The gradient field, one of the core magnetic fields in magnetic resonance imaging (MRI) systems, is generated by gradient coils and plays a critical role in spatial encoding and the generation of echo signals. The uniformity or linearity of the gradient field directly impacts the quality and distortion level of MRI images. However, traditional point measurement methods lack accuracy in assessing the linearity of gradient fields, making it difficult to provide effective parameters for image distortion correction. This paper introduced a spherical measurement-based method that involved measuring the magnetic field distribution on a sphere, followed by detailed magnetic field calculations and linearity analysis. This study, applied to assess the nonlinearity of asymmetric head gradient coils, demonstrated more comprehensive and precise results compared to point measurement methods. This advancement not only strengthens the scientific basis for the design of gradient coils but also provides more reliable parameters and methods for the accurate correction of MRI image distortions.
Magnetic Resonance Imaging/instrumentation* ; Humans ; Image Processing, Computer-Assisted/methods* ; Nonlinear Dynamics ; Magnetic Fields ; Algorithms ; Phantoms, Imaging

Nonunion of osteoporotic vertebral fractures (OVF), predominantly affecting the elderly, can lead to intractable pain, vertebral collapse, progressive kyphotic deformity, and neurological impairment, significantly compromising patients′ quality of life. There exists considerable debate on diagnosis and management of OVF, encompassing key issues such as clinical diagnosis and staging criteria for nonunion, surgical indications and procedure selection, and postoperative rehabilitation planning. Currently, there lacks standardized clinical guideline and expert consensus on the diagnosis and management of OVF nonunion in China. To address this gap, Minimally Invasive Surgery Group of Chinese Orthopedic Association, Osteoporosis Committee of Chinese Association of Orthopedic Surgeons, Prevention and Rehabilitation Committee for Osteoporosis of Chinese Association of Rehabilitation Medicine and Minimally Invasive Orthopedic Surgery Branch of China Association for Geriatric Care jointly organized domestic experts in spinal surgery, endocrinology, and rehabilitation to formulate the Clinical guideline for the diagnosis and treatment for nonunion of osteoporotic vertebral fractures ( version 2025), based on existing literature and clinical experience and adhering to principles of scientific rigor and practicality. The guideline provided 13 evidence-based recommendations encompassing diagnosis and treatment of OVF nonunion, aiming to standardize its clinical management.

Objective To observe the analgesic and rehabilitation effects of non μ-opioids anesthesia/analgesia(NΜOA)based on quadratus lumborum block(QLB)in emergency cesarean section under general anesthesia.Methods The retrospective study method was adopted,50 pregnant women undergoing hysterectomy under emergency general anesthesia in Langfang People's Hospital from January 2023 to December 2024 were selected as the study objects.The patients were divided into μ-opioids anesthesia/analgesia(ΜOA)group and NΜOA group according to different anesthesia/analgesia methods,25 cases in each group.ΜOA group received ΜOA;NΜOA group received NΜOA+QLB.Incisional pain and uterine contraction pain numerical rating scale(NRS)at out of the post-anesthesia care unit(T1),intravenous injection of oxytocin(T2),press the palace bottom 24 hours(T3),out of bed activity after operation(T4)and first analgesic time of incision pain,first analgesic time of uterine contraction pain,first no vomiting eating time,first exhaust time was observed and recorded.The incidence of vasoactive agents during the anesthetic period,rescue analgesia,rescue antiemetic,constipation,sleep disturbance after operation within 48 hours after operation were also recorded.Results The NRS scores at T1,T2,T3 and T4 in ΜOA group were significantly higher than those in NΜOA group(incisional pain 3.36±1.25 vs.1.12±0.97,3.68±1.18 vs.2.00±0.91,5.76±1.67 vs.4.20±1.00,4.48±1.29 vs.3.32±0.95;uterine contraction pain 3.72±1.49 vs.1.24±1.05,4.64±1.60 vs.3.04±1.27,7.56±1.71 vs.5.16±1.37,3.56±0.22 vs.2.56±0.16,all P<0.05).The first analgesic time of incision pain,first analgesic time of uterine contraction pain in ΜOA group were significantly less than that in NΜOA group(hours:3.06±2.02 vs.17.48±10.93,2.68±2.22 vs.15.80±11.39,both P<0.05),the first no vomiting eating time,first exhaust time in ΜOA group were significantly longer than those in NΜOA group(hours:8.56±0.57 vs.6.32±0.14,15.44±1.42 vs.10.16±1.14,both P<0.05),the incidence of vasoactive agents,rescue analgesia,rescue antiemetic,constipation,sleep disturbance after operation within 48 hours in ΜOA group were significantly higher than those in NΜOA group[64.0%(16/25)vs.32.0%(8/25),48.0%(12/25)vs.20.0%(5/25),44.0%(11/25)vs.16.0%(4/25),64.0%(16/25)vs.36.0%(9/25),60.0%(15/25)vs.32.0%(8/25),all P<0.05].Conclusion NΜOA based on QLB safely and effectively reduced side effects of μ-opioids and enhanced recovery compared to ΜOA on emergency cesarean section patients undergoing general anesthesia.

