reconstruction redshift. This suggests that, for earlier snapshots, only collections of progenitors may be effectively cross-identified.

  7. European bank for reconstruction and development

    Directory of Open Access Journals (Sweden)

    Kastratović Radovan

    2015-01-01

    Full Text Available European Bank for Reconstruction and Development - EBRD was established in the year 1991 and commenced operations in 1991. The objective of the Bank was to instigate market oriented approach to business in the countries of Central and Eastern Europe. This comprises support offered to structural reforms, privatisation, and development of entrepreneurship and legal system through financing of project conducive to the achievement of the aimed targets. The Bank approves loans both to the nation states and to the private sector. European Bank for Reconstruction and Development often appears in the role of investor. In addition, the Bank has also its consultative function. Owners of the European Bank for Reconstruction and Development are the developed countries and those that participate in the distribution of the Bank's profit. The Bank invests in the countries of Central, Eastern and South-East Europe, but also in those of Central Asia and Southern Mediterranean. The importance that the European Bank for Reconstruction and Development has for our country is best illustrated by the fact that this Bank is our largest institutional investor, with investments exceeding 3.5 billion EUR. This work begins with presentation of general information on the work of the European Bank for Reconstruction and Development, its objectives, activities, background history, ownership and organisational structure. It proceeds by giving relevant data on the Bank's business operations - the manner of project financing, the Bank's funds distribution per geographic criteria and activities, and the operative and financial results of the Bank's business activities. Brief description is also offered of the cooperation that the European Bank has with other international financial institutions. Finally, data is given bearing witness on the importance that the European Bank for Reconstruction and Development has for Serbia.

  8. Improved immediate breast reconstruction as a result of oncoplastic multidisciplinary meeting

    Directory of Open Access Journals (Sweden)

    El Gammal MM

    2017-04-01

    Full Text Available Mohsen M El Gammal,1 Maria Lim,1 Rajan Uppal,2 Richard Sainsbury1 1Department of Breast Surgery, Parapet Breast Centre, Frimley Health Foundation Trust, Windsor, 2Department of Plastic and Reconstructive Surgery, Wexham and Heatherwood Hospital, Frimley Health Foundation Trust, Slough, UK Introduction: The National Institute for Health and Clinical Excellence guidelines recommend that breast reconstruction should be available to all women undergoing mastectomy and discussed at the initial surgical consultation (2002, and updated 2009. The National Mastectomy and Breast Reconstruction Audit (2009 showed that 21% of mastectomy patients underwent immediate breast reconstruction (IBR and 11% had delayed breast reconstruction (DBR. Breast reconstruction has been shown to have a positive effect on quality of life postmastectomy. This retrospective study investigated the impact of the introduction of a dedicated oncoplastic multidisciplinary meeting (OP MDM on our unit’s breast reconstruction rate.Patients and methods: A retrospective analysis of 229 women who underwent mastectomy, of whom 81 (35% underwent breast reconstruction between April 2014 and March 2016. Data were analyzed before and after introduction of OP MDM in April 2015. Data on patient age, type of surgery (mastectomy only, mastectomy and reconstruction, timing of reconstruction (IBR, DBR, and type of reconstruction (implant, autologous were collected.Results: Between April 2015 and March 2016, following establishment of OP multidisciplinary team in April 2015, of the 120 patients who had mastectomy, 50 (42% underwent breast reconstruction with 78% (39/50 choosing IBR (56% implant reconstruction and 22% autologous. Compared to the period between April 2014 and March 2015 preceding the OP MDM, of 109 patients who underwent mastectomy, only 31 (28% had breast reconstruction with 64% (20/31 choosing IBR (45% implant reconstruction and 19% autologous. The rate of DBR was lower, 22% (11

  9. Mandibular reconstruction using bone allografts

    International Nuclear Information System (INIS)

    Chang Joon Yim

    1999-01-01

    Further understanding of bone healing mechanisms, bone physiology and bone biology, transplantation immunology, and development of Tissue Banking procedures has enabled oral and maxillofacial surgeons to reconstruct even the most difficult bony defects successfully with the preserved allogeneic bone implant. Although it had been known that bone allografts were clinically effective, its application has not been widespread until the reports of Inclan (I 942), Hyatt and Butler (I 950), and Wilson (I 95 1). Tissue Banking provides the surgeon with a readily available, relatively inexpensive, and relatively safe selection of allogeneic bone for clinical use. Now autogenous bone and allogeneic bone implants present a wide variety of surgical options to surgeons, whether used separately or in combination. The surgeons are able to make judicious and fruitful choices, only with a thorough knowledge of the above-mentioned biological principles and skillful techniques. Many kinds of bone grafting techniques have been tried for reconstructing defective osseous tissues of the oral and maxillofacial region, though they have varying degrees of success. The osseous defects which require grafting include those of various size, shape, position, or amount. Unlike autogenous grafts, whose function is to provide osteogenic cells, allografts are purely passive, offering only a matrix for the inductive phase of bone healing. The condition of the recipient bed is of primary importance, because the host must produce all of the essential elements for the bone allograft to become incorporated. Depending on the processing methods of the allogeneic bone, the bone graft materials have different qualities, different healing potentials and different indications. Proper selection of grafts and surgical techniques requires an understanding of graft immunology and the mechanisms of graft healing. The surgeons should know about the biological principles to raise the clinical success rate

  10. Apparatus and method for reconstructing data

    International Nuclear Information System (INIS)

    Pavkovich, J.M.

    1977-01-01

    The apparatus and method for reconstructing data are described. A fan beam of radiation is passed through an object, the beam lying in the same quasi-plane as the object slice to be examined. Radiation not absorbed in the object slice is recorded on oppositely situated detectors aligned with the source of radiation. Relative rotation is provided between the source-detector configuration and the object. Reconstruction means are coupled to the detector means, and may comprise a general purpose computer, a special purpose computer, and control logic for interfacing between said computers and controlling the respective functioning thereof for performing a convolution and back projection based upon non-absorbed radiation detected by said detector means, whereby the reconstruction means converts values of the non-absorbed radiation into values of absorbed radiation at each of an arbitrarily large number of points selected within the object slice. Display means are coupled to the reconstruction means for providing a visual or other display or representation of the quantities of radiation absorbed at the points considered in the object. (Auth.)

  11. An iterative reconstruction from truncated projection data

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    Various methods have been proposed for tomographic reconstruction from truncated projection data. In this paper, a reconstructive method is discussed which consists of iterations of filtered back-projection, reprojection and some nonlinear processings. First, the method is so constructed that it converges to a fixed point. Then, to examine its effectiveness, comparisons are made by computer experiments with two existing reconstructive methods for truncated projection data, that is, the method of extrapolation based on the smooth assumption followed by filtered back-projection, and modified additive ART

  12. Genital reconstruction in exstrophy patients

    Directory of Open Access Journals (Sweden)

    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

  13. Reconstruction of the Proximal Humerus after Wide Resection of Tumors: Comparison of Three Reconstructive Options

    International Nuclear Information System (INIS)

    EL-SHERBINY, M.

    2008-01-01

    Purpose: Assessment of the functional results and complications of three bone reconstructive procedures after resection of primary tumors of the proximal humerus. Material and Methods: Between 2000 and 2008, 32 patients having primary malignant, aggressive benign or metastatic tumors of the proximal humerous were selected for limb sparing surgery. Preoperative evaluation included CT chest, MRI. Limb sparing surgical resection was done including intraarticular or extra articular wide resection of the tumor. Bone defect was reconstructed with fusion shoulder using free vascularized fibular graft (FFFG) in 11 patients and pedicled lateral scapular crest graft (PLSCG) in 8 patients and mobile shoulder reconstruction using proximal humerus prosthesis in 13 patients. Those patients were followed-up at regular interval to detect bone union and complications related to bone flaps or prosthesis. Functional results were assessed for every patient after one year postoperatively. Results: The median age of the patients was 21 years and the follow-up period ranged from 19 months to 92 months. Postoperative resection margins were negative in all cases. The mean length of the resected humerus was 13 cm. The mean operative time for prosthesis cases was 3.5 hours and that for FVFG was 6.5 hours and was 5 hours for PLSCG cases. The mean time of bone union proximally and distally for FVFG and PLSCG was 4.2 and 5.5 months accordingly. At 1 year follow-up, the functional results for the three reconstructive procedures were nearly the same with a mean functional score for FVFG cases was 73%, for PLSCG cases was 68% and was 71% for prosthesis cases. Hand and elbow functions were preserved in all types of reconstruction. The range of shoulder abduction and flexion was grossly limited with prosthesis cases while it showed marked improvement with fusion by FVFG and PLSCG. Complications for prosthesis cases were one case proximal migration and one case posterior sublaxation. Complications of

  14. Reconstruction of 3D PIV data in complicated experimental arrangements

    Directory of Open Access Journals (Sweden)

    Pavlík David

    2017-01-01

    Full Text Available In this paper a three-dimensional reconstruction of flow field behind flat plate representing a wing is presented. The reconstruction is always performed for pair of 2D vector maps obtained by 3D PIV with two cameras which record measurement area from different locations. Three-dimensional reconstruction can be obtained in various ways. This paper summarizes two: the reconstruction based on the known correspondences and the reconstruction based on the knowledge of intrinsic and extrinsic parameters of cameras. The methods can be used in the cases when it is impossible to use a calibration pattern or when reconstruction by commercial software fails.

  15. Super-Resolution Image Reconstruction Applied to Medical Ultrasound

    Science.gov (United States)

    Ellis, Michael

    Ultrasound is the preferred imaging modality for many diagnostic applications due to its real-time image reconstruction and low cost. Nonetheless, conventional ultrasound is not used in many applications because of limited spatial resolution and soft tissue contrast. Most commercial ultrasound systems reconstruct images using a simple delay-and-sum architecture on receive, which is fast and robust but does not utilize all information available in the raw data. Recently, more sophisticated image reconstruction methods have been developed that make use of far more information in the raw data to improve resolution and contrast. One such method is the Time-Domain Optimized Near-Field Estimator (TONE), which employs a maximum a priori estimation to solve a highly underdetermined problem, given a well-defined system model. TONE has been shown to significantly improve both the contrast and resolution of ultrasound images when compared to conventional methods. However, TONE's lack of robustness to variations from the system model and extremely high computational cost hinder it from being readily adopted in clinical scanners. This dissertation aims to reduce the impact of TONE's shortcomings, transforming it from an academic construct to a clinically viable image reconstruction algorithm. By altering the system model from a collection of individual hypothetical scatterers to a collection of weighted, diffuse regions, dTONE is able to achieve much greater robustness to modeling errors. A method for efficient parallelization of dTONE is presented that reduces reconstruction time by more than an order of magnitude with little loss in image fidelity. An alternative reconstruction algorithm, called qTONE, is also developed and is able to reduce reconstruction times by another two orders of magnitude while simultaneously improving image contrast. Each of these methods for improving TONE are presented, their limitations are explored, and all are used in concert to reconstruct in

  16. [Pedicled versus free TRAM flap for breast reconstruction].

    Science.gov (United States)

    Galla, T J; Lukas, B; Feller, A M

    1999-03-01

    In breast reconstruction, the free TRAM-flap offers many advantages over the pedicled TRAM-flap. Due to its superior perfusion, the free flap rarely develops necrosis. Shaping of the flap is easier due to the lack of the thick muscle pedicle. Because the rectus muscle is spared, there is minimal donor site morbidity. However, the necessary microvascular anastomoses reduced the acceptance of the free TRAM-flap. During a 13-months period, 51 breast reconstructions were performed in 41 patients, 31 unilateral and ten bilateral. 45 flaps served for delayed reconstruction and six flaps for immediate reconstruction. The operations were performed by two teams working simultaneously. The average operating time was 3.9 hours for unilateral and 6.9 hours for bilateral delayed reconstruction. For immediate reconstruction, 6.2 and 6.3 hours were required for uni- and bilateral procedures, respectively. In 38 flaps, the thoracodorsal vessels served as recipient vessels; 13 flaps were anastomosed to the internal mammary artery and vein. Postoperative complications were observed in 13 patients. Three vessel anastomoses had to be revised. In one flap, a partial necrosis occurred; in two flaps hematoma evacuation was necessary. Two patients suffered from fat necroses at the abdomen and one umbilicus was lost. Skin irritations and seromas at the abdomen occurred in five patients. Pulmonary embolism was diagnosed in one patient three weeks postoperatively. Abdominal hernias or bulging in the epigastric area were not observed up to 15 months after reconstruction. These results reveal a low complication rate for breast reconstruction with the free TRAM-flap. The advantages of this technique as compared to the pedicled technique are discussed.

  17. A fast sparse reconstruction algorithm for electrical tomography

    International Nuclear Information System (INIS)

    Zhao, Jia; Xu, Yanbin; Tan, Chao; Dong, Feng

    2014-01-01

    Electrical tomography (ET) has been widely investigated due to its advantages of being non-radiative, low-cost and high-speed. However, the image reconstruction of ET is a nonlinear and ill-posed inverse problem and the imaging results are easily affected by measurement noise. A sparse reconstruction algorithm based on L 1 regularization is robust to noise and consequently provides a high quality of reconstructed images. In this paper, a sparse reconstruction by separable approximation algorithm (SpaRSA) is extended to solve the ET inverse problem. The algorithm is competitive with the fastest state-of-the-art algorithms in solving the standard L 2 −L 1 problem. However, it is computationally expensive when the dimension of the matrix is large. To further improve the calculation speed of solving inverse problems, a projection method based on the Krylov subspace is employed and combined with the SpaRSA algorithm. The proposed algorithm is tested with image reconstruction of electrical resistance tomography (ERT). Both simulation and experimental results demonstrate that the proposed method can reduce the computational time and improve the noise robustness for the image reconstruction. (paper)

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

    Science.gov (United States)

    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

  19. [Reconstruction of the ear in the burns patient].

    Science.gov (United States)

    Carrillo-Córdova, Jorge Raúl; Jiménez Murat, Yusef; Apellaniz-Campo, Armando; Bracho-Olvera, Hazel; Carrillo Esper, Raúl

    Face burns are a singular pathology with great functional and psychological impact in the patients suffering them. The ears play a fundamental role in personal interactions and damage to this organ results in physical and emotional distress. The reconstructive treatment of the burned ear is a challenge. Multiple procedures have been described to achieve success in the reconstruction of the burned ear; immediate reconstruction with autologous rib cartilage, secondary reconstruction, alloplastic material reconstruction, tissue expansion, skin grafts and also microvascular flaps are some of the most common procedures used in this patients. All these techniques focus on giving a natural appearance to the patient. Burns to the ears affect 30% of the patients with facial burns, they require an excellent treatment given by a multidisciplinary team. Copyright © 2017 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  20. Direct iterative reconstruction of computed tomography trajectories (DIRECTT)

    International Nuclear Information System (INIS)

    Lange, A.; Hentschel, M.P.; Schors, J.

    2004-01-01

    The direct reconstruction approach employs an iterative procedure by selection of and angular averaging over projected trajectory data of volume elements. This avoids the blur effects of the classical Fourier method due to the sampling theorem. But longer computing time is required. The reconstructed tomographic images reveal at least the spatial resolution of the radiation detector. Any set of projection angles may be selected for the measurements. Limited rotation of the object yields still good reconstruction of details. Projections of a partial region of the object can be reconstructed without additional artifacts thus reducing the overall radiation dose. Noisy signal data from low dose irradiation have low impact on spatial resolution. The image quality is monitored during all iteration steps and is pre-selected according to the specific requirements. DIRECTT can be applied independently from the measurement equipment in addition to conventional reconstruction or as a refinement filter. (author)

  1. Wind reconstruction algorithm for Viking Lander 1

    Science.gov (United States)

    Kynkäänniemi, Tuomas; Kemppinen, Osku; Harri, Ari-Matti; Schmidt, Walter

    2017-06-01

    The wind measurement sensors of Viking Lander 1 (VL1) were only fully operational for the first 45 sols of the mission. We have developed an algorithm for reconstructing the wind measurement data after the wind measurement sensor failures. The algorithm for wind reconstruction enables the processing of wind data during the complete VL1 mission. The heater element of the quadrant sensor, which provided auxiliary measurement for wind direction, failed during the 45th sol of the VL1 mission. Additionally, one of the wind sensors of VL1 broke down during sol 378. Regardless of the failures, it was still possible to reconstruct the wind measurement data, because the failed components of the sensors did not prevent the determination of the wind direction and speed, as some of the components of the wind measurement setup remained intact for the complete mission. This article concentrates on presenting the wind reconstruction algorithm and methods for validating the operation of the algorithm. The algorithm enables the reconstruction of wind measurements for the complete VL1 mission. The amount of available sols is extended from 350 to 2245 sols.

  2. Wind reconstruction algorithm for Viking Lander 1

    Directory of Open Access Journals (Sweden)

    T. Kynkäänniemi

    2017-06-01

    Full Text Available The wind measurement sensors of Viking Lander 1 (VL1 were only fully operational for the first 45 sols of the mission. We have developed an algorithm for reconstructing the wind measurement data after the wind measurement sensor failures. The algorithm for wind reconstruction enables the processing of wind data during the complete VL1 mission. The heater element of the quadrant sensor, which provided auxiliary measurement for wind direction, failed during the 45th sol of the VL1 mission. Additionally, one of the wind sensors of VL1 broke down during sol 378. Regardless of the failures, it was still possible to reconstruct the wind measurement data, because the failed components of the sensors did not prevent the determination of the wind direction and speed, as some of the components of the wind measurement setup remained intact for the complete mission. This article concentrates on presenting the wind reconstruction algorithm and methods for validating the operation of the algorithm. The algorithm enables the reconstruction of wind measurements for the complete VL1 mission. The amount of available sols is extended from 350 to 2245 sols.

  3. Radiotherapy and breast reconstruction: a meta-analysis.

    LENUS (Irish Health Repository)

    Barry, M

    2011-05-01

    The optimum sequencing of breast reconstruction (BR) in patients receiving postmastectomy radiation therapy (PMRT) is controversial. A comprehensive search of published studies that examined postoperative morbidity following immediate or delayed BR with combined radiotherapy was performed. Medical (MEDLINE & EMBASE) databases were searched and cross-referenced for appropriate studies where morbidity following BR was the primary outcome measured. A total of 1,105 patients were identified from 11 appropriately selected studies. Patients undergoing PMRT and BR are more likely to suffer morbidity compared with patients not receiving PMRT (OR = 4.2; 95% CI, 2.4-7.2 [no PMRT vs. PMRT]). Reconstruction technique was also examined with outcome when PMRT was delivered after BR, and this demonstrated that autologous reconstruction is associated with less morbidity in this setting (OR = 0.21; 95% CI, 0.1-0.4 [autologous vs. implant-based]). Delaying BR until after PMRT had no significant effect on outcome (OR = 0.87; 95% CI, 0.47-1.62 [delayed vs. immediate]). PMRT has a detrimental effect on BR outcome. These results suggest that where immediate reconstruction is undertaken with the necessity of PMRT, an autologous flap results in less morbidity when compared with implant-based reconstruction.

  4. Hanford environmental dose reconstruction project - an overview

    International Nuclear Information System (INIS)

    Shipler, D.B.; Napier, B.A.; Farris, W.T.

    1996-01-01

    The Hanford Environmental Dose Reconstruction Project was initiated because of public interest in the historical releases of radioactive materials from the Hanford Site, located in southcentral Washington State. By 1986, over 38,000 pages of environmental monitoring documentation from the early years of Hanford operations had been released. Special committees reviewing the documents recommended initiation of the Hanford Environmental Dose Reconstruction Project, which began in October 1987, and is conducted by Battelle, Pacific Northwest Laboratories. The technical approach taken was to reconstruct releases of radioactive materials based on facility operating information; develop and/or adapt transport, pathway, and dose models and computer codes; reconstruct environmental, meterological, and hydrological monitoring information; reconstruct demographic, agricultural, and lifestyle characteristics; apply statistical methods to all forms of uncertainty in the information, parameters, and models; and perform scientific investigation that were technically defensible. The geographic area for the study includes ∼2 x 10 5 km 2 (75,000 mi 2 ) in eastern Washington, western Idaho, and northeastern Oregon (essentially the Mid-columbia Basin of the Pacific Northwest). Three exposure pathways were considered: the atmosphere, the Columbia River, and ground water

  5. Confidence and sensitivity of sea-level reconstructions

    DEFF Research Database (Denmark)

    Svendsen, Peter Limkilde

    For the last two decades, satellite altimetry has provided a near-global view of spatial and temporal patterns in sea surface height (SSH). When combined with records from tide gauges, a historical reconstruction of sea level can be obtained; while tide gauge records span up to 200 years back...... nature of the data fields. We examine the sensitivity of a reconstruction with respect to the length of calibration time series, and the spatial distribution of tide gauges or other proxy data. In addition, we consider the eect of isolating certain physical phenomena (e.g. ENSO) and annual signals...... and modelling these outside the reconstruction. The implementation is currently based on data from compound satellite datasets (i.e., two decades of altimetry), and the Simple Ocean Data Assimilation (SODA) model, an existing reconstruction, where a calibration period can be easily extracted and our model...

  6. Reconstruction of Clear-PEM data with STIR

    CERN Document Server

    Martins, M V; Rodrigues, P; Trindade, A; Oliveira, N; Correia, M; Cordeiro, H; Ferreira, N C; Varela, J; Almeida, P

    2006-01-01

    The Clear-PEM scanner is a device based on planar detectors that is currently under development within the Crystal Clear Collaboration, at CERN. The basis for 3D image reconstruction in Clear-PEM is the software for tomographic image reconstruction (STIR). STIR is an open source object-oriented library that efficiently deals with the 3D positron emission tomography data sets. This library was originally designed for the traditional cylindrical scanners. In order to make its use compatible with planar scanner data, new functionalities were introduced into the library's framework. In this work, Monte Carlo simulations of the Clear-PEM scanner acquisitions were used as input for image reconstruction with the 3D OSEM algorithm available in STIR. The results presented indicate that dual plate PEM data can be accurately reconstructed using the enhanced STIR framework.

  7. Discrete Wigner Function Reconstruction and Compressed Sensing

    OpenAIRE

    Zhang, Jia-Ning; Fang, Lei; Ge, Mo-Lin

    2011-01-01

    A new reconstruction method for Wigner function is reported for quantum tomography based on compressed sensing. By analogy with computed tomography, Wigner functions for some quantum states can be reconstructed with less measurements utilizing this compressed sensing based method.

  8. Three-dimensional reconstruction and visualization system for medical images

    International Nuclear Information System (INIS)

    Preston, D.F.; Batnitzky, S.; Kyo Rak Lee; Cook, P.N.; Cook, L.T.; Dwyer, S.J.

    1982-01-01

    A three-dimensional reconstruction and visualization system could be of significant advantage in medical application such as neurosurgery and radiation treatment planning. The reconstructed anatomic structures from CT head scans could be used in a head stereotactic system to help plan the surgical procedure and the radiation treatment for a brain lesion. Also, the use of three-dimensional reconstruction algorithm provides for quantitative measures such as volume and surface area estimation of the anatomic features. This aspect of the three-dimensional reconstruction system may be used to monitor the progress or staging of a disease and the effects of patient treatment. Two cases are presented to illustrate the three-dimensional surface reconstruction and visualization system

  9. Monthly paleostreamflow reconstruction from annual tree-ring chronologies

    Science.gov (United States)

    Stagge, J. H.; Rosenberg, D. E.; DeRose, R. J.; Rittenour, T. M.

