Dynamic Characteristics of Lenke3 Type Idiopathic Scoliosis / 医用生物力学

Objective To investigate dynamic response of the finite element model of Lenke3 type scoliosis. Methods The finite element model was established based on CT scanning images from a patient with Lenke3 type scoliosis, and validation of the model was also conducted. Modal analysis, harmonic response analysis and transient dynamic analysis were carried out on the model. Results The first order natural frequency of this model was only 1-2 Hz.The amplitude of the finite element model was the largest at the first natural frequency. At the same resonance frequency, the amplitude of the thoracic curved vertebra was larger than that of the lumbar curved vertebra.The amplitude from T6 vertebra to L2 vertebra decreased successively. Conclusions The degree of spinal deformity may affect the perception of spine vibration, and the higher the degree of spinal deformity, the higher the sensitivity to vibration. The first natural frequency is most harmful to Lenke3 type scoliosis patients. Under cyclic loading, the thoracic curved vertebra is more prone to deformation than the lumbar curved vertebra. The closer to T1 segment, the greater the amplitude of the vibration is.

Effects of the lower energy and pulse stacking in carbon dioxide laser skin treatment: an objective analysis using second harmonic generation

ABSTRACT Purpose To evaluate the effect of fractional carbon dioxide (CO2) laser treatment using lower power associated with pulse stacking within collagen fibers, using second harmonic generation microscopy and computerized image analysis. Methods Twenty male Wistar rats aging eight weeks were used. Each treatment area received a single-pass CO2 fractional laser with different parameters. The 20 animals were divided into two groups and euthanized after 30 and 60 days. Second harmonic generation images were obtained and program ImageJ was utilized to evaluate the collagen organization within all areas. Collagen anisotropy, entropy and optical density were quantified. Results Increased anisotropy over time was observed in all four areas, but only reached statistical significance (p = 0.0305) when the mildest parameters were used (area four). Entropy decreased over time in all areas, but without significance(p = 0.1779) in area four. Density showed an overtime increase only in area four, but no statistical significance was reached (p = 0.6534). Conclusions When combined, the results obtained in this study regarding anisotropy, entropy and density tend to demonstrate that it is possible to achieve collagen remodeling with the use of lower power levels associated with stacked pulses.

Skeletonized bilateral internal mammary artery harvesting with harmonic scalpel in coronary artery bypass grafting / 中国胸心血管外科临床杂志

@#Objective    To summarize the use of harmonic scalpel to harvest bilateral internal mammary artery in coronary artery bypass grafting (CABG). Methods    The clinical data of 54 patients of bilateral skeletonized internal mammary artery harvesting for CABG in our hospital from January 2016 to May 2020 were analyzed retrospectively. There were 51 males and 3 females with a mean age of 62.37±9.56 years. Results    All patients went through the procedure unevently and discharged from hospital. The number of grafts was 4.07±0.85 per patient, the operation time was 267.21±47.00 min, mechanical ventilation time was 342.43±132.17 min and hospital stay was 12.21±4.43 d. Conclusion    It is safe and effective to use harmonic scalpel to harvest skeletonized bilateral internal mammary artery in CABG.

Detection method of nonlinear magnetized harmonic signal of medical magnetic nanoparticles / 生物医学工程学杂志

Medical magnetic nanoparticles are nano-medical materials with superparamagnetism, which can be collected in the tumor tissue through blood circulation, and magnetic particle imaging technology can be used to visualize the concentration of magnetic nanoparticles in the living body to achieve the purpose of tumor imaging. Based on the nonlinear magnetization characteristics of magnetic particles and the frequency characteristics of their magnetization, a differential detection method for the third harmonic of magnetic particle detection signals is proposed. It was modeled and analyzed, to study the nonlinear magnetization response characteristics of magnetic particles under alternating field, and the spectral characteristics of magnetic particle signals. At the same time, the relationship between each harmonic and the amount of medical magnetic nanoparticle samples was studied. On this basis, a signal detection experimental system was built to analyze the spectral characteristics and power spectral density of the detected signal, and to study the relationship between the signal and the excitation frequency. The signal detection experiment was carried out by the above method. The experimental results showed that under the alternating excitation field, the medical magnetic nanoparticles would generate a spike signal higher than the background sensing signal, and the magnetic particle signal existed in the odd harmonics of the detected signal spectrum. And the spectral energy was concentrated at the third harmonic, that is, the third harmonic magnetic particle signal detection that meets the medical detection requirement could be realized. In addition, the relationship between each harmonic and the particle sample volume had a positive growth relationship, and the detected medical magnetic nanoparticle sample volume could be determined according to the relationship. At the same time, the selection of the excitation frequency was limited by the sensitivity of the system, and the detection peak of the third harmonic of the detection signal was reached at the excitation frequency of 1 kHz. It provides theoretical and technical support for the detection of medical magnetic nanoparticle imaging signals in magnetic particle imaging research.

