Medical image instance segmentation: from candidate region to no candidate region / 生物医学工程学杂志

In recent years, the task of object detection and segmentation in medical image is the research hotspot and difficulty in the field of image processing. Instance segmentation provides instance-level labels for different objects belonging to the same class, so it is widely used in the field of medical image processing. In this paper, medical image instance segmentation was summarized from the following aspects: First, the basic principle of instance segmentation was described, the instance segmentation models were classified into three categories, the development context of the instance segmentation algorithm was displayed in two-dimensional space, and six classic model diagrams of instance segmentation were given. Second, from the perspective of the three models of two-stage instance segmentation, single-stage instance segmentation and three-dimensional (3D) instance segmentation, we summarized the ideas of the three types of models, discussed the advantages and disadvantages, and sorted out the latest developments. Third, the application status of instance segmentation in six medical images such as colon tissue image, cervical image, bone imaging image, pathological section image of gastric cancer, computed tomography (CT) image of lung nodule and X-ray image of breast was summarized. Fourth, the main challenges in the field of medical image instance segmentation were discussed and the future development direction was prospected. In this paper, the principle, models and characteristics of instance segmentation are systematically summarized, as well as the application of instance segmentation in the field of medical image processing, which is of positive guiding significance to the study of instance segmentation.

Clinical Presentation, Management and Outcome in Diverticular Colovesical Fistulas - Our Experience.

Colovesical fistula (CVF) is an abnormal communication between the urinary bladder and the large intestine, usually sigmoid colon. Diverticulitis is the most common cause of CVF in most of the western studies, accounting for approximately 70% of cases. Diverticular CVF is uncommon in Asia. This case series shares the experience of six cases of diverticular CVF in Indian population. METHODSMedical records of six patients with diverticular colovesical fistulas during the period January 2016 - August 2019 were reviewed with regard to symptoms, diagnostic investigations, and management. Various aspects of the disease were analysed to determine the common features of colovesical fistula in our population. RESULTSAll patients with diverticular colovesical fistula were presented with urinary symptoms and none were aware about their existing colonic diverticulosis. Five out of the six cases presented with pneumaturia. Contrast enhanced computed tomography (CECT) abdomen detected sigmoid diverticulosis with vesical fistula in all cases. The most common site of fistula found on cystoscopy was on the left superolateral wall of bladder. All cases were operated as a single stage procedure including fistula repair, colonic resection, omental interposition with no temporary colostomy which provided an excellent surgical cure. CONCLUSIONSColovesical fistula secondary to diverticular disease has shown a rising incidence and can be effectively managed by a multidisciplinary team. It requires prompt diagnosis, adequate preoperative evaluation, perioperative care including bowel preparation, nutritional supplementation, appropriate antibiotics, and meticulous surgical skills allowing an elective one-stage approach.

Single-stage resection of multiple pulmonary ground-glass opacities: A clinical analysis / 中国胸心血管外科临床杂志

@#Objective    To summarize our experience of surgical resection of multiple ground-glass opacity (GGO) in recent years. Methods    Clinical data of patients who underwent one-stage resections of multiple GGO from November 2015 to May 2019 in our hospital were collected, including 13 males and 52 females at an average age of 56.0±9.4 years. The clinical effects and pathological types of GGO were evaluated. Results    Time interval from first discovery to surgery was 8-1 447 (236.5±362.4) days. There were 48 patients with unilateral surgery and 17 patients with bilateral surgery during the same period. Except for 2 patients who underwent open thoracotomy due to total thoracic adhesions, other patients underwent video-assisted thoracoscopic surgery (VATS). The mean postoperative hospital stay was 12.2±4.3 days. No severe perioperative complication or death occurred. A total of 156 GGO lesions were resected, 80 lesions were pure GGO, including 58 (72.5%) malignant lesions and 22 (27.5%) benign lesions, with an average diameter of 7.7±3.3 mm and 5.5±2.6 mm, respectively. Another 76 lesions were mixed GGO, including 69 (90.8%) malignant lesions and 7 (9.2%) benign lesions, with an average diameter of 13.6±6.6 mm and 7.7±3.5 mm, respectively. Conclusion    Patients with multiple GGO should be treated with anti-inflammatory therapy firstly. When conservative treatment is ineffective and no benign outcomes are observed, surgical treatment should be considered. And when lung function is sufficient for patients to underwent surgeries, the simultaneous unilateral or bilateral thoracoscopic resection is suggested, and the sublobar resection or lobectomy methods can be adopted flexibly according to the clinical features of the lesion and the rapid pathological results, which will not increase the risk of postoperative complications. Otherwise, surgical resection should be given priority for pure GGO lesions with a diameter > 7.7 mm and mixed GGO lesions.