    2018-02-01

    Paleoclimate reconstructions are increasingly used to characterize annual climate variability prior to the instrumental record, to improve estimates of climate extremes, and to provide a baseline for climate-change projections. To date, paleoclimate records have seen limited engineering use to estimate hydrologic risks because water systems models and managers usually require streamflow input at the monthly scale. This study explores the hypothesis that monthly streamflows can be adequately modeled by statistically decomposing annual flow reconstructions. To test this hypothesis, a multiple linear regression model for monthly streamflow reconstruction is presented that expands the set of predictors to include annual streamflow reconstructions, reconstructions of global circulation, and potential differences among regional tree-ring chronologies related to tree species and geographic location. This approach is used to reconstruct 600 years of monthly streamflows at two sites on the Bear and Logan rivers in northern Utah. Nash-Sutcliffe Efficiencies remain above zero (0.26-0.60) for all months except April and Pearson's correlation coefficients (R) are 0.94 and 0.88 for the Bear and Logan rivers, respectively, confirming that the model can adequately reproduce monthly flows during the reference period (10/1942 to 9/2015). Incorporating a flexible transition between the previous and concurrent annual reconstructed flows was the most important factor for model skill. Expanding the model to include global climate indices and regional tree-ring chronologies produced smaller, but still significant improvements in model fit. The model presented here is the only approach currently available to reconstruct monthly streamflows directly from tree-ring chronologies and climate reconstructions, rather than using resampling of the observed record. With reasonable estimates of monthly flow that extend back in time many centuries, water managers can challenge systems models with a

  10. Iterative CT reconstruction via minimizing adaptively reweighted total variation.

    Science.gov (United States)

    Zhu, Lei; Niu, Tianye; Petrongolo, Michael

    2014-01-01

    Iterative reconstruction via total variation (TV) minimization has demonstrated great successes in accurate CT imaging from under-sampled projections. When projections are further reduced, over-smoothing artifacts appear in the current reconstruction especially around the structure boundaries. We propose a practical algorithm to improve TV-minimization based CT reconstruction on very few projection data. Based on the theory of compressed sensing, the L-0 norm approach is more desirable to further reduce the projection views. To overcome the computational difficulty of the non-convex optimization of the L-0 norm, we implement an adaptive weighting scheme to approximate the solution via a series of TV minimizations for practical use in CT reconstruction. The weight on TV is initialized as uniform ones, and is automatically changed based on the gradient of the reconstructed image from the previous iteration. The iteration stops when a small difference between the weighted TV values is observed on two consecutive reconstructed images. We evaluate the proposed algorithm on both a digital phantom and a physical phantom. Using 20 equiangular projections, our method reduces reconstruction errors in the conventional TV minimization by a factor of more than 5, with improved spatial resolution. By adaptively reweighting TV in iterative CT reconstruction, we successfully further reduce the projection number for the same or better image quality.

  11. Perforator based rectus free tissue transfer for head and neck reconstruction: New reconstructive advantages from an old friend.

    Science.gov (United States)

    Kang, Stephen Y; Spector, Matthew E; Chepeha, Douglas B

    2017-11-01

    To demonstrate three reconstructive advantages of the perforator based rectus free tissue transfer: long pedicle, customizable adipose tissue, and volume reconstruction without muscle atrophy within a contained space. Thirty patients with defects of the head and neck were reconstructed with the perforator based rectus free tissue transfer. Transplant success was 93%. Mean pedicle length was 13.4cm. Eleven patients (37%) had vessel-poor necks and the long pedicle provided by this transplant avoided the need for vein grafts in these patients. Adipose tissue was molded in 17 patients (57%). Twenty-five patients (83%) had defects within a contained space, such as the orbit, where it was critical to have a transplant that avoided muscle atrophy. The perforator based rectus free tissue transfer provides a long pedicle, moldable fat for flap customization, and is useful in reconstruction of defects within a contained space where volume loss due to muscle atrophy is prevented. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Seismic interferometry : Reconstructing the earth's reflection response

    NARCIS (Netherlands)

    Draganov, D.S.; Wapenaar, C.P.A.; Thorbecke, J.W.

    2006-01-01

    In 1968, Jon Claerbout showed that the reflection response of a 1D acoustic medium can be reconstructed by autocorrelating the transmission response. Since then, several authors have derived relationships for reconstructing Green's functions at the surface, using crosscorrelations of (noise)

  13. Angular self-reconstruction of petal-like beams

    CSIR Research Space (South Africa)

    Litvin, IA

    2013-09-01

    Full Text Available equation for predicting the self-reconstruction distance of superpositions of LG beams, which we confirm by numerical propagation as well as by experiment. We explain that the self-reconstruction process is not guaranteed and predict its dependence...

  14. Equilibrium Reconstruction in EAST Tokamak

    International Nuclear Information System (INIS)

    Qian Jinping; Wan Baonian; Shen Biao; Sun Youwen; Liu Dongmei; Xiao Bingjia; Ren Qilong; Gong Xianzu; Li Jiangang; Lao, L. L.; Sabbagh, S. A.

    2009-01-01

    Reconstruction of experimental axisymmetric equilibria is an important part of tokamak data analysis. Fourier expansion is applied to reconstruct the vessel current distribution in EFIT code. Benchmarking and testing calculations are performed to evaluate and validate this algorithm. Two cases for circular and non-circular plasma discharges are presented. Fourier expansion used to fit the eddy current is a robust method and the real time EFIT can be introduced to the plasma control system in the coming campaign. (magnetically confined plasma)

  15. [From the French Society of Plastic and Reconstructive Surgery to the French Society of Plastic Reconstructive and Aesthetic Surgery].

    Science.gov (United States)

    Glicenstein, J

    2004-04-01

    (The) 3rd December 1952, 11 surgeons and other specialists found the French Society of Plastic and Reconstructive Surgery (SFCPR) which was officially published on (the) 28 September 1953. The first congress was during October 1953 and the first president as Maurice Aubry. The first secretary was Daniel Morel Fatio. The symposiums were after about three of four times each year and the thematic subjects were initially according the reconstructive surgery. The review "Annales de chirurgie plastique" was free in 1956. The members of the Society were about 30 initially, but their plastic surgery in the big hospitals at Paris and other big towns in France. The "specialty" of plastic surgery was created in 1971. On "syndicate", one French board of plastic reconstructive and aesthetic surgery, the increasing of departments of plastic surgery were the front of increasing of the plastic surgery in French and of the number of the French Society of Plastic Reconstructive surgery (580 in 2003). The French Society organized the International Congress of Plastic Surgery in 1975. The society SFCPR became the French Society of plastic reconstruction and Aesthetic Surgery (SFCPRE) in 1983 and the "logo" (front view) was in the 1994 SOF.CPRE.

  16. Evaluation of a 3D point cloud tetrahedral tomographic reconstruction method

    Science.gov (United States)

    Pereira, N. F.; Sitek, A.

    2010-09-01

    Tomographic reconstruction on an irregular grid may be superior to reconstruction on a regular grid. This is achieved through an appropriate choice of the image space model, the selection of an optimal set of points and the use of any available prior information during the reconstruction process. Accordingly, a number of reconstruction-related parameters must be optimized for best performance. In this work, a 3D point cloud tetrahedral mesh reconstruction method is evaluated for quantitative tasks. A linear image model is employed to obtain the reconstruction system matrix and five point generation strategies are studied. The evaluation is performed using the recovery coefficient, as well as voxel- and template-based estimates of bias and variance measures, computed over specific regions in the reconstructed image. A similar analysis is performed for regular grid reconstructions that use voxel basis functions. The maximum likelihood expectation maximization reconstruction algorithm is used. For the tetrahedral reconstructions, of the five point generation methods that are evaluated, three use image priors. For evaluation purposes, an object consisting of overlapping spheres with varying activity is simulated. The exact parallel projection data of this object are obtained analytically using a parallel projector, and multiple Poisson noise realizations of these exact data are generated and reconstructed using the different point generation strategies. The unconstrained nature of point placement in some of the irregular mesh-based reconstruction strategies has superior activity recovery for small, low-contrast image regions. The results show that, with an appropriately generated set of mesh points, the irregular grid reconstruction methods can out-perform reconstructions on a regular grid for mathematical phantoms, in terms of the performance measures evaluated.

  17. Evaluation of a 3D point cloud tetrahedral tomographic reconstruction method

    International Nuclear Information System (INIS)

    Pereira, N F; Sitek, A

    2010-01-01

    Tomographic reconstruction on an irregular grid may be superior to reconstruction on a regular grid. This is achieved through an appropriate choice of the image space model, the selection of an optimal set of points and the use of any available prior information during the reconstruction process. Accordingly, a number of reconstruction-related parameters must be optimized for best performance. In this work, a 3D point cloud tetrahedral mesh reconstruction method is evaluated for quantitative tasks. A linear image model is employed to obtain the reconstruction system matrix and five point generation strategies are studied. The evaluation is performed using the recovery coefficient, as well as voxel- and template-based estimates of bias and variance measures, computed over specific regions in the reconstructed image. A similar analysis is performed for regular grid reconstructions that use voxel basis functions. The maximum likelihood expectation maximization reconstruction algorithm is used. For the tetrahedral reconstructions, of the five point generation methods that are evaluated, three use image priors. For evaluation purposes, an object consisting of overlapping spheres with varying activity is simulated. The exact parallel projection data of this object are obtained analytically using a parallel projector, and multiple Poisson noise realizations of these exact data are generated and reconstructed using the different point generation strategies. The unconstrained nature of point placement in some of the irregular mesh-based reconstruction strategies has superior activity recovery for small, low-contrast image regions. The results show that, with an appropriately generated set of mesh points, the irregular grid reconstruction methods can out-perform reconstructions on a regular grid for mathematical phantoms, in terms of the performance measures evaluated.

  18. Evaluation of a 3D point cloud tetrahedral tomographic reconstruction method

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, N F; Sitek, A, E-mail: nfp4@bwh.harvard.ed, E-mail: asitek@bwh.harvard.ed [Department of Radiology, Brigham and Women' s Hospital-Harvard Medical School Boston, MA (United States)

    2010-09-21

    Tomographic reconstruction on an irregular grid may be superior to reconstruction on a regular grid. This is achieved through an appropriate choice of the image space model, the selection of an optimal set of points and the use of any available prior information during the reconstruction process. Accordingly, a number of reconstruction-related parameters must be optimized for best performance. In this work, a 3D point cloud tetrahedral mesh reconstruction method is evaluated for quantitative tasks. A linear image model is employed to obtain the reconstruction system matrix and five point generation strategies are studied. The evaluation is performed using the recovery coefficient, as well as voxel- and template-based estimates of bias and variance measures, computed over specific regions in the reconstructed image. A similar analysis is performed for regular grid reconstructions that use voxel basis functions. The maximum likelihood expectation maximization reconstruction algorithm is used. For the tetrahedral reconstructions, of the five point generation methods that are evaluated, three use image priors. For evaluation purposes, an object consisting of overlapping spheres with varying activity is simulated. The exact parallel projection data of this object are obtained analytically using a parallel projector, and multiple Poisson noise realizations of these exact data are generated and reconstructed using the different point generation strategies. The unconstrained nature of point placement in some of the irregular mesh-based reconstruction strategies has superior activity recovery for small, low-contrast image regions. The results show that, with an appropriately generated set of mesh points, the irregular grid reconstruction methods can out-perform reconstructions on a regular grid for mathematical phantoms, in terms of the performance measures evaluated.

  19. Penalized maximum likelihood reconstruction for x-ray differential phase-contrast tomography

    International Nuclear Information System (INIS)

    Brendel, Bernhard; Teuffenbach, Maximilian von; Noël, Peter B.; Pfeiffer, Franz; Koehler, Thomas

    2016-01-01

    Purpose: The purpose of this work is to propose a cost function with regularization to iteratively reconstruct attenuation, phase, and scatter images simultaneously from differential phase contrast (DPC) acquisitions, without the need of phase retrieval, and examine its properties. Furthermore this reconstruction method is applied to an acquisition pattern that is suitable for a DPC tomographic system with continuously rotating gantry (sliding window acquisition), overcoming the severe smearing in noniterative reconstruction. Methods: We derive a penalized maximum likelihood reconstruction algorithm to directly reconstruct attenuation, phase, and scatter image from the measured detector values of a DPC acquisition. The proposed penalty comprises, for each of the three images, an independent smoothing prior. Image quality of the proposed reconstruction is compared to images generated with FBP and iterative reconstruction after phase retrieval. Furthermore, the influence between the priors is analyzed. Finally, the proposed reconstruction algorithm is applied to experimental sliding window data acquired at a synchrotron and results are compared to reconstructions based on phase retrieval. Results: The results show that the proposed algorithm significantly increases image quality in comparison to reconstructions based on phase retrieval. No significant mutual influence between the proposed independent priors could be observed. Further it could be illustrated that the iterative reconstruction of a sliding window acquisition results in images with substantially reduced smearing artifacts. Conclusions: Although the proposed cost function is inherently nonconvex, it can be used to reconstruct images with less aliasing artifacts and less streak artifacts than reconstruction methods based on phase retrieval. Furthermore, the proposed method can be used to reconstruct images of sliding window acquisitions with negligible smearing artifacts

  20. Detector independent cellular automaton algorithm for track reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Kisel, Ivan; Kulakov, Igor; Zyzak, Maksym [Goethe Univ. Frankfurt am Main (Germany); Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH (Germany); Collaboration: CBM-Collaboration

    2013-07-01

    Track reconstruction is one of the most challenging problems of data analysis in modern high energy physics (HEP) experiments, which have to process per second of the order of 10{sup 7} events with high track multiplicity and density, registered by detectors of different types and, in many cases, located in non-homogeneous magnetic field. Creation of reconstruction package common for all experiments is considered to be important in order to consolidate efforts. The cellular automaton (CA) track reconstruction approach has been used successfully in many HEP experiments. It is very simple, efficient, local and parallel. Meanwhile it is intrinsically independent of detector geometry and good candidate for common track reconstruction. The CA implementation for the CBM experiment has been generalized and applied to the ALICE ITS and STAR HFT detectors. Tests with simulated collisions have been performed. The track reconstruction efficiencies are at the level of 95% for majority of the signal tracks for all detectors.

  1. Optimization of reconstruction algorithms using Monte Carlo simulation

    International Nuclear Information System (INIS)

    Hanson, K.M.

    1989-01-01

    A method for optimizing reconstruction algorithms is presented that is based on how well a specified task can be performed using the reconstructed images. Task performance is numerically assessed by a Monte Carlo simulation of the complete imaging process including the generation of scenes appropriate to the desired application, subsequent data taking, reconstruction, and performance of the stated task based on the final image. The use of this method is demonstrated through the optimization of the Algebraic Reconstruction Technique (ART), which reconstructs images from their projections by a iterative procedure. The optimization is accomplished by varying the relaxation factor employed in the updating procedure. In some of the imaging situations studied, it is found that the optimization of constrained ART, in which a nonnegativity constraint is invoked, can vastly increase the detectability of objects. There is little improvement attained for unconstrained ART. The general method presented may be applied to the problem of designing neutron-diffraction spectrometers. 11 refs., 6 figs., 2 tabs

  2. Optimization of reconstruction algorithms using Monte Carlo simulation

    International Nuclear Information System (INIS)

    Hanson, K.M.

    1989-01-01

    A method for optimizing reconstruction algorithms is presented that is based on how well a specified task can be performed using the reconstructed images. Task performance is numerically assessed by a Monte Carlo simulation of the complete imaging process including the generation of scenes appropriate to the desired application, subsequent data taking, reconstruction, and performance of the stated task based on the final image. The use of this method is demonstrated through the optimization of the Algebraic Reconstruction Technique (ART), which reconstructs images from their projections by an iterative procedure. The optimization is accomplished by varying the relaxation factor employed in the updating procedure. In some of the imaging situations studied, it is found that the optimization of constrained ART, in which a non-negativity constraint is invoked, can vastly increase the detectability of objects. There is little improvement attained for unconstrained ART. The general method presented may be applied to the problem of designing neutron-diffraction spectrometers. (author)

  3. Direct cone beam SPECT reconstruction with camera tilt

    International Nuclear Information System (INIS)

    Jianying Li; Jaszczak, R.J.; Greer, K.L.; Coleman, R.E.; Zongjian Cao; Tsui, B.M.W.

    1993-01-01

    A filtered backprojection (FBP) algorithm is derived to perform cone beam (CB) single-photon emission computed tomography (SPECT) reconstruction with camera tilt using circular orbits. This algorithm reconstructs the tilted angle CB projection data directly by incorporating the tilt angle into it. When the tilt angle becomes zero, this algorithm reduces to that of Feldkamp. Experimentally acquired phantom studies using both a two-point source and the three-dimensional Hoffman brain phantom have been performed. The transaxial tilted cone beam brain images and profiles obtained using the new algorithm are compared with those without camera tilt. For those slices which have approximately the same distance from the detector in both tilt and non-tilt set-ups, the two transaxial reconstructions have similar profiles. The two-point source images reconstructed from this new algorithm and the tilted cone beam brain images are also compared with those reconstructed from the existing tilted cone beam algorithm. (author)

  4. Ray tracing reconstruction investigation for C-arm tomosynthesis

    Science.gov (United States)

    Malalla, Nuhad A. Y.; Chen, Ying

    2016-04-01

    C-arm tomosynthesis is a three dimensional imaging technique. Both x-ray source and the detector are mounted on a C-arm wheeled structure to provide wide variety of movement around the object. In this paper, C-arm tomosynthesis was introduced to provide three dimensional information over a limited view angle (less than 180o) to reduce radiation exposure and examination time. Reconstruction algorithms based on ray tracing method such as ray tracing back projection (BP), simultaneous algebraic reconstruction technique (SART) and maximum likelihood expectation maximization (MLEM) were developed for C-arm tomosynthesis. C-arm tomosynthesis projection images of simulated spherical object were simulated with a virtual geometric configuration with a total view angle of 40 degrees. This study demonstrated the sharpness of in-plane reconstructed structure and effectiveness of removing out-of-plane blur for each reconstruction algorithms. Results showed the ability of ray tracing based reconstruction algorithms to provide three dimensional information with limited angle C-arm tomosynthesis.

  5. Muon reconstruction and the search for leptoquarks at LHC

    CERN Document Server

    Ruckert, B

    2006-01-01

    This diploma thesis focuses on the reconstruction of high-energetic muons. This simulation study was performed within the ATLAS experiment at the Large Hadron Collider (LHC) which is a pp-collider with a centre-of-mass energy p s = 14 TeV. The purpose of this study was to identify muons with strongly overestimated transverse momentum using Monte Carlo simulated data which has been generated using Pythia and run through a full detector simulation. These muons can lead to a faked leptoquark signal, as leptoquark-decays can include high-energetic muons. If leptoquarks exist, only a small number of such events is expected which makes the safe momentum measurement a crucial point. To achieve an optimal reconstruction, selection criteria have been developed which compare the track’s 2, the particle’s -direction and the reconstructed pT s from the different reconstruction algorithms, namely the inner detector standalone reconstruction, the muon spectrometer standalone reconstruction and a combination of both. Th...

  6. Vertex Reconstruction in the ATLAS Experiment at the LHC

    CERN Document Server

    Bouhova-Thacker, E; The ATLAS collaboration; Kostyukhin, V; Liebig, W; Limper, M; Piacquadio, G; Lichard, P; Weiser, C; Wildauer, A

    2009-01-01

    In the harsh environment of the Large Hadron Collider at CERN (design luminosity of $10^{34}$ cm$^{-2}$ s$^{-1}$) efficient reconstruction of vertices is crucial for many physics analyses. Described in this paper are the strategies for vertex reconstruction used in the ATLAS experiment and their implementation in the software framework Athena. The algorithms for the reconstruction of primary and secondary vertices as well as for finding of photon conversions and vertex reconstruction in jets are described. A special emphasis is made on the vertex fitting with application of additional constraints. The implementation of mentioned algorithms follows a very modular design based on object-oriented C++ and use of abstract interfaces. The user-friendly concept allows event reconstruction and physics analyses to compare and optimize their choice among different vertex reconstruction strategies. The performance of implemented algorithms has been studied on a variety of Monte Carlo samples and results are presented.

  7. Reconstruction of FXR Beam Conditions

    International Nuclear Information System (INIS)

    Nexen, W E; Scarpetti, R D; Zentler, J

    2001-01-01

    Beam-envelope radius, envelope angle, and beam emittance can be derived from measurements of beam radius for at least three different transport conditions. We have used this technique to reconstruct exit parameters from the FXR injector and accelerator. We use a diamagnetic loop (DML) to measure the magnetic moment of the high current beam. With no assumptions about radial profile, we can derive the beam mean squire radius from the moment under certain easily met conditions. Since it is this parameter which is required for the reconstruction, it is evident that the DML is the ideal diagnostic for this technique. The simplest application of this technique requires at least three shots for a reconstruction but in reality requires averaging over many more shots because of shot to shot variation. Since DML measurements do not interfere with the beam, single shot time resolved measurements of the beam parameters appear feasible if one uses an array of at least three DMLs separated by known transport conditions

  8. Avoiding Complications with MPFL Reconstruction.

    Science.gov (United States)

    Smith, Marvin K; Werner, Brian C; Diduch, David R

    2018-05-12

    To discuss the potentially significant complications associated with medial patellofemoral ligament (MPFL) reconstruction. Additionally, to review the most current and relevant literature with an emphasis on avoiding these potential complications. Multiple cadaveric studies have characterized the anatomy of the MPFL and the related morphologic abnormalities that contribute to recurrent lateral patellar instability. Such abnormalities include patella alta, excessive tibial tubercle to trochlear grove (TT-TG) distance, trochlear dysplasia, and malalignment. Recent studies have evaluated the clinical outcomes associated with the treatment of concomitant pathology in combination with MPFL reconstruction, which is critical in avoiding recurrent instability and complications. Although there remains a lack of consensus regarding various critical aspects of MPFL reconstruction, certain concepts remain imperative. Our preferred methods and rationales for surgical techniques are described. These include appropriate work up, a combination of procedures to address abnormal morphology, anatomical femoral insertion, safe and secure patellar fixation, appropriate graft length fixation, and thoughtful knee flexion during fixation.

  9. Reconstructing a general inflationary action

    International Nuclear Information System (INIS)

    Bean, Rachel; Chung, Daniel J. H.; Geshnizjani, Ghazal

    2008-01-01

    If inflation is to be considered in an unbiased way, as possibly originating from one of a wide range of underlying theories, then observations need not be simply applied to reconstructing the inflaton potential V(φ) or a specific kinetic term, as in Dirac-Born-Infeld inflation, but rather to reconstruct the inflationary action in its entirety. We discuss the constraints that can be placed on a general single field action from measurements of the primordial scalar and tensor fluctuation power spectra and non-Gaussianities. The analytic form of the action that is consistent with data turns out to be surprisingly simple and easy to categorize. We also present the flow equation formalism for reconstructing a general inflationary Lagrangian L(X,φ), with X=(1/2)∂ μ φ∂ μ φ, in a general gauge, that reduces to canonical and DBI inflation in the specific gauge L X =c s -1 .