Effects of the lower energy and pulse stacking in carbon dioxide laser skin treatment: an objective analysis using second harmonic generation

ABSTRACT Purpose To evaluate the effect of fractional carbon dioxide (CO2) laser treatment using lower power associated with pulse stacking within collagen fibers, using second harmonic generation microscopy and computerized image analysis. Methods Twenty male Wistar rats aging eight weeks were used. Each treatment area received a single-pass CO2 fractional laser with different parameters. The 20 animals were divided into two groups and euthanized after 30 and 60 days. Second harmonic generation images were obtained and program ImageJ was utilized to evaluate the collagen organization within all areas. Collagen anisotropy, entropy and optical density were quantified. Results Increased anisotropy over time was observed in all four areas, but only reached statistical significance (p = 0.0305) when the mildest parameters were used (area four). Entropy decreased over time in all areas, but without significance(p = 0.1779) in area four. Density showed an overtime increase only in area four, but no statistical significance was reached (p = 0.6534). Conclusions When combined, the results obtained in this study regarding anisotropy, entropy and density tend to demonstrate that it is possible to achieve collagen remodeling with the use of lower power levels associated with stacked pulses.

A comparative study between harmonic scalpel hemostasis and conventional hemostasis in total thyroidectomy

Background: Thyroidectomy is the most commonly performed procedure in endocrine surgery. Since the thyroid gland is highly vascular, therefore, rapid and absolute hemostasis is extremely required. Conventional thyroidectomy is commonly used with acceptable outcomes, however, it is time‑consuming and resulted in significant intraoperative blood loss with the possible risk of postoperative hemorrhage, injury to parathyroid glands and laryngeal nerves. The advent of focus harmonic devices was encouraging for improving safety, effectiveness, and reduction of operative time, especially in thyroid surgery. Aim of this study: The purpose of this study was to analyze the effectiveness and surgical outcomes of using ultrasonic harmonic scalpel for thyroid surgery compared to conventional techniques.Methods: This was a prospective, randomized study in which 60 patients with various types of goiters presented for thyroidectomy. The patients were divided into two comparable groups. Group A (30 patients) included patients who had focus harmonic thyroidectomy and Group B (30 patients) included patients who underwent conventional thyroidectomy.Results: Focus harmonic thyroidectomy showed a significant reduction in operative time, intraoperative blood loss, volume of postoperative fluid drainage and meantime for hospital stay compared with conventional thyroidectomy. There were no significant differences in the incidence of postoperative hypocalcemia, seroma, hematoma, wound infection and laryngeal nerve injury between both groups.Conclusions: Focus harmonic thyroidectomy was a safe, effective, faster, and appealing alternative to conventional technique since it reduced the operative time, intraoperative blood loss, postoperative drainage and hospital stay with comparable postoperative complications.

Impact of different centroid means on the accuracy of orthometric height modelling by geometric geoid method

Background:Orthometric height, as well as geoid modelling using the geometric method, requires centroid computation. And this can be obtained using various models, as well as methods. These methods of centroid mean computation have impacts on the accuracy of the geoid model since the basis of the development of the theory of each centroid mean type is different. This paper presents the impact of different centroidmeans on the accuracy of orthometric height modelling by geometric geoid method.Methods:DGPS observation was carried out to obtain the coordinates and ellipsoidal heights of selected points. The centroid means were computed with the coordinates using three different centroid means models (arithmetic mean, root mean square and harmonic mean). The computed centroid means were entered accordingly into a Microsoft Excel program developed using the Multiquadratic surface to obtain the model orthometric heights at various centroid means. The root meanssquare error (RMSE) index was applied to obtain the accuracy of the model using the known and the model orthometric heights obtained at various centroid means.Results:The computed accuracy shows that the arithmetic mean method is the best among the three centroid means types.Conclusions:It is concluded that the arithmetic mean method should be adopted for centroid computation, as well as orthometric height modelling using the geometric method

