Directional Filter, Local Frequency Estimate and Algebraic Inversion of Differential Equation of Psoas Major Magnetic Resonance Elastography

Magnetic resonance elastography (MRE) can visualize the shear wave propagation of in vivo tissues, which can be mapped into viscoelastic properties. No study has measured the biomechanical properties of the PM muscle in vivo using MRE. In this study, we evaluated stiffness values calculated by local frequency estimate (LFE) and algebraic inversion of differential equation (AIDE) in PM-MRE. The PM muscles of 17 healthy male volunteers were scanned in supine position by MRE. The Laplacian-based estimate (LBE) phase wrapped image data were filtered by gaussian-bandpass filter (GBF), and by both directional and GBF. LFE (MREWave) and AIDE wave inversion methods were used to calculate the respective elastograms. The wave interferences were removed by directional filtering, and smooth wave fields were obtained. The stiffness values calculated by LFE of non-DF images were 1.39 ± 0.25 kPa and 1.33 ± 0.22 kPa for right and left PM respectively, whereas for DF images, they were 1.26 ± 0.20 kPa for right PM and 1.18 ± 0.28 kPa for left PM. The stiffness values calculated by AIDE of non-DF images were 0.78 ± 0.10 kPa and 0.78 ± 0.13 kPa for right and left PM respectively, whereas for DF images, they were 0.73 ± 0.12 kPa for right PM and 0.74 ± 0.11 kPa for left PM. There was no statistically significant difference in mean values of stiffness with/without applying directional filter whereas there was a statistically significant difference in mean values of stiffness between LFE and AIDE. Both LFE and AIDE could be used for psoas major MR Elastography.

A study to investigate needle insertion at Shenshu(BL23) to puncture psoas major muscle

OBJECTIVE： It is unknown whether the psoas major muscle, thought to be a key muscle for treatment of lower back pain, can be punctured at Shenshu（BL23）.METHODS： Twelve dissected specimens were used for studying the needling pathway of BL23 by perpendicularly inserting the depth-measuring blade of a vernier caliper at BL23. Dimensions of psoas muscle were measured. Correlation studies were conducted. In addition, our samples were grouped by gender and underlying medical conditions for analysis.RESULTS： Half（50%） of the needle insertions successfully punctured psoas muscle. The mean depth of needle insertion to puncture psoas muscle（D_（min）） in the group with short-term underlying medical conditions was 38.0 mm（interquartile range 29.0–51.8 mm）, approximately 6 mm deeper than 32.0（29.3–42.5） mm in the group with long-term health problems（P = 0.041）. The cross-sectional area（CSA） of psoas muscle in the former group was on average approximately 1.5 times that of the latter group（P = 0.04）. When the data were analysed by gender, the thickness of psoas muscle in the male group was 19.0（6.5–24.0） mm compared to 19.5（5.8–34.8） mm in the female group（P = 0.02）. The age in the female group（P = 0.04） and the body length of the total group（P = 0.04） negatively correlated to D_（min）.CONCLUSION： Needle insertion at BL23 might be able to puncture psoas muscle. Differences in the CSA of psoas muscle and D_（min） were observed in groups with short-term and long-term underlying medical conditions.

Is sarcopenia effective on survival in patients with metastatic gastric cancer?

BACKGROUND Sarcopenia is a progressively diminishing state characterized by the reduction of muscle mass and density,which is frequently observed in malignancies of solid organs.AIM To assess how sarcopenia affects the overall survival of individuals who have been diagnosed with metastatic gastric cancer.METHODS The study retrospectively included individuals who had been diagnosed with metastatic gastric cancer between January 2008 and December 2020.Sarcopenia was identified through the calculation of the average Hounsfield units(HUAC)using computed tomography(CT)images taken at the time of diagnosis in patients.RESULTS A total of 118 patients with metastatic gastric cancer were evaluated.Sarcopenia was detected in 29 patients(24.6%).The median survival of all patients was 8(1-43)mo.The median survival of patients with sarcopenia was 2 mo,while it was 10 mo for those without sarcopenia(P<0.001).A significant relationship was found between sarcopenia and survival.CONCLUSION Sarcopenia has been observed to impact survival outcomes in various types of solid tumor cancers.Sarcopenic patients can be identified in a short time,easily and inexpensively,by HUAC measurements from CT images used for diagnosis,and survival could be promoted with nutritional support.