Application of video-assisted thoracoscopic anatomic segmentectomy in single-stage bilateral thoracic surgery for the treatment of bilateral localized bronchiectasis / 中国胸心血管外科临床杂志

@#Objective    To explore the safety and feasibility of the application of video-assisted thoracic surgery (VATS) anatomic segmentectomy in single-stage bilateral thoracic surgery for the treatment of bilateral localized bronchiectasis. Methods    From June 2014 to June 2018, 19 patients with bilateral localized bronchiectasis underwent single-stage bilateral thoracic surgery with VATS anatomic segmentectomy, including 11 males and 8 females aged 38.0±12.5 years. The clinical efficacy of the surgery was evaluated. Results    All surgeries were successfully completed, of which 17 were bilateral VATS, 2 were unilateral VATS with the other lateral converted to thoracotomy. The average number of bilateral resected segments was 4-8 (5.9±1.2). Mean operation time was 330.0±40.0 min and mean blood loss was 150.0±60.0 mL. Mean ventilator-assisted breathing time was 6.0±1.8 h, mean duration of chest-tube placement was 4.0±1.0 d and mean hospital stay time was 14.0±1.5 d. Three patients suffered pulmonary infection and 1 patient received tracheotomy. No perioperative death occurred. Arterial oxygen pressures on postoperative day (POD) 1 (F=340.18, P<0.05) and POD 3 (F=131.26, P<0.05) were significantly lower than that before operation, arterial carbon dioxide pressures on POD 1 (F=46.62, P<0.05) and POD 3 (F=48.21, P<0.05) were significantly higher than that before operation, and pulse oximeter saturation on POD 1 was significantly lower than that before operation (F=210.82, P<0.05). The patients were followed up for one to five years without recurrence. Conclusion    Application of VATS anatomic segmentectomy in single-stage bilateral thoracic surgery for the treatment of bilateral localized bronchiectasis is safe and feasible with strictly selected patients. Postoperative airway management is very important. The surgery is worthy of wide clinical practice.

Single-stage "Fix and Flap" gives Good Outcomes in Grade 3B/C Open Tibial Fractures: A Prospective Study

@#Introduction:Grade 3B/C open tibial fractures with grossly contaminated degloving injuries have poor outcomes, with or without vascular injuries. Treatment decision oscillates between limb salvage and amputation. The standard protocol of repeated debridement and delayed wound cover is a challenge in developing countries due to overcrowded emergencies and limited operating room availability. We present results of our modified protocol involving primary stabilisation with external fixation and immediate wound cover as an aggressive modality of treatment. Material and Methods:Thirty-three patients with severe open tibial shaft fractures were managed using a standardised protocol of emergent debridement, external fixation and immediate wound cover with free distant/local rotational muscle flaps and fasciocutaneous flaps, and with vascular repair in Grade 3C fractures. Intra-articular fractures were excluded. Patients were followed for a minimum of three years, with an assessment of clinical, radiological and functional outcomes. Results: Wound cover was achieved with 24 distant free muscle flaps, four local rotational muscle flaps and five fasciocutaneous flaps. All fractures united with an average time to union of 40.3 weeks (16-88). Fifteen patients (45.4%) underwent only a single major surgery using primary definitive external fixation. Deep infection was seen in four patients (12.1%). Nineteen patients had excellent to good outcomes, six were fair, and eight were poor. Conclusion: “Fix and Flap” in the same sitting, using immediate wound cover and external fixation, has given good results in our hands despite the delayed presentation, the neurovascular deficit and the degloving injury. This may be a better management strategy in overcrowded tertiary care centres of developing countries, with a single surgical procedure in almost half the cases.