A study on patterns of needle - stick injuries among gynaecologic and general surgeons in open surgery

Background: An estimated 3,84,000 percutaneous injuries are reported by HCW in hospitals in the United States each year, placing them at risk of exposure to HIV, HBV, or HCV. Suture needles have been identified as the most frequent cause of injury. They are involved in as many as 44% of such injuries. This study is designed to note the NSI in major gynaecological procedures and surgical procedures using conventional method (CM) versus (VS) use of HK.Methods: Study was conducted over a period of 12 months from January 2017 to December 2017. 60 patients were included in this study and were divided into 2 groups A and B with 30 patients in each group. Group A was major surgery performed by conventional method; Group B was major surgery performed by using harmonic knife. NSI in two groups were studied and analyzed.Results: Most of the operated patients were between 41-50 years age group. 16.6% procedures were emergency and 83.3% were elective. NSI in conventional surgery was 63.3% in the surgeon and 33.3% with harmonic knife. There were 13.3% NSI in first assistant in conventional surgery and 23.3% in harmonic scalpel group. No such injuries were reported by second assistant in either group. Injuries were more in non-dominant hand in either groups in the surgeon and first assistant.Conclusions: It is concluded that NSI are common in surgeons and first assistant. Such injuries are more in non-dominant hand and in procedures where there is little exposure like vaginal hysterectomy. Use of innovative technologies like harmonic scalpel may be useful.

Spinal Accessory Dysfunction Following Neck Dissection with Harmonic Scalpel V/S Electrocautery – A Single Centre Experience

Aims:This study is an effort towards comparing the efficacy of the Harmonic Focus and Electrosurgical technique with regard to nerve injury especially spinal accessory nerve and its morbidity postoperatively after neck dissection.Sample:Ninety patients of oral carcinoma who required neck dissection were included in the study.Study Design:This is a prospective study.Place and Duration of Study:Bhagwan Mahaveer Cancer Hospital & Research Centre, Jaipur, Rajasthan, India for a period of 17 months from November 2016 to March 2018.Methodology:Patients’ post-operative recovery was studied prospectively by using parameters pertaining to shoulder function and shoulder pain.Results:There were significant differences in the pain and abduction deformity at various time periods after surgery. However differences in the quality of life did not show significant difference at the end of 3 months. For up to one month pain scores were lower for Harmonic Focus and shoulder function was better through 3 months.Conclusion:Though the technique of neck dissection (harmonic v/s electro cautery) has significant impact on shoulder dysfunction, despite that in postoperative period shoulder function measured by way of shoulder pain and shoulder abduction recover almost fully during follow-up period without causing significant morbidity and with minimal effect on quality of life. There are few recommendations we would like to suggest that if incorporated, they might significantly affect the outcome and better results.

Clipless Laparoscopic Cholecystectomy: Our Experience

Background:Laparoscopic cholecystectomy (LC) is acceptedas the gold standart treatment of gallstones. Various methodshave been developed to close the cystic duct (CD) and cysticartery (CA), but titanium clip application is currently themost frequently used technique. High-tech electrosurgicalinstruments, such as Harmonic Scalpel (HS), have been usedboth for dissection of the cystic artery and Cystic duct. Thepresent study was conducted to observe and establish efficacyof clipless cholecystectomy, by use of harmonic scalpel as analternative, for division and sealing of cystic artery and cysticduct.Methods: This study was a hospital based, retrospectivestudy, conducted in Govt. Medical College, Srinagar, usingmedical records. A total of 114 patients included in the study,having been operated by a single surgeon over time period of5 years from February 2014 to january 2019.Results: In our study of 114 patients 82 (71.92%) werefemales and 32 (28.07%) were males with average age of41.4years (16-72 yr). No patient was converted to open withaverage operating time of 24.2 minutes (18-46 minutes). Meanhospital study was 1.42 days (1-8 days) with no mortality.Postoperative complications were found in 6 (5.2%) patientswith bile leak from duct of Lushka in 1 (0.8%) patient, portsite infection in 2 (1.7%) patients and fever in 3 (2.6%)patients.Gallbladder perforation intraoperatively was seen in7 (6.2%) patients.Conclusions:Use of harmonic scalpel is an excellent optionfor the cystic duct closure with less time consumption and lesscomplications