  10. Using Purchasing Power Parity to Assess Construction Productivity

    Directory of Open Access Journals (Sweden)

    Rick Best

    2010-12-01

    Full Text Available For many reasons comparing construction productivity between countries is a difficult task. One key problem is that of converting construction costs to a common currency. This problem can be overcome relatively simply by using a basket of construction materials and labour, termed a BLOC (Basket of Locally Obtained Commodities, as a unit of construction cost. Average BLOC costs in each location are calculated from data obtained from a number of sources (quantity surveyors, estimators. Typical building costs obtained from published construction cost data are expressed in BLOC equivalents. Lower BLOC equivalents represent higher productivity as other inputs (largely materials are constant. The method provides a relatively simple and direct method for comparing productivity between different locations.

  11. Arterial cross-section reconstruction from bi-plane X-ray shadowgraphs

    International Nuclear Information System (INIS)

    Fenster, P.; Barba, J.; Suardiaz, M.; Wong, K.K.; Herrold, E.M.; Kenet, R.O.; Borer, J.S.

    1987-01-01

    An iterative algorithm was used to reconstruct the cross-section of a crescent-shaped vessel lumen. The accuracy of this method was evaluated by comparing reconstruction error in the presence of Gaussian noise of different magnitudes. The sensitivity of the reconstruction algorithm to initial boundary constraint error was also evaluated. Using this algorithm, the reconstruction error was 1.7% when applied to crescent shaped lumen. This error was found to increase significantly with increasing Gaussian noise (error range: 5.75 - 20.75% for noise variance 1-8 pixels). Median filtering of the noise-degraded density profiles improved the reconstruction error (error range: 3.25 - 10.5% for noise variance 1-8 pixels). The mean reconstruction error was not strongly influenced by initial boundary constraint error. The algorithm provided reasonable reconstruction results when applied to X-ray image derived density profiles of known luminal shapes

  12. Trends in breast reconstruction: Implications for the National Health Insurance Service.

    Science.gov (United States)

    Hong, Ki Yong; Son, Yoosung; Chang, Hak; Jin, Ung Sik

    2018-05-01

    Breast reconstruction has become more common as mastectomy has become more frequent. In Korea, the National Health Insurance Service (NHIS) began covering breast reconstruction in April 2015. This study aimed to investigate trends in mastectomy and breast reconstruction over the past 10 years and to evaluate the impact of NHIS coverage on breast reconstruction. Nationwide data regarding mastectomy and breast reconstruction were collected from the Korean Breast Cancer Society registry database. Multiple variables were analyzed in the records of patients who underwent breast reconstruction from January 2005 to March 2017 at a single institution. At Seoul National University Hospital, the total number of reconstruction cases increased 13-fold from 2005 to 2016. The proportion of immediate breast reconstruction (IBR) cases out of all cases of total mastectomy increased from 4% in 2005 to 52.0% in 2016. The proportion of delayed breast reconstruction (DBR) cases out of all cases of breast reconstruction and the overall number of DBR cases increased from 8.8% (20 cases) in 2012 to 18.3% (76 cases) in 2016. After NHIS coverage was initiated, the proportions of IBR and DBR showed statistically significant increases (PNHIS coverage (PNHIS coverage. It is expected that breast reconstruction will be a routine option for patients with breast cancer under the NHIS.

  13. Prevalence of Body Dysmorphic Disorder Among Patients Seeking Breast Reconstruction.

    Science.gov (United States)

    Metcalfe, Drew B; Duggal, Claire S; Gabriel, Allen; Nahabedian, Maurice Y; Carlson, Grant W; Losken, Albert

    2014-07-01

    Body dysmorphic disorder (BDD) is characterized by a preoccupation with a slight or imagined defect in physical appearance. It has significant implications for patients who desire breast reconstruction, because patient satisfaction with the aesthetic outcome is a substantial contributor to the success of the procedure. The authors estimated the prevalence of BDD among women seeking breast reconstruction by surveying patients with the previously validated Dysmorphic Concerns Questionnaire (DCQ). One hundred eighty-eight women who presented for immediate or delayed breast reconstruction completed the DCQ anonymously, during initial consultation with a plastic surgeon. Two groups of respondents were identified: those who desired immediate reconstruction and those who planned to undergo delayed reconstruction. The prevalence of BDD among breast reconstruction patients was compared between the 2 groups, and the overall prevalence was compared with published rates for the general public. Body dysmorphic disorder was significantly more prevalent in breast reconstruction patients than in the general population (17% vs 2%; P < .001). It also was much more common among patients who planned to undergo delayed (vs immediate) reconstruction (34% vs 13%; P = .004). Relative to the general public, significantly more women who sought breast reconstruction were diagnosed as having BDD. Awareness of the potential for BDD will enable clinicians to better understand their patients' perspectives and discuss realistic expectations at the initial consultation. Future studies are warranted to examine the implications of BDD on patient satisfaction with reconstructive surgery. 3. © 2014 The American Society for Aesthetic Plastic Surgery, Inc.

  14. Reconstructing European forest management from 1600 to 2010

    Science.gov (United States)

    McGrath, M. J.; Luyssaert, S.; Meyfroidt, P.; Kaplan, J. O.; Buergi, M.; Chen, Y.; Erb, K.; Gimmi, U.; McInerney, D.; Naudts, K.; Otto, J.; Pasztor, F.; Ryder, J.; Schelhaas, M.-J.; Valade, A.

    2015-04-01

    European forest use for fuel, timber and food dates back to pre-Roman times. Century-scale ecological processes and their legacy effects require accounting for forest management when studying today's forest carbon sink. Forest management reconstructions that are used to drive land surface models are one way to quantify the impact of both historical and today's large scale application of forest management on today's forest-related carbon sink and surface climate. In this study we reconstruct European forest management from 1600 to 2010 making use of diverse approaches, data sources and assumptions. Between 1600 and 1828, a demand-supply approach was used in which wood supply was reconstructed based on estimates of historical annual wood increment and land cover reconstructions. For the same period demand estimates accounted for the fuelwood needed in households, wood used in food processing, charcoal used in metal smelting and salt production, timber for construction and population estimates. Comparing estimated demand and supply resulted in a spatially explicit reconstruction of the share of forests under coppice, high stand management and forest left unmanaged. For the reconstruction between 1829 and 2010 a supply-driven back-casting method was used. The method used age reconstructions from the years 1950 to 2010 as its starting point. Our reconstruction reproduces the most important changes in forest management between 1600 and 2010: (1) an increase of 593 000 km2 in conifers at the expense of deciduous forest (decreasing by 538 000 km2), (2) a 612 000 km2 decrease in unmanaged forest, (3) a 152 000 km2 decrease in coppice management, (4) a 818 000 km2 increase in high stand management, and (5) the rise and fall of litter raking which at its peak in 1853 removed 50 Tg dry litter per year.

  15. Advances in bioprinting technologies for craniofacial reconstruction

    NARCIS (Netherlands)

    Visscher, D.O.; Farré-Guasch, E.; Helder, M.N.; Gibbs, S.; Forouzanfar, T.; van Zuijlen, P.P.; Wolff, J.

    2016-01-01

    Recent developments in craniofacial reconstruction have shown important advances in both the materials and methods used. While autogenous tissue is still considered to be the gold standard for these reconstructions, the harvesting procedure remains tedious and in many cases causes significant donor

  16. Maximum Likelihood Reconstruction for Magnetic Resonance Fingerprinting.

    Science.gov (United States)

    Zhao, Bo; Setsompop, Kawin; Ye, Huihui; Cauley, Stephen F; Wald, Lawrence L

    2016-08-01

    This paper introduces a statistical estimation framework for magnetic resonance (MR) fingerprinting, a recently proposed quantitative imaging paradigm. Within this framework, we present a maximum likelihood (ML) formalism to estimate multiple MR tissue parameter maps directly from highly undersampled, noisy k-space data. A novel algorithm, based on variable splitting, the alternating direction method of multipliers, and the variable projection method, is developed to solve the resulting optimization problem. Representative results from both simulations and in vivo experiments demonstrate that the proposed approach yields significantly improved accuracy in parameter estimation, compared to the conventional MR fingerprinting reconstruction. Moreover, the proposed framework provides new theoretical insights into the conventional approach. We show analytically that the conventional approach is an approximation to the ML reconstruction; more precisely, it is exactly equivalent to the first iteration of the proposed algorithm for the ML reconstruction, provided that a gridding reconstruction is used as an initialization.

  17. Speeding up image reconstruction in computed tomography

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    Computed tomography (CT) is a technique for imaging cross-sections of an object using X-ray measurements taken from different angles. In last decades a significant progress has happened there: today advanced algorithms allow fast image reconstruction and obtaining high-quality images even with missing or dirty data, modern detectors provide high resolution without increasing radiation dose, and high-performance multi-core computing devices are there to help us solving such tasks even faster. I will start with CT basics, then briefly present existing classes of reconstruction algorithms and their differences. After that I will proceed to employing distinctive architectural features of modern multi-core devices (CPUs and GPUs) and popular program interfaces (OpenMP, MPI, CUDA, OpenCL) for developing effective parallel realizations of image reconstruction algorithms. Decreasing full reconstruction time from long hours up to minutes or even seconds has a revolutionary impact in diagnostic medicine and industria...

  18. Increasing efficiency of reconstruction and technological development of coking enterprises

    Energy Technology Data Exchange (ETDEWEB)

    Rozenfel' d, M.S.; Martynenko, V.M.; Tytyuk, Yu.A.; Ivanov, V.V.; Svyatogorov, A.A.; Kolomiets, A.F. (NIISP, Voroshilovgrad (USSR))

    1989-07-01

    Discusses problems associated with reconstruction of coking plants in the USSR. Planning coking plant reconstruction is analyzed. Duration of individual stages of plant reconstruction is considered. A method developed by the Giprokoks research institute for calculating reconstruction time considering duration of individual stages of coke oven battery repair is analyzed: construction of storage facilities, transport of materials and equipment, safety requirements, coke oven cooling, dismantling, construction of coke oven walls, installation of machines and equipment. Advantages of using the methods for analysis of coke oven battery reconstruction and optimization of repair time are discussed.

  19. 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.)

  20. The ongoing emergence of robotics in plastic and reconstructive surgery.

    Science.gov (United States)

    Struk, S; Qassemyar, Q; Leymarie, N; Honart, J-F; Alkhashnam, H; De Fremicourt, K; Conversano, A; Schaff, J-B; Rimareix, F; Kolb, F; Sarfati, B

    2018-04-01

    Robot-assisted surgery is more and more widely used in urology, general surgery and gynecological surgery. The interest of robotics in plastic and reconstructive surgery, a discipline that operates primarily on surfaces, has yet to be conclusively proved. However, the initial applications of robotic surgery in plastic and reconstructive surgery have been emerging in a number of fields including transoral reconstruction of posterior oropharyngeal defects, nipple-sparing mastectomy with immediate breast reconstruction, microsurgery, muscle harvesting for pelvic reconstruction and coverage of the scalp or the extremities. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  1. Reconstruction dynamics of recorded holograms in photochromic glass

    Energy Technology Data Exchange (ETDEWEB)

    Mihailescu, Mona; Pavel, Eugen; Nicolae, Vasile B.

    2011-06-20

    We have investigated the dynamics of the record-erase process of holograms in photochromic glass using continuum Nd:YVO{sub 4} laser radiation ({lambda}=532 nm). A bidimensional microgrid pattern was formed and visualized in photochromic glass, and its diffraction efficiency decay versus time (during reconstruction step) gave us information (D, {Delta}n) about the diffusion process inside the material. The recording and reconstruction processes were carried out in an off-axis setup, and the images of the reconstructed object were recorded by a CCD camera. Measurements realized on reconstructed object images using holograms recorded at a different incident power laser have shown a two-stage process involved in silver atom kinetics.

  2. Image reconstruction design of industrial CT instrument for teaching

    International Nuclear Information System (INIS)

    Zou Yongning; Cai Yufang

    2009-01-01

    Industrial CT instrument for teaching is applied to teaching and study in field of physics and radiology major, image reconstruction is an important part of software on CT instrument. The paper expatiate on CT physical theory and first generation CT reconstruction algorithm, describe scan process of industrial CT instrument for teaching; analyze image artifact as result of displacement of rotation center, implement method of center displacement correcting, design and complete image reconstruction software, application shows that reconstructed image is very clear and qualitatively high. (authors)

  3. AIR-MRF: Accelerated iterative reconstruction for magnetic resonance fingerprinting.

    Science.gov (United States)

    Cline, Christopher C; Chen, Xiao; Mailhe, Boris; Wang, Qiu; Pfeuffer, Josef; Nittka, Mathias; Griswold, Mark A; Speier, Peter; Nadar, Mariappan S

    2017-09-01

    Existing approaches for reconstruction of multiparametric maps with magnetic resonance fingerprinting (MRF) are currently limited by their estimation accuracy and reconstruction time. We aimed to address these issues with a novel combination of iterative reconstruction, fingerprint compression, additional regularization, and accelerated dictionary search methods. The pipeline described here, accelerated iterative reconstruction for magnetic resonance fingerprinting (AIR-MRF), was evaluated with simulations as well as phantom and in vivo scans. We found that the AIR-MRF pipeline provided reduced parameter estimation errors compared to non-iterative and other iterative methods, particularly at shorter sequence lengths. Accelerated dictionary search methods incorporated into the iterative pipeline reduced the reconstruction time at little cost of quality. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Adaptive multiresolution method for MAP reconstruction in electron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Acar, Erman, E-mail: erman.acar@tut.fi [Department of Signal Processing, Tampere University of Technology, P.O. Box 553, FI-33101 Tampere (Finland); BioMediTech, Tampere University of Technology, Biokatu 10, 33520 Tampere (Finland); Peltonen, Sari; Ruotsalainen, Ulla [Department of Signal Processing, Tampere University of Technology, P.O. Box 553, FI-33101 Tampere (Finland); BioMediTech, Tampere University of Technology, Biokatu 10, 33520 Tampere (Finland)

    2016-11-15

    3D image reconstruction with electron tomography holds problems due to the severely limited range of projection angles and low signal to noise ratio of the acquired projection images. The maximum a posteriori (MAP) reconstruction methods have been successful in compensating for the missing information and suppressing noise with their intrinsic regularization techniques. There are two major problems in MAP reconstruction methods: (1) selection of the regularization parameter that controls the balance between the data fidelity and the prior information, and (2) long computation time. One aim of this study is to provide an adaptive solution to the regularization parameter selection problem without having additional knowledge about the imaging environment and the sample. The other aim is to realize the reconstruction using sequences of resolution levels to shorten the computation time. The reconstructions were analyzed in terms of accuracy and computational efficiency using a simulated biological phantom and publically available experimental datasets of electron tomography. The numerical and visual evaluations of the experiments show that the adaptive multiresolution method can provide more accurate results than the weighted back projection (WBP), simultaneous iterative reconstruction technique (SIRT), and sequential MAP expectation maximization (sMAPEM) method. The method is superior to sMAPEM also in terms of computation time and usability since it can reconstruct 3D images significantly faster without requiring any parameter to be set by the user. - Highlights: • An adaptive multiresolution reconstruction method is introduced for electron tomography. • The method provides more accurate results than the conventional reconstruction methods. • The missing wedge and noise problems can be compensated by the method efficiently.

  5. Endoscopic mucosal resection for middle and large colorectal polyps with a double-loop snare.

    Science.gov (United States)

    Yoshida, Naohisa; Saito, Yutaka; Hirose, Ryohei; Ogiso, Kiyoshi; Inada, Yutaka; Yagi, Nobuaki; Naito, Yuji; Otake, Yosuke; Nakajima, Takeshi; Matsuda, Takahisa; Yanagisawa, Akio; Itoh, Yoshito

    2014-01-01

    This study aimed to analyze the endoscopic mucosal resection (EMR) with a novel uniquely shaped, double-loop snare (Dualoop, Medico's Hirata Inc., Tokyo, Japan) for colorectal polyps. This was a clinical trial conducted in two referral centers, Kyoto Prefectural University of Medicine and National Cancer Center Hospital in Japan. First, the firmness of various snares including 'Dualoop' was experimentally analyzed with a pressure gauge. Five hundred and eighty nine consecutive polyps that underwent EMR with 'Dualoop' were compared to 339 polyps with the standard round snare. Lesion characteristics, en bloc resection, and complications were analyzed. 'Dualoop' had the most firmness among the various snares. The average tumor size was 9.3 mm (5-30), and en bloc resection was achieved in 95.4%. The rate of en bloc resection for middle polyps 15-19 mm in diameter was significantly higher with the 'Dualoop' than that with the round snare (97.9 vs. 80.0%, p < 0.05). The rate of en bloc resection was 64.7% for large polyps ≥20 mm in diameter using 'Dualoop'. Higher age, larger tumor size, and superficial polyps were associated with the failure of en bloc resection. EMR with 'Dualoop' was effective for resecting both middle and large polyps en-bloc. © 2014 S. Karger AG, Basel.

  6. Atmospheric muons reconstruction with Antares; Reconstruction de muons atmospheriques avec ANTARES

    Energy Technology Data Exchange (ETDEWEB)

    Melissas, M

    2007-09-15

    The ANTARES collaboration is building a neutrino telescope in the Mediterranean Sea. This detector contains 900 photomultiplier tubes, dispatched on 12 lines, in order to detect Cerenkov light from muon induced by neutrino interactions in the the vicinity of the detector. Currently the first 5 lines have been deployed. A first task consists in studying the stability of the detector calibration, which is a necessary step to understand the detector response. Then we studied optical properties of water, for this we developed a reconstruction method dedicated to LED Beacon. The extracted parameters are compatible with earlier measurements. A quality criteria to reject badly reconstructed track has been developed based on the likelihood of the tracks fit versus point fit. This has been applied to real data and a preliminary analysis of atmospheric muons with a 5-lines detector is performed. (author)

  7. Fast dictionary-based reconstruction for diffusion spectrum imaging.

    Science.gov (United States)

    Bilgic, Berkin; Chatnuntawech, Itthi; Setsompop, Kawin; Cauley, Stephen F; Yendiki, Anastasia; Wald, Lawrence L; Adalsteinsson, Elfar

    2013-11-01

    Diffusion spectrum imaging reveals detailed local diffusion properties at the expense of substantially long imaging times. It is possible to accelerate acquisition by undersampling in q-space, followed by image reconstruction that exploits prior knowledge on the diffusion probability density functions (pdfs). Previously proposed methods impose this prior in the form of sparsity under wavelet and total variation transforms, or under adaptive dictionaries that are trained on example datasets to maximize the sparsity of the representation. These compressed sensing (CS) methods require full-brain processing times on the order of hours using MATLAB running on a workstation. This work presents two dictionary-based reconstruction techniques that use analytical solutions, and are two orders of magnitude faster than the previously proposed dictionary-based CS approach. The first method generates a dictionary from the training data using principal component analysis (PCA), and performs the reconstruction in the PCA space. The second proposed method applies reconstruction using pseudoinverse with Tikhonov regularization with respect to a dictionary. This dictionary can either be obtained using the K-SVD algorithm, or it can simply be the training dataset of pdfs without any training. All of the proposed methods achieve reconstruction times on the order of seconds per imaging slice, and have reconstruction quality comparable to that of dictionary-based CS algorithm.

  8. Wavefront reconstruction using computer-generated holograms

    Science.gov (United States)

    Schulze, Christian; Flamm, Daniel; Schmidt, Oliver A.; Duparré, Michael

    2012-02-01

    We propose a new method to determine the wavefront of a laser beam, based on modal decomposition using computer-generated holograms (CGHs). Thereby the beam under test illuminates the CGH with a specific, inscribed transmission function that enables the measurement of modal amplitudes and phases by evaluating the first diffraction order of the hologram. Since we use an angular multiplexing technique, our method is innately capable of real-time measurements of amplitude and phase, yielding the complete information about the optical field. A measurement of the Stokes parameters, respectively of the polarization state, provides the possibility to calculate the Poynting vector. Two wavefront reconstruction possibilities are outlined: reconstruction from the phase for scalar beams and reconstruction from the Poynting vector for inhomogeneously polarized beams. To quantify single aberrations, the reconstructed wavefront is decomposed into Zernike polynomials. Our technique is applied to beams emerging from different kinds of multimode optical fibers, such as step-index, photonic crystal and multicore fibers, whereas in this work results are exemplarily shown for a step-index fiber and compared to a Shack-Hartmann measurement that serves as a reference.

  9. The structure of reconstructed chalcopyrite surfaces

    Science.gov (United States)

    Thinius, Sascha; Islam, Mazharul M.; Bredow, Thomas

    2018-03-01

    Chalcopyrite (CuFeS2) surfaces are of major interest for copper exploitation in aqueous solution, called leaching. Since leaching is a surface process knowledge of the surface structure, bonding pattern and oxidation states is important for improving the efficiency. At present such information is not available from experimental studies. Therefore a detailed computational study of chalcopyrite surfaces is performed. The structures of low-index stoichiometric chalcopyrite surfaces {hkl} h, k, l ∈ {0, 1, 2} have been studied with density functional theory (DFT) and global optimization strategies. We have applied ab initio molecular dynamics (MD) in combination with simulated annealing (SA) in order to explore possible reconstructions via a minima hopping (MH) algorithm. In almost all cases reconstruction involving substantial rearrangement has occurred accompanied by reduction of the surface energy. The analysis of the change in the coordination sphere and migration during reconstruction reveals that S-S dimers are formed on the surface. Further it was observed that metal atoms near the surface move toward the bulk forming metal alloys passivated by sulfur. The obtained surface energies of reconstructed surfaces are in the range of 0.53-0.95 J/m2.

  10. Oral cavity reconstruction with the masseter flap

    NARCIS (Netherlands)

    Mahieu, R.; Russo, S.; Gualtieri, T.; Colletti, G.; Deganello, A.

    The purpose of this report is to highlight how an unusual, outdated, unpopular and overlooked reconstructive method such as the masseter flap can be a reliable, straightforward and effective solution for oral reconstruction in selected cases. We report the transposition of the masseter crossover

  11. Modern approach to facial skin defects reconstruction

    Directory of Open Access Journals (Sweden)

    Mateusz Kister

    2017-10-01

    Full Text Available Reconstruction of a facial defect is usually a challenging endeavor. The article aims to describe different types of flaps that might be used to restore such deformities- including their characteristics, indications and guidelines that should be followed in the reconstructive procedures.

  12. [Development and current situation of reconstruction methods following total sacrectomy].

    Science.gov (United States)

    Huang, Siyi; Ji, Tao; Guo, Wei

    2018-05-01

    To review the development of the reconstruction methods following total sacrectomy, and to provide reference for finding a better reconstruction method following total sacrectomy. The case reports and biomechanical and finite element studies of reconstruction following total sacrectomy at home and abroad were searched. Development and current situation were summarized. After developing for nearly 30 years, great progress has been made in the reconstruction concept and fixation techniques. The fixation methods can be summarized as the following three strategies: spinopelvic fixation (SPF), posterior pelvic ring fixation (PPRF), and anterior spinal column fixation (ASCF). SPF has undergone technical progress from intrapelvic rod and hook constructs to pedicle and iliac screw-rod systems. PPRF and ASCF could improve the stability of the reconstruction system. Reconstruction following total sacrectomy remains a challenge. Reconstruction combining SPF, PPRF, and ASCF is the developmental direction to achieve mechanical stability. How to gain biological fixation to improve the long-term stability is an urgent problem to be solved.

  13. A clinical perspective of accelerated statistical reconstruction

    International Nuclear Information System (INIS)

    Hutton, B.F.; Hudson, H.M.; Beekman, F.J.