Single Stage Cementless Bilateral Total Hip Replacement Surgery: Case Report And Review Of Literature

Two staged bilateral total hip replacement (THR) is commonly performed for bilateral hip end stage arthritis and is preferred as THR is a complex planned surgery and performing both sides simultaneously may be fraught with risks and complications. However, many studies now indicate that in carefully selected patients , single stage or simultaneous bilateral THR can be performed with successful and cost effective results. We report a case of one-stage bilateral THR performed in a 22 year old with bilateral severe arthritis due to ankylosing spondylitis. Patient was severely disabled due to pain and was only ambulating on wheelchair. After a successful single stage bilateral THR, patient recovered fully and after 6 weeks was walking independently without any pain, with full function of both hips and performing his occupation normally. The surgical costs to the patient and hospital were both economical. We conclude that single stage bilateral THR is a better surgical option for young and fit patients with bilateral hip arthritis.

Efficacy evaluation of one-stage revision combined with intra-articular injection of antifungal agents in the treatment of chronic periprosthetic fungal infection / 中华外科杂志

Objective@#To investigate the clinical effect of one-stage revision combined with intra-articular injection of antifungal agents in the treatment of chronic periprosthetic fungal infection.@*Methods@#A retrospective analysis of 11 patients(4 hips, 7 knees) admitted with chronic periprosthetic fungal infection at Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University from January 2004 to April 2016.There were males and females with an age of 67 years (range:47-77 years). Each patient underwent single-stage revision including aggressive soft-tissue debridement. Liquid samples and tissue samples were immediately sent to the microbiology laboratory for drug sensitivity testing and histological analysis. Removed the infected components and cement thoroughly, pouring powdered vancomycin into the medullary cavity and direct intra-articular injection of fungussensitive antibiotics. The patients with infected hips received an uncemented prosthesis and 0.5 g of gentamicin loaded commercial cement was received by the patients with infected knee.After that, a new prosthesis was implanted.Long-term combination therapy of antibacterial agents and antifungal agents were given after operation. Recurrence of infection and clinical outcomes were evaluated. The follow-up period was 5 years (range: 2-12 years).@*Results@#One patient died of acute heart failure on the eighth postoperative day.Three infection cases were recurred.Eight cases had satisfactory outcomes and required no additional surgical or medical treatment for recurrence of infection. The Harris hip score assessed preoperatively and at latest follow-up was increased from 39.25±5.12 to 79.50±4.79, the difference was statistically significant (t=-11.356, P=0.001).The Hospital for Special Surgery knee score was improved from preoperative 46.25±5.61 to final follow-up 80.50±5.06, and the difference was statistically significant (t=-9.930, P=0.002).@*Conclusion@#Treatment of chronic fungal periprosthetic joint infection with single-stage revision can be fairly effective for achieving acceptable functional outcomes.

Single-stage bilateral pulmonary resections by video-assisted thoracic surgery for multiple small nodules / 中国胸心血管外科临床杂志

@#Objective To share the experience of single-stage bilateral pulmonary resections by video-assisted thoracic surgery (VATS) for multiple nodules. Methods Clinical records of patients undergoing one-stage bilateral resections of multiple pulmonary nodules between January 2015 and December 2016 in our institution were retrospectively reviewed and analyzed. There were 9 males and 15 females, aged from 33 to 69 (55.0±8.0) years. Two patients underwent bilateral lobectomy. Lobar-sublobar (L/SL) resection and bilateral sublobar resection (SL-SL) were conducted in 9 patients and 13 patients respectively. Results All operations completed successfully. Operation time was 135–330 (231.4±59.1) min, duration of use of chest drains was 2–17 (5.4±3.1) days. Overall duration of hospitalization after surgery was 5–37 (8.6±6.3) days. There was no perioperative death. Postoperative course was uneventful in 17 (70.8%) patients. The postoperative complications included one patient of incision infection and one patient of pulmonary infection. Persistent air leak for >3 days duration and unilateral pleural drainage for more than 200 ml/d were observed in 3 patients and 2 patients respectively. Conclusion Single-stage bilateral surgery in selected patients with synchronous bilateral multiple nodules is feasible and associated with satisfactory outcomes.