Outcomes of Congenital Talipes Equinovarus Treated with Ponseti Method

Introduction: Idiopathic clubfoot or congenital talipesequinovarus is characterized by an excessively turned-infoot and a high medial longitudinal arch is the commonestcongenital foot deformities having 1 in every 1000 childrenborn worldwide. Though described long back, there has beenan interest towards Ponseti method of conservative treatmentof clubfoot recently. Our study was aimed to assess theefficacy of Ponseti technique in correcting congenital talipesequinovarus deformity of foot.Material and methods: 65 patients were enrolled in the studyout of which 47 patients were available for final follow-up. Allpatients presenting with CTEV with age up to 2 years wereincluded and patients more than 2 years, operated cases andsyndromic clubfoot were excluded. We treated all patientswith Ponseti method of serial casting and tenotomy.Results: Out of the total 65 feet studied, 42 feet (64.62%)required tendo achilles tenotomy and 23 feet (35.38%) weretreated with casting alone and tenotomy was not required.In our study, there were 8 cases of relapes (12.31%).Out ofthese, 7 were idiopathic and 1 was syndromic. Out of these 8relapses, 2 required repeat tenotomy and 6 were treated withcasting as per ponseti technique. Complications due to plasterwere minimal in our study. Incidence of rocker bottom feet inour study is nil because of dedicated clubfoot manipulation inclubfoot clinic and patients were followed up regularly.Conclusion: To conclude, this study showed that clubfootdeformity can be managed successfully provided the techniqueand details of manipulation described by Ponseti are followedstrictly and patients can be followed up regularly by a team ofdedicated orthopedic surgeons.

Discussion and improvement methods of quantitative susceptibility mapping reconstruction / 生物医学工程学杂志

To assess the background field removal method usually used in quantitative susceptibility mapping (QSM), and to analyze the cause of serious artifacts generated in the truncated -space division (TKD) method, this paper discusses a variety of background field removal methods and proposes an improved method to suppress the artifacts of susceptibility inversion. Firstly, we scanned phase images with the gradient echo sequence and then compared the quality and the speed of reconstructed images of sophisticated harmonic artifact reduction for phase data (SHARP), regularization enable of SHARP (RESHARP) and laplacian boundary value (LBV) methods. Secondly, we analyzed the reasons for reconstruction artifacts caused by the multiple truncations and discontinuity of the TKD method, and an improved TKD method was proposed by increasing threshold truncation range and improving data continuity. Finally, the result of susceptibility inversion from the improved and original TKD method was compared. The results show that the reconstruction of SHARP and RESHARP are very fast, but SHARP reconstruction artifacts are serious and the reconstruction precision is not high and implementation of RESHARP is complicated. The reconstruction speed of LBV method is slow, but the detail of the reconstructed image is prominent and the precision is high. In the QSM inversion methods, the reconstruction artifact of the original TKD method is serious, while the improved method obtains good artifact suppression image and good inversion result of artifact regions.

Development of an Al-load-cell-based wireless ringer's solution monitoring and alarm system: insight into vibrational error correction

In this study, we developed an aluminum-load-cell-based wireless Ringer's solution monitoring and alarm (WRMA) system. The Al load cell was designed with a rectangular shape, and the load was concentrated in the lower beam part of the load cell because of the anisotropic thickness. From the static analysis, we identifi ed the appropriate location for a Wheatstone bridge circuit consisting of four strain gauges. In addition, the modal and harmonic analyses showed that the vibrational frequencies of the hospital environment do not seriously interfere with the output voltage of the Al load cell. However, random vibrations generated by the movement of the WRMA system on various surfaces severely increase the standard deviation of the measured solution weight by ± 10 g or more. Such vibrational error is too large because the average weight of Ringer's solution is 30–40 g at the time of replacing Ringer's solution. Thus, this error could be confusing for nurses and result in mistakes in the timely replacement of the Ringer's solution. However, the standard deviation of the measured weight was dramatically reduced to ± 3 g or less by using the vibration correction algorithm developed in the present study.