Psoas muscle metastasis from cervical carcinoma:Correlation and comparison of diagnostic features on FDG-PET/CT and diffusion-weighted MRI

Psoas muscle metastasis, though rare, is the commonest site of skeletal muscle involvement in cervical carcinoma. The appropriate clinical management of this condition, particularly of the pain related to malignant psoas syndrome, is still evolving and the diagnostic features on conventional morphological imaging modalities are often non specific, with the differential diagnosis lying between sarcoma, hematoma, and abscess. In this report, a comparison of various morphofunctional imaging modalities was made. Fluorodeoxyglucosepositron emission tomography(FDG-PET)/computed tomography(CT) was the first to suspect disease involvement of the psoas muscle, demonstrating intense FDG uptake(compared with the contralateral muscle), while ultrasound showed heterogeneous echotexture, and magnetic resonance imaging(MRI) showed subtle altered signal intensity in the right psoas muscle. Both anatomical imaging modalities and non contrast CT of the PET-CT examination demonstrated a bulky psoas muscle, without any focal abnormality. On diffusionweighted imaging of MRI(DWI-MRI), restricted diffusion of the involved muscle was an important observation. The psoas muscle metastatic involvement was proven histopathologically. Thus, enhanced glucose metabolism and restricted diffusion in the newer noninvasive molecular imaging modalities(e.g., PET/CT and DWI-MRI) could serve as valuable adjunctive parameters in diagnosing this entity in the absence of a focal abnormality in the anatomical modalities. In the treatment response monitoring scenario, FDG-PET/CT demonstrated near complete resolution following administration of 3 cycles of systemic chemotherapy and local external radiotherapy.

Appendicitis with psoas abscess successfully treated by laparoscopic surgery

Although acute appendicitis is a common disease, retroperitoneal abscesses are rarely observed. Here, we report a case consisting of a psoas abscess and cutaneous fistula caused by appendicitis. The patient was a 56-year-old male who was introduced to our institution due to an intractable right psoas abscess. Imaging tests had been performed over the previous 3 years; however, clinicians could not find the origin of the abscess and failed to resolve the problem. A successful operation was performed via a laparoscopic approach, and 17 mo have passed without recurrence. The advantage of laparoscopic surgery is well understood in cases of appendicitis with abscesses. However, the indication for laparoscopic approach is not clear for retroperitoneal abscesses. From our experience, we can conclude that appendicitis with retroperitonealabscesses can be managed and treated using a laparoscopic approach.

Value of the controlling nutritional status score and psoas muscle thickness per height in predicting prognosis in liver transplantation

BACKGROUND Patients with end-stage liver disease usually have varying degrees of malnutrition,and severe malnutrition may affect the prognosis of patients after liver transplantation(LT).However,there is no recommended standard for the nutrition assessment of patients waiting for LT,and it is unknown whether malnutrition has an impact on the occurrence of postoperative complications.AIM The study aim was to investigate the value of the controlling nutritional status(CONUT)score and psoas muscle thickness per height(PMTH)in predicting prognosis in LT.METHODS We retrospectively analyzed the clinical data of 313 patients who underwent classic orthotopic LT from January 2016 to December 2018 in Tianjin First Central Hospital affiliated with Tianjin Medical University.The CONUT score is derived from the preoperative serum albumin and total cholesterol levels,and total lymphocyte count.Patients were divided into low(≤4),medium(5–8),and high(9–12)CONUT score groups perioperative characteristics,Clavien-Dindo grade III/IV/V postoperative complications,graft loss and infection,and cumulative postoperative survival in the three groups were compared 3 mo after LT.PMTH was calculated as the ratio of the transverse thickness of the psoas muscle in the umbilical plane to the height of the patient.The cutoff values of receiver operating characteristic curves were determined separately for men and women.The values were 14.1 cm/m2 for women and 17.9 cm/m2 for men.The patients were then divided into low and high PMTH groups by the cutoff values.The comparison of data between the two groups was the same as above.RESULTS Patients with medium and high CONUT scores had lower preoperative serum hemoglobin,more intraoperative red blood cell(RBC)transfusions,longer postoperative intensive care unit stay and hospital stays,higher 7 and 14 preoperative-day serum bilirubin levels,and a higher incidence of postoperative grade III/IV complications and infections than patients with low CONUT scores.Differences in the 3-mo cumulative survival among the three groups were not significant.Patients with a low PMTH had higher preoperative serum urea nitrogen,more intraoperative packed RBC and frozen plasma transfusions,longer times to postoperative ventilator extubation,higher incidence of total postoperative complications,and a lower 3-mo cumulative survival than those with a high PMTH.CONCLUSION A CONUT score≥5 and a low PMTH were both associated with poor prognosis in LT.The CONUT score had no predictive value for short-term patient survival after LT,but the PMTH was predictive of short-term patient survival after LT.