Single Stage Transanal Endorectal Pull-through Operation for Hirschsprung’s Disease in Neonate: A Single Center Experience / 소아외과

PURPOSE: The single stage transanal pull-through (SSPT) for Hirschsprung’s disease is becoming the most popular procedure. This single center study compared the result of single stage operation with two-stage operation for Hirschsprung’s disease in neonates. METHODS: We retrospectively reviewed medical records of all patients who were diagnosed as Hirschsprung’s disease and underwent SSPT or two-stage operation operation in Asan Medical Center between January 2003 and July 2014. RESULTS: There were 17 SSPT and 28 two-stage operation. The mean age of SSPT group was 14.2±7.1 days, and the mean age of two-stage operation group was 15.4±8.6 days for stomy formation, and 188.6±36.3 days for Duhamel operation. The operation time of SSPT was shorter than Duhamel operation (145.0±37.0 minutes vs. 193.0±36.0 minutes, p<0.001). The mean follow-up period of SSPT and two-stage operation was 35.5±34.9 months (range, 2-132 months) and 56.6±35.5 months (range, 1-121 months), respectively. Defecation problem rate such as fecal soiling or fecal impaction showed no significant difference between the two groups (p=0.719). Two SSPT patients required botulinum toxin injection due to rectal stenosis. Three patients of SSPT group underwent re-do endorectal pull-through due to remnant aganglionic or hypoganglionic bowel. CONCLUSION: The SSPT showed shorter hospital days. However, few patients experienced rectal stenosis, but were manageable with botulinum toxin injection. The SSPT requires experienced-pathologist, as well as surgeon, because intra-operation pathology reading is critical for appropriate SSPT. SSPT is a feasible and reasonable option to treat Hirschsprung’s disease.

Single Stage Reduction Operation for Treatment of Toe Macrodactyly in Skeletally Immature Patients / 대한정형외과학회잡지

Macrodactyly is one of the most difficult congenital anomalies to treat. Treatment of macrodactyly requires surgical intervention because it gives rise to esthetic, social, and functional disability including difficulty in wearing shoes. A myriad of surgical techniques has been introduced to reduce the size of macrodactyly. However, treatment of toe macrodactyly has not been spotlighted due to less significant functional and social issues compared with finger macrodactyly. We treated two patients with toe macrodactyly by single stage reduction operation.

Results of Surgical Treatment for Congenital Vertical Talus / 대한정형외과학회잡지

PURPOSE: We performed clinical and radiological evaluation of surgical outcomes of congenital vertical talus. MATERIALS AND METHODS: Fifteen surgically treated feet in 9 patients (6 bilateral and 3 unilateral) which were followed-up for at least 2 years were included. Mean patient age at the time of surgery was 10.9 months. The surgical technique was a one-stage correction using the Kumar technique with a Cincinnati skin incision. In 7 feet we also transferred half of the tibialis anterior to the talar neck (the Grice technique). Radiologic parameters (talo-calcaneal angle, talo-first metatarsal angle, tibio-talar angle, tibio-calcaneal angle) were analyzed pre- and postoperatively and at the last follow-up, and clinical outcomes by the Laaveg-Ponseti score. RESULTS: Talus orientation was improved in all patients. All radiologic parameters showed statistically significant improvement by the last follow-up. The mean Laaveg-Ponseti score at the last follow-up was 16 for patient satisfaction, 16 for function, and 24 for pain. There was no recurrence, however one case of talar neck fracture occurred during the tibialis anterior transfer. CONCLUSION: One-stage surgical correction for congenital vertical talus at an early age provides satisfactory functional and cosmetic results.

Application of aesthetic sub-unit principle in Single-stage Soft tissue reconstruction of a traumatic nasal defects / 局解手术学杂志

Objective To evaluate the cosmetic outcomes of nasal aesthetic sub-unit principle. Methods From May 2007 to March 2015,19 patients with traumatic soft tissue defects of nose had a Single-stage reconstruction with suitable reconstructive method. Full-thick-ness skin transplantation was performed in 1 case,forehead nasal flap in 1 case,bilobed flaps in 2 cases,nasolabial flaps in 9 cases,a folded nasolabial flap in 2 cases,free auricular composite flap in 1 case,the temporal flap pedicled with the orbicular oculi muscle in 3 cases. All pa-tients were followed up for 5~27 months,evaluation items were recorded and analyzed. Results Skin transplantation and local flap were all survived. But 1 case with nasolabial flap infected was healing by second intention,the rest were primary healing,free auricular composite flap was gloomy,and it became normal 5 months after operation. The radian and the curve of the folded nasolabial flap to repair the nasal alar area were slightly poor. Condusion Good aesthetic effets come from nasal aesthetic sub-unit principle in Single-stage soft tissue reconstruction of a traumatic nasal defects.