A Study Of Harmonic Scalpel Assisted Haemorrhoidectomy At Tertiary Care Centre

Background:Conventional haemorrhoidectomy is still considered as gold standard therapy for grade III &IV haemorrhoids. The conventional haemorrhoidectomy can be made easier with the help of harmonic scalpel with associated less post-operative complications.This study evaluated in a randomized prospective manner the differences in; duration of hospital stay, postoperative complications, symptomatic recurrence and cost effectiveness between conventional and harmonic scalpel assisted haemorrhoidectomy. Methods: The prospective study was carried out in 60 patients of symptomatic grade III & IV haemorrhoids, presented during August 2015 to August 2017. Each group of 30 patients treated with harmonic scalpel assisted haemorrhoidectomy and conventional haemorrhoidectomy; followed up for 6 months for complications. Results: In present study, the severity of pain was significantly more following conventional haemorrhoidectomy than harmonic scalpel assisted haemorrhoidectomy. Urinary retention was more common with conventional haemorrhoidectomy. Anal incontinence had similar incidence in both the groups of haemorrhoidectomy. Two patients had anal stenosis after conventional haemorrhoidectomy as compared to none in the harmonic scalpel group. No recurrence noted in both the groups. Cost effectiveness of the procedure is measured in form of hospital stay and return to daily activity and harmonic scalpel group have advantage over the conventional haemorrhoidectomy group in terms of less hospital stay and early return to daily activity. Conclusion: Harmonic scalpel assisted haemorrhoidectomy appears to be a better procedure compared with conventional haemorrhoidectomy in terms of less post-operative complications and decreased hospital stay in symptomatic patients with grade III & IV haemorrhoids.

Clinical application of harmonic scalpel in subxiphoid and subcostal arch approach for resection of anterior mediastinal lesion / 中国胸心血管外科临床杂志

@#Objective    To evaluate the clinical outcomes of harmonic scalpel in subxiphoid and subcostal arch approach for resection of anterior mediastinal lesion. Methods    We retrospectively analyzed the clinical data of 217 patients with anterior mediastinal lesion at the Department of Thoracic Surgery of Tangdu Hospital of the Fourth Military Medical University from June 2015 to June 2017, among whom 162 underwent thoracoscopic surgery via subxiphoid and subcostal arch approach with harmonic scalpel (a harmonic scalpel group, 95 males and 67 females at an average age of 46.2±18.7 years ranging from 22 to 72 years) and 55 with Ligasure (a Ligasure group, 29 males and 26 females at an average age of 47.7±12.9 years ranging from 31 to 68 years). Operation time, intraoperative blood loss, intraoperative conversion rate, postoperative hospital stay, patients satisfaction score, patients pain score and postoperative complications were compared between both groups. Results    All operations were accomplished successfully, and there was no death or conversion to thoracotomy. There was a statistical difference in operation time (58.6±34.8 min vs. 72.8±32.6 min, P=0.01), and intraoperative blood loss (36.2±18.7 ml vs. 41.9±12.9 ml, P=0.04). There was no statistical difference between the two groups in length of hospital stay (4.2±2.6 d vs. 4.5±1.9 d, P=0.36), pain score at postoperative day 1, 3 and 30 (8.3±0.9 vs. 8.5±0.6, P=0.13; 6.4±1.5 vs. 6.9±1.1, P=0.19; 1.3±0.7 vs. 1.4±0.9, P=0.40), patients’ satisfaction score (8.6±1.2 vs. 8.4±1.7, P=0.34), or incidence of postoperative complications (5.6% vs. 9.1%, P=0.35). Conclusion    Har-monic scalpel plays an important role in resection of anterior mediastinal lesion via subxiphoid and subcostal arch approach. All tissues are separated and blood vessels are dissected only by the harmonic scalpel, so it is very important for   us to handle the harmonic scalpel skillfully.