    1997-01-01

    Although the potential benefits of maximum likelihood reconstruction have been recognised for many years, the technique has only recently found widespread popularity in clinical practice. Factors which have contributed to the wider acceptance include improved models for the emission process, better understanding of the properties of the algorithm and, not least, the practicality of application with the development of acceleration schemes and the improved speed of computers. The objective in this article is to present a framework for applying maximum likelihood reconstruction for a wide range of clinically based problems. The article draws particularly on the experience of the three authors in applying an acceleration scheme involving use of ordered subsets to a range of applications. The potential advantages of statistical reconstruction techniques include: (a) the ability to better model the emission and detection process, in order to make the reconstruction converge to a quantitative image, (b) the inclusion of a statistical noise model which results in better noise characteristics, and (c) the possibility to incorporate prior knowledge about the distribution being imaged. The great flexibility in adapting the reconstruction for a specific model results in these techniques having wide applicability to problems in clinical nuclear medicine. (orig.). With 8 figs., 1 tab

  14. A parametric reconstruction of the deceleration parameter

    Energy Technology Data Exchange (ETDEWEB)

    Al Mamon, Abdulla [Manipal University, Manipal Centre for Natural Sciences, Manipal (India); Visva-Bharati, Department of Physics, Santiniketan (India); Das, Sudipta [Visva-Bharati, Department of Physics, Santiniketan (India)

    2017-07-15

    The present work is based on a parametric reconstruction of the deceleration parameter q(z) in a model for the spatially flat FRW universe filled with dark energy and non-relativistic matter. In cosmology, the parametric reconstruction technique deals with an attempt to build up a model by choosing some specific evolution scenario for a cosmological parameter and then estimate the values of the parameters with the help of different observational datasets. In this paper, we have proposed a logarithmic parametrization of q(z) to probe the evolution history of the universe. Using the type Ia supernova, baryon acoustic oscillation and the cosmic microwave background datasets, the constraints on the arbitrary model parameters q{sub 0} and q{sub 1} are obtained (within 1σ and 2σ confidence limits) by χ{sup 2}-minimization technique. We have then reconstructed the deceleration parameter, the total EoS parameter ω{sub tot}, the jerk parameter and have compared the reconstructed results of q(z) with other well-known parametrizations of q(z). We have also shown that two model selection criteria (namely, the Akaike information criterion and Bayesian information criterion) provide a clear indication that our reconstructed model is well consistent with other popular models. (orig.)

  15. PET reconstruction via nonlocal means induced prior.

    Science.gov (United States)

    Hou, Qingfeng; Huang, Jing; Bian, Zhaoying; Chen, Wufan; Ma, Jianhua

    2015-01-01

    The traditional Bayesian priors for maximum a posteriori (MAP) reconstruction methods usually incorporate local neighborhood interactions that penalize large deviations in parameter estimates for adjacent pixels; therefore, only local pixel differences are utilized. This limits their abilities of penalizing the image roughness. To achieve high-quality PET image reconstruction, this study investigates a MAP reconstruction strategy by incorporating a nonlocal means induced (NLMi) prior (NLMi-MAP) which enables utilizing global similarity information of image. The present NLMi prior approximates the derivative of Gibbs energy function by an NLM filtering process. Specially, the NLMi prior is obtained by subtracting the current image estimation from its NLM filtered version and feeding the residual error back to the reconstruction filter to yield the new image estimation. We tested the present NLMi-MAP method with simulated and real PET datasets. Comparison studies with conventional filtered backprojection (FBP) and a few iterative reconstruction methods clearly demonstrate that the present NLMi-MAP method performs better in lowering noise, preserving image edge and in higher signal to noise ratio (SNR). Extensive experimental results show that the NLMi-MAP method outperforms the existing methods in terms of cross profile, noise reduction, SNR, root mean square error (RMSE) and correlation coefficient (CORR).

  16. Optimization-based reconstruction for reduction of CBCT artifact in IGRT

    Science.gov (United States)

    Xia, Dan; Zhang, Zheng; Paysan, Pascal; Seghers, Dieter; Brehm, Marcus; Munro, Peter; Sidky, Emil Y.; Pelizzari, Charles; Pan, Xiaochuan

    2016-04-01

    Kilo-voltage cone-beam computed tomography (CBCT) plays an important role in image guided radiation therapy (IGRT) by providing 3D spatial information of tumor potentially useful for optimizing treatment planning. In current IGRT CBCT system, reconstructed images obtained with analytic algorithms, such as FDK algorithm and its variants, may contain artifacts. In an attempt to compensate for the artifacts, we investigate optimization-based reconstruction algorithms such as the ASD-POCS algorithm for potentially reducing arti- facts in IGRT CBCT images. In this study, using data acquired with a physical phantom and a patient subject, we demonstrate that the ASD-POCS reconstruction can significantly reduce artifacts observed in clinical re- constructions. Moreover, patient images reconstructed by use of the ASD-POCS algorithm indicate a contrast level of soft-tissue improved over that of the clinical reconstruction. We have also performed reconstructions from sparse-view data, and observe that, for current clinical imaging conditions, ASD-POCS reconstructions from data collected at one half of the current clinical projection views appear to show image quality, in terms of spatial and soft-tissue-contrast resolution, higher than that of the corresponding clinical reconstructions.

  17. 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.

  18. Quantitative tomography simulations and reconstruction algorithms

    International Nuclear Information System (INIS)

    Martz, H.E.; Aufderheide, M.B.; Goodman, D.; Schach von Wittenau, A.; Logan, C.; Hall, J.; Jackson, J.; Slone, D.

    2000-01-01

    X-ray, neutron and proton transmission radiography and computed tomography (CT) are important diagnostic tools that are at the heart of LLNL's effort to meet the goals of the DOE's Advanced Radiography Campaign. This campaign seeks to improve radiographic simulation and analysis so that radiography can be a useful quantitative diagnostic tool for stockpile stewardship. Current radiographic accuracy does not allow satisfactory separation of experimental effects from the true features of an object's tomographically reconstructed image. This can lead to difficult and sometimes incorrect interpretation of the results. By improving our ability to simulate the whole radiographic and CT system, it will be possible to examine the contribution of system components to various experimental effects, with the goal of removing or reducing them. In this project, we are merging this simulation capability with a maximum-likelihood (constrained-conjugate-gradient-CCG) reconstruction technique yielding a physics-based, forward-model image-reconstruction code. In addition, we seek to improve the accuracy of computed tomography from transmission radiographs by studying what physics is needed in the forward model. During FY 2000, an improved version of the LLNL ray-tracing code called HADES has been coupled with a recently developed LLNL CT algorithm known as CCG. The problem of image reconstruction is expressed as a large matrix equation relating a model for the object being reconstructed to its projections (radiographs). Using a constrained-conjugate-gradient search algorithm, a maximum likelihood solution is sought. This search continues until the difference between the input measured radiographs or projections and the simulated or calculated projections is satisfactorily small

  19. FIRST: Fast Iterative Reconstruction Software for (PET) tomography

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz, J L [Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Espana, S [Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Vaquero, J J [Unidad de Medicina y CirugIa Experimental, Hospital GU Gregorio Maranon, Madrid (Spain); Desco, M [Unidad de Medicina y CirugIa Experimental, Hospital GU Gregorio Maranon, Madrid (Spain); UdIas, J M [Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain)

    2006-09-21

    Small animal PET scanners require high spatial resolution and good sensitivity. To reconstruct high-resolution images in 3D-PET, iterative methods, such as OSEM, are superior to analytical reconstruction algorithms, although their high computational cost is still a serious drawback. The higher performance of modern computers could make iterative image reconstruction fast enough to be viable, provided we are able to deal with the large number of probability coefficients for the system response matrix in high-resolution PET scanners, which is a difficult task that prevents the algorithms from reaching peak computing performance. Considering all possible axial and in-plane symmetries, as well as certain quasi-symmetries, we have been able to reduce the memory requirements to store the system response matrix (SRM) well below 1 GB, which allows us to keep the whole response matrix of the system inside RAM of ordinary industry-standard computers, so that the reconstruction algorithm can achieve near peak performance. The elements of the SRM are stored as cubic spline profiles and matched to voxel size during reconstruction. In this way, the advantages of 'on-the-fly' calculation and of fully stored SRM are combined. The on-the-fly part of the calculation (matching the profile functions to voxel size) of the SRM accounts for 10-30% of the reconstruction time, depending on the number of voxels chosen. We tested our approach with real data from a commercial small animal PET scanner. The results (image quality and reconstruction time) show that the proposed technique is a feasible solution.

  20. FIRST: Fast Iterative Reconstruction Software for (PET) tomography

    International Nuclear Information System (INIS)

    Herraiz, J L; Espana, S; Vaquero, J J; Desco, M; UdIas, J M

    2006-01-01

    Small animal PET scanners require high spatial resolution and good sensitivity. To reconstruct high-resolution images in 3D-PET, iterative methods, such as OSEM, are superior to analytical reconstruction algorithms, although their high computational cost is still a serious drawback. The higher performance of modern computers could make iterative image reconstruction fast enough to be viable, provided we are able to deal with the large number of probability coefficients for the system response matrix in high-resolution PET scanners, which is a difficult task that prevents the algorithms from reaching peak computing performance. Considering all possible axial and in-plane symmetries, as well as certain quasi-symmetries, we have been able to reduce the memory requirements to store the system response matrix (SRM) well below 1 GB, which allows us to keep the whole response matrix of the system inside RAM of ordinary industry-standard computers, so that the reconstruction algorithm can achieve near peak performance. The elements of the SRM are stored as cubic spline profiles and matched to voxel size during reconstruction. In this way, the advantages of 'on-the-fly' calculation and of fully stored SRM are combined. The on-the-fly part of the calculation (matching the profile functions to voxel size) of the SRM accounts for 10-30% of the reconstruction time, depending on the number of voxels chosen. We tested our approach with real data from a commercial small animal PET scanner. The results (image quality and reconstruction time) show that the proposed technique is a feasible solution

  1. Multifractal signal reconstruction based on singularity power spectrum

    International Nuclear Information System (INIS)

    Xiong, Gang; Yu, Wenxian; Xia, Wenxiang; Zhang, Shuning

    2016-01-01

    Highlights: • We propose a novel multifractal reconstruction method based on singularity power spectrum analysis (MFR-SPS). • The proposed MFR-SPS method has better power characteristic than the algorithm in Fraclab. • Further, the SPS-ISE algorithm performs better than the SPS-MFS algorithm. • Based on the proposed MFR-SPS method, we can restructure singularity white fractal noise (SWFN) and linear singularity modulation (LSM) multifractal signal, in equivalent sense, similar with the linear frequency modulation(LFM) signal and WGN in the Fourier domain. - Abstract: Fractal reconstruction (FR) and multifractal reconstruction (MFR) can be considered as the inverse problem of singularity spectrum analysis, and it is challenging to reconstruct fractal signal in accord with multifractal spectrum (MFS). Due to the multiple solutions of fractal reconstruction, the traditional methods of FR/MFR, such as FBM based method, wavelet based method, random wavelet series, fail to reconstruct fractal signal deterministically, and besides, those methods neglect the power spectral distribution in the singular domain. In this paper, we propose a novel MFR method based singularity power spectrum (SPS). Supposing the consistent uniform covering of multifractal measurement, we control the traditional power law of each scale of wavelet coefficients based on the instantaneous singularity exponents (ISE) or MFS, simultaneously control the singularity power law based on the SPS, and deduce the principle and algorithm of MFR based on SPS. Reconstruction simulation and error analysis of estimated ISE, MFS and SPS show the effectiveness and the improvement of the proposed methods compared to those obtained by the Fraclab package.

  2. Improvement of Quality of Reconstructed Images in Multi-Frame Fresnel Digital Holography

    International Nuclear Information System (INIS)

    Xiao-Wei, Lu; Jing-Zhen, Li; Hong-Yi, Chen

    2010-01-01

    A modified reconstruction algorithm to improve the quality of reconstructed images of multi-frame Fresnel digital holography is presented. When the reference beams are plane or spherical waves with azimuth encoding, by introducing two spherical wave factors, images can be reconstructed with only one time Fourier transform. In numerical simulation, this algorithm could simplify the reconstruction process and improve the signal-to-noise ratio of the reconstructed images. In single-frame reconstruction experiments, the accurate reconstructed image is obtained with this simplified algorithm

  3. 3D Reconstruction of NMR Images

    Directory of Open Access Journals (Sweden)

    Peter Izak

    2007-01-01

    Full Text Available This paper introduces experiment of 3D reconstruction NMR images scanned from magnetic resonance device. There are described methods which can be used for 3D reconstruction magnetic resonance images in biomedical application. The main idea is based on marching cubes algorithm. For this task was chosen sophistication method by program Vision Assistant, which is a part of program LabVIEW.

  4. RADON reconstruction in longitudinal phase space

    International Nuclear Information System (INIS)

    Mane, V.; Peggs, S.; Wei, J.

    1997-01-01

    Longitudinal particle motion in circular accelerators is typically monitoring by one dimensional (1-D) profiles. Adiabatic particle motion in two dimensional (2-D) phase space can be reconstructed with tomographic techniques, using 1-D profiles. A computer program RADON has been developed in C++ to process digitized mountain range data and perform the phase space reconstruction for the AGS, and later for Relativistic Heavy Ion Collider (RHIC)

  5. Sparse BLIP: BLind Iterative Parallel imaging reconstruction using compressed sensing.

    Science.gov (United States)

    She, Huajun; Chen, Rong-Rong; Liang, Dong; DiBella, Edward V R; Ying, Leslie

    2014-02-01

    To develop a sensitivity-based parallel imaging reconstruction method to reconstruct iteratively both the coil sensitivities and MR image simultaneously based on their prior information. Parallel magnetic resonance imaging reconstruction problem can be formulated as a multichannel sampling problem where solutions are sought analytically. However, the channel functions given by the coil sensitivities in parallel imaging are not known exactly and the estimation error usually leads to artifacts. In this study, we propose a new reconstruction algorithm, termed Sparse BLind Iterative Parallel, for blind iterative parallel imaging reconstruction using compressed sensing. The proposed algorithm reconstructs both the sensitivity functions and the image simultaneously from undersampled data. It enforces the sparseness constraint in the image as done in compressed sensing, but is different from compressed sensing in that the sensing matrix is unknown and additional constraint is enforced on the sensitivities as well. Both phantom and in vivo imaging experiments were carried out with retrospective undersampling to evaluate the performance of the proposed method. Experiments show improvement in Sparse BLind Iterative Parallel reconstruction when compared with Sparse SENSE, JSENSE, IRGN-TV, and L1-SPIRiT reconstructions with the same number of measurements. The proposed Sparse BLind Iterative Parallel algorithm reduces the reconstruction errors when compared to the state-of-the-art parallel imaging methods. Copyright © 2013 Wiley Periodicals, Inc.

  6. General surface reconstruction for cone-beam multislice spiral computed tomography

    International Nuclear Information System (INIS)

    Chen Laigao; Liang Yun; Heuscher, Dominic J.

    2003-01-01

    A new family of cone-beam reconstruction algorithm, the General Surface Reconstruction (GSR), is proposed and formulated in this paper for multislice spiral computed tomography (CT) reconstructions. It provides a general framework to allow the reconstruction of planar or nonplanar surfaces on a set of rebinned short-scan parallel beam projection data. An iterative surface formation method is proposed as an example to show the possibility to form nonplanar reconstruction surfaces to minimize the adverse effect between the collected cone-beam projection data and the reconstruction surfaces. The improvement in accuracy of the nonplanar surfaces over planar surfaces in the two-dimensional approximate cone-beam reconstructions is mathematically proved and demonstrated using numerical simulations. The proposed GSR algorithm is evaluated by the computer simulation of cone-beam spiral scanning geometry and various mathematical phantoms. The results demonstrate that the GSR algorithm generates much better image quality compared to conventional multislice reconstruction algorithms. For a table speed up to 100 mm per rotation, GSR demonstrates good image quality for both the low-contrast ball phantom and thorax phantom. All other performance parameters are comparable to the single-slice 180 deg. LI (linear interpolation) algorithm, which is considered the 'gold standard'. GSR also achieves high computing efficiency and good temporal resolution, making it an attractive alternative for the reconstruction of next generation multislice spiral CT data

  7. Class of reconstructed discontinuous Galerkin methods in computational fluid dynamics

    International Nuclear Information System (INIS)

    Luo, Hong; Xia, Yidong; Nourgaliev, Robert

    2011-01-01

    A class of reconstructed discontinuous Galerkin (DG) methods is presented to solve compressible flow problems on arbitrary grids. The idea is to combine the efficiency of the reconstruction methods in finite volume methods and the accuracy of the DG methods to obtain a better numerical algorithm in computational fluid dynamics. The beauty of the resulting reconstructed discontinuous Galerkin (RDG) methods is that they provide a unified formulation for both finite volume and DG methods, and contain both classical finite volume and standard DG methods as two special cases of the RDG methods, and thus allow for a direct efficiency comparison. Both Green-Gauss and least-squares reconstruction methods and a least-squares recovery method are presented to obtain a quadratic polynomial representation of the underlying linear discontinuous Galerkin solution on each cell via a so-called in-cell reconstruction process. The devised in-cell reconstruction is aimed to augment the accuracy of the discontinuous Galerkin method by increasing the order of the underlying polynomial solution. These three reconstructed discontinuous Galerkin methods are used to compute a variety of compressible flow problems on arbitrary meshes to assess their accuracy. The numerical experiments demonstrate that all three reconstructed discontinuous Galerkin methods can significantly improve the accuracy of the underlying second-order DG method, although the least-squares reconstructed DG method provides the best performance in terms of both accuracy, efficiency, and robustness. (author)

  8. Image quality in children with low-radiation chest CT using adaptive statistical iterative reconstruction and model-based iterative reconstruction.

    Directory of Open Access Journals (Sweden)

    Jihang Sun

    Full Text Available OBJECTIVE: To evaluate noise reduction and image quality improvement in low-radiation dose chest CT images in children using adaptive statistical iterative reconstruction (ASIR and a full model-based iterative reconstruction (MBIR algorithm. METHODS: Forty-five children (age ranging from 28 days to 6 years, median of 1.8 years who received low-dose chest CT scans were included. Age-dependent noise index (NI was used for acquisition. Images were retrospectively reconstructed using three methods: MBIR, 60% of ASIR and 40% of conventional filtered back-projection (FBP, and FBP. The subjective quality of the images was independently evaluated by two radiologists. Objective noises in the left ventricle (LV, muscle, fat, descending aorta and lung field at the layer with the largest cross-section area of LV were measured, with the region of interest about one fourth to half of the area of descending aorta. Optimized signal-to-noise ratio (SNR was calculated. RESULT: In terms of subjective quality, MBIR images were significantly better than ASIR and FBP in image noise and visibility of tiny structures, but blurred edges were observed. In terms of objective noise, MBIR and ASIR reconstruction decreased the image noise by 55.2% and 31.8%, respectively, for LV compared with FBP. Similarly, MBIR and ASIR reconstruction increased the SNR by 124.0% and 46.2%, respectively, compared with FBP. CONCLUSION: Compared with FBP and ASIR, overall image quality and noise reduction were significantly improved by MBIR. MBIR image could reconstruct eligible chest CT images in children with lower radiation dose.

  9. A Survey of Urban Reconstruction

    KAUST Repository

    Musialski, P.

    2013-05-10

    This paper provides a comprehensive overview of urban reconstruction. While there exists a considerable body of literature, this topic is still under active research. The work reviewed in this survey stems from the following three research communities: computer graphics, computer vision and photogrammetry and remote sensing. Our goal is to provide a survey that will help researchers to better position their own work in the context of existing solutions, and to help newcomers and practitioners in computer graphics to quickly gain an overview of this vast field. Further, we would like to bring the mentioned research communities to even more interdisciplinary work, since the reconstruction problem itself is by far not solved. This paper provides a comprehensive overview of urban reconstruction. While there exists a considerable body of literature, this topic is still under active research. The work reviewed in this survey stems from the following three research communities: computer graphics, computer vision and photogrammetry and remote sensing. Our goal is to provide a survey that will help researchers to better position their own work in the context of existing solutions, and to help newcomers and practitioners in computer graphics to quickly gain an overview of this vast field. Further, we would like to bring the mentioned research communities to even more interdisciplinary work, since the reconstruction problem itself is by far not solved. © 2013 The Eurographics Association and John Wiley & Sons Ltd.

  10. A Survey of Urban Reconstruction

    KAUST Repository

    Musialski, P.; Wonka, Peter; Aliaga, D. G.; Wimmer, M.; van Gool, L.; Purgathofer, W.

    2013-01-01

    This paper provides a comprehensive overview of urban reconstruction. While there exists a considerable body of literature, this topic is still under active research. The work reviewed in this survey stems from the following three research communities: computer graphics, computer vision and photogrammetry and remote sensing. Our goal is to provide a survey that will help researchers to better position their own work in the context of existing solutions, and to help newcomers and practitioners in computer graphics to quickly gain an overview of this vast field. Further, we would like to bring the mentioned research communities to even more interdisciplinary work, since the reconstruction problem itself is by far not solved. This paper provides a comprehensive overview of urban reconstruction. While there exists a considerable body of literature, this topic is still under active research. The work reviewed in this survey stems from the following three research communities: computer graphics, computer vision and photogrammetry and remote sensing. Our goal is to provide a survey that will help researchers to better position their own work in the context of existing solutions, and to help newcomers and practitioners in computer graphics to quickly gain an overview of this vast field. Further, we would like to bring the mentioned research communities to even more interdisciplinary work, since the reconstruction problem itself is by far not solved. © 2013 The Eurographics Association and John Wiley & Sons Ltd.

  11. Use of the Anterolateral Thigh in Cranio-Orbitofacial Reconstruction

    Directory of Open Access Journals (Sweden)

    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.

  12. Silicon and Germanium (111) Surface Reconstruction

    Science.gov (United States)

    Hao, You Gong

    Silicon (111) surface (7 x 7) reconstruction has been a long standing puzzle. For the last twenty years, various models were put forward to explain this reconstruction, but so far the problem still remains unsolved. Recent ion scattering and channeling (ISC), scanning tunneling microscopy (STM) and transmission electron diffraction (TED) experiments reveal some new results about the surface which greatly help investigators to establish better models. This work proposes a silicon (111) surface reconstruction mechanism, the raising and lowering mechanism which leads to benzene -like ring and flower (raised atom) building units. Based on these building units a (7 x 7) model is proposed, which is capable of explaining the STM and ISC experiment and several others. Furthermore the building units of the model can be used naturally to account for the germanium (111) surface c(2 x 8) reconstruction and other observed structures including (2 x 2), (5 x 5) and (7 x 7) for germanium as well as the (/3 x /3)R30 and (/19 x /19)R23.5 impurity induced structures for silicon, and the higher temperature disordered (1 x 1) structure for silicon. The model is closely related to the silicon (111) surface (2 x 1) reconstruction pi-bonded chain model, which is the most successful model for the reconstruction now. This provides an explanation for the rather low conversion temperature (560K) of the (2 x 1) to the (7 x 7). The model seems to meet some problems in the explanation of the TED result, which is explained very well by the dimer, adatom and stacking fault (DAS) model proposed by Takayanagi. In order to explain the TED result, a variation of the atomic scattering factor is proposed. Comparing the benzene-like ring model with the DAS model, the former needs more work to explain the TED result and the later has to find a way to explain the silicon (111) surface (1 x 1) disorder experiment.