Major Surgical Treatment of Osteoporotic Vertebral Fractures in the Elderly: A Comparison of Anterior Spinal Fusion, Anterior-Posterior Combined Surgery and Posterior Closing Wedge Osteotomy

STUDY DESIGN: A retrospective study. PURPOSE: To clarify the differences among the three major surgeries for osteoporotic vertebral fractures based on the clinical and radiological results. OVERVIEW OF LITERATURE: Minimally invasive surgery like balloon kyphoplasty has been used to treat osteoporotic vertebral fractures, but major surgery is necessary for severely impaired patients. However, there are controversies on the surgical procedures. METHODS: The clinical and radiographic results of patients who underwent major surgery for osteoporotic vertebral fracture were retrospectively compared, among anterior spinal fusion (group A, 9 patients), single-stage combined anterior-posterior procedure (group AP, 8 patients) and posterior closing wedge osteotomy (group P, 9 patients). Patients who underwent revision surgery were evaluated just before the revision surgery, and the other patients were evaluated at the final follow-up examination, which was defined as the end point of the evaluations for the comparison. RESULTS: The operation time was significantly longer in group AP than in the other two groups. The postoperative correction of kyphosis was significantly greater in group P than in group A. Although the differences were not significant, better outcomes were obtained in group P in: back pain relief at the end point; ambulatory ability at the end point; and average loss of correction. CONCLUSIONS: The posterior closing wedge osteotomy demonstrated better surgical results than the anterior spinal fusion procedure and the single-stage combined anterior-posterior procedure.

Comparative Study of Postoperative Complications in Patients With and Without an Obstruction Who Had Left-Sided Colorectal Cancer and Underwent a Single-Stage Operation After Mechanical Bowel Preparation

PURPOSE: The purpose of this study is to compare postoperative complications for single-stage surgery after mechanical bowel preparation in patients who experienced obstruction and those who did not. METHODS: From 2000 to 2011, 1,224 patients underwent a single-stage operation for left colorectal cancer after bowel preparation. Nonobstruction (NOB) and obstruction (OB) colorectal cancer patients were 1,053 (86.0%) and 171 (14.0%), respectively. Postoperative morbidity and mortality were compared between groups. RESULTS: The OB group had poor preoperative conditions (age, white blood cell, hemoglobin, albumin level, and advanced tumor stage) compared with the NOB group (P < 0.05). Mean on-table lavage time for the OB group was 17.5 minutes (range, 14-60 minutes). Mean operation time for the OB group was statistically longer than that of the NOB group (OB: 210 minutes; range, 120-480 minutes vs. NOB: 180 minutes; range, 60-420 minutes; P < 0.001). Overall morbidity was similar between groups (NOB: 19.7% vs. OB: 23.4%, P = 0.259). Major morbidity was more common in the OB group than in the NOB group, but the difference was without significance (OB: 11.7% vs. NOB: 7.6%, P = 0.070). Postoperative death occurred in 16 patients (1.3%), and death in the OB group (n = 7) was significantly higher than it was in the NOB group (n = 9) (4.1% vs. 0.9%, P = 0.001). Twelve patients had surgical complications, which were the leading cause of postoperative death: postoperative bleeding in five patients and leakage in seven patients. CONCLUSION: Postoperative morbidity for a single-stage operation for obstructive left colorectal cancer is comparable to that for NOB, regardless of poor conditions of the patient.

Single stage surgery for Blepharophimosis syndrome.