Harmonic scalpel in thoracoscopic surgery for lung cancer: A case control study / 中国胸心血管外科临床杂志

@#Objective    To evaluate the clinical effects of harmonic scalpel application in thoracoscopic surgery for lung cancer, which may guide its reasonable application. Methods    We retrospectively analyzed the clinical data of 145 lung cancer patients receiving thoracoscopic surgery from January to March 2017 in our hospital. There were 57 patients with thoracoscopic pulmonary wedge resection, and harmonic scalpel was used in 34 patients (8 males, 26 females at age of 59.68±10.91 years), and was not used in 23 patients (13 males and 10 females at age of 59.13±11.21 years). There were 88 patients receiving thoracoscopic pulmonary lobectomy, among whom harmonic scalpel was used in 80 patients (36 males and 44 females at age of 59.68±10.91 years), and was not used in 8 patients (5 males, 3 females at age of 61.63±5.60 years). We recorded the perioperative outcomes of all patients. Results    In the 34 patients undergoing thoracoscopic pulmonary wedge resection by harmonic scalpe, the operation time was 90.09±43.52 min, the blood loss was 21.32±12.75 ml, the number of lymph nodes resected was 5.12±4.26, duration of drainage was 3.15±1.16 d, volume of drainage was 535.00±291.69 ml, the length of postoperative hospital stay was 4.56±1.40 d, and no postoperative complication was observed. In the 80 patients receiving thoracoscopic pulmonary lobectomy by harmonic scalpel, operation time was 131.88±41.82 min, blood loss was 42.79±31.62 ml, the number of lymph nodes resected was 13.54±8.75, duration of thoracic drainage was 4.47±2.30 d, drainage volume was 872.09±585.24 ml, the length of postoperative hospital stay was 5.81±2.26 d, and 20 patients had postoperative complications. No complication occurred in the 8 patients without harmonic scalpel. Conclusion    Harmonic scalpel showed satisfactory effectiveness and safety in lung cancer thoracoscopic surgery.

Clinical outcomes of harmonic scalpel in esophageal cancer surgery / 中国胸心血管外科临床杂志

@#Objective    To assess the outcome of harmonic scalpel (HS) in esophageal cancer surgery and to provide evidence for the role of HS in the enhanced recovery after surgery (ERAS) and short-term prognosis after esophageal cancer surgery. Methods    We collected the clinical data of 81 esophageal cancer patients receiving surgery by HS between January 1 and December 31, 2016 and successfully followed up in our department. There were 67 males and 14 females with an average age of 64.07±7.52 years. Sweet approach was adopted in 16 patients, Ivor-Lewis approach in 23 and McKeown approach in 40. Intrathoracic anastomosis was completed in 41 patients and cervical anastomosis in 40. The length of total hospital stay and postoperative hospital stay, operation time, intraoperative blood loss, duration and volume of thoracic drainage and perioperative complications were recorded and compared in patients with different surgical approaches and anastomosis sites. Results    For these 81 patients, the operation time was 276.7±70.4 min, and the intraoperative blood loss was 115.9±69.7 ml. The postoperative duration of thoracic drainage, postoperative complication rate and the drainage volume were 12.3±5.3 d, 35.80% and 1 411.9±1 199.5 ml, respectively. During the follow-up, 15 patients died and the cumulative survival rate was 81.48%. There was no obvious HS-related complication. The operation time of Sweet approach was shorter than that of Ivor-Lewis or McKeown approach (P=0.012) and the dissected lymph nodes were less in Sweet approach (P=0.035). There was no significant difference in perioperative indexes and postoperative short-term prognosis between intrathoracic anastomosis and cervical anastomosis. Conclusion    HS is widely used in the surgery for esophageal cancer with safety and effectiveness, which is worthy of clinical application.