Robotic distal ureterectomy with psoas hitch and ureteroneocystostomy:Surgical technique and outcomes

Use of the da Vinci■surgical robotic system has expanded to numerous upper and lower urinary tract procedures.We describe our surgical technique and perioperative outcome of robotic distal ureterectomy with psoas hitch and ureteroneocystostomy for distal ureteral pathologies.Eight patients with a median age of 69.5 years old underwent robotic distal ureterectomy with psoas hitch and ureteroneocystostomy between April 2009 and August 2014.The entirety of all cases was performed robotically by a single surgeon at a tertiary academic medical center.Median operative time was 285 min(range:210-360 min),estimated blood loss was 50 mL(range:50-75 mL)and median length of hospital stay was 2.5 days(range:1-6 days).There was one post-operative complication,a readmission for dehydration(Clavien Ⅰ).It suggests that robotic distal ureterectomy with psoas hitch and ureteroneocystostomy is a safe and effective minimally invasive alternative for patients with distal ureteral pathology.

Psoas Hematoma Following Lumbar Sympathetic Block in a Patient with Renal and Liver Diseases and Recent Use of Aggrenox

Lumbar sympathetic block is an analgesic procedure frequently performed in chronic pain clinics for ischemic lower limb pain from peripheral arterial disease. Although the lumbar sympathetic ganglia are anatomically near major vascular and neural structures, complications such as severe hemorrhage is rarely reported. Aspirin/extended release dipyridamole (Aggrenox) is indicated for secondary stroke prevention. Stroke is frequently a co-morbid condition in patients with peripheral vascular disease. Interventional pain physicians frequently face the difficulty of deciding whether to continue or stop antithrombotic medications in the periprocedural period because of the devastating consequences of both hemorrhagic and thrombotic complications. Due to a paucity of data, no guidelines have been specifically written for interventional procedures for chronic pain. To aid future decision making, we present a case report of psoas hematoma developed after lumbar sympathetic block in a patient with end stage renal failure and hepatic dysfunction who had limb-threatening ischemia. The patient was treated with Aggrenox until three days before the procedure.

Psoas Muscle Hydatid Cyst Causing Ureteric Compression and Hydronephrosis

Psoas muscle is a rare location for hydatid disease. Here we present a case of infected hydatid cyst left psoas muscle presenting as left flank pain, fever, local flank tenderness, and raised blood counts. Preoperative diagnoses was made by Ultrasonography (USG) and Computed Tomography (CT) abdomen, although serology for hydatid disease was negative.

Hydatid Cyst of the Psoas: A Rare Location

Hydatid cyst of the psoas is rare even in countries endemic to hydatidosis. We hereby report a case of hydatid cyst of the psoas in a 69 years old patient with a history of hypertension and had received left nephrectomy due to a renal abscess 2 years prior to his admission.

Tuberculous Sacroiliitis with Secondary Psoas Abscess: A Case Report

Tuberculous sacroiliitis secondary to a psoas abscess is rare, only a few sporadic cases were reported in the literature. Tuberculous sacroiliitis is rare, usually unilateral, its symptomatology is misleading, its diagnosis is often delayed or even confused with damage to the hip or lumbosacral hinge, most often related to difficulties exploration of the sacroiliac joint. We report the case of a 66-year-old diabetic patient with low back pain, unilateral right with inflammatory appearance, insidious installation, evolving for about 8 months. The diagnosis of tuberculous sacroiliitis was made after biopsy of the sacroiliac joint. CT and MRI are necessary for lesion diagnosis. Tuberculosis treatment was started and the abscess was surgically drained. The aim of this work was to describe the diagnostic pathway of a patient with tuberculous sacroiliitis in a tropical environment. Conclusion: Tuberculous sacroiliitis, secondary to an abscess of the psoas muscle is an unusual cause of hip pain and is likely to be overlooked due to its atypical presentation.

Primary Abscess of the Psoas of the Child: About a Case Observed at the University Hospital Center of Bouake

The primary abscess of the psoas of the child is a rare affection, the pathogenesis of which is still unexplained. The positive diagnosis of this condition is difficult and relies mainly on medical imaging. We report a case of primary psoas abscess in an immunocompetent child, whose diagnosis was facilitated by the provision of abdominal radiography without preparation and abdominal ultrasound. The evolution was favorable thanks to the combination of antibiotic therapy and surgery.