  13. Spectral reconstruction for shifted-excitation Raman difference spectroscopy (SERDS).

    Science.gov (United States)

    Guo, Shuxia; Chernavskaia, Olga; Popp, Jürgen; Bocklitz, Thomas

    2018-08-15

    Fluorescence emission is one of the major obstacles to apply Raman spectroscopy in biological investigations. It is usually several orders more intense than Raman scattering and hampers further analysis. In cases where the fluorescence emission is too intense to be efficiently removed via routine mathematical baseline correction algorithms, an alternative approach is needed. One alternative approach is shifted-excitation Raman difference spectroscopy (SERDS), where two Raman spectra are recorded with two slightly different excitation wavelengths. Ideally, the fluorescence emission at the two excitations does not change while the Raman spectrum shifts according to the excitation wavelength. Hence the fluorescence is removed in the difference of the two recorded Raman spectra. For better interpretability a spectral reconstruction procedure is necessary to recover the fluorescence-free Raman spectrum. This is challenging due to the intensity variations between the two recorded Raman spectra caused by unavoidable experimental changes as well as the presence of noise. Existent approaches suffer from drawbacks like spectral resolution loss, fluorescence residual, and artefacts. In this contribution, we proposed a reconstruction method based on non-negative least squares (NNLS), where the intensity variations between the two measurements are utilized in the reconstruction model. The method achieved fluorescence-free reconstruction on three real-world SERDS datasets without significant information loss. Thereafter, we quantified the performance of the reconstruction based on artificial datasets from four aspects: reconstructed spectral resolution, precision of reconstruction, signal-to-noise-ratio (SNR), and fluorescence residual. The artificial datasets were constructed with varied Raman to fluorescence intensity ratio (RFIR), SNR, full-width at half-maximum (FWHM), excitation wavelength shift, and fluorescence variation between the two spectra. It was demonstrated that

  14. Early anterior cruciate ligament reconstruction can save meniscus without any complications

    Directory of Open Access Journals (Sweden)

    Chang-Ik Hur

    2017-01-01

    Conclusions: Early ACL reconstruction had excellent clinical results and stability as good as delayed reconstruction without the problem of knee motion, muscle power, and postural control. Moreover, early reconstruction showed the high possibility of meniscal repair. Therefore, early ACL reconstruction should be recommended.

  15. 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

  16. Selected event reconstruction algorithms for the CBM experiment at FAIR

    International Nuclear Information System (INIS)

    Lebedev, Semen; Höhne, Claudia; Lebedev, Andrey; Ososkov, Gennady

    2014-01-01

    Development of fast and efficient event reconstruction algorithms is an important and challenging task in the Compressed Baryonic Matter (CBM) experiment at the future FAIR facility. The event reconstruction algorithms have to process terabytes of input data produced in particle collisions. In this contribution, several event reconstruction algorithms are presented. Optimization of the algorithms in the following CBM detectors are discussed: Ring Imaging Cherenkov (RICH) detector, Transition Radiation Detectors (TRD) and Muon Chamber (MUCH). The ring reconstruction algorithm in the RICH is discussed. In TRD and MUCH track reconstruction algorithms are based on track following and Kalman Filter methods. All algorithms were significantly optimized to achieve maximum speed up and minimum memory consumption. Obtained results showed that a significant speed up factor for all algorithms was achieved and the reconstruction efficiency stays at high level.

  17. New weighting methods for phylogenetic tree reconstruction using multiple loci.

    Science.gov (United States)

    Misawa, Kazuharu; Tajima, Fumio

    2012-08-01

    Efficient determination of evolutionary distances is important for the correct reconstruction of phylogenetic trees. The performance of the pooled distance required for reconstructing a phylogenetic tree can be improved by applying large weights to appropriate distances for reconstructing phylogenetic trees and small weights to inappropriate distances. We developed two weighting methods, the modified Tajima-Takezaki method and the modified least-squares method, for reconstructing phylogenetic trees from multiple loci. By computer simulations, we found that both of the new methods were more efficient in reconstructing correct topologies than the no-weight method. Hence, we reconstructed hominoid phylogenetic trees from mitochondrial DNA using our new methods, and found that the levels of bootstrap support were significantly increased by the modified Tajima-Takezaki and by the modified least-squares method.

  18. Urgent reconstruction and re-equipping of coking plants

    Energy Technology Data Exchange (ETDEWEB)

    Kvitkin, I.A.; Martynenko, V.M.; Rozenfel' d, M.S.; Svyatogorov, A.A.; Shvartsman, I.G.

    1986-03-01

    This paper discusses the various options involved: complete or partial reconstruction of existing buildings and equipment or new construction with new equipment and new underground and surface communications. It explains that reconstruction work is divided into three phases: initial phase (clearance, dismantling, closing down coking batteries); basic phase (fitting heat-resistant materials, prestart-up assembly work); final phase (drying out, heating up, adjustments, start-up). A structured scheme for a typical initial phase is described and a method of calculating the durations of the various phases is discussed. Conclusion is that there is an urgent requirement for a document to be produced for the control of reconstruction work; it should contain standard durations and could serve as a standard for coking plant reconstruction work.

  19. Energy reconstruction in the long-baseline neutrino experiment.

    Science.gov (United States)

    Mosel, U; Lalakulich, O; Gallmeister, K

    2014-04-18

    The Long-Baseline Neutrino Experiment aims at measuring fundamental physical parameters to high precision and exploring physics beyond the standard model. Nuclear targets introduce complications towards that aim. We investigate the uncertainties in the energy reconstruction, based on quasielastic scattering relations, due to nuclear effects. The reconstructed event distributions as a function of energy tend to be smeared out and shifted by several 100 MeV in their oscillatory structure if standard event selection is used. We show that a more restrictive experimental event selection offers the possibility to reach the accuracy needed for a determination of the mass ordering and the CP-violating phase. Quasielastic-based energy reconstruction could thus be a viable alternative to the calorimetric reconstruction also at higher energies.

  20. Cosmological reconstruction of realistic modified F(R) gravities

    International Nuclear Information System (INIS)

    Nojiri, Shin'ichi; Odintsov, Sergei D.; Saez-Gomez, Diego

    2009-01-01

    The cosmological reconstruction scheme for modified F(R) gravity is developed in terms of e-folding (or, redshift). It is demonstrated how any FRW cosmology may emerge from specific F(R) theory. The specific examples of well-known cosmological evolution are reconstructed, including ΛCDM cosmology, deceleration with transition to phantom superacceleration era which may develop singularity or be transient. The application of this scheme to viable F(R) gravities unifying inflation with dark energy era is proposed. The additional reconstruction of such models leads to non-leading gravitational correction mainly relevant at the early/late universe and helping to pass the cosmological bounds (if necessary). It is also shown how cosmological reconstruction scheme may be generalized in the presence of scalar field.

  1. Superiority of CT imaging reconstruction on Linux OS

    International Nuclear Information System (INIS)

    Lin Shaochun; Yan Xufeng; Wu Tengfang; Luo Xiaomei; Cai Huasong

    2010-01-01

    Objective: To compare the speed of CT reconstruction using the Linux and Windows OS. Methods: Shepp-Logan head phantom in different pixel size was projected to obtain the sinogram by using the inverse Fourier transformation, filtered back projection and Radon transformation on both Linux and Windows OS. Results: CT image reconstruction using the Linux operating system was significantly better and more efficient than Windows. Conclusion: CT image reconstruction using the Linux operating system is more efficient. (authors)

  2. Research of ART method in CT image reconstruction

    International Nuclear Information System (INIS)

    Li Zhipeng; Cong Peng; Wu Haifeng

    2005-01-01

    This paper studied Algebraic Reconstruction Technique (ART) in CT image reconstruction. Discussed the ray number influence on image quality. And the adopting of smooth method got high quality CT image. (authors)

  3. 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

  4. Parallel Algorithm for Reconstruction of TAC Images

    International Nuclear Information System (INIS)

    Vidal Gimeno, V.

    2012-01-01

    The algebraic reconstruction methods are based on solving a system of linear equations. In a previous study, was used and showed as the PETSc library, was and is a scientific computing tool, which facilitates and enables the optimal use of a computer system in the image reconstruction process.

  5. Trends in breast reconstruction: Implications for the National Health Insurance Service

    Directory of Open Access Journals (Sweden)

    Ki Yong Hong

    2018-05-01

    Full Text Available Background Breast reconstruction has become more common as mastectomy has become more frequent. In Korea, the National Health Insurance Service (NHIS began covering breast reconstruction in April 2015. This study aimed to investigate trends in mastectomy and breast reconstruction over the past 10 years and to evaluate the impact of NHIS coverage on breast reconstruction. Methods Nationwide data regarding mastectomy and breast reconstruction were collected from the Korean Breast Cancer Society registry database. Multiple variables were analyzed in the records of patients who underwent breast reconstruction from January 2005 to March 2017 at a single institution. Results At Seoul National University Hospital, the total number of reconstruction cases increased 13-fold from 2005 to 2016. The proportion of immediate breast reconstruction (IBR cases out of all cases of total mastectomy increased from 4% in 2005 to 52.0% in 2016. The proportion of delayed breast reconstruction (DBR cases out of all cases of breast reconstruction and the overall number of DBR cases increased from 8.8% (20 cases in 2012 to 18.3% (76 cases in 2016. After NHIS coverage was initiated, the proportions of IBR and DBR showed statistically significant increases (P<0.05. Among the IBR cases, the percentage of prosthesis-based reconstructions increased significantly (P<0.05, but this trend was not found with DBR. Total mastectomy became significantly more common after the expansion of NHIS coverage (P<0.05. Conclusions Over the last decade, there has been an increase in mastectomy and breast reconstruction, and the pace of increase accelerated after the expansion of NHIS coverage. It is expected that breast reconstruction will be a routine option for patients with breast cancer under the NHIS.

  6. Quantum interferences reconstruction with low homodyne detection efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, Martina; Randi, Francesco [Universita degli studi di Trieste, Dipartimento di Fisica, Trieste (Italy); Titimbo, Kelvin; Zimmermann, Klaus; Benatti, Fabio [Universita degli studi di Trieste, Dipartimento di Fisica, Trieste (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Trieste (Italy); Kourousias, Georgios; Curri, Alessio [Sincrotrone Trieste S.C.p.A., Trieste (Italy); Floreanini, Roberto [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Trieste (Italy); Parmigiani, Fulvio [Universita degli studi di Trieste, Dipartimento di Fisica, Trieste (Italy); Sincrotrone Trieste S.C.p.A., Trieste (Italy); University of Cologne, Institute of Physics II, Cologne (Germany); Fausti, Daniele [Universita degli studi di Trieste, Dipartimento di Fisica, Trieste (Italy); Sincrotrone Trieste S.C.p.A., Trieste (Italy)

    2016-12-15

    Optical homodyne tomography consists in reconstructing the quantum state of an optical field from repeated measurements of its amplitude at different field phases (homodyne data). The experimental noise, which unavoidably affects the homodyne data, leads to a detection efficiency η<1. The problem of reconstructing quantum states from noisy homodyne data sets prompted an intense scientific debate about the presence or absence of a lower homodyne efficiency bound (η>0.5) below which quantum features, like quantum interferences, cannot be retrieved. Here, by numerical experiments, we demonstrate that quantum interferences can be effectively reconstructed also for low homodyne detection efficiency. In particular, we address the challenging case of a Schroedinger cat state and test the minimax and adaptive Wigner function reconstruction technique by processing homodyne data distributed according to the chosen state but with an efficiency η>0.5. By numerically reproducing the Schroedinger's cat interference pattern, we give evidence that quantum state reconstruction is actually possible in these conditions, and provide a guideline for handling optical tomography based on homodyne data collected by low efficiency detectors. (orig.)

  7. Time-Dependent-Asymmetric-Linear-Parsimonious Ancestral State Reconstruction.

    Science.gov (United States)

    Didier, Gilles

    2017-10-01

    The time-dependent-asymmetric-linear parsimony is an ancestral state reconstruction method which extends the standard linear parsimony (a.k.a. Wagner parsimony) approach by taking into account both branch lengths and asymmetric evolutionary costs for reconstructing quantitative characters (asymmetric costs amount to assuming an evolutionary trend toward the direction with the lowest cost). A formal study of the influence of the asymmetry parameter shows that the time-dependent-asymmetric-linear parsimony infers states which are all taken among the known states, except for some degenerate cases corresponding to special values of the asymmetry parameter. This remarkable property holds in particular for the Wagner parsimony. This study leads to a polynomial algorithm which determines, and provides a compact representation of, the parametric reconstruction of a phylogenetic tree, that is for all the unknown nodes, the set of all the possible reconstructed states associated with the asymmetry parameters leading to them. The time-dependent-asymmetric-linear parsimony is finally illustrated with the parametric reconstruction of the body size of cetaceans.

  8. Robot-Assisted Free Flap in Head and Neck Reconstruction

    Directory of Open Access Journals (Sweden)

    Han Gyeol Song

    2013-07-01

    Full Text Available BackgroundRobots have allowed head and neck surgeons to extirpate oropharyngeal tumors safely without the need for lip-split incision or mandibulotomy. Using robots in oropharyngeal reconstruction is new but essential for oropharyngeal defects that result from robotic tumor excision. We report our experience with robotic free-flap reconstruction of head and neck defects to exemplify the necessity for robotic reconstruction.MethodsWe investigated head and neck cancer patients who underwent ablation surgery and free-flap reconstruction by robot. Between July 1, 2011 and March 31, 2012, 5 cases were performed and patient demographics, location of tumor, pathologic stage, reconstruction methods, flap size, recipient vessel, necessary pedicle length, and operation time were investigated.ResultsAmong five free-flap reconstructions, four were radial forearm free flaps and one was an anterolateral thigh free-flap. Four flaps used the superior thyroid artery and one flap used a facial artery as the recipient vessel. The average pedicle length was 8.8 cm. Flap insetting and microanastomosis were achieved using a specially manufactured robotic instrument. The total operation time was 1,041.0 minutes (range, 814 to 1,132 minutes, and complications including flap necrosis, hematoma, and wound dehiscence did not occur.ConclusionsThis study demonstrates the clinically applicable use of robots in oropharyngeal reconstruction, especially using a free flap. A robot can assist the operator in insetting the flap at a deep portion of the oropharynx without the need to perform a traditional mandibulotomy. Robot-assisted reconstruction may substitute for existing surgical methods and is accepted as the most up-to-date method.

  9. Enhancing Tomo-PIV reconstruction quality by reducing ghost particles

    International Nuclear Information System (INIS)

    De Silva, C M; Baidya, R; Marusic, I

    2013-01-01

    A technique to enhance the reconstruction quality and consequently the accuracy of the velocity vector field obtained in Tomo-PIV experiments is presented here. The methodology involves detecting and eliminating spurious outliers in the reconstructed intensity field (ghost particles). A simulacrum matching-based reconstruction enhancement (SMRE) technique is proposed, which utilizes the characteristic shape and size of actual particles to remove ghost particles in the reconstructed intensity field. An assessment of SMRE is performed by a quantitative comparison of Tomo-PIV simulation results and DNS data, together with a comparison to Tomo-PIV experimental data measured in a turbulent channel flow at a matched Reynolds number (Re τ = 937) to the DNS study. For the simulation data, a comparative study is performed on the reconstruction quality based on an ideal reconstruction determined from known particle positions. The results suggest that a significant improvement in the reconstruction quality and flow statistics is achievable at typical seeding densities used in Tomo-PIV experiments. This improvement is further amplified at higher seeding densities, enabling the use of up to twice the typical seeding densities currently used in Tomo-PIV experiments. A reduction of spurious vectors present in the velocity field is also observed based on a median outlier detection criterion. The application of SMRE to Tomo-PIV experimental data shows an improvement in flow statistics, comparable to the improvement seen in simulations. Finally, due to the non-iterative nature of SMRE, the increase in processing time is marginal since only a single pass of the reconstruction algorithm is required. (paper)

  10. A protocol for generating a high-quality genome-scale metabolic reconstruction.

    Science.gov (United States)

    Thiele, Ines; Palsson, Bernhard Ø

    2010-01-01

    Network reconstructions are a common denominator in systems biology. Bottom-up metabolic network reconstructions have been developed over the last 10 years. These reconstructions represent structured knowledge bases that abstract pertinent information on the biochemical transformations taking place within specific target organisms. The conversion of a reconstruction into a mathematical format facilitates a myriad of computational biological studies, including evaluation of network content, hypothesis testing and generation, analysis of phenotypic characteristics and metabolic engineering. To date, genome-scale metabolic reconstructions for more than 30 organisms have been published and this number is expected to increase rapidly. However, these reconstructions differ in quality and coverage that may minimize their predictive potential and use as knowledge bases. Here we present a comprehensive protocol describing each step necessary to build a high-quality genome-scale metabolic reconstruction, as well as the common trials and tribulations. Therefore, this protocol provides a helpful manual for all stages of the reconstruction process.

  11. Software Architecture Reconstruction Method, a Survey

    OpenAIRE

    Zainab Nayyar; Nazish Rafique

    2014-01-01

    Architecture reconstruction belongs to a reverse engineering process, in which we move from code to architecture level for reconstructing architecture. Software architectures are the blue prints of projects which depict the external overview of the software system. Mostly maintenance and testing cause the software to deviate from its original architecture, because sometimes for enhancing the functionality of a system the software deviates from its documented specifications, some new modules a...

  12. Patellofemoral Pressure Changes After Static and Dynamic Medial Patellofemoral Ligament Reconstructions.

    Science.gov (United States)

    Rood, Akkie; Hannink, Gerjon; Lenting, Anke; Groenen, Karlijn; Koëter, Sander; Verdonschot, Nico; van Kampen, Albert

    2015-10-01

    Reconstructing the medial patellofemoral ligament (MPFL) has become a key procedure for stabilizing the patella. Different techniques to reconstruct the MPFL have been described: static techniques in which the graft is fixed rigidly to the bone or dynamic techniques with soft tissue fixation. Static MPFL reconstruction is most commonly used. However, dynamic reconstruction deforms more easily and presumably functions more like the native MPFL. The aim of the study was to evaluate the effect of the different MPFL fixation techniques on patellofemoral pressures compared with the native situation. The hypothesis was that dynamic reconstruction would result in patellofemoral pressures closer to those generated in an intact knee. Controlled laboratory study. Seven fresh-frozen knee specimens were tested in an in vitro knee joint loading apparatus. Tekscan pressure-sensitive films fixed to the retropatellar cartilage measured mean patellofemoral and peak pressures, contact area, and location of the center of force (COF) at fixed flexion angles from 0° to 110°. Four different conditions were tested: intact, dynamic, partial dynamic, and static MPFL reconstruction. Data were analyzed using linear mixed models. Static MPFL reconstruction resulted in higher peak and mean pressures from 60° to 110° of flexion (P .05). The COF in the static reconstruction group moved more medially on the patella from 50° to 110° of flexion compared with the other conditions. The contact area showed no significant differences between the test conditions. After static MPFL reconstruction, the patellofemoral pressures in flexion angles from 60° to 110° were 3 to 5 times higher than those in the intact situation. The pressures after dynamic MPFL reconstruction were similar as compared with those in the intact situation, and therefore, dynamic MPFL reconstruction could be a safer option than static reconstruction for stabilizing the patella. This study showed that static MPFL reconstruction

  13. Fast Dictionary-Based Reconstruction for Diffusion Spectrum Imaging

    Science.gov (United States)

    Bilgic, Berkin; Chatnuntawech, Itthi; Setsompop, Kawin; Cauley, Stephen F.; Yendiki, Anastasia; Wald, Lawrence L.; Adalsteinsson, Elfar

    2015-01-01

    Diffusion Spectrum Imaging (DSI) reveals detailed local diffusion properties at the expense of substantially long imaging times. It is possible to accelerate acquisition by undersampling in q-space, followed by image reconstruction that exploits prior knowledge on the diffusion probability density functions (pdfs). Previously proposed methods impose this prior in the form of sparsity under wavelet and total variation (TV) transforms, or under adaptive dictionaries that are trained on example datasets to maximize the sparsity of the representation. These compressed sensing (CS) methods require full-brain processing times on the order of hours using Matlab running on a workstation. This work presents two dictionary-based reconstruction techniques that use analytical solutions, and are two orders of magnitude faster than the previously proposed dictionary-based CS approach. The first method generates a dictionary from the training data using Principal Component Analysis (PCA), and performs the reconstruction in the PCA space. The second proposed method applies reconstruction using pseudoinverse with Tikhonov regularization with respect to a dictionary. This dictionary can either be obtained using the K-SVD algorithm, or it can simply be the training dataset of pdfs without any training. All of the proposed methods achieve reconstruction times on the order of seconds per imaging slice, and have reconstruction quality comparable to that of dictionary-based CS algorithm. PMID:23846466

  14. Higher order total variation regularization for EIT reconstruction.

    Science.gov (United States)

    Gong, Bo; Schullcke, Benjamin; Krueger-Ziolek, Sabine; Zhang, Fan; Mueller-Lisse, Ullrich; Moeller, Knut

    2018-01-08

    Electrical impedance tomography (EIT) attempts to reveal the conductivity distribution of a domain based on the electrical boundary condition. This is an ill-posed inverse problem; its solution is very unstable. Total variation (TV) regularization is one of the techniques commonly employed to stabilize reconstructions. However, it is well known that TV regularization induces staircase effects, which are not realistic in clinical applications. To reduce such artifacts, modified TV regularization terms considering a higher order differential operator were developed in several previous studies. One of them is called total generalized variation (TGV) regularization. TGV regularization has been successively applied in image processing in a regular grid context. In this study, we adapted TGV regularization to the finite element model (FEM) framework for EIT reconstruction. Reconstructions using simulation and clinical data were performed. First results indicate that, in comparison to TV regularization, TGV regularization promotes more realistic images. Graphical abstract Reconstructed conductivity changes located on selected vertical lines. For each of the reconstructed images as well as the ground truth image, conductivity changes located along the selected left and right vertical lines are plotted. In these plots, the notation GT in the legend stands for ground truth, TV stands for total variation method, and TGV stands for total generalized variation method. Reconstructed conductivity distributions from the GREIT algorithm are also demonstrated.

  15. Defining the Role of Free Flaps in Partial Breast Reconstruction.

    Science.gov (United States)

    Smith, Mark L; Molina, Bianca J; Dayan, Erez; Jablonka, Eric M; Okwali, Michelle; Kim, Julie N; Dayan, Joseph H

    2018-03-01

     Free flaps have a well-established role in breast reconstruction after mastectomy; however, their role in partial breast reconstruction remains poorly defined. We reviewed our experience with partial breast reconstruction to better understand indications for free tissue transfer.  A retrospective review was performed of all patients undergoing partial breast reconstruction at our center between February 2009 and October 2015. We evaluated the characteristics of patients who underwent volume displacement procedures versus volume replacement procedures and free versus pedicled flap reconstruction.  There were 78 partial breast reconstructions, with 52 reductions/tissue rearrangements (displacement group) and 26 flaps (replacement group). Bra cup size and body mass index (BMI) were significantly smaller in the replacement group. Fifteen pedicled and 11 free flaps were performed. Most pedicled flaps (80.0%) were used for lateral or upper pole defects. Most free flaps (72.7%) were used for medial and inferior defects or when there was inadequate donor tissue for a pedicled flap. Complications included hematoma, cellulitis, and one aborted pedicled flap.  Free and pedicled flaps are useful for partial breast reconstruction, particularly in breast cancer patients with small breasts undergoing breast-conserving treatment (BCT). Flap selection depends on defect size, location, and donor tissue availability. Medial defects are difficult to reconstruct using pedicled flaps due to arc of rotation and intervening breast tissue. Free tissue transfer can overcome these obstacles. Confirming negative margins before flap reconstruction ensures harvest of adequate volume and avoids later re-operation. Judicious use of free flaps for oncoplastic reconstruction expands the possibility for breast conservation. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  16. [ARTHROSCOPIC STUDY OF REMNANT-PRESERVED RECONSTRUCTION OF ANTERIOR CRUCIATE LIGAMENT].