Objective:To investigate the application effect of quadratus lumborum block (QLB) combined with less opioid anesthesia analgesia in laparoscopic total hysterectomy (LTH) in elderly patients with uterine prolapse.Methods:A total of 86 elderly patients with uterine prolapse who received LTH in the Langfang People’s Hospital from Jan. 2021 to Oct. 2023 were prospectively selected and divided into group A ( n=42) and group B ( n=44) according to the random number table method. Group A received transversus abdominis block (TAPB) + general anesthesia, and group B received QLB combined with less opioid anesthesia + general anesthesia. The pain duration at different time points after operation [Numeric Rating Scale (NRS) method to evaluate resting incision and visceral pain] was compared between the two groups. The dosage of opioids and the additional analgesia rate were compared between the two groups. The sleep quality of the two groups before and 72 hours after operation was compared, and the adverse reactions of anesthesia were counted. Results:Compared with 6 h after operation, NRS scores of resting incision pain and visceral pain in the two groups decreased gradually at 12, 24 and 48 h after operation, and it was lower in group B than in group A. There were statistically significant differences between groups ( P<0.05) . Dosage of sufentanil and remifentanil in group B was lower than that in group A, and the postoperative additional analgesia rate in group B (9.09%) was lower than that in group A (28.57%) ( P<0.05) . 72 hours after surgery, the sleep efficiency and total sleep time of patients in both groups were lower than those before surgery, and they were higher in group B than in group A; The awakening time and number of awakenings in both groups were higher than those before surgery, while they were lower in group B than in group A ( P<0.05) . The total incidence of adverse reactions in group B was 4.76% (2/44) , lower than 23.81% (10/42) of group A ( P<0.05) . Conclusion:QLB combined with less opioid anesthesia analgesia can effectively reduce the degree of incision and visceral pain after LTH in elderly patients with uterine prolapse, reduce the amount of opioids used during operation and the rate of additional analgesia, and reduce the incidence of adverse reactions of anesthesia.

Objective:To investigate the application effect of quadratus lumborum block (QLB) combined with less opioid anesthesia analgesia in laparoscopic total hysterectomy (LTH) in elderly patients with uterine prolapse.Methods:A total of 86 elderly patients with uterine prolapse who received LTH in the Langfang People’s Hospital from Jan. 2021 to Oct. 2023 were prospectively selected and divided into group A ( n=42) and group B ( n=44) according to the random number table method. Group A received transversus abdominis block (TAPB) + general anesthesia, and group B received QLB combined with less opioid anesthesia + general anesthesia. The pain duration at different time points after operation [Numeric Rating Scale (NRS) method to evaluate resting incision and visceral pain] was compared between the two groups. The dosage of opioids and the additional analgesia rate were compared between the two groups. The sleep quality of the two groups before and 72 hours after operation was compared, and the adverse reactions of anesthesia were counted. Results:Compared with 6 h after operation, NRS scores of resting incision pain and visceral pain in the two groups decreased gradually at 12, 24 and 48 h after operation, and it was lower in group B than in group A. There were statistically significant differences between groups ( P<0.05) . Dosage of sufentanil and remifentanil in group B was lower than that in group A, and the postoperative additional analgesia rate in group B (9.09%) was lower than that in group A (28.57%) ( P<0.05) . 72 hours after surgery, the sleep efficiency and total sleep time of patients in both groups were lower than those before surgery, and they were higher in group B than in group A; The awakening time and number of awakenings in both groups were higher than those before surgery, while they were lower in group B than in group A ( P<0.05) . The total incidence of adverse reactions in group B was 4.76% (2/44) , lower than 23.81% (10/42) of group A ( P<0.05) . Conclusion:QLB combined with less opioid anesthesia analgesia can effectively reduce the degree of incision and visceral pain after LTH in elderly patients with uterine prolapse, reduce the amount of opioids used during operation and the rate of additional analgesia, and reduce the incidence of adverse reactions of anesthesia.