基于动态自适应混沌粒子群优化算法的干线协调控制方法

针对城市道路连续交叉口控制效益较低的问题,提出一种基于动态自适应混沌粒子群优化算法(DACPSOA)的干线协调控制方法。首先,通过分析上下游断面交通需求的相关性,考虑交叉口信号配时、车辆转出、车队离散等因素,在Robertson离散模型的基础上,提出了基于上游交叉口信号配时参数的车流到达率预测。在此基础上,根据车队头车、尾车到达时间与协调相位的绿灯开启时间、结束时间以及非协调相位(左转、右转)车流释放结束时间的关系,建立干线交通双向绿波控制总延误模型;其次,根据总延误模型的特征,设计了一种动态自适应混沌粒子群优化算法;最后,利用微观仿真软件SUMO建立典型的交通环境,仿真结果表明,与传统的数解法和单点控制相比,协调相位的平均延误分别降低了24.97%和57.23%,协调相位的平均停车次数分别降低了27.88%和64.01%,有效提高了交叉口的通行效率。

相敏光放大器色散补偿特性的研究

介绍了一种全新的色散补偿方法———相敏光放大器技术，并以Ｇ６５２光纤为例，将系统中相敏光放大器（ＰＳＯＡ）与掺铒光纤放大器（ＥＤＦＡ）引起的脉冲展宽的差异进行了分析与比较。

超酸POSA催化酯化反应动力学及线性自由能关系

全氟辛基磷酸(C_8F_(17)SO_3H,Perfluorooctanesulfonic acid,POSA)是熔点为90℃的固体超酸.我们首次测得其酸度函数值是-12.11±0.03,并将其用于催化Friedel-Crafts烃基化反应和醇脱水制烯,取得了良好的结果.本文报导我们研究POSA催化酯化反应的动力学和线性自由能关系. 线性自由能关系是研究反应动力学微观过程的有效方法之一.对反应速度常数、平衡常数的测定,对于活化参数△E、△S、△H的计算以及反应机理的深入了解都是非常有用的.近年报导的Wittig反应线性自由能关系的研究即是一例. 我们测定了POSA催化对位取代苯甲酸的乙酯化反应的速率常数k。

Management of abdominal and pelvic abscess in Crohn's disease

Patients with Crohn's disease may develop an abdominal or pelvic abscess during the course of their illness.This process results from transmural in ammation and penetration of the bowel wall,which in turn leads to a contained perforation and subsequent abscess formation.Management of patients with Crohn's related intra-abdominal and pelvic abscesses is challenging and requires the expertise of multiple specialties working in concert.Treatment usually consists of percutaneous abscess drainage(PAD)under guidance of computed tomography in addition to antibiotics.PAD allows for drainage of infection and avoidance of a two-stage surgical procedure in most cases.It is unclear if PAD can be considered a definitive treatment without the need for future surgery.The use of immune suppressive agents such as anti-tumor necrosis factor-α in this setting may be hazardous and their appropriate use is controversial.This article discusses the management of spontaneous abdominal and pelvic abscesses in Crohn's disease.

重塑城市公园开放性--“开放街区化”的理念和启示

研究公园开放的内涵区别于管理开放的研究视角,依据城市空间密度变化和市民步行需求变化,从城市步行空间视角,反思通过管理手段开放的收费公园在空间状态上并未真正开放的现实问题,问题的出现在于收费管理模式引致的空间模式滞后。以公园城市为理念指导、开放街区化为技术路径,鉴别城市中心公园在城市步行网络中现有状态与应承角色之间的差异。多尺度比较传统公园模式与"开放街区"尺度的不协调性,理清传统公园空间模式向开放公园空间模式的转变途径,提出以外部城市空间步行肌理重塑内部公园交通,构建公园空间开放度评价体系(PSOA法)量化开放程度,以期定量描述空间的开放状态,改善并解决空间的开放问题,更好地应对城市中心地区的空间变化需求,服务城市步行体系,实现以人为本的公园空间和管理的双重开放。

Nuances of oblique lumbar interbody fusion at L5-S1:Three case reports

BACKGROUND Oblique lumbar interbody fusion is a mini-open retroperitoneal approach that uses a wide corridor between the left psoas muscle and the aorta above L5.This approach avoids the limitations of lateral lumbar interbody fusion,is considered less invasive than anterior lumbar interbody fusion,and is similarly effective for indirect decompression and improving lordosis while maintaining a low complication profile.Including L5-S1,when required,adds to these advantages,as this allows single-position surgery.However,variations in vascular anatomy can affect the ease of access to the L5-S1 disc.The nuances of three different oblique anterolateral techniques to access L5-S1 for interbody fusion,namely,left-sided intra-bifurcation,left-sided pre-psoas,and right-sided pre-psoas approaches,are illustrated using three representative case studies.CASE SUMMARY Cases of three patients who underwent multilevel oblique lumbar interbody fusion including L5-S1,using one of the three different techniques,are described.All patients presented with symptomatic degenerative lumbar pathology and failed conservative management prior to surgery.The anatomical considerations that affected the decisions to utilize each approach are discussed.The pros and cons of each approach are also discussed.A parasagittal facet line objectively assesses the relationship between the left common iliac vein and the L5-S1 disc and assists in choosing the approach to L5-S1.CONCLUSION Oblique retroperitoneal access to L5-S1 in the lateral decubitus position is possible through three different approaches.The choice of approach to L5-S1 may be individualized based on a patient’s vascular anatomy using preoperative imaging.While most surgeons will rely on their experience and comfort level in choosing the approach,this article elucidates the nuances of each technique.