    Science.gov (United States)

    Lu, Daifeng; Xiao, Mochao; Zhang, Yunpeng; Yan, Shi; Dong, Feng; Lian, Yongyun

    2015-08-01

    To investigate the value of ligament remnant preservation during anterior cruciate ligament (ACL) reconstruction by observing the integrity, the tension, the synovial membrane covering, and the color of the reconstructed ligament under arthroscopy. Between January 2011 and December 2013, 122 patients who underwent ACL reconstruction and arthroscopic internal fixation removal at 1 year after reconstruction were included in this study. Of these cases, 61 cases underwent ACL reconstruction using the remnant-preserved technique (preservation group); the other 61 cases underwent ACL reconstruction using non remnant-preserved technique (non preservation group). There was no significant difference in gender, age, injury side, body mass index, type of injury, the time from injury to reconstruction, and the result of KT-2000 examination between 2 groups (P > 0.05). The reconstructed ACL were observed under arthroscopy when internal fixation was removed, and the effectiveness was evaluated according to the criteria of AO Yingfang. In preservation group, the results were excellent in 34 cases, good in 22 cases, fair in 4 cases, and poor in 1 case; and in non preservation group, the results were excellent in 29 cases, good in 20 cases, fair in 10 cases, and poor in 2 cases; and there was no significant difference between 2 groups (Z= -1.320, P=0.187). In ACL reconstruction, the remnant-preserved technique is not obviously better than non remnant-preserved technique in the integrity, tension, membrane covering, and color.

  17. Accuracy improvement of CT reconstruction using tree-structured filter bank

    International Nuclear Information System (INIS)

    Ueda, Kazuhiro; Morimoto, Hiroaki; Morikawa, Yoshitaka; Murakami, Junichi

    2009-01-01

    Accuracy improvement of 'CT reconstruction algorithm using TSFB (Tree-Structured Filter Bank)' that is high-speed CT reconstruction algorithm, was proposed. TSFB method could largely reduce the amount of computation in comparison with the CB (Convolution Backprojection) method, but it was the problem that an artifact occurred in a reconstruction image since reconstruction was performed with disregard to a signal out of the reconstruction domain in stage processing. Also the whole band filter being the component of a two-dimensional synthesis filter was IIR filter and then an artifact occurred at the end of the reconstruction image. In order to suppress these artifacts the proposed method enlarged the processing range by the TSFB method in the domain outside by the width control of the specimen line and line addition to the reconstruction domain outside. And, furthermore, to avoid increase of the amount of computation, the algorithm was proposed such as to decide the needed processing range depending on the number of steps processing with the TSFB and the degree of incline of filter, and then update the position and width of the specimen line to process the needed range. According to the simulation to realize a high-speed and highly accurate CT reconstruction in this way, the quality of the reconstruction image of the proposed method was improved in comparison with the TSFB method and got the same result with the CB method. (T. Tanaka)

  18. Reconstruction after complex facial trauma: achieving optimal outcome through multiple contemporary surgeries.

    Science.gov (United States)

    Jaiswal, Rohit; Pu, Lee L Q

    2013-04-01

    Major facial trauma injuries often require complex repair. Traditionally, the reconstruction of such injuries has primarily utilized only free tissue transfer. However, the advent of newer, contemporary procedures may lead to potential reconstructive improvement through the use of complementary procedures after free flap reconstruction. An 18-year-old male patient suffered a major left facial degloving injury resulting in soft-tissue defect with exposed zygoma, and parietal bone. Multiple operations were undertaken in a staged manner for reconstruction. A state-of-the-art free anterolateral thigh (ALT) perforator flap and Medpor implant reconstruction of the midface were initially performed, followed by flap debulking, lateral canthopexy, midface lift with redo canthopexy, scalp tissue expansion for hairline reconstruction, and epidermal skin grafting for optimal skin color matching. Over a follow-up period of 2 years, a good and impressive reconstructive result was achieved through the use of multiple contemporary reconstructive procedures following an excellent free ALT flap reconstruction. Multiple staged reconstructions are essential in producing an optimal outcome in this complex facial injury that would likely not have been produced through a 1-stage traditional free flap reconstruction. Utilizing multiple, sequential contemporary surgeries may substantially improve outcome through the enhancement and refinement of results based on possibly the best initial soft-tissue reconstruction.

  19. Biologic collagen cylinder with skate flap technique for nipple reconstruction.

    Science.gov (United States)

    Tierney, Brian P; Hodde, Jason P; Changkuon, Daniela I

    2014-01-01

    A surgical technique using local tissue skate flaps combined with cylinders made from a naturally derived biomaterial has been used effectively for nipple reconstruction. A retrospective review of patients who underwent nipple reconstruction using this technique was performed. Comorbidities and type of breast reconstruction were collected. Outcome evaluation included complications, surgical revisions, and nipple projection. There were 115 skate flap reconstructions performed in 83 patients between July 2009 and January 2013. Patients ranged from 32 to 73 years old. Average body mass index was 28.0. The most common comorbidities were hypertension (39.8%) and smoking (16.9%). After breast reconstruction, 68.7% of the patients underwent chemotherapy and 20.5% underwent radiation. Seventy-one patients had immediate breast reconstruction with expanders and 12 had delayed reconstruction. The only reported complications were extrusions (3.5%). Six nipples (5.2%) in 5 patients required surgical revision due to loss of projection; two patients had minor loss of projection but did not require surgical revision. Nipple projection at time of surgery ranged from 6 to 7 mm and average projection at 6 months was 3-5 mm. A surgical technique for nipple reconstruction using a skate flap with a graft material is described. Complications are infrequent and short-term projection measurements are encouraging.

  20. ["Long-branch Attraction" artifact in phylogenetic reconstruction].

    Science.gov (United States)

    Li, Yi-Wei; Yu, Li; Zhang, Ya-Ping

    2007-06-01

    Phylogenetic reconstruction among various organisms not only helps understand their evolutionary history but also reveal several fundamental evolutionary questions. Understanding of the evolutionary relationships among organisms establishes the foundation for the investigations of other biological disciplines. However, almost all the widely used phylogenetic methods have limitations which fail to eliminate systematic errors effectively, preventing the reconstruction of true organismal relationships. "Long-branch Attraction" (LBA) artifact is one of the most disturbing factors in phylogenetic reconstruction. In this review, the conception and analytic method as well as the avoidance strategy of LBA were summarized. In addition, several typical examples were provided. The approach to avoid and resolve LBA artifact has been discussed.

  1. Simbol-X Formation Flight and Image Reconstruction

    Science.gov (United States)

    Civitani, M.; Djalal, S.; Le Duigou, J. M.; La Marle, O.; Chipaux, R.

    2009-05-01

    Simbol-X is the first operational mission relying on two satellites flying in formation. The dynamics of the telescope, due to the formation flight concept, raises a variety of problematic, like image reconstruction, that can be better evaluated via a simulation tools. We present here the first results obtained with Simulos, simulation tool aimed to study the relative spacecrafts navigation and the weight of the different parameters in image reconstruction and telescope performance evaluation. The simulation relies on attitude and formation flight sensors models, formation flight dynamics and control, mirror model and focal plane model, while the image reconstruction is based on the Line of Sight (LOS) concept.

  2. Oblique reconstructions in tomosynthesis. II. Super-resolution

    International Nuclear Information System (INIS)

    Acciavatti, Raymond J.; Maidment, Andrew D. A.

    2013-01-01

    Purpose: In tomosynthesis, super-resolution has been demonstrated using reconstruction planes parallel to the detector. Super-resolution allows for subpixel resolution relative to the detector. The purpose of this work is to develop an analytical model that generalizes super-resolution to oblique reconstruction planes.Methods: In a digital tomosynthesis system, a sinusoidal test object is modeled along oblique angles (i.e., “pitches”) relative to the plane of the detector in a 3D divergent-beam acquisition geometry. To investigate the potential for super-resolution, the input frequency is specified to be greater than the alias frequency of the detector. Reconstructions are evaluated in an oblique plane along the extent of the object using simple backprojection (SBP) and filtered backprojection (FBP). By comparing the amplitude of the reconstruction against the attenuation coefficient of the object at various frequencies, the modulation transfer function (MTF) is calculated to determine whether modulation is within detectable limits for super-resolution. For experimental validation of super-resolution, a goniometry stand was used to orient a bar pattern phantom along various pitches relative to the breast support in a commercial digital breast tomosynthesis system.Results: Using theoretical modeling, it is shown that a single projection image cannot resolve a sine input whose frequency exceeds the detector alias frequency. The high frequency input is correctly visualized in SBP or FBP reconstruction using a slice along the pitch of the object. The Fourier transform of this reconstructed slice is maximized at the input frequency as proof that the object is resolved. Consistent with the theoretical results, experimental images of a bar pattern phantom showed super-resolution in oblique reconstructions. At various pitches, the highest frequency with detectable modulation was determined by visual inspection of the bar patterns. The dependency of the highest

  3. Oblique reconstructions in tomosynthesis. II. Super-resolution

    Science.gov (United States)

    Acciavatti, Raymond J.; Maidment, Andrew D. A.

    2013-01-01

    Purpose: In tomosynthesis, super-resolution has been demonstrated using reconstruction planes parallel to the detector. Super-resolution allows for subpixel resolution relative to the detector. The purpose of this work is to develop an analytical model that generalizes super-resolution to oblique reconstruction planes. Methods: In a digital tomosynthesis system, a sinusoidal test object is modeled along oblique angles (i.e., “pitches”) relative to the plane of the detector in a 3D divergent-beam acquisition geometry. To investigate the potential for super-resolution, the input frequency is specified to be greater than the alias frequency of the detector. Reconstructions are evaluated in an oblique plane along the extent of the object using simple backprojection (SBP) and filtered backprojection (FBP). By comparing the amplitude of the reconstruction against the attenuation coefficient of the object at various frequencies, the modulation transfer function (MTF) is calculated to determine whether modulation is within detectable limits for super-resolution. For experimental validation of super-resolution, a goniometry stand was used to orient a bar pattern phantom along various pitches relative to the breast support in a commercial digital breast tomosynthesis system. Results: Using theoretical modeling, it is shown that a single projection image cannot resolve a sine input whose frequency exceeds the detector alias frequency. The high frequency input is correctly visualized in SBP or FBP reconstruction using a slice along the pitch of the object. The Fourier transform of this reconstructed slice is maximized at the input frequency as proof that the object is resolved. Consistent with the theoretical results, experimental images of a bar pattern phantom showed super-resolution in oblique reconstructions. At various pitches, the highest frequency with detectable modulation was determined by visual inspection of the bar patterns. The dependency of the highest

  4. Cone-beam local reconstruction based on a Radon inversion transformation

    International Nuclear Information System (INIS)

    Wang Xian-Chao; Yan Bin; Li Lei; Hu Guo-En

    2012-01-01

    The local reconstruction from truncated projection data is one area of interest in image reconstruction for computed tomography (CT), which creates the possibility for dose reduction. In this paper, a filtered-backprojection (FBP) algorithm based on the Radon inversion transform is presented to deal with the three-dimensional (3D) local reconstruction in the circular geometry. The algorithm achieves the data filtering in two steps. The first step is the derivative of projections, which acts locally on the data and can thus be carried out accurately even in the presence of data truncation. The second step is the nonlocal Hilbert filtering. The numerical simulations and the real data reconstructions have been conducted to validate the new reconstruction algorithm. Compared with the approximate truncation resistant algorithm for computed tomography (ATRACT), not only it has a comparable ability to restrain truncation artifacts, but also its reconstruction efficiency is improved. It is about twice as fast as that of the ATRACT. Therefore, this work provides a simple and efficient approach for the approximate reconstruction from truncated projections in the circular cone-beam CT

  5. An innovative seeding technique for photon conversion reconstruction at CMS

    International Nuclear Information System (INIS)

    Giordano, D; Sguazzoni, G

    2012-01-01

    The conversion of photons into electron-positron pairs in the detector material is a nuisance in the event reconstruction of high energy physics experiments, since the measurement of the electromagnetic component of interaction products results degraded. Nonetheless this unavoidable detector effect can also be extremely useful. The reconstruction of photon conversions can be used to probe the detector material and to accurately measure soft photons that come from radiative decays in heavy flavor physics. In fact a converted photon can be measured with very high momentum resolution by exploiting the excellent reconstruction of charged tracks of a tracking detector as the one of CMS at LHC. The main issue is that photon conversion tracks are difficult to reconstruct for standard reconstruction algorithms. They are typically soft and very displaced from the primary interaction vertex. An innovative seeding technique that exploits the peculiar photon conversion topology, successfully applied in the CMS track reconstruction sequence, is presented. The performances of this technique and the substantial enhancement of photon conversion reconstruction efficiency are discussed. Application examples are given.

  6. Implant breast reconstruction after salvage mastectomy in previously irradiated patients.

    Science.gov (United States)

    Persichetti, Paolo; Cagli, Barbara; Simone, Pierfranco; Cogliandro, Annalisa; Fortunato, Lucio; Altomare, Vittorio; Trodella, Lucio

    2009-04-01

    The most common surgical approach in case of local tumor recurrence after quadrantectomy and radiotherapy is salvage mastectomy. Breast reconstruction is the subsequent phase of the treatment and the plastic surgeon has to operate on previously irradiated and manipulated tissues. The medical literature highlights that breast reconstruction with tissue expanders is not a pursuable option, considering previous radiotherapy a contraindication. The purpose of this retrospective study is to evaluate the influence of previous radiotherapy on 2-stage breast reconstruction (tissue expander/implant). Only patients with analogous timing of radiation therapy and the same demolitive and reconstructive procedures were recruited. The results of this study prove that, after salvage mastectomy in previously irradiated patients, implant reconstruction is still possible. Further comparative studies are, of course, advisable to draw any conclusion on the possibility to perform implant reconstruction in previously irradiated patients.

  7. Longitudinal and transverse digital image reconstruction with a tomographic scanner

    International Nuclear Information System (INIS)

    Pickens, D.R.; Price, R.R.; Erickson, J.J.; Patton, J.A.; Partain, C.L.; Rollo, F.D.

    1981-01-01

    A Siemens Gammasonics PHO/CON-192 Multiplane Imager is interfaced to a digital computer for the purpose of performing tomographic reconstructions from the data collected during a single scan. Data from the two moving gamma cameras as well as camera position information are sent to the computer by an interface designed in the authors' laboratory. Backprojection reconstruction is implemented by the computer. Longitudinal images in whole-body format as well as smaller formats are reconstructed for up to six planes simultaneously from the list mode data. Transverse reconstructions are demonstrated for 201 T1 myocardial scans. Post-reconstruction deconvolution processing to remove the blur artifact (characteristic of focal plane tomography) is applied to a multiplane phantom. Digital data acquisition of data and reconstruction of images are practical, and can extend the usefulness of the machine when compared with the film output (author)

  8. Attractor reconstruction for non-linear systems: a methodological note

    Science.gov (United States)

    Nichols, J.M.; Nichols, J.D.

    2001-01-01

    Attractor reconstruction is an important step in the process of making predictions for non-linear time-series and in the computation of certain invariant quantities used to characterize the dynamics of such series. The utility of computed predictions and invariant quantities is dependent on the accuracy of attractor reconstruction, which in turn is determined by the methods used in the reconstruction process. This paper suggests methods by which the delay and embedding dimension may be selected for a typical delay coordinate reconstruction. A comparison is drawn between the use of the autocorrelation function and mutual information in quantifying the delay. In addition, a false nearest neighbor (FNN) approach is used in minimizing the number of delay vectors needed. Results highlight the need for an accurate reconstruction in the computation of the Lyapunov spectrum and in prediction algorithms.

  9. Performance of the ATLAS primary vertex reconstruction algorithms

    CERN Document Server

    Zhang, Matt

    2017-01-01

    The reconstruction of primary vertices in the busy, high pile up environment of the LHC is a challenging task. The challenges and novel methods developed by the ATLAS experiment to reconstruct vertices in such environments will be presented. Such advances in vertex seeding include methods taken from medical imagining, which allow for reconstruction of very nearby vertices will be highlighted. The performance of the current vertexing algorithms using early Run-2 data will be presented and compared to results from simulation.

  10. Adaptive Statistical Iterative Reconstruction-V Versus Adaptive Statistical Iterative Reconstruction: Impact on Dose Reduction and Image Quality in Body Computed Tomography.

    Science.gov (United States)

    Gatti, Marco; Marchisio, Filippo; Fronda, Marco; Rampado, Osvaldo; Faletti, Riccardo; Bergamasco, Laura; Ropolo, Roberto; Fonio, Paolo

    The aim of this study was to evaluate the impact on dose reduction and image quality of the new iterative reconstruction technique: adaptive statistical iterative reconstruction (ASIR-V). Fifty consecutive oncologic patients acted as case controls undergoing during their follow-up a computed tomography scan both with ASIR and ASIR-V. Each study was analyzed in a double-blinded fashion by 2 radiologists. Both quantitative and qualitative analyses of image quality were conducted. Computed tomography scanner radiation output was 38% (29%-45%) lower (P ASIR-V examinations than for the ASIR ones. The quantitative image noise was significantly lower (P ASIR-V. Adaptive statistical iterative reconstruction-V had a higher performance for the subjective image noise (P = 0.01 for 5 mm and P = 0.009 for 1.25 mm), the other parameters (image sharpness, diagnostic acceptability, and overall image quality) being similar (P > 0.05). Adaptive statistical iterative reconstruction-V is a new iterative reconstruction technique that has the potential to provide image quality equal to or greater than ASIR, with a dose reduction around 40%.

  11. Reconstructions with identical filling (RIF) of the heart: a physiological approach to image reconstruction in coronary CT angiography

    International Nuclear Information System (INIS)

    Reinartz, S.D.; Diefenbach, B.S.; Kuhl, C.K.; Mahnken, A.H.; Allmendinger, T.

    2012-01-01

    To compare image quality in coronary artery computed tomography angiography (cCTA) using reconstructions with automated phase detection and Reconstructions computed with Identical Filling of the heart (RIF). Seventy-four patients underwent ECG-gated dual source CT (DSCT) between November 2009 and July 2010 for suspected coronary heart disease (n = 35), planning of transcatheter aortic valve replacement (n = 34) or evaluation of ventricular function (n = 5). Image data sets by the RIF formula and automated phase detection were computed and evaluated with the AHA 15-segment model and a 5-grade Likert scale (1: poor, 5: excellent quality). Subgroups regarding rhythm (sinus rhythm = SR; arrhythmia = ARR) and potential premedication were evaluated by a per-segment, per-vessel and per-patient analysis. RIF significantly improved image quality in 10 of 15 coronary segments (P < 0.05). More diagnostic segments were provided by RIF regarding the entire cohort (n = 693 vs. 590, P < 0.001) and all of the subgroups (e.g. ARR: n = 143 vs. 72, P < 0.001). In arrhythmic patients (n = 19), more diagnostic vessels (e.g. LAD: n = 10 vs. 3; P < 0.014) and complete data sets (n = 7 vs. 1; P < 0.001) were produced. RIF reconstruction is superior to automatic diastolic non-edited reconstructions, especially in arrhythmic patients. RIF theory provides a physiological approach for determining the optimal image reconstruction point in ECG-gated CT angiography. (orig.)

  12. Reconstructions of the sulfur-passivated InSb (100) surface

    Energy Technology Data Exchange (ETDEWEB)

    Ciochoń, Piotr, E-mail: piotr.ciochon@doctoral.uj.edu.pl; Olszowska, Natalia; Wróbel, Sonia; Kołodziej, Jacek

    2017-04-01

    Highlights: • Two new surface reconstructions of a S-passivated InSb (001) surface are reported. • The reconstructions are obtained through partial loss of surface sulfur. • They are characterized by the thickness of ∼4 Å and good crystallographic ordering. • The reconstructions provide adequate electronic passivation of the surface. - Abstract: We have studied the properties of the InSb (100) surface passivated with sulfur dimers emitted by the solid-state electrochemical cell in ultra-high vacuum. Annealing the passivated surface in the temperature equal to T = 326 °C led to the formation of the c(4 × 8) surface reconstruction, while increasing the temperature to T = 348 °C resulted in the transition to c(4 × 12) reconstruction. To the best of our knowledge these reconstructions have not been reported to date and are characterized by the exceptionally good crystallographic order. XPS studies revealed that there are at least 4 different chemical species of sulfur present on the surface and the estimated thickness of the sulfur layers is equal to around 4 Å. The surface reconstructions are characterized by the lowered intensity of the surface electronic states and resonances near the Fermi level, compared to the clean InSb surface, making them potentially very useful for the fabrication of InSb-based electronic and optoelectronic devices.

  13. A Support-Based Reconstruction for SENSE MRI

    Directory of Open Access Journals (Sweden)

    Bradley S. Peterson

    2013-03-01

    Full Text Available A novel, rapid algorithm to speed up and improve the reconstruction of sensitivity encoding (SENSE MRI was proposed in this paper. The essence of the algorithm was that it iteratively solved the model of simple SENSE on a pixel-by-pixel basis in the region of support (ROS. The ROS was obtained from scout images of eight channels by morphological operations such as opening and filling. All the pixels in the FOV were paired and classified into four types, according to their spatial locations with respect to the ROS, and each with corresponding procedures of solving the inverse problem for image reconstruction. The sensitivity maps, used for the image reconstruction and covering only the ROS, were obtained by a polynomial regression model without extrapolation to keep the estimation errors small. The experiments demonstrate that the proposed method improves the reconstruction of SENSE in terms of speed and accuracy. The mean square errors (MSE of our reconstruction is reduced by 16.05% for a 2D brain MR image and the mean MSE over the whole slices in a 3D brain MRI is reduced by 30.44% compared to those of the traditional methods. The computation time is only 25%, 45%, and 70% of the traditional method for images with numbers of pixels in the orders of 103, 104, and 105–107, respectively.