Clinical Value of Contrast-Enhanced Harmonic Endoscopic Ultrasonography in the Differential Diagnosis of Pancreatic and Gallbladder Masses

BACKGROUND/AIMS: Recent studies have revealed that contrast-enhanced harmonic endoscopic ultrasonography (CEH-EUS) is beneficial in the differential diagnosis of malignant neoplasms of the pancreas and gallbladder from benign masses, in terms of the evaluation of microvasculature and real-time perfusion. In this study, we aimed to prove the clinical value of CEH-EUS in the differential diagnosis of pancreatic and gallbladder masses by direct comparison with that of conventional EUS. METHODS: We reviewed the sonographic images and medical information of 471 patients who underwent conventional EUS and CEH-EUS for the diagnosis of pancreatic and gallbladder masses at a single medical center (Severance Hospital, Seoul, Korea) between March 2010 and March 2016. RESULTS: The enhancement pattern of CEH-EUS of the pancreatic solid masses showed higher sensitivity and specificity in differentiating pancreatic adenocarcinoma and neuroendocrine tumors (82.0% and 87.9% for pancreatic adenocarcinoma and 81.1% and 90.9% for neuroendocrine tumors, respectively), and the area under the receiver operating characteristic curves was higher than that of conventional EUS. The enhancement texture of CEH-EUS of the gallbladder masses showed a higher sensitivity in differentiating malignant masses than that of conventional EUS; however, the difference between the areas under the receiver operating characteristic curves was not statistically significant. CONCLUSIONS: CEH-EUS can complement conventional EUS in the diagnosis of pancreatic and gallbladder masses, in terms of the limitations of the latter.

Dynamic Characteristics of an Adolescent Idiopathic Scoliotic Spine / 医用生物力学

Objective To establish the three-dimensional (3D) finite element (FE) model of thoracolumbosacral T1-S spine based on the computed tomography (CT) images of patients with scoliosis and study its dynamic characteristics. Methods The established scoliotic model was validated by axial compression and shear loading, and the predicted responses were in good agreement with the experimental data. The modal and harmonic analyses were performed using the ABAQUS software, and during the harmonic analysis, the dynamic response of the model was collected at frequencies 5 Hz and 10 Hz. Results From the modal analysis, the first fourth-order modal was extracted. The first- and second-order resonant frequencies of the model were 1.097 Hz and 1.384 Hz, respectively, and the vibration mode was longitudinal bending and lateral bending, respectively. The distribution of the second- and third-order modal resonant frequencies were 5.688 Hz and 28.090 Hz, and the vibration mode was vertical vibration and twisting around the long axis, respectively. The peak amplitude in the harmonic analysis appeared near the modal frequencies, and the average amplitude of vertebral body of the lateral convex segment was larger than that of other segments of the scoliotic spine. Under the vibration frequencies of 5 Hz and 10 Hz, the stress inhomogeneously concentrated on the concave and convex sides of the segments of the vertebral deformity as well as on the intervertebral disc. Conclusions The segments of the spinal deformity in patients with scoliosis were the weak links of their spines and more vulnerable to damage in a vibrating environment. Patients with scoliosis should avoid a vibrating environment, particularly in a sensitive frequency range. The research outcomes provide methodological assistance and mechanical analysis references for the protection, rehabilitation treatment, and clinical pathological studies of patients with scoliosis.

Contrast Enhanced Harmonic Endoscopic Ultrasound: A Novel Approach for Diagnosis and Management of Gastrointestinal Stromal Tumors

The histologic analysis of gastrointestinal stromal tumors (GISTs) is a common method to detect the mitotic activity and to subsequently determine the risk of GISTs for malignancy. The potential false negative error due to inadequate yield of specimens and actual determination of malignancy risk requires analysis of the whole tumor. We aimed to assess the role of contrast enhanced endoscopic ultrasound (CE-EUS) in the management of GISTs. Two authors individually did review of English literatures to identify nine peer-reviewed original articles using keywords- contrast endoscopic ultrasound, GIST and submucosal tumor. Studies were heterogeneous in their aims looking either at differentiating submucosal lesions from GISTs, estimating malignant potential of GISTs with histologic correlation or studying the role of angiogenesis in malignant risk stratification. CE-EUS had moderate to high efficacy in differentiating GISTs from alternative submucosal tumors. CE-EUS had a higher sensitivity than EUS-guided fine needle aspiration, contrast computed tomography and Doppler EUS for detection of neo-vascularity within the GISTs. However, the evidence of abnormal angiogenesis within GIST as a prognostic factor needs further validation. CE-EUS is a non-invasive modality, which can help differentiate GISTs and provide valuable assessment of their perfusion patterns to allow better prediction of their malignant potential but more experience is needed.