Robot-assisted laparoscopic ureteroneocystostomy in adults: A single surgeon experience and literature review

Objective:To present our experience and technique with robot-assisted uretero-neocystos tomy(RAUN)procedure in adults.Methods:Between February 2015 and August 2018,a total of 30(34 ureters)patients who un-derwent RAUN surgery under a single surgeon were retrospectively reviewed.Perioperative data such as age,sex,body mass index(BMI),American society of anesthes iologists score,esti-mated blood loss,surgical technique,operative time,complications,length of hospital stay,and stent removal time were recorded.During the follow-up,patients underwent renal func-tion test,urinalysis,and renal ultrasound examination for evaluation.Success was defined as symptomatic and radiologic relieve.Lastly,a literature search was conducted to review all published articles regarding RAUN surgery in adults.Results:The patients'mean age,BMI,EBL,operative time,and follow-up period were 45.4 years,23.1 kg/m^2,65.6 mL,182.9 min,and 21.3 months,respectively.The two most common indications for the surgery were benign ureteral strictures and ureteric injuries secondaryto a previous radical hysterectomy.Of the 34 cases,26(76.5%)and 8(23.5%)patients received pri-mary RAUN and RAUN with psoas hitch technique,respectively.Refluxing RAUN method was performed in all cases.No intraoperative complications were found.Two patients had a radio-logic and symptomatic recurrence;one was managed with a repeat surgery while the other received ureteral dilatation treatment.Conclusion:Both our study and the published literature showed that RAUN is a safe,less inva-sive,and effective surgical technique that can easily replicate the open ureteroneocystostomy for managing lower ureteral diseases.

Impact of sarcopenia on mortality in patients undergoing liver retransplantation

BACKGROUND Sarcopenia,which is a loss of skeletal muscle mass,has been reported to increase post-transplant mortality and morbidity in patients undergoing the first liver transplant.Cross-sectional imaging modalities typically determine sarcopenia in patients with cirrhosis by measuring core abdominal musculatures.However,there is limited evidence for sarcopenia related outcomes in patients undergoing liver re-transplantation(re-OLT).AIM To evaluate the risk of mortality in patients with pre-existing sarcopenia following liver re-OLT.METHODS This is a retrospective study of all adult patients who had undergone a liver re-OLT at the University of Nebraska Medical Center from January 1,2007 to January 1,2017.We divided patients into sarcopenia and no sarcopenia groups.“TeraRecon AquariusNet 4.4.12.194”software was used to evaluate computed tomography or magnetic resonance imaging of the patients done within one year prior to their re-OLT,to calculate the Psoas muscle area at L3-L4 intervertebral disc.We defined cutoffs for sarcopenia as<1561 mm2 for males and<1464 mm2 for females.The primary outcome was to compare 90 d,one,and 5-year survival rates.We also compared complications after re-OLT,length of stay,and readmission within 30 d.Survival analysis was performed with Kaplan-Meier survival analysis.Continuous variables were evaluated with Wilcoxon rank-sum tests.Categorical variables were evaluated with Fisher’s exact tests.RESULTS Fifty-seven patients were included,32 males:25 females,median age 50 years.Two patients were excluded due to incomplete information.Overall,47%(26)of patients who underwent re-OLT had sarcopenia.Females were found to have significantly more sarcopenia than males(73%vs 17%,P<0.001).Median model for end stage liver disease at re-OLT was 28 in both sarcopenia and no sarcopenia groups.Patients in the no sarcopenia group had a trend of longer median time between the first and second transplant(36.5 mo vs 16.7 mo).Biological markers,outcome parameters,and survival at 90 d,1 and 5 years,were similar between the two groups.Sarcopenia in re-OLT at our center was noted to be twice as common(47%)as historically reported in patients undergoing primary liver transplantation.CONCLUSION Overall survival and outcome parameters were no different in those with and without the evidence of sarcopenia after re-OLT.