Objective To observe the analgesic and rehabilitation effects of non μ-opioids anesthesia/analgesia(NΜOA)based on quadratus lumborum block(QLB)in emergency cesarean section under general anesthesia.Methods The retrospective study method was adopted,50 pregnant women undergoing hysterectomy under emergency general anesthesia in Langfang People's Hospital from January 2023 to December 2024 were selected as the study objects.The patients were divided into μ-opioids anesthesia/analgesia(ΜOA)group and NΜOA group according to different anesthesia/analgesia methods,25 cases in each group.ΜOA group received ΜOA;NΜOA group received NΜOA+QLB.Incisional pain and uterine contraction pain numerical rating scale(NRS)at out of the post-anesthesia care unit(T1),intravenous injection of oxytocin(T2),press the palace bottom 24 hours(T3),out of bed activity after operation(T4)and first analgesic time of incision pain,first analgesic time of uterine contraction pain,first no vomiting eating time,first exhaust time was observed and recorded.The incidence of vasoactive agents during the anesthetic period,rescue analgesia,rescue antiemetic,constipation,sleep disturbance after operation within 48 hours after operation were also recorded.Results The NRS scores at T1,T2,T3 and T4 in ΜOA group were significantly higher than those in NΜOA group(incisional pain 3.36±1.25 vs.1.12±0.97,3.68±1.18 vs.2.00±0.91,5.76±1.67 vs.4.20±1.00,4.48±1.29 vs.3.32±0.95;uterine contraction pain 3.72±1.49 vs.1.24±1.05,4.64±1.60 vs.3.04±1.27,7.56±1.71 vs.5.16±1.37,3.56±0.22 vs.2.56±0.16,all P<0.05).The first analgesic time of incision pain,first analgesic time of uterine contraction pain in ΜOA group were significantly less than that in NΜOA group(hours:3.06±2.02 vs.17.48±10.93,2.68±2.22 vs.15.80±11.39,both P<0.05),the first no vomiting eating time,first exhaust time in ΜOA group were significantly longer than those in NΜOA group(hours:8.56±0.57 vs.6.32±0.14,15.44±1.42 vs.10.16±1.14,both P<0.05),the incidence of vasoactive agents,rescue analgesia,rescue antiemetic,constipation,sleep disturbance after operation within 48 hours in ΜOA group were significantly higher than those in NΜOA group[64.0%(16/25)vs.32.0%(8/25),48.0%(12/25)vs.20.0%(5/25),44.0%(11/25)vs.16.0%(4/25),64.0%(16/25)vs.36.0%(9/25),60.0%(15/25)vs.32.0%(8/25),all P<0.05].Conclusion NΜOA based on QLB safely and effectively reduced side effects of μ-opioids and enhanced recovery compared to ΜOA on emergency cesarean section patients undergoing general anesthesia.

Nonunion of osteoporotic vertebral fractures (OVF), predominantly affecting the elderly, can lead to intractable pain, vertebral collapse, progressive kyphotic deformity, and neurological impairment, significantly compromising patients′ quality of life. There exists considerable debate on diagnosis and management of OVF, encompassing key issues such as clinical diagnosis and staging criteria for nonunion, surgical indications and procedure selection, and postoperative rehabilitation planning. Currently, there lacks standardized clinical guideline and expert consensus on the diagnosis and management of OVF nonunion in China. To address this gap, Minimally Invasive Surgery Group of Chinese Orthopedic Association, Osteoporosis Committee of Chinese Association of Orthopedic Surgeons, Prevention and Rehabilitation Committee for Osteoporosis of Chinese Association of Rehabilitation Medicine and Minimally Invasive Orthopedic Surgery Branch of China Association for Geriatric Care jointly organized domestic experts in spinal surgery, endocrinology, and rehabilitation to formulate the Clinical guideline for the diagnosis and treatment for nonunion of osteoporotic vertebral fractures ( version 2025), based on existing literature and clinical experience and adhering to principles of scientific rigor and practicality. The guideline provided 13 evidence-based recommendations encompassing diagnosis and treatment of OVF nonunion, aiming to standardize its clinical management.

Abstract Spinal curvatures has emerged as the third major chronic condition seriously threatening the physical and mental health of Chinese children and adolescents, with significant regional differences. Its etiology is complex and diverse, and early prevention and treatment are feasible, whereas treatment in later stages entails considerable difficulty and economic burden. Currently, the prevention and control of student spinal curvatures has been elevated to a national health strategy. A series of policy documents have been successively issued, and it has greatly facilitated the institutionalization and normalization of national routine screening for student spinal curvatures. However, it is still inadequate considering current prevention and control system for spinal curvatures in children and adolescents. There is an urgent need to establish a closed loop model based on China s institutional advantages, comprising Initial Screening-Diagnosis-Treatment-Preventive Control-Followup Assessment, to strengthen the safeguarding of spinal health in children and adolescents.