Purpose: The purpose of this study was to report the functional and cosmetic outcome of single stage surgical procedure for correction of the classic components of Blepharophimosis syndrome. Materials and Methods: We report a retrospective case file review of 11 patients with Blepharophimosis syndrome operated between July 2004 and April 2008. Each patient had undergone the correction of epicanthus inversus, telecanthus, palpebral phimosis, and bilateral ptosis as a single-stage surgical procedure. Patients were examined and photographed before and after surgery. The mean follow-up was 3 years (range 2-6 years). Results: A total of 11 patients (8 males, 3 females) with a mean age of 9 years (range 6--22 years) were reviewed. The surgical outcome was assessed both functionally and cosmetically. The mean preoperative visual acuity was 0.729 ± 0.316 SD and the mean postoperative visual acuity was 0.856 ± 0.277 SD (P <0.0428). There was a statistically significant decrease of astigmatism following ptosis correction (P<0.05), improvement of telecanthus (P<0.0001) in terms of IICD (inner intercanthal distance), and HPFL (horizontal palpebral fissure length) (P=0.019) along with improvement of the superior visual field. The mean preoperative and postoperative IICD was 3±0.33 SD and 2.418 ± 0.189 SD, respectively. There was also a significant postoperative improvement of ptosis (P< 0.01), as measured by IPFH (vertical interpalpebral fissure height). All the patients had a stable functional and cosmetic result after a mean follow-up period of 3 years. Conclusion: Single-stage surgical correction of the classic anomalies of Blepharophimosis syndrome provides stable and successful long-term results.

Wide Palatal Cleft - Single Stage or Two Stage Closure.

Clefts of lip and palate presents a distressing blow to the family of the patient and their surgical correction a challenging task for the reconstructive surgeon. The patients affected with this deformity are handicapped by the psychological feeling of separation from the society in addition to the horror of a chain of surgeries and visits to the dental office. In addition to these single procedures requiring two stage approach add to the existing sequence further hampering the psychological well being of the patient. Closure of a wide palatal cleft often entails a two stage closure to ensure proper speech and functional outcomes to prevent future dehiscence of wounds leading to fistulae formation. This paper discusses the report of a patient reporting with wide palatal cleft of hard and soft palate treated by a single stage closure in an attempt to reduce the number of surgical procedures for the patient, resulting in a satisfactory treatment outcome considering the width of the cleft and age of the patient at the time of presentation.

Single-Stage Removal of Thoracic Dumbbell Tumors from a Posterior Approach Only with Costotransversectomy

PURPOSE: Thoracic dumbbell tumors are relatively rare, usually arising from neurogenic elements. Methods for surgical removal thereof remain controversial. The purpose of this study was to evaluate the surgical results of a single-stage posterior approach with laminectomy and costotransversectomy only for the management of thoracic dumbbell tumors. MATERIALS AND METHODS: Eight cases of thoracic large dumbbell tumor were analyzed retrospectively: seven men and one woman (mean age, 49 years). Pathologic findings included schwannoma in five patients, neurofibroma in two patients (Recklinghausen in one patient), and ganglioneuroma in one patient. All patients underwent single-stage removal of dumbbell tumors by a posterior approach followed by laminectomy and costotransversectomy combined with instrumentation. Clinical and radiologic outcomes were reviewed, thereafter. RESULTS: Operative time ranged from 185 to 420 minutes (mean, 313 minutes), with estimated blood loss ranging from 71 to 1830 mL (mean, 658 mL). Postoperative complications included atelectasis in one case. All patients had tumors successfully removed with no neurological deterioration. Spinal deformities were not observed in any patients at the last follow-up (mean, 52 months), with instrumentation. CONCLUSION: Single-stage surgery with laminectomy and costotransversectomy may be useful for removing thoracic dumbbell tumors without a combined anterior approach.

Four Cases of Single-Stage Surgery of Abdominal Aortic Aneurysm with MIDCAB on Revascularization / 日本心臓血管外科学会雑誌

Many patients with abdominal aortic aneurysm have coexisting coronary artery disease. There is no evidence regarding the safety or efficacy of surgery, or whether surgery should be done in 1 session or in more than 1 session. Single-stage surgery is generally more invasive. We performed single-stage surgery using minimally invasive direct coronary artery bypass graft surgery (MIDCAB) for revascularization in 4 patients with abdominal aortic aneurysm and coronary artery disease. The average operation time was 399 min. The average number of bypassed grafts was 1.75 per patient. All patients were extubated within 24 h after surgery. The average discharge time was 29.3 postoperative days. No patients died during surgery or during hospitalization. Multidetector-row CT scan showed all bypassed grafts to be patent. MIDCAB surgery is safe and effective for revascularization in performing single-stage surgery in patients with abdominal aortic aneurysm and coronary artery disease.