  14. MR fingerprinting reconstruction with Kalman filter.

    Science.gov (United States)

    Zhang, Xiaodi; Zhou, Zechen; Chen, Shiyang; Chen, Shuo; Li, Rui; Hu, Xiaoping

    2017-09-01

    Magnetic resonance fingerprinting (MR fingerprinting or MRF) is a newly introduced quantitative magnetic resonance imaging technique, which enables simultaneous multi-parameter mapping in a single acquisition with improved time efficiency. The current MRF reconstruction method is based on dictionary matching, which may be limited by the discrete and finite nature of the dictionary and the computational cost associated with dictionary construction, storage and matching. In this paper, we describe a reconstruction method based on Kalman filter for MRF, which avoids the use of dictionary to obtain continuous MR parameter measurements. With this Kalman filter framework, the Bloch equation of inversion-recovery balanced steady state free-precession (IR-bSSFP) MRF sequence was derived to predict signal evolution, and acquired signal was entered to update the prediction. The algorithm can gradually estimate the accurate MR parameters during the recursive calculation. Single pixel and numeric brain phantom simulation were implemented with Kalman filter and the results were compared with those from dictionary matching reconstruction algorithm to demonstrate the feasibility and assess the performance of Kalman filter algorithm. The results demonstrated that Kalman filter algorithm is applicable for MRF reconstruction, eliminating the need for a pre-define dictionary and obtaining continuous MR parameter in contrast to the dictionary matching algorithm. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. New method for initial density reconstruction

    Science.gov (United States)

    Shi, Yanlong; Cautun, Marius; Li, Baojiu

    2018-01-01

    A theoretically interesting and practically important question in cosmology is the reconstruction of the initial density distribution provided a late-time density field. This is a long-standing question with a revived interest recently, especially in the context of optimally extracting the baryonic acoustic oscillation (BAO) signals from observed galaxy distributions. We present a new efficient method to carry out this reconstruction, which is based on numerical solutions to the nonlinear partial differential equation that governs the mapping between the initial Lagrangian and final Eulerian coordinates of particles in evolved density fields. This is motivated by numerical simulations of the quartic Galileon gravity model, which has similar equations that can be solved effectively by multigrid Gauss-Seidel relaxation. The method is based on mass conservation, and does not assume any specific cosmological model. Our test shows that it has a performance comparable to that of state-of-the-art algorithms that were very recently put forward in the literature, with the reconstructed density field over ˜80 % (50%) correlated with the initial condition at k ≲0.6 h /Mpc (1.0 h /Mpc ). With an example, we demonstrate that this method can significantly improve the accuracy of BAO reconstruction.

  16. Jet Vertex Charge Reconstruction

    CERN Document Server

    Nektarijevic, Snezana; The ATLAS collaboration

    2015-01-01

    A newly developed algorithm called the jet vertex charge tagger, aimed at identifying the sign of the charge of jets containing $b$-hadrons, referred to as $b$-jets, is presented. In addition to the well established track-based jet charge determination, this algorithm introduces the so-called \\emph{jet vertex charge} reconstruction, which exploits the charge information associated to the displaced vertices within the jet. Furthermore, the charge of a soft muon contained in the jet is taken into account when available. All available information is combined into a multivariate discriminator. The algorithm has been developed on jets matched to generator level $b$-hadrons provided by $t\\bar{t}$ events simulated at $\\sqrt{s}$=13~TeV using the full ATLAS detector simulation and reconstruction.

  17. Reconstruction Algorithms in Undersampled AFM Imaging

    DEFF Research Database (Denmark)

    Arildsen, Thomas; Oxvig, Christian Schou; Pedersen, Patrick Steffen

    2016-01-01

    This paper provides a study of spatial undersampling in atomic force microscopy (AFM) imaging followed by different image reconstruction techniques based on sparse approximation as well as interpolation. The main reasons for using undersampling is that it reduces the path length and thereby...... the scanning time as well as the amount of interaction between the AFM probe and the specimen. It can easily be applied on conventional AFM hardware. Due to undersampling, it is then necessary to further process the acquired image in order to reconstruct an approximation of the image. Based on real AFM cell...... images, our simulations reveal that using a simple raster scanning pattern in combination with conventional image interpolation performs very well. Moreover, this combination enables a reduction by a factor 10 of the scanning time while retaining an average reconstruction quality around 36 dB PSNR...

  18. Image reconstruction methods in positron tomography

    International Nuclear Information System (INIS)

    Townsend, D.W.; Defrise, M.

    1993-01-01

    In the two decades since the introduction of the X-ray scanner into radiology, medical imaging techniques have become widely established as essential tools in the diagnosis of disease. As a consequence of recent technological and mathematical advances, the non-invasive, three-dimensional imaging of internal organs such as the brain and the heart is now possible, not only for anatomical investigations using X-ray but also for studies which explore the functional status of the body using positron-emitting radioisotopes. This report reviews the historical and physical basis of medical imaging techniques using positron-emitting radioisotopes. Mathematical methods which enable three-dimensional distributions of radioisotopes to be reconstructed from projection data (sinograms) acquired by detectors suitably positioned around the patient are discussed. The extension of conventional two-dimensional tomographic reconstruction algorithms to fully three-dimensional reconstruction is described in detail. (orig.)

  19. Level-set-based reconstruction algorithm for EIT lung images: first clinical results.

    Science.gov (United States)

    Rahmati, Peyman; Soleimani, Manuchehr; Pulletz, Sven; Frerichs, Inéz; Adler, Andy

    2012-05-01

    We show the first clinical results using the level-set-based reconstruction algorithm for electrical impedance tomography (EIT) data. The level-set-based reconstruction method (LSRM) allows the reconstruction of non-smooth interfaces between image regions, which are typically smoothed by traditional voxel-based reconstruction methods (VBRMs). We develop a time difference formulation of the LSRM for 2D images. The proposed reconstruction method is applied to reconstruct clinical EIT data of a slow flow inflation pressure-volume manoeuvre in lung-healthy and adult lung-injury patients. Images from the LSRM and the VBRM are compared. The results show comparable reconstructed images, but with an improved ability to reconstruct sharp conductivity changes in the distribution of lung ventilation using the LSRM.

  20. Level-set-based reconstruction algorithm for EIT lung images: first clinical results

    International Nuclear Information System (INIS)

    Rahmati, Peyman; Adler, Andy; Soleimani, Manuchehr; Pulletz, Sven; Frerichs, Inéz

    2012-01-01

    We show the first clinical results using the level-set-based reconstruction algorithm for electrical impedance tomography (EIT) data. The level-set-based reconstruction method (LSRM) allows the reconstruction of non-smooth interfaces between image regions, which are typically smoothed by traditional voxel-based reconstruction methods (VBRMs). We develop a time difference formulation of the LSRM for 2D images. The proposed reconstruction method is applied to reconstruct clinical EIT data of a slow flow inflation pressure–volume manoeuvre in lung-healthy and adult lung-injury patients. Images from the LSRM and the VBRM are compared. The results show comparable reconstructed images, but with an improved ability to reconstruct sharp conductivity changes in the distribution of lung ventilation using the LSRM. (paper)

  1. Principles of Periocular Reconstruction following Excision of Cutaneous Malignancy

    International Nuclear Information System (INIS)

    Hayano, S. M.; Whipple, K. M.; Korn, B. S.; Kikkawa, D. O.

    2012-01-01

    Reconstruction of periocular defects following excision of cutaneous malignancy can present difficulties for oculofacial and reconstructive surgeons. The intricate anatomy of the eyelids and face requires precise restoration in order to avoid postoperative functional anesthetic concerns. Various reconstructive procedures based on common principles, location and size of the defect, can be applied to achieve restoration with the best possible functional and aesthetic outcomes.

  2. A very fast implementation of 2D iterative reconstruction algorithms

    DEFF Research Database (Denmark)

    Toft, Peter Aundal; Jensen, Peter James

    1996-01-01

    that iterative reconstruction algorithms can be implemented and run almost as fast as direct reconstruction algorithms. The method has been implemented in a software package that is available for free, providing reconstruction algorithms using ART, EM, and the Least Squares Conjugate Gradient Method...

  3. Morbidity and cost differences between free flap reconstruction and pedicled flap reconstruction in oral and oropharyngeal cancer: Matched control study

    NARCIS (Netherlands)

    Smeele, Ludwig E.; Goldstein, David; Tsai, Vance; Gullane, Patrick J.; Neligan, Peter; Brown, Dale H.; Irish, Jonathan C.

    2006-01-01

    To compare morbidity and cost in patients who underwent primary reconstruction with free tissue transfer with those with pectoralis major myocutaneous flap (PMMF) reconstructions after ablation of oral and oropharyngeal squamous cell carcinoma. Over a 6-year period, 36 patients had PMMF

  4. Practical implementation of tetrahedral mesh reconstruction in emission tomography

    Science.gov (United States)

    Boutchko, R.; Sitek, A.; Gullberg, G. T.

    2013-05-01

    This paper presents a practical implementation of image reconstruction on tetrahedral meshes optimized for emission computed tomography with parallel beam geometry. Tetrahedral mesh built on a point cloud is a convenient image representation method, intrinsically three-dimensional and with a multi-level resolution property. Image intensities are defined at the mesh nodes and linearly interpolated inside each tetrahedron. For the given mesh geometry, the intensities can be computed directly from tomographic projections using iterative reconstruction algorithms with a system matrix calculated using an exact analytical formula. The mesh geometry is optimized for a specific patient using a two stage process. First, a noisy image is reconstructed on a finely-spaced uniform cloud. Then, the geometry of the representation is adaptively transformed through boundary-preserving node motion and elimination. Nodes are removed in constant intensity regions, merged along the boundaries, and moved in the direction of the mean local intensity gradient in order to provide higher node density in the boundary regions. Attenuation correction and detector geometric response are included in the system matrix. Once the mesh geometry is optimized, it is used to generate the final system matrix for ML-EM reconstruction of node intensities and for visualization of the reconstructed images. In dynamic PET or SPECT imaging, the system matrix generation procedure is performed using a quasi-static sinogram, generated by summing projection data from multiple time frames. This system matrix is then used to reconstruct the individual time frame projections. Performance of the new method is evaluated by reconstructing simulated projections of the NCAT phantom and the method is then applied to dynamic SPECT phantom and patient studies and to a dynamic microPET rat study. Tetrahedral mesh-based images are compared to the standard voxel-based reconstruction for both high and low signal-to-noise ratio

  5. Practical implementation of tetrahedral mesh reconstruction in emission tomography

    International Nuclear Information System (INIS)

    Boutchko, R; Gullberg, G T; Sitek, A

    2013-01-01

    This paper presents a practical implementation of image reconstruction on tetrahedral meshes optimized for emission computed tomography with parallel beam geometry. Tetrahedral mesh built on a point cloud is a convenient image representation method, intrinsically three-dimensional and with a multi-level resolution property. Image intensities are defined at the mesh nodes and linearly interpolated inside each tetrahedron. For the given mesh geometry, the intensities can be computed directly from tomographic projections using iterative reconstruction algorithms with a system matrix calculated using an exact analytical formula. The mesh geometry is optimized for a specific patient using a two stage process. First, a noisy image is reconstructed on a finely-spaced uniform cloud. Then, the geometry of the representation is adaptively transformed through boundary-preserving node motion and elimination. Nodes are removed in constant intensity regions, merged along the boundaries, and moved in the direction of the mean local intensity gradient in order to provide higher node density in the boundary regions. Attenuation correction and detector geometric response are included in the system matrix. Once the mesh geometry is optimized, it is used to generate the final system matrix for ML-EM reconstruction of node intensities and for visualization of the reconstructed images. In dynamic PET or SPECT imaging, the system matrix generation procedure is performed using a quasi-static sinogram, generated by summing projection data from multiple time frames. This system matrix is then used to reconstruct the individual time frame projections. Performance of the new method is evaluated by reconstructing simulated projections of the NCAT phantom and the method is then applied to dynamic SPECT phantom and patient studies and to a dynamic microPET rat study. Tetrahedral mesh-based images are compared to the standard voxel-based reconstruction for both high and low signal-to-noise ratio

  6. 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.

  7. Accelerated gradient methods for total-variation-based CT image reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Joergensen, Jakob H.; Hansen, Per Christian [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Informatics and Mathematical Modeling; Jensen, Tobias L.; Jensen, Soeren H. [Aalborg Univ. (Denmark). Dept. of Electronic Systems; Sidky, Emil Y.; Pan, Xiaochuan [Chicago Univ., Chicago, IL (United States). Dept. of Radiology

    2011-07-01

    Total-variation (TV)-based CT image reconstruction has shown experimentally to be capable of producing accurate reconstructions from sparse-view data. In particular TV-based reconstruction is well suited for images with piecewise nearly constant regions. Computationally, however, TV-based reconstruction is demanding, especially for 3D imaging, and the reconstruction from clinical data sets is far from being close to real-time. This is undesirable from a clinical perspective, and thus there is an incentive to accelerate the solution of the underlying optimization problem. The TV reconstruction can in principle be found by any optimization method, but in practice the large scale of the systems arising in CT image reconstruction preclude the use of memory-intensive methods such as Newton's method. The simple gradient method has much lower memory requirements, but exhibits prohibitively slow convergence. In the present work we address the question of how to reduce the number of gradient method iterations needed to achieve a high-accuracy TV reconstruction. We consider the use of two accelerated gradient-based methods, GPBB and UPN, to solve the 3D-TV minimization problem in CT image reconstruction. The former incorporates several heuristics from the optimization literature such as Barzilai-Borwein (BB) step size selection and nonmonotone line search. The latter uses a cleverly chosen sequence of auxiliary points to achieve a better convergence rate. The methods are memory efficient and equipped with a stopping criterion to ensure that the TV reconstruction has indeed been found. An implementation of the methods (in C with interface to Matlab) is available for download from http://www2.imm.dtu.dk/~pch/TVReg/. We compare the proposed methods with the standard gradient method, applied to a 3D test problem with synthetic few-view data. We find experimentally that for realistic parameters the proposed methods significantly outperform the standard gradient method. (orig.)

  8. ADART: an adaptive algebraic reconstruction algorithm for discrete tomography.

    Science.gov (United States)

    Maestre-Deusto, F Javier; Scavello, Giovanni; Pizarro, Joaquín; Galindo, Pedro L

    2011-08-01

    In this paper we suggest an algorithm based on the Discrete Algebraic Reconstruction Technique (DART) which is capable of computing high quality reconstructions from substantially fewer projections than required for conventional continuous tomography. Adaptive DART (ADART) goes a step further than DART on the reduction of the number of unknowns of the associated linear system achieving a significant reduction in the pixel error rate of reconstructed objects. The proposed methodology automatically adapts the border definition criterion at each iteration, resulting in a reduction of the number of pixels belonging to the border, and consequently of the number of unknowns in the general algebraic reconstruction linear system to be solved, being this reduction specially important at the final stage of the iterative process. Experimental results show that reconstruction errors are considerably reduced using ADART when compared to original DART, both in clean and noisy environments.

  9. Rapidly 3D Texture Reconstruction Based on Oblique Photography

    Directory of Open Access Journals (Sweden)

    ZHANG Chunsen

    2015-07-01

    Full Text Available This paper proposes a city texture fast reconstruction method based on aerial tilt image for reconstruction of three-dimensional city model. Based on the photogrammetry and computer vision theory and using the city building digital surface model obtained by prior treatment, through collinear equation calculation geometric projection of object and image space, to obtain the three-dimensional information and texture information of the structure and through certain the optimal algorithm selecting the optimal texture on the surface of the object, realize automatic extraction of the building side texture and occlusion handling of the dense building texture. The real image texture reconstruction results show that: the method to the 3D city model texture reconstruction has the characteristics of high degree of automation, vivid effect and low cost and provides a means of effective implementation for rapid and widespread real texture rapid reconstruction of city 3D model.

  10. Quantitative tectonic reconstructions of Zealandia based on crustal thickness estimates

    Science.gov (United States)

    Grobys, Jan W. G.; Gohl, Karsten; Eagles, Graeme

    2008-01-01

    Zealandia is a key piece in the plate reconstruction of Gondwana. The positions of its submarine plateaus are major constraints on the best fit and breakup involving New Zealand, Australia, Antarctica, and associated microplates. As the submarine plateaus surrounding New Zealand consist of extended and highly extended continental crust, classic plate tectonic reconstructions assuming rigid plates and narrow plate boundaries fail to reconstruct these areas correctly. However, if the early breakup history shall be reconstructed, it is crucial to consider crustal stretching in a plate-tectonic reconstruction. We present a reconstruction of the basins around New Zealand (Great South Basin, Bounty Trough, and New Caledonia Basin) based on crustal balancing, an approach that takes into account the rifting and thinning processes affecting continental crust. In a first step, we computed a crustal thickness map of Zealandia using seismic, seismological, and gravity data. The crustal thickness map shows the submarine plateaus to have a uniform crustal thickness of 20-24 km and the basins to have a thickness of 12-16 km. We assumed that a reconstruction of Zealandia should close the basins and lead to a most uniform crustal thickness. We used the standard deviation of the reconstructed crustal thickness as a measure of uniformity. The reconstruction of the Campbell Plateau area shows that the amount of extension in the Bounty Trough and the Great South Basin is far smaller than previously thought. Our results indicate that the extension of the Bounty Trough and Great South Basin occurred simultaneously.

  11. Amplitude-based data selection for optimal retrospective reconstruction in micro-SPECT

    Science.gov (United States)

    Breuilly, M.; Malandain, G.; Guglielmi, J.; Marsault, R.; Pourcher, T.; Franken, P. R.; Darcourt, J.

    2013-04-01

    Respiratory motion can blur the tomographic reconstruction of positron emission tomography or single-photon emission computed tomography (SPECT) images, which subsequently impair quantitative measurements, e.g. in the upper abdomen area. Respiratory signal phase-based gated reconstruction addresses this problem, but deteriorates the signal-to-noise ratio (SNR) and other intensity-based quality measures. This paper proposes a 3D reconstruction method dedicated to micro-SPECT imaging of mice. From a 4D acquisition, the phase images exhibiting motion are identified and the associated list-mode data are discarded, which enables the reconstruction of a 3D image without respiratory artefacts. The proposed method allows a motion-free reconstruction exhibiting both satisfactory count statistics and accuracy of measures. With respect to standard 3D reconstruction (non-gated 3D reconstruction) without breathing motion correction, an increase of 14.6% of the mean standardized uptake value has been observed, while, with respect to a gated 4D reconstruction, up to 60% less noise and an increase of up to 124% of the SNR have been demonstrated.

  12. Unit Advancement Flap for Lower Lip Reconstruction.

    Science.gov (United States)

    Ogino, Akihiro; Onishi, Kiyoshi; Okada, Emi; Nakamichi, Miho

    2018-05-01

    Lower lip reconstruction requires consideration of esthetic and functional outcome in selecting a surgical procedure, and reconstruction with local tissue is useful. The authors reconstructed full-thickness defects with a unit advancement flap. Reconstruction was performed using this method in 4 patients with lower lip squamous cell carcinoma in whom tumor resection with preservation of the mouth angle was possible. The lower lip resection width was 30 to 45 mm, accounting for 50% to 68% of the entire width of the lower lip. The flap was prepared by lateral extension from above the mental unit and matched with the potential wrinkle line of the lower lip in order to design a unit morphology surrounded by the anterior margin of the depressor labii inferioris muscle. It was elevated as a full-thickness flap composed of the orbicularis oris muscle, skin, and mucosa of the residual lower lip from the bilateral sides, and advanced to the defect. Flap transfer was adjusted by small triangular resection of the skin on the lateral side of the mental unit. The postoperative scar was inconspicuous in all patients and there was no impairment of the mouth opening-closing or articulation functions. This was a relatively simple surgical procedure. A blood supply of the flap was stable, and continuity of the orbicularis oris muscle was reconstructed by transferred the residual lower lip advancement flap from the bilateral sides. The postoperative mouth opening-closing function was sufficient, and dentures could be placed from an early phase in elderly patients. The postoperative scar was consistent with the lip unit morphology, being esthetically superior. This procedure may be applicable for reconstruction of defects approximately 1/3 to 2/3 the width of the lower lip where the mouth angle is preserved.

  13. Application of iterative reconstruction in dynamic studies

    International Nuclear Information System (INIS)

    Meikle, S.R.

    1998-01-01

    Full text: The conventional approach to analysing dynamic tomographic data (SPECT or PET) is to reconstruct projections corresponding to each time interval separately and then fit a suitable tracer kinetic model to the dynamic sequence (method 1 ) . This approach assumes that the tracer distribution remains static during any given time interval and, for practical reasons, filtered back-projection (FBP) is the preferred reconstruction algorithm. However, alternative approaches exist which lend themselves to iterative algorithms, such as EM. One approach is to fit the model directly to the projection data, followed by EM reconstruction of the parameter estimates (method 2). This requires that the tracer model can be expressed as a linear function of the unknown model parameters. A third alternative is to incorporate the tracer model into the reconstruction algorithm (method 3). Such an extension was described during the early development of the EM algorithm, referred to as the EM parametric image reconstruction algorithm (EM-PIRA). We have investigated these various strategies for analysing dynamic data and their relative pros and cons. Tracer modelling was performed using a general model, referred to as spectral analysis, which makes no restriction on the number of physiological compartments and satisfies the linearity requirement of method 2. A kinetic software phantom was created and used to test the convergence and noise properties of the different approaches. In summary, method 2 is the most practical as it reduces the number of reconstructions by at least an order of magnitude and provides improved signal-to-noise ratios compared with method 1. EM-PIRA allows greater flexibility in the choice of parametric images and appears to have a regularising effect on convergence. Methods 2 and 3 are also better suited to dynamic scanning with a rotating camera, as they can potentially account for changes in tracer distribution between projections

  14. The reconstruction of thyroid dose following Chernobyl

    International Nuclear Information System (INIS)

    Stepanenko, V.; Kondrashov, A.; Yaskova, E.; Petin, D.; Skvortsov, V.; Parshkov, E.; Gavrilin, Yu.; Khrousch, V.; Shinkarev, S.; Makarenkova, I.; Volkov, V.; Zvonova, I.; Bratilova, A.; Kaidanovsky, J.; Minenko, V.; Drozdovich, V.; Ulanovsky, A.; Korneev, S.; Heinemann, K.; Pomplun, E.; Hille, R.; Bailiff, A.

    1996-01-01

    The report presents the overview of several approaches in working out the methods of thyroid internal dose reconstruction following Chernobyl. One of these approaches was developed (IBPh, Moscow; MRRC, Obninsk; IRM, Minsk) using the correlations between the mean dose calculation based on I 131 thyroid content measurements and Cs 137 contamination of territories. The available data on I 131 soil contamination were taken into account. The lack of data on I 131 soil contamination was supposed to be compensated by I 129 measurements in soil samples from contaminated territories. The semiempiric model was developed for dose reconstruction. The comparison of the results obtained by semiempiric model and empirical values are presented. The estimated values of average dose according semiempiric model were used for individual dose reconstruction. The IRH (St.-Petersburg) has developed the following method for individual dose reconstruction: correlation between the total I 131 radioiodine incorporation in thyroid and whole body Cs 137 content during first months after accident. The individual dose reconstruction is also mentioned to be performed using the data on individual milk consumption during first weeks after accident. For evaluation of average doses it is suggested to use the linear correlation: thyroid dose values based on radioiodine thyroid measurements vs Cs 137 contamination, air kerma rate, mean I 131 concentration in the milk. The method for retrospective reconstruction of thyroid dose caused by short-living iodine nuclides released after the Chernobyl accident has been developed by Research Centre, Juelich, Germany. It is based on the constant ratio that these nuclides have with the long-living I 129 . The contamination of soil samples by this nuclide can be used to assess thyroid doses. First results of I 129 contamination values and derived thyroid doses are to be presented

  15. Axially symmetric reconstruction of plasma emission and absorption coefficients

    International Nuclear Information System (INIS)

    Yang Lixin; Jia Hui; Yang Jiankun; Li Xiujian; Chen Shaorong; Liu Xishun

    2013-01-01

    A layered structure imaging model is developed in order to reconstruct emission coefficients and absorption coefficients simultaneously, in laser fusion core plasma diagnostics. A novel axially symmetric reconstruction method that utilizes the LM (Levenberg-Marquardt) nonlinear least squares minimization algorithm is proposed based on the layered structure. Numerical simulation results demonstrate that the proposed method is sufficiently accurate to reconstruct emission coefficients and absorption coefficients, and when the standard deviation of noise is 0.01, the errors of emission coefficients and absorption coefficients are 0.17, 0.22, respectively. Furthermore, this method could perform much better on reconstruction effect compared with traditional inverse Abel transform algorithms. (authors)

  16. Spectrotemporal CT data acquisition and reconstruction at low dose

    International Nuclear Information System (INIS)

    Clark, Darin P.; Badea, Cristian T.; Lee, Chang-Lung; Kirsch, David G.