Objective:To investigate the risk factors and cumulative risk of myopia in children and adolescents, providing a basis for identifying cumulative risk factors in preventing and controlling myopia.Methods:Baseline data from the mental and physical health cohort of children and adolescents established in Inner Mongolia Autonomous Region were used. A stratified random cluster sampling method was adopted to select 138 974 students from fourth to twelfth grade as participants. Distance visual exams, refractive assessments, and questionnaires were conducted on the included students. Logistic regression analysis was used to evaluate each risk factor's impact on myopia's prevalence. The number of risk factors was summed to form a cumulative risk score, and logistic regression analysis was conducted to examine the association between the cumulative risk score and the prevalence of myopia. Additionally, the association between the cumulative risk score of myopic students and their degree of refractivity was analyzed using a generalized estimating equation.Results:The study found a high prevalence of myopia among children and adolescents at baseline (70.2%). Girls exhibited a higher prevalence (74.8%) than boys (65.6%), urban areas (74.3%) surpassed suburban ones (68.6%), and the incidence was greater in high schools (80.3%) compared to middle schools (75.3%), which, in turn, was higher than in elementary schools (57.7%) (all P<0.05). Analysis of risk factors revealed that children and adolescents experiencing improper reading and writing distances ( OR=1.10, 95% CI: 1.07-1.13), excessive homework ( OR=1.09, 95% CI: 1.06-1.12), insufficient sleep ( OR=1.10, 95% CI: 1.07-1.13), having myopic father ( OR=1.98, 95% CI: 1.91-2.05), having myopic mother ( OR=2.04, 95% CI: 1.97-2.10), or using classroom chairs not matched to their height faced ( OR=1.04, 95% CI: 1.01-1.07) increased myopia risks. Additionally, the prevalence and significant odds ratio of myopia increased with the increase in cumulative risk score, with every additional unit of cumulative risk score increasing the right eye's refractive error by -0.10 D. Conclusion:The presence of multiple factors and their comprehensive score increases the prevalence of myopia in children and adolescents.

Objective: To explore the current status and progress of regional school health work to provide policy reference for school health improvement. Methods: Survey data on school health work in Tianjin from 2019, 2021 and 2023 was used. School health staff allocation and expenditure of the health administrative department, CDC and education department, as well as the annual implementation of health education, prevention and control of common diseases and infectious diseases, sports activities and food nutrition in primary and secondary schools were analyzed. Statistical analysis was conducted using KruskalWallis test, Chisquare test, and Fishers exact test. Results: The number of school health staff in the health commissions and education departments from 2019, 2021 and 2023 was relatively stable. Parttime staffs were often employed by health commissions while fulltime staffs were mainly employed by education departments. The number of school health staff at CDCs increased gradually (H=12.65, P<0.01). School health expenditure of administrative departments and schools in 2021 and 2023 increased significantly compared with that in 2019 (H=22.28, 23.75, P<0.05). More than 95% of schools set up clinics or health care rooms, and about 97% of schools had school health technicians or health teachers. More than 90% of schools had health education courses over 4 hours per semester. The rate of mental health education increased by year (86.87%, 89.91%, 96.30%, Z=2.40，P<0.05). Lack of courses regarded safety emergency and risk avoidance, growth and development, and adolescent health education. The provision rate of psychological counseling services (89.00%, 97.25%, 100.00%) and psychological problem prevention and control (56.12%, 71.56%, 81.48%) also increased by year (Z=3.83, 3.96, P<0.01). The implementation rates of prevention and control of poor vision, dental caries, overweight and obesity were all higher than 80%, and the prevention and control rate of abnormal spinal curvature showed an increasing trend (38.78%, 77.06%, 72.22%, Z=4.87, P<0.01). More than 90% of schools met the standard for physical education class hours, and the proportion of schools conducting at least 30 minutes of recess physical activities every day increased year by year (65.00%, 80.73%, 85.98%, Z=3.59, P<0.01). All schools did not have shops. Conclusions School health work in Tianjin is effective and constantly developing. It is necessary to continue to increase the investment of human resources and expenditure in school health, explore the approaches of cooccurrence and prevention of common diseases, and improve the school sports and nutrition environment.