Comparação de métodos para mapeamento digital de solos com utilização de sistema de informação geográfica / Comparison of methods for digital soil mapping using a geographical information system

Mapas pedológicos são fontes de informações primordiais para planejamento e manejo do uso do solo, porém apresentam altos custos de produção. A fim de produzir mapas de solos a partir de mapas existentes, neste trabalho, foram comparados métodos de classificação em estágio único (Regressões Logísticas Múltiplas Multinomiais e Bayes) e em estágios múltiplos (Classification and Regression Trees (CART), J48 e Logistic Model Trees (LMT)) com a utilização de sistemas de informações geográficas e de variáveis geomorfométricas para produção de mapas pedológicos com legenda original e simplificada. A base de dados foi gerenciada em aplicativo computacional ArcGis, em que as variáveis e o mapa original foram relacionados por meio de amostras de treinamento para os algoritmos. Os resultados dos algoritmos obtidos no software Weka foram implementados no ArcGis, para a confecção dos mapas. Foram geradas matrizes de erros para análise de acurácias dos mapas. As variáveis geomorfométricas de declividade, perfil e plano de curvatura, elevação e índice de umidade topográfica são aquelas que melhor explicam a distribuição espacial das classes de solo. Os métodos de classificação em estágio múltiplo apresentaram sensíveis melhoras nas acurácias globais, porém significativas melhoras nos índices Kappa. A utilização de legenda simplificada aumentou significativamente as acurácias do produtor e do usuário.

Soil maps are sources of important information for land planning and management, but are expensive to produce. This paper proposes testing and comparing single stage classification methods (Multiple Multinomial Logistic Regression and Bayes) and multiple stage classification methods (Classification and Regression Trees (CART), J48 and Logistic Model Trees (LMT)) using geographic information system and terrain parameters for producing soil maps with both original and simplified legend. The database was managed in ArcGis computer application in which the variables and the original map were related through training of the algorithms. The results from statistical software Weka were implemented in ArcGis environment to generate digital soil maps. The terrain parameters that best explained soil distribution were slope, profile and planar curvature, elevation, and topographic wetness index. The multiple stage classification methods showed small improvements in overall accuracies and large improvements in the Kappa index. Simplification of the original legend significantly increased the producer and user accuracies, however produced small improvements in overall accuracies and Kappa index.

Significance of Anterior Support in Thoracolumbar Burst Fracture: Single Stage Interbody Fusion with Transpedicular Screw Fixation Versus Pedicle Screw Fixation with Lamina Onlay Fusion

OBJECTIVE: Surgical approaches to unstable burst fractures of the thoracolumbar spine are variable and include anterior decompression with interbody fusion and fixation, anterolateral approach and posterior approach. The purpose of this study is to compare the clinical and radiological results of single-stage interbody fusion with transpedicular screw fixation and pedicle screw fixation with lamina onlay fusion. METHODS: Thirty-five patients with thoracolumbar burst fractures were enrolled in the present study. The subject group was composed of 21 men and 14 women, with a mean age of 47.68+/-13.93 years(range, 19~76 years). Eighteen patients(Group I, anterior-posterior group) were treated with interbody fusion with transpedicular screw fixation with and 17 patients(Group II, posterior only group) were treated with pedicle screw fixation with onlay fusion. Both procedures were performed through single staged posterior approach. The neurological states, clinical outcomes and radiological outcomes were analyzed. Radiologic results were evaluated on the basis of kyphotic angle, percentage of anterior body compression and interbody height immediately after surgery and at the final follow-up examination. RESULTS: Kyphotic angle, anterior body compression rate and interbody height were corrected in both groups. While the correction was maintained in the patients in group I, kyphosis and anterior body compression rate were aggravated in the patients in group II at follow-up. Both groups showed the same or improved modified Frankel grades and pain scores. CONCLUSIONS: Group I showed better correction of kyphotic angle and percentage of anterior body compression than group II. Anterior column support plays an important role in maintaining the correction of kyphosis and this procedure can be effectively performed using single-stage unilateral posterior approach together with transpedicular screw fixation.