    2015-01-01

    Purpose: X-ray computed tomography (CT) is widely used, both clinically and preclinically, for fast, high-resolution anatomic imaging; however, compelling opportunities exist to expand its use in functional imaging applications. For instance, spectral information combined with nanoparticle contrast agents enables quantification of tissue perfusion levels, while temporal information details cardiac and respiratory dynamics. The authors propose and demonstrate a projection acquisition and reconstruction strategy for 5D CT (3D + dual energy + time) which recovers spectral and temporal information without substantially increasing radiation dose or sampling time relative to anatomic imaging protocols. Methods: The authors approach the 5D reconstruction problem within the framework of low-rank and sparse matrix decomposition. Unlike previous work on rank-sparsity constrained CT reconstruction, the authors establish an explicit rank-sparse signal model to describe the spectral and temporal dimensions. The spectral dimension is represented as a well-sampled time and energy averaged image plus regularly undersampled principal components describing the spectral contrast. The temporal dimension is represented as the same time and energy averaged reconstruction plus contiguous, spatially sparse, and irregularly sampled temporal contrast images. Using a nonlinear, image domain filtration approach, the authors refer to as rank-sparse kernel regression, the authors transfer image structure from the well-sampled time and energy averaged reconstruction to the spectral and temporal contrast images. This regularization strategy strictly constrains the reconstruction problem while approximately separating the temporal and spectral dimensions. Separability results in a highly compressed representation for the 5D data in which projections are shared between the temporal and spectral reconstruction subproblems, enabling substantial undersampling. The authors solved the 5D reconstruction

  17. Evaluation of the spline reconstruction technique for PET

    Energy Technology Data Exchange (ETDEWEB)

    Kastis, George A., E-mail: gkastis@academyofathens.gr; Kyriakopoulou, Dimitra [Research Center of Mathematics, Academy of Athens, Athens 11527 (Greece); Gaitanis, Anastasios [Biomedical Research Foundation of the Academy of Athens (BRFAA), Athens 11527 (Greece); Fernández, Yolanda [Centre d’Imatge Molecular Experimental (CIME), CETIR-ERESA, Barcelona 08950 (Spain); Hutton, Brian F. [Institute of Nuclear Medicine, University College London, London NW1 2BU (United Kingdom); Fokas, Athanasios S. [Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB30WA (United Kingdom)

    2014-04-15

    Purpose: The spline reconstruction technique (SRT), based on the analytic formula for the inverse Radon transform, has been presented earlier in the literature. In this study, the authors present an improved formulation and numerical implementation of this algorithm and evaluate it in comparison to filtered backprojection (FBP). Methods: The SRT is based on the numerical evaluation of the Hilbert transform of the sinogram via an approximation in terms of “custom made” cubic splines. By restricting reconstruction only within object pixels and by utilizing certain mathematical symmetries, the authors achieve a reconstruction time comparable to that of FBP. The authors have implemented SRT in STIR and have evaluated this technique using simulated data from a clinical positron emission tomography (PET) system, as well as real data obtained from clinical and preclinical PET scanners. For the simulation studies, the authors have simulated sinograms of a point-source and three digital phantoms. Using these sinograms, the authors have created realizations of Poisson noise at five noise levels. In addition to visual comparisons of the reconstructed images, the authors have determined contrast and bias for different regions of the phantoms as a function of noise level. For the real-data studies, sinograms of an{sup 18}F-FDG injected mouse, a NEMA NU 4-2008 image quality phantom, and a Derenzo phantom have been acquired from a commercial PET system. The authors have determined: (a) coefficient of variations (COV) and contrast from the NEMA phantom, (b) contrast for the various sections of the Derenzo phantom, and (c) line profiles for the Derenzo phantom. Furthermore, the authors have acquired sinograms from a whole-body PET scan of an {sup 18}F-FDG injected cancer patient, using the GE Discovery ST PET/CT system. SRT and FBP reconstructions of the thorax have been visually evaluated. Results: The results indicate an improvement in FWHM and FWTM in both simulated and real

  18. Quantifying dose to the reconstructed breast: Can we adequately treat?

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Eugene; Marsh, Robin B.; Griffith, Kent A.; Moran, Jean M. [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Pierce, Lori J., E-mail: ljpierce@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States)

    2013-04-01

    To evaluate how immediate reconstruction (IR) impacts postmastectomy radiotherapy (PMRT) dose distributions to the reconstructed breast (RB), internal mammary nodes (IMN), heart, and lungs using quantifiable dosimetric end points. 3D conformal plans were developed for 20 IR patients, 10 autologous reconstruction (AR), and 10 expander-implant (EI) reconstruction. For each reconstruction type, 5 right- and 5 left-sided reconstructions were selected. Two plans were created for each patient, 1 with RB coverage alone and 1 with RB + IMN coverage. Left-sided EI plans without IMN coverage had higher heart Dmean than left-sided AR plans (2.97 and 0.84 Gy, p = 0.03). Otherwise, results did not vary by reconstruction type and all remaining metrics were evaluated using a combined AR and EI dataset. RB coverage was adequate regardless of laterality or IMN coverage (Dmean 50.61 Gy, D95 45.76 Gy). When included, IMN Dmean and D95 were 49.57 and 40.96 Gy, respectively. Mean heart doses increased with left-sided treatment plans and IMN inclusion. Right-sided treatment plans and IMN inclusion increased mean lung V{sub 20}. Using standard field arrangements and 3D planning, we observed excellent coverage of the RB and IMN, regardless of laterality or reconstruction type. Our results demonstrate that adequate doses can be delivered to the RB with or without IMN coverage.

  19. Biologic Collagen Cylinder with Skate Flap Technique for Nipple Reconstruction

    Directory of Open Access Journals (Sweden)

    Brian P. Tierney

    2014-01-01

    Full Text Available A surgical technique using local tissue skate flaps combined with cylinders made from a naturally derived biomaterial has been used effectively for nipple reconstruction. A retrospective review of patients who underwent nipple reconstruction using this technique was performed. Comorbidities and type of breast reconstruction were collected. Outcome evaluation included complications, surgical revisions, and nipple projection. There were 115 skate flap reconstructions performed in 83 patients between July 2009 and January 2013. Patients ranged from 32 to 73 years old. Average body mass index was 28.0. The most common comorbidities were hypertension (39.8% and smoking (16.9%. After breast reconstruction, 68.7% of the patients underwent chemotherapy and 20.5% underwent radiation. Seventy-one patients had immediate breast reconstruction with expanders and 12 had delayed reconstruction. The only reported complications were extrusions (3.5%. Six nipples (5.2% in 5 patients required surgical revision due to loss of projection; two patients had minor loss of projection but did not require surgical revision. Nipple projection at time of surgery ranged from 6 to 7 mm and average projection at 6 months was 3–5 mm. A surgical technique for nipple reconstruction using a skate flap with a graft material is described. Complications are infrequent and short-term projection measurements are encouraging.

  20. 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.

  1. Prompt data reconstruction at the ATLAS experiment

    International Nuclear Information System (INIS)

    Andrew Stewart, Graeme; Boyd, Jamie; Unal, Guillaume; Firmino da Costa, João; Tuggle, Joseph

    2012-01-01

    The ATLAS experiment at the LHC collider recorded more than 5 fb −1 data of pp collisions at a centre-of-mass energy of 7 TeV during 2011. The recorded data are promptly reconstructed in two steps at a large computing farm at CERN to provide fast access to high quality data for physics analysis. In the first step, a subset of the data, corresponding to the express stream and having 10Hz of events, is processed in parallel with data taking. Data quality, detector calibration constants, and the beam spot position are determined using the reconstructed data within 48 hours. In the second step all recorded data are processed with the updated parameters. The LHC significantly increased the instantaneous luminosity and the number of interactions per bunch crossing in 2011; the data recording rate by ATLAS exceeds 400 Hz. To cope with these challenges the performance and reliability of the ATLAS reconstruction software have been improved. In this paper we describe how the prompt data reconstruction system quickly and stably provides high quality data to analysers.

  2. Multichannel algorithm for fast 3D reconstruction

    International Nuclear Information System (INIS)

    Rodet, Thomas; Grangeat, Pierre; Desbat, Laurent

    2002-01-01

    Some recent medical imaging applications such as functional imaging (PET and SPECT) or interventional imaging (CT fluoroscopy) involve increasing amounts of data. In order to reduce the image reconstruction time, we develop a new fast 3D reconstruction algorithm based on a divide and conquer approach. The proposed multichannel algorithm performs an indirect frequential subband decomposition of the image f to be reconstructed (f=Σf j ) through the filtering of the projections Rf. The subband images f j are reconstructed on a downsampled grid without information suppression. In order to reduce the computation time, we do not backproject the null filtered projections and we downsample the number of projections according to the Shannon conditions associated with the subband image. Our algorithm is based on filtering and backprojection operators. Using the same algorithms for these basic operators, our approach is three and a half times faster than a classical FBP algorithm for a 2D image 512x512 and six times faster for a 3D image 32x512x512. (author)

  3. Microsurgical reconstruction of extensive oncological scalp defects

    Directory of Open Access Journals (Sweden)

    Ole eGoertz

    2015-09-01

    Full Text Available While most small to medium defects of the scalp can be covered by local flaps, large defects or complicating factors like a history of radiotherapy often require a microsurgical reconstruction.Several factors need to be considered in such procedures. A sufficient preoperative planning is based on adequate imaging of the malignancy and a multi-disciplinary concept. Several flaps are available for such reconstructions, of which the latissimus dorsi and anterior lateral thigh flaps are the most commonly used ones.In very large defects, combined flaps such as a parascapular / latissimus dorsi flaps can be highly useful or necessary. The most commonly used recipient vessels for microsurgical scalp reconstructions are the superficial temporal vessels, but various other feasible choices exist. If the concomitant veins are not sufficient, the jugular veins represent a safe backup alternative but require a vessel interposition or long pedicle. Postoperative care and patient positioning can be difficult in these patients but can be facilitated by various devices. Overall, microsurgical reconstruction of large scalp defects is a feasible undertaking if the mentioned key factors are taken into account.

  4. Muon reconstruction performance of the ATLAS detector in 2016

    CERN Document Server

    Marchese, Luigi; The ATLAS collaboration

    2017-01-01

    Muons are of key importance to study some of the most interesting physics topics at the LHC. We show the status of the performance of the muon reconstruction in the analysis of proton-proton collisions at the LHC, recorded by the ATLAS detector in 2016. Reconstruction efficiency and momentum resolution have been measured using "$J/\\psi$" and "$Z$" decays for different classes of reconstructed muons.

  5. Principles of Periocular Reconstruction following Excision of Cutaneous Malignancy

    Directory of Open Access Journals (Sweden)

    Scott M. Hayano

    2012-01-01

    Full Text Available Reconstruction of periocular defects following excision of cutaneous malignancy can present difficulties for oculofacial and reconstructive surgeons. The intricate anatomy of the eyelids and face requires precise restoration in order to avoid postoperative functional anesthetic concerns. Various reconstructive procedures based on common principles, location and size of the defect, can be applied to achieve restoration with the best possible functional and aesthetic outcomes.

  6. Reconstruction of an InAs nanowire using geometric tomography

    DEFF Research Database (Denmark)

    Pennington, Robert S.; König, Stefan; Alpers, Andreas

    Geometric tomography and conventional algebraic tomography algorithms are used to reconstruct cross-sections of an InAs nanowire from a tilt series of experimental annular dark-field images. Both algorithms are also applied to a test object to assess what factors affect the reconstruction quality....... When using the present algorithms, geometric tomography is faster, but artifacts in the reconstruction may be difficult to recognize....

  7. Free flap reconstruction for diabetic foot limb salvage.

    Science.gov (United States)

    Sato, Tomoya; Yana, Yuichiro; Ichioka, Shigeru

    2017-12-01

    Although free flap is gaining popularity for the reconstruction of diabetic foot ulcers, it is unclear whether free flap reconstruction increases the chances of postoperative independent ambulation. The aim of this study is to evaluate the relationship between free flap success and postoperative ambulation. This study reviewed 23 cases of free flap reconstruction for diabetic foot ulcers between January 2007 and March 2014. Free rectus abdominis, latissimus dorsi, and anterolateral thigh flaps were used in ten, eight, and five patients, respectively. A comparison was made between free flap success and postoperative independent ambulation using Fisher's exact test. Two patients developed congestive heart failure with fatal consequences within 14 days postoperatively, resulting in an in-hospital mortality rate of 8.7%. Five patients lost their flaps (21.7%). Of the 16 patients who had flap success, 12 achieved independent ambulation. Five patients with flap loss did not achieve independent ambulation, except one patient who underwent secondary flap reconstruction using a distally based sural flap. Fisher's exact test revealed that independent ambulation was associated with free flap success (p = 0.047). The present study indicates that free flap reconstruction may increase the possibility of independent ambulation for patients with extensive tissue defects due to diabetic ulcers. Intermediate limb salvage rates and independent ambulation rates were favourable in patients with successful reconstruction. The use of foot orthoses and a team approach with pedorthists were effective to prevent recurrence.

  8. 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.)

  9. Reconstruction of vacuum magnetic flux in QUEST

    International Nuclear Information System (INIS)

    Ishiguro, Masaki; Hanada, Kazuaki; Nakamura, Kazuo

    2010-01-01

    It is important to determine the best method for reconstructing the magnetic flux when eddy currents are significantly induced during magnetic measurement in spherical tokamaks (STs). Four methods for this reconstruction are investigated, and the calculated magnetic fluxes are compared to those measured in the cavity of a vacuum vessel. The results show that the best method is the one that uses currents from virtual coils for reconstruction. In this method, the placement of the virtual coils is optimized with numerical simulations using the Akaike information criterion (AIC), which indicates the goodness of fit of models used to fit measured data. The virtual coils are set on a line 15 cm outside the vacuum vessel. (author)

  10. Urogenital function after cloacal reconstruction, two techniques evaluated

    NARCIS (Netherlands)

    Versteegh, H.P.; Sloots, C.E.J.; Wolffenbuttel, K.P.; Jong, J.R. de; Sleeboom, C.; Feitz, W.F.J.; Heurn, L.W.E. van; Zee, D.C. van der; Wijnen, R.M.H.; Blaauw, I. de

    2014-01-01

    OBJECTIVE: Current surgical techniques for cloacal reconstruction are posterior sagittal anorecto vagino urethroplasty (PSARVUP) and posterior sagittal anorectoplasty (PSARP) with total urogenital mobilization (TUM). The aim of this study was to explore the results of reconstructive cloaca surgery

  11. Reconstruction of thermally quenched glow curves in quartz

    International Nuclear Information System (INIS)

    Subedi, Bhagawan; Polymeris, George S.; Tsirliganis, Nestor C.; Pagonis, Vasilis; Kitis, George

    2012-01-01

    The experimentally measured thermoluminescence (TL) glow curves of quartz samples are influenced by the presence of the thermal quenching effect, which involves a variation of the luminescence efficiency as a function of temperature. The real shape of the thermally unquenched TL glow curves is completely unknown. In the present work an attempt is made to reconstruct these unquenched glow curves from the quenched experimental data, and for two different types of quartz samples. The reconstruction is based on the values of the thermal quenching parameter W (activation energy) and C (a dimensionless constant), which are known from recent experimental work on these two samples. A computerized glow-curve deconvolution (CGCD) analysis was performed twice for both the reconstructed and the experimental TL glow curves. Special attention was paid to check for consistency between the results of these two independent CGCD analyses. The investigation showed that the reconstruction attempt was successful, and it is concluded that the analysis of reconstructed TL glow curves can provide improved values of the kinetic parameters E, s for the glow peaks of quartz. This also leads to a better evaluation of the half-lives of electron trapping levels used for dosimetry and luminescence dating.

  12. GPU accelerated CT reconstruction for clinical use: quality driven performance

    Science.gov (United States)

    Vaz, Michael S.; Sneyders, Yuri; McLin, Matthew; Ricker, Alan; Kimpe, Tom

    2007-03-01

    We present performance and quality analysis of GPU accelerated FDK filtered backprojection for cone beam computed tomography (CBCT) reconstruction. Our implementation of the FDK CT reconstruction algorithm does not compromise fidelity at any stage and yields a result that is within 1 HU of a reference C++ implementation. Our streaming implementation is able to perform reconstruction as the images are acquired; it addresses low latency as well as fast throughput, which are key considerations for a "real-time" design. Further, it is scaleable to multiple GPUs for increased performance. The implementation does not place any constraints on image acquisition; it works effectively for arbitrary angular coverage with arbitrary angular spacing. As such, this GPU accelerated CT reconstruction solution may easily be used with scanners that are already deployed. We are able to reconstruct a 512 x 512 x 340 volume from 625 projections, each sized 1024 x 768, in less than 50 seconds. The quoted 50 second timing encompasses the entire reconstruction using bilinear interpolation and includes filtering on the CPU, uploading the filtered projections to the GPU, and also downloading the reconstructed volume from GPU memory to system RAM.

  13. Digital reconstruction of Young's fringes using Fresnel transformation

    Science.gov (United States)

    Kulenovic, Rudi; Song, Yaozu; Renninger, P.; Groll, Manfred

    1997-11-01

    This paper deals with the digital numerical reconstruction of Young's fringes from laser speckle photography by means of the Fresnel-transformation. The physical model of the optical reconstruction of a specklegram is a near-field Fresnel-diffraction phenomenon which can be mathematically described by the Fresnel-transformation. Therefore, the interference phenomena can be directly calculated by a microcomputer.If additional a CCD-camera is used for specklegram recording the measurement procedure and evaluation process can be completely carried out in a digital way. Compared with conventional laser speckle photography no holographic plates, no wet development process and no optical specklegram reconstruction are needed. These advantages reveal a wide future in scientific and engineering applications. The basic principle of the numerical reconstruction is described, the effects of experimental parameters of Young's fringes are analyzed and representative results are presented.

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

    Science.gov (United States)

    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

  15. Research on compressive sensing reconstruction algorithm based on total variation model

    Science.gov (United States)

    Gao, Yu-xuan; Sun, Huayan; Zhang, Tinghua; Du, Lin

    2017-12-01

    Compressed sensing for breakthrough Nyquist sampling theorem provides a strong theoretical , making compressive sampling for image signals be carried out simultaneously. In traditional imaging procedures using compressed sensing theory, not only can it reduces the storage space, but also can reduce the demand for detector resolution greatly. Using the sparsity of image signal, by solving the mathematical model of inverse reconfiguration, realize the super-resolution imaging. Reconstruction algorithm is the most critical part of compression perception, to a large extent determine the accuracy of the reconstruction of the image.The reconstruction algorithm based on the total variation (TV) model is more suitable for the compression reconstruction of the two-dimensional image, and the better edge information can be obtained. In order to verify the performance of the algorithm, Simulation Analysis the reconstruction result in different coding mode of the reconstruction algorithm based on the TV reconstruction algorithm. The reconstruction effect of the reconfigurable algorithm based on TV based on the different coding methods is analyzed to verify the stability of the algorithm. This paper compares and analyzes the typical reconstruction algorithm in the same coding mode. On the basis of the minimum total variation algorithm, the Augmented Lagrangian function term is added and the optimal value is solved by the alternating direction method.Experimental results show that the reconstruction algorithm is compared with the traditional classical algorithm based on TV has great advantages, under the low measurement rate can be quickly and accurately recovers target image.

  16. Homotopic Object Reconstruction Using Natural Neighbor Barycentric Coordinates

    DEFF Research Database (Denmark)

    Sharma, Ojaswa; Anton, François

    2011-01-01

    on the edges of n-sided convex polygons as the area stolen by any point inside a polygon from the Voronoi regions of each open oriented line segment bounding the polygon. These allow us to formulate homotopies on edges of the polygons from which the underlying object can be reconstructed. We provide results...... of the reconstruction including the necessary derivation of the gradient at polygon edges and the optimal placement of cutting lines. Accuracy of the suggested reconstruction is evaluated by means of various metrics and compared with one of the existing methods....

  17. 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.

  18. On-line implant reconstruction in HDR brachytherapy

    International Nuclear Information System (INIS)

    Kolkman-Deurloo, Inger-Karine K.; Kruijf, Wilhelmus J.M. de; Levendag, Peter C.

    2006-01-01

    Background and purpose: To evaluate the accuracy of on-line planning in an Integrated Brachytherapy Unit (IBU) using dedicated image distortion correction algorithms, correcting the geometric distortion and magnetic distortion separately, and to determine the effect of the reconstruction accuracy on clinical treatment plans in terms of deviations in treatment time and dose. Patients and methods: The reconstruction accuracy has been measured using 20 markers, positioned at well known locations in a QA phantom. Treatment plans of two phantoms representing clinical implant geometries, have been compared with reference plans to determine the effect of the reconstruction accuracy on the treatment plan. Before clinical introduction, treatment plans of three representative patients, based on on-line reconstruction, have been compared with reference plans. Results: The average reconstruction error for 10 in. images reduces from -0.6 mm (range -2.6 to +1.0 mm) to -0.2 mm (range -1.2 to +0.6 mm) after image distortion correction and for 15 in. images from 0.8 mm (range -0.5 to +3.0 mm) to 0.0 mm (range -0.8 to +0.8 mm). The error in case of eccentric positioning of the phantom, i.e. 0.8 mm (range -1.0 to +3.3 mm), reduces to 0.1 mm (range -0.5 to +0.9 mm). Correction of the image distortions reduces the deviation in the calculated treatment time of maximally 2.7% to less than 0.8% in case of eccentrically positioned clinical phantoms. The deviation in the treatment time or reference dose in the plans based on on-line reconstruction with image distortion correction of the three patient examples is smaller than 0.3%. Conclusions: Accurate on-line implant reconstruction using the IBU localiser and dedicated correction algorithms separating the geometric distortion and the magnetic distortion is possible. The results fulfill the minimum requirements as imposed by the Netherlands Commission on Radiation Dosimetry (NCS) without limitations regarding the usable range of the field

  19. Urogenital function after cloacal reconstruction, two techniques evaluated

    NARCIS (Netherlands)

    Versteegh, Hendt P.; Sloots, Cornelius E. J.; Wolffenbuttel, Katja P.; de Jong, Justin R.; Sleeboom, Christien; Feitz, Wout F.; van Heurn, L. W. Ernest; van der Zee, David C.; Wijnen, Rene M. H.; de Blaauw, Ivo

    2014-01-01

    Current surgical techniques for cloacal reconstruction are posterior sagittal anorecto vagino urethroplasty (PSARVUP) and posterior sagittal anorectoplasty (PSARP) with total urogenital mobilization (TUM). The aim of this study was to explore the results of reconstructive cloaca surgery in the

  20. Reconstructions in ultrasound modulated optical tomography

    KAUST Repository

    Allmaras, Moritz; Bangerth, Wolfgang

    2011-01-01

    We introduce a mathematical model for ultrasound modulated optical tomography and present a simple reconstruction scheme for recovering the spatially varying optical absorption coefficient from scanning measurements with narrowly focused ultrasound signals. Computational results for this model show that the reconstruction of sharp features of the absorption coefficient is possible. A formal linearization of the model leads to an equation with a Fredholm operator, which explains the stability observed in our numerical experiments. © de Gruyter 2011.